Complement membrane attack complex
The membrane attack complex or terminal complement complex is a structure formed on the surface of pathogen cell membranes as a result of the activation of the host's complement system, as such is one of the effector proteins of the immune system. The membrane-attack complex forms transmembrane channels; these channels disrupt the cell membrane of target cells, leading to death. Active MAC is composed of the subunits C5b, C7, C8 and several C9 molecules. A number of proteins participate in the assembly of the MAC. Freshly activated C5b binds to C6 to form a C5b-6 complex to C7 forming the C5b-6-7 complex; the C5b-6-7 complex binds to C8, composed of three chains, thus forming the C5b-6-7-8 complex. C5b-6-7-8 subsequently binds to C9 and acts as a catalyst in the polymerization of C9. MAC is composed of a complex of four complement proteins that bind to the outer surface of the plasma membrane, many copies of a fifth protein that hook up to one another, forming a ring in the membrane. C6-C9 all contain a common MACPF domain.
This region is homologous to cholesterol-dependent cytolysins from Gram-positive bacteria. The ring structure formed by C9 is a pore in the membrane that allows free diffusion of molecules in and out of the cell. If enough pores form, the cell is no longer able to survive. If the pre-MAC complexes of C5b-7, C5b-8 or C5b-9 do not insert into a membrane, they can form inactive complexes with Protein S; these fluid phase complexes do not bind to cell membranes and are scavenged by clusterin and vitronectin, two regulators of complement. The membrane attack complex is initiated when the complement protein C5 convertase cleaves C5 into C5a and C5b. All three pathways of the complement system initiate the formation of MAC. Another complement protein, C6, binds to C5b; the C5bC6 complex is bound by C7. This junction alters the configuration of the protein molecules exposing a hydrophobic site on C7 that allows the C7 to insert into the phospholipid bilayer of the pathogen. Similar hydrophobic sites on C8 and C9 molecules are exposed when they bind to the complex, so they can insert into the bilayer.
C8 is a complex made of C8 alpha-gamma. C8 alpha-gamma has the hydrophobic area. C8 alpha-gamma induces the polymerization of 10-16 molecules of C9 into a pore-forming structure known as the membrane attack complex. MAC has a hydrophobic external face allowing it to associate with the lipid bilayer. MAC has a hydrophilic internal face to allow the passage of water. Multiple molecules of C9 can join spontaneously in concentrated solution to form polymers of C9; these polymers can form a tube-like structure. CD59 acts to inhibit the complex; this exists on body cells to protect them from MAC. A rare condition, paroxysmal nocturnal haemoglobinuria, results in red blood cells that lack CD59; these cells can, therefore, be lysed by MAC. Deficiencies of C5 to C9 components does not lead to generic infections, but only to increased susceptibility to Neisseria spp. since these bacteria have a thick cell wall and glycocalix. Terminal complement pathway deficiency Perforin Pore-forming toxin Media related to Complement membrane attack complex at Wikimedia Commons Complement+Membrane+Attack+Complex at the US National Library of Medicine Medical Subject Headings
An intrauterine device known as intrauterine contraceptive device or coil, is a small T-shaped birth control device, inserted into a woman's uterus to prevent pregnancy. IUDs are one form of long-acting reversible birth control. Among birth control methods, IUDs, along with contraceptive implants, result in the greatest satisfaction among users. One study found that female family planning providers choose LARC methods more than the general public. IUDs are safe and effective in adolescents as well as those who have not had children. Once an IUD is removed after long-term use, fertility returns to normal rapidly. Copper devices have a failure rate of about 0.8% while hormonal devices fail about 0.2% of the time within the first year of use. In comparison, male sterilization and male condoms have a failure rate of about 0.15% and 15%, respectively. Copper IUDs can be used as emergency contraception within 5 days of unprotected sex. Although copper IUDs may increase menstrual bleeding and result in painful cramps, hormonal IUDs may reduce menstrual bleeding or stop menstruation altogether.
However, women can have daily spotting for several months and it can take up to three months for there to be a 90% decrease in bleeding. Cramping can be treated with NSAIDs. More serious potential complications include expulsion and perforation of the uterus. IUDs do not affect breastfeeding and can be inserted after delivery, they may be used after an abortion. The use of IUDs has increased within the United States from 0.8% in 1995 to 5.6% from the period of 2006 to 2010. The use of IUDs as a form of birth control dates from the 1800s. A previous model known as the Dalkon shield was associated with an increased risk of pelvic inflammatory disease. However, current models do not affect PID risk in women without sexually transmitted infections during the time of insertion; the types of intrauterine devices available, the names they go by, differ by location. In the United States, there are two types available: Nonhormonal: Copper-containing IUD Hormonal: Progestogen-releasing IUD The WHO ATC labels both copper and hormonal devices as IUDs.
In the United Kingdom, there are more than 10 different types of copper IUDs. In the United Kingdom, the term IUD refers only to these copper devices. Hormonal intrauterine contraception is considered to be a different type of birth control and is labeled with the term intrauterine system. Most copper IUDs have a T-shaped frame, wound around with pure electrolytic copper wire and/or has copper collars; the arms of the frame hold the IUD in place near the top of the uterus. The Paragard TCu 380a measures 32 mm horizontally, 36 mm vertically. Copper IUDs have a first year failure rate ranging from 0.1 to 2.2%. They work by disrupting their motility so that they are not able to join an egg. Copper acts as a spermicide within the uterus by increasing levels of copper ions and white blood cells within the uterine and tubal fluids; the increased copper ions in the cervical mucus inhibit the sperm's motility and viability, preventing sperm from traveling through the cervical mucus, or destroying it as it passes through.
Copper can alter the endometrial lining, but studies show that while this alteration can prevent implantation of a fertilized egg, it cannot disrupt one, implanted. Advantages of the copper IUD include its ability to provide emergency contraception up to five days after unprotected sex, it is the most effective form of emergency contraception available. It works by preventing fertilization or implantation but does not affect implanted embryos, it contains no hormones, so it can be used while breastfeeding, fertility returns after removal. Copper IUDs last longer and are available in a wider range of sizes and shapes compared to hormonal IUDs. Disadvantages include the possibility of heavier menstrual periods and more painful cramps. IUDs that contain gold or silver exist. Other shapes of IUD include the so-called U-shaped IUDs, such as the Load and Multiload, the frameless IUD that holds several hollow cylindrical minuscule copper beads, it is held in place by a suture to the fundus of the uterus.
It is available in China and Europe. A framed copper IUD called the IUB SCu300 coils when deployed and forms a three-dimensional spherical shape, it is based on a nickel titanium shape memory alloy core. In addition to copper, noble metal and progestogen IUDs; this non-hormonal compound reduces the severity of menstrual bleeding, these coils are popular. Inert IUDs do not have a bioactive component, they are made of inert materials like stainless plastic. They are less effective than copper or hormonal IUDs, with a side effect profile similar to copper IUDs, their primary mechanism of action is inducing a local foreign body reaction, which makes the uterine environment hostile both to sperm and to implantation of an embryo. They may have higher rates of preventing pregnancy after fertilization, instead of before fertilization, compared to copper or hormonal IUDs. Inert IUDs are not yet approved for use in UK, or Canada. In China, where IUDs are the most common form of contraception, copper IUD production rep
Latex is a stable dispersion of polymer microparticles in an aqueous medium. It is found in nature, but synthetic latexes can be made by polymerizing a monomer such as styrene, emulsified with surfactants. Latex as found in nature is a milky fluid found in 10% of all flowering plants, it is a complex emulsion consisting of proteins, starches, oils, tannins and gums that coagulate on exposure to air. It is exuded after tissue injury. In most plants, latex is white. Since the 17th century, latex has been used as a term for the fluid substance in plants, it serves as defense against herbivorous insects. Latex is not to be confused with plant sap; the word latex is used to refer to natural latex rubber non-vulcanized rubber. Such is the case in products like latex condoms and latex clothing; the name given to latex by indigenous Equator tribes who cultivated the plant was “caoutchouc”, from the words “caa” and “ochu”, because of the way it is collected. The cells in which latex is found make up the laticiferous system, which can form in two different ways.
In many plants, the laticiferous system is formed from rows of cells laid down in the meristem of the stem or root. The cell walls between these cells are dissolved so that continuous tubes, called latex vessels, are formed. Since these vessels are made of many cells, they are known as articulated laticifers; this method of formation is found in the poppy family and in the rubber trees, members of the family Asteraceae. For instance, Parthenium argentatum the guayule plant, is in the tribe Heliantheae; this includes a species cultivated for latex production. In the milkweed and spurge families, on the other hand, the laticiferous system is formed quite differently. Early in the development of the seedling, latex cells differentiate, as the plant grows these latex cells grow into a branching system extending throughout the plant. In many euphorbs, the entire structure is made from a single cell – this type of system is known as a non-articulated laticifer, to distinguish it from the multi-cellular structures discussed above.
In the mature plant, the entire laticiferous system is descended from a single cell or group of cells present in the embryo. The laticiferous system is present in all parts of the mature plant, including roots, stems and sometimes the fruits, it is noticeable in the cortical tissues. Latex is exuded as a white liquid, but is some cases it can be clear, yellow or red, as in Cannabaceae. Latex is produced by 20,000 species from over 40 families occurring in multiple lineages in both dicotyledonous and monocotyledonous types of plant, it is found in conifers and pteridophytes. Among tropical plant species 14% create latex, as opposed to 6% of temperate plant species. Several members of the fungal kingdom produce latex upon injury, such as Lactarius deliciosus and other milk-caps; this suggests it is the product of convergent evolution and has been selected for on many separate occasions. Latex functions to protect the plant from herbivores; the idea was first proposed in 1887 by Joseph F. James, who noted that latex carries with it at the same time such disagreeable properties that it becomes a better protection to the plant from enemies than all the thorns, prickles, or hairs that could be provided.
In this plant, so copious and so distasteful has the sap become that it serves a most important purpose in its economy. Evidence showing this defense function include the finding that slugs will eat leaves drained of their latex but not intact ones, that many insects sever the veins carrying latex before they feed, that the latex of Asclepias humistrata kills by trapping 30% of newly hatched monarch butterfly caterpillars. Other evidence is that latex contains 50–1000× higher concentrations of defense substances than other plant tissues; these toxins include ones that are toxic to the plant and consist of a diverse range of chemicals that are either poisonous or "antinutritive". Latex is moved to the area of injury; the clotting property of latex is functional in this defense since it limits wastage and its stickiness traps insects and their mouthparts. It has been noted that while there exist other explanations for the existence of latex including storage and movement of plant nutrients and maintenance of water balance that "ssentially none of these functions remain credible and none have any empirical support".
The latex of many species can be processed to produce many materials. Natural rubber is the most important product obtained from latex; this latex is used to make many other products including mattresses, swim caps, condoms and balloons. Balatá and gutta percha latex contain an inelastic polymer related to rubber. Latex from the chicle and jelutong trees is used in chewing gum. Dried latex from the opium poppy is called opium, the source of several useful alkaloids, such as morphine and papaverine, as well as the street drug heroin. Synthetic latexes are u
International Standard Serial Number
An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication, such as a magazine. The ISSN is helpful in distinguishing between serials with the same title. ISSN are used in ordering, interlibrary loans, other practices in connection with serial literature; the ISSN system was first drafted as an International Organization for Standardization international standard in 1971 and published as ISO 3297 in 1975. ISO subcommittee TC 46/SC 9 is responsible for maintaining the standard; when a serial with the same content is published in more than one media type, a different ISSN is assigned to each media type. For example, many serials are published both in electronic media; the ISSN system refers to these types as electronic ISSN, respectively. Conversely, as defined in ISO 3297:2007, every serial in the ISSN system is assigned a linking ISSN the same as the ISSN assigned to the serial in its first published medium, which links together all ISSNs assigned to the serial in every medium.
The format of the ISSN is an eight digit code, divided by a hyphen into two four-digit numbers. As an integer number, it can be represented by the first seven digits; the last code digit, which may be 0-9 or an X, is a check digit. Formally, the general form of the ISSN code can be expressed as follows: NNNN-NNNC where N is in the set, a digit character, C is in; the ISSN of the journal Hearing Research, for example, is 0378-5955, where the final 5 is the check digit, C=5. To calculate the check digit, the following algorithm may be used: Calculate the sum of the first seven digits of the ISSN multiplied by its position in the number, counting from the right—that is, 8, 7, 6, 5, 4, 3, 2, respectively: 0 ⋅ 8 + 3 ⋅ 7 + 7 ⋅ 6 + 8 ⋅ 5 + 5 ⋅ 4 + 9 ⋅ 3 + 5 ⋅ 2 = 0 + 21 + 42 + 40 + 20 + 27 + 10 = 160 The modulus 11 of this sum is calculated. For calculations, an upper case X in the check digit position indicates a check digit of 10. To confirm the check digit, calculate the sum of all eight digits of the ISSN multiplied by its position in the number, counting from the right.
The modulus 11 of the sum must be 0. There is an online ISSN checker. ISSN codes are assigned by a network of ISSN National Centres located at national libraries and coordinated by the ISSN International Centre based in Paris; the International Centre is an intergovernmental organization created in 1974 through an agreement between UNESCO and the French government. The International Centre maintains a database of all ISSNs assigned worldwide, the ISDS Register otherwise known as the ISSN Register. At the end of 2016, the ISSN Register contained records for 1,943,572 items. ISSN and ISBN codes are similar in concept. An ISBN might be assigned for particular issues of a serial, in addition to the ISSN code for the serial as a whole. An ISSN, unlike the ISBN code, is an anonymous identifier associated with a serial title, containing no information as to the publisher or its location. For this reason a new ISSN is assigned to a serial each time it undergoes a major title change. Since the ISSN applies to an entire serial a new identifier, the Serial Item and Contribution Identifier, was built on top of it to allow references to specific volumes, articles, or other identifiable components.
Separate ISSNs are needed for serials in different media. Thus, the print and electronic media versions of a serial need separate ISSNs. A CD-ROM version and a web version of a serial require different ISSNs since two different media are involved. However, the same ISSN can be used for different file formats of the same online serial; this "media-oriented identification" of serials made sense in the 1970s. In the 1990s and onward, with personal computers, better screens, the Web, it makes sense to consider only content, independent of media; this "content-oriented identification" of serials was a repressed demand during a decade, but no ISSN update or initiative occurred. A natural extension for ISSN, the unique-identification of the articles in the serials, was the main demand application. An alternative serials' contents model arrived with the indecs Content Model and its application, the digital object identifier, as ISSN-independent initiative, consolidated in the 2000s. Only in 2007, ISSN-L was defined in the
A condom is a sheath-shaped barrier device, used during sexual intercourse to reduce the probability of pregnancy or a sexually transmitted infection. There are both female condoms. With proper use—and use at every act of intercourse—women whose partners use male condoms experience a 2% per-year pregnancy rate. With typical use the rate of pregnancy is 18% per-year, their use decreases the risk of gonorrhea, trichomoniasis, hepatitis B, HIV/AIDS. They to a lesser extent protect against genital herpes, human papillomavirus, syphilis; the male condom is rolled onto an erect penis before intercourse and works by blocking semen from entering the body of a sexual partner. Male condoms are made from latex and less from polyurethane or lamb intestine. Male condoms have the advantages of ease of use, easy to access, few side effects. In those with a latex allergy a polyurethane or other synthetic version should be used. Female condoms are made from polyurethane and may be used multiple times. Condoms as a method of preventing STIs have been used since at least 1564.
Rubber condoms became available followed by latex condoms in the 1920s. They are on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system; the wholesale cost in the developing world is about 0.03 to US$0.08 each. In the United States condoms cost less than US$1.00. Globally less than 10% of those using birth control are using the condom. Rates of condom use are higher in the developed world. In the United Kingdom the condom is the second most common method of birth control while in the United States it is the third most common. About six to nine billion are sold a year; the effectiveness of condoms, as of most forms of contraception, can be assessed two ways. Perfect use or method effectiveness rates only include people who use condoms properly and consistently. Actual use, or typical use effectiveness rates are of all condom users, including those who use condoms incorrectly or do not use condoms at every act of intercourse.
Rates are presented for the first year of use. Most the Pearl Index is used to calculate effectiveness rates, but some studies use decrement tables; the typical use pregnancy rate among condom users varies depending on the population being studied, ranging from 10 to 18% per year. The perfect use pregnancy rate of condoms is 2% per year. Condoms may be combined with other forms of contraception for greater protection. Condoms are recommended for the prevention of sexually transmitted infections, they have been shown to be effective in reducing infection rates in both women. While not perfect, the condom is effective at reducing the transmission of organisms that cause AIDS, genital herpes, cervical cancer, genital warts, chlamydia and other diseases. Condoms are recommended as an adjunct to more effective birth control methods in situations where STD protection is desired. According to a 2000 report by the National Institutes of Health, consistent use of latex condoms reduces the risk of HIV/AIDS transmission by 85% relative to risk when unprotected, putting the seroconversion rate at 0.9 per 100 person-years with condom, down from 6.7 per 100 person-years.
Analysis published in 2007 from the University of Texas Medical Branch and the World Health Organization found similar risk reductions of 80–95%. The 2000 NIH review concluded that condom use reduces the risk of gonorrhea for men. A 2006 study reports that proper condom use decreases the risk of transmission of human papillomavirus to women by 70%. Another study in the same year found consistent condom use was effective at reducing transmission of herpes simplex virus-2 known as genital herpes, in both men and women. Although a condom is effective in limiting exposure, some disease transmission may occur with a condom. Infectious areas of the genitals when symptoms are present, may not be covered by a condom, as a result, some diseases like HPV and herpes may be transmitted by direct contact; the primary effectiveness issue with using condoms to prevent STDs, however, is inconsistent use. Condoms may be useful in treating precancerous cervical changes. Exposure to human papillomavirus in individuals infected with the virus, appears to increase the risk of precancerous changes.
The use of condoms helps promote regression of these changes. In addition, researchers in the UK suggest that a hormone in semen can aggravate existing cervical cancer, condom use during sex can prevent exposure to the hormone. Condoms may slip off the penis after ejaculation, break due to improper application or physical damage, or break or slip due to latex degradation; the rate of breakage is between 0.4% and 2.3%, while the rate of slippage is between 0.6% and 1.3%. If no breakage or slippage is observed, 1–3% of women will test positive for semen residue after intercourse with a condom."Double bagging", using two condoms at once, is believed to cause a higher rate of failure due to the friction of rubber on rubber. This claim is not supported by research; the limited studies that have been done found that the simultaneous use of multiple condoms decreases the risk of condom breakage. Different modes of condom failure result in different levels of semen exposure. If a failure occurs during application, the damaged condom may be disposed of and a new condom applied before intercourse begins – such failures pose no risk to
Granule (cell biology)
In cell biology, a granule is a small particle. It can be any structure visible by light microscopy; the term is most used to describe a secretory vesicle. A group of leukocytes called granulocytes contain granules and play an important role in the immune system; the granules of certain cells, such as natural killer cells, contain components which can lead to the lysis of neighboring cells. The granules of leukocytes are classified as specific granules. Leukocyte granules are released in response to immunological stimuli during a process known as degranulation; the granules of platelets are alpha granules. In 1957, André and Rouiller first coined the term "nuage".. Its amorphous and fibrous structure occurred in drawings as early as in 1933. Today, the nuage is accepted to represent a characteristic, electrondense germ plasm organelle encapsulating the cytoplasmic face of the nuclear envelope of the cells destined to the germline fate; the same granular material is known under various synonyms: dense bodies, mitochondrial clouds, yolk nuclei, Balbiani bodies, perinuclear P granules in Caenorhabditis elegans, germinal granules in Xenopus laevis, chromatoid bodies in mouse, polar granules in Drosophila.
Molecularly, the nuage is a interwoven network of differentially localized RNA-binding proteins, which in turn localize specific mRNA species for differential storage, asymmetric segregation, differential splicing and/or translational control. The germline granules appear to be ancestral and universally conserved in the germlines of all metazoan phyla. Many germline granule components are part of the piRNA pathway and function to repress transposable elements. A specific type of granule found in the pancreas is an insulin granule. Insulin is a hormone that helps to regulate the amount of glucose in the blood from getting too high, hyperglycemia, or too low, hypoglycemia. Insulin granules are secretory granules, which can release their contents from the cell into the bloodstream; the beta cells in the pancreas are responsible for the storage of insulin and release of it at appropriate times. The beta cells control the release, use unusual mechanisms to do so. Immature insulin granules function as a sorting chamber during the maturation process listed below.
Insulin and other insoluble granule components are kept within the granules. Other soluble proteins and granule parts bud off from the immature granule in a clathrin-coated transport vesicle; the process of proteolysis, removes the unwanted parts from the secretory granule resulting in mature granules. Insulin granules mature in three steps: the lumen of the granule undergoes acidification, due to the acidic properties of a secretory granule; the endoproteases PC1/3 and PC2 aid in this transformation from proinsulin to insulin. Granules are one of the non-living cell organelle of plant cell, it serves as small container of starch in plant cell. In photosynthesis, plants use light energy to produce glucose from carbon dioxide; the glucose is stored in the form of starch granules, in plastids such as chloroplasts and amyloplasts. Toward the end of the growing season, starch accumulates in twigs of trees near the buds. Fruit, seeds and tubers store starch to prepare for the next growing season. Chromaffin granule Kurloff cell
Diaphragm (birth control)
The diaphragm is a barrier method of birth control. It is moderately effective, with a one-year failure rate of around 12% with typical use, it is placed over the cervix with spermicide before sex and left in place for at least six hours after sex. Fitting by a healthcare provider is required. Side effects are very few. Use may increase the risk of urinary tract infections. If left in the vagina for more than 24 hours toxic shock syndrome may occur. While use may decrease the risk of sexually transmitted infections, it is not effective at doing so. There are a number of types of diaphragms with different spring designs, they may be made from silicone, or natural rubber. They work by holding spermicide near the cervix; the diaphragm came into use around 1882. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. In the United Kingdom they cost the NHS less than 10 pounds each. In the United States they cost about 15 to 75 USD and are the birth control method of 0.3% of people.
These costs do not include that of spermicide. Before inserting or removing a diaphragm, one should first wash one's hands to avoid introducing harmful bacteria into the vaginal canal; the rim of a diaphragm is squeezed into an arc shape for insertion. A water-based lubricant may be applied to the rim of the diaphragm to aid insertion. One teaspoon of spermicide may be placed in the dome of the diaphragm before insertion, or with an applicator after insertion; the diaphragm must be inserted sometime before sexual intercourse, remain in the vagina for 6 to 8 hours after a man's last ejaculation. For multiple acts of intercourse, it is recommended that an additional 5 mL of spermicide be inserted into the vagina before each act. Upon removal, a diaphragm should be cleansed with warm mild soapy water before storage; the diaphragm must be removed for cleaning at least once every 24 hours and can be re-inserted immediately. Oil-based products should not be used with latex diaphragms. Lubricants or vaginal medications that contain oil will cause the latex to degrade and increases the chances of the diaphragm breaking or tearing.
Natural latex rubber will degrade over time. Depending on usage and storage conditions, a latex diaphragm should be replaced every one to three years. Silicone diaphragms may last much longer—up to ten years; the effectiveness of diaphragms, as of most forms of contraception, can be assessed two ways: method effectiveness and actual effectiveness. The method effectiveness is the proportion of couples and using the method who do not become pregnant. Actual effectiveness is the proportion of couples who intended that method as their sole form of birth control and do not become pregnant. Rates are presented for the first year of use. Most the Pearl Index is used to calculate effectiveness rates, but some studies use decrement tables. For all forms of contraception, actual effectiveness is lower than method effectiveness, due to several factors: mistakes on the part of those providing instructions on how to use the method mistakes on the part of the method's users conscious user non-compliance with methodFor instance, someone using a diaphragm might be fitted incorrectly by a health care provider, or by mistake remove the diaphragm too soon after intercourse, or choose to have intercourse without placing the diaphragm.
Contraceptive Technology reports that the method failure rate of the diaphragm with spermicide is 6% per year. The actual pregnancy rates among diaphragm users vary depending on the population being studied, with yearly rates of 10% to 39% being reported. Unlike some other cervical barriers, the effectiveness of the diaphragm is the same for women who have given birth as for those who have not; the diaphragm does not interfere with a woman's natural cycle, therefore, no reversal or wait time is necessary, if contraception is no longer wanted or needed. The diaphragm only has to be used during intercourse. Many women those who have sex less prefer barrier contraception such as the diaphragm over methods that require some action every day. Like all cervical barriers, diaphragms may be inserted several hours before use, allowing uninterrupted foreplay and intercourse. Most couples find; the diaphragm is less expensive than many other methods of contraception. There is some evidence that the cells in the cervix are susceptible to certain sexually transmitted infections.
Cervical barriers such as diaphragms may offer some protection against these infections. However, research conducted to test whether the diaphragm offers protection from HIV found that women provided with both male condoms and a diaphragm experienced the same rate of HIV infection as women provided with male condoms alone; because pelvic inflammatory disease is caused by certain STIs, diaphragms may lower the risk of PID. Cervical barriers may protect against human papillomavirus, the virus that causes cervical cancer, although the protection appears to be due to the spermicide used with diaphragms and not the barrier itself. Diaphragms are considered a good candidate as a delivery method for microbicides that are in development. Women who are allergic to latex should not use a latex diaphragm. Diaphragms are associated with an increased risk of urinary tract infection Urinating before inserti