Selective induction of protective MHC class I-restricted CTL in the intestinal lamina propria of rhesus monkeys by transient SIV infection of the colonic mucosa

The identification of mucosal immune responses required for protection against sexual transmission of HIV is essential for the development of an efficacious vaccine. To gain a better understanding of these responses, we have characterized the immune responses in the lamina propria (LP) and epithelium of the jejunum, the mesenteric lymph nodes, and peripheral blood (PBMC) of 11 rhesus monkeys following colonic exposure to two molecular clones of SIV. Two monkeys had no signs of infection. Three monkeys became persistently infected. Transient infections, characterized by the sporadic detection of virus in the periphery and/or detection of SIV-specific immune responses in either the gut-associated tissues or PBMC, were induced in six of the monkeys. One persistently infected and three transiently infected monkeys had high levels of SIV env-specific MHC class I restricted CTL in the jejunal LP. Another transiently infected monkey had SIV-specific IgA secreting B cells in the LP. Three or six months postexposure, these animals and four naive controls were challenged intracolonically with the heterologous primary isolate, SIV/DeltaB670. All four monkeys with strong SIV env-specific MHC-restricted CTL in the LP were protected, whereas none of the naive controls or the remaining seven monkeys with little or no CTL in the LP were protected. These experiments provide the first direct evidence that transient mucosal infection can induce SIV-specific immunity that remains localized to the gut-associated tissues. Furthermore, a strong correlation between SIV env-specific MHC-restricted CTL in the LP and protection against colonic mucosal challenge was observed.

Measurement of plasma D-dimer is not useful in the prediction or diagnosis of postoperative deep vein thrombosis in patients undergoing total knee arthroplasty

Plasma D-dimer, a highly sensitive marker of venous thromboembolism, was measured using an enzyme-linked immunosorbent assay pre-operatively, on the third postoperative day, and at the time of phlebography in 118 patients undergoing elective total knee arthroplasty. Deep venous thrombosis (DVT) was detected using systematic bilateral phlebography between the eighth and 12th postoperative day in 47 (39.8%) patients. D-dimer plasma concentrations did not differ between patients who had DVT and those who had no DVT, either pre-operatively (n = 118, P = 0.63) or at the time of phlebography (n = 111, P = 0.70). On the third postoperative day, D-dimer concentration was significantly higher (P < 0.01) in the patients who had DVT (median 3270 microg/l, range 1156-9996, n = 47) than in those who did not (2287 microg/l, 685-7062, n = 64). However, receiver operating characteristics curve analysis did not provide any useful cutoff values that would allow individual diagnoses to be made. In conclusion, the results of the present study suggest that plasma measurement of D-dimer concentration is of no value for predicting, diagnosing or ruling out DVT in patients undergoing total knee arthroplasty.

Evaluation of pluronic F127-based sustained-release ocular delivery systems for pilocarpine using the albino rabbit eye model

The overall objective of this study was to develop Pluronic F127 (PF127)-containing formulations of pilocarpine hydrochloride (PHCL) which can be used for sustained-release ocular delivery of PHCL. The PF127 formulations of PHCL containing methylcellulose (MC) or hydroxypropyl methylcellulose (HPMC) as an additive had previously exhibited the slowest dissolution rates and released the drug the slowest in vitro. This study was performed to assess the in vivo performance of these two formulations using miosis in the albino rabbit eye produced by PHCL as a measure of ocular bioavailability. The PF127MC formulation (20 microL) had a significantly greater intensity of miosis compared to the same volume of an isotonic solution of PHCL. The duration and the intensity of the miotic response increased significantly as the instilled volume of the PF127MC gel formulation increased. The miotic response, expressed as % bioactivity by assigning a value of 100% to the 20 microL PF127MC treatment, was increased as the volume instilled was reduced from 60 to 20 microL. However, no difference in bioactivity between the 60 and 100 microL volumes was observed. In addition, the 100 microL volumes of both the PF127MC and PF127HPMC gel formulations exhibited bioactivity equivalent to 20 microL of an isotonic PHCL solution. Thus, for a given instilled concentration, the larger the volume instilled the greater the amount of drug present in tear fluid and thus the higher the concentration delivered to the iris sphincter muscle and hence the greater the miotic response. However, the fraction of the dose reaching the iris sphincter muscle was greater for the smaller instilled volume. On the basis of these findings and previous in vitro results, the PF127 formulations of PHCL having MC or HPMC as an additive showed considerable potential as sustained-release ocular delivery systems for PHCL. This conclusion was based upon their ability to provide a substantial prolongation of drug action and an improvement in the ocular bioavailability of pilocarpine compared to conventional eye drops and previously utilized PF127 formulations of PHCL. It appears that ocular bioavailability can be increased more readily by altering both the rheological characteristics of the delivery system and by using a smaller dose volume.

A simplified and rapid high-performance liquid chromatographic assay for ketoprofen in isopropyl myristate

A high-performance liquid chromatographic (HPLC) procedure for quantitating ketoprofen in isopropyl myristate (IPM), a compound widely used as a receptor medium in drug diffusion studies of topical aqueous-based formulations, is developed. Previously reported HPLC assays for ketoprofen in IPM have employed relatively complex and tedious methods for purifying the IPM prior to injection onto the HPLC column. The present assay method utilizes a direct injection of the IPM-based sample onto a new reversed-phase ODS column and employs ultraviolet detection at 265 nm. Propyl paraben is employed as the internal standard. The mobile phase consists of acetonitrile-methanol-water (36:54:10, v/v/v) at a flow rate of 1.2 mL/min. The calibration curves are linear (correlation coefficient r > or = 0.988) over concentration ranges of 0.625-10 micrograms/mL and 6.25-100 micrograms/mL. The within-day and between-day precision exhibit coefficients of variation of 1.3-3.3%, and the accuracy (reported as relative error of the mean) varies from -1.9% to 0.6%. The retention times for ketoprofen and propyl paraben are approximately 2.3 and 3.3 min, respectively. The total run time per sample is approximately 7 min. The minimum quantitatable concentration is approximately 0.625 microgram/mL. The assay is stability-indicating, rapid, reproducible, sensitive, and readily adaptable for assaying other non-steroidal anti-inflammatory drugs.

The health of Canadians with diabetes

OBJECTIVES

This article focuses on the prevalence of diabetes mellitus among Canadians, the health status of those with the disease, their socioeconomic characteristics, personal health behaviours, and use of health services.

DATA SOURCE

The data are from the 1994/95 National Population Health Survey.

ANALYTICAL TECHNIQUES

Weighted counts were used in computing the prevalence of diabetes and the proportions of people with the characteristics and health behaviours considered.

MAIN RESULTS

In 1994/95, 3% of Canadians aged 12 and older--over 722,000 people--reported having diabetes that had been diagnosed by a health care professional. The prevalence of diabetes increases with age and is associated with low income. A higher percentage of adults with diabetes were overweight compared to those without the disease.

In vitro evaluation of pluronic F127-based controlled-release ocular delivery systems for pilocarpine

The overall objective of this study was to develop pluronic F127 (PF127)-containing formulations of pilocarpine hydrochloride (PHCL) suitable for controlled-release ocular delivery of PHCL. Various aqueous formulations were evaluated containing 1% w/v PHCL and 25% w/v PF127 alone or with one of the following additives present: poly(ethylene glycol) 4600 (PEG), poly(vinylpyrrolidone) 10,000 (PVP), poly(vinyl alcohol) 10,000 (PVA), methylcellulose 15 cP (MC), and hydroxypropyl methylcellulose 80-120 cP (HPMC). The in vitro dissolution of the PF127 formulations and the pilocarpine release profiles from them were obtained simultaneously at 34 degrees C and room temperature using a membraneless in vitro model. It was observed that the PEG- and PVP-containing PF127 formulations of PHCL dissolved the quickest and released the drug at a significantly faster rate than the control PF127 formulation, which had no additive present. The PF127 formulations of PHCL containing MC or HPMC exhibited the slowest dissolution rates and released the drug the slowest. The same rank order was observed at each temperature for the dissolution and PHCL release profiles of each formulation. On the basis of the in vitro results, the PF127 formulations of PHCL containing MC or HPMC as an additive showed potential for use as controlled-release ocular delivery systems for PHCL.

Pharmacokinetic perspectives on megadoses of ascorbic acid

Ascorbic acid (vitamin C) is commonly used as a dietary supplement, often in megadoses. However, as the daily oral dose is increased, the concentration of ascorbic acid in the plasma and other body fluids does not increase proportionally, but instead tends to approach an upper limit. For example, when the daily dose is increased from 200 to 2500 mg (from 1.1 to 14.2 mmol) the mean steady state plasma concentration increases only from approximately 12 to 15 mg/L (from 68.1 to 85.2 mumol/L). Published data were reanalyzed with an integrated modeling approach to shed new quantitative light on this phenomenon. This analysis is based on the renal clearance of ascorbic acid, which rises sharply with increasing plasma concentrations as a result of saturable tubular reabsorption. The analysis indicates that both saturable gastrointestinal absorption and nonlinear renal clearance act additively to produce the ceiling effect in plasma concentrations. As a consequence of this ceiling effect, there is no pharmacokinetic justification for the use of megadoses of ascorbic acid.

Shigellosis on Indian reserves in Manitoba, Canada: its relationship to crowded housing, lack of running water, and inadequate sewage disposal

OBJECTIVES

This study compares incidence and hospitalization rates for shigellosis between Indians and the rest of the population in Manitoba, Canada. It examines the relationship between shigellosis and environmental conditions on reserves.

METHODS

Rates were calculated with surveillance data and a survey of environmental infrastructure was done.

RESULTS

Indians had shigellosis incidence and hospitalization rates that were 29 and 12 times as high, respectively, as those of the rest of the population. Household crowding, lack of piped water, and inadequate sewage disposal were significantly associated with an increased incidence of shigellosis on reserves.

CONCLUSIONS

Many cases of shigellosis may be prevented by improving living conditions on Indian reserves.

Liver-directed gene transfer in non-human primates

To develop a primate model for liver-directed gene therapy, we studied several gene transfer vehicles and routes in eight rhesus monkeys (Macaca mulatta). For this purpose, we used first-generation, replication-deficient adenoviral vectors carrying the Escherichia coli lacZ gene (Ad.CMVlacZ) or a lacZ-containing plasmid (pCMV beta) with lipofectamine for transfection. The reporter gene construct was infused into either the portal vasculature, common bile duct, or saphenous vein. Adenovirus-mediated gene transfer via the portal vein resulted in expression of lacZ in over 70% of hepatocytes by days 3-7, but was accompanied by acute hepatitis. Adenovirus-mediated gene transfer via the common bile duct resulted in lacZ expression in less than 10% of hepatocytes and was accompanied by portal inflammation. The animals mounted a significant immune response, as demonstrated by adenoviral antigen-induced T-cell proliferation and production of neutralizing anti-adenovirus antibodies and antibodies to E. coli beta-galactosidase (beta-Gal). Activation of the immune response was associated with rapid decrease of the reporter gene by days 13-21. Lipofectamine-mediated gene transfer was inefficient, and no lacZ expression in the liver was detected. To limit the host immune response, 4 animals were immunosuppressed by cyclophosphamide/prednisone and then infused with the Ad.CMVlacZ via the portal vein or the saphenous vein. The monkeys showed sustained expression of lacZ for up to 35 days with no evidence of inflammation. The primates transduced via the saphenous vein showed a level of beta-Gal expression in the liver similar to that of the portal vein-infused animals. In conclusion, adenovirus-mediated gene transfer to non-human primate livers via the portal vein or saphenous vein is efficient, but it results in transient expression and is accompanied by an immune response to both vector and transgene products and acute hepatitis, whereas lipofectamine-mediated transfer is inefficient. Manipulation of the host immune response may expand potential applications of adenoviral vectors for liver-directed gene transfer.

Intrasplenic hepatocyte allotransplantation in dalmation dogs with and without cyclosporine immunosuppression

Hepatocyte allotransplantation has been performed successfully in several small animal models for the amelioration of inborn metabolic errors. Before a human clinical trial of hepatocyte allotransplantation can be attempted, preliminary experience in a large animal model is needed. We transplanted isolated mongrel hepatocytes into the spleen of dalmatians in the attempt to cure their inborn error of uric acid metabolism. Of 10 dalmatian recipients, two that received 9-10 x 10(9) mongrel hepatocytes died early after surgery of acute portal hypertension and hemorrhage. The eight long-term survivors received 5-6 x 10(9) hepatocytes and were randomized either to no treatment or to oral cyclosporine (CsA). Levels of CsA were adjusted to maintain trough levels between 400 and 800 ng/ml. In the four nonimmunosuppressed dalmatians, a reproducible average reduction in urinary uric acid excretion (UUAEx) of 23.7% was achieved; values returned to baseline within 14 days. In the CsA-immunosuppressed dalmatians, the average decline in UUAEx was 30%. The partial correction of the metabolic defect persisted for an average of 25 days in three immunosuppressed dogs, whereas in one dog, the partial correction lasted for over 90 days. No change in UUAEx was observed in two dalmatians that underwent sham laparotomy and intrasplenic injection of saline solution; CsA given alone to dalmatians did not modify UUAEx. We conclude that the dalmatian dog is a valuable large animal model for studies of the role of hepatocyte transplantation in the cure of inborn hepatic metabolic errors.

Skin pigmentation and pharmacokinetics of melanotan-I in humans

A comparative pharmacokinetic trial was performed with a superpotent synthetic melanotropic peptide, [Nle4-D-Phe7]-alpha-MSHi-13 (melanotan-I or MT-I) given by three routes of administration. Plasma levels were measured by RIA and tanning was quantiated using serial reflectometry. Doses of 0.16 mgkg-1 were administered intravenously (IV) and orally (PO), and doses from 0.08 to 0.21 mg kg-1 subcutaneously (SC), in a randomized crossover fashion to three male volunteers over five consecutive days for 2 weeks (ten doses). The results indicate that the SC dose is completely bioavailable compared to the IV dose. No detectable drug levels were observed following PO dosing. The plasma half-lives following SC dosing ranged from 0.07 to 0.79 h for the absorption phase and from 0.8 to 1.7 h for the beta-phase. Clearance ranged from 0.12 to 0.19 L kg-1 h-1 and 3.9% or less of the dose was recovered in the urine. Side-effects were minimal, consisting of occasional gastrointestinal upset and facial flushing. Significant tanning of the forehead, arms, and neck was noted following IV or SC dosing. This effect peaked at 1 week following drug administration but was still present 3 weeks after completing the ten-dose regimen. It is concluded that SC administration is an efficacious method of delivering melanotan-I.

A study of cadmium transport pathways using the Caco-2 cell model

The purpose of this study was to investigate the mechanism by which cadmium (Cd2+) crosses the intestinal epithelium using a Caco-2 cell model. Experimentation was designed to determine which of several possible pathways of transport are operative. These pathways include passive diffusion, transport via a calcium pathway, sulfhydryl-mediated transport, and carrier-mediated (active transport and/or facilitated diffusion) transport. To examine the diffusion pathway the effect of various apical cadmium concentrations on the amount of cadmium transported was tested. The effects of verapamil, calcium, and 1,25(OH)2 vitamin D3 (vit. D3) on Cd2+ transport were examined to investigate the possible existence of a calcium transport pathway. N-Ethylmaleimide, a sulfhydryl group blocker, was used to determine whether Cd2+ transport is sulfhydryl-mediated. Active transport was evaluated by examining the effect of 2,4-dinitrophenol, a metabolic inhibitor, on the transport of Cd2+. These studies indicated that: (1) a portion of the overall transport of Cd2+ can be attributed to diffusion, (2) stimulation of calcium binding protein transcription by vit. D3 enhances Cd2+ transport, and (3) the transport process for Cd2+ has both sulfhydryl-mediated and carrier-mediated components.

Controlled-release delivery system for the alpha-MSH analog melanotan-I using poloxamer 407

The overall objective of these studies was to develop a controlled-release formulation of Melanotan-I (MT-I) containing poloxamer 407 (P407). Various aqueous formulations were evaluated containing MT-I and 25% w/v P407 alone, or with one of the following additives present, i.e., poly(vinylpyrrolidone) 10000 (PVP), methylcellulose (MC), or hydroxypropyl methylcellulose (HPMC). The in-vitro release profiles of MT-I from the P407 formulations and the dissolution of the gel were obtained simultaneously using a membraneless in-vitro model. These data were obtained at 37 degrees C and room temperature (24 degrees C). It was observed that the PVP-containing P407 formulations of MT-I accelerated the dissolution of gel and the release of the peptide compared to the control formulation. The formulations containing MC or HPMC exhibited the slowest dissolution rates and release of MT-I. The same rank order was observed for the dissolution and release profiles of MT-I from the various formulations at both temperatures. The in-vivo release kinetics of selected formulations were analyzed in guinea pigs following intraperitoneal administration. The plasma concentration-time profiles showed an extended release of the peptide formulated with gel compared to the intraperitoneal administration of MT-I in solution. On the basis of the in-vitro and in-vivo results, the P407 formulations of MT-I with MC or HPMC as an additive showed potential for use as a controlled-release delivery system for MT-I.

An improved method for determination of acid dissociation constants of peptides

PURPOSE

The method described here enables the proton dissociation constants of several amino acid residues of a peptide to be determined simultaneously in aqueous solution without prior knowledge of the exact concentration of the peptide.

METHODS

The method used here employs a non-linear fitting program, the BEST program, or a linear least-squares method in combination with the BEST program. These methods are discussed in detail with an emphasis on the quality of the potentiometric titration data that are obtained. Two representative peptides, one with two proton dissociation constants (Ka1, Ka2) and the other with four proton dissociation constants (Ka1-Ka4) were used to illustrate the advantages and the limitations of these two complementary methods.

RESULTS

The pKa values of TVL, a schizophrenia-related tripeptide, were found to be 3.62 (+/- 0.02) and 7.17 (+/- 0.05); the pKa values of ELTLQE, a hexapeptide, were found to be 2.32, 3.77, 4.58 and 7.74.

CONCLUSIONS

The methods reported here are generally applicable to a variety of peptides. The possibility of integrating these procedures into a preparative chromatographic system for the "on-line" assessment of the pKa values of peptides during the purification stage is an attractive and novel feature of this method.

High-performance liquid chromatographic assay for Melanotan-1 ([Nle4-DPhe7]alpha-melanocyte-stimulating hormone) in biological matrices

The overall objective of this research was to develop a sensitive, specific, and stability-indicating HPLC assay for the determination of the [Nle4-DPhe7]alpha-melanocyte-stimulating hormone analog known as Melanotan-1 (MT-1) in biological matrices, i.e., cell culture transport media and human plasma. Separation was accomplished isocratically within 8.0 min using a C8 reversed-phase column. The mobile phase consisted of 0.1 M phosphate buffer-acetonitrile (80:20, v/v) with 18 microliters/l triethylamine at pH 2.50. The flow-rate was 1 ml/min with detection at 214 nm. Standard curves (n = 5) were linear over the concentration range 100-1000 ng/ml. The precision, accuracy, intra- and inter-day variations were good with C.V.s typically within 8.7% for concentrations greater than 100 ng/ml. This method was applied to a study of the transport of MT-1 in the Caco-2 cell monolayer model.

Enhancement of calcium transport in the Caco-2 cell monolayer model

The overall objective of this research was to identify enhancers of calcium transport using an in-vitro Caco-2 cell monolayer model. The enhancers studied were medium-chain triglycerides (MCT) and acylcarnitines (AC). The extent of cell damage associated with the use of these enhancers was determined by monitoring the release of cellular lactate dehydrogenase (LDH). The effect of chain-length and concentration dependence of these agents on enhancement were also determined. The effects of ACs were found to be superior to those of MCTs. However, the ACs elicited a greater release of LDH than the MCTs. The possible mechanisms of enhancer-mediated increase in calcium transport and the potential significance of this study with regard to the prevention of osteoporosis are discussed.

Potential role of nitric oxide in a model of chronic colitis in rhesus macaques

BACKGROUND/AIMS

Excess nitric oxide formation, via the inducible NO synthase isoform, has been implicated in the pathogenesis of experimental and clinical inflammatory bowel disease. The aim of this study was to assess the site, enzyme source, and magnitude of NO production in juvenile rhesus macaques with idiopathic colitis.

METHODS

NO production was assessed systemically from plasma and urine levels of reactive nitrogen intermediates and locally by the formation of [3H]citrulline from [3H]arginine and reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemistry. Inducible NO synthase gene expression was assessed by reverse-transcription polymerase chain reaction.

RESULTS

Plasma and urine levels of reactive nitrogen intermediates were greater in colitic animals than in control monkeys by 13- and 5-fold, respectively. NADPH diaphorase activity in normal animals was confined to the myenteric plexus. In colitis, staining was also apparent in crypt abscesses and superficial epithelial and mucosal bands. Gene expression for inducible NO synthase was only found in colitic specimens. Colonic [3H]citrulline formation was markedly elevated in colitic specimens, and the inducible isoform accounted for 58% of total activity.

CONCLUSIONS

It is proposed that excess NO, formed via the inducible form of NO synthase, contributes to the mucosal inflammation and symptoms of this idiopathic colitis model.

Mechanisms of acylcarnitine-mediated enhancement of calcium transport in the Caco-2 cell monolayer model

The overall objective of this study was to determine the mechanisms of acylcarnitine-mediated enhancement of calcium transport across Caco-2 cells. The different mechanisms of enhancement postulated are (a) loosening of tight junctions, thereby promoting paracellular transport; (b) opening of calcium channels, thus increasing calcium entry; and (c) stimulation of the basolateral Ca-ATPase pump, thereby aiding calcium extrusion. Although the existence of calcium channels and the reversal of verapamil-mediated inhibition of calcium uptake by acylcarnitines were demonstrated for the first time in Caco-2 cells, the channels do not appear to be a major contributing factor to the enhancement of calcium transport by acylcarnitines. Calmidazolium, a potent Ca-ATPase pump inhibitor in tissues such as rat intestinal segments, failed to inhibit this pump in Caco-2 cells. Thus, the predominant mechanism of enhancement of calcium transport by acylcarnitines in the Caco-2 model appears to be via promotion of paracellular transport.

Organization of the hamster intergeniculate leaflet: NPY and ENK projections to the suprachiasmatic nucleus, intergeniculate leaflet and posterior limitans nucleus

The intergeniculate leaflet (IGL) is an integral part of the circadian visual system. It receives direct retinal input and relays photic information to the circadian clock in the suprachiasmatic nucleus (SCN) through a geniculohypothalamic tract (GHT). In both rat and hamster, neuropeptide Y immunoreactive (NPY-IR) IGL cells project through the GHT to the SCN. However, the hamster GHT also contains enkephalin-IR (ENK-IR) fibers, presumably of IGL origin. In the present investigations, the IGL was examined for NPY-, ENK-, or dual-IR cells. Their projections to the SCN, contralateral IGL and pretectum were also studied. The results show that the hamster IGL contains both NPY- and ENK-IR neurons and that about 50% of these are immunoreactive to both peptides. Double-label retrograde analysis indicates that cells of each peptide class project to the SCN. Similarly, IGL neurons, many of which are NPY- and ENK-IR, project to the pretectum, particularly the posterior limitans nucleus. While numerous IGL neurons project contralaterally, very few are NPY- or ENK-IR. The distribution of SCN- and pretectum-projecting cells, in conjunction with the distribution of peptide-IR neurons, allows expansion of the IGL definition to include the region medial to the ventral lateral geniculate nucleus (VLG). The VLG is ventrolateral to the IGL and does not contain either neurons projecting to the SCN nor NPY- or ENK-IR cells, but does have numerous neurons projecting to the pretectum. The results substantiate and expand the previous definition of the hamster IGL, elaborate the species difference in IGL organization, and demonstrate the increased breadth of the circadian visual system.

Epidemiology of infection due to Chlamydia trachomatis in Manitoba, Canada

In a study of the epidemiology of Chlamydia trachomatis infection in Manitoba during 1981-1990, we retrospectively reviewed laboratory and clinical case notification records as well as hospital and health insurance data concerning pelvic inflammatory disease and ectopic pregnancy. After implementation of a control program in 1987, the annual incidence of chlamydial infection was highest among females aged 15-24 years (3,418 cases per 100,000 residents). Recurrent infection, which occurred in 13.4% of patients, was more common in women (P < .001), patients aged 15-24 years (P < .001), registered North American Indians (P < .001), and persons with concomitant gonorrhea (P < .001). Risk factors for dual (chlamydial and gonococcal) infection included male sex (P < .001) and young age (P < .001). Although the incidence of hospitalization and outpatient visits for pelvic inflammatory disease decreased (P < .001) from 1981 to 1990, the annual incidence of ectopic pregnancy increased from 10 to 16 cases per 1,000 reported pregnancies (P < .001). Control activities focusing on the primary prevention of C. trachomatis infection are presented. Strategies for improving secondary prevention (through case detection and treatment of lower genital infection) include the targeting of individuals with recurrent and multiple sexually transmitted diseases.