Evaluation of the impact of iPSC differentiation protocols on transcriptomic signatures

Human induced pluripotent stem cells (iPSC) have the potential to produce desired target cell types in vitro and allow for the high-throughput screening of drugs/chemicals at population level thereby minimising the cost of drug discovery and drug withdrawals after clinical trials. There is a substantial need for the characterisation of the iPSC derived models to better understand and utilise them for toxicological relevant applications. In our study, iPSC (SBAD2 or SBAD3 lines obtained from StemBANCC project) were differentiated towards toxicologically relevant cell types: alveolar macrophages, brain capillary endothelial cells, brain cells, endothelial cells, hepatocytes, lung airway epithelium, monocytes, podocytes and renal proximal tubular cells. A targeted transcriptomic approach was employed to understand the effects of differentiation protocols on these cell types. Pearson correlation and principal component analysis (PCA) separated most of the intended target cell types and undifferentiated iPSC models as distinct groups with a high correlation among replicates from the same model. Based on PCA, the intended target cell types could also be separated into the three germ layer groups (ectoderm, endoderm and mesoderm). Differential expression analysis (DESeq2) presented the upregulated genes in each intended target cell types that allowed the evaluation of the differentiation to certain degree and the selection of key differentiation markers. In conclusion, these data confirm the versatile use of iPSC differentiated cell types as standardizable and relevant model systems for in vitro toxicology.

The relationship between epigenetic age and the hallmarks of aging in human cells

Epigenetic clocks are mathematically derived age estimators that are based on combinations of methylation values that change with age at specific CpGs in the genome. These clocks are widely used to measure the age of tissues and cells1,2. The discrepancy between epigenetic age (EpiAge), as estimated by these clocks, and chronological age is referred to as EpiAge acceleration. Epidemiological studies have linked EpiAge acceleration to a wide variety of pathologies, health states, lifestyle, mental state and environmental factors2, indicating that epigenetic clocks tap into critical biological processes that are involved in aging. Despite the importance of this inference, the mechanisms underpinning these clocks remained largely uncharacterized and unelucidated. Here, using primary human cells, we set out to investigate whether epigenetic aging is the manifestation of one or more of the aging hallmarks previously identified3. We show that although epigenetic aging is distinct from cellular senescence, telomere attrition and genomic instability, it is associated with nutrient sensing, mitochondrial activity and stem cell composition.

The long-term effects of early oral feeding following minimal invasive esophagectomy

A nil-by-mouth regime with enteral nutrition via an artificial route is frequently applied following esophagectomy. However, early initiation of oral feeding could potentially improve recovery and has shown to be beneficial in many types of abdominal surgery. Although short-term nutritional safety of oral intake after an esophagectomy has been documented, long-term effects of this feeding regimen are unknown. In this cohort study, data from patients undergoing minimal invasive Ivor-Lewis esophagectomy between 04-2012 and 09-2015 in three centers in Netherlands were collected. Patients in the oral feeding group were retrieved from a previous prospective study and compared with a cohort of patients with early enteral jejunostomy feeding but delayed oral intake. Body mass index (BMI) measurements, complications, and nutritional re-interventions (re- or start of artificial feeding, start of total parenteral nutrition) were gathered over the course of one year after surgery. One year after surgery the median BMI was 22.8 kg/m2 and weight loss was 7.0 kg (9.5%) in 114 patients. Patients in the early oral feeding group lost more weight during the first postoperative month (P = 0.004). However, in the months thereafter this difference was not observed anymore. In the early oral feeding group, 28 patients (56%) required a nutritional re-intervention, compared to 46 patients (72%) in the delayed oral feeding group (P = 0.078). During admission, more re-interventions were performed in the delayed oral feeding group (17 vs. 46 patients P < 0.001). Esophagectomy reduces BMI in the first year after surgery regardless of the feeding regimen. Direct start of oral intake following esophagectomy has no impact on early nutritional re-interventions and long-term weight loss.

Atypical clinical presentation of internal herniation after laparoscopic Roux-en-Y gastric bypass

A 60-years old women with history of Roux-en-Y gastric bypass presented with progressive abdominal pain, mainly at the left loin. Imaging was aspecific. Exploratory laparoscopy showed an internal herniation trough the Petersen space.

Enhanced soluble interleukin-5 receptor alpha expression in nasal polyposis

BACKGROUND

Alternative splicing of the interleukin-5 receptor alpha (IL-5Ralpha)-subunit leads to the generation of a signalling, membrane-anchored (TM) isoform, or a secreted [soluble (SOL)], antagonistic variant. Given the key role of IL-5 in eosinophil function, we investigated SOL IL-5Ralpha expression pattern in an eosinophil-associated disease such as nasal polyposis (NP).

METHODS

An SOL IL-5Ralpha enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction (PCR) were established and applied in serum, nasal secretion and nasal tissue of controls (n = 12), and NP patients (n = 42) with or without asthma.

RESULTS

Analysis of serum, nasal secretion, and nasal tissue samples revealed that SOL IL-5Ralpha protein concentrations were significantly increased in NP vs control tissue. Within the NP group, there was a significant up-regulation of SOL IL-5Ralpha in patients with systemic airway disease. These findings were confirmed at the mRNA level, using an optimized real-time reverse-transcriptase PCR procedure.

CONCLUSIONS

This report demonstrates SOL IL-5Ralpha transcript and protein up-regulation in NP. Soluble IL-5Ralpha differentiates nasal polyps with or without concomitant asthma. As SOL IL-5Ralpha is strongly up-regulated for disease and has antagonistic properties in vitro, our studies shed new light on the mechanisms of specific immunomodulatory therapies, such as anti-IL-5.

[Radiation of parotid glands for salivary flow reduction in amyotrophic lateral sclerosis]

Radiation of the parotid and submandibular glands was performed in 18 patients with pronounced hypersalivation at a late stage of amyotrophic lateral sclerosis (ALS). Single bilateral radiation of the parotid and posterior submandibular glands was made in the dosage of 7.0-7.5 Gy. Salivation volume was measured before and after the radiation therapy. Sixteen patients exhibited satisfactory and marked salivary flow reduction during 4-6 months. Xerostomia developed in 1 patient who needed assignment of artificial salivary substitute and 1 patient did not respond to the therapy. The patient's caregivers reported a positive effect in all the cases. Tolerance of the therapy was good except rare side effects. Radiation of the parotid glands significantly reduced salivary flow in ALS, especially in patients receiving an adequate amount of water.

An in vitro model for the study of microglia-induced neurodegeneration: involvement of nitric oxide and tumor necrosis factor-alpha

The precise function of activated microglia and their secretory products remains controversial. In order to assess the role of microglial secretion products, we established an in vitro model of an inflammatory reaction in the brain by co-culturing microglial and neuronal cell lines. Upon stimulation with interferon-gamma and lipopolysaccharides, the microglial cells adopted an activated phenotype and secreted tumor necrosis factor-alpha (TNF-alpha), prostaglandin E(2) and nitric oxide (NO). Neuronal degeneration was quantified by measuring the concentrations of microtubule associated protein tau and neuron specific enolase, which are also used as diagnostic tool in Alzheimer's disease, in supernatants. In activated contact co-cultures, the levels of these neuronal markers were significantly raised compared to non-activated co-cultures. NO-synthase inhibitors significantly diminished the rise of tau in activated co-cultures, while indomethacin, superoxide dismutase, or a neutralizing TNF-alpha antibody did not. When a chemical NO-donor or TNF-alpha were added to pure neuronal cultures, cell viability was significantly reduced. TNF-alpha increased neuronal sensitivity towards NO. There were indications that a part of the cells died by apoptosis. This model demonstrates a neurotoxic role for NO in microglia-induced neurodegeneration and provides a valuable in vitro tool for the study of microglia-neuron interactions during inflammation in the brain.

Syphilis control during pregnancy: effectiveness and sustainability of a decentralized program

OBJECTIVES

This study sought to assess the performance, effectiveness, and costs of a decentralized antenatal syphilis screening program in Nairobi, Kenya.

METHODS

Health clinic data, quality control data, and costs were analyzed.

RESULTS

The rapid plasma reagin (RPR) seroprevalence was 3.4%. In terms of screening, treatment, and partner notification, the program's performance was adequate. The program's effectiveness was problematic because of false-negative and false-positive RPR results. The cost per averted case was calculated to be US$95 to US$112.

CONCLUSIONS

The sustainability of this labor-intensive program is threatened by costs and logistic constraints. Alternative strategies, such as the mass epidemiologic treatment of pregnant women in high-prevalence areas, should be considered.

Lectin-deficient TNF mutants display comparable anti-tumour but reduced pro-metastatic potential as compared to the wild-type molecule

In this study, we characterised the anti-tumour as well as the pro-metastatic activities of TNF mutants deficient in their lectin-like activity.1619 We report that, despite reduced systemic toxicity as compared to wild-type (wt) mTNF, a (T104A) and a (T104A-E106A-E109A) mTNF mutant (triple mTNF) retained most of their necrotic and tumouristatic activities, as measured in a CFS-1 fibrosarcoma and a B16BL6 melanoma tumour model, respectively. These mutants also conserved their anti-angiogenic activity, as measured in an in vitro endothelial morphogenesis assay.26 In contrast, the pro-metastatic activity of the T104A and the triple mTNF mutants in the CFS-1 fibrosarcoma and the 3LL-R Lewis lung carcinoma tumour model was significantly lower than that of the wt molecule. These results thus indicate that the lectin-like domain of TNF is not implicated in its necrotic, tumouristatic and anti-angiogenic activities, but that it can contribute to the pro-metastatic effect of the cytokine. In conclusion, in view of their reduced systemic toxicity and pro-metastatic capacity, but their retained anti-tumour activities, lectin-deficient TNF mutants might prove to be therapeutically interesting alternatives to wt TNF.

Model-based evaluation of single-round mass treatment of sexually transmitted diseases for HIV control in a rural African population

OBJECTIVES

To compare the impact of single-round mass treatment of sexually transmitted diseases (STD), sustained syndromic treatment and their combination on the incidence of HIV in rural Africa.

METHODS

We studied the effects of STD interventions by stochastic simulation using the model STDSIM. Parameters were fitted using data from a trial of improved STD treatment services in Mwanza, Tanzania. Effectiveness was assessed by comparing the prevalences of gonorrhoea, chlamydia, syphilis and chancroid, and the incidence of HIV, in the general adult population in simulations with and without intervention.

RESULTS

Single-round mass treatment was projected to achieve an immediate, substantial reduction in STD prevalences, which would return to baseline levels over 5-10 years. The effect on syphilis was somewhat larger if participants cured of latent syphilis were not immediately susceptible to re-infection. At 80% coverage, the model projected a reduction in cumulative HIV incidence over 2 years of 36%. A similar impact was achieved if treatment of syphilis was excluded from the intervention or confined to those in the infectious stages. In comparison with sustained syndromic treatment, single-round mass treatment had a greater short-term impact on HIV (36 versus 30% over 2 years), but a smaller long-term impact (24 versus 62% over 10 years). Mass treatment combined with improved treatment services led to a rapid and sustained fall in HIV incidence (57% over 2 years; 70% over 10 years).

CONCLUSIONS

In populations in which STD control can reduce HIV incidence, mass treatment may, in the short run, have an impact comparable to sustained syndromic treatment. Mass treatment combined with sustained syndromic treatment may be particularly effective.

Prevention of mother-to-child transmission of HIV in developing countries: recommendations for practice. The Ghent International Working Group on Mother-To-Child Transmission of HIV

OBJECTIVES

Different approaches to prevent mother-to-child transmission of HIV are being evaluated in developing countries. The first trials using a short regimen of zidovudine have been successful in Thailand, Côte d'Ivoire and Burkina Faso. International and local strategies are now being considered. The Ghent International Working Group on Mother-to-Child Transmission of HIV developed public health policy options to integrate these interventions into basic and maternal and child health (MCH) services.

METHODS

The following tasks were undertaken: a critical review of randomized trials; an international pooled analysis of late postnatal transmission of HIV through breastfeeding; a review of the cost-effectiveness and cost-benefit of antiretroviral prophylaxis; a feasibility assessment of preventive strategies, including a postal survey on HIV voluntary counselling and testing (VCT) of pregnant women; the identification of requirements and research priorities for prenatal, obstetric and paediatric care. These projects provided the background for a three-day workshop in Ghent, Belgium, in November 1997. Conclusions were further refined, based on 1998 research findings.

RESULTS

A summary of relevant evidence and ten public health recommendations are reported. VCT for pregnant women, a short regimen of zidovudine together with alternatives to breastfeeding currently represent the best option to reduce vertical transmission in most developing countries. The primary goal of the integrated package supporting these interventions is to alleviate overall maternal and infant morbidity and mortality.

CONCLUSION

Prevention of mother-to-child transmission of HIV should now be considered for integration into basic health and MCH services of selected countries, with the involvement of governments and donor agencies.

The lectin-like domain of tumor necrosis factor-alpha increases membrane conductance in microvascular endothelial cells and peritoneal macrophages

Herein, we show that TNF exerts a pH-dependent increase in membrane conductance in primary lung microvascular endothelial cells and peritoneal macrophages. This effect was TNF receptor-independent, since it also occurred in cells isolated from mice deficient in both types of TNF receptors. A TNF mutant in which the three amino acids critical for the lectin-like activity were replaced by an alanine did not show any significant effect on membrane conductance. Moreover, a synthetic 17-amino acid peptide of TNF, which was previously shown to exert lectin-like activity, also increased the ion permeability in these cells. The amiloride sensitivity of the observed activity suggests a binding of TNF to an endogenous ion channel rather than channel formation by TNF itself. This may have important implications in mechanisms of TNF-mediated vascular pathology.

Membrane interaction of TNF is not sufficient to trigger increase in membrane conductance in mammalian cells

Tumor necrosis factor TNF can trigger increases in membrane conductance of mammalian cells in a receptor-independent manner via its lectin-like domain. A lectin-deficient TNF mutant, lacking this activity, was able to bind to artificial liposomes in a pH-dependent manner, but not to insert into the bilayer, just like wild type TNF. A peptide mimicking the lectin-like domain, which can still trigger increases in membrane currents in cells, failed to interact with liposomes. Thus, the capacity of TNF to trigger increases in membrane conductance in mammalian cells does not correlate with its ability to interact with membranes, suggesting that the cytokine does not form channels itself, but rather interacts with endogenous ion channels or with plasma membrane proteins that are coupled to ion channels.

The lectin-like domain of tumor necrosis factor-alpha increases membrane conductance in microvascular endothelial cells and peritoneal macrophages

Herein, we show that TNF exerts a pH-dependent increase in membrane conductance in primary lung microvascular endothelial cells and peritoneal macrophages. This effect was TNF receptor-independent, since it also occurred in cells isolated from mice deficient in both types of TNF receptors. A TNF mutant in which the three amino acids critical for the lectin-like activity were replaced by an alanine did not show any significant effect on membrane conductance. Moreover, a synthetic 17-amino acid peptide of TNF, which was previously shown to exert lectin-like activity, also increased the ion permeability in these cells. The amiloride sensitivity of the observed activity suggests a binding of TNF to an endogenous ion channel rather than channel formation by TNF itself. This may have important implications in mechanisms of TNF-mediated vascular pathology.

Declining syphilis prevalence in pregnant women in Nairobi since 1995: another success story in the STD field?

Untreated maternal syphilis during pregnancy will cause adverse pregnancy outcomes in more than 60% of the infected women. In Nairobi, Kenya, the prevalence of syphilis in pregnant women of 2.9% in 1989, showed a rise to 6.5% in 1993, parallel to an increase of HIV-1 prevalence rates. Since the early 1990s, decentralized STD/HIV prevention and control programmes, including a specific syphilis control programme, were developed in the public health facilities of Nairobi. Since 1992 the prevalence of syphilis in pregnant women has been monitored. This paper reports the findings of 81,311 pregnant women between 1994 and 1997. A total of 4244 women (5.3%) tested positive with prevalence rates of 7.2% (95% CI: 6.7-7.7) in 1994, 7.3% (95% CI: 6.9-7.7) in 1995, 4.5% (95% CI: 4.3-4.8) in 1996 and 3.8% (95% CI: 3.6-4.0) in 1997. In conclusion, a marked decline in syphilis seroprevalence in pregnant women in Nairobi was observed since 1995-96 (P<0.0001, Chi-square test for trend) in contrast to upward trends reported between 1990 and 1994-95 in the same population.

Both TNF receptors are required for direct TNF-mediated cytotoxicity in microvascular endothelial cells

The conditions under which tumor necrosis factor-alpha (TNF) induces apoptosis in primary microvascular endothelial cells (MVEC) were investigated. In the absence of sensitizing agents, TNF induced apoptosis after 3 days of incubation in confluent MVEC. In contrast, upon addition of the transcriptional inhibitor actinomycin D (Act. D), confluence was no longer required and apoptosis occurred already after 16 h. To assess the role of either TNF receptor (TNFR) type in apoptosis, MVEC isolated from mice genetically deficient in TNFR1 (Tnfr1o mice) or TNFR2 (Tnfr2o mice) were incubated with TNF in the presence or absence of Act. D. Under sensitized conditions, Tnfr2o MVEC were lysed like controls, whereas Tnfr1o MVEC were completely resistant, indicating an exclusive role for TNFR1. In contrast, in the absence of Act. D, confluent monolayers of wild-type cells were lysed by TNF, but both Tnfr1o and Tnfr2o MVEC were resistant to TNF-mediated toxicity, indicating a requirement for both TNFR types. Overexpression of the anti-apoptotic protein bcl-xL in MVEC led to a protection against the direct, but not the sensitized cytotoxicity of TNF. In conclusion, in pathophysiologically relevant conditions, both TNFR appear to be required for TNF-induced apoptosis in MVEC.

Prospective evaluation of a flow chart using a risk assessment for the diagnosis of STDs in primary healthcare centres in Libreville, Gabon

BACKGROUND

The serious impact of STDs on women and children in particular, and the linkage between STDs and HIV infection are a profound concern to public health worldwide. One of the main strategies against STDs is based on early diagnosis and treatment. However, this approach is limited by the lack of appropriate laboratory facilities. A syndromic approach has been recommended by the WHO but needs to be evaluated under field conditions. A preliminary cross sectional study on STD prevalence and risk factors in Libreville showed that 13.5% of pregnant women had gonococcal and/or chlamydial infection which justifies systematic screening of STDs. Based on the results of this study, different flow charts with or without a risk factor assessment (score) were designed. The flow chart with the best performances for diagnosing chlamydial or gonococcal cervical infection and routinely acceptable, was a score algorithm, based on two risk factors (age and marital status) and four simple clinical signs (pelvic or lumbar pain, vaginal discharge and its characteristics). Sensitivity and specificity were 76.9% and 40.4% respectively. Thus, the objective of this study was to evaluate this strategy under field conditions.

METHODS

A prospective study among pregnant women attending antenatal clinics was done. The score was applied to each woman by a midwife and a physician, and specimens were collected for the reference laboratory tests. Validation of the algorithm was done by comparing the performances with the gold standard laboratory diagnosis.

RESULTS

646 pregnant women were enrolled. The prevalence of cervical infection was 11.3. The sensitivity and specificity of this algorithm recorded by the midwives were 73.3% and 54.8%, respectively and by the physician 76.7% and 50.6%. The proportion of women correctly classified by the midwives and by the physician was not significantly different.

CONCLUSION

The score applied was well accepted by healthcare workers and patients, and was routinely practised. Results obtained by the midwives and by the physician were similar. Thus, the use of flow charts which adds a risk assessment to the syndromic approach for diagnosing cervical infections is feasible. However, the performances of such flow charts need to be improved before being used routinely.

Systematic analysis of STD control: an operational model

BACKGROUND

Sexually transmitted diseases (STDs) enhance HIV transmission, and improved management of STD in primary health care decreases HIV incidence. In resource poor countries, those responsible for planning and managing STD control programmes need to be able to analyse the STD situation in their setting and the interventions which are therefore likely to be most cost effective. However, the data required for such decision making are often not available in developing countries. This paper presents an operational model, developed as a practical tool to support planning, monitoring, and evaluation of STD intervention strategies in settings where data are unavailable or inadequate.

METHOD

The operational model is based on the approach developed for estimating the effectiveness of control measures in tuberculosis programmes. Using available data, the model takes a step by step approach. It begins with analysis of the total male and female population, the proportion of men and women aged 15-49 years, and the proportion of these who are sexually active. Subsequent steps analyse numbers with STDs, and loss of cases to the health system at each stage between infection and cure. The model was tested in Nairobi, Kenya using available demographic, epidemiological, and public health data; no original data were collected. Data for the total population of Nairobi were not available to illustrate all the steps in the model. For these steps, relevant information was taken where available from a specific study population using a large STD referral centre.

RESULTS

Despite the lack of precise data for Nairobi, the model highlighted sex imbalances in population, which has potential implications for STDs. It also showed significant disparities in terms of public health policy--for example, between the number of people infected with STDs and the number who have symptoms, and between the number with symptoms and those who seek treatment from public health facilities. It also showed differences between the numbers who attend a health facility, and those that are correctly diagnosed and treated, and, of these, the proportion that are cured.

CONCLUSION

Even where data are incomplete or not available, the model can be a useful tool for analysis. Application of the model, as the Nairobi example illustrates, provides a useful starting point in terms of determining both general and specific determinants of STDs, identifying problems, highlighting significant sex differences, and indicating where it might be appropriate to focus interventions. The model showed that, in Nairobi, only a small proportion of STD cases are removed from the reservoir of infection in the community through curative services, that cases are lost to the health services at every step, and therefore that interventions are required at every step to achieve comprehensive STD control. It highlights the need for strategies to prevent infections, to identify and treat those with and without symptoms, to motivate those who are aware of their infection to seek treatment, and to improve the effectiveness of partner notification and treatment. Finally, the model points to areas where data are inadequate and where STD control programmes need to concentrate information collection efforts.

Drugs for STD management in developing countries: choice, procurement, cost, and financing

OBJECTIVES

(i) To compare acquisition costs of drugs between countries to treat one standardised STD episode. (ii) To explain variations, treatment protocols, purchasing policies, procurement systems, and sources of financing.

METHODS

National STD guidelines, purchasing mechanisms, and drug acquisition costs from 15 countries were compiled, using information from ministries of health and European Commissions headquarters. Prices were converted in European currency unit (ecu). Acquisition costs per episode were calculated for the four main STD syndromes--urethral discharge, vaginal discharge, lower abdominal pain in women, and genital ulcer disease (GUD). To compare costs in different countries the relative distribution of the four main STD syndromes was calculated.

RESULTS

Treatment protocols. All 15 countries recommended treatment for urethral discharge with drugs effective against Neisseria gonorrhoeae and Chlamydia trachomatis. For vaginal discharge two patterns emerged. In 11 countries women with vaginal discharge were divided into high risk of STDs and low risk of STDs. Women at low risk were treated for candidiasis, trichomoniasis, and bacterial vaginosis and those at high risk were also treated for N gonorrhoeae and C trachomatis. Guidelines for abdominal pain all included treatment for N gonorrhoeae, C trachomatis, and anaerobic infections. All countries except the Philippines recommended treating GUD with drugs effective against chancroid and syphilis. Costs per episode. Acquisition costs per episode varied from 0.40 ecu to 7.89 ecu with wide variations. The standardised acquisition cost of STD drugs for the public sector varied between 0.54 ecu in Tanzania and 5.80 ecu in Swaziland. The choice of drugs was the main factor explaining this difference. In countries which only use generic drugs, acquisition costs were lower (between 0.54 ecu and 1.07 ecu). However, important variations exist between countries which use similar treatment protocols (for example, 2.54 ecu in Namibia, 5.80 ecu in Swaziland). These variations are mainly explained by differences in procurement methods. Acquisition costs for peripheral public services are higher than at central level (for example, 0.89 ecu versus 0.54 ecu in Tanzania) as a result of mark ups for transport, handling, and inflation. Acquisition cost of drugs per standardised STD episode for patients through private pharmacies may be as high as 11.93 ecu in Senegal. This is more than 10 times the acquisition cost for public sector at central level in this country (of 1.04 ecu) and is mainly due to the fact that drugs in private pharmacies are branded drugs, which are imported at a high price, taxes, and mark ups in the distribution chain. In 11 of the 15 countries studied, effective STD drugs are now available through public services, in at least in a part of the country. In Botswana, Ghana, Ivory Coast, Mauritania, Lesotho, Namibia, Senegal, Seychelles, and Swaziland these drugs are supplied throughout the country within the existing essential drug programme and financed by the government budget or through a revolving fund for drugs. In Tanzania and Mozambique, all STD drugs in the public sector are funded through donor support. In Nepal recommended STD drugs are widely available at low cost through private outlets.

CONCLUSIONS

Reducing antimicrobial susceptibility of N gonorrhoeae and Haemophilus ducreyi is a continuous threat for sustainable STD drug supply as alternative patented drugs are more expensive. If patented STD drugs are required drug cost may be minimised by selecting the most appropriate management protocols and by improving procurement. Moreover, recent studies have confirmed the continued susceptibility of N gonorrhoeae to low cost generic drugs in some countries (Mozambique, Tanzania, and Senegal). Even under these circumstances, continued donor support will be needed for the poorest countries to ensure the availability of effective STD management as an esse

Cost-effectiveness of improved treatment services for sexually transmitted diseases in preventing HIV-1 infection in Mwanza Region, Tanzania

BACKGROUND

A community-randomised trial was undertaken to assess the impact, cost, and cost-effectiveness of averting HIV-1 infection through improved management of sexually transmitted diseases (STDs) by primary-health-care workers in Mwanza Region, Tanzania.

METHODS

The impact of improved treatment services for STDs on HIV-1 incidence was assessed by comparison of six intervention communities with six matched communities. We followed up a random cohort of 12,537 adults aged 15-54 years for 2 years to record incidence of HIV-1 infection. The total and incremental costs of the intervention were estimated (ingredients approach) and used to calculate the total cost per case treated, the incremental cost per HIV-1 infection averted, and the incremental cost per disability-adjusted life-year (DALY) saved.

FINDINGS

During 2 years of follow-up, 11,632 cases of STDs were treated in the intervention health units. The baseline prevalence of HIV-1 infection was 4%. The incidence of HIV-1 infection during the 2 years was 1.16% in the intervention communities and 1.86% in the comparison communities. An estimated 252 HIV-1 infections were averted each year. The total annual cost of the intervention was US$59,060 (1993 prices), equivalent to $0.39 per head of population served. The cost for STD case treated was $10.15, of which the drug cost was $2.11. The incremental annual cost of the intervention was $54,839, equivalent to $217.62 per HIV-1 infection averted and $10.33 per DALY saved (based on Tanzanian life expectancy) or $9.45 per DALY saved (based on the assumptions of the World Development Report). In a sensitivity analysis of factors influencing cost-effectiveness, cost per DALY saved ranged from $2.51 to $47.86.

INTERPRETATION

Improved management of STDs in rural health units reduced the incidence of HIV-1 infection in the general population by about 40%. The estimated cost-effectiveness of this intervention ($10 per DALY) compares favourably with that of, for example, childhood immunisation programmes ($12-17 per DALY). Cost-effectiveness should be further improved when the intervention is applied on a larger scale. Resources should be made available for this highly cost-effective HIV control strategy.

Generation of a mouse tumor necrosis factor mutant with antiperitonitis and desensitization activities comparable to those of the wild type but with reduced systemic toxicity

In this study, we investigated whether the recently identified lectin-like domain of tumor necrosis factor (TNF) is implicated in its biological activities on mammalian cells. To this end, a mouse TNF (mTNF) triple mutant, T104A-E106A-E109A mTNF (referred to hereafter as triple mTNF), lacking the lectin-like affinity of mTNF for specific oligosaccharides, was compared with the wild-type molecule for various TNF effects in vitro and in vivo. The triple mTNF displayed a 50-fold-reduced TNF receptor 2 (TNFR2)-mediated bioactivity but only a 5-fold-reduced TNFR1-mediated bioactivity in vitro. The specific activity of the triple mutant on L929 fibrosarcoma cells was slightly reduced compared with that of the wild type. We subsequently assessed the systemic toxicity of triple versus wild-type mTNF, since TNFR2 is partially implicated in this activity. The triple mTNF had a significantly reduced toxicity compared with that of wild-type mTNF in vivo. Moreover, we compared the effects of the triple and the wild-type mTNFs in TNFR1-mediated phenomena, such as (i) induction of tolerance towards a lethal mTNF dose and (ii) protective activity in cecal ligation and puncture-induced septic peritonitis. No significant differences between the mutant and wild-type forms were observed. In conclusion, these results indicate that triple mTNF, lacking TNF's lectin-like binding capacity, has reduced systemic toxicity but retains the tolerance-inducing and peritonitis-protective activities of wild-type mTNF.

[Development and evaluation of screening algorithms for sexually transmitted diseases in pregnant women at Libreville, Gabon]

The struggle against sexually transmitted diseases (STD) constitutes a priority of public health in developing countries: STD cause complications, particularly in pregnant women, and facilitate the transmission of HIV. One of the strategies in the struggle against STD is the diagnosis and the early treatment of these infections. The STD, and in particular infections of Neisseria gonorrhea and Chlamydia trachomatis, are difficult to diagnose in women without complementary analyses, which primary health care may not be able to supply. Health care provided to patients could be standardized and improved by considering the signs and symptoms. We studied the prevalence and risk factors of STD among 192 pregnant women consulting the health clinic in Libreville, Gabon, in September 1993. The prevalence of STD was high (13.5% rate of cervical infection with gonorrhea or Chlamydia trachomatis). We then evaluated the different diagnostic strategies or algorithms. Regardless of the type of examination (medical interview, simple clinical examination or examination with a speculum), the use of scores integrating risk factors, the clinical signs and symptoms outperformed hierarchical algorithms. This approach was more sensitive and specific and easy to perform. Use of this method may enable more effective screening of STD and also avoid most maternal and perinatal complications.

STD/HIV prevention in Turkey: planning a sequence of interventions

This study was initiated to assess which mix of early STD/HIV prevention interventions would potentially be effective, cost-effective and sustainable in Turkey; and to program an intervention sequence to maximize synergy among the interventions. During rapid assessment we: 1) reviewed past issues of 3 leading newspapers; 2) collected information on TV coverage; 3) interviewed key informants including taxicab drivers, hotel employees, grocery store owners, academicians in public health and law, investigators of STD/HIV and reproductive tract infections, and officials in the ministry of health; 4) reviewed available evidence on STD/HIV morbidity, sexual behavior patterns, migration patterns and same/opposite gender sex trade. We found: 1) discrepancies between decision makers' perceptions and social realities with respect to the epidemiology of sexual behavior and STDs, and the state of public health programs; 2) discrepancies between sexual practices and public expression regarding sexual practices; 3) economic, demographic, and political pressures in Turkey and in surrounding countries for the expansion of prostitution; 4) a sexual double standard and gender specific migration patterns which sustain a high demand for commercial sex; 5) patterns of health care seeking behaviors and provision of STD clinical services which indicate other STDs may play a very important role in spread of HIV infection; 6) an important mass media role in opinion formation; 7) consensual denial of risk for the majority based on beliefs embedded in machismo, nationalism and religion, and a resulting marginalization and externalization of STD/HIV risk; 8) high prevalence of syphilis among both Turkish and immigrant female prostitutes in Istanbul (early latent 8 and 13%; late latent 0 and 4%; previous history 9 and 22%) 9) and high rates of syphilis among male prostitutes (early latent 11%, late latent 21% and previous history 58%). We concluded that interventions should initially include, in the following order; 1) awareness raising for decision makers and opinion leaders including members of parliament and mass media; 2) awareness raising for members of the general population; 3) needs assessment and intervention development for sex workers; 4) training in HIV and other STDs for medical personnel; and 5) quality assurance and control for laboratory procedures for STDs/HIV.

Syphilis control in pregnancy: decentralization of screening facilities to primary care level, a demonstration project in Nairobi, Kenya

A decentralized syphilis control program in pregnant women was implemented in nine Nairobi City Council antenatal clinics between July 1992 and August 1993, whereby pregnant women were screened for syphilis, treated before leaving the clinic if RPR seroreactive, and counselled on the importance of partner treatment and sexual abstinence during treatment in order to protect their unborn babies from getting congenital syphilis. A total of 13,131 pregnant women were screened for syphilis (RPR test), 87.3% of seroreactive women were treated on site and 50% of partners returned to the clinic and were treated. The prevalence of RPR reactivity was 6.5%. Based on other data the program could theoretically have prevented 413 cases of congenital syphilis at a cost of approximately 50 USD per prevented case. This demonstration project shows that decentralized prevention of congenital syphilis in antenatal clinics by nurses is feasible and inexpensive and should receive priority in resource allocation in reproductive health and child survival programs.

Impact of counselling on safer sex and STD occurrence among STD patients in Malawi

In developing countries where professional manpower and basic supplies are lacking for STD control, low-cost prevention strategies must be explored. This study assesses the impact of counselling on STD treatment and prevention in Malawi. Increases in safer sex practices are used as indicators of prevention behaviour. A pre-test post-test control group design over a 4-month interval was conducted in 1991 in 2 comparable hospitals approximately 100 km apart. STD was diagnosed symptomatically and Knowledge Attitude Practice and Behaviour (KAPB) data collected using a structured questionnaire. In one group, trained counsellors discussed modes of transmission and prevention of STD/AIDS including a condom demonstration; symptoms and treatment of STDs; partner notification; risk taking and reasons for doing so; and motivations for behaviour change. The results show that counselling reduces the occurrence of STDs; increases concern for sexual partners; increases knowledge about and use of condoms; reduces mean number of partners; and reduces health costs due to fewer hospital visits. Although the observed behaviour change was short term, these outcomes argue in favour of counselling as a low-cost effective strategy for STD control.

Characterization of a rat C6 glioma-secreted follistatin-related protein (FRP). Cloning and sequence of the human homologue

A protein was isolated from rat C6 glioma-conditioned medium and was biochemically characterized. The heparin-binding protein has a native molecular mass of 55-75,000 Da, a molecular mass of 40-48,000 Da under denaturing conditions, and a pI of 5.0-6.0. Based on the determined partial amino acid sequences, the full lenght cDNA encoding the rat and human proteins were cloned. The cDNA sequences identified the isolated rat and human protein as the homologue of a recently reported mouse osteoblast-transforming-growth-factor-beta 1-inducible protein, encoded by the TSC-36 gene [Shibanuma, M., Mashimo, J., Mita, A., Kuroki, T. & Nose, K. (1993) Eur. J. Biochem. 217, 13-19]. Analysis of the human, rat and mouse amino acid sequences indicates that these proteins are highly conserved (> 92% sequence identity). Sequence similarities with follistatin and the follistatin-like domain of agrin are revealed. The relationship with follistatin and agrin points to possible common functions for the cloned follistatin-related proteins (FRP). The protein has no effect on the inhibitory action of transforming growth factor-beta 1, on CCl-64 cell growth.

Management of STDs and cost of treatment in primary health care centres in Pikine, Senegal

We studied the current management of STD-related syndromes by urban health facilities in Pikine (Senegal) in 252 consecutive patients presenting with STD-related complaints, to assess the cost and effectiveness of services and to estimate the potential benefit by introducing management protocols. Most common presenting complaints for women were vaginal discharge and low abdominal pain, reported for 122 (82.9%) and 22 (15.0%) of 147 female patients. Urethral discharge and genital ulceration were reported for 80 (76.2%) and for 17 (16.2%) of 105 male patients. The average cost was 4.01 ECU (1 European Currency Unit = 1.2 US$ = 334 Franc CFA) for male patients (ranging from 0.57 to 25.70 ECU) and 12.75 ECU for female patients (ranging from 0.57 to 37.60 ECU). Only 20 of 80 patients with urethral discharge (25%) received effective treatment. Effectiveness was not related to cost of therapy or qualification of staff. Utilization of management protocols improves the quality and accessibility of care for STD, by potentially doubling effectiveness and reducing the costs for patients to 12% of the current level.

Mapping the lectin-like activity of tumor necrosis factor

Tumor necrosis factor (TNF), but not lymphotoxin (LT), is directly trypanolytic for salivarian trypanosomes. This activity was not blocked by soluble 55-kilodalton and 75-kilodalton TNF receptors, but was potently inhibited by N,N'-diacetylchitobiose, an oligosaccharide that binds TNF. Comparative sequence analysis of TNF and LT localized the trypanocidal region, and synthetic peptides were trypanolytic. TNF molecules in which the trypanocidal region was mutated or deleted retained tumoricidal activity. Thus, trypanosome-TNF interactions occur via a TNF domain, probably with lectin-like affinity, which is functionally and spatially distinct from the mammalian TNF receptor binding sites.

Interleukin-2 induces tumor necrosis factor-alpha production by activated human T cells via a cyclosporin-sensitive pathway

We examined requirements for TNF-alpha production by purified human blood T cells, completely depleted of monocyte-accessory cells, under different conditions of stimulation. Activation of T cells with immobilized anti-CD3 induced the appearance of mRNA for TNF-alpha and of functionally active TNF-alpha in the culture supernatant. Anti-CD3-induced TNF-alpha production could be inhibited by blocking the IL-2R with a combination of anti-Tac and Mik beta 1 (mAbs against the p55 and p75 chain of the IL-2R respectively) thus indicating an essential role of IL-2 in TNF-alpha induction. When purified T cells were activated with a combination of two anti-CD2 mAbs (9-1 and 9.6), additional signals (rIL-2 or rIL-1 beta or anti-CD28) were required for TNF-alpha mRNA production and protein secretion. rIL-1 beta supported anti-CD2-induced TNF-alpha production indirectly through an IL-2-dependent pathway. These same helper signals also enhanced TNF-alpha production by anti-CD3-stimulated T cells. IL-4, IL-6, GM-CSF and IFN-gamma had no effect on TNF-alpha production by T cells activated via either pathway. Addition of rIL-1 beta alone, rIL-2 alone or endotoxins to resting human T cells did not induce detectable amounts of TNF-alpha. Both helper/inducer CD4(+) and suppressor/cytotoxic CD8(+) subsets of T cells were shown to produce TNF-alpha upon stimulation. We conclude that CD3 or CD2 triggering are not sufficient for TNF-alpha production by T cells, but that the latter is dependent (apparently at the transcriptional level) on the interaction of IL-2 with its functionally active cell surface receptors. We could further demonstrate that TNF-alpha production was completely blocked by cyclosporin A. The inhibitory effect of this agent on TNF-alpha production was also observed in the presence of rIL-2, thus excluding an indirect effect through inhibition of IL-2 production.

IFN-gamma-induced L-arginine-dependent toxoplasmastatic activity in murine peritoneal macrophages is mediated by endogenous tumor necrosis factor-alpha

Activated murine peritoneal macrophages inhibit the intracellular proliferation of Toxoplasma gondii and produce a number of cytokines, such as TNF-alpha and IL-1. Both TNF-alpha and IL-1 have been reported to be involved in the immune response against various microorganisms, but the mechanisms responsible for these effects are not known. In the present study it was investigated whether endogenously produced TNF-alpha and IL-1 are involved in the activation of peritoneal macrophages by rIFN-gamma leading to toxoplasmastatic activity and the production of reactive nitrogen intermediates. The rIFN-gamma-induced toxoplasmastatic activity was inhibited by neutralizing antibodies against mouse TNF-alpha in a dose-dependent and time-dependent way, but neutralizing antibodies against mouse IL-1 alpha and IL-1 beta did not affect this activity. Involvement of TNF-alpha in the induction of toxoplasmastatic activity was confirmed by our finding that rTNF-alpha in combination with a nonactivating concentration of rIFN-gamma inhibited the intracellular proliferation of T. gondii. No synergistic activity of rIL-1 and rIFN-gamma on the inhibition of T. gondii proliferation was found. Both rTNF-alpha and rIL-1 alpha alone inhibited the intracellular proliferation of T. gondii only slightly. Because it has been reported recently that activated macrophages produce reactive nitrogen intermediates that are essential in the induction of toxoplasmastatic activity, we investigated whether these intermediates are involved in the TNF-dependent induction of toxoplasmastatic activity. Neutralizing antibodies against mouse TNF-alpha inhibited also the release of NO2- by rIFN-gamma-activated macrophages almost completely. Macrophages incubated with rTNF-alpha in combination with a nonactivating concentration of rIFN-gamma released substantial amounts of NO2-, but rTNF-alpha and rIL-1 alpha alone, and the combination of rIL-1 alpha and a nonactivating concentration of rIFN-gamma induced only little NO2(-)-release by macrophages. To assess whether reactive nitrogen intermediates act directly or indirectly on the intracellular proliferation of T. gondii, macrophages were incubated with the L-arginine analog NG-monomethyl-L-arginine or the NADPH-inhibitor diphenylene iodonium, both inhibitors of the generation of reactive nitrogen intermediates. Good correlation was found between toxoplasmastatic activity and the release of NO2- during the 24-h activation period before infection of the macrophages with T. gondii, but no correlation was found between toxoplasmastatic activity and the release of NO2- during infection of the macrophages.(ABSTRACT TRUNCATED AT 400 WORDS)

IFN-gamma-induced L-arginine-dependent toxoplasmastatic activity in murine peritoneal macrophages is mediated by endogenous tumor necrosis factor-alpha

Activated murine peritoneal macrophages inhibit the intracellular proliferation of Toxoplasma gondii and produce a number of cytokines, such as TNF-alpha and IL-1. Both TNF-alpha and IL-1 have been reported to be involved in the immune response against various microorganisms, but the mechanisms responsible for these effects are not known. In the present study it was investigated whether endogenously produced TNF-alpha and IL-1 are involved in the activation of peritoneal macrophages by rIFN-gamma leading to toxoplasmastatic activity and the production of reactive nitrogen intermediates. The rIFN-gamma-induced toxoplasmastatic activity was inhibited by neutralizing antibodies against mouse TNF-alpha in a dose-dependent and time-dependent way, but neutralizing antibodies against mouse IL-1 alpha and IL-1 beta did not affect this activity. Involvement of TNF-alpha in the induction of toxoplasmastatic activity was confirmed by our finding that rTNF-alpha in combination with a nonactivating concentration of rIFN-gamma inhibited the intracellular proliferation of T. gondii. No synergistic activity of rIL-1 and rIFN-gamma on the inhibition of T. gondii proliferation was found. Both rTNF-alpha and rIL-1 alpha alone inhibited the intracellular proliferation of T. gondii only slightly. Because it has been reported recently that activated macrophages produce reactive nitrogen intermediates that are essential in the induction of toxoplasmastatic activity, we investigated whether these intermediates are involved in the TNF-dependent induction of toxoplasmastatic activity. Neutralizing antibodies against mouse TNF-alpha inhibited also the release of NO2- by rIFN-gamma-activated macrophages almost completely. Macrophages incubated with rTNF-alpha in combination with a nonactivating concentration of rIFN-gamma released substantial amounts of NO2-, but rTNF-alpha and rIL-1 alpha alone, and the combination of rIL-1 alpha and a nonactivating concentration of rIFN-gamma induced only little NO2(-)-release by macrophages. To assess whether reactive nitrogen intermediates act directly or indirectly on the intracellular proliferation of T. gondii, macrophages were incubated with the L-arginine analog NG-monomethyl-L-arginine or the NADPH-inhibitor diphenylene iodonium, both inhibitors of the generation of reactive nitrogen intermediates. Good correlation was found between toxoplasmastatic activity and the release of NO2- during the 24-h activation period before infection of the macrophages with T. gondii, but no correlation was found between toxoplasmastatic activity and the release of NO2- during infection of the macrophages.(ABSTRACT TRUNCATED AT 400 WORDS)

The provision of safe blood--policy issues in the prevention of human immunodeficiency virus transmission

The AIDS epidemic has focused attention on the constraints and deficiencies present in many blood transfusion services in the developing world. We discuss a variety of options for reducing transfusion-related HIV transmission, and suggest how new transfusion strategies may be implemented. We show that a transfusion service cannot rely solely on the screening of donor blood for anti-HIV antibodies and that a more comprehensive approach is needed. Important components of this approach include donor selection and improved clinical practice, in which blood and blood products are prescribed only when really necessary.

[Sexually transmitted diseases in the female population of Pikine, Senegal]

The prevalence of some sexually transmitted disease is determined in 250 gynaecology patients and in 200 pregnant women seen in primary health centers in Pikine, Senegal. The main reason for consultation at gynaecology is infertility. Gonorrhoea and Chlamydia trachomatis infection are present respectively in 1.5% and 7% of pregnant women and in 4.4% and 7.6% of gynaecology patients. Human papillomavirus infection, determined by DNA extraction and hybridization technique, is seen in 4% of obstetric and in 1.2% of gynecology patients. Cytological anomalies is found in 5.5% of pregnant women and in 4.8% of gynecology patients.

Expression and processing of the activin-A/erythroid differentiation factor precursor: a member of the transforming growth factor-beta superfamily

The biosynthesis and intracellular processing of the polypeptide precursor of the beta A-chain of the fertility hormone inhibin were assessed by infecting a wide spectrum of cell types with a recombinant vaccinia virus. Most cell lines, including follicular granulosa cells, secrete both prohormone and mature hormone as homodimers (activin) composed of disulfide-linked subunits of 54 kDa (proactivin-A) and 14 kDa (activin-A), respectively, and a small amount of prohormone-mature hormone heterodimers. Mature activin is secreted from mouse pituitary cells (AtT-20), while pig kidney cells [PK(15)] secrete mostly proactivin. More prohormone is secreted in the presence of NH4Cl, suggesting that prohormone processing is facilitated by low pH. Proactivin-A is not a ligand for the mannose-6-phosphate/insulin growth factor-II receptor. The recombinant activin stimulates FSH release from pituitary cells and differentiates erythroleukemia cell lines in vitro.

Poly I:C activated macrophages are tumoricidal for TNF-alpha-resistant 3LL tumor cells

Successive coculture of Lewis lung carcinoma (3LL) cells with T cell-derived lymphokines and LPS-activated macrophages has led to the acquisition of 3LL tumor variants (macrophage-resistant 3LL tumor variants (3LL-R)), manifesting a highly reduced sensitivity to the cytotoxic potential of T cell-derived lymphokines and LPS-activated macrophages and TNF-alpha. However, when 3LL-R cells are cocultured with Poly I:C-activated macrophages or with conditioned medium derived from these effector cells a significant lysis is observed. TNF-alpha participates in the cytolytic process of Poly I:C-activated macrophages as anti-TNF-alpha antibodies abolish the cytotoxic effect of these effector cells. In addition, class I IFN is involved because IFN-alpha and IFN-beta act synergistically on TNF-alpha mediated lysis of 3LL-R cells within 18 h. Moreover, anticlass I IFN antibodies abolish the cytolytic capacity of Poly I:C-activated macrophages. Hence, Poly I:C-induced macrophage-mediated cytolysis of 3LL-R cells may result from 1) the induction of macrophages by Poly I:C to secrete high amounts of TNF-alpha and class I IFN and 2) a synergism between IFN-alpha/IFN-beta and TNF-alpha on lysis of 3LL-R cells. This synergism does not result from a class I IFN-mediated enhancement of TNF-alpha receptor expression on 3LL-R cells. Therefore, the sensitivity of 3LL-R cells to TNF-alpha-mediated lysis in the presence of class I IFN is most probably regulated at the post-TNF-alpha receptor level. Furthermore, treatment of mice with Poly I:C strongly reduces the metastatic capacity of 3LL-R tumor cells, suggesting the participation of macrophages in the eradication of the established metastasis. Hence, TNF-alpha-resistant 3LL-R tumor cells may serve as a useful tool for the detection of alternative macrophage-related cytotoxins leading to the destruction of neoplastic cells both in vitro and in vivo.

Poly I:C activated macrophages are tumoricidal for TNF-alpha-resistant 3LL tumor cells

Successive coculture of Lewis lung carcinoma (3LL) cells with T cell-derived lymphokines and LPS-activated macrophages has led to the acquisition of 3LL tumor variants (macrophage-resistant 3LL tumor variants (3LL-R)), manifesting a highly reduced sensitivity to the cytotoxic potential of T cell-derived lymphokines and LPS-activated macrophages and TNF-alpha. However, when 3LL-R cells are cocultured with Poly I:C-activated macrophages or with conditioned medium derived from these effector cells a significant lysis is observed. TNF-alpha participates in the cytolytic process of Poly I:C-activated macrophages as anti-TNF-alpha antibodies abolish the cytotoxic effect of these effector cells. In addition, class I IFN is involved because IFN-alpha and IFN-beta act synergistically on TNF-alpha mediated lysis of 3LL-R cells within 18 h. Moreover, anticlass I IFN antibodies abolish the cytolytic capacity of Poly I:C-activated macrophages. Hence, Poly I:C-induced macrophage-mediated cytolysis of 3LL-R cells may result from 1) the induction of macrophages by Poly I:C to secrete high amounts of TNF-alpha and class I IFN and 2) a synergism between IFN-alpha/IFN-beta and TNF-alpha on lysis of 3LL-R cells. This synergism does not result from a class I IFN-mediated enhancement of TNF-alpha receptor expression on 3LL-R cells. Therefore, the sensitivity of 3LL-R cells to TNF-alpha-mediated lysis in the presence of class I IFN is most probably regulated at the post-TNF-alpha receptor level. Furthermore, treatment of mice with Poly I:C strongly reduces the metastatic capacity of 3LL-R tumor cells, suggesting the participation of macrophages in the eradication of the established metastasis. Hence, TNF-alpha-resistant 3LL-R tumor cells may serve as a useful tool for the detection of alternative macrophage-related cytotoxins leading to the destruction of neoplastic cells both in vitro and in vivo.

Neonatal ophthalmia in the developing world. Epidemiology, etiology, management and control

In the 19th century, the incidence of neonatal conjunctivitis varied between 1 and 14% in Europe, and the disease was a main cause of blindness at that time. Since then the epidemiology of ophthalmia neonatorum (ON) has changed and Chlamydia trachomatis is more frequent than Neisseria gonorrhoeae. Both are still very common causes of ON in the developing world. ON can not be differentiated clinically as to the etiology, but Intracellular Gram Negative Diplococci (IGND) on a Gram stain of an eye smear has an excellent validity and further differentiation can be made using microbiological cultures. All cases of presumed gonococcal conjunctivitis must be treated with effective systemic antibiotics. Systemic treatment with penicillin can still be used in areas where the percentage of beta-lactamase producing strains of gonococci is very low. For other areas a single dose of ceftriaxone intramuscular combined with saline eye washes is the treatment of choice. Chlamydial ON necessitates also systemic treatment with erythromycin. Parents of infants with gonococcal or chlamydia ON also need to be examined and treated. Prevention of gonococcal and chlamydial disease can be done following 3 strategies: antenatal diagnosis and treatment of maternal infections or disinfection of the infants eyes at birth or adequate treatment of infants and parents as soon as a ON has been diagnosed. Crédé's eye prophylaxis with silver nitrate has become a controversial issue, because of concern about the occurrence of chemical conjunctivitis and its ineffectiveness against infections with C. trachomatis.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of single-dose spectinomycin with five days of trimethoprim-sulfamethoxazole for the treatment of chancroid

In a controlled trial 32 patients with ulcers culture-positive for Haemophilus ducreyi were treated with a single 2-g dose of spectinomycin, and 20 patients were treated with a five-day course of trimethoprim-sulfamethoxazole (TMP-SMZ; 160/800 mg) twice daily. Both regimens rapidly eradicated H. ducreyi from ulcers, with subsequent healing of ulcers and buboes. The cure rates 14 days after initiation of therapy were 94% for spectinomycin and 95% for TMP-SMZ. Patients with H. ducreyi-negative ulcers who were treated with the same regimens also healed and did not show a significantly different efficacy for either regimen. Thus we found that the one-day regimen of spectinomycin was as effective for the treatment of chancroid as was TMP-SMZ given for five days. Further studies on a larger number of patients are needed to confirm our findings.