Prediction of the Nitrogen Content of Rice Leaf Using Multi-Spectral Images Based on Hybrid Radial Basis Function Neural Network and Partial Least-Squares Regression.

This paper's novel focus is predicting the leaf nitrogen content of rice during growing and maturing. A multispectral image processing-based prediction model of the Radial Basis Function Neural Network (RBFNN) model was proposed. Moreover, this paper depicted three primary points as the following: First, collect images of rice leaves (RL) from a controlled condition experimental laboratory and new shoot leaves in different stages in the visible light spectrum, and apply digital image processing technology to extract the color characteristics of RL and the morphological characteristics of the new shoot leaves. Secondly, the RBFNN model, the General Regression Model (GRL), and the General Regression Method (GRM) model were constructed based on the extracted image feature parameters and the nitrogen content of rice leaves. Third, the RBFNN is optimized by and Partial Least-Squares Regression (RBFNN-PLSR) model. Finally, the validation results show that the nitrogen content prediction models at growing and mature stages that the mean absolute error (MAE), the Mean Absolute Percentage Error (MAPE), and the Root Mean Square Error (RMSE) of the RFBNN model during the rice-growing stage and the mature stage are 0.6418 (%), 0.5399 (%), 0.0652 (%), and 0.3540 (%), 0.1566 (%), 0.0214 (%) respectively, the predicted value of the model fits well with the actual value. Finally, the model may be used to give the best foundation for achieving exact fertilization control by continuously monitoring the nitrogen nutrition status of rice. In addition, at the growing stage, the RBFNN model shows better results compared to both GRL and GRM, in which MAE is reduced by 0.2233% and 0.2785%, respectively.

Late consolidation of the scaphoid. Case report and literature review.

Scaphoid fractures are a common wrist injury accounting for 2-7% of all adult fractures. Nonunion is described in 5-12% of cases leading to osteoarthritis. Several classifications have been developed focused on this pathology and its complication. We present a case of a 28 years old male patient with a scaphoid fracture and nonunion who spontaneously consolidates without treatment. We performed a literature review to recognize this pathology, its common evolution and possible treatment options.

Las fracturas de escafoides son una lesión frecuente de la muñeca y representan de 2-7% de todas las fracturas en adultos. La no unión se describe en 5-12% de los casos y conduce a la osteoartritis. Se han desarrollado varias clasificaciones centradas en esta patología y su complicación. Presentamos el caso de un paciente varón de 28 años con fractura y no unión de escafoides que consolida espontáneamente sin tratamiento. Realizamos una revisión bibliográfica para reconocer esta patología, su evolución habitual y las posibles opciones de tratamiento.

[Digital artery pseudoaneurysm. Case report and systematic review of the literature]. / Pseudoaneurisma de arteria digital. Reporte de un caso y revisión sistemática de la bibliografía.

INTRODUCTION: aneurysms are focal and permanent dilations of an artery; in pseudoaneurysms, the normal layers of the blood vessel are replaced by fibrous tissue. Due to their low incidence, as well as the diagnostic and therapeutic challenge they represent; our objective is to present the clinical case of a pseudoaneurysm of a digital artery of the hand and to carry out a systematic review of this pathology. MATERIAL AND METHODS: literature search in Medline, using the terms "digital artery" and "aneurysm." Studies of vascular dilation pathology affecting the hand and fingers were incorporated. Studies with pathology of proximal involvement of the hand were excluded. CASE PRESENTATION: a 79-year-old female patient who, after a sharp force trauma to the fifth finger of the left hand, develops a rapidly growing necrotic tumor. She had ultrasound and angiography that suggested hematoma. Surgical management was decided, during which it was observed that the tumor involved ulnar collateral digital artery of the fifth finger. The lesion and the arterial segment involved were resected. Post-surgical course without complications. The histopathological diagnosis of pseudoaneurysm of the lesion was confirmed. DISCUSSION: traumatic etiology is the most frequent cause of digital aneurysms. Risk factors for pseudoaneurysms include sharp force trauma and alterations of the coagulation pathways, as in the case presented. CONCLUSION: the pseudoaneurysm of a digital artery is a rare pathology with great variability of therapeutic management. Surgical resection of the lesion with vascular flow reconstruction is the recommended treatment.

INTRODUCCIÓN: los aneurismas son dilataciones vasculares localizadas y permanentes de una arteria; en los pseudoaneurismas, las capas normales del vaso sanguíneo son reemplazadas por tejido fibroso. Debido a su baja incidencia, así como el desafío diagnóstico y terapéutico que representan; nuestro objetivo es presentar el caso clínico de un pseudoaneurisma de una arteria digital de la mano y realizar una revisión sistemática sobre dicha patología. MATERIAL Y MÉTODOS: búsqueda bibliográfica en Medline, utilizando los términos "arteria digital" y "aneurisma". Se incorporaron estudios de patología de dilatación vascular que afecte la mano y los dedos. Se excluyeron trabajos con patología de afección proximal de la mano. PRESENTACIÓN DE CASO: paciente femenino de 79 años de edad, que posterior a herida cortante de quinto dedo de mano izquierda, desarrolla tumoración necrótica de rápido crecimiento. Contaba con ecografía y angiografía que sugerían hematoma. Se decidió manejo quirúrgico, durante el cual se observó que la tumoración involucraba arteria digital colateral cubital del quinto dedo. Se resecó lesión y segmento arterial involucrado. Cursó postquirúrgico sin complicaciones. Se confirmó el diagnóstico histopatológico de pseudoaneurisma de la lesión. DISCUSIÓN: la etiología traumática es la causa más frecuente de los aneurismas digitales. Los factores de riesgo para los pseudoaneurismas incluyen lesiones penetrantes y alteraciones de la cascada de coagulación, como en el caso presentado. CONCLUSIÓN: el pseudoaneurisma de una arteria digital es una patología rara y con gran variabilidad de manejo terapéutico. La resección quirúrgica de la lesión con la reconstrucción del flujo vascular, es el tratamiento recomendado.

Perceived Impact of COVID-19 Among Callers to the National Suicide Prevention Lifeline.

Background: Research indicates that the COVID-19 pandemic caused increases in psychological distress and suicidal ideation. Aims: To describe the ways suicidal callers to the National Suicide Prevention Lifeline (Lifeline) perceived COVID-19 to have impacted them and assess whether these callers perceived COVID-19-related stress as contributing to their suicidal thoughts. Method: Telephone interviews were conducted with 412 suicidal callers to 12 Lifeline centers. Logistic regression analyses were used to examine the associations between demographic factors and individual COVID-19 stressors and to determine whether callers who endorsed COVID-19-related stress as contributing to their suicidal thoughts differed from those who did not regarding demographics, current suicide risk, history of suicidality, Lifeline use, or individual COVID-19 stressors. Results: Over half of callers reported that COVID-19-related stress contributed to their suicidal ideation (CRSSI). Callers who endorsed CRSSI had higher odds than those who did not of mentioning financial difficulties when asked how COVID-19 impacted them. The two groups of callers did not differ on the other factors examined. Limitations: Interviewed callers may not be representative of all Lifeline callers. Conclusion: Despite the subjective burden of COVID-19-related stress on suicidal Lifeline callers, this was not associated with new suicidality or heightened suicide risk.

Successful treatment of recurrent epithelial ingrowth associated with interface fluid syndrome, flap necrosis, and epithelial defects following LASIK.

PURPOSE: to report the successful treatment of two patients who developed flap necrosis preceded by recurrent epithelial ingrowth and interface fluid syndrome after LASIK. METHODS: patient 1 was treated with epithelial debridement and flap suturing. Patient 2 was initially treated with epithelial debridement and flap suturing, but developed recurrent epithelial ingrowth in the right eye and 2 weeks later in the left eye. RESULTS: patient 1 developed diffuse interface fluid accumulation in the left eye after epithelial debridement and flap suturing and was treated with timolol meleate 0.5% solution and methazolamide. The interface fluid resolved and the cornea and flap became clear. Slit-lamp examination identified a small area of epithelial ingrowth recurrence, which has remained stable for 3 years. Patient 2 was successfully retreated with epithelial debridement followed by fibrin tissue adhesive application. Five months after debridement and fibrin tissue adhesive, no recurrence of epithelial ingrowth or interface fluid accumulation was noted. CONCLUSIONS: epithelial ingrowth and interface fluid syndrome may be associated with secondary flap necrosis following LASIK, which can be effectively treated with debridement and flap suturing or fibrin tissue adhesive application.

ICESat-2/ATLAS Onboard Flight Science Receiver Algorithms: Purpose, Process, and Performance.

The Advanced Topographic Laser Altimetry System (ATLAS) is the sole instrument on the Ice, Cloud, and land Elevation Satellite 2 (ICESat-2). Without some method of reducing the transmitted data, the volume of ATLAS telemetry would far exceed the normal X-band downlink capability or require many more ground station contacts. The ATLAS Onboard Flight Science Receiver Algorithms (hereinafter Receiver Algorithms or Algorithms) control the amount of science data that is telemetered from the instrument, limiting the data volume by distinguishing surface echoes from background noise, and allowing the instrument to telemeter data from only a small vertical region about the signal. This is accomplished through the transfer of the spacecraft's location and attitude to the instrument every second, use of an onboard Digital Elevation Model, implementation of signal processing techniques, and use of onboard relief and surface type reference maps. Extensive ground testing verified the performance of the Algorithms. On-orbit analysis shows that the Algorithms are working as expected from the ground testing; they are performing well and meeting the mission requirements.

[Intra-articular fracture of the calcaneus associated with injury to lateral collateral ligaments of the ankle]. / Fractura intraarticular de calcáneo asociada a lesión de ligamentos colaterales laterales del tobillo.

Calcaneal fractures are the most frequent of the tarsus (3.5% of all fractures). Young adults are mainly affected, being more frequent in men (5.9:1). On the other hand, ligament injuries associated with fracture of the calcaneus are very infrequent. We describe a case of a 39 year old patient who suffered ankle trauma. He presented instability in plantar flexion and inversion. A fracture of the calcaneus was diagnosed. During surgery, a complete lesion of the lateral ligament complex was found. The reduction and osteosynthesis associated with ligament reconstruction was performed. We consider important to confirm the stability of the ankle after a calcaneus fracture. Lack of diagnosis in this type of injuries can evolve into chronic instability.

Las fracturas de calcáneo son las más frecuentes del tarso (3.5% de todas las fracturas). Afectan a adultos jóvenes, siendo más frecuentes en hombres (5.9:1). Por otro lado, las lesiones ligamentarias asociadas a fractura de calcáneo no son muy frecuentes. Presentamos un caso de un paciente de 39 años que sufrió entorsis de tobillo. Mostraba inestabilidad en flexión plantar e inversión. Radiografías mostraron una fractura de calcáneo. Durante la cirugía se evidenció una lesión completa del complejo ligamentario lateral. Se realizó la reducción y osteosíntesis asociada a la reconstrucción ligamentaria. Ante fracturas de calcáneo es importante corroborar la estabilidad del tobillo. La falta de diagnóstico en este tipo de lesiones puede generar inestabilidades crónicas.

MRI Spectrum of Brain Involvement in Sphingosine-1-Phosphate Lyase Insufficiency Syndrome.

SGPL1 encodes sphingosine-1-phosphate lyase, the final enzyme of sphingolipid metabolism. In 2017, a condition featuring steroid-resistant nephrotic syndrome and/or adrenal insufficiency associated with pathogenic SGPL1 variants was reported. In addition to the main features of the disease, patients often exhibit a range of neurologic deficits. In a handful of cases, brain imaging results were described. However, high-quality imaging results and a systematic analysis of brain MR imaging findings associated with the condition are lacking. In this study, MR images from 4 new patients and additional published case reports were reviewed by a pediatric neuroradiologist. Analysis reveals recurring patterns of features in affected patients, including isolated callosal dysgenesis and prominent involvement of the globus pallidus, thalamus, and dentate nucleus, with progressive atrophy and worsening of brain lesions. MR imaging findings of abnormal deep gray nuclei, microcephaly, or callosal dysgenesis in an infant or young child exhibiting other typical clinical features of sphingosine-1-phosphate lyase insufficiency syndrome should trigger prompt genetic testing for SGPL1 mutations.

[Association of hypertension and antihypertensive agents and the severity of COVID-19 pneumonia. A monocentric French prospective study]. / Association entre l'hypertension artérielle, les traitements inhibiteurs du système rénine angiotensine et les formes graves de COVID-19. Étude prospective monocentrique française.

BACKGROUND AND AIM: Angiotensin converting enzyme (ACE) type 2 is the receptor of SARSCoV-2 for cell entry into lung cells. Because ACE-2 may be modulated by ACE inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs), there are concern that patients treated with ACEIs and ARBs are at higher risk for COVID-19 infection or severity. This study sought to analyse the association of severe forms of COVID-19 and mortality with hypertension and a previous treatment with ACEI and ARB. METHODS: Prospective follow-up of 433 consecutive patients hospitalised for COVID-19 pneumonia confirmed by PCR or highly probable on clinical, biological, and radiological findings, and included in the COVHYP study. Mortality and severe COVID-19 (criteria: death, intensive care unit, or hospitalisation >30 days) were compared in patients receiving or not ACEIs and ARBs. Follow-up was 100% at hospital discharge, and 96.5% at >1month. RESULTS: Age was 63.6±18.7 years, and 40%) were female. At follow-up (mean 78±50 days), 136 (31%) patients had severity criteria (death, 64 ; intensive care unit, 73; hospital stay >30 days, 49). Hypertension (55.1% vs 36.7%, P<0.001) and antihypertensive treatment were associated with severe COVID-19 and mortality. The association between ACEI/ARB treatment and COVID-19 severity criteria found in univariate analysis (Odds Ratio 1.74, 95%CI [1.14-2.64], P=0.01) was not confirmed when adjusted on age, gender, and hypertension (adjusted OR1.13 [0.59-2.15], P=0.72). Diabetes and hypothyroidism were associated with severe COVID-19, whereas history of asthma was not. CONCLUSION: This study suggests that previous treatment with ACEI and ARB is not associated with hospital mortality, 1- and 2-month mortality, and severity criteria in patients hospitalised for COVID-19. No protective effect of ACEIs and ARBs on severe pneumonia related to COVID-19 was demonstrated.

An LC/MS/MS method for quantitation of chemopreventive sphingadienes in food products and biological samples.

Colorectal cancer (CRC) is a leading cause of cancer mortality. Diet has a significant influence on colon cancer risk. Identifying chemopreventive agents, dietary constituents, practices and/or diet supplements that promote gut health and reduce the incidence of intestinal neoplasias and CRC could significantly impact public health. Sphingadienes (SDs) are dietary sphingolipids found in plant-based food products. SDs are cytotoxic to colon cancer cells and exhibit chemopreventive properties. The aim of the present study was to develop a sensitive and robust ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for quantifying SDs in food products and biological samples. The assay was linear over a concentration range of 80nM to 50µM and was sensitive to a detection limit of 3.3nM. Post-extraction stability was 100% at 24h. SD content in soy oils was approximately 10nM. SDs were detected transiently in the plasma of adult mice 10min after gavage delivery of a 25mg/kg bolus and declined to baseline by 1h. SD uptake in the gut was maximal in the duodenum and peaked 1h after gavage delivery. Disappearance of SDs in the lower gastrointestinal tract suggests either rapid metabolism to yet unidentified products or potentially luminal export.

Is there a difference in the efficacy of peripartum antiretroviral regimens in reducing mother-to-child transmission of HIV in Africa?

BACKGROUND: Peripartum antiretroviral regimens have been shown to prevent mother-to-child transmission of HIV (MTCT) in randomized clinical trials; however, direct comparison of published results is impossible given methodological and population differences. OBJECTIVE: To directly compare the efficacy of different antiretroviral regimens in reducing the risk of 6-week MTCT rate in African breastfeeding populations. METHODS: Pooled analysis including all mother-infant pairs from any relevant trial: West African ZDV-placebo trials, Petra ZDV+3TC [two regimens A (pre/intra/post-partum) and B (intra/post-partum), placebo from Uganda and Tanzania], SAINT (NVP and Petra arm B), HIVNET012 (NVP, ultra short ZDV pp) and the Vitamin A trial (as placebo arm in South Africa). Peripartum HIV infection was any positive RNA or DNA polymerase chain reaction test < day 60. The MTCT risk was estimated at 6 weeks for each treatment arm and compared with placebo or single-dose NVP using logistic regression adjusting for maternal CD4 cell count, breastfeeding and birthweight. RESULTS: Overall, 4125 singleton live-births were included; 3629 (88%) were assessed for HIV status at 6 weeks of age. In comparison with placebo, zidovudine + lamivudine (ZDV+3TC) arm A [adjusted odds ratio (AOR), 0.23; P < 0.0001], ZDV+3TC arm B (AOR, 0.49; P < 0.001), antenatal ZDV short (AOR, 0.55; P = 0.006) and nevirapine (NVP) (AOR, 0.60; P = 0.0007) significantly reduced MTCT. In comparison with NVP, only the longest regimen of ZDV+3TC (AOR, 0.39, P < 0.0005) was significantly more effective. CONCLUSION: These results are in line with current World Health Organisation guidelines suggesting equivalence of choice between single-dose NVP and short-course ZDV, and confirm the greater efficacy of ZDV+3TC than with any single antiretroviral drug.

Accumulation of phosphorylated sphingoid long chain bases results in cell growth inhibition in Saccharomyces cerevisiae.

Sphingolipid metabolites in mammals can function as signaling molecules with cell-specific functions. In Saccharomyces cerevisiae, phosphorylated long chain bases, such as dihydrosphingosine 1-phosphate and phytosphingosine 1-phosphate, have also been implicated in stress responses. To further explore the biological roles of these molecules, we created disruption mutants for LCB4, LCB5, DPL1, YSR2, YSR3, and SUR2. LCB4 and LCB5 encode kinases that phosphorylate long chain bases. DPL1 and YSR2/YSR3 are involved in degradation of the phosphorylated long chain bases. SUR2 catalyzes conversion of dihydrosphingosine to phytosphingosine. We adapted an HPLC method to measure intracellular concentrations of the phosphorylated long chain bases. Double mutants of dpl1 and ysr2 were inviable, whereas dpl1 ysr2 lcb4 triple mutants were viable. Further, growth inhibition associated with accumulated phosphorylated long chain bases was observed in the triple mutant dpl1 ysr2 lcb4 overexpressing LCB4 or LCB5. These results indicate that phosphorylated long chain bases can inhibit cell growth. Mutants defective in both YSR2 and SUR2, which accumulated dihydrosphingosine 1-phosphate only, grew poorly. The phenotypes of the ysr2 sur2 mutants were suppressed by overexpression of DPL1. Our results clearly show that elevated levels of phosphorylated long chain bases have an antiproliferative effect in yeast.

Regulation of Immune Cell Migration by Sphingosine-1-Phosphate.

Sphingosine-1-phosphate [S1P] is a potent bioactive sphingolipid molecule. In response to a stimulus, S1P is produced intracellularly by the action of two sphingosine kinases, and then it is exported to the extracellular environment or acts as an intracellular second messenger. S1P binds to its cognate G-protein coupled receptors, which are known as S1P receptors. There are five S1P receptors that have been identified in vertebrates. By activating S1P receptors, S1P controls a variety of physiological and pathological processes including cell migration, angiogenesis, vascular maturation, inflammation, and invasion, metastasis, and chemoresistance in cancer. S1P has emerged as a critical regulator of leukocyte migration and plays a central role in lymphocyte egress from the thymus and secondary lymphoid organs. In the current review article, we summarize the current understanding of the emigration of lymphocytes and other leukocytes from bone marrow, thymus and secondary lymphoid organs to the circulation, as well as the clinical implications of modulating the activity of the major S1P receptor, S1PR1.

Melanocortin 4 receptor activates ERK-cFos pathway to increase brain-derived neurotrophic factor expression in rat astrocytes and hypothalamus.

Melanocortins are neuropeptides with well recognized anti-inflammatory and anti-apoptotic effects in the brain. Of the five melanocortin receptors (MCR), MC4R is abundantly expressed in the brain and is the only MCR present in astrocytes. We have previously shown that MC4R activation by the α-melanocyte stimulating hormone (α-MSH) analog, NDP-MSH, increased brain-derived neurotrophic factor (BDNF) expression through the classic cAMP-Protein kinase A-cAMP responsive element binding protein pathway in rat astrocytes. Now, we examined the participation of the mitogen activated protein kinases pathway in MC4R signaling. Rat cultured astrocytes treated with NDP-MSH 1 µM for 1 h showed increased BDNF expression. Inhibition of extracellular signal-regulated kinase (ERK) and ribosomal p90 S6 kinase (RSK), an ERK substrate, but not of p38 or JNK, prevented the increase in BDNF expression induced by NDP-MSH. Activation of MC4R increased cFos expression, a target of both ERK and RSK. ERK activation by MC4R involves cAMP, phosphoinositide-3 kinase (PI3K) and the non receptor tyrosine kinase, Src. Both PI3K and Src inhibition abolished NDP-MSH-induced BDNF expression. Moreover, we found that intraperitoneal injection of α-MSH induces BDNF and MC4R expression and activates ERK and cFos in male rat hypothalamus. Our results show for the first time that MC4R-induced BDNF expression in astrocytes involves ERK-RSK-cFos pathway which is dependent on PI3K and Src, and that melanocortins induce BDNF expression and ERK-cFos activation in rat hypothalamus.

Cost-effectiveness of antiviral drug therapy to reduce mother-to-child HIV transmission in sub-Saharan Africa.

OBJECTIVE: To assess the potential cost-effectiveness of short-course antiviral regimens to prevent mother-to-child transmission (MCT) of HIV in sub-Saharan Africa. DESIGN: Cost-effectiveness analysis. METHODS: No intervention was compared with three regimens of twice daily zidovudine and lamivudine: regimen A, starting at 36 weeks of gestation and continuing to 1 week postpartum; regimen B, from intrapartum through 1 week postpartum; and regimen C, intrapartum only. Model inputs were estimated from published and unpublished data. Absolute percentage reductions in HIV transmission extrapolated from zidovudine monotherapy trials were estimated at 12.4, 8.6 and 4.3% for regimens A, B, and C, respectively. Outcome measures were net costs to the public sector health-care system, cost per infection averted, and cost per disability-adjusted life-year (DALY) gained. Multiple sensitivity analyses were conducted. RESULTS: Based on the hypothetical efficacy estimates, regimen C was the most cost-effective. For a cohort of 100 women with 15% HIV prevalence, net costs to the public sector health-care systems were estimated at US$3617 for regimen A, US$ 1667 for regimen B, and US$351 for regimen C. Regimen C had a cost of US$ 1129 per HIV infection averted and a cost of US$60 per DALY. Regimens B and A cost US$2680 and 5134 per infection averted and US$143 and 274 per DALY, respectively. Cost-effectiveness declined rapidly at efficacy below 10% or HIV prevalence below 7%. Results were very sensitive to antiviral drug costs. For example, at 20% of current prices, the cost per DALY for regimen A fell to US$64, and to about US$42 for regimens B and C. CONCLUSION: Antiviral therapy may be cost-effective compared with other health interventions if HIV prevalence is high, if clinical trials confirm estimated efficacies, and if drug prices are reduced.

Preparation for phase III HIV vaccine efficacy trials: methods for the determination of HIV incidence.

OBJECTIVE: Accurate estimates of HIV incidence that reflect the effect of non-vaccine interventions (education, counselling, condom promotion, and possibly sexually transmitted disease treatment) and that may be provided in a Phase III vaccine efficacy trial, are needed so that vaccine trial population sample sizes can be accurately determined. In order to avoid delays in the implementation of efficacy trials, well characterized cohorts must also be developed and available to participate in such trials. We reviewed the potential study populations, the epidemiologic methods for the determination of HIV incidence (using open cohort, closed cohort, and seroprevalence data methods), and the need for the development of population cohorts in preparation for Phase III HIV vaccine efficacy trials. SETTING: Phase III trials in developed and developing countries. METHODS: Comparison of open and closed cohorts and those using seroprevalence data to estimate HIV incidence. RESULTS: Open and closed cohorts each have disadvantages and advantages. However, the open cohort may be more suitable for determining estimates of HIV incidence that reflect non-vaccine interventions and for the development of a well characterized cohort available to participate in efficacy trials. CONCLUSION: Careful preparation of research infrastructures and population cohorts will help ensure the successful conduct of scientifically and ethically sound HIV vaccine efficacy trials in the future.

Seroincidence of HIV-1 infection in African women of reproductive age: a prospective cohort study in Kigali, Rwanda, 1988-1992.

OBJECTIVE: To estimate the seroincidence of HIV-1 infection among women of reproductive age in Kigali, Rwanda. DESIGN: Fixed prospective cohort followed for 36 months between November 1988 and June 1992, as part of an ongoing study of mother-to-child transmission of HIV-1. SETTING: Centre Hospitalier, Kigali, Rwanda. SUBJECTS: A total of 216 HIV-seronegative women were enrolled at delivery between November 1988 and June 1989. METHODS: A blood sample was obtained at delivery to test for HIV antibodies (by enzyme-linked immunosorbent assay and Western blot). Serum was tested every 3 months during follow-up. Incidence density rates of HIV seroconversion were estimated. RESULTS: The follow-up rate after 3 years was 89%, assessed by the maximum person-years method. The seroincidence density rate was 3.5 per 100 women-years (95% confidence interval, 1.9-5.0). It decreased linearly from 7.6 during the first 6-months postpartum to 2.5 per 100 women-years during the last 6 months of the third year of follow-up. Maternal age did not affect HIV incidence rates. We examined the role of the cohort, counselling, and the first 6-month postpartum effects on this estimate. CONCLUSION: This fixed cohort provided an overall estimation of the HIV infection incidence rate and its dynamics. These figures could be used for programming future HIV preventive vaccine efficacy trials in Rwanda.

PIP: The objective was to estimate the seroincidence of HIV-1 infection among women of reproductive age in Kigali, Rwanda. A fixed prospective cohort followed a total of 216 HIV-seronegative women for 36 months between November 1988 and June 1992 at Centre Hospitalier, Kigali, Rwanda. A study of mother-to-child transmission of HIV-1 has been going on at the Centre Hospitalier de Kigali since November 1988. A group of HIV-seronegative women matched by maternal age and parity was consecutively selected as a comparison group. The mean maternal age was 25.1 years (SD, 4.5 years), and the total number of pregnancies was 2.7 (SD, 1.8). A blood sample was obtained at delivery to test for HIV antibodies (by enzyme-linked immunosorbent assay and Western blot). Serum was tested every 3 months during follow-up. The follow-up rate after 3 years was 89.2% (577/646.75), assessed by the maximum person-years method. 20 seroconversions were documented during the first 36 months of follow-up among the 216 women seronegative at inclusion, yielding a cumulative incidence of 11.2%. The largest number of seroconversions (8/20; 40%) was observed in the first 6 months of the postpartum period. The seroincidence density rate was 3.5/100 women-years (95% confidence interval, 1.9-5.0). It decreased linearly from 7.6 during the first 6-months postpartum to 2.5 per 100 women-years during the last 6 months of the third year of follow-up (P = 0.01). Maternal age did not affect HIV incidence rates. We examined the role of the cohort, counseling, and the first 6-month postpartum effects on this estimate. The study confirms that pregnant women may represent a population in which the HIV seroincidence is high and concentrated in the immediate postpartum period. Pregnant women should become a potential target group for future large scale vaccination trials and programs with adequate follow-up. These figures could be used for programming future HIV preventive vaccine efficacy trials in Rwanda.

Protection against sexually transmitted diseases by granting sex workers in Thailand the choice of using the male or female condom: results from a randomized controlled trial.

BACKGROUND: The male condom is the most effective barrier method available for protection against sexually transmitted diseases (STDs), including HIV infection. There is an urgent need to develop and evaluate other prevention methods, such as the female condom. This study estimated the additional protection against STDs offered to sex workers by giving them the option of using the female condom when clients refused to use a male condom. METHODS: Sex establishments in four cities in Thailand were randomized into two study groups: one in which sex workers were instructed to use male condoms consistently (male condom group); and one in which sex workers had the option of using the female condom if clients refused or were not able to use male condoms (male/female condom group). Randomization was done by sex establishments, and not by individuals, to minimize sharing of female condoms across study groups. The proportion of unprotected sexual acts (defined as sexual acts in which condoms were not used, tore, or slipped in or out) and incidence rate of STDs (gonorrhoea, chlamydial infection, trichomoniasis and genital ulcer disease) were measured over a 24-week period and compared between the two study groups. FINDINGS: Results are available from 34 sex establishments (249 women) in the male/female condom group, and 37 sex establishments (255 women) in the male condom group. Condom use was very high in both groups (97.9 and 97.3 % of all sexual acts, respectively, P > 0.05). Male condom use was lower in the male/female condom group when compared with the male condom group (88.2 and 97.5%, respectively, P < 0.001). However, this reduction in male condom use was counterbalanced by the use of female condoms in 12.0% of all sexual acts in the male/female condom group, contributing to a 17% reduction in the proportion of unprotected sexual acts in this group when compared to the male condom group (5.9 versus 7.1%, respectively, P = 0.16). Female condom use was sustained over the entire study period. There was also a 24% reduction in the weighted geometric mean incidence rate of STDs in the sex establishments of the male/female condom group compared to the male condom group (2.81 versus 3.69 per 100 person-weeks, P = 0.18).

Trimethoprim-sulfamethoxazole versus aerosolized pentamidine for primary prophylaxis of Pneumocystis carinii pneumonia: a prospective, randomized, controlled clinical trial. LFPMI Study Group. Ligue Française de Prévention des Maladies Infectieuses.

The objective was to compare the efficacy and tolerance of monthly aerosolized pentamidine versus trimethoprim-sulfamethoxazole (TMP-SMX) to prevent the first episode of Pneumocystis carinii pneumonia (PCP) in human immunodeficiency virus (HIV)-infected patients. In an open, prospective, randomized multicentric clinical trial, HIV-infected patients (n = 214) with CD4 cell counts < 200/mm3 or 20% without a history of PCP or cerebral toxoplasmosis were randomized to receive for at least 2 years aerosolized pentamidine (300 mg monthly) or low-dose daily TMP-SMX (400-80 mg). The mean follow-up was 578 days. The two groups (except for gender) were homogeneous for age, risk group for HIV infection, initial CD4+ lymphocyte count, and mean follow-up. The PCP rate per year of observation using an intent-to-treat analysis was 3.1% and 1.3% in the groups treated with pentamidine and TMP-SMX, respectively (p > 0.05). Moderate or severe clinical and biological side effects were observed in five patients on pentamidine and 33 on TMP-SMX (p < 0.05). Nineteen episodes of cerebral toxoplasmosis were diagnosed during the study. The analysis showed no significant difference in time of development of toxoplasmosis, but only one patient was actually treated with TMP-SMX. Survival was not significantly different in the two groups. Low-dose daily TMP-SMX or monthly aerosolized pentamidine effectively prevented a first episode of PCP in HIV-infected patients, but aerosolized pentamidine was better tolerated. However, TMP-SMX is less costly and should have a preventive effect for toxoplasmosis.

Use of the circular stapler in 1000 consecutive colorectal anastomoses: experience of one surgical team.

BACKGROUND: This study was performed to assess the exact performance of the conventional way of stapling colorectal anastomoses. Information collected from 1000 consecutive anastomoses performed by one surgical team could be considered as reliable reference with which results obtained by new approaches could be compared. METHODS: One thousand consecutive anastomoses were performed from 1979 to 1992. Characteristics of the procedure, intraoperative events, mortality rate, complications, and clinical outcome were detailed. RESULTS: There were 528 men and 472 women (age range, 20 to 90 years; average age, 63 years). Anastomoses were constructed by means of a circular stapler loaded with the largest cartridge in 82.3% of the cases. Imperfections were identified during operation in 124 cases. A diverting colostomy was performed in 127 cases. Postoperative mortality rate averaged 2.2%. Clinical anastomotic leaks developed in 35 patients: in 11.4% after low stapling (less than 5 cm from the dentate line) and in 2.2% after high stapling. The presence of a diverting colostomy influenced the leakage rate in patients with very low anastomoses. Total failure rate (death, definitive colostomy) as a result of anastomotic leak was 1.6%. Among the 933 survivors who had follow-up examination, the incidence of bad functional results decreased from 10% at the first attendance to 4.3% at the last one. Transanal dilatation and restapling were required for symptomatic narrowing in three and one patients, respectively. CONCLUSIONS: The conventional way of stapling colorectal anastomoses in reliable, but it requires strict observance of the rules for anastomosing intestine and a careful check of the stapled sutures. Results obtained by new approaches could be compared with these data.