Influence of tides on the dissemination and related health risks of intestinal helminths along the Kribi beaches (Atlantic Coast, Southern Cameroon)

Kribi is a seaside town that welcomes thousands of tourists each year. However, the poor sanitation condition of its beaches along the Atlantic coast is not without risk for visitors. In this study, we used the formol-ether concentration technique to identify and quantify larvae or eggs of intestinal helminths in waters of three regularly visited Kribi beaches (Mpalla, Ngoyè, and Mboamanga). Results revealed that all identified larvae and eggs were cestodes (Hymenolepis nana) and nematodes (Strongyloides sp., Ascaris sp., Ancylostoma duodenale and Trichuris trichiura). All the helminth eggs and larvae showed high abundance at low tide during rainy seasons. Ancylostoma duodenale eggs, totally absent at Mpalla, were densely present at low tide at Ngoyè (301 ± 15 eggs/L). Trichuris trichiura eggs showed the lowest abundance (0 to 62 eggs/L) at all sites. Abiotic variables indicated that waters at the various beaches were basic (pH: 8.75-9.77), generally warmer (32.44°C at Mpalla in the Short Rainy Season), more oxygenated at low tide, and moderately mineralized at high tide. Positive and significant correlations were observed at Ngoyè at low tide between Strongyloides sp. larvae and dissolved oxygen (P ˂ 0.05); and between Ancylostoma duodenale eggs and temperature (P ˂ 0.05). The overall results indicated that the beaches studied are subjected to fecal pollution. This pollution is more accentuated during low tides than during high tides. Depending on tidal movements, swimmers risk exposure to helminth eggs and larvae known to be responsible for gastroenteritis.

First molecular characterization of the hepatitis E virus in humans in Cameroon: Confirmation of the HEV outbreak in Touboro, North-Cameroon

Hepatitis E virus (HEV) is a major causative agent of acute viral hepatitis in many regions of the world including Africa. In Cameroon, there is no published molecular study on HEV in humans. However, based on serological assays, the first outbreak of HEV was detected in North-Cameroon. The objective of this study was to determine the molecular characterization of HEV that circulated during this period. A retrospective study design was used to select serum samples among those collected during the outbreak period. immunoglobulin M positive samples available in sufficient volumes to amplify HEV RNA were selected. RNA was extracted and then amplified by a real-time reverse transcription polymerase chain reaction (real time RT-PCR) assay, followed by a nested reverse transcription polymerase chain reaction (nested RT-PCR) assay for sequencing and phylogenetic analysis. Overall, 24 samples were selected and HEV RNA was amplified by real-time RT-PCR in 20 samples. Amongst these, 12 samples were positive for HEV RNA by nested RT-PCR and yielded good sequencing products. Phylogenetic analysis showed that 10 samples clustered with HEV genotype 1 (subtype 1e) and two samples clustered with HEV genotype 3 (subtype 3f). This study fills the gap of knowledge on the molecular epidemiology of HEV in Cameroon and confirms the first report of the hepatitis E outbreak in North-Cameroon.

Epidemiology of hepatitis E virus infection in animals in Africa: a systematic review and meta-analysis

BACKGROUND

Hepatitis E virus (HEV) is a major cause of acute hepatitis in humans worldwide and have high burden in the resource-limited countries. Better knowledge of the epidemiology of hepatitis in animals in Africa can help to understand the epidemiology among humans. The objective of this study was to summarize the prevalence of HEV infection and distribution of HEV genotypes among animals in Africa.

METHODS

In this systematic review and meta-analysis, we comprehensively searched PubMed, EMBASE, African Journals Online, and Africa Index Medicus from January 1st, 2000 to March 22th, 2020 without any language restriction. We considered cross-sectional studies of HEV infection in animals in Africa. Study selection, data extraction, and methodological quality of included studies were done independently by two investigators. Prevalence data were pooled using the random-effects meta-analysis. This review was registered in PROSPERO, CRD42018087684.

RESULTS

Twenty-five studies (13 species and 6983 animals) were included. The prevalence (antibodies or ribonucleic acid [RNA]) of HEV infection in animals varied widely depending on biological markers of HEV infection measured: 23.4% (95% confidence interval; 12.0-37.2) for anti-HEV immunoglobulins G, 13.1% (3.1-28.3) for anti-HEV immunoglobulins M, and 1.8% (0.2-4.3) for RNA; with substantial heterogeneity. In subgroup analysis, the immunoglobulins G seroprevalence was higher among pigs 37.8% (13.9-65.4). The following HEV genotypes were reported in animals: Rat-HEV genotype 1 (rats and horses), HEV-3 (pigs), HEV-7 (dromedaries), and Bat hepeviruses (bats).

CONCLUSIONS

We found a high prevalence of HEV infection in animals in Africa and HEV genotypes close to that of humans. Some animals in Africa could be the reservoir of HEV, highlighting the need of molecular epidemiological studies for investigating zoonotic transmission.

Burden of hepatitis E virus infection in pregnancy and maternofoetal outcomes: a systematic review and meta-analysis

Background

There is still a dearth of knowledge on the burden of HEV infection in the global population of pregnant women. Therefore, we conducted a systematic review and meta-analysis to estimate the global burden of HEV infection in pregnancy.

Methods

We searched PubMed, Embase, Web of Knowledge, and Global Index Medicus to identify articles published until January 26, 2020. We considered cross-sectional, case-control, and cohort studies reporting the immunoglobulins M HEV seroprevalence in asymptomatic and symptomatic (jaundice or elevated transaminases) pregnant women or investigating the association between HEV infection and maternofoetal outcomes. We used a random-effects model to pool studies. This review was registered with PROSPERO, CRD42018093820.

Results

For HEV prevalence estimates, we included 52 studies (11,663 pregnant women). The seroprevalence was 3.5% (95% confidence interval: 1.4–6.4) in asymptomatic women (most of whom from high endemic areas). The prevalence in symptomatic women was 49.6% (42.6–56.7) with data only from HEV high endemic countries. In the multivariable meta-regression model, the prevalence was higher in symptomatic women compared to asymptomatic (adjusted prevalence odds ratio [aPOR]: 1.76; 95%CI: 1.61–1.91) and decreased with increasing year of publication (by 10-year) (aPOR: 0.90; 95%CI: 0.84–0.96). The proportion of HEV vertical transmission was 36.9% (13.3–64.2). Risk of bias was low, moderate and high respectively in 12 (23%), 37 (70%), and 4 studies (7%) addressing HEV prevalence estimation. HEV infection was associated with maternal deaths (pooled OR 7.17; 3.32–15.47), low birth weight (OR: 3.23; 1.71–6.10), small for gestational age (OR: 3.63; 1.25–10.49), preterm < 32 weeks (OR: 4.18; 1.23–14.20), and preterm < 37 weeks (OR: 3.45; 2.32–5.13), stillbirth (OR: 2.61; 1.64–4.14), intrauterine deaths (OR: 3.07; 2.13–4.43), and not with miscarriage (OR: 1.74; 0.77–3.90). All studies which assessed the association between HEV infection and maternofoetal outcomes had a moderate risk of bias.

Conclusions

Findings from this study are suggestive of a high burden of HEV infection in pregnancy in high endemic countries, its association with poor maternofoetal outcomes, and a high rate of vertical transmission. This study supports the need for specific strategies to prevent exposure of pregnant women to HEV infection, especially in high endemic areas.

Serological and molecular investigation of hepatitis E virus in pigs reservoirs from Cameroon reveals elevated seroprevalence and presence of genotype 3

Background

Hepatitis E virus (HEV) is a zoonotic pathogen of which pigs have been established as reservoirs. In the present study, we investigated the presence of HEV among pigs in the Center and Littoral regions of Cameroon and performed the molecular characterization of positive strains.

Methodology

A total of 453 serum and stool samples were randomly collected from pigs in slaughterhouses in Obala, Douala and Yaounde. All samples were examined for the presence of anti-HEV IgG and IgM antibodies using ELISA assays. IgM positive stool samples were tested for HEV RNA using an RT-PCR assay, followed by a nested PCR assay for sequencing and phylogenetic analysis.

Results

Overall, 216 samples (47.7%, 95% CI: 43.1%-52.3%) were positive for at least one of the serological markers of HEV infection. Amongst these, 21.0% were positives for anti-HEV IgM, 17.7% for anti-HEV IgG, and 9.1% for both. A total of eight stool samples (5.9%) were positive for HEV RNA by nested RT-PCR. Phylogenetic analysis showed that the retrieved sequences clustered within HEV genotype 3.

Conclusion

This study shows a high prevalence of anti-HEV antibodies and the circulation of genotype 3 in the swine population in Cameroon. Subsequent studies will be needed to elucidate the zoonotic transmission of HEV from pigs to humans in Cameroon.

Seroprevalence of hepatitis E virus antibodies in different human populations of Cameroon

Hepatitis E virus (HEV) is a major cause of acute hepatitis worldwide. HEV infection is self-limiting, but fulminant hepatitis may occur with higher mortality rates. The aim of this study was to determine the seroprevalence of the HEV in three different populations in Cameroon and to assess alimentary risk factors of infection. A total of 903 individuals including 450 elderly people, 183 pregnant women, and 270 HIV-infected patients were enrolled during 2009-2015. All sera obtained were tested for the presence of anti-HEV antibodies with commercial enzyme-linked immunosorbent assay kits. The association between initial anti-HEV status and potential risk factors was assessed. Out of the 903 samples, 22.0% (199/903) were positives for anti-HEV immunoglobulin M (IgM), 5.8% (52/903) for anti-HEV IgG, and 3.5% (32/903) for both. The seropositivity for IgM was 7.0%, 13.1%, and 34.7%; meanwhile, the seropositivity for immunoglobulin G was 8.5%, 3.3%, and 5.1%, in HIV-infected patients, pregnant women, and the elderly population, respectively. Both antibodies were detected simultaneously in 2.2%, 1.6%, and 5.1% in HIV-infected patients, pregnant women, and the elderly population, respectively. No risk factors were significantly associated with HEV infection in these populations. This study showed a high prevalence of anti-HEV antibodies in three different populations in Cameroon.

Detection of hepatitis E virus antibodies among Cercopithecidae and Hominidae monkeys in Cameroon

We screened hepatitis E from 15 species of non-human primates. Anti-HEV IgG was detected in 11.1% (1/9) Mandrillus sphinx, 14.3% (2/14) Gorilla gorilla, 5.9% (4/67) pan troglodytes and 8.7% (2/23) Mandrillus leucophaeus, whereas anti-HEV IgM was detected in 1.5% (1/18) papio Anubis, 28.6% (2/7) Cercocebus agilis and 1.5% (1/67) pan troglodyte.

Epidemiology of hepatitis E virus infection in animals in Africa: a systematic review and meta-analysis protocol

BACKGROUND

Hepatitis E virus (HEV) is one of the major causes of acute hepatitis in humans worldwide with a case-fatality rate of 1-4% in the general population that might reach 30% in pregnant women. In the past decade in Africa, studies have shown that HEV infects not only humans but also animals. A systematic review summarizing the epidemiological data of HEV has been only performed in humans residing in Africa. We will perform this systematic review and meta-analysis to assess the prevalence of HEV infection in animal species in Africa.

METHODS

This review will include cross-sectional studies among different animal species that reported the prevalence of HEV in Africa. We will consider published and unpublished studies from January 1, 2000 to present. A comprehensive search of PubMed, Excerpta Medica, African Journals Online, and Africa Index Medicus will be conducted to identify all relevant articles. Reference lists of eligible items and relevant articles will be reviewed. The funnel plots and the Egger test will be used to assess the publication bias. Study-specific estimates will be aggregated using a DerSimonian and Laird random-effects meta-analysis model to obtain an overall summary estimate of HEV prevalence across studies. The heterogeneity of the studies will be evaluated by the χ2 test on the Cochran's Q test. The results will be presented by animal species.

DISCUSSION

HEV-infected animals are likely to transmit this virus to humans in Africa, as studies have already shown in developed countries. This systematic review and meta-analysis will provide a clear picture of the epidemiology of HEV in animals in Africa, to better understand this infection and to respond adequately to the epidemic challenges that often afflict Africa.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42018087684 .

High seroprevalence of hepatitis E among pigs suggests an animal reservoir in Cameroon

INTRODUCTION

Hepatitis E virus (HEV) is one of the most prevalent cause of acute hepatitis in humans worldwide. The risk of HEV transmission is not limited only to spread from human to human but the infection can also spread from animals to humans, especially from the domestic pigs. Despite mounting evidence regarding the zoonotic potential of porcine HEV infection, there are limited data on its prevalence in pigs in the sub-Sahara Africa region. Therefore, the present study aimed to determine the seroprevalence of HEV antibodies among pigs in two Cameroonian regions.

METHODOLOGY

A total of 162 sera were collected from slaughtered-age pigs from January to March 2012. To determine whether pigs might represent a HEV reservoir in the Northern and Western region in Cameroon, anti-HEV IgG and IgM were tested by ELISA using commercials available kits.

RESULTS

Overall, 70 of the 162 samples (43.2%, 95% CI: 35.5% - 51.2%) were positive for at least one of the serological markers of HEV infection (IgM and / or IgG).We observed a significant seroprevalence of HEV antibodies between the northern and western regions (60% (42/70) and 40% (28/70), p = 0.01796) respectively.

CONCLUSION

Overall, this study reports a high seroprevalence of Hepatitis E virus antibodies in slaughter pigs in Cameroon. Our findings suggest that pigs might be a cause of zoonotic HEV transmission in Cameroon. Therefore, further studies are warranted to establish the dynamics of zoonotic HEV and characterize the different genotypes circulating in humans and pigs.

The Value of Cell Proliferation and Angiogenesis in the Prognostic Assessment of Ovarian Granulosa cell Tumors

Objectives

Most cases of granulosa cell tumors (GCT) of the ovary are characterized by a relatively good outcome. However, some tumors behave aggressively and some tend to recur many years after the initial diagnosis. Tumor growth depends on cell proliferation and angiogenesis. Thus, proliferative indices and microvessel density were studied to determine possible valuable methods to assess the GCT patient's outcome.

Methods and study design

Paraffin-embedded tissue blocks were available for 60 patients with primary GCT and were investigated by immunostaining with monoclonal antibodies against PCNA, Ki-67 and factor VIII-related antigen. The follow-up was available for 51 patients and ranged from 25 to 206 months. A clinical follow-up distribution of patients was made: 8 patients with recurrence (group I); 6 patients who lived with no evidence of recurrence for 100 months or more (group II), and 37 patients alive with no evidence of recurrence in the follow-up period of less than 100 months (group III).

Results

There was a statistical correlation between PCNA and Ki-67 proliferative indices. A significant increase (P «0.05) of mean PCNA and Ki-67 proliferative indices and mean tumor size was seen in patients of Group I compared to those of Group II. The mean PCNA proliferative index positively correlated with the mean Ki-67 proliferative index for Groups I and II. Mean microvessel density showed a positive correlation with mean PCNA and Ki-67 proliferative indices and with mean tumor size for Group I, whereas it was negatively correlated with PCNA proliferative index and tumor size for Group II. A positive correlation was found between mean mitotic count and both proliferative indices only for Group II. The following features were indicative of a relatively poor prognosis: GCT measuring >9 cm in diameter, PCNA >4.0%, Ki-67 >1.2%, and diffuse, insular and sarcomatoid histologic patterns.

Conclusions

The findings support the importance of proliferative factors, tumor size and histologic patterns as possible prognostic indicators for estimating the biologic behavior of patients with GCT. Unfortunately, angiogenesis did not seem to be a useful determinant parameter of a possible aggressive behavior. However, a longer follow-up period with larger series may be required to assess the value of the parameters in prediction of patient survival.

Involvement of cell shape and flagella in the bacterial retention during percolation of contaminated water through soil columns in tropical region

Microorganisms' retention in soil contributes to the natural purification of groundwater. Bacteria found in groundwater are generally of various shapes. The aim of this study was to assess the importance of cell shape and flagella in bacterial retention during polluted water percolation through two soil columns CA and CB, in the equatorial region in Central Africa. Percolation tests were carried out using different water loads samples which were contaminated by Escherichia coli (straight rods, peritrichous flagella), Vibrio parahaemolyticus (rods bacteria, polar flagella), and Staphylococcus saprophyticus (spherical, free-flagellum). It has been noted that showed that through soil column CA, the mean values of cells retention ratios (T(R)) varied with bacteria species considered, and from one applied water load sample to another. E. coli T(R) and that of S. saprophyticus were not significantly different (P> 0.05) for the two soil columns. V. parahaemolyticus T(R) significantly differed from that of E. coli and S. saprophyticus through soil column CA (P< 0.01) when the highest water load was applied, and through soil column CB (P< 0.05) for each of water load applied. A relative hierarchical arrangement of retained cells based on the T(R) showed that V. parahaemolyticus was less retained through the 2 soil columns. S. saprophyticus in most cases was more retained than others. The physical properties of the bacterial cell must be taken into consideration when evaluating the transfer of bacteriological pollutants towards groundwater.

Physicochemical water quality of the Mfoundi River watershed at Yaoundé, Cameroon, and its relevance to the distribution of bacterial indicators of faecal contamination

Water quality of the Mfoundi River and four of its tributaries was studied by assessing some physicochemical variables (temperature, pH, conductivity, chlorides, phosphates and nitrogen ammonia, dissolved oxygen and carbon dioxide, organic matter content and Biological Oxygen Demand) and their influence on the distribution of bacterial indicators of faecal contamination (total coliform, faecal coliform and faecal streptococci). For this, standard methods for the examination of physicochemical parameters in water were followed, and statistical analysis (Pearson correlations) used to establish any relationships between physicochemical and biological variables. Our results revealed that almost all of the examined physicochemical variables exceeded World Health Organization (WHO) guidelines for recreational water. This was in agreement with a previous microbiological study indicating that these waters were not safe for human use or primary contact according to water quality standards established by the WHO. Results of our correlation analysis suggested that physicochemical and biological variables interact in complicated ways reflecting the complex processes occurring in the natural environment. It was also concluded that pollution in the Mfoundi River watershed poses an increased risk of infection for users and there exists an urgent need to control dumping of wastewater into this watershed.

Treatment of relapsed or refractory aggressive non-hodgkin lymphoma with two ifosfamide-based regimens, IMVP and ICE

We report the outcomes of 45 patients with relapsed or refractory aggressive non-Hodgkin's lymphoma (NHL) treated with a combination of ifosfamide, carboplatinum and etoposide (ICE) and 28 patients treated with a combination of ifosfamide, methotrexate and etoposide (IMVP) during two 5-year periods. The response rate (RR) to ICE was 47%, 2-year overall survival (OS) 31% and 2-year event-free survival (EFS) 22%. These results were similar to those obtained with IMVP (RR 39%, 2-year OS 23%, 2-year EFS 13%; p=0.355 for RR, 0.275 for OS, 0.668 for EFS). Higher IPI scores and refractoriness to treatment were negative prognostic factors, immunophenotype (B vs. T) had no influence on prognosis. Changing from IMVP to ICE does not substantially improve the outcome of patients with relapsed or refractory aggressive NHL. Patients with relapsed/refractory aggressive B-NHL do not have a superior outcome in comparison to those with T-NHL if treated with chemotherapy alone.

Microbiological water quality of the Mfoundi River watershed at Yaoundé, Cameroon, as inferred from indicator bacteria of fecal contamination

Using the membrane filtration technique to count total coliform (TC), fecal coliform (FC) and fecal streptococci (FS), the microbiological water quality of the Mfoundi River and four of its representative tributaries at Yaoundé, Cameroon, was assessed for human use and contact. Sampling was conducted so as to examine the potential origin of fecal contamination and how rainfall affects the measured concentrations of indicators organisms. Our results revealed that waters were not safe for human use or primary contact according to the standards for water quality established by the Word Health Organization (WHO). Indeed, these waters exhibited high concentrations of TC (Mean +/- SD = 5.6 x 10(8) +/- 2.5 x 10(6) CFU/100 ml), FC (Mean +/- SD = 6.8 x 10(5) +/- 2.4 x 10(3) CFU/100 ml) and FS (Mean +/- SD = 7.3 x 10(5) +/- 2.1 x 10(3) CFU/100 ml) that varied with the sampling sites and points. FC/FS ratio suggested that this contamination was more from warm-blooded animals than humans and correlation analysis points to the role of rainfall as a contributing factor, which enhanced the bacterial numbers detected. We conclude that there is a great potential risk of infection for users of waters from the Mfoundi River and its tributaries at Yaoundé.

Ureteral metastasis of occult breast cancer

We report the case of a 59-year-old woman who presented with right flank pain and fever. Diagnostic investigations revealed stenosis of the right ureter extending over about 1cm. Since a double-J prosthesis could not be passed through it, a percutaneous nephrostomy was constructed and surgical exploration and excision of the stenotic ureteral segment were then carried out. Histopathological analysis of the segment removed showed diffuse infiltration with epithelial tumor cells. On immunohistochemistry, these cells were found to be positive for cytokeratin and for estrogen and progesterone receptors. No primary cancer and no additional metastases were detected. Eleven months later a primary tumor with a metastasis in the left supraclavicular region was found in the patient's right breast.

Changes in Soil Chemical Properties and Microbial Activities in Response to the Fungicide Ridomil Gold Plus Copper

The purpose of the study was to investigate changes of soil chemical and biological properties changes resulting from a single application of the fungicide Ridomil Gold plus copper (Ridomil Gold plus)(mefenoxam 6% + copper oxide 60%) at the following rates 0.25, 0.5, 1, 2, and 10 g m(-2). Selected chemical properties generally differed between fungicide rates over longer incubation periods. Microbial activity indices (available N, ammonification rates and specific enzymatic systems) were more sensitive indicators of change. Values of these indicators generally increased with incubation period and decreased or increased at high rates. Significant changes in P availability occurred after 90 days of incubation at rates > or = 1 g m(-2). Incorporation of the fungicide significantly increased NH4+ levels in soil after 75 days of incubation. These changes stimulated soil microbial activity as evidenced by increased ammonification rates especially at long-term exposure. Of the enzyme activities studied, dehydrogenase and beta-glucosidase activities were the most sensitive to ridomil gold plus. This sensitivity was more pronounced with the dehydrogenase activity.

[Evaluation of bacterial and polluting loads of effluent from activated sludge wastewater treatment plants in Yaounde, Cameroon]

Activated sludge wastewater treatment plants in Yaounde are plagued by failures in their operation. A microbiological and physico-chemical study was carried out on wastewater effluent of an hospital, university campus, and two residential areas made up of more than 2,000 apartments connected to two collective sewase systems. Wastewater sampling was performed in the form of daily cycles during which composite samples were made every two hours with samples collected every half hour. Variables measured included incoming flow rates, suspended solids, pH, electrical conductivity, ammonia nitrogen, total Kjeldahl nitrogen (combination of ammonia and organic nitrogen) and total reactive phosphorus, BOD5 and COD. Microorganisms were isolated on selective culture media using membrane filter procedures. The results obtained show that effluent discharged in receiving waters are, in general, not treated. The suspended solids contents of raw sewage range from 120 to 2,600 mg/l. In General Hospital a mean value of suspended solids of 31.8 mg/l was obtained for treated wastewater. pH values of both raw and treated sewage range from 6 to 8.5 units. Mean values of the conductivity of treated and raw wastewater range from 449.7 to 1,038.3 microseconds/cm. The TKN contents of untreated wastewater are comprised between 36 and 259.2 mg/l. These values range from 5 to 20 mg/l for treated effluent in the General Hospital plant. Large amounts of total hydrolysable phosphorus varying from 3.8 to 27.9 mg/l are present in wastewater from the plants. Influent BOD5 of Grand Messa, Cite Verte and university campus wastewater range from 110 to 530 mgO2/l. Values recorded indicate an important input of organic matter to receiving waters. In the case of biotic components, test germs densities registered in the influent of Grand Messa and those of Cite Verte are comprised between 9 x 106 and 88 x 107 CFU/100 ml for fecal coliforms, and between 9 x 105 and 74 x 107 CFU/100 ml for fecal streptococci. The densities of Aeromonas hydrophila in Grand Messa and Cite Verte influent fluctuate between 30 x 106 and 65 x 108 CFU/100 ml. Influent of university campus harbour 10 x 105. Densities of Pseudomonas aeruginosa remain below 70 x 105 CFU/100 ml. Treated effluent BOD5 values range from 48 to 150 mgO2/l. Such values indicate an inefficient treatment. The decrease in bacterial densities is limited to 2 logarithmic units. Treated effluent still harbour 10 x 103 to 10 x 105 CFU/100 ml for fecal coliforms, and 20 x 102 to 12 x 104 CFU/100 ml for fecal streptococci. These values range from 10 x 104 to 50 x 105 CFU/100 ml for Aeromonas hydrophila. Pseudomonas aeruginosa densities remain in general below 40 x 104 CFU/100 ml. Discharges from these wastewater treatment plants are responsible for the permanent fecal contamination of the environment and a lack of proper hygiene. Furthermore, they produce overfertilization of receiving waters.

Computer-based teaching of pathology at the Zagreb University School of Medicine

AIM

To review the experience gained in transferring USA computer-based teaching system of medical school pathology to Croatia.

METHODS

Computer-based teaching program of pathology developed at the University of Kansas School of Medicine, Kansas City, Kansas, USA, was transferred to the University of Zagreb School of Medicine, Zagreb, Croatia. The experimental group of 49 students was enrolled into this computer-based program. Their performance was compared with that of 195 classmates enrolled in the standard course. Objective (performance on the examinations) and subjective data (students' interviews and written evaluations of the course) were analyzed.

RESULTS

The computer program was operational 5 months from the inception of the transfer. It was well received by the students, even though many initially complained that it required more effort and a continuous commitment. The major problems concerned scheduling, reflecting various requirements i mposed on students by other departments teaching in parallel with the Pathology course. Objective data gathered so far indicate that the students enrolled in the computer-based program took the first midterm examination at a significantly higher rate than the rest of the class (p<0.001), and passed the examination with significantly better grades (p<0.001).

CONCLUSION

Computer-based teaching programs can be readily transferred to other countries. Full implementation of the program, however, may require significant changes in the existing curriculum in the medical school to which such a program has been transferred or considerable modifications in the program adopted for transfer. It appears that the students enrolled in the computer-based program perform better than students in the standard pathology course.

Automated high-performance liquid chromatographic method for the determination of homocysteine in plasma samples

Plasma homocysteine determination is essential for the diagnosis of inborn errors of metabolism of sulfur amino acids and is achieving considerable importance as a possible risk marker in vascular occlusive pathology. The aim of this study was therefore to develop a fast and sensitive method to assay total and free homocysteine and total and free cysteine in plasma samples, using an automated precolumn sample pretreatment including reduction with 2-mercaptoethanol, carboxymethylation of free thiols and derivation with o-phthalaldehyde. The chromatographic separation was accomplished in 7 min, the within-run and between-run R.S.D.s were all less than 4.3%, the response was linear in the range 0.4-150 microM for homocysteine and 4-1000 microM for cysteine and the mean recoveries were higher than 96%. Moreover, with minimal modification, the method allowed the evaluation of methionine, another important marker of transsulfuration and remethylation defects. The method was applied to the diagnosis of inborn errors involving sulfur amino acids metabolism and to detect mild hyperhomocysteinemia.

Laparoscopic management of the cornual pregnancy

Traditional treatment of interstitial pregnancy includes cornual resection or hysterectomy by laparotomy, but advanced minimally invasive surgery allows successful endoscopic management. We report a case where interstitial pregnancy was successfully diagnosed by ultrasound and treated by laparoscopy. Patient had an unremarkable postoperative course. This case demonstrates that a laparoscopic approach toward cornual pregnancy is possible.

Effects of tamoxifen on steroid hormone receptors and hormone concentration and the results of DNA analysis by flow cytometry in endometrial carcinoma

OBJECTIVES

Tamoxifen is a nonsteroidal triphenylethylene derivate with a predominant antiestrogen activity, used in the endocrine treatment of breast and endometrial cancer. It is not known which endometrial carcinomas will respond favorably to tamoxifen and which ones will not. The aim of this study was to find out whether tamoxifen has an effect on hormone steroid receptors, hormone concentration, DNA content, and proliferative activity in endometrial cancer and to correlate the tamoxifen-induced changes with pathologic parameters such as clinical stage, tumor differentiation, depth of invasion, and histologic type.

METHODS

Thirty postmenopausal women with endometrial carcinoma were treated with 30 mg of tamoxifen daily for 7-10 days after curettage. Steroid hormone receptors (estrogen and progesterone receptors), levels of follicle-stimulating hormone, luteinizing hormone, prolactin, estradiol, progesterone, testosterone, dehydroepiandrosterone sulfate, sex hormone binding globulin, and DNA ploidy and proliferative activity were determined before and after therapy. The patients were also divided into favorable and unfavorable prognosis groups according to classical histological parameters. The patients in the favorable group consisted of patients with stage I disease, well and moderately differentiated tumors, favorable histologic type, and a depth of myometrial invasion of less than (1/3). The patients with only one of the unfavorable parameters (clinical stage II or III, poorly differentiated tumors, unfavorable histologic types, and deeper invasion of myometrium) were included in the unfavorable prognosis group.

RESULTS

After the treatment, there was a net increase in the progesterone receptors and sex hormone binding globulin and a significant decrease in the estrogen receptors. The increase in progesterone receptors and decrease in estrogen receptors occurred in the patient group with favorable prognosis regarding histologic type, degree of differentiation, and clinical stage, but also in the unfavorable prognosis group regarding the depth of myometrial invasion. Statistically significant decrease in the follicle-stimulating hormone concentration was observed in the groups with favorable prognosis regarding histologic type, depth of myometrial invasion, and grade of differentiation. Concentration of sex hormone binding globulin was significantly increased in groups with favorable prognosis if histologic type and grade of differentiation were taken into account. On the other hand, there was a significant decrease in the concentration of luteinizing hormone in the group with unfavorable histologic type and also a decrease in progesterone concentration in patients with unfavorable prognosis regarding the grade of differentiation. There was no statistical significance either in the concentrations of other hormones measured or in the DNA analysis by flow cytometry.

CONCLUSIONS

Our results revealed that tamoxifen can increase progesterone receptors and decrease estrogen receptors in endometrial cancer. The effect was most pronounced in tumors with favorable clinicopathologic parameters. We conclude that tamoxifen therapy can induce progesterone receptor synthesis even in tumors with low initial progesterone receptor levels, making such tumors potentially responsive to additional hormonal therapy with progesterone.

[Bacteriological quality of spring and well water in Yaounde (Cameroon)]

The drinking water supply in Yaounde, Cameroon, often fails to meet demand and this leads many people to seek water from springs and wells the microbiological quality of which is unknown. We carried out a microbiological survey of five spring water points and ten wells. The fifteen study sites were located in various residential districts and were selected according to geographical location and number of users. Microorganisms were isolated on specific culture media using the membrane filter technique. We found that these water supplies contained many types of bacteria including Pseudomonas aeruginosa, Aeromonas hydrophila and indicators of fecal contamination. Maximum annual concentrations differed at the various sites and over time, from 750 to 98,000 CFU/l for P. aeruginosa, 40 to 78,000 CFU/l for A. hydrophila and 300 to 58,000 CFU/l for fecal indicator bacteria. The density of fecal bacteria was strongly correlated (p < 0.01) with those of P. aeruginosa in spring water and A. hydrophila in well water. The degree of correlation between microbial concentrations differed between sites. The source of fecal contamination differed between sites and was animal, human or both. The densities of bacteria recorded were high. Therefore, consumers of water drawn from these sources are at short-term risk of contracting waterborne diseases.

Prognostic parameters for survival of patients with malignant mesenchymal tumors of the uterus

BACKGROUND

Malignant mesenchymal uterine neoplasms are the most aggressive type of primary uterine tumors, with most patients dying within a few years of diagnosis. Thus, it would be very important to define prognostic factors for predicting the malignancy potential of at least some of their subtypes.

METHODS

Flow cytometric cell cycle analysis (proliferative activity, DNA ploidy, and DNA index) was performed on archival paraffin embedded blocks from 80 patients with malignant mesenchymal uterine neoplasms (endometrial stromal sarcomas, malignant smooth muscle tumors, and malignant Müllerian mixed tumors). The Cox proportional hazards regression model was used to assess relative effects of the following factors on patient survival: clinical stage, mode of therapy, DNA+proliferative activity, DNA index, histologic type, cellularity, degree of atypia, mitotic activity, and depth of myometrial invasion.

RESULTS

There were 9 low grade stromal sarcomas, 17 high grade stromal sarcomas, 8 smooth muscle neoplasms with uncertain malignant potential, 23 leiomyosarcomas, and 16 homologous and 7 heterologous malignant Müllerian mixed tumors. In univariate analysis for stromal sarcomas, statistical significance was found for DNA ploidy+proliferative activity (P < 0.001), histologic type (P = 0.005), and DNA index (P < 0.001). In multivariate analysis, DNA index appeared to be the only significant parameter influencing patient survival (P = 0.005). In univariate analysis for malignant smooth muscle neoplasms, statistical significance was detected for mitotic activity (P = 0.049) and International Federation of Gynecology and Obstetrics classification (P = 0.021), but in multivariate analysis, clinical stage appeared to be the only significant parameter influencing patient survival (P = 0.032). In univariate analysis for malignant Müllerian mixed tumors, statistical significance was found for the depth of myometrial invasion (P = 0.039), DNA index (P = 0.037), and clinical stage (P = 0.013), but in multivariate analysis, only the depth of myometrial invasion (P = 0.036) and clinical stage (P = 0.025) were of statistical significance.

CONCLUSIONS

The most powerful prognostic indicator for stromal sarcomas was the DNA index, for malignant smooth muscle neoplasms it was the clinical stage, and for malignant Müllerian mixed tumors it was the depth of myometrial invasion.

Histopathologic findings of placenta and arcuate artery Doppler velociometry in preeclampsia and intrauterine growth retardation

The aim was to analyze the histopathologic changes of placentas and to compare them to the results of arcuate artery color Doppler velocimetry. Fifty four placentas were from pregnancies complicated with pre-eclampsia that ranged from mild forms to convulsions (group 1), 42 from pregnancies complicated with intrauterine growth retardation (IUGR) (group 2) and 40 from uncomplicated pregnancies (group 3). The arcuate artery resistance index (AARI) was increased in 66.66% in group 1 and 59.52% in group 2 (NS). In all uncomplicated pregnancies (group 3) AARI was normal. In group 2, increased AARI was significantly more frequently associated with minimal hypoxic damage (MHD) of placental tissue than in group 1 (p < 0.005), whereas multiple infarcts were more common in group 1 than in group 2 (p < 0.005). At normal AARI multiple infarcts were significantly more frequently found in group 1 than in groups 2 and 3 (p < 0.005), whereas normal placental findings were significantly more common in group 3 than in groups 1 and 2 (p < 0.001). Hypoxic lesions were significantly more often associated with increased AARI (p < 0.01). The positive predictive value of arcuate artery color Doppler velocimetry for hypoxic placental lesions was 93%, and negative predictive value was 10%. Sensitivity and specificity of the method in the prediction of hypoxic placental lesions was 62% and 91%, respectively.

Prognostic parameters for survival of patients with malignant mesenchymal tumors of the uterus

BACKGROUND

Malignant mesenchymal uterine neoplasms are the most aggressive type of primary uterine tumors, with most patients dying within a few years of diagnosis. Thus, it would be very important to define prognostic factors for predicting the malignancy potential of at least some of their subtypes.

METHODS

Flow cytometric cell cycle analysis (proliferative activity, DNA ploidy, and DNA index) was performed on archival paraffin embedded blocks from 80 patients with malignant mesenchymal uterine neoplasms (endometrial stromal sarcomas, malignant smooth muscle tumors, and malignant Müllerian mixed tumors). The Cox proportional hazards regression model was used to assess relative effects of the following factors on patient survival: clinical stage, mode of therapy, DNA+proliferative activity, DNA index, histologic type, cellularity, degree of atypia, mitotic activity, and depth of myometrial invasion.

RESULTS

There were 9 low grade stromal sarcomas, 17 high grade stromal sarcomas, 8 smooth muscle neoplasms with uncertain malignant potential, 23 leiomyosarcomas, and 16 homologous and 7 heterologous malignant Müllerian mixed tumors. In univariate analysis for stromal sarcomas, statistical significance was found for DNA ploidy+proliferative activity (P < 0.001), histologic type (P = 0.005), and DNA index (P < 0.001). In multivariate analysis, DNA index appeared to be the only significant parameter influencing patient survival (P = 0.005). In univariate analysis for malignant smooth muscle neoplasms, statistical significance was detected for mitotic activity (P = 0.049) and International Federation of Gynecology and Obstetrics classification (P = 0.021), but in multivariate analysis, clinical stage appeared to be the only significant parameter influencing patient survival (P = 0.032). In univariate analysis for malignant Müllerian mixed tumors, statistical significance was found for the depth of myometrial invasion (P = 0.039), DNA index (P = 0.037), and clinical stage (P = 0.013), but in multivariate analysis, only the depth of myometrial invasion (P = 0.036) and clinical stage (P = 0.025) were of statistical significance.

CONCLUSIONS

The most powerful prognostic indicator for stromal sarcomas was the DNA index, for malignant smooth muscle neoplasms it was the clinical stage, and for malignant Müllerian mixed tumors it was the depth of myometrial invasion.

Prognostic value of steroid hormone receptors concentration in patients with endometrial carcinoma

The concentrations of progesterone receptors in endometrial tumors of 160 patients were analyzed with respect to survival and presence of clinicopathologic prognostic factors. The concentration of 25 fmol/mg of proteins for progesterone receptors appeared to be most powerful for prediction of survival. The survival was also significantly correlated to age, depth of myometrial invasion and clinical stage of the tumor. Concentration of estrogen receptors could not be correlated with the probability of patients' actuarial survival.

Ultrastructural immuno-localization of CUT-1 and CUT-2 antigenic sites in the cuticles of the nematode Caenorhabditis elegans

CUT-1 and CUT-2 are two distinct proteins found in cuticlin, the insoluble residue of the cuticles of the nematode Caenorhabditis elegans. They are the products of genes which have been previously characterized molecularly. These proteins have been expressed as recombinant in Escherichia coli and specific antisera have been raised against them. The experiments reported here regard their ultrastructural immuno-gold localization either on purified cuticles or on whole worms of various stages of development of Caenorhabditis elegans. A location in the cortical layer of the isolated cuticles is common to all stages, whereas there is a dauer specific location in the fibrous ribbon underneath the alae. These localizations are compared with immuno-labelling obtained using a serum raised against the whole cuticlin residue. CUT-1 and CUT-2 epitopes are easily and specifically lost during conventional chemical fixation.

Tumor cell cycle in patients with stage I endometrial carcinoma

Flow cytometric cell cycle analysis was performed on paraffin-embedded blocks from 49 patients with stage I endometrial carcinoma. Care was taken to separate tumor tissue from normal tissue in each specimen; normal tissue was used as a control for each individual specimen. DNA index, proliferative activity, and cell DNA aneuploidy were correlated with known parameters of tumor malignancy. Increased DNA index corresponded well with the DNA aneuploid tumors, poor tumor differentiation (G3), myometrial invasion of more than one-third, more malignant histologic type of tumor, and low concentration of estrogen (< or = 10 fmole/mg) and progesterone (< or = 25 fmole/mg) receptors. Similar results were obtained for tumor cell proliferative activity (percentage of cells in S + G2/M phases) and for DNA aneuploid tumors. Since more than 90% of patients with stage I endometrial carcinoma survived the 5-year postoperation period, analyzed parameters could not be checked for survival-related prognostic significance. However, our data indicate that cell cycle analysis may be instrumental for objective ranking of several known prognostic parameters.