Do Riparian Buffers Protect Stream Invertebrate Communities in South American Atlantic Forest Agricultural Areas?

We investigated the influence and relative importance of insecticides and other agricultural stressors in determining variability in invertebrate communities in small streams in intensive soy-production regions of Brazil and Paraguay. In Paraguay we sampled 17 sites on tributaries of the Pirapó River in the state of Itapúa and in Brazil we sampled 18 sites on tributaries of the San Francisco River in the state of Paraná. The riparian buffer zones generally contained native Atlantic forest remnants and/or introduced tree species at various stages of growth. In Brazil the stream buffer width was negatively correlated with sediment insecticide concentrations and buffer width was found to have moderate importance in mitigating effects on some sensitive taxa such as mayflies. However, in both regions insecticides had low relative importance in explaining variability in invertebrate communities, while various habitat parameters were more important. In Brazil, the percent coverage of soft depositional sediment in streams was the most important agriculture-related explanatory variable, and the overall stream-habitat score was the most important variable in Paraguay streams. Paraguay and Brazil both have laws requiring forested riparian buffers. The ample forested riparian buffer zones typical of streams in these regions are likely to have mitigated the effects of pesticides on stream invertebrate communities. This study provides evidence that riparian buffer regulations in the Atlantic Forest region are protecting stream ecosystems from pesticides and other agricultural stressors. Further studies are needed to determine the minimum buffer widths necessary to achieve optimal protection.

Species at Risk (SPEAR) index indicates effects of insecticides on stream invertebrate communities in soy production regions of the Argentine Pampas.

We investigated relationships among insecticides and aquatic invertebrate communities in 22 streams of two soy production regions of the Argentine Pampas over three growing seasons. Chlorpyrifos, endosulfan, cypermethrin, and lambda-cyhalothrin were the insecticides most frequently detected in stream sediments. The Species at Risk (SPEAR) pesticide bioassessment index (SPEARpesticides) was adapted and applied to evaluate relationships between sediment insecticide toxic units (TUs) and invertebrate communities associated with both benthic habitats and emergent vegetation habitats. SPEARpesticides was the only response metric that was significantly correlated with total insecticide TU values for all three averaged data sets, consistently showing a trend of decreasing values with increasing TU values (r2=0.35 to 0.42, p-value=0.001 to 0.03). Although pyrethroids were the insecticides that contributed the highest TU values, toxicity calculated based on all insecticides was better at predicting changes in invertebrate communities than toxicity of pyrethroids alone. Crustaceans, particularly the amphipod Hyalella spp., which are relatively sensitive to pesticides, played a large role in the performance of SPEARpesticides, and the relative abundance of all crustaceans also showed a significant decreasing trend with increasing insecticide TUs for two of three data sets (r2=0.30 to 0.57, p-value=0.003 to 0.04) examined. For all data sets, total insecticide TU was the most important variable in explaining variance in the SPEARpesticides index. The present study was the first application of the SPEAR index in South America, and the first one to use it to evaluate effects of pesticides on invertebrate communities associated with aquatic vegetation. Although the SPEAR index was developed in Europe, it performed well in the Argentine Pampas with only minor modifications, and would likely improve in performance as more data are obtained on traits of South American taxa, such as pesticide sensitivity and generation time.

Ten-year review of disease pattern from percutaneous renal biopsy: an experience from a paediatric tertiary renal centre in Hong Kong.

OBJECTIVE: To study the childhood renal disease pattern based on the renal biopsy histology in a local paediatric tertiary renal centre. DESIGN: Retrospective study. SETTING: Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong. PATIENTS: All patients who underwent real-time ultrasound-guided closed renal biopsy from 1 April 1997 to 31 March 2007 were included. RESULTS: A total of 209 renal biopsies were performed, 162 on native kidneys and 47 on grafts. In the native group, major indications were renal manifestations secondary to systemic diseases (34%), followed by idiopathic nephrotic syndrome (28%) and haematuria (27%). In 94% the histopathology revealed glomerular diseases. Among the primary glomerular diseases, thin glomerular basement membrane disease, immunoglobulin A nephropathy, minimal change disease, and focal segmental glomerulosclerosis accounted for most. In all, 37% of patients with steroid-resistant nephrotic syndrome had focal segmental glomerulosclerosis and its relative incidence was increased when compared to previous studies. Minimal change disease and minimal change disease with mesangial immunoglobulin M deposits accounted for the majority of steroid dependent and frequent relapsers. Among patients with isolated microscopic haematuria, 73% had thin glomerular basement membrane disease, while patients with concomitant haematuria and proteinuria had a wide variety of pathology. In the kidney graft group, acute graft dysfunction was due to acute rejection in 38% of the patients, followed by calcineurin inhibitor toxicity in 14%. Chronic allograft nephropathy caused chronic allograft dysfunction in the majority of cases. Post-transplant proteinuria was caused by recurrence of the primary renal disease in all of our patients. CONCLUSION: This study provides updated epidemiological information for childhood renal disease and a change in the pattern of disease was observed.

Adolescent twin sisters with severe acute respiratory syndrome (SARS).

A novel coronavirus-associated communicable respiratory disease, severe acute respiratory syndrome (SARS), spread worldwide after an outbreak in Guangdong Province of the People's Republic of China in November 2002. Since late February 2003, there has been an epidemic in Hong Kong involving both adult and pediatric patients. The clinical course, intensive care, and outcome of adolescent twin sisters with SARS are described. Adolescents infected with SARS may develop severe illness as adults, and close monitoring for disease progression in terms of both clinical and radiologic deterioration is warranted.

Evaluation of the efficacy of treatment of Kawasaki disease before day 5 of illness.

We evaluated the efficacy of treating Kawasaki disease earlier than Day 5 of illness with a standard dose of immunoglobulin and aspirin. We performed a case-control study of patients with Kawasaki disease admitted to Princess Margaret Hospital from 1994 to 1999. Patients with pretreatment coronary aneurysm or those treated after day 10 of illness were excluded. All patients received immunoglobulin (2 g/kg) and aspirin (80-100 mg/kg/day) until fever subsided for 48 hours. Immunoglobulin retreatment was given for persistent fever 48 hours after the first dose of immunoglobulin or recrudescent fever. The case group consisted of 15 patients who received treatment earlier than day 5 of illness, and the control group consisted of 66 patients who were treated on or after day 5. Patients' sex, age, duration of posttreatment fever, need for additional immunoglobulin, and coronary artery status were noted. Treatment efficacy was assessed by the duration of posttreatment fever and the prevalence of coronary artery aneurysms. Eighty-one patients were included in this study. There were 15 patients in the case group and 66 in the control group. No significant difference was noted in age and sex between the case and control groups. Thirty-three percent (5/15) and 8% (5/66) of the case and control groups, respectively, had persistent/ recrudescent fever 48 hours after the first dose of immunoglobulin that required retreatment ( p = 0.017). Thirteen percent (2/15) and 5% (3/66) of the case and control groups, respectively, had coronary aneurysms ( p = 0.158). Treatment of Kawasaki disease before day 5 of illness was associated with persistent/recrudescent fever that required retreatment. However, there was no significant increase in the prevalence of coronary aneurysm if retreatment was given.

Clinical presentations and outcome of severe acute respiratory syndrome in children.

Hong Kong has been severely affected by severe acute respiratory syndrome (SARS). Contact in households and health-care settings is thought to be important for transmission, putting children at particular risk. Most data so far, however, have been for adults. We prospectively followed up the first ten children with SARS managed during the early phase of the epidemic in Hong Kong. All the children had been in close contact with infected adults. Persistent fever, cough, progressive radiographic changes of chest and lymphopenia were noted in all patients. The children were treated with high-dose ribavirin, oral prednisolone, or intravenous methylprednisolone, with no short-term adverse effects. Four teenagers required oxygen therapy and two needed assisted ventilation. None of the younger children required oxygen supplementation. Compared with adults and teenagers, SARS seems to have a less aggressive clinical course in younger children.

Use of prophylactic lamivudine and mycophenolate mofetil in renal transplant recipients with chronic hepatitis B infection.

Chronic HBsAg carriers are known to have a higher risk of hepatitis-related mortality and morbidity when undergoing kidney transplantation. Immunosuppressants might flare up the infection that could be fulminating. Lamivudine and mycophenolate mofetil (MMF) have been shown to be effective in inhibiting replication of hepatitis B virus (HBV). With these two drugs, hepatitis related adverse outcome might be preventable when these patients are being transplanted. Four Chinese adolescents with chronic HBV infection were transplanted in our Department from 1999 to 2001. Immunosuppresants included prednisolone, cyclosporin A and MMF; azathioprine was not used for its potentially liver toxic effect. Prophylactic lamivudine 3 mg/kg and maximum 100 mg daily was given just before transplantation and was continued afterwards. HBV status and liver enzymes were monitored serially. Patients were followed up for 26.0 +/- 10.3 (11-34) months post-transplant and no mortality was reported. All grafts were functioning and no rejection was noted. MMF and lamivudine were well tolerated. Alanine transaminase was only transiently elevated in the first 2 months post-transplant in all patients and became normal afterwards. The patients were clinically well and liver function was normal at the last follow-up. However, HBV DNA became positive in three patients after the transplantation. YMDD mutant HBV was negative in one patient and undeterminable in the other three due to low virus load. In summary, with prophylactic lamivudine and MMF, short-term follow-up showed that renal transplant might be feasible and safe in chronic HBV carriers.

Determination of urinary and salivary cotinine using gas and liquid chromatography and enzyme-linked immunosorbent assay.

The objective of this study was to compare cotinine concentrations in urine and saliva using gas chromatography (GC), high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA). Ninety-four subjects were selected (27 smokers and 67 non-smokers) and interviewed using questionnaire. Of the non-smokers, 39 had been exposed to environmental tobacco smoke (ETS) and 28 had not been exposed to ETS. Cotinine levels among smokers were highest using all three measurements, followed by ETS exposed subjects and non-smokers. Cotinine levels in urine, using HPLC, correlated significantly with levels measured using ELISA (r=0.92) and GC-nitrogen-phosphorus detection (NPD) (r=0.92). Salivary cotinine levels measured using ELISA did not correlate significantly with either HPLC (r=0.37) or GC-NPD (r=0.33) measurements. Multiple regression models were used to adjust for age, gender, drug use and health status, and it was found that cotinine levels in urine and saliva were significantly correlated with smoking pack-year. The authors conclude that urinary cotinine concentration is a more accurate biomarker for ETS than salivary cotinine concentration.

Peroxisome proliferator-activated receptor gamma 2 Pro12Ala gene variant is strongly associated with larger body mass in the Taiwanese.

The peroxisome proliferator-activated receptor gamma 2 (PPARgamma2) has been studied extensively because of its putative role in adipocyte differentiation and insulin sensitivity. The association of the Pro12Ala and Pro115Gln PPARgamma2 gene variants with type 2 diabetes mellitus, the body mass index (BMI), and other diabetes-related phenotypes was examined in the Taiwanese population. Genotypes were determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. Allele frequencies were compared between 280 subjects with type 2 diabetes mellitus and 310 subjects without diabetes using the chi-square test. Continuous phenotype analysis was performed by multiple logistic regression adjusting for age and BMI where appropriate. There was no significant association between the Pro12Ala gene variant and type 2 diabetes; the frequency of the Ala12 allele was 0.03 in type 2 diabetics and 0.04 in nondiabetics (P = .40). The Gln115 allele was not detected in any of the cases or controls. In multiple linear regression analysis of all cases and controls combined adjusted for age, sex, and diabetic status, carriers of the Ala12 allele had a mean BMI of 25.9+/-0.5 kg/m2 (mean +/- SE), compared with 24.2+/-0.1 kg/m2 in Pro12 homozygotes (P < .001). In addition, carriers of the Ala12 allele have a 2.9 times (95% confidence interval [CI], 1.5 to 5.5) higher odds of having a BMI of at least 25 kg/m2. These results suggest that in the Taiwanese, the Pro12Ala PPARgamma2 gene variant may contribute to fat accumulation and a higher BMI independent of type 2 diabetes. These results need to be confirmed in future studies, as a linkage disequilibrium of this variant with other mutations cannot be ruled out.

Measles epidemiology and outbreak response immunization in a rural community in Peru.

Only limited data are available on the impact of measles outbreak response immunization (ORI) in developing countries. We conducted a community survey in Espindola, a rural border community in northern Peru, following a measles outbreak and subsequent ORI to study the epidemiology and impact of the outbreak and to evaluate the costs and benefits of measles ORI. During the outbreak, 150 of the 553 Espindola residents developed clinical cases of measles. Adults accounted for 44.0% of cases, and were frequently identified as primary cases. The attack rate among all susceptible people was 45.5% and was highest (61.2%) for the 16-20 year age group. Among adults, significant risk factors for developing measles included being aged 16-20 years (relative risk [RR] = 3.06, 95% CI = 2.08, 4.49) and being male (RR = 1.73, 95% CI = 1.11, 2.71). Among serologically confirmed cases, 60.7% developed diarrhoea and 32.1% pneumonia. The overall case-fatality rate was 3.3%, but reached 19.1% in the 0-23-month age group. Failure to reach children through either routine immunization or national campaigns made this community vulnerable to the severe and extensive impact of measles virus importation. The ORI campaign targeted non-measles case children aged 6 months to 15 years, regardless of their previous immunization status, and was effective in terminating this measles outbreak and in preventing morbidity, loss of livelihood and death despite the involvement of large numbers of adults in measles transmission. The last measles case occurred within 3 weeks of completing ORI. The ORI campaign, which would have cost approximately US$ 3000 in 1998, saved as many as 1155 person-days of work among 77 adults, prevented an estimated 87 cases of diarrhoea and 46 cases of pneumonia, and averted 5 deaths.

PIP: A community survey of the epidemiology and impact of measles outbreak response immunization (ORI) in Espindola, Peru. Blood specimens from 29 clinical cases having the onset of symptoms within 5 weeks to collection were tested for the anti-measles virus nucleoprotein antibody. Questionnaires were given to the head of the household and the 29 clinical cases to identify clinical symptoms an disease outcomes and to determine vaccination coverage. Attack rates, vaccine effectiveness, and predictive value positive was also calculated. Findings showed that primary cases were frequent among adults, who accounted for 44% of cases. The attack rate among all susceptible people was 45.5% and was highest among adults aged 16-20 (61.2%). For the serologically confirmed cases, 60.7% developed diarrhea and 32.1% pneumonia. Case fatality rate was 19.1% for children aged 0-23 months and 1.5% for adults aged 16-40 years. The lack of national campaigns or access to routine immunization caused the severe impact of measles virus outbreak. The ORI campaign targeted nonmeasles case children aged 6 months to 15 years regardless of immunization status, which was effective in terminating measles outbreak, morbidity, and mortality. This campaign cost approximately US$3000 and in 1998 saved 1155 person-days of work among 77 adults. It also prevented 87 diarrhea and 46 pneumonia cases and averted 5 deaths.

Secular trend in the sexual maturation of southern Chinese girls.

In 1993, a cross-sectional study of sexual maturation of normal Chinese schoolgirls was performed in Hong Kong. The aim of the study was to obtain an up-to-date reference for normal pubertal development in Chinese girls. Breast development was assessed in 3749 girls aged 7-19 y, and pubic hair rating was assessed in 3745 girls. Menstrual status was recorded in 6467 girls over 6 y of age. The median age of onset of puberty as indicated by breast stage II or above was 9.78 (95% CI 9.70-9.85) y. The median age of onset of pubic hair development was 11.64 (95% CI 11.56-11.72) y. The median age of menarche was 12.38 (95% CI 11.98-12.78) years. Percentile values for the age at which each puberty staging appeared were constructed and incorporated into the height-for-age charts. When comparison is made with similar studies done in 1962 and 1979, a significant downward secular trend in sexual maturation is observed (p < 0.01). Except for breast development the downward secular trend in sexual maturation appears to be diminishing and may be coming to a halt in the Chinese girls in Hong Kong. Their median ages of sexual maturation are now among one of the earliest medians recorded in the world population studied.

A characteristic dissection microscopy appearance of a renal biopsy of a Fabry heterozygote.

We report a 15-year-old Fabry heterozygote presenting to us with asymptomatic proteinuria. During the dissection-microscopic examination, the glomeruli exhibited a characteristic swollen, glistening and white appearance. They were swollen and bulged out from the surface of the renal core. The glomerular tufts appeared to be filled with opaque and whitish material giving them a pale white discoloration. This appearance is due to the accumulation of glycosphingolipids in visceral epithelial cells of the kidney. This feature is important for the investigation of female patients with asymptomatic proteinuria, as in two thirds of Fabry heterozygotes the characteristic skin lesions are absent, and thus heterozygous Fabry disease may not be considered. We suggest that this easily demonstrable appearance can be the first evidence for the disease and pathologists should be aware of it in future.

Transient hyperammonemia related to chemotherapy with continuous infusion of high-dose 5-fluorouracil.

Hyperammonemic encephalopathy has been reported in patients receiving chemotherapy (CT). It is characterized by abrupt alteration in mental status with markedly elevated plasma ammonium levels in the absence of obvious liver disease. This paper reports seven patients who developed transient hyperammonemia during chemotherapy. The regimens all included continuous infusion of high-dose 5-fluorouracil (5-FU). The onset of hyperammonemic encephalopathy was 1.5-4 days after the start of CT. Five cases had infection and six had prerenal azotemia at the time of hyperammonemia. After management, plasma ammonium levels all returned to the normal range within 2 days. Except for one persistent coma, status of consciousness cleared completely. The true mechanism of transient hyperammonemia is unclear. The excess production of ammonium due to metabolites of 5-FU added to precipitating factors such as infection, hypovolemia or constipation may be the explanation for transient hyperammonemia in our study.