Diagnostic value of copper parameters to predict growth of suckling calves grazing native range in Argentina

A study was conducted to evaluate the predictive diagnostic value of different copper (Cu) parameters as indicators of average daily gain (ADG) in growing calves. The effects in calves of cow Cu supplementation in the last one-third gestation period were also evaluated. Five supplementation trials, with a total of 300 calves, were carried out. Two groups of 30 calves were randomly assigned to each trial, one group was parenterally supplemented (SG) and the other was not supplemented (NSG). Trials began when calves were three-month-old and ended at weaning time. At each sampling calves were weighed and blood was taken to determine Cu concentrations in plasma, Whole Blood (WB), Red Cells (RC) and Packed Cell Volume (PCV). Liver samples from six animals of each group were taken both at the beginning and at the end of the trial. In two trials the mothers of the SG received Cu supplementation at the last one- third gestation period. Four of the five trials exhibited low ADG in the NSGs. In these groups, plasma Cu concentration decreased rapidly before low ADG was detected, which occurred with values remaining below 25µg/dl. The decrease of RC Cu concentration was considerably slow. WB showed an intermediate position. PCV in the SGs was higher than in the NSGs in all trials. Cow supplementation was insufficient to generate a liver storage able to last after calves reached the 3 months of age. These data could be useful to predict the risk of low ADG in grazing calves.

Plasma metanephrines: a novel and cost-effective test for pheochromocytoma

Pheochromocytomas are rare chromaffin cell tumors that nevertheless must be excluded in large numbers of patients who develop sustained or episodic hypertension as well as in many others with suggestive symptoms or with a familial history of pheochromocytoma. Diagnosis of pheochromocytoma depends importantly on biochemical evidence of excess catecholamine production by a tumor. Imperfect sensitivity and specificity of commonly available biochemical tests and the low incidence of the tumor among the tested population mean that considerable time and effort can be expended in confirming or ruling out pheochromocytoma in patients where the tumor is suspected. Measurements of plasma free metanephrines provide a superior test compared to other available tests for diagnosis of pheochromocytoma. In particular, the high sensitivity of plasma free metanephrines means that a normal test result reliably excludes all but the smallest of pheochromocytomas so that no other tests are necessary. Measurements of plasma free metanephrines, when systematically combined with other diagnostic procedures outlined in this review, provide a more efficient, reliable and cost-effective approach for diagnosis of pheochromocytoma than offered by previously available approaches.

Salivary cortisol as a tool for physiological studies and diagnostic strategies

Salivary cortisol is an index of plasma free cortisol and is obtained by a noninvasive procedure. We have been using salivary cortisol as a tool for physiological and diagnostic studies, among them the emergence of circadian rhythm in preterm and term infants. The salivary cortisol circadian rhythm in term and premature infants was established between 8 and 12 postnatal weeks. In the preterm infants the emergence of circadian rhythm was parallel to the onset of sleep rhythm. We also studied the use of salivary cortisol for screening for Cushing's syndrome (CS) in control and obese outpatients based on circadian rhythm and the overnight 1 mg dexamethasone (DEX) suppression test. Salivary cortisol was suppressed to less than 100 ng/dl after 1 mg DEX in control and obese patients. A single salivary cortisol measurement at 23:00 h and again after 1 mg DEX above the 90th percentile of the obese group values had sensitivity and specificity of 93 and 93% (23:00 h), and 91 and 94% (after DEX), respectively. The sensitivity improved to 100% when we combined both parameters. We also studied 11 CS children and 21 age-matched primary obese children for whom salivary cortisol sensitivity and specificity were 100/95% (23:00 h), and 100/95% (1 mg DEX), respectively. Similar to adults, sensitivity and specificity of 100% were obtained by combining 23:00 h and 1 mg DEX. The measurement of salivary cortisol is a useful tool for physiological studies and for the diagnosis of CS in children and adults on an outpatient basis.

Diagnostic leaf to evaluate the nutritional status of Jatropha

ABSTRACT The analytical determination of nutrient levels in recently mature leaves in order to diagnose nutritional status is based on the fact that leaves are metabolically active and more sensitive to variation in nutrients of the soil. In most of cases, there is a direct well known between foliar content and the development and yield of the plant. However, for a more accurate interpretation, it is essential to establish the index leaf. There are few published studies about Jatropha with contrasting results. In order to establish the index leaf, in adult plants, the macronutrient levels were evaluated in samples collected in experimental plots, in which doses of nitrogen and phosphorus were applied, in two parts of the floral branches (in the top and in the middle thirds); and in three positions of leaves of the floral branch (between the 1st and 3rd, 6th and 8th, and 13th and 15th leaves below the inflorescence). The location of the leaf on the plant significantly affects nutrient contents. Nitrogen, phosphorus, potassium and sulfur tend to have higher concentration in young tissues. Calcium and magnesium showed higher levels in the basal leaves of floral branches. Samples collected in the top third of plants (between the 6th and 15th leaves of the floral branch) are more sensitive to variations of nitrogen and phosphorus fertilization. Therefore, we indicate the 6th to 15th leaves of the top third plants as index leaves estimate nutritional status of Jatropha.

Schizophrenia in males of cognitive performance: discriminative and diagnostic values

OBJECTIVE: To evaluate the discriminative and diagnostic values of neuropsychological tests for identifying schizophrenia patients. METHODS: A cross-sectional study with 36 male schizophrenia outpatients and 72 healthy matched volunteers was carried out. Participants underwent the following neuropsychological tests: Wisconsin Card Sorting test, Verbal Fluency, Stroop test, Mini Mental State Examination, and Spatial Recognition Span. Sensitivity and specificity estimated the diagnostic value of tests with cutoffs obtained using Receiver Operating Characteristic curves. The latent class model (diagnosis of schizophrenia) was used as gold standard. RESULTS: Although patients presented lower scores in most tests, the highest canonical function for the discriminant analysis was 0.57 (Verbal Fluency M). The best sensitivity and specificity were obtained in the Verbal Fluency M test (75 and 65, respectively). CONCLUSIONS: The neuropsychological tests showed moderate diagnostic value for the identification of schizophrenia patients. These findings suggested that the cognitive impairment measured by these tests might not be homogeneous among schizophrenia patients.

Body mass index for predicting hyperglycemia and serum lipid changes in Brazilian adolescents

OBJECTIVE: To determine the best cut-offs of body mass index for identifying alterations of blood lipids and glucose in adolescents. METHODS: A probabilistic sample including 577 adolescent students aged 12-19 years in 2003 (210 males and 367 females) from state public schools in the city of Niterói, Southeastern Brazil, was studied. The Receiver Operating Characteristic curve was used to identify the best age-adjusted BMI cut-off for predicting high levels of serum total cholesterol (>150mg/dL), LDL-C (>100mg/dL), serum triglycerides (>100mg/dL), plasma glucose (>100mg/dL) and low levels of HDL-C (< 45mg/dL). Four references were used to calculate sensitivity and specificity of BMI cut-offs: one Brazilian, one international and two American. RESULTS: The most prevalent metabolic alterations (>50%) were: high total cholesterol and low HDL-C. BMI predicted high levels of triglycerides in males, high LDL-C in females, and high total cholesterol and the occurrence of three or more metabolic alterations in both males and females (areas under the curve range: 0.59 to 0.67), with low sensitivity (57%-66%) and low specificity (58%-66%). The best BMI cut-offs for this sample (20.3 kg/m² to 21.0 kg/m²) were lower than those proposed in the references studied. CONCLUSIONS: Although BMI values lower than the International cut-offs were better predictor of some metabolic abnormalities in Brazilian adolescents, overall BMI is not a good predictor of these abnormalities in this population.

Active immunization against hepatitis B virus (HBV) with low-doses of plasma-derived vaccine by intradermal route

Schedule for vaccination against HBV infection has usually been based on three separate injections of 20 meg of the vaccine by intramuscular route. One of the main shortcomings to its use in large scale programs has been its high cost. Ninety out of 300 health workers were submitted to three injections of 2 meg of plasma-derived vaccine (PDV) by intradermal (ID) route on days 0, 30, and 180. Anti-HBs was detected in 74 (82.2%) after the second dose and in 80 (88.9%) after the third dose, a non-significant difference. However, levels above 10 times the cut-off were observed in 29 (32.2%) and 77 (85.5%), respectively (p < 0.001). The results showed that a low-dose schedule is effective when used in health workers and should be tried with other risk groups.

Epidemiological survey of Trypanosoma cruzi infection in North-Eastern Brazil using different diagnostic methods

A survey of the prevalence of Trypanosoma cruzi infection was carried out in Oitis, a small community in the State of Piaui, Brazil. Two hundred and sixty five individuals were screened by microscopic examination, hémoculture, indirect immunofluorescence (IFA), enzyme-linked immunosorbent assay (ELISA), and competitive enzyme-linked immunosorbent assay (C-ELISA) using the monoclonal antibody TCF87 against to a 25kd T. cruzi antigen. Seropositivity was 14.3% by the IFA test, 14.7% by ELISA, and 13.2% by C-ELISA. The C-ELISA using the TCF87 monoclonal antibody seems to be applicable in serodiagnosis of Chagas' disease.

Acute schistosomiasis: clinical, diagnostic and therapeutic features

Three distinct syndromes caused by schistosomiasis have been described: cercarial dermatitis or swimmer's itch, acute schistosomiasis or Katayama fever, and chronic schistosomiasis. Complications of acute schistosomiasis have also been reported. The absence of a serological marker for the acute stage has hindered early diagnosis and treatment. Recently, an ELISA test using KLH (keyhole limpet haemocyanin) as antigen, has proved useful in differentiating acute from chronic schistosomiasis mansoni. Clinical and experimental evidence indicate that steroids act synergistically with schistosomicides in the treatment of Katayama syndrome. In this paper, clinical, diagnostic and therapeutic features of acute schistosomiasis are updated.

Nocardia infection in renal transplant recipient: diagnostic and therapeutic considerations

In the present report the authors discuss the diagnostic difficulties, therapeutic measures and the clinical course of Nocardia infection which occurred among renal transplant recipients at the University Hospital of the Faculty of Medicine of Ribeirão Preto, University of São Paulo (UH-FRP), from 1968 to 1991. Among 500 individuals submitted to renal transplant, 9 patients developed Nocardiosis at varying times after transplant (two months to over two years). All the patients had pulmonary involvement and their most common symptoms were fever, cough and pleural pain. Dissemination of the process is common and three patients presented cutaneous abscesses, four CNS involvement and one had pericarditis due to Nocardia. The diagnostic is quite difficult since there is no specific clinical picture, concomitant infections are frequent and the microorganism presents slow growth in culture (ranging from four to forty days, in our experience). In this report, three cases were only diagnosed by necropsy. The treatment of choice is a combination of Sulfamethoxazole and Trimethoprim (SMX-TMP). In the present series, overall mortality was 77% (7 cases) and in five of the patients who died the diagnosis was late. All the patients who had CNS involvement died.

The diagnostic importance of species specific and cross-reactive components of Taenia solium, Echinococcus granulosus, and Hymenolepis nana

Sera from patients infected with Taenia solium, Hymenolepis nana and Echinococcus granulosus were tested against homologous and heterologous parasite antigens using an ELISA assay, and a high degree of cross-reactivity was verified. To identify polypeptides responsible for this cross reactivity, the Enzyme Linked Immunoelectro Transfer Blot (EITB) was used. Sera from infected patients with T.solium, H.nana, and E.granulosus were assessed against crude, ammonium sulphate precipitated (TSASP), and lentil-lectin purified antigens of T.solium and crude antigens of.H.nana and E.granulosus. Several bands, recognized by sera from patients with T.solium, H.nana, and E.granulosus infections, were common to either two or all three cestodes. Unique reactive bands in H.nana were noted at 49 and 66 K-Da and in E.granulosus at 17-21 K-Da and at 27-32 K-Da. In the crude cysticercosis extract, a specific non glycoprotein band was present at 61-67 K-Da in addiction to specific glycoprotein bands of 50, 42, 24, 21, 18, 14, and 13 K-Da. None of the sera from patients with H.nana or E.granulosus infection cross reacted with these seven glycoprotein bands considered specific for T.solium infection.

Plasma levels of tumor necrosis factor-alpha in patients with visceral leishmaniasis (Kala-Azar). Association with activity of the disease and clinical remisson following antimonial therapy

Evaluation of TNF-alpha in patients with Kala-azar has drawn increasing interest due to its regulatory role on the immune system, in addition to its cachetizing activity. The objective of this study was to examine the association between plasma levels of TNF-alpha, measured by immunore-activity (ELISA) and bioactivity (cytotoxicity assay with L-929 cells), and clinical manifestations of visceral leishmaniasis. Plasma samples from 19 patients with Kala-azar were obtained before, during and at the end of antimonial therapy. TNF-alpha determinations was done by using the cytotoxicity assay (all patients) and the enzyme-linked immunoassay (ELISA - 14 patients). A discrepancy between results obtained by ELISA and cytotoxicity assay was observed. Levels of circulating TNF-alpha, assessed by ELISA, were higher in patients than in healthy controls, and declined significantly with improvement in clinical and laboratory parameters. Plasma levels before treatment were 124.7 ± 93.3 pg/ml (mean ± SD) and were higher than at the end of therapy 13.9 ± 25.1 pg/ml (mean ± SD) (p = 0.001). In contrast, plasma levels of TNF-alpha evaluated by cytotoxicity assay did not follow a predicted course during follow-up. Lysis, in this case, might be not totally attributed to TNF-alpha. The discrepancy might be attributed to the presence of factor(s) known to influence the release and activity of TNF-alpha.

Relationship between acute diarrhoea and low plasma levels of vitamin A and retinol binding protein

The objective of this study was to assess vitamin A status and association between acute diarrhoea and plasma levels of vitamin A through cross-sectional comparison in children. Plasma vitamin A was measured by colorimetric method of Neeld & Pearson and RBP by radial immunodiffusion technique. Seventy eight children (aged 18-119 months), 26 with current history of diarrhoea and 52 children as controls (outpatient from the Santa Casa de Misericórdia Hospital in metropolitan area of São Paulo City, Brazil) were studied. Children with history of diarrhoea showed significant low levels (mean ± s.e.) as compared to controls, vitamin A (15.87 ± 1.4 µg/dl vs. 21.14 ± 1.15 µg/dl, p < 0.007) and RBP (1.70 ± 0.2 mg/dl vs. 2.52 ±0.11 mg/dl). Multivariate logistic regression adjusted by sex, age, nutritional status and mother education revealed association between diarrhoea and inadequate levels of vitamin A and RBP.

Clinical and diagnostic aspects of intestinal microsporidiosis in HIV-infected patients with chronic diarrhea in Rio de Janeiro, Brazil

The objectives of this study were to determine both the prevalence of microsporidial intestinal infection and the clinical outcome of the disease in a cohort of 40 HIV-infected patients presenting with chronic diarrhea in Rio de Janeiro, Brazil. Each patient, after clinical evaluation, had stools and intestinal fragments examined for viral, bacterial and parasitic pathogens. Microsporidia were found in 11 patients (27.5%) either in stools or in duodenal or ileal biopsies. Microsporidial spores were found more frequently in stools than in biopsy fragments. Samples examined using transmission electron microscopy (n=3) or polymerase chain reaction (n=6) confirmed Enterocytozoon bieneusi as the causative agent. Microsporidia were the only potential enteric pathogens found in 5 of the 11 patients. Other pathogens were also detected in the intestinal tract of 21 patients, but diarrhea remained unexplained in 8. We concluded that microsporidial infection is frequently found in HIV infected persons in Rio de Janeiro, and it seems to be a marker of advanced stage of AIDS.