Paracoccidioides brasiliensis protoplast production by enzymatic treatment

The action of the enzymes novozym 234, chitinase and zymolyase 20T on the yeast-like cells of Paracoccidioides brasiliensis was studied in an attempt to obtain protoplast release. Three enzyme systems were used: the first consisted of novozym 234 and chitinase plus 0.2 m phosphate buffer, 0.9 m sorbitol and 0.5 m sodium thioglycolate; the second consisted of novozym 234, chitinase, zymolyase 20T, buffer and osmotic stabilizer, with no sodium thioglycolate; the third consisted of the same enzymes as used in the second system but at twice the concentration, plus buffer and osmotic stabilizer. Protoplasts were only released from 72-hold cells cultured on solid peptone-yeast extract-glucose medium (PYG) treated with the third enzyme system. Sodium thioglycolate used as pretreatment favoured protoplast release but had no such action when added to the enzyme solution, possibly by altering the activity of the enzymes, novozym 234 in particular. The osmotic stabilizer used, 0.9 m sorbitol, was probably one of the factors, in addition to the enzymes, responsible for the cytoplasmic changes observed by transmission electron microscopy in yeast phase cells and in their protoplasts.     

Urinary nickel as bioindicator of workers' Ni exposure in a galvanizing plant in Brazil

Objectives: We measured urinary nickel (U-Ni) in ten workers (97 samples) from a galvanizing plant that uses nickel sulfate, and in ten control subjects (55 samples) to examine the association between occupational exposure to airborne Ni and Ni absorption. Methods: Samples from the exposed group were taken before and after the work shift on 5 successive workdays. At the same time airborne Ni (A-Ni) was measured using personal samplers. Ni levels in biological material and in the airborne were determined by a graphite furnace atomic absorption spectrometry validated method. In the control group the urine samples were collected twice a day, in the before and after the work shift, on 3 successive days. Results: Ni exposure low to moderate was detected in all the examined places in the plant, the airborne levels varying between 2.8 and 116.7 μg/m³ and the urine levels, from samples taken postshift, between 4.5 and 43.2 μg/g creatinine (mean 14.7 μg/g creatinine). Significant differences in U-Ni creatinine were seen between the exposed and control groups (Student's t test, P ≤ 0.01). A significant correlation between U-Ni and A-Ni (r = 0.96; P ≤ 0.001) was detected. No statistical difference was observed in U-Ni collected from exposed workers in the 5 successive days, but significant difference was observed between pre- and postshift samples. Conclusions: Urinary nickel may be used as a reliable internal dose bioindicator in biological monitoring of workers exposed to Ni sulfate in galvanizing plants regardless of the day of the workweek on which the samples are collected. Received: 28 January 1999 / Accepted: 10 July 1999     

In search of cochlear morphologic correlates for tinnitus

A correlative study was made of the cochlear pathologic features existing in the temporal bones of 83 subjects with a clinical history of tinnitus and 33 without tinnitus. None of 24 types of pathologic change assessed by light microscope occurred in more than 40% of tinnitus cases; nor was the prevalence of any of these pathologic changes significantly greater in subjects with tinnitus compared with control subjects. For five types of morphologic alteration the prevalence was significantly greater among control subjects compared with tinnitus cases, but this is interpreted cautiously because of the challenge in retrospectively selecting an appropriate control group. Under the conditions of the study, that is, using light-microscopic techniques on tissues obtained post mortem, we could not identify a pathologic correlate for tinnitus.     

Endocervical sampling by kevorkian curette or pipelle aspiration device: A randomized comparison

Objective: Our purpose was to compare two means of endocervical sampling—the Kevorkian curette and the Pipeline aspiration device (Unimar Co., Wilton, Conn.)—with respect to patient discomfort, tissue volume, and specimen adequacy for diagnosis.Study design: Fifty-two women undergoing investigation of abnormal cervical cytologic results were assigned randomly to endocervical sampling by Kevorkian or Pipeline instruments. Pain associated with the procedure was assessed by having east subject indicate her pain level on a visual analog scale. Tissue volume was graded by examination of the microscopic slides by two investigators blinded to assignment. Adequacy for diagnosis was evaluated by reviewing pathology reports.Results: Subjects having Pipeline endocervical aspiration (n = 24) had significantly lower mean (±SEM) pain scores (27 ± 5 vs 48.5 ± 7, p = 0.02) than those in whom the Kevorkian instrument was used (n = 28). However, there were no significant differences in tissue volume obtained or in proportions considered adequate for diagnosis.Conclusions: Use of the Pipelle instrument was associated with less patient discomfort that Kevorkian curettage for endocervical sampling while providing similar tissue volume and adequacy for diagnosis.     

Involvement of Escherichia coli exonuclease III and endonuclease IV in the repair of singlet oxygen-induced DNA damage

Singlet molecular oxygen (¹O₂ has been implicated in severalbiological processes that may lead to genetic damage. The relevanceof various repair pathways in plasmid inactivation mediatedby ¹O₂ was investigated. Plasmid treated with ¹O₂, chemicallygenerated, was transfected into Escherichia coli strains deficientin genes implicated in the DNA repair of oxidative damage. Theability to transform bacteria is significantly reduced in thedouble mutant xth,nfo, deficient in both exonuclease HI andendo-nuclease IV, although it was similar to wild-type cellsin single mutants. The products of these two genes are ableto cleave DNA damaged by ¹O₂ and to remove DNA polymerizationblocks from 3'-termini enerated either directly by ¹O₂ treatmentor after the action of the formami-dopyrimidine-DNA-N-glycosylase(Fpg protein). The results indicate that the exonuclease IIIand endonuclease IV participate in the excision of lethal lesionsinduced in DNA by ¹O₂     

Pharmaceutical care in primary health care: the experience of 3 Brazilian States

In the context of recent changes in the Brazilian drug supply system at the national level, mainly the deactivation of CEME (a government agency under the Ministry of Health that dealt with drug supply policy) and the increasing decentralization of activities under the Unified National Health System (SUS), three Brazilian States - Paraná, S?o Paulo, and Minas Gerais - have established programs for the distribution of essential drugs for primary health care. A nationwide program for the procurement and supply of 32 drugs for primary health care (the so-called "Basic Pharmacy Program") is currently being implemented by the Ministry of Health, to be decentralized subsequently. This article discusses the establishment of State-level drug policies for primary health care through the analysis of the three pioneering programs encompassing drug selection, procurement, storage, distribution, and use.     

Fetal and neonatal cortical adrenal function in birth asphyxia

Eighteen newborn infants, gestational age between 36 and 42 weeks with birth asphyxia were compared with 23 normal newborn infants to determine serum cortisol and dehydroepiandrosterone sulfate levels in cord blood and in venous blood samples collected 12-18 hours after birth. Both groups were similar in gestational age, birthweight, proportion of small for gestational age and large for gestational age infants, proportion of infants delivered by cesarean section with and without labor, and proportion of mothers with pre-eclampsia. There was no antenatal exposure to corticosteroid. The asphyxiated newborn infants had a significantly higher mean cord serum level of cortisol, and a significantly lower mean cord serum level of dehydroepiandrosterone sulfate than the control group. Mean serum cortisol and dehydroepiandrosterone sulfate levels collected 12-18 hours after birth were similar between both groups. It is suggested that elevated cord serum level of cortisol is related to birth asphyxia stress stimulating the adrenal definitive zone, and the low cord serum level of dehydroepiandrosterone sulfate is secondary to a transient hypoxemic-ischemic insult to the adrenal fetal zone.     

Premature acute myocardial infarction in a child with nephrotic syndrome

We report a case of acute myocardial infarction in a nephrotic child. A 7-year-old boy with a 4-year history of steroid-unresponsive nephrotic syndrome due to mesangial proliferation disease presented with acute vomiting and chest pain. An electrocardiogram showed ST elevation and pathological Q waves in leads consistent with anterior and septal myocardial infarction. Subsequent cardiac catheterization showed no evidence of atherosclerotic coronary artery disease, and thrombotic occlusion of the anterior descending coronary artery was the likely cause of the event. Myocardial scintigraphy showed extensive myocardial damage. The child had no long history of extreme hypercholesterolemia or hypertriglyceridemia. The case suggests that children with long-lasting nephrotic syndrome may be at increased risk for ischemic cardiovascular events, due to hyperlipidemia as well as a hypercoagulability state. The literature is reviewed regarding the relationship between nephrotic syndrome and the incidence of ischemic heart disease. Received: 2 May 2001 / Revised: 31 October 2001 / Accepted: 18 November 2001     

Metabolism of quercetin and kaempferol by rat hepatocytes and the identification of flavonoid glycosides in human plasma

1. The metabolism of the flavonoids quercetin and kaempferol by rat hepatocytes was investigated using liquid chromatography coupled with electrospray mass spectrometry (LC-ESI MS). Quercetin and kaempferol were extensively metabolized (98.8 +/- 0.1% and 81.0 +/- 5.1% respectively, n = 4), with four glucuronides of quercetin and two of kaempferol being detected after incubation. 2. The glucuronides of quercetin and kaempferol formed upon incubation with rat hepatocytes were identified as the same ones formed after incubation with the UDP-glucuronosyltransferase isoform UGT1A9. 3. In addition, plasma samples from human volunteers taken after consumption of capsules of Ginkgo biloba, a plant rich in flavonoid glycosides, were analysed by LC-MS for the presence of flavonoid glucuronides and flavonoid glycosides. Reported is evidence for the presence of flavonoid glycosides in samples of plasma. 4. The results suggest that UGT1A9 is a key UDP-glucuronosyltransferase isoform for the metabolism of flavonoids, and that absorption of intact flavonoid glycosides is possible.