Short isocapnic hyperoxia affects indices of vascular remodeling and intercellular adhesion molecules in healthy men.

In preparation for tracheal intubation during induction of anesthesia, the patient may be ventilated with 100% oxygen. To investigate the impact of acute isocapnic hyperoxia on endothelial activation and vascular remodeling, ten healthy young men (24±3 years) were exposed to 5-min normoxia (21% O2) and 10-min hyperoxia trials (100% O2). During hyperoxia, intercellular adhesion molecules (ICAM-1) (hyperoxia: 4.16±0.85 vs normoxia: 3.51±0.84 ng/mL, P=0.04) and tissue inhibitor matrix metalloproteinase 1 (TIMP-1) (hyperoxia: 8.40±3.84 vs normoxia: 5.73±2.15 pg/mL, P=0.04) increased, whereas matrix metalloproteinase (MMP-9) activity (hyperoxia: 0.53±0.11 vs normoxia: 0.68±0.18 A.U., P=0.03) decreased compared to the normoxia trial. We concluded that even short exposure to 100% oxygen may affect endothelial activation and vascular remodeling.

Short isocapnic hyperoxia affects indices of vascular remodeling and intercellular adhesion molecules in healthy men

In preparation for tracheal intubation during induction of anesthesia, the patient may be ventilated with 100% oxygen. To investigate the impact of acute isocapnic hyperoxia on endothelial activation and vascular remodeling, ten healthy young men (24±3 years) were exposed to 5-min normoxia (21% O2) and 10-min hyperoxia trials (100% O2). During hyperoxia, intercellular adhesion molecules (ICAM-1) (hyperoxia: 4.16±0.85 vs normoxia: 3.51±0.84 ng/mL, P=0.04) and tissue inhibitor matrix metalloproteinase 1 (TIMP-1) (hyperoxia: 8.40±3.84 vs normoxia: 5.73±2.15 pg/mL, P=0.04) increased, whereas matrix metalloproteinase (MMP-9) activity (hyperoxia: 0.53±0.11 vs normoxia: 0.68±0.18 A.U., P=0.03) decreased compared to the normoxia trial. We concluded that even short exposure to 100% oxygen may affect endothelial activation and vascular remodeling.

Discriminating between virilizing ovary tumors and ovary hyperthecosis in postmenopausal women: clinical data, hormonal profiles and image studies.

BACKGROUND: The presence of virilizing signs associated with high serum androgen levels in postmenopausal women is rare. Virilizing ovarian tumors (VOTs) and ovarian stromal hyperthecosis (OH) are the most common etiologies in virilized postmenopausal women. The differential diagnosis between these two conditions is often difficult. OBJECTIVE: To evaluate the contribution of clinical features, hormonal profiles and radiological studies to the differential diagnosis of VOT and OH. DESIGN: A retrospective study. SETTING: A tertiary center. MAIN OUTCOME MEASURES: Clinical data, hormonal status (T, E2, LH and FSH), pelvic images (transvaginal sonography and MRI) and anatomopathology were reviewed. PATIENTS: Thirty-four postmenopausal women with a diagnosis of VOT (13 women) and OH (21 women) were evaluated retrospectively. RESULTS: Clinical signs of hyperandrogenism were more prevalent in the VOT group than the OH group. Although the VOT group showed higher T and E2 levels and lower gonadotropin levels than the OH group, a great overlap occurred among the hormone levels. A pelvic MRI provided an accurate differentiation of these two conditions. CONCLUSION: In this group of patients, the main features contributing to the differential diagnosis of VOT and OH were serum levels of testosterone and gonadotropins and the presence of an ovarian nodule identified on the MRI. Although the association of clinical, hormonal and radiological features contributes to the differential diagnosis of these two conditions, histopathological analysis remains the gold standard for the diagnosis of ovarian hyperandrogenism in postmenopausal women.

Prooxidant activity of norbixin in model of acute gastric ulcer induced by ethanol in rats.

Free radicals and oxidative stress play a central role in gastric injuries caused by ethanol (EtOH). Antioxidant strategies to counteract EtOH toxicity are highly desirable. Norbixin (NBIX) is a carotenoid with antioxidant potential largely used in the food industry. This study evaluated the NBIX effects in a model of gastric ulcer induced by EtOH in rats. Male Wistar rats received NBIX doses of 0, 10, and 25 mg/kg by gavage 1 h after EtOH administration (0 or 75% solution, 1 mL/200 g of animal). The animals were euthanized 1 h after the NBIX administration, and their stomachs were removed for macroscopic and histopathological analyses, quantification of nonprotein sulfhydryl (NPSH) groups, lipid peroxidation (LPO) levels, and catalase (CAT) activity determination. NBIX increased LPO in gastric mucosa and caused CAT inhibition and NPSH depletion in EtOH-treated animals. Results showed that NBIX did not protect gastric tissue against EtOH damage, and this could be associated to a prooxidant effect.

Assessment of extended-spectrum ß-lactamase, KPC carbapenemase and porin resistance mechanisms in clinical samples of Klebsiella pneumoniae and Enterobacter spp.

The emergence and spread of resistance mechanisms in Gram-negative bacilli has complicated the treatment of serious nosocomial infections. Current automated systems for detection of Klebsiella pneumoniae carbapenemase (KPC)-producing isolates are unreliable. One possible straightforward alternative method is evaluation of ertapenem resistance. However, the accuracy of this method is affected by other resistance mechanisms such as AmpC gene expression or extended-spectrum ß-lactamase production associated with porin loss. This study included 128 samples of K. pneumoniae and Enterobacter spp. that were non-susceptible to ertapenem. The disk diffusion and Etest method were applied to determine susceptibility to imipenem, meropenem and ertapenem. Isolates exhibiting intermediate or complete resistance to ertapenem were evaluated for resistance mechanisms. bla(TEM), bla(SHV), bla(CTX-M), bla(CTX-M-2) and bla(KPC) genes were tested for by PCR, and the presence of outer membrane protein was investigated by dot-blot assay. bla(TEM) was detected in 52.9% and 10.3%, bla(SHV) in 29.4% and 0.94%, bla(CTX-M) in 41.4% and 1.9% and bla(CTX-M-2) in 23.5% and 1.9% of K. pneumoniae and Enterobacter cloacae isolates, respectively. The bla(KPC) gene was present in 12.6% of Enterobacter spp. isolates. OmpC and OmpF were present in 6.6% of E. cloacae isolates. These results indicate that several resistance mechanisms contribute to potential therapeutic failure of carbapenem therapy and point to the need for better detection methods and surveillance strategies.

Effect of Vernonia cognata on oxidative damage induced by ethanol in rats.

Free radicals production and oxidative stress play a central role in injuries caused by ethanol (EtOH) on gastric mucosal. Thus, strategies to counteract EtOH toxicity are highly desirable. This study was aimed at evaluating whether Vernonia cognata extract would reduce EtOH effects in rats. Rats received Vernonia cognata extract (0, 1 and 2 g/kg bw, by gavage) 1 hour after EtOH had been administered (0 or 70%, 0.5 mL/100 g bw, by gavage) and were killed 1 hour after Vernonia cognata extract administration. The stomach was removed for macroscopic and histopathological evaluation, as well as, oxidative stress markers such as lipoperoxidation (LPO) and non-protein thiol groups (NPSH) levels and catalase (CAT) activity. EtOH acute exposure increased LPO and decreased NPSH levels and CAT activity along with macroscopic and microscopic lesions in gastric tissue, confirming the involvement of oxidative stress in EtOH toxicity. Vernonia cognata extract attenuated oxidative and histopathological features induced by EtOH at all evaluated doses. Moreover, both studied doses of Vernonia cognata extract caused an increase in NPSH levels per se. However, only the dose of 2 g/kg reverted all macroscopic changes caused by EtOH toxicity. The protective effect of the extract could be attributed to antioxidant molecules present in the extract, such as flavonoids and phenolic acids, which were quantified by high performance liquid chromatography (HPLC). Thus, an antioxidant effect of the extract leads to a protection on gastric tissue. Our results indicate that Vernonia cognata hydroethanolic extract could have a beneficial role against EtOH toxicity by preventing oxidative stress and gastric tissue injury.

Effect of astaxanthin on kidney function impairment and oxidative stress induced by mercuric chloride in rats.

Reactive oxygen species are implicated as mediators of tissue damage in the acute renal failure induced by inorganic mercury. Astaxanthin (ASX), a carotenoid with potent antioxidant properties, exists naturally in various plants, algae, and seafoods. This paper evaluated the ability of ASX to prevent HgCl(2) nephrotoxicity. Rats were injected with HgCl(2) (0 or 5 mg/kg b.w., sc) 6h after ASX had been administered (0, 10, 25, or 50mg/kg, by gavage) and were killed 12h after HgCl(2) exposure. Although ASX prevented the increase of lipid and protein oxidation and attenuated histopathological changes caused by HgCl(2) in kidney, it did not prevent creatinine increase in plasma and delta-aminolevulinic acid dehydratase inhibition induced by HgCl(2). Glutathione peroxidase and catalase activities were enhanced, while superoxide dismutase activity was depressed in HgCl(2)-treated rats when compared to control and these effects were prevented by ASX. Our results indicate that ASX could have a beneficial role against HgCl(2) toxicity by preventing lipid and protein oxidation, changes in the activity of antioxidant enzymes and histopathological changes.

Indium square root 7 x square root 3 on Si(111): a nearly free electron metal in two dimensions.

We present measurements of the Fermi surface and underlying band structure of a single layer of indium on Si(111) with square root 7 x square root 3 periodicity. Electrons from both indium valence electrons and silicon dangling bonds contribute to a nearly free, two-dimensional metal on a pseudo-4-fold lattice, which is almost completely decoupled at the Fermi level from the underlying hexagonal silicon lattice. The mean free path inferred from our data is quite long, suggesting the system might be a suitable model for studying the ground state of two-dimensional metals.

Longitudinal differentiation in Melipona mandacaia (Hymenoptera, Meliponini) chromosomes.

Melipona mandacaia is a stingless bee endemic to northeast Brasil. We describe the M. mandacaia karyotype using C-banding technique. fluorochrome staining and treatment with restriction enzymes and discuss the position of this species in the context of the phylogeny of the genus. Melipona mandacaia has 2n = 18 (14 SM + 2 M + 2 A). Heterochromatin was detected in the pericentromeric region of pairs 1, 2 and 8 and in the form of small blocks in the remaining pairs. Staining with base-specific fluorochromes showed that this heterochromatin was rich AT (QM and DAPI), except in the region corresponding to the NOR which was rich GC (CMA3) and was cleaved by the HaeIII enzyme. Melipona mandacaia is a member of Group I Melipona. Treatment with DraI/Giemsa discloses a larger number of bands than treatment with DraI/QM. Pre-cleavage with DraI gave rise to a larger number of bands following QM staining; a circumstance evidently due to a removal of the DNA-protein complex that prevented the association of the fluorochrome with AT-rich DNA. The results highlight the complex nature of heterochromatin.

Synthesis and structural study of substituted thioxothiazolidinones and thioxoimidazolidinones.

A new set of derivative thioxothiazolidinones and thioxoimidazolidinones 3,5-dissubstituted has been synthesized with satisfactory yield from the condensation Knoevenagel type between benzaldéhydes and 4-thioxothiazolidin-2-one, 2-thioxothiazolidin-4-one and 1-méthyl-2-thioxoimidazolidin-4-one compounds following by N-alkylation with aryl or acyl halides. The physico-chemical properties of the 5-benzylidene-3-[2-(4-chlorophenyl)-2-oxoethyl]-2 (or 4)-thioxothiazolidin-4 (or 2)-ones and 5-benzylidene-1-methyl-2-thioxoimidazolidin-4-ones synthesized have been described.

Silver staining of nucleolar organizer regions (NOR) in some species of Hymenoptera (bees and parasitic wasp) and Coleoptera (lady-beetle).

Adaptations of the nucleolar organizer regions (NOR) banding technique using precipitation of silver salts significantly improved the NOR characterization of some species of hymenopterans and one coleopteran. The bee Melipona marginata (2n = 18) showed one metacentric pair of chromosomes with a NOR in the pericentromeric position. The parasitic wasp Mellitobia australica (2n = 12) also showed one metacentric pair with a strongly Ag-positive NOR. The male lady-beetle Cycloneda sanguinea (2n = 18 + Xy(p)) displayed a NOR on a pair of acrocentric autosomes. In the male Euglossa sp. (a haplodiploid species) (n = 21) the NOR were multiple, and occurred in five chromosomes. In the bee Plebeia sp. 1 (2n = 34) the NOR seemed restricted to one of the homologues of a metacentric pair. The systematic advances brought out by using this technique in the context of current theories of karyotypic evolution of these taxa are described and discussed.

Effect of chemically induced propionic acidemia on neurobehavioral development of rats.

High levels of propionic acid (PPA) comparable to those of human propionic acidemia were achieved in blood (1-5 mmol/l) and brain (1 micromol/g) of rats by administering saline-buffered propionate (pH 7.4) subcutaneously twice a day from the 6th to the 28th day of life. PPA doses ranged from 1.44 to 1.92 micromol/g body weight as a function of animal age. Control rats were treated with saline in the same volumes. Growth and development of physical landmarks were assessed by monitoring the following parameters daily: body weight, upper incisor eruption, eye opening, and hair coat. Development of some reflexes was also monitored, and a specific subset of motor skills was evaluated at days 14 and 21 of life by the free-fall righting test and the spontaneous alternation test. Chronic PPA administration had no effect on body weight, cerebral cortex weight, or cerebellum weight, but caused slight but significant delays in the day of appearance of hair coat and eye opening, indicating an effect of PPA on the development of physical parameters. Free-fall righting was impaired in PPA-treated animals. On the other hand, PPA administration had no effect on the performance of the animals in the spontaneous alternation tests. Long-term effects of early PPA administration were investigated by assessing animal performance in an aversive task (two-way shuttle avoidance task) and in a nonaversive (open-field task) behavioral task at 60 days of age. PPA-treated rats did not habituate to the open field, and presented a lack of retention of the shuttle-avoidance task. Our results suggest that early postnatal PPA administration to rats alters normal development and induces long-term behavioral deficits in aversive and nonaversive tasks.

Inhibition of mitogen-activated proliferation of human peripheral lymphocytes in vitro by propionic acid.

Recurrent infections are common features in patients affected by propionic acidaemia (McKusick 232000) and methylmalonic acidaemia (McKusick 251000). Since these disorders are biochemically characterized by tissue accumulation of propionic acid and methylmalonic acid respectively, it is possible that these compounds may act as immunosuppressants. We therefore investigated the effect of propionate and methylmalonate on cellular growth of human peripheral lymphocytes stimulated in vitro by phytohaemagglutinin, concanavalin A and pokeweed mitogen, a recognized test of cellular immunocompetence. Lymphocytes were cultured in flat-bottomed 96-well microplates at 37 degrees C for 96 h (phytohaemagglutinin and concanavalin A) or 144 h (pokeweed mitogen) in the presence of one mitogen at different concentrations and of one acid added at doses of 1.0, 2.5 or 5.0 mM. Cell blastogenesis was measured by the incorporation of tritiated thymidine into cellular DNA and compared with that of identical cultures with no acid added (controls). A consistent and progressive inhibitory effect of propionic acid with increasing concentrations in culture was identified with all mitogens and was more pronounced with pokeweed mitogen. Lymphocyte blastogenesis was not altered in the presence of methylmalonic acid. The effect of propionate was observed only when the drug was added at the beginning (phytohaemagglutinin-activated) or until 24 h (concanavalin A- and pokeweed mitogen-activated) of culture. The viability of lymphocytes after treatment with the drug, as assessed by the Trypan Blue exclusion test, revealed no change when compared with the same untreated lymphocytes, indicating no lymphocytotoxic activity. In conclusion, propionic acid, which accumulates in tissues of patients with propionic acidaemia, causes 'in vitro' immunosuppression, which may be related to the recurrent infections characteristic of these patients.

[The knowledge of neurological changes in patients with AIDS]. / Contribuição ao conhecimento das alterações neurológicas em pacientes com SIDA.

We performed a retrospective study of 154 patients with AIDS that presented lesions of the nervous system at necroscopic examination. Necropsies were performed in the Hospital Universitario Antonio Pedro (Niteroi, Brazil). We emphasize epidemiologic and clinical data, neuropathologic findings, evolution time, and anatomo-clinical correlation. Data obtained can contribute in the definition of consequences of neurologic symptoms and signs for early diagnosis and best prognosis in AIDS.

Massive hemoptysis in Takayasu's arteritis during pregnancy.

Takayasu's arteritis is an uncommon condition affecting predominantly young women. Because the disorder affects women in childbearing age, it may be recognized the first time during pregnancy. Various cardiovascular events may occur in the perinatal period. We describe a patient with Takayasu's arteritis who presented with massive hemoptysis. To our knowledge, this manifestation has not been documented previously.

Lung cancer in the young.

Lung cancer is uncommon in individuals age 40 or less. We reviewed the Cancer Registry files of the Ben Taub General Hospital (Houston, TX) from 1971 to 1989 and identified 1678 patients with a documented diagnosis of lung cancer. Among these 1678 patients, 50 (2.98%) were age 40 or less. Thirty-five (70%) of the 50 patients were men and 15 (30%) were women. Their median age was 37 (range of 24 to 40). A smoking history was available in 37 patients. Thirty-five (94.5%) of the 37 patients who were smokers had a > 20-pack per year history of smoking. Four patients were intravenous drug abusers, and one of these four tested positive for the immunodeficiency virus. Twenty-seven (54%) had adenocarcinoma, eight (16%) had squamous cell carcinoma, and six (12%) had other nondescript, nonsmall-cell carcinoma types. In contrast, the proportion of adenocarcinoma for the (all-age) group of 1678 patients with lung cancer was 28.2%. This difference in the proportion of adenocarcinoma between the two age groups was statistically significant (Pearson's Chi 2, 13.7039, p < 0.0005). Thirty-one (77.5%) of the 50 patients had unresectable disease at diagnosis (12 had stage IIIb and 19 had stage IV). The median survival from diagnosis was 26 weeks. These findings suggest that (1) smoking is an important risk factor for this subset of young patients, (2) the proportion of adenocarcinoma is higher in the young compared with the entire group of lung cancer patients, which included patients of all ages, and (3) young patients tend to present with advanced disease at diagnosis, resulting in an extremely poor survival.

Bioequivalence assessment of diltiazem preparations by means of discriminant analysis of data from solid-phase extraction and liquid chromatography.

A solid-phase extraction technique for sample clean-up coupled with a new LC procedure is reported for the assay of diltiazem in plasma. The use of disposable cartridges provides selective extraction and easy automation. A new LC system based on LiChrospher RP 60 Select B columns is described. For routine analysis, the procedure provides a rapid simultaneous clean-up of several samples prior to chromatography and reproducible recoveries over a concentration range of 10-800 ng. The procedure was used to analyse the plasma samples from a bioequivalence study of three commercial diltiazem preparations. The pharmacokinetic parameters in 12 healthy male volunteers were determined and the assessment of bioequivalence was conducted by discriminant analysis.

Erysipelothrix endocarditis with previous cutaneous lesion: report of a case and review of the literature.

This report describes the first documented case of Erysipelothrix rhusiopathiae endocarditis in Latin America. The patient was a 51-years-old male, moderate alcoholic, with a previous history of aortic failure. He was used to fishing and cooking as a hobby and had his left hand wounded by a fish-bone. The disease began with erysipeloid form and developed to septicemia and endocarditis. He was treated with antibiotics and surgery for aortic valve replacement. There are only 46 cases of E. rhusiopathiae endocarditis reported to date. The authors wonder if several other cases might go unreported for lack of microbiological laboratorial diagnosis.

[Bioavailability of 3 formulations of diltiazem]. / Estudo da biodisponibilidade de três formulações de diltiazem.

The plasma concentration profiles of diltiazem were determined in three series of twelve male volunteers to whom a single doses of 60 mg of diltiazem was administered. Three commercial diltiazem preparations, labelled A, B and C were evaluated. The plasmas were analysed for diltiazem concentration by a new HPLC technique and from the data on concentration profiles, the pharmacokinetic parameters, Cmax, Tmax, T1/2, AUC0-12 and AUC0-infinity were calculated from the function derived by computerized curve fitting and integration. Computerized Pattern Analysis was used for product comparison, based on the plasmatic concentration and the calculated pharmacokinetic data. Differences observed between the three products regarding plasmatic levels and pharmacokinetic, were within the range values defined by individual variation, and were similar to the ones described in the literature for single doses of diltiazem - 60 mg. However, the multiparametric analysis showed that the studied preparations formed two distinct groups: preparation B was different from preparations A and C. This means that preparation B was not bioequivalent to preparations A and C, both considered as bioequivalent.