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Biomedical subjects

J C Santos

Publications and source records attributed to J C Santos.

At least 19 recordsLinked to original sources
PubMed2007

Repeated-batch xylitol bioproduction using yeast cells entrapped in polyvinyl alcohol-hydrogel.

Xylose-to-xylitol conversion was investigated in a bench-scale bioreactor using Candida guilliermondii cells entrapped within polyvinyl alcohol-hydrogel beads in a system operated in repeated-batch mode with cell recycling. Yeast-viable cells were immobilized in the support using the freezing-thawing method. Bioconversion assays were performed in a stirred tank reactor operated at 400-rpm agitation speed, 30 degrees C temperature, and 1.04-vvm air flow rate. The system was explored during six successive cycles, and a small decrease in the conversion performance in the fifth cycle was observed, but the biocatalytic activity of the microorganism was recovered in the sixth cycle after washing the particles. During the process, the hydrogel beads maintained their shape and size without appreciable deterioration. Xylitol production, yield factor, and volumetric productivity increased with progressive recycling of cells and achieved their maximum values (P(F) = 39.7 g l(-1); Y(P/S) = 0.77 g g(-1); Q(P) = 0.53 g l(-1) h(-1), respectively) after the third cell recycling, probably because of cells' adaptation to the medium.

Biotechnology↗
PubMed2005

Survey of acarin fauna in dust samplings of curtains in the city of Campinas, Brazil.

The aim of this study was to investigate the mite fauna present in 33 living room and 22 bedroom curtain dust samples from 41 different homes in the southern Brazilian city of Campinas, SP. A total of 148 mite bodies were found. Of these, 83 were found in living-room curtain samples (56.1% of total) and 65 were in bedroom curtain dust samples (43.9%). The most frequently observed mite suborders were: Acaridida (n = 79; 53.4%), Actinedida (n=53; 35.8%), Oribatida (n=14; 9.5%), and Gamasida (n=2; 1.3%). The most frequent families were Pyroglyphidae (n=61; 41.2%), Eriophyidae (n=25; 16.9%), Tarsonemidae (n=15; 10.1%), and Glycyphagidae (n=13; 8.8%). No statistical difference was observed between the number of mites found in the samples from living room and bedroom curtains.

Animals↗
PubMed2004

Sigma-pi separation of the electron localization function and aromaticity.

The electron localization function (ELF) has been separated in its sigma and pi components. The topological analysis of the new ELFsigma and ELFpi functions has been used to quantify the concept of resonance. The highest bifurcation values of these functions describe in a correct way the aromaticity of classical ring molecules and some new aromatic compounds as B6CO6, Al4(2-), and N5-. In the case of Al4(2-), an important sigma delocalization contribution has been found, which is in agreement with previous interpretation.

Journal Article↗
PubMed2000

Angiotensin-(1-7) increases osmotic water permeability in isolated toad skin.

Angiotensin-(1-7) (Ang-(1-7)) increased osmotic water permeability in the isolated toad skin, a tissue with functional properties similar to those of the distal mammalian nephron. Concentrations of 0.1 to 10 microM were effective, with a peak at 20 min. This effect was similar in magnitude to that of frog skin angiotensin II (Ang II) and oxytocin but lower than that of human Ang II and arginine-vasotocin. The AT2 angiotensin receptor antagonist PD 123319 (1.0 microM) fully inhibited the response to 0.1 microM Ang-(1-7) but had no effect on the response to Ang II at the same concentration. The specific receptor antagonist of Ang-(1-7), A-779, was ineffective in blocking the response to Ang-(1-7) and to frog skin Ang II. The AT1 receptor subtype antagonist losartan, which blocked the response to frog skin Ang II, was ineffective in blocking the response to Ang-(1-7). The present results support the view of an antidiuretic action of Ang-(1-7) in the mammalian nephron.

Analysis of Variance↗
PubMed1998

Prognostic factors in supraglottic carcinoma patients treated by surgery or radiotherapy.

The decision regarding treatment of supraglottic carcinoma remains controversial, despite recent advances in radiotherapy and surgical procedures. The need to evaluate the prognostic importance of demographic, clinical, pathologic, and treatment-related variables prompted this study. The patient population was of 164 consecutive cases of supraglottic carcinoma. Clinical charts were reviewed and cases were restaged according to the 1987 version of the UICC-AJC classification based on the initial clinical description: 18 T1, 30 T2, 58 T3, 58 T4, 61 NO, 24 N1, and 79 N2a-N3. Management policy for these patients varied during the study, reflecting different opinions of the responsible physicians and technical advances. Seventy-seven patients (47%) underwent surgery, patients who underwent surgery and radiotherapy, respectively, remained alive with no evidence of disease. The 5-year actuarial survival rates were 58.5% for patients initially treated by surgery, and 16.3% for patients in the radiotherapy group. Although several demographic, clinical, and pathologic variables were studied, only initial treatment (p <.0001), N stage (p = .0003), and T stage (p = .0017) were deemed to have independent prognostic value by multivariate regression techniques based on Cox's proportional hazards model. This study has shown that survival of supraglottic carcinoma patients depends on the treatment modality, T stage, and N stage. Our results are disappointing with regard to radiotherapy as a treatment for supraglottic carcinoma in patients with tumors at clinical stages III and IV.

Adult↗
PubMed1994

Prospective randomized trial of mechanical bowel preparation in patients undergoing elective colorectal surgery.

A total of 149 patients admitted for elective colorectal surgery were randomly allocated to receive preoperative mechanical bowel preparation (group 1) or no mechanical bowel preparation (group 2). All patients received antimicrobial prophylaxis with cephalothin and metronidazole. The overall incidence of wound infection was 17.4 per cent (24 per cent for group 1, 12 per cent for group 2) and that of dehiscence 7.4 per cent (10 per cent for group 1, 5 per cent for group 2). The incidence of wound infection was significantly higher in group 1 (P < 0.05) but that of anastomotic dehiscence did not differ significantly between groups. Mechanical bowel preparation is unnecessary and may be harmful in terms of preventing wound infection and anastomotic dehiscence in patients undergoing elective colorectal surgery.

Adolescent↗
PubMed1994

[Intestinal obstruction. The experience of the Emergency Service of S. José Hospital 1981-1991].

The results of 3679 patients, with intestinal obstruction, submitted to emergency surgery at the UUC-HCL between November 1981 and November 1991, were analysed in a general way, with the use of a graphic presentation. In the mechanical group, hernia (1604 cases), adhesions and bands (568 cases) and cancer (713 cases) were the most common pathologies; intestinal ischaemia (143 cases) was the most frequent form in the neurogenic group. Surgical therapy was evaluated in a general way. However, we comment on the evolution of primary surgical treatment of colorectal cancer in obstruction (625 cases). The mortality rate was in general: 10.8% (adults). In relative terms, the main features were intestinal ischaemia (39%), cancer (23%) and intestinal volvulus (22%).

Adolescent↗
PubMed1993

Chronic indomethacin administration and its relation with the renal kallikrein kinin system during rat pregnancy.

The main purpose of the present study was to elucidate the potential role of vasodilator prostaglandins and the kallikrein kinin system in renal hemodynamic changes observed during rat gestation. Nineteen pregnant rats, un-treated and treated with Indomethacin (3 mg/kg body/wt) for 4 days during peak glomerular hyperfiltration, were studied before and during pregnancy. Twenty-two non-pregnant rats were also included as controls. Daily urinary volume, electrolytes and kallikrein excretion and creatinine clearance were measured along the experiment. Baseline creatinine clearance increased by 43% at the beginning of the third week of pregnancy to decline thereafter. Urinary kallikrein rose earlier, at the second week of pregnancy, and decreased near term while at the same time sodium excretion dropped by 30%. Indomethacin treatment prevented both the maximum increment in glomerular filtration rate occurring in normal pregnancy between days 14 to 18 and the physiological near term decline in kallikrein excretion. Furthermore, it induced an increase in sodium excretion in late pregnancy. These results suggest that vasodilator prostaglandins and the kallikrein kinin system may well participate in gestational hyperfiltration and sodium homeostasis of pregnant rats.

Animals↗
PubMed1992

Portal pressure, renal function and hormonal profile after acute and chronic captopril treatment in cirrhosis.

The acute effects of captopril in cirrhosis are well known but there are few descriptions of the pattern of response to chronic administration of captopril in this disease. Nine nonuraemic cirrhotic patients with ascites and portal hypertension were studied after 1 week on fixed sodium and water intake (balance diet) and following acute and chronic treatment with captopril (three doses of 25 mg every 30 min and 75 mg.day-1 for three weeks, respectively). Whilst on the balance diet, 7/9 patients were unable to excrete the amount of sodium ingested. After the acute administration of captopril, a significant reduction was seen in arterial blood pressure (86.9 vs 77 mm Hg), with no change in the intra-hepatic pressures (free suprahepatic pressure, FSHP: 15.0 vs 12.1 mm Hg and wedged suprahepatic pressure, WSHP: 22.9 vs 20.7 mm Hg). After chronic captopril treatment, a drop was observed in portal pressure (FSHP: 9.4 mm Hg and WSHP 18.8 mm Hg, NS) and the arterial pressure returned to its basal level. The plasma aldosterone concentration decreased, whilst noradrenaline and dopamine increased significantly, the latter more than the former, leading to a reduction in the noradrenaline/dopamine ratio (14.5 vs 5.0). Seven out of nine patients showed enhanced natriuresis and the remaining two, who previously had had a positive sodium balance failed to do so. These haemodynamic, hormonal and renal changes were interpreted as evidence of blockade of angiotensin II generation by captopril, and also as a homoeostatic response by the sympathetic nervous system.

Adult↗
PubMed1992

Importance of information in forensic toxicology.

Information in forensic toxicology plays a very important role. The forensic pathologist usually seeks toxicologic analyses on basis of the information available at the time of the medicolegal autopsy. Such information may be obtained from different sources: hospitals, authorities, relatives, friends, or neighbors of the deceased and, obviously, macroscopic findings at the time of the autopsy. In order to evaluate the relative importance of these different sources of information, the authors have studied, retrospectively, results of 580 postmortem examinations performed at the Institute of Legal Medicine of Lisbon, wherein toxicologic analyses had been requested. These cases pertain to the years 1987 and 1988, but do not include alcohol determination in the blood in cases of traffic accidents. In 274 (47.4%) of the 580 cases, there were positive findings while in the remaining 306 (52.6%) findings were negative. In cases with positive findings, circumstances and factors, which may have influenced the pathologist's decision to request toxicologic analysis, are discussed. In more than half the cases, hospital information was the decisive factor, while in approximately 25% of the cases, autopsy findings were the justification. In contrast, it is worth mentioning that in approximately 45% of the cases with analytical negative results, requests were made, in cases of blank autopsies, for toxicologic analyses in order to exclude the possibility of poisoning. It is interesting to note that in the same proportion requests were justified on grounds of hospital information. Some of the factors that may explain this apparent discrepancy are discussed. Finally, the relevance of background information is emphasized at the level of the interpretation of analytical results, whether positive or negative.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbon Monoxide Poisoning↗
PubMed1992

Reticular erythematous mucinosis and acral papulokeratotic lesions associated with myxoedema due to Hashimoto thyroiditis.

A case is described of a patient with generalized myxoedema due to Hashimoto thyroiditis involving lesions of reticular erythematous mucinosis and acral papulokeratotic lesions with 'church spire' histological pattern. Substitutive treatment with thyroid hormone led to a rapid regression of the cutaneous lesions. The infrequent association of reticular erythematous mucinosis lesions and other forms of cutaneous mucinoses with hypothyroidism is discussed, with special emphasis on the fact that the underlying thyroid disease in all cases was Hashimoto thyroiditis. The association of distal keratotic papules with hypothyroidism has not been previously reported in the literature.

Erythema↗
PubMed1988

Angiodysplasia of the colon: endoscopic diagnosis and treatment.

Of 34 patients with massive lower intestinal bleeding, 17 (11 men and 6 women, age range 33-85 years; mean 64.8 years) were diagnosed as having angiodysplasia of the colon. The diagnosis was made by colonoscopy and the lesions were treated successfully by fulguration in 13 (86.6 per cent) of 15 patients. Two of the 17 patients underwent surgical resection of the involved intestinal segment. One patient still has sporadic intestinal haemorrhage, and another patient died from bleeding of the left colon after blind right colectomy. The remaining 13 patients have had no further bleeding in the 1-7 years following colonoscopic fulguration. Colonoscopy is a useful method of diagnosing angiodysplasia of the colon and affords the possibility of treatment.

Adolescent↗
PubMed1988

Vascular reactivity to norepinephrine in rats with cirrhosis of the liver.

Vascular reactivity to norepinephrine was studied in rats with early cirrhosis of the liver and in control rats. Cirrhotic rats showed water and sodium retention but not ascites. Studies were performed in whole animals, isolated hindquarters, and isolated femoral arteries. Plasma catecholamine levels were measured by radioenzymoassay and their urinary metabolites by gas-liquid chromatography. Plasma norepinephrine was 331 +/- 49 pg/mL (mean +/- SEM) in control rats and 371 +/- 66 pg/mL in cirrhotic animals (p greater than 0.05). No differences in plasma epinephrine or dopamine were observed. Urinary excretion of catecholamine metabolites was increased in cirrhotic rats. These data suggest a moderate activation of the sympathetic nervous system. In basal conditions, cirrhotic rats showed lower mean arterial pressure than controls (101 +/- 4 vs. 116 +/- 4 mmHg (1 mmHg = 133.3 Pa); p less than 0.01). However, perfused hindlimb resistance was similar in cirrhotic and in control animals. In the whole animal and in the perfused hindquarter, the contractile response to norepinephrine was similar for control and for cirrhotic rats. The contractile response to norepinephrine exhibited by isolated femoral arteries was similar in those from cirrhotic and control rats. This indicates that the peripheral vascular bed has a well-maintained ability to constrict in response to norepinephrine, suggesting that circulatory abnormalities in early experimental cirrhosis are not caused by refractoriness of the vascular smooth muscle to norepinephrine.

Animals↗
PubMed1988

Urinary excretion and glomerular synthesis of prostaglandin E2 and prostaglandin F2 alpha in cirrhotic, non-ascitic rats: the effects of sodium overload.

The urinary excretion of aldosterone, kallikrein and prostaglandin E2 (PGE2) was studied in sodium-retaining (RC) and nonretaining (NRC), nonascitic cirrhotic rats, under basal conditions and after an oral sodium load (5 mmol). The glomerular synthesis of PGE2 was measured in RC rats under the same conditions. Both groups of cirrhotic animals showed a decreased urinary excretion of PGE2. Isolated glomeruli of RC rats produced less PGE2 than those of the control animals, both under basal conditions and after the sodium load. The NRC group was the only one able to increase the urinary excretion of kallikrein in response to the sodium load. These findings could contribute to explain the early physiopathological events of hepatic cirrhosis.

Aldosterone↗