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Biomedical subjects

J P Correia

Publications and source records attributed to J P Correia.

At least 19 recordsLinked to original sources
PubMed2006

Effect of electrochemical treatment of oleic acid on anaerobic digestion.

Electrochemical pre-treatment of oleate on anaerobic digestion was investigated using two anaerobic filters (AF and AFm) working, respectively, with increasing concentrations of electrochemically pre-treated oleate and oleate. Influents containing 25% and 50% of chemical oxygen demand (COD) of these substrates did not cause relevant alterations in either digester's performance. Comparatively, the pre-treated oleate unit (AF) showed a higher gas production but a lower COD removal than AFm (2.0 vs 1.5 m(3) CH4 m(-3) d(-1) 76-85 vs 91-93% COD removal). The raised AFm COD removal together with the larger proportion of VSS in its effluent than in AF (5.69 vs 0.26 kg m(-3)) indicate that the biomass washout can be a consequence of the encapsulated solids by lipidic compounds that were not fairly degraded. Further increases of oleate in AFm feed (75 and 100% COD) led to decreases of biogas production to half and COD removal from values higher than 90% to 83-75%. The simultaneous increase of effluent VSS concentrations to 10-12 kg m(3) emphasizes the oleate negative effect. The use of pretreated oleate as the only carbon source did not influence negatively the AF behaviour in terms of methane production. COD removal was maintained at values higher than 80% and the effluent VSS at low concentrations (0.15 kg m(-3)). The significantly higher methane yield achieved by AF than AFm indicates a higher accumulation of oleate than pre-treated oleate. Therefore, electrochemical process stands for a suitable pre-treatment for lipid rich effluents, allowing the application of higher organic loads keeping a higher methane yield.

Anaerobiosis↗
PubMed2001

Study of DNA hybridization on polypyrrole grafted with oligonucleotides by photocurrent spectroscopy.

Recognition of DNA sequences by biochemical sensor is generally performed by analysis after completion of hybridization. Using a technique able to directly translate the biological event into an electrical signal allows the in situ monitoring of the hybridization kinetics. In this aim, the photoelectrochemical behavior of one electroactive polymeric sensor based on a copolymer of polypyrrole and polypyrrole-oligonucleotide has been investigated in aqueous solution. This sensor has been studied as such (i) and in two other situations: (ii) when the copolymer is in presence of non-complementary oligonucleotides; and (iii) when the copolymer is in presence of complementary oligonucleotides. From the photocurrent spectra obtained at -0.6 V/SCE versus incident energy the allowed direct and indirect transitions for each polymer have been evidenced. The photocurrent evolution during hybridization and adsorption processes has been recorded in real time and the hybridization kinetics has revealed to be comparable with mass variations obtained by quartz crystal microbalance under the same experimental conditions.

Biosensing Techniques↗
PubMed1991

SISCOPE: a multiuser information system for gastrointestinal endoscopy.

SISCOPE is an integrated data management system for use in gastrointestinal endoscopy units which operates in the multiuser mode on UNIX minicomputers or MS-DOS personal computers and can be used for patient bookings, endoscopic data entry and retrieval, and automatic report generation in upper gastrointestinal endoscopy, proctologic examinations, colonoscopy and peritoneoscopy. The description of endoscopic findings is remarkably detailed and data entry very rapid due to an advanced design of input screens that incorporates several recent concepts, including windows, menu bars and pull-down menus; typing is eliminated as data is entered with a mouse by pointing at options within menus. Endoscopic findings can be described under eight headings: morphology, topography, qualifiers, modifiers, signs of bleeding, endoscopic diagnosis, pathological diagnosis and etiology. Terminology is based strictly 3on the OMED system. SISCOPE also allows recording of details on endoscopic procedures, indications for the examination, preparation, premedication, complications and late entry of pathology reports. After entering all data, a report in natural language is produced automatically, the entire process taking one minute on average. Data retrieval programs give on-line access to previous examinations of a given patient and automatically generate activity reports. A formal language allows direct queries to the database and transfer of data for statistical analysis or other data processing. The system is simple to learn and use because operation is intuitive and all endoscopic techniques share the same basic menu structure and screen design.

Computer Systems↗
PubMed1991

Nutritional support in Crohn's disease: which route?

Nutritional and clinical responses to three nutritional regimens were retrospectively evaluated in 81 Crohn's patients with active disease. Group 1 (n = 42) received a low residue oral diet, group 2 (n = 15) received chemically defined diets, and group 3 (n = 24), parenteral nutrition (PN). Weight gain was observed in a similar percentage of patients, whereas serum albumin increase was significant only in group 3: 3.15 +/- 0.66 versus 3.54 +/- 0.61 g/100 ml (p less than 0.05). Mean activity index decreased significantly in all groups (p less than 0.001), and length of stay in hospital was similar. Patients with intestinal obstruction had a better immediate response when submitted to PN: clinical remission was achieved in 75% of those in group 3, but in only 50% in groups 1 and 2 (p less than 0.05). Otherwise, short- and long-term outcome was similar.

Acute Disease↗
PubMed1989

Long-term prognosis of patients with cirrhosis of the liver and upper gastrointestinal bleeding.

A study has been carried out on the 5-yr survival curves of 287 patients admitted with upper gastrointestinal bleeding and portal hypertension. In 78.7%, the cause of bleeding was from esophageal varices. Only 2.4% had noncirrhotic portal hypertension, and 80% were alcoholics. At 5 yr, the overall survival probability was 26.2%. The curve had three segments with survival rates of 69% at 2 wk and 46.6% at 12 months. According to Child's grade, the curves were very different at 2 wk, 12 months, and 60 months: Group A, 94.0, 78.0, and 51.8%; group B, 77.0, 46.0, and 32.2; group C, 52.0, 11.0, and 2.3%. The largest differences were observed in the first 2 wk immediately after the first bleeding. The recurrence of bleeding in a period of 6 months significantly decreased the survival. Age, as well as the introduction of prophylactic measures (propranolol or sclerotherapy), did not influence long-term survival. Alcohol abstinence was accompanied by better survival. This difference was due to the impact of abstinence only in group B patients.

Age Factors↗
PubMed1982

Alcoholic liver diseases in Portugal. Clinical and laboratory picture, mortality, and survival.

Six main types of histopathological changes were found in 463 patients with chronic alcoholism admitted during the 10-year period from 1966 to 1975: group I, normal liver in 2.6%; group II, fatty liver in 8.4%; group III, acute alcoholic hepatitis (AAH) in 7.6%; group IV, cirrhosis with or without steatosis in 68.7%; group V, cirrhosis with AAH in 12.8%; group VI, liver cell carcinoma (LCC) in 1.9% (all of the latter patients were also included in group IV). Seventy-three % were males and 27% were females. Females tended to be older than males. Cirrhosis was found in 68% of the group between 21 and 30 yr and in 85% between 51 and 60 yr. Normal histology or steatosis was less frequent after the age of 50 yr. Ascites and jaundice were more frequent in patients with AAH than in patients with steatosis. The majority of patients had SGOT under 100 karmen units/ml; SGPT was normal in 80% of patients with cirrhosis and higher than 100 karmen units/ml in 10%. SGPT was higher than SGOT in only 11.9% of the patients. Mortality was 46.7% according to the followup until 1978. Survival was 38.4% at the end of the first year and decreased very slowly afterwards to 32.8% in males and 11.5% in females after a 5-yr period.

Adult↗
PubMed1981

SGOT-SGPT ratios.

Explore the source record for details and available documents.

Alanine Transaminase↗
PubMed1977

Bile salts secretion in cirrhosis.

The bile salts secretion was studied in ten normal subjects and sixteen patients with alcoholic cirrhosis, in a basal period and during 60 minutes after Secretin injection. Total bile salts were measured by a modification of the enzymatic method of Iwata and Yamasaki and the individual bile salts were separated by silica gel thin-layer chromatography. During the 60 minutes after Secretin the mean concentration was 2.88 +/- 2.58 muM/ml in normals and 1.96 +/- 1.25 muM/ml in cirrhotics. The difference is not significant. During the first 20 minutes however the concentration was higher than 3 muM/ml in 8 out of 10 normals and lower than 2 muM/ml in 10 out 16 cirrhotics. The ratios of tri-to dihydroxy bile salts was similar in both groups. The ratios between bile salts conjugated with glycine and with taurine was higher in normals, and the ratio between free to conjugated bile salts was higher in cirrhotics. The lower concentration of total bile salts immediatly after Secretin, the higher proportion of taurin conjugates and of free bile salts could be important factors in the difficulties of fact digestion and absorption frequently found in patients with alcoholic cirrhosis.

Adult↗
PubMed1975

Diffuse leiomyomatosis of the esophagus: a case report and review of the literature.

A case of diffuse leiomyomatosis of the esophagus in a 21-year-old woman with a 5-year history of dysphagia is presented. The radiological appearance was that of achalasia, but at esophagoscopy, a diagnosis of an organic stricture of the lower end of the esophagus was made. During the operation a diffuse tumor involving the lower end of the esophagus, cardia, upper portion of the stomach, and the tail of the pancreas was found. The histological diagnosis was diffuse leiomyomatosis of the esophagus. The individual characteristics of the microscopic picture are described. Distal esophagectomy and total gastrectomy resulted in complete recovery of the patient. This is a very rare condition; only a dozen similar cases have been published before. The data of these patients are presented.

Adult↗
PubMed1975

Ethanol metabolism in liver cirrhosis and chronic alcoholism.

Ethanol metabolism and its influence on serum lactate/pyruvate ratio was studied after intravenous infusion of ethanol in 17 patients: 4 controls, 5 alcoholics with cirrhosis, 4 non-alcoholic cirrhotics and 4 alcoholics without liver disease. All refrained from the use of alcohol and drugs 4 weeks prior to the experiment. After maximal ethanol blood levels were achieved at the end of the infusion, ethanol removal occurred at two different rates. This was probably due to the fact that different volumes of ethanol were distributed with time: a fast period (30 to 60 min) and a slow period (60 to 180 min). The rates of disappearence in the two periods were similar in all groups which suggests that liver cirrhosis, independent of clinical severity and/or chronic alcoholism with previous abstinence from alcohol, does not modify ethanol metabolic rates in the liver. The relation lactate/pyruvate doubled in all cases but it occurred within 30 minutes in the groups without liver disease and within 60 minutes in the cirrhotics. This could account for the decreased liability of cirrhotic patients to alcohol hypoglycemia.

Adult↗
PubMed1975

[Isolated malignant lymphoma of the rectum(author's transl)].

A case of primary and isolated, diffuse reticulosarcoma of the rectum is reported. There has been a history of blood diarrhea for 12 years in a 60 years old man, with no change in his general condition. Treatment with cyclophosphamide was started and maintained for two and a half years with complete local regression, and very good clinical results.

Diagnosis, Differential↗