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Biomedical subjects

J Pereira

Publications and source records attributed to J Pereira.

At least 91 records · Page 5Linked to original sources
PubMed1998

Immunoreactive riboflavin carrier protein concentration during ovulatory cycle in the common marmoset (Callithrix jachhus): role of estrogen.

Common marmoset, a non-human primate, is increasingly being used as a model system in reproductive endocrinology. Marmosets do not menstruate but have normal cycle length of 28 +/- 2 days. The presence of protein immunologically and functionally similar to the well characterized chicken riboflavin carrier protein (cRCP) has been demonstrated in circulation in pregnant marmosets. Marmoset RCP (mRCP) has been partially purified and the molecular weight of the immunoreactive protein is similar to cRCP. The source of RCP in rodents appears to be maternal liver, suggesting thereby that RCP levels could be modulated by changing hormonal pattern that occurs during the cycle. To study the hormonal control of marmoset RCP, immunoreactive RCP levels were monitored during normal cycle. Plasma progesterone was estimated by RIA and mRCP was measured using a heterologous cRCP RIA. When mRCP and progesterone were analysed for a period of 40 days (n = 5) in adult females, very low amount of mRCP was measured during the luteal phase and a single sharp peak was observed during the follicular phase of the cycle. These data suggested that the induction of mRCP was regulated by estrogen. Direct evidence for the role of estrogen in the elaboration of RCP, was the observation that exogenous administration of estradiol 17 B to immature marmosets resulted in a time and dose dependent increase in plasma RCP levels. As early as 24 hr following hormonal administration, a measurable increase in mRCP with a maximum increase, 5-fold over the zero period was seen 3 days following a single administration of estradiol 17 B (5 mg/kg body wt). RCP levels declined thereafter and was indistinguishable by day 7. These studies indicate that the marmoset RCP levels are regulated by estrogen.

Animals↗
PubMed1998

A prospective trial of self-expanding metal coated stents in the palliation of malignant dysphagia.

OBJECTIVE: To analyze the use of self-expanding metal coated esophageal stents a palliative therapy of malignant dysphagia. METHOD: We performed a one year prospective study placing 12 stents in 10 patients with malignant dysphagia. RESULTS: The insertion mean time was lower than 25 min, and most of our patients (70%) reported a good tolerance. Dysphagia score improved immediately and it lasted until death with no occlusions. Complications appeared early, 17% at the time of placement, with one patient having a life-threatening complication. The probability for these patients not to develop any complications after the three first weeks will be about 60%. CONCLUSIONS: Self-expanding metal coated esophageal stents provide a fast and lasting relief in malignant dysphagia, with a good tolerance.

Aged↗
PubMed1997

Endothelial cell markers in chronic uremia: relationship with hemostatic defects and severity of renal failure.

Plasma von Willebrand factor antigen, soluble thrombomodulin, and tissue factor were increased in 31 patients with severe chronic renal failure (creatinine clearance <20 ml/min) under conservative treatment, whereas plasminogen activator inhibitor antigen did not differ significantly from healthy controls. No correlation among plasma levels of these proteins was found. Three patterns of relationship between endothelial cell markers and hemostatic defects were identified: 1) Plasma thrombomodulin, a marker of endothelium damage, was found an independent predictor of bleeding time and platelet aggregation, and secretion defects, and was also related to the severity of renal failure; 2) von Willebrand factor antigen, an index of endothelial cell activation and secretion, was significantly correlated with intravascular markers of thrombin and plasmin generation and with platelet adenosine triphosphate content, but not with plasma creatinine levels; and 3) tissue factor and plasminogen activator inhibitor antigen levels were not statistically correlated with the diverse hemostatic defects. Activation of coagulation and fibrinolysis, secondary to endothelial cell activation, appearing early during the evolution of chronic renal failure, is pathogenically related to the platelet dysfunction, and probably to development of atherosclerosis and thrombotic events in this disease. The progression of chronic renal failure, through endothelial cell damage, would lead to aggravation of the platelet functional defect potentiating the hemorrhagic risk.

Antigens↗
PubMed1997

Bus rounds for palliative care education in the community.

Increasingly, patients with cancer are dying at home and in continuing care facilities. The purpose of bus rounds is to provide continuing education to physicians and nurse palliative care consultants, to familiarize family physicians with the delivery of care in these settings and to educate family medicine and specialty residents as well as medical students. A total of 18 4-hour bus rounds took place during 1996. A mean of 13 (range 9 to 17) participants attended, to discuss a mean of 3.5 (range 2 to 4) patients and 4.5 (range 3 to 8) journal articles. A questionnaire was filled out anonymously by 18 first-time medical and 24 first-time nursing participants. On a scale from 1 (worst) to 5 (best), they gave the rounds an overall rating of 5 (range 4 to 5). The mean cost per round was $245.40. The authors conclude that bus rounds provide an opportunity for intensive exposure to community-based learning for physicians, nurses and students and are highly satisfactory from the participants' perspective.

Alberta↗
PubMed1997

The frequency and clinical course of cognitive impairment in patients with terminal cancer.

BACKGROUND: Cognitive disorders are among the most frequent psychiatric complications of advanced cancer. This study reviews the frequency and clinical course of cognitive failure in patients with advanced cancer admitted to a palliative care unit. METHODS: In this retrospective study, all 348 patients admitted to the Edmonton General Palliative Care Unit over a period of 26 months were reviewed. The Mini-Mental State Examination (MMSE) was used as a screening tool to assess cognitive functioning and was performed on all patients at the time of admission and once to twice weekly thereafter. In all cases, when cognitive failure was diagnosed, a standardized management protocol was followed. RESULTS: Three hundred and twenty-one patients (92.2%) were evaluable. A total of 1441 MMSEs were performed. Each patient underwent an average of 4.7 +/- 4.26 MMSEs and every patient underwent an MMSE every 4.9 (+/- 3.3) days (median, 3.6 days). The mean age (standard deviation [SD]) of the study group was 64.2 (+/- 12) and the mean +/- SD (median) length of stay was 27 +/- 22 (20.5) days. Two hundred and thirty-one patients (71%) died on the unit. One hundred and forty-two patients (44%) had abnormal MMSE scores (MMSE < 0.8) on admission, whereas 176 patients (55%) had abnormal MMSE scores at the time of death or discharge. Of the 231 patients who died on the unit, 157 (68%) had abnormal MMSE scores prior to death. There was no significant difference in the first MMSE between patients who died and those who were discharged (P = 0.16). Of the 240 patients who underwent 2 or more MMSEs, 99 (41%) had normal initial and final MMSEs, 54 (23%) had normal initial MMSE scores but abnormal final scores, and 62 (26%) had both initial and final abnormal scores. Of the 87 surviving patients with an MMSE score of < 0.8 on admission, 25 (29%) had initial abnormal and final normal scores, indicating an improvement. Twelve of these 25 patients (48%) with abnormal initial scores but normal final scores were discharged versus 52 of 99 patients (53%) with normal initial and final MMSE scores (P > 0.2). Of 124 patients with normal final MMSE scores, 64 (52%) were discharged versus 16 of 116 patients (14%) who had abnormal MMSE final scores (P < 0.0001). CONCLUSIONS: These data suggest that cognitive screening should take place in patients with advanced cancer because cognitive failure is highly prevalent in this population, is reversible in a significant proportion of patients, and the presence of sustained cognitive impairment is a poor prognosticator for discharge. However, these results need to be confirmed in prospective studies.

Cognition Disorders↗
PubMed1997

Limonoids from Citrus reticulata and their moult inhibiting activity in mosquito Culex quinquefasciatus larvae.

Three limonoids, namely limonin, nomilin and obacunone, were isolated from the seeds of Citrus reticulata [Blanco Coorg Mandarin]. Their structures were confirmed by spectroscopic studies. With 4th instar larvae of mosquito Culex quinquefasciatus, the EC50 for inhibition of adult emergence was 6.31, 26.61 and 59.57 ppm for obacunone, nomilin and limonin, respectively. The pattern of mortality at around the EC50 levels was indicative of moult inhibiting activity. The efficacy of a limonoid enriched fraction was similar to that of limonin, probably due to the high content (70%) of limonin.

Animals↗
PubMed1997

Acute neuropsychiatric findings in a patient receiving fentanyl for cancer pain.

A 62-year-old man receiving subcutaneous fentanyl for the management of cancer pain developed generalized central excitation after an overdose of 5000 micrograms of fentanyl. The patient developed acute confusion, restlessness, generalized myoclonus, visual hallucinations, and hyperalgesia and tremors upon tactile stimulation of the arms or legs. These symptoms rapidly disappeared after the administration of 0.2 mg of naloxone. Within an hour the symptoms reappeared and once again, responded immediately after a second injection of 0.2 mg of naloxone. Our findings suggest that fentanyl overdose can occasionally present with general central irritability that responds to naloxone.

Adenocarcinoma↗
PubMed1997

A histopathological study of liver and kidney in male Wistar rats treated with subtoxic doses of t-butyl alcohol and trichloroacetic acid.

Tertiary butyl alcohol and trichloroacetic acid are known to be contaminants in drinking water. In order to evaluate the interactive toxicity of t-butyl alcohol with trichloroacetic acid, young male Wistar rats were dosed through water at a dose level of t-butyl alcohol (TBA)-0.5% (v/v), trichloroacetic acid (TCA)-25 ppm and a combined dose of TBA + TCA (0.5% v/v TBA-25 ppm TCA) for a period of 10 weeks ad libitum and were maintained on normal diet. The control animals received plain water and normal diet. The liver and kidney histology was undertaken to see whether subtoxic administration of TBA and TCA individually as well as combined administration for a period of 10 weeks would bring about any histological alterations. It was observed that TBA, TCA and TBA + TCA caused histological alterations in the liver such as centrilobular necrosis, vacuolation in hepatocytes and loss of hepatic architecture. TBA and TBA + TCA caused periportal proliferation and lymphocytic infiltration. Hypertrophy of hepatocytes in the periportal area was a characteristic feature in the liver of TCA treated rats. Moreover, in the histology of the kidney, in the three treated groups, degeneration of renal tubules, with syncitial arrangements of the nucleus of renal tubular epithelial cells was evident. In addition to this, degeneration of the basement membrane of the Bowmans capsule, diffused glomeruli and vacuolation of glomeruli was also evident in the three treated rat kidneys. Renal tubular proliferation in certain areas was also evident in certain areas of the kidney in TCA treated rats. The results indicate that, TBA and TCA do bring about alterations in histology of liver and kidney, but on combined administration, do not show enhanced toxicity in the form of increased hepatic and renal injury.

Animals↗
PubMed1997

Anterolateral lumbar lipomyelomeningocele: case report and review of the literature.

OBJECTIVE AND IMPORTANCE: Meningoceles associated with defects of the abdominal wall are exceedingly rare. One such complex case is presented along with a review of the relevant literature. The current pathophysiological theories and surgical management are discussed. CLINICAL PRESENTATION: A case of a patient with an anterolateral lumbar lipomyelomeningocele associated with multiple congenital anomalies, including defects in the abdominal wall and urogenital system, is presented. The lipomyelomeningocele presented as an expanding abdominal mass. INTERVENTION: Ventriculoatrial shunting and two operations to repair the myelomeningocele were performed to control the expanding abdominal mass. CONCLUSION: This report illustrates that the surgical management of complex lipomyelomeningoceles is similar to the more common types. It also demonstrates that in the infant in whom the intra-abdominal cerebrospinal fluid collection is the primary cause of the symptoms, cerebrospinal fluid shunting may be used to delay the definitive repair until the dura strengthens, thus avoiding the complications of complex repairs of dura with low tensile strength.

Abdominal Neoplasms↗
PubMed1997

Launching a palliative care homepage: the Edmonton experience.

The Internet, with its graphical subdivision, the World Wide Web (WWW). has become a powerful tool for the dissemination of information and for communication. This paper discusses the authors' experiences with creating, launching and maintaining an official publication on the Internet by the Edmonton Regional Palliative Care Program and the Division of Palliative Medicine, University of Alberta, Canada. It describes the content and format of the homepage and the process of publication. Over a six-month period there were 892 visits to the site and 84 separate items of correspondence to the site's editors. Of these correspondence items, 36 were requesting further information regarding clinical and other programme information. Sixty-nine of the 84 communications came from North America and Europe. The pattern of readership is briefly discussed as are some of the potential advantages and challenges when utilizing this electronic medium. To promote the dissemination of reliable information on the Internet, the authors encourage other palliative care groups and organizations to publish on the WWW. The URL is http:/(/)www.palliative.org (previously http:/(/)www.caritas.ab.ca/approximately palliate).

Alberta↗
PubMed1997

Genetic variability and geographic differentiation among three species of Triatomine bugs (Hemiptera-Reduviidae).

Three species of triatomine bugs, Triatoma sordida, T. guasayana, and T. patagonica, were examined by cytogenetic (C-banded karyotypes and male meiotic process) and isoenzymatic studies. These three species, with different importance as Chagas' disease vectors, were found to be closely related according to their known ethologic, ecologic, and morphologic traits. Although they have the same diploid chromosome number (2n = 22 constituted by 20 autosomes and an XY male/XX female sex mechanism), each species has a distinct chromosomal behavior during male meiosis and a specific amount and localization of C-heterochromatic blocks. Moreover, these chromosome characteristics allowed us to differentiate two T. sordida populations. Isoenzymatic data confirmed the taxonomic status of the three species and together with our cytogenetic results questioned the species homogeneity of T. sordida.

Animals↗
PubMed1997

[Skin and mucous membrane hemorrhages: clinical assessment, study sequence and relative frequency of hereditary diseases of the hemostasis in a Chilean population].

BACKGROUND: Skin and mucous membrane hemorrhages are distinctive manifestations of hereditary diseases of primary hemostasis and, among them, the different types of von Willebrand disease and of platelet function disorders are the most prevalent. AIM: To know the relative frequency of these disorders and to know the clinical features of patients with mucocutaneous hemorrhages. PATIENTS AND METHODS: Five hundred eighty nine patients whose main symptom was the presence of mucocutaneous hemorrhages were studied. Bleeding time, platelet count, coagulant activity of factor VIII (FVIII:C), FvW: Ag and FvW: CoRis and ABO blood group were measured in all patients in a first stage. According to the results of these tests, further studies were decided. RESULTS: In patients younger than 13 years old, male predominated and, in older patients, females consulted with higher frequency. There was a higher proportion of individuals with O blood type than in the normal population. Bleeding time was abnormal in 330 patients (56%). One hundred ten patients (19%) had won Willebrand disease and, among them, one third had a normal bleeding time. Isolated reduction of factor WII activity was found in 66 patients (11%, 51 males) and 32 of these had normal bleeding time. Eighty one patients (14%) were considered to have an hereditary platelet function defect. A precise diagnosis was not achieved in 332 patients (56%). CONCLUSIONS: Among patients consulting for mucocutaneous hemorrhages, 19% had von Willebrand disease, 11 had an isolated reduction of factor VIII activity, 14% had platelet function defects and in 56%, a precise diagnosis was not reached.

ABO Blood-Group System↗