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Biomedical subjects

R Martins

Publications and source records attributed to R Martins.

At least 37 records · Page 2Linked to original sources
PubMed1995

Cold: a risk factor for stroke?

A retrospective study was performed to investigate seasonal variation in stroke incidence and to evaluate the hypothesis that cold might be a risk factor. Data were obtained from the central registry of the Hospital de S. João, Porto, Portugal, concerning 4048 patients consecutively admitted for cerebrovascular disease during a period of 33 months. Monthly admissions for stroke and its subtypes were related to mean values of ambient temperature using linear correlation. There was a strong inverse correlation between average temperature and total admissions for cerebrovascular disease (r = -0.72, P < 0.00005), intracerebral haemorrhage (r = -0.66, P < 0.00005), ischaemic stroke (r = -0.46, P = 0.007) and transient ischaemic attack (r = -0.41, P = 0.017). These correlations were independent of any seasonal variation in the number of hospital admissions due to all causes. No relation was found between temperature and subarachnoid haemorrhage. The rhythmometric analysis showed the presence of a statistically significant rhythm with an acrophase in the coldest months. These results support the hypothesis of stroke being a chronorisk disease to which cold might represent a triggering factor.

Cerebrovascular Disorders↗
PubMed1995

Laser Doppler velocimetry and platelet-derived growth factor as prognostic indicators for the healing of ulcers and ischaemic lesions of the lower limb.

The prognostic potential of skin blood flow measured by laser Doppler and serum platelet-derived growth factor (PDGF) levels was evaluated in patients with ischaemic lesions or ulceration of the lower limb. The laser Doppler-derived skin blood flow and perfusion pressure were measured in 93 patients with ischaemic lesions or ulceration in 98 lower limbs. Of these lesions, 61% healed spontaneously or with conservative local therapy, while 39% required major surgery. The likelihood for healing was reduced by older age. Comparison of receiver operating curves demonstrated that the optimal sensitivity and specificity were obtained for a combination of skin blood flow and perfusion pressure measured at 44 degrees C rather than at room temperature. If the skin perfusion pressure and blood flow were greater than 15 mmHg and 100 U respectively at 44 degrees C, 91% lesions healed, while if they were less than these values none healed. This provided a sensitivity and specificity of 100% and 83% respectively. The serum PDGF concentration was measured by radioimmunoassay in 48 patients with ischaemic lesions or ulceration of the lower limb, and compared with that in 34 healthy controls and 15 patients who had undergone abdominal surgery 3-5 days previously. The median PDGF level in the control group (83 pmol/l) was significantly less than that in the post-laparotomy group (217 pmol/l). The median PDGF level in the 31 patients whose ulcers healed with conservative therapy (210 pmol/l) was significantly higher compared with that in the 17 patients with unhealed ulcers (70 pmol/l).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Cerebral toxoplasmosis after renal transplantation. Case report and review.

Infection caused by Toxoplasma gondii is a frequent event in Portugal. When this occurs in immunocompetent individuals, it is rarely a matter of concern; the contrary occurs with immunosuppressed patients or in pregnancy. Transplant patients are treated with immunosuppressive drugs which mainly disturb their mechanisms of cellular immunity, and that opens the way to infections by opportunistic intracellular microorganisms. We recently treated a renal transplant patient who suffered from cerebral toxoplasmosis, and this provided an opportunity for a review of the other 20 patients reported in medical literature to date.

Adult↗
PubMed1992

Risk factors for failure of immediate breast reconstruction with prosthesis after total mastectomy for breast cancer.

BACKGROUND: Immediate breast reconstruction (IBR) after mastectomy represents a clear improvement in the quality of life of patients with breast cancer, but prosthesis removal is relatively frequent. Therefore, it is important to identify risk factors related to this removal. METHODS: A series of 142 patients treated with mastectomy and IBR at the Institut Gustave-Roussy between January 1976 and December 1988 were studied. Forty-seven had an in situ carcinoma, 93 an infiltrating carcinoma, and 2 a fibrosarcoma. IBR failures were defined as removal of the prosthesis, and early failures as removal during the first 7 weeks after IBR. RESULTS: The early failure rate was significantly higher in patients with invasive carcinomas or fibrosarcomas than patients with in situ carcinomas (12% versus 0%, P = 0.04). The risk of late IBR failure was significantly higher in patients who had received postoperative radiation therapy than patients who did not (P = 0.0002). However, this increased risk applied only to women in whom the chest wall was exposed to radiation because of a high risk of recurrence. CONCLUSION: It might be preferable to postpone breast reconstruction for patients with infiltrating breast carcinoma because early complications are not infrequent and could delay adjuvant chemotherapy. Late complications associated with chest wall irradiation could be avoided with the use of alternative techniques such as the transverse rectus abdominis myocutaneous (TRAM) flap procedure.

Breast↗
PubMed1992

Phenytoin and carbamazepine decreased oral bioavailability of praziquantel.

Antiepileptic drugs, especially carbamazepine and phenytoin, are potent liver enzyme inducers. Since praziquantel, the drug used to treat neurocysticercosis, undergoes extensive liver first-pass metabolism, we carried out a prospective study to verify whether there was a decrease in oral bioavailability induced by carbamazepine and phenytoin. Carbamazepine and phenytoin significantly decreased concentrations of praziquantel, due to increased clearance secondary to induction of first pass-liver metabolism. The magnitude of the decrease is surprisingly high and may be responsible for failures of treatment.

Adult↗
PubMed1992

[Multidisciplinary experience in the approach to the hypertensive patient].

PURPOSE: To evaluate the impact of the educational activities on the approach of patients with hypertension, with an interdisciplinary team. METHODS: Fifty patients divided into two groups: A) with 25 patients who participated in educational activities in the Hypertension League (HL) and B) who were also registered and did not take part in the activities. They were studied regarding blood pressure (BP), weight control, smoking habits, alcoholic beverage consumption, physical activities and frequency of medical care. RESULTS: There was a drop in BP of 84% of the patients in group A and 88% in group B, a drop in weight in 60% of group A and 44% of group B. We registered the presence of 4% of smokers in group A and 16% in group B. Physical activities were regular in 56% of group A and 36% in group B. Absenteeism to meetings was slightly higher among group B (44%) when compared with group A (30%). CONCLUSION: In spite of not having observed any significant differences between both approaches, regarding to strict BP control, we were able to observe a noticeable advantage in favor of the educational approach to the group, with participation of interdisciplinary team.

Blood Pressure↗
PubMed1992

[Skin pathology in kidney transplant recipients].

Since 1990, 82 unselected renal allograft recipients were evaluated in order to establish the incidence of cutaneous disorders. This pathology was related to the period of immunosuppression according to time of transplantation: 0-3 months; 3-12 months; 12-36 months and beyond 36 months. Most of them were on triple immunosuppression (cyclosporine A, azathioprine and prednisone)--(51); Twenty-two also associated anti-timocyte globulin five days after transplantation; 7 were on Azathioprine and Prednisone and two of them associated Cyclosporine with Prednisone. Iatrogenic manifestations were the most common (80.5%) followed by infections in 63.4% and pre-malignant and malignant cutaneous lesions in 13.4%, other types of manifestations were found in 20.7% of patients. A significant incidence of pre-malignant and malignant lesions confirms other reports, making a dermatological surveillance advisable.

Adolescent↗
PubMed1991

Increased GDP binding and thermogenic activity in brown adipose tissue mitochondria during arousal of the hibernating garden dormouse (Eliomys quercinus L.).

1. The thermogenic activity of brown adipose tissue in hibernating garden dormice during hypothermic torpor and at different states of arousal were studied. High levels of GDP binding were observed on isolated brown fat mitochondria, indicating that the thermogenic proton conductance pathway is very active in brown fat during arousal. 2. In order to investigate this phenomenon, the uncoupling protein was assessed by immunological assay and the mRNA for UCP was analysed. 3. Animals during arousal exhibited neither increase in UCPmRNA nor an increase in UCP. 4. Our results suggest that during the rewarming of garden dormice there is an acute unmasking of GDP binding sites on the protein.

Adipose Tissue, Brown↗
PubMed1990

Liver and brown fat mitochondrial response to cold in the garden dormouse (Eliomys quercinus).

The involvement of two organs, i.e. the liver and the brown adipose tissue (BAT) in response to cold in a hibernating species such as the garden dormouse has been studied. 2. In animals living in the cold, mitochondrial respiratory rates significantly increased (with respect to those living at 28 degrees C) in both organs with a larger increase in the BAT (+152% in the BAT and 67% in the liver). 3. The increase in BAT activity was obtained by a concomitant increase in: (a) the BAT mass (+30%), (b) the total mitochondrial mass (+20%), and (c) the mitochondrial respiratory rate (+64%). In the liver the increase was due only to an augmentation in mitochondrial mass and activity. 4. These results indicate that: (a) the BAT exerts a pre-eminent role in the physiological response to cold of garden dormouse, (b) a certain non-shivering thermogenesis (NST) is present in the liver of such species. In addition we suggest that a local thermoregulatory response would take place in a metabolically important organ such as the liver.

Acclimatization↗
PubMed1989

Amyloid A4 protein and its precursor in Down's syndrome and Alzheimer's disease.

In patients with Alzheimer's disease, amyloid fibrils that are aggregates of A4 protein subunits are deposited in the brain. A similar process occurs at an earlier age in persons with Down's syndrome. To investigate the deposition of amyloid in these diseases, we used a radioimmunoassay to measure levels of the amyloid precursor (PreA4) in the serum of 17 patients with Down's syndrome, 15 patients with Alzheimer's disease, and 33 normal elderly controls. The mean (+/- SD) concentration of serum PreA4 was increased 1.5-fold in patients with Down's syndrome (2.49 +/- 1.13 nmol per liter) as compared with that in controls (1.68 +/- 0.49 nmol per liter; P less than 0.007); the levels in patients with Alzheimer's disease were similar to those in controls (1.83 +/- 0.78; P less than 0.98). We also found that the concentration of PreA4 in the brain tissue of two adults with Down's syndrome (100 and 190 pmol per gram) was higher than that in the brain tissue of either 26 patients with Alzheimer's disease (64.4 +/- 17.3 pmol per gram) or 17 elderly controls with neurologic disease (68.5 +/- 26.3 pmol per gram). Immunocytochemical studies of brain tissue from 26 patients with Down's syndrome showed that the deposition of A4 protein amyloid began in these patients approximately 50 years earlier than it began in 127 normal aging subjects studied previously, although the rate of deposition was the same. We conclude that, since the gene for PreA4 is on the long arm of chromosome 21, which is present in triplicate in Down's syndrome, overexpression of this gene may lead to increased levels of PreA4 and amyloid deposition in Down's syndrome. However, since increased levels of PreA4 are not present in Alzheimer's disease, additional factors must account for the amyloid deposition in that disorder.

Adolescent↗
PubMed1988

Uveomeningoencephalitis in a human immunodeficiency virus type 2-seropositive patient.

A 35-year-old woman developed longstanding uveitis and later a uveomeningoencephalitis of unknown origin and died of toxoplasmal brain abscesses. The presence of immunological impairment, human immunodeficiency virus type 2 (HIV-2) seropositivity, and multinucleated cells in the brain led us to suspect neurotropic properties for HIV-2 similar to those of HIV-1.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Haematological changes in retinal vasculitis.

Two selected cases of retinal vasculitis, apparently of unknown aetiology, are reported; one case without any systemic or laboratory manifestation and the second case with a clinical picture similar to VKH syndrome and immunodepression. Both cases showed abnormal haematological parameters related to blood viscosity in the early and acute phases which could be manipulated by therapy. Reduction or near normalisation of these haemorrheological parameters coincided with clinical and angiographic improvement. The second case with severe immunodepression was found to be retrovirus HIV-2 positive.

Adult↗
PubMed1988

A4 amyloid protein deposition and the diagnosis of Alzheimer's disease: prevalence in aged brains determined by immunocytochemistry compared with conventional neuropathologic techniques.

The histologic diagnosis of Alzheimer's disease (AD) might be aided if a more sensitive marker of aberrant A4 amyloid protein deposition were available. We screened a sample of aged brains, using immunocytochemical methods to detect the A4 protein deposition, and found that, in comparison with conventional histologic techniques (silver impregnation and Congo red), immunocytochemistry is more sensitive and allows an easier demarcation between "normal" and "abnormal." If A4 protein deposition is accepted as a definitive marker for AD, then the age-related prevalence of AD increases dramatically. To what degree these prevalence rates are reflected in clinically detectable impairment of higher cortical function remains to be determined.

Aged↗
PubMed1980

Pathological findings in one of two siblings with Sjögren-Larsson Syndrome.

The clinical features of 2 new cases of Sjögren-Larsson syndrome are described. Histopathological examination of the skin in 1 of the cases revealed an ichthyosis vulgaris, which does not agree with the clinical and genetic classification. In the same case, a neuroblastoma was the cause of death, and neuropathological examination showed a symmetrical demyelination of some ascending and descending long tracts in the medulla and spinal cord.

Adult↗
PubMed1979

Surveillance of antibiotics use in a community hospital.

An ongoing system of antibiotic surveillance was initiated in a community hospital. The system was based on the guideline audits of antimicrobial use published by the Veterans Administration Ad Hoc Interdisciplinary Advisory Committee on Antimicrobial Drug Usage. The surveillance is accepted well by the medical staff. It has proved to be cost-effective and educational. A changing pattern of antimicrobial drug use has been recognized that has resulted in decreased antimicrobial drug costs.

Anti-Bacterial Agents↗