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Biomedical subjects

M S Roy

Publications and source records attributed to M S Roy.

68 records · Page 4Linked to original sources
PubMed1986

Retinal cotton-wool spots: an early finding in diabetic retinopathy?

Five insulin dependent diabetic patients are reported on who had a few small retinal cotton-wool spots or 'soft exudates' either totally isolated or associated with fewer than 10 microaneurysms. These observations suggest that cotton-wool spots may be an early finding in diabetic retinopathy. Significant biological abnormalities in these patients were high levels of glycosylated haemoglobin and mild increases in thrombin generation, indicating slight activation of the coagulation system. The possible significance of these clinical and biological findings is discussed.

Adult↗
PubMed1985

Conjunctival sign in sickle cell anaemia: an in-vivo correlate of the extent of red cell heterogeneity.

A consecutive series of 22 stable adult inpatients with sickle cell anaemia were examined for the presence and severity of spontaneous 'comma' signs of the conjunctiva. Fifteen patients had severe conjunctival signs (more than 10 commas in the worse eye). The presence of severe conjunctival signs was associated with a broader distribution of intraerythrocytic haemoglobin concentrations (p = 0.0005). The patient group with severe conjunctival signs was not found to be significantly different from the group without such signs for age, sex, haemoglobin value, reticulocyte count, alpha-globin gene number, percentage fetal haemoglobin, or the proportion of very dense cells (CHC greater than 37 g/dl). Thus the singular heterogeneity of the erythrocytes in sickle cell disease may be indicative of the factor(s) responsible for the diagnostic comma sign.

Adult↗
PubMed1985

Vision loss without Amsler grid abnormalities in macular subretinal neovascularization.

An 87-year-old woman, with known atrophic senile macular degeneration in one eye, had isolated decreased reading ability while Amsler grid testing was normal. This led to the early diagnosis of macular subretinal neovascularization in the other eye. Thus patients at high risk for neovascular macular degeneration should be made aware of possible subtle changes in vision as well as abnormalities in the Amsler grid. Regular visual acuity check and careful biomicroscopic examination of the macula should be part of each follow-up examination.

Aged↗
PubMed1984

Colour vision in long-standing diabetes mellitus.

In 12 long-standing insulin-dependent diabetics with background diabetic retinopathy their 100-hue colour vision scores were positively related to the degree of retinopathy and negatively to fasting blood glucose levels. However, the 100-hue colour vision scores and types were not significantly different from those of normal subjects matched for age, sex, and social class.

Adult↗
PubMedDate not supplied

Monocular contribution to the peak time of the binocular pattern visual evoked potential.

The contribution of each monocular pathway to the timing of the binocular pattern visual evoked potential was assessed in situations where a significant interocular timing discrepancy was observed. Monocular and binocular pattern visual evoked potentials to 0.5 degree checks were recorded from normal subjects, normal subjects in whom one eye was blurred, patients with monocular amblyopia, and patients with resolved unilateral optic neuritis. Normal subjects showed facilitation, while suppression was evidenced in subjects with monocular blurring. In patients with amblyopia, the affected pathway had no effect on binocular pattern visual evoked potential latency, suggesting that the amblyopic eye was suppressed. In contrast, all patients with optic neuritis showed binocular averaging. Our results show that different forms of binocular interaction are evidenced in normal subjects, in amblyopia and in optic neuritis, and suggest that a comparative analysis of monocular and binocular pattern visual evoked potential peak times brings valuable information to the clinical evaluation that could be used to distinguish disease processes further.

Adolescent↗
PubMedDate not supplied

On- and off-responses in the photopic electroretinogram in complete-type congenital stationary night blindness.

We examined the on- and off-responses of the photopic electroretinogram in patients with complete congenital stationary night blindness. Standard flash electroretinograms as well as those produced in a ganzfeld modified for long-duration light stimuli (500 msec) permitted the separation of on- and off-responses in four patients and four normal subjects. The amplitude and latency of the elctroretinogram on-response (a- and b-waves) and off-response (d-wave) in addition to the oscillatory potentials of the off-response in normal subjects and patients were compared. The abnormal on-response was demonstrated in all the patients, and the off-response with its oscillatory potentials were preserved. We showed that the second portion of the off-response (of inner retinal origin) is normal. If congenital stationary night blindness is a defect of depolarizing bipolar cells, these results preclude input of the depolarizing bipolar cells and support the hyperpolarizing bipolar cells as the cellular origin of the off-response electroretinogram.

Adolescent↗
PubMedDate not supplied

Dependence of TLD thermoluminescence yield on absorbed dose in a thermal neutron field.

The emission from 6LiF and 7LiF thermoluminescence dosimeters (TLDs) exposed to the mixed field of thermal neutrons and gamma-rays of the thermal facility of a TRIGA MARK II nuclear reactor has been investigated for various thermal neutron fluences of the order of magnitude of those utilised in radiotherapy, with the purpose of investigating the reliability of TLD readouts in such radiation fields and of giving some information for better obtainment of the absorbed dose values. The emission after exposure in this mixed field is compared with the emission after gamma-rays only. The glow curves have been deconvoluted into gaussian peaks, and the differences in the characteristics of the peaks observed for the two radiation fields, having different linear energy transfers, and for different doses are shown. Irreversible radiation damage in dosimeters having high sensitivity to thermal neutrons is also reported, showing a memory effect of the previous thermal neutron irradiation history which is not restored by anneal treatment.

Fluorides↗
PubMedDate not supplied

Increased urinary-free cortisol outputs in diabetic patients.

We previously reported that diabetic patients show evidence of dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. To extend this work, we examined urinary-free cortisol (UFC) outputs in diabetic patients and whether or not they relate to diabetic complications. We compared a group of 35 insulin-dependent diabetic outpatients with a group of 32 normal controls for 24-h UFC outputs and examined the patients for relationship between UFC outputs and diabetic complications. Diabetic patients had significantly greater 24-h UFC outputs than controls. There was a significant positive correlation between 24-h UFC outputs and duration of diabetes. There were trends for patients with either diabetic retinopathy or diabetic cardiovascular complications to have higher 24-h UFC outputs than patients without these complications. These results further show that diabetic patients have mild dysregulation of the HPA axis. This dysregulation is related to longer duration of diabetes. A larger sample is needed to examine further for a relationship to diabetic complications.

Adolescent↗
PubMedDate not supplied

[A new method in the analysis of vitreous fluorophotometry. Results in early diabetic retinopathy].

New methodology to analyze posterior vitreous fluorophotometry (PVF) data is described. Values for D, fluorescein vitreous diffusion coefficient and P, permeability of the blood retinal barrier (BRB) to fluorescein are obtained. D was found to be significantly greater in diabetic patients with minimal retinopathy compared with either controls or patients with no retinopathy. P values were not significantly different between diabetic patients and controls or between diabetic subgroups, confirming the absence of breakdown of the BRB, as assessed by PVF, in early diabetic retinopathy.

Adult↗