Biomedical subjects

S M Rassam

Publications and source records attributed to S M Rassam.

4 recordsLinked to original sources

PubMed1992

Retinal vessel measurement: comparison between observer and computer driven methods.

A method of semi-automated image analysis for the measurement of retinal vessel diameters is described. This was compared with an observer-driven method for reproducibility and accuracy. The coefficient of variation for the data from the semi-automated method was 1.5-7.5% (depending on the vessel diameter) compared to 6-34% with the observer-driven method. The mean vessel diameters using the observer-driven method tended to be higher; however, this did not reach significance. The speed and low inter- and intra-observer variability for the semi-automated method make it a useful technique for measuring retinal blood vessel diameters. A larger variability was found between photographs taken at different times. This may be due to changes in retinal vessel diameter with changes in retinal perfusion pressure during the cardiac cycle.

Diabetic Retinopathy↗

PubMed1992

Abnormalities of chromosome 16q in myeloid malignancy: 14 new cases and a review of the literature.

Fourteen patients with abnormalities of chromosome 16q, 13 with acute myelogenous leukaemia (AML), and one with refractory anaemia with excess of blasts (RAEB), are described. Seven patients had inv(16)(p13q22), two had del(16)(q22), and five had other abnormalities of 16q. Six of the seven patients with inv(16) had AML M4Eo and, following treatment with adriamycin, cytosine arabinoside, and 6-thioguanine, all achieved complete remission (CR). Neither patient with del(16)(q22) had typical M4Eo morphology at diagnosis; CR was achieved in one and one had resistant leukaemia. Patients with other abnormalities of 16q had blasts of diverse morphology and, although morphologically abnormal eosinophils were seen in three patients, this was not as marked as in the patients with inv(16). CR was achieved in two of the four patients with other abnormalities of 16q but duration of remission was short in both cases. These results suggest that most patients with del(16)(q22) and other abnormalities of 16q22 do not have typical AML M4Eo. Such patients tend to have a worse prognosis, and are more likely to have complex karyotypes typical of secondary leukaemia.

Adult↗

PubMed1989

A myelokathexis-like variant of myelodysplasia.

A 34-year-old woman presented with pancytopenia, profound neutropenia and repeated infections. A bone marrow specimen revealed hypercellularity with trilineage dysplasia and bizarre granulocytic morphology identical to that of the rarely reported myelokathexis. Investigations revealed defects in platelet and neutrophil functions and markedly reduced colony-to-cluster ratio in bone marrow culture. She required treatment with antibiotics, surgical intervention for a gangrenous abdominal wall, and eventually underwent a successful allogeneic bone marrow transplant from her sister. This case suggests that myelokathexis is an unusual form of myelodysplasia with a relatively benign course and presenting at a young age.

Adult↗

PubMedDate not supplied

The effect of beta blockers on retinal blood flow in diabetic patients.

The effect of a single oral dose of propanolol 80 mg, dilevalol 200 mg, salbutamol 4 mg, and placebo on the systolic (BPs), diastolic blood (BPd), intraocular pressure (IOP), on retinal vessel diameter (D), blood velocity (Vmax) and volumetric retinal blood flow (RBF), was measured at baseline, 90 minutes and three hours after administration in normotensive diabetic volunteers. These drugs were chosen to demonstrate a range of beta receptor activity. Propanolol is a non-specific beta blocker, affecting beta 1 and beta 2 receptors, dilevalol has beta 1 antagonist and beta 2 agonist effects and salbutamol has beta 2 agonist effects. Retinal blood flow was measured by bidirectional laser Doppler velocimetry (BLDV) and red free photography. Dilevalol reduced the mean BPs by 10.4 mmHg (SD 4.2, P less than 0.05), the mean BPd by 7 mmHg (SD 3.8, P less than 0.05), whereas propanolol, salbutamol and placebo had no significant effect. Propanolol reduced the mean intraocular pressure by 4.88 mmHg (SD 1.8, P less than 0.01). No treatment had a significant effect on retinal perfusion pressure. In all treatments the vessel diameter and volumetric flow remained unchanged, and there was no significant difference between the treatments. The mechanisms of action of these drugs are analysed and the possible implications of their use in patients with retinal disease are discussed.

Administration, Oral↗