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Biomedical subjects

M A Hamid

Publications and source records attributed to M A Hamid.

8 recordsLinked to original sources
PubMed1991

Vestibular and postural findings in the motion sickness syndrome.

The motion sickness syndrome constitutes varying degrees of subjective motion intolerance and three objective findings: hyperactive VOR (79%), hip sway strategy (60%), and positional nystagmus (42%). It is present in subjects who have a strong history of motion sickness. Vestibular rehabilitation appears to help control symptoms. The study also suggests an inheritance pattern, but a structured pedigree could not be constructed. Prospective studies are warranted to further establish the patterns of the motion sickness syndrome.

Adolescent↗
PubMed1991

Determining side of vestibular dysfunction with rotatory chair testing.

Determining side of vestibular lesion remains a challenging task during neurotologic investigations, particularly if auditory lateralizing signs are absent. Traditionally, absent or decreased caloric response has been regarded as evidence of unilateral vestibular deficit. But, the inability of the chair test to detect side of lesion has been generally accepted because rotation stimulates both end organs. A retrospective study postulated and tested a hypothesis that low-frequency asymmetry of sinusoidal harmonic acceleration (SHA) testing can determine side of lesion when phase is abnormal. The present prospective, double-blind study was designed to further test the retrospective study hypothesis. Results showed that SHA asymmetry detects side of unilateral vestibular deficit when phase is abnormal in 97% of cases.

Caloric Tests↗
PubMed1990

An enzymatic assay for the colorimetric and fluorimetric determination of uric acid in sera.

The methods described in this paper are based on the uricase catalyzed oxidation of uric acid to allantoine and hydrogen peroxide. By making use of the catalytic activity of peroxidase the generated H2O2 is measured either spectrophotometrically with 3-methyl-benzothiazoline-2-one hydrazone (MBTH) and 3-dimethylaminobenzoic acid (DMAB) (M1) or fluorimetrically with tyramine (M2) or L-tyrosine (M3). The methods are simple, sensitive and selective. The procedures developed can be rapidly and readily performed on patient serum samples without deproteinization using 100 microliters and 5 microliters for colorimetric and fluorimetric assay, respectively.

Colorimetry↗
PubMed1990

Clinical value of sinusoidal harmonic acceleration test results. Site of lesion and side of lesion.

Sinusoidal harmonic acceleration tests can be used reliably to determine site and side of lesion. Results from 6000 patients collected over the past 10 years have shown that the temporal pattern of asymmetry can be reliably used to differentiate peripheral from central vestibular dysfunction. Peripheral cases tend to have a high level of asymmetry, with temporal regression to normal range, and a high correlation with patient symptoms. Central cases tend to have a low level of variable asymmetry and variable symptoms. In either case, phase can be abnormal or normal and cannot be reliably used to differentiate peripheral from central dysfunction. By combining phase and symmetry, the side of the lesion can be reliably determined. When phase is abnormal, asymmetry is toward the side of the lesion in 92 per cent of cases, whereas when phase is normal, asymmetry cannot be reliably used to determine side of lesion. SHA testing has contributed significantly to our clinical ability to fully evaluate the vestibular system and has become an indispensable part of the complete vestibular laboratory. It requires a relatively large patient load as well as software and hardware support to become a cost-effective utility.

Acceleration↗
PubMed1979

Implementing a computer-based electro-oculographic analysis system.

Electro-oculographic recordings of caloric-induced nystagmus were conducted in a number of normal and disordered subjects. On the basis of the results, implementation of a clinical measuring system is considered; this is based on the interbeat interval, selected in view of its favourable sensitivity and stability. Two stages of processing are involved; first, the determination of the interbeat intervals, second the analysis. The first stage has been implemented off-line on a general purpose computer and also, in on-line mode, by special purpose electronics. The second stage requires computer analysis. We have used the rank magnitude sequences of interbeat intervals as the basis of the analysis.

Adult↗
PubMed1975

Some aspects of gallstone: a clinico-biochemical correlation.

Bile samples obtained from gallbladders and common bile ducts of patients operated on for gallstone disease in the surgical unit, Medical School, University College Hospital, London between October 1971 and October 1972 were analyzed. The results presented support the view that the presence of cholesterol gallstones is usually associated with abnormal bile in which the relative concentrations of bile salts, phospholipids and cholesterol differ markedly from those found in normal or non-lithogenic bile.

Adult↗