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Biomedical subjects

J Howell

Publications and source records attributed to J Howell.

At least 55 records · Page 3Linked to original sources
PubMed1987

Reliability of NPT scoring and visual estimates of erectile fullness.

We report the reliability of nocturnal penile tumescence (NPT) scoring and visual estimates of erectile fullness performed by a group of eight registered polysomnographic technologists (RPSGTs). We achieved overall good to excellent interrater reliability (as measured by coefficients of variation, CVs) for seven widely used electrographic measures of NPT activity: number of episodes, categorization of episodes (full or partial), total tumescence changes, tip change, base change, duration of episode, and duration of 80% maximum tumescence. In two different visual estimate trials using photographs, separated by 2 weeks, female technologists (n = 4) made mean visual estimates of erectile fullness that were significantly higher than those of male technologists (n = 4). In addition, the CVs among the female technologists on visual estimates was consistently lower than those of the males. Higher correlations, however, were found between male technologists' estimates of fullness versus buckling force than for female technologists' estimates. Thus, the gender of a technologist may affect visual estimates of erectile fullness during NPT assessment.

Adult↗
PubMed1987

Do nocturnal penile tumescence recordings alter electroencephalographic sleep?

While concurrent monitoring of sleep is considered to be a necessary component of evaluating nocturnal penile tumescence (NPT), in order to ensure that NPT data are not invalidated by fragmented sleep or diminished REM sleep, it is not known whether NPT recording itself disrupts sleep beyond the expected first night effect. In this study of 42 outpatient men with major depression and 36 normal control subjects, we found no effect of NPT recording on measures of sleep continuity, proportion of NREM to REM sleep, or REM sleep in either depressed or healthy control subjects.

Depressive Disorder↗
PubMed1987

Cerebral dominance, sex, and callosal size in MRI.

We measured the MRI area of corpus callosum in 104 normal adults, 51 men, 53 women, 52 right- and 52 left-handers. There were no significant sex or handedness differences. Callosal areas did not correlate with brain size nor with measures of lateralization for hand performance, dichotic listening, or visual field preference. The results are contrary to the notion of increased callosal connectivity in left-handers, women, or individuals with less-lateralized function.

Adolescent↗
PubMed1986

Cerebral asymmetries on magnetic resonance imaging.

Magnetic Resonance Imaging (MRI) reveals anatomical asymmetries of the sulcal demarcation of the posterior operculum from the parietal cortex that correlate with handedness in normal subjects. The sulcal demarcation is greater on the right in most right handers, but evenly distributed in left handers. This in vivo asymmetry corresponds to the commonly larger planum temporale on the left side. Hand Preference, Hand Performance, Dichotic Listening and Visual Field Preference measures were correlated with several measures of anatomical asymmetries seen on MRI. The sulcal demarcation, anterior frontal width and parietal width correlated best with hand performance, as measured on a dot tapping task. The biological significance of the distribution of anatomical and functional asymmetries is discussed.

Adult↗
PubMed1985

Hypereosinophilic heart disease.

A 45-year-old patient with cardiac involvement from the idiopathic hypereosinophilic syndrome suffered from severe congestive cardiac failure with progressive deterioration despite intensive medical therapy. Investigations indicated bilateral ventricular infiltration with endomyocardial fibrosis which had caused severe haemodynamic restriction and bilateral atrioventricular valvular incompetence. Extensive surgery, which included bilateral ventricular endomyomectomy and mitral and tricuspid valve replacements, resulted in a significant improvement for six months.

Endomyocardial Fibrosis↗
PubMed1985

Pyridoxine deficiency in children treated with isoniazid.

Isoniazid-induced deficiency of pyridoxine (vitamin B6) is reportedly not uncommon in adults but rare in children. In the present study, 38 children had serum levels of pyridoxine tested while receiving therapy with isoniazid. A biologic assay using the protozoan Tetrahymena thermophila determined pyridoxine status after 2 to 18 months of therapy with isoniazid. Five children (13 percent) were deficient. None had definitive clinical symptoms or signs consistent with pyridoxine deficiency. Three had normal nerve conduction velocity. Children receiving isoniazid in dosages greater than 10 mg/kg/day had a higher incidence of deficiency. Present recommendations for withholding pyridoxine prophylaxis from children receiving isoniazid therapy must be reconsidered in light of these findings, particularly in those children who are debilitated or have a poor nutritional history with a known pyridoxine deficit prior to therapy with isoniazid.

Child↗
PubMed1981

Possible fenthion toxicity in magpies (Pica pica).

Unusual mortality in magpies (Pica pica) is described. Dead or sick birds were discovered in proximity to cattle in Alberta feedlots. Subsequent examinations indicated magpies were being exposed to fenthion, an organophosphate used on cattle for control of warble larvae and lice. The possibility of toxicity with fenthion is suggested.

Animals↗
PubMed1981

Adverse effects of caffeine and theophylline in the newborn infant.

The desirable effects of methylxanthine use in the neonate, appropriately prescribed and monitored, outweigh the importance of adverse effects. This view assumes that pharmacologic manipulation of apnea of prematurity is in itself a desirable goal and clearly superior to treatment of apneic episodes when they occur. While a considerable body of evidence supports this current practice, conclusive documentation awaits long-term follow-up studies.

Apnea↗
PubMed1979

Clinical significance of an ultrafast alkaline phosphatase isoenzyme.

We have studied five patients who have exhibited an unusual alkaline phosphatase isoenzyme (ALP EC 3.1.3.1) migrating in an ultrafast position electrophoretically on cellulose acetate. This ALP isoenzyme has been identified in patients with benign and malignant liver diseases. In addition, a number of these patients exhibited a regular ALP liver isoenzyme and a fast (preliver) ALP isoenzyme in conjunction with the ultrafast ALP liver isoenzyme.

Adult↗
PubMed1979

The presence of serum creatine kinase 2 (MB) in hypokalemic familial periodic paralysis.

We recently found 17 U/l of isoenzyme creatine kinase (CK) 2 (MB), or 3.2% of total 533 U/l CK activity, in a patient with hypokalemic familial periodic paralysis who did not show clinical or EKG evidence of acute myocardial necrosis. The myopathy associated with hypokalemic familial periodic paralysis is thus another cause for the presence of CK 2 (MB). CK 2 (MB) is not a specific isoenzyme for myocardial damage since it may be identified in the serum of patients with skeletal muscle conditions.

Adult↗
PubMed1979

Suspected reticuloendotheliosis in turkeys with cutaneous lesions reminiscent of fowl pox.

Twelve turkeys from a flock of 2,500 had cutaneous lesions somewhat resembling fowl pox. Lymphoid-like tumors were evident in livers and spleens. Closer examination of cutaneous lesions, and histopathological examinations indicated skin lesions were also infiltrative and not unlike reticuloendotheliosis. Electron micrographs revealed the presence of C-type virus particles.

Animals↗