Qualitative differences in tactuo-spatial motor learning by left-handers

Tactuo-spatial performance was studied as a function of subject handedness and hand employed in learning and transfer. Seventy-eight dextral and 75 sinistral blindfolded subjects learned a finger-maze with either dominant or nondominant hand. Transfer to the untrained hand was assessed with either an identical or a mirror-image version of the maze. Left hand acquisition required fewer trials; latencies were shorter when the dominant hand was used. All dextrals and those sinistral subjects who used the right hand in acquisition showed superior transfer to the identical maze. Sinistral subjects who used the left hand in acquisition demonstrated facilitated transfer to the mirror image maze. Results are suggested to provide evidence of two qualitatively different hemispheric strategies for encoding tactuo-spatial information.     

Physiology of sucking in the normal term infant using real-time US

Our study of 16 normal term, breast-fed infants documents real-time ultrasound as a technique for evaluating the oral portion of the sucking mechanism in infants. We also describe the mechanics of sucking used by the infants during breast-feeding.     

Potentiation of the Antiepileptic Activity of Phenobarbital by Nicotinamide

Nicotinamide is a ligand of the benzodiazepine receptor and has been reported to have anticonvulsant activity. In addition, our previous clinical experience has raised the possibility that it may also potentiate the action of barbiturates. Therefore, we have examined the anticonvulsant activity and neurotoxicity of nicotinamide alone and in combination with phenobarbital in mice. Nicotinamide had its maximal anticonvulsant effect 15 min and its maximal sedative effect 45 min after intraperitoneal injection. At 15 min, the median effective dose was 586.5 mg/kg against bicuculline and 2,019 mg/kg against pentylenetetrazol. Nicotinamide was ineffective against maximal electroshock. It had a sedative effect, with a median toxic dose of 874.8 mg/kg by the Rotorod Toxicity Test at 45 min. At doses that were ineffective by themselves (0.01 effective dose) nicotinamide potentiated the anticonvulsant activity of phenobarbital against bicuculline and pentylenetetrazol, but the toxicity was not potentiated and therefore the therapeutic index of phenobarbital was improved by nicotinamide. These results suggest that nicotinamide may be useful as a therapeutic adjunct for the treatment of epilepsy with phenobarbital or primidone.     

Head injury in child abuse: evaluation with MR imaging

To evaluate the usefulness of magnetic resonance (MR) imaging in the diagnosis of head injury in child abuse, the authors compared the findings at head MR imaging and computed tomography (CT) in 19 abused children. Subdural hematomas (15 cases), cortical contusions (six cases), and shearing injuries (five cases) were demonstrated to particular advantage with MR imaging. CT remained superior in the detection of subarachnoid hemorrhage. MR imaging appears to be valuable in the assessment of patients with suspected intracranial injury due to child abuse.     

Clinical characteristics of ovulation induction with human menopausal gonadotropins with and without leuprolide acetate in polycystic ovary syndrome

Ovulation induction in polycystic ovary syndrome (PCOS) with human menopausal gonadotropins (hMG) results in suboptimal cycle fecundity and frequently is complicated by ovarian hyperstimulation. The use of a gonadotropin releasing-hormone agonist (Gn-RH-a) with hMG induction of ovulation may improve the therapeutic outcome. In this prospective, randomized trial, 27 women with PCOS underwent a total of 25 cycles of hMG alone and 33 cycles with adjunctive GnRH-a (leuprolide) treatment. Premature luteinization was seen less frequently in the leuprolide-treated cycles than in cycles treated with hMG alone. There were no differences between the treatments in ovarian sensitivity to hMG. Cycle fecundity was 0.16 for hMG alone cycles, and 0.27 for leuprolide with hMG cycles, which were not statistically different. We conclude that the sensitivity of the PCOS ovary to hMG is not affected by 4 weeks of leuprolide pretreatment.     

PREVALENCE OF MITRAL VALVE PROLAPSE IN HONG KONG CHINESE A CLINICAL AND AUTOPSY STUDY

The prevalence of mitral valve pro.lapse in Chinese was determined by screening 156 heal- thy subjects and by patholobic examination of 86 adult autopsies. Mitral valve prolapse was found in 7.7% in the clinical study and 5.8% in the autopsy study. A slight female preponderance was noted.     

Serum thyroglobulin levels predict total body iodine scan findings in patients with treated well-differentiated thyroid carcinoma

Forty-eight consecutive patients with treated thyroid carcinoma were studied with 131-I total body scans and serum thyroglobulin (hTg) levels. Serum hTg levels during thyroxine treatment accurately predicted scan results (chi square = 18.6, p < 0.001). All patients with negative scans (24 patients) had serum hTg levels (< 7 ng/ml whereas in patients with metastatic thyroid cancer (eight patients) they ranged from 11 to 690 ng/ml. In patients with iodine uptake confined to the thyroid bed (16 patients) serum hTg values ranged from 2 to 17 ng/ml. Serum hTg levels rose in patients with negative scans during hypothyroidism or after exogenous TSH suggesting that hTg levels are more sensitive than iodine scans in detecting residual thyroid tissue. Serum hTg levels could replace total body iodine scans in many patients with treated thyroid carcinoma.     

Butyrate production from oligofructose fermentation by the human faecal flora: what is the contribution of extracellular acetate and lactate?

Butyrate is an important substrate for maintenance of colonic health and oligofructose fermentation by human faecal bacteria can increase butyrate production in vitro. However, oligofructose appears to be fermented by mainly acetate and lactate-producing bacteria rather than butyrate-producing bacteria. Isotope labelling studies using [U-(13)C(6)]glucose were used to show that (13)C(2) and (13)C(4) were the major labelled butyrate species produced from glucose fermentation, via [(13)C(2)]acetate-acetyl CoA as intermediate. Bacterial interconversion reactions were quantified and acetate conversion to butyrate and lactate conversion to acetate, propionate and butyrate were observed. Addition of oligofructose to faecal batch cultures significantly increased butyrate production. Of the newly synthesised butyrate from oligofructose fermentation, 80 % was derived from interconversion of extracellular acetate and lactate, with acetate being quantitatively more significant. Carbohydrates, such as oligofructose, have prebiotic properties. In addition, oligofructose selectively stimulates the bacterial conversion of acetate and lactate to butyrate. Carbohydrates with similar properties represent a refinement of the prebiotic definition, termed butyrogenic prebiotics, because of their additional functionality.