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Biomedical subjects

T V Nowak

Publications and source records attributed to T V Nowak.

29 records · Page 2Linked to original sources
PubMed1985

Effect of substance P on opossum duodenal smooth muscle.

Opossum duodenum was cut into strips measuring 2.0 X 15.0 mm. Strips cut along the oral-caudal axis were called longitudinal strips, while those cut 90 degrees to that axis were called circular strips. Each strip was placed in a heated, oxygenated organ bath and attached to a force-displacement transducer. Substance P produced tonic contraction in longitudinal strips and tonic and phasic contraction in circular strips. The ED50 for longitudinal and circular muscle was 1.9 X 10(-7) M and 2.8 X 10(-7) M, respectively. Longitudinal muscle was 1.3 times more sensitive to substance P than circular muscle. Phenoxybenzamine, atropine, curare, propranolol, haloperidol, and tetrodotoxin had no effect on the substance P-produced contractions in circular and longitudinal muscle. Trifluoperazine (10(-5) and 10(-4) M), D600 (10(-7) M), and nifedipine (10(-8) and 10(-7] inhibited both tonic and phasic contraction in circular and longitudinal strips. These studies suggest that substance P acts on both muscle layers at a site located at the muscle cell and that it produces tonic and phasic contraction through similar calcium-activating pathways.

Animals↗
PubMed1985

Effect of cholinergic agonists on muscle from rodent proximal and distal small intestine.

Proximal and distal rat small intestine was cut into strips measuring 6.0 X 10.0 mm. Strips cut along the oral-caudal axis were called longitudinal strips, whereas those cut 90 degrees to that axis were called circular strips. Stress in circular and longitudinal muscle strips was measured continuously as they were superfused with acetylcholine, carbamylcholine, methacholine, bethanechol, or physostigmine. Resting stress during stretch, acetylcholine-stimulated active stress, and total stress were determined. Proximal circular muscle was five times as sensitive to acetylcholine as distal circular muscle (p less than 0.05); proximal longitudinal muscle was 2.8 times as sensitive to bethanechol as distal muscle (p less than 0.05). Resting, active, and total stress were similar in proximal and distal muscle, but circular muscle showed nearly twice the resting stress of longitudinal muscle at either proximal or distal sites (p less than 0.05). Physostigmine (10(-6) M) increased acetylcholine-stimulated active stress in proximal and distal circular muscle by 29% and 70%, respectively (p less than 0.05), but not in longitudinal muscle (p greater than 0.05). This difference between proximal and distal circular muscle (41%) was also significant (p less than 0.05). Thus, the proximal and distal muscle of the rat small intestine differs in its sensitivity to various cholinergic agonists, but not in its length-stress properties.

Acetylcholine↗
PubMed1985

Prediction of kidney mercury content by isotope techniques.

A 61-year-old female patient accidentally aspirated liquid mercury during a medically ordered diagnostic procedure. To develop animal-based guidelines, liquid mercury was introduced into the lungs of four dogs. Based on the study of these animals, a method of predicting the kidney inorganic mercury burden was developed using radioactive isotope dilution techniques. It was further demonstrated in dogs that oral administration of dimercaptopropane sulfonate (DMPS) increased mercury excretion and reduced the kidney burden. A rat experiment was performed permitting a statistical evaluation of the assumptions basic to the use of the method. The method was applied to the patient with the result that the kidney inorganic mercury burden was predicted to be 28.1 mg, 8 months after the accident. Treatment with DMPS increased urinary excretion and the post-treatment kidney burden was estimated at 19.6 mg Hg. Inasmuch as the radioactive dose to the subject may be kept at a negligible level and because sensitive methods exist for measurement of radioactive and stable mercury concentrations, the technique may be applicable in special cases to the estimation of kidney inorganic mercury burdens incurred by industrial exposure.

Animals↗
PubMed1984

Small intestinal motility in myotonic dystrophy patients.

We performed jejunal manometric studies on 10 myotonic dystrophy patients who had symptoms of disordered gastrointestinal motility. Reduced peristalsis of the duodenum and proximal jejunum was noted in 1 patient who had an upper gastrointestinal series, but the small bowel was radiographically normal in 8 other patients. None of the myotonic dystrophy patients had a normal jejunal manometry. The abnormalities included low amplitude contractions during phases 2 and 3 of the migrating motor complex and after eating, as well as a higher frequency of contractions during phase 2. Retrograde propagation of phase 3 occurred in 2 patients, and interruption of contractions during phase 3 occurred in 4 patients. The incidence of tonic contractions was also higher in myotonic dystrophy patients. We conclude that (a) abnormal small intestinal motility is common in patients with myotonic dystrophy and (b) jejunal manometry is more sensitive than barium radiographic studies in detecting small intestinal motility abnormalities in this disorder.

Adolescent↗
PubMed1983

Celiac sprue in Down's syndrome: considerations on a pathogenetic link.

The association of celiac disease with Down's syndrome is described in two patients who presented with features of the malabsorption syndrome. The diagnosis was readily made by peroral jejunal mucosal biopsy. Both patients responded clinically to dietary gluten withdrawal and one patient demonstrated a recrudescence of symptoms and reappearance of jejunal mucosal atrophy upon rechallenge with dietary gluten. Genetic considerations in the etiology of both disorders are discussed.

Adolescent↗
PubMed1983

A familial visceral myopathy with external ophthalmoplegia and autosomal recessive transmission.

A new visceral myopathy family was identified. The disease in this family is transmitted by an autosomal recessive gene. Only 3 patients were identified from approximately 1500 family members. All 3 patients are the products of intermarriage. The patients had gastric atony, dilatation of the entire small bowel, and multiple diverticula throughout. Pathology of the jejunum showed fibrosis and degeneration, mainly of the longitudinal muscle layer, indistinguishable from that of previously reported families. Two of the patients also had ptosis and external ophthalmoplegia. Jejunal manometric studies were performed on the proband's asymptomatic mother and five siblings. All had normal esophageal manometric studies and upper gastrointestinal x-rays. The mother and three siblings had abnormal jejunal manometric studies characterized by the absence of phase 1 in some of the migrating motor complexes and increased motility indices in phase 2. We conclude that familial visceral myopathy can be transmitted by an autosomal recessive gene, and that jejunal manometry is a sensitive technique to identify asymptomatic heterozygotes.

Adult↗
PubMed1982

The substituted benzamides in gastroenterology.

The gastrointestinal tract possesses an intrinsic nervous system whose morphology, function, and neuropeptides show many similarities to those of the brain. The central nervous system and the gut's intrinsic nervous plexus are linked together by a network of extrinsic nerve fibers. The majority of these nerve fibers are afferent and relate messages from the gut to the central nervous system. The remainder are efferent fibers which can excite or inhibit gut activity by influencing mechanisms within the intrinsic nervous plexus. Many syndromes of altered gut activity are ascribed to psychosomatic factors, and treatment of these disorders is frequently directed at the central nervous system. Although substituted benzamides act on the central nervous system, enforcement of central nervous control of gut activity does not seem relevant to their clinical efficacy and little is known about their effect on sensations originating in the gut. It is tempting to ascribe similar activities for these agents both in the gut and in the brain. Nevertheless, it appears that cholinergic rather than antidopaminergic mechanisms govern the peripheral actions of these agents.

Benzamides↗
PubMed1982

Gastrointestinal manifestations of the muscular dystrophies.

Skeletal and cardiac muscle involvement is a recognized feature of the muscular dystrophies. Visceral smooth muscle involvement of the gastrointestinal tract is not as well appreciated. Gastrointestinal symptoms may herald the onset of a muscular disorder and may be the predominant feature of the disorder. In some instances, smooth muscle dysfunction may be the only clinical manifestation of the disease. The gastrointestinal manifestations of the various muscular dystrophies are reviewed. Clinical, radiographic, and histologic features are discussed. Further study of the histopathology and pathophysiology of visceral smooth muscle involvement in the muscular dystrophies will have a substantial impact on treatment that, to a large extent, remains empiric.

Adolescent↗
PubMed1979

Reye's syndrome in nonpediatric age groups.

Reye's syndrome (encephalopathy and fatty liver) is generally considered a disease of children. Four patients, aged 16, 18, 19, and 23 years, with Reye's syndrome were initially seen by internists. A viral prodrome followed by vomiting and encephalopathy without focal neurological signs or jaundice clinically suggested Reye's syndrome. Normal findings of CSF examination (except for increased opening pressure), abnormal findings of liver function tests, and increased blood ammonia further supported the diagnosis. None was hypoglycemic. Reye's syndrome was related to influenza B virus in three patients and to Varicella in another. Three patients survived. Reye's syndrome may be seen intially by general practitioners, emergency room physicians, internists, or psychiatrists. The importance of considering this syndrome in the differential diagnosis of unexplained encephalopathy in adults is stressed.

Adolescent↗