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Biomedical subjects

W E Karnes

Publications and source records attributed to W E Karnes.

At least 37 records · Page 2Linked to original sources
PubMed1990

The gastrin hypothesis. Implications for antisecretory drug selection.

Newer potent and long-acting inhibitors of acid secretion, such as the proton pump inhibitor omeprazole, are becoming available for general use. These drugs promise to control acid-peptic disease effectively in patients who do not respond adequately to conventional short-acting H2-receptor antagonists. The safety of chronic administration of these drugs has come into question, however. Lifelong profound inhibition of acid secretion in rats induced by superpotent inhibitors of acid secretion or subtotal fundectomy is associated with the development of carcinoid tumors of enterochromaffin-like (ECL) cells in the gastric corpus. Available evidence supports a role of gastrin, which becomes chronically elevated in animals subjected to prolonged and profound hypochlorhydria. In humans, hypergastrinemic states such as Zollinger-Ellison syndrome and atrophic gastritis are associated with an increased risk of ECL-cell carcinoid tumors. Such observations have raised concern that humans may also be susceptible to carcinoid tumor formation in response to potent inhibitors of acid secretion. To date, however, no cases of carcinoid tumor have been attributed to the use of omeprazole in humans. If achlorhydric doses are not used, significant hypergastrinemia can be avoided while effectiveness of treatment is maintained. Such measures should minimize any risk of ECL-cell carcinoid tumors in humans taking potent long-term antisecretory drugs.

Achlorhydria↗
PubMed1989

Prolonged inhibition of meal-stimulated acid secretion and gastrin release following single subcutaneous administration of octreotide (SMS 201-995) in man.

Single subcutaneous doses of the somatostatin analogue, SMS 201-995, were evaluated for the degree and duration of effects on acid secretion, serum gastrin levels, and gastric emptying in eight human male subjects (mean age 44 years) over an 8-h period. All the subjects received subcutaneous 50-micrograms and 100-micrograms doses of SMS 201-995 and placebo on three separate days in a double-blind random order. Drug or placebo was administered at time 0 followed by peptone meals at time 0, 2, 4, and 6-h. Peptone meals were evacuated at time 1, 3, 5 and 7-h to create 'basal' conditions between alternate hours. Gastric acid secretion was determined hourly beginning at time--1. Both the 50-micrograms and 100-micrograms doses of SMS 201-995 significantly inhibited 'basal' and peptone meal-stimulated gastric acid secretion throughout the 8-h measurement period. The minimum effective plasma concentration of SMS 201-995 for inhibition of peptone meal-stimulated gastric acid secretion was approximately 1000 pg/ml. Peptone meal-stimulated plasma gastrin concentrations were inhibited for 5 and 7 h after 50-micrograms and 100-micrograms doses of SMS 201-995, respectively, whereas 'basal' plasma gastrins were inhibited for 4 and 6 h, respectively. Gastric emptying determined by marker dilution was not significantly enhanced compared to placebo. These results indicate prolonged and potent effects of single subcutaneous doses of SMS 201-995 on peptone-meal stimulated acid secretion and gastrin release.

Adult↗
PubMed1987

Herpes zoster arteritis: pathological findings.

This paper describes the pathological findings in two cases of delayed contralateral hemiparesis following herpes zoster arteritis. Both died of cerebral haemorrhage and a necrotizing angiitis was found involving the major vessels of the ipsilateral cerebral hemisphere. No feature of granulomatous arteritis or of encephalitis was found. It is likely that the virus spreads along intracranial branches of the ophthalmic nerve supplying the major arteries and causes the inflammatory reaction by direct invasion of vascular muscle.

Aged↗
PubMed1982

Interictal psychopathology in patients with ictal fear: a quantitative investigation.

We assessed the hypothesis that psychopathology is overrepresented in patients with temporal lobe epilepsy (TLE) who experience ictal fear. Eleven such patients were matched with two control groups: patients who had TLE without ictal fear and patients who had generalized epilepsy. On several MMPI scales, the TLE-ictal fear group scored significantly higher than the two control groups, which did not differ significantly from each other. Furthermore, the TLE-ictal fear group had more MMPI clinical scales that were pathologically elevated, had significantly more patients with histories of admission to psychiatric hospitals, and had more MMPI profiles that were psychotic than either of the control groups.

Adult↗
PubMed1981

Psychosis and epilepsy: seizure-type comparisons and high-risk variables.

Compared 153 patients with temporal lobe epilepsy (TLE) and 79 patients with generalized epilepsy on the Goldberg Index, an MMPI-derived measure of psychosis. Analysis of covariance indicated that seizure type was not related to psychosis. Multiple regression analyses indicated that, in TLE, being female was correlated positively with Goldberg Index scores. In the group with generalized epilepsy, none of the variables was associated significantly with psychosis scores.

Adult↗
PubMed1981

Angiographic findings in herpes zoster arteritis.

Four adults patients who experienced an ipsilateral hemispheric deficit 6 to 8 weeks after having developed herpes zoster ophthalmicus were seen during a six-month period. All four patients underwent full-circle angiography, including study of the extracranial arteries in the three older patients. Each examination demonstrated areas of segmental constriction of arteries on the ipsilateral side; two locations that were especially affected were the A2 segment of the pericallosal artery beneath the genu of the corpus callosum and the M4 segment of the middle cerebral artery. The cerebral arteries of the opposite hemisphere and the extracranial vessels did not contain demonstrable abnormalities. Pathological studies suggest that patients with this syndrome may have a necrotizing arteritis of ipsilateral blood vessels; in patients with disseminated zoster, a granulomatous angiitis of cerebral blood vessels has been found. We propose that the pattern of angiographic abnormalities described here is characteristic of herpes zoster arteritis; furthermore, the distribution pattern of the lesions suggests that the virus may spread to these arteries via branches of the ophthalmic division of the trigeminal nerve.

Adult↗
PubMed1980

Psychopathology in epilepsy: relationship of seizure type to age at onset.

Study of patients with temporal lobe epilepsy and generalized epilepsy revealed no overall seizure type differences, nor overall age-at-onset effects, on MMPI measures of psychopathology. However, statistically significant interactions between seizure type and age at onset were obtained on several MMPI measures, and subsequent analyses revealed that patients with adolescent-onset temporal lobe epilepsy are at higher risk of developing psychological dysfunctions.

Adolescent↗
PubMed1980

Aggression and epilepsy: seizure-type comparisons and high-risk variables.

One hundred fifty-three patients with temporal lobe epilepsy and 79 patients with generalized epilepsy were compared on a measure of aggression (derived from the Minnesota Multiphasic Personality Inventory). Analysis of covariance indicated that seizure type was not related to aggression. Multiple-regression analyses for each seizure group indicated that in temporal lobe epilepsy the chronologic age was inversely correlated with aggression scores. In the group with generalized epilepsy, chronologic age and myoclonic seizures were inversely correlated with aggression, while akinetic seizures were directly associated with increased aggression.

Adult↗
PubMed1978

Near-fatal and fatal anaphylactic reactions to insect sting.

Two patients experienced anaphylactic reaction to insect stings, with residual encephalopathy. One patient had anaphylaxis despite hyposensitization with whole-body extracts, thus supporting recent reports that reliable protection cannot be achieved unless pure venom is used. The other patient had pathologic confirmation of anoxic encephalopathy, thus supporting the concept that encephalopathy with anaphylaxis is secondary to associated circulatory collapse rather than a primary allergic response of brain disease.

Allergens↗
PubMed1976

Clinical observations on thyrotoxicosis coexisting with myotonic dystrophy.

Two cases are presented and a third is cited from the literature in which the onset of hyperthyroidism exacerbated acute weakness in previously undiagnosed myotonic dystrophy. In two of the cases a return to the euthyroid state after treatment was associated with marked clinical improvement in muscle weakness. In the third case, severe bulbar and respiratory muscle weakness, which was apparently aggravated by the thyrotoxicosis, was followed by aspiration pneumonitis and death. Possible mechanisms for the effect of excessive thyroxine on muscle function are reviewed. Early diagnosis and aggressive treatment of the hyperthyroidism is extremely important.

Adult↗