Search PubMed⌕ Search

Biomedical subjects

M H Lewis

Publications and source records attributed to M H Lewis.

At least 109 records · Page 6Linked to original sources
PubMed1993

Genetic differences in social behavior: relation to natural killer cell function and susceptibility to tumor development.

The hypothesis that certain heritable personality traits would correlate with increased vulnerability to tumor development and reduced natural killer (NK) cell function was tested in mice selectively bred for high and low levels of aggression. This selection program produces a line of mice that fail to exhibit species typical, isolation-induced aggression, but appear socially inhibited in response to a novel partner mouse. All socially inhibited mice developed 3-methylcholanthrene-induced tumors compared with only 44% of the aggressive mice. Basal NK activity was also significantly lower among socially inhibited mice. Conversely, there were no line differences in NK activity between the aggressive line and nonselected, socially isolated mice, consistent with other unidirectional outcomes of this selective breeding program. No significant line differences were present for nonsocial measures of emotional reactivity (e.g., fearfulness) or serum corticosterone levels. These findings support the hypothesis that social "traits" may be related to immune function and tumor susceptibility.

Animals↗
PubMed1993

Malignant pancreatic polypeptide secreting tumour of islet cells: a case for aggressive surgical palliation.

A case of a malignant pancreatic polypeptide secreting tumour is reported. The tumour was metastatic at presentation at which time it was excised. Pancreatic duct obstruction occurred 3 years after excision causing severe pain on eating. Major palliative surgery, in the form of a pancreatico-jejunostomy, cured the severe symptoms. The patient survives, largely symptom free, over six years after original excision. This case illustrates the need for aggressive management of symptoms in tumours in which long term survival is possible despite locally advanced or metastatic disease.

Adult↗
PubMed1993

Cholecystectomy: a study of patient satisfaction.

A prospective study of 77 patients undergoing open cholecystectomy was undertaken to establish the degree of satisfaction experienced by these patients. Specific symptoms were recorded preoperatively and at one year postoperatively. Two patients died from unrelated diseases during the year of follow-up and were excluded from the analysis. All symptoms inquired about reduced in frequency postoperatively, the best cures being achieved for jaundice, upper abdominal colic, fatty food intolerance and back/shoulder pain. A third of patients developed at least one new symptom during the year of follow-up. Seventy-seven per cent graded themselves either completely or well satisfied. It was not possible to predict from preoperative symptoms those who would be dissatisfied or those who would develop a new symptom. This study refutes recent suggestions that up to 50% of patients are dissatisfied with cholecystectomy and provides data which may be used to counsel patients preoperatively.

Cholecystectomy↗
PubMed1992

Delayed presentation of an extradural abscess complicating thoracic extradural analgesia.

Extradural abscess is a rare but recognized complication of extradural anaesthesia. Previous reports have been associated with a short time interval between extradural catheterization and presentation. We report a patient with rheumatoid arthritis, receiving steroid therapy, in whom an extradural abscess did not present until 23 days after the insertion of a thoracic extradural catheter to provide postoperative analgesia.

Abscess↗
PubMed1992

A review of pancreatico-pleural fistula in pancreatitis and its management.

Pancreatico-pleural fistula is a rare condition in which pancreatic enzymes drain directly in to the pleural cavity, most commonly from an enlarging pseudocyst. We review the literature on the causes, investigations and treatment of pancreatico-pleural fistulae and compare this with our own experience of the case of a 41 year old man with a left sided pancreatico-pleural fistula associated with pancreatic duct obstruction. The fistula could not be demonstrated by USS, CT or ERCP, and after these investigations the patient was managed conservatively. However, deterioration in the patients' condition led to an urgent but not emergency laparotomy and operative pancreatogram. This demonstrated the distally obstructed pancreatic duct, with associated pleural fistula for which aggressive surgical intervention was indicated. The patient subsequently completely recovered.

Adult↗
PubMed1992

Evaluation of a new non-woven theatre swab.

A new non-woven theatre swab was compared with traditional gauze in laboratory and clinical studies. Results of both clinical and laboratory-based studies showed the non-woven swab to be as effective as traditional gauze in terms of softness, conformability, ability to pad or pack, resistance to snagging and shredding, and ease of counting when wet. The non-woven swabs were also superior to gauze with regard to their ability to retain fluid. Manufactured from polyester and hemisynthetic viscose, the non-woven swabs can be produced to a uniform standard and are less expensive. It is concluded that the new non-woven material has practical and economic advantages over traditional gauze.

Cellulose↗
PubMed1991

Dopamine receptor 'supersensitivity' occurring without receptor up-regulation.

Unilateral 6-hydroxydopamine (6-OHDA)-induced lesions of the substantia nigra have been widely used to study various aspects of dopamine neurobiology, and to screen for antiparkinsonian drugs. This study examined the role of receptor alterations in the pharmacological supersensitivity seen in response to lesioning of central dopamine pathways in rats by intracisternal (IC) administration of 6-OHDA (200 micrograms), as well as by bilateral (BIL) or unilateral (UNI) infusion of 6-OHDA into the substantia nigra (8 micrograms/side). Both IC and BIL lesions resulted in permanent decreases in dopamine concentration in the striatum, the major terminal projection from the substantia nigra. When challenged with apomorphine (0.3 mg/kg), IC-lesioned rats exhibited bursts of rapid locomotion interspersed by rearing, whereas BIL-lesioned rats displayed intense grooming or gnawing and nose poking of the cage floor; these behaviors were not seen in respective sham (i.e. vehicle)-lesioned rats injected with apomorphine. Scatchard analysis of saturation isotherms of both D1 [( 3H]SCH23390 binding sites) and D2 [( 3H]spiperone binding sites) dopamine receptors in the striatum revealed no difference in either the maximum number of binding sites (Bmax), or the dissociation constant (Kd) of either receptor type when BIL and IC lesioned rats were compared to appropriate controls. Conversely, the UNI lesioned rats had, under identical conditions of analysis, the expected increase in the density of D2 receptors on the lesioned side. There was no change in dopamine-sensitive adenylate cyclase activity in the striata of supersensitive IC-lesioned rats, but there was a shift to the left in the dose-response curve in striata from rats bilaterally-lesioned in the substantia nigra, similar to what occurs in UNI lesioned rats. Together, these data clearly demonstrate that although increases in receptor density and changes in cAMP systems are seen in the UNI model, neither mechanism is a requirement for functional supersensitivity in response to 6-OHDA lesions. These data suggest that other cellular events (e.g. alterations in receptor interactions) may play a role in the response to insult, and raise questions about the utility of the unilateral model as a screen for antiparkinsonian drugs.

Adenylyl Cyclases↗
PubMed1991

Oxygenation in the stomach and the effect of truncal vagotomy.

A Clark polarographic oxygen electrode allowed detailed mapping of tissue oxygen (PtO2) levels on the anterior surface of the stomach in five patients undergoing cholecystectomy. No significant difference in mean PtO2 was detectable between greater and lesser curvatures. A significant difference in mean PtO2 was detected between the body of the stomach and the pylorus (Mann-Whitney, P less than 0.01). The effect of truncal vagotomy on PtO2 was evaluated in six patients undergoing this procedure for duodenal ulceration. Mean postvagotomy stomach PtO2 levels (46 +/- 12 mmHg) were significantly lower (Wilcoxon test, P less than 0.001) than prevagotomy levels (59 +/- 14 mmHg). Truncal vagotomy did not have any significant effect on small intestinal PtO2. This work provides the first objective evidence of the relatively diminished tissue oxygenation in the gastric antrum and pyloric region, and confirms blood flow studies of the effects of vagotomy.

Adult↗