Biomedical subjects

A Sawchuk

Publications and source records attributed to A Sawchuk.

6 recordsLinked to original sources

PubMed1996

Carotid body tumors, inheritance, and a high incidence of associated cervical paragangliomas.

BACKGROUND: Current experience with carotid body tumors suggesting a high prevalence of associated cervical paragangliomas prompted this review. PATIENTS AND METHODS: An 8-year retrospective study of patients with carotid body tumors was undertaken, detailing presentation, diagnosis, and treatment. RESULTS: Eleven patients harboring 17 carotid body tumors were discovered. All patients had a neck mass. Seven patients (64%) had bilateral carotid body tumors. Six (55%) reported a positive family history-4 were first-generation relatives, 5 had bilateral tumors, and 3 had other head and neck paragangliomas. Angiography documented 4 associated vagal and 2 glomus jugulare paragangliomas in addition to the carotid body tumors. Precise surgical care limited blood loss to an average of 590 cc. The carotid artery was repaired during 5 resections (29%). Cranial nerve injury occurred in 3 cases, all following vagal body or glomus jugulare resection. Every patient is currently alive, stroke free, and functioning without major disability. CONCLUSIONS: Patients with carotid body tumors have a propensity for multiple head and neck paragangliomas. Angiography is diagnostic. The need for associated paraganglioma resection dramatically increases the risk of cranial nerve injury.

Adult↗

PubMed1987

Electrical pacing of the Roux limb resolves delayed gastric emptying.

This study compares antegrade gastric and Roux-limb electrical pacing in the evaluation and treatment of delayed gastric emptying following vagotomy, antrectomy and Roux-Y enterostomy. Twenty-four male Sprague-Dawley rats (250 g) underwent midline laparotomy, truncal vagotomy, antrectomy, and Roux-Y jejunostomy. Pacemaker leads were implanted 1 cm apart in both the gastric fundus and proximal Roux limb. Pacing was accomplished using a 0.5 mA, 50 msec, 0.33 Hz signal and monitored by an oscilloscope. Animals were fasted for 2 hr and then gavaged with 1.0 cc of 99mTc-labeled egg white. At 1 hr rats were anesthetized. The stomach, Roux limb, small intestine, and colon were doubly ligated and excised without disturbing their contents. The total number of counts per minute per rat was determined in a gamma radiation counter, and percentage gastric emptying (GE) was evaluated. Group I controls (n = 8) retained 76 +/- 15.8% for a GE of 24%. Group II gastric paced rats (n = 8) retained 64.5 +/- 19.2% (GE 35.5%) and Group III Roux-limb paced rats (n = 8) retained 46.8% +/- 13.2 (GE 53.2%) (P less than 0.005 III vs I, P less than 0.05 III vs II). The amount of radioactive meal distal to the Roux limb was also evaluated. Group I had 15.7 +/- 16.1%, Group II (gastric paced) 20.5 +/- 19.0%, and Group III (Roux-limb paced) 37.2 +/- 11.9% (P less than 0.005 III vs I, P less than 0.05 III vs II). These data imply that Roux-en-Y limb dysmotility may contribute to delayed gastric emptying following vagotomy, antrectomy, and Roux-Y enterostomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1987

Chemically induced bowel denervation improves survival in short bowel syndrome.

This study evaluates the effect of chemically induced bowel denervation on survival, weight gain or loss, transit time, and d-xylose absorption in rats following 80% small bowel resection. Forty-three male Sprague-Dawley rats (150 g) underwent 80% midsmall bowel resection and anastomosis. Twenty rats were short bowel controls (group I). In 23 rats (group II), a 2.0 cm segment of jejunum proximal to the anastomosis was denervated by application of 0.1% benzalkonium chloride (BK) for 30 minutes. Ten additional rats underwent sham laparotomy without bowel resection. Five remained untreated (group III) and in 5 (BK) denervation was added (group IV). Bowel denervation was confirmed by histologic study in all (BK) rats. Weight and daily food and water intake were measured for 30 days and the groups compared. Weight in group I was 43.8 +/- 52.9 g, group II 95.0 +/- 50.1, (P less than .005), group III 177 g, and group IV 175 g. Food intake was greater in group I than II (P less than .05) and was similar to groups III and IV. Water intake calculated as animal weight (g)/mL H2O ingested was lowest in group I (P less than .05). Mortality was 30% in group I (6/20) and only 8.6% in group II (2/23). No deaths were observed in unresected controls (III and IV). Twenty-four additional rats were evaluated for d-xylose absorption and transit time by bringing out a loop enterostomy 10.0 cm from the Ligament of Treitz. Twelve rats were ostomy controls (group V).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1986

Synergistic effect of coumadin and cytoxan in reducing lung metastases.

Lung metastasis is a frequent cancer complication resulting in significant mortality. This study evaluates the effect of coumadin and cytoxan alone and in combination on lung metastases in rats challenged with Morris hepatoma 3924A. Seventy-seven male American Cancer Institute (ACI) rats weighing 200 g were studied. Thirty-seven rats received coumadin orally for six days, which resulted in a prothrombin time 2 times that of controls (30 sec). All rats received 1 X 10(5) clumped Morris hepatoma cells via tail vein injection. Animals were divided into four groups: Group I (controls, n = 20) received no antitumor treatment; group II rats (n = 20) received 25 mg/kg cytoxan intraperitoneally at the time of tumor challenge; group III animals (n = 19) received coumadin alone; while group IV (n = 18) received both coumadin and cytoxan. Rats were evaluated for number of lung metastases and lung weight at 3 weeks postinjection. Data was subjected to statistical analysis by the Student's test. The mean number of lung metastases were 580 +/- 45 in group I, 350 +/- 310 in group II, 330 +/- 263 in group III, and 200 +/- 161 in group IV (P less than .005 [IV] v [I], P less than .05 [IV] v [II], [III]), (P less than .05 [II] v [I]), (P less than .05 [III] v [I]). Mean lung weights were 2.597 g +/- 1.65 in group I, 2.049 g +/- 0.75 in group II, 1.898 g +/- 0.80 in group III, and 1,677 g +/- 0.31 in group IV. (P less than .025 [IV] v [I], P less than .05 [IV] v [II]).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1986

Reverse electrical pacing improves intestinal absorption and transit time.

This study evaluates the effect of reverse electrical pacing on intestinal absorption and transit time in an enterostomy model. Twenty-five male Sprague-Dawley rats (148 to 208 gm) underwent division and anastomosis of the proximal jejunum to eliminate the proximal gastroduodenal pacemaker. A 30.0 cm loop ileostomy was formed, and leads were placed at 1.0 and 3.0 cm proximal to the stoma. Reverse pacing was done with a 0.25 Hz, 50 msec pulse at 0.1 mA. Transit time was evaluated with 1.0 ml barium gavage and was 12 +/- 4 minutes in group I controls (n = 13) versus 27 +/- 21 minutes in group II (n = 12) reverse-paced rats (p less than 0.025). D-Xylose absorption was determined in 18 rats. Levels were 14.0 +/- 3.6 mg/dl in control rats (n = 6) and 15.5 +/- 3.4 mg/dl in reverse-paced rats (n = 6). Increasing the pulse milliamperage to 2.0 mA (n = 6) increased D-xylose serum levels to 38.8 +/- 27.7 mg/dl (p less than 0.05). Transit rate and net water flux were determined in eight additional rats with 15 cm Theiry-Vella loops. Transit rate was measured with 0.2 ml of methylene blue and was 3.00 +/- 2.32 ml/min in unpaced rats compared with 9.95 +/- 0.71 ml/min with reverse pacing (p less than 0.025). Water flux studies showed that control rats had a net secretory loss of 0.20 +/- 0.48 ml/cm while paced rats absorbed 0.08 +/- 0.12 ml/cm. These data indicate that reverse electrical pacing increases transit time and nutrient and fluid absorption. These observations suggest that reverse electrical pacing may be a useful adjunct in instances of short gut associated with an enterostomy.

Animals↗

PubMed1986

A comparison between fructose 1,6-diphosphate, glucose, or normal saline infusions and species-specific blood exchange transfusions in the treatment of bowel ischemia.

Infusion of fructose 1,6-diphosphate, (FDP), the rate-limiting substrate in anaerobic metabolism, decreases infarction in the ischemic heart. This study evaluates the effect of FDP (5% in H2O), glucose (D5W), or normal saline (N/S) infusions and species-specific blood (SSB) exchange transfusions on mortality rates and bowel infarction in rats with intestinal ischemia. One hundred twenty Sprague-Dawley male rats (50 to 75 gm) were divided into six experimental groups. Group I controls (n = 20) underwent sham laparotomy. Group II (n = 20) underwent superior mesenteric artery (SMA) occlusion for 90 minutes. Group III rats (n = 20) were infused with FDP with SMA occlusion (90 minutes). Group IV rats (n = 20) were infused with D5W with SMA occlusion (90 minutes). Group V rats (n = 20) were infused with N/S with SMA occlusion (90 minutes). Group VI rats (n = 20) received species-specific exchange transfusion after SMA occlusion (90 minutes). A typical rat given 1 ml of D5W/75 gm had a serum glucose of 478 ng/dl with an osmolality of 293 mosm/L. After being given 1 ml of NS/75 gm, rats had a serum glucose level of 170 mg/dl with an osmolality of 291 mos/ml. Control rats had a serum glucose level of 139 mg/dl with an osmolality of 295 mosm/L. Survival at 48 hours without bowel infarction was 20 of 20 (100%) in group I, three of 20 (15%) in group II, 12 of 20 (60%) in group III, 12 of 20 (60%) in group IV, five of 20 (25%) in group V, and six of 20 (30%) in group VI (p less than 0.05 groups III and IV versus group II). FDP and D5W infusions increased survival after bowel ischemia in the rat. The mechanism of action may involve provision of a substrate for anaerobic metabolism to ischemic bowel via collateral pathways, hemodilution, and/or volume expansion.

Animals↗