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Biomedical subjects

G Alinder

Publications and source records attributed to G Alinder.

10 recordsLinked to original sources

Circadian rhythms in gastrin receptors in rat fundic stomach.

Circadian rhythmicity in the number of gastrin receptors in rat fundic mucosa was characterized and was related to the concentrations of gastrin in serum and in antrum. Male Sprague-Dawley rats were acclimated to 12 hr light alternating with 12 hr darkness. Subgroups of six rats each were killed at 4-hr intervals. Fundic mucosa was collected for measurement of gastrin receptors; serum and antral tissues were collected for measurement of gastrin levels by radioimmunoassay. Circadian periodicity in the data was determined by cosinor analyses. In both freely fed and fasted rats, gastrin receptors showed circadian variation (range 2.5-10 fmol/mg protein), as did serum gastrin concentrations (range in fed rats 195-407 pg/ml). The phasing of the intrinsic circadian variation in gastrin receptor level that was observed in the fasted rats was advanced by a few hours in fed rats. This shift is probably due to food-induced gastrin release, resulting in gastrin-mediated down-regulation of gastrin receptors, followed by up-regulation of gastrin receptors. Food-related effects were thus superimposed upon the intrinsic circadian rhythms in gastrin receptor levels, causing the circadian variation in gastrin receptor levels in the fed rats to be shifted forward compared to that in the fasted rats. No significant circadian rhythms, on the other hand, were found in concentrations of gastrin in the antrum. These results suggest that changes in sensitivity of target tissues to hormones are related to both intrinsic circadian rhythms in levels of hormone receptors and also to food-related changes in hormone-receptor levels mediated by changing serum hormone levels.

Analysis of Variance↗

Restricted feeding schedules alter the circadian rhythms of serum insulin and gastric inhibitory polypeptide.

Insulin and gastric inhibitory polypeptide (GIP) have a circadian rhythm of secretion that is altered by various feeding schedules. We acclimated rats over 3 weeks to one of 6 different feeding schedules. They were then killed at intervals over one feeding cycle. Blood was collected, and their stomachs were weighed. Hormones in the serum were measured by radioimmunoassay. When highest and lowest measured concentrations were compared in ad libitum fed rats, insulin more than doubled (445 +/- 50 to 993 +/- 180 pg/ml) and GIP more than tripled (682 +/- 108 to 1964 +/- 145 pg/ml) during a 24-h period. With restricted schedules, concentrations correlated with the feeding schedule, not the light-dark cycle. Hormone levels rose higher during feeding and fell lower with fasting than in ad lib fed rats. For example, GIP in one study fluctuated from 468 +/- 22 to 6433 +/- 432 pg/ml. In another example, insulin ranged from 30 +/- 5 to 2259 +/- 406 pg/ml during a 24-h period. However, insulin did not always correlate well with stomach weight. Circadian rhythms occurred for insulin with all feeding schedules and for GIP with all schedules except fasted rats. This finding implies an endogenous insulin rhythm, whereas food intake controls GIP secretion. Thus, disruption of normal circadian cycles of feeding may yield misleading information about gut hormone secretion.

Animals↗

Pre-operative infusion cholangiography compared to routine operative cholangiography at elective cholecystectomy.

Routine operative cholangiography (group 1) was compared with pre-operative intravenous infusion cholangiography and selective operative cholangiography (group 2) in 200 patients subjected to elective cholecystectomy. All patients were examined with pre-operative intravenous infusion cholangiography. In group 1 patients, this examination was not made available to the surgeon and not used in any way except for a later analysis. Thirteen patients had to be excluded for different reasons. In group 1, normal operative cholangiograms were obtained in 82/94 cases. Choledocholithotomy was performed in 7/12 cases, choledochotomy in 2/12 and no exploration in 3/12 cases. In group 2, pathological or inconclusive infusion cholangiograms were demonstrated in 17/91 cases. Choledocholithotomy was performed in 11/17 cases. One of 17 patients was subjected to choledochotomy only. In 5/17 patients, no exploration was carried out because of normal operative cholangiography. No residual or retained stone/s have been revealed during a follow-up period of 1 year. The general clinical outcome in the two groups of patients was similar. Significantly shorter operative time was an important advantage of the strategy in group 2 patients.

Adolescent↗

Accidental lesions of the common bile duct at cholecystectomy. Pre- and perioperative factors of importance.

The 65 reports of accidental lesions of the choledochus at cholecystectomy from the records of the Patients' Insurance Syndicate in Stockholm, Sweden, 1975-1982, were studied in order to characterize avoidable factors and/or situations at cholecystectomy. Compared with control materials, there were significantly less men (28 vs. 34%) and the patients were younger (46 vs. 54 years). The patients were without significant other diseases and former operations, and were slim or of a normal weight. The patients had a short history of known biliary tract disease and there was seldom a suspicion of common duct stone. Most of the surgeons were under training and 80% of them had done 25 to 100 cholecystectomies before, seldom assisted by a more experienced surgeon. The inflammation was never severe, the bleeding insignificant, and an anomaly was found after the lesion was done in only 16 of 55 cases. The lesion was done before cholangiography in 27 cases and after the cholangiography, but before the films were available in 32 cases. The gallbladder was excised about as often from the fundus as from the pouch. We have found it probable that most of these accidental injuries of the choledochus could have been prevented with a policy that considers cholecystectomy as a major operation that requires well-trained surgeons with a humble and concentrated approach to their task.

Adolescent↗

Contrast tomography of the gallbladder wall and ultrasonography in the diagnosis of acute cholecystitis.

Rapid and reliable diagnostic methods are necessary for regular early surgical intervention in patients with acute cholecystitis. Eighty-three patients with clinical suspicion of acute cholecystitis were investigated with ultrasonography (US) and contrast tomography of the gallbladder wall (CTGW). The diagnosis in each case included in the study was verified either at operation or follow-up cholecystography. The sensitivity and specificity of US were 69 and 100 per cent, respectively. With CTGW the corresponding figures were 73 and 100 per cent. The combined use of these methods resulted in a sensitivity of 89 per cent and a specificity of 100 per cent.

Acute Disease↗

The influence of total hepatectomy on cerebral energy state, ammonia-related amino acids of the brain and plasma amino acids in the rat.

The influence of total hepatectomy on cerebral energy state, ammonia-related amino acids of the brain tissue and plasma amino acids was studied in anaesthetized rats after total hepatectomy. The hepatectomy was performed with the aid of a microsurgical three-stage procedure. In the first stage, division of the inferior vena cava was performed. In the second stage 4 weeks later a porta-caval anastomosis was constructed, followed after 1 week by a total hepatectomy. The brain energy state, defined as the concentrations of phosphocreatine, ATP, ADP and AMP, was unchanged 4 h after the hepatectomy. Plasma amino acids did not differ significantly between hepatectomized and shunted control rats. On the other hand, clear-cut increases in the concentrations of glutamine, and decreases in the concentrations of glutamate and aspartate, were observed in the fronto-parietal part of the cerebral cortex and the brain stem. These changes might explain the minor manifestations of cerebral dysfunction in the early phase of the hepatectomized state.

Alanine↗

[Modern trends in biliary surgery].

Surgery of the bile tract is not so simple as it looked like in former times. There is an instant change concerning interpretation of findings and surgical methods applied. A surgeon performing operations on the bile ducts should nowadays also be experienced in endoscopy like ERCP and in sonography.

Cholangiography↗

A microsurgical method for total hepatectomy in the rat.

A microsurgical three-stage-procedure for total hepatectomy in the rat is described. In the first stage, suprarenal ligature and division of the inferior vena cava is performed. A modified portacaval shunt is constructed in the second stage and total hepatectomy is performed in the third stage. Microsurgical technique is of great benefit in both the second and third stages, especially in choosing the proper location for the shunt and minimizing blood loss. All the rats survived to the 6-hour study and 65% of the rats survived to the 18-hour study, despite the fact that body temperature was upheld to a level of 35-37 degrees C. Based on our experience in 165 hepatectomies, we recommend our method for metabolic studies in anhepatic rats.

Animals↗

Routine operative cholangiography or pre-operative infusion cholangiography at elective cholecystectomy--a cost-effectiveness analysis.

Previous data from our surgical department suggests that routine operative cholangiography (strategy I) can be replaced by a combination of pre-operative intravenous infusion cholangiography and selective operative cholangiography (strategy II). The general clinical results with the two strategies were similar during a follow-up period of one year. The present study compares the costs for the two strategies through cost-effectiveness analysis. The calculated average total hospital costs with the two strategies did not differ significantly. The costs obtained were SEK 9,150 for strategy I and SEK 9,430 for strategy II. These findings support the opinion that strategy II is approximately as cost-effective as strategy I in the management of patients subjected to cholecystectomy.

Adolescent↗