Biomedical subjects
H F Hoitsma
Publications and source records attributed to H F Hoitsma.
The effect of dietary saturated fat versus polyunsaturated fat on serum cholesterol and phospholipid concentrations in rabbits with partial ileal bypass.
Rabbits were fed semipurified diets containing either corn oil or coconut fat. Dietary coconut fat significantly elevated serum total cholesterol and phospholipid concentrations. Rabbits with partial ileal bypass (PIB) had significantly lower serum cholesterol and phospholipid values, irrespective of whether the diet contained corn oil or coconut fat. The effect on serum lipids of the type of fat was similar in control and PIB animals. Since PIB rabbits are known to excrete extremely high amounts of steroids with the feces, we suggest that our data point to a lack of interaction of the type of dietary fat with the fecal excretion of steroids.
Serum total bile acids monitoring after experimental orthotopic liver transplantation.
The aim of this study was to evaluate the usefulness of serum total bile acids estimation in monitoring liver allograft recipients. To this end frequent blood samples and simultaneous needle biopsies of the liver were taken after orthotopic liver transplantation in unimmunosuppressed pigs. Serum bile acids were found to rapidly increase during the anhepatic phase of the transplantation procedure and to decrease after implantation of the liver graft. A normal serum bile acids level in the early postoperative phase was indicative of a technically successful transplantation procedure. A total of 28 successful transplantations was performed. Six recipients accepted the allograft without any histological sign of rejection. In 18 pigs the liver was rejected, the survival time of these animals ranged from 6 to 80 days. Four animals showed a transient rejection episode during the first months after transplantation. In nonrejecting animals serum bile acids remained undisturbed during the entire 4-month study period. In all cases of rejection serum bile acids promptly increased to very high levels of 100 to 700 mumol/liter (reference range 1 to 14 mumol/liter). Serum bile acids were found to be superior to standard liver function tests in detecting the process of liver rejection at an earlier stage. These results indicate that serum total bile acid estimation is a simple and useful test to monitor liver allograft recipients.
Liver allograft rejection in pigs: histology of the graft and role of swine leukocyte antigen-D.
The porcine liver is often considered an immunologically privileged organ as liver allografts in unrelated pigs can survive without any form of immunosuppression. When donor and receptor animals were mismatched for swine leukocyte antigen-D (SLA-D) antigens as tested in mixed-lymphocyte culture (MLC), liver allografts were rejected in all but one of the 14 cases studied. In contrast, from the 10 animals receiving a liver from an MLC-matched donor 8 survived without any significant sign of rejection. The diagnosis of rejection was made by histologic examination of serial needle biopsies of the liver. Based on survival time and histological type of cellular infiltrate an early and a late form of rejection could be distinguished. The early form, with a survival time from 6 to 10 days, was characterized by lymphocytic infiltration of the portal tracts and the liver parenchyma. The late form, with a survival time ranging from 15 to 80 days, showed a lymphocytic and plasma cellular infiltration of the portal tracts. These results show that the outcome of liver allotransplantation in pigs is strongly dependent on SLA-D histocompatibility. It is concluded that porcine liver allografts are under immunological control.
Cyclosporin A in orthotopic porcine liver transplantation. Long-term survival after short-term treatment.
The aim of this study was to evaluate the efficacy of cyclosporin A (CyA) in prolonging graft survival after orthotopic porcine liver transplantation in mixed lymphocyte culture (MLC) mismatched couples. CyA was given intramuscularly for a period of 21 days, starting on the day before transplantation. In order to study the fate of the graft, frequent liver biopsies and blood samples were taken after transplantation. 4 pigs received CyA at a dose of 10 mg/kg/day, and 10 animals were treated with 20 mg/kg CyA per day. In the low-dose group 1 pure plasma cellular rejection was noted, while the grafts of 2 pigs showed a transient plasma cellular infiltration in the portal tract. By doubling the dose, only 1 out of 10 animals rejected the liver graft. The livers of the other 9 animals did not show any noteworthy histological sign of rejection, and also the liver function tests were normal. Total serum bile acids and routine liver function tests remained undisturbed in animals that accepted the MLC-mismatched graft and increased in cases of rejection. No nephrotoxicity was noted due to CyA treatment. The main complications encountered were infections leading to death in 4 CyA-treated pigs, while the liver graft was functioning well. Short-term treatment with CyA can overcome the rejection of a MLC-mismatched porcine liver graft and induces a state of long-term acceptance.
The role of A-O-incompatible blood transfusions in porcine orthotopic liver transplantations.
The consequences of administrations of A-O-incompatible blood transfusions during porcine orthotopic liver transplantations (OLT) are described. Two series, both subjected to the same standard procedure except for the administration of compatible or incompatible blood, are compared. The striking differences in peroperative and direct post-operative morbidity, mortality, and causes of death between the two series are presented. Although not generally applied, blood transfusions in experimental surgery should undergo the same precautionary measures as blood transfusions in humans.
Anaesthetic management in experimental orthotopic liver transplantation in the pig.
Anaesthesiological experiences are described with 103 porcine orthotopic liver transplantations. The animals were operated in neurolept anaesthesia. After premedication and induction, fentanyl and pancuronium were administered as a continuous infusion until hepatectomy was completed. Haemodynamic and metabolic changes during the procedure were monitored. Metabolic acidosis should be avoided by administration of sodium bicarbonate before declamping. Corrections of alterations in serum electrolytes and in blood glucose levels seem to be unnecessary. These above-mentioned observations have led to a safe anaesthetic procedure and management in experimental orthotopic liver transplantation.
Surgical treatment of pseudocysts of the pancreas--guidelines for management.
From 1968 to 1983 123 patients were admitted with a diagnosis of pancreatitis; in 28 patients a pseudocyst developed. To evaluate results of surgical therapy a study of the literature and a chart review were performed. From this study we conclude that asymptomatic patients with a pseudocyst of 4 cm or less in diameter can initially be treated expectantly. If the pseudocyst is larger than 4 cm in diameter and in those cases where the cyst shows no tendency to spontaneous resolution, operative intervention seems mandatory. If no complications occur, surgery is postponed until six weeks' observation to allow maturation of the cyst and facilitate cystenteric anastomosis. In pseudocysts related to blunt abdominal trauma, endoscopic retrograde cholangiopancreatography (ERCP) should be performed. If ERCP reveals a major duct lesion, resection should be considered.
Long term survival following orthotopic liver transplantation in pigs; with special reference to gastric ulcer complications.
A series of 56 orthotopic liver transplantations performed on pigs surviving more than three days is presented. No immunosuppressive agents were given. During life serial liver biopsies and liver function tests were performed. A 30% mortality rate (17 animals) due to gastric ulcer complications was observed. Rejection, as the sole cause of death, was seen in 12 animals; in nine of these a fulminant rejection caused death within 6 to 10 days after transplantation. Five animals died between seven and 60 days because of small bowel obstruction. The occurrence of gastric ulceration complicated by haemorrhage or perforation is not related to morphological and biochemical parameters while biliary drainage patency does not prevent gastric ulceration haemorrhage. Gastric ulceration can occur at any time postoperatively and seems to be unrelated to the liver transplantation itself.
The treatment of complete rectal prolapse by transabdominal posterior rectopexy.
Fourteen patients with complete rectal prolapse underwent transabdominal posterior rectopexy using a double peritoneal sling fixation technique. Symptoms, sphincter function assessment and a description of the operative technique are reported. Except for one small mucosal prolapse there were no recurrences. The results of our technique are encouraging.
The transsphincteric approach for removal of a huge foreign body from the rectum.
The case is reported of a patient with a huge foreign body of the rectum. A transsphincteric approach (Mason's approach) was used to remove this foreign body when other methods failed.
[A sigmoid stenosis of long duration in a patient with ulcerative colitis].
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[Follow-up study after surgery of colon or rectum carcinoma].
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Palliative resection in gastric cancer.
Fifty-one of 256 patients underwent a palliative procedure for advanced carcinoma of the stomach (TNM stage IV). The resection was classified as palliative if metastatic disease was left behind in the lymph nodes, if involvement of organs elsewhere in the abdominal cavity was present, or if microscopy revealed tumor tissue in the resection lines. Twenty-six patients underwent a resection for palliation. There were 14 total and 12 partial gastrectomies. There were 2 deaths after total gastrectomy because of anastomotic leakage. The mean survival time after operation was 9.5 months. In 13 patients (50%) palliation was good with preoperative symptomatic relief without initiating new symptoms, acceptable body weight, and solid food intake. In 7 patients (27%) palliation was moderate, and in 4 (15%) poor. The results after gastroenterostomy in 25 patients were poor. The study shows that palliative total and partial gastrectomy can produce palliation in advanced gastric cancer.
Malignant intrathoracic oncocytoma.
A case of malignant intrathoracic oncocytoma occurring in a 56-year-old man is reported. Preoperative films of the chest showed a large superior mediastinal tumor. Radical excision through a right-sided thoracotomy was impossible because of the extensive growth. Light and electron microscopic findings revealed a malignant oncocytoma with metastases in lymphoid tissue and tumor emboli in lymph vessels. Postoperative treatment with cyclophosphamide was recommended for one year. After two years there was no radiologic or scintigraphic evidence of metastases. Review of the literature on malignant oncocytoma suggests a relatively benign course after surgical excision. The role of radiotherapy and chemotherapy cannot yet be established.
The Hartmann procedure.
During a 10-year period, 59 patients had a Hartmann operation for diverticular disease (n = 19), carcinoma (n = 21), anastomotic disruption (n = 5), injury (n = 3) and various other conditions (n = 11). Twenty-two patients (37.3 per cent) died postoperatively. Wound infection or wound dehiscence occurred in 26 patients. Other complications inherent in this operation were colostomy necrosis or retraction (n = 12) and leakage of the rectal stump (n = 3). The mean hospital stay of the surviving patients was 28.4 days. Colorectal continuity was subsequently restored in 12 patients (32.4 per cent) and no difficulties were encountered with this procedure.
Cloacogenic tumors of the anorectal junction.
The cloacogenic zone of the anal canal is a vestigial remnant of the cloacal membrane. This region corresponds to the columnae anales and anal glands. The epithelial lining of the anal glands and of the cloacogenic zone is of the transitional variety. The anal glands are well known to the surgeon because of their role in the pathogenesis of perianal abscesses and fistula in ano. Tumors arising from the cloacogenic zone of the anal canal are rare. In most instants these carcinomas have characteristic clinicopathological features. These lesions are named transitional cloacogenic carcinoma. The therapy of choice is an abdominal-perineal rectum amputation with wide excision of the perineal soft tissue. Inguinal node dissection is indicated if the nodes appear clinically involved. No conclusions have been reached to determine the radiosensitivity of cloacogenic carcinomas. Five cases of cloacogenic carcinoma are reported and the clinicopathological and therapeutic aspects discussed.