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Biomedical subjects

R A Prinz

Publications and source records attributed to R A Prinz.

At least 127 records · Page 7Linked to original sources
PubMed1983

"Nonfunctioning" islet cell carcinoma of the pancreas.

Although most pancreatic islet cell tumors are associated with clinically evident hormone hypersecretion, a small group have no obvious signs or symptoms of excess endocrine activity and are termed "nonfunctioning." The clinical course of eight patients with "nonfunctioning" islet cell carcinoma seen during an eight-year period was reviewed. The six men and two women ranged in age from 36 to 68 years (mean--52). The initial complaint in six was a palpable abdominal mass associated with pain, steatorrhea, or jaundice. Two patients presented with abdominal pain that was initially thought to be of biliary tract origin, and the tumor was discovered at operation. Two patients underwent radical distal pancreatectomy and have no gross evidence of residual or recurrent tumor one and two years later. Five had a biopsy and biliary diversion; three of these also had a gastrojejunostomy. Five were given postoperative 5-fluorouracil and streptozotocin chemotherapy. One developed renal dysfunction and was switched to dimethyltriazenoimidazole carboxamide (DTIC) chemotherapy. Three patients are alive four, six, and eight years, respectively, after diagnosis. Two expired two and a half and three years after diagnosis. One patient had only biopsy of peripancreatic nodes, and he expired in one year. "Nonfunctioning" islet cell carcinoma presents with symptoms related to the mass effects of the tumor. An aggressive therapeutic approach utilizing surgery and chemotherapy is advocated for these slow growing neoplasms.

Adenoma, Islet Cell↗
PubMed1983

Neural regulation of pancreatic polypeptide release.

To clarify the nervous system's role in the regulation of pancreatic polypeptide (PP) release, extrinsic innervation to the in situ pancreas was eliminated in five dogs. Before and 2 weeks after denervation, PP was measured during insulin hypoglycemia and ingestion of a protein meal. Exogenous insulin caused a similar marked hypoglycemia in both control and denervated dogs. Hypoglycemia caused a significant increase in plasma PP in control dogs from a baseline of 42 +/- 8 pg/ml to 86 +/- 18 pg/ml at 20 minutes (P less than 0.01). In denervated dogs plasma PP did not increase with hypoglycemia, and levels were significantly less than in the control animals at 30 and 60 minutes (P less than 0.05). With a protein meal, PP increased in the control animals from 53 +/- 12 to 116 +/- 16 pg/ml at 10 minutes (P less than 0.05), 164 +/- 22 pg/ml at 20 minutes (P less than 0.05), and 193 +/- 20 pg/ml at 60 minutes (P less than 0.01). Denervation markedly blunted this response, and PP increased only from 53 +/- 6 to 64 +/- 4 pg/ml at 10 minutes, to 83 +/- 12 pg/ml at 20 minutes, and to 91 +/- 8 pg/ml at 60 minutes. PP became significantly elevated above baseline in denervated dogs only at 60 minutes (P less than 0.05), and PP was significantly lower than in the control group at 10, 20, and 60 minutes after the meal (P less than 0.05). Immunostaining for insulin, glucagon, somatostatin, and PP showed no difference in the number and distribution of these endocrine cells in predenervation and postdenervation specimens. Adrenergic and cholinergic nerves were seen in all control specimens but, except for a few adrenergic fibers, were not seen in denervated animals. Peptidergic nerves that contained vasoactive intestinal polypeptide (VIP) were seen in all areas of the pancreas before and after denervation. This study confirms that the initial rise in PP with a protein meal is governed by vagal cholinergic pathways. Later postprandial PP secretion is controlled by an interplay between these cholinergic pathways and other uncertain influences such as hormonal or substrate changes. The pancreas has a rich intrinsic peptidergic system of VIP-containing nerves.

Animals↗
PubMed1983

Parathyroid cysts: a report of eleven cases including two associated with hyperparathyroid crisis.

Eleven parathyroid cysts were found in 325 patients who underwent parathyroid operations. Ten cysts were located in the neck and one was located in the mediastinum. The cysts ranged in size from 1.6 to 10 cm with a mean of 3.9 cm. The patients who had cysts included six women and five men, and their ages ranged from 28 to 72 years with a mean of 51 years. In contrast to other reports that have suggested that most parathyroid cysts are nonfunctional, all but one of our patients had hyperparathyroidism, as evidenced by hypercalcemia, hypophosphatemia, and elevated parathyroid hormone level, which was corrected by cyst removal. The nonfunctional cyst first appeared to be an asymptomatic neck mass. Two patients had acute hyperparathyroid crises, which required emergency operations. It is postulated that the crises may have been the result of spontaneous necrosis of preexisting parathyroid adenomas. This is supported by the pathologic findings of degeneration and early organization as well as by the presence within the cyst of sanguineous fluid that contained a parathormone concentration greater than 100 times normal serum levels.

Acute Disease↗
PubMed1983

Effects of radiation on parafollicular C cells of the thyroid gland.

While radiation has well-recognized effects on follicular cells of the thyroid gland, those on parafollicular C cells are not yet established. Low-dose radiation that has been proved to be nonablative and carcinogenic to follicular cells was administered to 8-week-old Long-Evans rats to study the changes in C cell number and function. Circulating calcitonin levels were significantly reduced in animals that had undergone radiation at age 24 months. Mean calcitonin values were 0.66 (+/- 0.20) ng/ml and 1.64 (+/- 0.59) ng/ml for control males and females compared with 0.14 (+/- 0.06) ng/ml and 0.11 (+/- 0.01) ng/ml for males (P less than 0.05) and females (P less than 0.001) that had undergone radiation, respectively. These levels correlated well with C cell population density in thyroid glands in the control group and in the group that had undergone radiation as evidenced by light microscopy. Routine hematoxylin and eosin staining showed C cell hyperplasia in 77% of control animals of both sexes compared with 4% in animals that had undergone radiation (P less than 0.005). Immunoperoxidase staining with an anticalcitonin antibody showed virtual absence of C cells in most animals that had undergone radiation compared with diffusely scattered cells in animals in the control group. Medullary carcinomas occurred in 14% of animals in the control group compared with 3% of animals that had undergone radiation (P less than 0.05). These data indicate that the radiation dosage that is carcinogenic to the follicular epithelium causes lethal injury to C cells and thus suggest that C cells are more sensitive to radiation than are follicular cells. This increased sensitivity could explain the virtual absence of C cells, decrease in calcitonin levels, and reduced numbers of medullary carcinomas in the animals that had undergone radiation.

Animals↗
PubMed1982

Incidental asymptomatic adrenal masses detected by computed tomographic scanning. Is operation required?

Until recently, adrenal masses came to clinical attention either from local symptoms due to massive enlargement or from manifestations of excess hormones production. During the last year, an adrenal mass was identified as an incidental finding in nine patients undergoing abdominal computed tomographic (CT) scanning for unrelated problems. These five men and four women ranged in age from 41 to 73 years. Eight were hypertensive. After the CT scan, each was evaluated for catecholamine or steroid hypersecretion. Only one had clearly elevated urinary vanillylmandelic acid, metanephrine, and catecholamine levels. Equivocal evidence of catecholamine excess was seen in five patients who had slight elevation of one urinary metabolite or of plasma epinephrine or norepinephrine levels. Three patients had no evidence of medullary or cortical hyperfunction on repeated testing. Eight patients were good operative risks and underwent unilateral adrenalectomy without complication. Masses ranging in size from 1 to 4 cm were found in each. These included four cortical adenomas, two adrenal cysts, one adrenal lipoma, and one pheochromocytoma. The pheochromocytoma occurred in the patient with strong biochemical evidence of disease. With wider application of CT imaging, increasing numbers of asymptomatic adrenal masses will be detected. Care in interpreting the clinical significance of these masses and caution in recommending treatment are required.

Adenoma↗
PubMed1982

Prior irradiation and the development of coexistent differentiated thyroid cancer and hyperparathyroidism.

Twelve patients with coexistent well-differentiated thyroid carcinoma and primary hyperparathyoidism were studied to determine the frequency of previous radiation exposure. Eight were found to have received prior irradiation. External radiation was administered to the head and neck region for benign conditions such as tonsillar enlargement, acne, scrofula, and thyroid enlargement. One patient received 131I therapy for carcinoma of the thyroid. The observation that 67% of the patients in this series had previous radiation to the head and neck strongly implicates radiation exposure in the development of coexistent well-differentiated thyroid carcinoma and hyperparathyroidism.

Adult↗
PubMed1982

Evaluation of therapeutic options for pancreatic pseudocysts.

A review of 81 patients with pancreatic pseudocyst was conducted to assess the value of different treatment modalities. Resection was associated with 18% mortality (two of 11 patients) and 36% morbidity. In three of nine patients undergoing external drainage a recurrent pseudocyst developed, and in one additional patient, a pancreatic fistula persisted. Internal drainage by cystogastrostomy (21 patients) resulted in 9.5% mortality and 9.5% morbidity, whereas cystojejunostomy (33 patients) was associated with a 6% mortality and 6% morbidity. Endoscopic drainage through the posterior wall of the stomach was unsuccessful in the two patients in which it was used. Internal drainage into the stomach, duodenum, or jejunum is a safe and effective approach for most pseudocysts. Persistent symptoms following surgical treatment were primarily related to failure to recognize multiple cysts and/or pancreatic duct obstruction and dilation characteristic or chronic pancreatitis.

Adult↗
PubMed1982

Pancreatic abscess: an unresolved surgical problem.

Twenty patients with pancreatic abscesses were studied to determine if recent diagnostic and therapeutic advances have improved the outlook for those with the disease. An abscess developed as a complication of alcoholic pancreatitis in 10 patients and was due to previous surgery in 9. Ultrasonography and computerized tomographic scanning of the abdomen were helpful in the diagnosis and localization of the abscesses. All 20 patients were treated surgically. Operative mortality was 30 percent and was due to multiple system failure from continuing sepsis. Only 2 of 15 patients who had sump drainage died compared with 3 of 4 patients who were drained with Penrose drains alone. There were two deaths among 10 patients who received nutritional support and four deaths in 10 patients who did not receive hyperalimentation. Pancreatic abscess remains a life-threatening condition. Ultrasonography and computerized tomographic scanning have helped in diagnoses and localization. The addition of sump drainage has reduced the mortality rate from 75 ot 13 percent. Nutritional support also appears to be helpful in reducing mortality.

Abscess↗
PubMed1982

Simultaneous primary hyperparathyroidism and nodular thyroid disease.

Of 351 patients treated for primary hyperparathyroidism from 1966 to 1981, 70 (20%) had grossly evident nodular thyroid disease at the time of subtotal parathyroidectomy. These patients have been reviewed to determine if prior radiation exposure may play a role in their coexistence and if combined subtotal parathyroidectomy and thyroidectomy are safe and efficacious. Thirty-three of the 70 patients (47%) had received prior radiation therapy for benign conditions of the head and neck. Nine of 15 patients with nonmedullary thyroid carcinoma had received previous irradiation. In addition to subtotal parathyroidectomy, 28 patients underwent total thyroidectomy, 14 underwent bilateral subtotal thyroidectomy, and 28 underwent unilateral lobectomy. There were no deaths and no permanent recurrent laryngeal nerve injury from combined subtotal parathyroidectomy and thyroidectomy. Two patients in whom parathyroid tissue was not autotransplanted required calcium and vitamin D supplementation. This study shows that (1) primary hyperparathyroidism and nodular thyroid disease occur simultaneously with sufficient frequency to warrant careful preoperative and intraoperative evaluation of both glands, (2) radiation probably does play a role in the pathogenesis of coexistent primary hyperparathyroidism and nodular thyroid disease, and (3) in experienced hands combined subtotal parathyroidectomy and thyroidectomy can be safely performed.

Adenoma↗
PubMed1982

common duct obstruction in patients with intractable pain of chronic pancreatitis.

Fibrosis of chronic pancreatitis can cause obstructive jaundice by compressing the intrapancreatic portion of the common bile duct. The frequency and clinical manifestations of common bile duct stricture from symptomatic chronic pancreatitis have been evaluated in 26 patients undergoing lateral pancreaticojejunostomy for intractable pain between 1974 and 1980. Four patients (15%) had a stricture with partial obstruction of the common duct in addition to pancreatic duct obstruction. Three of the four strictures were identified prior to operation by ERCP. The fourth developed biliary obstruction six months after pancreaticojejunostomy. Slight elevation of alkaline phosphatase was common and occurred in 12 of 22 patients with chronic pancreatitis without biliary obstruction. Alkaline phosphatase was elevated greater than four times normal in three of the four patients with a biliary stricture. Elevation of total and direct serum bilirubin occurred only in patients with stricture of the distal common duct. A waxing and waning picture of jaundice was seen in these four patients. When a fixed smooth stricture of the common duct is demonstrated in a patient with symptomatic chronic pancreatitis, drainage of the biliary tree should be combined with pancreatic duct drainage in order to prevent cholangitis, biliary cirrhosis, diagnostic confusion with pancreatic carcinoma, and persistence of pain.

Adult↗
PubMed1982

Castration induces a marked reduction in the incidence of thyroid cancers.

Although thyroid disease in humans predominates in females, the prognosis of thyroid cancer in males is much less favorable. To further explore the role of male sex hormones, we utilized the experimental model of radiation-induced follicular cancer in the rat, studying the effects of castration on tumor development. Microscopic evidence of tumor formation was correlated with the biochemical parameters serum thyroxine (T4), thyrotropin (TSH), and thyrocalcitonin (TC) at 24 months. The incidence of follicular carcinomas in intact males ws 58%, compared to 28% in comparable females. Castration of males caused a reduction in the incidence to 22%. Mean circulating levels of TSH were markedly elevated in all three irradiated groups. Mean T4 levels were reduced significantly only in irradiated castrated animals. TC levels were reduced in all irradiated groups. We conclude that although elevated levels of TSH probably play a significant role in the development of radioactive iodine-triggered follicular thyroid neoplasms in the rat, male sex hormone may also play an important role beyond their known effect on basal and thyrotropin-releasing hormone-stimulated TSH.

Adenocarcinoma↗
PubMed1981

Unexpected parathyroid disease discovered at thyroidectomy in irradiated patients.

Eight of 23 patients undergoing total thyroidectomy for radiation-associated nodular thyroid disease were found to have unsuspected parathyroid hyperplasia or adenoma at operation. The total serum calcium level was normal preoperatively in each patient. Serum ionized calcium and parathyroid hormone levels were measured in five patients preoperatively and were normal in each case. These pathologic findings in normocalcemic patients may represent a preclinical form of hyperparathyroidism, which would be further evidence linking radiation to the pathogenesis of hyperparathyroidism. The parathyroid glands should be evaluated both pre-operatively and at operation in all patients who have a history of radiation and require thyroidectomy.

Adenoma↗
PubMed1981

Subtotal parathyroidectomy for primary chief cell hyperplasia of the multiple endocrine neoplasia type I syndrome.

To evaluate the efficacy of subtotal parathyroidectomy (STP) in the treatment of primary hyperparathyroidism due to multiple gland disease, 12 patients with multiple endocrine neoplasia (MEN) type I syndrome were reviewed out of 132 patients undergoing parathyroidectomy. Each patient had yearly follow-up examinations and calcium determinations for a minimum of four years except for one patient who died one year after S.T.P. Permanent hypoparathyroidism occurred in three patients. Two patients remained persistently hypercalcemic, and two patients developed recurrent hypercalcemia. One patient required oral administration of calcium and vitamin D for ten years following STP before recurrent hypercalcemia developed. Another patient was normocalcemic for three years before recurrent hypercalcemia was noted. Only five of these 12 patients remain normocalcemic without need of calcium and vitamin D therapy. In patients with MEN type I, the long-term results of STP are less than satisfactory. Not only is it difficult to gauge how viable parathyroid tissue must be left to prevent both permanent hypoparathyroidism and persistent hyperparathyroidism but there is also a long-term risk of recurrence.

Calcium↗
PubMed1981

Pancreatic duct drainage in 100 patients with chronic pancreatitis.

Although the development of islet cell autotransplantation has focused attention on extended resections of the pancreas, drainage of a dilated pancreatic duct remains an effective means of relieving intractable pain of chronic pancreatitis. Between 1954 and 1980, 98 men and two women with chronic pancreatitis were treated for pain with ductal drainage. All patients had a history of chronic alcoholism. Pancreatic calculi were found in 68 patients. Operative procedures include: seven caudal pancreaticojejunostomies, 42 longitudinal pancreaticojejunostomies, and 54 side-to-side pancreaticojejunostomies. Two caudal pancreaticojejunostomies were converted to longitudinal pancreaticojejunostomies, and one longitudinal pancreaticojejunostomy required revision. The operative mortality rate was 4%. Follow-up studies, lasting up to 24 years, were conducted for all but seven patients. Eighty per cent of these patients have had substantial improvement or complete resolution of their pain. Diabetes, as evidence by an elevated fasting blood sugar level, was present prior to operation in 30% of the patients, and developed after operation in 14%. Only nine of 21 insulin-dependent diabetics in this series did not require insulin prior to pancreaticojejunostomy. Pancreatic enzyme replacement was needed for control of steatorrhea in 18 patients. Four patients with continued pain underwent total or near total pancreatectomies. Three of these patients died of uncontrolled diabetes. Only one patient with a drainage procedure alone has died of uncontrolled diabetes. In patients with dilated pancreatic ducts, pancreaticojejunostomy is a safe, reliable means of providing pain relief, with minimal loss of endocrine and exocrine function.

Adult↗
PubMed1981

Operative and chemotherapeutic management of malignant glucagon-producing tumors.

Glucagon-producing tumors of the pancreas are among the rarest forms of islet cell tumors. Two patients are described in whom the characteristic dermatitis, glucose intolerance, weight loss, and anemia of the glucagonoma syndrome were due to a metastasizing islet cell carcinoma. In both, removal of the primary tumor with a distal pancreatectomy brought marked relief of all clinical symptoms for 1- and 2-year periods. Because streptozocin, the usual chemotherapeutic agent for these tumors, is quite toxic and frequently unsuccessful dimethyltriazenoimidazole carboximide (DTIC) was used for recurrence after operation. The first patient began taking DTIC when his rash reappeared and his immunoreactive glucagon (IRG) level rose to 6,000 pg/ml (normal, less than 200 pg/ml). Within 3 months, his rash was gone, and IRG level was 75 pg/ml. The second patient developed a neoplastic gastrocolic fistula and was extremely emaciated. With DTIC, the fistula healed, and he gained weight and returned to work. His IRG level has decreased from 2,975 to 200 pg/ml. No side-effects were noted during chemotherapy. Temporary palliation of malignant glucagon-producing neoplasms can be achieved by cytoreductive surgery. When the life-threatening symptoms of this syndrome recur, DTIC chemotherapy seems indicated because of its safety and effectiveness.

Adenoma, Islet Cell↗