Biomedical subjects

H Buhr

Publications and source records attributed to H Buhr.

At least 37 records · Page 2Linked to original sources

PubMed1995

Preoperative diagnostics and surgical management of tertiary hyperparathyroidism after chronic renal failure in a child.

Although hyperparathyroidism if a rare condition in young children, the pediatric surgeon is asked occasionally to participate in the management of a child with parathyroid disease. In this paper we report on a girl with global glomerulosclerosis, an unsuccessful renal transplantation and a long-term peritoneal dialysis, who developed an autonomous hyperparathyroidism. Emphasis is placed on the preoperative diagnosis and surgical management in children.

Child, Preschool↗

PubMed1995

Somatostatin receptor imaging in persistent medullary thyroid carcinoma.

OBJECTIVE: Somatostatin is secreted from thyroid C-cells and seems to play an important part in the regulation of calcitonin secretion. We therefore evaluated the usefulness of somatostatin receptor scintigraphy in the localization of tumour tissue in patients with persistent medullary thyroid carcinoma. DESIGN: A prospective clinical study. PATIENTS: The series consisted of 26 patients with elevated calcitonin levels after total thyroidectomy for histologically proven medullary thyroid carcinoma. METHODS: Somatostatin receptor scintigraphy using 111In-pentetreotide (Octreoscan) was performed in all patients and the results correlated with histology, ultrasonography, computerized tomography, magnetic resonance imaging, plain radiography, bone scintigraphy and selective venous catheterization. Calcitonin and carcinoembryonic antigen levels were measured. RESULTS: The sensitivity of somatostatin receptor scintigraphy for localization of persistent medullary thyroid carcinoma was 57% in patients with histologically proven disease. The results depended on tumour mass (low sensitivity (33%) in minimal residual disease) and on the location of metastases (insensitive in detecting liver metastases). CONCLUSIONS: Somatostatin receptor scintigraphy is of value as an additional diagnostic tool in localizing medullary thyroid carcinoma, especially pulmonary metastases. It is of minor importance in detecting minimal residual disease.

Adolescent↗

PubMed1995

Hyperoncotic dextran and systemic aprotinin in necrotizing rodent pancreatitis.

BACKGROUND: Dextrans improve pancreatic microcirculation in acute experimental pancreatitis. They could therefore facilitate the transport of a protease inhibitor to ischemic areas of tissue injury and be of additional benefit. METHODS: To compare the effects of dextrans with and without aprotinin, necrotizing pancreatitis was induced in 33 male dextran-resistant Wistar rats by intraductal infusion of low-dose glycodeoxycholic acid (10 mmol/l) followed by intravenous cerulein (5 micrograms/kg/h) for 6 h. Three and four hours after the start of the cerulein infusion the animals received infusions of either Ringer's lactate (RL) (12 ml/kg), 70,000 Da dextran (10%) (DEX-70) (4 ml/kg) alone, or DEX-70 (4 ml/kg) with aprotinin (5000 IU/kg) (DEX-70/A). RESULTS: The death rate was 60% within 9 h in the RL group (6 of 10) but only 10% in the DEX-70 group (1 of 10) (p < 0.03; Fisher's exact test) and 23% in the DEX-70/A group (3 of 13). Histomorphometry demonstrated a significant reduction of acinar necrosis in both treatment groups compared with control animals (p < 0.014; t test). Total amounts of trypsinogen activation peptides (TAP) in ascites were also significantly lower in these groups (p < 0.05; t test). CONCLUSIONS: DEX-70 given 3 h and 4 h after induction of pancreatitis significantly reduced the levels of TAP, limited acinar necrosis, and improved survival rate in acute necrotizing rodent pancreatitis. There was no additional benefit from the combination with aprotinin.

Acute Disease↗

PubMed1994

Impact of microcirculatory flow pattern changes on the development of acute edematous and necrotizing pancreatitis in rabbit pancreas.

Impairment of pancreatic microcirculation has often been advocated as one pathogenic mechanism in necrotizing pancreatitis. In contrast, data on pancreatic capillary perfusion in edematous pancreatitis are scarce. It was the aim of this experimental study to compare changes in pancreatic microcirculation in edematous and necrotizing pancreatitis. Twelve rabbits were allocated to two groups. Two different models of acute pancreatitis were used. Edematous pancreatitis was elicited by intravenous administration of cerulein (25 micrograms/kg/hr) (N = 6). Necrotizing pancreatitis of the biliary type was induced by pressure-controlled intraductal infusion of a mixture of taurocholate, trypsin, and blood (N = 6). Pancreatic microcirculation was quantified by means of intravital microscopy assessing functional capillary density, blood cell velocity, and distribution of the plasma marker FITC-dextran 70. Systemic hemodynamics were maintained at baseline values by fluid administration. Regardless of edema or necrosis, pronounced extravasation of FITC-dextran was recorded in the early stage of pancreatitis. In cerulein-induced pancreatitis, hyperemia developed as indicated by an increase in blood cell velocity in the presence of homogeneous capillary perfusion. In contrast, a progressive reduction of the number of perfused capillaries was detected in necrotizing pancreatitis. In conclusion, pancreatic microvascular perfusion may be regarded as an important pathogenetic factor for the determination of acute pancreatitis.

Acute Disease↗

PubMed1993

[The prognostic importance of calcitonin screening in familial medullary thyroid carcinoma].

In 34 of 139 patients (63 men, 76 women, mean age 41.2 +/- 15.6 years) with medullary thyroid carcinoma (MTC) the disease was of the familial variety. 13 of the 34 cases were discovered in the preclinical stage by screening (calcitonin stimulation with pentagastrin). This group was on average younger (16.8 +/- 10.7 years) than the 21 clinically manifest patients with MTC (28.0 +/- 11.9 years) or the 105 patients with sporadic MTC (45.7 +/- 13.6 years). The patients diagnosed through the screening programme had a more favourable tumour stage (12 in stage I or II) and were thus more likely to be cured. Their survival rate was higher (100% at both 5 and 10 years) than the survival rate of the patients with clinically manifest tumour (94 and 87%, respectively). But the group with manifest familial MTC did not differ from those with sporadic occurrence as regards the tumour stage (predominantly advanced stages), limited chance of cure and survival rate (5 years: 94%, 10 years: 81%). These data show that screening of family members decisively improves the prognosis of MTC of the familial variety.

Adult↗

PubMed1993

Prognostic factors in medullary thyroid carcinoma: evaluation of 741 patients from the German Medullary Thyroid Carcinoma Register.

A retrospective study of 741 patients with medullary thyroid carcinoma diagnosed between 1967 and 1991 was carried out by members of the German Medullary Thyroid Carcinoma Study Group to evaluate prognostic factors. A total of 559 patients (75%) were considered to have sporadic disease, and 182 (25%) had the familial type. The sex ratio (male to female) was 1:1.4 in sporadic disease patients, and the mean age at diagnosis was 45.9 years (range 5-81 years). For familial disease patients the sex ratio was 1:1.1, and the mean age at diagnosis was 33.4 (range 5-77 years). The follow-up time for 630 patients ranged from 1 month to 20.8 years (mean 13.0 years). The overall adjusted survival rate was 86.7% at 5 years and 64.2% at 10 years. In a univariate analysis the stage of disease at diagnosis, age, sex, and type of disease (sporadic, familial) were relevant prognostic factors, with a better prognosis for young female patients with familial disease and diagnosed at an early stage. In a multivariate proportional hazards analysis, the difference in the survival rate of patients with familial disease versus those with the sporadic form disappeared, while prognostic information provided by age and sex was still significant. The poorer prognosis of patients with sporadic medullary thyroid carcinoma may be related to the patients' older age at detection and more advanced tumor stage at diagnosis. There seems to be no difference in biological behavior between tumors of the sporadic and those of the familial type.

Adolescent↗

PubMed1993

Isovolemic hemodilution with dextran 60 as treatment of pancreatic ischemia in acute pancreatitis. Clinical practicability of an experimental concept.

OBJECTIVE: This phase-I study transferred the concept of isovolemic hemodilution, which has been proven beneficial in the treatment of experimental acute pancreatitis to the patient. SUMMARY BACKGROUND DATA: Pancreatic ischemia represents one main mechanism in the pathogenesis of necrotizing pancreatitis. Isovolemic hemodilution with dextran 60 has been shown experimentally to limit the progression of pancreatic necrosis by improving pancreatic microcirculation. METHODS: Thirteen patients with clinically severe nonbiliary pancreatitis and CT-classification E according to Balthazar were enrolled. Exclusion criteria were anemia, coronary heart disease, chronic obstructive pulmonary disease, coagulopathies, and secondary referral. The volume of blood to be exchanged for dextran 60 was calculated from a nomogram based on body surface. Isovolemic hemodilution aimed at a hematocrit of 30%. Independent from the exchange procedure conventional fluid resuscitation was performed to adjust the central venous pressure at 6 +/- 2 mm Hg. RESULTS: Whole blood (750-1,700 mL) was exchanged for dextran 60 during 45 to 70 minutes. No adverse effect was encountered; central hemodynamics were not affected. Considering a mean Ranson score of 5, mortality was low (7.7%). Progression of pancreatic necrosis was registered in only two patients subsequently undergoing surgical treatment (15%). CONCLUSIONS: Isovolemic hemodilution is practicable in patients. A randomized trial has to prove whether isovolemic hemodilution can substantially alter the course of acute pancreatitis as anticipated from animal studies.

Acute Disease↗

PubMed1992

[Endocrinously active parathyroid cysts. Their diagnosis by the determination of intact parathormone in the cyst fluid].

A 53-year-old woman with recurrent nephrolithiasis was found to have hypercalcaemia of 3.12 mmol/l and an intact parathormone level of 166 pg/ml, indicating primary hyperparathyroidism. Preoperative ultrasound examination to localize the parathyroid adenoma revealed a clear fluid-containing cyst in the right lobe of the thyroid. The aspirated fluid had an intact parathormone level of 306 pg/ml, twice that in serum. The cyst was removed surgically. 14 days postoperatively calcium and parathormone levels in serum had become normal without any calcium administration. Measuring the concentration of intact parathormone in the aspirated cyst fluid made possible not only the distinction from a thyroid cyst but also the precise preoperative localization of the parathyroid cyst.

Body Fluids↗

PubMed1992

[The value of clinical, laboratory and sonographic findings in acute appendicitis--effect of surgical experience and bacteriologic diagnosis on the rate of wound healing disorders].

A total of 361 patients were admitted to the Department of Surgery of the University of Heidelberg between January 1989 and April 1990 for acute appendicitis. Neither the physical examination nor laboratory results were unequivocally diagnostic in a third of the patients. The ultrasonographic visualization of the inflamed appendix could confirm the diagnosis in 50% of the clinically doubtful cases (predictive value: 84%). Further diagnostic procedures were rarely necessary. The perforation rate was independent of the duration of the preoperative hospitalization due to the rapid surgical treatment. Contrary to previous reports, the likelihood of an intraoperatively innocent appendix increased with delayed surgery. Wound infection rates were similar after appendectomies by surgeons in training and by fully qualified surgeons although perforated appendices were typically removed by the latter ones. Antibiotic therapy was usually administered for severely inflamed appendices depending on the intraoperative findings and for perforated appendices and reduced the rate of wound infections if more than two bacteria had been cultured from a routine intraoperative swab. The documentation used in Baden-Württemberg for quality control should include the result of an intraoperative appendiceal swab.

Adolescent↗

PubMed1992

[Animal experiment studies of carcinogen-induced tumor development in colotomies in relation to suture materials].

To assess the possible risk of cancer in the operated colon after stapling compared with vicryl sutures, the influence of the nickel-containing staples was tested in caecum-resected and carcinogen-treated rats. The nickel-containing staples were seen as a cocarcinogen. The aim of the study was to determine whether a higher incidence of cancer occurs at the anastomotic suture line depending on stapler vs. vicryl sutures after subcutaneous application of carcinogens (dimethylhydrazine). The results show that there is no increased risk of cancer following mechanical stapling.

1,2-Dimethylhydrazine↗

PubMed1992

Evaluation of sensitive PDN-21 (katacalcin) determination as tumor marker in medullary thyroid carcinoma.

PDN-21 (katacalcin), a peptide from the calcitonin (CT) gene, was measured in plasma from healthy persons and patients with medullary thyroid carcinoma (MTC). PDN-21 was detectable (greater than or equal to 10 ng/l) in 73% of normal persons (n = 40). In 17 normal persons with undetectable basal plasma levels, PDN-21 became detectable (greater than or equal to 10 ng/l) by stimulation with iv pentagastrin in 7 cases. Basal levels were more often detectable in men than in women. In 65 patients with MTC, PDN-21 levels were highly correlated with CT levels as determined by an "in house" RIA (r = 0.99); the mean ratio of CT/PDN-21, on a molar base, was 0.96 +/- 0.33 over the entire range. In iv stimulation tests with pentagastrin, PDN-21 and CT showed good parallelism (mean ratio of CT/PDN-21: 1.1 +/- 0.62); in MTC patients with normal basal levels, however, peak to basal ratios during iv pentagastrin testing were higher for PDN-21 than for CT, due to the more sensitive PDN-21 assay. In a selective venous catheter study of a patient with MTC, the mean CT/PDN-21 ratio for all samples was 1.04 +/- 0.12, but the peak to peripheral levels were higher for PDN-21 (4.1-fold) than for CT (2.8-fold). In conclusion, determination of PDN-21 by RIA is equivalent to determination of CT in diagnosing MTC patients. In few patients, it might be even slightly more sensitive. PDN-21 should be determined in all cases with borderline CT results.

Biomarkers, Tumor↗

PubMed1991

Stereology, flow cytometry, and immunohistochemistry of follicular neoplasms of the thyroid gland.

A retrospective analysis of surgically resected thyroid cold solitary nodules was performed by stereology, DNA flow cytometry, and immunohistochemistry in 15 follicular adenomas and 15 well-differentiated follicular carcinomas to determine if a differential diagnosis of both follicular neoplasms can be done exclusively from cytologic criteria. Between 150 and 200 tumor cell nuclei (TCN) were studied per case for their TCN profile area, perimeter, and density, as well as for stereologic estimates, including the new parameter, volume-weighted mean particle volume (Vv). Flow-cytometric analyses included measurement of the DNA index and the percentage of cells in S phase and G2M phase. The same tumors were examined for the expression of thyroglobulin and the intermediate filaments vimentin and keratin. Follicular adenomas and follicular carcinomas did not show any significant differences in stereologic estimates related to TCN size. Both groups included similar proportions of diploid and aneuploid neoplasms. Aneuploid follicular neoplasms showed a significantly greater area, perimeter, and volume of TCN as compared with diploid tumors, regardless of their histologic diagnosis. Follicular adenomas and follicular carcinomas expressed a similar staining pattern for the tested immunoreagents, with a few cases coexpressing vimentin and keratin. From our results, a differential diagnosis of follicular neoplasms cannot be performed on the basis of cytologic aspirates exclusively. Infiltration of capsula or vessels remains the only safe indicator of malignancy in the absence of metastases. The lack of cytologic differences suggests that some follicular adenomas are preinvasive carcinomas, not yet showing infiltrative growth at the time of resection.

Adenocarcinoma↗

PubMed1990

[Status of tracheotomy in treatment of the respiratory emergency in anaplastic thyroid cancer].

A review is presented on the 69 patients requiring intraoperative tracheotomy amongst 170 patients with locally infiltrating carcinoma of the thyroid operated on over a 30-year period. 55% of these patients underwent this procedure for absolute indications; in 45% of cases it was performed as a prophylactic procedure to prevent later respiratory complications due to further infiltration by the anaplastic tumour. The follow-up showed that there was no benefit for patients with anaplastic neoplasms from this additional procedure. Most of these patients suffered from local wound healing complications so that obligatory postoperative external radiation could not be administered. The overall prognosis was very poor. Survival was significantly lower still in the group of patients in whom tracheotomy had been performed.

Adult↗

PubMed1990

Intact parathyroid hormone in primary hyperparathyroidism.

In 49 patients with primary hyperparathyroidism, intact parathyroid hormone (PTH) was measured with a recently developed immunoradiometric assay, and midregional PTH fragments (sequence 44-68) were measured with an established radioimmunoassay technique. In 47 normal subjects, the concentration of intact PTH ranged from 2.0 to 6.8 pmol/l, and in 49 patients with primary hyperparathyroidism it ranged from 6.4 to 80.0 pmol/l. In contrast, midregional PTH fragments were normal in seven of 49 patients with primary hyperparathyroidism. In five healthy controls and in 12 patients with surgically confirmed primary hyperparathyroidism and serum calcium levels below 3.0 mmol/l, a rapid calcium loading test was performed. In healthy controls, intact PTH was in the low normal to subnormal range within 2.5-5.0 min, and had recovered within 15 min of calcium infusion. In patients with primary hyperparathyroidism, the calcium infusion also led to a 30-50 per cent decrease in intact PTH levels within 5.0-7.5 min after injection, with a slow recovery after 10-15 min. In six of the patients with only slightly elevated basal intact PTH, a suppression to the normal range was observed. In 24 patients (16 patients with a solitary adenoma and eight patients with four-gland hyperplasia) the intact PTH levels were followed intraoperatively during parathyroidectomy, revealing a significantly different rate of decline for single adenomas compared with hyperplasia during the first 15 min after removal of the primary enlarged gland. Intact PTH values remained constantly elevated in one patient with primary hyperparathyroidism and an unsuccessful neck exploration. These results confirm that (a) the measurement of intact PTH in patients with primary hyperparathyroidism is superior to the measurement of midregional fragments; (b) PTH secretion in primary hyperparathyroidism is not totally autonomous; and (c) intraoperative monitoring of intact PTH values could be used to monitor the success of surgery.

Adenoma↗

PubMed1990

[Protein C deficiency with recurrent infarct of the small intestine].

Protein C and antithrombin III represent main inhibitors of the plasmatic coagulation system. Due to the lack of practicable assays the clinical importance of protein C was only established during the last six years. In familial protein C deficiency 77% of patients present with recurrent venous thromboses, half of them below the age of 30. In addition to recurrent superficial thrombophlebitis more serious manifestations like deep vein thrombosis and pulmonary embolism have been described. Mesenteric vein thrombosis has been reported in only 5 cases all of which could be controlled by conservative treatment. In our patient protein C deficiency was discovered 10 years after the angiographic diagnosis of portal and mesenteric vein thrombosis. Thereafter, the patient complained of recurrent abdominal discomfort. Intestinal ischaemia due to mesenteric vein thrombosis required segmental resection twice. Postoperatively the patient was heparinized. After excluding a secondary protein C deficiency due to a lack in vitamin K, hepatic disease, or disseminated intravascular coagulation, long-term anticoagulation by dicumarol was implemented as therapy of first choice.

Female↗

PubMed1990

[When should incidentalomas of the adrenal gland be surgically treated?].

Between January 1981 and December 1988 a total of 95 patients underwent surgery for adrenal tumors. In 24 cases (25.3%) a so-called "incidentaloma" was found. While seven of these tumors showed hormonal activity, in seventeen patients the tumor was hormonal inactive. The size of the tumors ranged between 2 and 11 cm. Histologically all tumors were found to be benign neoplasms. Because of the lack of lethality and minimal morbidity we indicate surgery on incidentaloma of the adrenal gland for the following reasons: tumors with hormone activity, tumor size larger than 3 cm, suspecting malignoma or metastasis and finally in proven enlargement of small tumors. Only in adrenal tumors smaller than 3 cm we suggest a follow-up by ultrasound or computed tomography.

Adenoma↗

PubMed1989

[Primary hyperaldosteronism without arterial hypertension].

Treatment-resistant hypokalaemia (2.27 mmol/l) developed in a 43-year-old woman. Plasma renin activity was depressed (0.24 ng/ml.h), aldosterone and hydroxycorticosterone concentrations were elevated (123 ng/dl and 688 ng/dl, respectively). Mean blood pressure value (30 readings) was 133/88 mm Hg. An adrenal adenoma was diagnosed by ultrasound, computed tomography and subtraction angiography and then removed. Postoperatively the signs of hyperaldosteronism (Conn's syndrome) regressed and the average blood pressure was 112/76 mm Hg. Blood-gas analysis, which preoperatively had shown a minimal metabolic alkalosis, now revealed a mild metabolic acidosis. Preoperatively present bilateral renal calcifications in the region of the papillary tips were confirmed by computed tomography. An acid loading test revealed diminished renal acid secretion, making the diagnosis of distal renal-tubular acidosis. The latter, in combination with the primary hyperaldosteronism, may have been the cause of the low blood pressure, unusual in Conn's syndrome.

18-Hydroxycorticosterone↗

PubMed1989

[Problems of tracheotomy in locally invasive anaplastic thyroid cancer].

Between 1955-1985 515 patients with carcinoma of the thyroid have been operated. Among 170 cases with a local infiltration 69 tracheostomies were performed in 55% for lesions of both laryngeal nerves or intratracheal bleeding (absolute indication), in 45% as a prophylactic intraoperative procedure to avoid later death from asphyxiation (relative indication). In a retrospective study clinical results were analysed with special reference to the question whether patients profit by the tracheostomy. Follow-up examinations showed that tracheostomy did not influence the outcome of patients with a differentiated thyroid carcinoma while there was a remarkable difference in survival of patients with anaplastic tumors where those with a tracheostomy had a worse survival. In this group postoperative external radiotherapy often could not be administered or was delayed due to local complications of the tracheostoma.

Adenocarcinoma↗