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Biomedical subjects

M Boehnert

Publications and source records attributed to M Boehnert.

6 recordsLinked to original sources
PubMed1999

Prevalence, predictors and patterns of postoperative polyuria and hyponatraemia in the immediate course after transsphenoidal surgery for pituitary adenomas.

OBJECTIVE: Disturbances of osmoregulation, leading to diabetes insipidus and hyponatraemia are well known complications after surgery in the sella region. This study was performed to examine the prevalence and predictors of polyuria and hyponatraemia after a complete and selective removal of pituitary adenomas was attempted via the transnasal-transsphenoidal approach. DESIGN: 1571 patients with pituitary adenomas (238 Cushing's disease, 405 acromegaly, 534 hormonally inactive adenomas, 358 prolactinoma, 23 Nelson's syndrome, and 13 thyrotropinoma) were daily examined within a 10-day postoperative inpatient observation period. Prevalence of patterns of polyuria (> 2500 ml) and oliguria/hyponatraemia (< 132 mmol/l) were surveyed as well as predictors of postoperative morbidity. RESULTS: 487 patients (31%) developed immediate postoperative hypotonic polyuria, 161 patients (10%) showed prolonged polyuria and 37 patients (2.4%) delayed hyponatraemia. A biphasic (polyuria-hyponatraemia) and triphasic (polyuria-hyponatraemia-polyuria) pattern was seen in 53 (3.4%) and 18 (1.1%) patients, respectively. Forty-one patients (2.6%) displayed immediate postoperative (day 1) hyponatraemia. Altogether, 8.4% of patients developed hyponatraemia at some time up to the 10th day postoperative, with symptomatic hyponatraemia in 32 patients (2.1%). Risk analysis showed that patients with Cushing's disease had a fourfold higher risk of polyuria than patients with acromegaly and a 2.8-fold higher risk for postoperative hyponatraemia. Younger age, male sex, and intrasellar expansion were associated with a higher risk of hypotonic polyuria, but this was not considered clinically relevant. CONCLUSIONS: The analysis illustrates that disturbances in osmoregulation resulting in polyuria and pertubations of serum sodium concentration are of very high prevalence and need observation even after selective transsphenoidal surgery for pituitary adenomas, especially in patients with Cushing's disease.

Acromegaly↗
PubMed1998

Severe hyponatremia after transsphenoidal surgery for pituitary adenomas.

Severe hyponatremia has been described after elective surgery with subsequent permanent brain damage. Other authors, however, have noted that morbidity and mortality rates of severe hyponatremia have been greatly overestimated. We retrospectively examined 19 patients (8 male, 11 female) who developed severe hyponatremia (100 to 124 mmol/liter) after transsphenoidal surgery for pituitary adenomas. Eight patients had hormonally inactive adenomas, 5 ACTH-secreting adenomas, 2 GH-secreting adenomas and 4 prolactin-secreting adenomas. The mean age of the patients was 47.5 years, with a range from 16 to 71 years. The mean preoperative serum sodium level was 137.8 mmol/liter. The timing of hyponatremia showed two different patterns. Five patients developed early postoperative hyponatremia (mean 114.0 mmol/liter +/- 4.85) and 14 patients showed the lowest mean serum level one week after surgery (118.1 mmol/liter +/- 6.86). Patients with early hyponatremia had fewer and less severe symptoms than patients with delayed hyponatremia. None of the patients developed seizures or a demyelination syndrome. Despite severe degree of hyponatremia for most of our patients treatment with water restriction and oral sodium supplementation was sufficient.

Adenoma↗
PubMed1993

Treatment of neonatal hyperbilirubinemia with repetitive oral activated charcoal as an adjunct to phototherapy.

The efficacy of multiple dose oral activated charcoal (OAC) therapy for neonatal hyperbilirubinemia was prospectively studied in 30 jaundiced newborns receiving phototherapy, randomly assigned to a study group (n = 14) or control group (n = 16). The study group received OAC before meals with a total amount of 8.5 +/- 0.85 gms (M +/- SEM). Serum bilirubin levels upon initiation of phototherapy were (M +/- SEM) 265 +/- 8 and 253 +/- 4 mumol/L respectively. After 24 hours there was no significant decrease in serum bilirubin levels in the control group (M +/- SEM = 240 +/- 8 mumol/L) but bilirubin levels of the study group decreased (M +/- SEM = 235 +/- 7 mumol/L, p < 0.02). At 48 hours serum bilirubin levels were significantly lower than baseline values in both groups. However, the decline in bilirubin levels in the study group (M +/- SEM = 56 +/- 10 mumol/L) was greater than that of the controls (M +/- SEM = 21 +/- 10 mumol/L p < 0.02). Oral activated charcoal seems to be an effective adjunct to phototherapy in the treatment of neonatal hyperbilirubinemia.

Administration, Oral↗
PubMed1978

Purification of human parathyroid hormone: recent studies and further observations.

During the isolation of human parathyroid hormone there is an extensive loss of immuno-assayble hormone over the successive extraction steps, due in part to the presence of fragments that are soluble in 4% trichloroacetic acid. These fragments are derived from both the amino- and carboxyl-terminal regions of the hormone. The hormonal fractions precipitated with trichloroacetic acid were further purified by gel filtration and ion-exchange chromatography. At the final ion-exchange purification step, some preparations of the hormone eluted in multiple fractions. When the various components were characterized separately by immunoassay, amino acid composition, enzymic cleavage and partial sequence analysis, they were found to be closely comparable, although the most acidic fraction contained a blocked terminal amino group. Extraction of a number of batches of tissue permitted revision of the amino acid composition of human parathyroid hormone. Biosynthetic studies with labelled amino acids confirmed the absence of tyrosine and the presence of phenylalanine and threonine and localized these residues to definite regions of the molecule.

Amino Acid Sequence↗