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Biomedical subjects

M Berger

Publications and source records attributed to M Berger.

At least 19 recordsLinked to original sources
PubMed1992

Right-sided endocarditis in intravenous drug users. Prognostic features in 102 episodes.

OBJECTIVE: To describe the clinical, laboratory, and echocardiographic findings in a large group of patients with right-sided endocarditis and to determine whether any of these findings is predictive of prognosis. DESIGN: Retrospective survey of medical records to evaluate the course of hospitalization with follow-up on 6-month survival. Review of two-dimensional echocardiograms by an observer blinded to clinical information. SETTING: Large, metropolitan, voluntary hospital. PATIENTS: One hundred twenty-one intravenous drug users with clinical and bacteriologic evidence of 132 episodes of endocarditis. The presence of a right-sided valvular vegetation detected by two-dimensional echocardiography was required for entry into the study. MEASUREMENTS AND RESULTS: Staphylococcus aureus was the most common infecting organism (82%, 108 of 132). Vegetations involved the tricuspid valve in 127 episodes, the pulmonic in 4, and both in 1; they ranged in size from 0.4 to 4.3 cm (mean, 1.5 +/- 0.7 cm). Vegetations greater than 1.0 cm were present in 106 cases (80%). Among patients with isolated native right-sided endocarditis who reached a definite end point in treatment, mortality was 7% (7 of 98). Vegetations greater than 2.0 cm were associated with a significantly higher mortality compared with vegetations of 2.0 cm or less (33% compared with 1.3%, P less than 0.001). CONCLUSIONS: Overall, right-sided endocarditis has a favorable prognosis. Although complications and prolonged fever are common, most cases respond to medical therapy. Our findings suggest that vegetation size may be an important predictor of outcome and that vegetations greater than 2.0 cm are associated with increased mortality.

Adolescent↗
PubMed1992

Photooxidation of d(TpG) by phthalocyanines and riboflavin. Isolation and characterization of dinucleoside monophosphates containing the 4R* and 4S* diastereoisomers of 4,8-dihydro-4-hydroxy-8-oxo-2'-deoxy-guanosine.

Phthalocyanine mediated photosensitization of 2'-deoxyguanosine (dG) in oxygen saturated aqueous solution has previously been shown to result in the addition of molecular oxygen to the guanine base generating the 4R* and 4S* diastereoisomers of 4,8-dihydro-4-hydroxy-8-oxo-2'-deoxyguanosine (dO) (the asterisk denotes unambiguous assignment of the 4R and 4S diastereoisomers). The data presented here show that the same guanine modified bases are generated in a 1:1 ratio when thymidylyl-(3',5')-2'-deoxyguanosine (d(TpG)) is similarly photo-oxidized. These modified dinucleoside monophosphates, labelled d(TpO)-A and -B, have been isolated by high performance liquid chromatography and characterized by proton NMR spectrometry, fast atom bombardment mass spectrometry, and enzymatic digestions. Photosensitization in D2O instead of H2O leads to an increase in the rate of d(TpO) formation that is consistent with a type II (singlet oxygen) reaction mechanism. Three interesting properties of these modified dinucleoside monophosphates are: i) the rate of their digestion with spleen phosphodiesterase is greatly reduced relative to d(TpG), ii) they are not digested by snake venom phosphodiesterase, and iii) they are stable to 1.0 M piperidine at 90 degrees C for 30 min. The latter observation indicates that 4,8-dihydro-4-hydroxy-8-oxoguanine is not a base lesion responsible for the strand breaks observed following hot piperidine treatment of DNA exposed to type II photosensitizers or chemically generated singlet oxygen.

Chromatography, High Pressure Liquid↗
PubMed1992

Reversed-phase high-performance liquid chromatography-thermospray mass spectrometry of radiation-induced decomposition products of thymine and thymidine.

High-performance liquid chromatography-thermospray mass spectrometry was applied to the analysis of various radiation-induced decomposition products of thymidine including N-(2-deoxy-beta-D-erythro-pentofuranosyl)formamide and the various diastereomers of 5,6-dihydroxy-5,6-dihydrothymidine, 5-hydroxy-5,6-dihydrothymidine and 5,6-dihydrothymidine. This method combines high sensitivity and product resolution, rendering it particularly useful for monitoring the formation of radiation-induced base damage within DNA.

Chromatography, High Pressure Liquid↗
PubMed1992

Differentiation of a primitive neuroectodermal tumor into a benign ganglioglioma.

We describe a case of cerebellar neuroblastoma with histologic documentation of maturation into a ganglioglioma sixteen months later. Only chemotherapy was administered following the initial surgery and the child is well and disease-free three years following her final surgical procedure. The outcome of this patient supports previous hypotheses that the cerebellar neuroblastoma may be a less malignant tumor than its other primitive neuroectodermal posterior fossa counterparts. Furthermore, this case suggests a role for second-look surgery in the management of selected pediatric brain tumors.

Cell Differentiation↗
PubMed1992

The prognostic significance of postoperative residual contrast enhancement on CT scan in pediatric patients with medulloblastoma.

The clinical and therapeutic features of 20 patients with medulloblastoma treated at Children's Hospital and Medical Center, Seattle, from 1980 to 1987, were retrospectively analyzed with regard to prognosis. The overall actuarial 5-year survival rate was 63%, with 57% of patients free from recurrence at 5 years. Residual contrast enhancement on CT scans taken immediately postoperatively was associated with a significantly decreased 5-year recurrence-free survival rate; the 5-year recurrence-free survival rate was 100% for those patients without post-operative residual enhancement compared to 41% for those patients with residual enhancement. A high risk group of patients with residual contrast enhancement persisting one year following diagnosis was identified. No patient in this group survived without disease progression. Other factors, including sex, age at diagnosis, evidence of tumor dissemination, or extent of surgical resection as reported by the neurosurgeon, did not significantly influence prognosis.

Adolescent↗
PubMed1992

Hyperinsulinaemia is not linked with blood pressure elevation in patients with insulinoma.

We have investigated the hypothesis that insulin is a causal and independent risk factor for blood pressure elevation in humans by comparing pre- and post-operative blood pressure values of 34 consecutive patients with histologically-confirmed diagnosis of insulinoma and 34 age- and sex-matched control patients. In patients with insulinoma hypoglycaemic symptoms were present for 18 (9-36) months. (Values are given as median and 95% confidence interval or mean and SD). After removal of insulinoma fasting plasma insulin levels decreased from 22 (16-28) mU/l to 11 (6-20) mU/l (p less than 0.003) and minimal fasting plasma glucose concentrations increased from 2.5 (2.0-3.0) to 4.4 (4.2-5.7) mmol/l (p less than 0.002) while blood pressure values remained unchanged. Body mass index before operation was comparable between the groups: 25.5 (5.4) kg/m2 in insulinoma patients and 24.8 (4.7) kg/m2 in control subjects. Pre-operative and post-operative blood pressure values did not differ between the groups, being (systolic/diastolic) 133 (18)/82 (9) mm Hg in insulinoma patients and 128 (15)/78 (10) mm Hg in control subjects before and 129 (19)/80 (10) mm Hg and 125 (11)/76 (7) after surgery. Chronic hyperinsulinaemia in patients with insulinoma is not associated with a detectable elevation of blood pressure values. Correction of hyperinsulinaemia after surgery for insulinoma does not result in blood pressure changes. These results argue against the hypothesis that insulin is an independent causal factor in the development of essential hypertension in humans.

Blood Glucose↗
PubMed1992

Quality assessment of diabetes care according to the recommendations of the St. Vincent Declaration: a population-based study in a rural area of Austria.

Using a mobile ambulance the quality of diabetes care was evaluated, according to the recommendations of the St. Vincent Declaration, in 95% of all known diabetic patients (n = 395) in a geographically defined rural area of Austria with 7871 inhabitants. Fourteen of the 395 patients had Type 1 (insulin-dependent) diabetes with age at onset of diabetes below 30 years. Of the 375 patients examined (women 61%, age 66 +/- 13 years, median diabetes duration 6 years) 16% were treated with insulin and 47% with oral agents; HbA1c levels were 7.3 +/- 1.7%. Prevalence of known hypertension was 54%; 68% of these patients had their blood pressure uncontrolled (systolic greater than or equal to 160 and/or diastolic greater than or equal to 95 mmHg); a further 15% of patients with previously unknown hypertension had blood pressure values of greater than or equal to 160 and/or greater than or equal to 95 mmHg. Urinary albumin concentrations of greater than 200 mg/l were found in 15% of patients, 2% had a serum creatinine level of greater than 177 mumol/l, no patient had renal replacement therapy. Six patients (1.5%) were blind. Screening for retinopathy identified six patients (out of 317 in whom the retina could be evaluated) for whom consultation with an ophthalmologist as soon as possible was recommended. Of the total patient group (n = 395) 20 patients (5%) had foot complications (amputations and/or ulcers): 14 patients had a total of 21 lower limb amputations (eight above knee, six below knee, seven below ankle); eight of these 14 patients lived in a nursing home; 11 patients had a total of 13 foot ulcers.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

The juvenile hormone analogue, methoprene, inhibits ecdysterone induction of small heat shock protein gene expression.

The small heat shock protein (hsp) genes of Drosophila are expressed in cultured cells in response to the moulting hormone, ecdysterone. We show here that juvenile hormone (JHIII) and the juvenile hormone analogue, methoprene, inhibit that induction in a dose-dependent manner. Heat shock induction is not inhibited. In transient expression studies using S3 line cells transfected with EcRE-CAT constructs, methoprene inhibition was found to require a 2-hr pretreatment (before ecdysterone addition), and methoprene's continued presence was essential. Farnesol, farnesyl acetate, and retinoic acid did not cause inhibition. Several models of methoprene inhibition are discussed.

Animals↗
PubMed1992

The sleep structure of patients with anxiety disorders in comparison to that of healthy controls and depressive patients under baseline conditions and after cholinergic stimulation.

This study investigated sleep EEG during placebo and after cholinergic stimulation with RS 86 in 36 healthy subjects, 34 patients with major depression and 20 patients with anxiety disorders. Cholinergic stimulation with RS 86 led to a decrease of slow wave sleep and REM latency. RS 86 had a more profound impact on REM latency in patients with major depression than in healthy controls and patients with anxiety disorders. Six out of 36 healthy controls, three out of 20 patients with anxiety disorders and 24 of 34 patients with depression displayed sleep onset REM periods after cholinergic stimulation. Also effects on REM density and duration of the first REM period were more pronounced in major depression. Even in those patients with anxiety disorders and a secondary major depression no depression-like sleep abnormalities could be provoked. The results underline the usefulness of the cholinergic REM induction test to differentiate patients with major depression from those with other psychiatric disorders. The results can be interpreted as further evidence for the cholinergic-aminergic imbalance model of depression and for the reciprocal interaction model of nonREM-REM regulation.

Adult↗
PubMed1992

Sleep, age, depression and the cholinergic REM induction test with RS 86.

1. Healthy volunteers and patients with a major depressive disorders were administered 1.5 mg RS 86 (a cholinergic agonist) and placebo in a randomized double-blind cross-over design at 10 p.m. prior to bedtime. 2. Polysomnographic recordings demonstrated a significantly more pronounced shortening of REM latency after cholinergic stimulation in depressed patients compared to healthy subjects. 3. Even those depressed patients displaying placebo REM latencies in the normal range showed sleep onset REM periods after cholinergic stimulation. 4. The results support the reciprocal interaction model of NonREM-REM sleep regulation and the cholinergic-aminergic imbalance model of depression.

Adult↗
PubMed1992

Cryptococcal osteomyelitis and cellular immunodeficiency associated with interleukin-2 deficiency.

We describe an unusual example of cellular immunodeficiency associated with interleukin-2 deficiency in an otherwise healthy 15-year-old boy who had isolated cryptococcal osteomyelitis of the scapula at 10 years of age. His previous medical history was remarkable only for prolonged, severe varicella infection at 6 years of age. He had persistent moderate lymphopenia, anergy, and absent lymphocyte blastogenic responses to mitogens, antigens, or monoclonal T cell antibodies. Subnormal blastogenic responses were seen after exposure to high concentrations of phorbol esters. Immunoglobulin levels and specific antibodies were normal. The patient has been in good health since treatment of his osteomyelitis. However, his lymphocyte blastogenic responses to mitogens have remained absent during 4 years of observation; investigation of the cause revealed a specific interleukin-2 deficiency resulting from defective generation of interleukin-2 messenger ribonucleic acid. Secretion of interleukin-1 by monocytes was normal, suggesting that the abnormal blastogenic response and interleukin-2 production were due to a problem intrinsic to T lymphocytes. The generation of messenger ribonucleic acid for interleukin-4 was not affected. Interferon-gamma was produced at subnormal levels. The addition of recombinant interleukin-2 restored lymphocyte blastogenic responses and increased the expression of interleukin-2 receptors. The clinical findings and immunologic abnormalities present in this patient differ from other primary and secondary immunodeficiencies associated with interleukin-2 deficiency. Thus our observations in this patient extend the spectrum of immunodeficiencies associated with abnormalities in the production of this important cytokine.

Adolescent↗