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Biomedical subjects

M Steiner

Publications and source records attributed to M Steiner.

At least 55 records · Page 3Linked to original sources
PubMed2000

Phenol sulphotransferase SULT1A1 polymorphism in prostate cancer: lack of association.

Preliminary evidence suggests that genetic polymorphisms in certain enzymes involved in xenobiotic metabolism and chemical defense could modify a susceptibility to prostate cancer. In the present study, two recently described phenol sulphotransferase SULT1A1 alleles (SULT1A1*1, SULT1A1*2) were investigated using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach. Genotyping was performed on DNA isolated from white blood cells from 134 patients with prostate cancer and 184 healthy control subjects. Both the prostate cancer patients and the controls demonstrated similar frequencies of the variant allele SULT1A1*2 (35.1% vs 39.1%). Homozygosity for the variant allele was slightly less frequent in cancer patients than controls (12.7% vs 17.4%). Our study does not support the hypothesis that the phenol sulphotransferase variant allele SULT1A1*2 with a G/A transition at nucleotide 638 is a risk modifier for prostate cancer in the Caucasian population.

Alleles↗
PubMed2000

A PET study of brain 5-HT2 receptors and their correlation with platelet 5-HT2 receptors in healthy humans.

RATIONALE: Platelets share many properties with brain serotonergic neurons such as active 5-hydroxytryptamine (5-HT) transport, 5-HT2 receptors, and mitochondrial monoamine oxidase. OBJECTIVES: We measured brain 5-HT2 receptors and platelet 5-HT2 receptors in healthy volunteers to determine if there was any correlation between the two measures. METHODS: Ten healthy volunteers with no lifetime history of psychiatric illness or family history in first-degree relatives were recruited. 5-HT2 receptor binding was determined for each subject with positron emission tomography and [18F]setoperone scan in the brain and with 3H-LSD binding in platelets. RESULTS: We found no significant correlation between 5-HT2 binding potential (BP) in platelets (Bmax/Kd) and a semiquantitative estimate of 5-HT2 BP in frontal, parietal, and temporal cortical regions. SPM voxel based analysis also showed no significant correlation between the 5-HT2 BP in platelets and in the brains of the study subjects. CONCLUSIONS: Brain 5-HT2 receptor binding was not significantly correlated to platelet 3H-LSD binding in healthy subjects. This raises questions about the validity of generalizing findings from platelet studies to 5-HT neurons in the brain.

Adult↗
PubMed2000

Gamma surgery for hemangiopericytomas.

A retrospective analysis of a consecutive series of 12 patients with 15 intracranial hemangiopericytomas treated at the University of Virginia using Gamma surgery is presented. Clinical and radiographic follow up of 3 to 56 months is available for 10 patients with 12 tumors. There was one tumor present at the time of initial Gamma surgery in each patient. Two new tumors occurred in patients previously treated. Nine of the tumors decreased in volume and three remained stable. Four of the nine tumors that shrank later progressed at an average of 22 months after treatment. Of the tumors that decreased in volume and have not progressed, the response has been for an average of 11 months. The follow-up for two tumors that remained unchanged was 10 and 34 months (average 22 months). A third tumor was unchanged at 42 months but the patient died of new disease adjacent to the treated area in the anterior skull base. There were no complications and the quality of life following the procedure was maintained or improved in every case. Gamma surgery is effective in palliating the patients by decreasing tumor volume and delaying recurrence.

Adult↗
PubMed2000

Separation of Tc-99 in soil and plant samples collected around the chernobyl reactor using a Tc-selective chromatographic resin and determination of the nuclide by ICP-MS

Technetium (Tc) is known to have high mobility in a soil-water system and also high bioavailability for plants, because the most stable form of Tc in natural surface environment is thought to be TcO4- which is highly soluble. The chemical form of Tc, however, changes with environmental conditions. Thus, it is necessary, for realistic assessment, to obtain transfer parameters, such as transfer factors, under natural conditions. However, it is difficult to obtain these parameters using global fallout 99Tc in actual fields due to its low concentration. In this study, 99Tc concentrations in surface soil and plant leaf samples collected from forest sites within the 30-km zone around the Chernobyl reactor were measured for the first time. In the case of soil samples, a simple and rapid analytical method for determination of 99Tc is used which consists of volatilizing and trapping Tc in a combustion apparatus, purifying the Tc with an extraction chromatographic resin, and measuring it by inductively coupled plasma mass spectrometry (ICP-MS). For plant samples, a wet digestion method in combination with the resin is applied and the 99Tc is measured by ICP-MS. Concentrations of 99Tc in organic soil samples and leaves of strawberry (Fragaria vesca) range from 1.1-14.8 Bq kg(-1) dry weight and 0.2-6.0 Bq kg(-1) dry weight, respectively. Our results indicate that soil-to-plant transfer factors for Tc are similar to those for Cs.

Journal Article↗
PubMed2000

Pulmonary cytolytic thrombi: a newly recognized complication of stem cell transplantation.

Over the past 5 years we have recognized a new pulmonary complication of hematopoietic stem cell transplantation (HSCT) associated with fever and pulmonary nodules termed 'pulmonary cytolytic thrombi' (PCT). Retrospective analysis of medical and radiographic records and pathologic material from 13 HSCT recipients with PCT and a review of the Blood and Marrow Transplant Database for all patients with radiographic evidence of pulmonary nodules or who underwent open-lung biopsy from 1 January 1993 to 31 December 1998 (n = 1228) were performed. The median age of patients with PCT was 11.9 years (range, 1.3-29.7 years). All patients developed fever at a median of 72 days (range, 8-343 days) post transplant, followed by pulmonary nodules on chest CT. Eleven patients were receiving therapy for active GVHD (acute, grades I-IV (n = 10); extensive chronic (n = 1)). Biopsy of the pulmonary nodules revealed a unique pattern of necrotic, basophilic thromboemboli with amorphous material suggestive of cellular breakdown products. This was descriptively labeled 'pulmonary cytolytic thrombi'. Immunohistochemical staining revealed entrapped leukocytes and disrupted endothelium, but was negative for histiocytes. Cultures and immunohistochemical stains were negative for infectious agents. Empiric therapy included systemic corticosteroids (n = 9) and amphotericin (n = 7). Nine patients survive with resolution of PCT at a median follow-up of 1.5 years. Bone Marrow Transplantation (2000) 25, 293-300.

Adolescent↗
PubMed2000

Severe hypophosphatemia during hematopoietic reconstitution after allogeneic peripheral blood stem cell transplantation.

A patient suffering from acute myeloid leukemia (FAB M5a) received a PBSC allograft from a matched, related donor. On day 13 after transplantation severe hypophosphatemia (0.21 mmol/l) was first noted which persisted irrespective of intravenous phosphate administration, and within 2 days reached concentrations below 0.13 mmol/l. After repeated phosphate substitution serum phosphate returned to 1.40 mmol/l on day 17. Phosphate in urine, and calcium in serum were recorded as unchanged throughout. Clinical signs and symptoms due to severe hypophosphatemia were not observed except for paresthesia in the lower extremities. The precipitous fall in serum phosphate coincided with hematopoietic reconstitution as reflected by a steep rise in leukocyte count from 0.08 x 109/l on day 10 to 5. 94 x 109/l on day 15 after transplantation. Thus, isolated hypophosphatemia was likely the result of excessive cellular phosphate uptake during hematopoietic reconstitution. Electrolyte monitoring after PBSCT should include serum phosphate to identify the hypophosphatemia associated with hematopoietic recovery.

Adult↗
PubMed2000

Cohort study of occupational risk factors of low back pain in construction workers.

OBJECTIVES: To identify work related risk factors of future low back pain (LBP) in a cohort of construction workers free of LBP at the start of follow up. METHODS: The Hamburg construction worker study comprises 571 male construction workers who have undergone two comprehensive interview and physical examination surveys. A cohort of 285 subjects without LBP at baseline was identified. After a follow up of 3 years, the 1 year prevalence of self reported LBP was determined in the 230 men followed up (80.7%). Prevalence ratios (PRs) with 95% confidence intervals (95% CIs) of LBP at follow up according to self reported work tasks of construction workers measured at baseline were estimated from Cox's regression models which were adjusted for age, and anthropometric measures. RESULTS: At follow up 71 out of 230 workers (30.9%) reported LBP during the preceding 12 months. Four work tasks (scaffolding, erecting roof structures, sawing wood, laying large sandstones) with an increased risk of 1 year prevalence of LBP at follow up were further evaluated. After further adjustment for occupation the relative risk was increased for workers who had reported > or = 2 hour/shifts laying large sandstones (PR = 2.6; 95% CI 1.1 to 6.5). Work load of bricklayers was additionally estimated by an index on stone load (high exposure: PR = 4.0; 95% CI 0.8 to 19.8), and an index for laying huge bricks/blocks (yes/no: PR = 1.7; 95% CI 0.5 to 5.7). CONCLUSIONS: The results suggest that self reported differences in brick characteristics (size and type of stone) and temporal aspects of the work of bricklayers (average hours per shift laying specified stones) can predict the future prevalence of LBP. The data have to be interpreted with caution because multiple risk factors were tested.

Adolescent↗
PubMed2000

International publication trends of JABA authorship.

The present study addressed international publication trends in JABA authorship between 1970 and 1999. First, we analyzed authorship patterns to identify trends in the appearance of new first authors, unfamiliar authors, and frequent contributors. Second, articles were assigned to either a North American or an international category. The data show a decline in the number of articles by new authors and an increase in the publications of frequent contributors from North America. Trends are shown in comparison to those from the American Journal on Mental Retardation.

Authorship↗
PubMed2000

Gamma surgery for vestibular schwannoma.

OBJECT: The goal of this study was to assess the results of gamma surgery (GS) for vestibular schwannoma (VS) in 200 cases treated over the last 10 years and to review the role of this neurosurgical procedure in the management of VS. METHODS: Follow-up reviews ranging from 1 to 10 years were available in 153 of these patients. Follow-up images in these cases were analyzed using computer software that we developed to obtain volume measurements for the tumors, and the clinical condition of the patients was assessed using questionnaires. Gamma surgery was the primary treatment modality in 96 cases and followed microsurgery in 57 cases. Tumors ranged in volume from 0.02 to 18.3 cm(3). In the group in which GS was the primary treatment, a decrease in volume was observed in 78 cases (81%), no change in 12 (12%), and an increase in volume in six cases (6%). The decrease was more than 75% in seven cases. In the group treated following microsurgery, a decrease in volume was observed in 37 cases (65%), no change in 14 (25%), and an increase in volume in six (11%). The decrease was more than 75% in eight cases. Five patients experienced trigeminal dysfunction; in three cases this was transient and in the other two it was persistent, although there has been improvement. Three patients had facial paresis (in one case this was transient, lasting 6 weeks; in one case there was 80% recovery at 18 months posttreatment; and in one case surgery was performed after the onset of facial paresis for presumed increase in tumor size). Over a 6-year period, hearing deteriorated in 60% of the patients. Three patients showed an improvement in hearing. No hearing deterioration was observed during the first 2 years of follow-up review. CONCLUSIONS: Gamma surgery should be used to treat postoperative residual tumors as well as tumors in patients with medical conditions that preclude surgery. Microsurgery should be performed whenever a surgeon is confident of extirpating the tumor with a risk-benefit ratio superior to that presented in this study.

Adolescent↗
PubMed2000

Gamma surgery for intracranial metastases from renal cell carcinoma.

OBJECT: The goal of this study was to evaluate the effectiveness and limitations of gamma surgery (GS) in the treatment of renal cell carcinoma that has metastasized to the brain. METHODS: The authors performed a retrospective analysis of a consecutive series of 21 patients with 37 metastatic brain deposits from renal cell carcinoma who were treated with GS at the University of Virginia from 1990 to 1999. Clinical data were available in all patients. No patient died of progression of intracranial disease or deteriorated neurologically following GS. Eight patients clinically improved. Follow-up imaging studies were available for 23 tumors in 12 patients. Nine patients did not undergo follow-up imaging. One patient lived 17 months and succumbed to systemic disease: no brain imaging was performed in this case. Another patient refused further imaging and lived 7 months. Seven patients lived up to 4 months after the procedure; however, their physicians did not require these patients to undergo follow-up imaging examinations because of their general conditions-all had systemic progression of disease. Of the 23 tumors that were observed posttreatment, one remained unchanged in volume, 16 decreased in volume, and six disappeared. No tumor progressed at any time, and there were no radiation-induced changes on follow-up imaging an average of 21 months after GS (range 3-63 months). CONCLUSIONS: Gamma surgery provides an alternative to surgical resection of metastatic brain deposits from renal cell carcinoma. Neurological side effects were seen in only one case; freedom from progression of disease was achieved in all cases.

Adult↗
PubMed2000

Gamma surgery for vein of Galen malformations.

OBJECT: The goal of this study was to evaluate the results of gamma surgery in nine patients treated for vein of Galen malformations (VGMs). METHODS: A consecutive series of nine VGMs in eight children aged 4 to 14 years and in one adult were treated with gamma surgery. Six of the patients were male, including the adult, and three were female. Among these patients there were three Yasargil Type I, one Type II, two Type III, and three Type IV malformations. Previous embolization had failed in four cases. Three VGMs were treated with gamma surgery twice. An additional patient with a Type III VGM underwent stereotactic angiography in preparation for gamma surgery but was judged to be suitable for direct embolization. Follow-up angiograms were obtained in eight of the VGMs treated. Four no longer filled; one has probably been obliterated, but this cannot be confirmed because the patient refused to undergo final angiography; one patient has residual fistulas not included in the initial treatment field, which were retreated recently; and two other patients have marked reduction of flow through their VGMs. CONCLUSIONS: Gamma surgery is a viable option in the treatment of VGMs in clinically stable patients. Combined endovascular therapy and gamma surgery is of benefit in complex malformations.

Adolescent↗
PubMed2000

Premenstrual dysphoria and the serotonin system: pathophysiology and treatment.

The inclusion of research diagnostic criteria for premenstrual dysphoric disorder (PMDD) in the DSM-IV recognizes the fact that some women have extremely distressing emotional and behavioral symptoms premenstrually. PMDD can be differentiated from premenstrual syndrome (PMS), which presents with milder physical symptoms, headache, and more minor mood changes. In addition, PMDD can be differentiated from premenstrual magnification of physical and/or psychological symptoms of a concurrent psychiatric and/or medical disorder. As many as 75% of women with regular menstrual cycles experience some symptoms of PMS, according to epidemiologic surveys. PMDD is much less common; it affects only 3% to 8% of women in this group. The etiology of PMDD is largely unknown, but the current consensus is that normal ovarian function (rather than hormone imbalance) is the cyclical trigger for PMDD-related biochemical events within the central nervous system and other target organs. The serotonergic system is in close reciprocal relationship with the gonadal hormones and has been identified as the most plausible target for interventions. Thus, beyond the conservative treatment options such as lifestyle and stress management, other nonantidepressant treatments, or the more extreme interventions that eliminate ovulation altogether, the serotonin reuptake inhibitors (SRIs) are emerging as the most effective treatment option for this population. Results from several randomized, placebo-controlled trials in women with PMDD have clearly demonstrated that the SRIs have excellent efficacy and minimal side effects. More recently, several preliminary studies indicate that intermittent (premenstrual only) treatment with selective SRIs is equally effective in these women and, thus, may offer an attractive treatment option for a disorder that is itself intermittent.

Diagnosis, Differential↗
PubMed2000

Non-antidepressant treatment of premenstrual syndrome.

Although selective serotonin reuptake inhibitors are considered the first-line treatment option for premenstrual syndrome, several other such options are also available. Multiple studies have indicated that medications that suppress ovulation alleviate premenstrual emotional and physical symptoms. However. the use of such medications, such as the gonadotropin-releasing hormone agonists, leads to prolonged low estrogen levels and cardiac and osteoporotic health risks. A recent double-blind, placebo-controlled study of 466 women with premenstrual syndrome reported that calcium was effective in reducing emotional, behavioral, and physical premenstrual symptoms. Recent preliminary trials have suggested efficacy for cognitive therapy, light therapy, and tryptophan. Future studies of diet recommendations, exercise, relaxation, magnesium, nonsteroidal anti-inflammatory drugs, diuretics, opiate antagonists, and alternative therapies are needed.

Anti-Anxiety Agents↗
PubMed2000

Premenstrual syndrome and premenstrual dysphoric disorder: guidelines for management.

The inclusion of research diagnostic criteria for premenstrual dysphoric disorder (PMDD) in the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, recognizes the fact that some women have extremely distressing emotional and behavioural symptoms premenstrually. PMDD can be differentiated from premenstrual syndrome (PMS), which presents with milder physical symptoms, headache, and more minor mood changes. In addition, PMDD can be differentiated from premenstrual magnification of physical or psychological symptoms of a concurrent psychiatric or medical disorder. As many as 75% of women with regular menstrual cycles experience some symptoms of PMS, according to epidemiologic surveys. PMDD is much less common; it affects only 3% to 8% of women in this group. The etiology of PMDD is largely unknown, but the current consensus is that normal ovarian function (rather than hormone imbalance) is the cyclical trigger for PMDD-related biochemical events within the central nervous system and other target organs. The serotonergic system is in a close reciprocal relation with the gonadal hormones and has been identified as the most plausible target for interventions. Thus, beyond conservative treatment options such as lifestyle and stress management, other non-antidepressant treatments, or the more extreme intervneitons that eliminate ovulation altogether, selective serotonin reuptake inhibitors (SSRIs) are emerging as the most effective treatment option. Results from several randomized, placebo-controlled trials in women with PMDD have clearly demonstrated that SSRIs have excellent efficacy and minimal side effects. More recently, several preliminary studies indicate that intermittent (premenstrual only) treatment with selective SSRIs is equally effective in these women and, thus, may offer an attractive treatment option for a disorder that is itself intermittent.

Adult↗
PubMed2000

Diagnosis and treatment of premenstrual dysphoric disorder: an update.

Premenstrual dysphoric disorder (PMDD) appears in the appendix of the DSM-IV under the heading 'depressive disorder not otherwise specified'. Yet, recently, a group of experts reached a consensus that PMDD is a distinct clinical entity with characteristic symptoms of irritability, anger, internal tension, dysphoria, and mood lability. PMDD is the more severe form of premenstrual symptomatology, whereas premenstrual syndrome (PMS) is milder and more prevalent and both must be differentiated from premenstrual magnification/exacerbation of an underlying major psychiatric disorder or a medical condition. Accurate assessment and diagnosis of significant premenstrual symptomatology is paramount and can be influenced by subjective perception, retrospective versus prospective reporting, and cultural context. The serotonergic system, which is in a close reciprocal relationship with the gonadal hormones, has been identified as the most plausible target for intervention. Results from randomized placebo-controlled trials in women with PMDD have clearly demonstrated that serotonin reuptake inhibitors (SSRIs), with daily or intermittent dosing, have excellent efficacy and minimal adverse effects and should be considered first-line treatment. Luteal phase only SSRI administration may offer an attractive treatment option for a disorder that is itself intermittent. Hormonal interventions, in particular the suppression of ovulation will eliminate premenstrual symptomatology; however, the benefits-risk ratio of these approaches should be carefully evaluated with the patient.

Adolescent↗
PubMed1999

Serotonergic dysfunction in women with pure premenstrual dysphoric disorder: is the fenfluramine challenge test still relevant?

The fenfluramine (FEN) neuroendocrine challenge paradigm, which involves measuring the response of prolactin (PRL) release to an oral challenge dose of FEN, provides a means of assessing serotonin (5-HT) function. The purpose of this study was to ascertain the role of 5-HT in premenstrual dysphoric disorder (PMDD) by measuring: (1) PRL and cortisol (CORT) responses to FEN; and (2) platelet 3H-imipramine binding levels, in females with pure PMDD (without a past or present comorbid mood disorder) in comparison to healthy controls. FEN challenge tests were administered to nine female patients with pure PMDD and nine healthy female controls during the follicular and late luteal phases of a menstrual cycle. There were no differences in the PRL response to FEN for women with PMDD compared to healthy controls. However, the trend toward a delayed response to FEN and a significant negative correlation between delta(max) PRL and basal CORT in patients but not in controls during both phases of the menstrual cycle suggest an underlying 5-HT dysfunction in patients as compared to controls. This is further supported by the finding of significantly lower Bmax 3H-imipramine binding levels in the patients during the late luteal phase.

Journal Article↗
PubMed1999

609 C --> T polymorphism in NAD(P)H:quinone oxidoreductase gene in patients with prostatic adenocarcinoma or benign prostatic hyperplasia.

Allelic variations at the NQO1 locus encoding for NAD(P)H:quinone oxidoreductase have recently been implicated in carcinogenesis, cancer chemoprevention and chemotherapy. Two naturally occurring alleles differ at nucleotide position 609 with the variant allele leading to diminished or absent enzyme activity. Using polymerase chain reaction-restriction fragment length polymorphic analysis, NQO1 genotyping was performed in DNA from blood cells from 54 patients with prostatic adenocarcinoma, 49 patients with benign prostatic hyperplasia and 100 healthy control subjects. Prostatic adenocarcinoma patients and healthy controls demonstrated almost identical genotype distribution and frequencies of the variant allele (17.6 versus 17.5%). The variant allele was slightly more frequent in benign prostatic hyperplasia patients (23.5%). Established prostate cancer-derived cell lines LnCAP, DU-145, and PC-3 demonstrated NQO1 wild-type genotype. Our study does not support the hypothesis that the variant NQO1 allele is a risk modifier for prostatic adenocarcinoma and/or benign prostatic hyperplasia in the Caucasian population.

Adenocarcinoma↗