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Biomedical subjects

M Michael

Publications and source records attributed to M Michael.

At least 37 records · Page 2Linked to original sources

Phase I/II study of concurrent twice-weekly paclitaxel and weekly cisplatin with radiation therapy for stage III non-small cell lung cancer.

The optimal chemoradiation regimen for stage III non-small cell lung cancer (NSCLC) has not been determined. In this phase I/II study, the use of twice-weekly paclitaxel concomitant with weekly cisplatin and thoracic radiotherapy (RT) was evaluated. Patients with stage III NSCLC (without pleural effusion or cervical lymphadenopathy) were treated with thoracic RT (60 Gy in 30 fractions over 6 weeks) with concurrent weekly cisplatin 20 mg/m(2) and escalating doses of twice-weekly paclitaxel (starting dose of paclitaxel of 20 mg/m(2) increased in increments of 5 mg/m(2)) in successive cohorts of three to six patients until two or more patients experienced dose limiting toxicities (DLTs) at a particular dose level. All patients were planned to be given a further two cycles of consolidation chemotherapy consisting of paclitaxel 175 mg/m(2) and carboplatin AUC 5 after completion of RT. Twenty-five patients were enrolled in this study from two institutions. At a dose of paclitaxel 35 mg/m(2), two of four treated patients had DLTs (1 grade 3 oesophagitis and pulmonary toxicity; 1 grade 3 oesophagitis and infection). The recommended dose was therefore determined to be 30 mg/m(2) and a total of 15 patients were enrolled in an expanded cohort at this level. The overall response rate for all patients was 64% (95% CI: 43-82%). The estimated median survival was 23.6 months with an estimated 1-year and 2-year survival of 72 and 49%, respectively. Paclitaxel can be safely given twice-weekly at a dose of 30 mg/m(2) in combination with weekly cisplatin (20 mg/m(2)) and thoracic RT (60 Gy), and this regimen has significant activity in stage III NSCLC.

Adult↗

The immunohistochemical expression of metallothionein in inflammatory bowel disease. Correlation with HLA-DR antigen expression, lymphocyte subpopulations and proliferation-associated indices.

Metallothionein (MT) expression in intestinal resection specimens from 41 patients with ulcerative colitis (UC) and 10 patients with Crohn's disease (CD ) was immunohistochemically studied by the avidin-biotin (ABC) method. In addition, the possible relationship of its expression with HLA-DR antigen expression, lymphocyte subpopulations and proliferation-associated indices was studied in order to elucidate the role of this molecule in inflammatory bowel disease (IBD). The MT immunoreactivity was recorded by staining and intensity-distribution scores. MT staining varied in and was mainly localized in the cytoplasm, although a combined nuclear/cytoplasmic reactive pattern was also seen in epithelial cells. MT expression was decreased in UC, and CD compared with normal mucosa. No difference in MT expression between UC and CD was noted. In UC, a gradually decreased expression from remission, to resolving and to active phase was observed. An inverse correlation of MT expression with HLA-DR antigen expression was detected (p = 0.018) in the cases of UC. The data suggest that a low level of MT expression in inflammatory bowel disease and particularly in active phase of UC may indicate a decreased endogenous intestinal protection and it may be implicated in the pathogenesis of the disease.

Antigens, CD↗

Tumoral drug metabolism: perspectives and therapeutic implications.

Drug metabolising enzymes (DME) in tumors are capable of biotransforming a variety of xenobiotics. Over a long period of time, many studies have reported the presence of DME in tumors, however quantitation and sampling techniques and heterogeneous patient populations have resulted in many generalisations, provoking more questions than they answer. In addition, many of the studies have focussed on a potential role of DME in procarcinogenesis rather than for modulation for therapeutic advantage. With the need to target anticancer therapies to tumor cells to avoid undesirable systemic effects, tumoral processes such as drug metabolism must be considered as both a potential mechanism of resistance to therapy and a potential means of achieving optimal therapy. This review discusses drug metabolism by tumors by firstly addressing the level and activity of individual DME in the common cancers: breast, gastrointestinal, brain, lung and haematological malignancies in comparison to peritumoral and nontumoral tissue. This is then put into perspective through consideration of the therapeutic implications of tumoral drug metabolism especially with regard to the new anticancer agents. The contribution of tumoral metabolism and its significance in cancer therapy must be ascertained through prospective studies. Only then can efforts be concentrated in the design of better prodrugs or combinations of therapy to improve intracellular drug concentrations. Various gene therapy approaches have been attempted experimentally with promising results. However, there are major gaps in understanding the implications of tumoral DME in disease progression (including metastasized tissue) and relapse.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Complications of laparoscopic hysterectomy: the Monash experience.

A retrospective review of medical records was performed to assess the incidence and type of significant complications encountered during laparoscopic hysterectomy Two hundred and sixty-five consecutive patients were reviewed between the years 1994 and August 2001. Two hundred and thirty-two laparoscopic vaginal hysterectomies and 33 total laparoscopic hysterectomies were performed. The operations were performed at Monash Medical Centre, a Melbourne tertiary public hospital, and two Melbourne private hospitals, by three surgeons. Ten significant complications occurred. There were two cases of ureteric fistula, two bladder injuries, two bowel obstructions, two postoperative haematomas, one case of a bladder fistula and one superficial epigastric artery injury. In-patient stay ranged from two to six days. Our complication and in-patient stay rates are consistent with previously reported rates.

Female↗

Short compared with standard duration of antibiotic treatment for urinary tract infection: a systematic review of randomised controlled trials.

AIMS: To compare the effectiveness of short course (2-4 days) with standard duration oral antibiotic treatment (7-14 days) for urinary tract infection (UTI). METHODS: Meta-analysis of randomised controlled trials using a random effects model. Ten trials were eligible, involving 652 children with lower tract UTI recruited from outpatient or emergency departments. Main outcome measures were UTI at the end of treatment, UTI during follow up (recurrent UTI), and urinary pathogens resistant to the treating antibiotic. RESULTS: There was no significant difference in the frequency of positive urine cultures between the short (2-4 days) and standard duration therapy (7-14 days) for UTI in children at 0-7 days after treatment (eight studies: RR 1.06; 95% CI 0.64 to 1.76) and at 10 days to 15 months after treatment (10 studies: RR 1.01; 95% CI 0.77 to 1.33). There was no significant difference between short and standard duration therapy in the development of resistant organisms in UTI at the end of treatment (one study: RR 0.57, 95% CI 0.32 to 1.01) or in recurrent UTI (three studies: RR 0.39, 95% CI 0.12 to 1.29). CONCLUSION: A 2-4 day course of oral antibiotics is as effective as 7-14 days in eradicating lower tract UTI in children.

Adolescent↗

The palliative benefit of irinotecan in 5-fluorouracil-refractory colorectal cancer: its prospective evaluation by a Multicenter Canadian Trial.

Most patients with colorectal cancer (CRC) who have failed initial 5-fluorouracil (5-FU) chemotherapy have worsening of disease-related symptoms (DRS) and quality of life (QOL). Irinotecan has a reported response rate of 10%-20% in such patients. The aim of this phase II trial was to prospectively determine the palliative benefit of irinotecan utilizing DRS as primary endpoints of response. Patients had advanced CRC refractory to 5-FU with at least 1 DRS defined as (1) Karnofsky performance status (KPS) 60%-80%, (2) baseline analgesic use > or = 10 mg morphine/day (or equivalent), or (3) disease-related pain score > 1 cm on a 10-cm linear analogue self-assessment (LASA) scale. Patients received irinotecan 125 mg/m2 weekly for 4 weeks on an every-6-weeks schedule. The primary endpoint was palliative response defined as > or = 50% decrease in pain score or analgesic usage, or 10% increase in KPS, from baseline for 4 weeks. QOL was assessed by the European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire Core 30 (EORTC QLQ-C30) version 2 instrument. A total of 65 patients were entered onto the study. Median baseline parameters were KPS 70%, analgesic score 11 mg/day, and pain score 2.4 cm. A palliative response was achieved in 27 patients (42%), improvement in pain score predominated. LASA and EORTC QLQ-C30 instruments showed parallel changes in DRS. The radiological response rate was 11% (complete responses and partial responses, n = 46); 23 patients achieved stable disease. Median overall survival was 7.2 months. Irinotecan provides a rate of palliative benefit higher than the radiological response rate. Patients-oriented palliative endpoints can be useful in assessing the benefit of agents in early-phase clinical trials.

Adult↗

[Epidural vs general anaesthesia].

BACKGROUND: Aim of this study is to determine if and how the anaesthesia technique can significantly influence the outcome in patients after major orthopaedic surgery in terms of: patrimony of red blood cells (blood loss and erythropoiesis), incidence of intra and postoperative complications, postoperative pain control and hospital stay. METHODS: 210 patients, ASA physical status I-III, undergoing elective primary total hip replacement were randomly allocated in three groups of 70 patients to receive either epidural anaesthesia (Group EA), general anaesthesia (GA), or epidural anaesthesia integrated with mild general anaesthesia (IA). RESULTS: Data show a significant difference between the amount of pain measured by VRS immediately after surgery: prevalently absent in groups IA (84.3%) and EA (85.7%) and prevalently severe and moderate in group AG (34.3%). The measurement of the basic circulating erythrocyte mass in the first, third and fifth postoperative day, calculated by the Mercuriali formula, which considers blood loss, autologous and homologous transfusions and erythropoiesis, showed that general anaesthesia leads to a significant delay in the resumption of haemopoiesis. This result was attenuated by its combination with epidural anaesthesia. CONCLUSIONS: On the basis of the literature and the results of our study, epidural anaesthesia seems to be the most appropriate technique for patients scheduled for total hip replacement: due to its simpler analgesic cover, its tendency to be associated with a lower incidence of complications in the first 24 hours after surgery. The incidence of relevant hypotension is minor compared to integrated anaesthesia. General anaesthesia produced a significant decrease in postoperative erythropoiesis.

Aged↗

16 X-chromosome STR loci frequency data from a German population.

Allele frequencies for 16 X-linked STRs, suitable for forensic purposes, were obtained from a sample of unrelated German individuals (male and female). The presented data show also repeat sequence structures and statistic parameters describing there information content.

Alleles↗

CD44 standard form expression as a predictor of progression in high risk superficial bladder tumors.

OBJECTIVE: The purpose of this study was to assess the significance of the standard CD44 adhesion molecule expression in predicting progression of high risk superficial bladder carcinoma in the short term. METHODS: Sixty-six patients (51 males and 15 females, aged 27 to 89 years (mean 64.75 years) with primary superficial transitional cell bladder cancer initially treated with transurethral resection (TURBT) were enrolled in the study. Only pTa/pT1 grade 2 multiple tumors as well as all grade 3 tumors were included in this study. All tumor samples obtained after the resection were immunohistochemically evaluated for the expression of the CD44 standard molecule. Fifty eight patients remained during the follow up period which ranged from 3 to 36 months (mean 11.8 months). Tumor progression in the short term was considered as the critical end point of interest in this study. The prognostic significance of tumor stage, grade, presence of carcinoma-in-situ (CIS) and expression of CD44 in determining the risk for progression, was studied with both univariate (log rank test) and multivariate (Cox proportional hazards) methods of analysis. RESULTS: Kaplan-Meier survival curves indicated that a shorter median progression-free survival is expected for those patients with G3 bladder tumors (p = 0.0055), concomitant CIS (p = 0.0051), and loss of expression of CD44 (p = 0.0015), whereas a similar association with stage was not detected (p = 0.5793). The cox regression multivariate analysis did not yield a significant result for any of the studied parameters therefore no one of the factors taken into account can serve as an independent predictor of progression in superficial bladder cancer in the short term. CONCLUSION: The immunohistochemically detectable loss of the expression of CD44 standard form from superficial bladder tumor samples may be, complementary to the established prognostic factors, a useful predictor of tumor progression in the short term.

Adult↗

Crack cocaine, alcohol, and other drug use patterns among homeless persons with other mental disorders.

This study examined the co-occurrence of cocaine, alcohol, marijuana, and other drug use among treatment seeking homeless persons to determine whether alcohol use predicted cocaine use differently than marijuana and other drugs predicted cocaine use. Participants were 141 homeless persons with substance use and other nonpsychotic mental disorders seeking drug treatment at a metropolitan health care agency for homeless persons. They were 72.3% male, 27.7% female, 82.7% African American, 17.3% Caucasian, with an average age of 37.7 (SD 7.1) years and had 13.1 (SD 2.4) average years of education. Results supported the assertion that cocaine use was strongly associated with extent of alcohol use and that the association between cocaine and alcohol was stronger than the association between cocaine and other drug use, including marijuana. Participants with cocaine plus alcohol disorders were retained longer in treatment than disorders of cocaine only with no differences in abstinence outcome. The findings should drive further research into the use of alcohol as a trigger or predictor of cocaine use, the deleterious effects of the combined use of cocaine and alcohol, and specialized treatments for polysubstance users.

Adult↗

Heterogeneous tissue distribution of a mitochondrial DNA polymorphism in heteroplasmic subjects without mitochondrial disorders.

CONTEXT: Several maternally inherited point mutations of the mitochondrial genome cause mitochondrial disorders, but the correlation between genotype and phenotype remains obscure in many cases. The same mutation may cause various diseases, probably because of a different tissue distribution. OBJECTIVE: To assess the role of random somatic segregation in generating interperson differences by analysis of an apparently neutral polymorphism. DESIGN: Screening of 81 brain samples from subjects without mitochondrial disorders and selection of five necropsy cases showing a high level of heteroplasmy for the polymorphism. MAIN OUTCOME MEASURES: A proportion of various distinct genotypes in the mtDNA pool of the tissues, identified by fluorescent PCR products, representing a short polycytosine tract of variable length in the mitochondrial displacement loop. RESULTS: Differences were found between organs or groups of organs within subjects, pointing towards somatic segregation of mtDNA. In addition, marked differences of this organ distribution occurred between subjects, which cannot be explained by tissue specific selection. CONCLUSIONS: The observed interperson differences can be explained by somatic segregation, which occurs randomly at various developmental stages. Besides tissue specific selection, this process might participate in the distribution of pathogenic mtDNA mutations.

Adolescent↗

Switching between science and culture in transpecies transplantation.

This article discusses xenotransplantation (XTP: the surgical role of nonhuman tissues, organs, and cells for human transplantation) and examines the way its scientific promoters have defended their technology against potentially damaging public representations. The authors explore the criteria used to legitimate the selection of the pig as the best species from which to "harvest" transplant tissues in the future. The authors' analysis shows that scientists and medical practitioners routinely switch between scientific and cultural repertoires. These repertoires enable such actors to exchange expert identities in scientific discourse for public identities in cultural discourse. These discourses map onto similarities and differences between animal donors and human hosts. Finally, the case is used to comment on a number of related approaches where the dynamics of medical and scientific authority are discussed.

Animal Rights↗

Estimation of body fatness by air displacement plethysmography in African American and white children.

The purpose of this study was to determine the ability of air displacement plethysmography (ADP) to estimate body fatness in prepubertal and early pubertal African American and white children. One hundred nineteen nonoverweight and overweight boys (N = 56) and girls (N = 63), age (mean +/- SD) 9.8 +/- 1.7 y, body mass index 25.9 +/- 7.6 kg/m2 (range, 14.2-47.0 kg/m2), and mean percent body fat (%BF) by dual-energy x-ray absorptiometry (DXA) 39.2 +/- 11.7% (range, 12.2-57.5%), were studied. %BF by ADP was compared with DXA %BF estimates and with body fat by several field methods: skinfold thicknesses using the Slaughter et al. equations (Hum Biol 60: 709-723, 1988), bioelectrical impedance analysis (BIA) using the Houtkooper et al. equation (J Appl Physiol 72: 366-373, 1992), and a predictive equation using skinfold thicknesses, BIA, and weight (Goran et al.: Am J Clin Nutr 63: 299-305, 1996). All methods used to estimate %BF were significantly correlated with DXA (all p < 0.0001), with r2 ranging from 0.85 (skinfold measurements) to 0.95 (ADP). ADP using the Siri equation underestimated %BF by -1.9% (p < 0.001); the Bland-Altman limits of agreement (defined as +/-2 SD) were +/-7.4%. %BF by ADP-Siri underestimated %BF by DXA by 3.0% for girls (p < 0.001) and by 0.6% for boys (NS). Agreement between body fat estimation by ADP and DXA did not vary with age, race, or pubertal stage. Application of the age-adjusted Lohman model to ADP significantly increased the magnitude of the underestimation to -6.9% (p < 0.0001). Prediction of %BF by the Slaughter skinfold thickness equation showed no significant mean bias for the overall data, but significantly underestimated %BF in girls (-3.7%) while overestimating %BF in boys (+2.4%) with wide limits of agreement (+/-17.7%, p < 0.01 versus ADP). %BF by the Houtkooper BIA equation or Goran model underestimated %BF to a significantly greater degree than ADP (Houtkooper, -8.1%; Goran, -10.1%; both p < 0.0001 versus DXA or ADP). Determination of %BF from ADP using the Siri model slightly underestimates %BF as determined by DXA in girls, but appears to be superior to existing field methods both in accuracy and limits of agreement. Because of the ease with which it can be performed, ADP may prove useful for investigations of adiposity in children.

Adipose Tissue↗

Phase I dose-finding and pharmacokinetic study of paclitaxel and carboplatin with oral valspodar in patients with advanced solid tumors.

PURPOSE: To evaluate the maximum-tolerated dose (MTD), dose-limiting toxicities (DLTs), and pharmacokinetic (PK) profile of paclitaxel and carboplatin when administered every 3 weeks with the oral semisynthetic cyclosporine analog valspodar (PSC 833), an inhibitor of P-glycoprotein function. PATIENTS AND METHODS: Fifty-eight patients were treated with escalating doses of paclitaxel ranging from 54 to 94.5 mg/m(2) and carboplatin area under the plasma concentration versus time curve (AUC) ranging from 6 to 9 mg.min/mL, every 21 days. The dose of valspodar was fixed at 5 mg/kg every 6 hours for a total of 12 doses from day 0 to day 3. The MTD was determined for the following two groups: (1) previously treated patients, where paclitaxel and carboplatin doses were escalated; and (2) chemotherapy-naïve patients, where paclitaxel dose was escalated and carboplatin AUC was fixed at 6 mg.min/mL. PK studies of paclitaxel and carboplatin were performed on day 1 of course 1. RESULTS: Fifty-eight patients were treated with 186 courses of paclitaxel, carboplatin, and valspodar. Neutropenia, thrombocytopenia, and hepatic transaminase elevations were DLTs. In previously treated patients, no DLTs occurred at the first dose level (paclitaxel 54 mg/m(2) and carboplatin AUC 6 mg.min/mL). However, one of 12, two of six, two of four, four of 11, and two of five patients experienced DLTs at doses of paclitaxel (mg/m(2))/carboplatin AUC (mg.min/mL) of 67.5/6, 81/6, 94.5/6, 67. 5/7.5, and 67.5/9, respectively. In chemotherapy-naïve patients, one of 17 developed DLT at paclitaxel 81 mg/m(2) and carboplatin AUC 6 mg/mL.min. There was prolongation of the terminal phase of paclitaxel elimination as evidenced by an increased time that plasma paclitaxel concentration was >/= 0.05 micromol/L, ranging from 16.6 +/- 6.7 hours to 41.5 +/- 9.8 hours for paclitaxel doses of 54.5 mg/m(2) to 94.5 mg/m(2), respectively. CONCLUSION: The recommended phase II dose in chemotherapy-naïve patients is paclitaxel 81 mg/m(2), carboplatin AUC 6 mg.min/mL, and valspodar 5 mg/kg every 6 hours. In previously treated patients, the recommended phase II dose is paclitaxel 67.5 mg/m(2), carboplatin AUC 6 mg.min/mL, and valspodar 5 mg/kg every 6 hours. The acceptable toxicity profile supports the rationale for performing disease-directed evaluations of paclitaxel, carboplatin and valspodar on the schedule evaluated in this study.

Administration, Oral↗

Mitochondrial DNA in the Central European population. Human identification with the help of the forensic mt-DNA D-loop-base database.

Sequencing of mtDNA is an advanced method for the individualisation of traces. Disadvantages of this method are expensive and time-consuming analysis and evaluation procedures as well as the necessary stock of population-genetic data which is still insufficient. Central European institutes of forensic medicine from Germany, Austria, and Switzerland have been working together since the beginning of 1998 to establish a mtDNA database. The aim is to build up a large stock of forensically established data and provide population-genetic data for frequency investigations, which will serve as a basis for expert opinions and scientific research. Good data quality is ensured by using original sequences only. Ring tests, which have been conducted to enhance analytical reliability, revealed a high correspondence rate of the analytical results obtained by the individual member institutes. Today 1410 sequences are available for comparison, of which 1285 sequences in the HV1 and HV2 regions cover the full ranges from 16051 to 16365 and from 73 to 340 (according to Anderson). The major part is formed by Central European sequences comprising 1256 data sets from Germany, Austria, and Switzerland. Today the database contains sequences from a total of 12 European, six African and three Asian countries including 100 sequences from Japan. This paper is aimed at discussing the individualisation potentials of mtDNA as well as the possibilities and limits of ethnic differentiation by means of pairwise sequence differences on the basis of the data stock available.

Austria↗