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Biomedical subjects

C Muller

Publications and source records attributed to C Muller.

At least 109 records · Page 6Linked to original sources
PubMed1994

Results of the ACSUS for pediatric AIDS patients: utilization of services, functional status, and social severity.

OBJECTIVE: This study describes demographic characteristics of pediatric AIDS patients, describes hospital and community-based service utilization patterns, and analyzes medical and social support service usage patterns with respect to patient demographic characteristics, clinical trial participation, functional/developmental status, and social environment. DATA SOURCES AND STUDY SETTING: Data reported in this study are from the AIDS Costs and Service Utilization Survey (ACSUS) and cover the six-month period beginning March 1991 (N = 135). Pediatric patients who sought care for HIV-related problems were sampled at seven different hospitals in five metropolitan regions of the United States. All of the participating hospitals had clinics specifically serving pediatric patients infected with HIV. The sample consists of HIV-positive patients who had had at least one HIV-related symptom or condition. STUDY DESIGN: A stratified probability sample design guided the sampling strategy, which included oversampling in two large hospitals from two of the five metropolitan areas. Survey data cover an 18-month time period of health care utilization, cost, and financing information from HIV-infected patients and their providers. Utilization measures are standardized to a six-month period. Per capita income, family structure, informal personal network, functional status, and clinical trial participation are tested for associations with patterns of utilization. In addition, a weighted ten-point social severity scale was developed to assess family/household stability. DATA COLLECTION: Data were collected through a screener instrument completed by the person accompanying the child to a hospital clinic visit (usually a a parent), and through two interviews conducted in person with the patients' primary caregivers. Data from the questionnaires were coded and assembled into computerized SAS analysis files by WESTAT: PRINCIPAL FINDINGS: Children in this sample are 62 percent African American, 25 percent Hispanic, and 10 percent White. Medicaid is the primary payer for 92 percent. Mean per capita income is $3,440. Fewer than one-half (41 percent) of the families of the children receive Aid to Families with Dependent Children (AFDC). (AFDC). Within the six-month period, approximately one-third of the sample (29.6 percent) was hospitalized. Mean length of stay was 16.0 days. Clinical trial participation was positively related to mean number of hospital clinic visits and receipt of formal (paid) home care. There were no differences in use of community clinic, mental health, and inpatient facilities by clinical trial status. Participation in clinical trials was positively related to income and negatively related to social severity. In four cities, emergency room use was consistently lower for clinical trial participants than for nonparticipants. CONCLUSIONS: Data from the first six months of the ACSUS pediatric sample suggest that participation in clinical trials may bring about access to social services that appear to reduce emergency room use. However, the findings reported here are descriptive and exploratory. Further multivariate, nonparametric analyses of the full 18-month provider-patient merged data set are necessary to confirm the simple correlations found in this study.

Acquired Immunodeficiency Syndrome↗
PubMed1994

[Pap cell test laboratory report].

The Papanicolaou smear is done to detect preinvasive lesions (eg. dysplasia, carcinoma-in-situ) as well as invasive lesions. To ensure that a smear is suitable for laboratory examination, the nurse must know the reasons why a smear cannot be analysed. When a smear is sent to the laboratory it will analysed to see if any of the following are present: atypical cells, neoplastic cells, endometrial cells or infections. When the nurse gets the result back she must be able to interpret the results and be able to guide the patient to the correct form of treatment.

Cervix Mucus↗
PubMed1994

B-cell lymphoma following polycythemia vera: evidence for the involvement of two different clones.

We report here two patients with polycythemia vera (PV) who developed secondary non-Hodgkin's lymphoma (NHL). Both cases were high grade B-cell NHL. Cytogenetic analysis of bone marrow and lymph node was performed in each case and showed numerous chromosomal abnormalities. Of interest, chromosomal abnormalities of the PV and of the NHL clones were different, suggesting the possible involvement of two different clones. A 11q23 breakpoint was common between the two cases and the putative role of this breakpoint in the pathogenesis of the NHLs is discussed.

Aged↗
PubMed1993

Plasma and cellular pharmacokinetics of mitoxantrone in high-dose chemotherapeutic regimen for refractory lymphomas.

We have studied the plasma and peripheral leukocyte pharmacokinetics of mitoxantrone associated, in a high-dose regimen, with cyclophosphamide, carmustine, and etoposide in patients with refractory lymphoma undergoing autologous bone marrow transplantation. Nineteen patients with refractory lymphoma were involved in a clinical trial with escalated doses (15-90 mg/m2) of mitoxantrone administered by 30-min i.v. infusion 8 days before an autologous bone marrow transfusion. Mitoxantrone was measured by high-performance liquid chromatography in plasma and peripheral lymphocytes. The plasma pharmacokinetics of mitoxantrone was linear between 15 and 90 mg/m2: total body clearance (19.3 +/- 6.2 liter/h/m2) and volume of distribution at steady state (486 +/- 254 liter/m2) were not altered by increasing the dose. The exposure of bone marrow transplant to the plasma residual concentration of mitoxantrone was correlated with the limiting hematological toxicity of the regimen (P < 0.001). At all times, the mitoxantrone concentration in peripheral cells was much higher than in plasma and was retained at a constantly high concentration level. Whereas cellular versus plasma maximum concentration ratio was near 1, the area under the concentration +/- time curve ratio reached 100, suggesting a long elimination half-life from cells. Plasma and cellular pharmacokinetics data of mitoxantrone reinforce the idea that this drug is a good candidate for high-dose chemotherapy regimen.

Adult↗
PubMed1993

Characterization and chemosensitivity of a human epithelioid sarcoma cell line (SARCCR 2).

A new cell line was derived from the epithelioid sarcoma of a Caucasian woman who had previously received chemotherapy. The cells grew as an adherent monolayer, with a doubling time of 28 hr and had mainly epithelial morphology, but with areas of mesenchymal-like cytoplasmic extensions. The cells were tumorigenic in nude mice, with a short growth time, and a doubling time of 8 days. The cell line showed over-expression of P-glycoprotein by Western blot analysis, and its sensitivity to doxorubicin and vincristine was low. This sensitivity could be enhanced by reversants of multidrug resistance (MDR), such as cyclosporin or verapamil. This cell line constitutes an excellent model for studying compounds able to reverse MDR.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Cellular pharmacokinetics of doxorubicin in patients with chronic lymphocytic leukemia: comparison of bolus administration and continuous infusion.

The purpose of this study was to determine whether administration of doxorubicin (DOX) as a continuous infusion or a bolus injection resulted in similar leukemic cell drug concentration in patients with refractory chronic lymphocytic leukemia (CLL). This study was carried out on five patients with refractory CLL, with DOX administered either as a bolus injection (35 mg/m2; CHOP protocol) or as a constant-rate infusion for a period of 96 h (9 mg/m2 per day; VAD protocol). The two types of drug administration were used alternatively with the same patient. Plasma and cellular DOX concentration were determined using high-performance liquid chromatography. Peak plasma DOX levels were higher after the bolus injection than after continuous administration (1509 +/- 80 ng/ml vs 11.6 +/- 1.8 ng/ml, respectively), whereas the plasma area under the curve (AUC) levels were similar. Maximum DOX cellular concentrations were 8629 +/- 2902 ng/10(9) cells (bolus injection) and 2745 +/- 673 ng/10(9) cells (96 h infusion). The cellular AUC after the bolus injection was 2.85 times greater than that observed after continuous administration. This difference was due to a higher cellular peak level followed by a relatively prolonged retention of the drug, with a loss of only 25% in the first 24 h following. These findings demonstrated that in CLL the cellular DOX exposure can be notably modified by the method of drug administration, with higher drug intracellular concentrations being achieved after bolus administration than with the infusion schedule.

Aged↗
PubMed1993

Effect of propofol and thiopentone on regional blood flow in brain and peripheral tissues during normoxia and hypoxia in the dog.

The effect of propofol and thiopentone on cerebral (CBF), myocardial (MBF), muscular, and arterial hepatic blood flow was assessed with radiolabelled microspheres in 12 chronically instrumented dogs, six given propofol and six thiopentone. Tissue blood flows were measured in the awake animal, after 30 min of normoxic anaesthesia (room air), and after 30 min of hypoxic anaesthesia using a mixture of 10% O2 and 3% CO2 in nitrogen. The decrease in CBF from awake to normoxic anaesthesia was similar with propofol and thiopentone (propofol: 77 +/- 8 to 38 +/- 3 ml min-1 100 g-1, P < 0.01; thiopentone: 66 +/- 3 to 33 +/- 2 ml min-1 100 g-1, P < 0.01). During hypoxia, CBF rose moderately in the two groups (respectively +19% and +28%, P < 0.05). The MBF increased in propofol and thiopentone groups after 30 min of anaesthesia with air (propofol: 97 +/- 23 to 137 +/- 15 ml min-1 100 g-1; thiopentone: 82 +/- 7 to 141 +/- 10 ml min-1 100 g-1) and increased still more during hypoxia. The increase in MBF was related to an increase in heart rate and blood pressure. The quadriceps blood flow decreased during anaesthesia in normoxia and in hypoxia. The diaphragmatic blood flow increased with thiopentone under hypoxia. The hepatic arterial blood flow was unchanged. It is concluded that the effects of propofol on regional blood flows are very similar to those of thiopentone.

Anaerobiosis↗
PubMed1993

[Do pulmonary changes appear after elective laparoscopic cholecystectomy?].

30 patients without history of pulmonary disease who underwent elective laparoscopic cholecystectomy were examined on the day before and on the 2nd day after operation. Investigations included physical examination, chest X-ray and a spirometry. In case of postoperative pathological findings the same examinations were repeated 14 days after operation. On the chest X-ray 5 patients had postoperative alterations which disappeared within 14 days. The spirometry showed a slight decrease of VC, FRC and FEV1 which after 2 weeks had almost regained normal values. Therefore we do not consider it necessary to perform routine respiratory prophylaxis in patients undergoing elective laparoscopic cholecystectomy.

Adolescent↗
PubMed1993

[Preoperative ERCP and laparoscopic cholecystectomy for treatment of choledocholithiasis].

Out of 110 patients suffering from gallstone-related symptoms, 21 underwent ERCP prior to laparoscopic cholecystectomy. Indications for this combined treatment were laboratory signs of cholestasis (36%), pancreatitis (29%), pathological IVC (18%), sonographic evidence for bile duct dilatation (10%) and cholangitis (7%). Local and general complications were not increased neither intraoperatively nor postoperatively. Median duration of postoperative hospital stay was four days for ERCP-treated patients as compared to three days for patients subjected to laparoscopic cholecystectomy only. In summary treatment of choledocholithiasis by a combination of preoperative ERCP and laparoscopic cholecystectomy offers the following advantages: high patient comfort, low incidence of complications and short hospitalization compares favourably with conventional common bile duct exploration.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1993

Effects of H-7 and staurosporine on proliferation and self-renewal of acute myeloid leukemia progenitors.

In this study, we compared the impact of two protein kinase (PK) inhibitors, H-7 and staurosporine, on the normal myeloid progenitors (CFU-GM) and acute myeloid leukemia progenitors (AML-CFU) proliferation measured by in vitro clonogenic assay. H-7 and staurosporine displayed a biphasic dose-effect on both CFU-GM and AML-CFU recovery. At the lowest concentration range (0.1 microM to 20 microM for H-7 and 0.1 nM to 1 nM for staurosporine), we observed growth stimulation whereas higher concentrations induced dose-dependent growth inhibition. Moreover, AML-CFU proved to be significantly more sensitive to the inhibitory effect of both H-7 and staurosporine than CFU-GM (3.16- and 2.12-fold, respectively). These results were further confirmed with comparable murine cell line models (FDC-P1, a hematopoietic cell line generated from normal bone marrow and WEHI, a myelomonocytic leukemia cell line). Furthermore, we report that both H-7 and staurosporine present similar inhibitory effects on proliferation (PE1) as on self-renewal (PEs) of AML-CFU. In an attempt to understand more fully the mechanism of action of H-7 and staurosporine, we investigated their impact (when used at their D50) on the human myelogenous leukemia cell line, K562. H-7 and staurosporine induced a transient decrease of cell growth, between 0 and 24 hours, and produced a transient blockade of K562 cells in the S-phase, either 24 or 48 hours after the addition of staurosporine and H-7, respectively.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1992

Cost effectiveness of cervical cancer screening for the elderly.

OBJECTIVE: To analyze the costs and benefits of alternative cervical cancer screening schedules among elderly women. SETTING: Population-based screening programs. DESIGN: A Markov model predicts the outcomes of periodic screening, diagnosis, and treatment for cervical cancer among women from 65 to 109 years of age. PATIENTS: A hypothetical cohort of one million 65-year-old women; representative of the U.S. population. MEASUREMENTS: The costs and yields of screening. RESULTS: Triennial screening reduced mortality from cervical cancer among the elderly by 74% at a cost of $2254 per year of life saved. Annual screening increased costs to $7345 per year of life saved; less frequent schedules yielded lower costs but decreased savings in life. These results were most sensitive to the quality of the Papanicolaou smear and the characteristics of the women using the benefit. If the sensitivity of the Papanicolaou smear was reduced from a baseline estimate of 75% to 50% and the specificity was decreased to 87% from 95%, the cost effectiveness ratio increased by nearly $7000 per year of life saved. If triennial screening is targeted to women who have not had regular screening, the program will save money as well as years of life; however, screening women who have been screened regularly is considerably less efficient, increasing costs to $33,572 per year of life saved. CONCLUSION: The success of the new Medicare benefit depends substantially on physicians assuring that their elderly patients, particularly women without regular prior screening, obtain high quality Papanicolaou smears. The data also show that after a woman 65 years of age or older has a history of regular negative smears, screening is inefficient and can cease.

Aged↗
PubMed1992

Sensitivity of fresh acute myeloid leukemia cells to etoposide: relationship with cell growth characteristics and DNA single-strand breaks.

In this study, we evaluated the individual in vitro sensitivity of fresh acute myeloid leukemia (AML) cells to VP-16, and attempted to correlate VP-16 cytotoxicity with AML cell growth characteristics and drug-induced DNA single-strand breaks (SSB). Primary (PE1) colony inhibition assays allowed us to characterize two distinct groups of AML: group I (patients 1 through 6), which displayed sensitivity to VP-16 similar to that of normal CFU-GM (IC90 of 20.52 +/- 2.44 micrograms/mL v 20.48 +/- 2.23 micrograms/mL after 1 hour drug exposure, respectively); and group II (patients 7 through 11), which was more sensitive to VP-16 (IC90 of 7.26 +/- 2.93 micrograms/mL, P = .004). Subsequently, groups I and II were termed normosensitive and hypersensitive, respectively. This objective VP-16 sensitivity classification, as determined by PE1, remained unaltered when assessed by secondary (PE2) colony inhibition assay (evaluating the self-renewal fraction of AML progenitors), or by cytofluorometric viability assay (evaluating the ultimately differentiated blast cell population). These findings would suggest that individual sensitivity to VP-16 of a particular cell population is maintained throughout CFU-AML differentiation. Finally, we report that sensitivity of AML cells to VP-16 did not correlate either with cell growth characteristics or with SSB generation. Indeed, AML cell sensitivity to VP-16 appeared more closely related to DNA repair kinetics after drug removal, ie, hypersensitivity being essentially characterized by a prolonged retention of SSB during the posttreatment period. Interestingly, the established HL-60 cell line, which presented greater sensitivity to VP-16 cytotoxicity than KG1, HEL, and K562, was also found to exhibit delayed DNA SSB repair kinetics, as compared with the other AML cell lines. These results suggest that hypersensitivity to VP-16 of some AML cells may be related to a deficient DNA-repair mechanism.

Cell Division↗