Search PubMed⌕ Search

Biomedical subjects

C Martin

Publications and source records attributed to C Martin.

At least 415 records · Page 23Linked to original sources
PubMed1998

Pancreas transplantation: results and indications.

Pancreatic transplantation is the best method of replacing the endocrine function of the gland in Type 1 insulin-dependent diabetic patients. At the end of 1996, 9,000 pancreas transplants had been reported to the international Pancreas Transplant Registry. For 1994-1996, one-year pancreas survival rates were 81% for simultaneous pancreas and kidney transplantation (n = 1,516), 71% for pancreas after kidney (n = 141) and 64% for pancreas alone (n = 64). In patients with a functional graft, glycosylated haemoglobin, fasting blood sugar, and 24-h metabolic profiles are normal. The effect of pancreatic transplantation on secondary complications often appears after several years of normal pancreatic function. Successful transplantation is associated with an improvement in different aspects of the quality of life. The decision to perform pancreatic transplantation depends on the balance between the risks of transplantation, mainly surgical or related to immunosuppression, and those of diabetes development. The advantages and drawbacks of pancreatic transplantation and insulin therapy need to be honestly and carefully analysed for specific populations of diabetic patients as well as for each individual. At present, simultaneous pancreaticorenal transplantation is the best treatment for diabetic patients with chronic renal failure. Transplantation of the pancreas alone in non-uraemic patients may also be considered in carefully selected subjects.

Diabetes Mellitus, Type 1↗
PubMed1998

[Significance of lasers in surgery of cerebellopontine angle tumors].

The use of the laser in otology has demonstrated its effectiveness and safety. The aim of this paper is to show its application in otoneurosurgery. After comparing the advantages and disadvantages of various lasers (Yag, CO2, KTP), we soon opted for the KTP laser, which we have since used exclusively in otology and otoneurosurgery. 25 patients with cerebello-pontine angletumours were operated using the KTP laser (22 neuromas and 3 meningiomas). Although in the absence of rigourous methodology it is difficult to assert the superiority of the laser over the classical techniques of resection, the results seem better since we have been using the laser for otoneurosurgery, especially for facial function. In any case, the laser is merely an instrument, which it is necessary to learn to manipulate; it does allow lesions to be vaporized without traction, and has a haemostatic action. It should never be used directly in contact with nervous structures, especially nerves. It seems to us to be most helpful in dealing with large and very vascular tumours.

Cerebellar Neoplasms↗
PubMed1997

Imaging human intra-cerebral connectivity by PET during TMS.

Non-invasive imaging of human inter-regional neural connectivity by positron emission tomography (PET) during transcranial magnetic stimulation (TMS) was performed. The hand area of primary motor cortex (M1) in the left cerebral hemisphere was stimulated with TMS while local and remote effects were recorded with PET. At the stimulated site, TMS increased blood flow (12-20%) in a highly focal manner, without an inhibitory surround. Remote covariances, an index of connectivity with M1, were also focal. Connectivity patterns established in non-human species were generally confirmed. Excitatory connectivity (positive covariance) was observed in ipsilateral primary and secondary somatosensory areas (S1 and S2), in ipsilateral ventral, lateral premotor cortex (M2) and in contralateral supplementary motor area (SMA). Inhibitory connectivity (negative covariance) was observed in contralateral M1.

Brain Mapping↗
PubMed1997

Prevalence and risk factors for HTLV-II infection in 913 injecting drug users in Stockholm, 1994.

The prevalence and risk factors for acquisition of human T-cell lymphotropic virus type I and II (HTLV-I and II) were investigated in a prospective study of 913 injecting drug users (IDUs) in Stockholm in 1994. Epidemiologic data were recorded, and blood samples were tested for antibodies against HTLV-I and HTLV-II; human immunodeficiency virus (HIV) types 1 and 2; and hepatitis A (HAV), B (HBV), C (HCV), and D (HDV). Positive serologic results for HTLV were confirmed by Western blot (WB) and polymerase chain reaction (PCR). Of the 905 participants with conclusive HTLV-II status, 29 (3.2%) were HTLV-II positive, and all but three were of Nordic descent. None was HTLV-I infected. One person was infected as early as 1981, before HIV had reached the IDU population in Sweden. The prevalence of HTLV-II infection was 12% among HIV-1-seropositive and 1.8% among HIV-1-seronegative participants. The overall seroprevalences were 14% for HIV-1, 0% for HIV-2, 41% for HAV, 75% for HBV, 92% for HCV, and 8% for HDV. Although amphetamine has been the main injecting drug in Sweden for several decades, heroin abuse combined with a debut of injecting drugs before 1975 was identified as the most important risk factor associated with HTLV-II infection. HAV and HIV seropositivity were also independent risk factors.

Adult↗
PubMed1997

Investigation of the variation in orientation and crystallinity in poly(ethylene terephthalate) containers using microfocus X-ray diffraction.

The microfocus X-ray beamline at the European Synchrotron Radiation Facility has been used to investigate the variation in molecular orientation and crystallinity in the wall of a container fabricated from poly(ethylene terephthalate). Two-dimensional wide-angle X-ray scattering patterns were recorded and displayed in real time as the specimen was tracked across the incident X-ray beam enabling the measurement of textural changes to be made with a spatial resolution of ~2 mum.

Journal Article↗
PubMed1997

Spinal intraosseous arteriovenous malformation as a cause of juvenile scoliosis. A case report.

STUDY DESIGN: A case report. OBJECTIVES: To report and discuss an unusual case of scoliosis resulting from an arterial malformation of the spine. SUMMARY OF BACKGROUND DATA: This is a report of clinical manifestation, physical findings, computed tomography scan, magnetic resonance imaging, bone scan, and results after surgery in an 8-year-old boy with a painful scoliosis resulting from an intraosseous arteriovenous malformation of the spine. METHODS: Radiographs, computed tomography scan, magnetic resonance imaging, and bone scans were studied and oriented us to the diagnosis of scoliotic attitude secondary to a benign-appearing tumor in the right lamina of L4. Surgery was performed through a posterior midline approach to remove the lesion en bloc. Postoperative treatment was performed with a Boston orthosis. RESULTS: Final pathology reports diagnosed an intraosseous arteriovenous malformation. After 32 months, the boy had no pain, and scoliotic attitude diminished despite radiographs still showing a single 10 degrees right lumbar curve. CONCLUSIONS: Primary intraosseous arteriovenous malformations are rare. This case shows the scarce specificity of clinical findings, radiology, and bone scan in the diagnosis of these lesions when they are localized in vertebral territory. Surgical excision of the lesion relieves pain but does not completely correct the scoliotic attitude.

Arteriovenous Malformations↗
PubMed1997

Association between hemodynamic parameters and the degeneration of sustained ventricular tachycardias into ventricular fibrillation in rats.

UNLABELLED: Sustained ventricular tachycardias (VT) often degenerate into ventricular fibrillation (VF). In the present study, the impact of VT on mean arterial blood pressure (MAP), myocardial blood flow (MBF), and myocardial oxygen consumption (MVCO2) was assessed. In addition, the degeneration of sustained VT into VF was analysed with respect to MAP. MBF was measured in 48 anesthetized rats with colored microspheres; arterial catecholamine levels were measured by HPLC in 16 additional rats during control conditions and VT. MBF (4. 66+/-1.29 ml/g/min; mean+/-s.d.) did not change with the onset of VT (5.37+/-1.92 ml/g/min, n.s.). Epinephrine (0.22+/-0.13 ng/ml) and norepinephrine (0.37+/-0.12 ng/ml) increased during VT (3.55+/-2.68 ng/ml, P<0.01; 0.88+/-0.44 ng/ml, P<0.05), respectively. VF was more frequent when MAP remained normal (MAP>80 mmHg: 26%) than with hypotension (MAP<80 mmHg: 2%, P<0.05). Mechanical failure was observed in 10% of rats with severe hypotension (MAP<60 mmHg), and 2% with moderate hypotension (MAP 60-80 mmHg). The endo-epicardial MBF ratio in the VF group was significantly lower than that in the non-VF group (0.94+/-0.17 v 1.11+/-0.24, P<0.05). CONCLUSIONS: severe hypotension predisposes to the occurrence of acute mechanical failure during VT; moderate hypotension during VT, however, serves as a protective mechanism against VF in structurally normal hearts. Subendocardial hypoperfusion in the presence of an increased energy demand during VT is suggested to be responsible for the initiation of VF.

Animals↗
PubMed1997

Laparoscopically assisted vaginal hysterectomy as an alternative to abdominal hysterectomy in patients with fibroids.

OBJECTIVE: Introduction of laparoscopically assisted vaginal hysterectomy (LAVH) was evaluated for its usefulness to replace abdominal hysterectomy in fibroids. STUDY DESIGN: A total of 240 women with a mean age of 46.7 years underwent hysterectomy over a period of one year. The technique of LAVH was introduced starting in the second quarter of the study period. Clinical data of 60 patients undergoing either LAVH or abdominal hysterectomy for fibroids were compared in a cross-sectional study by chi 2- and t-test. RESULTS: A comparison between the first and the last quarter of the study period showed that the rate of abdominal hysterectomies decreased from 66% to 12%, whereas LAVH increased from 0 to 40% (p < 0.05). The rate of vaginal hysterectomies remained between 34% and 48%. Compared to abdominal hysterectomy, LAVH operating time was about 1/3 longer, hospital stay was shorter (3 days), and LAVH proved more cost-effective than abdominal hysterectomy (significance of all differences: p < 0.05). CONCLUSIONS: LAVH is a valid alternative to abdominal hysterectomy in fibroids.

Adult↗
PubMed1997

Gemcitabine: safety profile and efficacy in non-small cell lung cancer unaffected by age.

Gemcitabine, a novel anticancer agent, was demonstrated to be well tolerated in both elderly and younger patients. Safety data were collected from 18 completed clinical studies (790 patients) in a variety of solid tumor types. All studies used a starting dose of 800-1250 mg/m2 administered once a week for 3 weeks followed by a week of rest. Patients were initially divided using a cut-off age of 65 years, and subsequently using a cut-off age of 70 years. Gemcitabine was well tolerated by patients of all ages, with few clinically meaningful differences between the age groups. Gemcitabine was also found to be as efficacious in older patients as in younger ones. Efficacy data was collected from four studies (329 evaluable patients) in non-small cell lung cancer with consistent response rates of 20%. When patients were divided into two groups, those aged below 70 years and those 70 years and above, the response rates were 19.0% (95% C.I., 14.6-23.4) and 25.0% (95% C.I., 10.0-40.0) respectively. In conclusion, elderly patients should benefit from gemcitabine treatment.

Adult↗
PubMed1997

Neurological disturbances and hyperdynamic shock in a patient with esophagocoloplasty.

A 39-year-old man, with no history of alcohol intake, who had had an esophago-ileo-colo-gastroplasty with ileotransversostomy, developed diplopia, seizures, metabolic acidosis, and cardiac failure and finally refractory hyperdynamic shock. He died 20 h after admission to our intensive care unit from cardiocirculatory collapse. Postmortem results revealed low erythrocyte transketolase activity, which was increased by 22% by in vitro addition of thiamine diphosphate (TDP effect). Cerebral pathology showed the alterations of Wernicke's encephalopathy. We discuss the possible mechanisms of fatal cardiovascular collapse and the unusual presentation of a case without a history of alcoholic intake or clinical malnutrition.

Acidosis↗
PubMed1997

Implication of CYP 3A in the toxicity of cyclosporin G (CsG), cyclosporin A (CsA) and FK506 on rat hepatocytes in primary culture.

FK506, cyclosporin A (CsA), and its structural analog cyclosporin G (CsG) are immunosuppressant drugs mainly metabolized by hepatic cytochrome P-450 3A (CYP 3A) oxygenase. FK506 metabolites exhibit greater toxicity than the parent drug, while CsA metabolites are far less toxic than CsA itself. The aim of our study was to compare the toxicity of CsG with CsA and FK506 as a function of CYP 3A induction. Hepatocytes from Wistar rats with or without dexamethasone (DEX) induction (200 mg/kg per day, p.o for 4 days) were used in primary culture. The DEX-inductive effect on CYP 3A was assessed by SDS-PAGE. After 6 h incubation with CsG, CsA or FK506 (5 to 200 microM), cell viability (expressed as IC50), intracellular calcium content and apoptosis were evaluated. Concerning cytotoxicity, IC50 values for CsG, CsA and FK506 were 75, 50 and 180 microM respectively in non-induced cultures, and 150, 120 and 25 microM in induced cultures. For intracellular calcium content, a dose-dependent increase was observed in all cultures. However this increase is more important for CsG and CsA in non-induced cultures (150%) compared to induced cultures (110%) at 150 microM. Conversely for FK506, this increase is greater in induced cultures (150%) than in non-induced cultures (127%). Estimation of the percentage of apoptotic cells shows similar variations. Our results show that the toxicity of the three drugs in rat hepatocytes is dependent on CYP 3A induction: increased for FK506, decreased for CsA and CsG. Moreover, with regard to the three tests used, the toxic effects of CsG are close to those of CsA, indicating that CsG metabolites are also less toxic than the parent drug.

Animals↗
PubMed1997

Modulation of energy status and cytotoxicity induced by FK506 and cyclosporin A in a renal epithelial cell line.

FK506 and cyclosporin A (CsA) are two potent immunosupressants with similar toxicity profile. Nephrotoxicity is the main adverse effect of both compounds. The aim of this study is to compare the in vitro nephrotoxic effects on renal epithelial cell line LLC-PK1 by measuring cell viability and energy status as evaluated by concentrations of ATP and ATP metabolites. Cell viability (expressed as IC50 was assessed via thiazolyl blue (MTT) assay after incubation for 4-24 h with FK506 or CsA. ATP and its metabolites were determined by HPLC after 4 and 6 h incubation with FK506 or CsA alone at the respective IC50. Both FK506 and CsA decreased cell viability to similar extents, in a dose- and time-dependent manner. After 4 h incubation, both drugs decreased ATP levels (-25%) and increased uric acid levels. However, the latter percentage increase was twofold higher with CsA (18%) than with FK506 (9%). The energy charge, calculated according to levels of adenine nucleotides, was decreased by 10% in FK506-treated cells and by 27% in CsA-treated cells. At the end of 6-h incubation, FK506-treated cells maintained ATP levels coupled with energy charge at near control levels whereas the levels were 32% lower in CsA treated cells. Compared to the 4 h-incubation, the increase in uric acid was similar for FK506 but was doubled with CsA. The decrease in cell integrity and ATP depletion induced by CsA in LLC-PK1 cells was only transiently observed with FK506. By preserving energy status, FK506 leads to fewer metabolic disturbances than CsA in the renal epithelial cell line LLC-PK1, demonstrating a minor potential nephrotoxicity.

Adenosine Triphosphate↗
PubMed1997

Does hydrosalpinx reduce the pregnancy rate after in vitro fertilization?

OBJECTIVE: To determine the effect of hydrosalpinges on the pregnancy rate in an IVF program. DESIGN: Multicentric retrospective analysis of clinical and laboratory data. SETTING: Two assisted reproductive technology centers in university hospitals. PATIENT(S): Four hundred forty-three women, under 38 years of age, with pure tubal infertility. The patients were classified into the following five groups: bilateral hydrosalpinges (n = 37), unilateral hydrosalpinx (n = 54), bilateral tubal occlusion (n = 207), unilateral tubal occlusion (n = 55), and severe tubal disease without complete occlusion (n = 90). MAIN OUTCOME MEASURE(S): Pregnancy and implantation rates. RESULT(S): The pregnancy and the implantation rates per transfer (12.3% and 5.4%) obtained by women with bilateral hydrosalpinges are significantly lower than the rates (means = 23.1% and 12%) for all other tubal infertility groups. CONCLUSION(S): Bilateral hydrosalpinges have a deleterious effect on the outcome of IVF program.

Adult↗
PubMed1997

Combined effect of HLA-DRB1*1501 and interleukin-1 receptor antagonist gene allele 2 in susceptibility to relapsing/remitting multiple sclerosis.

Susceptibility to multiple sclerosis (MS) is associated with HLA-DRB1*1501. Many reports have suggested associations with other loci but these results remain unconfirmed. We studied the IL-1 receptor antagonist (IL-1ra) gene polymorphism and the HLA-DR and DQ allele frequencies by DNA-based methods in both the primary chronic progressive form (PP MS) and the relapsing/remitting form (R/R MS). The frequency of DRB1*1501 and IL-1ra allele 2 were significantly higher in R/R MS. Association was more marked in the female sex and in patients with benign forms of R/R MS. On the other hand DR4 subtypes carrying a Val at position 86 in the DR beta chain were increased in PP MS. The present study indicates that MS is genetically heterogeneous and shows a combined effect of HLA-DR and IL-1ra genes in susceptibility to the R/R form of the disease.

Alleles↗