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Biomedical subjects

C Lucas

Publications and source records attributed to C Lucas.

At least 253 records · Page 14Linked to original sources

Place of culdocentesis in the diagnosis of ectopic pregnancy.

In developing countries the high incidence of anaemia and pelvic infection often makes the diagnosis of ectopic pregnancy difficult. Culdocentesis has been used in 100 doubtful cases out of 144 consecutive cases of ectopic pregnancy. The preoperative diagnosis was correct in 93 out of the 100 cases. There were three false-negative and four false-positive results; only two unnecessary laparotomies were performed. It is suggested that culdocentesis has an essential place in the early diagnosis of doubtful or atypical ectopic pregnancy. It was simple, safe, and reliable. Owing to earlier diagnosis maternal mortality and morbidity and the duration of stay in hospital have all been reduced.

Adult↗

Effect on intimal hyperplasia of dexamethasone released from coated metal stents compared with non-coated stents in canine femoral arteries.

PURPOSE: Polymer-coated, dexamethasone (DXM)-releasing stents were tested in order to assess the efficacy of DXM released locally for the prevention of stent restenosis due to intimal hyperplasia. METHODS: Strecker stents coated with a biodegradable membrane containing DXM were implanted percutaneously into the femoral artery in 14 dogs. The contralateral artery received a conventional non-coated stent serving as control. The drugs are eluted by degradation of the carrier membrane. Follow-up intraarterial digital subtraction angiography (DSA) was obtained at 3, 6, 9, 12, and 24 weeks with subsequent autopsy. Specimens for gross and microscopic pathology were obtained and histomorphometry was performed. RESULTS: Four of 14 DXM-coated stents showed thrombotic occlusion within the first 3 weeks; ten DXM-coated stents remained patent. At follow-up DSA, DXM-coated stents showed a significantly wider lumen than the non-coated stents. At morphometry there was less intimal hyperplasia over DXM-coated stents than over non-coated stents (p < 0.05). CONCLUSION: DXM-coated stents reduce neointimal hyperplasia in dogs when compared with non-coated stents.

Angiography↗

Prevention of menstruation with leuprorelin (GnRH agonist) in women undergoing myelosuppressive chemotherapy or radiochemotherapy for hematological malignancies: a pilot study.

Vaginal bleeding during aplasia can induce transfusion support, infection and discomfort. Oral and intramuscular hormonotherapy can be toxic and/or difficult to manage (mucositis). This single-center pilot study evaluated the efficacy and safety of leuprorelin (L) in preventing heavy vaginal bleeding in 20 nonmenopausal women with leukemia, lymphoma or myeloma and foreseable therapy-induced thrombocytopenia. Until platelet recovery, patients received subcutaneous injections of L, with concomitant nomegestrol acetate (NA) during the first 35 days to prevent flare-up. Median age was 33 years (18-48). Platelet nadir was < 20 x 10(9)/l in 17 patients; 103 L injections were performed (median per patient: 4 [1-14]). No moderate or severe adverse event was related to hormonal therapy. Seventeen patients did not experience any clinically or therapeutically relevant bleeding. Eleven spottings and 8 metrorrhagias (mean duration: 3 days) occurred in 11 patients, requiring enhanced NA in 3 cases (baseline platelet count was < 20 x 10(9)/l in 1 pt, premature termination of NA [the single platelet transfusion for metrorrhagia] in 1 pt, and endometrial hyperplasia (EH) in the third). In patients without EH, only 5 spottings were observed after the third injection, without neither clinical nor therapeutic impact (63 injections). In conclusion, leuprorelin administration is safe and effective in preventing vaginal bleeding. The sustained-release form and subcutaneous administration offer quality of life advantages.

Adolescent↗

[Susac syndrome: clinical and diagnostic approach. A new case report].

INTRODUCTION: The Susac syndrome is made up of the clinical triad: encephalopathy, visual and hearing defects. It is caused by microangiopathy of unknown origin affecting the small arteries of the brain, retina and cochlea. It is very uncommon. It mainly affects young women. The course of the illness is usually monophasic and self-limiting. The deficit of visual acuity is caused by occlusion of tributaries of the retinal artery. The auditory defect is bilateral and symmetrical, and particularly affects medium and low frequencies. NMR is of great diagnostic value, showing multiple lesions in the grey and white matter. Our case gives more data regarding the evolution of this condition and the contribution of cerebral SPECT to diagnosis, the results of systemic treatment, use of hyperbaric oxygen and reflections on the physiopathology of the process. CLINICAL CASE: We present the clinical case of a young woman who presented with psychiatric symptoms and migraine followed by clinical encephalopathy and acute/subacute coma. There were also visual and auditory deficits. Other types of systemic disease were ruled out. CONCLUSIONS: Findings on SPECT suggested the presence of a microangiopathic disorder of the brain. The patient responded to systemic treatment with cortico-steroids. The encephalopathy resolved in a few days and two months later she had resumed her former daily activities. Treatment with hyperbaric oxygen definitely reduced visual sequelae.

Adult↗

Determination of avoparcin in animal formulations by capillary electrophoresis.

The separation of two closely related glycopeptides, alpha- and beta-avoparcin, which differ by the presence or absence of a Cl atom, is achieved by capillary zone electrophoresis (CZE) using 20 mM borate (pH 9.2) in bare, fused-silica capillaries. The pKa values of these two glycopeptides are determined from spectrophotometric titrations of the mixture. Absorption spectra recorded between pH 3 and 12 produced a maximum pH transition at 258 nm. Titration data fitted to two sigmoidal functions reveal pKas of 7.99 for beta-avoparcin and 10.3 for alpha-avoparcin. The differing pH dependence of the effective electrophoretic mobilities of alpha- and beta-avoparcin resulted in an optimum pH of 9.2 (roughly the average of the pKa values) for their separation. Borate is shown to be necessary for the optimal CZE separation. A linear dynamic range of 0.5-50 ppm is achieved with regression coefficients of 0.9999. The limit of detection ranges from 0.2 to 0.5 ppm using a pressure injection of 15 sec in a 50-cm (effective length) fused-silica capillary with UV detection. Finally, the effects of sodium dodecyl sulfate (SDS) concentration in the migration buffer on apparent mobility, efficiency, migration times, and resolution are discussed. The addition of 75 mM SDS to the running buffer allows baseline resolution of alpha- and beta-avoparcin, including its minor components. Both the CZE and micellar electrokinetic chromatography (MEKC) separations of alpha- and beta-avoparcin are highly reproducible and can readily be applied to the analysis of avoparcin bulk drug and formulated products.

Animals↗

Hepatitis C in Peru: risk factors for infection, potential iatrogenic transmission, and genotype distribution.

A large seroepidemiologic and genotyping study of hepatitis C virus (HCV) was conducted in Lima, Peru, during the periods of 1986 to 1993 (cohort A) and 1994 (cohort B). Anti-HCV seroprevalence rates were 15.6% (216 of 1,389) and 11.7% (168 of 1,438), respectively. Low rates were seen among volunteer blood donors (1.1% and 0.8%). Anti-HCV rates were much higher among patients undergoing hemodialysis (43.7% and 59.3%), hemophiliacs (60.0% and 83.3%), in those more than 39 years old (18.2% and 26.0%), in females (25.0% and 27.4%), and in less-educated persons (16.9%). Age- and gender-adjusted risk factors in cohort B included blood transfusion history (adjusted odds ratio [AOR] = 29.8), prior organ transplantation (AOR = 9.1) or a history of hepatitis (AOR = 4.9), previous hospitalization (AOR = 3.7), a history of intravenous drug use (AOR = 3.5), prior major surgery (AOR = 2.6), a history of acupuncture (AOR = 2.1), previous dental procedures (AOR = 1.2), and prior medical injections (AOR = 1.04). The most prevalent HCV genotype was type 1 (86%), followed by type 3 (10%) and type 2 (2%). Transmission through unsafe injection-related and medical/dental procedures appears to play an important role in HCV infection among Peruvians.

Adolescent↗

[Anomalies of corticotropin secretion in chromophobe adenomas].

Corticotrophic secretion has been studied in several groups of subjects during metopirone test and arginine L-Dopa infusion. In animals, a net plasma ACTH increase is observed under while it is inconstant after arginine L-Dopa. In hypopituitarism, metopirone ACTH levels are low and unchanged during the tests. In chromophobe adenoma, basal ACTH levels are high, ACTH increase is normal during test and significantly higher than in controls after L-Dopa injection. Significance of these metopirone corticotrophic abnormalities is discussed.

Adenoma, Chromophobe↗

Factors involved in successful psychotherapy referral in rural primary care.

Many primary care patients are identified as needing psychotherapy. Often family physicians choose to refer these patients for comprehensive treatment, yet psychotherapy referrals are traditionally difficult to transact successfully in comparison with referrals for other biomedical complaints. Previous reports have been published on the beliefs held by family physicians and psychologists regarding factors that affect the success of a referral. This follow-up study reviewed 138 referrals from rural family physicians to psychotherapists. Fifty-nine percent of the referrals were considered successful by the family physicians and 73% by the patients. Successful psychotherapy referral, as evaluated by physicians, was related to psychotherapist-initiated post-referral communication with the referring physician. There was no relationship between success of referral outcome and the number of preparatory (or follow-up) visits with the physician, physician's knowledge about the psychotherapy process, patient economic status, or insurance coverage. However, attending more than one therapy session was associated with the number of physician visits prior to referral, distance to the therapist's office, and referral by a physician who included counseling in his or her practice. Findings indicate that when physicians are kept informed about patients' treatment, they are more likely to evaluate the treatments as beneficial.

Adult↗

[The value of MRI in popliteal entrapment syndrome].

The popliteal artery entrapment syndrome (PAES) is a frequent disease of especially young patients, often following a muscular exertion. To avoid the complications, the diagnosis must rapidly be done. According to this report of a 12 year old child, we think that magnetic resonance imaging (MRI) is very accurate to diagnose the abnormalities of the popliteal artery course, the muscular hypertrophies and can relieve of more invasive procedures such as the arteriography associated with known morbidity in young patients.

Child↗