Biomedical subjects

M Durand

Publications and source records attributed to M Durand.

At least 145 records · Page 8Linked to original sources

PubMed1991

Combined effects of nicardipine and hypocapnic alkalosis on cerebral vasomotor activity and intracranial pressure in man.

The effect of hypocapnic alkalosis (HA) on nicardipine-induced cerebral vasodilatation was studied in 2 groups of patients undergoing stereotaxic brain biopsy under general anaesthesia. Arterial diameter (AD) was measured in 16 different locations on a carotid arteriogram (lateral view), and intracranial pressure (ICP) was recorded with an intraventricular catheter. At time T0, in normocapnia an arteriogram was performed in both groups. The first group (GI) was then studied in hypocapnia (T1) and following an injection of nicardipine (T2), while the second group (GII) was studied first after injection of nicardipine (T1) and then in hypocapnia (T2). Groups GI (n = 6; 44 y) and GII (n = 6; 46 y) were similar with regard to age, blood pressure, heart rate and PaO2 at all three phases of the study. HA caused a 9.5% decrease in AD (GI.T1) compared to baseline values, and a 15.2% decrease when preceded by injection of nicardipine (GII.T2). In the latter case the decrease was 3% in comparison with baseline. Nicardipine increased AD by 14.7% (GII.T1) and by 18.5% when preceded by HA (GI.T2), but the rise (7.3%) was not significant in comparison with the baselines value. The changes variations were similar whether the entire arterial trunk or only the supraclinoid region were studied. HA decreased ICP by 44% (GI.T1) and by 50% after nicardipine (GII.T2). Nicardipine did not cause an increase in ICP. Nicardipine and HA antagonise each others vasomotor effects, as previously shown in the baboon using nimodipine.

Adult↗

PubMed1991

Expression of myosin regulatory light chains in rat brain: characterization of a novel isoform.

We have characterized cDNA clones of mRNAs encoding two distinct isoforms of myosin regulatory light chain expressed in rat brain. One clone, isolated from a cultured astrocyte cDNA library, is derived from a 1200-base mRNA that is expressed at high levels in cultured astrocytes, and at higher levels in the embryonic brain than in the adult brain. The nucleotide sequence of this cDNA is essentially identical to a previously reported cDNA encoding a smooth muscle isoform from rat aorta cells (Taubman et al., J. Cell Biol., 104 (1987) 1505-1515). The second clone hybridized to a 1300-base mRNA that is expressed abundantly in the adult brain and is the predominant species in cultured neuroblasts. Both mRNAs are expressed, to varying extents, in other muscle and nonmuscle tissues. The deduced amino acid sequences of the two isoforms differ in 4 residues out of 171. On the basis of the tissue distribution of their mRNAs and a comparison of identities among the known amino acid sequences of myosin regulatory light chains we suggest that both proteins should be considered as non-muscle isoforms. We conclude that there are at least two isoforms of the myosin regulatory light chain expressed in rat brain and that their expression is under both cell-specific and developmental regulation.

Amino Acid Sequence↗

PubMed1991

Effects of primary chemotherapy in conservative treatment of breast cancer patients with operable tumors larger than 3 cm. Results of a randomized trial in a single centre.

272 women with operable breast adenocarcinomas larger than 3 cm were included in a randomized trial. The patients in group A (n = 138) with histological nodal involvement (N+) or a lack of estrogen and progesterone receptors (EPR-) were treated by initial mastectomy and axillary node dissection + adjuvant chemotherapy. Those in group B (n = 134) were treated by initial chemotherapy (the same as in group A) followed by loco-regional treatment, adjusted according to their response to chemotherapy. Prognostic factors were identical in the two groups. In group A, 32 patients received no adjuvant treatment (N- and EPR+), while 104 were given adjuvant chemotherapy (N+ and/or EPR-). Two patients were lost to follow-up. In group B, all patients received initial chemotherapy; 44 were in complete clinical remission and were treated with radiotherapy only; 40 with residual tumor (less than 20 mm) were treated with tumorectomy + axillary node dissection + radiotherapy; 49 with residual tumors (greater than 20 mm) had mastectomies. Conservative treatment was administered to 84 patients in group B (62.6%). EPR-tumors responded better to chemotherapy than did EPR+ ones (p = .003). After a median follow-up of 34 months, isolated local recurrences were more frequent in the group with initial chemotherapy, which, however, experienced a better overall survival (p = 0.04).

Adenocarcinoma↗

PubMed1991

Glucose and lactate catabolism by bacteria of the pig large intestine and sheep rumen as assessed by 13C nuclear magnetic resonance.

The fermentation of [1-13C] glucose and [3-13C]lactate by bacteria isolated from sheep rumen and pig large intestine was compared by the nuclear magnetic resonance (NMR) technique. Washed cell suspensions were incubated directly in the NMR spectrometer and spectra were recorded every 10 min after injection of the labelled substrates. The results showed large differences in the fermentation patterns between rumen and hindgut bacteria. The latter pattern indicated a greater ability for formation and fermentation of lactate than that of the rumen. Moreover, with both substrates the amount of propionate formed via the acrylate pathway was always greater with hindgut than with rumen bacteria, 50% and 20% of the total, respectively.

Animals↗

PubMed1991

The prognosis of Hodgkin's disease in older adults.

This investigation was undertaken to assess the apparent poor survival of older patients with Hodgkin's disease. The clinical course of Hodgkin's disease in 136 patients, 60 to 79 years of age, was compared with that of 223 patients, 40 to 59 years of age. The patients registered from November 1977 through December 1983 had not been previously treated, and were treated at eight cancer centers. When the prognosis of all patients was examined by age, a definite change in the pattern of survival first appeared in the 60- to 69-year-old cohort. The entire older group (60 to 79 years) experienced twice the risk of dying from Hodgkin's disease and four times the risk of dying from other causes than did the younger group. In both groups, stage of disease was the strongest factor in predicting adjusted survival. Delay in treatment and advanced stage at presentation were not characteristic of Hodgkin's disease in older patients as has been postulated. Older patients responded to therapy with a similar complete remission rate (84% v 88% in the younger group, P = .24). From this study, we conclude that (1) Hodgkin's disease in the older adult does not have a different natural history, its major risk factors are similar to those known in other age groups, and thus should be amenable to existing therapeutic approaches; and (2) the prognosis of older patients with Hodgkin's disease has been obscured in previous studies by the inclusion of deaths due to other causes in survival estimates.

Adult↗

PubMed1991

A forced perturbation method of assessing pulmonary mechanical function in intubated infants.

Short pulses in airway pressure were used to assess the pulmonary mechanical function of nine infants suffering acute respiratory distress syndrome or bronchopulmonary dysplasia. All patients were intubated, spontaneously breathing, and mechanically ventilated at the time they were examined. The endotracheal tube was disconnected from the ventilator and connected to a mechanical oscillator that produced brief pulses in airway pressure at a rate of two pulses/s. These pulses were applied to the infants airway for 20-30 s, at which time the infant was replaced on the ventilator. The mean airway pressure during the procedure was maintained at the level of the positive and expiratory pressure that was set on the ventilator. Two classes of patients were identified from the pulse response primarily by the presence or absence of a local resonance in the impedance spectra. Similar results were obtained in five other patients who were examined with zero mean airway pressure, suggesting that the pulse response is little influenced by changes in mean lung volume or total lung compliance. Patient classification appeared related to the duration of ventilation therapy and the transition from one class to another was consistent with the development of high peripheral airway resistance and significant volume shunting in the central airways. These results suggest that brief pulses in airway pressure can be used to detect changes in the pulmonary mechanical function of preterm infants that result from long-term ventilation therapy.

Airway Resistance↗

PubMed1991

[Impact of induction chemotherapy in the treatment of breast cancer].

Two hundred and six women with a breast cancer T2 ou T3, N0, N1, M0 were randomized. One hundred and one had mastectomy and 78 with at least one poor prognosis factor received adjuvant chemotherapy. One hundred and five received first chemotherapy and 64 out of the 105 were proposed breast conservation. Retrospectively, costs of treatment in time, trips and physical sequelae were evaluated. Treatment was ten weeks longer and trips one thousand kilometers longer in conserving therapy. The cosmetic result evaluated by a nurse was good for 95% of women with conserving therapy. A self evaluation on physical, psychological, sexual and social conditions made by 64 women, one year after the end of treatment, showed no difference between the two groups. Review of literature confirmed that the impact of treatment has to be considered and carefully evaluated.

Adult↗

PubMed1991

[Tumor of the urinary tract discovered after renal trauma. Medico-legal implications of a case].

A case of a tumor of the urinary tract discovered after renal trauma is reported. The clinical and radiolocal observations are presented as well as the interest of this case in forensic medicine. A review of the legal aspects recalls the principles of imputability in cases of cancer and trauma. While malignant tumors discovered after renal trauma are often renal cancers, urinary tract tumors can also be revealed after renal trauma. This unfrequent circumstance of discovery underlines the importance of control urography in cases of renal trauma, of history taking (smoking), and of the requirement for follow-up investigations if intra-luminal urographic abnormalities persist without damage to the renal parenchyma on the CAT scan.

Adult↗

PubMed1990

Circular dichroism studies of an oligodeoxyribonucleotide containing a hairpin loop made of a hexaethylene glycol chain: conformation and stability.

An oligodeoxyribonucleotide, d(GCTCACAAT-X-ATTGTGAGC), where X represents a hexaethylene glycol chain, was studied using circular dichroism spectroscopy. Its conformation and conformational stability were compared to those of compounds where X was replaced by four thymines and to the duplex of same sequence without loop. The compound with the hexaethylene glycol chain can form a hairpin looped structure as well as a bulged duplex structure. In both cases the duplex region of the oligodeoxyribonucleotide exhibits the same conformation. In similar conditions the oligodeoxyribonucleotide with a four thymines loop forms exclusively a hairpin structure. Comparison between the thermodynamic parameters (delta H, delta S, delta G) associated with the formation of the structure of the three compounds are presented. In the case of the compound with the hexaethylene glycol chain it is shown that the large increase in its melting temperature (by about 35 degrees C in our experimental conditions) when compared to the non looped structure is mainly due to the fact that its melting process is intramolecular (monomolecular) whereas the other one is bimolecular.

Base Sequence↗

PubMed1990

Oxygenation index in patients with meconium aspiration: conventional and extracorporeal membrane oxygenation therapy.

The use of the alveolar-arterial oxygen difference P(A-a)O2 and the oxygenation index (mean airway pressure [Paw] FIO2 x 100/PaO2) have been proposed for selecting infants who will require extracorporeal membrane oxygenation (ECMO) therapy. However, the use of the oxygenation index (OI) in conjunction with Paw in an exclusive population of patients with meconium aspiration syndrome (MAS) has not been reported. Fourteen patients born in our facility and managed with conventional therapy and five infants treated with ECMO were enrolled in the study. All patients had clinical and x-ray evidence of MAS. Infants who received conventional treatment required mechanical ventilation greater than 48 h, FIO2 1.0, and were under the care and supervision of one neonatologist. Management was directed to minimize barotrauma by avoidance of routine hyperventilation, use of lower Paw, and sufficient expiratory time. One patient died before ECMO and 13 infants survived. Six survivors had an OI greater than 25 (three had an OI greater than 40), six had a Paw greater than or equal to 12 cm H2O (12 to 15 cm H2O in five infants) and six patients had a P(A-a)O2 greater than or equal to 610 torr. One surviving infant was transferred for ECMO therapy (OI 67, Paw 20 cm H2O). The five patients treated with ECMO survived (OI 48 to 92, Paw 20 to 29.5 cm H2O P(A-a)O2 627 to 650 torr). One patient in each group developed chronic lung disease with evidence of resting tachypnea. Our findings indicate that an OI greater than 40 in association with a Paw greater than or equal to 20 cm H2O may be helpful in predicting which infants with MAS need ECMO, whereas patients requiring a Paw less than or equal to 15 cm H2O can be managed with conventional therapy. An OI greater than or equal to 25 but less than 40 is not associated with high mortality in these patients. The predictive value of Paw of 16 to 20 cm H2O and the duration of an OI greater than 40 in patients with MAS need further investigation.

Airway Resistance↗

PubMed1990

NMR study of 13CO2 incorporation into short-chain fatty acids by pig large-intestinal flora.

The nuclear magnetic resonance technique was used to study carbon dioxide reduction by the pig large-intestinal flora. Washed bacterial cell suspensions were incubated for 6 and 15 h under 13CO2 and H2 as the gas phase and with a buffer containing NaH13CO3 and cellobiose and amino acids (casein hydrolysate) as substrates. Methane was produced in all incubation media. Significant amounts of single- as well as multiple-labelled acetate and butyrate were formed, demonstrating synthesis of acetate from H2 + CO2. Propionate was labelled mainly on the carboxyl group, which was attributed to an enzymatic exchange of the carboxyl group of propionate with 13CO2. These results indicate that the reduction of CO2 to acetate may be an important pathway for microbial production of acetate in the pig large intestine even in the presence of methanogenesis.

Acetates↗

PubMed1990

[Effect of nicardipine on cerebral vasomotor activity in hypocapnia].

Nicardipine, a calcium channel antagonist derivative of dihydropyridine, is a cerebral vasodilatator used in the treatment of cerebral vasospasms induced by subarachnoid hemorrhage after rupture of intracranial aneurysm. Hypocapnia is a powerful vasoconstrictor of cerebral arteries, and antagonizes in the baboon the cerebral vasodilative effect of nimodipine, another derivative of dihydropyridine. The action of nicardipine in presence of hypocapnia was not yet study in human. The study of the interaction of nicardipine and hypocapnia on the cerebral arteries show that hypocapnia antagonizes the cerebral vasodilatator properties of nicardipine.

Adult↗

PubMed1990

[First evaluation of three years of assessment of medical activity within the framework of PMSI in cancer prevention centers].

In June 1982, the Direction of the French Hospitals introduced the project for the medicalisation of the system of information (PMSI) derived from the American Fetter system. The aim of this project was the collection of basic data necessary to the establishment of a national minimum data set base (MDS). Since 1985, a french regional cancer center, the Foundation Bergonié, has collected MDS by computer. Now, we give the results of the analysis concerning 28,379 MDS collected from 1986 to 1988. However, 11,127 (39%) MDS have not yet been analyzed by PMSI as they are connected with external activity or ambulatory care. It is possible to form a diagnosis related group (DRG) from the MDS to analyze the management of hospitals and utilization of means. 279 DRG were formed from 12,252 MDS, in our Institute. In fact, only 30 DRG with a sufficient number of MDS (over 100) were studied. This descriptive study shows that a few DRG maintain homogeneity in terms of length of hospitalisation especially in the surgical sector. It seems necessary to incorporate new criteria for MDS in order to improve the study of DRG; however groups sufficiently large for statistical analysis must be maintained.

Diagnosis, Computer-Assisted↗

PubMed1990

[Relay chemotherapy using continuous perfusion of cisplatin and fluoro-uracil in advanced cancer of the breast. Analysis of a series of 50 cases].

Fifty patients with advanced breast cancer (21 undergoing first and second stage palliative treatment: group 1, and 29 undergoing stage three or more: group 2), were included in a phase II trial with administration of a combination relay chemotherapy consisting of cisplatin (100 mg/m2/day) and fluorouracil (1,000 mg/m2/day), in continuous perfusion during 4 days, in cycles of five days repeated every three weeks (mean duration: 12 weeks). Toxicity was frequent and severe (a total of 17 treatments discontinued, and five deaths, 3 in group 1, 2 in group 2). The main manifestations of intolerance were threefold: haematological and leucopenia, in almost half of the patients, including 2 severe with 1 case of infectious complication and 4 thrombopenias requiring discontinuation of the treatment, including 2 with a severe haemorrhagic syndrome; cardiovascular, with three deaths due to heart failure; renal, most of the time laboratory tests disorders with 1 clinical syndrome. An objective response of more than fifty p. cent was obtained in five patients in group 1 (29.4%) and 3 patients in group 2 (11.1%); it lasted an average of 6.5 months and varied according to the locations: nodes (43%), liver (40%), pleuro-pulmonary (22%). Responses were obtained (13%) for lesions which resisted to previous chemotherapy. Five patients (14%) presented a functional improvement. The survival (mean = 4.8 months) was correlated, in group 1, to initial life conditions (p = 0.01) and was longer in group 1 for menopausal patients who had well tolerated the treatment (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1989

Thermodynamic parameters of the binding of an oligo-alpha-thymidylate to its complementary oligo-beta-adenylate sequences.

The temperature dependence of the formation of a double-stranded complex between an oligo-alpha-thymidylate and its complementary sequence, beta-riboadenylate or beta-deoxyriboadenylate, was studied using circular dichroism and compared to the duplexes formed using an oligo-beta-thymidylate. Analysis of the melting profiles allowed us to determine the thermodynamic parameters (delta H, delta S and delta G) associated with the formation of the various duplexes. The order of the stability was found: alpha-dT:beta-dA approximately alpha-dt:beta-rA greater than beta-dT:beta-dA greater than beta-dT:beta-rA.

Adenine Nucleotides↗

PubMed1989

Oligothymidylates covalently linked to an acridine derivative and with modified phosphodiester backbone: circular dichroism studies of their interactions with complementary sequences.

Oligothymidylates involving alternating alkyl phosphotriester-phosphodiester or methylphosphonate-phosphodiester backbones and covalently linked to an acridine derivative have been studied using circular dichroism. Two isomers with the same diastereoisomeric configuration for all the phosphotriesters (ethyl triester and neopentyl triester) or the methylphosphonate linkages were studied. These six compounds were compared to the parent oligonucleotide with unmodified phosphodiester bonds. Intramolecular interactions between the acridine and the bases of the oligonucleotides were revealed by the induced circular dichroism of the acridine dye. Binding to poly(rA) and poly(dA) induced large changes in the circular dichroism signal. All oligothymidylates formed double-stranded complexes with poly(rA). Substitution of phosphotriesters and methylphosphonates to phosphates allowed both double- and triple-stranded structures to be formed with with poly(dA). The double-stranded structures formed with poly(rA) and poly(dA) were characterized by different environments of the acridine dye. The circular dichroism spectra of the complexes with poly(dA) and the thermal stabilities of the complexes formed with both poly(rA) and poly(dA) were drastically dependent of the diastereoisomeric configuration of the phosphate modification. For the complexes formed with the pseudoequatorial stereoisomer the modification of the phosphate groups increased the stability of the complexes as compared with the oligothymidylate containing only phosphodiester linkages whereas it decreased it for pseudoaxial modifications.

Aminoacridines↗

PubMed1989

[Intraoperative nitroglycerin: value of determining individual doses: (surgery of the abdominal aorta)].

Thirteen patients requiring infrarenal aortic clamping were studied during flunitrazepam, fentanyl, pancuronium and nitrous oxide anaesthesia. Each awake patient was submitted to a volume loading test to determine the haemodynamic status and his optimal left pre-load. Anesthetic induction was well tolerated. Nitroglycerin was administered by continuous infusion before aortic clamping and we determined the dose necessary to decrease the systemic vascular resistance by 20 per cent. This dose was very variable and needed to be increased in five of 13 patients at the time of clamping. With nitroglycerin, we noticed no significant alteration of MVO2 at clamping. Volume loading allowed good stability at declamping.

Aged↗

PubMed1989

In vivo 13C NMR studies of glucose catabolism by isolated rumen bacteria.

Nuclear magnetic resonance (NMR) was used to study the metabolism of the rumen bacterial ecosystem. The fermentation of 1-13C-glucose was investigated. This system showed a transient build-up and decay of lactate labelled at the C3 position. The degradation of lactate gave rise to volatile fatty acids. These results agree with in vivo data on diets rich in available carbohydrates.

Animals↗