Biomedical subjects

F Girard

Publications and source records attributed to F Girard.

At least 37 records · Page 2Linked to original sources

PubMed2001

Voluntary hyperventilation before a rapid-sequence induction of anesthesia does not decrease postintubation PaCO2.

UNLABELLED: To prevent hypercapnia, voluntary hyperventilation is recommended for patients with increased intracranial pressure before the induction of general anesthesia. We sought to determine whether this maneuver results in a lower PaCO2 than breathing 3 min of oxygen 100% by face mask (preoxygenation) after intubation. Thirty patients requiring general anesthesia were randomly assigned to breathe either 3 min of oxygen 100% by face mask (Group P) or 1 min of oxygen 100% followed by 2 min of voluntary hyperventilation with oxygen 100% (Group H). All patients received a standard rapid-sequence induction of anesthesia followed by a 90-s period of apnea. Patients were then tracheally intubated and mechanically ventilated. Five arterial blood gas samples were taken: with room air, after preoxygenation or hyperventilation, after 60 and 90 s of apnea, and after tracheal intubation. Voluntary hyperventilation decreased PaCO2 before rapid-sequence induction (hyperventilation, 30.0 +/- 3.5 mm Hg versus preoxygenation, 37.9 +/- 5.2 mm Hg; P < 0.0001), but after 60 s of apnea, both groups had similar PaCO2 (hyperventilation, 36.1 +/- 3.3 mm Hg versus preoxygenation, 35.6 +/- 3.4 mm Hg; P = 0.673), and no benefit was found after intubation (hyperventilation, 40.5 +/- 3.9 mm Hg versus preoxygenation, 41.4 +/- 2.7 mm Hg; P = 0.603). We conclude that voluntary hyperventilation before rapid-sequence induction does not provide protection against potential hypercapnia during intubation. IMPLICATIONS: Voluntary hyperventilation before anesthesia induction is recommended for patients with increased intracranial pressure to prevent hypercapnia. This randomized, prospective study demonstrated that this maneuver does not result in a lower postintubation PaCO2 than standard preoxygenation.

Adult↗

PubMed2001

Elevated plasma level of lipotropin revealing an occult carcinoid tumor with normal plasma adrenocorticotropin.

The increases in the level of plasma lipotropin (LPH) and in the LPH/ACTH ratio are considered diagnostic tools in ectopic ACTH syndrome. However, plasma ACTH is also elevated in this syndrome. We report a case of a small carcinoid tumor with an increase in both ACTH and LPH in plasma before surgery. Eight months after the tumoral resection, plasma LPH alone was increased again, whereas plasma ACTH and plasma and urinary cortisol remained normal in this apparently cured patient. This repeated abnormality was the only available feature that allowed successful removal of the occult tumoral residue.

Adrenocorticotropic Hormone↗

PubMed2001

[Adult medulloblastoma. Review of 22 patients].

BACKGROUND AND PURPOSE: Medulloblastoma is a malignant neuro-ectodermal tumor classically considered as a pediatric tumor. Adult medulloblastoma is rare. This low incidence results in a lack of data concerning the management of treatment. We report our experience and propose a review of the literature to clarify the main therapeutic options that are nowadays suggested. METHODS: We reviewed 22 adult patients treated for cerebellar medulloblastoma between 1979 and 1999. Actuarial relapse-free and overall survival were determined by the Kaplan-Meier method. Prognosis factors were studied by Log- Rank test. RESULTS: The five years relapse free and overall survival rates were respectively 63.1% and 81.3%. These rates are superior to those reported in the literature. None of the studied factors (age, gender, histological subtype, total or partial surgery, presence of a CSF derivation device, radiotherapy, chemotherapy) were significantly associated to remission or survival. However our statistical results should be interpreted with caution in this small population. CONCLUSION: Adult medulloblastoma prognosis seems to improve since chemotherapy has been introduced in the therapeutic protocols. Prospective and multicentric studies should determine the exact pattern of treatment.

Adolescent↗

PubMed2001

[Three-dimensional reconstruction calibrated with ultrasonographic images. Application to the measurement of clot volume in vitro].

OBJECTIVE: We used 3D ultrasonographic reconstruction with manual acquisition to study the volume of venous clots in vitro. MATERIAL AND METHODS: Native 2D ultrasound slices were acquired free hand for 3D reconstruction. The spatial coordinates of each slice were delivered in real time with an electromagnetic captor. We applied a standard ultrasound protocol to test the calibrated 3D reconstruction quantitatively. The volume of 5 clots of increasing size was quantified in vitro using manual segmentation in a double-blind manner by two independent operators. RESULTS: The comparison tests and the interoperator regression lines evidenced good agreement between real and measured volumes, confirming the coherence of the reconstruction protocol and the feasibility of this technique in a routine medical setting. Intraoperator variability was 7 to 11% and interoperator variability 16.9%. CONCLUSION: This calibrated 3D reconstruction is compatible with in vitro measurement of venous clots. This technique could be useful to follow the evolution of the head of proximal deep vein thrombi in vivo. It will be more reliable with semi-automatic or even automatic segmentation becomes available.

Calibration↗

PubMed2001

[Severe pulmonary sarcoidosis].

Mediastinal and pulmonary localizations are found in 90% of al patients with sarcoidosis. In half the cases, the disease is not severe and is reversible without treatment. In the other half of cases, early or late respiratory complications can be seen. Early complications include subacute respiratory insufficiency by interstitial lung disease or by bronchial airway obstruction. Among late complications, the most frequent is pulmonary fibrosis. Four computed tomography patterns are found with variable functional impairments and course. Chronic obstructive respiratory insufficiency can be the consequence of specific bronchial lesions or pulmonary fibrosis surrounding proximal bronchi. Cor pulmonale is seen in 5% of cases. Aspergilloma seen in fibroemphysematous lesions can be the cause of major hempoptysis. Respiratory complications account for half of the 5% of deaths due to sarcoidosis. Respiratory complications are most often seen in radiographic stage III and IV disease. Treatments, mainly corticosteroids, only exert a suspensive effect but reduce the incidence and severity of respiratory manifestations. The gain obtained by treatment depends on the choice of the best time of institution and on the quality of monitoring. Lung transplantation is useful in most severe cases unresponsive to medical treatment.

Airway Obstruction↗

PubMed2001

[Prevalence of hyperhidrosis in a population treated by beta-blocker].

INTRODUCTION: Some cases of hyperhidrosis with beta-blocker therapy have been reported in the literature. We studied the prevalence of hyperhidrosis in a population treated by beta-blockers compared with an untreated control group. PATIENTS AND METHODS: Patients attending the cardiologic consultation of the Nancy hospital were included. Past medical history and medication were collected. Interrogation assessed whether the patient felt hyperhidrosis, and defined a hyperhidrosis score. RESULTS: Sixty-five subjects treated by beta-blocker and 100 controls were included. 36.9 p. 100 of treated patients and 38 p. 100 of controls experienced hyperhidrosis (p=0.88). 23.07 and 23 p. 100, respectively, had hyperhidrosis defined by a high score of sweating (p=0.99). Retrospectively, 8 of 24 patients experienced hyperhidrosis after the beginning of beta-blocker therapy. DISCUSSION: We observed the same prevalence of hyperhidrosis in the two groups. However sweat gland innervation involved both cholinergic and adrenergic stimulations. Furthermore, experimental studies showed an increase in sweating on efforts with beta-blocker therapy.

Adrenergic beta-Antagonists↗

PubMed2001

[Severe complications of pregnancy and delivery: the situation in Lorraine based on the European investigation].

The level of maternal mortality appears to be higher in France than in other European countries according to the data collected in the 1995 European survey. We performed a retrospective analysis of severe hemorrhage, pregnancy induced hypertension, and maternal sepsis in 1995 in the Lorraine region and reviewed the management scheme used in each case. There was one maternal death and 223 cases of severe maternal morbidity (110 cases of hemorrhage, 105 cases of pregnancy induced hypertension, 8 cases of maternal sepsis). The frequency of these maternal diseases was an estimated 8 per 1000 births. Ninety percent of the children (90.7%) were living 7 days after birth. Pregnancy after the age of 35 years, obesity, and an intermediate level of vocational training were well-documented high risk factors in the Lorraine area. All of the women who developed complications had been followed regularly during their pregnancy. High parity and a scarred uterus were high risk factors for post partum hemorrhage. About 45% (45.5%) of the patients were transferred to an emergency unit for intensive care. Pregnancy-induced hypertension was treated within the normal hospital network, most of the mothers being transferred to a reference center prior to delivery. This retrospective study demonstrates the need for reporting more information on medical records. The data observed improved our knowledge of the prevalence and management of the main causes of direct maternal death in the Lorraine area. It improved our knowledge on the prevalence and management of the main causes of direct maternal death in Lorraine area.

Adult↗

PubMed2001

[Inflammatory pseudotumors of the lung with severe course].

Pulmonary inflammatory pseudotumors are usually unique lesions of unknown etiology with good prognosis. We report two severe cases with mediastinal invasion, local recurrence, extrathoracic locations, one of them with a fatal evolution. Certain microscopic features, which were present in our cases (increased cellularity, nuclear pleomorphism, mitotic activity, focal necrosis, bizarre giant cells, vascular invasion), may have prognostic relevance in determining an aggressive behavior of these tumors. Surgical resection is the recommended treatment, and incomplete resection, as in our cases, seems to be a risk factor for developing recurrent inflammatory pseudotumor. Immunosuppressive therapy was ineffective as well as radiotherapy in one of our cases. Only high doses of corticosteroids seemed to slow the evolution of the disease.

Adult↗

PubMed2000

Negative relationships between erythrocyte Ca-pump activity and lead levels in mothers and newborns.

Lead poisoning induces hematological, gastrointestinal and neurological dysfunctions. One of the potential mechanisms is the inhibition of calcium-pump (Ca-pump), a transport protein. We investigated the effects of an environmental low lead exposure on Ca-pump activity in 247 mothers and their newborns. Maternal and cord blood, and newborn and mother hair, were sampled at delivery. Geometric means for mother and cord blood lead (Pb-B), and for mother and newborn hair lead (Pb-H), were 6.3 and 4.8 microg/dl, and 1.7 and 1.1 microg/g. Means for mother and cord basal Ca-pump activities were 2,442 and 2,675 nM/mg/hr. Mother enzymatic activity was negatively related to her Pb-B and Pb-H and to the cord Pb-B and newborn Pb-H levels. Newborn enzymatic activity was negatively related to his Pb-H level only. Adjustment for gestational age, child's sex, mother's age at delivery, alcohol, coffee and tea consumption, and smoking habits during pregnancy did not modify these relationships. Our findings support the hypothesis that lead toxicity could be in part mediated by a reduction of Ca-pump activity. This effect could be observed at low environmental exposure, in mothers and newborns.

Adult↗

PubMed2000

Does selenium reduce the risk of threatened preterm delivery associated with placental cytochrome P450-1A1 activity?

Selenium (Se), an essential trace element in human nutrition, is thought to have an important role in the prevention of oxygen damage by organic hydroperoxides generated by oxidative metabolism. Epidemiological studies have shown an association between placental cytochrome P450-1A1 (CYP1) activity and threatened preterm delivery (TPD), and other experimental studies have shown alterations in fetal development with CYP1 activity or toxicity. The present study examined the possible protective effect of selenium on the potential toxicity of maternal exposure to polycyclic aromatic hydrocarbons (PAHs) on the normal course of pregnancy. Placental CYP1 activity was used as a risk factor resulting from maternal exposure to PAHs. TPD occurrence was used as a general indicator of troubles in the normal course of pregnancy. A group of TPD patients and a group of controls were selected from 178 pregnant women attending obstetrical care in a maternity hospital. Selenium concentrations in maternal plasma were lower in the TPD group: 63.7 ng/ml (CI 95% confidence bounds = 43.6-82.2) vs 69.2 ng/ml (CI 95% confidence bounds = 49. 3-96.3) (t test, P<0.01). When placental CYP1 was induced, an association between TPD and selenium was found, with an increase of 10 ng/ml for the latter. An adjusted odds ratio of 0.55 (CI 95% confidence bounds = 0.34-0.88; chi(2), P<0.01) was estimated. When placental CYP1 was not activated, the odds ratio was estimated at 0.99 (CI 95% confidence bounds=0.95-1.03; NS). This epidemiologic finding suggests that antioxidant Se status may be a protective factor against the potential toxic effect of PAHs on the normal course of pregnancy. The downward trend that we observed supports the hypothesis that the one-electron pathway metabolism of PAHs may explain a large fraction of TPD and some preterm deliveries.

Adult↗

PubMed2000

Sox neuro, a new Drosophila Sox gene expressed in the developing central nervous system.

We describe the identification and detailed expression pattern of a second Drosophila Sox gene, SoxNeuro (SoxN), highly related to mammalian group B Sox1, 2, 3 genes. SoxN is expressed in a highly dynamic pattern during embyogenesis, being associated with the development of the central nervous system (CNS), from the early steps onwards. We present strong evidence that the early SoxN neuroectoderm expression is controlled by the zygotic dorso-ventral patterning genes (dpp, sog, brk, twi).

Amino Acid Sequence↗

PubMed2000

The HIV-1(Lai) RNA dimerization. Thermodynamic parameters associated with the transition from the kissing complex to the extended dimer.

Retroviruses contain dimeric RNA consisting of two identical copies of the genomic RNA. The interaction between these two RNA molecules occurs near their 5' ends. A region upstream from the splice donor comprising an auto-complementary sequence has been identified as being responsible for the initiation of the formation of dimeric HIV-1(Lai) RNA. This region (SL1), part of the PSI encapsidation domain, can adopt a stem-loop structure. It has already been shown that this stem-loop structure can initiate the formation of two distinct dimers differing in their thermostability: a loop-loop dimer or 'kissing complex' and an extended dimer. We report here a study using UV and 1D NMR spectroscopy of the dimerization of a short oligoribonucleotide (23 nucleotides) spanning nucleotides 248-270 of the HIV-1(Lai) SL1 sequence, in order to derive the thermodynamic parameters associated with the transition from the loop-loop complex to the extended dimer. The temperature dependence of the UV absorbency shows an hypochromicity for this transition with a small enthalpy change equal to - 29.4 +/- 5 kcal x mol-1, together with a concentration independent transition which implies a monomolecular reaction. On the other hand, our NMR results don't indicate a dissociation of the GCGCGC sequence engaged in the loop-loop interaction during the rearrangement of the loop-loop complex into the extended dimer. Our data suggest that the loop-loop interaction is maintained during the temperature dependent conformational change while the intramolecular base-pairing of the stems is disrupted and then reconstituted to form an intermolecular base-pairing leading to an extended dimer.

Base Sequence↗

PubMed2000

Anatomic MR images obtained with silent sequences.

The authors evaluated silent magnetic resonance (MR) imaging sequences for their suitability in providing high-spatial-resolution anatomic images that are of sufficient quality to be useful in a clinical setting. The authors compared the images obtained with a silent rapid acquisition with relaxation enhancement (RARE) sequence to its standard counterpart with respect to signal-to-noise ratio, distribution of gray level, and spatial resolution. No real differences were observed between the standard and the silent RARE MR images. Anatomic images were also acquired with a silent spin-echo sequence. Acoustic noise levels with the silent sequences were at least 22 dB (A-weighted scale) lower than those with standard sequences, without loss of image quality.

Adult↗

PubMed2000

[Evaluation of professional practices].

Concepts and methods in professional practices evaluation are often confused. After a description of the classical conceptual framework, we present these methods in an approach in which practice is the principal result to be measured. Thus it makes it possible to apply the traditional epidemiological concepts to the evaluation of the professional practices with their three traditional fields: 1) In the descriptive approach, cross-sectional practice studies allow an observation and description of the usual behaviors, possibly compared to references. The methodological constraints are the same as which of descriptive epidemiological studies; 2) In the analytical approach, factors associated with practice - simple or conformed to criteria - are evidenced on a representative sample; 3) In the evaluative approach of practices improvement, the objectives are the assessment of formative, organizational or structural interventions, aiming at modifying practices. Three types of studies are to be used: quasi experimental in which clinical audit is the reference method in the field of medical care. The six main steps of clinical audit are described; experimental, based on the community randomized trial scheme, which have the advantage to provide results that can be immediately generalized; observational in which no control on the implementation of intervention is done. "Here and else" and "before and after" studies are used. To be effective for evaluation of professional practice, theses methods must come within the scope of a favorable institutional context.

Epidemiologic Methods↗

PubMed1999

Systemic adjuvant effect of cholera toxin in the chicken.

Cholera toxin (CT) is a well-known mucosal adjuvant in mammals, but it does not give conclusive results in chickens. Cells from the chicken immune system may be insensitive to CT activity. Our results showed that intravenously administered CT had strong immunomodulatory effects on chicken antigen-specific T- and B-cell immune responses. Seven and eight days post-inoculation (p.i.), chickens immunized with KLH and CT exhibited a faster and higher specific proliferative response in the spleen after in vitro restimulation than chickens immunized with KLH alone. At the same time, the specific antibody response in serum was significantly higher, with a strong IgG enhancement and a peak of IgA in chickens immunized with KLH and CT. The anti-KLH splenic antibody response in vitro involved a significant increase in specific IgG and IgA isotypes when CT was used as adjuvant. In conclusion, as in mammals, systemic CT demonstrated strong adjuvant properties in chickens enhancing T-cell priming in vivo and, thus, leading to increased specific antibody production, including IgA.

Adjuvants, Immunologic↗

PubMed1999

Environmental lead exposure and activity of delta-aminolevulinic acid dehydratase (ALA-D) in maternal and cord blood.

The hypothesis that environmental lead exposure measured from blood (Pb-B) inhibits delta-aminolevulinic acid dehydratase activity (ALA-D) from whole blood was tested in 241 urban mothers and their newborns. Geometric means and (5th and 95th Percentiles) for maternal and cord Pb-B were 6.4 microg dl(-1) (3.4-11.9) and 4.6 microg dl(-1) (2.8-9.2). Spearman correlations between mother and cord Pb-B and ALA-D were all negative but statistically significant only for cord Pb-B and mother ALA-D. A potential lead threshold, was identified between 3.2 and 4.8 microg dl(-1), above which ALA-D may be inhibited by lead, and below which ALA-D may be insensitive or even activated. In conclusion, low environmental exposure to lead is responsible for a demonstrable biochemical effect. This potential ALA-D inhibition may lead to neurotoxic effects, especially in newborns who have high level of neurogenesis.

Adult↗

PubMed1999

Adjuvant effect of cholera toxin on systemic and mucosal immune responses in chickens infected with E. tenella or given recombinant parasitic antigen per os.

We investigated the adjuvant effect of cholera toxin (CT) on the intestinal and systemic immune systems of chickens. The CT was given orally, mixed with a non-replicating antigen, a recombinant Eimeria protein, IPEI, or with a replicating one, Eimeria tenella parasite. There were increases in the specific IgA and IgG responses to the recombinant protein IPEI, with a significant anti-1PE1 IgG response in the duodenum (p < 0.05) and caecum (p < 0.05) 4 weeks after immunization and a specific IgA (p < 0.05) response in the duodenum after 3 weeks. A transient anti-1PE1 IgG (p < 0.05) response was detected in the serum 1 week post-injection and an IgA response (p < 0.05) at 2 weeks. CT given with the replicative parasite caused no change in the intestinal and systemic immune responses with 1 or 3 immunizations although a specific antiparasitic in vitro proliferation of the spleen cells from infected chickens was observed. Nevertheless, 0.05 mg CT given per os to chickens was strongly immunogenic in both experiments. A strong serum IgG (p < 0.01) response was detected as soon as 1 week after the end of the immunization protocol with 1PE1 and 2 weeks after infection with E. tenella. Strong anti-CT IgG responses were also detected by the second week post-immunization in the duodenum and caeca (p < 0.01). Hence, CT can be used as a mucosal adjuvant in chickens to improve the intestinal immune response.

Adjuvants, Immunologic↗

PubMed1999

"Silent" MRI with soft gradient pulses.

A method to reduce the acoustic noise generated by gradient systems in magnetic resonance imaging (MRI) is proposed based on the linear response theory. Since the acoustic frequency response function of typical gradient coils is low in the range below 200 Hz, the noise level can be significantly reduced by using gradient pulse sequences whose spectra are limited to this frequency range. Such "soft," i.e., band-limited, pulse shapes can be designed using sinusoidal ramps individually adjusted to available delays. "Silent" versions of three basic MRI sequences [gradient-echo (GE), spin-echo (SE), and rapid acquisition with relaxation enhancement (RARE)] were programmed on 2 and 3 T whole-body scanners. High-quality images could be acquired at noise levels as low as 40 dBA (GE and SE) and 60 dBA (RARE).

Brain↗