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G Perrin

Publications and source records attributed to G Perrin.

At least 37 records · Page 2Linked to original sources
PubMed1998

Behaviour and enterotoxin production by Staphylococcus aureus during the manufacture and ripening of raw goats' milk lactic cheeses.

To study the possible presence of staphylococcal enterotoxin A in raw goats' milk lactic cheese, milk was inoculated with an enterotoxigenic Staphylococcus aureus strain to a final concentration of 4, 5 and 6 log(cfu/ml). Cheese was prepared following industrial specifications and ripened for 42 d. Detection of the enterotoxins was by the Vidas Staph enterotoxin test (BioMérieux) and by an indirect double-sandwich ELISA technique using anti-enterotoxin monoclonal antibodies. Staphylococcal counts declined markedly after draining, and by the end of ripening they had disappeared from some cheeses. In contrast, aerobic mesophilic organisms grew well. The level of staphylococcal enterotoxin A recovered varied from 1 to 2.5 ng/g cheese made with an initial population of 10(5) or 10(6) cfu/ml. Only traces of enterotoxin A (0.5 ng/g) were detected in cheeses made with the lowest Staph. aureus inoculum used in this study. Enterotoxin A was also detected in cheeses from which Staph. aureus had disappeared.

Animals↗
PubMed1998

Growth and enterotoxin production of Staphylococcus aureus during the manufacture and ripening of Camembert-type cheeses from raw goats' milk.

Tests were carried out to determine the effect of manufacturing procedures for a Camembert-type cheese from raw goats' milk on the growth and survival of Staphylococcus aureus organisms added to milk at the start of the process, and to study the possible presence of staphylococcal enterotoxin A in these cheeses. The initial staphylococcal counts were, respectively, 2, 3, 4, 5 and 6 log cfu ml-1. Cheese was prepared following the industrial specifications and ripened for 41 d. Detection of enterotoxins was done by the Vidas SET test and by an indirect double-sandwich ELISA technique using antienterotoxin monoclonal antibodies. Generally, numbers of microbes increased at a similar rate during manufacture in all cheeses until salting. During the ripening period, the aerobic plate count population and Staph. aureus levels remained stable and high. There was an approximately 1 log reduction of Staph. aureus in cheeses made with an initial inoculum of Staph. aureus greater than 10(3) cfu ml-1 at the end of the ripening period (41 d) compared with the count at 22 h. The level of staphylococcal enterotoxin A recovered varied from 1 to 3.2 ng g-1 of cheese made with an initial population of 10(3)-10(6) cfu ml-1. No trace of enterotoxin A was detected in cheeses made with the lowest Staph. aureus inoculum used in this study.

Animals↗
PubMed1997

North American and French caprine arthritis-encephalitis viruses emerge from ovine maedi-visna viruses.

The full extent of genetic diversity among small ruminant lentiviruses (SRLVs), i.e., caprine arthritis encephalitis viruses (CAEVs) and maedi-visna viruses (MVVs), remains unknown. This is due in part to the fact that few sequences of CAEV are available. To contribute to this knowledge, gag, pol, and env nucleotide sequences from an SRLV named CA680 originating from a goat from western France were determined. This analysis revealed that this virus is closely related to the Cork and 63 CAEV American isolates. Mismatched amino acids between the CA680 virus and prototype CAEVs ranged from 6.7, 0. 7, and 17.5% for gag, pol, and SU sequences, respectively. The differences between the CA680 virus and MVV prototypes ranged from 16.5, 12.5, and 32.3% for the protein sequences, respectively. A screening using a heteroduplex mobility assay (HMA) adapted to SRLVs revealed that 6 of 10 caprine virus field isolates were closely related to CA680, indicating that this latter isolate was a prototype of CAEVs common in the west of France. Phylogenetic trees drawn using CA, RT, or SU sequences of numerous SRLVs and rooted with EIAV sequences revealed that CA680 and CAEV prototypes, all infectious for goat, clustered in one group. From these HMA and phylogenetic analyses, it appears that U.S. and French caprine SRLVs form a clade that had emerged from a much more diverse group containing all SRLVs infectious for sheep. These ovine SRLVs form a more ancient group in which the EIAV is rooted.

Amino Acid Sequence↗
PubMed1997

Phospholipase A2 activity in herniated lumbar discs. Clinical correlations and inhibition by piroxicam.

STUDY DESIGN: Prospective study of phospholipase A2 activity in the serum and intervertebral discs of patients undergoing surgery for sciatica due to disc herniation. OBJECTIVES: To determine correlations between herniated disc phospholipase A2 and clinical, radiographic, and anatomic signs of common sciatica; to evaluate serum phospholipase A2 activity as a marker of disc phospholipase A2; and to investigate the in vivo effect of piroxicam on disc phospholipase A2. SUMMARY OF BACKGROUND DATA: Several studies suggest disc inflammation as a mechanism of sciatica due to disc herniation, and phospholipase A2 emerges as a key enzyme of cartilage and disc tissues. METHODS: Phospholipase A2 activity was determined, using the degradation of a specific substrate, in the serum and discs of 31 patients (14 treated with acetaminophen and 17 treated with piroxicam) undergoing surgery for sciatica due to lumbar disc herniation. Visual analog scale for pain, Dallas Pain Questionnaire, Lasègue's sign, radiographic stage of degeneration of the herniated disc, volume of disc herniation shown by computed tomography, and surgical findings were recorded. RESULTS: Disc phospholipase A2 activity was independent of the patient's age or sex, the radiologic stage of disc degeneration, and the volume of the herniation, and showed no significant correlation with Lasègue's sign or pain measured on a visual analog scale. The correlation between disc phospholipase A2 and the Dallas category of items measuring the impact of pain on daily activities approached the level of significance (P = 0.07). Disc phospholipase A2 activity was significantly higher in cases of sequestrated discs than in other herniations. Disc phospholipase A2 was significantly correlated with serum phospholipase A2, and was significantly lower in patients treated with piroxicam than in those treated with acetaminophen. CONCLUSIONS: Disc phospholipase A2 is thought to participate in the physiopathology of sciatica and to bemodulated by nonsteroidal anti-inflammatory drug therapy. Serum phospholipase A2 is suggested as a biologic marker of disc inflammation in patients with sciatica.

Acetaminophen↗
PubMed1997

Fas ligand expression by astrocytoma in vivo: maintaining immune privilege in the brain?

Astrocytomas are among the most common brain tumors that are usually fatal in their malignant form. They appear to progress without significant impedance from the immune system, despite the presence of intratumoral T cell infiltration. To date, this has been thought to be the result of T cell immunosuppression induced by astrocytoma-derived cytokines. Here, we propose that cell contact-mediated events also play a role, since we demonstrate the in vivo expression of Fas ligand (FasL/CD95L) by human astrocytoma and the efficient killing of Fas-bearing cells by astrocytoma lines in vitro and by tumor cells ex vivo. Functional FasL is expressed by human, mouse, and rat astrocytoma and hence may be a general feature of this nonlymphoid tumor. In the brain, astrocytoma cells can potentially deliver a death signal to Fas+ cells which include infiltrating leukocytes and, paradoxically, astrocytoma cells themselves. The expression of FasL by astrocytoma cells may extend the processes that are postulated to occur in normal brain to maintain immune privilege, since we also show FasL expression by neurons. Overall, our findings suggest that FasL-induced apoptosis by astrocytoma cells may play a significant role in both immunosuppression and the regulation of tumor growth within the central nervous system.

Animals↗
PubMed1997

TCR analysis reveals significant repertoire selection during in vitro lymphocyte culture.

The in vitro stimulation of T lymphocytes is frequently used as a technique to expand specific cells present at low precursor frequency in vivo. However, cells analysed after such procedures may no longer reflect those originally present in vivo because of the variable efficiency of outgrowth of different T cell subpopulations. To systematically assess this and to complement functional assays, we have analysed the TCR repertoire using a new high resolution RT-PCR method to determine TCR beta chain CDR3 transcript length. In the ex vivo analysis of tumor infiltrating lymphocytes (TIL) of renal cell carcinoma and glioblastoma patients, we observed and quantified oligoclonally expanded populations of T cells that were very susceptible to repertoire modification upon subsequent in vitro culture with autologous tumor cells. This in vitro repertoire skewing occurred preferentially with TIL rather than peripheral blood lymphocytes and we noted that tumor cells rather than normal cells of the same tissue type were the most potent inducers of the effect. It was striking that this selection was sometimes negative: certain prominent T cell populations that were highly represented in vivo disappeared after in vitro re-stimulation. This suggests that the presentation of tumor associated antigens during culture may eliminate rather than enrich for in vivo primed T cells. It is clear that in vitro functional tests cannot adequately describe all T cells with tumor specificity. Approaches that allow the assessment of potentially antigen-reactive T cell populations ex vivo are thus an important advance in the global appraisal of anti-tumor T cell immune responses.

Amino Acid Sequence↗
PubMed1996

Production of congenic mouse strains carrying NOD-derived diabetogenic genetic intervals: an approach for the genetic dissection of complex traits.

Insulin-dependent (Type 1) diabetes (IDD) in the NOD mouse is inherited as a complex polygenic trait making the identification of susceptibility genes difficult. Currently none of the non-MHC IDD susceptibility genes in NOD have been identified. In this paper we describe the congenic mouse approach that we are using for the dissection of complex traits, such as IDD. We produced a series of six congenic strains carrying NOD-derived diabetogenic genomic intervals, which were previously identified by linkage analysis, on a resistant background. These congenic strains were produced for the purpose of characterizing the function of each of these genes, alone and in combinations, in IDD pathogenesis and to allow fine mapping of the NOD IDD susceptibility genes. Histological examination of pancreata from 6 to 8-month-old congenic mice reveals that intervals on Chromosomes (Chrs) 1 and 17, but not 3, 6, and 11, contain NOD-derived genes that can increase the trafficking of mononuclear cells into the pancreas. Insulitis was observed only very rarely, even in older congenic mice, indicating that multiple genes are required for this phenotype. These results demonstrate the utility of this congenic approach for the study of complex genetic traits.

Animals↗
PubMed1996

Identification of micrococcaceae isolated from goat's milk and cheese in the Poitou-Charentes region.

One hundred and ninety strains of coagulase-negative staphylococci were isolated from goat's milk, whey and cheese at various stages of manufacture. Sixteen different coagulase negative Staphylococci (CNS) species were recovered, 3 of which were predominant: Staphylococcus simulans, Staphylococcus epidermidis and Staphylococcus xylosus. The prevalent species were recovered at least at two different stages of cheese manufacturing, suggesting a better adaptation to the environment. After 15 days of ripening, the cheeses showed lower counts of Micrococcaceae.

Animals↗
PubMed1996

Relationships between pathological diagnosis and clinical parameters in acromegaly.

From our series of 185 somatotropic adenomas with acromegaly, we found that sparsely granulated adenomas were more frequent (56%) than densely granulated ones. Immunocytochemistry detected growth hormone (GH) plurihormonal adenomas in 68% of patients. GH-alpha-subunit (alpha SU) and GH-alpha SU-prolactin (PRL) were more frequent (38%) than GH monohormonal adenomas (32%). The colocalization of GH and alpha SU in the same cell was obvious in many tumors. In contrast, colocalization of GH and PRL was demonstrated in only 25% of GH-PRL adenomas. The relationships between age, sex, tumor size, GH and PRL plasma levels, granularity, and percentage of GH-, alpha SU-, and PRL-immunoreactive cells were established in 105 acromegalic patients by three statistical methods, mainly by a principal component analysis. Correlations were found between the percentage of alpha SU- and GH-immunoreactive cells, and between densely granulated character and the percentage of GH-immunoreactive cells. Tumor size was not correlated with alpha SU, but was positively correlated with PRL plasma levels. Patients' age and percentage of GH-immunoreactive cells were inversely related to tumor size. Plurisecretion and sparsely granulated aspect are not related to age and tumor size.

Acromegaly↗
PubMed1996

Cloning of the cDNA for a human homologue of the Drosophila white gene and mapping to chromosome 21q22.3.

In an effort to contribute to the transcript map of human chromosome 21 and the understanding of the pathophysiology of trisomy 21, we have used exon trapping to identify fragments of chromosome 21 genes. Two trapped exons, from pools of chromosome 21-specific cosmids, showed homology to the Drosophila white (w) gene. We subsequently cloned the corresponding cDNA for a human homologue of the Drosophila w gene (hW) from human retina and fetal brain cDNA libraries. The gene belongs to the ATP-binding cassette transporter gene family and is homologous to Drosophila w (and to w genes from other species) and to a lesser extent to Drosophila brown (bw) and scarlet (st) genes that are all involved in the transport of eye pigment precursor molecules. A DNA polymorphism with 62% heterozygosity due to variation of a poly (T) region in the 3' UTR of the hW has been identified and used for the incorporation of this gene to the genetic map of chromosome 21. The hW is located at 21q22.3 between DNA markers D21S212 and D21S49 in a P1 clone that also contains marker BCEI. The gene is expressed at various levels in many human tissues. The contributions of this gene to the Down syndrome phenotypes, to human eye color, and to the resulting phenotypes of null or missense mutations are presently unknown.

ATP-Binding Cassette Transporters↗
PubMed1996

When is spinal fusion warranted in degenerative lumbar spinal stenosis?

This study, conducted by a group of neurosurgeons who devote a large portion of their professional time to the treatment of degenerative lumbar spine lesions, was prompted by the dramatic increase in the number of lumbar spinal fusion procedures performed over the last few years in a broad spectrum of disorders ranging from chronic incapacitating low back pain to lumbar spinal stenosis. In the authors' experience, lumbar spinal fusion is rarely warranted and often of dubious efficacy. To investigate this contradiction, the authors reviewed the medical literature on lumbar spinal fusion for the treatment of degenerative spinal stenosis. They have defined lumbar instability as objectively as possible, reviewed clinical and roentgenographic features, described spinal fusion techniques with the drawbacks of each, and evaluated outcomes of surgery for degenerative lumbar spinal stenosis with or without fusion. Findings demonstrate that spinal fusion is a technique of unproven benefit that should be used only in carefully selected patients until results of reliable, prospective, comparative clinical trials become available. In the authors' opinion lumbar spinal fusion should be used as the first-line treatment only in young patients with clinical manifestations directly related to lumbar instability as defined in this study, when decompression requires removal of both facet joints and of the disk (which is rarely the case) or when simple decompression is followed by a recurrence of symptoms ascribable to worsening vertebral slippage.

Adult↗
PubMed1994

Prognostic values of serum cytokines in septic shock.

OBJECTIVE: To prospectively evaluate the prognostic values of two serum cytokine levels, TNF alpha and IL6 serially measured at predetermined intervals in septic shock patients unresponsive to correction of hypoxaemia and plasma volume expansion and treated according to a strict protocol designed to meet specific therapeutic goals (goal-directed therapy). The evolution of serum lactate levels and oxygen-derived parameters was also investigated. DESIGN: A prospective case series study. Patients were followed-up until they were discharged from the hospital, or died. SETTING: ICU of a university hospital. PATIENTS: 30 consecutive patients with septic shock of various origins. INTERVENTIONS: The therapy was aimed at achieving and maintaining for at least 24 h supranormal values CI (> or = 4.0 l.min-1.m-2), oxygen delivery (DO2 > or = 550 ml.min-1.m-2) and oxygen uptake (VO2 > or = 150 ml.min-1.m-2) using a combination of fluid loading, norepinephrine, dobutamine and dopamine. A significant decrease in TNF alpha levels was associated with a favourable outcome while TNF alpha levels remained elevated in the patients who died in shock or of multiple organ failure. No prognostic value was associated with changes in IL 6 concentrations. In a stepwise logistic regression analysis, only TNF alpha levels contributed significantly to prediction of patients' outcome. A significant decrease in serum lactate concentrations was observed both in survivors and in patients who survived the episode of septic shock, but subsequently died of multiple organ failure. A positive DO2/VO2 relationship was observed only in survivors but did not contribute significantly to prediction of patient outcome. CONCLUSIONS: TNF alpha is a major mediator involved in the pathogenesis of septic shock and its decrease was significantly associated with a favourable outcome. IL 6 is certainly involved in the pathophysiology of septic shock but further studies are required to determine whether or not it is directly involved in the mediation of late and lethal complications of septic shock. Serum lactate levels and oxygen-derived variables were of less interest as prognostic factors.

Adult↗
PubMed1994

Effects of norepinephrine on right ventricular function in septic shock patients.

OBJECTIVE: To study the effects of norepinephrine on right ventricular function in patients with hyperdynamic septic shock. DESIGN: Prospective, open study. SETTING: A 15 bed ICU in a university hospital. PATIENTS: 9 patients with hyperdynamic septic shock (SBP < 90 mmHg, Cl > or = 4 l.min-1.m-2, SVRI < or = 850 dynes.s.cm-5m-2 and oliguria). INTERVENTIONS: Plasma volume expansion was used to correct a suspected volume deficit and then, norepinephrine infusion was started and titrated to restore systemic blood pressure to the normal range (mean infusion rate: 1.1 +/- 0.2 mcg.kg-1.min-1). Norepinephrine was the only vasoactive agent used in these patients. MEASUREMENTS AND RESULTS: A modified Swan-Ganz catheter mounted with a fast response thermistor was inserted in each patient, allowing repeated measurements of RVEDVI and RVEF. At time of inclusion to the study, all but one patient had elevated MPAP (23 +/- 4 mmHg) and RVEF < or = 50%, and all patients had RVEDVI > or = 90 ml.m-2. During norepinephrine infusion, MAP increased from 51 +/- 9 to 89 +/- 10 mmHg (p < 0.0001), PVRI increased from 204 +/- 35 to 286 +/- 63 dynes.s.cm-5.m-2 (p < 0.05), and despite this increase in right ventricular afterload, no detrimental effect in RVEF (36 +/- 11 to 36 +/- 10%) or in RVEDVI (116 +/- 30 to 127 +/- 40 ml.m-2) was observed. A Frank-Starling relationship for the right ventricle was constructed by plotting an index of ventricular performance (RVSWI) against an index of ventricular preload (RVEDVI). A significant upward shift to the right of the relationship was observed during norepinephrine infusion. CONCLUSION: It was concluded that norepinephrine exerted a favourable effect on right ventricular function.

Adult↗
PubMed1994

Right ventricular end-systolic pressure-volume relation during propofol infusion.

The effects of propofol on right ventricular function were studied in 11 ICU patients who needed sedation for acute respiratory failure or neurological diseases. Right ventricular function was studied using a thermodilution method at patients' bedside. Right ventricular ejection fraction (RVEF), cardiac output (CO), right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV), right ventricular end-systolic pressure (RVESP) and pulmonary capillary wedge pressure (PCWP) were obtained from a modified Swan-Ganz catheter. Calculation of right ventricular end-systolic pressure-volume relation (ESPVR) allowed to assess changes in right ventricular inotropic state. A baseline ESPVR was obtained before propofol infusion: RVESP = 0.21 RVESV + 2.4, r = 0.83, P < 0.0001. Then, patients were given an induction dose of 1 to 2.5 mg.kg-1 propofol over 1 min followed by a continuous infusion of 3 mg.kg-1.h-1. During propofol infusion heart rate, mean arterial pressure, PCWP, CO, systemic vascular resistance and RVEF significantly decreased. No change in RVEDV and RVESV was observed. ESPVR was significantly altered with a dramatic decrease in the slope of the relation: RVESP = 0.12 RVESV + 6.9 (P < 0.001 from baseline). Dobutamine was used in five patients with clinically significantly cardiac dysfunction and restored the slope of the ESPVR to the baseline value: RVESP = 0.22 RVESV + 6.3 (NS from baseline). In the study patients, propofol altered the inotropic state of the right ventricle.

Anesthesia, Intravenous↗
PubMed1994

Rupture of the thoracic trachea with a Sengstaken-Blakemore tube.

Tracheal rupture from within is uncommon and always iatrogenic. We report a case of a tracheal rupture following the use of a Sengstaken-Blakemore tube to control a gastroesophageal hemorrhage. Emergency surgical repair was required. Although complications associated with balloon tamponade are well-documented, no major tracheal injury has ever been reported.

Aged↗
PubMed1994

Preservation of humidity and heat of respiratory gases in patients with a minute ventilation greater than 10 L/min.

OBJECTIVE: To compare the temperature and humidification output of one heated humidifier system (Bennett Cascade 2 Humidifier) and two heat and moisture exchangers (Pall Ultipor, BB 50, and Humid-Vent Filter) in intensive care unit (ICU) patients submitted to a minute ventilation of > 10 L/min. DESIGN: Prospective, controlled, randomized, unblinded study. SETTING: ICU of a university hospital. PATIENTS: Eleven sedated and paralyzed patients who required controlled mechanical ventilation with a minute ventilation of > 10 L/min for > 3 days. INTERVENTIONS: After a randomized selection process, the patients were ventilated for 24-hr periods with the humidifier and one of the heat and moisture exchangers. Both heat and moisture exchangers were first tested for 45 mins; then, the heat and moisture exchanger that demonstrated the best performance in terms of temperature and water preservation was tested for 24 hrs. MEASUREMENTS AND MAIN RESULTS: During the inspiration phase for each patient, the following measurements were performed: mean and minimum values of temperature, relative and absolute humidity of inspired gases. During the 45-min test period, the Humid-Vent Filter had a better temperature and humidification output than the Pall Ultipor Filter and thus was tested for 24 hrs. The Bennett Cascade 2 Humidifier and the Humid-Vent Filter had a better thermic capacity than the Pall Ultipor Filter (p < .001). No difference was ever observed between the Bennett Cascade 2 Humidifier and the Humid-Vent Filter regarding relative humidity. The Pall Ultipor Filter had a lower temperature and humidification output when compared with the other two systems (p < .007). Concerning absolute humidity of inspired gases, the Pall Ultipor Filter achieved a lower performance than any other tested systems (p < .02). A small but significant decrease in temperature and absolute humidity, but not in relative humidity, was seen after 24 hrs of use with the Humid-Vent Filter. However, with this heat and moisture exchanger, all patients had an absolute humidity of > 28 mg H2O/L and a relative humidity of > 93% after 24 hrs of use. CONCLUSIONS: In patients with a minute ventilation of > 10 L/min (> 10.5 to 16.0 L/min), the Humid-Vent Filter had a temperature and humidification output close to the reference system (the Bennett Cascade 2 Humidifier). The Pall Ultipor Filter had a significantly lower temperature and humidification output in these patients.

Acute Disease↗