Development and evaluation of an enzyme-linked immunosorbent assay for use in the detection of bovine tuberculosis in cattle.

As a consequence of continued spillover of Mycobacterium bovis into cattle from wildlife reservoirs and increased globalization of cattle trade with associated transmission risks, new approaches such as vaccination and novel testing algorithms are seriously being considered by regulatory agencies for the control of bovine tuberculosis. Serologic tests offer opportunities for identification of M. bovis-infected animals not afforded by current diagnostic techniques. The present study describes assay development and field assessment of a new commercial enzyme-linked immunosorbent assay (ELISA) that detects antibody to M. bovis antigens MPB83 and MPB70 in infected cattle. Pertinent findings include the following: specific antibody responses were detected at ∼90 to 100 days after experimental M. bovis challenge, minimal cross-reactive responses were elicited by infection/sensitization with nontuberculous Mycobacterium spp., and the apparent sensitivity and specificity of the ELISA with naturally infected cattle were 63% and 98%, respectively, with sensitivity improving as disease severity increased. The ELISA also detected infected animals missed by the routine tuberculin skin test, and antibody was detectable in bulk tank milk samples from M. bovis-infected dairy herds. A high-throughput ELISA could be adapted as a movement, border, or slaughter surveillance test, as well as a supplemental test to tuberculin skin testing.

Cardioprotection by omega-3 fatty acids: involvement of PKCs?

It has been known since the 1970s that an increased consumption of n-3 long chain polyunsaturated fatty acids such as eicosapentaenoic acid and docosahexaenoic acid has cardioprotective effects. Epidemiological studies have reported that this effect is due to the prevention of the arrhythmias responsible for sudden cardiac death. Mechanistically, different hypotheses have been put forward to give an explanation. Among them, there are a direct effect of the polyunsaturated fatty acids on ion channels and/or a modification of the regulation of ion channels by protein kinase C's.

Empalamiento tóraco-abdominal: reporte de un caso / Impalement involving abdomen and thorax: report of one case

Impalements, especially those involving more than one anatomical region, are uncommon. We report a 30 years old male that was injured by a steel jimmy bar that entered by the left inguinal region and exited by the posterior part of the left hemithorax, causing multiple intestinal lesions, a lung and diaphragmatic lesion, costal and scapular fractures. He was operated, extracting the jimmy bar and correcting the multiple lesions. He was discharged ten days later.

Los casos de empalamiento son altamente infrecuentes, sobre todo aquellos que comprometen más de una región anatómica. Damos a conocer el caso de un obrero de 30 años que accidentalmente fue transfixiado por un chuzo, con entrada a nivel inguinal izquierdo y salida por hemitórax ipsilateral, lo que ocasionó múltiples lesiones intestinales, lesión diafragmática, lesión pulmonar y fracturas expuestas costales y escapular izquierda. Su evolución fue exitosa debido a un adecuado manejo pre e intrahospitalario.

Comparative analysis of QTLs affecting domestication traits between two domesticated x wild pearl millet ( Pennisetum glaucum L., Poaceae) crosses.

Comparative mapping of Quantitative trait loci (QTLs) involved in domestication of adaptative syndrome traits of pearl millet was realized at the intra-specific level using two F(2) populations derived from domesticated ( Pennisetum glaucum ssp. glaucum) x wild ( Pennisetum glaucum ssp. monodii) crosses. The two domesticated parents analyzed differ in their geographical origins, agronomic characteristics and life cycles. In both populations, two regions of the genome were identified on linkage groups 6 and 7, that controlled most of the key morphological differences. The importance of these two linkage groups reveals their central role both in the developmental control of spikelet structure and in the domestication process of this crop. In contrast, QTLs involved in traits that are components of yield and measure differences in resource allocation (such as the shape of the spike, the number of spikes per plant and plant height) show a low level of correspondence among our two crosses. The results of the comparative mapping between cereals, although preliminary, reveal that genes involved in seed-shattering could correspond in maize, rice and sorghum. The evolutionary significance of our results, and especially the relationships between genome organization and cereal domestication, are discussed. The potential use of these results in pearl millet genetic-resources enhancement are presented.

Hemodynamic effects of MF 10058, a new cardioselective muscarinic M(2) receptor antagonist, in conscious dogs.

The 5-¿4-[4-(diethylamino)butyl]-1-piperidinyl¿acetyl-5H-dibenz[b, f]-azepine (MF 10058) is a new potent and selective muscarinic M(2) receptor antagonist. The hemodynamic effects of MF 10058 were investigated in conscious freely moving dogs. Placebo and three doses of MF 10058 (2, 4 and 8 mg/kg) were orally administered according to a randomised four-way crossover design. Heart rate, cardiac conduction times, systolic and diastolic blood pressure were telemetrically recorded for 12-24 h after dosing. After placebo administration, a consistent reduction over time in heart rate was observed during the night-time period (-15%, P=0.019). MF 10058 administration antagonised the nocturnal bradycardia and shortened QT interval. The effect of the drug reached statistically significance, compared to placebo, with the highest dose of 8 mg/kg (+19% on heart rate, P=0.013; -4% on QT interval, P=0.049). The effect on heart rate lasted for the entire 24-h observation period (+16%, P=0.030). Nocturnal systolic and diastolic blood pressure were not significantly affected by MF 10058. No other signs of peripheral or central cholinergic block were observed at any dose. The results of this study demonstrated that oral administration of MF 10058 produces long-lasting hemodynamic effects in the conscious dog. The drug has a therapeutic potential for the treatment of bradycardic disorders.

Effects of clomipramine hydrochloride on heart rate and rhythm in healthy dogs.

OBJECTIVE: To determine the effects of clomipramine hydrochloride on heart rate and rhythm in dogs. ANIMALS: 17 healthy Beagles. PROCEDURES: In experiment 1, 8 dogs received placebo or clomipramine (20 mg/kg of body weight, q 24 h, PO) for 7 days in a 2-way crossover design. In experiment 2, 9 dogs were evaluated for 48 hours before and 24 hours after oral administration of clomipramine (4 or 12 mg/kg) in a 2-way crossover design. Electrocardiogram and heart rate were monitored continuously by use of telemetry. RESULTS: A significant diurnal rhythm in heart rate was detected; minimum values were recorded at night. Administration of 20 mg of clomipramine/kg induced a significant reduction in heart rate, with peak effect achieved approximately 12 hours after dosing. Administration of 4 or 12 mg of clomipramine/kg did not result in significant changes in heart rate. Sinoatrial and second-degree atrioventricular block and ventricular escape beats were observed during periods of slow heart rate in more dogs that received clomipramine (3 to 4 of 8 dogs), compared with dogs that received placebo (1 to 2 of 8 dogs), but this difference was not significant. CONCLUSIONS AND CLINICAL RELEVANCE: Short-term administration of clomipramine induced benign cardiovascular effects in dogs rather than the potentially dangerous arrhythmias or tachycardia reported following administration of tricyclic antidepressants to humans. Precautions regarding cardiovascular effects may not be needed for the use of clomipramine in healthy dogs.

The preclinical assessment of the risk for QT interval prolongation.

Some drugs have been reported to induce severe ventricular arrhythmias, including torsades de pointes, and have been responsible in some cases for sudden death of patients. Although the mechanisms of these arrhythmias are not well understood, they are often, but not always, associated with QT interval prolongation. Regulatory authorities (CPMP in Europe) have recently pointed out the necessity to assess most carefully the potential, especially of non-cardiovascular drugs, for QT interval prolongation. Different methodological approaches are presented in this paper and experimental protocols are suggested; limitations and advantages of the presently available in vitro and in vivo models are discussed. It appears that both in vitro and in vivo approaches are complementary. In particular it is pointed out that only the in vitro models using isolated cardiac tissues (Purkinje fibres or papillary muscles) enable assessment of the drug properties under low cardiac rhythm conditions. This model allows us to mimic pathological situations of long QT interval (such as acquired or congenital long QT syndrome) in which most of the major clinical problems are encountered. Finally, a strategy for the preclinical assessment of the potential of a molecule for QT interval prolongation is presented.

Norepinephrine kinetics in the rat with tail-suspension-induced central hypervolemia, as a model of cardio-vascular deconditioning.

Tail-suspension (TS) in the rat represents an interesting experimental condition to mimic, on Earth, the microgravity-induced cardiovascular deconditioning although the rat's profile of response is partially different from human's. To investigate underlying pathophysiological mechanisms, we have speculated on a decreased activity of the sympathetic system, (sigma S) triggered by the increase of the central venous pressure (CVP) induced by TS. Thus a decreased activity of the sigma S could account, at least partly, for the deconditioning of the cardiovascular system. The sympathetic activity (sigma A) was evaluated through measurement of the norepinephrine (NE) kinetics in rats that were tail-suspended for either 6, 24 or 48 hours. Neither NE spillover rate nor metabolic clearance rate were changed during TS, as compared to control. Thus, TS for a short period of time in the rat is unlikely to trigger a decrease of the sigma A.

Results of reoperation on the upper esophageal sphincter.

OBJECTIVE: Reoperation on the upper esophageal sphincter is infrequent. We reviewed our experience in patients who underwent reoperation on the upper esophageal sphincter. METHODS: This is a retrospective report of accumulative series from 2 separate institutions. RESULTS: From September 1, 1976, to February 28, 1997, 37 patients underwent reoperation on the upper esophageal sphincter for recurrent or persistent obstructive symptoms. There were 29 men and 8 women. The median age was 69 years (range, 38-87 years). The original indication for the operation was a pharyngoesophageal (Zenker's) diverticulum in 33 patients (89.2%), oculopharyngeal dystrophy in 3 patients (8.1%), and muscular dystrophy in 1 patient (2.7%). One prior upper esophageal sphincter operation had been performed in 26 patients (70.3%), two operations in 9 patients (24. 3%), and three operations in 2 patients (5.4%). All patients were symptomatic; 35 patients (94.6%) had dysphagia; 23 patients (62.2%) had regurgitation; and 12 patients (32.4%) had episodes of aspiration. Thirty of the patients (91.0%) with Zenker's diverticulum were found to have a recurrent or persistent diverticulum at reoperation. A diverticulectomy and cricopharyngeal myotomy were performed in 23 patients (62.2%); cricopharyngeal myotomy alone, in 7 patients (18.9%); diverticulopexy and cricopharyngeal myotomy, in 6 patients (16.2%); and diverticulectomy alone, in 1 patient (2.7%). There were no operative deaths. Complications developed in 10 patients (27.0%). Follow-up was complete in 34 patients (91.9%) and ranged from 2 to 149 months (median, 39 mo). Thirty-two patients (94.1%) were improved. Functional results were classified as excellent in 26 patients (76. 5%), good in 2 patients (5.9%), fair in 4 patients (11.7%), and poor in 2 patients (5.9%). CONCLUSIONS: Reoperation for patients who have persistent or recurrent symptoms after an operation on the upper esophageal sphincter is associated with acceptable morbidity and mortality rates. Resolution of symptoms occurs in most patients.

Further study on the carotid baroreflex system in the cardiovascular deconditioning induced by head-down tilt.

HYPOTHESIS: The responses of the carotid baroreflex and of the peripheral sympathetic system to stimulations induced by either lower body negative pressure (LBNP -40 mmHg) or cold pressor test were investigated in eight volunteers before and after 48 h in the -6 degrees head-down tilt (HDT). METHODS: Geometry (diastolic diameter and pulsatile distention) and dynamics (cross-sectional compliance and tangential tension) of the bulb and the common carotid artery were investigated using ultrasonic devices, echotracking and aplanation tonometry. The activity of the sympathetic system was evaluated through measurements of plasma concentrations of catecholamines (CAs) and 3,4-dihydroxyphenyl glycol (DHPG). RESULTS: During LBNP -40 mmHg, the pulsed tangential tension was decreased and the pressure amplification, induced by the reflexion of the pressure wave, was increased with no difference between before and after HDT. Since cross-sectional compliance and distensibility coefficient remained unchanged and the carotid contour of the waveform unaltered, it is concluded that the carotid reflexogenic area reads the same message during LBNP whether the cardiovascular system was deconditioned or not. Nonetheless, during LBNP after 48 h HDT, the heart rate accelerated faster and CAs and DHPG concentrations increased out of proportion, suggesting that the peripheral sympathetic activity was more reactive after HDT than before. Finally, forearm vascular resistances were measured in response to cold pressor test; they increased in the same proportion after HDT when compared with before. CONCLUSION: Results indicate that the carotid baroreflex and the peripheral sympathetic system were not deficient after 48 h HDT.

Mechanisms of the cardiovascular deconditioning induced by tail suspension in the rat.

The aim of the present work was to obtain insights into the pathophysiology of cardiovascular deconditioning (CVD) induced by tail suspension (TS) in the rat: during TS, when central venous pressure (CVP) has been normalized (E. Martel, P. Champéroux, P. Lacolley, S. Richard, M. Safar, and J. L. Cuche. J. Appl. Physiol. 80: 1390-1396, 1996), and during simulated orthostatism (SO), when transient episodes of hypotension and bradycardia are disclosed, bradycardia with SO represents a response that seems peculiar to the rat compared with humans. According to basic physiology, a reduced activity of the sympathetic system induced by increased CVP was suspected but was not supported by data obtained through spectral analysis of blood pressure (BP) and heart rate (HR) variability or measurements of plasma catecholamine concentration during TS. Nonetheless, indirect evidence was obtained. During SO, plasma catecholamine concentration was lower in TS rats than in controls, suggesting a reduced synthesis of catecholamines, itself secondary to reduced activity of the sympathetic system. Furthermore, after 48 h of TS, the number of binding sites and affinity of alpha-receptors in rat aorta were increased, compatible with a reduced level of neurotransmitter in the synaptic cleft. A second series of experiments was carried out to study hypotension and bradycardia in TS rats during SO. Hypersensitivity of serotonergic mechanisms was suspected. Two 5-HT3 receptor antagonists (ondansetron and MDL-72222) blocked hypotension and restored tachycardia, basic features of orthostatic adaptation of the circulatory system. Response to the 5-HT3 receptor agonist was measured through dose-response curves of BP and HR after injection of 2-methylserotonin. After low doses, hypotension (10 micrograms/kg) and bradycardia (3 and 10 micrograms/kg) were significantly greater in 48-h TS rats than in controls. Thus CVD in the rat induced by TS appears to implicate at least two mechanisms: reduced activity of the sympathetic system and hypersensitivity of serotonergic mechanisms.

Pitfalls and complications of cricopharyngeal myotomy.

Despite a meticulous operative technique, complications still may occur following cricopharyngeal myotomy. In our series of 205 patients, infection was seen in 11 patients (5.3%) with fistula formation for two patients (1.0%). These complications were seen more frequently in patients treated for a pharyngoesophageal diverticulum. Mortality directly related to the surgical procedure was seen in three patients (1.4%), all suffering from muscular dystrophy.

Assessment of genome organization among diploid species (2n = 2x = 14) belonging to primary and tertiary gene pools of pearl millet using fluorescent in situ hybridization with rDNA probes.

Two contrasting forms of Pennisetum belonging to the primary and tertiary gene pools were assessed for genomic organization using in situ hybridization with rDNA probes (18S-5.8S-25S and 5S) on metaphase and interphase cell nuclei. The primary gene pool is represented by diploid (2n = 2x = 14) cultivated pearl millet (Pennisetum glaucum) and its close wild relatives (Pennisetum violaceum and Pennisetum mollissimum). Pennisetum schweinfurthii (2n = 2x = 14) was taken as representative of the tertiary gene pool, owing to its diploid status and its similarity to the accessions of the primary gene pool in chromosome number. Using the 18S-5.8S-25S probe, we observed two sites of distribution in the four species but at different locations. Within the primary gene pool, signals were detected on the telomeric part of the short arm of chromosome pair VI and at the nucleolar organizing region (NOR) of the satellited chromosome pair (VII). Signals were observed at the NOR of the two satellited chromosome pairs (I and IV) of P. schweinfurthii. The 5S probe was detected at the telomeric part of the short arm of metacentric chromosome pair IV of the three species of the primary gene pool, while it occured in an intercalary position on the short arm of chromosome pair II of P. schweinfurthii. These results showed a chromosomal similarity of rDNA sequence locations within the primary gene pool and are in agreement with the high genetic identity between wild and cultivated forms of pearl millet previously revealed by allozyme studies. Implications of genomic organization for genetic resource enhancement are discussed. Key words : Pennisetum, in situ hybridization, rDNA probes, genomic organization.

Central hypervolemia in the conscious rat: a model of cardiovascular deconditioning.

The aim of the present study as to investigate whether increased central hypervolemia induced by tail suspension (TS) in the rat is an appropriate model of cardiovascular deconditioning (CVD). First, the physiological relationship between central venous pressure (CVP) and extracellular fluid volume (ECFV) was studied. TS (20 degrees) increased CVP (5.8 +/- 0.7 vs. 2.8 +/- 0.8 mmHg; P < 0.01). After 24 h of TS, CVP had returned to control range while ECFV was reduced by 19%. CVP kinetics during 24 h of TS was not affected by either reduction (-20%) or augmentation (/35%) of the ECFV. The normalization of CVP is likely to be a consequence of ECFV reduction, which itself is reduced by increased urinary excretion of water and sodium. Second, recovery from TS was studied. Resumption of the horizontal position was shown to be associated with a significant increase of heart rate (HR) and a slight reduction of blood pressure (BP); there was an apparent delay between increased HR and reduced BP. This imbalance between HR and BP is compatible with CVD. A model of simulated orthostatism (SO) was developed to further investigate the responses of HR and BP. Interestingly, SO (90 degrees rotation) in the normal rat was associated with significant tachycardia and a slight increase of BP. This pattern remained stable for at least 3 h. In rats that were tail suspended for 48 h, episodes of hypotension and bradycardia (5 +/- 1 in 3 h) suggested a defect in adaptation to increased hydrostatic pressure. In conclusion, TS appears to be an appropriate model of CVD. Reduction process. Return to horizontal position in TS rats induced a tachycardia with minimal effects on BP; this pattern is close to that observed in humans assuming upright posture. SO in previously TS rats disclosed episodes of hypotension and bradycardia that deserve further investigation.

[Ambulatory anal surgery: a feasibility study]. / Chirurgie anale ambulatoire: étude de faisabilité.

Because of the current economic situation, ambulatory surgery has become a "modus vivendi" for the surgeon. The aim of this study is to examine the feasibility of anal ambulatory surgery and the results obtained over a period of 12 months. 141 consecutive patients underwent anal surgery: 108 on an ambulatory basis (77%) and 33 were admitted to the hospital (23%). The reasons for admitting the patients were the complexity of the operation in 19 (8 sphincteroplasty, 5 complex fistulae, 3 recto-vaginal fistulae...) emergency procedures in 9 and miscellaneous reasons in 5 patients. All 108 patients operated on an ambulatory basis could be discharged at the end of the day but two, one for urinary retention and another because he underwent a more extensive procedure than first planned. Three more had urinary retention; they were catheterized and discharged on the same day. The four patients (3 women and 1 man) developed urinary retention following spinal anesthesia. Three patients (2.7%) had to come back to the emergency room in the first 24 hours for bleeding from the operative site. One of them had to be transfused and reoperated for hemostasis. In conclusion, ambulatory anal surgery is feasible in a large proportion of cases (77%) with a low rate of complications (7.4%) and low rate of unexpected hospital admission (2.7%). In a specialized colorectal unit, 23% of patients required hospitalization for a longer stay.

Early disturbance of baroreflex control of heart rate after tail suspension in conscious rats.

Experiments were performed on conscious chronically instrumented rats maintained on tail suspension to determine the time course of changes in baroreceptor control of heart rate produced by this procedure. Pressor responses were elicited by bolus injections of graded doses of phenylephrine and sodium nitroprusside, permitting evaluation of the totality of the sigmoidal curve relating mean arterial pressure to heart rate. Compared with control rats maintained at 0 degrees, rats maintained at 20 degrees using tail suspension for 24 h showed a significant reduction in reflex gain (-3.9 +/- 0.1 vs. -5.8 +/- 0.3 beats/min; P < 0.001) together with a reduction in the upper (472 +/- 11 vs. 512 +/- 5 beats/min; P < 0.01) and lower (270 +/- 3 vs. 284 +/- 2 beats/min; P < 0.01) plateaus of the sigmoidal curve. In three groups of rats, the sigmoidal curve was studied successively after returning for 1, 24, and 48 h at 0 degrees. The observed change in the gain of the reflex returned toward control values after 48 h, whereas the other parameters characterizing the sigmoidal curve did not change significantly. Transient but significant modifications of heart rate (tachycardic response) after the immediate return to the horizontal position were observed. The study provides evidence that 1) a significant change of the totality of the sigmoidal curve characterizing baroreceptor control of heart rate occurs very early after tail suspension in rats and 2) the gain of the reflex is restored during the 48 h after release of tail suspension, whereas the other parameters characterizing the curve, particularly the plateaus, remain altered.

Twenty four hours head-down tilt decreases arterial baroreflex function in conscious rat.

In human zero gravity induces a cardiovascular deconditioning. The transfer of blood from the periphery to the thoracic compartment, occuring immediately at the beginning of the exposure to microgravity seems to be involved in this phenomenon. We have previously shown that LBNP (-40 mm Hg) produced an exaggerated heart rate response at the end of 24 hours of bed rest without modification of the cardiopulmonary receptors in human. Some other studies have shown that microgravity induces an impairment of the baroreflex sensitivity in human, but its involvement in the cardiovascular deconditioning is not completely understood. The aim of this study was to determine the modification of the arterial baroreflex using a model of simulated weightlessness in conscious rats during the exposure to microgravity.

Pressor responses to endothelin-1 in normotensive and spontaneously hypertensive rats.

In freely moving rats, endothelin-1 (0.0135-4.5 nmol/kg) administered as an intravenous bolus injection, produced an immediate, short-lasting, dose-related fall in blood pressure followed by a long-lasting, dose-related increase in blood pressure. There was a higher sensitivity in the pressor responses to endothelin-1, in spontaneously hypertensive (SH) rats (ED(50) = 0.11 +/- 0.02 and 0.28 +/- 0.02 nmol/kg, in SH and normotensive rats, respectively), but no change in the maximal pressor effect of endothelin-1 in SH rats. In rat isolated aorta, endothelin-1 induced a greater vasocontractile effect in SH rats than in normotensive rats. In both rat strains, removal of the endothelium did not change the concentration-effect curves obtained in endothelium-intact preparations. These data add further support to the hypothesis that endothelin-1 could play a role in genetic hypertension, at least in the maintenance of high blood pressure.

Test of the prevention of blindness health education programme for Ethiopian primary schools.

Trachoma is a major cause of blindness in Ethiopia and is widespread throughout the country. No health education for blindness prevention is conducted in schools even though 62% of the eligible children attend primary school. Because of the low cost and potential benefit of such a strategy, we developed a programme of health education for eye infections targeted to primary schools and tested it in the rural town of Metahara. Students were given examinations before and after the programme. Their knowledge improved from a mean score of 4.3/9 to 6.2/9 (p less than 0.005). The prevalence of moderate and severe Trachoma decreased from 12.1% to 3.3% (p less than 0.001) in one year, and the prevalence of conjunctivitis from 7.5% to 0.4% (p less than 0.001). Health education for the prevention of blindness in primary schools should be a priority in Ethiopia and yearly eye examinations of school children by local health staff should be reinstated.