Detection of bovine herpesvirus 1 and 5 in semen from Brazilian bulls.

Bovine herpesvirus 1 (BoHV-1) and 5 (BoHV-5) are important pathogens of the respiratory and genital tract of cattle and may also affect the central nervous system and cause meningoencephalitis. Both virus types are estimated to be widely distributed in Southern Brazil. In the present study, BoHV-1 and/or BoHV-5 DNA were detected in bovine semen samples from two states of Brazil by two species-specific nested polymerase chain reactions (nPCRs). These nPCRs were used to assay 53 samples of fresh semen and 23 samples of frozen semen from breeding bulls. Viral DNA was detected in all 76 semen samples: all were positive for BoHV-5, whereas 34 of these were positive for BoHV-1 as well. Moreover, in five fresh and in 13 frozen semen samples-of a total number of 40 samples suitable for virus isolation-infectious BoHV-1 and/or BoHV-5 virus were detected. In conclusion, that both BoHV-1 and BoHV-5 were detected in bovine semen in Brazil highlighted the importance of examining bull semen in search for both agents to reduce the risk of transmitting these viruses.

[Evaluation of QRS voltage in 12 derivations and Cornell criteria in the diagnosis of left ventricular hypertrophy]. / Estudo da voltagem do QRS em 12 derivações e do critério Cornell na detecção de hipertrofia ventricular esquerda.

PURPOSE: To search for the existence and degree of correlation between total 12 lead ECG amplitude and the sum of RaVL + SV3 > 28 mm (for men) or > 20mm (for women) and left ventricular hypertrophy (LV mass calculated by echocardiography > 215g for both sexes). METHODS: ECG and echocardiograms of 227 consecutive patients were examined and submitted to statistical analysis searching for correlation between total 12 lead ECG amplitude and Cornell criteria and LV mass (ASE formula modified by Devereux). RESULTS: Patients had ischemic heart disease, hypertension, valvular disease, cardiomyopathy or other less common heart diseases, or had no cardiac illness at all. There was statistically significant association of total 12 lead amplitude > 120mm and Cornell criteria with LV mass > 215g (p = 0.02 and p = 0.01 respectively). Total ECG amplitude showed 74.3% sensitivity, 42.6% specificity, and 52.4% accuracy. Cornell criteria showed values of 37.8%, 82.7% and 68.7% respectively. CONCLUSION: Total 12-lead amplitude presented limited diagnostic performance for detecting LV hypertrophy, as well as did ECG Cornell criteria, although the latter was more specific and more accurate.

[Percutaneous balloon aortic valvuloplasty in the newborn]. / Valvoplastia aórtica por balão no recém-nascido.

Two cases of aortic valvar stenosis are presented, each of them submitted to balloon valvoplasty in the newborn period, with instant relief of the obstruction and clinical improvement. Studies about the aortic balloon valvuloplasty are being accomplished, showing results similar to the surgical approach, but with lower risks.

[Left arterial overload. Electro-echocardiographic correlations]. / Sobrecarga atrial esquerda. Correlação eletro-ecocardiográfica.

PURPOSE: To compare the accuracy of left atrial enlargement (LAE) diagnosis made by electrocardiographic criteria with those obtained using M-mode echocardiography. METHODS: We studied 273 patients age 17 to 87 (mean 49) years, 115 men, white 95.5%, black 3.5% mulattos 1%, with or without heart disease of different etiologies. The ECG criteria studied were: a) P terminal force in V1 > or = 0.04 mmx s; b) Pt force in V1 duration > 0.04s; c) Pt force in V1 depth > or = 1 mm; d) P wave notching in D2 with interpeak distance > or = 40ms; f) presence of atrial fibrillation. The gold-standard for LAE was left atrial dimension > 40 mm obtained by echocardiography. RESULTS: The percentage of correct diagnosis were: atrial fibrillation (88%), Morris index (75%), PtfV1 negativity > or = 1 mm (74%), notched P wave in D2 with interpeak distance > or = 0.04 s (70%), PtfV1 with duration > 0.04 s (64%) and P wave duration in D2 > 0.11s (46%). CONCLUSION: Conventional ECG has limited value for detecting LAE. A higher correlation was found between atrial fibrillation and changes in P wave in V1 and the echocardiographic LAE.

Discharge pattern of tonically activated motor units during unloading.

In order to analyse the EMG pattern during unloading of brachial biceps muscle, the interference EMG and single motor unit activity were investigated. The measurements were done on seven healthy subjects with two types of unloading techniques: a) active unloading, when the subjects resisted against an external load (10, 20, 30 and 40 N) which is suddenly released, and b) passive unloading, performed by low inertia torque motors with independently adjustable background extension and suddenly applied flexion torques. Following active unloading the silent period duration, the amplitude of the rebound and its segmentation into consecutive bursts is changing with initial load, whereas the silent period latency remains constant. Following passive unloading the acceleration influences predominantly the amplitude of the rebound, without changing its latency and silent period duration. The initial voluntary activity influences both silent period duration and rebound parameters (latency, amplitude and duration).

Spindle activity and monosynaptic reflex excitability during foreperiod.

Healthy volunteers were instructed to perform an isometric plantar foot flexion as quickly as possible after a foreperiod (FP) of 1000 msec defined by two clicks (warning signal (WS) and response signal (RS). In 6 volunteers the H reflex was evoked in triceps surae muscle and recorded by surface electrodes (stimulus intensity 30% of maximum). The H reflex was elicited at WS and RS as well as during FP at intervals of 100 msec. H reflex amplitudes were taken as a sign of monosynaptic reflex excitability (MSRE). Amplitudes during FP were compared with the average control values at rest. Relaxation of lower limb muscles before and during FP was controlled by EMG. MSRE was increased in the first part of FP with a maximum at 300 msec after WS and decreased in the second part, with a minimum at 800 msec after WS. In a second series of experiments, in 10 volunteers, single fiber activity from primary muscle spindle afferents was recorded with tungsten electrodes from deep peroneal nerve (6 records) and from tibial nerve (3 records). The activity of primary spindle afferents before and during the FP was calculated by instantaneous discharge frequency and histograms of spike distribution. The EMG was taken from sural triceps and anterior tibial muscles with needle electrodes; a mechanogram of tendon deflection was taken by an appropriate strain gauge. In 5 primary afferents without spontaneous activity at rest and during FP, discharge started with a delay of 10-15 msec after the onset of EMG activity during the motor reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Estimation of generator potentials in primary spindle endings evoked by brief tendon taps in man.

The ligamentum patellae in human subjects was tapped by a random triangular waveform, while single primary spindle afferent spikes were recorded from the femoral nerve. Cross-correlation between the primary spindle afferent spikes and the taps revealed a prominent peaked distribution of the discharge probability. The cross-correlograms showed that response time from the onsets of taps to the afferent spike was 7.5 +/- 0.6 msec in 6 units and that the width between the feet of the peaked distribution was 3.3 +/- 0.2 msec in 6 units. The width of the peak implies jitter of the response time of the primary spindle spikes which appear to correspond with the time-to-peak of generator potentials elicited by the taps in primary endings of muscle spindles. Integration of the peaked distribution showed a slow slope at the beginning and near the summit and a steep slope on the way. This curve is assumed to represent the rising phase of the generator potentials in primary spindle endings.

Soleus motoneurone excitability in man: an indirect approach for obtaining quantitative data.

Using combinations of H and T reflexes, spatial summation has been studied in the human soleus motoneurone pool. With certain assumptions, mathematical treatment of the results yielded estimates of the thresholds of motoneurones to monosynaptic activation by Ia nerve fibres. It was found that, on average, about 62 EPSPs were required to discharge a motoneurone and that a single Ia fibre supplied about 139 neurones.