Mate choice and reproductive success in the red-legged partridge (Alectoris rufa)

Behavioral patterns, reproductive success, and concentrations of plasma-luteinizing hormone, testosterone, and estrogen were compared in pairs of red-legged partridges which had either selected their own mates or had been randomly paired. Males in self-selected pairs called more frequently than males in non-self-selected pairs. Females in self-selected pairs but not those in non-self-selected pairs guarded their nests. Females in self-selected pairs had a greater egg production and laid more of their eggs in nests than females in non-self-selected pairs. There was a significant difference between the two groups in the concentration of plasma testosterone in males, which was higher in males from self-selected pairs prior to the onset of egg laying. These results are consistent with the hypothesis that mate choice affects both reproductive parameters and nest defense in monogamous birds.

NADPH diaphorase activity is inhibited by EDTA in neurons but not in choroid plexus epithelium

NADPH diaphorase histochemical staining was investigated in rat brain and choroid plexuses. All epithelial cells of the latter as well as some sparse neurons in striatum and cerebral cortex showed strong NADPH reaction product. While staining was homogeneous in neuronal cytoplasm, it was particulate in epithelial cells. Preincubation with EDTA (0.1 mM, 2h) prevented appearance of NADPH diaphorase reaction in neurons but not in choroid plexuses. These data show that in rat brain two forms of NADPH diaphorase are present; they are specifically localized in neurons and choroidal cells, respectively.

Photoperiodic adaptation to breeding at different latitudes in great tits

The photoperiodic responses in testicular growth and plasma levels of LH in nonmigratory great tits from Tromsö, Norway (69 degrees 40'N), Göteborg, Sweden (57 degrees 42'N), and Milano, Italy (45 degrees 26'N) were compared under the same lighting conditions. Male great tits, collected during midwinter, were transferred to Göteborg, and shifted from an 8-hr day in early January to a lighting regime in which day length was increased by 1/2 hr per week for 16 weeks. Control birds (only from Sweden) were kept on a 8L:16D light regime during the entire study. Blood samples were collected weekly, and laparotomies were performed every other week. Initially testicular size (approximately 1.6 mm) and plasma levels of LH (approximately 0.45 ng/ml) were similar among the four groups. Between 4 and 8 weeks after the onset of the experiment testes gradually, but significantly, increased to about 2 mm in length in the control group. This slow growth was also observed in the experimental groups. The control bird testes did not increase in size any further. The onset of the rapid testicular growth phase differed among the three experimental groups. In great tits from Milano it began when day length exceeded 11 hr; in birds from Tromsö, when day length was greater than 12 hr; and in great tits from Göteborg, when day length was between 11 and 12 hr. Once the rapid gonadal growth phase had begun it took about 6 weeks for the testes to reach maximal size (approximately 6.8 mm) in all three populations.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective effect of clonazepam on ischemic brain damage induced by 10-minute bilateral carotid occlusion in Mongolian gerbils

A 10-min bilateral carotid occlusion (BCO) in a control group of Mongolian gerbils, induced a transient generalized epileptic activity both in the hippocampal and in the cortical regions, associated with motor manifestations. After recirculation, spiking activity persisted, reaching its maximum peak within 18-36 h and then slowly decreasing till its total disappearance on the 6th-7th day. On the 7th day, histological studies manifested a selective loss of CA1 hippocampal neurons. The treated gerbils (divided in 2 groups according to the dosage used) were administered clonazepam (CZP), a benzodiazepine receptor agonist, immediately after clamping and again every 24 h for the following three days at dosages of 0.05 and 0.1 mg/kg i.p., respectively. The drug inhibited epileptic activity in a dose-dependent manner, while it prevented CA1 neuronal loss at both doses. These results point to a possible derangement of the GABAergic system which probably in turn triggers an exaggerated excitation.

Loss and renewal of thick myofilaments in glucocorticoid-treated rat soleus after denervation and reinnervation

Denervation of rat soleus muscle and simultaneous administration of high doses of corticosteroids for 7 days caused marked muscle fiber atrophy and selective loss of thick myofilaments from many muscle fibers by light and electron microscopy. Myosin heavy chain/actin ratios were greatly reduced on polyacrylamide gel electrophoresis. Nerve crush instead of cut permitted reinnervation after 2 weeks and demonstrated the reversibility of the muscle changes within a week after reinnervation. There was formation of new thick filaments and their reintegration into myofibrils without further breakdown, although large areas of Z-disc streaming appeared. The mechanism of A-band breakdown remains obscure, but it presumably starts with limited proteolysis and continues with disaggregation of myosin molecules. This is consistent with our observation that the muscle fibers retain a relatively good reactivity to antibodies against myosin heavy chain 1 week after denervation and corticosteroid administration. A syndrome recalling these experiments is seen in severely asthmatic patients receiving corticosteroids and pharmacologically paralyzed for mechanical respiration.

Active muscle length reduction progressively damages soleus in hindlimb-suspended rabbits

This study describes the morphologic changes in rabbit soleus muscle following hindlimb suspension (HS) for 1 to 4 weeks (group A); or following HS with hindfeet passively dorsiflexed, by means of an elastic band, for 1 to 2 weeks (group B). In the latter, elastic band use allowed phasic contractions of foot extensor muscles against resistance and prevented 35% chronic soleus shortening, which occurred in group A animals. In group A, the soleus revealed progressive muscle atrophy and myofibrillar damage. Myofibrils underwent dissolution, muscle regeneration was ineffective, and adipose tissue developed from about 2-week suspension onward. Conversely, passive dorsiflexion of unloaded hindfeet was essential in maintaining mass and structural muscle integrity in the soleus of group B. It is hereby demonstrated that HS-induced soleus damage in the rabbit is progressive, and can be prevented, avoiding long-term shortening of soleus and its phasic unloaded contractions. Soleus sensitivity to unloading conditions, such as HS, tenotomy, and hypogravity, may depend on the particular physiology of this tonic antigravity muscle, engaged mainly in developing long-lasting isometric contractions in a stretched length.

Epileptic activity following cerebral ischemia in Mongolian gerbils is depressed by CPP, a competitive antagonist of the N-methyl-D-aspartate receptor

A 10-min bilateral carotid occlusion (BCO) in Mongolian gerbils induces transient generalized epileptic discharges in the hippocampal and cortical regions, which are followed by long lasting interictal spiking activity. An initial peak of this activity occurs within 18-36 h after BCO, then it decreases slowly and completely disappears by the 6th-7th day. On the 7th day, morphological evidence shows a selective loss of CA1 hippocampal neurons. 4-(3-Phosphonopropyl)-2-piperazine-carboxylic acid (CPP), a competitive antagonist of the N-methyl-D-aspartate (NMDA) receptor was administered (7 or 15 mg/kg i.p.) immediately after clamping, and again every 12 h for 3 consecutive days. It induced a dose-related depression of epileptic activity, while, on the other hand, at both dosages, it always prevented the loss of CA1 neurons. The results are discussed in view of the different mechanisms mediating cell damage and epileptic activity.

Glucocorticoids and immunosuppressants do not change the prevalence of necrosis and regeneration in mdx skeletal muscles

Therapeutic doses of methylprednisolone, azathioprine, cyclosporin A, and cyclophosphamide administered to mdx mice between 15 and 45 days of age failed to significantly influence the time course and prevalence of necrosis and regeneration or serum creatine kinase activity. This finding contrasts with previously reported findings of beneficial effects of glucocorticoids in Duchenne muscular dystrophy (DMD). This may indicate that, mechanisms upon which beneficial effects of glucocorticoids depend in DMD, do not operate (sufficiently) in mdx mice.

[Use of 5 French catheters in percutaneous femoral coronaro-ventriculography (500 consecutive procedures with 5 French catheters)]

To verify the advantages and the systematic use of 5 French catheters in femoral percutaneous coronaroventriculography, 500 consecutive unselected patients with confirmed or suspected coronary artery disease underwent this procedure. In one case only (0.2%) we had recourse to 7 French catheters on account of the inability to enter the left coronary ostium. There were no major local complications. General complications were represented by vagal reactions in 20 cases (4%) and by transient minor motor aphasia in one case (0.2%). The cardiac complications were represented by: -1 (0.2%) atrio-ventricular isorhythmic dissociation; -1 (0.2%) complete right bundle branch block; -3 (0.6%) atrial fibrillation; (all had a rapid and spontaneous regression) -1 (0.2%) ventricular fibrillation treated successfully with D.C. shock; -1 (0.2%) non fatal acute myocardial infarction (at the end of the procedure); -2 (0.4%) attacks of cardiac asthma treated successfully with medical therapy. 5 French catheters have proved to be extremely efficacious, with some technical experience, in percutaneous coronaroventriculography via femoral approach. The possible advantages could consist of a reduction in local complications, a patient's precocious mobilization and a minor traumatism on the arterial wall. The major complications are comparable with those observed using 7-8 French catheters. In the future it might be possible, in selected patients, to use 5 French catheters to perform ambulatory cardiac catheterization with reduction of both costs and hospitalization period.

Bilateral carotid occlusion in normotensive rats: olds facts and new observations

This work describes that prolonged mild cerebral ischemia may lead to either general or regional derangement of brain morphofunctional integrity. Normotensive adult Wistar rats were used. Under anesthesia with volatile agents or thiopental, the common carotid arteries were ligated permanently. In one group of animals local cerebral blood flow (1CBF) was measured two hours after carotid occlusion using the [14C]iodoantipyrine method. The other carotid-occluded animals were used for clinical rating and histological evaluation, which was performed two days to 4 weeks after surgical operation. The [14C]iodoantipyrine method showed widespread reduction in the cerebral circulation of carotid-occluded animals. Several hours after carotid occlusion, 40% of the animals showed dramatic neurological signs and died on the day of operation. In 35% of surviving animals, brain infarctions were observed in one and exceptionally two areas of the sensorimotor cortex, thalamus, hippocampus or cerebellum. The evolutionary sequence of the histopathological changes seems to date the induction of the infarcts to the early period of carotid occlusion. In conclusion, reduction of cerebral blood flow causes, in a high percentage of animals, various degrees of acute brain damage after an apparent symptom-free interval.

Familial inclusion body myositis among Kurdish-Iranian Jews

We report two cases of adult-onset, slowly progressive limb-girdle muscle weakness with a remarkable sparing of quadriceps muscles that developed in patients from different families of Iranian-Kurdish-Jewish origin. Each patient had a similarly affected sibling. The findings by means of muscle biopsies showed abnormalities typical of inclusion body myositis, including abundant lined vacuoles and characteristic cytoplasmic inclusions of 15- to 18-nm filaments. Remarkably, many vacuolated muscle fibers showed immunoreactivity to neural cell adhesion molecule, a fetal muscle antigen. The common origin of these patients from an isolated ethnic group with frequent consanguinity and the familial incidence is indicative of a genetic causation or predisposition, probably with an autosomal recessive inheritance. This familial myopathy is one of several clinical syndromes that share the typical pathological findings of inclusion body myositis. The pathogenic relationship between these different familial forms and the more common sporadic form of inclusion body myositis is not known.

Myofibrillar disruption in the rabbit soleus muscle after one-week hindlimb suspension

Relevant muscle- and species-specific differences may be found in the reaction of muscles to hindlimb suspension. This problem has been studied in 5 rabbits following a one-week hindlimb suspension, and in 5 ground-based controls. The soleus and the tibialis were prepared for light and transmission electron microscopy. In suspension the animals occasionally extended and flexed the hindlimbs, but, when standing still, their hindfeet were plantar-flexed to an angle of 180 degrees. In this position the length of the soleus was determined to be 35% less than in controls, whereas that of the tibialis was 30% more. Histologically, the tibialis fibers usually exhibited a preserved sarcomeric pattern, whereas soleus fibers displayed a regular sequence of areas of shortened sarcomeres, alternating with areas of myofibrillar disruption. These findings demonstrated that hindlimb suspension induces a focal breakdown of the soleus myofibrils, probably dependent on the reduced longitudinal tension of the suspended soleus and its phasic contractions against no load. It is conceivable that similar factors could also be responsible for soleus muscle atrophy induced by hypogravity as well as by other clinical conditions during which a stressful plantar flexion of the feet occurs against no load.

An external carotid artery shunt to prevent cerebral ischaemia during carotid surgery

The contribution of the external carotid artery to cerebral blood flow in the presence of an internal carotid occlusion or severe stenosis is well documented. This study was undertaken in order to try and exploit the external carotid artery as a collateral pathway to avoid cerebral ischaemia during carotid surgery. The main problem is to ascertain when the external carotid artery is relevant to cerebral perfusion, and to assess if the insertion of a shunt from the common to the external carotid artery is a useful way of ensuring adequate cerebral perfusion in patients with cerebral ischaemia during carotid clamping. In order to do this, it was necessary to assay the haemodynamic role of the external carotid artery by means of a technique which monitors cerebral function in a reliable way. We tried to evaluate this possibility by an intra-operative haemodynamic study during carotid surgery in 35 patients operated on under local anaesthesia. The insertion of a shunt between the common and external carotid artery was able to reverse brain ischaemia during clamping in four of eight patients with a neurological deficit during temporary carotid occlusion. In selected cases therefore cerebral protection with an external carotid shunt might be a valuable adjunct in the performance of carotid surgery.

Epileptic activity following 10 minute cerebral ischemia in Mongolian gerbils: an electrophysiological study

The effects of bilateral carotid occlusion (BCO) on electroencephalographic (EEG) activity and hippocampal structural integrity was studied in 25 Mongolian gerbils. During BCO EEG became flat in frontal cortex and hippocampus but bilateral spikes and motor signs were recorded during this period. Following release of clamping EEG gradually recovered within 36 h but interictal activity persisted disappearing on the 6th-7th day. At the end of 7 days a selective necrosis of CA1 hippocampal neurons was observed. The results indicate that 10 min cerebral ischemia induces a transient epileptic activity followed by the CA1 neuronal loss. Mechanisms underlying ischemic damage are complex and probably they involve an altered synaptic transmission.

New experimental technique for detecting the effect of low-frequency electric fields on enzyme structure

A new experimental approach has been developed to determine kinetic and thermodynamic parameters of the inactivation of an enzyme under labile conditions both with and without exposure to electrical currents as sources of perturbation. Studies were undertaken to investigate if low-frequency electric currents can accelerate the thermal inactivation of an enzyme through interactions with dipole moments in enzymatic molecules and through related mechanical stresses. The experiments were conducted with the enzyme acid phosphatase. The enzyme was exposed to a 50-Hz current at different densities (10 to 60 mA/cm2 rms) or to a sinusoidal or square-wave current at an average density of 3 mA/cm2 and frequencies from, respectively, 50 Hz to 20 kHz and 500 pulses per second (pps) to 50,000 pps. Positive-control experiments were performed in the presence of a stabilizer or a deactivator. The results indicate that the technique is sensitive to conformational changes that otherwise may be impossible to detect. However, exposure to electric currents under the experimental conditions described herein showed no effects of the currents.

Transcranial unifocal stimulation in rabbit: subcutaneous and meningeal changes

The possible acute morphological changes induced by electrical transcranial unifocal stimulation (eTCS) in the rabbit extracerebral tissues were studied by light and scanning electron microscopy. In order to do this, a wide range of electric stimuli with respect to those employed in the clinical practice were utilized. Either surface electrodes were attached to the scalp, or needle electrodes were infixed in the subcutaneous tissue. Beneath the cathode a blood extravasation was constantly observed in the subcutaneous tissue of the scalp; the different electrode arrays produced either a large hemorrhagic lesion or a few petechiae. Beneath the anode, the damage was limited to the scalp, or reached the meninges when stimuli longer than 0.2 ms were used. Irrespective of the electrode arrays, the scalp and the dura mater displayed hemorrhagic petechiae over a limited area about 2-3 mm in extent. Moreover, the leptomeningeal membrane was microscopically disrupted over an area less than 1 mm large; therein the squamous, overlapping cells were transformed into fusiform or macrophage-like cells. Unduly intense eTCS produces evident hemorrhagic lesions in the scalp and in the dura mater, whereas it induces microscopic, reactive changes in the leptomeninx.

Prevention of deep venous thrombosis in vascular surgical procedures by LMW-heparin

The risk of Deep Venous Thrombosis (DVT) in the immediate postoperative period varies from 0.8 to 96% of cases depending on major or minor operations and on age of patients. We have employed 8,000 I.U. AXa/daily of LMW-Heparin injected subcutaneously from one day preoperatively and prolonged for 8 days after surgical procedures in 40 patients operated upon by an aorto-femoral bypass in 25 cases, a femoro-popliteal below the knee in 8 and an extra-anatomical bypass in 7. The onset of DVP in the lower limbs was investigated by clinical examination, venous Doppler pressure evaluation, waveform analysis and echotomography and the 125I-Fibrinogen uptake test. There was no intraoperative increased bleeding and the preclotting of the prosthetic grafts was inaffected. A DVT was detected during the second postoperative day, by means of the 125I-Fibrinogen test in the calf of only one patient (1/40-2.5%), submitted to an aorto-bifemoral bypass, in whom the clinical pattern and ultrasound investigations were negative. The single daily subcutaneous administration has never caused side effects in the site of injection and it seems a real improvement in the heparin treatment. These results emphasize the advantage of the use of LMW-Heparins in patients submitted to arterial surgical reconstructions of the lower limbs for the prevention of the DVT.

Arterial repair of the lower limbs: prevention of prosthetic grafts occlusion by LMW-heparin

The postoperative thrombosis of prosthetic grafts may be due to many factors: technical errors, poor run-off, prosthetic material, graft length, trauma by subcutaneous tunnellization or repeated microtrauma across the joint areas, evolution of atherosclerotic lesions, emorheological changes. In 50 patients submitted to surgical arterial repair of the lower limbs, we have employed 8,000 I.U. AXa/daily of LMW-Heparin, injected subcutaneously for 6 months after the operations to prevent immediate and late thrombosis. During the follow-up, one patient died, four stopped any treatment and in two the medication was changed. Hence our results are based on 43 cases: 10 patients operated upon by aorto-femoral bypass, 19 femoro-popliteal and 14 extra-anatomical procedures. During the follow-up all the patients were investigated by ultrasounds (pressure measurement, waveform analysis and duplex scanning echotomography); moreover 13/43 (30%) were studied by angioscintigraphy and 11/43 (25.5%) by a conventional or digital subtraction angiography. Thrombosis of the grafts at one year term occurred in none aorto-femoral, in one femoro-popliteal (5.2%) and in one extra-anatomical bypass (7.1%). This figure compares favourably with the results obtained in our experience in the patients treated by a variety of drugs. In such group the incidence of occlusion is 3.9% in aorto-femoral, 9.3% in femoro-popliteal and 11% in extra-anatomical grafts. Those results emphasize the possibility to improve the patency of the grafts in the arterial repair of the lower limbs by LMW-Heparin overall in femoro-popliteal and extra-anatomical areas.

Effect of progesterone on the sexual behavior of the male Japanese quail

The reduced metabolites of testosterone produced in the central nervous system of birds are known to be involved in the regulation of male sexual behavior. Since progesterone may compete with testosterone for 5 alpha- and 5 beta-reduction, it may also interfere with the sexual behavior of birds. In order to test this hypothesis, progesterone was administered to male quail either transferred from short days to long days or kept in short days and treated with testosterone. Sexual behavior and crowing were scored at intervals for 21 days and the size of the cloacal gland was measured at the same times. On Day 21, the birds were killed and their testes were weighed. The administration of a large dose (1 mg/day) of progesterone depressed the sexual behavior of the birds stimulated either by long days or by the administration of testosterone. It is suggested that progesterone may compete with testosterone for the active sites of 5 alpha- and 5 beta-reductase; alternatively, its effect may be due to an antiandrogenic activity.

Prognostic evaluation of brainstem hematomas: the role of CT scan and brainstem auditory evoked potentials

6 cases of brainstem hematoma were studied utilizing CT scan and brainstem auditory evoked potential (BAEP) recordings. CT scan did not contribute to an early discrimination between primary and secondary hematomas. Size of the hematoma and the presence of blood in the CSF did not represent evident signs in differentiating benign from unfavourable brainstem hematomas or hemorrhages. BAEP recordings showed the presence of electrophysiological anomalies at the level of the lesion, demonstrating that bleeding as well as tumor in the brainstem can provoke a focal damage.