Level of circulating concentrations of progesterone during ovulatory follicle development affects timing of pregnancy loss in lactating dairy cows.

The objective of this experiment was to determine the effect of high versus low progesterone (P4) during the pre-dominance or dominance phase (or both) of ovulatory follicle development on follicular dynamics and fertility of lactating dairy cows. Progesterone (P4) was manipulated to reach high (H) or low (L) serum concentrations during the pre-dominance phase (d 0 to 4 of the wave) and dominance phase (d 5 to 7 of the wave) of a second follicular wave ovulatory follicle, creating 4 treatments: H/H, H/L, L/H, and L/L. Luteolysis was induced with PGF2α on d 7 of the wave and ovulation was induced with GnRH 56 h after PGF2α. Cows (n = 558) received artificial insemination (AI) 16 h following GnRH. Pregnancy was determined at 6 intervals during gestation and at calving to quantify pregnancy loss beginning at d 23 post-AI utilizing pregnancy-specific protein B (PSPB) in novel within-cow comparisons. Cows with single ovulations assigned to the L/L treatment had greater pre-ovulatory follicle diameter compared with cows assigned to the L/H or H/L treatments. Cows with single ovulations had greater pre-ovulatory follicle diameter compared with cows with double ovulations. Low P4 in H/L, L/H, and L/L increased double ovulation rate compared with H/H. Cows with double ovulations had greater pregnancies per AI (P/AI) on d 23 post-AI compared with cows with single ovulations but had greater losses if ovulations were unilateral. Cows with low P4 during the entire period of the ovulatory follicle development also had greater P/AI on d 23 post-AI compared with cows with high P4 during both phases. However, full-term P/AI was not different between treatments. This was a result of the greater incidence of pregnancy losses between d 35 and 56 of gestation for cows with unilateral double ovulations compared with bilateral double ovulations and single ovulatory cows. Cows with single ovulation and low circulating P4 during the dominance period of follicle development had increased pregnancy losses between d 35 and 56 of gestation compared with cows with single ovulations and high P4. The PSPB measurements on d 16 and 23 post-AI were highly accurate in the prediction of pregnancy at d 28. The PSPB differed on d 23 and 28 between cows that had versus cows that did not have pregnancy losses between d 28 and 35 of gestation. In summary, circulating concentrations of P4 during ovulatory follicle development affected numbers of follicles ovulated and timing of subsequent pregnancy losses.

Experimental evaluation of birds as disseminators of the cosmopolitan tick Rhipicephalus sanguineus (Acari: Ixodidae).

Rhipicephalus sanguineus is believed to be the most widespread tick species of the world and its dissemination seems to rely on the diffusion of its main host, the dog. Empirical observations indicate that several bird species in urban areas regularly steal dog food. Such circumstances create a chance for R. sanguineus ticks to climb on birds and carry ticks to another site. In this work we evaluated experimentally the likelihood of birds (chicks) to either feed and/or carry R. sanguineus ticks from an infested site to another and to infest a host (rabbit) in the new location. Chicks were not suitable hosts for R. sanguineus ticks. Not a single adult tick engorged on chicks, yield as well as weight of engorged larvae and nymphs were very low and feeding period of these ticks was very long. However, a few larvae and, chiefly, nymphs were delivered to a new location either mechanically or after attachment and engorging total or partially on chicks. A few of these ticks fed successfully on rabbits. Further evidence on the capacity of birds to introduce R. sanguineus into non-infested dog settings should be provided by systematic examination of birds from urban areas, close to tick infested households.

Effect of follicular wave stage on potential fertility predictors and their repeatability coefficient in prepubertal Bos indicus (Nellore) and Bos taurus (Caracu) heifers.

In an attempt to develop accessible methods for the precocious individual selection based on phenotypic attributes related to reproductive superiority, this study evaluated the effects of follicular wave stages (emergence and dominance) and the repeatability coefficients of potential fertility predictors (vulvar morphometry, uterine biometry, echogenicity and echotexture, ovarian biometry, and antral follicle count - AFC) in two breeds of purebred prepubertal heifers. Nellore (n = 30) and Caracu (n = 28) heifers were submitted to a sequence of 11 evaluations conducted every 48 h (D0 - random day of the antral follicular wave until D20) to study potential fertility indicators under natural conditions. The data obtained were compared according to breed and follicular wave stage. Statistical analysis included the fixed effects of breed, evaluation day, and their statistical interaction and was performed using MIXED, GENMOD, GLM, and CORR procedures of the SAS program. Breed was found to influence rima height, ovarian area, and AFC, which were greater in Nellore heifers (P < 0.02). The follicular wave stage also influenced most of the potential predictors, highlighting AFC which was higher in the presence of a dominant follicle in both breeds (P < 0.0001). The repeatability coefficients for vulvar width (0.76 and 0.66), ovarian area (0.70 and 0.62), and AFC (0.76 and 0.74) were considered to be high in Nellore and Caracu heifers, respectively. Only ovarian biometry was able to predict AFC (Pearson correlation coefficient ≥ 0.66; P < 0.0001) in prepubertal heifers. The results indicate that most of the phenotypic reproductive parameters analyzed can be characterized throughout prepuberty using a single measure since they are intrinsic attributes of the individual.

Brain stem structures responsible for the electroencephalographic patterns of desynchronized sheep.

Contrary to the results of transecting one half of the rostral pons, unilateral partial lesions of the rostral pons, involving either "specific" or "aspecific" structures, do not prevent the appearance of the desynchronized electroencephalographic patterns of deep sleep in the ipsilateral hemi sphere in cats. This effect, however, is obtained by lesions of the medial as well as lateral tegmental structures of the midbrain. These findings seem to indicate that (i) there is not a single pontine structure or group of structures of crucial importance for the EEG desynchronization of deep sleep; the whole rostral pons appears to contrib ute to the EEG-desynchronizing influ ence; (ii) this influence runs rostrally through the midbrain tegmentum, without following any known fiber pathway.

Retrospective analysis of variables favouring good surgical outcome in posterior epilepsies.

AIM: to determine variables favouring good surgical outcome in posterior epilepsies. METHODS: Fourteen patients submitted to epilepsy surgery were included in the study. The epileptogenic zone was located in temporo-parieto-occipital areas as assessed by both invasive and non-invasive pre-surgical evaluation. Several variables (age at first seizure; age at surgery; disease duration; type, frequency and clinical semiology of seizures; presence of lesion; scalp ictal and interictal EEG; localization and extension of epileptogenic zone; completeness of surgical resection) were compared (Fisher's exact test) with freedom from seizures to determine whether surgical outcome (Engel's classification) could be related to any of them. RESULTS: Seven patients were seizure free (Ia) and very satisfying results were obtained for 3 patients (2 Ib, 1 Ic). New post-surgical visual deficits occurred only in 3 patients. Surgical outcome was related significantly to two variables: scalp ictal EEG (focal versus non-focal; p: 0.014) and completeness of surgical resection of epileptogenic zone (p: 0.0023). A significant trend towards a better outcome for focal interictal intracranial activity versus a non-focal one (p: 0.07) was found. CONCLUSIONS: The correlation between completeness of epileptogenic zone resection and surgical outcome suggests that a presurgical protocol, allowing a precise definition of the area of resection, could help in obtaining more satisfying results in posterior epilepsies.

Interhemispheric integration of simple visuomotor responses in patients with partial callosal defects.

Because of the organization of visual and motor pathways, simple manual responses to a light stimulus in the right or left visual hemifields are performed faster with uncrossed hand-field combinations than with crossed hand-field combinations. Uncrossed responses can be integrated within a single hemisphere, whereas crossed responses require a time-consuming interhemispheric transfer via the corpus callosum which is reflected in the difference between crossed and uncrossed reaction times. We investigated crossed-uncrossed differences (CUDs) in speed of simple visuomotor responses to lateralized flashes in seven subjects with an anterior section of the corpus callosum sparing the splenium and in one subject with an agenetic absence of the splenium due to a cerebrovascular malformation. There was no evidence of an abnormal prolongation of the CUDs in any of these subjects, in sharp contrast with the very long CUDs exhibited by an epileptic subject with a complete callosal section and two subjects with total callosal agenesis tested in the same experimental situation [1]. The normality of the CUDs in the subjects with partial callosal defects was not due to a postoperatory reorganization of interhemispheric communication, since there was no indication of an increased CUD in a patient tested as early as 5 days after the anterior callosotomy. These results are compatible with the assumption that both anterior and posterior callosal routes may subserve the integration of speeded manual responses to a visual stimulus directed to the hemisphere ipsilateral to the responding hand.

Considerations on the principles of surgical treatment of partial epilepsy.

Some considerations on the principles of surgical treatment of partial epilepsy are prompted by the still relatively high number of unsatisfactory surgical results. The fundamental principle of surgical treatment, based on the view that partial epilepsy is due to the hyperactivity of given neuronal aggregates consequent to a cerebral lesion (the lesional-functional epileptogenic complex), is still regarded as satisfactory. The present concept of the lesional-functional epileptogenic complex and the means to topographically locate and delimit it are illustrated and discussed. Surgical failures are ascribed mainly to the difficulty in reaching a complete and detailed spatial definition, and then a complete removal, of the epileptogenic complex.

Anatomo-clinical correlations in normotensive hydrocephalus. Reports on three cases.

The brains of 3 adult subjects suffering from normotensive hydrocephalus have been examined pathologically. The diagnosis of normotensive hydrocephalus was based on clinical symptoms, pneumoencephalography and isotope cisternography, in 1 case integrated with the results of the constant-infusion manometric test. Part of the neuropathological findings were common to the 3 patients: leptomeningeal non-obstructive fibrosis, ventricular ependymal disruption, subependymal glial reaction, periventricular demyelination and spongiosis. Other neuropathological abnormalities were peculiar to each patient: leptomeningeal signs of previous subarachnoid haemorrhage; arteriosclerosis and multiple brain cystic infarcts; Alzheimer's plaques in the gray matter. The possible pathogenetic significance of the neuropathological findings summarized above in relation to the development of normotensive hydrocephalus is discussed.

Surgical treatment of craniopharyngiomas: an evaluation of the transsphenoidal and pterional approaches.

Fifty-seven patients with craniopharyngiomas underwent a total of 64 operations. Their clinical follow-up ranged from 2.5 to 15.5 years, with a mean follow-up of 6.5 years. A transsphenoidal approach was used in 35 patients (61%), whereas 22 (39%) were operated on using a pterional approach (in 16 patients, the tumor was found in the suprasellar cisterns, and in 6, the tumor was found in the third ventricle and was removed passing through the lamina terminalis). Total removal of the tumor was achieved in 43 patients (75%). In six patients (11%), fragments of the capsule remained attached to the hypothalamus (subtotal removal), and, in eight patients (14%), the tumor was partially removed. No recurrence occurred in those patients in whom removal was total. Regrowth was observed in two patients (33%) in whom removal was subtotal and in two (25%) in whom removal was partial. Three of them underwent subsequent operations, and a total removal with good clinical outcome was achieved. All patients except two had good postoperative recovery. Twenty patients (35%) required hormonal replacement therapy. When transsphenoidal surgery was used, a total removal of the tumors was achieved in 23 (66%) of the patients. Good clinical outcome was seen in all 35 patients. Six patients (17%) required hormonal replacement therapy. When the pterional approach was used for tumors in the suprasellar cisterns, we achieved total removal of tumors in 15 patients (94%). Good clinical outcome was seen in 20 patients (91%). Eleven patients (50%) required hormonal replacement therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Spinal cord stimulation in management of chronic pain. A 9-year experience.

Between 1978 and 1986, 109 patients with chronic pain underwent spinal cord stimulation (SCS) at the authors' institute as part of their pain treatment program. The results of SCS in these patients at the end of the test period and at the latest follow-up examination are analyzed in relation to the etiology of their pain. In 40 patients pain was associated with an obstructive peripheral vasculopathy, in 10 with a previous herpes zoster infection, in 15 with an incomplete traumatic spinal cord lesion, in nine with root and/or nerve damage, in 11 with cancer, and in 19 with previous back surgery. The etiology of the pain in five patients was uncertain. This experience supports the conclusion that the best indications for SCS are vasculopathic pain and post-herpetic neuralgia. No clinical usefulness was found for SCS in cancer pain or in central deafferentation types of pain.

Superior cervical ganglion regenerating axons through peripheral nerve grafts and reversal of behavioral deficits in hemiparkinsonian rats.

The superior cervical ganglion (SCG) has been grafted to the brain of adult rats in an attempt to reverse the parkinsonian syndrome that follows destruction of central dopamine systems. However, the main limitation to this approach is the massive cell death that occurs in the grafted SCG after direct transplantation into the brain. In adult rats, 6-hydroxydopamine (6-OHDA) was stereotactically injected into the right substantia nigra (SN). One month later, dopamine denervation was assessed using the apomorphine-induced rotational test. In rats with a positive test, an autologous peripheral nerve (PN) graft was tunneled from the right cervical region to the ipsilateral parietal cortex. One end of PN graft was sutured to the transected postganglionic branch of the SCG and the other end was inserted into a surgically created cortical cavity. The apomorphine test was repeated at 3 days and again at 1, 3, and 5 months after surgery. The brain, SCG, and PN graft were studied under light and electron microscopy and with the tyrosine hydroxylase immunohistochemical and horseradish peroxidase tracing methods. Three days after grafting, there were no significant differences on the apomorphine test as compared to the preoperative test. Conversely, 1,3, and 5 months after grafting, the number of rotations was reduced by 69% (+/-20.2), 66.6% (+/-17.1), and 72.5% (+/-11.3), respectively. Control rats that received a free PN graft to the brain and underwent section of the postganglionic branch of the SCG did not show significant changes on the apomorphine test after surgery. Histological examination revealed that the PN graft was mostly reinnervated by amyelinic axons of small caliber. Approximately 40% of the SCG neuronal population that normally projects to the postganglionic branch survived axotomy and regenerated the transected axons into the PN graft. Axons arising from the SCG elongated the whole length of the graft, crossed the graft-brain interface and extended into brain regions adjacent to the denervated striatum up to 2037 micrometer from the graft insertion site. This work shows that the ingrowth of catecholamine-regenerating axons from the SCG to dopamine-depleted brain parenchyma significantly reduces behavioral abnormalities in hemiparkinsonian rats. This effect cannot be ascribed either to the brain cavitation or to the PN tissue placement in the brain.

Surgical treatment of clival chordomas: the transsphenoidal approach revisited.

This is a report of 12 cases of clival chordomas that were surgically treated at the Catholic University Medical School, Rome, Italy, over a 7-year period. The study emphasizes the role of the transsphenoidal approach. The study group included seven men and five women whose ages ranged from 26 to 80 years (mean 49.8 years). Diplopia was the most common presenting symptom (eight cases). The tumor involved the upper and middle clivus in five cases, the middle clivus in five, and the lower clivus in two cases. One patient developed spinal metastasis. On histological examination, eight cases proved to be typical chordomas, three cases had a chondroid component, and one case of chordoma had atypical features. Immunohistological staining for vimentin and epithelial membrane antigen was positive in all cases. Follow-up periods ranged from 14 to 86 months (mean 40.2 months). The primary treatment consisted of surgery. Ten patients with chordomas of the upper and middle clivus underwent a total of 13 transsphenoidal procedures. Total tumor removal was achieved in seven cases, subtotal removal in two, and partial removal in one case. In the two cases of lower clival chordomas, total removal was accomplished in one and partial removal in the other. After total removal, no recurrence was noted at 14 to 86 months (mean 37.5 months). In the cases undergoing operation via a transsphenoidal approach, there was zero morbidity and one cerebrospinal fluid fistula that resolved without surgery. The tumor recurred in two patients after subtotal and partial removal, respectively. The authors opted to reoperate in cases of recurrence. Postoperative radiotherapy was administered in only two cases in which further surgery was not indicated because of medical reasons or because such a procedure was contrary to the patient's wishes. When mortality and morbidity rates of this group are compared to those of chordoma patients who were treated with extensive skull-base surgery, the results prompt a reappraisal of the transsphenoidal approach in the treatment of clival chordomas.

Intracranial pressure behaviour and its relation to the outcome of surgical CSF shunting in normotensive hydrocephalus.

Twenty-four patients with suspected normotensive hydrocephalus were surgically treated by cerebrospinal fluid (CSF) ventriculoatrial or peritoneal shunt. The results of surgery were considered in relation to clinical history and different diagnostic examinations: pneumoencephalography, CT scan, isotope cisternography, transfer from CSF to blood of isotope-labelled serum albumin, constant infusion manometric test, intraventricular pressure recording. Intracranial pressure (ICP) was analysed during both resting conditions and spontaneously (REM phase of sleep) or artificially induced (jugular compression) increases. The ventricular enlargement (as shown by CT scan) and the slope of the intracranial elastance (the ratio of the differences between the maximum and minimum values of pulse ICP and the correspondent values of the diastolic ICP under the same dynamic conditions) provided the most reliable data for diagnosis and surgical prognosis.

Effect of magnesium valproate on amygdala-kindled seizures in the rat: comparison with sodium valproate.

The anticonvulsant activity of a salt of valproic acid (VA), magnesium valproate (MgV), was assessed against amygdala-kindled seizures in rats. The anti-epileptic power of MgV was compared with that of sodium valproate (NaV). Kindling was obtained by delivering daily to one of the amygdala a 2 s train of monophasic square-wave pulses (1 ms, 60 c.p.s., 100-130 microA) via chronically implanted electrodes. Magnesium valproate and NaV were tested once kindling was stabilized and the post-kindling threshold for generalized convulsions was determined. The drugs were administered intraperitoneally in doses ranging from 25 to 200 mg/kg. The injection/test interval was 30 min. Each animal received a single dose every 24 h. Magnesium valproate exhibited an anticonvulsant activity qualitatively and quantitatively similar to that of NaV. Statistically significant differences were not found between the two drugs with respect to the reduction of seizure severity and afterdischarge (AD) duration. The calculated ED50's were 94.58 and 97.41 mg/kg for the suppression of generalized seizures, 176.96 and 129.26 mg/kg for the suppression of partial seizures, 275.96 and 224.13 mg/kg for the suppression of the local AD in the MgV and NaV treated groups, respectively.

Callosotomy for generalized seizures associated with hypothalamic hamartoma.

A case is reported of intractable epilepsy associated with a hypothalamic hamartoma in an 18 year old man. The patient underwent a two-third anterior callsotomy and, subsequently, removal of the hamartoma. Callosotomy did not affect the generalized seizure pattern. The authors believe this to be the first documented case of hypothalamic hamartoma in which callosotomy for seizure control was attempted. The poor response to callosotomy suggests the extracallosal diffusion of the generalized seizures from hypothalamic hamartomas.

Effects of L-carnitine, L-acetylcarnitine and gangliosides on the regeneration of the transected sciatic nerve in rats.

Three pharmacological agents, L-carnitine, L-acetylcarnitine and gangliosides, were tested for their ability to enhance the regeneration of the rat sciatic nerve following transection and microsurgical repair. The drugs were administered intraperitoneally at the dose of 50 mg/kg/d for 28 and 56 d postoperatively. At the end of treatment, the motor function recovery of the peroneal component of the sciatic nerve was assessed and the regenerated nerves were analysed morphometrically on histological semi-thin sections. Also, the reinnervated extensor digitorum longus (EDL) muscles were studied histochemically using the adenosine-triphosphatase (ATP-ase) technique 56 d after surgery. Motor function assessment at 56 d after nerve repair revealed that L-acetylcarnitine-treated animals recovered a clinical grade significantly higher (p less than 0.05) than the control animals. Twenty-eight days after nerve repair, the number of myelinated fibres was significantly higher (p less than 0.05) in L-acetylcarnitine and ganglioside-treated animals than in control animals. However, 56 d after nerve repair the number of regenerated fibres in all the drug-treated groups was not significantly different from that of the control group. The EDL muscles of the drug-treated animals did not show significant differences from those of control animals with respect to fibre composition and fibre diameter although the L-acetylcarnitine-treated animals exhibited a significantly lower (p less than 0.05) degree of muscle atrophy than did the control animals. The results of the present work seem to indicate that L-acetylcarnitine and to a lesser extent gangliosides exert some favourable effect on the regeneration of the transected sciatic nerve in rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Indications of stereotactic biopsy.

Stereotactic biopsy is nowadays considered a diagnostic procedure indispensable for anyone dealing with neuro-oncology, though its role is still debated especially in comparison with the one of the direct surgical approach. The Authors examine the indications of stereotactic biopsy in the management of intracranial expanding lesions, reviewing their personal series of 793 cases surgically treated in the last 7 years; of these, 210 underwent stereobiopsy. The possibilities of the procedure, its reliability as well as the possible complications are analysed in detail. Finally, the crucial role played by the pathological examination in the diagnosis of neoplasia is particularly stressed.

L-DOPA treatment of comatose states due to cerebral lesions. Preliminary findings.

The results of a study on the effects of L-Dopa in brain-injured patients showing impairment of consciousness are reported. Fifteen patients were selected for this study. The degree of consciousness impairment, or level of coma, varied in the different patients. In all of them, however, the comatose state persisted unchanged for at least 6 days before the beginning of L-Dopa treatment. A gradual and progressive improvement of the level of consciousness, as well as of the EEG patterns, followed the administration of L-Dopa in patients whose treatment commenced while they were in comas III, II and I (classification of Fishgold and Mathis, 1959, and Rossi, 1962). On the other hand, the results of the treatment were questionable in the sequelae of coma (apallic syndrome, coma vigil, akinetic mutism). A direct relation between L-Dopa and consciousness improvement appears to be supported by: 1) the fact that the level of coma was stabilized for several days prior to L-Dopa treatment (see above); 2) the fact that consciousness improvement occurred abreast of L-Dopa dosage; 3) the observation in some patients that worsening followed the temporary withdrawal of L-Dopa treatment and, vice-versa, improvement followed its resumption. The hypothesis of neurochemical components in the processes responsible for the decrease of vigilance following cerebral injury would appear supported by the findings reported.

Possibilities and limits of brachycurietherapy in brain tumors.

Brachicurietherapy represents a low dose-rate irradiation able to deliver high focal doses within relatively small tumor volumes. Its application to brain tumors utilizing the stereotactic techniques is nowadays considered with growing interest. The Authors analyze, on the basis of their personal experience, the possibilities and the limits offered by this therapeutic procedure in neuro-oncology. The choice of the sources and their modality of application, the definition of the optimal dose/time and dose/volume ratio are the main problems taken into consideration and discussed.

Some differences in steroid receptors between meningeal and neuroepithelial tumors.

In our study we evaluated the presence of steroid hormone receptors in a large series of endocranial tumors and investigated the possible correlations between receptor presence and levels and patient's age and sex. Our data indicate that steroid receptor behavior in the neoplasias considered is quite different from that observed in endocrine-related tumors, such as breast and endometrial cancer. Moreover, in neuroepithelial tumors an interesting difference between male and female subjects has been found regarding the receptor distribution in poor differentiated neoplasias.