Cyclic adenosine monophosphate (cAMP)-specific phosphodiesterase is functional in bovine mammary gland.

Previous studies have shown that using nonspecific phosphodiesterase (PDE) inhibitors such as caffeine improved milk production, supporting the premise that modulation of intracellular concentration of cyclic nucleotides (cyclic AMP, cyclic guanosine 3'-5'-monophosphate) is involved. Intracellular cyclic nucleotides are degraded by the PDE enzyme family. The contribution of type IV PDE (PDE4) in the secretion of casein has been reported in rat mammary gland. The objective of this study was to demonstrate the functional presence of the PDE4 family in the bovine mammary gland. To understand the enzymatic expression pattern in the mammary gland, tissue samples were taken randomly from udders obtained from a local slaughterhouse. Reverse transcription PCR revealed that the PDE4D transcript was amplified, and the expected size fragment was obtained in a 1% agarose gel. Sequence analysis of the amplicon resulted in 99% homology to PDE4D. Moreover, Western blotting using a specific PDE4D antibody has confirmed that the protein of the isoenzyme PDE4D1 is present. A clear immunoreactive signal was also observed within the acini where epithelial cells are located. Assaying cyclic AMP PDE activity reported a total activity of 38.71 +/- 3.22 fmol/min per microg of total protein. Rolipram, a specific PDE4 inhibitor, showed a sensitive activity of 8.48 +/- 1.28 fmol/min per microg of total protein, indicating that PDE4 is responsible for one-fifth of the total enzymatic activity of PDE in the mammary gland. To further validate the presence of PDE4D in the bovine mammary epithelial cells, protein extracts from bovine mammary epithelial cells were separated on SDS-PAGE gels, and PDE4D protein was detected. The PDE assays reported a total activity of 30.16 +/- 4.82 fmol/min per microg of total protein. Rolipram showed a sensible activity of 11.91 +/- 5.93 fmol/min per microg of total protein. In conclusion, these results not only demonstrate the presence of PDE4D transcript and protein, but also show an active enzyme, suggesting a functional role of PDE4D in bovine mammary gland.

Role of the striatum, cerebellum and frontal lobes in the automatization of a repeated visuomotor sequence of movements.

Recently, Doyon et al. [20] demonstrated that lesions to both the striatum and to the cerebellum in humans produce a similar deficit in the learning of a repeated visuomotor sequence, which occurs late in the acquisition process. We now report the results of two experiments that were designed to examine whether this impairment was due to a lack of automatization of the repeating sequence of finger movements by using a dual-task paradigm and by testing for long-term retention of this skill. In Experiment 1, the performance of groups of patients with Parkinson's disease, or with damage to the cerebellum or to the frontal lobes, was compared to that of matched control subjects on the Repeated Sequence Test (primary task) and the Brooks' Matrices Test (secondary task). These two tests were administered concomitantly in both early and late learning phases of the visuomotor sequence. Overall, the groups did not differ in their ability to execute the primary task. By contrast, in accordance with the predictions, patients in Stages 2-3 of Parkinson's disease or with a cerebellar lesion failed to reveal the expected increase in performance on the secondary task seen with learning, suggesting that the latter groups of patients did not have access to the same level of residual cognitive resources to complete the matrices compared to controls. In Experiment 2, the same groups of patients and control subjects were retested again 10-18 months later. They were given four blocks of 100 trials each of the repeating sequence task, followed by a questionnaire and a self-generation task that measured their declarative knowledge of that sequence. The results revealed a long-term retention impairment only in patients who changed from Stage I to Stage II of the disease (suggesting further striatal degeneration) during the one-year interval, or who had a cerebellar lesion. By contrast, performance of the three clinical groups did not differ from controls on declarative memory tests. These findings suggest that both the striatum and the cerebellum participate to the automatization process during the late (slow) learning stage of a sequence of finger movements and that these structures also play a role in the neuronal mechanism subserving long-term retention of such a motor sequence behavior.

Role of the striatum, cerebellum, and frontal lobes in the learning of a visuomotor sequence.

This study was designed to examine the role of the striatum, cerebellum, and frontal lobes in the implicit learning of a visuomotor sequence. The performance of patients with idiopathic Parkinson's disease (PD), with damage to the cerebellum, or with a circumscribed lesion to the frontal lobes was thus compared to that of separate groups of matched normal control subjects on an adapted version of the Repeated Sequence Test. This paradigm consists of a visual reaction-time task with a fixed embedded sequence of finger movements to be performed based on presentation of visual stimuli. Subjects received four blocks of trials (i.e., 40 presentations of a 10-item sequence) per day over 6 training days. Following the last experimental session, subjects were also given two tests measuring their declarative knowledge of the sequence. Only PD patients with a bilateral striatal-dysfunction or patients with lesions to the cerebellum failed to improve their performance in the last three training sessions, hence suggesting an impairment late in the acquisition process. Further analyses revealed that such impairment was mainly implicit in nature, and that it could not be ascribed to a general decline in cognitive functioning, to mood disturbances, or to the severity of the motor symptoms. By contrast, the level of declarative knowledge of the sequence did not differ between the three clinical groups and their respective groups of normal subjects. These findings suggest that, unlike declarative memory, the incremental acquisition of a new visuomotor skill depends upon the integrity of both the striatum and the cerebellum, but not of the frontal lobes.

[X-ray computed tomographic aspects of malignant meningioma and meningeal hemangiopericytoma]. / Aspect tomodensitométrique des méningiomes malins et des hémangiopéricytomes méningés.

OBJECTIVE: To correlate the computed tomography (CT) features with the histologic findings of meningiomas. PATIENTS AND METHODS: The authors reviewed 184 intracranial meningiomas (161 primary and 23 recurrent lesions in 172 patients) and classified the lesions on the basis of six histologic characteristics as benign (82), atypical (64), anaplastic (26) or sarcomatous (12). Among the last two groups, the characteristics of 12 tumours were histologically compatible with hemangiopericytoma. The authors also reviewed the available CT scans for 86 meningiomas: 51 benign lesions, 23 anaplastic or sarcomatous (13 primary and 10 recurrent), and 12 hemangiopericytomas (8 primary and 4 recurrent). RESULTS: Of the 12 radiologic characteristics studied, 8 were associated significantly more often with malignant than with benign meningiomas: presence of necrosis (in 54% of primary malignant meningiomas and 8% of benign cases), cysts (15% and 2%), poorly defined margins (38% and 6%), fringes (23% and 4%), "mushrooming" (8% and 0%) and substantial edema (31% and 8%); large size (62% and 25%); and absence of calcifications (100% and 58%). Despite the fact that the risk of malignancy of meningioma was higher for men, patients with benign and malignant meningiomas did not differ by age or sex. In contrast, more of the patients with hemangiopericytoma were men (5 [56%] of 9 patients), and these patients were younger (average age 45 years, compared with 57 years for those with all other types of meningioma). From a radiologic point of view, the presence of necrosis (in 38% of hemangiopericytomas and 8% of benign meningiomas) and large size (in 75% and 25%) distinguished hemangiopericytoma from benign meningioma. CONCLUSION: None of these CT findings is an absolute sign of malignancy, but the association of two or more of them should suggest the aggressive nature of a meningioma.

Corpus callosum agenesis and psychosis in Andermann syndrome.

Recent illustrations by cerebral magnetic resonance imaging of anomalies of the corpus callosum in schizophrenics have kindled renewed interest in this association. We studied 62 patients affected by the Andermann syndrome, a polymalformative familial syndrome combining frequent congenital corpus callosum agenesis, mental retardation, psychotic episodes, peripheral neuropathy, and some dysmorphic features. Twenty of 62 patients presenting with psychosis were compared with 20 nonpsychotic patients matched according to sex and age. The psychotic patients presented an atypical psychosis as defined by the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, beginning in postadolescence. No significant relationship was observed between corpus callosum agenesis and psychosis. However, a significant association between posterior fossa atrophy and psychosis was established in our study. Although there are limitations in using cross-sectional data for this purpose, the findings suggest an association between cerebellar anomalies and schizophrenialike syndrome and rule out an implication of developmental callosal defects in such psychiatric disorders.

[Motor and sensory neuropathies with or without agenesis of the corpus callosum: a radiological study of 64 cases]. / Neuropathie sensitivo-motrice héréditaire avec ou sans agénésie du corps calleux: étude radiologique et clinique de 64 cas.

In 1971, Andermann and Andermann described an autosomal recessive syndrome found within the Charlevoix and the Saguenay populations (Quebec, Canada) characterized by agenesis of the corpus callosum (ACC) associated with motor and sensory neuropathy, mental retardation and dysmorphic features. A study of CT in 64 patients demonstrated a total ACC in 37 cases (57.8%), partial ACC in 6 cases (9.4%) and the presence of the corpus callosum in 21 cases (32.8%). The latter was confirmed by MRI in 3 cases. CT of patients without ACC revealed a high frequency of developmental or degenerative midline anomalies, particularly interhemispheric fissure enlargement and posterior fossa atrophy. The clinical presentation and the natural course of the neuropathy, the intellectual impairment and the behavioural manifestations are identical amongst individuals with or without ACC. Individuals with or without ACC are found within the same family and often within the same sibship. These observations support the hypothesis of a single genetic syndrome in which the constant manifestation is the motor and sensory neuropathy.

Influence of gonadal steroids on human and monkey cerebrospinal fluid homovanillic acid concentrations.

The influence of gonadal steroids on central dopaminergic function was assessed by measuring concentrations of the dopamine metabolite homovanillic acid (HVA) in cerebrospinal fluid (CSF) in humans and monkeys. CSF HVA and 5-hydroxyindoleacetic acid (5-HIAA) concentrations were measured by high performance liquid chromatography with electrochemical detection. Thirteen intact adult female monkeys (Macaca fascicularis) and six ovariectomized monkeys had a lumbar puncture to collect CSF. Ovariectomized monkeys had higher HVA concentrations in their CSF while 5-HIAA levels remained unchanged. In a second experiment, 40 human subjects were divided into six groups as follows: I, women with menses; II, menopaused or ovariectomized women taking estrogens; III, hysterectomized women of unknown hormonal status; IV, menopaused or ovariectomized women; V, women taking dopaminergic drugs or showing signs of parkinsonism; VI, men. CSF was collected by lumbar puncture. 5-HIAA levels were constant. Hysterectomized (III) as well as menopaused or ovariectomized (IV) women had significantly (p less than 0.05) higher CSF HVA concentrations compared to men. While women in group IV were older, those in group III were of the same age as the men. These results provide further evidence for the role of endogenous ovarian factors as modulators of central dopaminergic activity.

Successful removal of an entirely calcified aneurysm of the vein of Galen.

The authors describe the successful removal of a completely thrombosed and entirely calcified aneurysm of the great vein of Galen in a 45-year-old woman. Computerized axial tomography showed that the center and the periphery of the aneurysm were calcified. The infratentorial supracerebellar approach permitted the removal of the lesion with minimal distortion of the normal anatomy.

Lateral ventricle plexus papilloma and communicating hydrocephalus.

A choroid plexus papilloma was found in the right lateral ventricle of a five-month-old boy. Though it was associated with an important communicating hydrocephalus, it was seen at operation to be freely mobile and did not directly obstruct the flow of the cerebrospinal fluid. Computerized axial tomography was the most helpful para-clinical investigation for diagnostic purposes, and for follow-up study. Tumor removal alone was sufficient to cure the hydrocephalus, and no shunt was necessary. We feel that this case demonstrates that hyperproduction of CSF is sufficient alone to cause communicating hydrocephalus in patients with choroid plexus papilloma of the lateral ventricle.