Effects of anti-parkinsonian drugs on the motor activity and EEG of cats with subthalamic lesions

Bilateral lesions of the subthalamic region of the diencephalon interrupt ascending catecholamine pathways and render animals hypophagic, hyporesponsive, and hypokinetic. Spontaneous motor activity levels and cortical EEG were examined in cats with chronically-implanted electrodes and unilateral and bilateral subthalamic lesions before and after various anti-parkinsonian drugs. The activity measurements consisted of recording the number of 23-cm squares traversed in 5 min. Unilateral subthalamic lesions produced a moderate decrease in activity. Bilateral lesions resulted in a severe reduction in movement and led to predominately slow-wave and spindling EEG activity from sensorimotor and parietal-occiptal areas with short, intermittent periods of desynchronization. A decarboxylase inhibitor and l-dopa, d-amphetamine, and amantadine-HCl all increased behavioral alertness and spontaneous motor activity in cats with bilateral subthalamic lesions and converted the slow-wave EEG to one of generalized desynchronization. In cats with unilateral subthalamic lesions, l-dopa and amphetamine caused marked ipsilateral circling, and amantadine, at doses which increased spontaneous motor activity of cats with bilateral lesions, produced no turning tendency in those with unilateral lesions. Thus ascending catecholamine pathways passing through the subthalamus appear to be important for normal motor activity, behavioral attention and responsiveness, and electrocortical desynchronization. It is now important to determine the interactions between these ascending catecholamine systems and descending corticifugal influences on the reticular formation.     

Transient hypogammaglobulinemia in the adult. Functional assessment of T and B lymphocytes

The woman described suffered from a pruritic erythematous rash, edema, malaise and fever which appeared during Tegretol therapy. The patient was shown to have a severe hypogammaglobulinemia with absence of circulating B lymphocytes, but normal cell-mediated immunity. There was an absence of in vitro immunoglobulin production by the patient's cells, but this was not due to excessive T-suppressor activity or lack of T-cell help. When drug administration was stopped the edema and rash began to recede promptly, and a few months later her serum immunoglobulin levels, antibody titers and in vitro immunoglobulin production became normal. This transient, probably drug-dependent case of hypogammaglobulinemia, added to three previously reported cases, stresses the need of considering non-conventional immunosuppressive drugs as a potential-etiological agent in acquired hypogammaglobulinemia.     

Restricted Genetic Heterogeneity in Families of Patients with Acute Lymphocytic Leukemia

HLA antigens of the A and B loci were determined on the lymphocytes of 30 patients with acute lymphocytic leukemia (A.L.L.), as well as all of their mothers and 26 of the fathers. Seven of the 26 parents shared a common haplotype. This incidence of 269 per 1,000 contrasts with an expected incidence of 90.7 per 1,000, calculated from haplotype frequencies in a North American population (x²= 7.61, P < 0.01) and a frequency of one in 27 in parents of patients with renal failure in the local population (x²= 3.91, P < 0.05). There was no statistical difference between the latter group and the North American controls (x²= 0.39, P > 0.10). This suggests that the genetic background of a large proportion of patients with A.L.L. has restricted heterogeneity, presumably leading to the increased expression of leukemia associated recessive genes.     

Incidence of meningeal involvement by rhabdomyosarcoma of the head and neck in children: a report of the Intergroup Rhabdomyosarcoma Study (IRS)

141 patients with embryonal rhabdomyosarcoma (RMS) of the head and neck are reviewed. 57/141 had lesions of para-meningeal sites. 20/57 (35%) developed evidence of direct meningeal extension. 18/20 (90%) died of this complication. Radiation portals and doses were limited in 42% and 32%, respectively. All patients had chemotherapy for 6 weeks prior to radiation. The significance of the adequacy of radiation factors and the timing of chemotherapy are reviewed. Recommendations for managing these patients include earlier use of radiation and increased coverage of adjacent meninges by radiation including total craniospinal axis radiation when brain meningeal involvement exists.     

A combined therapeutic protocol for aseptic nonunion of the humeral shaft: a report of 25 cases

Twenty-five patients with aseptic nonunion of the humeral shaft, treated by a combined therapeutic procedure, are reported. The initial treatment of these 21 closed and four open fractures had been nonoperative in 21 patients and surgical in four. Seven further open procedures had been performed in four of these patients, also undergoing failure. The time period between the fracture and our treatment averaged 13 months (range, 6-46 months). A uniform therapeutic protocol, consisting of decortication, internal fixation with a broad, straight DCP ASIF plate and autologous cancellous bone grafting, was performed in all cases, supplemented with the use of surgical cement in one. Radiologic healing was achieved primarily in 24 patients in periods averaging 6 months and after renewal of the protocol in one patient. Followup averaged 35 months (range, 8-69 months): results were good in 21 patients.     

Outpatient lumbar myelography. Initial results in 79 examinations using a low-dose metrizamide technique

Seventy-nine patients underwent lumbar myelography on an outpatient basis, with a low (3.75 g) dose of metrizamide as the radiocontrast agent and a 25-gauge spinal needle used for lumbar puncture. No patient experienced significant neurotoxicity following the examination; 70.8% (56 of 79) experienced minimal (23%) or no (48%) side effects. Three patients (3.8%) were admitted to the hospital for management of common side effects (headache, nausea/vomiting, back pain). We obtained postmyelographic computed tomographic scans on 96% (76 of 79) of the patients. Our initial results suggest that outpatient lumbar myelography is safe and can be performed with a very acceptable incidence of side effects.     

Neovascularization produced by angiotensin II

Following vascular occlusion, development of collateral circulation occurs in at least two time-related phases: (1) the fast enhancement of the function of preexisting channels and (2) the slow formation of new vessels. Inasmuch as the renin-angiotensin system can act as a protective mechanism against local ischemia by activating preexisting collateral vessels, it is of interest to establish whether angiotensin II also produces stimulation of new vessel formation. Angiotensin II or cholecystokinin, an unrelated peptide, was incorporated in a slow-release formulation polyacrylamide gel and implanted in a pocket made in the rabbit cornea. Periodic examinations revealed that angiotensin II significantly stimulates new vessel formation; maximum values were attained in approximately 2 to 3 weeks. In contrast, cholecystokinin or polyacrylamide gel alone failed to stimulate any significant new vessel formation. Positive neovascularization was present in 85% of the total number of corneas implanted with angiotensin II, whereas 14% and 8% positive results were seen in the corneas implanted with either cholecystokinin or polyacrylamide gel alone, respectively. It is concluded that angiotensin II not only facilitates the activation of preexisting collateral vascular pathways but also has angiogenic properties and therefore could play an active role not only in the fast but also in the slow phase of the development of collateral circulation.     

Hypofrontality in schizophrenia: Influence of normalization methods

1. 1. Studies with Single Photon Emission Computed Tomography (SPECT) in schizophrenia research have utilized different approaches to normalization of data, such as cerebellar ratio and whole brain ratio methods, leading to conflicting findings.

2. 2. The authors compared these two methods to test the hypofrontality hypothesis of schizophrenia.

3. 3. Eighteen chronic and medicated DSM-IV schizophrenic patients and 10 healthy controls underwent two SPECT examinations using ^99mTc-HMPAO as a tracer at baseline and during frontal activation while applying the Wisconsin Card Sorting Test.

4. 4. The hypofrontality hypothesis was supported with both indexes of relative perfusion, although the whole brain ratio method appeared to be more reliable and specific than the cerebellar ratio method.

5. 5. Further studies are required to confirm these preliminary results on the specificity and sensitivity of both methods.