Acetylcholinesterase activity and acetylcholine effects in the cerebello-rubro-thalamic pathway of the cat

Unilateral transections of the brachium conjunctivum (BC) of cats resulted, after 2–3 weeks, in marked loss of acetylcholinesterase (AChE) activity from the contralateral red nucleus (RN) and ventral tier nuclei of the thalamus (VA-VL). Significant changes in activity were not observed in other locations. Sensitivity of RN neurons to iontophoretically applied acetylcholine (ACh) was studied under conditions which should maximize ACh sensitivity, including AChE inhibition, but ACh was found to have only a weak depressant effect on excitability or no effect at all. Intravenous physostigmine usually increased spontaneous activity of RN neurons, and sometimes increased potentials evoked by electrical stimulation of cerebellar nuclei, to a small extent. Anticholinergic drugs were found not to influence such evoked responses, except to reverse the effects of physostigmine. It is concluded that ACh is not a major transmitter in the excitatory cerebello-rubral tract in spite of the relationship of AChE to this pathway.     

Complications of spinal cord arteriography: prospective assessment of risk for diagnostic procedures

A prospective study was done of complications associated with 134 consecutive diagnostic spinal cord arteriograms in 96 patients (63 men and 33 women aged 17-78 years). Patients were examined for either arteriovenous malformation (n = 88) or tumor (n = 8), as indicated by myelography. Among the complications, 11 (8.2%) were local, five (3.7%) were systemic nonneurologic, and three (2.2%) were neurologic (two were associated with full recovery in less than 24 hours, and one was associated with full recovery in less than 1 week). No specific clinical or technical factors were significantly associated with the development of neurologic complications. Details of the clinical profile, angiographic technique, and pathologic findings for each patient were recorded and analyzed with respect to the potential risk for arteriographic complications. Diagnostic spinal cord arteriography had an acceptable risk within the range of other neuroangiographic diagnostic procedures.     

Spacing of cytochrome oxidase blobs in visual cortex of normal and strabismic monkeys

Some models of visual cortical development are based on the assumption that the tangential organization of V1 is not determined prior to visual experience. In these models, correlated binocular activity is a key element in the formation of visual cortical columns, and when the degree of interocular correlation is reduced the models predict an increase in column spacing. To examine this prediction we measured the spacing of columns, as defined by cytochrome oxidase (CO) blobs, in the visual cortex of monkeys whose binocular vision was either normal or disrupted by a strabismus. The spatial distribution of blobs was examined in seven normal and five strabismic macaques. Tangential sections through the upper layers of the visual cortex were stained to reveal the two-dimensional (2D) pattern of CO blobs. Each blob was localized and their center-to-center spacing, packing arrangement and density were calculated using 2D nearest-neighbor spatial analyses. The mean center-to-center spacing of blobs (590 microm for normally reared and 598 microm for strabismic macaques) and the mean density of blobs (3.67 blobs/mm2 for normally reared and 3.45 blobs/mm2 for strabismic macaques) were not significantly different. In addition, the 2D packing arrangement of the blobs was not affected by strabismus. While it is clear that neural activity plays a key role in the elaboration and refinement of ocular dominance cortical modules, we conclude that it does not determine the spatial period of the pattern of CO blobs. This suggests that aspects of the neural circuitry underlying the columnar architecture of the visual cortex are established prenatally and its fundamental periodicity is not modifiable by experience.      

The role of the routine pre-operative chest X-ray in the elderly general surgical patient

In an unselected group of 233 patients aged 65 years and over undergoing non-cardiopulmonary surgery, 57·5% had some abnormality on routine pre-operative chest X-ray and 40·3% had an abnormality which was regarded as clinically significant. Of all patients, 32·2% subsequently required a postoperative chest film for diagnostic purposes, and in these cases the pre-operative X-ray was invaluable as a baseline. During the study period there were ten occasions where the discovery of an abnormality on a routine pre-operative chest film directly affected the treatment plan. Pre-operative chest radiology proved ineffective as a method of predicting postoperative respiratory complications and was of only limited effectiveness in predicting postoperative cardiac morbidity.     

A rare variation of the inferior mesenteric artery in man

A case in which the inferior mesenteric artery arose from the superior mesenteric artery is recorded in the cadaver of a 76-year-old Caucasian male who had died of carcinoma of the lung. A review of the literature since 1736 indicates that this is an extremely rare abnormality.     

Axon reaction in the red nucleus of the rat

Summary Two groups of 60 day old male Wistar Rats were subjected to right-sided rubro-spinal tractotomy at the fourth cervical and thirteenth thoracic vertebral levels respectively. Four animals in each group were sacrificed at each of the time intervals 1, 3, 4, 7, 14, 21 and 55 days. Counts of chromatolytic neurons from both groups of animals at time intervals ranging from 1–21 days established a time course for the chromatolytic response. Morphological observations showed a more severe central chromatolysis in the cervical group commencing at Day 3, and a much less severe central chromatolysis in the thoracic group starting at Day 4. By Day 21 the majority of the neurons of the cervical group were atrophic and by 55 days all were atrophic. The reaction following thoracic lesions was less intense and the maximum number of reacting neurons was observed at Day 7. Following this stage the neurons gradually returned to a normal morphological state which was complete by Day 55. Measurements of neuronal diameters from semi-thin Epon sections in the cervical group yielded statistically significant alterations in the perikaryal diameters of experimental neurons, demonstrating swelling at Days 1, 3 and 4 followed by shrinkage at Days 7, 14 and 21.The findings of this study suggest that the severity of the chromatolytic reaction in intrinsic neurons is intimately related to the distance of the lesion from the neuronal soma, while the time of onset of chromatolysis varies with lesion distance but is not directly proportional to it.This investigation was supported by Medical Research Council of Canada Grants MA-3417 and MA-4471.     

Breast carcinoma during pregnancy. International recommendations from an expert meeting

BACKGROUND: Breast carcinoma during pregnancy (BCP) is a difficult clinical situation, as it appears to put the health of the mother in conflict with that of the fetus. METHODS: An international expert meeting was conducted to form guidelines on how to diagnose and treat women with BCP. RESULTS: The goal for treatment of the pregnant woman with breast carcinoma is the same as that of the nonpregnant breast carcinoma patient: local control of disease and prevention of systemic metastases. However, certain treatment modalities need to be modified because of the potential for adverse effects on the fetus. There is evidence to support the safety of anthracycline-based chemotherapy during the second and third trimesters of pregnancy (Oxford Level of Evidence [LOE] 2b). Because of the lack of evidence, the expert opinion was not to recommend the routine use of newer cytotoxic drugs like the taxanes during pregnancy (LOE 5). CONCLUSION: The recommendations provided should help to reach informed decision making by the patient. The ongoing prospective collection of data on BCP, such as that at the University of Texas M.D. Anderson Cancer Center (UTMDACC) and that of the German Breast Group/Breast International Group (GBG/BIG), is necessary to further our knowledge regarding the treatment of this unique group of breast carcinoma patients.