Partition of function in the morphological subdivisions of the lateral geniculate nucleus of the tammar wallaby (Macropus eugenii).

Extra-cellular recordings from single cells in the dorsal lateral geniculate nucleus (dLGN) of the tammar wallaby, Macropus eugenii, were made to find out whether the stratification of the nucleus could be correlated with the receptive field properties of units. Retinofugal fibres terminate in the lateral geniculate nucleus of the wallaby in nine interleaved eye-specific layers. These may be grouped into a lateral alpha segment of six laminae and a medial beta segment of three, in which the cells are less densely packed. Ninety percent of the geniculate neurons recorded from in the alpha segment gave brisk responses to stimulation of their receptive fields. Cells with sluggish responses predominated in the beta segment, but there was also a sizable minority of cells with brisk responses that were indistinguishable from those recorded in the alpha segment. In contrast, other response properties were rarely differentiated in individual layers. Thus, in most layers, the numbers of cells with transient or sustained responses were not significantly different, and this was also true for cells with ON- or OFF- responses. For each of these response pairings, however, the numbers of one type (ON- and transient) predominated in every layer. The accumulation of this laminar distinction lead to significant differences in the alpha and beta segments and in the nucleus as a whole. We conclude that cells in the individual layers of the dLGN of the tammar wallaby show no evidence of having receptive field properties in common that might correlate with separate functional streams. There is a functional segregation of receptive field properties between the alpha and beta segments. The organization of these two segments resembles that of the A and the C layers of the dLGN in cats and, possibly, the magnocellular and koniocellular components of the dLGN in primates. These broad similarities in functional partition of the dLGN of different species suggests that this aspect of the organization of the nucleus is independent of lifestyle.     

Trans-perineal implantation of radio-opaque treatment verification markers into the prostate: an assessment of procedure related morbidity, patient acceptability and accuracy.

On-line imaging of prostate markers can be used to compensate for errors in radiation delivery. This study assessed the patient acceptability and morbidity associated with the trans-perineal route of implantation. A minority experienced acute pain or bleeding. Placement was accurate in all but one subject. An operator related learning curve exists. Although this is an invasive procedure most patients found it acceptable. Implementation for routine clinical practice is feasible.     

Congenital dyserythropoietic anemia type II diagnosed in a 69-year-old patient with iron overload.

Congenital dyserythropoietic anemia type II is a rare disorder that is often diagnosed in patients before age 20 years. Patients with this disorder, which is also called hereditary erythroblastic multinuclearity associated with a positive acidified serum lysis test, may have symptoms of iron overload. The purpose of this case report is to alert physicians to consider the diagnosis of congenital dyserythropoietic anemia type II in elderly patients who have anemia and iron overload.     

New approach to management of intraaortic balloon pumps in patients with peripheral vascular disease: Case reports of four patients requiring urgent IABP insertion

Four selected cases of emergent IABP insertion in PV patients are presented. After angiographic documentation of critical iliac stenosis, conservative peripheral angioplasty was performed prior to IABP insertion. No patient experienced a peripheral ischemic event associated with IABP use. © 1992 Wiley-Liss, Inc.     

Nine Years of the Freebase Cocaine Epidemic in the Bahamas

Nine years after the beginning of the epidemic of freebase (crack) cocaine abuse in the Bahamas, this historical study was done to characterize the natural course of the epidemic and to estimate the effectiveness of control measures. The authors' data include the incidence of new cases at the only psychiatric hospital in the Bahamas and at the primary community psychiatric clinic in the nation. The Bahamian response included 1) demand reduction, 2) supply reduction, and 3) reduction of money laundering. The annual number of new cases of crack abuse presenting for treatment declined from 1987 to mid-1991 in both facilities, but in 1992 it began rising again in the inpatient setting only. The changes in recent years have been accompanied by an increase in violent crimes against persons, especially robberies. (American Journal on Addictions 1994; 3:14–24)