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Biomedical subjects

A P Filho

Publications and source records attributed to A P Filho.

5 recordsLinked to original sources
PubMed1999

An automatic temperature-control system for solutions in free flow.

We describe a temperature-control system for solutions in free flow, suitable for electrophysiological or optical studies of isolated cells, natural epithelia or cell culture monolayers. The system is small enough to be located close to the preparation and was designed specifically to be coupled to the inlets of a modified, continuous-flow Ussing chamber, allowing rapid change of the solutions bathing tissue surfaces. The system consists of a highly compact monoblock heating unit and a control circuit. Solutions from different reservoirs, kept at room temperature or lower (from an ice bath), can be rapidly switched at the inlet of the heating unit by manually or electrically actuated microvalves without affecting the temperature of the fluid leaving the heating unit. The control unit consists of a bead thermistor firmly placed close to the heating unit outlet and an electronic circuit which is basically a proportional controller. This unit continuously regulates the electric current through the Ni-Cr heater, keeping the temperature of the fluid leaving the heating unit constant at a preset value. The system allows control of fluid temperature (normally 37 degrees C) for flow rates in the range of 1.0 ml/min to 12 ml/min. However, the temperature can be set at any value above that of the incoming fluid.

Cell Separation↗
PubMed1975

Intramedullary cysticercosis. Case report, literature review and comments on pathogenesis.

A 60-year-old woman developed progressive spastic crural paraplegia and global anesthesia and global anesthesia below T10, succumbing to urinary infection and bronchopneumonia 8 months after the onset of symptoms. At necropsy, the spinal cord was completely destroyed by a necrotic intramedullary cysticercus at T8. Six cysticerci were found in the brain. A review of the 17 published cases of intramedullary cysticercosis (including this one) showed this condition to be clinically indistinguishable from spinal cord tumours. The surgical prognosis was fair in 8 of 11 operated patients. The role of hematogenous and ventriculo-ependymal pathways in the pathogenesis of intramedullary cysticercosis was examined. The topographical distribution of intramedullary cysticerci (5 cervical, 12 thoracic, 2 lumbar, none sacral) was found to be statistically proportional to the blood flow to each of these regions; this favours the hematogenous route of infestation. The low spinal cord blood flow (100 times less than that to the brain), the type of vascularization of the cord (low calibre vessels under low pressure) and peculiarities of the cord tissue (such as its harder consistency) are all thought to be contributory factors accounting for the scarcity of intramedullary cysticerci. No evidence for an ependymal route of spread could be adduced.

Adult↗