Determination of serotonin and 5-hydroxyindoleacetic acid in guinea pig and human prostate using HPLC

The finding of significant numbers of endocrine-paracrine (EP) cells in the prostate glands of guinea pigs and man suggests that these cells may be important in the regulation or modulation of prostatic function. Serotonin is a biogenic amine common to most prostatic EP cells. In order to extend current knowledge relating to these cells, an assay was developed using high-performance liquid chromatography to quantitate serotonin and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in guinea pig and human prostatic tissue extracts. Levels of serotonin and 5-HIAA in the guinea pig whole-gland preparation were 105.4 +/- 70.6 ng/g and 48.4 +/- 95.7 ng/g, respectively. Normal human prostatic tissue contained 1423.9 +/- 750.8 ng/g serotonin and 66.7 +/- 92.8 ng/g 5-HIAA. Recoveries ranged between 60 and 100%. The detection limits were 24 pg/injection for serotonin and 12 pg/injection for 5-HIAA. This assay provides an expeditious, specific and highly sensitive method for the simultaneous determination of monoamines in guinea pig and human prostatic tissue.     

Motor nerve conduction velocity distributions in man: results of a new computer-based collision technique

A new computer-based collision technique for direct measurement of the human motor nerve conduction velocity distribution is described. In contrast to previous collision techniques, the test muscle response is progressively cancelled to a null using an arrangement of proximal and distal stimuli which eliminates distortion of the test response caused by transient changes in nerve and muscle fibre conduction. The increased sensitivity of this new technique permits accurate measurement of the slowest 1% of alpha motor nerve fibres. We have used our modified collision technique to determine motor nerve conduction velocity distributions for the median nerve in 20 normal subjects aged between 19 and 59 (mean 35) years. 150% maximal stimulus intensities were used, with a controlled limb temperature of 35 degrees C. Group mean velocities (+/- S.D.) for the fastest (95%), mean (50%) and slowest (5% and 1%) motor fibres were 59.1 +/- 3.0, 56.9 +/- 2.9, 52.7 +/- 3.1 and 51.2 +/- 3.7 m/sec respectively. Data are also presented for the ulnar and peroneal nerves.     

Human immunodeficiency virus-related connective tissue diseases: a Zimbabwean perspective

Our clinical experience with patients in Zimbabwe suggests that an arthropathy may be a feature of HIV disease. This takes two forms: the first is a reactive arthropathy usually affecting the large, lower limb joints with no other clinical features of a connective tissue disease. The second form is seen in association with features of complete or incomplete Reiter's syndrome with involvement of large and small peripheral joints (having an asymmetric distribution). Although this arthropathy may been seen in association with HIV positive asymptomatic disease and often is the reason for first presentation at hospital, the majority of our patients have clinical features of persistent generalized lymphadenopathy, plus or minus features of constitutional illness (such as fever, weight loss, and diarrhea). A small percentage of our patients have arthropathy in association with secondary systemic infection. Other locomotor conditions have been observed, although their numbers are too small to determine whether or not they truly are related to HIV disease. In Zimbabwe there is no association between the development of HIV-associated arthropathy and the presence of HLA-B27.     

Nonspecific immunity in pregnancy: monocyte surface Fcγ receptor expression and function

The state of pregnancy is an immunological enigma during which the body must prevent rejection of the antigenically foreign fetus while at the same time maintain sufficient maternal host defense mechanisms to combat infection. Although most studies on the immunology of pregnancy focus on immune suppression, several studies have shown an increase in nonspecific host defense, which is postulated to be a compensatory mechanism for decreased specific immunity during pregnancy. Studies in this laboratory have shown that monocyte surface FcγRI (CD64) and FcγRII (CD32) expression progressively increase throughout pregnancy, while surface MHC class II expression remains unchanged. Functional studies revealed that the number of phagocytic monocytes which could be isolated from pregnant women was increased. These cells exhibited an increased capacity to ingest IgG-opsonized human erythrocytes. This study shows for the first time that monocyte surface FcγR expression and FcγR-mediated functions are increased during pregnancy. These results support the hypothesis that nonspecific immunity as represented by FcγR expression and function is increased during pregnancy.     

A low cost modification of an old Leksell stereotactic frame to allow CT-guided stereotaxy

The high cost of commercial CT-compatible stereotactic frames has restricted the availability of CT-guided stereotaxy for many neurosurgical centres. However, many of these centres do possess the standard stereotactic frames for projection radiography, of which the old type Leksell frame is probably the most common. We have devised a simple and low-cost modification to an old Leksell frame to allow CT-guided stereotaxy. The nature of the modifications allow complete freedom of positioning of the frame relative to the CT scanner and coordinate transformations can be performed simply and effectively. The modified frame has been used successfully for some 18 months and the modification has now been performed at two centres in the North West Regional Health Authority. We hope this modification will allow many other centres to embark on CT-guided stereotaxy.     

Fibrinolysis inhibitors.

The fibrinolytic system involves a series of enzymatic reactions that results in the conversion of the proenzyme, plasminogen, into the trypsin-like lytic enzyme, plasmin. The major physiologic target of plasmin is fibrin. Free plasmin in plasma is a nonspecific lytic enzyme that will degrade other proteins such as fibrinogen and coagulation factors V and VIII. Plasmin and activators of plasminogen also play a role in ovulation, embryo implantation, tissue remodeling, and inflammation.     

Why all finger fractures should be referred to a hand surgery service: a prospective study of primary management

The quality of the treatment of finger fractures by Accident and Emergency Department staff has been prospectively assessed during a six-month period. 678 finger fractures were seen in the A. & E. Department. The primary treatment of 624 of these was performed by the A. & E. staff, but in 169 of these (27%), the treatment was inappropriate. Most management errors were elementary; they included failure to prescribe antibiotics for compound fractures, failure to reduce displaced fractures accurately and unsatisfactory splintage. It is recommended that all finger fractures should be assessed and treated by surgeons with training in the management of hand injuries.     

Chronic haloperidol and chlorpromazine treatment alters in vitro beta-endorphin metabolism in rat brain

To determine if chronic haloperidol (3.0 mg/kg per day) or chlorpromazine (4.2 mg/kg per day) treatment alters central beta-endorphin metabolism, haloperidol and chlorpromazine were perfused via Alzet minipumps into male Sprague-Dawley rats for 8 days. Crude twice-washed membranes, purified synaptic plasma membranes and Golgi-enriched membranes, respectively, were isolated from rat brains and time course incubated with beta-endorphin. All samples were analyzed by high resolution, reversed-phase high performance liquid chromatography. The half-lives of beta-endorphin for animals treated with haloperidol or chlorpromazine were not statistically different from control animals at the crude washed membranes. At the purified synaptic plasma membranes, however, the half-lives of beta-endorphin from haloperidol (t 1/2 = 45.1 min)- and chlorpromazine (t1/2 = 47.0 min)-treated animals were significantly decreased as compared to the control animals (t1/2 = 78.0 min). The half-life of beta-endorphin at the Golgi-enriched membranes was increased for haloperidol (t1/2 = 112.3 min) and chlorpromazine (t1/2 = 103.0 min)-treated animals when compared to control animals (t1/2 = 80.2 min). The findings indicate a differential effect of the dopamine receptor antagonists haloperidol and chlorpromazine on the extracellular fate at the synaptic plasma membranes of beta-endorphin and the intracellular processing at the Golgi-enriched membranes in vitro.