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Biomedical subjects

S Conway

Publications and source records attributed to S Conway.

65 records · Page 4Linked to original sources

Effect of the B-D Urine Culture Kit on an automated bacteriuria screen.

The effect of urine collected in the B-D Urine Culture Kit (BDT; Becton, Dickinson & Co., Rutherford, N.J.) on the Autobac urine screen (General Diagnostics, Warner-Lambert Co., Morris Plains, N.J.) was investigated. Upon collection, 1,000 clean-voided urine specimens were divided into sterile urine tubes and BDTs. Within 24 h of collection, urine from each tube was cultured by a semiquantitative plate method and screened by the Autobac system. Overall, when screened by the Autobac system, urine collected in the BDT gave fewer false-positive results: 14.4 compared with 22.7% from the sterile urine tubes. However, in comparison with the sterile urine tubes, the BDT false-negative rate was 10.5 versus 4.7%, the detection time was longer, and the cost was increased.

Bacteria↗

Catecholamine synthesis inhibitors acutely modulate [3H]estradiol binding by specific brain areas and pituitary in ovariectomized rats.

Drugs known to alter endogenous levels of catecholamines were administered to adult ovariectomized rats to assess catecholaminergic effects on estradiol (E2) uptake and binding in nuclear and supernatant fractions of pituitary and specific brain regions and on cytoplasmic E2 receptor numbers and affinities. Specific (i.e. diethylstilbestrol-blockable) binding in vivo was measured 1 h after the iv injection of [3H]E2 (1 micrograms/kg). Administration of the tyrosine hydroxylase inhibitor alpha-methyl-p-tyrosine (alpha MPT) 2 h before [3H]E2, to reduce levels of dopamine (DA), norepinephrine (NE), and epinephrine (Ep), decreased total and specific [3H]E2 binding by 36-56% in the nuclear fraction of the anterior pituitary, basal hypothalamus, and anterior hypothalamus. The dopamine-beta-hydroxylase inhibitor diethyldithiocarbamate (DDC), administered 2 h before [3H]E2 to reduce levels of only NE and Ep, increased the total and specific uptake of [3H]E2 by 62-140% in nuclear and supernatant fractions of the anterior pituitary and also increased uptake in several brain areas. In vitro analysis of hypothalamic and pituitary cytoplasms showed that in vivo administration of DDC increased E2 binding. Scatchard analysis showed that DDC increased receptor numbers 18-29%, with no change in the dissociation constant in pituitary cytoplasms. At the same time, plasma PRL levels were reduced by DDC treatment, indicating that DDC had increased DA output. Phenoxybenzamine (a blocking agent at alpha 1 postsynaptic binding sites) and a high dose of clonidine (a pre- and postsynaptic alpha-receptor agonist) did not significantly alter specific uptake in the cell nuclear fraction of any tissue, suggesting that postsynaptic alpha-receptors do not play a major role in modulating [3H]E2 uptake. No drug altered plasma levels of radioactivity. Because alpha-methyl-p-tyrosine and DDC both inhibit synthesis of NE and Ep, it is suggested that their opposite effects on uptake of [3H]E2 are related to their opposite effects on DA output. This interpretation is compatible with our previous observations that DA agonists increase [3H]E2 uptake in brain and pituitary in ovariectomized rats.

Animals↗

Fine-needle aspiration biopsy of malignant tumours of the abdomen.

Our initial experience of 50 patients who underwent fine-needle aspiration biopsy for suspected abdominal malignant disease confirms the safety and effectiveness of the technique. A positive diagnosis of malignant tumour was made in 36 out of 42 patients who were finally shown to have malignant disease. The correct diagnosis was made on 13 out of 17 patients with a pancreatic tumour; in 17 out of 17 with a liver tumour; in 3 out of 3 with renal masses; and in 3 out of 5 with other malignant lesions. Ultrasound was used for localization of the aspiration site in 38 patients, angiography in 11 patients and direct puncture in 2. During the biopsy of 55 sites, the needle was inserted into the abdomen 190 times and the only significant complication was the development of retroperitoneal haematoma in 2 patients.

Abdominal Neoplasms↗

A new technique of dermabrasion.

Dermabrasion is an accepted method for improving the appearance of facial scars. It allows the epidermis to regenerate as a smooth surface after the defective dermis and epidermis have been removed. Several methods and instruments are currently being employed for dermabrasion. Sandpaper wrapped around a motor-driven cylinder is effective in broad, flat areas but is difficult to use around the eyes and nose. A wire-mesh brush of multiple short, curved, stainless steel wires driven by a motor is useful; but the skin is easily abraded too deeply, it is hazardous to use the device near the eyes, and gauze sponges are easily enmeshed in the rapidly whirling brush. Consequently, we have modified the use of this wire-mesh brush. It is as effective and more safely used by hand, without the motor.

Cicatrix↗

The influence of acute ethanol exposure on growth hormone release in female rats.

This study investigates the site (hypothalamic or pituitary) at which ethanol (ETOH) alters GH release in female rats. Both the hypothalamic response to clonidine (CLON), an alpha 2-adrenergic agonist, and the pituitary response to growth-hormone releasing hormone (GRH) were tested. Jugular cannulae were inserted for drug administration and undisturbed blood sampling. ETOH was injected IP 24 and 1 h before experimentation. In animals receiving saline or ETOH (1, 2, or 3 g/kg), there was no response to CLON and no difference in GH levels between groups. On the other hand, there was a significant surge in GH release in response to a high dose of GRH (1000 ng/kg) in both saline controls and in ETOH (3 g/kg) animals. Although there was no difference in the height of the surge between groups, baseline GH levels were higher in animals that received ETOH. In response to a low dose of GRH (250 ng/kg) the GH surge was only significant in the ETOH animals. In animals receiving somatostatin antiserum (anti-SRIF; 0.5 ml) in combination with the low GRH dose, the surge in GH levels was significant in both saline and ETOH animals, however, the surge was higher in saline compared to ETOH animals. The results of this study suggest that: 1) ETOH alters the SRIF system (release of reception) in female rats and that this interaction is evident when GRH concentration is low, and 2) ETOH may also inhibit GH release by interfering with the GRH system, however, the site of this influence most likely does not involve an alpha 2-GRH component.

Animals↗

The effect of acute ethanol exposure on clonidine-induced growth hormone release in male rats.

The influence of acute ethanol (ETOH) on the regulation of GH release has not been clearly elucidated. In this study the effect of ETOH on clonidine (CLON)-induced GH secretion was examined. To test the effect of ETOH on CLON-induced GH release doses of 1, 2, and 3 g/kg ETOH in a 25% ETOH/saline solution or 10 ml/kg saline were injected IP 24 and 1 h before CLON (30 micrograms/kg BW IV). Blood samples were withdrawn through a chronic jugular cannula. ETOH was found to alter the GH surge, which occurred 15 min after CLON administration in controls, in a dose-dependent manner. The 1 g/kg dose reduced the GH surge slightly but not significantly. The 2 g/kg dose suppressed the GH surge which was significantly lower than in controls. The 3 g/kg dose eliminated the GH surge completely. To determine if pituitary GH release is directly influenced by ETOH, animals were injected with GRH (250 ng/kg IV) one hour after the second dose of ETOH (3 g/kg IP). There was no difference in the GH surge in control or ETOH-injected animals. Anti-SRIF administered 30 minutes before ETOH or saline did not alter the response to GRH. These results suggest that ETOH reduces the GH responsiveness to alpha 2-GRH stimulation.

Animals↗