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Biomedical subjects

R Black

Publications and source records attributed to R Black.

At least 109 records · Page 6Linked to original sources
PubMed1978

Narcotic antagonist treatment: clinical experience with naltrexone.

Narcotic antagonist (naltrexone) treatment experience with 22 opioid addicts over a 29-month period shows that the mean duration of receipt of naltrexone was 6.2 weeks, and 12 subjects (55%) continued in treatment after cessation of naltrexone for an average of 5.6 weeks. Analysis of physical and behavioral measured revealed no toxicity, indicating that naltrexone appears to be a safe drug. Clinical evaluation of the patients receiving naltrexone suggests that ingestion of naltrexone provides a degree of external control, reducing the preoccupation with heroin and releasing energy for the pursuit of other goals. Subject follow-up at an average of 45.3 weeks after cessation of naltrexone indicated that 11 (58%) were known to be abstinent, and 9 (47%) subjects were employed compared with 3 (16%) employed at the onset of treatment.

Adolescent↗
PubMed1978

Collagen in 155 human bladders.

The percentage of bladder collagen, as obtained by the dosage of hydroxyproline, was determined in autopsy specimens from 48 female and 107 male cadavers. The average percentage of collagen in the human bladder is 57.4 per cent (+/- 9) of the dry weight of insoluble protein. There is good correlation (r = 0.55) between detrusor and trigone collagen content. There is no significant difference between pre- and postpuberty age groups in relative collagen content. In females more than 50 years of age there is a significant increase in collagen.

Adolescent↗
PubMed1977

A multiple-electrode hearing prosthesis for cochlea implantation in deaf patients.

A multiple-electrode hearing prosthesis for cochlea implantation in deaf patients has been developed at the University of Melbourne. It has been designed as a multiple-electrode implant to provide the best chance of enabling patients to understand speech. It has been shown that an electrode array can be threaded along the coills of the inner ear close to residual auditory nerves. Experimental studies have indicated that the long-term implantation of the array will not lead to significant degeneration of auditory nerve fibres. Loss of platinum from the stimulating electrodes can be minimized with a biphasic constant current pulse, where the first phase is negative with respect to ground. The receiver-stimulator component has also been designed to provide 10-15 channels of stimulation. Furthermore, the phase and amplitude of the stimuli to individual electrodes can be varied to enable the localization of the electrical fields to discrete groups of nerve fibres, and the correct method of frequency and intensity coding to be determined. Finally, the device should be used in the first instance for a specially selected group of adults who are post-lingually deaf.

Animals↗
PubMed1977

A multiple electrode cochlear implant.

The University of Melbourne Departments of Otolaryngology and Electrical Engineering (UMDOLEE) receiving and stimulating component of a multiple-electrode cochlear implant hearing prosthesis produces constant stimulation. It has a stimulating pulse shape that minimizes the production of toxic substances and loss of metal from the electrodes, and this is achieved with a biphasic rectangular waveform where the first phase is negative with respect to ground. The duration of each stimulus phase in 180 msec, which is long enough to allow low levels of current stimulation, and short enough to permit rates of 1000 pulses/second to be achieved. In order to be consistent with our present understanding of the perception of pitch, the device permits the independent stimulation of a number of electrodes. Furthermore, to electrically isolate the stimulus to small areas, there is the capacity to vary the current and set the threshold independently at individual electrodes. The phase and amplitude of the pulses to neighbouring electrodes with also be varied to assist in localizing the current flow. The pattern to stimulation to individual or groups of electrodes can also be altered to enable studies to be carried out to determine ways of conveying frequency and intensity information over a more normal dynamic range.

Animals↗
PubMed1977

Implications of inorganic/organic interconversion on fluxes of arsenic in marine food webs.

An organic form of arsenic is commonly encountered in marine organisms; in greysole and shrimp, it accounted for all arsenic found in muscle tissue. It has been isolated from flounder tissue by two independent procedures; it was hydrophilic, cationic, and was not decomposed to inorganic arsenic by hot nitric and sulfuric acids. NMR spectroscopy indicated all nonexchangeable protons to be equivalent; they behaved more like N-methyl protons than As-methyl protons. High-resolution mass spectroscopy from a heated probe yielded a spectrum corresponding to tetramethylarsonium (AsMe4+); the authentic ion, however, had TLC and ion-exchange behavior different from that of the natural product. Infrared spectrometry likewise produced conflicting or uninterpretable data. Decomposition of the compound for analytical purposes was accomplished by dry ashing under oxidizing conditions. Sea urchins, like trout, converted arsenic to an organic form, but to a more limited degree. Arsenic found naturally in sea urchins and in a species of macroalga was also organic. In individual containers, sea urchins were fed on the alga for 7 weeks. During this time they consumed 0.203 +/- 0.075 mg total As and excreted only 0.036 +/- 0.015 mg as feces. Measurement of inorganic As in the seawater did not account for the discrepancy, but measurements of total As did (0.202 +/- 0.095 mg). Sea urchins, like humans, appear to be able to rapidly excrete these organic forms of arsenic.

Animals↗
PubMed1976

Bacteroides fragilis resistant to the administration of clindamycin.

The susceptibility of Bacteroides fragilis to the administration of clindamycin, and the efficacy of this agent in Bacteroides infections are well documented. Clindamycin-resistant strains of B. fragilis were isolated from two patients with bacteremia at two institutions. Clinically significant resistance to clindamycin therapy has not been noted previously in B. fragilis infections.

Aged↗
PubMed1972

Crying in infancy.

Explore the source record for details and available documents.

Child Development↗
PubMedDate not supplied

Efficacy of bone marrow, blood, stool and duodenal contents cultures for bacteriologic confirmation of typhoid fever in children.

The relative efficacy of cultures made from duodenal contents (obtained by string capsules), bone marrow, blood and rectal swab was compared in 118 pediatric patients, 2 to 13 years old with suspected typhoid fever. Only 47% of children 2 to 6 years old tolerated the string device, as compared with 89% in children 7 to 13 years old (P less than 0.05). The four culture techniques were performed and at least one was positive for Salmonella typhi in 43 patients. Bone marrow cultures were positive in 84% of the confirmed cases, a sensitivity significantly greater than for duodenal contents (42%), blood (44%) and stool (65%) cultures. Higher recovery rates for blood cultures were found during the first week of illness than later (70 vs. 22%). Bone marrow cultures remain the most effective method for the recovery of S. typhi. Stool cultures appear to be more effective in children than in adults. Duodenal contents cultures offer little advantage in young (2 to 6 years old) children.

Adolescent↗
PubMedDate not supplied

Access to the internet in an acute care area: experiences of nurses.

The internet is expected to play a key role in delivering evidence-based practice (Department of Health (DoH), 1997, 1998a; Beyea, 2000). In the UK, poor access to the internet and a lack of knowledge and confidence have been identified as barriers to nurses accessing evidence via the internet. The study described here aimed to evaluate how open access to the internet in an acute ward area had an impact upon the evidence-based practice of nurse and allied health professionals. The study was funded by the Department of Health. It incorporated a survey of over 200 staff, semi-structured interviews and monitoring of internet use. The results indicate that the ward-based internet facilities were valued and used by nurses. However, time, support and training are required for nurse to realize the full potential of the internet. Future partnerships between health science libraries and the NHS are recommended to help staff to access and use the internet in order to answer clinically derived questions.

Access to Information↗