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Biomedical subjects

C M Holmes

Publications and source records attributed to C M Holmes.

At least 19 recordsLinked to original sources
PubMed2001

The use of outdoor freshwater pond microcosms. III. Responses of phytoplankton and periphyton to pyridaben.

An outdoor freshwater microcosm study was conducted in which pyridaben, an insecticide-miticide, was directly applied to water to determine its biological effects on phytoplankton and periphyton. Twenty-four microcosms (24 m3 each) were monitored for 11 months, then four treatments of pyridaben were applied two times at three concentrations (0.34, 3.4, 34.0 micrograms/L), including an untreated control. The succession of algal groups observed and the major genera found in microcosms during the baseline phase of the study were typical of oligo-mesotrophic systems in Florida. Following application of pyridaben, the most remarkable effect was a positive correlation of phytoplankton abundance with pyridaben concentrations in water; indicating increased abundance as a result of exposure. Both Chlorophyta and Pyrrophyta exhibited a significant increase (p = 0.05) in population abundance at 3.4 and 34.0 micrograms/L pyridaben. Chrysophyta also elicited a trend of increased abundance at 34.0 micrograms/L, although the effect was not significant. The effects on phytoplankton populations were associated with the decline of zooplankton populations as a result of a direct effect of pyridaben exposure. There were no effects of pyridaben on periphyton communities or on functional endpoints.

Chlorophyll↗
PubMed1985

The acquired immune deficiency syndrome and related complex. A report of 2 confirmed cases in Cape Town with comments on human T-cell lymphotropic virus type III infections.

We report a case of acquired immune deficiency syndrome (AIDS) and one of AIDS-related complex presenting in Cape Town. The first patient was probably infected in the USA. In turn he infected the second patient by regular homosexual contact. Human T-cell lymphotropic virus type III (HTLV-III) was cultured, we believe for the first time in Africa, from the peripheral blood lymphocytes and a lymph node of our patient with AIDS. HTLV-III infection and high-risk groups in South Africa are discussed in comparison with those in the USA. It is suggested that HTLV-III infection and AIDS will increasingly affect women. Prevention of the spread of HTLV-III infection and AIDS is discussed in relation to close medical surveillance and the protection of blood and blood products from contamination. Counselling of patients with AIDS and persons infected with HTLV-III, general health education, and the protection of health care staff are important in preventing spread but beyond the scope of this article.

Acquired Immunodeficiency Syndrome↗
PubMed1982

Midazolam/fentanyl. A total intravenous technique for short procedures.

Midazolam (RO 21-3981), a water soluble benzodiazepine, was used in combination with fentanyl as a total intravenous anaesthetic for outpatient cystoscopy. It was compared with a similar technique using Althesin and fentanyl. In both series good conditions were produced, and patient acceptance was high, with absence of pain on injection, no inappropriate muscle movements and no nausea or vomiting. The induction and recovery times were slightly longer in the midazolam series, but not undesirably so. There appeared to be a slight incidence of phlebitis with midazolam, but because the patients were discharged from hospital, the exact incidence could not be ascertained with certainty.

Adult↗
PubMed1980

Etomidate: a foreshortened clinical trial.

A clinical evaluation of etomidate for outpatient cystoscopy was embarked upon. Unpremedicated patients were given fentanyl 1 microgram/kg followed by etomidate 0.3 mg/kg. Anaesthesia was maintained with intermittent etomidate in 2-4 mg doses. Patients were interviewed personally later the same day, and by questionnaire three to four weeks later. The trial was discontinued after 20 cases because of an unacceptable incidence of side effects. Venous pain occurred in 68% of patients and 50% had redness, pain or swelling related to the injection site, in some cases lasting up to three weeks after anaesthesia. Skeletal movements occurred in 50% of patients; 30% experienced respiratory upset, one sufficiently severe to necessitate abandoning the technique. Nausea and vomiting occurred in 40% and 25% had disturbing emergence psychoses.

Anesthesia, Intravenous↗
PubMed1978

An oxygen failure warning and patient protection system. The Howison Unit.

A device is described which sounds an alarm to warn of oxygen supply failure. A the same time the nitrous oxide flow is cut off, and a reservoir in the device provides a continuing oxygen flow to the patient for about a minute. This results in increased inspired oxygen levels temporarily, reducing the risk to the patient while the oxygen failure is being corrected.

Anesthesiology↗
PubMed1978

The elimination of pollution by a non inhalational technique.

A method is described whereby major surgery can be accomplished without inhalational anaesthtic agents, thus completely eliminating operating room pollution. The method is based on the balanced use of three intravenous agents--morphine, alcuronium and gamma-hydroxybutyrate (GHB). In the dose chosen for GHB, reliable unconsciousness can be produced for surgery of any length, and using physostigmine as an antidote, patients can be wakened within ten minutes. The advantages are convenience, simplicity of equipment, low cost, absence of pollution and good patient acceptance. The disadvantages are a certain incidence of hypertension and in this series, a small failure rate with the antidote.

Adult↗
PubMed1977

Very-nearly-closed-circuit anaesthesia. A computer analysis.

A simple analogue study of inspired oxygen concentrations in a circle absorber system was made. Good agreement with clinical observations and figures reported by others was obtained. The suggested low-flow regime was nitrous oxide 1 litre/min and oxygen 0.6 litre/min, which provides inspired oxygen concentrations between 35-25%, over a range of oxygen consumption from 150-300 ml/min. The use of such low flows is economical and reduces atmospheric pollution in the operating theatre.

Air Pollution↗
PubMed1976

Supplementation of general anaesthesia with narcotic analgesics.

Four analgesic drugs--fentanyl, phenoperidine, morphine and pethidine--were compared in a double-blind trial involving 113 patients paralysed and ventilated with nitrous oxide and oxygen. The differences between the drugs were relatively small. There were only slight differences in "duration of action", a term which is questioned in this context. Pethidine appeared to have a slightly longer duration of action than the other drugs. The problems inherent in studying analgesics in this manner are discussed.

Adult↗
PubMed1976

Reversal of the anaesthetic action of sodium gamma-hydroxybutyrate.

Physostigmine was administered intravenously to 25 patients, anaesthetised with sodium gamma-hydroxybutyrate (GHB), and their emergence from anesthesia was studied. Physostigmine (2 mg) brought about rapid, safe, reliable and sustained awakening after a "latent period" varying from 2-10 minutes (mean 6-2 minutes+/-S.D. 2-2) in 24 patients. In the one patient not awake at 10 minutes, a second dose of physostigmine produced awakening in an additional 8 minutes. No serious side effects were attributable to the physostigmine. This finding may warrant a reconsideration of the place of GHB in anaesthetic practice.

Adjuvants, Anesthesia↗