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Biomedical subjects

C D Miller

Publications and source records attributed to C D Miller.

At least 55 records · Page 3Linked to original sources

IV lignocaine fails to attenuate the cardiovascular response to laryngoscopy and tracheal intubation.

I.v. lignocaine has been used with varying success to attenuate the cardiovascular responses to laryngoscopy and tracheal intubation. We determined the optimal time of administration in 45 ASA I and II Chinese patients premedicated with morphine and hyoscine, and anaesthetized with thiopentone and suxamethonium. Patients were allocated randomly to a control group or three treatment groups to receive lignocaine 1.5 mg kg-1 i.v. 1, 2, or 3 min before laryngoscopy. Analysis of variance for measured and derived cardiovascular variables failed to show any significant difference between any of the groups.

Adult↗

Pupillary effects of alfentanil and morphine.

We have measured the onset and extent of the miotic effect of morphine and alfentanil in conscious patients. Forty unpremedicated ASA I and II patients were allocated randomly to four groups to receive either i.v. saline (control group), morphine 0.1 mg kg-1, alfentanil 4.0 micrograms kg-1 or a combination of these doses, and pupil diameters were measured for the next 30 min. There were no significant differences in the control diameters. In the opioid groups, a significant decrease in diameter (about 1 mm), occurred 4 min after administration of the drug and persisted throughout the study. The opioid groups behaved similarly for 25 min. After 10 min the mean diameter of the alfentanil group began to increase, but this did not reach statistical significance until after 25 min.

Adult↗

Effect of isoflurane on the canine hepatic circulation and hepatic oxygen balance.

We have studied the effects of increasing concentrations of isoflurane (1%, 1.5% and 2%) on the hepatic circulation and the oxygen supply and demand of the liver in six barbiturate-anaesthetized greyhounds. Following laparotomy, the hepatic arterial and portal venous blood flows were measured continuously using electromagnetic flow probes, and mean arterial pressure and cardiac output were measured as appropriate. Cardiac output was maintained while mean arterial pressure and systemic vascular resistance decreased in a dose dependent manner. Hepatic arterial and total liver blood flows and oxygen supplies decreased significantly at all isoflurane concentrations. Portal venous blood flow and portal venous oxygen supply did not decrease significantly until the concentration of isoflurane was increased to 2% and 1.5%, respectively. Hepatic oxygen consumption was reduced with 2% isoflurane (P less than 0.05), but this was insufficient to offset the reduction in hepatic oxygen supply and resulted in an increased extraction of oxygen by the liver.

Anesthesia, General↗

Recurrent bronchospasm during anaesthesia.

Bronchospasm complicated several anaesthetics in a diabetic patient with chronic renal failure. The bronchospasm was accompanied frequently by bradycardia. The pathophysiology, treatment and implications for future anaesthetic management are discussed.

Adult↗

The ballet technique shoe: a preliminary study of eleven differently modified ballet technique shoes using force and pressure plates.

Ballet dancers are vulnerable to various stress-related injuries; foot and ankle injuries are the most common. This study determined if the pressure across the foot could be more evenly distributed by wearing various modified technique shoes padded with PPT, Spenco, or Sorbathane, alone or in combinations. A professional ballet dancer performed a jump by taking a single step on his left foot, jumping and landing with his right foot on the force and pressure plates with each modified shoe plus one unmodified shoe. The results of this study revealed: (1) total force cannot be reduced, (2) center of gravity and the majority of the pressure is maintained over the first and second metatarsal heads, and (3) the modified technique shoe can more evenly distribute pressure to the medial arch and away from the toes, metatarsal heads, and heel.

Athletic Injuries↗

In vitro effects of cyclopiazonic acid mycotoxin on turkey papillary muscles.

An in vitro bioassay system was used to study the effects of cyclopiazonic acid (CPA) mycotoxin on cardiac muscle. Acute exposure to 6 micrograms of CPA/ml of modified Krebs-Henseleit solution significantly (P less than 0.05) decreased 5 in vitro turkey cardiac muscle performance criteria: maximal weight a muscle could lift; maximal contraction velocity; relaxation velocity; time to peak contraction; and total time for muscle contraction and relaxation. The effect on these 5 criteria appeared to result from intracellular changes partially associated with calcium availability and were irreversible, suggesting that physiologic changes had developed after acute exposure to CPA.

Animals↗

Comparison of enflurane and halothane in hypotensive eye surgery.

Thirty patients undergoing elective eye surgery had anaesthesia induced with sodium thiopentone, suxamethonium and d-tubocurarine chloride. Patients were ventilated with nitrous oxide, oxygen and either halothane or enflurane. The volatile agents were used to decrease the systolic blood pressure to 80 mmHg. The volatile agent concentration in the blood was measured at 30 min intervals. Both agents were effective in producing hypotension, but enflurane was the more potent hypotensive agent in terms of MAC equivalents. There was no significant differences between the agents with respect to speed of recovery.

Adolescent↗

Human gamma-glutamyl transpeptidase cDNA: comparison of hepatoma and kidney mRNA in the human and rat.

gamma-Glutamyl transpeptidase (GGT) is a glutathione-metabolizing enzyme that has been extensively studied in relation to hepatocarcinogenesis. Using a cDNA for rat kidney GGT as a probe, we have isolated a full-length cDNA for human GGT from a hepatoma cell-line library. Nucleotide sequence analysis of the clone revealed a 2326-bp insert that includes a 5'-untranslated region of 487 nucleotides (nt), an open reading frame (ORF) of 1707 nt, and a 3'-untranslated region of 132 nt. The ORF encodes a protein with an amino acid sequence that is highly similar to that of the rat GGT precursor peptide, with an overall identity of 79%. The cDNA clone was used to probe Northern blots of hepatoma and kidney RNA from both human and rat. In both species, the GGT mRNA is longer in hepatoma than in kidney. In addition, the human mRNAs were longer than their counterparts in the rat. None of three human hepatocellular carcinomas examined showed a marked elevation in GGT mRNA levels relative to surrounding liver tissue.

Amino Acid Sequence↗

Fine structural defects in a case of congenital microcoria.

A case of congenital miosis associated with myopia and cataract is described. Tissue obtained at iridectomy was examined with the electron microscope and compared with a specimen of normal iris. The miotic iris was found to be hypoplastic and to display differences in the cellular density of the stroma. The contractile processes of the dilator myoepithelium were conspicuously absent from the underlying stroma, and the existing myofibrils were much disarranged.

Adult↗

Effect of a high-intensity static magnetic field on sciatic nerve regeneration in the rat.

The effect of a high-intensity static magnetic field on peripheral nerve regeneration is evaluated in rat sciatic nerve. Forty-four rats underwent sciatic nerve repair using polyethylene nerve guides. Postoperatively, the animals were exposed to a 1-tesla magnetic field for 12 hours per day for 4 weeks with appropriate controls. Our results demonstrate that a 1-tesla static magnetic field has no statistically significant effect on nerve regeneration as determined by myelinated axon counts and electrophysiologic studies. Also, the specific orientation of the sciatic nerve with respect to the magnetic field has no influence on axonal growth or nerve conduction. Periods of restraint of 12 hours per day for 4 weeks significantly inhibit weight gain but have no effect on peripheral nerve regeneration.

Animals↗

Outpatient paediatric dental anaesthesia. A comparison of halothane, enflurane and isoflurane.

One hundred and fifty unpremedicated children who presented for dental extractions were anaesthetised with nitrous oxide and halothane, enflurane or isoflurane. Ventricular arrhythmias occurred only in the halothane group (14%). Respiratory problems and desaturation were significantly more common in the isoflurane group. Induction times differed significantly between the groups halothane less than enflurane less than isoflurane, while recovery time and induction to recovery time were significantly shorter in the enflurane group. We suggest that enflurane is the most suitable agent for anaesthetising these patients.

Ambulatory Surgical Procedures↗

Silent regurgitation in day case gynaecological patients.

The effect of metoclopramide premedication on the incidence of gastric regurgitation and postoperative nausea and vomiting was studied in 101 women during gynaecological procedures performed under mask anaesthesia. All patients were premedicated orally with carmine red and temazepam. A treatment group of 48 women also received oral metoclopramide. Anaesthesia was standardised in both groups. None of the women regurgitated gastric contents. Pharyngeal pH was measured in the last 68 patients and found to be greater than 5 in all instances. Postoperative nausea and vomiting were significantly less frequent in the treatment group.

Adult↗

Rationales for the use of alcohol, marijuana, and other drugs by eighth-grade native American and Anglo youth.

This study examined rationales for alcohol, marijuana, and other drug use among Indian and non-Indian youth. Differences were found between reservation Indian and rural non-Indian rationales for alcohol, marijuana, and other drug use. A majority of both Indian and non-Indian eighth graders indicate that they use drugs to enhance positive affective states, for excitement, for parties, to be with friends, to relax, and to handle negative affective states including worries and nervousness. Indian youth appear to also use drugs to cope with boredom. Unlike non-Indian youth, Indian youth have no strong rationales for their use of other drugs. Interventions will have to be impactful and pervasive in order to counter the many positive and negative rationales associated with drug use.

Adaptation, Psychological↗

In vitro evaluation of isolated turkey cardiac muscle function.

Turkey papillary muscles can function in an isolated chamber containing oxygenated, pH-regulated, modified Krebs-Henseleit solutions. Experiments were conducted for up to 6 hr without dimunition of muscle function. Our data indicate that different calcium concentrations affect muscle contraction and relaxation velocities, load values, and latencies. This controlled in vitro biological assay system can be used in further studies to evaluate species specific cardiac toxins or drugs.

Animals↗

A twenty-five year review of laboratory-acquired human infections at the National Animal Disease Center.

The National Animal Disease Center's experience with personnel exposure or infection with pathogenic agents is summarized. A total of 128 laboratory-associated exposures to infectious disease agents were reported. Of these exposures, 103 resulted from known accidents. The other 25 were identified only after the development of clinical or serological manifestations of infection. Thirty-four cases of laboratory-acquired infections were reviewed. Class 3 organisms--Chlamydia sp., Brucella sp. and Mycobacterium sp.--were responsible for 76% of the infections encountered, with Brucella sp. incriminated most frequently. The most commonly reported cause of exposure was associated with hypodermic syringe use. Unknown routes of exposure, presumed to be aerosol related, were the overwhelming explanation involved in the laboratory-associated infections.

Animals↗

Peer review of utilisation of medical beds at Flinders Medical Centre.

A clinical audit of all medical inpatients was undertaken and the appropriateness of admissions and of length of stay was assessed from a clinical viewpoint on 4 separate days within an 11 day period. In addition, the mode of entry of hospital, length of stay of patients, occupancy rate, and the vacancy interval were analysed for all medical patients during the preceding three months. The mean length of stay of medical patients in hospital during this 3 months period was 5.6 days, with an occupancy rate of 93% and a vacancy interval of 0.43 days. Seventy-four percent of all medical inpatients were admitted through the Accident and Emergency Department (A&E). The short length of stay, high occupancy rate and low vacancy interval indicated that bed usage in the medical wards was efficient. A total of 493 reviews was carried out on 294 individual patients. In 87% of cases, both admission to hospital and length of stay were appropriate on clinical grounds alone. The number of patients whose admission to hospital (11), or length of stay (27) was not justified on medical grounds alone was 38 (13% of total patients). These patients were elderly, or had complex social and psychological problems contributing to their illness. It was concluded that stricter control of admissions or length of stay was unlikely to make a significant numbers of beds available for other admissions.

Australia↗