Biomedical subjects

N Lau

Publications and source records attributed to N Lau.

26 records · Page 2Linked to original sources

PubMed1994

Prevalence of Toxocara canis in dogs in the City of Havana.

A study on the prevalence of Toxocara canis in domestic dogs of City of Havana was carried out for the first time in Cuba. 22 dogs were selected in each municipality, totalling 330 as the study universe. Dogs' feces samples were processed through direct examination using Willis' flotation method (1921). The results attained showed a 17.9% prevalence of Toxocara canis, a high figure constituting an important risk factor for transmission to humans. This was influenced by the age of the animals and the hygienic conditions of the houses, significant factors from the epidemiological point of view. Sex did not play a significant role.

Animals↗

PubMed1991

Nursing care of pituitary surgery: an example of advanced clinical practice.

Because we have one of the leading pituitary surgeons in Canada, Dr. Harley Smyth, on our neurosurgical service we have nursed over 53f cases of pituitary tumor resection at the Wellesley Hospital. This series of patients represents a major ongoing international research project in Endocrinology and Neurosurgery and involves close teamwork between these two services and the nursing service. The paper gives a brief overview of pituitary surgery from its beginnings with Sir Victor Horsley in 1904 and details major breakthroughs since the 1960's. The three principal clinical groups of pituitary problems treated at the Wellesley are then outlined. The preoperative work-up on the endocrinology ward delineating clinical symptoms and precise hormonal values, the operation with the new anatomical approach developed by Dr. Smyth, and postoperative care with precise monitoring of fluid and electrolyte balance, methods of nasal packing, treatment of cerebrospinal fluid leaks and tracking of hormone levels are all examined in detail. We explain new developments such as the move to less steroid coverage and the better understanding of the ultrastructure and functional microbiology of pituitary tumors. We conclude by pointing out the excellent management of these patients, with a short hospital stay and much of the preoperative work-up done on an outpatient basis. As well these patients are an extremely satisfying group to nurse because of the high correction rate achieved. Finally, as nursing protocols constantly change and as we continually learn more from this research project, we emphasize the need for the flexibility and knowledge of the advanced nursing practitioner.

Humans↗

PubMed1990

Measurement of brain tissue density using pycnometry.

A novel method to measure specific gravity (SG) of tissues, pycnometry (PYC), is described. This method utilizes a 2ml glass pycnometer filled with distilled H2O to determine the displacement volume of a tissue sample and an equation to compute SG from the sample's weight and the pycnometer's weight before and after adding the sample. The PYC method was validated using glass SG standards over the range 1.02-1.26, and against the column density gradient (DG) method using brain tissue from 250-300 g male rats. Factors which affect PYC accuracy, i.e. sample size, were also evaluated. Our results indicate that PYC SG values are highly correlated with the glass SG standards (slope = 1.0107, r = 0.9955, p less than 0.001), and highly correlated with DG when approximately 0.120 ml tissue samples are used in the pycnometer. The DG method was preferable to the PYC method, however, when small tissue samples, i.e. 0.60 ml or less, were used.

Animals↗

PubMed1989

An animal model of epidural compression of the spinal cord.

A new model of subacute compression of the spinal cord is described. Using an expanding epidural mass, a gradual, progressive, and highly reproducible neurological deficit was induced in rats over a 7-day period, resulting in paraplegia. Studies of spinal cord edema, disruption of the blood-spinal cord barrier, and somatosensory evoked responses, as well as histopathological and microangiographical studies, revealed a marked similarity to changes produced in other spinal compression models and in humans. The model may serve to answer some fundamental questions regarding the pathophysiology and efficacy of various treatment modalities of spinal cord compression.

Animals↗

PubMed1989

Optimal reuse of cuprammonium rayon hollow-fibre dialyzers.

The optimal number of times a hollow-fibre cuprammonium rayon (Terumo TAF) dialyzer could be used was determined in twelve patients. Each dialyzer was reused six times. There was a highly significant decrease in neutrophil count (46.9 +/- 6.9%, mean +/- s.e.m.), platelet count (9.6 +/- 3.8%, mean +/- s.e.m.) and serum C3 concentration (10.25 +/- 2.4%, mean +/- s.e.m.) 30 minutes after the commencement of dialysis The intensity of these changes decreased with the re-use of the dialyzers up to the fourth time. There was a small, but significant increase in serum beta 2-microglobulin concentrations after a 6-hour dialysis. The difference between pre- and post-dialysis serum beta 2-microglobulin concentrations appeared to be greater during the 5th and the 6th use (18.8% and 20.5% vs 5.0% during the first use). The clearance rates of urea and creatinine showed a trend to decrease from the fourth use onwards and the ultrafiltration coefficient was significantly reduced from the third use (8.5 +/- 4.0 mean +/- s.e.m.) onwards so that at the sixth use it was only 75.8 +/- 4.8%, (mean +/- s.e.m.) of the value at the first use. It is concluded that the optimal number of uses a cuprammonium rayon hollow-fibre dialyzer can be put to is four.

Biocompatible Materials↗

PubMed1988

High dose versus low dose dexamethasone in experimental epidural spinal cord compression.

A compound of methylcellulose-silicone expanding progressively over a 1-week period by moisture absorption was implanted in the midthoracic epidural space of 17 Sprague Dawley adult rats. When the animals became paraplegic 6.3 +/- 1.6 days later, they were randomized into three groups: untreated control (n = 5), high dose dexamethasone (HD, 1.25 mg/kg intramuscularly, twice daily, n = 5), and low dose dexamethasone (LD, 0.125 mg/kg intramuscularly, twice daily, n = 7). Motor strength was evaluated daily by an observer unaware of the treatment given to the rats. Animals treated with dexamethasone (HD or LD) improved faster than untreated control animals. No significant difference in the rate of recovery or degree of motor improvement was noted between the HD and LD groups. Mortality was higher in the HD group because of infections and gastrointestinal perforation/bleeding.

Animals↗

PubMedDate not supplied

Pediatric pain management (Part II).

This article is the second in a two-part series on pediatric pain management. It primarily contains information about the use of narcotic analgesics for pediatric patients.

Child↗

PubMedDate not supplied

Pediatric pain management (Part I).

This article is the first in a two-part series on pediatric pain management. It contains primarily a general discussion of pediatric pain, myths and misconceptions about pediatric pain, and the use of nonnarcotic analgesics for pain control. In the second article, the use of narcotic analgesics for the pediatric population will be discussed.

Analgesics↗