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Biomedical subjects

D Nichols

Publications and source records attributed to D Nichols.

At least 55 records · Page 3Linked to original sources
PubMed1993

Developing actual costs of patient services: the University of Alberta Hospitals.

Analysis of the costs of diagnostic and therapeutic services provided to patients yields a multitude of useful results: a sophisticated tool to assist in streamlining the underlying processes of patient care; an improved understanding of the nature and extent of case-based resource requirements; maximization of existing patient information collected through various feeder systems; a key step in the direction of measuring quality and the cost of quality, when linked to patient outcomes realization of the strategic significance of information management in today's complex, data-intensive health industry.

Alberta↗
PubMed1992

The catecholamine response to multisystem trauma.

We studied the catecholamine response in two groups of patients with multisystem injuries according to the presence (group 1, N = 124) or absence (group 2, N = 82) of head injury. Markers of injury severity included the injury Severity Score, the Glasgow Coma Scale, the need for intubation, admission hypotension, the amount of blood products and fluid expanders administered during the first 24 hours, and patient outcome. In group 1, higher norepinephrine levels always and epinephrine concentrations usually were associated with worsening indexes of injury severity. The best correlations were between the Injury Severity Score and the Glasgow Coma Scale and norepinephrine concentrations. In group 2, despite elevated catecholamine levels, such associations were seldom present. Thus, circulating catecholamine levels, especially norepinephrine levels, significantly correlated with the severity of injury in patients who had suffered multisystem injury, but only if the injury included the brain.

Adolescent↗
PubMed1992

Endovascular treatment of posterior circulation aneurysms by electrothrombosis using electrically detachable coils.

In a multicenter study, 120 patients with intracranial aneurysms presenting a high surgical risk were treated using electrolytically detachable coils and electrothrombosis via an endovascular approach. The results of treatment in patients with posterior fossa aneurysms (42 patients with 43 aneurysms) are presented. The most frequent clinical presentation was subarachnoid hemorrhage (24 cases). The clinical follow-up periods ranged from 1 week to 18 months. Complete aneurysm occlusion was obtained in 13 of 16 aneurysms with a small neck and in four of 26 wide-necked aneurysms. A 70% to 98% thrombosis of the aneurysm was achieved in 22 of 26 aneurysms with a wide neck and in three of 16 small-necked aneurysms. One aneurysm could not be treated due to a technical complication. Two cases required postprocedural surgical clipping of a residual aneurysm. One patient (originally in Hunt and Hess Grade V) experienced procedural rupture of the aneurysm requiring an emergency parent artery occlusion. He eventually died 5 days later. Another patient (originally in Grade IV) had coil migration and posterior cerebral artery territory ischemia. A third patient developed a permanent neurological deficit (hemianopsia) after complete occlusion of a wide-necked basilar bifurcation aneurysm. One patient, harboring an inoperable giant basilar bifurcation aneurysm, died from aneurysm bleeding 18 months after partial occlusion. Overall morbidity and mortality rates related to treatment were 4.8% (two cases) and 2.4% (one case), respectively (2.6% and 0% if considering only patients in Hunt and Hess Grades I, II, and III). It is suggested that this technique is a viable alternative in the management of patients with posterior fossa aneurysms associated with high surgical risk. Longer angiographic and clinical follow-up study is necessary to determine the long-term efficacy of this recently developed endovascular occlusion technique. Close postoperative angiographic and clinical monitoring of patients with wide-necked subtotally occluded aneurysms is mandatory to check for potential aneurysmal recanalization, regrowth, and rupture.

Adolescent↗
PubMed1991

Effects of intoxication on the catecholamine response to multisystem injury.

In patients suffering isolated head trauma, we have previously shown that levels of circulating catecholamines obtained within 48 hours of trauma correlate with the severity of brain injury and predict outcome and that intoxication blunts this response. The effects of alcohol on the increase in catecholamines in systematically injured patients, however, have not been well defined. From 1983 to 1990, 78 patients (74% male; median age 30 years) with blunt head and multisystem injury, who also had alcohol levels measured within 5 hours of injury, were studied. Norepinephrine and epinephrine levels were assayed by a radioenzymatic technique. Injury severity was assessed by the admission Glasgow Coma Scale (GCS) score (4-15; median, 12), the Injury Severity Score (ISS) (13-50; median, 25) and the volume of blood products administered within the first 24 hours (0-14.4 L; median, 0.5 L). The impact of alcohol on the norepinephrine response to injury was analyzed using multiple linear regression models, including polynomial interaction terms. Norepinephrine levels significantly (p less than 0.0001) correlated with the GCS score and ISS. However, alcohol significantly lowered the norepinephrine response to decreasing GCS score (R = 0.49, p less than 0.002) and to increasing ISS (R = 0.51, p less than 0.0006). The blunting of the catecholamine response was most marked in those severely injured. The rise in norepinephrine concentrations seen with increasing volume of blood replacement was not affected by intoxication. An association between injury severity and epinephrine levels was also present, but not as consistently. Epinephrine concentrations rose with falling GCS score and with increasing ISS values, but unlike norepinephrine, there were no apparent effects of alcohol on changes in epinephrine levels. Thus, in patients suffering head and multisystem injury, catecholamine changes reflect the severity of injury using three different scalers. Furthermore, intoxication blunts only the norepinephrine component of this important biologic response.

Adolescent↗
PubMed1991

HIV and chlamydia infections among prostitutes in Yaoundé, Cameroon.

Eleven selected prostitute leaders were recruited who subsequently recruited 157 of their peers, bringing the total to 168. Sera was collected and tested for antibodies to HIV-1 and HIV-2 using a commercial enzyme-linked immunoabsorbent assay (ELISA); positive cases were confirmed by Western Blot (Dupont). A direct immunofluorescent method was performed on smears from the endocervical junction. Twelve of 168 (7.1%) of the women tested were found to be HIV-1 positive; none were found positive for HIV-2. Sixty six of 168 (38.3%) were found to be Chlamydia trachomatis (CT) positive; three cases (1.8%) were found to be positive for both HIV-1 and CT. Prostitutes are a high risk group in Yaoundé for HIV and chlamydia infections. The results in this study may not reflect the seriousness of the situation given the selected population used. Similar studies still need to be carried out. Prostitutes need to be educated about AIDS, other STDs and the use of condoms to protect their clients and themselves.

Adolescent↗
PubMed1991

Complications of calcaneal osteotomies.

This article describes the associated complications encountered with calcaneal osteotomies. The paper stresses the importance of preoperative evaluation, surgical technique, and postoperative care. We also emphasize the triplanar nature of calcaneal deformities that calcaneal osteotomies correct.

Calcaneus↗
PubMed1990

The adrenocortical response to brain injury: correlation with the severity of neurologic dysfunction, effects of intoxication, and patient outcome.

To test the hypothesis that cortisol levels reflect the extent of neurologic dysfunction and predict patient outcome, neurologic function and cortisol levels were determined in 120 traumatically brain injured patients who never received glucocorticoid treatment. Their mean age was 29 years and 78% were men. The impact of intoxication was examined in 59 patients who had ethanol levels measured. Ethanol was detectable in 40 patients and greater than or equal to 100 mg/dl in 31. There were significant correlations between the extent of neurologic dysfunction, determined by the Glasgow Coma Score and plasma cortisol concentrations 1 and 4 days postaccident. Cortisol levels were universally elevated on admission and approached normal 7 days later. Multiple linear regression analysis revealed significant effects of circulating ethanol levels on the association between cortisol concentrations and progressively worsening neurologic function, i.e., ethanol reduced the magnitude of the cortisol elevations in a dose dependent manner, abolishing this relationship at levels above 100 mg/dl. Analysis of the relationships between circulating cortisol levels and patient outcome provided a second method for ascertaining the association between injury severity and the magnitude of adrenocortical activation. Admission and day 1 cortisol concentrations were 25 to 40% lower in patients having good recoveries or moderate disabilities than those who remained severely disabled, persistently vegetative or died; serum cortisol values of less than 20 micrograms/dl one day after the accident were more likely to be associated with a good outcome than a poor one (55 vs. 25%, p less than 0.001). The worsening prognosis of patients having higher cortisol values is further reflected in the duration of acute hospitalization of these individuals.(ABSTRACT TRUNCATED AT 250 WORDS)

Accidents, Traffic↗
PubMed1990

Identification of two related markers for common acute lymphoblastic leukemia as heat shock proteins.

By direct analysis of the polypeptide constituents of leukemic cells, we have previously detected several polypeptides that are restricted in their expression to acute lymphoblastic leukemia (ALL). In this study, we provide evidence that two polypeptides designated L2 and L4 are structurally related and represent novel markers for common ALL. Partial amino acid sequence analysis did not uncover differences between L2 and L4. The sequences obtained correspond to a previously cloned human gene designated hsp 27 that is expressed, following heat shock treatment, in a variety of cells. 32Pi incorporation studies indicate that L4 is an unphosphorylated form and L2 is a phosphorylated form of hsp27. The two forms were inducible by heat shock in leukemic and nonleukemic lymphoid cells. Thus, in acute leukemia, the common ALL subtype is uniquely characterized by the constitutive expression of a polypeptide that represents a major cellular phosphoprotein.

Amino Acid Sequence↗
PubMed1990

The adenosine/neutrophil paradox resolved: human neutrophils possess both A1 and A2 receptors that promote chemotaxis and inhibit O2 generation, respectively.

Occupancy of specific receptors on neutrophils by adenosine or its analogues diminishes the stimulated release of toxic oxygen metabolites from neutrophils, while paradoxically promoting chemotaxis. We now report evidence that two distinct adenosine receptors are found on neutrophils (presumably the A1 and A2 receptors of other cell types). These adenosine receptors modulate chemotaxis and O2- generation, respectively. N6-Cyclopentyladenosine (CPA), a selective A1 agonist, promoted neutrophil chemotaxis to the chemoattractant FMLP as well as or better than 5'N-ethylcarboxamidoadenosine (NECA). In contrast, CPA did not inhibit O2- generation stimulated by FMLP. Pertussis toxin completely abolished promotion of chemotaxis by CPA but enhanced inhibition by NECA of O2- generation. Disruption of microtubules by colchicine or vinblastine also abrogated the enhancement by NECA of chemotaxis whereas these agents did not markedly interfere with inhibition by NECA of O2- generation. FMLP receptors, once they have bound ligand, shift to a high affinity state and become associated with the cytoskeleton. NECA significantly increased association of [3H]FMLP with cytoskeletal preparations as it inhibited O2-. Disruption of microtubules did not prevent NECA from increasing association of [3H]FMLP with cytoskeletal preparations. Additionally, CPA (A1 agonist) did not increase binding of [3H]FMLP to the cytoskeleton as well as NECA (A2 agonist). These studies indicate that occupancy of one class of adenosine receptors (A1) promotes chemotaxis by a mechanism requiring intact microtubules and G proteins whereas engagement of a second class of receptors (A2) inhibits O2- generation. Signalling via A2 receptors is independent of microtubules, insensitive to pertussis toxin and is associated with binding of [3H]FMLP to cytoskeletal preparations.

Adenosine↗
PubMed1989

Identification of a cellular polypeptide that distinguishes between acute lymphoblastic leukemia in infants and in older children.

We analyzed the polypeptide pattern of leukemic cells of infants and older children with acute lymphoblastic leukemia (ALL), using two-dimensional polyacrylamide gel electrophoresis (PAGE). Patterns were analyzed for the occurrence of a previously detected cytosolic polypeptide, designated L3. Quantitative analysis of L3 in 12 infants and 91 older children with non-T ALL indicated lack of expression of polypeptide L3 in leukemic cells of infants which, in most cases, expressed HLA-DR and CD19 and lacked CD10. Quantitative analysis of L3 in relation to cell surface marker expression revealed that L3 was limited in its occurrence to non-T ALL and was not coordinately expressed with any of the surface markers included in the study. Among patients in the HLA-DR-positive, CD19-positive, and CD10-negative group, different levels of polypeptide L3 were observed between infants and older children. These results indicate differences in leukemic cell constituents between infants and older children with ALL and an otherwise similar cell surface marker phenotype.

Adolescent↗
PubMed1988

Identification of a polypeptide associated with the malignant phenotype in acute leukemia.

A novel polypeptide, designated p18, was detected in a variety of hematopoietic cells by two-dimensional polyacrylamide gel electrophoresis. Quantitative analysis of p18 indicated its occurrence in a substantially greater amount in acute leukemia relative to nonleukemic cells. The increased amount of p18 in leukemia could not be explained on the basis of specific lineage, differentiation stage, or cell proliferation and thus appears to be a part of the malignant phenotype of the leukemic cells.

Acute Disease↗
PubMed1985

An ear asymmetry for gap detection following anterior temporal lobectomy.

A threshold elevation in the performance of auditory temporal order judgment in man has been reported in the ear contralateral to the side of an anterior temporal lobectomy. On the basis of temporal order judgments alone it is not possible to determine whether the deficit is attributable to an impairment of recognition, identification, or temporal resolution. The present monaural experiments compared the performance of the two ears in the detection of a gap in a broad-band noise burst in normal and temporal lobectomized subjects. The results revealed a right-left symmetry in gap detection performance by normal subjects but a significant deficit in gap detection in the ear contralateral to the side of an anterior temporal lobectomy--a finding interpreted as revealing the existence of a bonafide deficit in auditory temporal resolution induced by such resection.

Adult↗
PubMed1985

Life-threatening airway obstruction as a complication to the management of mediastinal masses in children.

Life-threatening airway obstruction from large mediastinal masses in children poses a difficult diagnostic and therapeutic dilemma, requiring the close coordination of a pediatric surgeon, anesthesiologist, radiologist, and oncologist. To focus on this problem, the anesthetic and surgical management of 50 consecutive children with mediastinal masses treated between 1978 and 1984 were reviewed. Thirty children presented with respiratory symptoms; nine had life-threatening respiratory compromise with dyspnea, orthopnea, and stridor. Thirteen of these symptomatic children had marked compression of the trachea and/or mainstem bronchi on radiographic studies. The tracheal cross-sectional area which was measured by computed tomography was decreased by 35% to 93% of the normal tracheal dimensions in these children. Nonresectable malignant neoplasms including lymphoma, Hodgkin's disease, rhabdomyosarcoma, and neuroblastoma were the eventual diagnoses in 10 of these patients. The other 3 patients were less than 4 years old and had benign lesions. General anesthesia was judged to be prohibitively risky in 5 of 13 patients. The diagnosis was established by node or needle biopsy under local anesthesia, and general anesthesia was deferred until the compromised airway was alleviated by radiation and chemotherapy. General anesthesia with endotracheal intubation was administered to 8 patients, 5 of whom developed total airway obstruction. Using a variety of maneuvers, ventilation was reestablished in all 5 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1984

Safety and effectiveness of weight reduction using a very-low-calorie formulated food.

Careful medical and laboratory monitoring of 27 subjects during a 28-day use of a 330-calorie (Cal)/day liquid formula, with weight loss averaging 9.1 kg (range, 3.2 to 19.1 kg), included a 22-factor automated blood chemistry analysis, BP, hematology, urine analysis, lipid profile, delayed cutaneous hypersensitivity, differential cell count, ECG, and Holter monitoring. Results suggest that very-low-calorie diets can be an effective and safe means of substantial weight reduction. Cautions for specific individuals are noted. The possible beneficial effects on hypertension and on serum cholesterol and triglycerides levels are discussed.

Blood Proteins↗
PubMed1983

Infant and child survival and contraceptive use in the closed pregnancy interval.

While previous studies have examined the relationship between child survival and contraceptive use, they have not considered the impact of the sequence of child mortality on the practice of family planning. The present paper addresses this issue by considering how the birth order of nonsurviving outcomes affects the decision to contracept in the subsequent interval, using data collected from over 10,000 women at the time of hospital delivery. Results indicate that, even when gravidity and the total number of surviving children are held constant, the outcome of the penultimate pregnancy is highly associated with interval contraception.

Birth Intervals↗
PubMed1983

Osteoglophonic dwarfism in two generations.

A father and son, both affected by a skeletal dysplasia with severe craniofacial deformities, are reported and compared to three previously described isolated cases of the same dwarfism. The principal features are craniosynostosis, multiple lucent metaphyseal defects, flattening and anterior beaking of the vertebral bodies, and abnormal dentition. Autosomal dominant inheritance is suggested.

Adult↗