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Biomedical subjects

D Clark

Publications and source records attributed to D Clark.

At least 145 records · Page 8Linked to original sources
PubMed1994

Ocular biometry in pre-term infants without retinopathy of prematurity.

Serial ocular A-scan ultrasound biometry was performed on 100 pre-term infants (less than 32 weeks gestation and/or less than 1500 g) who did not show features of retinopathy of prematurity (ROP) during a screening programme. Axial length increased from 15.38 +/- 0.25 mm at 33 weeks post-menstrual age to 16.88 +/- 0.59 mm at 41 weeks (rate of growth 0.18 mm/week, r = 0.99). The rate of growth appeared to slow down after 40 weeks (term) to 3 months post-term. Male infants had longer eyes and a greater rate of growth than female infants. Axial length (AL) was significantly correlated with birth weight, biparietal and occipito-frontal diameter in the weeks after birth. Between weeks 33 and 41, the anterior chamber depth (ACD) increased from 1.92 +/- 0.13 mm to 2.43 +/- 0.18 mm, and lens thickness (LT) increased from 3.82 +/- 0.33 mm to 3.90 +/- 0.13 mm. The largest percentage growth between weeks 33 and 41 occurred in ACD (22%), followed by vitreal length (10%), AL (9%) and LT (2%). These data will help in future studies on the role which ROP plays in the development of ocular growth.

Anthropometry↗
PubMed1994

Some mechanical properties of 10/0 monofilament nylon sutures.

A short pilot study is described which investigates some of the mechanical properties of ophthalmic sutures. The Alcon 10/0 monofilament nylon suture was found to behave in a mechanically consistent manner. Like all nylon it possesses the property of 'creep', which helps to compensate for overtightening of the section during surgery.

Astigmatism↗
PubMed1994

Energy metabolism in free-living, 'large-eating' and 'small-eating' women: studies using 2H2(18)O.

The doubly-labelled water (2H2(18)O) technique was used to assess the long-term rates of energy expenditure and, after accounting for any changes in body composition, the derived rates of energy intake in weight-stable 'large-eating' (n 6) and 'small-eating' (n 6) women. The self-reported energy intakes (approximately 11.2 v. 5.6 MJ/d) and energy expenditures (approximately 8.5 v. 12.4 MJ/d) for the 'large-eating' and 'small-eating' groups respectively, should not be sustainable without significant body-weight changes. 2H2(18)O-assessed rates of energy expenditure for the 'large-eaters' (approximately 8.5 MJ/d) and 'small-eaters' (approximately 11.3 MJ/d) were in close agreement with the results obtained using 5 d, self-reported activity diaries but the derived rates of energy intake for the 'large-' (approximately 8.5 MJ/d) and 'small-eaters' (approximately 10.8 MJ/d) were markedly different from those obtained using self-reported, weighed food diaries. When two 'small-eaters' were supplied with their self-reported energy intakes (approximately 5 MJ/d) for up to 28 d both subjects lost about 0.75 kg body-weight/week. These results provide no support for the existence of 'metabolically efficient' women in the community.

Adult↗
PubMed1994

Ixodes scapularis (Acari: Ixodidae) deer tick mesoscale populations in natural areas: effects of deer, area, and location.

Nymphal Ixodes scapularis Say deer ticks were collected at 22 parks or other natural areas on Long Island, New York, to examine the relationship between tick populations and geographic position, size of area, presence of white-tailed deer, Odocoileus virginianus (Zimmerman), and numbers of human Lyme disease cases in adjacent communities. Nymphal ticks were 93% less abundant when deer were absent and were also less common in smaller natural areas. Geographic position on Long Island was not important. Tick numbers were significantly correlated with human Lyme disease incidence in adjacent townships. A second survey of larval ticks from five areas where deer were absent and six where deer were present found larvae present at four of the five sites without deer, but at only 2% of the levels found where deer were present. These results suggest that populations of I. scapularis can occur and reproduce in the absence of white-tailed deer, so that eradication of all deer would greatly reduce, but not eliminate, all risk of Lyme disease.

Animals↗
PubMed1994

Non-cardiac chest pain and benign palpitations in the cardiac clinic.

OBJECTIVES: To assess the characteristics of consecutive patients referred from general practice with the presenting disorder of chest pain or palpitations, and to determine the outcome at six months and three years. SETTING: A single consultant teaching hospital cardiac clinic receiving new referrals from a health district. DESIGN: 94 consecutive referrals by general practitioners to a cardiac clinic with the presenting disorder of chest pain or palpitations were assessed at first attendance (research interview, cardiologists' ratings, systematic medical case note information), home interview six months later, and by a postal questionnaire at three years. OUTCOME MEASURES: Physical and psychological symptoms, limitation of activities, satisfaction with care, and use of health care resources. RESULTS: 39 patients were given a cardiac diagnosis and 51 patients were not given a cardiac or other major physical diagnosis. The non-cardiac group was more likely to be young women, and to report other physical symptoms and previous psychiatric problems. The cardiac and non-cardiac groups reported progressive improvement in presenting symptoms and disability at the six months and three year follow up, but little change in mental state. Even so, three quarters of the non-cardiac subjects described continuing limitation of activities, concern about the cause of their symptoms, and dissatisfaction with medical care. CONCLUSIONS: A substantial proportion of the consecutive referrals continued to describe symptoms and disability throughout the three years after clinic attendance. Outcome was poor for those who had negative investigations and were reassured that they had no cardiac disorder or other serious physical finding. These results have implications for defining the role of psychological assessment and for the formulation of cost effective clinical measures to (a) minimise disability associated with cardiac disorder; and (b) prevent and treat handicaps in those without major physical diagnoses.

Activities of Daily Living↗
PubMed1994

Benign intracranial hypertension: a cause of CSF rhinorrhoea.

Four patients undergoing treatment for benign intracranial hypertension presented with spontaneous CSF rhinorrhoea. The four patients, all women, were aged between 33 and 44 years. They had been receiving treatment for benign intracranial hypertension for a period ranging from eight months to 11 years, before developing the CSF leak. There was no history of previous head injury and there were no congenital anomalies of the floor of the anterior fossa. The site of the CSF fistula was localised to the cribriform plate in all four cases. The pathophysiology of the CSF rhinorrhoea and the surgical management of this group of patients are discussed. The authors propose that benign intracranial hypertension should be included in the classification of high pressure CSF leaks.

Adult↗
PubMed1994

Identification of war victims in Croatia.

The intention of this paper is to describe the organizational principles and indicate the results already achieved in the identification of war victims in Croatia. By 25 February 1993, 6,493 victims had been identified. A model is proposed that could be used in the course of identification processes, examining the methods and principles of identification which have been complicated by the time interval of more than a year from the time of death, for a presumed number of several thousand (up to 14,000) unidentified victims, possibly in mass graves. Identification is further complicated by the lack of ante-mortem medical and dental records and the incapacity to utilize more expensive methods of identification. Attention is drawn to a group of more complex cases examined at the Institute of Forensic Medicine and Criminology.

Croatia↗
PubMed1994

Multiple cycles of dose-intensive cyclophosphamide, etoposide, and cisplatinum (DICEP) produce durable responses in refractory non-Hodgkin's lymphoma.

Patients whose lymphoma is resistant to standard treatment regimens continue to do poorly, with only an occasional patient achieving long-term remission even with bone marrow transplantation. Twenty-three patients with primarily refractory (11), or refractory relapsed (12) non-Hodgkin's lymphoma were treated with repeated cycles of dose-intensive cyclophosphamide, etoposide, and cisplatin (DICEP) without bone marrow transplantation. Each cycle of DICEP consisted of cyclophosphamide (2500 mg/m2/day, days 1-2), etoposide (500 mg/m2/day, days 1-3), and cisplatin (50 mg/m2/day, days 1-3). Twelve patients (52%) have achieved a complete response and 6 (26%)r a partial response. Three of the complete responders remain continuously free of disease for 19, 29, and 32 months, and 3 more are disease-free at 58, 59, and 65 months after receiving further therapy. Three-year survival for all patients is 45%. Patients with a good initial performance status (Zubrod 0 or 1) had a 58% complete response rate and a 2-year survival rate of 53%. One of 19 patients with an initial performance status of 0 or 1 had treatment-related mortality. Repeated cycles of DICEP can produce long-term responses in patients with refractory non-Hodgkin's lymphoma.

Adult↗
PubMed1994

Nursing process: teaching elderly clients.

1. Nurses responsible for teaching older persons must adjust traditional approaches to address special age-related physical and psychosocial changes. 2. In order to develop effective teaching strategies, nurses should use the nursing process as a guide for identifying key knowledge deficits, establishing realistic goals, incorporating appropriate content, and evaluating learning. 3. The teaching environment, the actual presentation, and the presenter of information all influence the older adult's ability to learn important health-related information.

Aged↗
PubMed1993

A lipoprotein signal peptide plus a cysteine residue at the amino-terminal end of the periplasmic protein beta-lactamase is sufficient for its lipid modification, processing and membrane localization in Escherichia coli.

By genetic exchange and in vitro mutagenesis a hybrid beta-lactamase was constructed that contained the pCloDF13-encoded bacteriocin release protein signal peptide plus a cysteine residue coupled to the mature portion of beta-lactamase. Immunoblotting, labelling with [3H]palmitate in the presence and absence of globomycin, and pulse-chase experiments revealed that this hybrid construct is modified with lipid and processed into a lipid-modified beta-lactamase. Subcellular localization studies revealed that this hybrid is localized both in the cytoplasmic and outer membranes of Escherichia coli cells. A mutant derivative with an incomplete lipobox (LVG instead of LVAC+1) was not processed and was found in the cytoplasmic membranes.

Amino Acid Sequence↗
PubMed1993

The apparent role of blood transfusions in the development of retinopathy of prematurity.

During a 30-month-period, 184 very low birth weight infants from two Liverpool neonatal intensive care units were screened for evidence of retinopathy of prematurity (ROP). Seventeen clinical variables previously considered relevant to the development of ROP, blood gas and blood pressure data over the first 7 days, and the maximum stage of ROP reached in either eye were recorded, together with the need for cryotherapy and current visual status. Ninety-two infants developed any stage of ROP and 15 required cryotherapy or became blind. Logistic regression showed that only gestational age and frequency of blood transfusion were independently associated both with the risk of occurrence of ROP and its severity.

Female↗
PubMed1993

Time sampling observation procedure for studying drug effects: interaction between d-amphetamine and selective dopamine receptor antagonists in the rat.

A rapid time sampling observation procedure combined with two forms of automatic activity assessment is described. The methods are illustrated by examination of the behavioral effects of d-amphetamine, administered to rats either alone or in combination with antagonists selective for D1 or D2 dopamine (DA) receptors. Low doses of d-amphetamine (0.5-4.0 mg/kg) increased photocell counts, rearing, ambulation, and various forms of sniffing. Similar effects were observed in the first 30 min following administration of 8.0 mg/kg d-amphetamine. However, animals exhibited licking, intense sniffing down, and repetitive head and limb movements in the following 30 min; minimal ambulation, rearing, and sniffing up were observed. The "traditional" total photocell count measure did not differentiate between these time-dependent changes in locomotion. On the other hand, latch counts-where subjects had to move between the beams to register a count-adequately demonstrated this change in locomotion. The selective D1 receptor antagonist SCH23390 and selective D2 antagonist raclopride dose dependently inhibited the behavioral changes produced by 1.5 mg/kg d-amphetamine. Higher doses of SCH23390, but not raclopride, produced a behavioral pattern indistinguishable from that observed in control sessions. Both DA antagonists equipotently blocked the intense sniffing down and repetitive head/body movements produced by 8.0 mg/kg d-amphetamine. A narrow intermediate range of doses of SCH23390 reduced the incidences of these behaviors and produced levels of locomotion and sniffing straight that were significantly higher than those observed in control session. This form of behavioral activation was not observed with raclopride. Therefore, this observation procedure revealed subtle differences between the inhibitory effects of SCH23390 and raclopride on d-amphetamine-induced behavioral changes.

Animals↗