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Biomedical subjects

K Andrews

Publications and source records attributed to K Andrews.

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

Recovery of patients after four months or more in the persistent vegetative state.

A retrospective review was made of the case notes of 43 consecutive patients admitted to a unit specialising in the rehabilitation of people in the persistent vegetative state. Eleven of these patients regained awareness four months or more after suffering brain damage. The time to the first reported incidence of eye tracking was between four months and three years, and the time to the first response to command was between four and 12 months. Only one patient was eventually unable to communicate, six could use non-verbal methods of indicating at least a yes or no response, and four were able to speak. Six patients remained totally dependent while two became independent in daily activities. Four patients became independent in feeding, three required help, and four remained on gastrostomy feeding. Thus some patients can regain awareness after more than four months in a vegetative state, and, although few reach full independence, most can achieve an improved quality of life within the limitations of their disabilities. The recovery period is prolonged and may continue for several years. Even patients with profound brain damage should be offered the opportunity of a specialist rehabilitation programme.

Activities of Daily Living↗
PubMed1993

Patients in the persistent vegetative state: problems in their long term management.

Physicians responsible for the long term management of patients in the persistent vegetative state face several problems. These include deciding whether tube feeding is treatment or nutritional care, whether withdrawal of tube feeding is an appropriate form of management, what clinical advantage there is in active treatment; at what level of awareness can a patient be said to have a quality of life; and who should determine a patient's right to die. These problems are determined more by social, legal, emotional, cultural, religious, and economic forces than by clinical facts.

Brain Damage, Chronic↗
PubMed1993

Carrier erythrocytes from white-tailed deer: morphology, osmotic fragility and survival of circulating sickled erythrocytes.

Carrier erythrocytes are used to disseminate drugs in the circulatory system of animals. Carrier erythrocytes prepared from white-tailed deer (Odocoileus virginianus) do not circulate well in vivo. Although carrier cells were prepared from sickle and non-sickle cells with no apparent differences, their 24-hour survival was only 10 per cent. Osmotic fragility of carrier cells was increased over that of normal deer erythrocytes. Unlike erythrocytes from other ruminants, deer carrier erythrocytes are extremely fragile. Scanning electron micrographs of deer erythrocytes (sickle or non-sickle) in different stages of carrier cell preparation revealed no morphological differences. These data suggest that carrier cells from deer would not be amenable for use in long-term dissemination of drugs.

Animals↗
PubMed1993

The effect of changes in temperature and humidity on the accuracy of von Frey hairs.

A series of von Frey hairs was subjected to changes in temperature and relative humidity (RH) simulating those encountered on a neonatal intensive care unit. The effect of each environmental change on their calibrated value was monitored. It was found that changes in RH significantly affected their calibration, whereas changes in temperature had a smaller effect. The results of the study indicate that the environmental conditions in which von Frey hairs are used should be taken into account.

Calibration↗
PubMed1993

Differentiation-associated switches in protein 4.1 expression. Synthesis of multiple structural isoforms during normal human erythropoiesis.

Erythroid differentiation is accompanied by dramatic alterations in morphology and membrane mechanical properties resulting, in large part, from reorganization of the membrane skeletal protein network. The 80-kD protein 4.1 is an important organizational component of this membrane skeleton. Recently, it has been recognized that multiple structural isoforms of 4.1 are encoded by a single gene via alternative pre-mRNA splicing, and that an upstream ATG can be spliced in and used for translation of high molecular weight 4.1. We are exploring the hypothesis that differentiation-associated switches in protein 4.1 structure play an important role in membrane reorganization. To study changes in 4.1 gene expression during normal human differentiation, we analyzed 4.1 protein and mRNA structure at various developmental stages. Using immunofluorescence microscopy, we observed high molecular weight 4.1 isoforms in preproerythroblasts producing punctate, predominantly cytoplasmic staining with a perinuclear area of intense fluorescence, while mature red cells expressed very little high molecular weight 4.1. Isoforms containing an alternatively expressed 102-nucleotide exon near the COOH terminus were abundant in both preproerythroblasts and mature cells but produced a punctate distribution of fluorescence over the entire preproerythroblast and intense membrane-associated fluorescence in the erythrocyte. Characterization of RNA by polymerase chain reaction and nuclease protection assays revealed a differentiation-associated switch in pre-mRNA splicing in the spectrin-actin binding domain. Since this domain plays a critical role in regulating membrane material properties, we speculate that this switch may be crucial to reorganization of the skeletal network during erythropoiesis. We conclude that 4.1 isoforms are differentially expressed and differentially localized during erythropoiesis, and that this isoform family is likely to have diverse functions during terminal differentiation.

Alternative Splicing↗
PubMed1992

Assessment of the percutaneous endoscopic gastrostomy feeding tube as part of an integrated approach to enteral feeding.

The insertion of percutaneous endoscopic gastrostomy has been well documented. The possible benefits for patient nutrition and nursing practice have, however, not been assessed. We report a study of enteral feeding by percutaneous endoscopic gastrostomy in 30 patients, the majority with a persistent vegetative state. All patients had previously been fed through a nasogastric tube using manual administration and a dietitian assessed protein calorie intake. Based upon body mass index (weight/height2), midarm circumference and triceps skinfold thickness, 20 (67%) were malnourished, with 10 patients having a body mass index less than 17 (severe malnutrition); attributed to high rates of both tube displacement and feed regurgitation. Patients were observed over six to 12 months after percutaneous endoscopic gastrostomy insertion combined with overnight continuous pump feeding. All patients attained a body mass index greater than 17, and 17 (56%) of the total number achieved the normal range with no change in protein-calorie intake (pre: 2110 kcal, post: 1880 kcal). Complications of percutaneous endoscopic gastrostomy in the study group included peritonitis (one), tube site infection (two) and displacement (two); all without serious sequelae. As part of an integrated approach percutaneous endoscopic gastrostomy proved a safe and efficient method of enteral feeding and justifies wider consideration in the United Kingdom.

Adult↗
PubMed1991

Prevalence, characteristics and factors associated with falls among the elderly living at home.

Attempts to determine the underlying causes of falls have come to conflicting conclusions, partly because subject groups studied have not been representative of all elderly people. Two hundred and three randomly selected people of 75 years and over, living at home, were visited and questioned about falls experienced in the previous 12 months, and about factors that might be related to falling. Eighty-six subjects (42.4%) had suffered one or more falls during this time, and of fallers, 49 (59.3%) were injured, 9 of them seriously. Women were slightly more likely to have had falls and were more likely to have suffered injury, but no increase in frequency of falls with age was demonstrated. Only a minority of fallers (43.0%) sought medical attention following their fall. Falls outside the home accounted for 39.5% of falls and these were more likely to be due to simple trips or slips. Analysis of the factors related to falls showed a considerable overlap between fallers and non-fallers. Fallers had significantly greater dependency and cognitive impairment, more physical symptoms, and higher scores for anxiety and depression, but there was no association with postural hypotension, neurological abnormalities, or measurements relating to nutritional state. The factors found to be significant on discriminant analysis were combined to determine a "fall risk score". This type of easily calculated score might be of use to medical and paramedical personnel for assessing the risk of falling among the elderly living at home.

Accidental Falls↗
PubMed1991

Identification of a cloned sequence activated during multi-stage carcinogenesis in mouse skin.

Differential screening of cDNA libraries made from chemically induced malignant mouse skin squamous cell carcinomas (SCC) identified three sequences, including one called mal2, that were upregulated in their expression at both the benign papilloma and malignant SCC stages. The mal2 plasmid cDNA clone (containing a 350 bp insert) was used to screen lambda phage cDNA libraries made from chemically induced SCCs. Two of the largest mal2-related cDNA inserts obtained from the phage libraries were sequenced. In addition a mal2-related genomic clone was obtained by hybridization probing of a mouse spleen genomic DNA library. The sequence of the genomic clone overlapped and was identical with both the mal2 plasmid and lambda cDNA clones. Identity was found between the mal2 cDNAs, the mal2 genomic sequence and the cDNA sequence for a mouse hyperproliferative keratin called K6. A synthetic oligonucleotide specific for the 3' untranslated region of the mal2 or keratin K6 gene was used in Northern analyses to demonstrate elevated steady-state levels of K6 keratin transcripts in SCCs induced by various protocols involving both chemical and ionizing radiation initiation of tumors as well as complete chemical and radiation carcinogenesis protocols. Metastatic lung lesions derived from SCCs generated by repeated doses of benzo[a]pyrene showed moderate levels of K6 keratin transcripts, whereas normal lung showed very low levels of K6 transcripts. The overexpression of the mal2 or keratin K6 gene in malignant SCCs was independent of the protocol, either chemical or radiation, that was used to induce the tumors.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1991

Primary nursing and the role of the nurse preceptor in changing long-term mental health care: an evaluation.

The main aims of this action research study were to implement primary nursing in two long-term psychiatric rehabilitation/continuing-care wards and to investigate the effects of the intervention of the quality of nursing care provision. This evaluation took the form of a quasi-experimental time series analysis. A package of measures together with a number of peripheral indicators was used before primary nursing was introduced on each ward and again after primary nursing had become established. The results showed that the implementation of primary nursing led to nurses being more accountable for care, resident who were seen to be more self-sufficient and independent and wards which had an improved environment for care and rehabilitation.

Attitude of Health Personnel↗
PubMed1991

Encapsulation by hypotonic dialysis in human erythrocytes: a diffusion or endocytosis process.

Human erythrocytes subjected to controlled hypotonic dialysis are capable of encapsulating and retaining drugs. Under selected conditions encapsulation has been reported to occur by an endocytosis process. The mechanism by which encapsulation occurs under conditions which are conducive for endocytosis to occur was studied. An analysis of the percentage of cells with endocytic vacuoles was made for cells dialyzed to optimal and suboptimal osmotic pressures for encapsulation. No differences were found with approximately 20% of cells from all preparations containing vacuoles. Transmission electron micrographs of cells in different stages of carrier cell preparation reveal endocytic vacuoles both with and without hemoglobin. However, based on the percentage of exogenous substance encapsulated, encapsulation appears to occur primarily by diffusion and secondarily by endocytosis.

Dialysis↗
PubMed1990

Rehospitalization after initial rehabilitation for acute spinal cord injury: incidence and risk factors.

Many acute spinal cord injury (SCI) patients require rehospitalization after discharge from initial rehabilitation. Previous studies of rehospitalization for these patients have been cross-sectional with respect to time since injury (in years), and have not allowed for comparison of patients with equal exposure to the risk of medical complications once they have reentered the community. To examine the incidence, cause, and monetary cost of rehospitalizations during the first year after discharge from initial rehabilitative care (day 365), the medical records of 88 consecutive, acute SCI patients who completed initial rehabilitation at a regional model SCI care system were reviewed. Cases were excluded from the study if the patient was lost to follow-up before day 365. All readmissions to the regional SCI care system during the follow-up period were reviewed for primary diagnosis, length of stay (LOS), and hospital charges incurred. Thirty-four patients (39%) were readmitted at least once by day 365. There was a total of 47 readmissions; mean LOS was 11.9 +/- 2.1 days per admission (+/- 1SE), and mean hospital charge per admission was $9,683. Univariate comparisons between the characteristics of patients who were readmitted vs those who were not indicated that the readmitted group was less educated (11.8 +/- 2.1 years vs 12.9 +/- 0.3 years, p less than 0.05) and had a substantially longer initial rehabilitation LOS (88.9 +/- 6.6 days vs 72.9 +/- 5.1 days, p less than 0.05). Readmissions were less common among patients who were discharged at Frankel class C or D (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Biological and molecular aspects of radiation carcinogenesis in mouse skin.

The process of mouse skin carcinogenesis can be operationally subdivided into at least three stages which have been termed initiation, promotion, and progression. Ionizing radiation has been found to be a weak initiator of malignant squamous cell carcinomas (SCCs) when radiation was followed by repeated treatments of the skin with the tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Besides SCCs, ionizing radiation was found to induce, independent of tumor promoters, basal cell carcinomas (BCCs), a tumor histology not normally seen with chemical carcinogens and mouse skin. Fractionated doses of 1 MeV electrons were found to enhance the conversion of chemically induced benign papillomas to malignant SCCs. In addition to the biological studies, questions related to dominant transforming genes and differential gene expression in the radiation-initiated mouse skin tumors have been explored. Distinct non-ras dominant transforming gene(s) have been detected in radiation-initiated, TPA-promoted SCCs. Differences in the expression pattern of tumor-associated genes were seen in comparing chemically to radiation-induced benign and malignant skin tumors. Therefore, ionizing radiation has been shown to be active in the initiation of malignant skin tumors and progression of benign to malignant tumors in the mouse skin. The ability to divide the process of carcinogenesis into multiple stages in the mouse skin model has facilitated mechanistic studies that may elucidate the molecular pathways involved in radiation-versus chemically induced tumor development.

Animals↗