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Biomedical subjects

M Collins

Publications and source records attributed to M Collins.

At least 379 records · Page 21Linked to original sources

High-frequency precise excision of the Drosophila foldback transposable element.

Precise excision of transposable elements in prokaryotes is a rare event which occurs at a significantly lower rate than transposition and other element-mediated events. Thus, we were intrigued by a eukaryotic transposable element which seemed capable of precise excision at high frequencies. The white-crimson (wc) mutation in Drosophila, a highly unstable allele of the X-linked eye colour locus, white, resulted from the insertion of a member of the foldback (FB) transposable element family. This mutation reverts to its parental phenotype at a frequency of greater than 1 in 10(3) X chromosomes. Characterization of these revertants by Southern blots of genomic DNA indicated that they resulted from loss of the wc insertion. Here we report the nucleotide sequence of the excision point in these revertants, and conclude that the FB element responsible for the wc mutation is capable of precise excision at high frequencies.

Alleles↗

Structure of chromosomal rearrangements induced by the FB transposable element in Drosophila.

Examination of 10 chromosomal rearrangements induced by foldback transposable elements in Drosophila demonstrates that sequences located between two closely linked elements are frequently deleted. Rearrangement and recombination events occurring within or adjacent to a foldback element are also observed. The type and frequency of rearrangement generated depend on element structure and the organization of flanking DNA.

Alleles↗

Comparison of ADCC and NK activities of peripheral blood mononuclear cells from patients at risk for acquired immune deficiency syndrome (AIDS).

Numerous cellular immune defects have been described in patients with acquired immune deficiency syndrome (AIDS). These include anergy, reduced numbers of helper T cells, and decreased effectiveness of natural killer (NK) cells. In this study, we have measured the lytic activity of antibody-dependent cellular cytotoxic (K) cells using a recently described 51Cr release assay in patients clinically displaying lymphadenopathy syndrome (LAD). We then compared ADCC activity with NK activity, T helper/T suppressor ratios and NK cell number in these same patients. Our results indicate that a reduction of ADCC activity can occur in patients with LAD. In our study, patients that showed reduced ADCC activity also showed reduced NK cell function. Other individuals in this study had reduced NK function while ADCC values remained within the normal range. The degree of reversal of the T helper/T suppressor cell ratio was not a useful indicator of cellular immune function as measured by these assays in that individuals with very low ratios often had normal cytotoxic cell function while some patients with ratios in the normal range had decreased cytotoxicity. The percentage of NK cells as determined by HNK-1 monoclonal antibody also did not prove useful in defining potential cytotoxic activities.

Acquired Immunodeficiency Syndrome↗

GC-MS-MS confirmation of unusually high delta 9-tetrahydrocannabinol levels in two postmortem blood samples.

Unusually high levels of delta 9-tetrahydrocannabinol (delta 9-THC) were detected in two postmortem blood samples. Because of sample decomposition, the major metabolite, 11-nor-9-carboxy-tetrahydrocannabinol (delta 9-THCCOOH), could not be determined using the routine EI-MS technique, which cast some doubt on the delta 9-THC result. Analysis of the sample extracts by GC-MS-MS confirmed the presence of delta 9-THC, although no delta 9-THCCOOH was detected.

Dronabinol↗

Fibrous lesion of the distal femur associated with angular deformity.

Unilateral femoral angulation is uncommon. We describe two children with unilateral progressive distal femoral varus and limb-length discrepancy. These deformities were associated with a fibrous lesion involving the medial aspect of the distal femoral metaphysis. Both patients were 15 to 16 months old. In both, the deformity was progressive, resulting in excisional biopsy and osteotomy. The gross and microscopic appearance of both lesions was similar, and the histology was dense fibrous connective tissue. The patients' femoral alignment was maintained at follow-up of a minimum of 16-36 months. The etiology of these lesions is unknown; they are associated with progressive deformity and appear to respond well to surgical intervention.

Biopsy, Needle↗

Teaching children about skin cancer: the draw-and-write technique as an evaluation tool.

Childhood exposure to sunlight is a risk factor for melanoma. To formulate a meaningful program to educate children about the ill effects of the sun, their extant knowledge base must be determined. We have used the "draw-and-write" technique to assess children's perceptions about the sun, suntans, and skin cancer. A total of 693 school children aged 4 to 13 years were asked to draw pictures and label them in response to a series of carefully worded questions. Awareness of the need to apply sunscreen increased from 44% in children aged 4 to 6 years to 95% in children aged 9 to 10 years. Ten percent of children aged 4 to 6 years already perceived a suntan as attractive. While almost all children were aware of the negative immediate effects of sun exposure, namely sunburn, just 30% of American children aged 11 to 13 were aware that sun exposure is a risk for skin cancer. No differences between boys and girls were seen. The "draw-and-write" technique allows assessment of the attitudes and perceptions of children regarding the sun and skin cancer. It also provides valuable information on which to base health education and evaluate its cost-effectiveness.

Adolescent↗

The effect of music as a conditioning aid in prepared childbirth education.

The addition of self-selected music as a conditioning aid during prepared childbirth education and subsequent family performance in labor within a musical environment were examined. Thirty primigravida couples received the same psychoprophylactic instruction, with 15 randomly selected couples receiving the added musical conditioning aid. Medication use remained minimal, without significant difference, for couples who did and couples who did not use music. However, the value of music to both the family and the health care staff is felt to be of enough subjective significance to warrant its use as a normal component of prepared childbirth education.

Anesthesia, Obstetrical↗

Practice variation in the management of pharyngitis: the importance of variability in patients' clinical characteristics and in physicians' responses to them.

The objective of this study was to assess whether geographic differences in antibiotic-prescribing rates for patients with pharyngitis could be explained by intersite differences in patients' clinical characteristics and in how physicians responded to these clinical cues when making decisions. As part of the initial phase of a prospective controlled trial to improve physicians' diagnostic ability, the authors enrolled cohorts of consecutive patients seen at staff-model--HMO student health services in Pennsylvania and Nebraska. Physicians' decisions whether to prescribe antibiotics for 310 consecutive patients presenting with pharyngitis to the former and 214 such patients presenting to the latter at the time of the initial visit were examined. There was a large discrepancy between the antibiotic-prescribing rates at the student health services in Pennsylvania, 106/310, 32.4%, and Nebraska, 156/214, 72.9%. The clinical variables significantly independently associated with treatment at both sites in a logistic regression model were fever, adjusted odds ratio = 2.1 (95% CI = 1.1, 3.8); exudates, 5.4 (2.8, 10); palatine petechiae, 6.5 (1.5, 28); rhinorrhea, 0.46, (0.25, 0.85); and high risk of complications, 3.8 (1.04, 14). There was a significant interaction between site and anterior cervical adenopathy, 5.5 (1.6, 19); and a borderline interaction between site and rhinorrhea, 2.4 (0.89, 6.7). Site was not a significant independent predictor of treatment, 1.8 (0.45, 6.6.). Practice variation was related to geographic differences in patients' clinical characteristics and in how physicians responded to these factors when prescribing antibiotics. How physicians weight patients' clinical characteristics when making decisions may be an important element of their "practice styles."

Anti-Bacterial Agents↗

A protocol for status epilepticus in a long-term care facility using rectal diazepam (Diastat).

INTRODUCTION: A growing population of residents in long-term care facilities (LTCF) is likely to present with status epilepticus (SE), which requires rapid treatment to avoid permanent neuronal damage, associated morbidity, and mortality. The treatment of choice for SE is an intravenous benzodiazepine; however, this is not feasible in most LTCFs because of the training level of the personnel and the risk of respiratory depression. Transport to acute care facilities is often delayed and, in addition, many LTCF residents have "do not hospitalize" orders. As an alternative to an intravenous benzodiazepine, rectal delivery of diazepam has been shown to be effective in stopping prolonged seizures and is more easily accomplished in the LTCF setting. METHODS: The Badger Prairie Health Care Center (BPHCC), a 132-bed LTCF in Verona, WI, developed a protocol for SE that uses a rectal diazepam gel preparation (Diastat) when intravenous access is unavailable. The protocol provides for initiation of long-term anticonvulsant therapy as a follow-up to the acute treatment of SE. RESULTS: BPHCC staff successfully employed the protocol eight times from August 1999 to November 2000; this article describes the protocol and three representative cases.

Journal Article↗

Plastered in Paris.

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Casts, Surgical↗