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Biomedical subjects

R Dickey

Publications and source records attributed to R Dickey.

25 records · Page 2Linked to original sources
PubMed1984

Total hip arthroplasty with a low-modulus porous-coated femoral component.

Fifty-seven patients had sixty-three total hip replacements, performed using a femoral stem with a soft, low-modulus porous coating of Proplast and a conventional acrylic-cemented acetabular component. Forty-seven of the hips were followed for an average of thirty-seven months. Seventeen (36 per cent) of the forty-seven hips were judged to be clinical failures, and five of the failures were revised by inserting a new femoral component and fixing it with acrylic cement. The prostheses were thought to have failed because they had inadequate support, due to deficiencies in the design of the stem and in the fit of the implant in the femur. The five retrieved prostheses were found to have fibrous-tissue ingrowth into the coating, which had failed by shear within its substance. Therefore, we concluded that the coating had insufficient strength to withstand normal weight-bearing loads. To improve performance, a more stable prosthesis with a stronger porous coating is needed. In addition, a posterior surgical approach through a transtrochanteric osteotomy may give better exposure of the femoral canal and facilitate the use of longer-stem (140 to 153-millimeter) designs, which are less likely to be inserted in a varus position.

Biocompatible Materials↗
PubMed1977

Thyrotoxicosis and pregnancy. Use of preoperative propranolol for thyroidectomy.

Propranolol has been utilized safely and successfully in the preparation for thyroidectomy in four pregnant patients with thyrotoxicosis. No ill effects were noted in mothers or infants. No change in fetal heart function was noted while two mothers were receiving propranolol. The major advantage of propranolol over the thiourea drugs is the rapidity with which the patient can be prepared for operation. Preparation with beta blockage can be accomplished in five to ten days. This limited experience suggests that propranolol is probably the drug of choice for preparation of the gravid thyrotoxic patient for whom thyroidectomy is planned.

Adult↗
PubMedDate not supplied

Polyketide synthase genes from marine dinoflagellates.

Rapidly developing techniques for manipulating the pathways of polyketide biosynthesis at the genomic level have created the demand for new pathways with novel biosynthetic capability. Polyketides derived from dinoflagellates are among the most complex and unique structures identified thus far, yet no studies of the biosynthesis of dinoflagellate-derived polyketides at the genomic level have been reported. Nine strains representing 7 different species of dinoflagellates were screened for the presence of type I and type II polyketide synthases (PKSs) by polymerase chain reaction (PCR) and reverse transcriptase PCR. Seven of the 9 strains yielded products that were homologous with known and putative type I PKSs. Unexpectedly, a PKS gene was amplified from cultures of the dinoflagellate Gymnodinium catenatum, a saxitoxin producer, which is not known to produce a polyketide. In each case the presence of a PKS gene was correlated with the presence of bacteria in the cultures as identified by amplification of the bacterial 16S ribosomal RNA gene. However, amplification from polyadenylated RNA, the lack of PKS expression in light-deprived cultures, residual phylogenetic signals, resistance to methylation-sensitive restriction enzymes, and the lack of hybridization to bacterial isolates support a dinoflagellate origin for most of these genes.

Animals↗
PubMedDate not supplied

Case report: the management of bone demineralization associated with long-term treatment of multiple paraphilias with long-acting LHRH agonists.

A patient with multiple paraphilias had been successfully treated for 10 years with a long-acting LHRH agonist with complete suppression of deviant sexual activity. However, during treatment, he demonstrated bone demineralization, as documented by serial bone densitometry studies. A treatment regimen was instituted, which resulted in the cessation or partial reversal of bone loss.

Adult↗
PubMedDate not supplied

Haff disease: from the Baltic Sea to the U.S. shore.

Haff disease, identified in Europe in 1924, is unexplained rhabdomyolysis in a person who ate fish in the 24 hours before onset of illness. We describe a series of six U.S. patients from 1997 and report new epidemiologic and etiologic aspects. Although Haff disease is traditionally an epidemic foodborne illness, these six cases occurred in two clusters and as one sporadic case.

Adult↗