Search PubMedSearch

Biomedical subjects

R Davidson

Publications and source records attributed to R Davidson.

At least 19 recordsLinked to original sources

Endoluminal stenting for benign colonic obstruction.

We report a case of complete descending colon obstruction due to diverticular disease that was initially managed by endoscopic stent placement followed by single-stage left colectomy with primary anastomosis. Traditional management of complete large bowel obstruction, whether due to benign or malignant disease, most often requires a temporary colostomy because of unprepared colon. In this case, preparation of the colon was accomplished by successful stenting of the benign colonic obstruction. We believe that endoscopic colonic stenting is an effective way of avoiding a temporary colostomy in patients with complete large bowel obstruction.

Colonic Diseases

P67L: a cystic fibrosis allele with mild effects found at high frequency in the Scottish population.

Only three mutant cystic fibrosis (CF) alleles have to date been established as conferring a dominant mild effect on affected subjects who are compound heterozygotes. We now add a fourth, P67L, which occurs on about 1.4% of Scottish CF chromosomes. Among 13 patients (12 unrelated) with this allele, the average age at diagnosis was 22.5 +/- 11.3 years. None of the cases had consistently raised sweat chloride concentrations, the average value being 57 +/- 9 mmol/l; 77% of the patients were pancreatic sufficient. When compared to three other established mild CF alleles, R117H, A455E, and 3849 + 10kb C-T, a compound heterozygote for P67L has minimal disease and clinical suspicions are unlikely to be confirmed other than by DNA typing.

Adolescent

What's in a name?

Explore the source record for details and available documents.

Dental Research

A comparison of the effect of shoes on human tibial axial strains recorded during dynamic loading.

Percutaneous axial extensometers were mounted on the medial cortex of the midtibial diaphysis in seven male volunteers and the effect of three different shoes on in vivo peak-to-peak axial compression-tension strains measured during dynamic loading. Zohar shoes had lower axial strains and strain rates during treadmill walking than Nike Air Max running shoes or Israeli infantry boots. During running on a running track, there was no statistically significant difference between the axial strains or strain rates between the shoes tested. Shoe gear can modify tibial strains and strain rates that contribute to the development of tibial stress fractures.

Adult

Efficacy and safety of liposomal amphotericin B (AmBisome) for visceral leishmaniasis in endemic developing countries.

Reported are the results of a study to determine the efficacy and safety of liposomal amphotericin B (AmBisome) for treating visceral leishmaniasis (kala-azar) in several developing countries where the disease is endemic (Brazil, India, and Kenya). At each study site, sequential cohorts of 10 patients each were treated with AmBisome at a dose of 2 mg.kg-1.day-1 (2 MKD). The first cohort received regimen 1:2 MKD on days 1-6 and day 10 (total dose: 14 mg/kg). If the efficacy with this regimen was satisfactory, a second cohort received regimen 2:2 MKD on days 1-4 and 10 (total dose: 10 mg/kg); and a third cohort received regimen 3:2 MKD on days 1, 5, and 10 (total dose: 6 mg/kg). In India, regimens 1, 2, and 3 (which were studied concurrently) each cured 100% of 10 patients. In Kenya, regimen 1 cured all 10 patients, regimen 2 cured 90% of 10 patients, but regimen 3 cured only 20% of 5 patients. In Brazil, regimen 1 was only partially curative: 5 of 13 patients (62%). Therefore, 15 patients were administered regimen 4 (2 MKD for 10 consecutive days; total dose, 20 mg/kg) and 13 patients were cured (83%). These results suggest that for the treatment of kala-azar the following doses of AmBisome should be administered: in India and Kenya, 2 mg/kg on days 1-4 and day 10; and in Brazil, 2 mg/kg on days 1-10.

Adolescent

A detailed investigation of two cases exhibiting characteristics of the 6p deletion syndrome.

Deletions of the short arm of chromosome 6 are relatively rare, only 16 cases having been described in the literature so far. Here we present a detailed investigation by fluorescence in situ hybridisation of two further cases with different but overlapping interstitial deletions involving 6p22, 6p23 and 6p24. The main features involved are craniofacial malformations, heart and kidney defects, mental retardation/developmental delay, hypotonia and hydrocephalus. By using 36 yeast artificial chromosome and cosmid clones from a contig covering 6p22.3-6p25 and other probes with defined cytogenetic locations within 6p21-6p22 we have precisely localised the breakpoints involved in each of the cases, estimated the sizes of the deleted regions and defined the region that is hemizygously deleted in both cases.

Abnormalities, Multiple

Liposomal amphotericin B (AmBisome) in the treatment of complicated kala-azar under field conditions.

An open trial of liposomal amphotericin B (AmBisome [L-AmB]; Vestar, San Dimas, CA) for treatment of complicated visceral leishmaniasis was performed in Sudan. Forty-nine patients were treated, and there were six deaths (12% mortality); these were not attributed to therapy. Thirty-seven patients were selected for the trial because of (1) relapse after treatment with a combination of pentavalent antimony (Sbv) and aminosidine, (2) incomplete parasitological response to Sbv and aminosidine, or (3) severe illness. Drug regimen 1 (3 doses of 3-5 mg/kg, on days 0, 3, and 10) cured 8 (50%) of 16 patients; regimen 2 (6 doses of 3-5 mg/kg, on days 0, 3, 6, 8, 10, and 13) cured 14 (88%) of 16. For four of 10 partial responders, "rescue" therapy with L-AmB alone (3 mg/kg daily for 10 days) resulted in cure. Twelve less-unwell patients received regimen 3 (4 doses of 4-5 mg/kg, on days 0, 2, 5, and 7); seven of 11 patients evaluated (64%) were cured. The optimal regimen of L-AmB in these circumstances is administration of 4 mg/kg on days 0, 3, 6, 8, 10, and 13.

Adolescent

'Stakes are even higher'.

While Congress continues to debate how and where to slice more than $450 billion out of the future growth of the federal Medicare/Medicaid programs, the American Hospital Association is in the midst of an aggressive advocacy campaign intended to minimize the impact on America's hospitals and health systems. In an exclusive interview with the editors of Georgia Hospitals TODAY, American Hospital Association President Richard Davidson outlined AHA's efforts and goals during the legislative process and stressed the need for all hospitals to be involved in educating their legislative representatives.

American Hospital Association

A novel mutation of the fibrillin gene causing ectopia lentis.

Ectopia lentis (EL), a dominantly inherited connective tissue disorder, has been genetically linked to the fibrillin gene on chromosome 15 (FBN1) in earlier studies. Here, we report the first EL mutation in the FBN1 gene confirming that EL is caused by mutations of this gene. So far, several mutations in the FBN1 gene have been reported in patients with Marfan syndrome (MFS). EL and MFS are clinically related but distinct conditions with typical manifestations in the ocular and skeletal systems, the fundamental difference between them being the absence of cardiovascular involvement in EL. We report a point mutation, cosegregating with the disease in the described family, that displays EL over four generations. The mutation changes a conserved glutamic acid residue in an EGF-like motif, which is the major structural component of the fibrillin and is repeated throughout the polypeptide. In vitro mutagenetic studies have demonstrated the necessity of an analogous glutamic acid residue for calcium binding in an EGF-like repeat of human factor IX. This provides a possible explanation for the role of this mutation in the disease pathogenesis.

Amino Acid Sequence

Replication in cultured C2C12 muscle cells correlates with the neuroinvasiveness of California serogroup bunyaviruses.

The neuroinvasiveness of California serogroup bunyaviruses is determined by the ability of the virus to replicate in striated muscle after peripheral inoculation of mice. Neuroinvasiveness was mapped to the medium (M) RNA segment of the virus, which encodes the viral glycoproteins, when reassortants were made between La Crosse/original virus, a neuroinvasive isolate, and Tahyna-181/57 virus, a nonneuroinvasive clone. We have tested the murine muscle cell line C2C12 as a surrogate for myotropism and have found that there is a slight, but reproducible difference in the replication of virus clones bearing the M RNA segment of La Crosse/original virus compared to clones bearing the M RNA segment of Tahyna-181/57 virus, as determined by viral titer, antigen expression, and plaque formation.

Animals

A family with adult-onset cerebral adrenoleucodystrophy.

A family in which three members presented with cerebral adrenoleucodystrophy in adulthood is described. The implications on our understanding for the mechanisms controlling the phenotypic expression of this genetic disorder are discussed.

Adrenoleukodystrophy