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Biomedical subjects

J Yoon

Publications and source records attributed to J Yoon.

101 records · Page 6Linked to original sources
PubMed1983

Electron microscopy of renal and ocular changes in virus-induced diabetes mellitus in mice.

The eyes, kidneys and pancreas of mice (SJL/J) infected with encephalomyocarditis virus were examined by light and electron microscopy. Diabetic mice with the longest duration (6 months) of diabetes showed marked renal and ocular alterations. Fasting blood glucose levels were 17.8-21.9 mmol/l and glycosuria was present. Clinically, based on ophthalmoscopy and fluorescein angiography, retinal vessels were normal. Histologically, moderately decreased numbers of pericytes were noted following trypsin digestion. The basement membrane of inner retinal vessels showed significant thickening in diabetic mice. Corneal epithelial oedema was present and surface microvillus projections were decreased compared with control mice. The kidneys of the same animals showed nodular and diffuse glomerulosclerosis and mesangial thickening. Electron microscopy showed excessive accumulation of basement membrane-like material in the mesangium and the peripheral glomerular region. Histologically, moderate to advanced kidney disease was associated with relatively early retinopathy.

Animals↗
PubMed1982

Phase II study of 3-deazauridine in advanced colorectal adenocarcinoma.

A phase II study of 3-deazauridine (DAUR) showed poor activity in previously treated patients with advanced colorectal adenocarcinoma. There were no responses among 15 patients treated on a dose schedule of 1200 mg/m2/day for 5 days repeated at 3-week intervals. Toxicity included mild nausea and vomiting, occasional mucositis, diarrhea, and dizziness. A minimal degree of myelosuppression was observed.

3-Deazauridine↗
PubMed1981

Indications for cholecystectomy in ligation of the hepatic artery.

Ligation of the hepatic artery has been successfully used in the management of massive bleeding, secondary to hepatic trauma, and in the treatment of metastatic neoplastic disease. The indications for a concomitant cholecystectomy are less well defined. It is generally accepted that cholecystectomy should be performed when ligation is used to control bleeding. In our study, ligation of the hepatic artery was performed, leaving the gallbladder in situ. At autopsy, no pathologic process could be detected in the gallbladder. Microscopic analysis showed fibrosis in the mucosal surface, mild chronic inflammation and nonspecific mononuclear infiltration. We conclude that the changes are insufficient to warrant the removal of a normal gallbladder when ligation of the hepatic artery is performed as treatment for neoplastic disease.

Adult↗
PubMed1977

Virus-induced diabetes mellitus: VIII. Passage of encephalomyocarditis virus and severity of diabetes in susceptible and resistant strains of mice.

The diabetogenic capacity of the M-variant of encephalomyocarditis (EMC) virus was markedly diminished after passage in mouse kidney cell cultures. One passage in mice fully restored this capacity. Virus harvested after five passages in either susceptible (SWR/J) or resistant (C57BL/6J) strains of mice was capable of producing diabetes in susceptible SWR/J mice but not in resistant C57BL/6J mice. Resistance was not overcome by inoculating mice with high concentrations of virus. Immunofluorescence studies showed that islets from strains of mice (i.e. CBA, AKR, C57BL/6J, A/J) that did not develop diabetes after infection with EMC virus, nonetheless, contained virus antigens. The percentage of cells in the islets containing virus antigens varied from 3-6% in CBA to 13-5% in A/J. In contrast 38% of the islet cells in susceptible SWR/J mice contained virus antigens. It is concluded that both the genetic background of the host and the passage history of the virus influence the development of diabetes.

Animals↗
PubMedDate not supplied

Chelation-enhanced fluorescence chemosensing of Pb(II), an inherently quenching metal ion.

Pb(II) ion serves as a quencher of anthracene fluorescence both intermolecularly and in intracomplex systems reported to date. The advantages of intensimetric analyses showing increasing signal require the design of mechanistically novel fluorescent chemosensors capable of yielding enhanced fluorescence upon chelation of inherently quenching metals. We synthesized both 2- and 9-derivatives of anthracene bearing the N-methylthiohydroxamate ligand, which is capable of quenching fluorescence in the uncomplexed form and which shows some selectivity for Pb(II). Complexation of the 2-derivative to Pb(II) results in rapid metal ion-catalyzed hydrolysis, rendering this compound useless as a sensor with real-time response. However, complexation of the 9-derivative with Pb(II) results in a 13-fold fluorescence increase, reversible upon dissociation of the metal ion. While blood lead analysis is a major potential application for fluorescent chemosensors, the present compound is insufficiently selective for this use.

Anthracenes↗
PubMedDate not supplied

Suprageneric classification of peptidoglycan group B actinomycetes by nucleotide sequencing of 5S ribosomal RNA.

5S ribosomal RNA sequences were determined for thirteen actinomycetes mainly representatives with the rare group B type peptidoglycan. The primary and secondary structure of the resultant sequences were of the type characteristic of Gram-positive bacteria with DNA rich in guanine plus cytosine. The sequencing and associated chemotaxonomic data provide compelling grounds for classifying actinomycetes with a group B type peptidoglycan in a single family. The family Microbacteriaceae fam. nov. is proposed to accommodate actinomycetes classified in the genera Agromyces, Aureobacterium, Clavibacter, Curtobacterium and Microbacterium.

Actinomyces↗
PubMedDate not supplied

Canalographic evaluation of the external ear canal in dogs.

Canalography was performed to measure the diameter of the horizontal ear canal and to assess the clinical relevance of the measurements in identifying abnormalities of the ear canal. The diameter of the proximal and distal end of the annular cartilage in the horizontal ear canal was measured using canalography in 222 ears. The tympanic membrane could not be visualized with otoscopic examination in 70 ears even after ear cleansing. These canals were classified as being stenotic. The diameter of the proximal annular cartilage in the stenotic canals ranged from 0.8 to 3.1 mm (mean = 2.6 +/- 0.8 mm). The proximal annular cartilage was consistently smaller in diameter than the distal annular cartilage. The ratio between the diameter of the proximal and distal annular cartilage varied between dogs. In stenotic ear canals (70 ears) the ratio was less than 0.65. Total ear canal ablations and histopathological analysis were performed in 70 ear canals classified as stenotic after canalography. Hyperplasia of the epidermal layer was found in 56 stenotic canals. Stenosis of the canal due to otitis externa was found in the other 14 canals. Three canals with severe otitis externa were also diagnosed with canalography as having a ruptured tympanic membrane. The results suggest that canalography can be used to measure the diameter of the horizontal ear canal and to assess whether or not the tympanic membrane is ruptured prior to conservative or surgical therapy.

Animals↗
PubMedDate not supplied

Syndrome of painful legs and moving toes: a case study.

Painful legs and moving toes syndrome is characterized by spontaneous causalgic pain in the lower extremities associated with peculiar involuntary movements of the lower extremities, especially the toes and feet. The pain is diffuse, intractable, aching, and deep. The movements consist of persistent writhing movements in the digits that cannot be limited voluntarily. The syndrome has been observed after a variety of abnormalities affecting the posterior nerve roots, the spinal ganglia, and the peripheral nerves. This article reviews commonly reported findings and current concepts in the etiology and management of this condition.

Female↗
PubMedDate not supplied

Clinical results of Ahmed glaucoma valve implantation in refractory glaucoma with adjunctive mitomycin C.

OBJECTIVE: To study the surgical outcome and complications of Ahmed glaucoma valve (AGV) implantation with mitomycin C (MMC) in refractory glaucoma. PATIENTS AND METHODS: The authors retrospectively reviewed the records of 40 eyes in 37 consecutive patients who underwent combined AGV with MMC (0.4 mg/mL; 5 minutes). All patients had a minimum of 6 months of follow-up. Outcome measures were best corrected visual acuity, intraocular pressure (IOP), the number of medications, success rates, and the incidence of complications. RESULTS: The Kaplan-Meier life table analysis revealed that the probabilities of surgical success based on our success criteria at 1 year and 2 years postoperatively were 80% and 77%, respectively. Postoperative IOP was significantly lower at all follow-up intervals. At the final visit fewer glaucoma medications were used (2.5 vs 0.7, preoperative vs postoperative). The most frequent complication was hypotony (17%). CONCLUSION: In this retrospective case series with relatively short follow-ups, AGV implantation with mitomycin C in refractory glaucoma appears to be effective without increased complication rates.

Adolescent↗