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Biomedical subjects

D H Lee

Publications and source records attributed to D H Lee.

At least 19 recordsLinked to original sources

Serial cranial and spinal cord magnetic resonance imaging in multiple sclerosis.

Twenty-nine mildly disabled patients with multiple sclerosis underwent serial clinical and magnetic resonance imaging (MRI) evaluations (pre- and postgadolinium cranial and spinal cord MRI) on at least 3 occasions at 13-week intervals and during periods of suspected relapse. Using clinical judgment of the presence of recent active disease as the gold standard, combined MRI studies confirmed the clinical impression of active disease in 93% of follow-up visits (sensitivity) and the absence of active MS in 63% of follow-up visits (specificity). None of the cranial and spinal MRI-detected abnormalities disappeared. Gadolinium administration particularly increased the yield of spinal MRI. Cranial MRI alone detected 80% of the MRI-active visits. Clinical and MRI concordance was significantly better for the presence of recent disease activity than for the anatomical localization of the presumed site of activity. MRI evidence of apparent ongoing disease activity was seen more frequently in patients believed to have active multiple sclerosis in the preceding year (13 of 21) than in patients who had been in clinical remission for at least the 2 preceding years (2 of 8). Although clinical evidence of new disease activity was much less common in patients with active, chronic-progressive disease (1 of 8) than in patients with active, relapsing disease (9 of 13), the proportion of patients with either infrequent relapses, frequent relapses, or slow chronic-progressive disease in the preceding year in whom MRI activity developed and the pattern of this new MRI activity was similar between these types of active patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain

Frequency and distribution of phenylketonuric mutations in Orientals.

The frequency and distribution of eight mutations (R111X, IVS4nt-1, Y204C, R243Q, IVS7nt-2, W326X, Y356X, and R413P) in the phenylalanine hydroxylase gene of Orientals in Japan and Korea were examined by allele-specific oligonucleotide hybridization. The mutant alleles comprised 54 and 55% of the phenylketonuria (PKU) chromosomes examined in 36 patients in Japan and 10 patients in Korea, respectively. The spectrum of PKU mutations in Japan was similar to that in China, particularly in northern China, but different from that in Korea. The IVS4nt-1 mutation had a high frequency in Korea and southern China, due to the result of the founder effect and genetic drift. The R413P mutation, which may have originated in the regions surrounding the Baikal, expanded to northern China and Japan. We did not find Caucasian mutations in the Japanese or Korean PKU chromosomes. Thus, PKU mutations occurred after racial divergence between Caucasians and Mongoloids, and there were different founding populations for PKU in the two populations.

Alleles

Calcified gastric carcinoma: CT findings.

The computed tomographic (CT) findings of 13 cases of calcified gastric carcinoma were analyzed retrospectively. Eleven cases were confirmed as a mucinous adenocarcinoma by surgery (three cases), or endoscopic biopsy (eight cases). Two cases were diagnosed as adenocarcinoma by endoscopic biopsy. In all cases the calcifications were of the punctate or miliary shape and the size varied from 1-3 mm in diameter. The calcifications were located in the thickened gastric wall in all cases, and were seen in metastatic lesions such as lymph nodes and the liver in two cases. In 10 cases, some tumor portions showed lower attenuation number than that of the muscle on CT scans, and corresponded to mucin pool in tumor portions histologically. Twelve cases were in inoperable advanced stage.

Adenocarcinoma, Mucinous

Methylparaben and propylparaben do not alter cerebral blood flow in humans.

In vitro studies suggest that the preservatives methylparaben and propylparaben included in some multidose vials of succinylcholine are the cerebral vasodilators responsible for the increases in intracranial pressure (ICP) documented after succinylcholine administration. To test this hypothesis, we measured cerebral blood flow (CBF) and cerebral blood flow velocity (CBFV) with inhaled 133Xenon and transcranial Doppler respectively in healthy humans before and after the intravenous administration of methylparaben and propylparaben. We found no change in either CBF or CBFV after the paraben injections and therefore conclude that it is unlikely that the rise in ICP seen with succinylcholine is caused by cerebral arterial vasodilatation from the preservatives methylparaben and propylparaben.

Cerebrovascular Circulation

The medical treatment of a tuberculous tracheo-oesophageal fistula.

Tracheo-oesophageal (TE) fistulas caused by Mycobacterium tuberculosis are rare and usually require both surgical treatment and medical treatment with antituberculosis drugs. A patient with a tuberculous TE fistula and mediastinal lymphadenitis was successfully treated by medical management alone.

Adult

Endoscopic carpal tunnel release: a cadaveric study.

Five surgeons performed endoscopic (Dyonics) carpal tunnel releases on 24 fresh cadaver wrists. In 50% of the specimens, transection of the transverse carpal ligament was incomplete. The average amount of incomplete release was 31% (range, 0% to 53%). Three types of incomplete release were noted: (1) release of Guyon's canal release--one, (2) incomplete distal ligament release--five, and (3) incomplete central or superficial release--six. Other technical errors were noted in nine of 24 specimens. There were no nerve lacerations. Endoscopic carpal tunnel release is either a technically demanding procedure, commonly results in incompletely released ligaments, or both. Proper training, followed by practice on several cadaver specimens before its clinical use, is recommended.

Anthropometry

Endobronchial tuberculosis. Clinical and bronchoscopic features in 121 cases.

The clinical and bronchoscopic features of endobronchial tuberculosis in 121 patients were retrospectively investigated. The peak incidence occurred in the second decades, with 3.8 times higher incidence noted in female than in male subjects. A barking cough with sputum was the most common chief complaint in 61.1 percent. Parenchymal infiltration and/or consolidation was the most common roentgenographic finding of the chest in 58.6 percent. Hypertrophy with luminal narrowing was the most common bronchoscopic finding in 43 percent. Bronchoscopically, right upper and right main bronchus were the most frequently involved in 30.5 percent. It was concluded from these data that using fiberoptic bronchoscopy allows not only substantial meaningful assessment of endobronchial tuberculosis but also relieves atelectasis eventually resulting in successful treatment with antituberculosis drugs.

Bronchi

Mass treatment of head louse infestation with Sumithrin powder in primary schools in Korea.

A mass treatment of head louse infestation with Sumithrin powder (0.4% phenothrin) in primary school children was implemented during the period of September 1991-May 1992. The infestation rate of total 2,515 children was 38.6% in average (21.2% in boys and 57.2% in girls). The reduction rate of head louse infestation was 93.4% with a single treatment and 94.8% with double consecutive treatments with about 10 days interval, which indicated that a single treatment would be recommended for the mass treatment in the community. Long term follow-up after Sumithrin powder application for head louse control in a primary school showed that the infestation rate dropped from 33.1% before treatment to 5.4% by seven months after treatment, giving a 83.4% reduction rate.

Age Factors

UV absorption complicates PCR decontamination.

UV irradiation is widely used to inactivate contaminating DNA in PCR. Highly UV-absorbent deoxyribonucleoside triphosphates in PCR mixtures reduce the efficiency of UV decontamination. Optimal decontamination may be achieved by irradiating the PCR mixture without the deoxyribonucleoside triphosphates.

Artifacts

Myelin basic protein-stimulated rosette-forming T cells in multiple sclerosis.

A subpopulation of T lymphocytes sensitized to human myelin basic protein in peripheral blood of patients with multiple sclerosis, central nervous system (CNS) tumors, and cerebrovascular accidents was demonstrated by the antigen-stimulated, rosette-forming T-cell assay. A significant increase in the percent of active rosette-forming T cells was detected after in vitro exposure of peripheral blood lymphocytes to human myelin basic protein but not to histones. In contrast, peripheral blood lymphocytes from healthy controls and from patients with benign and malignant breast diseases were unresponsive to stimulation by either antigen. These results demonstrate a functionally active T-lymphocyte subpopulation sensitized to myelin basic protein in patients with multiple sclerosis and in patients with certain other CNS diseases.

Adult

Cell-mediated immunity to donor antigens in renal allograft recipients.

The antigen-stimulated active rosette-forming T-cell (AgARFC) assay was adapted for the preoperative study of 21 consecutive kidney transplants (17 cadaver donors and four living related donors; five retransplants). Recipient peripheral blood lymphocytes were incubated for 15 minutes with donor histocompatibility antigens preparaed by sonication of donor peripheral blood or splenic lymphocytes. Recipient presensitization to donor antigens was expressed as the difference between active rosette formation in the presence (%AgARFC) and in the absence (%ARFC) of donor antigens. This antigen-induced difference is rosette formation (%AgARFC - %ARFC) for all patients ranged from - 7.0% to 24.2%. Of those patients with pretransplant sensitization greater than 6.3% (group I: mean, 13.2 +/- 3.0; n = 7), 71% had severe acute rejection requiring dialysis within the first 2 weeks of transplantation. In contrast, none of the patients with pretransplant values below 6.3% (group II: mean, -0.8 +/- 1.0; n = 14) had rejection requiring dialysis within the first 2 weeks. Group I patients had 43% graft survival at 1 month and 14% survival at 2 months, whereas group II had 86% graft survival at 1 month and 71% at 2 months. The AgARFC assay provided a rapid means of measuring recipient T-cell presensitization to donor alloantigens, which was correlated with the accelerated rejection of renal allografts.

Antigen-Antibody Reactions

Composition of O-alkyl and O-alk-1-enyl moieties in the glycerolipids of the human adrenal.

A comparison of human adult and fetal adrenals with respect to their levels of glyceryl ether lipids and other lipid components is reported. Fetal glands contained significantly lower levels of alk-1-enyl phosphoglycerides and of cholesterol. Neutral glyceryl ether diesters, and ethanolamine and choline phosphoglycerides were isolated from adult adrenal tissue. The composition of the O-alkyl glycerol groups in these lipid fractions was obtained by means of gas chromatography of the trimethylsilyl ethers and diacetyl derivatives; O-alk-1-enyl glycerols were analyzed as their diacetates. About one-half of the alkyl and alk-1-enyl glycerol moieties present in glyceryl ether diesters contained hydrocarbon side chains with 20, 22, or 24 carbon atoms. Long hydrocarbon chains (C19-24) were also found in the O-alkyl glycerol moieties present in the total lipids of fetal adrenals.

Adrenal Glands

A simple cost control format in clinical laboratories.

Laboratory scientists must be able to demonstrate their proficiency not just in the analysis of specimens but also financial management. The cost information in real dollar term is the only way to measure the productivity of a laboratory. We have demonstrated a simple procedure in tabulating the income and expenditure of our laboratories. In our hand, we have found the information to be useful and timely for various decisions and plannings.

Chemistry, Clinical

Radiation injury to abdominal aorta and iliac artery sustained in infancy.

Late complications of radiation therapy will become more common as treatment of neoplasms in childhood becomes more successful. A patient with a successfully treated Wilm's tumour presented with hypertension 3 years after therapy. Angiography revealed extensive damage to the aorta and left common iliac artery, probably caused by the radiation therapy. The hypertension was the result of renal artery stenosis.

Aorta, Abdominal