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Biomedical subjects

L Ho

Publications and source records attributed to L Ho.

149 records · Page 9Linked to original sources
PubMed1971

Deficiency of coenzyme Q 10 in gingival tissue from patients with periodontal disease.

The specific activities of the succinate dehydrogenase-coenzyme Q(10) reductase in gingival tissue from patients with periodontal disease have been compared with the corresponding specific activities of normal human periodontal tissue. The gingival biopsies from patients having diseased periodontal tissue showed a deficiency of coenzyme Q(10), in contrast to those of the normal periodontal tissue which showed no deficiency. The presence or absence of a deficiency of coenzyme Q(10) in the succinate-coenzyme Q(10) enzyme system is appraised by determining the specific activity in the absence and again in the presence of exogenous coenzyme Q(3). An increase in specific activity of this mitochondrial enzyme system in the presence of exogenous coenzyme Q(3) reflects the mitochondrial deficiency of coenzyme Q(10). Such increases ranged from 38-120% and averaged 81% for the individuals with periodontal disease, and were highly significant statistically. These data correlate with clinical studies in Japan that have indicated a therapeutic benefit of the administration of coenzyme Q(7) to many patients with severe and destructive periodontal disease and with the benefit of administration of hexahydrocoenzyme Q(4) to one such patient in the current work.

Adolescent↗
PubMedDate not supplied

Olfactory neuroblastoma: the results of modern treatment approaches at the University of Michigan.

A retrospective study was undertaken to review patterns of treatment and survival for patients with olfactory neuroblastomas at the University of Michigan since the introduction of craniofacial resection in the late 1970s. Recent results were compared to previous reports. Disease-free and overall survival for patients with Kadish stage B tumors were unchanged from prior years. Improvement in both disease-free intervals and overall survival was evident for patients with stage C tumors. Interestingly, in two patients with "unresectable" local disease, complete responses to induction chemotherapy followed by radiotherapy were noted.

Adolescent↗
PubMedDate not supplied

Accumulation of beta-amyloid fibrils in pancreas of transgenic mice.

Some forms of familial Alzheimer's disease are caused by mutations in the amyloid beta protein precursor (beta APP), and there is excellent evidence that these mutations foster amyloid deposition by increasing secretion of total amyloid beta protein (A beta) or the highly amyloidogenic A beta 1-42 form. These observations provide a powerful rationale for developing an animal model of AD by generating transgenic mice in which cerebral amyloid deposition is induced by A beta overproduction. To produce substantial A beta in vivo, we generated mice expressing the transgene of signal peptide and 99 residues of carboxyl-terminal fragment (CTF) of beta APP under control of the cytomegalovirus enhancer/chicken beta-actin promoter. The transgenic mRNA was detected in many tissues of these mice, but the levels of transgenic mRNA, CTF, and A beta did not correlate well indicating that tissue-specific posttranslational processing may play an important role in determining the amount of A beta that accumulates in various tissues. A beta was detected biochemically in brain, kidney, and pancreas with the largest amount present in pancreas. In transgenic plasma, there was a marked accumulation of human A beta 1-40 and A beta 1-42(43) to levels over 30-times those observed in normal human plasma. Thus, the transgenic mice produce and secrete considerable A beta. Despite this increase in A beta secretion and the elevated A beta in brain, immunohistochemistry revealed no consistent cerebral A beta deposition. In pancreas, however, intracellular A beta deposits were detected immunohistochemically in acinar cells and interstitial macrophages, some of which showed severe degeneration. In addition, examination of these cells by immunoelectron microscopy revealed many putative amyloid fibrils (7-12 nm) that were stained by anti-A beta antibodies. Overall, our findings indicate that tissue-specific posttranslational processing may play a pivotal role in A beta production and amyloid fibril formation in vivo. By carefully analyzing the changes that occur in the transgenic mice described here as compared to the transgenic line that has recently been shown to form extracellular amyloid plaques in brain, it may be possible to gain considerable insight into the factors that determine the location and amount of A beta that accumulates as amyloid.

Amyloid beta-Peptides↗
PubMedDate not supplied

The cognitive failures questionnaire in psychiatry.

As a self-report questionnaire, the Cognitive Failures Questionnaire (CFQ) was originally devised to measure perception, memory, and motor lapses in daily life. CFQ scores have been found to correlate with some psychiatric symptoms associated with stress; hence, high scores on the CFQ are considered by some as an indicator of increased vulnerability to stress. Attempts to identify a stable factor structure for the CFQ have produced disparate results. However, there is a measure of agreement with regard to the presence of a "general cognitive" factor that includes loadings from most items and accounts for the lion's share of the variance. Not enough is known about the performance of the CFQ in clinical populations to use it as a measure of change. The current study sought to explore the performance of the CFQ in three groups of patients, organic (n = 209), mixed (n = 115), and functional (n = 322), and to identify correlations with measures of psychiatric morbidity (General Health Questionnaire [GHQ]), depression (Beck Depression Inventory [BDI]), and recognition memory (Signal Detection Memory Test). In the organic and functional samples, the CFQ score significantly correlated with the BDI and GHQ but not with the recognition memory measure. Three factors were found to be common to the organic and functional samples: cognitive, dissociation, and clumsiness. No characteristic pattern of CFQ item endorsement to differentiate between the organic and functional samples was found. Seven items of the CFQ performed badly because of ceiling or floor effects. The "negative" results reported herein are of relevance to researchers who may be planning to use the CFQ in clinical research. The CFQ remains a promising instrument, particularly on account of its "ecological" features, but far more investigation is needed before it is used as a standard measure in clinical practice.

Cognition Disorders↗