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Biomedical subjects

K S Ho

Publications and source records attributed to K S Ho.

35 records · Page 2Linked to original sources
PubMed1997

Costal2, a novel kinesin-related protein in the Hedgehog signaling pathway.

The Hedgehog (HH) signaling proteins control cell fates and patterning during animal development. In Drosophila, HH protein induces the transcription of target genes encoding secondary signals such as DPP and WG proteins by opposing a repressor system. The repressors include Costal2, protein kinase A, and the HH receptor Patched. Like HH, the kinase Fused and the transcription factor Cubitus interruptus (CI) act positively upon targets. Here we show that costal2 encodes a kinesin-related protein that accumulates preferentially in cells capable of responding to HH. COS2 is cytoplasmic and binds microtubules. We find that CI associates with COS2 in a large protein complex, suggesting that COS2 directly controls the activity of CI.

Animals↗
PubMed1997

2-hydroxyethyl methacrylate-terminated polyurethane/polyurethane interpenetrating polymer networks.

The interpenetrating polymer networks (INPs) of polyurethane (PU) and 2-hydroxyethyl methacrylate (MEHA)-terminated polyurethane (HPU) were prepared by solution polymerization. PU prepolymer was synthesized from 4,4-diphenyl methane diisocyanate (MDI) and poly(propylene oxide) glycol (PPG). HPU prepolymer was synthesized from MDI, poly(tetramethylene oxide) glycol and HEMA. Dynamic mechanical analysis showed that the resultant IPN membranes have good compatibility between their constituents. As the HPU content increased, the tensile strength of the IPNs first increased and then decreased. For the highest tensile strength, the optimum HPU content was about 25 wt %. The value of surface tension of IPNs varied from 44.4 to 50.5 dyne/cm, and polarity ranged from 0.59 to 0.91. The relative index of platelet adhesion (RIPA) of the IPN membranes was measured by the dynamic thrombosis test at constant shaking speed and temperature. By the criteria of this test, the IPN membranes with HPU content of about 25 wt% to the minimum platelet adhesion. When measured by the angular dependent ESCA technique on the surface of IPN samples, the variation in the RIPA correlated to the change in the surface soft segment to hard segment ratio. Higher HPU content resulted in more migration of soft segments toward the surface. The platelet adhesion was observed to be minimized when the surface O/N ratio was around 12.

Animals↗
PubMed1995

Binge eating disorder, retention, and dropout in an adult obesity program.

OBJECTIVE: The purpose of this study was to identify factors associated with dropout in a weight reduction program among obese, nonpurging binge and nonbinge eaters. METHOD: We categorized 156 obese, nonpurging women previously randomized to a behavior modification-based (BM) or a food addiction theory-based (FD) weight reduction intervention by binge status using the DSM-IV criteria for binge eating disorder (BED). Subjects were monitored prospectively for dropout during the 6-month intervention period. RESULTS: Results of a Cox proportional hazards survival analysis indicated binge status had a statistically significant (p = .04) protective effect against dropout. Binge eaters were half as likely to dropout versus nonbinge eaters. DISCUSSION: We conclude that (1) the DSM-IV criteria for BED is a useful method of classifying obese individuals in weight loss interventions and (2) the identification of subgroups among obese subjects is an important step in understanding retention in weight loss programs. Future research can confirm this finding.

Adult↗
PubMed1995

[Ulcerative colitis in Taichung Veterans General Hospital: a clinical study].

This report concerns 34 patients of ulcerative colitis admitted to Taichung Veterans General Hospital, from 1983 to 1994. Among them 26 were male and 8 were female. The age at onset were mostly from 50 to 60. The average duration between onset of symptoms and the date of definite diagnosis was 10 months. The most common presenting symptom was bloody diarrhea (64.7%). Most of our patients were in the moderately severe group of disease (67.6%), according to the severity defined by Truelove and Witts. The most frequent endoscopic findings of mucosa was classified as Grade III (38.2). Descending colon (91.2), rectum (85.3%), and sigmoid colon (88.2%) were the most frequently involved areas. The major clinical course were chronic intermittent and chronic continuous type (55.9%). Extraintestinal manifestations were found in 2 cases: one was found in the skin, and the other in the joint, respectively. Treatment of ulcerative colitis in our series was mainly medical (91.2%). However, 3 patients received emergent surgical intervention, and 10 patients finally underwent operation because of major complications or failure to respond to medical treatment.

Adolescent↗
PubMed1995

Effect of oral erythromycin on patients with diabetic gastroparesis.

BACKGROUND: Abnormal gastrointestinal motility is a well recognized complication of diabetes mellitus, and disordered gastric emptying may hamper glycemic control. The objects of this study were to investigate the effect of oral erythromycin on gastric emptying and to evaluate the effect of corrected gastric emptying on glycemic control in patients with diabetic gastroparesis. METHODS: Twenty patients of Type II (non-insulin-dependent) diabetes mellitus with typical symptoms of gastroparesis and delayed solid phase gastric emptying were studied. There were 18 males and 2 females, aged 49 to 72 years. Erythromycin (erythromycin estolate) was given orally at a dose of 250 mg, 3 times daily, 30 minutes before each meal. Radionuclide-labelled solid phase gastric emptying and fasting blood sugar (FBS) were studied after one day of erythromycin therapy, and again after 2 weeks of the therapy. The half time of gastric emptying (GETt1/2) represented the time needed for 50 percent of the initial radioactivity to leave the stomach, and was used to express the gastric emptying status. RESULTS: The GETt1/2 decreased from 198.0 +/- 58.9 minutes at baseline to 139.1 +/- 67.6 minutes following one day of erythromycin therapy (p < 0.01), and to 137.1 +/- 71.2 minutes after two weeks of treatment (vs. baseline p < 0.01). The FBS decreased from 159.0 +/- 40.2 mg/dl at baseline to 149.0 +/- 38.5 mg/dl following one day of therapy (p = 0.12, NS), and to 139.2 +/- 39.8 mg/dl after two weeks of treatment (vs. baseline p < 0.02). CONCLUSIONS: It was concluded that erythromycin is an effective prokinetic agent for diabetic gastroparesis, and that corrected gastric emptying may improve glycemic control.

Administration, Oral↗
PubMed1995

Effects of intravenous erythromycin on antroduodenal motility in humans: non-invasive observations with real-time ultrasound.

Erythromycin has been shown to act on motilin receptors on gastrointestinal smooth muscle in vitro and to accelerate gastric emptying in normal subjects as well as in patients with diabetic mellitus. To evaluate the motor pattern that accounts for this accelerated emptying, the effects of 12.5 mg/min erythromycin vs. placebo on postprandial motility of the antroduodenum was examined with real-time ultrasound in 15 normal subjects. During 10 minutes of observation, erythromycin significantly increased forward transpyloric flow episode (1.04 +/- 0.19 vs. 0.37 +/- 0.41; p < 0.05), forward transpyloric flow duration (5.79 < 4.49 vs. 3.19 < 1.72 seconds; p < 0.05) and improved antro-pyloro-duodenal coordination (0.43 +/- 0.23 vs. 0.21 +/- 0.17; p < 0.05). However, no significant differences were found for gastric peristaltic cycle (22.62 +/- 3.06 vs. 23.40 +/- 2.14 seconds; p > 0.05), retrograde transpyloric flow episode (0.13 +/- 0.16 vs. 0.18 +/- 0.29; p > 0.05), and retrograde transpyloric flow duration (1.24 +/- 0.30 vs. 1.38 +/- 0.58 seconds; p > 0.05). We conclude that erythromycin increases episode and duration of forward transpyloric flow, and improves antro-pyloro-duodenal coordination, which may play a role in accelerating gastric emptying.

Adult↗
PubMed1995

Use of real-time ultrasound for detection of gastric motility.

BACKGROUND: To evaluate the clinical applications and reproducibility of real-time ultrasound in detecting gastric motility, result of study of gastric motility in normal volunteers is reported. METHODS: From January to May 1994, 21 normal volunteers, with a mean age of 31.7 years, 10 females and 11 males, entered this study. They fasted overnight. After consuming a liquid test meal (500 cc, 80.627 Kcal, containing sieved bran particles), they received real-time ultrasound examinations immediately to detect gastric peristalsis and transpyloric fluid flow. To evaluate the reproducibility of real-time ultrasound methods in gastric motility, four of the volunteers repeated this examination at an interval of one week. RESULTS: The results showed that the mean gastric peristaltic cycle in humans is 24.29 seconds (s); mean forward transpyloric flow duration is 4.00 s; mean retrograde transpyloric flow duration is 1.45 s and mean time needed for initiating gastric peristaltic contractions after the test meal is 138.06 s. Age, body weight and body surface have a positive correlation to the mean gastric peristaltic cycle. Females, with a less body weight and body surface than males, exhibit a faster gastric peristaltic cycle. Real-time ultrasound is a reproducible method for studying gastric motility. CONCLUSIONS: Real-time ultrasound is an inexpensive, reproducible and practical method for studying gastric motility. In addition, age, body weight and body surface have a positive correlation to gastric peristaltic cycle, with females, whose body weight and body surface are less than males, showing a shorter gastric peristaltic cycle.

Adult↗
PubMed1993

Prior esophageal variceal bleeding does not adversely affect survival after orthotopic liver transplantation.

Prior variceal bleeding may adversely affect the prognosis of orthotopic liver transplantation. We studied this question by evaluating all 175 adult patients undergoing orthotopic liver transplantation at our institution to determine risk factors associated with mortality after transplantation. Seventy patients demonstrated prior variceal bleeding, and of those, 32 had a course of sclerotherapy. Thirteen also had portal systemic shunts. Compared with the 105 transplant patients who had no prior bleeding, patients who bled were more likely to have parenchymal liver disease (74% vs. 50%), equally likely to have cholestatic liver disease (19%), and less likely to have malignancy (6% vs. 19%) or fulminant liver failure (1% vs. 12%). Bleeding patients also were more likely to be Child-Pugh class C (46% vs. 35%). By the common closing date of December 31, 1990, 26 patients (37%) with prior bleeding and 48 patients (46%) without bleeding died after transplantation. From survival curves, patients with prior bleeding had improved survival rates at 1 yr (65% vs. 54%), at 3 yr (60% vs. 47%) and at 5 yr (55% vs. 43%), although the differences were not statistically significant. With a proportional hazards model to adjust for confounding effects, the relative risk of mortality among patients with prior bleeding was 0.60 (95% confidence interval, 0.27 to 1.30). Sclerotherapy or portal systemic shunts did not alter survival. Important adverse risk factors for mortality included older age at transplantation, black race, malignant disease and more advanced Child-Pugh class. This study suggests that prior esophageal variceal bleeding did not adversely affect the mortality of patients undergoing orthotopic liver transplantation.

Adult↗
PubMed1991

Friction ... Friction resistance between edgewise brackets and archwires.

This study quantified the dynamic frictional force encountered when TMA, Orthonol and multistranded stainless steel archwires were pulled a distance of 2mm through ceramic and stainless steel brackets. The current literature is inadequate and incomplete, for example, no data was found on rectangular multistranded archwires. The following factors were investigated: archwire material, archwire size, archwire-to-bracket angulation, bracket material, archwire and bracket slot surface roughness and lubrication in the form of artificial saliva. A total of 156 different combinations were investigated. A universal testing machine was used to pull the ligated archwires through the brackets, and record the friction. A four way analysis of variance with one nesting (archwire size) was carried out on 1,560 measurements to assess the results. All factors and interactions tested were significant in determining friction. Friction was found to increase with: archwire angulation and archwire size (exceptions were seen in some TMA archwires). Friction decreased with lubrication. There was a definite relationship between friction and archwire and bracket material. There was no definite relationship between archwire surface roughness and friction. Highest friction was observed with ceramic bracket and TMA archwire. The range of friction was 1.02 to 9.95 Newtons. The magnitude of the friction recorded is substantially larger than the forces applied in orthodontic movement clinically. It is proposed that the values recorded should be utilised as a means of comparing the effects of different factors, rather than for the quantification of friction in vivo.

Analysis of Variance↗
PubMed1975

Two mutations which confer temperature-sensitive radiation sensitivity in the yeast Saccharomyces cerevisiae.

X-ray survival curves for two mutations, rad54 and rad55, in the yeast Saccharomyces cerevisiae are presented. These mutations confer temperature sensitive X-ray sensitivity; that is rad54 and rad55 strains display a wild type X-ray survival response at permissive temperatures and a radiosensitive X-ray survival response at restrictive temperatures. The survival response of cells which were shifted from a permissive to a restrictive temperature or vice versa at various post-irradiation times indicates that repair and fixation of X-ray induced lesions is largely complete three hours after X-irradiation. Experiments to determine the utilization sequence of the rad54 and rad55 gene products in the repair of X-ray induced damage suggest that the two products are required in an interdependent manner.

DNA Repair↗
PubMed1975

The gene dosage effect of the rad52 mutation on X-ray survival curves of tetraploid yeast strains.

The mutation rad52 in the yeast Saccharomyces cerevisiae confers sensitivity to X-rays. The gene dosage effect of this mutation on X-ray survival curves of tetraploid yeast strains is shown. With increasing number of rad52 alleles, both a decrease in the survival for a given dose and a decrease in the survival curve shoulder width are observed. The generation of such a family of survival curves using three different mathematical models is discussed.

Aneuploidy↗
PubMed1975

Induction of DNA double-strand breaks by X-rays in a radiosensitive strain of the yeast Saccharomyces cerevisiae.

Sedimentation profiles for chromosomal DNA from unirradiated and X-irradiated yeast cells of wild type and rad 52 strains are presented. These profiles indicate that, whereas wild type strains rejoin DNA double-strand breaks, rad 52 strains apparently do not. These data suggest that the rad 52 mutant lacks a repair system for X-ray induced damage and are consistence with the proposal that an unrepaired chromosome break leads to reproductive cell death.

Chromosomes↗
PubMedDate not supplied

[The implementation of a strategy for the primary prevention of diabetes mellitus].

A pyruvate test for glucose tolerance was used during prophylactic medical examination of 47 students and 27 children without risk factors, 54 students with risk factors, 31 patients with type I diabetes mellitus and 220 construction workers in order to test a new methodological basis for the strategy of primary prevention of diabetes mellitus. The investigations showed the presence in a general population of 3-modal distribution of a variant of the capillary blood pyruvate level on the 120th min. of a GTT according to physiological glucose tolerance, potential (prediabetic) and actual (diabetic) carbohydrate metabolic derangements. A high informative value of the pyruvate test for glucose tolerance makes this method appropriate for identification of persons, genetically predisposed to the development of diabetes mellitus, for implementation of a population strategy of prevention of this disease as well as strategy of prevention of diabetes among persons with risk factors.

Adolescent↗
PubMedDate not supplied

Maintenance of cholesterol reduction using automated telephone calls.

A critical problem in the dietary treatment of hypercholesterolemia is the long-term maintenance of cholesterol reduction. A system to maintain contact and provide feedback through a computer-interactive phone system was used with 115 subjects who completed a four-week diet and behavioral cholesterol reduction program. The subjects, mean age 48 years, were 87% non-Hispanic Caucasian and 74.8% were female. They were randomized to a control or maintenance group. The maintenance group received calls twice a month for six months. Total cholesterol (TC) and weight (lb) were obtained before and after a four-week program and after the six-month maintenance period. Neither group of subjects with all cholesterol measurements fully maintained initial cholesterol reductions (mean TC: in maintenance [n = 48) 248, 221, 231 versus control [n = 43] 243, 224, 232 mg/dL). All (n = 59) of the maintenance subjects used the phone system, with 83.3% of a subset evaluating it indicating the phone messages were helpful. Patients (n = 25) with > or = 5 lb weight loss and 10% TC decrease from baseline had a better maintenance of TC reduction in the maintenance versus control group (273,208,231 versus 259,205,246 mg/dL) (P < .05). We conclude that (1) maintenance remains a problem for cholesterol-lowering diet interventions, (2)automated phone calls are capable of maintaining contact and providing patient feedback, and (3) this system may help in the maintenance of TC levels for patients who made greater changes.

Cholesterol↗