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Biomedical subjects

M Ho

Publications and source records attributed to M Ho.

At least 127 records · Page 7Linked to original sources
PubMed1997

Randomized trial of varying mineral intake on total body bone mineral accretion during the first year of life.

OBJECTIVE: The effect of varying mineral intakes on total body bone mass accretion during the first year of life in healthy full-term infants is unknown. The purpose of this study was to determine whether total body bone mass accretion during the first year of life was influenced by the calcium and phosphorus intake of an infant and whether early differences in bone accretion persist through 1 year of age. DESIGN: This prospective, randomized trial was conducted in two phases. In phase I, 67 infants were randomized within the first 2 weeks of life into either a low (439 mg of calcium per liter and 240 mg of phosphorus per liter) or moderate (510 mg of calcium per liter and 390 mg of phosphorus per liter) mineral-containing formula feeding group. An additional group of 34 human milk-fed (low mineral) infants also was enrolled. Phase II involved an additional randomization of all infants at 6 months of age into moderate-mineral formula (see above), high-mineral formula (1350 mg of calcium per liter and 900 mg of phosphorus per liter), or cow milk (1230 mg of calcium per liter and 960 mg of phosphorus per liter) feeding group. Anthropometric measurements, nutrient intake, and total body bone mineral content (BMC) by dual-energy x-ray absorptiometry were measured at 1, 3, 6, 9, and 12 months. RESULTS: During the first 6 months, the moderate-mineral group had a greater increase in weight (3.42 +/- 0.62 kg) compared with the human milk group (2.93 +/- 0.56 kg); the low-mineral group (3.19 +/- 0.62 kg) was intermediate. Bone mass accretion differed in a similar direction, with the moderate-mineral feeding group having a greater increase than the human milk group and the low-mineral group being intermediate of the two. Including weight, length, and bone area as covariates, both the low-mineral formula- and human milk-fed groups had similar BMC, which was lower than that of the moderate-mineral group at 3 and 6 months of age. Adjusted mean BMC values for the moderate-mineral formula-fed group compared with the low-mineral formula- and human milk-fed groups were 127.8 +/- 1.5 (SEM) g vs 119. 2 +/- 1.5 and 122.1 +/- 1.4 g, respectively, at 3 months of age and 168.7 +/- 2.5 g vs 157.6 +/- 2.5 and 158.7 +/- 2.4 g, respectively, at 6 months of age. The BMC at 6 months of age among the formula-fed infants was correlated with both average dietary phosphorus intake (r = .592) and average daily calcium intake (r = .620) during the first 6 months. The relationships between BMC and these minerals remained significant even after controlling for caloric intake. It was not possible to determine the independent effects of dietary calcium and phosphorus on BMC because of the strong correlation of these minerals with each other. Despite significant differences in both calcium and phosphorus intakes during the second 6 months of life, there were no differences in growth parameters or bone mass accretion. Means for BMC, adjusted for body weight, length, and bone area, were not significantly different among feeding groups at either 9 or 12 months of age. Adjusted means were 199 +/- 2 (SEM) and 237 +/- 3 g at 9 and 12 months of age for infants receiving moderate-mineral formula; 198 +/- 2 and 236 +/- 3 g at 9 and 12 months of age for infants receiving the high-mineral formulas and 202 +/- 5 and 233 +/- 5 g at 9 and 12 months of age for infants receiving cow milk. The gain in bone mass during the second 6 months differed by the first 6-month feeding group; mean changes in BMC between 6 and 12 months, adjusted for changes in weight, length, and bone area, were greater in human milk-fed infants than in either the low- or moderate-mineral-containing formula groups: 81 +/- 16 g in human milk-fed infants and 73 +/- 15 and 71 +/- 15 g in the low- and moderate-mineral formula groups, respectively. Infants fed whole cow milk during the second 6 months were excluded from this analysis because of the small number of infants completing the study. By 12 months of age t

Absorptiometry, Photon↗
PubMed1997

Is the quality of diabetes care better in a diabetes clinic or in a general medicine clinic?

OBJECTIVE: To compare the quality of ambulatory diabetes care delivered by physicians in the diabetes clinic versus the general medicine clinic of a university-affiliated Veterans Administration medical center. RESEARCH DESIGN AND METHODS: This is a retrospective study that involved the review of medical records against predetermined process-of-care criteria. A total of 112 patients with diabetes were randomly selected, of whom 56 were cared for in the general medicine clinic and 56 in the diabetes clinic. The following main outcome measures were examined: 1) the compliance with individual criteria; and 2) the proportion of patient visits in each clinic receiving minimally acceptable quality, defined as a blood pressure measurement, a record of type of hypoglycemic medication, a glycated hemoglobin measurement within the past year, a urinalysis within the past year, an ophthalmologist or optometrist eye examination within the past year or scheduled in the next six months, a record of change in therapeutic management, and a scheduled return visit. RESULTS: The diabetes clinic performed significantly better than the general medicine clinic on the following criteria: a record of a patient's self-monitoring of blood glucose levels; a foot examination; a comprehensive eye examination; a glycated hemoglobin measurement; and a referral for diabetic education. The proportion of patient visits meeting the minimally acceptable levels of quality was better in the diabetes clinic than the general medicine clinic (73 vs. 52%, P = 0.02). CONCLUSIONS: Patients cared for by physicians in the diabetes clinic receive better quality of diabetes care than do patients cared for by physicians in the general medical clinic. If patient care is to be shifted from specialists to generalists, additional attention needs to be paid to ensure that generalists have the knowledge and system resources necessary to deliver an acceptable quality of diabetes care.

Blood Glucose Self-Monitoring↗
PubMed1997

Opisthorchis viverrini infection in Thailand: studies on the morbidity of the infection and resolution following praziquantel treatment.

A community study on opisthorchiasis was conducted in Prachinburi Province in eastern Thailand during 1990-1992. The morbidity from opisthorchiasis in the community and reversibility of biliary pathology following treatment with praziquantel at a single dose of 40 mg/kg were assessed by longitudinal investigations of clinical, laboratory, and ultrasonographic changes. A total of 913 voluntary subjects infected with Opisthorchis viverrini were randomly selected for longitudinal study, and 579 subjects without liver fluke infection were recruited as controls. The majority of the study group suffered from mild and moderate infections that were associated with nonspecific gastrointestinal symptoms. Grade I and II ultrasonographic changes, which indicated chronic inflammation of the biliary tract and gallbladder, were detected in 32% of the infected individuals. Clinical symptoms and ultrasonographic changes were common in subjects 21-40 years of age and older. Satisfactory resolution of morbidity was observed during two years follow-up on days 0, 60, 180, 360, and 720, as shown by significant clinical improvement, normalization of laboratory parameters, and downgrading of ultrasonographic abnormalities. Portable ultrasonography has proved to be a reliable noninvasive technique in the evaluation of the morbidity due to opisthorchiasis in rural areas.

Adolescent↗
PubMed1996

A combination of the effects of rare genotypes at the XK and KEL blood group loci results in absence of Kell system antigens from the red blood cells.

The 22 antigens of the Kell blood group system are located on a red blood cell (RBC) membrane glycoprotein that shows sequence homology with a family of metalloendopeptidases. Expression of the Kell system antigens is partially governed by XK, an X-linked gene that encodes the Kx protein; absence of Kx results in reduced Kell antigen expression. Almost total absence of Kell antigens from the RBCs of a German man with no symptoms of neuroacanthocytosis could not be due to the Kell-null phenotype, Ko, because his RBCs had very weak expression of Kx antigen and his three children were Kp(a + b+). Kell antigens were normal on the RBCs of his son but weak on those of his two daughters. An Nla III restriction fragment-length polymorphism within the KEL gene showed the Kpa/Kpa genotype in the propositus. Sequencing of his XK gene showed a single base change within the donor splice consensus sequence of intron 2. A BsaAl restriction fragment-length polymorphism showed the mutation in both of his daughters but not in his son. The extreme depression of the Kell antigens of the propositus must be due to a combination of effects, ie, homozygosity for Kpa and deficiency of Kx protein, each of which is capable of causing some degree of weakening of Kell antigens.

Erythrocyte Membrane↗
PubMed1996

Receptor specificity of clinical Plasmodium falciparum isolates: nonadherence to cell-bound E-selectin and vascular cell adhesion molecule-1.

The pathogenicity of Plasmodium falciparum is due largely to the parasite's unique ability to adhere to capillary and postcapillary venular endothelium during the second-half of the 48-hour life cycle. The resulting sequestration of infected erythrocytes (IRBC) in deep vascular beds leads to tissue hypoxia, metabolic disturbances, and organ dysfunction which characterize severe falciparum malaria. Several endothelial receptors of cytoadherence have been identified, but their clinical relevance remains controversial. In the present report, the receptor specificity of 60 clinical P falciparum isolates was determined using transfectants each expressing one of CD36, intercellular adhesion molecule-1 (ICAM-1), E-selectin, and vascular cell adhesion molecule-1 (VCAM-1). All isolates tested adhered to CD36 and ICAM-1, but the adherence to CD36 was at least 10-fold higher. Seven isolates adhered to E-selectin whereas none of 19 isolates adhered to VCAM-1. From a population standpoint, about 30% of IRBC in each isolate adhered to CD36, and 2% to 3% adhered to ICAM-1. The percentage adherent to E-selectin and VCAM-1 was negligible. IRBC selected on CD36 adhered almost exclusively to CD36 whereas 80% to 90% of IRBC selected on ICAM-1 could also adhere to CD36. Selected IRBC did not adhere to E-selectin or VCAM-1. These findings indicate that cytoadherence to multiple endothelial receptors is a rare occurrence with natural P falciparum isolates, but do not exclude a role for the adhesion molecules in promoting other IRBC-endothelial interactions such as rolling under flow conditions. Receptor specificity in vivo may be dictated by the ligand-receptor combination which provides the best survival potential for the parasite.

Animals↗
PubMed1996

The effect of blood transfusion on tumor growth in sarcoma-bearing rats.

BACKGROUND: The effect of blood transfusion on tumor growth is controversial. Under experimental conditions, even similar animal models can give varied results. This study was undertaken to characterize the nature of the effect of blood transfusion on tumor growth. METHODS: Sixty-five Fischer 344 rats subcutaneously implanted with a methylcholanthrene-induced sarcoma were studied with additive blood transfusion at 1% tumor burden in two separate experiments. In experiment 1, the effects of syngeneic fresh whole blood transfusion (5, 10, and 15 ml/kg) and allogeneic (5 ml/kg) were tested. To determine if stored blood influenced the results, experiment 2 was performed with syngeneic blood transfusion (15 ml/kg) and allogeneic blood transfusion at 5 ml/kg. Tumor dimensions were determined daily by external measurement, and tumor weight and growth rate were calculated. RESULTS: No significant differences in final tumor weights or tumor growth rates were found in transfused rats compared with controls. This held true for syngeneic blood transfusion regardless of dose, allogeneic blood transfusion, and regardless of whether the blood was fresh or stored. CONCLUSIONS: Additive blood transfusion does not affect tumor growth in this animal model. This finding, together with the general inconclusiveness in the reported literature on this topic, speaks against a dominant role for the effect of blood transfusion on tumor behavior.

Animals↗
PubMed1996

Gender and race differences in bone mass during infancy.

The purpose of this study was to determine whether race or gender differences in total body bone mineral content (BMC) are evident within the first 18 months of age. Total body bone mineral measurements were obtained on 64 healthy infants 1-18 months of age. There were no significant differences in age, weight, or height between race and gender groups. Taking into account weight and age, both bone mineral density (BMD) and BMC were greater in male infants compared with female infants (both, P = 0.02) and BMD was slightly higher in black infants compared with white infants (P = 0.07).

Age Factors↗
PubMed1996

Increased incidence of Clostridium difficile-associated diarrhea following decreased restriction of antibiotic use.

Removal of antimicrobial agents from formulary restriction status at our center was followed by an increase in the incidence of Clostridium difficile-associated diarrhea. The mean monthly incidence of C. difficile diarrhea for the 12-month period before institution of decreased restriction of antibiotic use was 3.4 infections per 1,000 admissions and rose to 6.2 infections per 1,000 admissions during the following 4-month period (P < .05). Patients who developed disease before and after decreased restriction of antibiotics were similar in terms of the mean number of antimicrobial agents administered and mean duration of therapy. The most commonly administered agents whose use preceded the onset of disease were cefazolin, trimethoprim-sulfamethoxazole, ampicillin, ticarcillin/clavulanate, and gentamicin (the latter drug was always used in combination with other agents). Immunoblot typing indicated that there was no association between C. difficile strains and administration of specific agents. There was no coincidental epidemic to account for the increased incidence of infection. The increased incidence of C. difficile disease is a potential problem that may occur following removal of extended-spectrum antimicrobial agents from formulary restriction status.

Adult↗
PubMed1996

Use of antiherpes drugs and the risk of Kaposi's sarcoma: data from the Multicenter AIDS Cohort Study.

To determine if use of antiherpes drugs protects against the development of AIDS-associated Kaposi's sarcoma (KS), data from 935 homosexual men with AIDS from the Multicenter AIDS Cohort Study were analyzed. In nested case-control analysis, neither acyclovir use for human immunodeficiency virus infection (odds ratio [OR], 0.84; 95% confidence interval [CI], 0.56-1.26; P = .39) nor acyclovir use for any indication (OR, 1.02; 95% CI, 0.76-1.38; P = .89) was associated with a reduced risk of KS as initial AIDS diagnosis. In longitudinal analysis, acyclovir was also not protective against developing KS as a late manifestation of AIDS (after initial non-KS AIDS diagnosis). Among men with cytomegalovirus disease, ganciclovir use (relative risk [RR], 0.56; 95% CI, 0.22-1.44; P = .23) and foscarnet use (RR, 0.40; 95% CI, 0.051-3.10; P = .38) were associated (although not significantly) with a reduced risk of KS. Thus, acyclovir use does not appear to reduce the risk of KS, but further study of other antiherpes drugs such as ganciclovir and foscarnet is warranted.

AIDS-Related Opportunistic Infections↗
PubMed1996

Neurodevelopmental outcome of infants with viral meningitis in the first three months of life.

We prospectively evaluated the neurodevelopmental outcome of infants with documented viral meningitis to determine (1) whether deficits in physical growth, development, speech and language, hearing, or intelligence occur; and (2) if so, at what age these deficits can be detected. Sixteen infants with documented enteroviral meningitis under the age of 90 days and a control group of 13 patients matched for age, race, sex, and socioeconomic status were followed up prospectively for 3 years with annual evaluations, which included a developmental evaluation by a pediatric developmentalist, articulation and language tests by a speech-language pathologist (Sequenced Inventory of Communication Development, Receptive-Expressive Emergent Language Scale (REEL), Preschool Language Scale (PLS), Revised Peabody Picture Vocabulary Test (PPVT-R), Photo Articulation Test, audiometric screening), and intelligence tests by a psychometrist (Bayley Scales of Infant Development [BSID] and Stanford-Binet). No deficits were demonstrated in growth, development, hearing, BSID, articulation, and expressive language. Subtle but significant (P < 0.05) deficits were documented in the study group compared with the control group in the receptive component of the REEL, all subsections of the PLS, the PPVT-R, and the verbal comprehension/language-processing section (Factor II) of the Stanford-Binet. These differences could be reliably detected by 3 years of age. We conclude that viral meningitis in young infants may cause subtle deficits in language skills, particularly receptive language. We recommend that children who have had enteroviral meningitis during early infancy be monitored carefully for language development and, perhaps, receive increased language stimulation in the home prior to school entry in order to optimize their learning potential.

Analysis of Variance↗
PubMed1996

Pharmacotherapy of Raynaud's phenomenon.

Primary Raynaud's phenomenon is common, particularly in younger women, and may be familial. Vasospasm is not confined to the digits and may involve, for example, the tongue and nose, and also visceral organs like the heart, oesophagus or lung and cerebral circulation. Symptoms tend to be milder in primary compared with secondary Raynaud's phenomenon, which is associated with other disorders such as the connective tissue diseases. Indeed, the severity of symptoms often acts as the predictor for the much later onset of the associated systemic disease. Occupational Raynaud's phenomenon is related to the use of vibrating instruments, and a significant proportion of patients may be cured by an early change in job. In those over 60 years of age, Raynaud's phenomenon is commonly a result of atherosclerotic obstructive arterial disease, and screening for and treatment of the risk factors is appropriate. The best-studied mechanisms in Raynaud's phenomenon involve the blood and vascular endothelium. Microcirculatory flow may be impeded by activated platelet clumps, rigid red and white blood cells and damaged endothelium. These platelet clumps, white blood cells and damaged endothelium also release vasoactive/vasoconstrictive compounds which may additionally trigger the clotting cascade and thrombosis. Initial management for mild disease should focus on support and advice regarding avoidance of known precipitating factors, including vasospastic drugs. Cold protection with warming agents, 'Abel' shoes and also electrically heated gloves and socks is effective, but may be too cumbersome and inconvenient for some patients. Simple vasodilators like naftidrofuryl, inositol nicotinate and possibly pentoxifylline (oxpentifylline) are useful in mild disease, with adverse effects like headache and flushing being less problematic. The 'gold standard' of Raynaud's phenomenon treatment is nifedipine, a calcium channel antagonist/blocker. Full dosage, however, can be limited by ankle swelling, headache and flushing, but adverse effects may be reduced by using the 'retard' or long-acting preparations. Adverse effects are also reduced with the newer calcium channel antagonists like diltiazem but at the expense of efficacy. Useful, enhanced benefit is also achieved by combination therapy with vasodilators. Newer treatments include the prostaglandin analogues which are effective but disadvantaged by their parenteral route of administration, and lack of licence in some countries. Oral preparations are, however, being studied and are in the pipeline. Essential fatty acid supplementation is mildly effective, while ketanserin and calcitonin gene-related peptide both look promising. Lumbar sympathectomy retains its important role in the treatment of Raynaud's phenomenon involving the lower limbs. Satisfactory symptomatic relief is now possible for many patients with Raynaud's phenomenon and this should certainly be the aim for all patients seeking medical help.

Calcium Channel Blockers↗
PubMed1996

P53 expression in choroid plexus neoplasms: an immunohistochemical study.

OBJECTIVE: To evaluate choroid plexus neoplasms for p53 expression. CASE MATERIAL: We studied 10 choroid plexus tumors (four papillomas and six carcinomas) by immunohistochemistry using the DO7 anti-p53 monoclonal antibody. RESULTS: Three of four choroid plexus papillomas demonstrated no staining. Scattered nuclear and rare cytoplasmic positivity was present in one papilloma, which showed foci of increased mitotic activity (labeling index 2.5%). Six of six carcinomas were immunoreactive for p53, and three cases had labeling indexes of over 70%. All immunopositive choroid plexus tumors (7/7) exhibited nuclear staining. Punctate cytoplasmic positivity was identified in 5 of 7 cases. CONCLUSION: Our study suggests that altered p53 expression is detectable by immunohistochemistry in choroid plexus neoplasms and is consistently present in choroid plexus carcinomas.

Adolescent↗
PubMed1996

Expression of p53 in conjunctival melanocytic nevi. An immunohistochemical study.

The objective of this study was to evaluate conjunctival nevi for p53 gene mutations. We studied 11 conjunctival nevi by immunohistochemistry with the DO7 monoclonal p53 antibody as well as the cell proliferation marker, MIB1. Of the 11 cases, 2 were negative, 2 had less than 1%, and 7 had more than 2% p53 immunopositive nuclei with no direct correlation with MIB1 positivity. Our results suggest altered expression of p53 in conjunctival nevi.

Antibodies, Monoclonal↗
PubMed1995

High-resolution comparative mapping of the proximal region of the mouse X chromosome.

The murine homologues of the loci for McLeod syndrome (XK), Dent's disease (CICN5), and synaptophysin (SYP) have been mapped to the proximal region of the mouse X chromosome and positioned with respect to other conserved loci in this region using a total of 948 progeny from two separate Mus musculus x Mus spretus backcrosses. In the mouse, the order of loci and evolutionary breakpoints (EB) has been established as centromere-(DXWas70, DXHXF34h)-EB-Clcn5-(Syp, DXMit55, DXMit26)-Tfe3-Gata1-EB-Xk-Cybb-telomere. In the proximal region of the human X chromosome short arm, the position of evolutionary breakpoints with respect to key loci has been established as DMD-EB-XK-PFC-EB-GATA1-C1CN5-EB-DXS1272E-ALAS2-E B-DXF34-centromere. These data have enabled us to construct a high-resolution genetic map for the approximately 3-cM interval between DXWas70 and Cybb on the mouse X chromosome, which encompasses 10 loci. This detailed map demonstrates the power of high-resolution genetic mapping in the mouse as a means of determining locus order in a small chromosomal region and of providing an accurate framework for the construction of physical maps.

Animals↗
PubMed1995

Randomized study of didanosine monotherapy and combination therapy with zidovudine in hemophilic and nonhemophilic subjects with asymptomatic human immunodeficiency virus-1 infection. AIDS Clinical Trial Groups.

To evaluate the safety and efficacy of didanosine (ddl) monotherapy and three different combinations of zidovudine (ZDV) and ddl in asymptomatic human immunodeficiency virus-1 (HIV-1) infection, we conducted an open-label, phase I/II study in 126 asymptomatic HIV-1-infected hemophilic and nonhemophilic subjects with a CD4 count of 200 to 500/mm3 stratified for prior zidovudine treatment and baseline CD4 count. Study arms included arm A, low-dose combination (ZDV 150 mg and ddl 134 mg, daily); arm B, moderate-dose combination (ZDV 300 mg and ddI 334 mg, daily); arm C, high-dose combination (ZDV 600 mg and ddl 500 mg, daily), and arm D, ddl monotherapy (ddl 500 mg, daily). Earlier, more frequent hepatotoxicity was experienced by hemophilic subjects (P = .008), but there were no differences in toxicity between treatment arms (P = .51), nor were there any differences in the rate of development of clinical endpoints by treatment (P = .41). Smaller median CD4 increases occurred over the first 12 weeks for arms A and D, 44/mm3 and 42/mm3, than arms B and C, 105/mm3 and 114/mm3, respectively, (P = .015). Hemophilia status (P = .0004) and prior ZDV experience (P = .044) independently predicted weaker CD4 responses during the first 12 weeks of treatment. Using a regression model and adjusting for hemophilia status, prior ZDV treatment, and baseline CD4, there was a significant reduction in quantitative viral load from baseline by week 12 for all treatment arms combined (P = .0001), with significantly lower median percent reduction for arm A (56.3%) than arms B, C, and D (94.6%, 98.5%, and 91.9%, respectively, P = .015). Although greater hepatoxicity and weaker CD4 responses occur in hemophilic subjects, didanosine monotherapy and combination therapy with zidovudine are safe and effective in asymptomatic HIV-1-infected patients.

Adult↗