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Biomedical subjects

E Park

Publications and source records attributed to E Park.

At least 109 records · Page 6Linked to original sources
PubMed1984

B cell origin of non-T cell acute lymphoblastic leukemia. A model for discrete stages of neoplastic and normal pre-B cell differentiation.

The expression of B cell associated and restricted antigens on tumor cells isolated from 138 patients with non-T cell acute lymphoblastic leukemia (non-T cell ALL) was investigated by flow cytometric analysis by means of a panel of monoclonal antibodies. Tumor cells from these patients could be assigned to one of four subgroups: human leukocyte antigen-DR-related Ia-like antigens (Ia) alone (4%, stage I); IaB4 (14%, stage II); IaB4CALLA (33%, stage III); and IaB4CALLAB1 (49%, stage IV). The expression of B cell-restricted antigens (B4 and B1) and rearrangements of Ig heavy chain genes provided strong evidence for the B cell lineage of stages II, III, and IV tumors. The lineage of the Ia alone group is still unknown. The B4 antigen was expressed on approximately 95% of all non-T cell ALLs tested, and given its absence on T cell and myeloid tumors, it appears to be an exceptional marker to define cells of B lineage. The demonstration that Ia alone, IaB4, IaB4CALLA, and IaB4CALLAB1 positive cells can be readily identified by dual fluorescence analysis in normal fetal and adult bone marrow provided critical support for the view that these leukemic pre-B cell phenotypes were representative of the stages of normal pre-B cell differentiation. It was interesting that the IaB4+ cell was more frequently identified in fetal bone marrow than in adult marrow, whereas the predominant cell found in adult marrow expressed the IaB4CALLAB1 phenotype. These data suggest that the leukemogenic event may be random, since the predominant pre-B cell leukemic phenotype appears to correspond to the normal pre-B cell phenotype present in these hematopoietic organs. Our observations provide an additional distinction between adult and childhood ALL, since these studies show that most non-T cell ALLs seen in children less than 2 yr old are of stage II phenotype, whereas the majority of non-T ALLs in adults are of stage IV phenotype. Finally, it should be noted that the present study suggests that the analysis of leukemic B cell phenotypes and their normal counterparts can provide a mechanism for the investigation and orderly definition of stages of pre-B cell differentiation in man.

Adult↗
PubMed1983

B4, a human B lymphocyte-associated antigen expressed on normal, mitogen-activated, and malignant B lymphocytes.

The characterization of a new B cell-specific antigen (B4) is described in this report. With the use of a monoclonal antibody to B4, it was shown that B4 is present on B cells isolated from peripheral blood and lymphoid organs, on cell lines derived from normal and malignant B cells, and on tumor cells isolated from patients with B cell-derived neoplasms. B4, in contrast, was not detected on normal, activated, or malignant cells of T or myeloid origin. The B4 antigen is distinct from known B cell antigens, including sIg, Ia, B1, B2, Fc, and C3. Examination of mitogen-stimulated B lymphocytes suggests that the B4 antigen initially increases with B cell activation and then is lost at the terminal stage of B cell differentiation. Moreover, the observation that B4 is expressed on almost all early B cell tumors suggests that it may precede B1, CALLA, cytoplasmic mu, and B2 in early B cell ontogeny.

Animals↗
PubMed1981

Pharmacokinetics of digoxin in the turkey and comparison with other species.

Digoxin was administered by bolus intravenous injection to seven broad-breasted white turkey poults at doses of 0.1, 0.15, or 0.2 mg/kg. Plasma digoxin concentrations were measured by a 125I radioimmunoassay at selected times over the subsequent 24 hr. The data were fitted to a two compartment open pharmacokinetic model. Overall mean values for kinetic variables were: distribution halflife, 38.96 min; elimination halflife, 11.03 hr; volume of distribution in the central compartment, 1.54 liters/kg; total body clearance, 5.81 ml/min/kg. Different doses did not appear to have a significant effect on the identifiable pharmacokinetic variables, suggesting that digoxin disposition is dose independent in the turkey. The results obtained in turkeys were compared with data reported for rats, cats, dogs, and humans. The value for total body clearance of digoxin in the turkey was similar to values found in man, dogs, and cats but considerably less than values reported for rats. The value for elimination halflife in turkeys was somewhat less than values reported for infants and dogs; however, it was considerably different than values reported for rats and cats.

Adult↗
PubMed1977

Cortical bone measurements in Turner's syndrome.

Cortical bone width measurements taken at midshaft on the second metacarpal were obtained from 156 hand X-rays of 80 karyotypically documented individuals with Turner's syndrome age 1 to 25 years. Total shaft width, medullary width, cortical width and percent cortical area were grouped by bone age and compared with normal female standards. Total width was significantly and increasingly below normal; medullary width was not consistently different from normal; cortical width was significantly lower from normal from age 14 onward, although it did rise at age 17 (adult bone age); percent cortical area was significantly below normal at ages 14 and 15, but was normal by adulthood. Values for percent cortical area did not indicate severe or widespread osteoporosis. Within the Turners sample cortical bone measurement were not significantly decreased in the presence of the XO sex chromosome constitution compared with other sex chromosome variants. Nor were the measurements decreased in the presence of positive metacarpal sign or a combination of typical Turner stigmata (web neck, low posterior hairline, shield chest). There was evidence that cortical width and percent cortical area increased significantly following estrogen treatment or spontaneous menarche.

Adolescent↗
PubMed1977

Radiological anthropometry of the hand in Turner's syndrome.

Metacarpal-phalangeal (M-P) lengths, metacarpal sign, and carpal angle were studied using 142 pairs of hand X-rays from 81 individuals with Turner's syndrome age 6 to 25 years. Left M-P lengths, grouped by bone age, were compared with normal female standards and Z-score pattern profiles calculated for each bone age. Differences between Turners and normals in most M-P lengths increased with age, particularly after puberty. Calculation of inter-individual and intra-individual variability yielded good evidence for a M-P pattern profile typical of Turner's syndrome, with increasing growth deficiency from distal to proximal and lateral to medial. The incidence of positive metacarpal sign was 33.8%, with no significant difference between XO and non-XO Turners. It did not appear that M4 ceased growth prematurely, suggesting that short M4 is not the result of early epiphyseal fusion. Carpal angle, reported to be abnormally decreased in Turners, was not found to differ from normal. There was no difference between right and left sides or between XO and non-XO Turners, but carpal angle did decrease significantly with both decreasing ulnar deviation in positioning of the hand and increasing age. In the latter respect Turners differ from normals who show an increase in carpal angle with age.

Adolescent↗
PubMed1977

Postnatal growth of infants of less than 1.3 kg birth weight: effects of metabolic acidosis, of caloric intake, and of calcium, sodium, and phosphate supplementation.

Weekly increments of length, weight, head circumference, and skinfold thickness in response to a series of dietary changes were measured in 108 healthy infants who weighed less than 1.3 kg at birth. The serial manipulations included prevention of late metabolic acidosis, increased caloric intake, and calcium, sodium, and phosphorus supplementation. The study comprised four phases; the infants were divided into ten groups according to dietary regimen. AGA and SGA infants were studied separately. Growth in length was primarily influenced by a change to a formula providing a higher caloric intake and a 60:40 whey protein/casein ratio. Correction of late metabolic acidosis, sodium, and phosphorus supplementation had minor additive effects on growth in length. Increased caloric intake also influenced growth of head circumference, but only in AGA infants. Only the sodium intake was shown to influence body weight increments significantly with the range of caloric intake used in the study (132 to 160 calories/kg/day).

Acidosis↗
PubMed1975

Growth and mineral metabolism in very low birth weight infants. II. Effects of calcium supplementation on growth and divalent cations.

Infants of two groups, one of 16, one of 14 infants, who weighed less than 1.3 kg at birth (mean 1.01 +/- 0.05 kg), were studied from age 14 days until they reached 1.8 kg body weight. Infants were pair-matched for gestational age and birth weight and one member was randomly allocated to two treatment groups. Infants in group A received no calcium supplement and those in group B received calcium lactate, 800 mg/kg/24 hr hr, in divided doses with each feed. All were fed "Improved" SMA, 200 ml/kg/24 hr, 160 cal/kg/24 hr, and were given a multivitamin preparation containing 500 IU vitamin D2/dose. The infants' weekly length gain did not differ between groups (1.08 +/- 0.04 cm/week vs 1.11 +/- 0.04 cm/week; mean +/- SEM). Mean weight and head cercumference increments also were similar (group A, 163 +/- 6 g/week; 1.12 +/- 0.03 cm/week; group B, 170 +/- 6 g/week and 1.18 +/- 0.03 cm/week). An increase in blood pH from 7.33 +/- 0.01 to 7.41 +/- 0.01 (P less than 0.01) in group A babies was associated with a decrease in PCO2 from 44.2 +/- 1.0 to 38.9 +/- 1.4 mm Hg. Values remained unchanged with age in group B babies...

Birth Weight↗
PubMed1974

Procollagen: intermediate forms containing several types of peptide chains and non-collagen peptide extensions at NH2 and COOH ends.

A population of procollagen molecules has been isolated from the culture medium of a clonal line of calf dermatosparactic cells and shown to have the amino-acid composition, physical properties, and molecular structure consistent with collagen precursors. Although this procollagen population shares immunologic determinants with the procollagen obtained from dermatosparactic skin, it differs from the latter in aminoacid composition, in subunit properties, and by its content of both amino and carboxyl terminal non-collagen peptide appendages. We propose that the cell culture procollagen contains earlier biosynthetic forms of dermatosparactic procollagen.

Carbon Radioisotopes↗
PubMedDate not supplied

Dementia and age at death.

The objective of this paper is to investigate changes in dementia mortality, as recorded on death certificates in Canada. Use is made of data available at Statistics Canada for the period 1990-1991. During this period there have been appreciable changes over time in the ages at death and in the percentage of death certificates that mention dementia. This increase in mortality associated with dementia can be explained, in large part, by an increased tendency for dementia to be listed as an underlying cause of death on the death certificate. Also, the median ages at death of persons in Canada for the period 1990-1991, for whom dementia is recorded as the underlying cause of death, are similar to or greater than the ages at death reported for all other causes of death but excluding dementia. Because those who have dementia are living longer, there is an increase in the number of people with dementia (prevalence of dementia); this has important implications concerning public policy on health and aging. We discuss the significance of these changes with respect to the future prevalence of dementia.

Adult↗
PubMedDate not supplied

Cardiac rehabilitation participation patterns in a large, tertiary care center: evidence for selection bias.

BACKGROUND: Clinical practice guidelines have been published for cardiac rehabilitation, directing programs to address secondary risk-reduction issues. The role of risk factor profiles in the referral of patients to cardiac rehabilitation programs has not been evaluated. METHODS: Patients from the Cardiovascular Information Registry at the Cleveland Clinic Foundation (CCF) who entered the CCF hospital-based cardiac rehabilitation program (n = 371) were compared with those who did not participate in the CCF program (n = 2960) with respect to gender, demographics, and risk factor profile for CAD. A random subset of those who did not participate in the CCF program (n = 100) was interviewed by phone to determine participation patterns in other rehabilitation programs. RESULTS: Only 11% of patients participated in CCF-based program. Standard risk factors were similar between participants and nonparticipants. Rehabilitation patients were younger (63 +/- 10 versus 66 +/- 10, P < 0.01) and as a group had better left ventricular function (moderate-severe left ventricle: 16% versus 23%, P < 0.01) than nonparticipants. Women were underrepresented in the CCF rehabilitation population (20% versus 30%, P < 0.01). Of the phone survey sample, 21% of patients entered other community-based rehabilitation programs. Similar trends with respect to risk factors, younger age, and better left ventricular function were noted for the community subset. However, women accounted for a greater percentage of the participants in the community programs than the CCF-based program (42.8% versus 19.7%, P < 0.03). CONCLUSIONS: Conclusions based on institution-specific programs likely underestimate overall participation in cardiac rehabilitation. Traditional risk factors apparently are not considered when referring patients to cardiac rehabilitation programs. Younger patients with lower mortality risks preferentially participate in rehabilitation programs. Women are more likely to participate in community-based programs. Overall use of cardiac rehabilitation programs remains low.

Aged↗
PubMedDate not supplied

Taurine protects rat bronchioles from acute ozone-induced lung inflammation and hyperplasia.

Ozone is a potent respiratory irritant known to induce lung injury in humans and experimental animals. The present studies determined if ozone-induced lung inflammation was modified by pretreatment of animals with taurine, a detoxifying antioxidant. Rats were pretreated for 10 days with 5% taurine in their drinking water (controls received water only) prior to exposure to 2 ppm ozone for 3 h. At 2, 6, 12, 24, 48, and 72 h after ozone exposure, rats were anesthetized and the lungs were perfusion-fixed for histopathologic evaluation. An additional group of rats was used to examine bronchoalveolar lavage cell counts and hydroxyproline levels. A count of bronchoalveolar lavage cells 48 h after ozone exposure showed significantly fewer total inflammatory cells and fewer polymorphonuclear leukocytes accompanied by a reduction in hydroxyproline in the lavage fluid of ozone-exposed rats pretreated with taurine compared to rats that did not receive taurine. Light microscopy revealed an inflammatory cell infiltrate in the lungs of rats exposed to ozone. This was followed by focal hyperplasia in the terminal and respiratory bronchioles. Rats pretreated with taurine and then exposed to ozone showed none of these alterations. In addition, although there was a significant reduction in cell proliferation as measured by DNA precursor incorporation in the lungs of rats pretreated with taurine prior to ozone exposure compared to unsupplemented rats, the distribution of labeled cells was the same in taurine supplemented and unsupplemented groups. Also, significantly higher levels of taurine were found in the plasma, whole blood, and lavage fluid of rats pretreated with dietary taurine compared to rats that received water only. The results suggest that supplemental taurine protects rat lung epithelium from acute ozone-induced lung inflammation and hyperplasia.

Acute Disease↗