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Biomedical subjects

B Miller

Publications and source records attributed to B Miller.

At least 343 records · Page 19Linked to original sources
PubMed1985

Retinal function of the diabetic retina after argon laser photocoagulation assessed electroretinographically.

Electroretinographic (ERG) responses were measured in diabetic patients before, during, and after panretinal photocoagulation treatment with argon laser. The laser applications reduced considerably the amplitudes of the a and b waves of the ERG. Moreover, the relationship between the amplitude of the b wave and that of the a wave was severely affected, resulting in ERG responses of abnormal pattern. The b waves were smaller than expected from the a waves. These findings indicated that the photocoagulation treatment not only destroyed the retinal areas directly illuminated by the laser beam, but also affected the functional integrity of adjacent areas. These additional effects resulted in subnormal signal transmission from the photoreceptors to the proximal retina.

Adult↗
PubMed1985

European Cooperative Crohn's Disease Study (ECCDS): colonoscopy.

130 patients with Crohn's disease were colonoscopied in a multicenter trial. The obtained data were analyzed with respect to gathering information on the inflammation pattern, as well as on the importance and prognostic value of special lesions in Crohn's colitis. In 52 patients a second endoscopy was performed at the end of the 2-year study period. Ulcerations and aphthous lesions were the most common lesions, followed by pseudopolyps, cobblestone lesions and stenosis. In general, there was an increasing, distal gradient in the frequency of severe lesions. patients with Crohn's colitis alone had more signs of inflammation than patients with additional involvement of the small intestine. A segmental pattern was the most common form of inflammation. The group of patients (14%) with a continuous pattern did not deviate from the whole collective in clinical activity. In patients with previous resections, inflammation near the anastomosis was accompanied more often than not by stenosis. Patients with ulcerations had a rather short time since confirmation of the diagnosis. Cobblestone lesions and pseudopolyps correlated with short symptomatology. During the follow-up of the study, patients taking steroids or a combination with prednisolone and sulfasalazine seem to have better results than those under placebo or sulfasalazine alone, as regards the more severe symptoms.

Adult↗
PubMed1985

Determination of the hemoglobin F program in human progenitor-derived erythroid cells.

The absolute adult and fetal hemoglobin (HbF) contents of the erythroid cells derived from the differentiation of normal human and simian erythroid progenitors and of the peripheral blood erythroid burst-forming units (BFU-E) of patients with nondeletion hemoglobinopathies have been measured with a sensitive radioligand immunoassay. The HbF content varied between 0.13 and 2.96 pg/cell, representing between 0.7% and 19.6% of the total hemoglobin with a mean value of 7.0%. The absolute content of HbF was indistinguishable in the well-hemoglobinized progeny of marrow erythroid colony-forming units, marrow or blood BFU-E, or of mixed colony-forming units. The term HbF program refers to this inherent capacity to produce fetal hemoglobin (HbF) in the erythroid cells derived from these progenitors in vitro. The HbF content of marrow erythroblasts as determined by the same radioligand immunoassay was similar to that found in the peripheral blood, suggesting that the switch off of gamma-chain production occurs after the erythroid colony-forming unit stage of maturation. Increasing concentrations of a crude erythropoietin-containing preparation induced higher numbers of erythroid colonies, which were larger in size, but the HbF program was unaffected. In contrast to the hemoglobin accumulation in human progenitor-derived colonies, simian progenitor-derived colonies produced considerably more HbF, and the amount of HbF was strongly influenced by progenitor maturity. Assays of the HbF content of erythroblasts derived from culture of the peripheral blood BFU-E of patients with nondeletion hemoglobinopathies and their parents showed that the HbF program in the progenitors of such patients is highly variable. Some produce only a slight excess of HbF in progenitor-derived erythroblasts, whereas others have extraordinarily high HbF programs. The molecular basis of this variability is presently unknown.

Animals↗
PubMed1985

Somatostatin-like material is present in flowering plants.

Extracts of spinach contain somatostatin (SRIF)-related material (6-80 pg/g wet wt). The SRIF-related material, when purified on HPLC, was recovered as two major mol wt forms; one that eluted with a retention time similar to that of synthetic SRIF-28 and reacted in both N- and C-terminal-specific immunoassays, and a second peak that eluted with a retention time similar to that of SRIF-14 and reacted only in the C-terminal immunoassays. The purified material was active in a sensitive bioassay, and the bioactivity was neutralized in the presence of anti-SRIF antiserum. Since we have previously described the presence of similar material in bacteria, we also tested extracts of the flowering plant Lemna gibba G3, which was grown under sterile conditions. The Lemna extracts also had SRIF-related material (3.0 pg/g wet wt). Since plants are probably derived evolutionarily from unicellular organisms, the presence of SRIF-like material in higher plants gives support for the hypothesis that vertebrate-type peptide hormones have early evolutionary origins.

Animals↗
PubMed1985

Insulin's effect on Leucine turnover changes during early fasting in the conscious dog.

To study the effects of insulin on leucine turnover during fasting, acute insulin deficiency was induced by the simultaneous infusion of somatostatin and glucagon in conscious dogs fasted 18 h (N = 10) and 48 h (N = 11). Insulin levels during the basal period (before hormone perturbation) were similar in both groups of dogs (12 +/- 3 versus 10 +/- 3 microU/ml, respectively). Glucagon levels were similar in the two groups (94 +/- 9 versus 106 +/- 19 pg/ml). Leucine levels rose from 118 +/- 9 mumol/L to 155 +/- 12 mumol/L as fasting progressed (P less than 0.005). Its rate of appearance also increased by 30% (P less than 0.005) from 3.4 +/- 0.3 to 4.3 +/- 0.4 mumol/kg/min (P less than 0.005), while its clearance remained unchanged. Acute insulin deficiency caused an increase in leucine levels in both 18-h and 48-h-fasted dogs by 55% (to 181 +/- 10 mumol/L) and 45% (to 225 +/- 20 mumol/L), respectively (P less than 0.005). However, while the rate of appearance of leucine remained unchanged in dogs fasted overnight, it rose to 5.1 +/- 0.3 mumol/kg/min (P less than 0.01) in those fasted 48 h. The metabolic clearance rate fell in both groups, although this drop was twice as great in the 18-h group (from 28 +/- 3 to 17 +/- 3 ml/kg/min, P less than 0.005) as in the 48-h group (from 28 +/- 3 to 23 +/- 2 ml/kg/min, P less than 0.005). We conclude that insulin has disparate effects on protein turnover as fasting becomes more prolonged.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

UB-82 and you.

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Forms and Records Control↗
PubMed1985

[HLA haplotype study in familial Crohn disease].

Among others, genetical factors have been discussed in the aetio-pathogenesis of inflammatory bowel diseases. This is supported by many studies reporting familial accumulation of Crohn's disease and ulcerative colitis. The use of HLA typing to demonstrate a genetical disposition has so far proved disappointing. Accordingly, if there is any association with definite HLA antigens, it is likely to be weak. We therefore investigated the HLA haplotypes in 13 families with multiple occurrences of Crohn's disease. Comparing observed and expected occurrences of HLA-haplotypes, we found a pronounced tendency towards common haplotypes in the affected siblings, uncles and nieces, and cousins. Although the data suggest a possible genetical disposition, additional factors such as microorganisms or possibly nutritional habits must be considered as causes for Crohn's disease.

Crohn Disease↗
PubMed1984

Direct comparison of the rates of internalization and degradation of covalent receptor-insulin complexes in 3T3-L1 adipocytes. Internalization of occupied receptors is not the rate-limiting step in receptor-hormone complex degradation.

Insulin receptors on the surface of 3T3-L1 adipocytes were photolabeled using the iodinated analog, B29-lysine-substituted N-[N'-(2-nitro-4-azidophenyl)glycyl]insulin. Under optimal labeling conditions (below 15 degrees C), greater than 95% of the labeled receptor remained on the cell surface prior to incubation at 37 degrees C. When the labeled monolayers were returned to their normal culture environment (37 degrees C), the covalent receptor-insulin complexes were rapidly internalized at initial rates equivalent to 130-170% of labeled surface receptor/h. Internalization of the complexes proceeded to an equilibrium or end point distribution of 40% internal receptor and 60% cell-surface receptor. Under the several labeling conditions tested, covalent receptor-insulin complexes were degraded in an apparent first order process at 37 degrees C with half-lives between 5 and 7 h. This rate was equivalent to only 10% of the labeled receptor being degraded per h and was 13-17-fold slower than the initial rate of labeled receptor internalization. This study directly demonstrates that the initial rate of internalization of covalent receptor-insulin complexes is not the rate-limiting step in their degradation in 3T3-L1 adipocytes. Furthermore, 3T3-L1 adipocytes are unable to internalize all of the labeled surface receptor, suggesting that two classes of internalization competent and incompetent receptor may exist or that an equilibrium distribution of internal and cell-surface receptor is established by the relative rates of internalization and recycling of labeled receptor.

Adipose Tissue↗
PubMed1984

The syndrome of unexplained generalized lymphadenopathy in young men in New York City. Is it related to the acquired immune deficiency syndrome?

To establish whether the syndrome of unexplained generalized lymphadenopathy in homosexual men was new and related epidemiologically to the acquired immune deficiency syndrome (AIDS), we reviewed 3,139 pathology reports of lymph node biopsies performed at seven hospitals in New York City during the years 1977 through 1981. Three hundred twenty-nine patients (10%) were categorized as having unexplained lymph node hyperplasia; a detailed medical record review of 30% of these patients revealed three, two, six, eight, and 16 cases of unexplained generalized lymphadenopathy in the five years studied, respectively. Of these 35 cases, 26 (74%) occurred in males aged 16 to 44. A record review of 68 additional male patients aged 16 to 44 years with unexplained lymph node hyperplasia in two of the hospitals showed a similar increase in cases of unexplained generalized lymphadenopathy during the five-year period. Twenty-one of 25 cases in males with known sexual orientation were homosexual or bisexual. The increase in the syndrome of unexplained generalized lymphadenopathy from 1978 to 1981 and the characteristics of the population affected are similar to those observed for AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Intravitreal expanding gas bubble. A morphologic study in the rabbit eye.

The morphologic changes induced by an expanding bubble of perfluoropropane (C3F8) gas in the vitreous body have been studied in the rabbit eye by dissecting microscopy and scanning and transmission electron microscopy. Initial expansion of the gas displaces water from the vitreous; the remaining vitreous forms a compressed layer on the retinal surface. Subsequent absorption and contraction of the gas bubble is associated with gradual detachment of the compressed vitreous from the retina. Eventually, vitreous detachment is complete, except for residual attachments posteriorly to the medullary rays and anteriorly to the ciliary processes. The plane of vitreous separation is predominantly at the anatomic vitreoretinal junction, although scattered islands of outer cortical vitreous are found on the surface of the retina.

Animals↗
PubMed1984

A prone bed.

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Beds↗
PubMed1984

Hydroxyurea enhances fetal hemoglobin production in sickle cell anemia.

Hydroxyurea, a widely used cytotoxic/cytostatic agent that does not influence methylation of DNA bases, increases fetal hemoglobin production in anemic monkeys. To determine its effect in sickle cell anemia, we treated two patients with a total of four, 5-d courses (50 mg/kg per d, divided into three oral doses). With each course, fetal reticulocytes increased within 48-72 h, peaked in 7-11 d, and fell by 18-21 d. In patient I, fetal reticulocytes increased from 16.0 +/- 2.0% to peaks of 37.7 +/- 1.2, 40.0 +/- 2.0, and 32.0 +/- 1.4% in three successive courses. In patient II the increase was from 8.7 +/- 1.2 to 50.0 +/- 2.0%. Fetal hemoglobin increased from 7.9 to 12.3% in patient I and from 5.3 to 7.4% in patient II. Hemoglobin of patient I increased from 9.0 to 10.5 g/dl and in patient II from 6.7 to 9.9 g/dl. Additional single-day courses of hydroxyurea every 7-20 d maintained the fetal hemoglobin of patient I t 10.8-14.4%, and the total hemoglobin at 8.7-10.8 g/dl for an additional 60 d. The lowest absolute granulocyte count was 1,600/mm3; the lowest platelet count was 390,000/mm3. The amount of fetal hemoglobin per erythroid burst colony-forming unit (BFU-E)-derived colony cell was unchanged, but the number of cells per BFU-E-derived colony increased. Although examination of DNA synthesis in erythroid marrow cells in vitro revealed no decreased methylcytidine incorporation, Eco RI + Hpa II digestion of DNA revealed that hypomethylation of gamma-genes had taken place in vivo after treatment. This observation suggests that hydroxyurea is a potentially useful agent for the treatment of sickle cell anemia and that demethylation of the gamma-globin genes accompanies increased gamma-globin gene activity.

Adolescent↗
PubMed1984

A new immunologic test for CNS cysticercosis.

A new radioimmunoassay for cerebral cysticercosis was studied in 70 patients. The assay showed nearly 100% sensitivity for ventricular cysts or meningitis, 86% sensitivity for multiple parenchymal cysts, and a false-positive rate of 7%. Both serum and CSF antibody levels were useful diagnostically, and the contribution of both improved accuracy. In some patients, there was endogenous CNS production of IgG against the cysticercus antigen, which leads to elevated CSF levels and normal serum levels. Patients with high CSF total IgG levels may show false-positive CSF antibody elevation with normal serum levels.

Antibodies↗