Biomedical subjects

K Miller

Publications and source records attributed to K Miller.

At least 595 records · Page 33Linked to original sources

PubMed1984

Normal lymphocyte responses to mitogens in term and premature neonates following normal and abnormal intrauterine growth.

Cord blood lymphocyte responses to a panel of four mitogens were studied in 242 neonates using a whole blood technique. The patient population was divided into five gestational-age groups: 20-27.9, 28-32.9, 33-37.9, 38-41.9, and 42-44 weeks. Neonatal lymphocytes undergo a continuous reduction in proliferative responsiveness to the polyclonal ligands phytohemagglutinin (PHA) and concanavalin A (Con A) as gestation progresses from 20 to 44 weeks postconception. This is consistent with their change in unstimulated in vitro blastogenesis which when measured over the same developmental period is greatest in more immature neonates. Neonatal lymphocyte proliferative responsiveness to pokeweed mitogen (PWM) and staphylococcus protein A (SpA), however, was unrelated to gestational age. The influence of intrauterine nutritional deprivation on lymphocyte proliferative responses was studied in clinically uninfected newborns and compared to gestational age-matched controls with a normal nutritional status. Intrauterine nutritional deprivation was not associated with a decrease in mitogen-induced lymphocyte proliferation. Further, we explored the influence of several perinatal clinical settings commonly associated with fetal distress on cord blood lymphocyte responses to mitogens. Although perinatal stress in the form of low Apgar scores, meconium-stained amniotic fluid, and prolonged rupture of the amniotic membranes was not related to differences in mitogen induced lymphocyte proliferation, mode of delivery was. Cesarean section delivery as compared to vaginal delivery was associated with a significantly greater PHA-, Con A-, and SpA-induced neonatal lymphocyte response. Several alternative explanations for this finding are explored. Lastly, the purified protein thymosin fraction 5 was not associated with alteration in either neonatal or adult mitogen-induced lymphocyte proliferation.

Adolescent↗

PubMed1984

Strategies for detection of transfusion-transmitted viruses eluding identification by conventional serologic tests. II. Detection of host DNA in human plasmas with elevated alanine aminotransferase.

As a prelude to the development of nucleic acid probes specific for non-A, non-B hepatitis virus(es) (NANBV), plasmas with alanine aminotransferase levels greater than or equal to 110 IU were assayed for DNA by a radioimmunoassay. Approximately 50% of such plasmas are expected to contain NANBV. One-hundred and seventy-eight of 420 plasma samples tested (42.4%) contained sequestered DNA resistant to DNAse I. The DNA has a molecular weight of approximately equal to 0.8 to 1.4 X 10(6) daltons and hybridizes with a 32P-labeled human DNA probe. The DNA in plasma is mostly bound to IgM. The presence of host DNA will have to be taken into account in planning experiments aiming at the preparation of nucleic acid probes specific for NANBV using infected plasmas as source material. Such experiments will have to utilize recombinant DNA technology and will require the separation of bacterial colonies containing recombinant DNA with viral DNA sequences from colonies with human DNA inserts. The feasibility of this approach is demonstrated using plasma-containing hepatitis B virus.

Alanine Transaminase↗

PubMed1984

Effect of orally administered food-grade carrageenans on antibody-mediated and cell-mediated immunity in the inbred rat.

Experiments were performed to investigate the immunological consequences associated with the persorption of poorly degradable carregeenans from the diet. Using an inbred strain of rat it was demonstrated histochemically, by the carrageenan-specific Alcian blue staining technique, that small quantities of food-grade carrageenans given at 0.5% in drinking-water for 90 days could penetrate the intestinal barrier of adult animals. This apparently occurred via an intact mucosa in the absence of inflammatory or pathological lesions. The carrageenan was demonstrated in macrophage-like cells present within the villi and lamina propria of the small intestine. The oral administration of kappa, lambda or iota food-grade carrageenans did not affect local (biliary) or systemic antibody responses to gut commensal microorganisms, or to orally-administered sheep erythrocytes. However, when sheep red blood cells were administered parenterally the ensuing anti-sheep red blood cell haemagglutinating antibody response was temporarily suppressed in carrageenan-fed rats. lambda-Carrageenan and iota-carrageenan both significantly (P less than or equal to 0.01 and P less than or equal to 0.05, respectively) reduced the mid-phase (14-28 days) haemagglutinin response; kappa-carrageenan (L100) was less effective but caused significant depression at day 21 (P less than or equal to 0.01). Individual responses were, however, within the control range 35 days after sheep erythrocyte administration, thus indicating the temporary nature of this effect. Although carrageenan administration depressed the anti-sheep erythrocyte antibody response, it did not affect T-cell immune competence as measured by the popliteal lymph node assay for graft-versus-host reactivity.

Administration, Oral↗

PubMed1984

Inhibitory effect of deoxynivalenol, 3-acetyldeoxynivalenol and zearalenone on induction of rat and human lymphocyte proliferation.

Deoxynivalenol (DON), 3-acetyldeoxynivalenol (acetylDON) and zearalenone (Ze) were examined for their in vitro effect on mitogen-induced lymphocyte blastogenesis using rat or human peripheral blood lymphocytes (PBL). A dose-dependent reduction of lymphocyte proliferation was demonstrated for each mycotoxin. However, the inhibitory effect of DON was significantly higher than that of the acetylated compound. Concentrations of 90 ng/ml and 220 ng/ml inhibited rat and human lymphocyte blastogenesis by 50%, respectively, whereas 450 ng/ml and 1060 ng/ml acetylDON were required to produce the same effect. The amount of Ze necessary to inhibit blastogenesis by 50% was 250 times greater than required for DON. There was no evidence of cell death and combinations of DON and Ze did not alter the expected response.

Animals↗

PubMed1984

Cognitive arithmetic: comparison of operations.

Adults' performance of simple arithmetic calculations (addition, multiplication, and numerical comparison) was examined to test predictions of digital (counting), analog, and network models. Although all of these models have been supported by studies of mental addition, each leads to a different prediction concerning relations between the times required for addition, multiplication, and numerical comparison. Pairs of single-digit integers were presented and reaction times (RTs) for adding, multiplying, and comparing the stimuli were collected. A high correlation between RT for addition and multiplication of the same digits was obtained. This result is consistent with a network model, but presents difficulties for both analog and counting models. A "ties" effect of no increase in RT with increases in problem size for doubles such as 2 + 2 has been found in previous studies of addition using verification procedures, but was not found with the production task employed in the present study. Instead, a different kind of ties effect was found. Reaction time for both addition and multiplication of ties increased more slowly with problem size than did RT for non-tie problems. This ties effect, and the finding that probability of making errors contributes independently of problem size to RT support a distinction between location and accessibility of information in a network.

Adult↗

PubMed1984

Photon absorptiometry for non-invasive measurement of bone mineral content.

Bone mineral content of the distal radius was determined in 106 patients by single photon absorptiometry using iodine-125 monochromatic source. The technique provided a reliable means to assess the degree of mineral loss in conditions such as osteoporosis, renal osteodystrophy in patients on chronic maintenance dialysis, subjects on long-term steroid therapy, and those with diabetes mellitus. It is more sensitive than conventional radiography and completely noninvasive compared to bone biopsy. It is suggested that photon absorptiometry is a simple, sensitive, and reliable technique for assessment and follow-up of the bone mineral content in a host of disorders associated with bone demineralization.

Adult↗

PubMed1984

Development of tolerance to the side effects of primidone.

Side effects and antiepileptic drug levels were measured during initiation of and chronic treatment with primidone (PRM). A significant change in the toxicity/serum level ratio was observed 6 h after the initial PRM dose. The amount of toxicity manifested by patients receiving PRM as their initial antiepileptic drug was not different from that of those patients previously treated with phenytoin (PHT) or carbamazepine (CBZ). These findings indicate rapid development of functional tolerance to side effects of PRM, which is not altered by previous exposure to PHT or CBZ. Phenobarbital pretreatment appears to produce cross-tolerance to the effects of PRM.

Adult↗

PubMed1984

Relationship between the per cent of marrow cells in S phase and the outcome of remission-induction therapy for acute nonlymphocytic leukaemia.

The relationship between the pretherapy cell cycle characteristics of leukaemic marrow cells and the outcome of remission-induction therapy for acute nonlymphocytic leukaemia was studied in newly diagnosed and relapsed patients who were then treated with either combination chemotherapy consisting of cytosine arabinoside/anthracycline antibiotic +/- 6 thioguanine or with single agent high-dose cytosine arabinoside therapy. The outcome of high-dose cytosine arabinoside therapy was highly dependent upon the per cent of pretherapy cells in S phase with no remissions occurring in patients in whom the 3H-TdR labelling index was less than 6%. In contrast, the outcome of cytosine arabinoside/anthracycline antibiotic therapy was independent of the pretherapy cell cycle characteristics of the leukaemic cells.

Acute Disease↗

PubMed1984

Immunoglobulin class heterogeneity of platelet alloantibodies.

The immunoglobulin classes of platelet alloantibodies were studied using monospecific antisera in a radiolabeled technique. 14 of 28 consecutively studied multiply transfused oncology patients demonstrated platelet antibodies. These 14 patients were also refractory to random donor platelets. The immunoglobulin classes of these platelet antibodies were found to be: IgG alone 4, IgM alone 4, IgG and IgM 5, IgM plus IgA1. The results in this study suggest that using monospecific antisera other than anti-IgG alone, one can detect additional antibodies involved in the immune destruction of platelets.

Blood Platelets↗

PubMed1984

Enhancement of contact sensitization in mice fed a diet enriched in vitamin A acetate.

Various methods have been used to enhance the ability of laboratory animals to develop contact sensitivity to so-called weak sensitizers. The present studies have examined whether diets supplemented with vitamin A acetate (VAA) could enhance induction and elicitation of contact sensitivity to oxazolone in the mouse. Application of 0.3% oxazolone to VAA-fed mice resulted in increased DNA synthesis in the draining lymph nodes and increased ear thickness after challenge, in comparison with mice on a stock (standard) diet. Moreover, VAA-fed (but not control) mice were sensitized to 0.03% oxazolone as shown by DNA synthesis, increased arrival of syngeneic 51Cr-labelled lymphocytes in the draining lymph nodes, and ear swelling after challenge. These findings demonstrate that vitamin A enhances delayed hypersensitivity responses, and point to a role for vitamin A in developing an animal model capable of detecting weak contact sensitizers after topical application.

Animal Feed↗

PubMed1984

Financial analysis, personnel planning and organizational requirements for the installation of a kidney lithotripter in a urologic department.

The first clinical experiences with extracorporeal shockwave lithotripsy (ESWL)--the method of choice in noninvasive treatment of renal calculi--were so encouraging that more ESWL units are now being installed and a still larger number can be predicted. A cost-efficiency analysis shows that, in spite of high investment costs, a net saving of about DM 4,599 (deutsche marks) can be figured for each 'ESWL patient' compared to the expenses of an open operation. This benefit is due to the reduction of disability time, hospital stay and dialysis cases. For the management of an ESWL unit a trained team of urologists and anesthesiologists, as well as a clinic with an 'operative background' is necessary.

Cost-Benefit Analysis↗

PubMed1984

Prolonged iodine clearance with a depletion regimen for thyroid carcinoma: concise communication.

Prior studies suggested iodine depletion as a means of enhancing radioiodine uptake into metastases from well-differentiated thyroid cancer. Data are not available regarding the secondary effects of this maneuver on iodine clearance and on total-body radiation. Accordingly we have measured inorganic iodine clearance, total body iodine, tumor and total-body retention of radioactive iodine before and during a diet-and-diuretic regimen designed to induce iodine depletion. Total-body iodine decreased by 25% to 66% (p less than 0.05). The amount of radioiodine taken up and retained by tumor tissue increased 146% (range 48-243%) following the depletion regimen in three studies (two patients). However, because the iodine clearance decreased by 56% (range 40-71%), the total-body radiation per standard 150-mCi dose increased by 68% (range 19-111%). Consequently, the increase in lesion irradiation relative to the increment delivered to the total body was only 46% (range 24-82%). We conclude that iodine-depletion regimens are less effective than prior studies suggest.

Adult↗

PubMed1983

Desmopressin response of enuretic children. Effects of age and frequency of enuresis.

To characterize the children with enuresis likely to respond to desmopressin acetate, we performed a double-blind crossover study that included the use of a placebo. During the two weeks of desmopressin administration, six children (12%) had 13 or 14 dry nights, and 15 children (29%) had eight to 12 dry nights. Among the 17 children aged 9 years or older, with four to seven dry nights during the two-week baseline period, 12 children (71%) responded to desmopressin (eight to 14 dry nights). In contrast, none of the 15 children younger than 9 years of age with fewer than three dry nights before therapy responded. During the posttreatment period, only four of the 21 drug responders reported a persistent effect. Desmopressin may be effective in reducing the frequency of enuresis, especially in children older than 9 years of age without nightly enuresis.

Adolescent↗

PubMed1983

Alcohol, affect, and the disinhibition of verbal behavior.

A study was conducted to investigate the effects of acute alcohol administration on affective states and verbal behavior during the ascending and descending limbs of the blood alcohol curve. Sixteen male social drinkers were given alcohol (1.0 g/kg) or placebo in a double-blind crossover research design. Subjects tested while blood alcohol levels (BAL) were ascending close to peak concentration (0.11 g%) described themselves as more elated, friendly, and vigorous than when tested under placebo conditions. As BAL declined, subjects described themselves as more angry, depressed, and fatigued. Cognitive confusion, hostile verbal interaction, and aggressive thematic content were also greater during alcohol intoxication, but these measures were unrelated to direction of change in the BAL curve. It was concluded that (1) the effects of alcohol on affect are biphasic and are closely related to direction of change in the BAL curve, (2) the disinhibition of certain types of verbal behavior is related neither to affective state or to direction of the BAL curve, and (3) the perception of cognitive disorientation may mediate the effects of alcohol on those behaviors normally suppressed by various controlling influences.

Adult↗

PubMed1983

Phospholipid and protein analysis of pulmonary surfactant.

Quantitative analysis of the phospholipid composition of pulmonary surfactant preparations has been achieved by a modification of the phosphorus-31 nuclear magnetic resonance method of E London and G Feigenson (J. Lipid Res. 20, 408-412, 1979). Resolution of the protein components by a 2-dimensional isoelectric-focussing-SDS/polyacrylamide-gel-electrophoresis technique is reported for the first time.

Animals↗

PubMed1983

Surgical treatment of congenital esotropia.

We conducted a retrospective study of 133 children (69 boys and 64 girls) who underwent bilateral medial rectus muscle recession (most by the augmented or en-bloc technique) for congenital esotropia. Esotropia was diagnosed before the age of 6 months in 84 patients and after the age of 6 months in the other 49. A total of 27 children underwent surgery before the age of 12 months; of these, three required second procedures. A total of 106 children underwent surgery after the age of 12 months; of these, eight required second procedures. The mean preoperative deviation was 40 prism diopters. Two patients had significant A pattern deviations and 17 had significant V pattern deviations. Six patients had dissociated vertical deviations. Five to 60 days after surgery, 52 patients had no deviation and 99 were within +/- 10 prism diopters of no deviation. Two months after surgery, 67 patients had no deviation and 114 were within +/- 10 prism diopters of no deviation. Final alignments (five months to seven years postoperatively) showed that 51 patients had no deviation and 109 were within +/- 10 prism diopters of no deviation. Despite adequate alignment, none of 13 patients whose esotropia was diagnosed before the age of 6 months, who underwent surgery before the age of 12 months, and who cooperated with testing achieved stereopsis. This suggested that there may be two types of congenital esotropia--one without fusion potential and one in which fusion is possible but lost secondarily because of peripheral esotropic factors.

Child, Preschool↗

PubMed1983

The stimulation of human B and T lymphocytes by various lectins.

The response of human peripheral blood lymphocytes to different lectins was tested in vitro by monitoring DNA synthesis, blast transformation, and mitotic activity. One group of lectins - RCA, VGA, HPA, PNA, and UEA - showed no stimulating effects at all. WGA and VVA induced DNA synthesis and blast transformation but failed in stimulating mitosis. The mitogens PHA, ConA, LCA, and PWM showed peaks of mitotic activity at 50-60 hours for PHA, 70 hours for ConA, 80 hours for LCA, and between days 4 and 5 for PWM. The stimulation of different subpopulations of lymphocytes was investigated by immunological methods for the detection of B- and T-cell-specific surface structures during the whole incubation period. PHA proved to be a predominantly T cell stimulating agent, whereas ConA seemed to activate a higher proportion of B cells than yet known. PWM and the so-called T cell mitogen LCA turned up to stimulate a large number of B cells, but lead also to a T cell activation. The analysis of SCE events in stimulation experiments with these two lectins showed the early proliferation of a cell population with low SCE frequencies and the late propagation of a cell population with higher SCE rates. It could be assumed that the first population is represented by B- and the second by T-cells.

B-Lymphocytes↗

PubMed1983

Bacterial growth in human milk during continuous feeding.

The present study was undertaken to determine both the time at which exponential growth of bacteria ensued in human milk during a continuous feeding and whether the fat content of the milk changed during a continuous feeding. Breast milk samples were obtained from 19 healthy lactating women between the 7th and 28th postpartum day. Nine samples were refrigerated and utilized in a simulated continuous feeding within 24 hours of collection. The remaining 10 samples were frozen for four to six weeks until use in the simulated feeding study. Bacterial colony counts and fat content (by creamatocrit) were then measured at the beginning of the simulated feeding and at hourly intervals from five to eight hours after the initiation of the study. Results indicated that logarithmic growth of the contaminating bacteria was not observed during the study time. No significant increase in total colony count was observed over the course of study in the frozen milk samples, whereas a significantly increased colony count was apparent by six hours for the fresh milk samples. Fat content of the milk decreased significantly within six hours for the frozen samples and within eight hours for the fresh milk. These data would suggest that when continuous drip feeding methods are employed for providing human milk to newborn infants, it may be desirable to change the entire feeding apparatus (syringe, tubing, and milk) at four hour intervals in order to optimize caloric intake and minimize the risk of bacterial overgrowth.

Bacteria↗