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Biomedical subjects

J Miller

Publications and source records attributed to J Miller.

At least 1,009 records · Page 56Linked to original sources
PubMed1981

Physical linkage of the constant region genes for immunoglobulins lambda I and lambda III.

During differentiation from a stem cell to an antibody-secreting cell, the immunoglobulin genes within a B cell undergo a rearrangement that juxtaposes a variable region gene to a constant region gene. To analyze the genetic organization of an immunoglobulin gene family in nonrearranged, germ-line DNA, we have constructed a recombinant DNA library from randomly cleaved mouse kidney DNA fragments. From this library, we have isolated three overlapping recombinant clones containing the constant region gene for lambda I light chains (C lambda I). These clones spanned 24.9 kilobases of mouse DNA and contained no variable region sequences. Hybridization of these clones with lambda II cDNA demonstrated the presence of an additional constant region gene and a joining region 3.2 kilobases 5' of C lambda I. This gene was tentatively identified as C lambda III by the absence of an Ava I endonuclease site, which is present within C lambda II. The C lambda III amino acid sequence has recently been reported [Azuma, T., Steiner, L. A. & Eisen, H. N. (1981) Proc. Natl. Acad. Sci. USA 78, 569-573] and is very closely related to the C lambda II amino acid sequence.

Animals↗
PubMed1981

Perioperative management of diabetes mellitus.

Hourly plasma glucose concentrations in 191 diabetic patients undergoing 200 operations were measured. The glucose infusion rate was controlled. Insulin-taking diabetics given no insulin or a fraction of their usual dose preoperatively developed rising plasma glucose concentrations beginning with the start of operation. The mean rate was 22 mg.dl-1.h-1 (no insulin) and 17 mg.dl-1.h-1 (one-half to one-fourth the usual dose of insulin). Eight per cent of the patients achieved plasma glucose concentrations greater than 400 mg/dl. Patients given regular insulin during the operation had no hourly rise in plasma glucose. However, hypoglycemia occurred in 5.5 per cent of these patients. The authors suggest that arbitrary management regimens should be abandoned. Plasma glucose levels should be measured frequently and insulin and/or sugar should be given to each patient as needed.

Aged↗
PubMed1981

A radioimmunoassay for neurotensin.

A specific radioimmunoassay for neurotensin has been developed with a sensitivity of 40 pg/ml. Neurotensin-like immunoreactivity in human plasma shows characteristics similar to synthetic neurotensin on Sephadex G-25 (f) gel chromatography.

Animals↗
PubMed1981

Search for resistances controlling canine gastric emptying of liquid meals.

Previous work has indicated that a chemoselective resistance controls gastric emptying. By use of meals of glucose or oleate, which were shown to empty spontaneously from dogs' stomachs half as fast as saline, we sought to locate this resistance by studying flow under controlled pressures in various regions of the gastrointestinal tract. In intact dogs, gastric outflow of glucose or oleate rose one-third as fast as outflow of saline as gastric pressure was raised, and this increased resistance to outflow of nutrients was unaffected by truncal vagotomy and pyloroplasty. In fistula dogs, gastroduodenal outflow rose linearly with gastroduodenal pressure gradients; outflow was markedly inhibited in a dose-related manner by intestinal oleate but not glucose. Inhibition by oleate was abolished by pyloroplasty. Glucose or oleate flowed into the small bowel from a barostat only slightly slower than saline. However, there was a strong inhibition of intestinal inflow of all three meals by gastric distension, an effect unaltered by truncal vagotomy. The findings suggest that gastric emptying is controlled by complex interactions among pressures and resistances, both within and beyond the stomach.

Animals↗
PubMed1981

Hypoxemia and pulmonary gas exchange during hemodialysis.

With measured values of arterial blood gas tensions, of expired respiratory gas fractions, and volume of the expired ventilation, the determinants of alveolar oxygen tension (PAO2) were used to evaluate their influence on the development of the arterial hypoxemia that occurs in spontaneously breathing patients undergoing hemodialysis using an acetate dialysate. Dialysis produced no significant changes in the alveolar-arterial O2 tension gradient (AaDO2). The extracorporeal dialyzer removed an average of 30 ml.m-2.min-1 of CO2. Accordingly the pulmonary gas exchange ratio (R) dropped from a mean predialysis value of 0.81 to 0.62 (P less than 0.001). The arterial CO2 tension remained constant throughout, whereas the minute ventilation, both total (P less than 0.01) and alveolar (P less than 0.01), decreased during dialysis. This decrease in ventilation accounts for more than 80% of the fall in PAO2. During dialysis there was a decrease (P less than 0.001) in arterial oxygen tension (PaO2), which varied among the individuals from 9 to 23% of control. During the postdialysis hour PaO2 returns to control values concomitant with increase in ventilation. The quantitative gas exchange relationships among R, alveolar ventilation, and AaDO2 predict the PaO2 values actually measured.

Adult↗
PubMed1981

Long-term study of vascularized free-draining intraperitoneal pancreatic segmental allografts in beagle dogs.

The purpose of the present study was to evaluate the significance of immunogenetic factors on the survival of pancreatic allografts in beagle dogs. Donors and recipients were leukocyte antigen (DLA)-typed and mixed lymphocyte culture (MLC)-tested. Recipients were made diabetic by total pancreatectomy and immediately implanted intraperitoneally with a vascularized, free-draining (duct unligated) pancreatic segmental (FDPS) allograft. Two groups of dogs were studied. In group I consisting of donor-recipient littermates, recipients were immunosuppressed with prednisone and azathioprine (n = 16 dogs), or not immunosuppressed (n = 4). In group II, recipients were made specifically unresponsive by total body radiation, autologous marrow implantation, and kidney transplantation from DLA-MLC identical donors, 1 yr before FDPS transplantation from the corresponding original kidney donors. Survival of the FDPS grafts in group I was inversely related to pretransplant MLC reactivity, irrespective of DLA genotyped match between donor and recipient. Thus, immunosuppressed high MLC reactors (n = 8) rejected FDPS grafts between 7 and 14 d, whereas immunosuppressed low MLC reactors (n = 8) accepted grafts for 25 to 260+ days, and nonimmunosuppressed low MLC reactors (n = 4) accepted grafts for 9-55 d. Rejection (hyperglycemia) of FDPS grafts was sudden, permanent, and unpredictable despite weekly intravenous glucose tolerance tests with measurements of glucose disappearance rates and serum insulin responses. Nevertheless, serial in vitro cell-mediated lymphocytotoxicity (CML) assays revealed increases in CML before graft rejection in low MLC reactors, and decreases in both CML and MLC responses before graft rejection in high MLC reactors. FDPS graft survival was indefinite (>6 mo) in group II dogs, despite low-grade MLC reactivity (2:4 dogs) and CML responses (4:4 dogs). Biopsies of FDPS grafts at 6 mo in normoglycemic dogs showed disappearance of exocrine tissue and coalescence of islets in both groups I and II, but with less fibrosis in group I (immunosuppressed). These results indicate that (a) pancreatic islets in vascularized grafts (FDPS) may survive indefinitely in the presence of a good tissue match best predicted by MLC testing, (b) tissue specific histocompatibility factors appear to be common enough between kidney and pancreas to allow for long-term survival of both organs transplanted from the same donor, at least in appropriate recipients (group II), and (c) immunosuppression is associated with less fibrosis in FDPS allografts.

Animals↗
PubMed1981

Responses of canine lymphocytes to allogeneic and autologous Islets of Langerhans in mixed cell cultures.

Because successful allotransplantation of islets of Langerhans isolated by collagenase digestion has been difficult in many animal species, we asked whether isolated islet preparations might have tissue specific determinants conferring amplified immunogenicity in vitro. Lymphocyte proliferative responses ([(3)H]thymidine uptake) were studied in beagle dogs in mixed culture combinations of lymphocyte vs. lymphocyte (MLC) and lymphocyte vs. islet (MLIC). In five MLC responder and five nonresponder pairs, peripheral blood lymphocytes of dogs A and B were used as responding cells, and dog B x-irradiated lymphocytes (Bx), x-irradiated (or nonirradiated) islets (BI), or hepatic cells (BH) were used as stimulating cells in primary and secondary reactions. For the secondary reactions, A + Bx, A + BI, or B + BI were incubated for 9 d (A'B, A'BI, B'BI, respectively) before addition of new stimulating cells. The results showed that islets were autostimulatory, eliciting a tissue-specific lymphoproliferative response in a primary MLIC. Thus, B + BI reactivity was evident at 3,5, and 7 d in primary culture, whereas collagenase-digested liver cells, or lymphocytes obtained from collagenase-digested lymph nodes did not stimulate autologous lymphocytes. A separate reactivity was observed in the allogeneic A + BI combination in MLC responder pairs, and the peak response of A + BI at 9 d was markedly greater than that of B + BI, suggesting the presence of major histocompatibility complex lymphocyte-defined locus determinants in the islet preparations, in addition to islet-specific determinants. A secondary reaction was observed if lymphocytes were primed with islets and challenged with islets (A'BI + BI or B'BI + BI), but not if they were challenged with lymphocytes (A'BI + Bx, B'BI + Bx) or hepatic cells (A'BI + BH, B'BI + AH). Furthermore, priming of lymphocytes with autologous islets (B'BI) led to exclusion of any reactivity against allogeneic lymphocytes, i.e., B'BI suppressed A + Bx, and B'BI also markedly suppressed phytohemagglutinin-stimulated lymphoproliferative responses. Experiments were performed that excluded the possibility that the insulin levels present in the MLIC, the presence of passenger lymphocytes in the islets, or the maintenance of islets in tissue culture for 1-7 d affected the observations. These results provide evidence for the existence of alloantigens as well as tissue-specific antigens on collagenase-isolated islets of Langerhans.

Animals↗
PubMed1981

Tomographic mapping of human cerebral metabolism: normal unstimulated state.

Positron computed tomography (PCT) and F-18 2-fluorodeoxyglucose (FDG) were used to study the living human brain in coronal and transverse sections. Scans taken at 1-cm intervals in both directions clearly delineated the cerebral substructures (e.g., cortical areas, basal ganglia, internal capsule, and cerebellum). A compartmental model was used to calculate local cerebral metabolic rates for glucose from the images. Values agreed well with previous global and local human values and demonstrated metabolic symmetry of the left and right hemispheres at rest. Baseline anatomic maps such as these are a necessary prelude to the study of human brain metabolism in stimulated and pathologic states.

Adult↗
PubMed1981

Cadmium, lead and zinc in growing rats fed corn leaf tissue grown on soil amended with sewage sludge or heavy metal salts.

Rats were fed, from weaning through 11 weeks of age, dried leaf tissue of corn plants grown on soil amended with regular NPK fertilizer (150-22-62), with 33.6 ad 67.2 metric ton/ha of sewage sludge or with salts of cadmium (10kg/ha), lead (25kg/ha), and/or zinc (50kg/ha). A very high proportion of the cadmium (cd) consumed was eliminated in feces. Only in rats fed diets containing leaf tissue from plants grown on soil to which CdCl2 salt or the high level of sludge had been added did the metal accumulate in significantly greater quantity than in rats fed a standard diet without leaf tissue. Most of the carcass accumulation of Cd could be accounted for by that in the liver and kidneys. The proportion of dietary zinc (Zn) that was excreted in feces was less than that for Cd, indicating that more Zn was absorbed into the body. There was no correlation between intake and accumulation of Zn in the tissues, however, so that much of the absorbed Zn must have been eliminated in some way. Fecal elimination did not serve as a way to rid the body of excessive intake of lead (Pb). However, with intakes ranging from 2 to 11 mg total in this study, the carcass load did not exceed 1.1 mg of Pb. Thus absorbed Pb, like Zn, must also be eliminated efficiently. No gross signs of toxicity or of physiological impairment were observed in rats fed any of the plant tissue samples.

Animal Feed↗
PubMed1981

Kidney transplantation by use of splenectomy and transfusions, cadaver haplotype matching, suppressor cell assays, and T-cell monitoring.

We attempted to modulate several determinants of the host immunologic profile to improve kidney transplant survival: (1) genotype matching of the cadaver donor with the recipient, (2) assessment in recipients of living related donors (LRD) for predisposition to generate suppressor cells in mixed lymphocyte culture (MLC), (3) pretransplant splenectomy and transfusions, and (4) posttransplant immunologic monitoring. Between January, 1979, and July, 1980, 48 primary renal transplants were performed and followed up between 6 and 24 months. Pretransplant splenectomy was performed, and transfusions were administered in 38 of 48 and 48 of 48 patients, respectively. Donors and recipients of 10 of 11 cadaveric transplants were genotyped and selected for one HLA haplotype identity. All 10 proved to also be one DR antigen matches. There were no cadaveric kidney losses, but one surgical antibody to T cell subtest were used to modulate rejection therapy. The LRD group (n = 37) included 13 HLA-identical, seven haploidentical low MLC reactors, and 17 haploidentical high MLC reactors. Three deaths occurred (diabetes and myocardial infarction, stroke, and pancreatitis). A three-component coculture assay was used in the LRD group before transplantation to determine the capacity to generate specific and nonspecific MLC suppressor cells. Suppressor cells were seen in 17 patients given standard immunosuppression postoperatively without rejection episodes. However, in 20 patients incapable of generating suppressor cells, seven biopsy-proved rejection episodes occurred. There were no kidney losses, with 44 of 48 surviving recipients demonstrating normal renal function.

Adolescent↗
PubMed1981

Global precedence in attention and decision.

This article examines the order in which people recognize and respond to different levels of structure within a visual display. Certain previous experiments have been interpreted as showing that information about global characteristics of an array is extracted by the visual system before information about local characteristics. Results from a task in which the observer must attend to both global and local information demonstrate that local information has a large influence on reaction time even when information at the global level is sufficient to determine the response. This finding implies that local information becomes available to decision processes with a time course similar to that of global information. Effects previously attributed to the order in which different levels of structure are recognized may result from differential ease of directing attention to these different levels and selecting responses based on them.

Attention↗
PubMed1981

Prevention of hypoxemia during dialysis by the use of sequential isolated ultrafiltration-diffusion dialysis with bicarbonate dialyzate.

Previous studies have demonstrated that hypoxemia does not occur during isolated ultrafiltration, but does occur during diffusion dialysis with acetate, whether it is performed alone or following a period of isolated ultrafiltration. To determine if the substitution of bicarbonate for acetate in dialyzate could prevent hypoxemia, we studied the effect of sequential isolated ultrafiltration-diffusion dialysis with bicarbonate on arterial oxygen concentration. There was no significant change in pO2 during isolated ultrafiltration or the subsequent period of diffusion dialysis. In addition, excess body fluid could be removed and effective dialysis achieved without marked tachycardia or fluctuation in blood pressure. We conclude that sequential isolated ultrafiltration diffusion dialysis with bicarbonate is a safe and effective way of dialyzing patients without producing hypoxemia or cardiovascular instability.

Bicarbonates↗