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Biomedical subjects

G Graham

Publications and source records attributed to G Graham.

16 recordsLinked to original sources
PubMed1992

Isolated diffusing capacity reduction in systemic sclerosis.

OBJECTIVE: To determine the long-term outcome of patients with systemic sclerosis (SSc) and an isolated reduction in the diffusing capacity for carbon monoxide (DLCO) at the time of initial evaluation. METHODS: Patients with an isolated reduction in DLCO (i.e., normal forced vital capacity [FVC] and normal ratio of the forced expiratory volume in one second [FEV1] to the FVC) on initial evaluation were identified from among 815 patients with SSc who were carefully followed up throughout their illness. We requested that patients have repeat pulmonary function testing (PFT), and the outcomes of these tests, as well as cardiopulmonary and survival outcomes, were determined. RESULTS: An isolated reduction in DLCO, with a normal FVC was detected in 152 (19%) of the 815 patients. A subset of those with an isolated reduction in DLCO (11%) developed isolated pulmonary hypertension and had severely reduced survival rates. Pulmonary hypertension was strongly associated with an initial DLCO of less than 55% of predicted normal and a FVC (% predicted)/DLCO (% predicted) ratio of greater than 1.4. Among all patients in whom this ratio was greater than 1.4, 22% developed isolated pulmonary hypertension, compared with only 2% of those whose ratio was less than 1.4 (P less than 0.01). Of the 152 patients with isolated DLCO reduction, 73 (48%) underwent PFTs a mean of 5.4 years (range 2.0-13.2) after the initial PFT. Only 6 (8%) of these 73 patients ever had serious pulmonary disease: 5 had isolated pulmonary hypertension, and 1 had severe pulmonary fibrosis. Half of the patients with a low initial DLCO demonstrated a significant improvement (greater than 20%) at followup testing that could not be explained by the demographic, clinical, or laboratory findings at the first visit. CONCLUSION: Isolated reduction in DLCO is a frequent abnormality in SSc. Overall, it is associated with a good prognosis for survival and for pulmonary morbidity. A small subset of patients (11%) who have a very low DLCO (less than 55% of predicted) have developed isolated pulmonary hypertension, all of whom had limited scleroderma.

Carbon Monoxide↗
PubMed1992

Multidisciplinary preoperative assessment and late function in dysvascular amputees.

During a three-year period, 95 adults were treated by lower-extremity amputations for peripheral vascular insufficiency. A multidisciplinary team for presurgical evaluation determined all to be potentially independent walkers with a prosthesis. Patients were graded for level of independent walking before amputation and again at a minimum two-year follow-up examination using a seven-level functional grading system. Seventy-six of 90 patients (84%) ambulated within one functional level of their preamputation status. This return to preamputation level of function was maintained whether comparing preamputation functional level or surgical amputation level. Prosthetic use increased and the use of walking aids decreased with increased functional ambulation levels, but did not correlate with surgical levels. Peripheral vascular insufficiency patients can maintain walking independence. Multidisciplinary presurgical evaluation helps selection of the amputation level and correct prosthetic limb fitting.

Adult↗
PubMed1991

Investigation of varicella-zoster virus infection by polymerase chain reaction in the immunocompetent host with acute varicella.

A polymerase chain reaction (PCR) method developed to detect varicella zoster virus (VZV) in clinical samples is based on amplifying sequences of viral gene 31, the coding region for glycoprotein II. Its sensitivity was evaluated by amplification from plasmid VZV DNA containing VZV gene 31; 45 copies were detected in 1 microgram of human DNA. In testing within 24 h after the onset of varicella exanthem, 21 (75%) of 28 lesion samples were positive by VZV PCR, whereas VZV was isolated from only 21% by a standard tissue culture method. Only 1 (3.3%) of 30 samples of oropharyngeal secretions but peripheral blood mononuclear cells from 8 (67%) of 12 patients were positive. The sensitivity and specificity of the VZV PCR method indicates its usefulness for investigating the pathogenesis of VZV infection. Direct contact with cutaneous lesions rather than respiratory secretions may be the most important route of VZV transmission from healthy individuals with acute varicella.

Acute Disease↗
PubMed1991

Differential effect of interleukin 3 on the metabolism of high-dose cytosine arabinoside in normal versus leukemic human bone marrow cells.

We have examined the effect of recombinant interleukin 3 (rIL-3) on the metabolism of high-dose cytosine arabinoside (Ara-C), an S-phase-specific agent, in normal human bone marrow mononuclear cells (BMMC) and leukemic blasts from patients with acute myeloid leukemia (AML). Exposure to rIL-3 for 24 h significantly increased the percentage of cycling S-phase cells in normal BMMC as well as leukemic cells. A concomitant expansion of intracellular deoxycytidine triphosphate (dCTP) levels occurred to a significantly greater extent in normal BMMC. Compared to treatment with Ara-C (10 mumol/liter) alone, prior and coadministration of rIL-3 with Ara-C increased Ara-CTP levels in leukemic blasts. However, an identical treatment produced significantly higher dCTP levels in normal BMMC, resulting in a significantly lower mean Ara-CTP to dCTP pool ratio in normal BMMC compared to that observed in each of the samples of AML blasts. Following treatment with Ara-C plus rIL-3 versus Ara-C alone, the alteration in Ara-C DNA incorporation corresponded with the change in Ara-CTP to dCTP ratio observed in normal BMMC and AML blasts. The differential effect of rIL-3 on the metabolism of high-dose Ara-C in normal versus leukemic cells may indicate a role for rIL-3 in enhancing the selectivity of Ara-C toward leukemic myeloblasts.

Bone Marrow↗
PubMed1990

A generalized information function applied to the genetic code.

The problem of the partitioning of the degeneracy of the codons in the genetic code is considered in the framework of a generalized information function IG = c sigma kpk(ln pk + G(Ek] where k represents the number of codons in a specific degeneracy class and G(Ek) is an arbitrary real valued function. For G(Ek) = 0 the Shannon information function is recovered. For a particular choice of G(Ek) that takes the dominance of even degeneracies into account, it is found by direct numerical calculations that the correct degeneracy partitioning appears as optimal values of the Ig function. This results is also supported by optimization calculations in which the generalized information function is regarded as a continuous function in the degeneracy variables.

Amino Acids↗
PubMed1978

Non-specific serum iron in thalassaemia: an abnormal serum iron fraction of potential toxicity.

Iron binding in the sera of 35 patients with beta thalassaemia major and intermedia was studied. In patients receiving regular blood transfusions since infancy transferrin was completely saturated and about 2.7--7.1 mumol/l of the serum iron could be removed by dialysis or ultrafiltration in the presence of a chelating agent or by filtration on DEAE-Sephadex-catecholdisulphonic acid columns. In contrast, less than 1.0 mumol/l of transferrin bound iron was removed when subjected to the same procedures. The non-specific iron of thalassaemic sera could no longer be demonstrated after incubation with normal serum. These findings indicate that non-specific iron is a chelatable with normal serum. These findings indicate that non-specific iron is a chelatable compound which is readily available for transferrin binding. In view of the known toxicity of unbound iron, its identification in thalassaemic sera might be of relevance to the pathogenesis of tissue damage and the protective effect of iron chelating therapy in this disease.

Adolescent↗
PubMed1977

Hormone changes in relation to the time of fetal death after prostaglandin-induced abortion.

The changes in unconjugated estradiol-17beta and estriol, progesterone and chorionic somatomammotropin (HCS) in peripheral plasma have been studied in 18 women at 30-minute intervals following intra-uterine prostaglandin E2 administration for therapeutic termination of second trimester pregnancy. The hormonal changes were related to the time of fetal death detected by the disappearance of fetal heart pulsations. Prostaglandin E2 was given by the intra-amniotic route with urea (5 patients) or with intravenous oxytocin (5 patients), or by the extra-amniotic route with intravenous oxytocin (8 patients). Fetal death occurred rapidly with intra-amniotic PGE2, but usually at a late stage with extra-amniotic PGE2. Three fetuses in the extra-amniotic group died at or just before abortion. A variety of fetal heart changes were noted and the time of fetal death did not appear to influence the time of abortion within each treatment subgroup. Estradiol and estriol showed a sligh but persistent fall over 24 hours prior to induction of abortion. A more rapid fall usually occurred after induction, with a consistent fall around the time of fetal death. Progesterone and HCS usually fell much less before and immediately after fetal death. A marked rise in estradiol sometimes occurred before fetal death, particularly in the intraamniotic PGE2 and urea subgroup. Estriol levels declined more rapidly before than after fetal death, whereas fetal death had less consistent effects on the other hormones. All hormones had usually fallen considerably at the time of abortion, and in some individuals marked fluctuations in hormone levels were seen.

Abortion, Induced↗
PubMed1976

Single-dose evaluation of a new enteric-coated aspirin preparation.

The bioavailability of a new enteric-coated tablet of aspirin (Ecotrin, Smith, Kline and French) was evaluated after single doses to eight volunteers. One tablet was administered to each subject on four occasions--twice after a light breakfast, once after a heavy breakfast and once after pretreatment with metoclopramide. The study utilized non-invasive techniques. The rate of absorption of aspirin was estimated by the time course of concentrations of salicylate in saliva, while the total bioavailability was determined by the recovery of total salicylate in urine. The urinary recovery of aspirin from all 32 trials was 575 +/- 25 mg (mean +/- standard error), representing 89% +/- 4% of the administered dose. The different treatments did not significantly alter the urinary recovery. The absorption of aspirin from the enteric-coated tablets was delayed and slow. Absorption was retarded by a heavy meal and hastened by pretreatment with metoclopramide. The effect of metoclopramide is consistent with the release of aspirin in the small intestine. Overall, the single-dose tests indicated satisfactory functioning of the enteric coating.

Adult↗
PubMed1975

The effect of serum and experimental variables on the transferrin and reticulocyte interaction.

The transfer of iron from transferrin to the developing erythrocyte is a research area of high interest and considerable controversy. We have found that the results of transferrin-reticulocyte incubation studies are quite sensitive to the experimental procedures that are utilized. Reticulocytosis has been induced in rabbits by phelbotomy and phenylhydrazine injections. While the latter gives a higher reticulocyte count, the cells appear to exhibit an altered transferrin-membrane interaction. Transferrin has been iodinated by published methods utilizing chloramine-T and molecular iodine. The iodotransferrin products exhibit the same iron donation ability, however, evidence was found that the chloramine-T treatment leads to a nonspecific binding of transferrin to the reticulocyte. The means of saturating transferrin with 59Fe is also of prime importance. Fe(NH4)2(SO4)2 and especially FeCl3 were found to yield nonspecifically bound iron when added to transferrin or serum. This artifact was reflected in an altered transferrin-reticulocyte interaction. Using what we believe to be optimal conditions, the effect of serum on the transferrin-reticulocyte system was re-examined. The results clearly indicated an enhancement of iron uptake by reticulocytes in the presence of serum, as well as an accelerated incorporation of iron by the cytoplasmic fraction.

Animals↗
PubMed1975

[Effect of cyclophosphamide on themetabolism of erythrocytes].

Cyclophosphamide was applied i.p. in the dose of 100 mg kg-1 to rats. After one, two, three, and seven days the animals were killed and in the collected heparinized blood the incorporation of o-phosphate 32P in erythrocytes was determined in vitro at 37 degrees C and in 35 minutes. Decreased incorporation in animals with Cyclophosphamide indicated, compared with the control, disturbed metabolism of phosphate. The method can be applied as a criterion of secondary toxic effects in the treatment of cancerostatics of alkylation type.

Animals↗
PubMedDate not supplied

Neuroendocrine carcinoma of the stomach with extensive somatostatin immunoreactivity.

Upper gastrointestinal tract neuroendocrine tumors producing predominantly somatostatin have thus far been described only in the duodenum; their characteristic features include the frequent presence of psammoma bodies (psammomatous somatostinomas), and the association with von Recklinghausen's neurofibromatosis. Gastric neuroendocrine tumors, on the other hand, tend to display immunoreactivity to serotonin but may include small subpopulations producing gastrin, motilin, pancreatic polypeptide, and somatostatin. In this report we describe a neuroendocrine carcinoma of the stomach with rapidly fatal outcome, displaying neurosecretory granules by electron microscopy and immunoreactivity to pan-neuroendocrine markers, ie, chromogranin and neuron-specific enolase. The only neuroendocrine regulatory peptide detected in the tumor was somatostatin, identified by immunohistochemistry in the majority of neoplastic cells. In contrast with duodenal somatostinomas, there were no psammoma bodies and no demonstrable association with von Recklinghausen's neurofibromatosis. To our knowledge this appears to be the first report of a malignant neuroendocrine tumor with diffuse somatostatin immunoreactivity.

Aged↗