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Biomedical subjects

L Gordon

Publications and source records attributed to L Gordon.

At least 127 records · Page 7Linked to original sources
PubMed1991

Acute plastic deformation of the ulna in a skeletally mature individual.

Acute plastic deformation of a bone refers to traumatic bending or bowing without a detectable cortical defect. We present a case that is unusual in that bowing of the ulna occurred in a skeletally mature individual and was associated with injury to the distal radioulnar joint. In this patient, the symptoms were severe enough to warrant an ulnar osteotomy. The patient regained satisfactory function. Acute plastic deformity should be suspected whenever abnormal curvature of a long bone is noted, even in adults. If the distal radioulnar joint is dislocated, the deformation should be corrected as soon as possible to avoid permanent loss of forearm rotation.

Adolescent↗
PubMed1991

A new system for high-resolution DNA sequence mapping interphase pronuclei.

Cosmid clones containing human or hamster inserts have been hybridized in situ and localized with fluorescent reporter molecules in interphase nuclei (pronuclei) obtained after fusion of hamster eggs with either human or hamster sperm. Hamster egg cytoplasm processes the tightly packaged sperm DNA into large diffuse networks of chromatin fiber bundles, providing hybridization targets more extended than those available in somatic interphase cell nuclei. Pronuclear physical distances between hybridization signals were measured in micrometers and correlated to genomic distances determined by restriction fragment analyses, using cosmids from the Chinese hamster DHFR region and from the human Factor VIII/color vision pigment gene region (Xq28). The mean pronuclear distances between hybridization sites were about three times as large as those measured in somatic interphase cells for equivalent genomic distances. The relationship between physical and genomic distances was linear from less than 50 kb to at least 800 kb. The results show that physical distance in the sperm-egg system promises to extend the mapping range obtainable in somatic interphase nuclei below 50 kb and up to at least 800 kb.

Animals↗
PubMed1991

Comparison of four objective methods of monitoring digital venous congestion.

This study sought to determine which of the four most commonly used objective monitoring modalities--pulse oximetry, laser Doppler flowmetry, skin surface temperature measurement, and skin surface fluorescence--is best able to detect early digital venous congestion. Digital venous congestion was induced in 12 hands by inflating a digital cuff to 5 mm Hg above the resting diastolic pressure. The cuff remained inflated for 1 hour while monitoring was done at 10-minute intervals. The baseline and experimental laser Doppler indices differed by at least 30% in each subject, and the laser Doppler index was always less than 40% during venous congestion. Skin surface fluorescence gave falsely normal results in three of eight hands, while pulse oximetry failed to detect venous congestion in any hand. The difference in temperature between the control and experimental fingers almost always exceeded the threshold of 2.5 degrees C. The results indicate that both laser Doppler flowmetry and skin surface temperature measurement are highly accurate methods of monitoring early digital venous congestion that are noninvasive and easy to use. Skin surface temperature measurement has further advantages in that thermometers are less expensive and easier to transport than laser Doppler devices. In contrast, skin surface fluorescence is invasive and cumbersome in addition to being less sensitive to experimentally induced early digital venous congestion than either laser Doppler flowmetry or skin surface temperature measurement. Pulse oximetry is unreliable in detecting early digital venous congestion.

Adult↗
PubMed1991

The Allen's test: analysis of four methods.

Forty nonrandomly selected hands were studied with use of four types of Allen's test: (1) the digital systolic blood pressure method, (2) the subjective method, (3) the pulse oximeter method, and (4) the laser Doppler flowmetry method. The digital systolic blood pressure method, regarded as the standard, indicated abnormal pressure in three hands. Laser Doppler flowmetry gave the same results as those obtained by the digital systolic pressure method and, in addition, was easier to perform. Pulse oximetry falsely indicated adequacy of the collateral circulation in two of the three hands with abnormal digital systolic pressure. Eleven hands, including the three with abnormal digital systolic pressure, were abnormal according to the subjective method. The results of the present study indicate the following: (1) the laser Doppler Allen's test is accurate, quick, and easy to perform; (2) the pulse oximeter Allen's test should not be used because of potentially dangerous consequences to the patient in the event of a falsely normal result; and (3) the subjective Allen's test can be used as a quick screening test.

Adult↗
PubMed1991

Occurrence of schizotypal and borderline symptoms in parasuicide patients: comparison between subjective and objective indices.

Seventy-six patients were interviewed within a week of admission following a parasuicide episode. Axis II diagnosis on DSM-III was made for schizotypal, borderline, histrionic, and antisocial personality disorder. In addition patients completed a self-rating questionnaire, the Schizotypy Questionnaire of Claridge & Broks (1984), which assesses schizotypal and borderline personality traits. The objective and subjective indices of schizotypal and borderline symptoms correlated significantly but allocation of patients to a diagnosis missed several patients who nevertheless rated themselves as having a high frequency of these symptoms. There was an asymmetry of symptom pattern reminiscent of Foulds & Bedford's (1975) hierarchy model. The presence of schizotypal symptoms appeared to be higher in the hierarchy: they predicted borderline symptoms, but a high frequency of borderline symptoms did not necessarily predict schizotypy. We suggest that the occurrence of schizotypal symptoms should become a more explicit focus of clinical assessment and treatment of these patients, especially those who repeatedly harm themselves and we suggest ways in which cognitive therapies may be adapted to do this.

Adolescent↗
PubMed1991

Male-sex-ratio trait in Drosophila pseudoobscura: frequency of autosomal aneuploid sperm.

Males with the SR X chromosome show the "sex-ratio" (sr) phenotype in which they produce almost entirely daughters. The few sons (about 1%) are invariably sterile X/O males and result entirely from nullo-XY sperm. The "male-sex-ratio" (msr) phenotype is a modified form of sr in which SR/Y males produce a higher frequency of sterile X/O sons. The msr trait is due to the presence of the SR X-chromosome in males which are also homozygous for one or more autosomes from the L116 strain. Here the frequency of nullo-3 and diplo-3 sperm from msr males was measured by crossing to a compound-3 strain and found to be 13.8% and 3.2%, respectively, of the total viable sperm. The sr males produced very low levels of nullo-3 sperm at a frequency not different from control X/Y males and a slightly elevated frequency of diplo-3 sperm over X/Y males. The msr males were found to have only 12% the fecundity of sr males and in matings to cause a high frequency of brown inviable eggs. These results indicate that high rates of autosomal aneuploidy are not restricted to chromosome 3 but also occur for chromosomes 2, 4 and 5. The overall frequency of autosomal aneuploid sperm is estimated to be approximately 50%. Microscopic studies of meiosis in testes from msr males indicates meiotic nondisjunction and meiotic chromosome loss are responsible for the msr phenotype. Last, microscopic studies of sperm cysts from msr males reveal high levels of spermiogenic failure.

Anaphase↗
PubMed1991

Localization of endothelin binding sites and endothelin-like immunoreactivity in human fetal heart.

The localization of [125I]endothelin-1 ([125I]ET-1) and [125I]endothelin-3 ([125I]ET-3) binding sites, as well as ET-like immunoreactivity, was investigated in sections of human fetal heart, using in vitro autoradiographic and immunohistochemical techniques. High-affinity [125I]ET-1 binding sites showed a tissue-specific distribution pattern, with high-density binding to the atria, ventricles (77-100 amol/mm2), and cardiac valve cusps (120.6 +/- 2.6 amol/mm2). Specific high-density binding of [125I]ET-3 was also exhibited on valve cusps (143.2 +/- 2 amol/mm2), whereas a much lower density of binding was displayed on atria and ventricles (10-15 amol/mm2). Microautoradiographic examination demonstrated binding sites on the wall of the aorta, pulmonary and coronary arteries, myocardium, ventricular conduction system, endocardium, and endothelial lining of valve cusps. Regional differences in the density and affinity of ET binding sites suggest that subpopulations of receptors are present in the human fetal heart. ET-like immunoreactivity was localized to a heterogeneous population of endothelial, endocardial, and epicardial mesothelial cells. The concordant localization of specific binding sites and ET-like immunoreactive cells indicates that locally released peptide might have a paracrine or autocrine role, possibly influencing cardiovascular development and function.

Autoradiography↗
PubMed1991

Safety and immunogenicity of subcutaneous H. influenzae vaccines in 15-17 month-old children.

To evaluate the safety and immunogenicity of subcutaneously administered PRP and PRP-D, one hundred and one healthy 15 to 17 month-old children were randomly assigned to receive two subcutaneous doses, 2 months apart, of either vaccine. The incidence of local and systemic reactions did not differ significantly between the two groups. PRP antibody levels in the pre-immunization sera of 95% of subjects were below the level associated with immediate protection from Hib disease (less than 0.15 microgram/ml). After the first dose, 32% of PRP and 70% of PRP-D (p less than 0.001) recipients achieved antibody levels of greater than or equal to 0.15 microgram/ml, and 8% and 26% (p = 0.003) respectively achieved levels greater than or equal to 1 microgram/ml, a level believed to predict long-term protection. After the second dose, antibody levels greater than or equal to 0.15 microgram/ml were reached in 38% of PRP and 88% of PRP-D (p less than 0.001) recipients and levels of greater than or equal to 1 microgram/ml were reached in 22% and 78% respectively (p less than 0.001). The geometric mean levels of PRP antibody after immunization were significantly higher in the PRP-D group after both the first and second doses (p less than 0.001). These results suggest that subcutaneous administration of both vaccines is safe, but PRP-D results in significantly higher antibody levels compared to PRP. The levels were lower than what has been reported following intramuscular administration.

Antibodies, Bacterial↗
PubMed1991

Development of laparoscopic anterior seromyotomy and right posterior truncal vagotomy for ulcer prophylaxis.

This study investigated the feasibility of a laparoscopic antiulcer procedure. The following antiulcer operations were performed laparoscopically in 20 pigs: truncal vagotomy and pyloroplasty (n = 5), highly selective vagotomy (n = 5), right truncal vagotomy and left highly selective vagotomy (n = 5), and anterior seromyotomy and posterior truncal vagotomy (n = 5). Each procedure was videotaped and assessed in terms of ease of access, need for additional trocars, requirements for suturing, and complexity of the procedure. The anterior seromyotomy and posterior truncal vagotomy provided the optimal combination of antiulcer prophylaxis and adaptivity to the laparoscopic approach. We employed a Nd:YAG laser operating at 20 W delivered via a 600 micron sculpted tip which simplified the anterior seromyotomy. Anterior seromyotomy-posterior truncal vagotomy was then performed in three cadavers without evidence of perforation of the stomach. Our initial experience in a 46-year-old male demonstrates that the procedure can be performed with relative ease in humans. Thus, an effective antiulcer operation, anterior seromyotomy-posterior truncal vagotomy can be performed laparoscopically and may be a reasonable alternative for treating those patients who had a poor response to medical therapy.

Animals↗
PubMed1991

The Sauve-Kapandji procedure for the treatment of posttraumatic distal radioulnar joint problems.

The appropriate management of distal radioulnar joint (DRUJ) problems has no consensus. Although the Sauve-Kapandji procedure is not new, little has been written on the indications for its use. Our experience shows that this operation is an effective treatment for patients with some combination of posttraumatic DRUJ problems that involve arthritis, instability of the distal ulna, and ulna-plus variance.

Adolescent↗
PubMed1991

Indium-111-labeled leukocyte scan in detection of synthetic vascular graft infection: the effect of antibiotic treatment.

To determine the sensitivity and specificity of the indium-111-(111In) labeled leukocyte scan for prosthetic vascular graft infection in patients treated with antibiotic therapy, a retrospective study was performed. Of 41 consecutive 111In-labeled leukocyte scans performed to evaluate possible vascular graft infection, 23 scans were performed in patients treated with antibiotics. The average duration of antibiotic therapy was 21 days. Twelve positive and 11 negative scans for graft infection were found. By surgical and autopsy correlation of all positive cases, and clinical correlation (of all negative cases), there were 10 true-positive, 11 true-negative, 2 false-positive, and no false-negative scans for graft infections, for an overall sensitivity of 100% and specificity of 85%.

Anti-Bacterial Agents↗
PubMed1990

Trisomy 13: a new recurring chromosome abnormality in acute leukemia.

A new recurring chromosome abnormality was identified in 8 of 621 consecutive successfully karyotyped adults with de novo acute leukemia. These eight patients had trisomy 13 as the sole cytogenetic abnormality. On central morphologic review, five cases were classified as subtypes of acute myeloid leukemia, one as acute mixed lymphoid and myeloid leukemia, one as acute lymphoid leukemia, and one as acute undifferentiated leukemia. Blasts of all eight cases expressed one or more myeloid differentiation antigens. Three also expressed T-lineage-associated antigens; however, none of these had rearrangement of the T-cell receptor beta, gamma, or delta genes. Four of six cases tested were TdT positive. All eight patients with trisomy 13 were treated with intensive induction chemotherapy; only three entered a short-lived complete remission. Survival of patients with trisomy 13 ranged from 0.5 to 14.7 months, and was significantly shorter than that of the remaining patients (median 9.5 v 16.2 months, P = .007). We conclude that trisomy 13 is a rare, recurring clonal chromosome abnormality in acute leukemia associated with a poor prognosis. Malignant transformation of an immature hematopoietic precursor cell is suggested by the expression of antigens characteristic of both the myeloid and lymphoid lineage, the high incidence of TdT positivity, and the morphologic heterogeneity in these leukemias.

Acute Disease↗
PubMed1990

Failure to phosphorylate the retinoblastoma gene product in senescent human fibroblasts.

Heterokaryon studies suggest that senescent and quiescent human diploid fibroblasts (HDF) contain a common inhibitor of entry into S phase. DNA synthesis can be induced in senescent and quiescent HDF by fusing them with cells containing DNA viral oncogenes such as SV40 T antigen, adenovirus E1A, or human papillomavirus E7. Both senescent and quiescent HDF contained the unphosphorylated form (p110Rb) of the retinoblastoma protein, a putative inhibitor of proliferation. After serum stimulation, senescent HDF did not phosphorylate p110Rb and did not enter S phase, whereas quiescent HDF phosphorylated p110Rb and entered S phase. These findings, combined with the observations that T antigen, E1A, and E7 form complexes with, and presumably inactivate, unphosphorylated p110Rb, suggest that failure to phosphorylate p110Rb may be an immediate cause of failure to enter S phase in senescent HDF.

Adenovirus Early Proteins↗
PubMed1990

Expression of neural cell adhesion molecule immunoreactivity in hypertrophic myocardium.

Myocardial neural cell adhesion molecule (N-CAM) is temporally regulated, being expressed during cardiac morphogenesis and innervation and suppressed in the adult heart. We have investigated the plasticity of N-CAM expression in hypertrophic muscle using the rat model of chronic hypoxia to selectively induce right ventricular hypertrophy over a 14 day time course. Sarcolemmal and intercalated disc N-CAM immunostaining was more extensive in the ventricular myocardium of hypoxic rats compared to normoxic controls. Quantitative assessment of the immunoreactivity in tissue extracts demonstrated a selective increase in the amount of N-CAM immunoreactivity in the hypertrophic myocardium of the right ventricle of rats exposed to hypoxia and this was associated with an increase of the 125 kDa isoform. We conclude that myocardial hypertrophy may be a factor influencing N-CAM expression in the heart and adhesion molecules may have a role in cardiac remodelling.

Animals↗
PubMed1990

The effect of halothane on morphine disposition: relative contributions of the liver and kidney to morphine glucuronidation in the dog.

The present study determined the effect of halothane on the disposition of morphine by defining the effect of halothane anesthesia on the systemic, renal, and hepatic clearance of the parent compound, morphine, and on the generation of the primary metabolite, morphine-3-glucuronide (M3G) in the dog. Unlabeled morphine, 3H-morphine, and 14C-morphine were simultaneously administered into the portal vein, femoral vein, and renal artery, respectively, first during pentobarbital anesthesia and second during halothane (1.5 MAC) anesthesia; blood samples were taken for estimation of unlabeled plasma morphine and M3G concentrations by high performance liquid chromatography (HPLC). 3H- and 14C-morphine concentrations and corresponding M3G concentrations were determined by dual-channel liquid scintillation counting of the eluant corresponding to the appropriate peak on the HPLC. The portal clearance of morphine was not altered by halothane. However, intravenous (iv) morphine clearance (CLs) decreased (P less than 0.05) by 40% from 963 +/- 131 to 579 +/- 91 ml/min during halothane anesthesia, accompanied by an increase (P less than 0.05) in half-life from 78 +/- 8 to 106 +/- 8 min. The reduction in CLs of morphine occurred putatively on the basis of a halothane-induced decrease in hepatic blood flow, whereas morphine metabolism, reflected by morphine portal (intrinsic) clearance, was not significantly decreased by halothane. There was no significant effect of halothane on the partial metabolic clearance of morphine to M3G, and the ratio of area under the plasma concentration-time curve (AUC)-M3G to AUC unchanged morphine was not significantly altered by halothane, indicating that morphine glucuronidation is unaffected by halothane anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Inhalation↗
PubMed1990

Utility of Tc-99m DTPA aerosol inhalation scans following perfusion lung scans in the diagnosis of pulmonary embolism.

The authors report their experience with the use of Tc-99m DTPA aerosol following a perfusion lung scan. The study includes 422 consecutive patients with suspected pulmonary embolism. The final diagnosis was determined by (a) clinical follow-up for 2 months or more, (b) pulmonary angiography, or (c) autopsy. There were 79 patients (19%) who had a normal or near-normal perfusion study and in whom no aerosol study was required. Interpretation groups were classified and divided as follows: Normal or low probability 281 (66.5%) High probability 75 (18.0%) Intermediate 60 (14.0%) Technically inadequate 6 (1.5%) There was autopsy or angiographic confirmation of 72 patient studies with confirmation of the scan diagnosis in 29 of 31 classified as normal or low probability and 24 of 25 classified as high probability. The background perfusion albumin activity was not computer-subtracted from the combined aerosol-perfusion image. Technical improvements included the use of eight standard views for both the perfusion and the subsequent aerosol scan, and the use of 75 mCi (2,775 MBq) of Tc-99m DTPA in the radioaerosol nebulizer. This allowed for easy accumulation of more than three times the count rate in a posterior aerosol image when compared with the previous posterior perfusion image. The authors' experience shows that the perfusion lung scan followed by this radioaerosol technique is a reliable means to evaluate suspected pulmonary embolism.

Administration, Inhalation↗
PubMed1990

A single gel for determining genetic variants of equine erythrocyte carbonic anhydrase (CA) and catalase (Cat).

We describe a method for agarose IEF under acid conditions in which a single gel can be used to diagnose from equine red cell lysates genetic variants for carbonic anhydrase (CA) and catalase (Cat). Family and population data for 4801 horses of 27 breeds and seven trap sites of Great Basin feral horses are presented to support the presence of a sixth CA allele, CAE, which has been recognized previously, but not described by published data. Allelic frequencies for the two systems suggest it may be appropriate to use this gel for parentage verification programmes or to obtain population data for studies of the genus Equus.

Alleles↗