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Biomedical subjects

G L Davis

Publications and source records attributed to G L Davis.

At least 181 records · Page 10Linked to original sources
PubMed1980

Intraaortic balloon pumping women: effects of balloon size on survival.

Between 1972 and 1978, 429 patients underwent intraaortic balloon pump (IABP) counterpulsation in our institution. Ninety-six were women (22.4). The overall mortality was 52.9% for men and 69.8% for women. During 1978, however, the mortality for women decreased to 57.1%, even though they comprised a larger percentage of patients (28.2%) than before. The major indication for IABP support in these women was ischemic myocardial dysfunction resulting in failure to wean from cardiopulmonary bypass (THI hemodynamic Classification C) despite volume expansion and pharmacologic support. Improved results were obtained with the use of larger intraaortic balloons and direct ascending aortic IABP insertion (which allowed use of larger, more effective 30 or 40 ml balloons), combined with delayed sternal closure.

Adult↗
PubMed1980

Sound transfer function of the congested canine lung.

Alterations of sound transfer function of the lung in pre-congested and congested states were studied in a canine model as an index of the accumulation of lung liquids. Pulmonary congestion was produced by graduated inflations of a balloon in the left atrium. Different degrees of pulmonary congestion were documented by post-mortem wet to dry lung weight ratios. Sound transfer function of the lung was determined utilizing passive sound transmission in the audio freqency range consisting of sinusoidal oscillations swept from 50 Hz to 2 kHz. Sound transfer function in dB was defined as 20 times the logarithm of sound output divided by sound input. These functions were computed for pre-congested and congested states of the lung and the differential values correlated with the post-mortem wet to dry weight ratios of the lung. The magnitude of sound transfer function of the lung correlated well with increasing accumulation of intravascular and extravascular lung liquids and provided a quantitative index of pulmonary congestion.

Animals↗
PubMed1979

Congenital cytomegalovirus and hearing loss: clinical and experimental observations.

The effects of congenital cytomegalovirus infection vary from severe central nervous system destruction to asymptomatic viuria. Yet children with the latter have a high incidence of unsuspected hearing loss. Histopathology of temporal bones from children who die with cytomegalic inclusion disease shows viral infected cells in non-sensory endolabyrinthine epithelium. Experimental mouse cytomegalovirus causes an age related cranial neuronitis and perilabyrinthitis. Immunopathologic localization of different viral antigens in experimental inner ear infections shows differential vulnerability of labyrinthine structures to infections. Adaptation of such techniques to human temporal bone pathology could yield information regarding pathogenesis of viral labyrinthitis. The development of a human cytomegalovirus vaccine may eliminate the risks of this congenital infection.

Animals↗
PubMed1979

Sexual stereotyping of black males in interracial sex.

Beliefs about black males' sexuality are pervasive in this society, but little studied. This investigation examined white subjects' perceptions of black and white characters in sexually explicit stories, some of which depicted interracial pairings. The perceptions were then examined in relationship to authoritarianism and sexual repression. Overall results suggest that black males are stereotyped as more potent than white males. The theoretical implications of this finding are discussed.

Adolescent↗
PubMed1979

Age-related neurocytotropism of mouse cytomegalovirus in explanted trigeminal ganglions.

Human cytomegalovirus (CMV) causes severe congenital neurologic disease; adult neural infection is associated with transient cranial nerve palsies. In our experimental model, mouse CMV (MCMV) infects neurons and Schwann and satellite cells of cranial nerve ganglions. To study the fate of MCMV in nerve tissue, we explanted trigeminal ganglions from newborn, suckling, and weanling mice, 3 to 36 days after intracranial inoculation. Negative explants were co-cultivated with mouse embryo tissue culture (METC) to test for latency. MCMV, identified by electron microscopy, replicated in fibroblasts, Schwann cells, and/or satellite cells and neurons of trigeminal explants from newborn and suckling, but not weanling, mice. No latent virus was detected by our methods. The age differences in viral replication may be due to the age-dependent intrinsic cellular mechanisms and host inflammatory and immunologic response. Though neurons are infected, they remain relatively resistant to CMV replication.

Age Factors↗
PubMed1979

Transmural eosinophilic gastroenteritis with ascites.

An atopic patient with recurrent abdominal pain, diarrhea, and ascites was shown to have eosinophilic gastroenteritis. Transmural involvement was inferred from the findings of dense eosinophilic infiltrates in the jejunal mucosa and eosinophilia in the ascitic fluid. An impressive response to steroid treatment occurred. The reported cases of eosinophilic gastroenteritis with ascites are reviewed.

Adult↗
PubMed1977

Nonsecretory multiple myeloma. Immunohistologic and ultrastructural observations on two patients.

Two well documented examples of nonsecretory multiple myeloma were studied by electron microscopic and immunohistologic methods. In one case, repeat studies revealed no intracytoplasmic immunoglobulins, and the cells displayed a "plasmacytoid" appearance with poor development of rough endoplasmic reticulum and Golgi regions. In the other case, most cells contained intracytoplasmic immmunoglobulins of a monoclonal type and the ultrastructural appearance was that of cells actively engaged in protein synthesis. These findings and others in the literature suggest that myelomas without an M component can be separated into nonproducers and true nonsecretors of immunoglobulins. In one case, immunofluorescence of bone marrow smears with double labels demonstrated three different plasma cell populations: those producing either monoclonal immunoglobulins M (IgM) or A (IgA) and those synthesizing simultaneously IgM and IgM. Dual immunoglobulin production, although known to occur in myelomas with paraproteinemia, has not been previously documented in the nonsecretory variety.

Bone Marrow↗
PubMed1977

Fluid and electrolyte shifts in women during +Gz acceleration after 15 days' bed rest.

Twelve women (23-34 yr), comprising a bed-rest (BR) group of eight subjects and an ambulatory (AMB) group of four subjects, were centrifuged after 14 days of ambulatory control (C),after 15 days of a 17-day BR period, and on the third day of recovery (R). Venous blood was taken before and after the third +3.0 G acceleration run (1.8 G/min). Relative to (C), the +Gz tolerance after BR was reduced -49.0% (P less than 0.05) in the BR group and -38.7% (NS) in the AMB group; during (R) the BR group regained up to 89.4% and the AMB group up to 87.1% of their (C) tolerances. In each of the three test periods, the shifts in plasma Na, Cl, PO4, and osmotic contents, which accompanied +Gz, followed the outward shift of plasma volume (PV). The correlation of the shift of PV during acceleration with the +Gz tolerance was 0.72 (P less than 0.01). During acceleration, the PV and electrolyte loss for both groups after BR was about half the loss of (C) and (R). Compared with (C) and (R) values, potassium shifts were variable but the mean corpuscular volume and mean corpuscular Hb contents and concentrations were unchanged during all +Gz runs; The results indicate that: 1) the higher the (C) + Gz tolerance, the greater the tolerance decline due to BR; 2) relative confinement and reduced activity contribute as much to the reduction in tolerance as does the horizontal body position during BR; 3) bed-rest deconditioning has no effect on the erythrocyte volume during +3.0 Gz; and 4) about one-half the loss in tolerance after BR can be attributed to PV and electrolyte shifts.

Acceleration↗
PubMed1977

Cytomegalovirus endolabyrinthitis.

A premature male infant, who died 22 days after birth with hyaline membrane disease, was found to have had cytomegalic inclusion disease at autopsy. Histopathologic examination of the temporal bones showed cytomegalovirus (CMV) infection of the entire endolabyrinth without involvement of the neural and sensory structures. These findings support the thesis that late gestational or perinatal fetal CMV infection results in an endolymphatic labyrinthitis. We hypothesize that blood-borne virus passes from the stria vascularis into the endolymphatic spaces and infects the nonneurosensory epithelium. This pattern of infection differs from the perilabyrinthitis of human varicellazoster and experimentally produced mouse CMV.

Cytomegalovirus↗
PubMed1977

Experimental cytomegalovirus infection and the developing mouse inner ear: in vivo and in vitro studies.

Mouse cytomegalovirus causes perilabyrinthitis in the cochlea following intracranial inoculation of the newborn mouse. In spite of infection of cranial nerve ganglion cells and Schwann cells the organ of Corti achieves normal adult morphology including efferent nerve endings. No involvement of neuroaxons is seen. In comparison human cytomegalovirus infection causes endolabyrinthitis without involving periotic connective tissues or nerves even in the presence of meningoencephalitis. The lack of epithelial infection and susceptibility of periotic connective tissues to mouse cytomegalovirus was confirmed by infection of fetal mouse otocysts in organ culture. The mouse model of cytomegalovirus ear infection shows greater similarities to other herpesvirus infections of the ear such as varicella-zoster than to human cytomegalovirus and thus remains extremely useful for the study of herpetic neuronal and ear infection.

Animals↗
PubMed1976

Fibrinolytic and hemostatic changes during and after maximal exercise in males.

To evaluate changes in fibrinolytic activity, factor VIII and other hematological variables during and after a progressive step increment in work load, 10 healthy male subjects (22-27 yr of age) were exercised to exhaustion on an electromagnetic bicycle ergometer. Blood samples were drawn serially throughout the experiment. Little change in fibrinolytic activity was observed before 70-80% maximum heart rate (MHR) was achieved. Major changes occurred after 80% MHR. Peak values coincided with maximum exercise. In contrast major changes in factor VIII were observed between 95 and 100% MHR with peak values occurring 5-10 min postexercise. An increase in white blood cell count, platelet count, and retention was observed at maximum exercise. One individual failed to demonstrate an increase in either fibrinolytic or factor VIII activity. Relating the data to either the percent maximal oxygen uptake or percent maximal heart rate demonstrates the importance of the exercise protocol and exerting all subjects to the same relative level of physiological work.

Adult↗
PubMed1976

Leiomyosarcoma of the superior vena cava. A first case with resection.

Leiomysarcomas, rare malignant tumors of the veins, are located predominantly in the inferior vena cava. We report our experience with a leiomyosarcoma in the superior vena cava of a 44-year-old white man. The lesion had been locally excised and then recurred 2 1/2 years later. The recurrent tumor was widely excised and the superior vena cava was repaired with a saphenous vein patch graft. The area of the recurrence was treated with cobalt 60 therapy. Four years later, 6 1/2 years after initial treatment, the patient is alive and well without evidence of recurrence.

Adult↗
PubMed1975

Experience with total hip replacement at Ochsner Clinic.

Eighty-four patients had 97 total hip replacement procedures. Standard Müller components were used in the first 40 operations; the Aufranc-Turner acetabular component was used with the Müller-femoral component in the final 57 procedures. The trochanter was detached only in exceptional circumstances. Seventy-six patients with 87 replacements were followed up for 12 to 34 months. Complications, occasionally multiple, occurred in more than one third of our patients; thromboembolic disease was the most frequent. No significant wound complications occurred; there was no infection. In 71 replacements the results were excellent; in 15, good; and in 1 fair.

Aged↗