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Biomedical subjects

D E Martin

Publications and source records attributed to D E Martin.

At least 91 records · Page 5Linked to original sources

Physiochemical characterization of lymphocyte inhibitory factor (LyIF) isolated from avian B and T cells.

Thymic (T) or bursal (B) lymphocytes from chicks sensitized to Mycobacterium tuberculosis produce an avian lymphocyte inhibitory factor (LyIF). The physiochemical properties of both T and B LyIF were established by ultrafiltration which yielded four fractions with molecular weight ranges of greater than 100,000; 50,000-100,000; 10,000-50,000; and less than 10,000; enzymatic treatment with chymotrypsin and neuraminidase; varying pH; and heat exposure. These studies demonstrated that the maximum activity for both T and B LyIF was within a molecular weight range of 10,000-50,000. Both were sensitive to chymotrypsin and neuraminidase treatment. Both were stable at 56 degrees C for 30 min and resistant to changes in pH from 5 to 9. T-Cell migration was inhibited equally by B or T LyIF, while B-cell migration was inhibited to a lesser extent by T LyIF and B LyIF. Further experiments should establish the reasons for these observed differences in cross-reactivity.

Animals↗

Cardiovascular monitoring during elective aortic surgery.

We designed a prospective study to determine whether cardiac ejection fraction as measured noninvasively could isolate a subset undergoing aortic surgery for whom central venous pressure (CVP) predicted pulmonary artery wedge pressure (PAWP). Sixteen patients were studied. Simultaneous values of PAWP and CVP were analyzed, using linear regression analysis. A significant correlation between CVP and PAWP was found for the entire patient population and for each of four time periods: preoperative, before and after aortic cross-clamping, during aortic cross-clamping, and postoperative. A significant correlation between PAWP and CVP was found during the entire perioperative period for 14 of the 16 patients. However, the slope of the regression line, or the sensitivity of the CVP in reflecting changes in PAWP, was greater than 0.5 in only seven of the 16 patients. There was no correlation between the preoperative ejection fraction and the CVP/PAWP. We conclude that the CVP is an insensitive indicator of left ventricular filling pressure in most patients accepted for elective infrarenal aortic surgery, and monitoring of the PAWP is recommended.

Aorta, Abdominal↗

Initiation of erection and semen release by rectal probe electrostimulation (RPE).

Instrumentation and methodology are described for rectal probe electrostimulation (RPE) in human males to elicit erection and allow semen collection. This system virtually eliminates shock hazard; the simultaneous monitoring of current, voltage and impedance ensures reliability and repeatability. It was tested with 8 neurologically intact subjects, and 12 paraplegic patients with lesions between T4 and L2. Platinum electrodes delivered current (density never exceeding 0.37 mA per mm. at the electrode) at frequencies of 60 Hz, 20 Hz, and 0.25 Hz. Erection was elicited repeatably in only 1 of the intact subjects, and no seminal emissions or ejaculations occurred. Discomfort prevented current delivery beyond levels even 50 per cent of those safely acceptable. Six of 10 paraplegic patients (2 others had penile implants) developed erections with 20 Hz; the other 2 frequencies were much less effective. The extent of RPE-induced penile tumescence varied directly with electrode surface area and applied current intensity. Discomfort was minimal. Retrograde seminal emission in 5 of the 12 paraplegics was verified by post-stimulation recovery of sperm via voiding or bladder irrigation via catheter. Although motility was very low, 4 of 8 recovered bladder-urine/seminal fluid specimens indicated sperm counts and morphology consonant with use in artificial insemination. Thus, RPE, if combined with techniques to allow antegrade semen collection, may be a useful technique for spinal cord-injured men who, as part of their sexual rehabilitation, are interested in siring children.

Adult↗

The hypertensive surgical patient. Controversies in management.

The authors use data gathered from recent clinical and laboratory studies to deal with the following six questions often facing the physician caring for hypertensive patients before, during, and after surgery. Which hypertensive patient is at increased surgical risk? When must elective surgery be delayed? Should antihypertensive medication be discontinued preoperatively? What is the ideal intraoperative blood pressure? What anesthetic techniques are best suited for hypertensive patients? Which patients are at most risk of a postoperative hypertensive crisis?

Adrenal Gland Neoplasms↗

Effect of partially purified B- and T-lymphocyte inhibitory factors on the mitogenic and chemotactic responses.

Avian lymphocyte inhibitory factor (LyIF) is produced by thymic (T) and bursal (B) lymphocytes following sensitization of chicks to Mycobacterium tuberculosis. Our previous studies showed that maximum activities for both B- and T-LyIF were within a molecular weight range of 10,000 to 50,000 daltons (LyIF-III). These results led us to question what other functional differences may exist. The chemotactic and mitogenic properties of B- and T-LyIF-III were investigated. Neither B- nor T-LyIF-III had chemotactic properties whereas both lymphokines significantly inhibited the uptake of [3H]-thymidine in the presence of phytohemagglutinin-M. Inhibition of migration by LyIF-III may be a reflection of LyIF-III inhibition of deoxyribonucleic acid synthesis.

Animals↗

Calorie-protein deficiencies and the immune response of the chicken. II. Cell-mediated immunity.

Calorie-protein deficiency affects humoral immunity in the chicken. Secondary responses to sheep-red blood cells, a T-dependent antigen, were lower in birds fed diets two-thirds deficient in calories (C), amino acids (AA), or both (C/AA). These results led us to question what effects might be found in cell-mediated immunity after nutritional deficiency. Birds fed the same diets as in our previous study showed no reduction in total white blood cells, absolute lymphocytes, or absolute heterophils. Splenic lymphocytes from 3- or 7-week-old nutritionally deficient chickens with the exception of the AA group at 7 weeks, produced a nonsignificant increase in graft-versus-host (GvH) response of 12-day-old embryos. Thymic cells from 3-week-old nutritionally deficient birds were not deficient in the GvH potential. Thymic histology revealed reduced cellularity in AA-deficient birds. The reduced cellularity may not have been in response to stress since the mean corticosterone levels were not significantly different. Birds fed the deficient diets for 10 weeks had a significantly reduced delayed hypersensitivity response to human gamma globulin. The results indicate that the chickens' ability to produce a GvH response was not compromised and that T-cell subpopulations may have differential sensitivities to nutritional deficiencies.

Amino Acids↗

Low-dose fentanyl blunts circulatory responses to tracheal intubation.

The effect of fentanyl, 8 micrograms/kg, used as an adjunct to thiopental for induction of anesthesia, on the circulatory response to tracheal intubation was investigated in 36 patients undergoing major vascular surgery. Patients were randomly assigned to receive either thiopental, 6 mg/kg, alone (N = 18), or thiopental, 3 mg/kg, along with fentanyl, 8 micrograms/kg (N = 18), for induction of anesthesia. The electrocardiogram, arterial pressure, pulmonary capillary wedge pressure, cardiac output, and central venous pressure were measured during induction of anesthesia, laryngoscopy, and intubation. Mean arterial blood pressure increased more following intubation in patients given thiopental than in patients given fentanyl-thiopental, reaching a peak value of 144 +/- 4 torr in patients receiving thiopental only, compared with 108 +/- 6 torr in those receiving fentanyl and thiopental (p less than 0.0001). Increases in systolic blood pressure, diastolic blood pressure, and pulmonary capillary wedge pressure with intubation were also significantly greater following administration of thiopental than following fentanyl-thiopental. Doses of fentanyl that are low enough to cause little postoperative respiratory depression significantly blunt postintubation hypertension when used as an adjunct to thiopental.

Anesthesia↗

Rectal probe electroejaculation of primates.

The technique of rectal probe electroejaculation has been developed to permit collection of semen using equipment proven safe, simple, and effective on the 30 primate species so far tested. This paper provides information on the construction and operation of this equipment, together with electrical parameters applicable to primate species. Seminal emission or ejaculation occurs in all species when alternating current is delivered at 0.25 mA/mm2 electrode area. The most effective frequency is 20 Hz, and the most acceptable anesthetic is ketamine hydrochloride.

Animals↗

The location of DNA homologous to human satellite III DNA in the chromosomes of chimpanzee (Pan troglodytes), gorilla (Gorilla gorilla) and orang utan (Pongo pygmaeus).

Radioactive RNA with sequences complementary to human DNA satellite III was hybridised in situ to metaphase chromosomes of the chimpanzee (Pan troglodytes), the gorilla (Gorilla gorilla) and the orangutan (Pongo pygmaeus). A quantitative analysis of the radioactivity, and hence of the chromosomal distribution of human DNA satellite III equivalent sequences in the great apes, was undertaken, and the results compared with interspecies chromosome homologies based upon Giemsa banding patterns. In some instances DNA with sequence homology to human satellite III is present on the equivalent ("homologous") chromosomes in identical positions in two or more species although quantitative differences are observed. In other cases there appears to be no correspondence between satellite DNA location and chromosome homology determined by banding patterns. These results differ from those found for most transcribed DNA sequences where the same sequence is located on homologous chromosomes in each species.

Animals↗

Correlation of serum testosterone levels with age in male chimpanzees.

Serum testosterone was measured in a group of male chimpanzees of varying ages by radioimmunoassay using a specific antiserum to testosterone-3-carboxym ethyloxime-bovine serum albumin. The juvenile age group, ranging from one through six years (n=26), had a mean serum testosterone value of 13ng/100ml (range 3.5-59ng/100ml). The adolescent age group, spanning years seven through ten (n=19), had a mean value of 178ng/100ml (range 14.6-238ng/100ml). The adult group, comprised of animals over eleven years of age (n=29), had a mean peripheral serum testosterone value of 397ng/100ml (range 92-680ng/100ml). These data suggest that serum testosterone levels may be useful in determing the age and sexual maturity of chimpanzees of unknown age.

Aging↗

Acquisition of esophageal speech subsequent to learning pharyngeal speech: an unusual case study.

Laryngectomees who are delayed in obtaining alaryngeal voice therapy may develop pharyngeal voice, an undesirable type of alaryngeal voice. Pharyngeal voice is usually self-developed; however, it may also be acquired in the clinical setting when the patient is being taught to inject air for esophageal sound production. This report describes the principal findings involving a laryngectomee who had developed and used pharyngeal speech as his primary method of communication for two years prior to enrollment in alaryngeal voice therapy. A clinical technique that was found to be successful in altering the pharyngeal voice to esophageal voice is reported. Findings pertaining to the overall intelligibility as well as vocal fundamental frequency of the two different types of alaryngeal speech are included.

Aged↗

A chromosome rearrangement in orangutan studied with Q-, C-, and G-banding techniques.

A constitutional chromosome rearrangement is a phenotypically normal male organutan is described. The rearrangement resulted from three breakages in chromosome 9 and involved a pericentric inversion and additional reciprocal transpositions of the terminal segments of both arms. Q-, G-, and C-banding studies were carried out, and it was shown that the chromosomes affected was a member of the only pair in the complement that lacked a centromeric C-band and that its G-banding pattern closely resembled that of chromosome 12 in man. The origin of the rearrangement and the role of such rearrangement in producing chromosome polymorphisms are discussed, particularly in relation to evolution and speciation. An additional pair of heteromorphic chromosomes (No.23) is also described. The short arm satellited region of one member of the pair was found to be variable and strongly C-banded.

Animals↗

Description of a team approach to the rehabilitation of the laryngectomized speaker.

This article describes the multi-disciplinary approach to rehabilitation of the laryngectomee followed by the Michigan Cancer Foundation-Wayne State University Laryngectomee Clinic. The program serves a patient population in excess of 100 each year in a total rehabilitation paradigm. The rehabilitation effort centers around an intensive speech rehabilitation program encompassing as much as 10 hours of speech therapy per week. This effort is supplemented by a professional staff including a psychologist, social work staff, audiologist, public health nurse, vocational rehabilitation specialist, and atrained laryngectomized esophageal speech teacher. The contribution of each member of the team and the benefits of a unified approach are described.

Cooperative Behavior↗