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Biomedical subjects

J McCarthy

Publications and source records attributed to J McCarthy.

At least 109 records · Page 6Linked to original sources
PubMed1993

The use of cortical allograft struts for fixation of fractures associated with well-fixed total joint prostheses.

Nineteen patients with 19 fractures around or below a well-fixed femoral stem, were treated by open reduction and internal fixation using massive cortical allograft struts and cerclage wires or cables. The first procedure was performed in 1982 and the last in 1990. Follow-up averaged 28 months. Seventeen patients united their fractures and returned to their preoperative functional status at an average time of 41/2 months. Sixteen healed anatomically. There was one mild malunion and there were two nonunions, both requiring further surgery.

Aged↗
PubMed1992

Inter-organizational responses to AIDS: a case study of the Worcester AIDS Consortium.

This case study focuses on development and community coordination of AIDS-related services and on coalition building. Its subject is the Worcester (Massachusetts) AIDS Consortium. The objectives are to: (1) describe the environmental conditions and pre-existing networks which facilitated the formation of the Worcester AIDS Consortium; (2) articulate processes which occurred during the formative, organizational and operational phases of the Worcester AIDS Consortium's development; (3) explore social and community goals and Consortium activities; and (4) document Consortium accomplishments. Data were collected through key informant interviews and review of archival materials. Information about the Worcester AIDS Consortium experience is compared with concepts and principles suggested by organizational theories and frameworks.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Anterior subcapsular plaque cataract in hyperornithinaemia gyrate atrophy--a case report.

Hyperornithinaemia gyrate atrophy (HOGA) is a rare autosomal recessive disorder in which chorioretinal degeneration occurs with cataracts, myopia, and hyperornithinaemia. We report the case of an 18-year-old female who presented with the typical features of HOGA, including posterior subcapsular cataracts and elevated plasma ornithine. She later developed distorted vision in both eyes owing to wrinkling of the anterior lens capsules. Histological examination following lens extraction showed the wrinkling was caused by focal distortion from capsular fibrosis (anterior subcapsular plaque cataract). This specific lens change has not been linked previously with HOGA.

Adolescent↗
PubMed1991

Surgical treatment of space-occupying cerebellar infarctions--4 1/2 years post-operative follow-up.

Case reports of three patients with cerebellar infarction causing brain stem dysfunction and obstructive hydrocephalus as seen in computed tomography are presented. Surgical treatment, either ventricular puncture with drainage or suboccipital craniectomy and resection of the necrotic cerebellar tissue, was carried out. Indications for surgical treatment of space-occupying cerebellar infarction and post-operative follow-up of 4 1/2 years are discussed.

Adult↗
PubMed1991

Identification and partial characterization of angiogenesis bioactivity in the lower respiratory tract after acute lung injury.

Survival after acute lung injury (ALI) depends on prompt alveolar repair, a process frequently subverted by the development of granulation tissue within the alveolar airspace. Immunohistochemical examination of the intraalveolar granulation tissue confirmed that capillaries as well as myofibroblasts were the principal cellular constituents. We therefore hypothesized that angiogenesis factors would be present on the air-lung interface after ALI. To evaluate this hypothesis, bronchoalveolar lavage fluid from patients with ALI (n = 25) and patient controls (n = 8) was examined for angiogenesis bioactivity by its ability of induce endothelial cell migration. While lavage fluid from controls had no bioactivity, lavage fluid from 72% of patients with ALI promoted endothelial cell migration. Heparin affinity, ion exchange, and gel filtration chromatography resolved the bioactivity into at least two moieties. One appeared identical to the well characterized endothelial cell growth factor, basic fibroblast growth factor. The other was a 150-kD non-heparin binding protein that mediated endothelial cell migration and attachment in vitro, and the growth of new vessels in vivo. These data are consistent with the hypothesis that the growth of capillaries into the alveolar airspace results from angiogenesis factors present on the alveolar surface of the lung after ALI.

Acute Disease↗
PubMed1990

Ecologically relevant stimuli and color memory.

Ecologically relevant stimuli were developed as an alternative to Munsell color chips. Colored pictures of familiar objects were used to study color memory. We investigated the typicality of color to particular objects. Contextually typical colors were remembered more accurately than atypical colors were. Moreover, this variable had a stronger effect on memory than focality did. We concluded that memory for ecologically relevant material is more impressed by a color's relation to experience than by its intrinsic properties.

Adult↗
PubMed1989

The mentalis muscle: an essential component of chin and lower lip position.

The soft-tissue chin may become ptotic following surgery in this area. The mentalis muscles which are responsible for proper central lip motion and chin point position may be affected. The mentalis muscle origin may require resuspension at a proper level. This reattachment may be performed by means of an intraoral approach. Non-absorbable sutures are used to hold the soft-tissue chin upward. The exact method involves placing drill holes through the alveolar bone, into which sutures are passed. These sutures are then placed through the lower mentalis muscles and tightened. Chin and lip position may be corrected in certain cases. Ancillary procedures are required to correct vestibular scarring and submental scars.

Adult↗
PubMed1988

One free sulfhydryl group of plasma fibronectin becomes titratable upon binding of the protein to solid substrates.

The accessibility in human plasma fibronectin of the two free sulfhydryl groups per chain to sulfhydryl reagents 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) and a maleimide derivative has been examined. For soluble fibronectin, the free sulfhydryl groups are not accessible to DTNB unless urea or guanidine hydrochloride is added [Smith et al. (1982) J. Biol. Chem. 257, 5831-5838]. Upon binding to polystyrene beads, 0.87 +/- 0.05 sulfhydryl group per chain becomes titratable to DTNB. Experiments using fibronectin fragments demonstrate that this newly exposed sulfhydryl group is located in a Type III homologous unit between the DNA-binding and the cell-binding domains. The results suggest that, upon adsorption to solid substrates, plasma fibronectin undergoes a conformational change, thereby exposing one buried sulfhydryl group. These findings have implications regarding the "surface activation" of adhesion activities of fibronectin.

Chromatography, High Pressure Liquid↗
PubMed1988

Ryanodine and caffeine prevent ventricular arrhythmias during acute myocardial ischemia and reperfusion in rat heart.

This study investigates the possible role of oscillatory release of calcium from sarcoplasmic reticulum in the genesis of ventricular arrhythmias during acute myocardial ischemia and reperfusion in isolated rat hearts. We used ryanodine and caffeine, which are known to modulate the oscillatory release of calcium from sarcoplasmic reticulum. During 30 minutes of left main coronary artery ligation, all 13 control hearts developed ventricular premature beats (number of beats, 225 +/- 51) and ventricular tachycardia (duration, 123 +/- 21 seconds); five hearts developed ventricular fibrillation. In a separate series of experiments, reperfusion after 15 minutes of coronary artery ligation caused ventricular fibrillation to occur within 15 seconds in all 12 hearts. Ryanodine (10(-9) to 10(-7) M) abolished ventricular arrhythmias during coronary artery ligation and prevented reperfusion ventricular fibrillation. Ryanodine (10(-9), 10(-8), and 10(-7) M) caused 15%, 23%, and 74% decreases in the maximal rate of rise of left ventricular pressure development and 20%, 32%, and 85% decreases in the maximal rate of fall of left ventricular pressure development, respectively, prior to coronary artery ligation. During acute myocardial ischemia, ryanodine 10(-9) M maintained and 10(-8) M impaired left ventricular function; 10(-7) M caused left ventricular failure. Coronary perfusion rate did not increase during ischemia. Antiarrhythmic activity occurred independent of preservation of high energy phosphates, reduction in tissue lactate, or tissue cyclic adenosine monophosphate in the ischemic myocardium. Caffeine 10(2) M decreased the incidence of ventricular arrhythmias during ischemia and upon reperfusion; protection occurred coincident with development of diastolic contracture. Caffeine increased ischemic tissue cyclic adenosine monophosphate content and worsened tissue energy status.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaloids↗
PubMed1988

The effect of vascularization on avian flexor tendon repair. A biochemical study.

Although it has been demonstrated in experimental animals that vascular perfusion functions less effectively than diffusion as a nutrient pathway to the uninjured flexor tendon, it is recognized that the nutritional requirements of an injured flexor tendon may be different. The present study examines several biochemical parameters of avian flexor tendon repair, during a six-week period, in the presence of an intact vinculum longum and with the vinculum longum ligated. Formation of collagen/noncollagen protein, glycosaminoglycan synthesis, and tissue levels of both DNA and hexosamine were quantified. The absence of the vincular blood supply did not affect the levels of total DNA and hexosamine, did not alter the pattern of either protein or glycosaminoglycan formation in the early healing phase, and did not impair the overall synthesis of collagen and noncollagen protein throughout the six-week study period. However, the pattern of collagen and noncollagen protein synthesis differed in lacerated tendons during the period of repair; noncollagen protein synthesis peaked at ten days, while collagen synthesis increased uniformly throughout the 42-day period of study. There was a notable decrease in total matrix hydroxyproline (collagen) during repair, which continued throughout the entire first three weeks after laceration. Thus, the actual percentage of collagen synthesis decreased during the first three weeks of repair and began to return to its normal uninjured level by the sixth week.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗