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Biomedical subjects

J A Sullivan

Publications and source records attributed to J A Sullivan.

At least 127 records · Page 7Linked to original sources
PubMed1981

Interaction between Entamoeba histolytica and human polymorphonuclear neutrophils.

The interaction of human polymorphonuclear neutrophils (PMNs) with two strains of Entamoeba histolytica that exhibit different degrees of "virulence" was examined in animal and tissue culture systems. PMNs actively migrated toward both strains of amoebae. Less virulent amoebae (strain 303) were surrounded by PMNs (greater than or equal to 300/amoeba), fragmented and ingested by PMNs by means that appeared to be independent of oxygen. In contrast, contact with virulent amoebae (HM1) caused loss of PMN motility, PMN degranulation, death, and occasional phagocytosis by the amoebae, which survived concentrations of greater than 1,000 PMNs/amoeba. PMNs that did not directly contact virulent amoebae remained alive and active. At least two separate components of cytopathogenicity by virulent amoebae were observed: first, extracellular, contact-dependent, serum-independent cytolysis that was dependent on intact microfilament function; and second, amoeba phagocytosis of human PMNs. This contact-dependent ability of virulent amoebae to kill and phagocytize host neutrophils may be important in their pathogenic capacity.

Blood↗
PubMed1981

An evaluation of nuclear scanning in orthopaedic infections.

Making a diagnosis of osteomyelitis or septic arthritis in its early stages if often difficult but is extremely important if one is to reduce the morbidity of these diseases. Nuclear scintigraphy has been proposed as a means of making this early diagnosis with an accuracy rate in the literature that has varied from 85 to 100%. We reviewed 35 patients with osteomyelitis, septic arthritis, and cellulitis who had had nuclear scanning as a part of their initial workup. While we found a 77% accuracy rate, we found three false positives and five false negatives. In order to interpret the scintigraphic results of nuclear imaging accurately, one must be familiar with the mechanisms, both biochemical and physiological, that affect the variable uptake of the nuclear agents employed. Both "hot" and "cold" scans may have multiple causes.

Adolescent↗
PubMed1981

Treatment of stage I and II mediastinal Hodgkin disease. A comparison of involved fields, extended fields, and involved fields followed by MOPP in patients staged by laparotomy.

Three treatment programs for Stage I and II mediastinal Hodgkin disease (established by laparotomy) were compared. Involved-field radiotherapy + MOPP gave a disease-free survival rate of 97%, significantly different from 62% and 55% for involved and extended fields, respectively. Corresponding survival figures of 97%, 88%, and 84% were not significantly different statistically due to salvage with radiotherapy and/or chemotherapy. Among patients given radiotherapy alone, the survival figure of 94% for limited mediastinal disease was significantly better than 63% for extensive mediastinal and hilar disease; corresponding disease-free figures of 72% and 35% were also significantly different. Constitutional symptoms were an important prognostic factor in disease-free survival following the use of involved fields; hilar disease was important only with large mediastinal masses. Most relapses were intrathoracic; MOPP alone salvaged only 47%. Treatment of Stage I and II Hodgkin disease should be based on symptoms, extent of mediastinal disease, and hilar involvement.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1980

Receptors for concanavalin A cluster at the front of polarized neutrophils.

Polymorphonuclear neutrophils (PMN) can recognize, engulf and kill microorganisms and are thus an important host defence against infection. The initial encounter between a microbe and the neutrophil takes place at the neutrophil surface. Receptors, including those for the Fc end of the immunoglobulin G (ref. 1), the C3b component of complement, formyl peptides and plant lectins have been identified on the surface of neutrophils. We have now examined the surface pattern and arrangement of receptors for the plant lectin concanavalin A (Con A) to determine if the surface receptor array varied with the functional state of the neutrophil. We found that receptors for Con A clustered at the front of polarized neutrophils.

Cell Compartmentation↗
PubMed1980

Trichomonacidal activity of human polymorphonuclear neutrophils: killing by disruption and fragmentation.

Polymorphonuclear neutrophils (PMNs) were shown to kill Trichomonas vaginalis in vitro; 10(2)-10(3) trichomonads were incubated with 3 x 10(6) PMNs on tissue culture plates, and surviving organisms were enumerated in pour plates. After 60 min of aerobic incubation at 37 C, 100% (+/- 0) of the trichomonads had been killed, and nitroblue tetrazolium was reduced at the interface between the PMNs and trichomonads. The importance of oxidative microbicidal systems was confirmed by the observations that only 12% +/- 12% of trichomonads were killed under anaerobic conditions and that aerobic killing was eliminated by the addition of catalase or superoxide dismutase. PMNs killed trichomonads in fresh or absorbed serum but not in bovine serum albumin, in heat-inactivated serum, or in the presence of 1 mM trypan blue; this finding suggested a role for alternative pathway activation of complement. Phase-contrast cinemicrography and electron microscopy revealed the pursuit and surrounding of individual trichomonads by groups of PMNs that were able to fragment the large protozoa and to phagocytize the pieces.

Animals↗
PubMed1980

The modified radical mastoidectomy.

The historical evoluation of mastoid surgery is described. The indications, technique, and postoperative management of modified radical mastoidectomy are discussed and clinical illustrations are presented.

Adult↗
PubMed1979

The relationship of the accessory navicular to the development of the flat foot.

The Kidner procedure has been the most frequently recommended form of surgical treatment for the painful accessory navicular. This formal relocation of the posterior tibial tendon is said to restore the dynamic balance to the foot which is lost when the posterior tibial tendon gives an abnormal insertion into the accessory ossicle. The literature was reviewed to ascertain what is known or what is believed about the accessory navicular and the role of the posterior tibial tendon in the support of the longitudinal arch of the foot. Eighteen patients who had simple excision of the accessory navicular were reviewed to assess the success of such a procedure. In follow-up they all had very satisfactory results. A second group of 208 patients with non-traumatic foot complaints were reviewed to determine the incidence of accessory navicular and its association with the flat foot. Twenty-nine cases of previously undetected accessory navicular were identified in this group giving us a total of 179 patients without accessory navicular and 49 patients with accessory navicular available for study. There was no significant difference between the arch in these 2 groups of patients. Based on the findings in this study, the accessory navicular plays no role in the development of a flat foot. Simple excision of the prominent ossicle seems to be the surgical procedure of choice when conservative means of management fail.

Adult↗
PubMed1978

The rural nurse practitioner: a challenge and a response.

From a cohort of 525 employed nurse practitioners (NPs) who graduated between May 1975 and June 1976, 85 (16 per cent) reported practicing in rural areas. While 91 per cent of the rural NPs chose the short-term certificate programs rather than the master's degree for their NP preparation, 47 per cent had already earned a baccalaureate or master's degree prior to NP training. Family NPs comprised the most frequent specialty area chosen, followed by pediatric and adult specialties. Of the 85, 99 per cent were actually providing a broad array of primary care services to clients over a wide age range. Physicians were periodically available on site in about 80 per cent of the practices, by telephone in 97 per cent of the practices, and in 60 per cent of the practices provided additional consulation by record review. Major motivations of the NPs for entering rural practice were to participate in a creative approach to health care delivery (50 per cent of the practice setting were less than five years old), and for the opportunity for role autonomy. Over 95 per cent of these NPs and employers were satisfied with the NP role.

Economics, Nursing↗
PubMed1978

Overcoming barriers to the employment and utilization of the nurse practitioner.

A national longitudinal cohort study of nurse practitioners and their employers conducted during 1973--1976 provided data on barriers to the development of the nurse practitioner role in primary care. Nearly 90 per cent of the 500 primary care nurse practitioners responding and 75 per cent of the 407 employers responding reported encountering one or more barriers to the role development of the nurse practitioner in their practice setting. Nurse practitioners identified an average of 2.2 barriers and employers identified an average of 1.6 barriers each. Specific barriers identified by 20 per cent or more of the nurse practitioners and employers were legal restrictions, limitations of space and facilities, and resistance from other providers. The data and other evidence suggest that these barriers are not insurmountable and that progress is being made in overcoming these obstacles.

Attitude of Health Personnel↗
PubMed1975

A male pseudohermaphrodite white-tailed deer resembling an antlered doe.

A male pseudohermaphrodite white-tailed deer (Odocoileus virginianus) is described. The animal shot in Aiken County, South Carolina on November 4, 1971, was 1.5 years old and had the external appearance of an antlered doe. The 6 point antlers were in velvet, a vulva was present, and the testes were located in the body cavity. Other male reproductive organs present were epididymides, vasa deferentia and ampullae. Female reproductive organs present were cervix, vagina and clitoris.

Animals↗