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Biomedical subjects

J A Sullivan

Publications and source records attributed to J A Sullivan.

At least 19 recordsLinked to original sources
PubMed1992

Amplification for listeners with steeply sloping, high-frequency hearing loss.

Two experiments were conducted to determine the effects of various upper cutoff frequencies on performance of listeners with steeply sloping, high-frequency hearing loss. The upper cutoff frequency of individually prescribed responses was systematically adjusted to 0.71, 1.79, and 6.0 kHz. Measures of nonsense syllable recognition and subjective ratings of speech intelligibility and speech quality were obtained at three overall gain settings for each frequency response. Experiment 1 assessed performance on tests in quiet and Experiment 2 assessed performance on tests in noise. Nonsense syllable recognition improved as the upper cutoff frequency increased, particularly for tests in noise. In contrast, the subjects gave significantly poorer quality ratings for the shaped response with the highest cutoff frequency (6.0 kHz). Few significant effects of cutoff frequency were found for ratings of intelligibility in either quiet or noise.

Aged↗
PubMed1992

Hip stabilization in severely involved cerebral palsy patients.

Thirty-two patients (48 hips) with total body involved cerebral palsy (CP) underwent medial release and proximal femoral osteotomy for hip subluxation or dislocation. Twenty-eight hips were rated good, 15 were rated fair, and five were rated poor at follow-up. The better located the hip preoperatively and the better the reduction obtained at operation, the better the final result. The major factor that correlated with a good result was early operation, performed before significant deformity had occurred.

Adolescent↗
PubMed1991

The accuracy of tibial intramedullary alignment devices in total knee arthroplasty.

The accuracy of a tibial medullary alignment device is assessed radiographically in 30 varus and 30 valgus knees undergoing total knee arthroplasty. The results suggest that although the device is reliable and accurate for varus knees, it may lead to malalignment of up to 5 degrees in valgus knees. Overall neutral alignment was achieved in 83% of the varus knees and 37% of the valgus knees. Tibial bowing was the main source of error and was present in 66% of the valgus knees, with mean of 3 degrees. Preoperative long films or cross-checking with external alignment devices is recommended to assure neutral alignment in genu valgus deformity.

Congenital Abnormalities↗
PubMed1990

Does cardiopulmonary bypass alter enflurane requirements for anesthesia?

This study on dogs determined whether the requirement for enflurane anesthesia was different pre- versus postcardiopulmonary bypass (CPB). Male mongrel dogs (n = 16) were anesthetized with enflurane in oxygen. Tracheal intubation was performed, monitors placed, and end-tidal enflurane concentration measured via a Puritan-Bennett Anesthesia Agent Monitor. MAC was determined by the tail-clamp method. CPB was then initiated using aortoatrial (n = 6, group 1) or femoral artery-vein (n = 4, group 2) cannulation or none (n = 6, group 3, control). CPB was maintained for 1 h using a bubble oxygenator, a crystalloid prime, and flows of approximately 70-80 ml/kg with a mean systemic pressure maintained between 50-70 mmHg. Following separation from CPB, MAC was again determined. The reduction in enflurane MAC following CPB was 30.1 +/- 21.5% (mean +/- SD; P less than 0.05 vs. pre-CPB) in group 1 but there was a wide range of reduction produced (3.8-58.8%). The degree of MAC reduction (19.8 +/- 8.6%; P less than 0.05 vs. pre-CPB) produced by CPB in group 2 was much less variable in degree (range 13.0-32.4%) but did not differ from group 1. Although pre- versus post-CPB mean systemic pressure fell from 83 +/- 13 to 69 +/- 15 mmHg (P less than 0.05), this is above the level likely to produce a reduction in MAC. No other significant hemodynamic changes were observed. Temperature pre- versus post-CPB was not different. The degree of hemodilution and acid-base disturbances are unlikely to be the explanation.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Inhalation↗
PubMed1990

Ligamentous injuries of the knee in children.

Ligamentous injuries, although uncommon in the skeletally immature patient, can be found in isolation or associated with physeal injury or long-bone fracture. Four new cases of ligamentous injury in the child show that recognition and management of these injuries are important to achieve good recovery. In addition to history and physical examination, standard and stress roentgenographs, examination under anesthesia, and arthroscopy are important for early diagnosis.

Adolescent↗
PubMed1989

Both recombinant interleukin-1 (beta) and purified human monocyte interleukin-1 prime human neutrophils for increased oxidative activity and promote neutrophil spreading.

Both purified human monocyte interleukin-1 and recombinant interleukin-1 (beta) primed neutrophils for increased superoxide production and chemiluminescence in response to f-met-leu-phe. In addition, purified human monocyte interleukin-1 and recombinant interleukin-1 (beta) altered neutrophil shape. Recombinant interleukin-1 (alpha) used at the same concentration of interleukin-1 (beta) did not prime neutrophils for increased superoxide production after stimulation with f-met-leu-phe. Interleukin-1 expressed by monocytes in response to endotoxin stimulation could act as a modulator of neutrophil function.

Humans↗
PubMed1988

Spontaneous oscillations of intracellular calcium and growth hormone secretion.

A novel combination of two single cell assays allowed the simultaneous measurement of intracellular calcium concentration and hormone secretion in normal pituitary cells. [Ca2+]i was recorded using the fluorescent Ca2+ indicator fura-2 and digital imaging microscopy. This technique was combined with a reverse hemolytic plaque assay for growth hormone in order to identify somatotropes and quantitate the amount of hormone released. A dynamic profile of rhythmic calcium oscillations was found in spontaneously secreting somatotropes. Each somatotrope displayed a distinct frequency (one pulse every 5-30 s) and amplitude (range 50-450 nM) generated asynchronously from cell to cell. The amount of growth hormone (GH) released correlated directly with both the frequency and amplitude of calcium oscillations at the level of single GH cells. Furthermore, calcium excursions in somatotropes were rapidly suppressed by either (i) removal of extracellular calcium, (ii) somatostatin (1 mM), or (iii) the calcium channel blockers cobalt (2 mM) and verapamil (100 microM). These observations demonstrate that spontaneous calcium oscillations are characteristic for normal somatotropes. These oscillations are related to spontaneous hormone secretion and due to influx through calcium channels in the membrane. Somatostatin, the physiologic inhibitor of GH secretion, suppresses calcium transients. These findings suggest that the intracellular signaling information may be encoded both in the frequency and amplitude of calcium oscillations.

Animals↗
PubMed1987

Comparison of mammary serum antigen (MSA) and CA15-3 levels in the serum of patients with breast cancer.

Serum levels of mammary serum antigen (MSA) and CA15-3 were evaluated in 135 individuals in order to determine their single and combined value in the diagnosis and monitoring of breast cancer. Raised MSA levels (greater than 300 IU) were found in 68% of patients with Stage I and II breast cancer compared to only 3% having raised CA15-3 levels (greater than 40 U ml-1). Of 38 patients with Stage IV breast cancer, 95% had raised levels of MSA and CA15-3 combined with each test individually detecting 82% of those with Stage IV disease. No correlation was found between MSA and CA15-3 levels. Four patients being treated for breast cancer were followed over a 5-17 week period; MSA levels correlated with disease course in 3 and CA-15 in 2. The overall sensitivity, specificity and accuracy in detecting breast cancer were 76%, 91% and 96% for MSA; and 47%, 95% and 97% for CA15-3 respectively. When both tests were used together combined evaluation gave the highest sensitivity (84%) and specificity (100%). MSA seems to be superior to CA15-3 for early breast cancer diagnosis and a combination of the two tests gave the best results for metastatic disease.

Antigens, Neoplasm↗
PubMed1985

Prognostic factors for Stage IV Hodgkin's disease treated with MOPP, with or without bleomycin.

Prognostic factors for 53 previously untreated patients with Stage IV Hodgkin's disease were analyzed for their effects upon complete remission rate, survival, and disease-free survival following treatment with mechlorethamine, Oncovin (vincristine), procarbazine, and prednisone (MOPP) or MOPP plus bleomycin (MOPP-Bleo). Although 75% of those patients with only one site of extranodal disease achieved complete remission, only 25% of those with more than one site of involvement entered complete remission. Seven of the eight patients with more than one extranodal site were dead of disease at 4 years, compared with a 5-year survival of 75% for those with only one site of involvement. Disease-free survival from complete remission was dependent upon the percentage of planned doses of nitrogen mustard actually administered. Patients who received higher doses of nitrogen mustard had significantly longer freedom from relapse and survival after attaining complete remission than those who received reduced doses. Age, symptoms, pathologic features, and presence or size of mediastinal disease did not affect the couple remission rate, survival, or disease-free survival. Patients with Stage IV disease treated with MOPP alone should receive the highest tolerable dose of nitrogen mustard early in their treatment, since those receiving lower doses have a higher risk of relapse.

Adolescent↗
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↗