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Biomedical subjects

J Roberts

Publications and source records attributed to J Roberts.

At least 361 records · Page 20Linked to original sources
PubMed1992

Migration of intravascular balloon after percutaneous embolotherapy of varicocele.

Migration of an intravascular balloon following embolic therapy for varicocele is uncommon. A third case is reported of migration of a left internal spermatic vein embolic balloon to the right lung in an otherwise healthy twenty-five-year-old male who was treated for a symptomatic left varicocele. The patient, a student naval aviator in the jet pilot program, has had his career adversely affected by this complication.

Adult↗
PubMed1992

Combined treatment with oral etretinate and electron beam therapy in patients with cutaneous T-cell lymphoma (mycosis fungoides and Sézary syndrome).

BACKGROUND: Total skin irradiation for early-stage mycosis fungoides produces clinical remission in 90% of patients, but the median duration of remission is only 2 to 4 years. Etretinate has proven efficacy in advanced mycosis fungoides. Its potential as adjuvant therapy to radiation could be limited by toxicity from the combination. OBJECTIVE: Our purpose was to determine whether oral etretinate at 1 mg/kg can be combined with 35 Gy of radiation without intensifying or prolonging the radiation reaction and to determine the relapse-free survival rate. METHODS: Twenty-three patients began etretinate on day one of radiation and the dose was reduced for nose bleeds, dry skin, or hyperlipidemia. During the reaction skin toxicity questionnaires were completed weekly. Nine concurrent patients receiving only radiation completed identical forms. RESULTS: Etretinate did not intensify the skin reaction but did prolong it by 2 weeks. At a median follow-up of 2 years the relapse-free survival rate in complete responders was similar to stage-matched concurrent and historic control subjects. CONCLUSIONS: Both radiation and etretinate can be given together with acceptable toxicity and without compromising either therapy.

Administration, Oral↗
PubMed1992

Priming of face matching in amnesia.

Priming was studied in a task that required a speeded response to photographs of faces. On each trial, subjects viewed two faces and decided if the same person was shown twice or if two different people were shown. Both familiar and unfamiliar (i.e., well-known and unknown) faces were used, and some face pairs were repeated with a mean delay of about 10 min. Repetition was associated with faster reaction times in young subjects (Experiment 1) as well as in amnesic patients and age-matched control subjects (Experiment 2). The patients' reaction times were slower overall, although the magnitude of the priming effect did not differ from that in the control subjects. This preservation of a normal reaction-time facilitation in subjects with impaired recognition memory for faces occurred for both familiar and unfamiliar faces, suggesting that amnesia does not necessarily interfere with the acquisition of new information as indexed by this priming effect.

Adult↗
PubMed1992

Groin dissection versus groin radiation in carcinoma of the vulva: a Gynecologic Oncology Group study.

PURPOSE: The objective of this study was to determine if groin radiation was superior to and less morbid than groin dissection. METHODS AND MATERIALS: Members of the Gynecologic Oncology Group randomized 58 patients with squamous carcinoma of the vulva and nonsuspicious (N0-1) inguinal nodes to receive either groin dissection or groin radiation, each in conjunction with radical vulvectomy. Radiation therapy consisted of a dose of 50 Gray given in daily 200 centiGray fractions to a depth of 3 cm below the anterior skin surface. RESULTS: The study was closed prematurely when interim monitoring revealed an excessive number of groin relapses on the groin radiation regimen. Metastatic involvement of the groin nodes was projected to occur in 24% of patients based on this Group's previous experience. On the groin dissection regimen, there were 5/25 (20.0%) patients with positive groin nodes. These patients received post-operative radiation. There were five groin relapses among the 27 (18.5%) patients on the groin radiation regimen and none on the groin dissection regimen. The groin dissection regimen had significantly better progression-free interval (p = 0.03) and survival (p = 0.04). CONCLUSION: Radiation of the intact groins as given in this study is significantly inferior to groin dissection in patients with squamous carcinoma of the vulva and N0-1 nodes.

Adult↗
PubMed1992

Gender differences in the effect of age on adrenergic neurotransmission in the heart.

In male rats, there is an age-associated decline in the capacity of cardiac sympathetic nerves to release norepinephrine. To investigate whether this phenomenon also occurs in female rats, we examined adrenergic neurochemical transmission in the hearts of female and male Fischer 344 rats. Rats aged 6, 12, and 24 months were employed. Hearts with the right cardiac sympathetic nerve intact were isolated and perfused with Krebs-Ringer solution. Stimulations were performed following the administration of cocaine or metanephrine separately and in combination or following the combination of cocaine, metanephrine, and yohimbine. Cocaine (1 microM) was used to block uptake 1, metanephrine (1 x 10(-5) M) to block uptake 2, and yohimbine (3 microM) to block alpha 2 receptor presynaptically. The nerve was stimulated with frequencies of 2, 6, and 12 Hz, and norepinephrine amount in the effluent was determined by high performance liquid chromatography/electrochemical detection methods. Neither norepinephrine release nor the effects of yohimbine, cocaine, or metanephrine were found to be affected in older female rats (24 month). This suggests that age-related changes in adrenergic neurochemical transmission in the heart of female rats differ from those seen in older male rats.

Aging↗
PubMed1992

A profile of users of specialty pain clinic services: predictors of use and cost estimates.

During the past decade, the multidisciplinary pain clinic has become a popular alternative to the traditional treatment of persistent pain. There is, however, little information describing this population of health care users nor the impact this new demand has on utilization of health care services. The objectives of this study were three fold: to develop a profile of the characteristics of patients referred to a specialty pain clinic including their psychosocial adjustment to their condition; to identify predictors of the use of the specialty services; and to estimate the cost of health service utilization. This historical cohort analytic survey of 571 patients referred to the clinic assessed them for exposure to selected referral variables through a chart review and sampled (n = 222) these patients' current adjustment and health service use through mailed questionnaire. There were four types of use of specialty clinic services. These included: non-users (n = 210); consultation only (n = 180); and the remaining 32% of the referrals were divided between "users-non complete" (n = 98) and "users-complete" (n = 83). "User" groups were similar in characteristics to each other at referral and follow-up on all the major variables with the exception of two factors: non-users lived further from the clinic than users and users were rated as psychologically more vulnerable than non-users. The best predictors for attending the clinic were the presence of referral information from the referring physician and the geographic location of the patient's referring physician. The prevalence of poor psychosocial adjustment was 55.7%, high by comparison with other specialty clinics. Seventy percent of the variance in psychosocial adjustment to chronic pain was explained by social and cognitive variables. In addition, users of specialty pain clinic services generated proportionately less costs in the use of other health services when they were compared to non-users. The importance of social support and meaning of illness variables in predicting psychosocial adjustment to chronic pain is corroborated in this study as is the relevance of the pain clinic cognitive behavioural approach for these problems. In addition, compared to other chronic pain sufferers with similar characteristics, it appears that the use of the pain clinic contains the use of other services and thus has an important economic impact.

Adaptation, Psychological↗
PubMed1992

Gastric lymphoma treatment. Medical versus surgical.

The treatment of gastric lymphoma is an area of ongoing controversy. Surgical resection has been the standard therapy. Recent advances, however, have been developed in other treatment modalities. A comparison of treatment options is presented.

Humans↗
PubMed1992

Group-analytic psychotherapy.

Group analysis is a flexible and effective method of providing group psychotherapy, thereby promoting maturation and symptom relief. Its metapsychology remains incompletely worked out but provides potentially exciting interfaces with biological and physical sciences, through Foulkes's (1973) seminal concept of the group matrix.

Humans↗
PubMed1992

Effect of age on potassium- and tyramine-induced release of norepinephrine from cardiac synaptosomes in male F344 rats.

Potassium (K+)-induced norepinephrine (NE) release was examined in preparations of cardiac synaptosomes and sliced atria from 6-, 24-, and 26-mo-old male F344 rats. Cardiac synaptosomes were prepared from rat hearts by collagenase digestion followed by homogenization in 0.32 M sucrose and centrifugation. The synaptosome preparations and the sliced atria were labeled with 3H-NE and then placed in a superfusion system. K(+)-induced net fractional release of NE from synaptosomes prepared from 24- and 26-mo-old rats (4.3% and 3.0%, respectively) was significantly reduced when compared to NE release from synaptosomes from 6-mo-old rats (5.2%). K(+)-induced NE release from sliced atria from 24-mo-old rats (4.7%) was also significantly reduced when compared to NE release from atria from 6-mo-old rats (6.3%). Perfusion of cardiac synaptosomes with buffer prepared without calcium (CA++free, < 5 microM) reduced K(+)-induced release by 50% in all age groups studied. Perfusion with tyramine induced identical rates of NE release from cardiac synaptosomes prepared from 6- and 24-mo-old rats. These results confirm that depolarization-induced NE release from cardiac sympathetic nerves is reduced in the old male F344 rat.

Adrenergic Fibers↗
PubMed1992

Impact of hemodialysis on left and right ventricular Doppler diastolic filling indices.

Hemodialysis is associated with acute reduction in intravascular volume. To assess the impact of volume reduction on left and right ventricular diastolic filling indexes obtained by Doppler echocardiography, 24 patients on chronic hemodialysis were consecutively studied before, during, and immediately after one hemodialysis session. Twenty four normal sex and age-matched volunteers served as a control group. Study patients had abnormal diastolic indexes when compared to controls. At 2 hours of dialysis (mid dialysis) there was a significant decrease in peak early mitral flow velocity (E), no change in peak atrial filling velocity (A), and a reduction in the E/A ratio. The deceleration time of the mitral E wave also was prolonged compared to baseline. Similar findings were observed with respect to right ventricular filling indices. These changes occurred during the first 2 hours of dialysis and remained unaltered at end dialysis. When patients were subdivided according to weight loss, only the group that lost 1 or more kilograms had significant changes in the Doppler parameters of the left and right ventricle, as well as reduction of the left ventricular dimensions. These findings suggest that preload reduction is the main mechanism that accounts for acute changes in Doppler diastolic indices observed during hemodialysis.

Analysis of Variance↗
PubMed1992

RS-61443 (mycophenolate mofetil). A multicenter study for refractory kidney transplant rejection.

RS-61443 (mycophenolate mofetil) inhibits a key enzyme of the de novo synthesis of purine nucleotides in T and B lymphocytes. The purpose of this study was to evaluate the efficacy of RS-61443 in patients with refractory renal allograft rejection. Patients eligible for the study had previously undergone anti-rejection therapy with high-dose steroids or OKT3 monoclonal antibody. All rejection episodes were proven by renal biopsy. Successful rescue was achieved in 52 (69%) patients. Rescue was more successful when patients were entered with a creatinine of 4 mg/dL or lower (79%), versus a 52% rescue rate in patients entered with a creatinine of 4 mg/dL or above. Major side effects were predominantly gastrointestinal, but there was no overt nephrotoxicity, hepatotoxicity, or bone marrow suppression. The overall infection rate was 40%, with the spectrum of infections characteristic for the highly immunocompromised patient. The conclude that this pilot study suggests that RS-61443 is effective in refractory kidney allograft rejection. Based on this study, prospectively randomized multi-center trails have been planned and are in progress.

Adolescent↗
PubMed1992

Multiple sigma binding sites in guinea-pig and rat brain membranes: G-protein interactions.

1. Evidence is accumulating for multiple sigma (sigma) sites in the mammalian CNS. 2. We have addressed this problem and have examined sigma site - G-protein coupling in guinea-pig and rat brain membranes. 3. Ditolylorthoguanidine (DTG), (+)-3-(3-hydroxyphenyl)-N-1-(propyl)piperidine (3PPP) and dextromethorphan displaced [3H]-DTG (3.4 nM) with low Hill slopes of 0.5, 0.6 and 0.6, respectively in guinea-pig brain membranes. 4. In the presence of 5'-guanylylimidodiphosphate (Gpp(NH)p; 100 microM), the specific binding of [3H]-DTG was reduced by 36.7%, the Hill slope of 3PPP was increased to near unity, the ability of dextromethorphan to displace DTG was virtually abolished and the Hill slope for DTG remained low (0.7), indicating the presence of at least two binding sites. These data indicate that although Gpp(NH)p removes a dextromethorphan high affinity site, two DTG selective sites remain in the presence of Gpp(NH)p. 5. The present study suggests that DTG binds to at least three sites in guinea-pig brain membranes, at least one of which is G-protein linked. 6. In rat brain membranes, DTG displaced itself (3.4 nM) with a Hill slope near 1. 3PPP displacement of [3H]-DTG was comparable with the guinea-pig (Hill slope 0.5) and displaced from more than 1 site. Dextromethorphan did not displace [3H]-DTG at concentrations below 10 microM. 7. The heterogeneity of sigma sites appears to be less in rat than in guinea-pig brain membranes.

Animals↗
PubMed1992

"You'll feel me touching you, sweetie": vaginal examinations during the second stage of labor.

Videotapes of women during the second stage of labor and their caregivers were examined in this descriptive study to determine how caregivers performed sterile vaginal examinations. Conversational analysis techniques were used to analyze the data. Results showed that the examinations were performed in a ritualistic manner by all caregivers, and the way the ritual was enacted repeatedly demonstrated the power of the caregivers over the women. The most common reason for performing the procedure, to help the woman push better, seems to be specific to the second stage of labor and is not described in the literature. The authors offer suggestions for better use of the examination, and recommend that it be performed far less frequently than is common.

Adolescent↗
PubMed1992

Change in locus of control following admission in adolescent in-patients.

A multidimensional measure of children's perception of control was administered to 56 adolescents before and after admission. Different sources of control ('internal', 'powerful others' and 'unknown') were analysed by domain (sphere of behaviour) and outcome ('success' or 'failure'). There were changes across domain and outcome for all three sources of control with significant changes away from 'powerful others' and 'unknown' control. The trend towards internality was also evident in significant changes in the adolescents' perceptions in the 'general' domain and for a 'success' outcome. Changes towards 'internal' source of control were associated with higher cognitive ability, whereas changes away from 'powerful others' were most marked in girls, and changes away from 'unknown' were greatest in the older adolescents. These preliminary observations may help us understand beneficial effects of in-patient care and plan strategies for sustained change in these patients.

Adolescent↗
PubMed1992

Age-related decrease in omega conotoxin binding to rat cardiac synaptosomes.

A cardiac synaptosomal preparation developed by this laboratory was used to study neuronal calcium channels in aging rat heart. Ca2+ channels were quantified by measuring binding of iodinated omega conotoxin, which is reported to specifically block neuronal Ca2+ channels. We determined the binding of [125I]-omega conotoxin GVIA to a synaptosomal preparation from the hearts of 6- and 24-month-old male Fisher 344 rats. The maximum number of binding sites (Bmax +/- SD, fmol/mg protein) is lower in preparations from 24-month (2.2 +/- 0.6) than from 6-month (3.4 +/- 0.7)-old rats. This decrease in number of binding sites suggests an age-related reduction in the number of neuronal calcium channels. Since calcium is essential for exocytotic release of norepinephrine and is made available intracellularly through neuronal calcium channels, the reduction in neuronal calcium channel number may explain, in part, our previous observations of diminished release of norepinephrine in senescent hearts.

Age Factors↗