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Biomedical subjects

G B Russell

Publications and source records attributed to G B Russell.

At least 37 records · Page 2Linked to original sources
PubMed1999

Sudden and cardiac death rates in hemodialysis patients.

BACKGROUND: Sudden and cardiac death (including death from congestive heart failure, myocardial infarction, and sudden death) are common occurrences in hemodialysis patients. The intermittent nature of hemodialysis may lead to an uneven distribution of sudden and cardiac death throughout the week. The purpose of this study was to assess the septadian rhythm of sudden and cardiac death in hemodialysis patients. METHODS: Data from the United States Renal Data System (USRDS) were obtained to examine the day of death for United States hemodialysis and peritoneal dialysis patients from 1977 through 1997. The days of death were also determined for patients in the Case Mix Adequacy Study of the USRDS. RESULTS: There was an even distribution of sudden and cardiac deaths for patients on peritoneal dialysis, and hemodialysis patients dying of noncardiac deaths also had an even distribution. For all hemodialysis patients, Monday and Tuesday were the most common days of sudden and cardiac death. For patients in the Case Mix Adequacy Study designated as Monday, Wednesday, and Friday dialysis patients, 20.8% of sudden deaths occurred on Monday compared with the 14.3% expected (P = 0.002). Similarly, 20.2% of cardiac deaths occurred on Monday compared with the 14.3% expected (P = 0.0005). Similar trends were found on Tuesday for Tuesday, Thursday, and Saturday dialysis patients. CONCLUSIONS: The intermittent nature of hemodialysis may contribute to an increased sudden and cardiac death rate on Monday and Tuesday for patients enrolled in the USRDS.

Age Factors↗
PubMed1999

Tryptophan requirement of the commercial hen.

An experiment was conducted to determine the Trp requirement of the commercial laying hen. A corn-soybean meal diet was used that contained gelatin, which is low in Trp. Tryptophan was the first-limiting amino acid in this diet. Methionine, Lys, Arg, Thr, Val, and Ile were added to ensure that they were not deficient. Experimental diets containing 0.0, 0.02, 0.04, 0.06, 0.08, 0.10, and 0.12% Trp were fed, and a corn-soybean meal diet served as the positive control. Egg production (EP), egg mass (EM), and egg content (EC) were significantly increased by the addition of supplemental Trp. Broken-line regression indicated that the Trp requirement for EP and EC for this experiment was 136.0 (R2 = 0.81) and 136.5 (R2 = 0.82) mg per hen per d, respectively. These hens produced 43.5 g of EC, resulting in a Trp requirement of 3.14 mg/g of EC. Therefore, assuming an output of 50 g of EC, we suggest 157 mg per hen per d as the requirement for maximum production of EC.

Animal Feed↗
PubMed1999

Dialysis modality and delayed graft function after cadaveric renal transplantation.

The purpose of this investigation was to compare outcomes in the immediate posttransplant period for hemodialysis (HD) and peritoneal (PD) dialysis patients who received cadaveric renal transplantation. Data were obtained from the United Network of Organ Sharing on all cadaveric graft recipients who were dialysis-dependent at the time of transplantation between April 1994 and December 1995. Baseline characteristics were compared between groups, and multivariate logistic regression was performed with outcome measures including urine production in the first 24 h posttransplantation (U24), requirement for dialysis in the first week posttransplant (FWDIAL), and treatment for acute rejection during the initial hospitalization. The odds of oliguria (not producing urine in the first 24 h) were 1.49 (1.28 to 1.74) times higher in HD versus PD patients. After adjustment for other comorbid conditions including age, gender, race, HLA mismatch, time on dialysis, panel-reactive antibodies, and cold and warm ischemia time, the odds of oliguria were 1.60 (1.14 to 2.25) times higher in black HD patients compared with PD patients and 1.29 (1.06 to 1.57) times higher in white HD patients. In a similar manner, after adjustment for significant comorbid conditions, the odds of requiring dialysis in the first week were 1.56 (1.22 to 2.0) times higher in black HD patients versus PD patients and 1.40 (1.21 to 1.60) times higher in white HD patients. The rate of acute rejection was similar during the first hospitalization. These results suggest that there is an association between hemodialysis and delayed graft function. Differences in biocompatibility between the two modalities could potentially be responsible.

Adult↗
PubMed1998

Nonlinear additivity of nitrous oxide and isoflurane potencies in rats.

PURPOSE: To test the hypothesis that the MAC values of nitrous oxide (N2O) and isoflurane were not linearly additive, as theorized by the postulated mode of action based on lipid solubility, in a rat model. METHODS: Eight Long Evans rats were randomly assigned to order of measurement of MAC for isoflurane and N2O alone and in combination using standard 45 sec supramaximal electrical stimulation (50 volts x 10 msec duration pulses at 50.sec-1 applied for 45 sec s.c. to the lower abdominal groin area). The MAC of N2O was measured at hyperbaric compression to 2.25 atmospheres absolute, 1710 mmHg. RESULTS: The MAC values found were: isoflurane -0.98 +/- 0.12 and N2O - 159 +/- 12 volume (vol)%, or 1.59 +/- 0.12 atmospheres absolute (ATA) (All values are mean +/- standard deviation). The linear additivity theory suggests % MAC agent A + % MAC agent B = 1.0. However, % MAC isoflurane + % MAC N2O = 1.37 +/- 0.15 (P < .001). CONCLUSION: Nonlinear additivity was demonstrated with direct MAC measurement for both isoflurane and N2O in rats. This suggests an agonist-antagonist relationship.

Anesthetics, Inhalation↗
PubMed1998

Quality of life and psychological distress of bone marrow transplant recipients: the 'time trajectory' to recovery over the first year.

The purpose of this study was to measure the trajectory of psychosocial recovery over the first year after bone marrow transplantation (BMT). BMT patients were assessed at baseline (n = 86), hospital discharge (n = 74), 100 days (n = 64) and at 1 year (n = 45). Participants completed the Functional Assessment of Cancer Therapy-Bone Marrow Transplant Scale (FACT-BMT), the Profile of Mood States Total Mood Disturbance Scale (POMS-TMDS), the Medical Outcomes Social Support Survey (MOS-SSS), the Center for Epidemiologic Studies-Depression (CES-D) scale screener, a performance Status Rating Scale (PSR), and an interview questionnaire. The recovery trajectory in this patient population showed three distinct trends. The trajectory for distress was linear and improved over time with approximately 20% of patients continuing to have psychological distress at 1 year. Secondly, the trend for overall quality of life was parabolic, worsening at discharge, then improving at 100 days and at 1 year. However, there were individual areas of deficit at follow-up, eg fatigue, even while overall quality of life mean scores improved. Thirdly, the trend for patient concerns over time was linear and worsening. These recovery trajectories suggest psychosocial interventions before and after BMT that may prepare patients for increasing and worsening concerns even as physical well-being improves.

Adult↗
PubMed1998

Alternative-site anesthesia: guidelines affecting clinical care.

The delivery of anesthesia care to patients in alternative sites outside the operating room is a rapidly growing area of clinical activity. We have reviewed our patient care guidelines and standards developed for the operating room and applied them to sites as varied as a magnetic resonance imaging center in radiology to a plastic surgery office. Now specific societies and guidelines are being developed for alternative site practice.

Journal Article↗
PubMed1998

Peritoneal dialysate fill-volumes and hernia development in a cohort of peritoneal dialysis patients.

A retrospective case control study was performed on a cohort of 244 peritoneal dialysis patients followed over 5 years to determine whether dialysate fill-volume was associated with hernia development. The laboratory and clinical parameters of patients who developed hernias during this time period were compared with those of patients who did not develop hernias. Information on 27 patients who developed hernias was compared with that on 217 patients who did not develop hernias. Dialysate fill-volume was similar between groups (2.2 +/- .3 L for patients with hernias vs. 2.2 +/- .3 L for controls). Three patients with fill-volumes of 1.5 L developed hernias, and no patients with fill-volumes of 3 L developed hernias. Age, duration of time on dialysis, and body surface area were also similar between groups. This investigation could not find a relationship between fill-volume and hernia formation. From this study it would appear that physicians should not hesitate to increase fill-volume based on concerns of hernia development.

Case-Control Studies↗
PubMed1997

Quality of life measurement in bone marrow transplantation: development of the Functional Assessment of Cancer Therapy-Bone Marrow Transplant (FACT-BMT) scale.

We developed a 12-item bone marrow transplant subscale (BMTS) for the general Functional Assessment of Cancer Therapy (FACT) measure. The subscale combined with the FACT, (FACT-BMT) is a 47-item, valid and reliable measure of five dimensions of quality of life in bone marrow transplant patients. The three-step validation process involved the generation and selection of BMT-specific items and the testing of the overall measure. Items were selected from a list produced by seven oncology experts and 15 patients and were designed to assess content not represented in the general FACT items. A total of 182 patients completed the FACT-BMT at baseline, prior to BMT. An analysis measuring sensitivity to change was performed with 74 patients after transplantation and 60 patients over the three time-points of baseline, hospital discharge and 100 days. The FACT-BMT and all subscales were correlated, sensitivity to change was measured, and the internal consistency for each scale was calculated. Coefficients of reliability and validity ranged from 0.86 to 0.89 for the entire FACT-BMT and 0.54 to 0.63 for the BMTS. The BMTS was able to discriminate patients on the basis of performance status rating and also demonstrated sensitivity to change over time. The FACT-BMT has good psychometric properties for use in assessing quality of life in bone marrow transplant patients. The addition of the bone marrow transplant subscale to the general FACT measure makes it an excellent choice for use in BMT clinical trials.

Adolescent↗
PubMed1997

Treatment and prevention of malignant ascites associated with disseminated intraperitoneal malignancies by aggressive combined-modality therapy.

No satisfactory treatment exists to treat or prevent malignant ascites secondary to nonovarian intraperitoneal (IP) disseminated malignancies. A Phase I/II clinical trial combining radical cytoreductive surgery (CS) and IP hyperthermic chemotherapy (IPHC) with mitomycin C is presented. Between December 9, 1992 and July 31, 1995, 39 patients (pts) were explored for IP cancer. Five pts with known liver metastases were excluded, leaving 34 pts (15 female, 19 male) of median age 53 (range, 17-76). The majority of pts had disseminated IP cancers of gastrointestinal origin (80%). Prior therapy included the following: chemotherapy, 20 pts (59%); surgery, 29 pts (85%); and radiation, 2 pts (6%). Following CS, IPHC with mitomycin C was done. At surgery, 12 pts (35.3%) had frank ascites, and 12 pts (35.3%) had positive IP cytology without ascites. The median hospital stay was 9 days (range, 5-65) with no 30-day mortality. Complications for 36 treatments included: thrombocytopenia Eastern Cooperative Oncology Group grade 3 or 4, two cases (5.6%); neutropenia requiring granulocyte colony-stimulating factor, seven cases (19.4%); sepsis, four cases (11.1%); bowel leak, two cases (5.6%); and serous wound leak, two cases (5.6%). Ascites correlated with worse resection status (P = 0.025). Ascites was controlled in 9 of 12 (75.0%) pts, with failures at 1, 4, and 14 months (median follow-up, 7.5 months). No cytology-positive ascites-negative pts developed clinical ascites (median follow-up, 9.4 months). The median survival time in pts with ascites was 10.1 months versus 32.7 for patients without ascites (P = 0.013). For the entire study population, the 1- and 2-year survival rates were 74.6 and 48.5 per cent, respectively (median follow-up, 18.2 months). In this study, malignant ascites was controlled in 75 per cent of cases and prevented in all pts with positive IP cytology. CS plus IPHC appears to be relatively well tolerated and may be effective for the treatment and prevention of malignant ascites.

Antibiotics, Antineoplastic↗
PubMed1997

Traumatic adult respiratory distress syndrome.

ARDS is the pulmonary manifestation of both direct and indirect insults to the lung. Trauma patients are at particular risk for ARDS from the direct effects of their injuries, as well as from complications that may occur during their hospital courses. ARDS prevention can be enhanced through diverse areas of medical focus. Public health issues addressing trauma prevention, improved understanding and treatment of trauma-related pathophysiology, as well as a better understanding of basic pathophysiology of this disease process will allow refinement and improvement of our management practices. Newer modes of mechanical ventilation may help us to avoid ventilator-induced exacerbation of lung injury. As we define the role of nonconventional therapies, such as anti-inflammatory and anticytokine therapies, our ability to actively interrupt and reverse the progression of the inflammatory cascade will be enhanced. As yet, ARDS continues to be a challenging disease process to both fully understand and successfully treat in our critically ill patients.

Humans↗
PubMed1996

Laryngeal biomechanics of the singing voice.

By transnasal fiberoptic laryngoscopy, patients with functional voice often demonstrate abnormal laryngeal biomechanics, commonly supraglottic contraction. Appropriately, such conditions are sometimes termed muscle tension dysphonias. Singers working at the limits of their voice may also transiently demonstrate comparable tension patterns. However, the biomechanics of normal singing, particularly for different singing styles, have not been previously well characterized. We used transnasal fiberoptic laryngoscopy to study 100 healthy singers to assess patterns of laryngeal tension during normal singing and to determine whether factors such as sex, occupation, and style of singing influence laryngeal muscle tension. Thirty-nine male and 61 female singers were studied; 48 were professional singers, and 52 were amateurs. Examinations of study subjects performing standardized and nonstandardized singing tasks were recorded on a laser disk and subsequently analyzed in a frame-by-frame fashion by a blinded otolaryngologist. Each vocal task was graded for muscle tension by previously established criteria, and objective muscle tension scores were computed. The muscle tension score was expressed as a percentage of frames for each task with one of the laryngeal muscle tension patterns shown. The lowest muscle tension scores were seen in female professional singers, and the highest muscle tension scores were seen in amateur female singers. Male singers (professional and amateur) had intermediate muscle tension scores. Classical singers had lower muscle tension scores than nonclassical singers, with the lowest muscle tension scores being seen in those singing choral music (41%), art song (47%), and opera (57%), and the highest being seen in those singing jazz/pop (65%), musical theater (74%), bluegrass/country and western (86%), and rock/gospel (94%). Analyzed also were the influences of vocal nodules, prior vocal training, number of performance and practice hours per week, warm-up before singing, race, smoking, and alcohol consumption.

Adult↗
PubMed1996

Combination cisplatin and carboplatin in advanced squamous cell carcinoma of the head and neck.

Twenty-three patients with advanced squamous cell carcinoma of the head and neck who had received no prior chemotherapy were treated with carboplatin 350 mg/m2 followed by cisplatin 50 mg/m2 every 28 days. Twenty-one of 23 patients were evaluable for response and toxicity. Eight patients (38%) achieved complete response (CR) or partial response (PR) with 2 CR and 6 PR. The overall median survival was 8.4 months (range 19 days-56+ months). The major toxicity was hematological with grade III/IV granulocytopenia in 32% and grade III/IV thrombocytopenia in 32%. There was very little nonhematological toxicity and no nephrotoxicity. There were no therapy-related deaths. The combination carboplatin/cisplatin is tolerable in patients with squamous cell carcinoma of the head and neck, with objective responses in 38%; however, the response rate was not superior to single-agent carboplatin or cisplatin. Further studies with a higher dose of cisplatin should be considered.

Adult↗
PubMed1996

Ability of commercial laying hens producing different egg outputs to meet their methionine and energy requirements when fed the same diet.

An experiment was conducted to determine whether commercial laying hens with different egg outputs could meet their Met requirement when fed the same diet. Three groups of hens were selected with either low, medium, and high egg output. Body weight of hens was positively related to egg output. As egg output increased, feed consumption increased. This resulted in essentially the same amount of energy consumed per gram of egg content (EC) for all three groups. Egg weight was greatest with hens producing the greatest EC. The Met intake of hens was increased with increased EC; however, the Met per gram of EC was not different for the three groups of hens. These data indicate that the Met and energy requirements of commercial layers can be met with one feed when individual hens produce different amounts of EC.

Animals↗
PubMed1996

Quality of life in breast cancer patients before and after autologous bone marrow transplantation.

The purpose of this study was to compare pre- and posttreatment quality of life (QOL) in breast cancer patients undergoing high-dose chemotherapy with autologous bone marrow transplantation (ABMT). Fifty-two female breast cancer patients were assessed on overall QOL, mood status, and social support before transplantation. After ABMT, 24 patients were assessed on the same measures as well as a measure of depressive symptoms and specific concerns identified in a structured interview. Mean pre- and post-transplant scores on the quality of life measure, mood scores and social support were not significantly different. Eight patients (33%) reported depressive symptoms post-transplantation. In the structured interview, a percentage of patients reported concerns in the following areas: job or work situation (25%); finances (42%); general physical health (50%); general frame of mind (25%); appearance (33%); health or life insurance (37%); personal or intimate physical relations (33%); planning for the future (38%). QOL and mood following ABMT improved slightly and compares favorably with breast cancer patients treated with conventional treatment. However, approximately 30% of patients had problems with sexuality, fatigue and depressive symptoms and may need follow-up psychosocial care in these areas. ABMT may pose no more threat to quality of life than conventional chemotherapy.

Adult↗
PubMed1996

Phase I study of N-(phosphonacetyl)-L-aspartate with fluorouracil and with or without dipyridamole in patients with advanced cancer.

We conducted a combined biochemical modulation trial of N-(phosphonacetyl)-L-aspartate (PALA), dipyridamole (DP), and fluorouracil (5-FU) in patients with cancer. Eighty-eight patients with advanced cancer were entered into this Phase I trial. During the first part of the study, four doses of PALA (125, 250, 500, and 1000 mg/m2, administered on day 1) were evaluated to determine the PALA dose with maximal suppression of aspartate transcarbamylase (ATCase) activity that was clinically tolerable. Patients were randomized to receive DP (or no DP), 50 mg/m2, p.o. every 6 h on days 1-6, and all patients received 5-FU, 400 mg/m2, by bolus administration on days 2-5. Prior to and during therapy, WBCs were collected and assayed for ATCase activity. After the maximally tolerated PALA dose with 400 mg/m2 5-FU +/- 50 mg/m2 DP was defined, the 5-FU dose was escalated using the same administration schedule of 5-FU, PALA, and DP. The dose of 5-FU was escalated by 25% in each of the DP cohorts until dose-limiting toxicity was reached. ATCase activity was inhibited in a dose-dependent manner with PALA doses of 125, 250, 500, and 1000 mg/m2, resulting in 0, 13, 17, and 49% inhibition of ATCase activity. Only at the higher PALA doses (i.e., 500 and 1000 mg/m2) was ATCase activity suppressed during days 2-5, but the activity returned to pretreatment levels by day 15. Based on the clinical tolerance and significant suppression of ATCase activity, a PALA dose of 500 mg/m2 was selected for the 5-FU dose escalation phase. At a 5-FU dose of 625 mg/m2, dose-limiting toxicity (leukopenia, stomatitis, and diarrhea) occurred in both DP cohorts. We recommend that for this monthly treatment schedule, 500 mg/m2 PALA and 500 mg/m2 5-FU, with or without 50 mg/m2 DP, be used in subsequent Phase II trials.

Adult↗