Physical performance standards in the ADF.
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Australia↗
Biomedical subjects
W Payne
Publications and source records attributed to W Payne.
An analysis of the forces required to drag sheep over various surfaces.
Some occupational health and safety hazards associated with sheep shearing are related to shearing shed design. One aspect is the floor of the catching pen, from which sheep are caught and dragged to the shearing workstation. Floors can be constructed from various materials, and may be level or gently sloping. An experiment was conducted using eight experienced shearers as participants to measure the force exerted by a shearer when dragging a sheep. Results showed that significant changes in mean dragging force occurred with changes in both surface texture and slope. The mean dragging forces for different floor textures and slopes ranged from 359 N (36.6 kg) to 423N (43.2 kg), and were close to the maximum acceptable limits for pulling forces for the most capable of males. The best floor tested was a floor sloped at 1:10 constructed of timber battens oriented parallel to the path of the drag, which resulted in a mean dragging force 63.6N (15%) lower than the worst combination.
Animal Husbandry↗
Skin pH changes associated with iontophoresis.
STUDY DESIGN: Randomized controlled trial. The researcher measuring skin pH was blinded to group assignment. OBJECTIVES: To compare the skin surface pH changes associated with iontophoresis. The investigation was designed to address the question of whether significant skin pH changes occur under the cathode on the skin surface when performing iontophoresis and assessed the influence of different electrode-buffering systems intended to stabilize skin pH (surface). BACKGROUND: Whether buffers are needed to stabilize skin pH during iontophoresis has not been thoroughly addressed in the literature. The effectiveness of immobile resins versus simple phosphate buffers is also unclear. METHODS AND MEASURES: Sixty volunteer subjects were administered iontophoresis of normal saline using buffered or nonbuffered electrode systems. Each subject participated in 1 of the 12 doses by electrode conditions (i.e., 5 subjects per group). Surface skin pH was measured before and after iontophoresis with a flat-surface pH electrode in concert with an analog pH meter. The independent variables were electrode type (4 levels) and dosage (3 levels). The dependent variable was the change in skin surface pH. RESULTS: A significant change in skin pH was found only when the treatment dose was 80 mA/minute with a nonbuffered electrode (x = 3.14 +/- 1.09). CONCLUSIONS: The skin pH changes that occur during a properly delivered iontophoresis treatment at dosages of 20 and 40 mA/min were small and not significantly different with or without the addition of buffers. Those pH changes associated with 80 mA/min doses were significantly greater when no buffer was employed but were stabilized by each of the buffers used in the study (preloaded immobile resins or simple phosphates added at point of treatment).
Adult↗
[Techniques of laparoscopic preparation and current-induced complications. Results of a survey in Germany].
138 surgical institutions in Germany retrospectively answered a questionnaire on available energy sources, techniques of preparation and complications due to the use of electric current in laparoscopic surgery. The median experience in this field of surgery was 6 years. For common laparoscopic operations the majority of surgeons use electrosurgery; only 8% never do so. Except in appendectomy, monopolar cautery is preferred for all operations. Other energy devices are of minor importance. The overall number of operations reported was nearly 138,000. The rate of complications due to the use of electric current was 0.1%. This figure is accounted for in equal part by intra- and postoperative burns. The complication rate is at the lower end of the range known from the literature. Even though the retrospective nature of this analysis may hide a certain number of injuries electric, current plays a minor role for complications in laparoscopic surgery.
Burns, Electric↗
Double volume exchange transfusion for ABO incompatible liver transplantation in paediatric patients: intraoperative and preoperative approach.
Double volume blood exchange transfusions (DBVET) were used to reduce the serum antibody levels in six paediatric patients receiving ABO incompatible hepatic allografts. In four patients, the exchange transfusions took place on the ward prior to surgery. In three of these four patients who had titres measured, the anti-A IgM titres fell from 1024 to 64, 64 to 8, and 128 to 16, respectively. The anti-A IgG titres fell from 32 to 16 and 512 to 64 in two patients, but rose from 16 to 32 in the third. In two patients DBVET were performed intraoperatively using a rapid infusion device. The IgM titres fell from 256 to 32 and 64 to 1, respectively, and the IgG titres fell from 16 to 4 and 2 to 0. Intraoperative DBVET can acutely and effectively reduce blood group antibodies. Intraoperative DBVET may reduce graft ischaemia time and allow red blood cell salvage.
ABO Blood-Group System↗
Residency training in aesthetic surgery: maximizing the residents' experience.
Plastic surgery residency programs often rely on a residents' aesthetic clinic to help train residents in aesthetic surgery. The television media may be used to help boost interest in such clinics. We report our experience with a local television station in helping to produce a "health segment" broadcast that chronicled the experience of an aesthetic patient in the residents' aesthetic clinic. As a result of this broadcast, approximately 150 people responded by telephone and subsequently attended a series of seminars designed to screen patients and educate the audience about the aesthetic clinic. A total of 121 patients (112 women and 9 men) signed up for personal consultations. The age distribution and requested procedures are presented. From the data, we conclude that there is a healthy demand for reduced-fee plastic surgery procedures performed by residents in plastic surgery. The number and variety of cases generated are sufficiently diverse to provide a well-rounded operative experience. The pursuit of media coverage of a not-for-profit clinic has the potential for generating large patient volume. Such efforts, although very attractive, are not without their own risks, which must be taken into consideration before engaging the media in the public interest arena.
Adult↗
Sentinel lymph node biopsy in melanoma of the head and neck.
BACKGROUND: The sentinel lymph node is the first node or nodes to drain a cutaneous melanoma. Sentinel lymph node biopsy is performed to determine whether regional metastases are present. The authors' experience with the new technique of sentinel lymph node biopsy for melanoma of the head and neck is reported. PATIENTS AND METHODS: During the period of January of 1992 to December of 1995, 58 consecutive patients were identified from the melanoma database who had localization of the sentinel lymph node for primary cutaneous melanoma of the head and neck. Techniques for identification of the sentinel node(s) include preoperative lymphoscintigraphy and intraoperative Lymphazurin dye (vital blue dye) and technetium-99m-labeled sulfur colloid injection around the primary tumor site with Neoprobe mapping. RESULTS: Fifty-eight patients (13 female, 45 male), mean age 61 years, with melanoma of the head and neck with a mean Breslow thickness of 2.21 mm. (range, 0.82-6.87 mm.) and no regional lymphadenopathy underwent sentinel node mapping. The sentinel node was successfully identified in 55 patients (95 percent). Blue dye was visualized in 85 of 126 sentinel nodes excised (67 percent), whereas the remainder of the sentinel nodes were localized with the Neoprobe. Forty-nine patients who had successful mapping and sentinel node biopsy had no evidence of metastatic disease in the sentinel node or other nodes in the basin. Six of the fifty-five patients (11 percent) had evidence of micrometastatic disease, and all six had the sentinel node as the only site of metastasis. Five of six patients with micrometastases had a subsequent neck dissection and/or superficial parotidectomy. None of these patients had evidence of "skip metastases" with a negative sentinel node and higher level nodes positive for metastases. In total, 6 of the 18 sentinel nodes (33 percent) identified in these six patients contained micrometastatic disease, whereas none of the 139 other nodes sampled had any evidence of metastases. The exact probability that all six unpaired observations would consist of involvement of only the sentinel nodes is p = 0.0312. CONCLUSIONS: By combining the two mapping techniques in patients with melanoma of the head and neck, the sentinel node(s) can be mapped and identified individually, similar to melanoma in other locations. The sentinel nodes have been shown to contain the first evidence of regional metastatic melanoma. This staging information can be used to plan therapeutic node dissections and adjuvant therapy that may have a survival benefit in patients with stage III melanoma of the head and neck. Lymphatic mapping can be used to make the surgical care of the melanoma patient more conservative, so that only those patients with solid evidence of regional node metastases are subjected to the morbidity and expense of a complete node dissection and the toxicities of adjuvant therapy.
Biopsy↗
Extra-abdominal closure of enterocutaneous fistula.
Enterocutaneous fistula is a dread complication of gastrointestinal disease and gastrointestinal operation. These patients typically have undergone numerous abdominal operations, often with peritoneal contamination, carcinoma, and/or a history of radiation, making operation for repair daunting, if not impossible. We describe a method for closure of enterocutaneous fistula, which we have used successfully in four such patients. After failure of nonsurgical management, each patient's fistula was closed with a combination of skin, muscle, and fascial flaps after intubation of the fistula with a Malecot catheter. No intra-abdominal dissection was necessary. All fistulas healed completely. We recommend this closure in any patient who has failed surgical or nonsurgical therapy or in whom celiotomy is contraindicated or is to be avoided.
Cutaneous Fistula↗
Optimization of the MGH repair using an algorithm for tenorrhaphy evaluation.
Previous investigations have demonstrated the superior strength and toughness of the MGH four-strand tendon repair technique and shown that it neither weakens during maximum tendon softening nor interferes with healing in an in vivo rabbit model. In the current study, the biomechanical performance of the modified Becker (MGH) and the modified Kessler repairs were compared in situ using a dynamic human cadaveric model to evaluate strength, toughness, glide efficiency, and operator variability. Three different surgeons performed a total of 42 zone II flexor digitorum profundus repairs in 14 fresh human cadaver hands. The modified Becker (MGH) repairs were stronger (79 +/- 3 versus 64 +/- 4 N; p < 0.01) and tougher (0.092 +/- 0.002 versus 0.078 +/- 0.003 J; p < 0.01) than the Kessler repairs while allowing equally efficient glide (32 +/- 6 versus 33 +/- 4 percent; p > 0.9). Strength was operator-dependent only for the modified Kessler repair (p < 0.005). We then established the optimal configuration of the MGH tenorrhaphy (number of preloaded crosses on either side of the tendon transection) by examining gap resistance ex vivo. Fifty-one MGH flexor tendon repairs were performed on explanted fresh human cadaver tendons. The experimental groups were randomly assigned to receive 0, 1, 2, 3, or 4 crosses on each side of the tenorrhaphy. Strength and toughness to gap formation and to ultimate failure were assessed tensiometrically. The MGH two-cross configuration was most resistant to gap formation (peak load 39 +/- 3 N; p < 0.05), establishing this configuration as the optimal design of this four-strand crisscrossing repair technique. The augmented Becker (MGH) repair is significantly stronger and tougher than the modified Kessler repair and demonstrates no operator dependence. It is a superior technique for zone II tenorrhaphy in the human hand. An algorithm is presented as a systematic approach that includes the important elements necessary for the rigorous biomechanical evaluation of any tendon repair technique.
Algorithms↗
A comparison of active and passive warm ups on energy system contribution and performance in moderate heat.
The effect of either an active warm up (AWU) or a passive warm up (PWU) on performance and energy system contribution in a moderately hot ambient environment (30 degrees C, 50% Relative humidity) was investigated. The AWU procedure involved exercise at 100% VO2 max followed by four 30 sec efforts at 100% of VO2 max and the PWU involved the application of heat pads to the quadriceps for 60 min. Following either warm up procedure, (randomized cross over design) a 60 s supramaximal test on a Monark bicycle ergometer was performed. The AWU procedure elicited the greatest average power output (0-30 s: 669 +/- 28 W vs 645 +/- 30 W, p < 0.05) and (0-60 s 529 +/- 20 W vs 513 +/- 20 W, p < 0.05), the greatest peak power output (917 +/- 45 W vs 880 +/- 46 W, p < 0.01) and VO2 peak during the initial 30 s (1.4 +/- 0.1 vs 1.2 +/- 0.1 l.min-1, p < 0.01) and over the duration of the 60 s test (3.2 +/- 0.1 vs 2.9 +/- 0.2 l.min-1, p < 0.05). The estimated anaerobic energy release was not significantly different between the trials. The performance benefits of an AWU occurred within the first 30 s of exercise as there was no significant differences in average power output or VO2 peak in the final 30 s of exercise. In conclusion, an AWU enhances sprinting performance in a moderately hot ambient environment, despite a higher rectal temperature than a PWU. The increased power output is derived from greater oxygen consumption in the initial stages of exercise.
Adult↗
A percutaneous technique for venous return cannula insertion for veno-venous bypass in hepatic transplantation.
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Adolescent↗
Effect of cyclosporine dosing on creatinine levels in hepatic transplant recipients.
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Adolescent↗
A new defective retroviral vector system based on the Bryan strain of Rous sarcoma virus.
We have constructed a helper cell line and vector system based on the Bryan high titer (BH) strain of Rous sarcoma virus (RSV). BH-RSV is a defective virus which lacks an env gene; however, if env is supplied in trans, it replicates to a very high titer. Like BH-RSV, the vector contains gag and pol genes and lacks an env gene. The helper cell line supplies env in trans and permits the production of infectious virions. To construct the helper cell line the subgroup A env gene from the Schmidt-Ruppin-A (SRA) RSV was stably transfected into Qt6 cells, a chemically transformed quail fibroblast line. To minimize homology between the vector and helper cell line, transcription of the env gene is driven by a MuLV LTR, and 3' processing is controlled by the simian virus 40 (SV40) polyadenylation signal. This combination of vector and helper cells can be used to produce high-titer viral stocks in which recombinant replication-competent virus have not been detected even when the stocks were used to inoculate chickens. This system should be useful for developing transgenic chickens, studying cell lineage, and introducing genes into cultured cells.
Animals↗
Pediatric renal transplants--results with sequential immunosuppression.
Cyclosporine has improved the results of renal transplantation. In 1984, we began using it as part of a sequential immunosuppression protocol (MALG, AZA, P, and delayed administration of CsA) in our pediatric renal transplant recipients. We studied the outcome of the 131 pediatric renal transplants (less than or equal to 18 years of age at transplant) performed at our institution between June 1984 and March 1991. We compared these results with the 144 similar transplants performed since January 1980 that did not involve CsA immunosuppression. In the sequential immunosuppression group, there were 97 primary (74%) (26 [27%] cadaver, 71 [73%] living donor [LD]) and 34 (26%) retransplant (23 [68%] CAD, 11 [32%]) recipients. Age at transplant (mean +/- SD) was 7.4 +/- 5.5. Overall, 1-year actuarial graft survival was 93%; 1-year patient survival was 100%. The mean number of hospital readmissions was 3.0 +/- 3.5; 26 (20%) were readmission-free. The mean number of rejection episodes was .87 +/- 1.3 per patient; 73 (56%) were rejection-free. Importantly, LD (vs. CAD) recipients had fewer rejection episodes (P = 0.06). In the first post-transplant year, the serum creatinine level was significantly lower in primary (vs. retransplant) recipients and in LD (vs. CAD) recipients (P less than 0.05). In the 144 patients not receiving CsA, there were 129 (90%) primary (27 CAD, 102 LD) and 15 (10%) retransplant (7 CAD, 8 LD) recipients. Age at transplant was 6.9 +/- 5.3 years. The 1-year actuarial graft survival rate was 82%; the 1-year patient survival rate was 94%. The mean number of hospital readmissions was 3.3 +/- 2.3; 5 (8%) were readmission-free. The mean number of rejection episodes was 1.2 +/- 1.5; 27 (45%) were rejection-free. There was no difference in the serum creatinine level based on donor source or transplant number. Sequential immunosuppression has significantly improved patient (P = 0.003) and graft survival (P = 0.004) rates. Comparing sequential vs. non-CsA immunosuppression, there was no difference in the number of readmissions (P = 0.47), number of rejection episodes (P = 0.17), or serum creatinine level. The number of rejection-free patients was significantly lower in LD (vs. CAD) recipients (P less than 0.05). There was no evidence of progressive deterioration in renal function in the sequential (vs. non-CsA) recipients.
Adolescent↗
The expression of mouse tyrosinase in chick cells in vitro and in vivo when controlled by a constitutive promoter.
Virally introduced mouse tyrosinase expression was checked both in vitro and in vivo in chicken cells and tissues. The results indicate that a constitutive promoter is able to express mouse tyrosinase in a variety of cells and tissues both in vitro and in vivo. Tyrosinase expression is marked by pigment production in situ, which is visible at macroscopic as well as microscopic levels without the use of substrates. It is concluded that tyrosinase can be a valuable marker for tracking gene insertion since it is spontaneously expressed. The expression of tyrosinase in some cells and tissues has a detrimental effect, however, and should be controlled by tissue-specific promoters.
Animals↗
Appropriate in vivo expression of a muscle-specific promoter by using avian retroviral vectors for gene transfer [corrected].
The promoter regions of the chicken skeletal muscle alpha-actin (alpha sk-actin) and the cytoplasmic beta-actin genes were linked to the bacterial chloramphenicol acetyltransferase (CAT) gene. Replication-competent retroviral vectors were used to introduce these two actin/CAT cassettes into the chicken genome. Chickens infected with retroviruses containing the alpha sk-actin promoter expressed high levels of CAT activity in striated muscle (skeletal muscle and heart); much lower levels of CAT activity were produced in the other nonmuscle tissues. In contrast, chickens infected with retroviruses containing the beta-actin promoter linked to the CAT gene expressed low levels of CAT activity in many different tissue types and with no discernible tissue specificity. Data are presented to demonstrate that the high levels of CAT activity that were detected in the skeletal muscle of chickens infected with the retrovirus containing the alpha sk-actin promoter/CAT cassette were not due to preferential infectivity, integration, or replication of the retrovirus vector in the striated muscles of these animals.
Actins↗
Hematin therapy for the neurologic crisis of tyrosinemia.
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Amino Acid Metabolism, Inborn Errors↗
Risk factors for second renal allografts immunosuppressed with cyclosporine.
Second renal allograft survival rates are lower than those of primary allografts. For recipients immunosuppressed with azathioprine, prednisone, and Minnesota ALG (conventional immunosuppression), risk factors associated with decreased second graft survival have been identified: age greater than 40, cadaver donor, less than 6 months between primary graft loss and retransplantation, duration of primary graft function (6 months or 1 year, depending on the study), high peak panel-reactive antibody, number of human leukocyte antigen mismatches, and delayed graft function. In this study, we used a multivariate analysis to identify risk factors associated with decreased second graft survival in patients who did or did not receive cyclosporine. Results were compared with primary graft survival rates. Risk factors for patients receiving conventional immunosuppression were: (a) primary graft loss caused by rejection greater than or equal to 6 months (P = 0.01 vs. either rejection less than 6 months or nonimmunologic loss); (b) cadaver donor (P = 0.005 vs. living related); and (c) interval between primary graft loss and retransplantation of greater than or equal to 6 months (P = 0.05 vs. less than 6 months). For CsA, risk factors that most decreased second graft survival were: (a) primary graft loss caused by rejection less than 6 months (P = 0.11 vs. nonimmunologic loss); (b) conventional immunosuppression for the primary graft (P = 0.08 vs. CsA immunosuppression); and (c) a peak PRA of greater than or equal to 21 (P = 0.14 vs. peak PRA of 1-20). For second graft recipients immunosuppressed with CsA, primary graft loss to either rejection greater than 6 months posttransplant or nonimmunologic causes was not a risk factor for second graft survival. These data extend the recent reports of other investigators by identifying risk factors for retransplant recipients treated with CsA and by demonstrating that subgroups of patients in the retransplant population can be retransplanted without additional risk (i.e., their second graft survival rates are similar to primary graft survival rates). This may become more important if, in the future, organ distribution is based on graft survival data. If so, our data would support retransplantation in patients who are immunosuppressed with CsA, especially those who lost their primary graft to either rejection greater than or equal to 6 months posttransplant or nonimmunologic causes; who receive living related grafts; and who have a peak PRA of 1-20.
Adult↗