Biomedical subjects
Publications and source records attributed to J Ryan.
Patients who deliberately harm themselves can present with a variety of disorders. The case is reported of a patient who deliberately self-harms by inducing hypoglycaemic episodes. This patient has placed great demands on the emergency services over the last 9 years. Early involvement by senior accident and emergency staff is advised.
This study was performed to test the hypothesis that attaching a tendon to a trough in cancellous bone results in tendon-healing that is biomechanically superior to that after direct fixation of a tendon to cortical bone. Twenty adult female goats were treated with a bilateral tenotomy of the infraspinatus tendon with subsequent reattachment of the tendon. In shoulders randomized to the cancellous-fixation group, a cancellous bed was prepared with a motorized burr and a template measuring twenty by five by five millimeters. The repair in the shoulders randomized to the cortical-fixation group was performed in the same manner, except that the tendon was attached to cortical bone. Three outcome measures were assessed, six and twelve weeks after the repair, with the Student paired t test and analysis of variance: load to failure, energy to failure, and stiffness. The types of repair were not significantly different with regard to any of the three outcomes. When the six and twelve-week data were combined, an average difference in load to failure of 3.9 per cent in favor of cancellous repair was observed but it was not significant (p = 0.78). The associated 95 per cent confidence interval for the difference ranged from 10.5 per cent in favor of cortical repair to 18.3 per cent in favor of cancellous repair. Histological analysis at six and twelve weeks revealed progressive maturation and reorganization of the bone-tendon interface with re-establishment of collagen-fiber continuity between the tendon and bone. This process was indistinguishable between the cortical and cancellous specimens. This study demonstrated no significant benefit from the creation of a trough to expose the tendon to cancellous bone. In this model, at both six and twelve weeks, the tendon-to-bone healing process of the two groups appeared similar and the biomechanical properties were approximately equal.
PURPOSE: To investigate bis (tri-n-hexylsiloxy) silicon 2,3-naphthalocyanine (SINc; 0.5 mg/kg) for photodynamic therapy of an experimental ocular melanoma in pigmented rabbits. METHODS: SINc was dissolved in canola oil by heating, emulsified with Tween 80, and administered by ear vein. Pharmacokinetics were studied in frozen tumor sections by fluorescence microscopy using a charge coupled device, camera-based, low-light detection system with digital image processing at 1 and 24 hours. A Ti:sapphire laser and a microlens were used to deliver the light (770 nm; 40 mW/cm2; 20 J/cm2). A control rabbit received light without SINc. RESULTS: Localization studies of SINc showed intravascular distribution shifting to a tumor stromal and perivascular distribution 24 hours after treatment. Tissue thermal damage after irradiation was minimal in the control. Exudative retinal detachments were not observed. Tumor destruction was observed, with sharp demarcation to a depth of 3.5 mm. CONCLUSIONS: Tumor light penetration was good at 770 nm, and thermal effects from the exciting light alone were minimal. Photodynamic therapy with SINc resulted in localized tumor destruction reflecting the light beam path without damage to adjacent tissue or intraocular complications.
OBJECTIVE: To describe a series of adult patients with annular pancreas, their presentation, and treatment modalities. METHOD: A retrospective chart review of patients seen at a multispecialty referral center from 1977 to 1994. RESULTS: Seven adult patients (ages ranging from 33 to 77 yr, four females and three males) presented with various symptoms and signs: abdominal pain (six patients) gastric outlet obstruction (two), pancreatitis (two), pancreatic mass (two), gastric/duodenal ulcer (one), and/or postoperative obstructive jaundice (one). The duration of symptoms ranged from 1 wk to 16 yr before diagnosis (median 18 months). Upper GI radiography was consistent with annular pancreas in two cases, CT scan in two cases (neither of which actually depicted the annulus), and four of six successful endoscopic retrograde cholangiopancreatographies. Three patients were diagnosed during operative procedures. Five of the seven patients required therapeutic operative procedures that included transduodenal sphincteroplasty, duodenojejunostomy, gastrojejunostomy, subtotal gastrectomy, or Whipple procedure. Four of the five had significant symptomatic relief. In one case, endoscopic sphincterotomy and biliary stent placement was therapeutic. CONCLUSIONS: 1) Annular pancreas occasionally presents in the adult population. 2) Although gastric outlet obstruction was seen in two of seven patients, a plethora of additional presentations included pancreatic mass, pancreatitis, peptic ulcer disease, and post-operative obstructive jaundice. 3) Diagnosis of annular pancreas was most commonly suggested by upper GI series or endoscopic retrograde cholangiopancreatography. However, fully 40% of diagnoses required surgery for confirmation. 4) In contrast to the pediatric population in whom gastrojejunostomy or duodenojejunostomy is the treatment of choice, a variety of surgical as well as interventional endoscopic procedures were utilized for effective treatment in adults with annular pancreas.
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A practical application of an experimental design, suitable for the comparison of several treatments, and based on combining balanced incomplete blocks and Latin squares balanced for carryover effects, is presented in the context of comparing a number of paediatric antibiotic formulations for taste, smell and colour. The recommended designs originally suggested by Patterson, have the advantage of balanced incomplete blocks, in that a single trial may be used to compare a larger number of treatments than may reasonably be given to any individual subject. In addition, the incorporation of suitably chosen Latin squares allows for assessment of any effect of order of presentation of the treatments and for any simple first-order carryover effect of one treatment into the following treatment period. Inclusion of such effects in the overall analysis could result in the reduction of bias in the comparisons of the treatments.
OBJECTIVE: To determine whether subzonal insemination of multiple sperm is an effective treatment for male factor infertility. DESIGN: Subzonal insemination by micromanipulation of sperm and oocytes for male factor patients. PATIENTS: Two hundred eight patients were selected on previous fertilization history and/or semen parameters. They could be assigned to one of three groups: group A had previous IVF failure, group B had a low fertilization rate with previous IVF, and group C had insufficient sperm for IVF. INTERVENTIONS: Oocytes were inseminated by subzonal insertion of multiple sperm. MAIN OUTCOME MEASURES: Fertilization and pregnancy rates. RESULTS: There have been 208 patients treated through 332 treatment cycles. Of 2,789 oocytes inseminated, 784 oocytes were fertilized (28%) and 516 of these (66%) were monospermic. This represents normal fertilization in 207 cycles (62% of total patient cycles). These 207 cycles produced an average of 2.6 +/- 1.8 embryos. The resultant 487 embryos were either transferred or cryopreserved for future transfer. A total of 42 pregnancies (21% per ET) resulted from 200 ET procedures with 397 embryos. Miscarriages or elective terminations have occurred (11/42 pregnancies, 26% to date) and 21 deliveries have resulted in 26 babies. There are nine ongoing pregnancies. Three of the pregnancies have been from cryopreserved embryos. Group B patients had the highest fertilization rate (23%) but the lowest pregnancy rate (7%). No other significant relationships between patient group and outcome were found. CONCLUSIONS: Subzonal insemination of multiple sperm is an effective treatment for some forms of male factor infertility.
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We describe the case of a 17-year-old girl, who presented to our Accident and Emergency (A&E) department following minor trauma to her forearm. Initial x-rays were misread as normal. Radiographs demonstrated classical features of rotatory subluxation of the scaphoid, which was found to be bilateral.
OBJECTIVE: The study attempted to increase understanding of nursing staff members' beliefs and concerns about work safety and patient assault. METHODS: A study conducted at a university-affiliated psychiatric facility in California in the late 1980s was replicated in five other psychiatric settings. Data were collected using the Attitudes Toward Patient Physical Assault Questionnaire, containing 31 statements designed to elicit nurses' beliefs about safety concerns, staff performance, and legal issues related to assaults. RESULTS: A total of 557 nursing staff members at the six sites responded to the questionnaire; 84 percent were female. The majority (76 percent) had been physically assaulted at least once, but 71 percent reported feeling safe in their work environment most of the time. Compared with female staff members, males tended to believe that assaults were to be expected, that assaulted staff have personality traits that make them vulnerable to assault, and that legal action against assaultive patients might jeopardize their jobs. Recently hired staff were more confident that their facilities did not admit unmanageable patients and that the environment was adequate to prevent assaults. Staff who had been assaulted more frequently tended to believe that assaults were to be expected. CONCLUSIONS: The study highlights a nationwide concern among nursing staff about safety. Ensuring a safe working environment requires better training, more adequate staffing, and a security plan to protect staff, patients, and others.
Medically fragile infants and children present a host of challenges. The neonatal intensive care unit (NICU) is initially the mainstay of care for these infants, but it does not meet the critical developmental interactive needs of the child and parents to ensure positive psychosocial bonding. The care of these infants is further complicated by high daily costs (ranging from $1,000 to $2,500 per neonatal intensive care bed day) and lengthy, expensive inpatient stays (typically ranging from one week to five months or more). FHP Utah, a managed care organization, met these challenges through an innovative case management-oriented home care program called "Welcome Home." The program has produced a major impact on the quality and the cost of care for medically fragile infants. This article summarizes the first year's experience in implementing and operating the program.
This study investigated the reliability and validity of the Index of Spouse Abuse (ISA) when used with a sample of 504 African-American women. The initial factor validity analysis for the ISA (Hudson & McIntosh, 1981) resulted in two subscales: a physical abuse scale (ISA-P) and a nonphysical abuse scale (ISA-NP). Factor analysis with this sample of African-American women revealed three factors instead of two. Coefficient alpha estimates of reliability were over .90 for the original ISA subscales and with the African-American sample. The discussion compares and contrasts the factor structure observed with the sample of African-American with the factor structure reported in the original validation studies. The study demonstrates the need to critically evaluate the extent to which instruments developed to measure spouse or partner abuse are valid and reliable when used with diverse groups that may not have been represented in the samples used for initial instrument development and validation work.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
To compare the injury rates of male and female postal workers, the authors reanalyzed data on a cohort of 2,337 new postal employees in Boston, Massachusetts, hired between 1986 and 1989. The analysis controlled for potential confounding by age, race, smoking status, and drug use. Using Cox proportional hazards models with time-dependent variables, the authors found that, compared with men, women had an increased relative risk for occupational injuries in each of the three largest job classifications: letter carrier, letter-sorting machine clerk, and mail handler. The relative risks were not constant over time. For letter carriers and letter-sorting machine clerks, the increased risks for women were noted only during the first year of employment (relative risk (RR) = 1.93, 95% confidence interval (CI) 1.40-2.67) and RR = 2.60, 95% CI 1.31-5.15, respectively). For mail handlers, the increased risks for women were noted only after the first year of employment (RR = 2.13, 95% CI 1.09-4.15). As the percentage of women in the work force increases, these results suggest the need for further research to define sex-specific injury risks and to devise prevention strategies.
Vascular permeability factor/vascular endothelial growth factor (VPF/VEGF) is a polypeptide mediator, elaborated by certain tumors and other cell types, that exerts multiple effects on endothelium via interaction with a class of high-affinity binding sites. In this report, the interaction of VPF/VEGF with human mononuclear phagocytes (MPs) is characterized. Radioligand binding studies at 4 degrees C showed the presence of a single class of binding sites, kd approximately 300 to 500 pmol/L (approximately 20 times lower affinity than the high-affinity binding site on endothelial cells [ECs]), the occupancy of which correlated with VPF/VEGF-induced MP migration and expression of tissue factor. These binding results were paralleled by functional experiments which indicated that the same VPF/VEGF preparations were about an order of magnitude less effective in stimulating MP chemotaxis than in inducing EC proliferation. When MPs with surface-bound 125I-VPF/VEGF were warmed to 37 degrees C, endocytosis and degradation occurred. Occupancy of VPF/VEGF binding site resulted in subsequent activation of intracellular signal transduction mechanisms, as shown by an increase in MP intracellular calcium concentration. Cross-linking studies with 125I-VPF/VEGF showed a new high-molecular weight band (corresponding to putative 125I-VPF/VEGF-receptor complex), the appearance of which was blocked by excess unlabeled VPF/VEGF. Consistent with these results, immunoprecipitation of 32PO4-labeled MPs exposed to VPF/VEGF showed a single band of similar mobility, not seen in untreated controls. These results demonstrate that the interaction of VPF/VEGF with MPs, though of lower affinity than that observed with ECs, also results from interaction of the polypeptide with a specific cell-surface protein and leads to activation of intracellular transduction mechanisms.
Factor Xa is a central procoagulant enzyme, linking the intrinsic and extrinsic activation mechanisms to the final common pathway of coagulation. To assess its contribution to pathologic thrombosis, studies were performed in a canine coronary thrombosis model. Thrombus formation was initiated by the application of electric current via a needle electrode placed in the lumen of the left circumflex coronary artery. When 50% occlusion of the vessel developed, the current was stopped and animals received an intravenous bolus of either saline, bovine glutamyl-glycinyl-arginyl-factor Xa (Xai), a competitive inhibitor of factor Xa assembly into the prothrombinase complex, Factor X, or heparin. Animals infused with saline or factor X (300 micrograms/kg) developed total occlusion of the vessel due to a fibrin/platelet thrombus in 70 +/- 11 minutes (36 of 36 animals) and 74 +/- 13 minutes (8 of 8 animals), respectively. In contrast, infusion of Xai prevented thrombus formation completely at a dose of 300 micrograms/kg (8 of 8 animals). As the dose of Xai was decreased, its antithrombotic effect was diminished, with a patency rate of only 2 of 6 animals at a dose of 90 micrograms/kg. Xai at 300 micrograms/kg prevented the accumulation of 125I-fibrinogen/fibrin at the site of the coronary thrombus by approximately 63% and decreased deposition of 111In-labeled platelets by approximately 57%. Hemostatic parameters of animals infused with Xai demonstrated prolongation of the PT and dose-dependent increased extravascular bleeding tendency. These data indicate that factor Xa has a comparably important role in thrombus formation and extravascular hemostasis, and contrast with previous results in this same animal model in which IXai selectively prevented clotting in the coronary vasculature.