Regeneration in higher vertebrates: limb buds and digit tips.
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Animals↗
Biomedical subjects
G Taylor
Publications and source records attributed to G Taylor.
Neuroleptic influences on a lateralized behavioral bias in unoperated rats.
RATIONALE: Abnormalities of the ascending dopaminergic system have been associated with hemineglect, and evidence suggests that neuroleptic treatments normalize the right hemispatial attentional impairment that is sometimes observed in acutely psychotic schizophrenic patients. OBJECTIVE: A research program was initiated to develop an animal model of hemineglect-drug interactions. METHODS: Female rats were tested repeatedly on removing a "nuisance stimulus" - strips of surgical tape applied loosely to the forelimbs. Subjects were assigned to groups dependent upon showing a behavioral orientation preference (BOP) during pre-drug baseline tests. Animals representing left-BOP, right-BOP and no preference continued to be tested during chronic exposure either to a dopamine antagonist (0.05 mg haloperidol/kg) or agonist (1.0 mg d-amphetamine/kg) or vehicle only. RESULTS: Three weeks of haloperidol treatments to rats only with an initial right BOP gradually eliminated the response bias, as revealed by declines in choosing the right forepaw and the latencies between attending to the two forepaws. CONCLUSION: The results recommend right BOP female rats as a simple, non-invasive behavioral animal model for evaluating and comparing neuroleptic medications.
Amphetamine↗
Metanephric adenoma of the kidney: a case report.
Metanephric adenoma (MA) of the kidney is an uncommon benign epithelial tumor of the kidney that presents at any age. The histology of the lesion is well established, but the imaging findings have been described in only a few cases. We report the sonographic and computed tomographic appearance of MA in a 9-year-old girl to increase awareness among radiologists of this entity. Its recognition may facilitate nephron-sparing surgery.
Adenoma↗
CT-guided percutaneous needle biopsy of small lung nodules in children.
Malignant pulmonary nodules in a patient with neoplasia alters clinical staging and therapy. Although it may be difficult, it is imperative to obtain a tissue diagnosis of such nodules. We describe a coaxial technique using controlled respirations, which we have found useful for biopsy of small pulmonary nodules in children. Clinical records, imaging and pathology (histology and cytology) were reviewed for 17 children who had 18 nodules biopsied in the method described. A diagnosis of malignant or benign tissue was made in 15 nodules. One biopsy was inadequate and there was one false-negative. Adequate cores were obtained in 15 nodules, cytology in 2 and inadequate material in 1. There was no significant morbidity.
Adolescent↗
Eosinophilic cystitis following an infected urachal remnant.
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Child, Preschool↗
Tubulointerstitial nephritis and uveitis in children and adolescents. Four new cases and a review of the literature.
We identified 35 cases of tubulointerstitial nephritis and uveitis (TINU), 31 from a MEDLINE search (1966-1996) of the English literature and 4 from our hospital records (1988-1996). To meet the case definition, the patient had to be less than 18 years old and have TINU of unknown cause. Common presenting symptoms included fatigue, weight loss, fever, and abdominal pain. The uveitis was usually anterior and could occur at any time with respect to the onset of the renal disease. Common laboratory features included anemia, increased erythrocyte sedimentation rate, and decreased creatinine clearance. Most patients (33 of 35) had renal biopsies that commonly revealed an intense inflammatory interstitial infiltrate, glomerular sparing, and negative immunofluorescence studies. Of the 35 patients, 26 received systemic corticosteroid therapy (5 of 26 for eye disease); 22 had follow-up for at least 1 year; 13 of 35 patients had a recurrence of their uveitis. The outcome in all 35 cases was normal renal function with no documented visual loss. In conclusion, TINU is a unique syndrome with characteristic clinical features, laboratory changes, and renal biopsy results. Treatment is controversial, and the outcome in children, even if untreated, is excellent.
Adolescent↗
Baseline fruit and vegetable intake among adults in seven 5 a day study centers located in diverse geographic areas.
OBJECTIVE: To examine baseline rates of fruit and vegetable consumption among adults in the 5 A Day research trials in order to identify any regional and sociodemographic differences associated with daily servings. DESIGN: The main outcome measure was the frequency of fruits and vegetables consumed within 1 month of the baseline survey as assessed by a 7-item food frequency questionnaire (FFQ). SUBJECTS/SETTING: Participants (N = 15,060) were from 7 study centers. Study centers included schools (N = 48), worksites (N = 60), churches (N = 50), or the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) clinics (N = 15) in interventions to increase fruit and vegetable consumption. STATISTICAL ANALYSES: Means and standard errors, adjusting for clusters, were calculated. A mixed linear model analyzed relationships between fruit and vegetable consumption and regional center, gender, age, race, education, income, marital status, food-shopping responsibility, and whether one lives with children. RESULTS: Results indicate an overall mean intake of 3.6 daily servings of fruits and vegetables. Significant differences in mean daily servings were found among the regional study centers (low of 3.0 to high of 4.1). There were significant differences in mean daily consumption by age (< 30 years = 3.7 servings per day; 30 to 49 years = 3.4; > or = 50 years = 3.7), education (> high school = 3.4 servings per day; high school graduate = 3.4; some college = 3.5; college graduate = 3.9), race (black = 3.7 servings per day; Hispanic = 3.0; white = 3.6; other = 3.7), marital status (married = 3.6 servings per day; single = 3.5), and food-shopping responsibilities (little = 3.2 servings per day; about half = 3.6; most = 3.8). Only 17% of respondents ate 5 or more servings of fruits and vegetables per day. CONCLUSIONS: The 7 regions showed significant variability in daily fruit and vegetable consumption, suggesting that a single national message to increase fruit and vegetable consumption may not reach the population segments most in need of changing. It is advisable to spend more time understanding the food consumption habits of the population under investigation to develop messages to foster behavior change.
Adolescent↗
Tissue engineering of autologous aorta using a new biodegradable polymer.
BACKGROUND: Ovine pulmonary valve leaflets and pulmonary arteries have been tissue-engineered (TE) from autologous cells and biodegradable polyglycolic acid (PGA)-polyglactin copolymers. Use of this cell-polymer construct in the systemic circulation resulted in aneurysm formation. This study evaluates a TE vascular graft in the systemic circulation which is based on a new copolymer of PGA and polyhydroxyalkanoate (PHA). METHODS: Ovine carotid arteries were harvested, expanded in vitro, and seeded onto 7-mm diameter PHA-PGA tubular scaffolds. The autologous cell-polymer vascular constructs were used to replace 3-4 cm abdominal aortic segments in lambs (group TE, n = 7). In a control group (n = 4), aortic segments were replaced with acellular polymer tubes. Vascular patency was evaluated with echography. All control animals were sacrificed when the grafts became occluded. Animals in TE group were sacrificed at 10 days (n = 1), 3 (n = 3), and 5 months (n = 3). Explanted TE conduits were evaluated for collagen content, deoxyribonucleic acid (DNA) content, structural and ultrastructural examination, mechanical strength, and matrix metalloproteinase (MMP) activity. RESULTS: The 4 control conduits became occluded at 1, 2, 55, and 101 days. All TE grafts remained patent, and no aneurysms developed by the time of sacrifice. There was one mild stenosis at the anastomotic site after 5 months postoperatively. The percent collagen and DNA contents approached the native aorta over time (% collagen = 25.7%+/-3.4 [3 months] vs 99.6%+/-11.7 [5 months], p < 0.05; and % DNA = 30.8%+/-6.0 [3 months] vs 150.5%+/-16.9 [5 months], p < 0.05). Histology demonstrated elastic fibers in the medial layer and endothelial specific von Willebrand factor on the luminal surface. The mechanical strain-stress curve of the TE aorta approached that of the native vessel. A 66 kDa MMP-2 was found in the TE and native aorta but not in control group. CONCLUSIONS: Autologous aortic grafts with biological characteristics resembling the native aorta can be created using TE approach. This may allow the development of "live" vascular grafts.
Animals↗
Contribution of advances in immunology to vaccine development.
During the last 10 years, investigation of the bovine immune system has generated knowledge and reagents that can now be applied to study the mechanisms of immunity to disease and the identity of antigens recognized by protective immune responses. Such studies can indicate which antigens are likely to be effective in subunit vaccines and also highlight the type of antigen delivery system that will be required for a vaccine to induce a protective immune response. In the case of bovine RSV, studies of immune responses in the target host have demonstrated that both antibody and CTL responses play an important role in immunity. Both the F and G glycoproteins have been identified as targets of protective antibodies, and systems have been established that will allow the identification of the viral antigens recognized by CTL. Further studies of CD4+ T-cell responses to the virus are required to determine whether or not components of the response have the potential to enhance disease and, therefore, need to be avoided in vaccination strategies.
Allergy and Immunology↗
No change in O2 saturation but measurable difference in thenar flexor power after radial artery harvest.
OBJECTIVES: Objective measures of morbidity will be required to establish the radial artery (RA) as a viable long term alternative to saphenous vein. The RA is the dominant arterial supply to the thenar musculature. We hypothesised that RA harvest should decrease O2 saturation and thenar muscle power. METHODS: RA was harvested from non-dominant (ND) limbs only (left n = 58, right n = 21). Oximeter values of O2 saturation were taken from the thumb of the dominant (D) and non-dominant (ND) limb pre and post operatively. A syringe filled with 25 cc of air is emptied against a one way valve connected to a pressure generator MX 100 by MEDEX, Inc, Ohio, USA. Three measures of thenar flexor power (TFP) were taken and mean values obtained in the ND and D limbs. RESULTS: O2 saturation ranged from 92 to 98% in the thumb of the ND limbs 24 h post RA harvest. The values for TFP (mean +/- SD) were 1246 +/- 246 mmHg (ND) and 1240 +/- 258 mmHg (D) pre-operatively and 1216 +/- 250 (ND) and 1259 +/- 233 (D) post operatively. The changes in TFP between the ND and D limbs (37.0 +/- 60.6 ND and 1.86 +/- 65.9 D) were significant for the D against the ND limb (P < 0.001). This reduction in TFP for the harvested limb was also found when considering handedness (28.0 +/- 24.2 and 40.3 +/- 69.2 for the left and right handed patients respectively). CONCLUSION: Our findings confirm the hypothesis that there are objective differences in TFP pre and post RA harvest at 3 months. Further studies are required to assess the clinical significance and persistence of the loss of TFP.
Adult↗
Clinical scale isolation of highly purified peripheral CD34+progenitors for autologous and allogeneic transplantation in children.
We present our experience with three clinical scale isolation methods for positive selection of CD34+ progenitors from peripheral blood for autologous and allogeneic transplantation in children. A combination of the CellPro device and the Magnetic Activated Cell Sorting system (MACS), as well as two different combinations of MACS systems were used (VarioMACS-SuperMACS and SuperMACS-SuperMACS). With the CellPro-MACS combination (16 separations), a median purity of 96.2% and a median recovery of 42% CD34+ cells could be achieved, whereas the two step MACS systems (55 and 29 separations) showed a median purity of 97.6% and 98.0% and a median recovery of 96.5% and 97%, respectively. Depletion of T cells was profound (4-5 log). A total of 34 patients in the autologous and 18 patients in the allogeneic setting have been transplanted with highly enriched CD34+ cells, obtained by these methods. Only one patient failed to engraft, all other patients showed a rapid and sustained hematological engraftment with the longest follow-up of 3 years. In summary, especially the two step MACS systems have proven to be appropriate tools for enrichment of CD34+ cells, yielding both high purity and good recovery, and can thus be used for tumor cell purging in the autologous setting and for effective T cell depletion in the allogeneic setting.
Adolescent↗
The emerging needs of persons living with haemophilia and HIV/AIDS in British Columbia.
The Haemophilia Programme Enhancement Project (HPEP) was initiated in 1991 to assist Haemophilia Programme staff meet the increasing and complex needs of persons living with haemophilia and HIV/AIDS. A review of the HPEP in 1997 revealed that the needs of this population have changed due to the advances in medical treatment, laboratory monitoring and the proliferation of HIV/AIDS expertise and resources. Continued roles for the HPEP include triage and liaison with HIV specialists to ensure appropriate care, given the possible haematological complications that coexist with HIV and/or liver disease. Access to resources remains problematic for those living in remote regions of British Columbia, and a strong advocacy presence is needed. Services to families and children of persons with HIV and haemophilia is required, especially around disclosure and preparation for the stresses incurred during hospitalization. The fact that many long-term survivors are living in relatively good health has sparked renewed optimism amongst this group. Those who continue to do well are in the process of re-evaluating their lives and may need assistance in establishing both short- and long-term goals. Interventions to sustain hope could include individual and family counselling, facilitated support meetings and a commitment to the provision of vocational rehabilitation counselling, re-training and job placement. For the first time in years, many persons living with haemophilia and HIV are facing an opportunity to look forward into the future and devise ventures which will enhance their feelings of productivity.
Acquired Immunodeficiency Syndrome↗
Phenotypic analysis of local cellular responses in calves infected with bovine respiratory syncytial virus.
Changes in lymphocyte subsets in the trachea, pulmonary tissue, bronchoalveolar lavage (BAL), peripheral blood and bronchial lymph node (BLN) of gnotobiotic calves infected with bovine respiratory syncytial virus (BRSV) were analysed by flow cytometry. Following BRSV infection, virus titres in the nasopharynx reached a peak between days 5 and 7 and infection was resolving from day 10. Although calves did not develop signs of clinical respiratory disease, there was evidence of gross pneumonia and histological changes typical of BRSV bronchiolitis, which were most extensive from day 710 of infection. Following BRSV infection there was a recruitment of CD8+ T cells into the trachea and lung, which peaked on day 10 after infection. Thus, there were approximately equal numbers of CD8+ and CD4+ T cells in the lung and trachea of uninfected calves, whereas by day 10 of infection, CD8+ cells outnumbered CD4+ cells by 3:1 in the lungs and 6:1 in the trachea of the infected calves. Although the increase in CD4+ T cells into the lungs was less marked than that of CD8+ T cells, changes in expression of CD45R, CD45RO, L-selectin and interleukin-2 receptors all suggested that CD4+ T cells were activated during BRSV infection. Changes in gamma delta T cells were not observed in BRSV-infected calves. There was a marked increase in B cells in the BLN after infection and BLN CD4+ T cells changed from the majority expressing L-selectin and CD45R in uninfected calves to a predominance of L-selectin- CD45R- CD45RO+ phenotype, 10 days after infection. In conclusion, CD8+ T cells constitute the major lymphocyte subpopulation in the respiratory tract of calves recovering from BRSV infection.
Animals↗
A qualitative study of pre-registration house officers in general practice.
OBJECTIVES: To evaluate a unique pre-registration house officer (PRHO) rotation involving half a week in general practice over a 4-month period. House officers' and supervisors' views were sought on the value of this type of rotation. DESIGN: Qualitative study using semi-structured interviews. SETTING: A four-partner postgraduate training practice in a deprived urban part of North-east England. SUBJECTS: Pre-registration house officers and supervisors. RESULTS: House officers gained in educational and clinical terms from their period in general practice. They had a high level of individual supervision and teaching and encountered a wider spectrum of illness than in hospital. They found certain aspects of general practice stressful. The supervision required was greater than that needed for a registrar. The supervision of house officers requires support and possibly further education for the supervisor. CONCLUSIONS: General practice can provide valuable supervised experience at this stage of a doctor's career.
Communication↗
Cross-Canada spread of methicillin-resistant Staphylococcus aureus via transplant organs.
We report our investigation of the transmission of methicillin-resistant Staphylococcus aureus (MRSA) through transplantation. The kidneys, liver, and corneas were harvested from a child who died in Nova Scotia. Several days postmortem it was learned that culture of a premortem endotracheal tube aspirate from the donor yielded MRSA. Both kidneys were transplanted into a child in Nova Scotia and the liver into a child in Alberta. Both recipients subsequently became blood culture-positive for MRSA. One corneal ring from the donor was MRSA-positive. All four MRSA isolates were mecA-positive by polymerase chain reaction (PCR). The relatedness of the MRSA isolates was examined by restriction fragment length polymorphism (RFLP) analysis, a 16S-23S ribosomal PCR typing method, and comparison of antibiograms. Results were identical for all four MRSA isolates. These findings indicate that MRSA from the donor was transferred to recipients during implantation of harvested organs in Alberta and Nova Scotia, a cross-Canada spread.
Adolescent↗
Isolation of highly purified autologous and allogeneic peripheral CD34+ cells using the CliniMACS device.
The CliniMACS CD34+ selection device was used for positive selection of apheresis products for autologous transplantation from 10 patients with malignant diseases and for allogeneic transplantation from 26 healthy donors. A total of 71 separations were performed. In 1 allogeneic donor, CD34+ progenitors were also isolated from bone marrow. Between 0.27 and 8.9 x 10(10) nucleated cells (median 4.9 x 10(10)) containing 0.09%-10.8% (median 0.67%) CD34+ progenitor cells were separated. After separation, a median number of 227 x 10(6) mononuclear cells (MNC) (51-524) were recovered, with a median viability of 99% (22%-100%) and a median purity of 97.0% (68.3%-99.7%) CD34+ cells. Depletion of T cells was extensive, with a median of 0.04% residual CD3+ cells (range <0.01%-0.92%). Residual CD19+ cells were between <0.01% and 17%, including CD34+CD19+ cells. Recovery of CD34+ cells was calculated according to the ISHAGE guidelines and ranged from 24% to 105% (median 71%). We conclude that with the CliniMACS device CD34+ cells with high purity and recovery can be isolated with concomitant effective T cell depletion in the allogeneic setting and with a high purging efficacy in the autologous setting.
Antigens, CD34↗
Adult ontogeny of rat working memory of social interactions.
BACKGROUND: Social memory has features that may make it uniquely appropriate for studying normal aging. We used a cross-section experimental design with an animal model to survey the lifetime adult ontogeny of memory of a brief social interaction. METHODS: Groups of healthy adult male rats representing young adulthood (5 months), middle age (10 months), or old age (19-27 months) were tested weekly over a month in two paradigms. Basic social memory and social interference memory were quantified by differences between investigation times of a juvenile rat during a 5-min interaction (acquisition trial) and a second exposure (recall testing), with interexposure intervals (IEI) ranging from 15 min to 24 h. RESULTS: Although basic social memory of all age groups was similar at the brief or longer IEI, there were memory declines at intermediate IEI delays in older males, especially the oldest groups. Decrements to working memory appeared as early as middle-age when an unfamiliar juvenile was inserted between acquisition and recall testing. Nonetheless, our healthy old animals retained a robust ability to recall identity of a conspecific that a minute by minute comparison suggested involves similar behavioral means of gathering social information. CONCLUSIONS: Normative aging of working social memory in male rats can be characterized as being more fragile, beginning at middle age but without significant further decline until near the end of the life span. Functional impact of these age-dependent changes in social memory, on the other hand, may be minimal for all but the very oldest animals in the social group.
Aging↗
Analysis of chromosome 22q as an aid to the diagnosis of rhabdoid tumor: a case report.
Malignant rhabdoid tumor is a highly aggressive tumor of childhood that may present as a soft-tissue primary tumor. We report a soft-tissue neoplasm that was polyphenotypic by immunohistochemical expression of epithelial, mesenchymal, and neural markers and did not meet the criteria for any of the usual pediatric small round-cell tumors. The findings raised the diagnosis of rhabdoid tumor, leading to testing for WT1 mRNA and protein expression, which were positive, as has been reported for renal rhabdoid tumor. This tumor had the typical clinical behavior of rhabdoid tumor with therapy resistance and early tumor-related death. Multicolor spectral karyotyping of this neoplasm showed a balanced translocation between chromosomes 1 and 22 with breakpoints at 1p36 and 22q11-12. The latter region is commonly involved in rhabdoid tumor. This change was also identified by fluorescence in situ hybridization. This case suggests that studies of chromosome 22 may be required to distinguish rhabdoid tumor from other soft-tissue tumors.
Chromosomes, Human, Pair 22↗