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Biomedical subjects

J White

Publications and source records attributed to J White.

At least 217 records · Page 12Linked to original sources
PubMed1998

Preschool behaviour problems in a multicultural Australian urban area.

OBJECTIVE: This paper reports on a survey of behaviour problems in a sample of 4-year-old preschoolers from the western suburbs of metropolitan Melbourne. This region consists of a diverse multicultural population and families from lower socio-economic status (SES) backgrounds. METHODOLOGY: Nineteen preschools participated in the study and information was obtained for 743 preschool children (Refer to MS) age=4.7 years). Parents were asked to complete the Preschool Behaviour Questionnaire (PBQ) and additional questions referring to demographic and family information. Teachers were also asked to complete the PBQ on each of the children. Three factors were extracted from the PBQ (anxious-fearful, hostile-aggressive, hyperactive), and also a combined externalising behaviours factor. RESULTS AND CONCLUSIONS: Findings indicated lower levels of behaviour problems in this sample compared to that of other Australian studies. Boys showed higher rates of externalising behaviour problems than girls. The relationships between behaviour problems and language difficulties, ethnicity, and socio-economic status are discussed.

Australia↗
PubMed1998

Intervention within days for some orbital floor fractures: the white-eyed blowout.

Management of blowout fractures involving the orbital floor has been controversial over the past several decades. One school of thought recommends conservative treatment for 4 to 6 months while another recommends a 'wait and watch' period of 2 weeks before intervention. The authors have encountered a group of patients with such fractures, commonly children (less than 16 years of age), who have sustained a blow to the periocular area, yet have marked motility restrictions in up and down gaze, minimal soft tissue signs of trauma, lack of enophthalmos, and very minimal evidence of floor disruption on radiologic exam. A 2-week waiting period has been found to be of little benefit in these persons and possibly harmful to their motility. We advocate surgery within the first few days after injury as it may help to avoid permanent motility restriction. The authors have termed this entity 'the white-eyed blowout fracture.'

Adolescent↗
PubMed1998

Protein kinase C inhibition improves ventricular function after thermal trauma.

OBJECTIVE: To examine the effect of protein kinase C (PKC) inhibition on cardiac performance and intracellular Ca2+ homeostasis. DESIGN: Previous studies have shown that trauma impairs cardiac mechanical function, and recent studies suggest that PKC activation and subsequent perturbations in Ca2+ sequestration/release contribute to this cardiac dysfunction. In this study, anesthetized guinea pigs were given third-degree scald burns over 43 +/- 1% of the total body surface area and resuscitated with lactated Ringer's solution (LR) 4 mL/kg per percent of burn, Parkland formula. Animals with sham burns served as controls (n = 18). Burns were randomly divided into two groups: LR alone (N = 18) or LR + PKC inhibitor, calphostin C (0.1 mg/kg, intravenous bolus), given 30 minutes and 3, 6, and 21 hours after burn (n = 18). MATERIALS AND METHODS: Cardiac function was assessed by Langendorff preparation 24 hours after burn in 8 to 12 animals per group. Intracellular calcium concentration ([Ca2+]i) was measured in cardiac myocytes (collagenase digestion) from additional animals in each experimental group (n = 5-9 per group) after Fura-2 AM loading of myocytes; fluorescence ratios were measured with a Hitachi spectrofluorometer. RESULTS: Cardiac dysfunction occurred 24 hours after burn in LR burns as indicated by lower left ventricular pressure and a reduced rate of left ventricular pressure rise and fall, +/-dP/dt (61 +/- 3 mm Hg, 1,109 +/- 44 mm Hg/s, and 880 +/- 40 mm Hg/s, respectively) compared with values measured in sham-burned animals (86 +/- 2 mm Hg, 1365 +/- 43 mm Hg/s, and 1183 +/- 30 mm Hg/s, respectively; p < 0.05). Ventricular function curves confirmed significant postburn contractile depression despite aggressive fluid resuscitation. Cardiac injury in burned animals was indicated by an increase in perfusate creatine kinase and lactate dehydrogenase, and Ca2+ dyshomeostasis was confirmed by increased myocyte [Ca2+]i (sham 151 +/- 6 vs. burn 307 +/- 20 nmol/L, p < 0.05). PKC inhibition improved all indices of cardiac performance, producing left ventricular pressure (82 +/- 3 mm Hg), +/-dP/dt (1,441 +/- 48 and 1,294 +/- 32 mm Hg/s), and left ventricular function curves that were comparable with those of sham-burned animals. In addition, [Ca2+]i in calphostin-treated burned animals (154 +/- 11 nmol/L) was identical to values in sham-burned animals. CONCLUSION: Our data suggest that PKC may serve as a final common pathway in signal transduction events mediating postburn cardiac dysfunction.

Animals↗
PubMed1998

Generation and properties of a Streptococcus pneumoniae mutant which does not require choline or analogs for growth.

A mutant (JY2190) of Streptococcus pneumoniae Rx1 which had acquired the ability to grow in the absence of choline and analogs was isolated. Lipoteichoic acid (LTA) and wall teichoic acid (TA) isolated from the mutant were free of phosphocholine and other phosphorylated amino alcohols. Both polymers showed an unaltered chain structure and, in the case of LTA, an unchanged glycolipid anchor. The cell wall composition was also not altered except that, due to the lack of phosphocholine, the phosphate content of cell walls was half that of the parent strain. Isolated cell walls of the mutant were resistant to hydrolysis by pneumococcal autolysin (N-acetylmuramyl-L-alanine amidase) but were cleaved by the muramidases CPL and cellosyl. The lack of active autolysin in the mutant cells became apparent by impaired cell separation at the end of cell division and by resistance against stationary-phase and penicillin-induced lysis. As a result of the absence of choline in the LTA, pneumococcal surface protein A (PspA) was no longer retained on the cytoplasmic membrane. During growth in the presence of choline, which was incorporated as phosphocholine into LTA and TA, the mutant cells separated normally, did not release PspA, and became penicillin sensitive. However, even under these conditions, they did not lyse in the stationary phase, and they showed poor reactivity with antibody to phosphocholine and an increased release of C-polysaccharide from the cell. In contrast to ethanolamine-grown parent cells (A. Tomasz, Proc. Natl. Acad. Sci. USA 59:86-93, 1968), the choline-free mutant cells retained the capability to undergo genetic transformation but, compared to Rx1, with lower frequency and at an earlier stage of growth. The properties of the mutant could be transferred to the parent strain by DNA of the mutant.

Carbohydrate Sequence↗
PubMed1998

Injury in summer rugby league football: the experiences of one club.

OBJECTIVE: To investigate whether the movement of the playing season from winter to summer would alter the risk of injury to players taking part in first team European professional rugby league. METHODS: The study design was a historical cohort design comparing winter and summer seasons in first team European rugby league, which recorded injuries received by players during match play. Each injury was classified according to site, type, player position, activity at the time of injury, and time off as a result of injury. RESULTS: The risk of injury when playing summer rugby league was higher than when playing winter rugby league (relative risk = 1.67 (95% confidence interval 1.18 to 2.17)). Both forwards (1.08 (0.28 to 1.88)) and backs (2.36 (2.03 to 2.69)) experienced an increased risk of injury. CONCLUSIONS: Summer rugby may have resulted in a shift of injury risk factors as exhibited by a change in injury patterns. This may be due to playing conditions, but there were also some law changes. Changes in playing style, team tactics, player equipment, fitness preparation, and the reduced preseason break may also have had confounding effects on injury risk.

Athletic Injuries↗
PubMed1998

Arginine in burn injury improves cardiac performance and prevents bacterial translocation.

This study examined the effects of arginine supplement of fluid resuscitation from burn injury on cardiac contractile performance and bacterial translocation after a third-degree burn comprising 43% of the total body surface area in adult rats. Before burn injury, rats were instrumented to measure blood pressure; after burn (or sham injury), paired groups of sham-burned and burned rats were given vehicle (saline), L-arginine, D-arginine, or N-methyl-L-arginine (300 mg/kg in 0.3 ml of saline 30 min, 6 h, and 23 h postburn) plus fluid resuscitation; sham-burned rats received drug only. Twenty-four hours after burn trauma, hemodynamics were measured; the animals were then killed and randomly assigned to Langendorff heart studies or to studies examining translocation of gut bacteria. Burn rats treated with vehicle, D-arginine, or N-methyl-L-arginine had well-defined cardiocirculatory responses that included hypotension, tachycardia, respiratory compensation for metabolic acidosis, hypocalcemia, cardiac contractile depression, and significant bacterial translocation. Compared with values measured in vehicle-treated burn rats, L-arginine given after burn improved blood pressure, prevented tachycardia, reduced serum lactate levels, improved cardiac performance, and significantly reduced bacteria translocation, confirming that L-arginine administration after burn injury provided significant cardiac and gastrointestinal protection. Circulating neutrophil counts fell after burn trauma and serum glucagon levels rose, but these changes were not altered by pharmacological intervention. Our finding of significantly higher coronary perfusate guanosine 3',5'-cyclic monophosphate concentration in L-arginine-treated burn rats suggests that the beneficial effects of L-arginine were mediated by nitric oxide production.

Animals↗
PubMed1998

Geriatric psychiatry outreach practices in the province of Ontario: the role of the psychiatrist.

OBJECTIVE: To determine the mode of practice of multidiscliplinary and interdisciplinary teams in the field of geriatric psychiatry in the province of Ontario with specific reference to the role of the psychiatrist on the teams. METHOD: Teams were identified, and a simple questionnaire was developed and submitted to every team at an annual conference. RESULTS: Responses were obtained from 38 out of 47 teams. The composition of the teams is variable as regards size and represented discliplines. Nine teams do not have psychiatrists directly affiliated with them. Eighteen teams, 4 of which are based in teaching hospitals, have fewer than 1 full-time equivalent (FTE) psychiatrist. Among these teams, 4 have fewer than 0.1 FTE psychiatrist and 10 have fewer than 0.5 FTE psychiatrist. Eleven teams include between 1 and 1.5 FTE psychiatrists on their staff. Four teams (10.5%) require that the initial assessment of all patients be undertaken by a psychiatrist. In 18 (47%) of the teams, assessment by a psychiatrist can be infrequent or nonexistent. Discussion of the referral with a psychiatrist occurs in the majority of teams, but in a significant minority (10 [27%]), this occurs quite infrequently or not at all. CONCLUSION: Geriatric psychiatry outreach practices in Ontario involve many different disciplines in the assessment and follow-up of geriatric psychiatry patients, often without the ready availability of psychiatric input. We applaud the expanding roles of different disciplines in this practice. We are concerned, however, at the paucity of psychiatrists working in this field.

Aged↗
PubMed1998

Localization of three human polypeptide GalNAc-transferases in HeLa cells suggests initiation of O-linked glycosylation throughout the Golgi apparatus.

O-glycosylation of proteins is initiated by a family of UDP-N-acetylgalactosamine:polypeptide N-acetylgalactos-aminyltransferases (GalNAc-T). In this study, we have localized endogenous and epitope-tagged human GalNAc-T1, -T2 and -T3 to the Golgi apparatus in HeLa cells by subcellular fractionation, immunofluorescence and immunoelectron microscopy. We show that all three GalNAc-transferases are concentrated about tenfold in Golgi stacks over Golgi associated tubular-vesicular membrane structures. Surprisingly, we find that GalNAc-T1, -T2 and -T3 are present throughout the Golgi stack suggesting that initiation of O-glycosylation may not be restricted to the cis Golgi, but occur at multiple sites within the Golgi apparatus. GalNAc-T1 distributes evenly across the Golgi stack whereas GalNAc-T2 and -T3 reside preferentially on the trans side and in the medial part of the Golgi stack, respectively. Moreover, we have investigated the possibility of O-glycan initiation in pre-Golgi compartments such as the ER. We could not detect endogenous polypeptide GalNAc-transferase activity in the ER of HeLa cells, neither by subcellular fractionation nor by situ glycosylation of an ER-retained form of CD8 (CD8/E19). However, upon relocation of chimeric GalNAc-T1 or -T2 to the ER, CD8/E19 is glycosylated with different efficiencies indicating that all components required for initiation of O-glycosylation are present in the ER except for polypeptide GalNAc-transferases.

Base Sequence↗
PubMed1998

Orientation of lumbar pars defects: implications for radiological detection and surgical management.

Lateral oblique radiographs are considered important for the identification of spondylolytic lesions, but these projections will give a clear view only when the radiological beam is in the plane of the defect. We studied the variation in orientation of spondylolytic lesions on CT scans of 34 patients with 69 defects. There was a wide variation of angle: only 32% of defects were orientated within 15 degrees of the 45 degrees lateral oblique plane. Lateral oblique radiographs should not be considered as the definitive investigation for spondylolysis. We suggest that CT scans with reverse gantry angle are now more appropriate than oblique radiography for the assessment of spondylolysis. Variation in the angle of the defect may also need consideration when direct repair is being planned.

Adolescent↗
PubMed1998

C-reactive protein level after total hip and total knee replacement.

Our study has determined the response of C-reactive protein (CRP) after total knee replacement (TKR). The peak level occurs on the second postoperative day and is significantly greater than that after total hip replacement (THR). The level returns to normal at similar times after both procedures. The physiological response to TKR as measured by the area under the CRP/time curve is significantly greater than that after THR. Rising CRP levels after the third postoperative day may indicate a complication of surgery such as infection.

Adult↗
PubMed1997

Anti-CD3 epsilon F(ab')2 fragments inhibit T cell expansion in vivo during graft-versus-host disease or the primary immune response to nominal antigen.

This study was undertaken to distinguish between several mechanisms responsible for graft-vs-host disease (GVHD) protection in anti-CD3epsilonF(ab')2 fragment (Fr)-treated recipients: TCR down-modulation, deletion, failure of expansion, or anergy induction. To quantify alloreactive T cell expansion and function, thoracic duct lymphocytes (TDL) were analyzed. Sixfold fewer donor TDL T cells were recoverable from anti-CD3epsilonF(ab')2 Fr as compared with irrelevant F(ab')2 Fr-treated recipients at the time of peak T cell expansion in vivo. Kinetic analysis revealed that donor T cell expansion was inhibited and not simply delayed by anti-CD3epsilonF(ab')2 Fr. Similar proportions of TDL T cells in irrelevant and anti-CD3epsilonF(ab')2 Fr were undergoing apoptosis. Although TCR modulation was observed, donor TDL T cells had intact anti-host alloresponses as compared with irrelevant F(ab')2 Fr-treated recipients. Because donor CD4+ T cells are primarily responsible for GVHD in this model, an adoptive transfer system was used in which the function and kinetics of expansion of OVA-specific CD4+ TCR transgenic cells could be physically tracked. Relevant Fr severely blunted CD4+ TCR transgenic T cell clonal expansion after OVA administration. Nonviable transgenic and nontransgenic T cells were proportionally similar in OVA-pulsed recipients, regardless of whether relevant or irrelevant F(ab')2 Fr were given. After discontinuing Fr, transgenic T cells were found to have intact in vitro OVA-specific responses. Our current and previous results suggest that reduced donor T cell expansion and T cell depletion both contribute to GVHD protection by anti-CD3epsilonF(ab')2 Fr. These data have implications for designing therapeutic approaches directed toward TCR targeting in humans.

Adoptive Transfer↗
PubMed1997

The role of regional nodal irradiation in the management of patients with early-stage breast cancer treated with breast-conserving therapy.

PURPOSE: To determine the incidence of regional nodal failure (RNF) and indications for regional nodal irradiation (RNI) in patients with Stage I and II breast cancer treated with breast-conserving therapy (BCT). METHODS AND MATERIALS: Four hundred fifty-six patients with Stage I/II breast cancer were treated with BCT at William Beaumont Hospital. All patients underwent excisional biopsy and 288 (63%) were reexcised. A Level I/II ipsilateral axillary lymph node dissection was performed on 431 patients (95%). Pathologically involved nodes were found in 106 (23%) cases (69 with one to three nodes and 37 with > or = four nodes involved). All patients received whole breast irradiation (median dose 50 Gy) and 415 (91%) were boosted to the tumor bed (median total dose 60.4 Gy). Three hundred and sixty (79%) patients received breast alone irradiation and 96 (21%) also received RNI. The median axilla/supraclavicular fossa dose was 50 Gy. RESULTS: With a median follow-up of 83 months, 15 patients developed a RNF for a 5- and 8-year actuarial rate of 3 and 4%, respectively. The 5- and 8-year actuarial rates of axillary failure (AF) were 0.7 and 1.0%, respectively. The incidence of RNF or AF was not affected by the use of RNI in N0 or N1 patients with one to three positive nodes. Only in patients with four or more positive nodes was there a trend towards improved regional control with RNI (p = 0.09). However, patient numbers were extremely small, and this improvement was limited to a reduction in the rate of failure in the supraclavicular fossa (SCF) (20 vs. 0%, p = 0.04). Multiple clinical, pathologic, and treatment related factors were analyzed for an association with AF. On univariate analysis, AF was associated with the number of lymph nodes excised (p < 0.0001) estrogen receptor status (p = 0.0016), and pathologic node status (p = 0.0021). CONCLUSIONS: Regional nodal failure as the first site of failure is uncommon in patients with early-stage breast cancer treated with BCT with < or = three positive lymph nodes and appears unaffected by RNI. For patients with four or more positive lymph nodes, a trend towards improved RNF was noted with RNI, primarily in the SCF. However, patient numbers were extremely small in all subsets analyzed. Additional studies are needed to further define the need for RNI in these patients and help determine other factors associated with RNF.

Adult↗
PubMed1997

The malEFG gene cluster of Streptomyces coelicolor A3(2): characterization, disruption and transcriptional analysis.

The malEFG gene cluster of the Gram-positive mycelial actinomycete Streptomyces coelicolor A3(2) was cloned and sequenced. MalEFG show only limited similarity to homologues involved in maltose and maltodextrin transport in other bacteria. Disruption of malE prevented the utilization of maltose as carbon source. Transcription of malE was induced by maltose and repressed by glucose.

ATP-Binding Cassette Transporters↗
PubMed1997

Changing patterns of case ascertainment and trends in meningococcal disease in England and Wales.

We have reviewed data on meningococcal disease routinely collected in England and Wales from 1989 to 1995 to illustrate and explain changing patterns and guide future surveillance. Statutory notifications of meningococcal meningitis and septicaemia, laboratory confirmed infections, and death registrations coded as meningococcal disease were analysed in terms of their numbers, the age of cases, season of the report, and (if available) site of isolation, serogroup, and serotype. Case fatality rates were estimated for clinically diagnosed and culture confirmed cases. The number of cases notified each year, in particular those notified as septicaemia, rose significantly over the period (p < 0.0001) but there was no net change in the number of culture confirmed cases. Case fatality rates estimated from routine data fell, most markedly for cases notified as septicaemia, but the true case fatality rate of culture confirmed cases did not change between 1993 and 1995. These data suggest that reporting practice changed between 1989 and 1995 and that the ascertainment of clinically diagnosed disease improved, particularly for meningococcal septicaemia. Late in 1995, reports from all data sources increased and the age distribution of both notified and laboratory confirmed cases changed. These changes were accompanied by an increase in the proportion of infections due to Neisseria meningitidis of serogroup C and a significant increase in serotype C2a infections (p < 0.0001). Continuing efforts to reconcile data from several sources will be needed to ensure that routine data can be interpreted accurately to provide evidence for the development of future vaccination policy and to monitor vaccination programmes. In addition, the role of non-culture diagnosis will be crucial in enhancing surveillance based on clinical diagnoses.

Adolescent↗
PubMed1997

Long-term outcome with interstitial brachytherapy in the management of patients with early-stage breast cancer treated with breast-conserving therapy.

PURPOSE: We reviewed our institution's experience with interstitial implant boosts to determine their long-term impact on local control and cosmetic results. METHODS AND MATERIALS: Between January 1, 1980 and December 31, 1987, 390 women with 400 cases of Stage I and II breast cancer were managed with breast-conserving therapy (BCT) at William Beaumont Hospital. All patients were treated with an excisional biopsy and 253 (63%) underwent reexcision. Radiation consisted of 45-50 Gy external beam irradiation to the whole breast followed by a boost to the tumor bed to at least 60 Gy using either electrons [108], photons [15], or an interstitial implant [277] with either 192Ir [190] or 125I [87]. Long-term local control and cosmetic outcome were assessed and contrasted between patients boosted with either interstitial implants, electrons, or photons. RESULTS: With a median follow-up of 81 months, 25 patients have recurred in the treated breast for a 5- and 8-year actuarial rate of local recurrence of 4 and 8%, respectively. There were no statistically significant differences in the 5- or 8-year actuarial rates of local recurrence using either electrons, photons, or an interstitial implant. Greater than 90% of patients obtained a good or excellent cosmetic result, and no statistically significant differences in cosmetic outcome were seen whether electrons, photons, or implants were used. CONCLUSIONS: We conclude that patients with Stage I and II breast cancer undergoing BCT and judged to be candidates for boosts can be effectively managed with LDR interstitial brachytherapy. Long-term local control and cosmetic outcome are excellent and similar to patients boosted with either electrons or photons.

Adult↗