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J Worrall

Publications and source records attributed to J Worrall.

10 recordsLinked to original sources
PubMed1998

Metal wear particle characterization from metal on metal total hip replacements: transmission electron microscopy study of periprosthetic tissues and isolated particles.

The less intense tissue reaction around metal on metal total hip replacements (THRs) compared to metal on polyethylene (PE) THRs may be explained by the differences in the characteristics of metal wear particles. In this study, transmission electron microscopy was used to study metal wear particles that were either in situ in cells or had been extracted from the cells by a new technique based on enzymatic tissue digestion. The tissues were obtained from 13 patients undergoing revision of metal on metal THRs with cobalt-chromium-molybdenum (CoCrMo) bearing couples. Most of the CoCrMo wear particles were smaller than 50 nm (range 6-834 nm) and round to oval in shape with irregular boundaries. This size range is considerably smaller than that reported for PE particles. While even a small volume of metal wear will produce high numbers of particles, the apparently less severe local tissue reaction to metal particles may be due to the possibility that corrosion, dissolution, and dissemination of metal particles may result in fewer local biological effects than the long-term retention of PE particles in the periprosthetic tissues.

Adult↗
PubMed1995

Effect of diabetes and peritonitis on the peritoneal equilibration test.

Peritoneal equilibration tests (PET) were performed on 47 patients (15 diabetics) who had been on CAPD for 1 to 112 months. Among new patients on CAPD (1 to 3 months) with no history of peritonitis, diabetics had higher D/PCr than non-diabetics (P < 0.02). However, after > or = 7 months of CAPD, in patients with < or = 2 episodes of peritonitis, glucose and creatinine transport rates were lower (P < 0.05) in diabetic than non-diabetic patients. Among patients on CAPD for > or = 7 months, creatinine (P < 0.05) and glucose transport (P < 0.01) were higher in patients with a history of > or = 3 episodes of peritonitis than in those with < or = 2 episodes. Drain volumes did not differ between any of the subgroups (all P > 0.05). The observations in patients newly established on CAPD were substantiated in a larger study of 55 non-diabetic and 35 non-insulin dependent diabetic patients. D/D0 glucose correlated with plasma glucose (r = 0.40, P < 0.02) in the diabetic group. Net ultrafiltration was reduced in hyperglycemic (P = 0.022) but not normoglycemic diabetics (non-diabetics 231 +/- 167 ml, hyperglycemic diabetics 127 +/- 177 ml, normoglycemic diabetics 238 +/- 159 ml). Creatinine clearance was higher in normoglycemic (P = 0.02) but not hyperglycemic diabetics (non-diabetics 6.8 +/- 0.9 ml/min, hyperglycemic diabetics 6.9 +/- 0.8 ml/min, normoglycemic diabetics 7.4 +/- 0.7 ml/min). These data show that diabetes and peritonitis incidence should be borne in mind when interpreting results of the PET.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

An effect of gravity on bud-burst in balsam fir.

Bud-burst on first order lateral branches of Abies bafsamea L. (balsam fir) was delayed when the branches were rotated 180 degrees about their long axis. This was not a consequence of injury caused by the treatment because buds rotated 180 degrees on inverted plants flushed at the same time as the controls, whereas flushing of all other buds was delayed. Buds thus appear to be more vigorous when maintained in the same orientation to gravity in which they are formed and the site of gravitational stimulus perception appears to be the bud itself. Except on the leading shoot, leaves from inverted buds turned so that their adaxial surface faced upward, unless there was intense illumination from below. However, both anisophylly and positioning of leaves on lateral shoots were apparently predetermined because the shorter, more forward pointing leaves appeared below the longer distichous leaves on shoots from inverted buds. Shoots with normally oriented leaves appeared the next season.

Journal Article↗
PubMed1979

Comparison of radioimmunoassay with homogeneous enzyme immunoassay for the determination of theophylline concentration in serum.

The homogeneous enzyme immunoassay (EMIT) and radioimmunoassay (RIA) procedures for the quantitation of theophylline concentrations in serum were evaluated and compared. Both methods exhibited curves linear over the therapeutic range (range of concentration, 2.0-33.0 microgram/ml). Precision was acceptable for both methods with the coefficient of variation being less than 8.3%. The RIA procedure was found to be slightly more precise. The correlations between the EMIT and RIA procedures was found to be sufficient to allow the procedures to be used interchangeably. This would facilitate the test availability on a 24 hr, 7 day basis.

Humans↗
PubMed1976

Evaluation of a discrete-sample computer-directed clinical analyzer.

The operational characteristics of the Gilford System 3500 were evaluated for six months as to accuracy, precision, carry-over, reliability, and ease of operation. Accuracy was evaluated by comparison to manual methods of established accuracy. The tests evaluated and their respective correlation coefficients are as follows: glucose (0.99), blood urea nitrogen (0.99), calcium (0.97), total bilirubin (0.99), aspartate aminotransferase (0.97), alkaline phosphatase (0.98), albumin (0.96), and total protein (0.96). Within-run precision (CV) for three commercial calibration sera of differing analyte concentrations (low, intermediate, and high) were respectively: 0.69, 1.02, 1.18; 5.4, 1.2, 1.09; 0.83, 0.77, 0.86; 5.9, 1.0, 0.86; 6.4, 5.2, 2.1; 3.7, 1.5, 1.3; 0.0, 1.4, 0.97; and 1.2, 1.3, 0.75. Day-to-day precision, similarly evaluated during 101-164 days, met accepted criteria for clinically acceptable precision. Carry-over for each of the eight tests was less than 1%. Instrument reliability has been excellent, and training time is short. In summary, we have found the Gilford System 3500 to be sufficiently precise and fast, easy to operate, highly accurate, and flexible.

Alkaline Phosphatase↗
PubMedDate not supplied

Kinship care of the abused child: the New Zealand experience.

The concept of continuity--keeping children within their own kinship, community, and cultural networks--has found international favor in contemporary child welfare practice. This principle is reflected in the 1989 New Zealand Children, Young Persons, and Their Families Act. The Act represents a significant shift--from the state to the family--in responsibility for children in need of care. The increasing use of the Family Group Conference process allows families to make decisions about the future of kin children and reflects the belief that, although most abuse is intrafamilial, the family will also be the most committed to keeping the child safe. Other countries have adapted this model to suit their own cultural child welfare needs. The international trend toward formal use of kinship care for children who have suffered abuse or neglect is likely to continue as foster care resources shrink. Drawing on qualitative research, this article describes the experiences of caregivers and their kin children who have been the subject of a care and protection order.

Child↗