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Biomedical subjects

D J Berry

Publications and source records attributed to D J Berry.

At least 73 records · Page 4Linked to original sources
PubMed1994

Catastrophic failure of the polyethylene liner of uncemented acetabular components.

Ten cases are described of catastrophic failure of the polyethylene liner of three different designs of uncemented acetabular component. Failure occurred as a result of either 'wearthrough' to the metal backing, liner fracture or a combination of both, at a mean of 4.6 years after implantation (2 to 7.6). At revision there was metallosis in all hips and osteolysis of the femur or the pelvis in six. Catastrophic failure was seen only in cups with a minimum polyethylene thickness of less than 5 mm.

Acetabulum↗
PubMed1993

Pharmacokinetics of single oral doses of feprazone in patients with rheumatoid arthritis or with impaired renal clearance.

1. The pharmacokinetics of feprazone have been studied in 10 patients with rheumatoid arthritis (RA), and in a further six patients with renal impairment (RI) who were not suffering from rheumatoid disease. 2. For RA patients, the mean elimination half-life (t1/2) of feprazone after a single oral dose was 21 +/- 5 h (SD), the mean apparent clearance (Cl) was 0.012 +/- 0.009 l/h per kg, and the mean apparent volume of distribution (Vd) was 0.33 +/- 0.17 l/kg. Corresponding values for RI patients were 25 +/- 13 h, 0.016 +/- 0.011 l/h per kg, and 0.46 +/- 0.24 l/kg, respectively. 3. These results show no impairment of the elimination of feprazone in RA or RI patients; Vd and Cl are greater than in healthy young volunteers or elderly subjects, the AUC values are lower, but t1/2 values are similar in all groups. 4. It is suggested that the greater Cl and Vd, and lower AUC, in RA and RI patients may be due to renal insufficiency and decreased plasma protein binding of feprazone and its metabolite, or to induction of glucuronyl transferase activity by the prior medication, thus enhancing the formation of the major metabolite, the C(4)-glucuronide, and increasing drug elimination.

Administration, Oral↗
PubMed1993

Extensive osteolysis around an aseptic, stable, uncemented total knee replacement.

Extensive osteolysis occurred around an aseptic, well-fixed, stable, uncemented total knee prosthesis. At the time of revision, tibial polyethylene wear and minimal metal-on-metal contact were present. A hypertrophic synovium-like membrane abutted bone in regions of osteolysis. Examination of this membrane revealed polyethylene-wear debris and significant levels of chromium, cobalt, and titanium. Wear debris--polyethylene, metal, or a combination of both--may be responsible for the osteolytic process in this case.

Bone Cements↗
PubMed1993

Chevron osteotomy and single wire reattachment of the greater trochanter in primary and revision total hip arthroplasty.

Even at a medical center where hip arthroplasty is performed routinely without trochanteric osteotomy, selected arthroplasties still require greater trochanteric osteotomy. A technique of greater trochanteric biplane osteotomy and reattachment with one wire is described. The technique provides maximum stability with a minimum of internal fixation and it can be performed quickly. The postoperative rehabilitation protocol is the same as that used in hip arthroplasty patients without trochanteric osteotomy. Results with a minimum two-year follow-up period disclosed osseous union in 98% of 53 primary arthroplasties and 97% of 74 revision hip arthroplasties. Problems related to the greater trochanter necessitated reoperation in only two patients: one for reattachment of a migrated trochanter and one for trochanteric wire removal.

Arthroplasty↗
PubMed1993

Isolated patellar component revision of total knee arthroplasty.

Forty-two knees in 41 patients required isolated patellar component revision of a total knee arthroplasty (TKA). Revision was performed for loosening in 14 knees, wear to metal backing in 13, fracture of the fixation peg in seven, dissociation of polyethylene from metal backing in two, anterior knee pain in two, patellar instability in two, and component malposition with fat pad proliferation in two. Thirty-six knees were evaluated two to eight years after patellar revision. The Hospital for Special Surgery knee scores improved from an average of 71 preoperatively to 81 postoperatively. Eighteen knees were excellent; 12, good; four, fair; and two, poor. Complications associated with patellar revision included late patellar fractures in five knees, patellar instability in three, peroneal nerve palsies in two, patellar polyethylene wear to metal backing in two, infection in one, and extensor lag in one. This seemingly straight-forward procedure is associated with a high complication rate.

Adult↗
PubMed1992

Revision arthroplasty using an anti-protrusio cage for massive acetabular bone deficiency.

Revision hip arthroplasty in patients with massive acetabular bone deficiency has generally given poor long-term results. We report the use of an 'anti-protrusio cage', secured to the ischium and ilium, which bridges areas of acetabular bone loss, provides support for the acetabular socket, and allows pelvic bone grafting in an environment protected from excessive stress. Forty-two failed hip arthroplasties with massive acetabular bone loss were revised with the Burch-Schneider anti-protrusio cage and evaluated after two to 11 years (mean five years). There was failure due to sepsis in five hips (12%) and aseptic loosening in five (12%); the remaining 32 hips (76%) showed no evidence of acetabular component failure or loosening.

Acetabulum↗
PubMed1991

Evidence for localized calcium mobilization and influx in single rat gonadotropes.

Dynamic video-imaging microscopy was used to investigate the spatial and temporal nature of Ca2+ mobilization and Ca2+ influx in acutely dissociated, fura-2-loaded, rat gonadotropes. Addition of luteinizing hormone-releasing hormone (LHRH) to an isolated gonadotrope stimulated a wave of Ca2+ originating from a specific locus of the cell. This probably reflects Ca2+ mobilization from an intracellular store, since this response was unaffected by the removal of extracellular Ca2+. Application of the dihydropyridine-sensitive Ca2+ channel agonist Bay K 8644 (Bay K) stimulated a rise in cytosolic free Ca2+ concentration in the rat gonadotrope. This response was blocked by the removal of extracellular Ca2+ and probably reflects the influx of Ca2+ across the cell membrane. High speed (30 frames.s-1) imaging of the Bay K-induced Ca2+ influx revealed a wave of Ca2+ originating from a localized part of the cell membrane, which, in general, was spatially distinct from the LHRH-induced Ca2+ wave produced in the same cell. This suggests that Ca2+ channels in the cell membrane may be clustered in a specific area of the cell membrane. The velocity of the LHRH-induced Ca2+ mobilization wave was faster (mean = 79 +/- 5 microns.s-1, n = 9) than the Bay K-induced Ca2+ influx wave (39 +/- 7 microns.s-1, n = 9) (p less than or equal to 0.01, Wilcoxon signed rank test) measured in the same cells. Thus, both Ca2+ mobilization from intracellular stores and Ca2+ influx through the cell membrane appear to be spatially localized in the rat gonadotrope. These findings may have important implications in the intracellular regulation of Ca(2+)-dependent cell functions such as hormone biosynthesis and secretion.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1991

An evaluation of the national measles vaccination campaign in the new shanty areas of Khayelitsha.

A local component of the national measles vaccination campaign was evaluated in an area undergoing rapid urbanisation near Cape Town. Four serial cross-sectional cluster samples were used. Proven vaccination coverage before the campaign was 55.8% (95% confidence interval (CI) 46-66%), immediately afterwards it was 71.1% (95% CI 65-77%), and 6 months later 73.6% (95% CI 67-80%). The increase was not sustained among Transkei-born children. Significant determinants of vaccination coverage were: place of birth (chi 2 = 9.7; 2 df; P = 0.008); less than or equal to 6 months stay in Cape Town (odds ratio (OR) 2.22; 95% CI 1.2-4.0%); and home birth (OR 3.21; 95% CI 1.2-8.4%). The value of campaigns in controlling measles, as well as the role of a comprehensive health care service are discussed.

Child, Preschool↗
PubMed1991

Measles control in the urbanising environment.

The relationship between urbanisation and measles control is examined. In urban settings in developing regions measles is a disease of particular importance, since it tends to affect children at a younger age and with greater severity than in rural settings. A further finding in urban areas, especially peri-urban slums, is the lower measles vaccination coverage rates compared with rural regions. Factors identified as determinants of measles vaccination coverage among children under 2 years of age in urban areas include: home delivery; being born outside the urban setting; and length of stay in the city. These factors are probably related to the low socioeconomic status and lack of social integration experienced by new urban immigrants. A number of additional obstacles, such as distance, economic and cultural barriers, and inconvenient clinic hours all prevent parents from gaining easy access to vaccination services. In order to address the problems of measles control in expanding urban settings, a regional approach--with full integration of curative and preventive services--is called for. A more effective use of existing services will probably go a long way towards improving urban vaccination coverage with resultant measles control.

Health Services Accessibility↗
PubMed1991

The analysis of clobazam and its metabolite desmethylclobazam by high-performance liquid chromatography.

The analysis of clobazam and its metabolite desmethylclobazam by high-performance liquid chromatography is described. After adding an internal standard 500 microliters of plasma is extracted under basic conditions into dichloroethane. The organic solvent is then evaporated to dryness and the residue reconstituted in 100 microliters of mobile phase prior to injecting an aliquot (30 microliters) onto a Hypersil 5 MOS column, which is eluted with acetonitrile/acetate buffer (pH 5.4) 40:60 vol/vol. The components are separated in approximately 12 min. Using this method, 15 micrograms L-1 of clobazam and 30 micrograms L-1 of desmethylclobazam can be detected. The method is suitable for the therapeutic monitoring of these two drugs in patient samples.

Anti-Anxiety Agents↗
PubMed1991

The pharmacokinetics of single oral doses of feprazone in healthy volunteers and elderly patients.

1. The pharmacokinetics of feprazone were studied in nine healthy volunteers and 10 elderly patients. 2. The mean elimination half-life of feprazone after a single oral dose in the healthy volunteers was 22.3 h, the mean apparent clearance 0.0051 1/h per kg and the mean volume of distribution 0.1681/kg. Corresponding values for the elderly patients were 22.6 h, 0.00561/h per kg and 0.1651/kg, which are not different from those for the volunteers. Thus, we were unable to detect any changes in feprazone pharmacokinetics which are related to age, or to the concurrent use of chronic medications, such as digoxin, diuretics, or hormones.

Adult↗
PubMed1991

The use of bone allografts in two-stage reconstruction after failure of hip replacements due to infection.

Bone allografts were used to reconstruct deficient acetabular and femoral bone in eighteen patients during two-stage revision of a hip arthroplasty that had failed due to infection. At a mean of 4.2 years after reimplantation, only two patients had had recurrence of the infection. Four patients needed another revision arthroplasty for reasons other than infection. These results suggest that allografts of bone are useful for the reconstruction of osseous deficiencies in carefully selected patients who have a hip arthroplasty after infection. The results do not support the concern that allografts that are used under these circumstances necessarily lead to a high rate of recurrence of infection. However, the long-term results of the use of allografts in hip arthroplasty after infection remain unknown.

Acetabulum↗
PubMed1990

Determination of zonisamide (3-sulphamoylmethyl-1,2-benzisoxazole) in plasma at therapeutic concentrations by high-performance liquid chromatography.

A selective and sensitive liquid chromatographic method for the determination of zonisamide in small (0.1 ml) plasma samples is described. After adding internal standard, a direct solvent extract of the sample is examined by reversed-phase liquid chromatography with ultra-violet spectrophotometric detection. The method is rapid, simple and capable of determining plasma levels after therapeutic ingestion of zonisamide. Some results from a dose-ranging clinical trial are presented.

Anticonvulsants↗
PubMed1990

Clearance of phenylethylmalonamide during haemodialysis of a patient with renal failure.

Information is presented for the serum concentrations during haemodialysis of primidone, phenobarbitone, and phenylethylmalonamide (PEMA) in a patient with renal failure receiving chronic primidone therapy. The concentrations of drug and metabolites fell during haemodialysis, but PEMA concentrations were above normal at all times. The average renal clearance of PEMA during 6 h of dialysis was found to be 84.7 +/- 4.6 ml min-1.

Humans↗
PubMed1988

Chloramphenicol in paediatrics: current prescribing practice and the need to monitor.

Two hundred and fifty-five neonates, infants and children, from 45 hospitals, who were receiving chloramphenicol therapy for serious infections were the subject of this study. Samples of serum and cerebrospinal fluid (CSF) were assayed for chloramphenicol and the patients' treatment regimens analysed. Less than 50% of neonates and 25% of infants received the "recommended" dose of chloramphenicol. In older children the recommended dose was used. Only 34% babies under 1 year of age and 50% older children had serum concentrations within the therapeutic range (15-25 mg/l). Thirty-one percent of neonates and infants had potentially toxic serum concentrations. Forty-three percent of neonates receiving chloramphenicol every 6 h had subtherapeutic peak serum levels compared to 20% of those receiving the antibiotic every 12 h. Concomitant administration of phenobarbitone or phenytoin had no effect on mean serum chloramphenicol levels. Serum concentrations of chloramphenicol were significantly higher in patients also receiving penicillin. CSF levels in 77 samples (39 patients) ranged from 1-60 mg/l. CSF from 44% patients contained less than 4 mg/l. Twelve neonates and infants (5.5%) suffered toxic side effects, four died. A further eight babies received an accidental 2- to 10-fold overdose and in three others an overdose was assumed following assay. No overdoses or toxic effects were reported in children over 1 year of age. Eight patients with impaired renal function had elevated serum levels and three showed toxic effects. In 22% patients dosage regimens were altered following assay.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

The micro gas-liquid chromatographic analysis of 4-(3',3'-dimethylallyl)-1,2-diphenylpyrazolidine-3,5-dione (feprazone) in human biosamples.

A gas-liquid chromatographic method for the determination of feprazone in various biological matrixes, employing a choice of detector options, is described. After rapid, micro-scale extraction of the sample with n-butyl acetate at physiological pH, the solution was injected directly onto the chromatograph. Separation was with either an OV7 column and flame ionisation or electron capture detection, or with a carbowax high polymer column and nitrogen specific detection. When 100 microl of plasma was extracted the limit of accurate measurement was 2 mg 1(-1) for F.I.D. and N.P.D. and 0.5 mg 1(-1) with E.C. detection. Quantification was by comparison with a range of plasma calibrators carried throughout the procedure, and determination of peak height ratios against an internal standard incorporated into the extracting solvent. The CV of the assay throughout the concentration range normally encountered in patients undergoing feprazone treatment, ranged between 2.4 and 7.8% for the various detector options. The analytical method has been applied to samples collected both from patients and normal volunteers undergoing treatment with a range of feprazone maintenance doses.

Journal Article↗