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Biomedical subjects

J F Osborn

Publications and source records attributed to J F Osborn.

At least 37 records · Page 2Linked to original sources
PubMed1998

Reliability of procalcitonin concentrations for the diagnosis of sepsis in critically ill neonates.

We evaluated the reliability of serum concentrations of procalcitonin for the diagnosis of early- and late-onset sepsis in a neonatal intensive care unit (NICU) setting. Timed procalcitonin determinations were prospectively obtained during two postnatal periods: 0-48 hours of age (period 1) and 3-30 days of age (period 2). In period 1, we measured procalcitonin concentrations in 83 healthy newborns (group 0) and in 120 NICU patients (14 with culture-proven sepsis, group 1A; 14 with clinical septicemia, group 1B; 75 with no evidence of infection, group 2; and 17 with uncertain findings, group 3). After we established 95% hour-specific reference ranges for group 0, we performed multiple linear regression analyses to determine which maternal, intrapartum, and neonatal complications would affect normal procalcitonin values. Maternal diabetes was the only variable identified in group 2 patients that induced a significant deviation from procalcitonin reference ranges. Analyses of the pooled procalcitonin values obtained for group 1 patients over the 48-hour period after birth yielded a sensitivity of 92.6% and a specificity of 97.5% for procalcitonin concentrations in the detection of early-onset sepsis. In period 2, blood samples from 23 cases with systemic infections were analyzed for procalcitonin concentrations at the onset of signs of infection. The control group was formed by matching four uninfected NICU patients to each infected case. None of the procalcitonin values for the 92 controls overlapped those for the cases (sensitivity and specificity, 100%). Procalcitonin is a promising marker for the diagnosis of early- and late-onset sepsis in neonates at high risk for this infection.

C-Reactive Protein↗
PubMed1995

Prostaglandin release from rat femurs after implantation of hydroxylapatite and aluminium oxide ceramics.

The bony reaction after implantation of uncemented ceramics is of special interest. Therefore porous and dense hydroxylapatite and aluminium oxide ceramics were implanted in rat femurs. One group received no surgical manipulation and another with a sham procedure where no ceramics were implanted served as controls. After 6 and 10 days the rat femurs were harvested and the release of PGE2 and 6-keto-PGF1 alpha was measured with specific radioimmunoassays. Decrease in the release of PGE2 from day 6 to day 10 was present in all three implants. In contrast, 6-keto-PGF1 alpha increased from day 6 to day 10. Comparing the ceramic types an increase in 6-keto-PGF1 alpha release was seen in the porous hydroxylapatite group. These prostaglandin (PG) release patterns after ceramic implantation are similar to those of fracture healing, but aluminium oxide seems to be inert, while hydroxylapatite, especially the porous type, stimulates 6-keto-PGF1 alpha release.

Aluminum Oxide↗
PubMed1995

Risk factors for caesarean section in Italy: results of a multicentre study.

A recent large increase in Caesarean section (CS) in Italy was the initial stimulus for a study to identify risk factors for CS and, if possible, to suggest strategies to counteract the rise. The study was conducted in three hospitals where a wide range of individual variables was collected from the clinical records and from personal interviews. Crude CS rates and odds ratios were evaluated for each single variable while logistic regression has been used to investigate possible confounding factors. The study involved 1316 consecutive deliveries. Crude CS rates were 29.4%, 15.7% and 16.1%. Variables identified as high risk factors were pre-eclampsia, previous CS, breech and other non-vertex presentations. Antenatal care under an obstetrician working in the same hospital, a low number of antenatal consultations, previous miscarriages, offer (by obstetrician) and request (by women) for CS showed significantly high odds ratios (ORs). Previous live births was strongly negatively associated with CS. No relationship between type of delivery and social status was observed while a physician factor was detected in all three hospitals where rates for different physicians ranged from 0% to 52.8%. Apart from the main medical indications for Caesarean section (previous CS, breech presentation), the results seem to indicate that individual practice style may be an important determinant of the wide variation in the rates of Caesarean delivery. While this may have been suspected before this study, these results are the first hard data to indicate that, in Italy, CS is widely performed for non-medical reasons.

Adult↗
PubMed1994

Survival and prognostic factors in patients with localised cutaneous melanoma observed between 1980 and 1991 at the Istituto Dermopatico dell'Immacolata in Rome, Italy.

530 patients with localised cutaneous melanoma consecutively observed between 1980 and 1991 at a hospital for skin diseases in Rome, Italy, were studied. Crude survival proportions were calculated with the method of Kaplan and Meier. Cox proportional hazards regression analysis was used to estimate the effect of prognostic factors on death rates. Females and younger patients had better 5- and 10-year survival rates, while increasing tumour thickness was associated with a decrease in survival time. In the multivariate analysis, an independent association with survival was found for tumour thickness, presence of ulceration, age, sex and cross-sectional profile of neoplasia. Our study confirms that females and young patients with thin melanomas have a better prognosis, while the importance of cross-sectional profile needs further study.

Adolescent↗
PubMed1993

Anterior cervical discectomy and vertebral interbody fusion with hydroxy-apatite ceramic. Preliminary results.

Intervertebral plates of hydroxy apatite ceramic (HAC) have been used in three patients for cervical vertebral interbody fusion after anterior discectomy. In one case a pure HAC "Disc" was used, which proved to be too friable. Specially designed intervertebral plates, which were composed of an HAC-coated core of alumina ceramic, were used in the other two cases. Clinically and radiologically optimal results after 1-year- and 2-year-follow-up suggest that HAC-ceramic might be a very promising material for vertebral interbody fusion. Possible complications and pain due to bone removal from the iliac crest are avoided, and the operative procedure is simplified.

Adult↗
PubMed1993

HLA-DQA1 and DQB1 gene polymorphisms in type I diabetic patients from central Italy and their use for risk prediction.

Susceptibility to type I diabetes has been shown to be highly correlated with the presence of an amino acid other than Asp at position 57 of the DQ beta-chain (non-Asp57) and also with the presence of an Arg at position 52 of the DQ alpha-chain (Arg52). In this study we analyzed the DQA1 and DQB1 gene polymorphisms in 65 patients from central Italy and 93 randomly selected control subjects. Polymerase chain reaction amplification of DNA encoding the first polymorphic domain of the DQB1 and DQA1 chains was performed, and DQB1 gene polymorphism was evaluated by dot blot analysis using 11 sequence-specific oligonucleotide probes. For DQA1 typing, a new simple procedure based on allele-specific amplification and analysis of heteroduplex DNA molecules formed by the annealing of mismatched allelic strands was used. This technique allows the discrimination of Arg52 and non-Arg52 DQA1 alleles. We then calculated by logistic regression the contribution of these genetic markers to the development of diabetes. Frequencies and odds ratios relative to the amino acid in position 57 of the DQ beta-chain and the amino acid in position 52 of the DQ alpha-chain showed that the highest odds ratio (odds ratio = 161; 95% confidence interval 19-1386) was that of the homozygous combination of the two susceptibility markers (non-Asp57 and Arg52).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

The effects of the Chernobyl explosion on induced abortion in Italy.

Four regression models have been fitted to data of the monthly number of induced abortions in Italy between January 1984 and April 1986, in order to predict the number which would have occurred in the 5 months following the Chernobyl explosion. In model I the average number of abortions per day in each month was the dependent variable and calendar months, a linear time trend and previous month's value were the independent variables. Model II included a quadratic time trend term in addition to the independent variables used in model I. Models III and IV were like models I and II except that the dependent variable was the average number of abortions per working day in each month and the effect of the previous month's value was omitted. The 4 models all implied that an excess number of abortions were performed in the 5 months following the Chernobyl accident. The mean daily excess was estimated to be 28 and 52 per day for models I and II and the mean excess per working day was estimated to be 20 and 30 by models III and IV, respectively. Clearly the estimated magnitude of the excess depends on whether the quadratic time trend is included among the explanatory variables, but these results imply that the excess is unlikely to be merely due to chance.

Abortion, Induced↗
PubMed1991

Fixation of hip prostheses by hydroxyapatite ceramic coatings.

We report the histological findings in post-mortem specimens obtained ten days, 17 days and seven weeks after implantation of hydroxyapatite-coated femoral components of hip arthroplasties. There was early deposition of woven bone on the hydroxyapatite ceramic, identical to that deposited on surviving cancellous trabeculae. The space between these deposits became bridged from both sides by new trabeculae, and there was no evidence of an inflammatory reaction or of fibrous tissue formation. The use of an hydroxyapatite coating seems to allow early, sound, secondary fixation of implants.

Biocompatible Materials↗
PubMed1991

Minimising errors in clinical studies by proper selection of sample size.

In the planning of a clinical trial, the statistical aspects of the choice of sample size should be considered. The meaning of statistical terms such as Type I and Type II errors, significance and power are explained. Formulae are given for calculating the required sample size for parallel groups' designs (two independent samples) and matched pair or cross-over designs for both quantitative and qualitative responses. Samples size tables are given with instructions for their use and there are four worked examples. The sample size for a trial depends on the specification of the levels of significance and power and the size of the difference the trial is designed to detect, and these can be somewhat arbitrary. Furthermore, it is often necessary to estimate the standard deviation on the basis of limited information. Thus, the sample size required for a trial cannot be determined precisely, and there can be no exactly right or wrong sample size. However, sensible consideration of sample size should ensure that the trial is not so small as to make the results trivial, nor so large as to be unethical or a waste of resources.

Clinical Trials as Topic↗
PubMed1990

General anaesthesia, a risk factor for complication following induced abortion?

Of the 10,000 abortions performed at the Regional hospital at Modena in Italy between 1982 and 1986, 199 (2%) led to early complications. Investigation of the relationship between the risk of haemorrhage, injury, other complications and all complications and eight explanatory variables revealed that the adjusted odds ratio associated with the use of general anaesthetic compared with local anaesthetic was 4.6 (95% CI, 2.2-9.5) for haemorrhage, 1.3 (95% CI, 0.78-2.2) for injury, 1.6 (95% CI, 1.0-2.6) for other complications and 1.8 (95% CI, 1.4-2.5) for all complications. It is speculated that if the relationship between use of general anaesthetic and risk of complication is causal there could be about 40% fewer cases of complications and 75% fewer cases of haemorrhage following induced abortion if local anaesthesia were used rather than general anaesthesia.

Abortion, Induced↗
PubMed1990

Hydroxyapatite ceramic as a bone substitute.

We have used hydroxyapatite ceramic as a bone substitute for grafting in extensive bone replacement. Hydroxyapatite is composed of calcium phosphate and is incorporated into bone as a physiological mineral. It is not antigenic, carcinogenic or osteogenic. The material used in this study differs from other hydroxyapatite ceramics in that it is an interconnected porous system. Between 1981 and 1986 we used this material on forty five occasions in 44 patients. It was combined with autologous cancellous bone graft in 38 cases and used alone in a further seven. It was usually employed to fill defects after removal of bone cysts and for long fusions in patients with scoliosis. It was also used to fill bone defects after trauma, for non-union in the lumbosacral area, for anterior vertebral fusions, in limb sparing operations for malignant bone tumours, and in exchange operations after failed joint endoprostheses. We have not seen incompatibility or rejection of the implanted material. The rate of postoperative infection was higher than usual due to the selection of patients, but did not appear to be connected with the use of hydroxyapatite ceramic. We were able to review 36 patients up to sixty months after operation. The results are encouraging with no difference in progress compared with patients in whom simple autologous bone grafts had been used.

Adolescent↗
PubMed1990

[Osprovit: hydroxylapatite ceramic for the reconstruction of blow-out fractures of the orbital floor].

Common polymeric implantations, in use for the orbital floor reconstruction, form usually a surrounding fissural space and thus tend to dislocations. With the conservative methods that have been available up to now, the Dura Mater cannot be definitely sterilised so that a transmission of a virus may be possible, which causes the Creutzfeld-Jacob Encephalopathy. As an appropriate alternative-both for primary and secondary reconstruction of the orbital floor-an implantation of dense hydroxylapatite ceramics (Osprovit), anatomically shaped, is indicated. According to x-ray techniques of evaluation it presents itself without artifacts. It does not dislocate because it coalesces physiologically with the surrounding tissues and because of its biocompatibility, it is undoubtedly suitable as a permanent implantation. Post-operative examinations of 20 patients showed neither enophthalmus nor diplopia. All patients were without subjective symptoms.

Adult↗
PubMed1989

Measuring diagnostic consistency.

Statistical analysis can only be as reliable as the data analysed. In clinical or epidemiological dental research, variations in the interpretation of diagnostic criteria can have a marked effect on the reliability of subsequent analysis. Methods of measuring examiner consistency in these circumstances are discussed, and illustrative examples provided.

Child↗
PubMed1989

Comparison of several groups.

Techniques for the comparison of several samples are described. If the response is quantitative, comparison of the sample means is achieved by one-way analysis of variance. If the response is qualitative, comparison of several proportions is achieved by chi 2 tests.

Dentistry↗