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Biomedical subjects

K Jones

Publications and source records attributed to K Jones.

At least 289 records · Page 16Linked to original sources
PubMed1992

A risk-based prospective payment system that integrates patient, hospital and national costs.

We suggest that a desirable form for prospective payment for inpatient care is hospital average cost plus a linear combination of individual patient and national average cost. When the coefficients are chosen to minimize mean squared error loss between payment and costs, the payment has efficiency and access incentives. The coefficient multiplying patient costs is a hospital specific measure of financial risk of the patient. Access is promoted since providers receive higher reimbursements for risky, high cost patients. Historical cost data can be used to obtain estimates of payment parameters. The method is applied to Medicare data on psychiatric inpatients.

Costs and Cost Analysis↗
PubMed1992

Spermine dialdehyde, a novel ex vivo purging agent for both allogenic and autologous bone marrow transplantations.

The use of ex vivo purging agents has shown to be beneficial for both allogeneic and autologous bone marrow transplantations. We have shown previously that spermine dialdehyde (SDA), an oxidized product of spermine, when used in phosphate-buffered saline (PBS) preferentially inhibits T-cell proliferation while sparing myeloid cells. Lethally irradiated mice were rescued by reconstitution with SDA-treated allogeneic marrow and showed no sign of graft-vs-host disease (GVHD). In this paper, we show by HPLC analysis that SDA degraded rapidly in PBS but remained intact in saline. Administered in saline, SDA was more inhibitory on leukemic cell lines than normal myeloid or T-cells. Lethally irradiated mice receiving a syngeneic bone marrow leukemic cell mixture treated ex vivo with SDA in saline did not manifest leukemia. Thus, the preferential inhibitory effect of SDA and its degraded products in different buffers suggest that SDA could act as a novel purging agent for both allogeneic and autologous bone marrow transplantations.

Acrolein↗
PubMed1992

A conservative approach to the management of otitis media with effusion in cleft palate children.

Otitis media with effusion (OME) is almost universal in children born with a cleft palate. Early placement of a ventilation tube to alleviate hearing problems is common. A retrospective study has been carried out to assess whether the practice of tube placement only for definite clinical indications is successful in terms of subsequent hearing levels and speech and language development. This was assessed by a case note review, analysis of speech therapy data and by means of a special follow-up clinic. There was no difference in speech development between those treated with tube insertion for OME and those untreated. Audiological thresholds were worse in the treated group. A similar number in each group required regular speech therapy. More abnormal otological findings were present at follow up in those who had tubes inserted, some of these were directly attributable to the presence of tubes. A conservative management of OME in cleft palate children, with tube insertion for only definite clinical indications, is an appropriate management, and will lead to fewer otological complications of tube insertion.

Adolescent↗
PubMed1992

Diagnostic performance of teleradiology in cervical spine fracture detection.

This study was done to assess the diagnostic accuracy of high-resolution (5 lp/mm) teleradiology for detecting cervical spine fractures. Single radiographs from 25 patients with and 25 patients without cervical spine fractures were transmitted between two units of our teleradiology system (Dupont DTR 2000) located 5 miles apart. Each image was examined by four readers. Fracture detection accuracy was assessed by generating receiver operating characteristic (ROC) curves and comparing the areas under each reader's curves for original and transmitted images. Two readers had statistically significant better fracture detection using nontransmitted images, whereas two had no significant differences in accuracy. The authors conclude that high resolution in and of itself is not adequate for fracture detection, and that issues concerning image contrast manipulation also will have to be addressed before teleradiology systems can be used for clinical cervical spine fracture screening.

Cervical Vertebrae↗
PubMed1992

Immunization status of casualty attenders: risk factors for non-compliance and attitudes to 'on the spot' immunization.

Outbreaks of vaccine preventable infections have focused attention on 'missed opportunities' for immunizing children. The immunization status of 520 consecutive children attending Casualty during a 10 day period was studied. Only 70% of children had received their diphtheria, tetanus, pertussis (DTP) and poliomyelitis immunization at the appropriate time, 13% had completed the schedule later than recommended and 17% had immunizations overdue by 4 weeks or more. For measles (mumps/rubella) vaccine (MM or MMR) 75% were up to date, 10% were given late and 15% were overdue. A subset of 171 families was interviewed to evaluate factors affecting compliance. Families possessing a Social Security 'Health Care Card', whose father was unemployed, who spoke poor English or who had lived in Australia for 5 years or less were significantly more likely (P < 0.02) to be inadequately immunized. There were 84 children whose immunization was overdue and who were well enough to be immunized. The parents of 70 (83%) of these 84 said that they would agree to 'on the spot' immunization if it were available; 14 (17%) parents refused, the commonest reason for refusal being that the parents felt that the child was too sick at the time to be immunized.

Child↗
PubMed1992

Impact of an interest in asthma on prescribing costs in general practice.

OBJECTIVE: To examine the effect on total prescribing costs and prescribing costs for respiratory drugs for practices with at least one general practitioner with a special interest in asthma. DESIGN: Postal questionnaire survey. SETTING: General practitioners in England and Wales. SUBJECTS: 269 members of the General Practitioners in Asthma Group, of whom 103 agreed to participate. MAIN MEASURES: Individual practitioners' and their practices' PACT prescribing costs from the winter quarters of 1989-90 compared with average costs for their family health services authority (FHSA) and a notional national average of all FHSAs combined. RESULTS: The response rate was 57%; the average total prescribing costs for the practices of the 59 respondents were significantly lower than those of their respective FHSAs (mean difference 505 pounds per 1000 patients per quarter (95% confidence interval -934.0 to -76.2, p = 0.022) and lower than the national average. The average prescribing costs for respiratory drugs for the practices were significantly greater than those for their FHSA (195 pounds per 1000 patients per quarter (84.4 to 306.0, p = 0.001) and the national average. Both types of costs varied widely. CONCLUSION: An interest in asthma care in general practice is associated with higher average prescribing costs for respiratory drugs but no increase in overall prescribing costs compared with those for respective FHSAs and national averages. IMPLICATIONS: FHSAs and their medical advisors should not examine high prescribing costs for individual doctors or one therapeutic category but in the context of practice total costs.

Anti-Inflammatory Agents↗
PubMed1992

Factor structure and reliability of the Reasons for Living Inventory.

This study examined the factor structure and internal consistency reliability of the Reasons for Living Inventory for 275 college students. Principal components factor analysis with varimax rotation extracted five factors, based on the scree test. The derived factors were identical with the inventory's subscales, except for the Fear of Suicide subscale and Social Disapproval subscale items loading on the same factor. Significant gender differences were obtained on the Responsibility to Family, the Fear of Suicide, and the Moral Objections subscales. The pattern of subscale correlations was similar for the subsamples. The coefficients alpha for the subscales ranged from moderate to high.

Adult↗
PubMed1992

Reliability and validity of the Cognitive Slippage Scale in two populations.

Analyses of responses from a clinical sample of 120 patients (primarily schizophrenics) and from 158 college students to the Cognitive Slippage Scale, a scale designed by Miers and Raulin to identify speech deficits and confused thinking in schizophrenic and schizotypal personality disorders showed high internal reliability; Cronbach's coefficients alpha were .89 and .86 in the clinical and college student samples, respectively. The mean scale scores significantly differentiated the two samples. Also, change scores over 4 wk. showed adequate stability for both samples. Item analysis indicated Items 11, 20, 21, and 28 may not reliably discriminate between schizophrenic and college student samples. Over-all, these preliminary results are consistent with the reliability and validity of the scale.

Adult↗
PubMed1992

Schoolteachers' perceptions and knowledge of asthma in primary schoolchildren.

Schoolteachers are known to be concerned about asthma in their pupils but their opinions about the best method of addressing this concern have not previously been investigated. Eleven headteachers and 76 class teachers from 11 primary schools in the Southampton area--eight from the state sector and three private day schools--completed questionnaires. These inquired about the organization of care for asthmatic pupils, the teachers' knowledge, concerns and training regarding the disease, and their perceptions of the need for and source of further education for teachers about asthma. All 10 National Health Service school health services in the Wessex region and 16 teacher training colleges responded to questions about their provision of such education for teachers. The results demonstrated that asthma care in the 11 schools was generally disorganized, with the responsibility for keeping and administering inhalers falling on the school secretary in seven of the schools. All but two of the 11 headteachers and 89% of the class teachers were concerned about asthma, primarily in managing emergencies. Levels of knowledge were low, particularly regarding exercise, and education about asthma was almost non-existent. The great majority of class teachers (86%) wanted more information about asthma and most (67%) looked to the school health services to provide this. None of the school health services in Wessex and only one teacher training college had any planned education about asthma for teachers. Clearly, schools need to receive more information about asthma, both to enable them to cope more ably with their asthmatic pupils and to allay the anxieties of teachers.(ABSTRACT TRUNCATED AT 250 WORDS)

Asthma↗
PubMed1992

Experimental hydroxyapatite cement cranioplasty.

Hydroxyapatite cement is a calcium phosphate-based material that when mixed with water forms a dense paste that sets within 15 minutes and isothermically converts in vivo to a microporous hydroxyapatite implant. This cement was used to reconstruct bilateral 2.5-cm-diameter full-thickness critical-sized parietal skull defects in six cats. One side was reconstructed with 100 percent hydroxyapatite cement, and the other with a mixture of 50 percent hydroxyapatite cement and 50 percent ground autogenous bone by weight. These animals were sacrificed at 6 and 12 months after implantation. Positive and negative controls also were prepared. The anatomic contour of the soft tissue overlying all hydroxyapatite cement implants was well maintained, there were no wound infections or structural failures, and the implants were well tolerated histologically. None of the negative (unreconstructed) control defects was completely filled with repair bone, and all positive (methyl methacrylate) controls demonstrated foreign-body giant-cell formation and fibrous encapsulation of the implants. Examination of decalcified and undecalcified sections revealed progressive but variable replacement of the cement by new bone and soft tissue without a change in the shape or volume of the hydroxyapatite cement-reconstructed areas. New bone comprised 77.3 and 64.7 percent of the tissue replacing the hydroxyapatite cement and hydroxyapatite cement-bone implants, respectively. Replacement of the hydroxyapatite cement implants by new bone is postulated to occur by a combination of osteoconduction and implant resorption. These results indicate that further experimental research leading to the possible application of hydroxyapatite cement for full-thickness calvarial defect reconstruction in humans is warranted.

Animals↗
PubMed1992

Cleft lip with or without cleft palate: associations with transforming growth factor alpha and retinoic acid receptor loci.

The first association study of cleft lip with or without cleft palate (CL/P), with candidate genes, found an association with the transforming growth-factor alpha (TGFA) locus. This finding has since been replicated, in whole or in part, in three independent studies. Here we extend our original analysis of the TGFA TaqI RFLP to two other TGFA RFLPs and seven other RFLPs at five candidate genes in 117 nonsyndromic cases of CL/P and 113 controls. The other candidate genes were the retinoic acid receptor (RARA), the bcl-2 oncogene, and the homeobox genes 2F, 2G, and EN2. Significant associations with the TGFA TaqI and BamHI RFLPs were confirmed, although associations of clefting with previously reported haplotypes did not reach significance. Of particular interest, in view of the known teratogenic role of retinoic acid, was a significant association with the RARA PstI RFLP (P = .016; not corrected for multiple testing). The effect on risk of the A2 allele appears to be additive, and although the A2A2 homozygote only has an odds ratio of about 2 and recurrence risk to first-degree relatives (lambda 1) of 1.06, because it is so common it may account for as much as a third of the attributable risk of clefting. There is no evidence of interaction between the TGFA and RARA polymorphisms on risk, and jointly they appear to account for almost half the attributable risk of clefting.

Blotting, Southern↗
PubMed1991

Multilevel assessment of immunisation uptake as a performance measure in general practice.

OBJECTIVE: To provide a measure of general practitioners' performance regarding uptake of immunisation against pertussis, taking account of the impact of patient characteristics on levels of uptake. DESIGN: Multilevel model of immunisation status against six measures of patient characteristics (level 1 predictor variables) with practice constraints as level 2 variables. SETTING: 126 practices in southern England. SUBJECTS: 2048 infants identified from infant surveillance and immunisation records. MAIN OUTCOME MEASURES: Top 10 practices with respect to uptake of pertussis immunisation according to a "null" model (model A) and according to a model that included six level 1 variables (model B); differences in ranking between the two models. RESULTS: Practices with low numbers of infants' requiring immunisation had imprecise and unstable uptake rates (range 0%-100%). With the multilevel procedure, after controlling for patient characteristics, practices in suburban catchment areas comprised largely of mature or young professionals performed best. Most improved performances when patient characteristics were taken into account were in practices in areas with a stable population and local authority housing--one such practice improved its ranking by 47 places. CONCLUSIONS: Crude uptake rates are inadequate performance indicators. Alternative approaches suggest that praiseworthy efforts to raise immunisation rates in unpromising areas are unrewarded by simple target based assessments.

Achievement↗
PubMed1991

Stress fractures in athletes. How to spot this underdiagnosed injury.

Stress fractures are an increasingly common injury in competitive athletes, especially runners. Amenorrheic athletes are at particularly high risk. A radionuclide bone scan should be considered when the index of suspicion for stress fracture is high. Plain radiographs are of little use in establishing the diagnosis in the early stages of the injury. Early diagnosis and prompt institution of conservative therapy allow for a favorable outcome in most cases. Avoidance of or reduced participation in the inciting activity is important for pain control. Certain stress fractures, such as those involving the femoral neck, should be monitored closely and treated aggressively with internal fixation when conservative measures fail. Runners who have exercise-induced amenorrhea should be advised to decrease their training intensity to a level where menses resume. Cyclic therapy with conjugated estrogens and progesterone should also be considered, as should daily calcium supplementation.

Adipose Tissue↗
PubMed1991

Hydroxyapatite cement. I. Basic chemistry and histologic properties.

Hydroxyapatite cement is a unique calcium phosphate preparation that can be shaped intraoperatively and sets in vivo to an implant composed of microporous hydroxyapatite. The histologic response to this cement was evaluated by implanting disks made of this material within the heads of nine cats. Three sets of 12 hydroxyapatite cement disks were produced containing 0%, 10%, and 20% macropores by volume, respectively. The disks were implanted subcutaneously, intramuscularly, above the periosteum of the skull, and directly onto the surface of the calvarium. Each macropore percentage was represented in each tissue plane, and animals were killed up to 9 months postoperatively. There were no toxic reactions, implants extruded, or wound infections. Histologic examination of the implant-soft-tissue interfaces revealed a transient inflammatory response without foreign body reaction. The disks were resorbed over time in direct proportion to their macropore content (surface areas) in all groups except for those disks placed directly onto the surface of the calvarium below the periosteum. In this group, numerous foci of bone formed at the skull-implant interface, with variable replacement of the deep surface of these implants by bone. Implant replacement by bone is postulated to occur through a combination of implant resorption coupled with osteoconduction. Based on these properties, hydroxyapatite cement may prove useful when applied to the reconstruction of non-stress-bearing skeletal tissue.

Animals↗
PubMed1991

Hydroxyapatite cement. II. Obliteration and reconstruction of the cat frontal sinus.

Frontal sinus obliteration and reconstruction can be performed with autogenous grafts or synthetic implants, each of which has significant limitations. Hydroxyapatite cement, which can be shaped intraoperatively and sets to a microporous hydroxyapatite implant, was applied to this problem. Nine cats had the anterior table of their frontal sinus unilaterally removed and the sinus cavity stripped of its mucosa. Hydroxyapatite cement was used to obliterate the cavity and reconstruct the overlying anterior table defect. The unoperated side served as the control, and the animals were sacrificed up to 18 months postoperatively. There were no adverse reactions, infections, mucoceles, or implant extrusions. The normal anatomic contour of the forehead region overlying the hydroxyapatite cement implants was maintained in all animals. Histologic examination of undecalcified whole sinus sections revealed progressive replacement of the implants with woven bone without a loss of volume. Replacement of the hydroxyapatite cement by woven bone is postulated to occur through a combination of implant resorption coupled with osteoconduction. The use of hydroxyapatite cement proved successful for the reconstruction and obliteration of cat frontal sinuses, and may be appropriate for the same application in humans.

Animals↗