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Biomedical subjects

P Arnold

Publications and source records attributed to P Arnold.

At least 19 recordsLinked to original sources
PubMed1996

Follow-up (6-9 years) results of the uncemented CLS Spotorno stem.

The aseptic loosening rate in uncemented hip endoprostheses, especially the stem, is one of the most discussed problems among hip surgeons within the last few years. The first generation of uncemented stems had an essentially higher loosening rate compared with cemented stems. Although there are many reasons for this disappointing fact, the type of primary fixation and polyethylene wear are the two main ones. We reviewed 145 sequential uncemented CLS Spotorno stems, which achieved their primary fixation and bony in- or ongrowth predominantly in the metaphyseal region. The mean age of the patients was 54.9 years (range 37-76 years), and average follow-up was 7.8 years. The evaluation included both clinical (Merle d'Aubigne and Harris Hip Score) and radiographic parameters (plain X-rays). The medium-term follow-up showed a survival rate of 96.7% and good functional score results in more than 90%. Special attention was paid to the so-called thigh pain phenomenon which, despite current views, was found to be unexpectedly low (only one case). Although these results are encouraging, a further long-term follow-up of more than 10 years will have to show whether or not comparable results to cemented stems can be realised.

Adult↗
PubMed1996

Uncemented total hip replacement and thigh pain.

We reviewed 145 consecutive patients who had total hip replacements using uncemented CLS Spotorno femoral stems which achieve primary fixation with bony ingrowth which occurs later mainly in the metaphyseal region. The mean age was 54.9 years and average follow up 7.8 years. The Merle d'Aubigne and Harris hip scores were used for evaluation, together with plain radiographs. Current medium term follow up showed a survival rate of 96.7% and a good functional score in more than 90%. Special attention was paid to postoperative thigh pain which occurred in only one patient. These results are encouraging, but a follow up of more than 10 years is required before comparable results to cemented stems can be claimed.

Adult↗
PubMed1996

Lipreading, reading and memory of hearing and hearing-impaired children.

The relationship between lipreading, reading and visual and sequential memory was investigated in hearing 10-year-olds and two groups of hearing-impaired 10-year-olds, one educated through the medium of English and the other through British Sign Language. The scores and the pattern of correlations between the variables were hypothesized to be different in the three groups and this was found to be the case. In the case of the hearing, visual memory for complex shapes was significantly correlated with lipreading. For the oral deaf, reading ability was significantly correlated with lipreading, but for the bilingual deaf the correlation was not significant. The possible implications of these findings for the relationships between the cognitive processes involved in lipreading and for the education of the deaf are discussed.

Child↗
PubMed1996

[The "activated coagulation time (ACT)": two simple screening methods for evaluating coagulation disorders in dogs].

The use of the activated coagulation time (ACT) for testing the intrinsic coagulation is well established among veterinary practitioners in the USA. The advantage of the ACT compared to other coagulation tests is its ease to be performed under practice conditions. The ACT may be measured manually or instrumentally. The reference range of our instrumental measurement is between 90 and 120 seconds (median 105 seconds), of the manual measurement at room temperature between 115 and 145 seconds (median 125 seconds). Advantages of the instrumental method are the smaller amount of blood (0.4 ml versus 2.0 ml) necessary to perform the test, and the smaller potential for errors by unexperienced examiners. The spread is comparable between the two methods. The most important cause of false results is poor venipuncture technique: traumatic venipuncture will trigger the coagulation cascade already during venipuncture causing an artificially shortened ACT.

Animals↗
PubMed1996

[Wear behavior of coupled aluminum oxide ceramics-carbon fiber bond as hip acetabulum inlay in a simulated trial].

Hip-simulator studies were carried out to investigate the initial wear between a femoral head made of aluminium oxide ceramic and a CFRP-(carbon fibre-reinforced plastic) inlay in a titanium cup. A load of 2500 N and a frequency of 0.857 Hz were applied. After 200,000 cycles, the centre of the head had moved 9 microns into the liner. After 500,000 cycles, the cup centre had moved inwards by a further micron, and the near radius had increased by 2 microns. After 750,000 cycles the position of the centre of the head remained unchanged, while the mean radius had increased a further 2 microns. After one million cycles any further changes remained below the measuring capability (1 micron) of the system.

Aluminum Oxide↗
PubMed1995

Wayward doctors.

Explore the source record for details and available documents.

Australia↗
PubMed1995

Specific IgG1 and IgG2 antibody responses of dogs to Leishmania infantum and other parasites.

Sera from dogs naturally infected with Leishmania infantum were analysed for the IgG subclass specificity of their antibody response by ELISA. Dogs infected with L. infantum produced both IgG1 and IgG2 antibodies with IgG2 being associated with asymptomatic infections and IgG1 being associated with disease (symptomatic dogs, non- or low-responsive to chemotherapy). The differential responses of IgG1 and IgG2 serum antibodies in asymptomatic and symptomatic dogs may indicate a dichotomous immune response to infection with L. infantum. To confirm this, on a broader scale, sera from dogs naturally exposed to an asymptomatic protozoan infection, Toxoplasma gondii, were also analysed as were sera from dogs exposed to the helminths, Dirofilaria immitis and Toxocara canis. Antibodies specific for T. gondii antigen detected in sera from 17 dogs were of the IgG2 subclass only. Both IgG1 and IgG2 antibodies to D. immitis and T. canis were present in the sera of naturally infected dogs but IgG1 appeared to be the predominant subclass. Furthermore, in dogs experimentally infected with T. canis, selective regulation of IgG2 and IgG1 responses was apparent since production of the two subclasses occurred at different times following infection, with IgG2 levels declining as IgG1 levels rose. Thus, the analysis of IgG subsets in parasitized dogs provides evidence of a dichotomous response to infection: IgG2 is associated with asymptomatic protozoan infections and IgG1 is associated with helminth infections and disease caused by protozoan infection.

Animals↗
PubMed1995

[Enteral forced feeding using blind fixed stomach probes: two practical methods].

Whereas fasting is well tolerated by the healthy organism, protein-energy malnutrition in the sick animal has a negative impact on organ functions, immunocompetence, wound healing, and reconvalescence. Sick animals, physically unable to eat or held off food for medical reasons for more than 5 days, consequently need some sort of nutritional support. Force feeding through a gastrostomy tube has several advantages compared to other forms of enteral nutrition. Gastrostomy tube feeding is relatively physiological, is quite comfortable for the animals and their owners, can replace oral feeding for weeks, and is associated with only rare complications. Gastrostomy tubes can be placed surgically, by use of a gastroscope, or blindly. Blind percutaneous gastrostomy tube placement is minimally invasive, fast, does not require any expensive equipment, and hence is well suited for practice.

Animals↗
PubMed1995

[Juvenile bone cysts. Relative value and therapy results of cortisone injections].

Seventy-one children and adolescents with unicameral bone cysts were treated between 1982 and 1992. Fifty-one percent were in the proximal humerus, 34% in the femur, 10% in the tibia, and only 5% in other sites. Until 1986 biopsies were routinely done. Since then, only selected cases have been biopsied because of uncertainty in the radiological diagnosis. In 70% the diagnosis was a pathological fracture as a result of the cyst. Cortisone injections were introduced in 1982. It replaced currettage and bone grafting, which was the routine treatment until then. Ninety-two percent of the cysts healed or healed with residuals according to the Neer classification. Additional osteosynthesis was done in pathological fractures of the femoral neck. The results are achieved with little morbidity, and low cost which justifies continuation of this treatment protocol.

Adolescent↗
PubMed1994

Continuous motion analysis of the head-neck complex under impact.

The objective of the present study was to analyze the localized kinematic biodynamics of the human head-neck complex under impact loading. Unembalmed human cadaveric head-neck complexes were subjected to axial compressive forces delivered using an electrohydraulic testing device. The head-neck complex was aligned along the stiffest-axis; musculature was simulated using preloaded springs and cables; and retroreflective targets were inserted into the vertebral body, the facet joint articulation, and the spinous process at every level of the cervical column. At dynamic loading rates (1.8-5.1 m/min), mid to lower cervical spine injuries consistently occurred in these preparations. Continuous motion analysis of the components (vertebral body, intervertebral disk, facet joint, and the spinous process) at all levels of the cervical spine showed the temporal order of the transfer of the external load. Injuries documented by computed tomography and cryomicrotomy techniques correlated with the kinematics of the structure. The application of dynamic loading to the head-neck complex coupled with high-speed, continuous-motion analysis of the intervertebral components of the entire cervical column makes possible the definition of the temporal kinematic mechanics that are fundamental to the understanding of the biodynamics of cervical spine trauma. Using these procedures, we have correlated the kinematics with the onset and pattern of neck injury secondary to impact forces.

Aged↗
PubMed1994

[Case report: dirofilariasis in a dog].

A Siberian Husky from the Milan region was referred to the Clinic for clarification of a history of weight loss and rapid fatigue. On clinical examination increased vesicular sounds and dyspnea after physical excitement and effort were the only abnormal findings demonstrable. Radiologically demonstrated changes of the pulmonary arteries led to a tentative diagnosis of Dirofilariosis. The parasitological diagnosis based on serology and the morphology of microfilariae isolated from the blood indicated an infection by microfilariae and adult stages of Dirofilaria immitis. After premedication with Aspirin, the patient was treated against adult filariae with Caparsolate, and a month later with Ivermectin against the microfilariae. At the time of reexamination, 5 months after initiation of therapy, the dog was clinically healthy and free of any demonstrable infection with Dirofilaria. In a second, clinically normal Husky from the same kennel, isolated Dirofilaria repens microfilariae were demonstrated. This dog was not treated.

Animals↗
PubMed1993

Distinct metal binding configurations in ACE1.

The ACE1 protein of Saccharomyces cerevisiae mediates the metal-induced expression of the CUP1 metallothionein (MT) genes. Curiously, ACE1 resembles the MT protein in the types of metal complexes that form. ACE1 binds Cd(II) and Cu(I) ions in distinct configurations, but only the Cu(I) conformer of ACE1 forms a high-affinity and specific complex with DNA. Cu(I) ions associated with ACE1 are known to assemble in a polymetallic CuI-thiolate cluster that resembles Cu-metallothionein in metal coordination properties [Dameron, C. T., Winge, D. R., George, G. N., Sansone, M., Hu, S., & Hamer, D. (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 6127-6131]. In contrast to the Cu(I) nuclearity of 6-7 mol equiv in ACE1 and 7 mol equiv in yeast MT, divalent ions, including Cd(II), Zn(II) and Co(II), bind with a maximal stoichiometry of near 4 mol equiv in ACE1 and 4 mol equiv in yeast MT. Charge-transfer bands consistent with metal:thiolate coordination were observed in CdACE1 and CoACE1. Spectroscopic studies of CoIIACE1 and EXAFS analysis of CdIIACE1 revealed tetrahedral coordination geometry in these complexes. Similar tetrahedral coordination complexes were observed with Co(II) and Cd(II) complexes of MT from S. cerevisiae. Metal binding in ACE1 is clearly similar to that in MT, and therefore the MT-metal clusters appear to be a good structural model of the metal center of ACE1.

Bacteriophage T7↗
PubMed1993

The optimization of hearing-impaired children's speechreading.

As more hearing-impaired and deaf children are mainstreamed into regular schools and as age related hearing loss in advanced countries become more prevalent, so the need for optimal methods to teach speechreading increases. The numbers of children and adults who would benefit from improved methods of teaching speechreading must be considerable. No new methods of teaching speechreading have been developed since 1938. Speechreading is a skill that does not require complex technology, although it does augment the effectiveness of hearing aids. Increased knowledge of this skill would have great benefits in psychological, social and economic terms. Some relevant experimental psychological literature and the views of educators are discussed with the goal of contributing to the optimization of hearing-impaired children's speechreading.

Child↗
PubMed1993

Handedness distribution and figure drawing ability in a deaf school population, with severe learning difficulties: a research note.

The handedness distribution of 71 deaf pupils with severe learning difficulties, was found to be similar to that reported by Soper et al. (1987, American Journal of Mental Deficiency, 92, 94-102) in a mentally handicapped sample, who also found a high incidence of ambiguously handed individuals. Soper's theory, however, that the "acquired" left-handed and the ambiguously-handed are more handicapped and so, we might infer, draw more primitive human figures, was not supported. The left, ambiguously-handed and right-handed had the same scores on human figure drawing. Neither was there a difference in handedness or figure drawing between the "acquired", the "genetic" and the "unknown" cause groups; nor between males and females.

Adolescent↗