Mechanisms of rapid bone loss following cardiac transplantation

Rapid bone loss after orthoptic cardiac transplantation (OHTX) is a major problem; however, the mechanisms are poorly understood. To investigate these mechanisms we measured biochemical and hormonal indices of bone turnover serially in 25 patients (21 men, 4 women) after OHTX. Serum osteocalcin was reduced immediately post-OHTX (2.2 +/- 0.5 ng/ml) but rose significantly by 6 and 12 months (14.1 +/- 2.5 and 15.7 +/- 2.2 respectively). Bone resorption indices (urinary hydroxyproline/creatinine and calcium/creatinine ratios) were increased immediately post-OHTX but fell by 6 months. Serum testosterone was reduced in males but recovered towards normal values by 6-12 months. Regression analysis showed lumbar bone loss was predicted independently by the change in both serum osteocalcin and testosterone. The data suggest that bone loss post-OHTX is due to a combination of accelerated turnover and hypogonadism.

Further evidence for the efficacy of imidocarb dipropionate in the treatment of Ehrlichia canis infection

Three dogs experimentally infected with Ehrlichia canis developed thrombocytopaenia and high antibody titres to E. canis in indirect fluorescent antibody tests. One dog also became leukopaenic. At Weeks 6 and 8 post-infection, the dogs were treated with imidocarb dipropionate (5 mg kg-1 subcutaneously) and a further dose was administered at Week 12 (5 mg kg-1 intramuscularly). Twelve weeks after the last treatment (post-treatment), all dogs had normal platelet counts which persisted for a further 10 weeks until the end of the experiment. The leukopaenia resolved 20 weeks post-treatment. Although antibody titres (< 1/5) to E. canis could not be detected prior to infection, titres of 1/2 560 to 1/5 120 developed by Week 6. By Week 8 post-treatment titres began to decline and by the end of the experiment were 5- to 6-fold serum dilutions lower (1/80 to 1/320). Sub-inoculation experiments 18 weeks post-treatment, failed to cause disease or stimulate antibody responses in susceptible dogs. Serology and sub-inoculation studies on 2 dogs experimentally infected with E. canis but not treated with imidocarb dipropionate, showed that these animals remained infected for the duration of the experiment. The results of these experiments confirm that imidocarb dipropionate is effective in the treatment of canine ehrlichiosis.

Lifestyle factors and bone density in the elderly: implications for osteoporosis prevention

Epidemiologic evidence suggests that lifestyle factors, such as exercise, calcium intake, and tobacco consumption, have effects on bone density. However, the influence of these factors in the elderly has not been well documented. To examine the effects of lifestyle factors in the elderly, we measured bone density (BMD) at the lumbar spine and proximal femur in 709 elderly men and 1080 women participating in the Dubbo Osteoporosis Epidemiology study (DOES), a community-based, longitudinal, epidemiologic study of osteoporosis in men and women over the age of 60. BMD was significantly higher in men than in women (20% at all sites). There was an age-related decline in BMD at the femoral neck in both sexes and at the lumbar spine in women. Between the ages of 60 and 80, the decrease in BMD at the femoral neck among women was 18.9%, which is almost twice the decrease in BMD among men (10.1%). Tobacco consumption was associated with a reduction in BMD at both sites in both sexes (5-8%), and this effect was independent of calcium intake or body weight. Exsmokers had BMD intermediate between that of current smokers and never smokers, suggesting the influence of tobacco was partially reversible. Quadriceps strength predicted bone density at the proximal femur in elderly men but not in women. Analyzing BMD (adjusted for age and weight) in tertiles of muscle strength and calcium intake revealed an interaction between calcium intake and muscle strength on bone density; BMD at the femoral neck among those with higher quadriceps strength and calcium intake was approximately 5% higher (P < 0.05) than in those with low quadriceps strength and calcium intake in both men and women.(ABSTRACT TRUNCATED AT 250 WORDS)

Emergency department utilization by adolescents

PURPOSE

To review adolescents' utilization of a hospital emergency department (ED) in a rural area, to identify their characteristics, and to explore their motivation to seek health care in this setting.

METHODS

A retrospective chart survey of all 4932 adolescent visits (ages 12-18 years, 55.5% females) to the ED in a small town with a population of 55,000 serving a rural area was conducted for the calendar year 1989. Chief complaints and diagnoses were retrospectively categorized according to six groups: injury, pulmonary problems, Ob/Gyn, infection, nonspecific pain (complaint)/no diagnosis (diagnoses), and "other."

RESULTS

There was an increasing number of visits with increasing age. Adolescents with private insurance, who accounted for 50% of patients, were more likely than self-paying adolescents (14%) and adolescents on Medicaid (36%) to have a primary care source and to have access to a telephone. Injury was the most common diagnosis with motor vehicle accidents (MVA) accounting for 15% of all injuries. Self-paying adolescents and those on Medicaid were more likely to be diagnosed with an infection or an Ob/Gyn problem than adolescents with health insurance. Only 5.9% of adolescents were admitted to the hospital service. 8.5% of adolescents were discharged from the ED without a diagnosis. 78% of these had complained about nonspecific pain.

CONCLUSIONS

Many adolescents in this rural area were found not to have an identified primary care source and to seek health care in EDs. Illnesses that could have been prevented or treated in a more cost-effective setting thus become "emergencies." Primary care sources are needed that are accessible and acceptable to adolescents.

Extratemporal cortical resections and lesionectomies for partial epilepsy: complications of surgical treatment

Fifty patients with medically refractory extratemporal seizures underwent epilepsy surgery at our institution between 1988 and 1992. Twenty-nine patients (group I) had an extratemporal (mainly frontal lobe) corticectomy, and 21 patients (group II) had an epileptogenic lesion extirpated without resection of the epileptic brain tissue. Comprehensive neurologic evaluation was performed preoperatively, soon after operation, and approximately 3 months postoperatively to assess operative outcome. Magnetic resonance imaging (MRI) in group I patients usually showed no abnormality or a large destructive lesion. Neuroimaging showed a foreign tissue lesion in most group II patients. Thirteen of the 29 patients who underwent corticectomy had at least one adverse event (AE) potentially related to operation at the time of initial assessment. Four of the 13 patients required a surgical procedure to treat the operative complication, but only 1 of the 13 patients had a persistent neurologic deficit at follow-up examination. Three of the 21 patients who received lesionectomy had acute and persistent neurologic morbidity. Patients undergoing cortical resection remained intubated longer postoperatively (p < 0.005), and required longer hospitalization after operation (p < 0.001) and in the intensive care unit (p < 0.001) as compared with the lesionectomy group. Results of this study may prove useful in counseling patients regarding neurologic outcome after extratemporal surgery.

Diseases and management of backyard chicken flocks in Chitungwiza, Zimbabwe

To gather information on backyard chicken flocks in Chitungwiza, an urban center in Zimbabwe, 85 flock owners were interviewed. The mean flock size was 53 birds (range 1-650), and most birds were kept for meat, for either domestic consumption or local sale. Mean age at slaughter was 12.4 weeks (range 8-24). None of the owners vaccinated their birds, and reported mortality rates were high (mean 25%), most commonly being associated with diseases causing eye and respiratory problems. Most owners complained of a lack of technical and veterinary advice. Commercial enzyme-linked immunosorbent assays on sera from 460 birds in 52 flocks showed that the birds had been exposed to avian reovirus (3%), avian leukosis virus (9%), avian encephalomyelitis virus (11%), Newcastle disease virus (27%), Mycoplasma gallisepticum and M. synoviae (33%), Pasteurella multocida (52%), infectious bursal disease virus (55%), reticuloendotheliosis virus (65%), and infectious bronchitis virus (86%). Parasite infections were detected only rarely.

A serosurvey using enzyme-linked immunosorbent assay for antibodies against poultry pathogens in ostriches (Struthio camelus) from Zimbabwe

Horseradish peroxidase-conjugated goat anti-ostrich IgG was raised and used in commercial enzyme-linked immunosorbent assay kits to detect antibodies reactive with 11 poultry pathogens in sera from 149 ostriches from nine farms around Zimbabwe. Antibodies were detected to turkey rhinotracheitis virus (99%), Newcastle disease virus (23%), avian reovirus (19%), infectious bursal disease virus (15%), avian encephalomyelitis virus (15%), Mycoplasma gallisepticum and/or M. synoviae (11%), reticuloendotheliosis virus (10%), Salmonella enteritidis (8%), avian leukosis virus (3%), infectious bronchitis virus (2%), and Pasteurella multocida (< 1%). Although evidence of prior infection with turkey rhinotracheitis and newcastle disease virus was present on all farms tested, there was marked variation between farms in the prevalence of exposure to other poultry pathogens.

Isolation and characterization of serum immunoglobulin classes of the ostrich (Struthio camelus)

Immunoglobulins were separated from ostrich sera by ammonium sulfate precipitation and ion-exchange chromatography. Two classes of immunoglobulin could be identified, corresponding to IgG and IgM of other species, based on elution profiles from ion-exchange columns and molecular mass estimation on gel-filtration chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). On SDS-PAGE, the heavy chains of IgG and IgM were shown to have molecular masses of 67.5 kDa and 65 kDa, respectively, and the light chains common to both were shown to have a molecular mass of 27 kDa. The ostrich immunoglobulins were not recognized by monoclonal and polyclonal antibodies against immunoglobulins of many species of animals tested, nor by antibodies against chicken immunoglobulins.

Species-specific BALB/c mouse antibodies to rickettsiae studied by western blotting

BALB/c mice were inoculated intraperitoneally either once only, or up to four times at weekly intervals, with viable Rickettsia rickettsii, Rickettsia conorii or the Israeli spotted fever group rickettsia. Sera collected one week after the last inoculation were tested for the presence of antibodies reactive with the above organisms by indirect fluorescent antibody testing and Western blot. With repeated inoculations there was a general progressive rise in homologous and heterologous immunofluorescence titers although the increase after the first inoculation was always the greatest. For each rickettsia, the homologous titers were higher than the heterologous titers. Western blots showed that the reactive antibodies were against rickettsial high molecular mass species specific protein antigens and homologous species-specific antibody reactions were detectable earlier than heterologous cross-reacting antibody reactions. Antibodies in mice sera did not react with the group specific lipopolysaccharide-like antigens of the rickettsiae although such reactivity was strong in Western blots with sera from patients suffering from acute Rickettsia conorii infections. Our findings suggest that the intraperitoneal route of inoculation of BALB/c mice can be used for the differentiation of spotted fever group rickettsiae.

Postural stability, falls and fractures in the elderly: results from the Dubbo Osteoporosis Epidemiology Study

OBJECTIVE

To assess measures of postural stability in a large population of persons aged over 60 years in order to compare performance between fallers and non-fallers and relate postural stability to fracture prevalence.

METHODS

The sensorimotor, visual and balance functions were measured in 1762 ambulatory, community-dwelling patients aged between 60 and 100 years (mean age, 70.1 years) living in a large semi-urban Australian city. A history of recent falls and fractures was recorded at the time of assessment.

RESULTS

The prevalence of impairment in all tests increased with age. Men performed significantly better than women in tests of muscle strength, visual field dependence, sway on the floor with eyes open and dynamic balance. In the 12 months before testing, 72.3% of the patients experienced no falls, 18.4% fell only once and 9.3% fell on two or more occasions. Multiple fallers had weaker quadriceps, poorer tactile sensitivity, greater visual field dependence and greater body sway than other patients. Test scores for once-only fallers were mostly between those for non-fallers and multiple fallers. Those who suffered recent fall-related fractures had significantly reduced tactile sensitivity and quadriceps strength and increased body sway. Postural stability was also impaired in patients taking psychoactive and/or anti-hypertensive medications.

CONCLUSION

Tests of postural stability can identify, independently of age, individuals living in the community who are at risk of falls and fall-related fractures.

Genetic influences on type I collagen synthesis and degradation: further evidence for genetic regulation of bone turnover

Circulating osteocalcin, a marker of bone formation, is under strong genetic influence, and this effect is related to the genetic influence on bone density. To examine genetic influences on bone turnover further, other markers of bone formation (serum carboxyterminal propeptide of type I procollagen, PICP), bone resorption (serum pyridinoline cross-linked carboxyterminal telopeptide of type I collagen, ICTP), and nonosseous connective tissue synthesis (serum aminoterminal propeptide of type III procollagen, PIIINP) were studied in 82 female twin pairs: 42 monozygotic (MZ) and 40 dizygotic (DZ) twin pairs (mean age, MZ; 48.4 yr; DZ; 45.6 yr). The intraclass correlation coefficients of MZ twin pairs, rMZ, for serum PICP (0.78) and serum ICTP (0.68) were significantly greater than the corresponding rDZ (0.31 and 0.36, respectively), but a genetic effect on serum PIIINP was not demonstrable. Within DZ twin pair differences in serum PICP predicted differences in lumbar spine bone density (r = -0.37); higher serum PICP levels indicating the twin with the lower lumbar spine bone density. Also within pair differences in serum ICTP and PICP predicted differences in bone density at the lumbar spine independent of serum osteocalcin. These data indicate that both synthesis and degradation of type I collagen are genetically determined and that this phenomenon is related to the genetic regulation of bone density.

A new pathogenic spotted fever group rickettsia from Africa

A spotted fever group (SFG) rickettsia was isolated in Zimbabwe from a patient with tick-bite, fever, headache and regional lymphadenopathy. A further six isolates were obtained from Amblyomma hebraeum ticks collected in Zimbabwe. These human and tick isolates were indistinguishable from each other, and from an Ethiopian SFG rickettsia, by microimmunofluorescence (MIF), sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), Western blotting and polymerase chain reaction followed by restriction fragment length polymorphism analysis (PCR-RFLP). They were, however, distinguishable from other SFG ricketsiae by MIF serotyping and in the case of the most closely related serotypes, Rickettsia conorii and the Israeli SFG rickettsia, by SDS-PAGE and Western blot. PCR-RFLP failed to distinguish between the Zimbabwean and Israeli SFG rickettsia, though each of these gave different digestion products from R. conorii. The Zimbabwean human and tick isolates and the Ethiopian SFG rickettsiae therefore represent a previously undescribed rickettsial serotype which apparently is pathogenic in human beings. It is proposed that the new serotype be named the agent of African tick-bite fever in order to distinguish it from R. conorii, which until now has been recognized as the only SFG rickettsia to infect man in Africa.

Reactivity of sera collected from dogs in Mutare, Zimbabwe, to antigens of Ehrlichia canis and Cowdria ruminantium

Six of 20 sera from apparently healthy dogs in Mutare, Zimbabwe, contained antibodies which were reactive with Cowdria ruminantium and Ehrlichia canis in indirect fluorescent antibody tests at similar titres. In Western blots these sera recognised the immunodominant antigen bands of the two organisms. Sera with high titres (> 1/80) recognised additional antigen bands of each organism. It was not possible to determine whether these dogs had been exposed to C ruminantium, E canis or other Ehrlichia species. In areas where these organisms coexist serological tests for canine ehrlichiosis should be interpreted with caution.

Experimental study of the effect of weight bearing on fracture healing in the canine tibia

The authors compared the effects of decreased loading, increased loading, and baseline loading on the early (six weeks) and intermediate (12 weeks) healing of tibial fractures treated with an external fixator in adult dogs. The different loading conditions were verified by gait studies. Periosteal bone in the increased-loading fracture site was significantly increased compared with the decreased-loading site at both time intervals, and with the baseline-loading site at six weeks. The mechanical variables of energy absorption and angle of rotation at six weeks were significantly increased in the increased-loading fracture site compared with the decreased-loading site and baseline-loading site. Blood flow to the increased-loading fracture site was significantly higher than that to the decreased-loading fracture site at six weeks. Five dogs were studied at 12 weeks to compare the effects of decreased loading to increased loading. The increased-loading fracture showed significantly increased rotation, torque, and energy absorption to failure. Blood flow was not measured in the 12-week animals.

Tussometry and lung function

The tussometric parameter peak value time (PVT) has been proposed as an objective measure of laryngeal function. Whether the lower respiratory tract function influences its value is, however, unknown. This study investigates the relationship between lung function parameters forced expiratory volume in 1 second, vital capacity, peak expiratory flow rate, forced expiratory flow at 50% of vital capacity and total lung capacity (FEV1, VC, PEFR, FEF50, TLC) and PVT in 79 subjects. PVT proved to be independent of lung function. It is therefore specifically a measure of laryngeal function, and lung function need not be considered when interpreting PVT values.

The effect of systemically-administered flurbiprofen as an adjunct to toothbrushing on the resolution of experimental gingivitis

Non-steroidal anti-inflammatory drugs (NSAIDs) have been widely researched in an attempt to control periodontal diseases. This double-blind parallel group study investigated the effect of a systemic flurbiprofen preparation (100 mg daily), when combined with toothbrushing on the resolution of experimental gingivitis in human volunteers. 47 volunteers abstained from tooth cleaning for 21 days. On day 21, 23 subjects were prescribed 100 mg of flurbiprofen daily whereas 24 subjects were prescribed placebo. In both groups, toothbrushing was re-introduced and all subjects used the Bass technique for 2 min each day. Both treatment regimens were continued for 7 days. Plaque indices, gingival indices and gingival crevicular fluid flow were assessed at baseline (day 0) and on days 21 and 27. There were no significant differences at p = 0.05 between the groups for plaque indices or gingival crevicular fluid flow. The flurbiprofen group, however, demonstrated greater resolution of gingival inflammation by day 27 when compared to the placebo controls (p = 0.04). The plasma levels of flurbiprofen in the test group showed mean concentrations of flurbiprofen of 4.7 (+/- 2.1) micrograms/ml at 1 h after dosing. After 6 h, this had fallen to 4.4 (+/- 1.6) micrograms/ml. It is concluded that these serum concentrations of flurbiprofen are sufficient to produce significant anti-inflammatory effects in the gingival tissues.

Symptomatic glial cysts of the pineal gland

Small asymptomatic cysts of the pineal gland represent a common incidental finding in adults undergoing computerized tomography or magnetic resonance (MR) imaging or at postmortem examination. In contrast, large symptomatic pineal cysts are rare, being limited to individual case reports or small series. The authors have reviewed 24 cases of large pineal cysts. The mean patient age at presentation was 28.7 years (range 15 to 46 years); 18 were female and six male. Presenting features in 20 symptomatic cases included: headache in 19; nausea and/or vomiting in seven; papilledema in five; visual disturbances in five (diplopia in three, "blurred vision" in two, and unilateral partial oculomotor nerve palsy in one); Parinaud's syndrome in two; hemiparesis in one; hemisensory aberration in one; and seizures in one. Four lesions were discovered incidentally. Magnetic resonance imaging typically demonstrated a 0.8- to 3.0-cm diameter mass (mean 1.7 cm) with homogeneous decreased signal intensity on T1-weighted images, increased signal intensity on T2-weighted images, and a distinct margin. Hydrocephalus was present in eight cases. The cysts were surgically excised via an infratentorial/supracerebellar approach (23 cases) or stereotactically biopsied (one case). Histological examination revealed a cyst wall 0.5 to 2.0 mm thick comprised of three layers: an outer fibrous layer, a middle layer of pineal parenchymal cells with variable calcification, and an inner layer of hypocellular glial tissue often exhibiting Rosenthal fibers and/or granular bodies. Evidence of prior hemorrhage, mild astrocytic degenerative atypia, and disorganization of pineal parenchyma were often present. Postoperative follow-up review in all 24 cases (range 3 months to 10 years) revealed no complications in 21, mild ocular movement deficit in one, gradually resolving Parinaud's syndrome in one, and radiographic evidence of a postoperative venous infarct of the superior cerebellum with ataxia of 1 week's duration in one. Of the patients referred for study, the cysts were most often initially misdiagnosed as a pineocytoma in eight and a pilocytic astrocytoma in three. Only two patients were correctly diagnosed as having pineal cysts. This stresses the importance of recognizing the histopathological spectrum of pineal cysts, as well as correlation with radiographic findings, if a correct diagnosis is to be attained.

Serological evidence for antigenic relationships between Ehrlichia canis and Cowdria ruminantium

The sera from dogs experimentally infected with Ehrlichia canis reacted at very similar titres in indirect fluorescent antibody (IFA) tests with E canis and Cowdria ruminantium antigen. In Western blots these sera reacted strongly with the immunodominant antigens of E canis (27 kDa) and C ruminantium (25 and 32 kDa). The dogs experimentally infected with C ruminantium showed no clinical evidence of infection, though the presence of organisms in the blood was demonstrable, for up to two weeks after inoculation, by a polymerase chain reaction. The sera from these dogs were also reactive with both organisms in the IFA tests, but the antibody titres were four- to fivefold higher with C ruminantium than with E canis antigen. In Western blots, these sera reacted strongly with the 25 and 32 kDa antigens of C ruminantium but weakly with the 27 kDa antigen of E canis. These results provide strong evidence that the immunodominant antigens of E canis and C ruminantium contain cross-reacting epitopes.

The Nottingham System: objective assessment of facial nerve function in the clinic

The House-Brackmann is the most widely accepted system for the clinical assessment of facial nerve function. It is, however, being subjective and discontinuous, prone to interobserver variation. The need for an objective system persists. The Nottingham System is described and compared to the Burres-Fisch system in a study of 29 subjects with varying degrees of facial nerve function, ranging from normal to total paralysis. Within-group component of variance analysis was 7% for the Nottingham System compared to 26% for the Burres-Fisch system. Bland and Altmans' analysis showed the Burres-Fisch system to be biased, overestimating small percentage scores, and underestimating large ones. The Nottingham System proved unbiased. The Nottingham System is recommended as an accurate objective continuous grading system for the rapid assessment of facial nerve function in the clinic.

Prediction of bone density from vitamin D receptor alleles

Bone density achieved in early adulthood is the major determinant of risk of osteoporotic fracture. Up to 60% of women suffer osteoporotic fractures as a result of low bone density, which is under strong genetic control acting through effects on bone turnover. Here we show that common allelic variants in the gene encoding the vitamin D receptor can be used to predict differences in bone density, accounting for up to 75% of the total genetic effect on bone density in healthy individuals. The genotype associated with lower bone density was overrepresented in postmenopausal women with bone densities more than 2 standard deviations below values in young normal women. The molecular mechanisms by which bone density is regulated by the vitamin D receptor gene are not certain, although allelic differences in the 3' untranslated region may alter messenger RNA levels. These findings could open new avenues to the development and targeting of prophylactic interventions. It follows that other pathophysiological processes considered to be subject to complex multifactorial genetic regulation may also be modulated by a single gene with pleiotropic transcriptional actions.