Brain trauma in aged transgenic mice induces regression of established abeta deposits

Traumatic brain injury (TBI) increases susceptibility to Alzheimer's disease (AD), but it is not known if TBI affects the progression of AD. To address this question, we studied the neuropathological consequences of TBI in transgenic (TG) mice with a mutant human Abeta precursor protein (APP) mini-gene driven by a platelet-derived (PD) growth factor promoter resulting in overexpression of mutant APP (V717F), elevated brain Abeta levels, and AD-like amyloidosis. Since brain Abeta deposits first appear in 6-month-old TG (PDAPP) mice and accumulate with age, 2-year-old PDAPP and wild-type (WT) mice were subjected to controlled cortical impact (CCI) TBI or sham treatment. At 1, 9, and 16 weeks after TBI, neuron loss, gliosis, and atrophy were most prominent near the CCI site in PDAPP and WT mice. However, there also was a remarkable regression in the Abeta amyloid plaque burden in the hippocampus ipsilateral to TBI compared to the contralateral hippocampus of the PDAPP mice by 16 weeks postinjury. Thus, these data suggest that previously accumulated Abeta plaques resulting from progressive amyloidosis in the AD brain also may be reversible.

Changes in patterns of 24-hr heart rate variability after kidney and kidney-pancreas transplant

BACKGROUND

Transplantation has been shown to improve cardiorespiratory reflex measures of autonomic function. However, there are limited data on how kidney or kidney-pancreas transplantation influence continuous autonomic modulation of heart rate and the clinical utility of 24-hr heart rate variability (HRV) monitoring.

METHODS

Ninety nondiabetic kidney and 30 diabetic kidney-pancreas transplant recipients underwent 24-hr Holter monitoring before and again at 6 and 12 months posttransplantation. Tapes were submitted for determination of HRV including interbeat variability (the proportion of adjacent R-R intervals having a difference <50 msec, the SD of all R-R intervals for the entire recording, and the SD of the averages of R-R intervals calculated over 5-min blocks for the entire recording) which is associated with vagal function, sudden death, and circadian function, respectively. Power spectral analysis quantified total neural, sympathetic, and parasympathetic modulation of the heart in ln(msec2).

RESULTS

Nondiabetic kidney recipients showed improvement (P< or =0.05) in the SD of the averages of R-R intervals calculated over 5-min blocks (83.2 vs. 95.7 msec) and the SD of all R-R intervals (94.5 vs. 104.4 msec) by 6 months and all groups showed improvement by 12 months. Kidney-pancreas recipients also showed improved total neural (4.35 vs. 4.64) and sympathetic modulation (2.70 vs. 3.13). Kidney-pancreas recipients had significantly poorer values for each measure (P< or =0.05) at all time points.

CONCLUSIONS

Cardiac autonomic neuropathy arises in the presence of uremia and diabetes, with severe dysfunction seen when these conditions occur concomitantly. Improvement in cardiac autonomic function follows both kidney and kidney-pancreas transplantation with more pronounced improvement in the circadian measures. Therefore, circadian measures of 24-hr HRV could be used to monitor the restoration of cardiac autonomic function.

Assessment of lead toxicity to the marine bacterium, Vibrio fischeri, and to a heterogeneous population of microorganisms derived from the Pearl River in Jackson, Mississippi, USA

Microorganisms are known to be excellent test organisms because of the relative ease for handling and suitability for analysis related to their small size, large number and convenient growing conditions. In this research, we tested the toxic effects of lead against a marine bacterium (Vibrio fischeri), and a heterogeneous population of bacteria derived from the Pearl River in Jackson, Mississippi. Using the level of bioluminescence in the Microtox Assay (V. fischeri), and the kinetics of dissolved oxygen uptake and growth (mixed bacterial population) as measures of toxicity, lead concentrations effecting a 50% reduction in these parameters (EC50) were determined as the toxic end-points. The activity quotients were also computed to determine the degrees of toxicity. Optical density (measure of growth) and oxygen uptake were measured over an extended period of time (20 h). EC50 values of 0.34 +/- 0.03, 3.10 +/- 0.01, and 3.80 +/- 0.02 mg/L were recorded for bioluminescence, growth, and oxygen uptake, respectively. As expected, the results indicated that the sensitivity to lead toxicity of V. fischeri was about one order of magnitude (10 times) greater than that of the mixed population of Pearl River microorganisms. Reductions in bioluminescence, growth, and oxygen uptake were directly correlated to lead concentrations, with toxic levels ranging from slightly toxic in lower concentrations to extremely toxic in higher concentrations. Upon 20 h of exposure, the times required to produce 50% reduction in dissolved oxygen uptake were (TD50S) 8.01 +/- 0.44, 9.60 +/- 0.46, 11.29 +/- 0.46, 13.03 +/- 0.57, 17.32 +/- 0.95, and 20.00 +/- 0.00 h in 0, 1, 2, 3, 4, 5, and 6 mg/L of lead, respectively, indicating a time-response relationship with respect to lead toxicity.

Mutation-specific functional impairments in distinct tau isoforms of hereditary FTDP-17

Tau proteins aggregate as cytoplasmic inclusions in a number of neurodegenerative diseases, including Alzheimer's disease and hereditary frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17). Over 10 exonic and intronic mutations in the tau gene have been identified in about 20 FTDP-17 families. Analyses of soluble and insoluble tau proteins from brains of FTDP-17 patients indicated that different pathogenic mutations differentially altered distinct biochemical properties and stoichiometry of brain tau isoforms. Functional assays of recombinant tau proteins with different FTDP-17 missense mutations implicated all but one of these mutations in disease pathogenesis by reducing the ability of tau to bind microtubules and promote microtubule assembly.

Pathogenic implications of mutations in the tau gene in pallido-ponto-nigral degeneration and related neurodegenerative disorders linked to chromosome 17

Pallido-ponto-nigral degeneration (PPND) is one of the most well characterized familial neurodegenerative disorders linked to chromosome 17q21-22. These hereditary disorders are known collectively as frontotemporal dementia (FTD) and parkinsonism linked to chromosome 17 (FTDP-17). Although the clinical features and associated regional variations in the neuronal loss observed in different FTDP-17 kindreds are diverse, the diagnostic lesions of FTDP-17 brains are tau-rich filaments in the cytoplasm of specific subpopulations of neurons and glial cells. The microtubule associated protein (tau) gene is located on chromosome 17q21-22. For these reasons, we investigated the possibility that PPND and other FTDP-17 syndromes might be caused by mutations in the tau gene. Two missense mutations in exon 10 of the tau gene that segregate with disease, Asn279(Lys) in the PPND kindred and Pro301(Leu) in four other FTDP-17 kindreds, were found. A third mutation was found in the intron adjacent to the 3' splice site of exon 10 in patients from another FTDP-17 family. Transcripts that contain exon 10 encode tau isoforms with four microtubule (MT)-binding repeats (4Rtau) as opposed to tau isoforms with three MT-binding repeats (3Rtau). The insoluble tau aggregates isolated from brains of patients with each mutation were analyzed by immunoblotting using tau-specific antibodies. For each of three mutations, abnormal tau with an apparent Mr of 64 and 69 was observed. The dephosphorylated material comigrated with tau isoforms containing exon 10 having four MT-binding repeats but not with 3Rtau. Thus, the brains of patients with both the missense mutations and the splice junction mutation contain aggregates of insoluble 4Rtau in filamentous inclusions, which may lead to neurodegeneration.

Frequency of 22q11 deletions in patients with conotruncal defects

OBJECTIVES

This study was designed to determine the frequency of 22q11 deletions in a large, prospectively ascertained sample of patients with conotruncal defects and to evaluate the deletion frequency when additional cardiac findings are also considered.

BACKGROUND

Chromosome 22q11 deletions are present in the majority of patients with DiGeorge, velocardiofacial and conotruncal anomaly face syndromes in which conotruncal defects are a cardinal feature. Previous studies suggest that a substantial number of patients with congenital heart disease have a 22q11 deletion.

METHODS

Two hundred fifty-one patients with conotruncal defects were prospectively enrolled into the study and screened for the presence of a 22q11 deletion.

RESULTS

Deletions were found in 50.0% with interrupted aortic arch (IAA), 34.5% of patients with truncus arteriosus (TA), and 15.9% with tetralogy of Fallot (TOF). Two of 6 patients with a posterior malalignment type ventricular septal defect (PMVSD) and only 1 of 20 patients with double outlet right ventricle were found to have a 22q11 deletion. None of the 45 patients with transposition of the great arteries had a deletion. The frequency of 22q11 deletions was higher in patients with anomalies of the pulmonary arteries, aortic arch or its major branches as compared to patients with a normal left aortic arch regardless of intracardiac anatomy.

CONCLUSIONS

A substantial proportion of patients with IAA, TA, TOF and PMVSD have a deletion of chromosome 22q11. Deletions are more common in patients with aortic arch or vessel anomalies. These results begin to define guidelines for deletion screening of patients with conotruncal defects.

Diagnosis and initial management of blunt pancreatic trauma: guidelines from a multiinstitutional review

OBJECTIVE

The authors' objective was to resolve the current controversies surrounding the diagnosis and management of blunt pancreatic trauma (BPT).

SUMMARY BACKGROUND DATA

The diagnosis of BPT is notoriously difficult: serum amylase has been claimed to be neither sensitive nor specific, and recent anecdotal reports have suggested a role for computed tomography. The therapy of BPT has been controversial, with some suggesting selective observation and others advocating immediate exploration to prevent a delay-induced escalation in morbidity and death.

METHODS

The authors conducted a retrospective chart review of documented BPT from six institutions, using a standardized binary data form composed of 187 items and 237 data fields.

RESULTS

A significant correlation between pancreas-specific morbidity and injury to the main pancreatic duct (MPD) was noted. Patients requiring delayed surgical intervention after an unsuccessful period of observation demonstrated notably higher pancreas-specific mortality and morbidity rates, principally because of the incidence of unrecognized injuries to the MPD. Although detection of MPD injuries by computed tomography was no better than flipping a coin, endoscopic pancreatography was accurate in each of the five cases in which it was used.

CONCLUSIONS

The principal cause of pancreas-specific morbidity after BPT is injury to the MPD. Parenchymal pancreatic injuries not involving the ductal system rarely result in pancreas-specific morbidity or death. Delay in recognizing MPD injury leads to increased mortality and morbidity rates. CT is unreliable in diagnosing MPD injury and should not be used to guide therapy. Initial selection of patients with isolated BPT for observation or surgery can be based on the determination of MPD integrity.

Adverse patient occurrences as a measure of nursing care quality

OBJECTIVE

The purpose of this study was to describe relationships among adverse patient occurrences aggregated at the unit level of measurement. Relationships between adverse occurrences and a patient acuity measure were also described.

BACKGROUND

Adverse patient occurrence data have been traditionally a major indicator of quality care in hospitals; however, few studies have examined relationships among these indicators or the usefulness of these indicators for assessing the quality of nursing care.

METHODS

A correlational design was used to examine and describe patterns of relationships among in-patient units in a tertiary care hospital. The results demonstrated positive correlations between medication error rates and patient falls; these adverse occurrences correlated negatively with pressure ulcers, infections, patient complaints, and death. Pressure ulcers, infections, patient complaints and death intercorrelated positively and also related positively to patient acuity levels.

RESULTS

An examination of these same rates for a subset of units with similar patient acuity levels revealed that most of the interrelationships among the entire set of adverse occurrence indicators were positive. When patient acuity was taken into account, these adverse outcomes appeared to indicate some common underlying characteristic of the units, such as quality of nursing care.

CONCLUSIONS

This study suggests a relationship between the adverse occurrences that were correlated (pressure ulcers, patient complaints, infection, and death) and the severity of patient illness. Medication error rates and patient fall rates were not correlated with patient acuity and are more likely to indicate quality of nursing care across all types of units.

Pharmaceutical practice management

BACKGROUND

Being accomplished in the short span of 21 years the number of states granting therapeutic optometric privileges has now reached 50. Since health care reform is also expanding, optometrists' prescribing responsibilities will probably increase in proportion to their clinical demands.

PURPOSE

In addition to clinical expertise, optometrists should possess practical knowledge about pharmaceutical industry practices and the effects of managed care. This article addresses issues such as drug pricing and distribution, reimbursement, and patient costs, which can affect pharmaceutical dispensing.

CONCLUSION

Optometrists should become aware of "nonclinical" prescribing influences that can affect patients. By doing so, they can make informed decisions about the products they prescribe, to ensure optimum patient care and compliance.

Nurse staffing and patient outcomes

BACKGROUND

Nursing studies have shown that nursing care delivery changes affect staff and organizational outcomes, but the effects on client outcomes have not been studied sufficiently.

OBJECTIVE

To describe, at the level of the nursing care unit, the relationships among total hours of nursing care, registered nurse (RN) skill mix, and adverse patient outcomes.

METHODS

The adverse outcomes included unit rates of medication errors, patient falls, skin breakdown, patient and family complaints, infections, and deaths. The correlations among staffing variables and outcome variables were determined, and multivariate analyses, controlling for patient acuity, were completed.

RESULTS

Units with higher average patient acuity had lower rates of medication errors and patient falls but higher rates of the other adverse outcomes. With average patient acuity on the unit controlled, the proportion of hours of care delivered by RNs was inversely related to the unit rates of medication errors, decubiti, and patient complaints. Total hours of care from all nursing personnel were associated directly with the rates of decubiti, complaints, and mortality. An unexpected finding was that the relationship between RN proportion of care was curvilinear; as the RN proportion increased, rates of adverse outcomes decreased up to 87.5%. Above that level, as RN proportion increased, the adverse outcome rates also increased.

CONCLUSIONS

The higher the RN skill mix, the lower the incidence of adverse occurrences on inpatient care units.

Perceptual and behavioral manifestations of the Chronic Illness and Recovery models among clinical transplant coordinators

This descriptive, qualitative study examines manifestations of the Chronic Illness and Recovery models among clinical transplant coordinators. Data collected through focused group interviews revealed that the Chronic Illness model fosters patient dependency, education about the illness itself, a perception that transplantation does not change the chronic nature of illness, a view of patients as socioeconomically disadvantaged and dependent on the transplant center, and the use of reactive approaches to care. In contrast, the Recovery model encourages patient independence, limits coordinators' protective feelings toward patients, provides education for life tasks, perceives patients as socioeconomically advantaged people capable of managing their own lives, and conducts patient care in a proactive manner.

Juvenile rheumatoid arthritis-like polyarthritis in chromosome 22q11.2 deletion syndrome (DiGeorge anomalad/velocardiofacial syndrome/conotruncal anomaly face syndrome)

OBJECTIVE

To investigate the association of polyarthritis and chromosome 22q11.2 deletions.

METHODS

Eighty patients with chromosome 22q11.2 deletion syndrome followed up at The Children's Hospital of Philadelphia were examined for evidence of arthropathy or arthritis. Patients with chromosome 22q11.2 deletion syndrome and polyarthritis underwent laboratory evaluations of immunologic function to determine the relationship of their immunodeficiency to the polyarthritis.

RESULTS

The prevalence of polyarthritis in patients with chromosome 22q11.2 deletion syndrome was markedly increased over the prevalence of polyarticular juvenile rheumatoid arthritis (JRA) in the general population. All 3 patients with polyarthritis had evidence of impaired T cell function. Two of the patients with polyarthritis also had IgA deficiency.

CONCLUSION

The chromosome 22q11.2 deletion syndrome represents a primary T cell disorder which can be associated with a JRA-like polyarthritis. All 3 patients with polyarthritis had evidence of more extensive immunoregulatory derangements than those typically seen in patients with chromosome 22q11.2 deletion, and these derangements may have predisposed to the development of polyarthritis.

Cerebral amyloid angiopathy presenting as a nonhemorrhagic, infiltrating mass

We present a case of biopsy-proven cerebral amyloid angiopathy mimicking a unilateral, non-hemorrhagic, infiltrating, intra-axial mass on MRI. The patient was treated with steroids, with clinical improvement and significant resolution of the MRI abnormalities.

Who should give lifestyle advice in general practice and what factors influence attendance at health promotion clinics? Survey of patients' views

BACKGROUND

Health promotion activity in general practice has increased greatly since 1990. A large proportion of this work is undertaken by practice nurses. Little is known about patients' views about the providers of health promotion or their views about general practice health promotion clinics.

AIM

A study was carried out in 1992 to determine patients' views about the provision of health promotion advice by general practitioners and practice nurses and their views about attending health promotion clinics.

METHOD

A postal questionnaire was sent to a random sample of 1750 patients aged 16 years and over from five general practices in south Tyneside. The questionnaire explored patients' preferences regarding health promotion advice from the general practitioner or practice nurse in relation to four areas of lifestyle advice and factors that might encourage patients to attend a health promotion clinic.

RESULTS

A response rate of 75% was obtained from 1639 eligible patients. Receiving health promotion advice from either the general practitioner or the practice nurse was the most commonly preferred option expressed by patients overall. The ability of health promotion clinic staff to deal with patients' concerns about their illness and short waiting times were more likely to influence patients' attendance at health promotion clinics than the presence of a general practitioner or practice nurse.

CONCLUSION

In the present study, many patients found health advice received from practice nurses and general practitioners equally acceptable. However, it was the ability of health professionals to respond to patients' health concerns in the health promotion clinic rather than the type of health professional running the clinic that was important for patients.

"Low-dose" growth hormone therapy during peritoneal dialysis or following renal transplantation

The minimal effective dose of growth hormone (GH) to promote growth in children on dialysis or following renal transplantation remains unsettled. In order to study the issue, "low-dose" GH was administered to children with end-stage renal disease (ESRD) receiving chronic automated peritoneal dialysis (APD, n = 6, 4 males, 2 females) or following renal transplantation (T, n = 9, 8 males, 1 female). No APD patient was GH deficient, while 1 T patient (no. 2) had data consistent with GH deficiency, although he was obese (body mass index = 34 kg/m2). The mean dose of GH after 6 and 12 months of treatment was 0.16 +/- 0.02 and 0.22 +/- 0.07 versus 0.16 +/- 0.03 and 0.27 +/- 0.21 mg/kg per week for APD and T patients, respectively. When analyzing all patients, there were no significant differences before or after 6 and 12 months of GH therapy within or between the two groups, in terms of height velocity, bone age, renal function (in the T group) and height Z-scores (Z-Ht). However, the height velocity Z-score (Z-HV) increased significantly at 6 and 12 months compared with baseline in the APD patients only (P < 0.05). When the 2 T patients with the most impaired renal function were excluded from the analysis, Z-HV also increased significantly in the T patients after 12 months of GH (P < 0.02). We conclude that following "low-dose" GH therapy, children with ESRD treated with APD or T have similar increases in HV, allowing maintenance of Z-Ht but not "catch-up" growth.