Slow axonal transport of neurofilament protein in cultured neurons

We have investigated the axonal transport of neurofilament protein in cultured neurons by constricting single axons with fine glass fibers. We observed a rapid accumulation of anterogradely and retrogradely transported membranous organelles on both sides of the constrictions and a more gradual accumulation of neurofilament protein proximal to the constrictions. Neurofilament protein accumulation was dependent on the presence of metabolic substrates and was blocked by iodoacetate, which is an inhibitor of glycolysis. These data indicate that neurofilament protein moves anterogradely in these axons by a mechanism that is directly or indirectly dependent on nucleoside triphosphates. The average transport rate was estimated to be at least 130 micrometer/h (3.1 mm/d), and approximately 90% of the accumulated neurofilament protein remained in the axon after detergent extraction, suggesting that it was present in a polymerized form. Electron microscopy demonstrated that there were an abnormally large number of neurofilament polymers proximal to the constrictions. These data suggest that the neurofilament proteins were transported either as assembled polymers or in a nonpolymeric form that assembled locally at the site of accumulation. This study represents the first demonstration of the axonal transport of neurofilament protein in cultured neurons.

A novel human STE20-related protein kinase, HGK, that specifically activates the c-Jun N-terminal kinase signaling pathway

The yeast serine/threonine kinase STE20 activates a signaling cascade that includes STE11 (mitogen-activated protein kinase kinase kinase), STE7 (mitogen-activated protein kinase kinase), and FUS3/KSS1 (mitogen-activated protein kinase) in response to signals from both Cdc42 and the heterotrimeric G proteins associated with transmembrane pheromone receptors. Using degenerate polymerase chain reaction, we have isolated a human cDNA encoding a protein kinase homologous to STE20. This protein kinase, designated HPK/GCK-like kinase (HGK), has nucleotide sequences that encode an open reading frame of 1165 amino acids with 11 kinase subdomains. HGK was a serine/threonine protein kinase that specifically activated the c-Jun N-terminal kinase (JNK) signaling pathway when transfected into 293T cells, but it did not stimulate either the extracellular signal-regulated kinase or p38 kinase pathway. HGK also increased AP-1-mediated transcriptional activity in vivo. HGK-induced JNK activation was inhibited by the dominant-negative MKK4 and MKK7 mutants. The dominant-negative mutant of TAK1, but not MEKK1 or MAPK upstream kinase (MUK), strongly inhibited HGK-induced JNK activation. TNF-alpha activated HGK in 293T cells, as well as the dominant-negative HGK mutants, inhibited TNF-alpha-induced JNK activation. These results indicate that HGK, a novel activator of the JNK pathway, may function through TAK1, and that the HGK --> TAK1 --> MKK4, MKK7 --> JNK kinase cascade may mediate the TNF-alpha signaling pathway.

Microbial Dynamics in Oil-Impacted Prairie Soil

A remote site in the Tallgrass Prairie Preserve (Osage County, OK) was contaminated with crude oil by a pipeline break in 1992. In 1996, the contaminated soil was bioremediated by blending with uncontaminated soil, prairie hay, buffalo manure, and commercial fertilizers, and spreading in a shallow layer over uncontaminated soil to create a landfarm. The landfarm was monitored for two years for aerobic and anaerobic bacteria, soil gases indicative of microbial activity, and for changes in the concentration of total petroleum hydrocarbons (TPH). Levels of hydrocarbon degraders and soil gas indicators of aerobic degradation were stimulated in the landfarm during the first warm season relative to uncontaminated prairie soil. However, these same indicators were less conclusive during the second warm season, indicating depletion of the more easily degradable hydrocarbons, although the landfarm still contained 6,800 mg/kg TPH on the average at the beginning of the second warm season. Methane formation and methanogen counts were clearly stimulated in the first warm season relative to uncontaminated prairie soil, indicating that methanogenesis plays an important role in the mineralization of hydrocarbons even in these shallow soils.

EYA4, a novel vertebrate gene related to Drosophila eyes absent

We have isolated a family of four vertebrate genes homologous to eyes absent (eya), a key regulator of ocular development in Drosophila. Here we present the detailed characterization of the EYA4 gene in human and mouse. EYA4 encodes a 640 amino acid protein containing a highly conserved C-terminal domain of 271 amino acids which in Drosophila eya is known to mediate developmentally important protein-protein interactions. Human EYA4 maps to 6q23 and mouse Eya4 maps to the predicted homology region near the centromere of chromosome 10. In the developing mouse embryo, Eya4 is expressed primarily in the craniofacial mesenchyme, the dermamyotome and the limb. On the basis of map position and expression pattern, EYA4 is a candidate for oculo-dento-digital (ODD) syndrome, but no EYA4 mutations were found in a panel of ODD patients.

Enzymatically active papain preferentially induces an allergic response in mice

Human exposure to papain, a cysteine proteinase, is associated with hypersensitivity reactions. We demonstrate in mice that enzymatically active papain preferentially induces an IgG1 response and results in mast cell degranulation, both features typical of an allergic reaction. Inactive papain, blocked with E-64, appears to desensitize mice to subsequent challenge by active enzyme. These results suggest that the enzymatic activity of papain is critical in inducing an allergic response and that the use of inactive allergens may be a possible strategy for desensitizing allergic individuals.

Efficacy and safety of acarbose in metformin-treated patients with type 2 diabetes

OBJECTIVE

To demonstrate the efficacy, tolerability, and safety of acarbose compared with placebo in patients with type 2 diabetes inadequately controlled with diet and metformin (2,000 or 2,500 mg/day in divided doses).

RESEARCH DESIGN AND METHODS

This study had a multicenter randomized double-blind placebo-controlled parallel-group comparison design. The trial lasted 31 weeks and consisted of a 1-week screening period, a 6-week placebo pretreatment period, and a 24-week period of acarbose or placebo, with a forced titration from 25-50 mg t.i.d. and a titration of 50-100 mg tid that was based on glucose control. The primary efficacy variable was the mean change from baseline in HbA1c. Secondary efficacy variables included mean changes from baseline in fasting and postprandial plasma glucose, serum insulin, and triglyceride levels.

RESULTS

The addition of acarbose to patients on background metformin and diet therapy showed a statistically significant reduction in mean HbA1c of 0.65%. There were statistically significant reductions in fasting and postprandial plasma glucose and serum insulin levels compared with placebo. Gastrointestinal side effects were more frequently reported in the acarbose-treated patients. No significant differences in liver transaminase elevations were observed between patients treated with acarbose and those treated with placebo.

CONCLUSIONS

The results of this study demonstrate that the addition of acarbose to patients with type 2 diabetes who are inadequately controlled with metformin and diet is safe and generally well tolerated and that it significantly lowers HbA1c and fasting and postprandial glucose and insulin levels.

Risk of admission within 4 weeks of discharge of elderly patients from the emergency department--the DEED study. Discharge of elderly from emergency department

OBJECTIVE

to identify risk factors for admission for patients aged 75 years and older after discharge from the emergency department (DEED: discharge of elderly from emergency department).

DESIGN

Prospective evaluation of discharged elderly patients from the emergency department who were followed up after 4 weeks.

SETTING

emergency department of a teaching hospital for 1 year.

SUBJECTS

patients aged 75 and over discharged to their home or hostel.

MAIN OUTCOME MEASURES

demographic data, indices of function and cognitive status and admission to hospital within 4 weeks.

RESULTS

468 patients aged 75 and over (mean age 81.7 years; range 75-98) were enrolled; 80 patients (17.1%) were admitted to hospital during the subsequent 4 weeks. Risk factors for admission included dependence in the following activities of daily living (relative risk; 95% confidence interval): bathing (2.41; 1.32-4.41); dressing (2.38; 1.22-4.63); stairs (1.60; 1.09-2.33); finance (1.66; 1.23-2.25); shopping (1.39; 1.12-1.73) and transport (1.61; 1.25-2.06), as well as use of a community nurse (1.88; 1.12-3.17). Logistic regression analysis found two variables to be significant in predicting admission or not: dependence in transport and use of a community nurse.

CONCLUSIONS

older patients are at increased risk of readmission within 4 weeks of being sent home from the emergency department. It is possible to identify high-risk patients by a questionnaire. This allows targeting of these patients for more intensive follow-up in an attempt to ameliorate further deteriorations in their health.

Nigrostriatal dopaminergic activities in dementia with Lewy bodies in relation to neuroleptic sensitivity: comparisons with Parkinson's disease

BACKGROUND

In dementia with Lewy bodies (DLB) mild extrapyramidal symptoms are associated with moderate reductions in substantia nigra neuron density and concentration of striatal dopamine. Many DLB patients treated with typical neuroleptics suffer severe adverse reactions, which result in decreased survival.

METHODS

In a series of DLB cases, with and without neuroleptic sensitivity, substantia nigra neuron densities, striatal dopamine and homovanillic acid concentrations, and autoradiographic [3H]mazindol and [3H]raclopride binding (to the dopamine transporter and D2 receptor, respectively) were analyzed and compared to control and idiopathic Parkinson's disease cases.

RESULTS

D2 receptors were up-regulated in neuroleptictolerant DLB and Parkinson's disease compared to DLB without neuroleptic exposure and controls. D2 receptors were not up-regulated in DLB cases with severe neuroleptic reactions. Dopamine uptake sites were reduced concomitantly with substantia nigra neuron density in Parkinson's disease compared to controls, but there was no significant correlation between substantia nigra neuron density and [3H]mazindol binding in DLB groups. There was no significant difference in substantia nigra neuron density, [3H]mazindol binding, and dopamine or homovanillic acid concentration between neuroleptic-tolerant and -sensitive groups.

CONCLUSIONS

Failure to up-regulate D2 receptors in response to neuroleptic blockade or reduced dopaminergic innervation may be the critical factor responsible for neuroleptic sensitivity.

Rate of accumulation of Luxol Fast Blue staining material and mitochondrial ATP synthase subunit 9 in motor neuron degeneration mice

The rate of accumulation of Luxol Fast Blue staining material in the hippocampus of motor neuron degeneration (mnd/mnd) mice, a model of Batten Disease, was quantitated. Stained material increased linearly up to 8 months of age. A quantitative immunoassay was used to measure levels of mitochondrial ATP synthase subunit 9 in brain and liver of mnd/mnd mice. Levels of subunit 9 increased progressively throughout the lifespan of mnd/mnd mice reaching levels approximately 5-fold higher than in control animals. The rate of accumulation of subunit 9 is not consistent with any simple complete or partial degradation defect that is constant throughout the animal's life. Two more complicated models are discussed which are consistent with the observed accumulation rate of subunit 9.

Re-engineering the elective surgical service of a tertiary hospital: a historical controlled trial

OBJECTIVE

To study the clinical effects of re-engineering the processes associated with elective surgery.

DESIGN

A prospective, historical controlled trial. Control patients were enrolled from March 1995 to January 1996, and postintervention patients from February 1996 to October 1996.

SETTING

A major teaching, tertiary care hospital (Prince of Wales Hospital, Sydney).

PATIENTS

224 patients (123 before and 101 after the intervention) undergoing elective herniorrhaphy of laparoscopic cholecystectomy who lived in the local area.

INTERVENTION

Introduction of a re-engineered surgical service consisting of preadmission assessment and education, admission on day of surgery, and postacute care after discharge. There were no changes to the operative methods or infection control procedures.

MAIN OUTCOME MEASURES

Length of stay, operative complications, pain scores and patient satisfaction.

RESULTS

The risk of a patient suffering one or more complications was reduced in the postintervention group (postintervention v. control patients: 25.7% v. 38.2%; relative risk [RR], 0.66; 95% confidence interval [CI], 0.44-0.98; P = 0.035) because of a reduced risk of wound infections (5.0% v. 16.3%; RR, 0.30; 95% CI, 0.12-0.78; P = 0.0075). Other complications (perioperative or postoperative) and pain scores were unchanged. Patients treated by the re-engineered service had a significantly shorter length of stay, reported a higher level of satisfaction with the preoperative and postdischarge care, and were more likely to say that they would have the same treatment again (92.9% v 82.6%; P = 0.037).

CONCLUSIONS

Re-engineering surgical services, with an associated reduction in length of stay, does not lead to a deterioration in care and may decrease postoperative complications and increase patient satisfaction.

Surfing the wave of clinical laboratory science evolution in Hawai'i

OBJECTIVE

To describe the steps taken by the Hawaii Society for Clinical Laboratory Science, an affiliate of the American Society for Clinical Laboratory Science, to inform local laboratory professionals of current trends and to prepare for the future.

RESULTS

A Strategic Planning workshop was conducted at the 1997 Hawaii Society for Clinical Laboratory Science Annual Meeting where participants reviewed the essential (but non-traditional) functions of clinical laboratory scientists, and described current realities, identified forces and players affecting the changes, and envisioned the future of our profession.

CONCLUSION

As the way health care is provided changes in response to economics and advances in technology, the role of clinical laboratory scientists needs to be redefined. The Hawaii Society for Clinical Laboratory Science continues to provide timely support for members, and plans to work collaboratively with the local chapter of the Clinical Laboratory Managers' Association to advance clinical laboratory science to an appropriate place in the health care community.

Asymptomatic embolization in subjects with atrial fibrillation not taking anticoagulants: a prospective study

BACKGROUND AND PURPOSE

Embolism is believed to be the major cause of stroke in patients with nonvalvular atrial fibrillation (NVAF). The detection of asymptomatic embolic signals (ES) in individuals with NVAF might allow identification of patients at high risk of stroke and monitoring of therapy in individual subjects. We determined the frequency of asymptomatic ES in patients with NVAF who were not taking warfarin.

METHODS

Bilateral transcranial Doppler recordings were made for 1 hour from the middle cerebral arteries of 111 successive patients with NVAF taking aspirin alone or no antithrombotic or anticoagulant therapy. Adequate recordings could be made in 86 patients. In 79 subjects, recordings were performed on a second occasion to study temporal variability. Recordings for a single hour were also made in 30 age-matched control subjects.

RESULTS

ES were detected in 13 (15.1%) of NVAF subjects but in no control subjects (P=0.02). ES were detected both in subjects with symptomatic NVAF (4 of 30 [13.1%], P=0.04 versus controls) and asymptomatic NVAF (9 of 56 [16.1%], P=0.02 versus controls). There was no correlation between the presence of ES and smoking status, diabetes, hypertension, aspirin use, aspirin dose, symptomatic status, left atrial size, left ventricular function, or the presence of left atrial thrombus detected on transthoracic echocardiography. Repeating the recording increased the number of patients with ES to 21 (26.6%). On considering the results of both recordings, again there was no association for either recording between the presence of ES and smoking status, diabetes, hypertension, aspirin use, aspirin dose, age, symptomatic status, left atrial size, or left ventricular function. On repeating the recording, in the symptomatic group only 2 patients (8%) changed status, in contrast to 15 (29%) in the asymptomatic group.

CONCLUSIONS

ES can be detected in patients with NVAF at a low frequency. Particularly in asymptomatic patients, ES show marked temporal variability. We found no correlation between the presence of previously reported clinical and echocardiographic markers of increased stroke risk and the presence of ES. This association requires further investigation before the clinical utility of this technique in patients with NVAF is decided.

Effect of preoperative chemotherapy on the outcome of women with operable breast cancer

PURPOSE

To determine, in women with primary operable breast cancer, if preoperative doxorubicin (Adriamycin) and cyclophosphamide (Cytoxan; AC) therapy yields a better outcome than postoperative AC therapy, if a relationship exists between outcome and tumor response to preoperative chemotherapy, and if such therapy results in the performance of more lumpectomies.

PATIENTS AND METHODS

Women (1,523) enrolled onto National Surgical Adjuvant Breast and Bowel Project (NSABP) B-18 were randomly assigned to preoperative or postoperative AC therapy. Clinical tumor response to preoperative therapy was graded as complete (cCR), partial (cPR), or no response (cNR). Tumors with a cCR were further categorized as either pathologic complete response (pCR) or invasive cells (pINV). Disease-free survival (DFS), distant disease-free survival (DDFS), and survival were estimated through 5 years and compared between treatment groups. In the preoperative arm, proportional-hazards models were used to investigate the relationship between outcome and tumor response.

RESULTS

There was no significant difference in DFS, DDFS, or survival (P = .99, .70, and .83, respectively) among patients in either group. More patients treated preoperatively than postoperatively underwent lumpectomy and radiation therapy (67.8% v 59.8%, respectively). Rates of ipsilateral breast tumor recurrence (IBTR) after lumpectomy were similar in both groups (7.9% and 5.8%, respectively; P = .23). Outcome was better in women whose tumors showed a pCR than in those with a pINV, cPR, or cNR (relapse-free survival [RFS] rates, 85.7%, 76.9%, 68.1%, and 63.9%, respectively; P < .0001), even when baseline prognostic variables were controlled. When prognostic models were compared for each treatment group, the preoperative model, which included breast tumor response as a variable, discriminated outcome among patients to about the same degree as the postoperative model.

CONCLUSION

Preoperative chemotherapy is as effective as postoperative chemotherapy, permits more lumpectomies, is appropriate for the treatment of certain patients with stages I and II disease, and can be used to study breast cancer biology. Tumor response to preoperative chemotherapy correlates with outcome and could be a surrogate for evaluating the effect of chemotherapy on micrometastases; however, knowledge of such a response provided little prognostic information beyond that which resulted from postoperative therapy.

Persistent nonconvulsive status epilepticus after the control of convulsive status epilepticus

PURPOSE

Convulsive status epilepticus (CSE) is a major medical and neurological emergency that is associated with significant morbidity and mortality. Despite this high morbidity and mortality, most acute care facilities in the United States cannot evaluate patients with EEG monitoring during or immediately after SE. The present study was initiated to determine whether control of CSE by standard treatment protocols was sufficient to terminate electrographic seizures.

METHODS

One hundred sixty-four prospective patients were evaluated at the Medical College of Virginia/VCU Status Epilepticus Program. Continuous EEG monitoring was performed for a minimum of 24 h after clinical control of CSE. SE and seizure types were defined as described previously. A standardized data form entry system was compiled for each patient and used to evaluate the data collected.

RESULTS

After CSE was controlled, continuous EEG monitoring demonstrated that 52% of the patients had no after-SE ictal discharges (ASIDS) and manifested EEG patterns of generalized slowing, attenuation, periodic lateralizing epileptiform discharges (PLEDS), focal slowing, and/or burst suppression. The remaining 48% demonstrated persistent electrographic seizures. More than 14% of the patients manifested nonconvulsive SE (NCSE) predominantly of the complex partial NCSE seizure (CPS) type (2). These patients were comatose and showed no overt clinical signs of convulsive activity. Clinical detection of NCSE in these patients would not have been possible with routine neurological evaluations without use of EEG monitoring. The clinical presentation, mortality, morbidity, and demographic information on this population are reported.

CONCLUSIONS

Our results demonstrate that EEG monitoring after treatment of CSE is essential to recognition of persistent electrographic seizures and NCSE unresponsive to routine therapeutic management of CSE. These findings also suggest that EEG monitoring immediately after control of CSE is an important diagnostic test to guide treatment plans and to evaluate prognosis in the management of SE.

Protein recovery using gas-liquid dispersions

Two separation techniques, foam separation and colloidal gas aphrons (CGAs), both of which are based on gas-liquid dispersions, are compared as potential applications for protein recovery in downstream processing. The potential advantages of each method are described and the concentration and selectivity achieved with each method, for a range of proteins is discussed. The physical basis of foam separation is the preferential adsorption of surface active species at a gas-liquid interface, with surface inactive species remaining in bulk solution. When a solution containing surface active species is sparged with gas, a foam is produced at the surface: this foam can be collected, and upon collapse contains surface active species in a concentrated form. CGAs are microbubble dispersions (bubble diameters 10-100 microm) with high gas hold ups (>50%) and relatively high stability, which are formed by stirring a surfactant solution at speeds above a critical value (typically around 5000 rpm). It is expected that when proteins are brought into contact with aphrons, protein adsorbs to the surfactant through electrostatic and/or hydrophobic forces. The aphron phase can be separated easily from the bulk solution due to its buoyancy, thus allowing separation of protein in a concentrated form.

Genistein modulates neuroblastoma cell proliferation and differentiation through induction of apoptosis and regulation of tyrosine kinase activity and N-myc expression

Genistein is a specific inhibitor of protein tyrosine kinase (PTK) and is considered as a therapeutic candidate for various cancers. In this paper we investigate the effects of genistein on cell proliferation and differentiation in neuroblastoma (NB) cell lines and its possible mechanism of action. Genistein substantially inhibited the growth of five (N2A, JC, SKNSH, MSN and Lan5) of the six tumor cell lines examined in a dose-dependent manner with an IC50 value of approximately 5 microg/ml. The exception was GC cells. N2A cells were treated with genistein for 6 days and exhibited morphological features of differentiation, as evidenced by the development of dendritic extensions. Terminal deoxynucleotidyl transferase (TDT) histochemical staining showed a significant elevation in darkly stained nuclei in genistein-treated N2A cells compared with controls, indicating the occurrence of apoptosis. Fluorescent quantitation of DNA fragments confirmed apoptosis in genistein-treated N2A cells. To further elucidate the possible mechanisms by which genistein modulates NB cell growth and differentiation we investigated the effect of genistein on the activities of PTK and mitogen-activated protein (MAP) kinase and N-myc proto-oncogene expression in N2A cells. The results showed that genistein down-regulated intrinsic PTK activity by approximately 33% and inhibited insulin-like growth factor (IGF)-stimulated PTK activity by 75%. The effect of genistein on the intrinsic activity of MAP kinase was insignificant. In addition, genistein significantly reduced N-myc expression in a dose-dependent fashion. Our study suggests that genistein arrests cell growth and induces NB cell differentiation by mediating apoptosis and modulating PTK activity and N-myc proto-oncogene expression.

The incidence and prevalence of HIV infection among childbearing women living in Edinburgh city, 1982-1995

OBJECTIVE

To track the complete course of the HIV epidemic among women from the city of Edinburgh who delivered babies during 1982-1995.

METHODS

The performance of the modified Serodia HIV test on dried blood spots from archived neonatal metabolic screening cards stored for up to 11 years was evaluated by testing 221 cards from neonates whose mothers' HIV infection status was already known (100 HIV-positive, 121 HIV-negative). Unlinked anonymous HIV testing of cards from neonates born during 1982-1989 was then performed and the resulting prevalence data were combined with existing data from 1990-1995. Maximum and minimum limits of HIV incidence among women during the 36-month period prior to delivery were calculated using data held on a clinical database of HIV-infected pregnant women that had been generated under strict conditions of confidentiality; these data included the date of the woman's first HIV-positive and, if available, last HIV-negative specimen.

RESULTS

The evaluation revealed a sensitivity of 91%, not clearly related to storage time, and a specificity of 100%. HIV infection first entered Edinburgh's childbearing population during the early 1980s with prevalence peaking at 0.4% in 1986 and then decreasing to 0.1% in 1995; a similar incidence profile was seen during this period. Since 1986, the first full year that HIV testing was available, 78% of all infections were known during the pregnancy, 13% were identified retrospectively, and only 10% (10 cases) remain unaccounted for. For infected cases during 1984-1987, 78% were injecting drug users (IDU) and only 22% acquired their infection sexually; this distribution had reversed by 1992-1995.

CONCLUSION

HIV testing of neonatal metabolic screening cards stored for up to 11 years can yield results of sufficient accuracy for epidemiological purposes. There has been a substantial decline in the prevalence and incidence of HIV since the mid-1980s. Although new infections are still occurring, the numbers are small. The decline may largely be explained by the impact of preventive measures on the spread of HIV amongst IDU, and thus from IDU to their sexual partners.