Prospective Bidirectional Relationship Between Sleep Duration and Posttraumatic Stress Disorder Symptoms After Suspected Acute Coronary Syndrome

OBJECTIVE

Sleep disturbance is a "hallmark" symptom of posttraumatic stress disorder (PTSD). Poor sleep (including short sleep) after combat-related trauma can also predict subsequent PTSD. Less is known about the association between sleep duration and PTSD symptoms when PTSD is induced by acute coronary syndrome (ACS). We examined the bidirectional relationship between sleep duration and PTSD symptoms over the year after hospital evaluation for ACS.

METHODS

Participants were enrolled in this observational study after emergency department evaluation for ACS. Sleep duration ("During the past month, how many hours of actual sleep did you get at night?") and cardiac event or hospitalization-induced PTSD symptoms (PTSD Checklist) were assessed at 1, 6, and 12 months after hospital discharge. Cross-lagged path analysis was used to model the effects of sleep duration and PTSD symptoms on each other. Covariates included age, sex, race/ethnicity, cardiac severity, baseline depression symptoms, and early acute stress disorder symptoms.

RESULTS

The sample included 1145 participants; 16% screened positive for probable PTSD (PTSD Checklist score ≥33). Mean sleep duration across time points was 6.1 hours. Higher PTSD symptoms predicted shorter sleep duration at the next time point (i.e., 1-6 and 6-12 months; B = -0.14 hours/10-point difference, SE = 0.03, p < .001). Shorter sleep duration was associated with higher PTSD symptoms at the next time point (B = -0.25 points/hour, SE = 0.12, p = .04).

CONCLUSIONS

Short sleep duration and PTSD symptoms are mutually reinforcing across the first year after ACS evaluation. Findings suggest that sleep, PTSD symptoms, and their relationship should be considered in the post-ACS period.

The association between sleep and psychological distress among New York City healthcare workers during the COVID-19 pandemic

BACKGROUND

Healthcare workers (HCWs) treating patients with COVID-19 report psychological distress. We examined whether disturbed sleep was associated with psychological distress in New York City (NYC) HCWs during the initial peak of the COVID-19 pandemic (April-May 2020).

METHODS

HCWs completed a survey screening for acute stress (4-item Primary Care PTSD screen), depressive (Patient Health Questionaire-2), and anxiety (2-item Generalized Anxiety Disorder scale) symptoms. Insomnia symptoms (modified item from the Insomnia Severity Index) and short sleep (SS, sleep duration <6 h/day) were assessed. Poisson regression analyses predicting psychological distress from SS and insomnia symptoms, adjusting for demographics, clinical role/setting, redeployment status, shifts worked, and multiple comparisons were performed.

RESULTS

Among 813 HCWs (80.6% female, 59.0% white) mean sleep duration was 5.8 ± 1.2 h/night. Prevalence of SS, insomnia, acute stress, depressive, and anxiety symptoms were 38.8%, 72.8%, 57.9%, 33.8%, and 48.2%, respectively. Insomnia symptoms was associated with acute stress (adjusted prevalence ratio [PR]: 1.51, 95% CI: 1.35, 1.69), depressive (PR: 2.04, 95% CI: 1.78, 2.33), and anxiety (PR: 1.74, 95% CI: 1.55, 1.94) symptoms. SS was also associated with acute stress (PR: 1.17, 95% CI: 1.07, 1.29), depressive (PR: 1.36, 95% CI: 1.233, 1.51), and anxiety (PR: 1.38, 95% CI: 1.26, 1.50) symptoms.

LIMITATIONS

Our cross-sectional analysis may preclude the identification of temporal associations and limit causal claims.

CONCLUSIONS

In our study, SS and insomnia were associated with psychological distress symptoms in NYC HCWs during the COVID-19 pandemic. Sleep may be a target for interventions to decrease psychological distress among HCWs.

Factors Associated with Insomnia Symptoms in a Longitudinal Study among New York City Healthcare Workers during the COVID-19 Pandemic

Background: Few studies have examined the longer-term psychological impact of COVID-19 in healthcare workers (HCWs). Purpose: We examined the 10-week trajectory of insomnia symptoms in HCWs during the COVID-19 pandemic. Methods: HCWs completed a web-based survey at baseline (9 April–11 May 2020) and every 2 weeks for 10 weeks. The main outcome was the severity of insomnia symptoms in the past week. Multivariable-adjusted generalized estimating equation analyses examined factors associated with insomnia symptoms. Results: n = 230 completed surveys at baseline. n = 155, n = 130, n = 118, n = 95, and n = 89 completed follow-ups at weeks 2, 4, 6, 8, and 10, respectively. Prevalence of insomnia symptoms of at least moderate severity was 72.6% at baseline, and 63.2%, 44.6%, 40.7%, 34.7%, and 39.3% at weeks 2, 4, 6, 8, and 10, respectively. In multivariable analyses, factors significantly associated with increased odds of insomnia symptoms were younger age (OR: 0.98, 95% CI: 0.96–1.00), working in a COVID-facing environment (OR: 1.75, 95% CI: 1.15–2.67) and hours worked (OR: 1.16, 95% CI: 1.06–1.27). Conclusions: The initial high rates of insomnia symptoms improved as time passed from the peak of local COVID-19 cases but four out of ten HCWs still had moderate-to-severe insomnia symptoms ten weeks after baseline.

Psychological distress, coping behaviors, and preferences for support among New York healthcare workers during the COVID-19 pandemic

OBJECTIVE

The mental health toll of COVID-19 on healthcare workers (HCW) is not yet fully described. We characterized distress, coping, and preferences for support among NYC HCWs during the COVID-19 pandemic.

METHODS

This was a cross-sectional web survey of physicians, advanced practice providers, residents/fellows, and nurses, conducted during a peak of inpatient admissions for COVID-19 in NYC (April 9th-April 24th 2020) at a large medical center in NYC (n = 657).

RESULTS

Positive screens for psychological symptoms were common; 57% for acute stress, 48% for depressive, and 33% for anxiety symptoms. For each, a higher percent of nurses/advanced practice providers screened positive vs. attending physicians, though housestaff's rates for acute stress and depression did not differ from either. Sixty-one percent of participants reported increased sense of meaning/purpose since the COVID-19 outbreak. Physical activity/exercise was the most common coping behavior (59%), and access to an individual therapist with online self-guided counseling (33%) garnered the most interest.

CONCLUSIONS

NYC HCWs, especially nurses and advanced practice providers, are experiencing COVID-19-related psychological distress. Participants reported using empirically-supported coping behaviors, and endorsed indicators of resilience, but they also reported interest in additional wellness resources. Programs developed to mitigate stress among HCWs during the COVID-19 pandemic should integrate HCW preferences.

Exercise as a therapeutic intervention for motor and non-motor symptoms in Parkinson's disease: Evidence from rodent models

Parkinson's disease (PD) is characterised by degeneration of dopaminergic neurons of the nigrostriatal pathway, which leads to the cardinal motor symptoms of the disease - tremor, rigidity and postural instability. A number of non-motor symptoms are also associated with PD, including cognitive impairment, mood disturbances and dysfunction of gastrointestinal and autonomic systems. Current therapies provide symptomatic relief but do not halt the disease process, so there is an urgent need for preventative strategies. Lifestyle interventions such as aerobic exercise have shown potential to lower the risk of developing PD and to alleviate both motor and non-motor symptoms. However, there is a lack of large-scale randomised clinical trials that have employed exercise in PD patients. This review will focus on the evidence from studies on rodent models of PD, for employing exercise as an intervention for both motor and non-motor symptoms.

Patient Barriers and Facilitators to Ambulatory and Home Blood Pressure Monitoring: A Qualitative Study

BACKGROUND

Guidelines recommend that patients with newly elevated office blood pressure undergo ambulatory blood pressure monitoring (ABPM) or home blood pressure monitoring (HBPM) to rule-out white coat hypertension before being diagnosed with hypertension. We explored patients' perspectives of the barriers and facilitators to undergoing ABPM or HBPM.

METHODS

Focus groups were conducted with twenty English- and Spanish-speaking individuals from underserved communities in New York City. Two researchers analyzed transcripts using a conventional content analysis to identify barriers and facilitators to participation in ABPM and HBPM.

RESULTS

Participants described favorable attitudes toward testing including readily understanding white coat hypertension, agreeing with the rationale for out-of-office testing, and believing that testing would benefit patients. Regarding ABPM, participants expressed concerns over the representativeness of the day the test was performed and the intrusiveness of the frequent readings. Regarding HBPM, participants expressed concerns over the validity of the monitoring method and the reliability of home blood pressure devices. For both tests, participants noted that out-of-pocket costs may deter patient participation and felt that patients would require detailed information about the test itself before deciding to participate. Participants overwhelmingly believed that out-of-office testing benefits outweighed testing barriers, were confident that they could successfully complete either testing if recommended by their provider, and described the rationale for their testing preference.

CONCLUSIONS

Participants identified dominant barriers and facilitators to ABPM and HBPM testing, articulated testing preferences, and believed that they could successfully complete out-of-office testing if recommended by their provider.

Attitudes about end-of-life care: a national cross-sectional study

BACKGROUND

Major concerns have been expressed about the preparation of physicians to provide end-of-life care. Little is known about how well academic health centers prepare students and residents to care for patients at the end-of-life and about the values about end-of-life care transmitted by faculty.

METHODS

In 1997, we conducted a telephone survey of a nationally representative sample of first-year medical students (n = 287), fourth-year medical students (n = 173), residents (n = 473), clinical faculty (n = 728), internal medicine residency training directors (n = 143), department chairs (n = 186), and medical school deans (n = 101) within U.S. academic health centers (response rate = 80.2%).

RESULTS

U.S. medical students, residents and faculty evaluate themselves as inadequately prepared to provide end-of-life care. Academic health center constituents perceive that providing care at the end of life requires medium to high levels of expertise. Academic health center constituents are divided about whether responsibility for providing care at the end of life rests with generalists or with specialists and view managed care as nearly equivalent to the fee-for-service sector in its capacity to provide excellent end-of-life care.

CONCLUSIONS

Academic leaders and faculty, as well as their students, lack confidence in their own skills in providing end-of-life care. They also question the ability of the current and evolving health care delivery system to provide excellent end-of-life care.

Heparin-binding epidermal growth factor-like growth factor: a component in chromaffin granules which promotes the survival of nigrostriatal dopaminergic neurones in vitro and in vivo

Chromaffin cells can restore function to the damaged nigrostriatal dopaminergic system in animal models of Parkinson's disease. It has been reported that a protein which is released from chromaffin granules can promote the survival of dopaminergic neurones in vitro and protect them against N-methylpyridinium ion toxicity. This neurotrophic effect has been found to be mediated by astroglial cells and blocked by inhibitors of the epidermal growth factor (EGF) receptor signal transduction pathway. Here we report the identification of bovine heparin-binding EGF-like growth factor (HB-EGF) in chromaffin granules and the cloning of the respective cDNA from bovine-derived adrenal gland. Protein extracts from bovine chromaffin granules were found to promote the survival of embryonic dopaminergic neurones in culture, to the same extent as recombinant human HB-EGF. Furthermore, the neurotrophic action of the chromaffin granule extract could be abolished by antiserum to recombinant human HB-EGF. We also show that intracerebral injection of recombinant human HB-EGF protected the nigrostriatal dopaminergic system in an in vivo adult rat model of Parkinson's disease. Intracerebral administration of this protein at the same time as a 6-hydroxydopamine lesion of the medial forebrain bundle was found to spare dopamine levels in the striatum and tyrosine hydroxylase-immunopositive neurones in the midbrain. This study has found that the main component in chromaffin granules responsible for their neurotrophic effect on dopaminergic neurones is HB-EGF. Furthermore, HB-EGF has significant protective effects on nigrostriatal dopaminergic neurones in vivo, making it a potential candidate for use in the treatment of Parkinson's disease.

Viability of dopaminergic neurones is influenced by serum and astroglial cells in vitro

Transplantation of embryonic nigral grafts into the striatum of Parkinson's disease patients is not optimal, mainly due to low survival of grafted neurones. Current strategies focus on enhancing neuronal survival by transplanting enriched neuronal cell populations. There is growing evidence for the importance of astroglia in neuronal survival.To characterise the effects of glial cells on dopaminergic neurones, 5-fluoro-2'-deoxyuridine was added to embryonic rat ventral mesencephalic cultures in the presence or absence of serum. The survival and morphology of glial fibrillary acidic protein immunopositive astroglia and tyrosine hydroxylase immunopositive dopaminergic neurones was examined. In serum-containing medium, astroglial cells predominated and 5-fluoro-2'-deoxyuridine had no significant effect on either astroglia or dopaminergic neurone survival. In serum-free medium, astroglial growth was attenuated and numbers were significantly lower in 5-fluoro-2'-deoxyuridine treated compared with untreated cultures. There was no significant difference in the numbers of dopaminergic neurones between 5-fluoro-2'-deoxyuridine treated and untreated cultures. However, by the eighth day in vitro, there were differences in the morphology of these neurones between treated and untreated cultures. This study shows that the use of 5-fluoro-2'-deoxyuridine and serum-free medium can produce a neurone-enriched culture. However, the dopaminergic neurone population present in these cultures appeared to be morphologically dissimilar to those found in control cultures as neurites were retracted and the cell somas of these cells appeared enlarged. These results provide information on the effects of astrocytes on dopaminergic neurones in ventral mesencephalic cultures and thus have implications for transplantation in Parkinson's disease.

The effect of medical education on primary care orientation: results of two national surveys of students' and residents' perspectives

PURPOSE

To examine changes among a nationally representative sample of students and residents in their orientations toward primary care as reflected in their attitudes toward the psychosocial and technical aspects of medicine and their perceptions of the academic environment for primary care.

METHOD

Confidential telephone interviews of stratified national probability samples of first- and fourth-year medical students and residents were conducted in 1994 and 1997. The 1997 survey included 219 students and 241 residents who had also been interviewed in 1994. Participants were asked about their attitudes toward addressing psychosocial issues in medicine and their perceptions of faculty and peer attitudes toward primary care. Responses were compared over time and across groups.

RESULTS

Between the first and fourth years of medical school, there was a decline over time in students' reported orientations to socioemotional aspects of patient care (61.6% versus 42.7%, p =.001) and their perceptions that working with psychosocial issues of patients made primary care more attractive (56.3% versus 43.5%, p =.01). This pattern continued for 1997 residents (PGY-3), who were even less likely to say that addressing psychosocial issues made primary care more attractive (26.9%). For fourth-year students in 1994 who became PGY-3 residents in 1997, there was an increased perception that non-primary-care house officers and specialty faculty had positive attitudes toward primary care (20.8% versus 33.0%, p =.005; 28.3% versus 45.7%, p <.0001; respectively).

CONCLUSIONS

Between 1994 and 1997 students and residents perceived a positive shift in the attitudes of peers and faculty toward primary care. During the course of their education and training, however, the students experienced an erosion of their orientations to primary care as they progressed through medical school into residency.

Profile of a comprehensive psychiatric emergency program in a New York City municipal hospital

This paper profiles the services provided, and the patient population treated, in a busy inner city Comprehensive Psychiatric Emergency Program (CPEP) located in Elmhurst, Queens, New York City. For each CPEP component, including the emergency room, extended observation unit and crisis services two years of data are reviewed. A diagnostic profile of patients seen, description of services, patient referrals and dispositions are presented. The children and adolescents treated in the CPEP are described in more detail, focusing on the high frequency of violence to self or others seen in their presenting problems. The CPEP's role in providing comprehensive community based services is discussed.

Views of managed care--a survey of students, residents, faculty, and deans at medical schools in the United States

BACKGROUND AND METHODS

Views of managed care among academic physicians and medical students in the United States are not well known. In 1997, we conducted a telephone survey of a national sample of medical students (506 respondents), residents (494), faculty members (728), department chairs (186), directors of residency training in internal medicine and pediatrics (143), and deans (105) at U.S. medical schools to determine their experiences in and perspectives on managed care. The overall rate of response was 80.1 percent.

RESULTS

Respondents rated their attitudes toward managed care on a 0-to-10 scale, with 0 defined as "as negative as possible" and 10 as "as positive as possible." The expressed attitudes toward managed care were negative, ranging from a low mean (+/-SD) score of 3.9+/-1.7 for residents to a high of 5.0+/-1.3 for deans. When asked about specific aspects of care, fee-for-service medicine was rated better than managed care in terms of access (by 80.2 percent of respondents), minimizing ethical conflicts (74.8 percent), and the quality of the doctor-patient relationship (70.6 percent). With respect to the continuity of care, 52.0 percent of respondents preferred fee-for-service medicine, and 29.3 percent preferred managed care. For care at the end of life, 49.1 percent preferred fee-for-service medicine, and 20.5 percent preferred managed care. With respect to care for patients with chronic illness, 41.8 percent preferred fee-for-service care, and 30.8 percent preferred managed care. Faculty members, residency-training directors, and department chairs responded that managed care had reduced the time they had available for research (63.1 percent agreed) and teaching (58.9 percent) and had reduced their income (55.8 percent). Overall, 46.6 percent of faculty members, 26.7 percent of residency-training directors, and 42.7 percent of department chairs reported that the message they delivered to students about managed care was negative.

CONCLUSIONS

Negative views of managed care are widespread among medical students, residents, faculty members, and medical school deans.

Incidence of coagulase positive Staphylococcus on beef carcasses in three Australian abattoirs

The contamination of beef carcasses with coagulase-positive staphylococci (CPS) was studied at three beef abattoirs (A, B and C). The incidence and the number of CPS were determined on cattle hides immediately after slaughter and on three carcass sites (brisket, flank and round) at different points during processing along the slaughter line. The incidence of CPS on cattle hides ranged from 20 to 68.6%. At abattoir A, 6.5% of the carcasses sampled before evisceration were contaminated with CPS, compared to 40% of the carcasses after evisceration. The incidence on carcasses changed little during further processing; however, after chilling for 72 h, the incidence increased to 83%. After evisceration, the brisket and flank areas were more often contaminated than the round. A similar pattern of contamination was observed at abattoir B. At abattoir C, 26.7% of the samples collected before evisceration were contaminated and this fell to 16.7% after evisceration. After chilling for 72 h, the incidence of carcass contamination with CPS increased to 46.7%. The average number of CPS on contaminated carcasses prior to and after overnight chilling was less than 50 colony-forming units (cfu)/cm2 and, after weekend chilling, increased to 64 and 112 cfu/cm2 in abattoirs A and B, respectively. Of the isolates tested, 71.4% produced staphylococcal enterotoxin and 21% could not be classified phenotypically. The hands of workers and environmental sites associated with the evisceration process were examined for CPS at abattoir A. Hands were heavily contaminated and were the likely source of CPS contamination at this abattoir.

Neuroprotective effects of growth/differentiation factor 5 depend on the site of administration

Growth/differentiation factor 5 (GDF5) is a neurotrophin which protects the rat nigrostriatal dopaminergic pathway from 6-hydroxydopamine-induced damage. Here we used amphetamine-induced rotational testing, high-performance liquid chromatography and immunocytochemistry to investigate the minimum effective dose of GDF5. We also compared the effectiveness of injecting GDF5 into either the substantia nigra pars compacta (SNpc), the lateral ventricle (LV) or the striatum (or combinations of these sites).

Growth/differentiation factor 5 and glial cell line-derived neurotrophic factor enhance survival and function of dopaminergic grafts in a rat model of Parkinson's disease

Growth/differentiation factor 5 is a member of the transforming growth factor beta superfamily, which has neurotrophic and neuroprotective effects on dopaminergic neurons both in vitro and in vivo. Here we investigate the effects of growth/differentiation factor 5 on foetal mesencephalic grafts transplanted into a rat model of Parkinson's disease, and compare them with those of glial cell line-derived neurotrophic factor. Mesencephalic tissue was suspended in solutions containing either growth/differentiation factor 5 or glial cell line-derived neurotrophic factor prior to transplantation into the left striatum of rats with 6-hydroxydopamine lesions of the left medial forebrain bundle. Both proteins enhanced graft-induced compensation of amphetamine-stimulated rotations. Positron emission tomography studies showed that both neurotrophins increased graft-induced recovery of striatal binding of [11C]RTI-121, a marker for dopaminergic nerve terminals. Post mortem analysis at 8 weeks after transplantation showed that both neurotrophins significantly increased the survival of grafted dopaminergic neurons. This study shows that growth/differentiation factor 5 is at least as effective as glial cell line-derived neurotrophic factor in enhancing the survival and functional activity of mesencephalic grafts, and thus is an important candidate for use in the treatment of Parkinson's disease.

Phage types of Australian isolates of Salmonella enterica subsp. enterica serovar Virchow

Australian isolates (79) of Salmonella enterica subsp. enterica serovar Virchow (Salmonella Virchow) were characterized by phage typing. Thirteen phage types were identified, of which phage type (PT) 8, representing 54 of 79 isolates, was predominant, as it had been in England and Wales up to 1994 when it was replaced by PT26. Other phage types identified in Australia were distinct from those observed in England and Wales. This suggests that PT8 may be a global phage type, while others may be distinct to particular geographical regions.

Back-up bone marrow is frequently ineffective in patients with poor peripheral-blood stem-cell mobilization

PURPOSE

To assess hematologic recovery and procedure-related mortality in patients who received high-dose therapy with stem-cell support, in whom the peripheral-blood stem-cell (PBSC) collection fails (CD34+ cells < 1 x 10(6)/kg). The predictive value of granulocyte-monocyte colony-forming cell (GM-CFC) measurements and the value of bone marrow obtained after PBSC collection failure was assessed.

PATIENTS AND METHODS

The study group comprised 324 consecutive patients mobilized with granulocyte colony-stimulating factor (G-CSF) and cyclophosphamide (273 patients), G-CSF with other chemotherapy (37 patients), and G-CSF alone (14 patients). Between one and four aphereses were performed.

RESULTS

In 51 of 324 patients, there was failure to obtain 1 x 10(6)/kg CD34+ cells. Twenty-three patients had greater than 1 x 10(5)/kg GM-CFC; 22 patients proceeded to high-dose therapy. Neutrophil recovery occurred within 21 days, but platelet independence was delayed (> 28 days) in eight patients. Of 28 patients with less than 1 x 10(5)/kg GM-CFC, six received high-dose therapy with PBSC alone and five had delayed engraftment. Twelve patients with less than 1 x 10(5)/kg GM-CFC received high-dose therapy supported by bone marrow collected after PBSC collection failure. Eleven patients were assessable for engraftment; four patients had slow (> 21 days) or delayed (> 28 days) neutrophil recovery and eight patients had delayed platelet recovery. In the group of patients who received less than 1 x 10(5)/kg GM-CFC, there were five procedure-related deaths.

CONCLUSION

This study shows that delayed hematologic recovery is frequent if less than 1 x 10(6)/kg CD34+ cells are infused after high-dose therapy, particularly with GM-CFC less than 1 x 10(5)/kg. The procedure-related mortality in this latter group is high. In most patients whose PBSC collection contains less than 1 x 10(5)/kg GM-CFC, the use of bone marrow cells does not improve engraftment, which suggests that poor PBSC mobilization usually indicates poor marrow function.

Long-term protection of the rat nigrostriatal dopaminergic system by glial cell line-derived neurotrophic factor against 6-hydroxydopamine in vivo

Glial cell-line-derived neurotrophic factor (GDNF) has been shown to enhance the survival of dopaminergic neurones both in vitro and in vivo, and to protect the rodent dopaminergic system from neurotoxic damage. However, most previous studies have only examined the short-term protective effects of GDNF. We have investigated the long-term effects of GDNF on a 6-hydroxydopamine (6-OHDA)-induced lesion of the rat medial forebrain bundle (MFB), which results in complete and irreversible destruction of the nigrostriatal pathway, and is a robust model of Parkinson's disease. GDNF was administered ipsilaterally above the substantia nigra and into the lateral ventricle immediately before a unilateral 6-OHDA injection into the MFB. The effects of GDNF were examined in vivo by behavioural testing and positron emission tomography (PET) at weekly intervals, for 12 weeks. GDNF prevented the development of amphetamine-induced rotations at all time-points. PET studies, using [11C]-RTI-121 as a tracer for the dopamine transporter, indicated that GDNF prevented 6-OHDA-induced reduction of dopamine reuptake sites in the ipsilateral striatum. Post-mortem neurochemical analysis at 13 weeks after surgery found that GDNF significantly inhibited 6-OHDA-induced loss of dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid in the ipsilateral striatum. Immunocytochemistry showed that GDNF reduced 6-OHDA-induced loss of tyrosine hydroxylase-positive neurones in both the substantia nigra pars compacta and ventral tegmental area. We have shown that a single treatment with GDNF can confer long-term protective effects against a 6-OHDA lesion, which suggests that this factor may be useful for the treatment of Parkinson's disease.

Growth/differentiation factor 5 protects nigrostriatal dopaminergic neurones in a rat model of Parkinson's disease

Growth/differentiation factor 5 (GDF5), a novel member of the transforming growth factor beta superfamily, promotes the survival of dopaminergic neurones in vitro. We present here the first evidence for a neuroprotective action of GDF5 in vivo. We investigated the effects of intracerebral administration of GDF5 on a rat model of Parkinson's disease. GDF5 was administered just above the substantia nigra and into the lateral ventricle immediately before ipsilateral injection of 6-hydroxydopamine into the medial forebrain bundle. GDF5 prevented the development of amphetamine-induced rotations and preserved the integrity of striatal dopaminergic nerve terminals, as measured by positron emission tomography. Post-mortem studies showed that GDF5 spared dopamine levels in the striatum and tyrosine hydroxylase positive neurones in the midbrain. This study suggests that GDF5 has potential for the treatment of Parkinson's disease.

Evaluation of clinical scale CD34+ cell purification: experience of 71 immunoaffinity column procedures

Seventy-one mobilised PBSC collections were subject to CD34+ cell purification using the CEPRATE SC stem cell concentration system. The overall median purity of CD34+ cells was 69% (6-93%). CD34+ cell, and GM-CFC recoveries were 52% (8-107%) and 36% (3-118%). Purity was logarithmically related to the input percentage of CD34+ cells and starting requirements were established of 1% CD34 cell content for optimal purity and a minimum of 2 x 10(6)/kg CD34+ cells to ensure recovery of our minimum engraftment threshold of 1 x 10(6)/kg CD34+ cells. Reduction of the washing steps reduced non-specific cell losses and shortened the procedure but did not affect progenitor cell recovery. Purified CD34+ cells were reinfused following high-dose therapy in 35 patients. The median time to neutrophil recovery of 0.5 x 10(9)/l was 12 (10-23) days and to the attainment of platelet independence was 13 (7-100) days. The risks of delayed platelet recovery were related to the CD34+ cell dose infused and were identical to the risks when non-purified PBSC collections were used. In conclusion, purification of CD34+ cells using the CEPRATE device is reliable and the purified product results in prompt engraftment. The cell losses that occur do however restrict its use in many patients.

Progenitor-cell mobilization after low-dose cyclophosphamide and granulocyte colony-stimulating factor: an analysis of progenitor-cell quantity and quality and factors predicting for these parameters in 101 pretreated patients with malignant lymphoma

PURPOSE

To define parameters that predict for rapid engraftment after peripheral-blood stem-cell (PBSC) transplantation, progenitor thresholds, the proportion of patients who achieve these thresholds with a standardized mobilization regimen, and the factors that predict for mobilization efficiency.

PATIENTS AND METHODS

One hundred and one patients with pretreated lymphoma were mobilized with cyclophosphamide 1.5 g/m2 and granulocyte colony-stimulating factor (G-CSF), with the first apheresis performed when the recovery WBC count was > or = 5.0 x 10(9)/L. The relationship between the number of progenitor cells collected and patient age, sex, diagnosis, prior radiotherapy, and time since last chemotherapy was determined by multivariate analysis. The relationship between these factors, progenitor numbers returned, post-PBSC G-CSF, and hematologic recovery was performed in 81 patients following chemotherapy with carmustine (BCNU), etoposide, cytarabine, and melphalan (BEAM protocol).

RESULTS

No BEAM recipients had delayed neutrophil recovery beyond 28 days. Delayed platelet recovery occurred in 7.4% and minimum and optimum thresholds of 1 x 10(6) and 3.5 x 10(6) CD34+ cells/kg and 1 x 10(5) and 3.5 x 10(5) granulocyte-macrophage colony-forming cells (GM-CFC)/kg were established. Hematologic recovery was adversely affected by prior treatment with mini-BEAM, and neutrophil recovery was accelerated by post-PBSC G-CSF. The minimum GM-CFC threshold was achieved with a single apheresis in 83% of patients and in 90% with two aphereses. The optimal threshold was achieved with two leukaphereses in 69% of patients. Prior radiotherapy adversely affected mobilization.

CONCLUSION

Hematopoietic recovery following PBSC is dependent on progenitor-cell number infused and affect of previous chemotherapy on progenitor quality. Progenitor-cell mobilization is adversely affected by prior radiotherapy. The minimum threshold of GM-CFC required is achieved in most patients with a single apheresis, but an optimal collection usually requires at least two harvests.

Cortical induction of c-fos by intrastriatal endothelin-1 is mediated via NMDA receptors

Endothelin (ET) is a potent vasoconstrictor which has also been proposed to act as a neuromodulator. We have investigated the action of ET-1 on neurones in vivo, using c-fos as a marker of neuronal activation. Intrastriatal injection of ET-1 caused seizures and barrel rolling which were prevented by pretreatment with the N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 and attenuated by the nitric-oxide synthase inhibitor N omega-nitro-L-arginine (L-NNA). In association with these behaviours, a dramatic increase in c-fos mRNA expression was seen in the cerebral cortex. This increase was blocked by both MK-801 and L-NNA. We suggest that ET-1 modulates the activity of cortical afferents to the striatum, and causes seizures via an NMDA receptor-dependent mechanism.

Endothelins induce Fos expression in neurons and glia in organotypic cultures of rat cerebellum

Endothelins (ETs) and their receptors are present in high levels in the brain and have been proposed to act as neuromodulators or neurotransmitters. However, neither their role nor their precise mechanism of action in the brain is understood. In this study, c-fos expression was used as a marker of neuronal activation in organotypic cultures of rat cerebellum. ETs induced Fos protein expression in both granule cells and glia but not in Purkinje cells. Granule cells and glia were both very sensitive to ETs, but different receptor subtypes appeared to be involved, because granule cells did not respond to ET-3. However, they did respond to the ETB-selective agonist BQ3020, suggesting the possible existence of a novel neuronal ETB-like receptor. The induction of Fos in granule cells was independent of extracellular calcium ion concentration, but the ryanodine receptor antagonist dantrolene significantly inhibited the response to ETs, suggesting that the mobilisation of calcium ions from intracellular stores is important. These data support previous evidence that ETs act directly on neurones and show that the intracellular pathways after ET receptor activation are complex. It appears likely that ETs play an important neuromodulatory role in the cerebellum.

Peripheral blood stem cell support does not accelerate haemopoietic recovery from miniBEAM chemotherapy

Intermediate-dose salvage therapy is frequently given for relapsed and resistant lymphomas and is usually intensely myelosuppressive. In an attempt to reduce the haematological toxicity of miniBEAM, one of the commonly used salvage regimens, peripheral blood stem cell (PBSC) support was given to 21 consecutive patients who received miniBEAM chemotherapy. The outcome was compared with a non-randomised control group of consecutive patients who were similar to the supported group apart from the fact that it was not possible to collect PBSC before miniBEAM therapy. Apart from a small, marginally significant difference between the supported and unsupported groups in the number of days for which intravenous antibiotics were required, there were no other differences between the two groups in supportive care required and times to haematological recovery. In conclusion, PBSC support does not accelerate haematological recovery from miniBEAM therapy.

Lack of permanent nigrostriatal dopamine deficit following 6-hydroxydopamine injection into the rat striatum. Short communication

The lesion caused by a single 6-hydroxydopamine injection into rat striatum was evaluated. In vivo positron emission tomography using a dopamine reuptake tracer revealed no consistent reduction in striatal dopamine transporter. Amphetamine rotation test was negative up to 18 weeks. A 21% reduction in striatal dopamine seen at 11 weeks was not detectable at 18 weeks. Tyrosine hydroxylase-positive neurone counts showed no decline in substantia nigra. Our results suggest that this lesion may be subject to compensation and therefore should be used with caution in studies on neuroprotective treatments of Parkinson' disease.

Accessory cells do not contribute to G-CSF or IL-6 production nor to rapid haematological recovery following peripheral blood stem cell transplantation

Haemopoietic recovery is more rapid after peripheral blood stem cell (PBSC) transplantation than after autologous bone marrow transplantation, and the aim of this study was to assess the role of the large number of lymphocytes and monocytes (accessory cells) in a PBSC leukapheresis product in this rapid regeneration. Haematological recovery was therefore assessed in 10 PBSC recipients with lymphoma or myeloma in whom monocytes and T cells were depleted by a median of 2.3 and 3.3 logs by CD34+ cell selection using the CEPRATE SC stem cell concentration system and compared with recovery in 59 recipients who received whole PBSC. After allowing for the number of progenitor cells reinfused, there was no significant delay in engraftment induced by accessory cell depletion. Plasma levels of granulocyte-colony stimulating factor (G-CSF), granulocyte/monocyte-colony stimulating factor (GM-CSF), interleukin-6 (IL-6), stem cell factor (SCF) and macrophage-inhibition factor-alpha (MIP-1-alpha) during the transplant procedure were similar whether or not accessory cells were given. The G-CSF and IL-6 levels rose between days 5 and 14 post transplantation to approximately 1 ng/ml and 50 pg/ml respectively. This study indicates that accessory cells reinfused with PBSC collections are not responsible for the subsequent cytokine profile or rapid haematological recovery.

Preliminary crystallographic analysis of chloroperoxidase fromCaldariomyces fumago

Chloroperoxidase from the fungus Caldariomyces fumago has been crystallized in two space groups, C222(1) and P2(1)2(1)2(1) both of which are suitable for high-resolution X-ray studies. Parent data sets have been obtained to 2.16 A in space group C222(1) and 2.00 A in space group P2(1)2(1)2(1). Heavy-atom derivatives have been obtained with both forms and electron-density maps calculated. The heme has been located and continuous electron density between the heme and protein clearly indicates the location of the proximal ligand.

A third generation immunoassay for tumor necrosis factor alpha

Tumor necrosis factor alpha (TNF alpha) is a polypeptide cytokine produced primarily by monocytes and macrophages. It is involved in a wide variety of immune reactions. Measurement of TNF alpha originally depended upon bioassays that are of varying reliability and reproducibility. Early immunoassays for TNF alpha required handling of radioisotopes and costly disposal of radioactive waste. Subsequent use of enzymes as reporter molecules in enzyme immunoassay (EIA) has eliminated the burden of radioisotope handling and its associated costs. However, EIA has presented new challenges. Use of thimerosal as a preservative in EIAs may require high disposal costs due to its mercury content. In addition, many EIAs lack the sensitivity achievable in radioimmunoassay (RIA). We have developed a simple microplate enzyme-linked immunosorbent assay (ELISA) for the detection of TNF alpha in serum, plasma and culture supernatants. Our high affinity capture antibody has enabled us to achieve a sensitivity of 1.5 pg/mL. The assay is calibrated to the World Health Organization (W.H.O.) first international standard for TNF alpha (87/650) and exhibits excellent precision and reproducibility. Tetramethylbenzidine is used to generate the colored end product of the reaction, and thimerosal has been removed from all components.

Resonance Raman spectroscopy of the catalytic intermediates and derivatives of chloroperoxidase from Caldariomyces fumago

Near-ultraviolet resonance Raman spectra of chloroperoxidase derivatives and high valent intermediates show frequencies that can be systematically assigned. In accord with previous observations of low v4 frequencies for the ferric enzyme, and quite low v4 frequencies for the ferrous enzyme, low v4 frequencies are observed for ferryl compound II and several ferric derivatives. Resonance Raman spectra of chloroperoxidase compound I feature upshifted v2, v11, and v37 frequencies and other characteristics that argue for a 2A1u in preference to a 2A2u ground state for the porphyrin phi-cation radical. A moderately intense anomalously polarized band is observed at a frequency typical for octaethylporphyrin phi-cation radicals, which have been previously assigned as the 2A1u radical type. Similar resonance Raman spectral attributes are observed for horseradish peroxidase compound I, supporting a 2A1u symmetry state assignment for this species also. A 2A1u symmetry state assignment for chloroperoxidase and horseradish peroxidase compounds I is consistent with the beta-pyrrole substituent pattern of the protoporphyrin hemes found in these enzymes.

The mentally ill homeless: isolation and adaptation

Project HELP was established in New York City in 1982 as a mobile outreach unit providing crisis medical and psychiatric services to impaired homeless persons. The authors describe the demographic characteristics of the population served, the disposition of patients accepting treatment or shelter services, and the adaptation of the homeless to weather extremes. They discuss the difficulties in providing services to a population whose members are distrustful of authority and are unwilling to provide information about themselves. They conclude that the more disaffiliated members of the homeless population, such as those served by Project HELP, need even more extensive services than the homeless who use some kind of existing sheltered care, and they suggest various kinds of services to meet their needs.

A model career ladder approach to medical technology education

The medical technology program at the University of Vermont was modified in 1972 to create a 2 + 2 integrated curriculum with specialty options progressing that associate degree to baccalaureate degree. This design allows the fundamentals acquired in the associate degree curriculum of the medical laboratory technician (MLT) to serve as a practical and theoretical foundation that can be expanded upon in the baccalaureate degree curriculum of the medical technologist (MT). Options in the baccalaureate degree curriculum are generalist, specialist in clinical chemistry, in hematology, and in clinical microbiology. The design of this program provides a response to the changing role of the clinical laboratory practitioner.