Our dementia challenge: arise palliative care

While many of the maladies of the 20th century are steadily coming under control, the march of neurodegenerative disorders continues largely unchecked. Dementias are an exemplar of such disorders; their incidence and prevalence continue to rise, in large part due to a steadily ageing population worldwide. They represent a group of chronic, progressive and, ultimately, fatal neurodegenerative diseases. Dementia has remained therapeutically recalcitrant. It is not a single disease, and because of that, we cannot expect a single panacea. While primary prevention rightly gains prominence, those with established disease currently require a shift in focus from curative intent towards improved quality of life. Enter palliative care. The sheer number and complexity of needs of patients with dementia, from the physical to the psychosocial and spiritual, necessitates the engagement of a wide range of medical disciplines, nursing and allied health professionals. One of those disciplines, as highlighted in the recent Australian Royal Commission into Aged Care Quality and Safety, is palliative care. This paper shall expand upon that role in the overall context of care for those with dementia.

Regulation of human cortical interneuron development by the chromatin remodeling protein CHD2

Mutations in the chromodomain helicase DNA binding protein 2 (CHD2) gene are associated with neurodevelopmental disorders. However, mechanisms by which CHD2 regulates human brain development remain largely uncharacterized. Here, we used a human embryonic stem cell model of cortical interneuron (hcIN) development to elucidate its roles in this process. We identified genome-wide CHD2 binding profiles during hcIN differentiation, defining direct CHD2 targets related to neurogenesis in hcIN progenitors and to neuronal function in hcINs. CHD2 bound sites were frequently coenriched with histone H3 lysine 27 acetylation (H3K27ac) and associated with high gene expression, indicating roles for CHD2 in promoting gene expression during hcIN development. Binding sites for different classes of transcription factors were enriched at CHD2 bound regions during differentiation, suggesting transcription factors that may cooperatively regulate stage-specific gene expression with CHD2. We also demonstrated that CHD2 haploinsufficiency altered CHD2 and H3K27ac coenrichment on chromatin and expression of associated genes, decreasing acetylation and expression of cell cycle genes while increasing acetylation and expression of neuronal genes, to cause precocious differentiation. Together, these data describe CHD2 direct targets and mechanisms by which CHD2 prevents precocious hcIN differentiation, which are likely to be disrupted by pathogenic CHD2 mutation to cause neurodevelopmental disorders.

Motor neuron disease: The last 12 months

BACKGROUND

For patients with motor neuron disease (MND), the final 12 months of life can be a tumultuous period, with rapid and significant losses in function and independence, regular contact with the health system and carer stress.

OBJECTIVE

The aim of this article is to provide an outline of the challenges encountered during the last 12 months of life and the role of the specialised multidisciplinary team in managing the challenges that may arise.

DISCUSSION

While MND remains rare overall, it is likely that most general practitioners (GPs) will encounter at least one patient with MND during their career. An understanding of the complexity of this group of diseases, including management in the terminal phase, is important given the GP is a valuable member of the multidisciplinary team.

The neuropalliative multidisciplinary team-Members and their roles

Neurodegenerative conditions are prominent contributors to both morbidity and mortality worldwide. They pose a significant challenge to health professionals, health systems, and the often unpaid, untrained family members and carers. The many and varied challenges encountered are best managed by a multidisciplinary neuropalliative team, as it is impossible for a single clinician to possess and deliver the wide range of skills and services required to optimally care for these patients. This chapter discusses the assembly, maintenance, and care of such a team, as well as potential difficulties and solutions in domains such as funding, training, geographical remoteness, as well as the potential lack of awareness and acceptance by colleagues. A comprehensive description of the role of all possible team members is discussed. The chapter outlines the concept, content, and potential benefits of a multidisciplinary team in neuropalliative care. Its thesis is twofold: that multidisciplinary care is vital and, second, that the sum of the whole of a team can be greater than the individual parts with respect to organization, planning, experience, and creativity of approach. With all these factors considered, and implemented wherever possible, we may all move closer to optimizing the comfort and care of our shared neuropalliative patients.

Parkinsonism and cerebrovascular disease

The relationship between cerebrovascular disease and parkinsonism is commonly seen in everyday clinical practice but remains ill-defined and under-recognised with little guidance for the practising neurologist. We attempt to define this association and to illustrate key clinical, radiological and pathological features of the syndrome of Vascular Parkinsonism (VaP). VaP is a major cause of morbidity in the elderly associated with falls, hip fractures and cognitive impairment. Although acute parkinsonism is reported in the context of an acute cerebrovascular event, the vast majority of VaP presents as an insidious syndrome usually in the context of vascular risk factors and radiological evidence of small vessel disease. There may be an anatomic impact on basal ganglia neuronal networks, however the effect of small vessel disease (SVD) on these pathways is not clear. There are now established reporting standards for radiological features of SVD on MRI. White matter hyperintensities and lacunes have been thought to be the representative radiological features of SVD but other features such as the perivascular space are gaining more importance, especially in context of the glymphatic system. It is important to consider VaP in the differential diagnosis of Parkinson disease (PD) and in these situations, neuroimaging may offer diagnostic benefit especially in those patients with atypical presentations or refractoriness to levodopa. Proactive management of vascular risk factors, monitoring of bone density and an exercise program may offer easily attainable therapeutic targets in PD and VaP. Levodopa therapy should be considered in patients with VaP, however the dose and effect may be different from use in PD. This article is part of the Special Issue "Parkinsonism across the spectrum of movement disorders and beyond" edited by Joseph Jankovic, Daniel D. Truong and Matteo Bologna.

132 Brushstrokes after stroke – art and neuroplasticity

Introduction

Despite current developments in acute stroke therapies, 65% of stroke patients have varying degrees of disability. Whilst focus on acute stroke reperfusion strategies is vital, stroke survivors still need support and appropriate opportunities for rehabilitation.

Methods and results

This is an inspiring story of an 86-year old patient with locked in syndrome who rediscovered her artistic talent after a disabling stroke. She presented with right hemiparesis, bilateral ptosis, ophthalmoplegia and aphasia. Her MRI showed multiple infarcts affecting the midbrain, thalamic, cerebellar and occipital regions. There was stenosis of the right vertebral artery- the left was hypoplastic, and new atrial fibrillation was detected.

There was no response to early rehabilitation strategies and her husband decided to care for her at home. He used creative strategies to encourage motor skills and participation in daily activities, and despite never regaining speech or independent mobility, she was able to interact meaningfully with him and her environment. They enjoyed a full and active life until her demise last year.

The patient was an accomplished artist and, with the help of her husband, reengaged in painting. This resulted in an original collection of paintings that formed an exhibition in Wollongong Art Gallery.

Conclusion

This is a life affirming story of love, enablement and ingenuity after disabling strokes, and a reminder that neuroplasticity can occur at any age. Art can provide a way to harness neuroplasticity to improve neurological deficits and quality of life, even despite significant disability. ‘A man paints with his brains and not with his hands. ‘(Michaelangelo).

111 Recurrent headaches with psychosis, CSF lymphocytosis, vessel beading and papilloedema- autoimmune/viral encephalitis with vasculopathy or unusual presentation of reversible cerebral vasoconstriction syndrome (RCVS)?

Introduction

Headache is a common Neurology presentation in both outpatient and ED settings. We present a challenging headache in a previously asymptomatic young female patient.

Case

A 27 year old female patient presented to ED with severe headache, vomiting and photophobia, after multiple presentations elsewhere, diagnosed as migraine, with normal neurological examination and MRI. Episodes of excruciating headache were associated with writhing and vomiting but spontaneously resolved with residual background pain. Indomethacin helped but she re-presented with headache and psychosis requiring intubation and ICU admission.

Investigations included CSF - protein 0.85, leucocytosis 58 cells (lymphocytic) and normal cerebral venography. Acyclovir was commenced but viral PCRs were negative and she was extubated. MRI was suspicious for subtle posterior sulcal hyperintensity and beading in occipital and posterior cerebral arteries.

Another episode occurred ten days later requiring intubation, examination showed papilloedema. CSF examination showed raised pressure, normal protein and 48 lymphocytes; flow cytometry and cytology were unrevealing. NMDA receptor antibody returned positive in serum but not CSF. Subtle beading in right PCA branches remained. IVIG and steroids were used with dramatic response. Further investigation revealed positive EBV serology only and papilloedema resolved. Steroids were weaned and she remains in remission.

Conclusion

We present an interesting case of recurrent acute headaches with intracranial hypertension, psychosis and CSF lymphocytosis. The recurrent headaches and vessel beading suggest RCVS, perhaps triggered by viral or autoimmune encephalitis. The NMDA receptor antibody result should be interpreted with caution given the absence of antibody in CSF and dramatic recovery.

Isolated painful trigeminal neuropathy as an unusual presentation of chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids: A case report

BACKGROUND

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is an inflammatory central nervous system disorder, typically presenting with subacute symptoms referable to brainstem and cerebellar pathology. This is the first report of CLIPPERS presenting with a painful trigeminal neuropathy.

CASE REPORT

We report an unusual case of CLIPPERS presenting with facial pain and sensory symptoms, in the absence of other brainstem or cerebellar signs. Perivascular enhancement of peri-pontine structures on neuroimaging, lymphocytic infiltrate on histopathology and rapid clinical and radiological responsiveness to glucocorticosteroids were key to diagnosis. Extensive investigations excluded various differential aetiologies.

CONCLUSION

The pathogenesis of CLIPPERS is poorly understood, and the diagnostic criteria are yet to be validated. In this case, facial pain was not associated with other brainstem or cerebellar signs, broadening current understanding of how CLIPPERS may present. This has clinical implications in guiding future investigations for patients presenting with painful trigeminal neuropathy.

Prospective study of POLG mutations presenting in children with intractable epilepsy: prevalence and clinical features

Purpose

To assess the frequency and clinical features of childhood-onset intractable epilepsy caused by the most common mutations in the POLG gene, which encodes the catalytic subunit of mitochondrial DNA polymerase gamma.

Methods

Children presenting with nonsyndromic intractable epilepsy of unknown etiology but without documented liver dysfunction at presentation were eligible for this prospective, population-based study. Blood samples were analyzed for the three most common POLG mutations. If any of the three tested mutations were found, all the exons and the exon–intron boundaries of the POLG gene were sequenced. In addition, we retrospectively reviewed the notes of patients presenting with intractable epilepsy in which we had found POLG mutations. All available clinical data were collected by questionnaire and by reviewing the medical records.

Key Findings

We analyzed 213 blood DNA samples from patients fulfilling the inclusion criteria of the prospective study. Among these, five patients (2.3%) were found with one of the three common POLG mutations as homozygous or compound heterozygous states. In addition, three patients were retrospectively identified. Seven of the eight patients had either raised cerebrospinal fluid (CSF) lactate (n = 3) or brain magnetic resonance imaging (MRI) changes (n = 4) at presentation with intractable epilepsy. Three patients later developed liver dysfunction, progressing to fatal liver failure in two without previous treatment with sodium valproate (VPA). Furthermore, it is worth mentioning that one patient presented first with an autism spectrum disorder before seizures emerged.

Significance

Mutations in POLG are an important cause of early and juvenile onset nonsyndromic intractable epilepsy with highly variable associated manifestations including autistic features. This study emphasizes that genetic testing for POLG mutations in patients with nonsyndromic intractable epilepsies is very important for clinical diagnostics, genetic counseling, and treatment decisions because of the increased risk for VPA-induced liver failure in patients with POLG mutations. We recommend POLG gene testing for patients with intractable seizures and at least one elevated CSF lactate or suggestive brain MRI changes (predominantly abnormal T₂-weighted thalamic signal) with or without status epilepticus, epilepsia partialis continua, or liver manifestations typical for Alpers disease, especially when the disease course is progressive.

Electrophysiological entrapment syndromes in chronic inflammatory demyelinating polyneuropathy

We do not know if peripheral nerves are more susceptible to entrapment syndromes in chronic inflammatory demyelinating polyneuropathy (CIDP). We studied 31 prospectively recruited patients with CIDP. We determined whether entrapment zones were more frequently affected by demyelination than adjacent segments. The median, ulnar, and fibular nerves were studied at the wrist, elbow, and fibular head bilaterally. Motor conduction velocity and motor conduction block were evaluated at entrapment sites and compared with contiguous segments. Demyelination was significantly more frequent for ulnar and fibular nerves away from entrapment sites. No significant difference was observed for median nerves. CIDP is not associated with increased frequency of demyelination at entrapment sites. The presence of diffuse entrapment neuropathies at compression sites does not favor a diagnosis of CIDP. Although electrophysiological study of entrapment sites is not diagnostically useful in CIDP, it may help distinguish it from other neuropathies and confirm clinically relevant, surgically treatable compressions.

Mitotic raptor promotes mTORC1 activity, G(2)/M cell cycle progression, and internal ribosome entry site-mediated mRNA translation

The mTOR signaling complex integrates signals from growth factors and nutrient availability to control cell growth and proliferation, in part through effects on the protein-synthetic machinery. Protein synthesis rates fluctuate throughout the cell cycle but diminish significantly during the G(2)/M transition. The fate of the mTOR complex and its role in coordinating cell growth and proliferation signals with protein synthesis during mitosis remain unknown. Here we demonstrate that the mTOR complex 1 (mTORC1) pathway, which stimulates protein synthesis, is actually hyperactive during mitosis despite decreased protein synthesis and reduced activity of mTORC1 upstream activators. We describe previously unknown G(2)/M-specific phosphorylation of a component of mTORC1, the protein raptor, and demonstrate that mitotic raptor phosphorylation alters mTORC1 function during mitosis. Phosphopeptide mapping and mutational analysis demonstrate that mitotic phosphorylation of raptor facilitates cell cycle transit through G(2)/M. Phosphorylation-deficient mutants of raptor cause cells to delay in G(2)/M, whereas depletion of raptor causes cells to accumulate in G(1). We identify cyclin-dependent kinase 1 (cdk1 [cdc2]) and glycogen synthase kinase 3 (GSK3) pathways as two probable mitosis-regulated protein kinase pathways involved in mitosis-specific raptor phosphorylation and altered mTORC1 activity. In addition, mitotic raptor promotes translation by internal ribosome entry sites (IRES) on mRNA during mitosis and is demonstrated to be associated with rapamycin resistance. These data suggest that this pathway may play a role in increased IRES-dependent mRNA translation during mitosis and in rapamycin insensitivity.

The value of sensory electrophysiology in chronic inflammatory demyelinating polyneuropathy

OBJECTIVE

The purpose of this study was to evaluate the usefulness of sensory nerve conduction studies in comparison and in combination with motor conductions in diagnosing chronic inflammatory demyelinating polyneuropathy (CIDP).

METHODS

We retrospectively compared the electrophysiology of 20 patients with CIDP to that of 20 controls with axonal polyneuropathy, and 20 controls with myopathy. Five sensory abnormality patterns were evaluated.

RESULTS

The "abnormal radial normal sural" ("ARNS") pattern showed a sensitivity of 25% for CIDP and specificity of 100% versus axonal neuropathies (p=0.047). The "abnormal sural normal radial" ("ASNR") pattern had a sensitivity of 75% for axonal neuropathy with a specificity of 80% versus CIDP (p=0.0012). Presence of ARNS or absence of ASNR patterns showed equivalent or superior sensitivity and specificity to most individual motor demyelinating defects for CIDP. Presence of ARNS or absence of ASNR patterns, integrated within three different sets of electrodiagnostic criteria for CIDP, increased sensitivity in all without significantly altering specificity. Effects were most remarkable with the American Academy of Neurology criteria (1991), which showed significantly improved sensitivity (50-85%; p=0.041), with preserved specificity of 100%.

CONCLUSIONS

The use of sensory abnormality patterns appears justified in comparison and combination with motor defects in diagnosing CIDP.

SIGNIFICANCE

Sensory studies may be useful in contributing to the electrodiagnosis of CIDP and their inclusion in existing electrodiagnostic criteria deserves consideration.

Transforming Growth Factor-β and microRNA:mRNA Regulatory Networks in Epithelial Plasticity

Noncoding microRNAs act as posttranscriptional repressors of gene function and are often deregulated in cancers and other diseases. Here we review recent findings on microRNA roles in tumorigenesis and report a microRNA profiling screen in transforming growth factor-beta1 (TGF-beta)-induced epithelial-mesenchymal transition (EMT) in human keratinocytes, a model of epithelial cell plasticity underlying epidermal injury and skin carcinogenesis. We describe a novel EMT-specific microRNA signature that includes induction of miR-21, a candidate oncogenic microRNA associated with carcinogenesis. By integrating the microRNA screen results with target prediction algorithms and gene expression profiling data, we outline a framework for TGF-beta-directed microRNA:messenger RNA (mRNA) regulatory circuitry and discuss its biological relevance for tumor progression.

Venlafaxine induces P-glycoprotein in human Caco-2 cells

PURPOSE

The objective of this study was to evaluate the effect of a treatment with venlafaxine on the expression of multidrug resistance-associated protein (MRP) gene and multidrug resistance-related proteins (MDR) in human colon carcinoma cells (Caco-2) compared to a known P-glycoprotein (PGY1) inducer, rifampine.

METHODS

Caco-2 cells were treated with venlafaxine (50 microM, 100 microM, 250 microM, and 500 microM) and rifampin (25 microM and 50 microM) to test the possible induction of MRP and MDR expression. The treatment times used were 1.5, 3, 6, 12, 24, 48, and 72 h. RNA was isolated from the cells, and MDR and MRP genes were amplified using PCR.

RESULTS

Both venlafaxine and rifampine had the most dramatic effect at the 50 microM concentration. There was an increase in MDR and MRP expression in Caco-2 cells after the acute treatment (1.5, 3, and 6 h) with venlafaxine. These results were similar to those with rifampine.

CONCLUSIONS

PGY1 contributes to renal and biliary elimination of drugs by transporting the drug out of the cell and back into the intestinal lumen, where drugs may be further metabolized by intestinal enzymes such as Cytochrome P (CYP)-450 3A4. Its function is to limit the bioavailability of orally administered compounds. Due to the increase in MDR and MRP gene expression seen after the acute treatment with venlafaxine, there could be a potential drug-drug interaction with other medications that are metabolized via CYP450-3A4 when coadministered with venlafaxine.

Treatment-refractory depression: definitions and characteristics

Forty to 50% of depressed patients who are initially prescribed antidepressant medications or administered electroconvulsive therapy do not experience a timely remission. This group typifies treatment-refractory depression (TRD), defined as a failure to demonstrate an "adequate" response to an "adequate" treatment trial (i.e., sufficient intensity of treatment for sufficient duration). The approach to the patient with TRD must be methodical. The clinician should examine potential factors contributing to apparent non-response: trial adequacy, compliance, differential diagnosis, and treatable comorbid conditions. After addressing these variables, a patient who does not demonstrate a remission may be considered treatment resistant (relative or absolute). Although many of these patients will respond to a subsequent treatment regimen, there are no (or only nominally useful) predictors for the initial selection of that "subsequent" antidepressant treatment. Hence, the initial treatment is typically chosen on the basis of safety and convenience, not differential efficacy. The search for the clinical and biological correlates of long-term or acute outcome presents a major nosologic conundrum: Who will respond to treatment? Which treatment? In this manner, TRD challenges the prognostic utility of our current phenomenologic-based diagnostic system.

A randomized clinical trial of repetitive transcranial magnetic stimulation in the treatment of major depression

BACKGROUND

Multiple groups have reported on the use of repetitive transcranial magnetic stimulation (rTMS) in treatment-resistant major depression. The purpose of this study is to assess the efficacy of rTMS in unmedicated, treatment-resistant patients who meet criteria for major depression.

METHODS

Depressed subjects, who had failed to respond to a median of four treatment trials, were assigned in a randomized double-blind manner to receive either active (n = 10; 20 2-sec trains of 20 Hz stimulation with 58-sec intervals; delivered at 80% motor threshold with the figure-of-eight coil positioned over the left dorsolateral prefrontal cortex) or sham (n = 10; similar conditions with the coil elevated and angled 45 degrees tangentially to the scalp) rTMS. These sequences were applied during 10 consecutive weekdays. Continuous electroencephalogram sampling and daily motor threshold determinations were also obtained.

RESULTS

The group mean 25-item Hamilton Depression Rating Scale (HDRS) score was 37.2 (+/- 2.0 SEM) points. Adjusted mean decreases in HDRS scores were 14.0 (+/- 3.7) and 0.2 (+/- 4.1) points for the active and control groups, respectively (p <.05). One of 10 subjects receiving active treatment demonstrated a robust response (i.e., HDRS decreased from 47 to 7 points); three other patients demonstrated 40-45% decreases in HDRS scores. No patients receiving sham treatment demonstrated partial or full responses.

CONCLUSIONS

A 2-week course of active rTMS resulted in statistically significant but clinically modest reductions of depressive symptoms, as compared to sham rTMS in a population characterized by treatment resistance.

Transient depressive relapse induced by catecholamine depletion: potential phenotypic vulnerability marker?

BACKGROUND

Although state-related alterations in catecholamine function have been well-described in depressed subjects, enduring abnormalities have been less reliably identified. In our study, medication-free subjects with fully remitted major depression underwent a paradigm of catecholamine depletion, via use of the tyrosine hydroxylase inhibitor alpha-methylparatyrosine.

METHOD

Subjects underwent 2 sets of testing conditions in a double-blind, random-ordered, crossover design, approximately 1 week apart. They underwent active catecholamine depletion (via oral administration of 5 g alpha-methylparatyrosine) or sedation-controlled, sham catecholamine depletion (via oral administration of 250 mg diphenhydramine hydrochloride), during a 2-day observation. Serial mood ratings and blood samples were obtained.

RESULTS

Fourteen subjects completed the active testing condition; 13 completed sham testing. Subjects experienced marked, transient increases in core depressive and anxiety symptoms, as demonstrated by a mean 21-point increase on Hamilton Depression Rating Scale scores. Furthermore, 10 (71%) of 14 subjects fulfilled relapse criteria during active testing, whereas 1 (8%) of 13 subjects did so during sham testing. The severity of the depressive reaction correlated with baseline plasma cortisol levels (r = 0.59; P =.04).

CONCLUSIONS

Euthymic, medication-free subjects with a history of major depression demonstrate significant depressive symptoms when undergoing testing with alpha-methylparatyrosine. This depressive reaction may represent a reliable marker for a history of depression. Further work is needed to clarify the significance of this finding.

Carbohydrate binding and resistance to proteolysis control insecticidal activity of Griffonia simplicifolia lectin II

Griffonia simplicifolia leaf lectin II (GSII), a plant defense protein against certain insects, consists of an N-acetylglucosamine (GlcNAc)-binding large subunit with a small subunit having sequence homology to class III chitinases. Much of the insecticidal activity of GSII is attributable to the large lectin subunit, because bacterially expressed recombinant large subunit (rGSII) inhibited growth and development of the cowpea bruchid, Callosobruchus maculatus (F). Site-specific mutations were introduced into rGSII to generate proteins with altered GlcNAc binding, and the different rGSII proteins were evaluated for insecticidal activity when added to the diet of the cowpea bruchid. At pH 5.5, close to the physiological pH of the cowpea bruchid midgut lumen, rGSII recombinant proteins were categorized as having high (rGSII, rGSII-Y134F, and rGSII-N196D mutant proteins), low (rGSII-N136D), or no (rGSII-D88N, rGSII-Y134G, rGSII-Y134D, and rGSII-N136Q) GlcNAc-binding activity. Insecticidal activity of the recombinant proteins correlated with their GlcNAc-binding activity. Furthermore, insecticidal activity correlated with the resistance to proteolytic degradation by cowpea bruchid midgut extracts and with GlcNAc-specific binding to the insect digestive tract. Together, these results establish that insecticidal activity of GSII is functionally linked to carbohydrate binding, presumably to the midgut epithelium or the peritrophic matrix, and to biochemical stability of the protein to digestive proteolysis.

Adhesion molecules (E-selectin and ICAM-1) in pulmonary allograft rejection

Vascular endothelial cells act as antigen-presenting cells in the lung allograft and stimulate alloreactive host lymphocytes. Activated lymphocytes and cytokines can induce expression of leukocyte-endothelial adhesion molecules that facilitate invasion of the allograft by circulating leukocytes. To define the role of endothelial HLA class II antigen and adhesion molecule expression in lung allograft rejection, we prospectively analyzed endothelial expression of HLA class II, E-selectin, and intercellular adhesion molecule-1 (ICAM-1) antigens in 52 transbronchial biopsy specimens from 24 lung allograft recipients as compared to normal control subjects. Thirty-one of 52 specimens showed histologic rejection and 8 of 24 patients developed histologic obliterative bronchiolitis (OB) by the end of the study period. Increased expression of HLA class II antigen was seen in 32 of 52 (62%) lung allograft specimens, but increased expression did not correlate with acute rejection or OB. In contrast, E-selectin expression was seen in 30 of 52 (58%) biopsy specimens and was associated with acute rejection (p < 0.005) and with the development of OB (p < 0.05). Increased expression of ICAM-1 was seen in only 18 of 52 (35%) biopsy specimens and did not correlate with acute rejection or OB. These data suggest that E-selectin expression may be a tissue marker of acute and chronic lung rejection possibly by promoting leukocyte adhesion to the allograft endothelium. The high levels of endothelial HLA class II expression may reflect long-term antigenic stimulation of the allograft even in the absence of rejection.

A NaCl-regulated plant gene encoding a brain protein homology that activates ADP ribosyltransferase and inhibits protein kinase C

A cDNA clone pCZ1, with a 1.1 kb insert, was isolated from a NaCl-adapted tobacco cell cDNA library that encodes an apparently full-length 29 kDa protein (251 amino acids) with a calculated pI of 5.7. The encoded peptide had a high amino acid sequence identity with bovine 14-3-3 protein which was originally found as an abundant protein in the animal central nervous system. Recently, proteins with sequence identity to 14-3-3 protein have also been found in plants, insects and yeast, and appear to have diverse physiological functions. Similar to the bovine brain 14-3-3 protein, the recombinant pCZ1 protein stimulated ADP-ribosylation of protein substrate by ADP-ribosyltransferase from the plant and animal pathogenic bacterium Pseudomonas aeruginosa. This recombinant protein also inhibited protein kinase C activity in vitro. Southern blot analyses indicated that most likely five genes encoding 14-3-3-like proteins are present in tobacco. The pCZ1 cDNA insert hybridized to a single mRNA of 1.1 kb from cultured tobacco cells. The level of this mRNA transcript in tobacco cells was downregulated upon adaptation to NaCl but was unaffected by short-term treatment with NaCl, ABA or ethylene. In tobacco plants, expression of transcript that hybridized to pCZ1 was tissue specific, and was most abundant in roots and flower parts. Monoclonal antibody raised against GF14 protein, a maize protein with substantial sequence identity with 14-3-3 protein detected two bands on SDS-PAGE of total proteins from unadapted tobacco cells and only a single band from cells adapted to NaCl. The GF14 antibody was also used to illustrate that the G-box element of a salt-induced gene is associated with a 14-3-3-type protein.

Derived amino acid sequence and identification of active site residues of Escherichia coli beta-hydroxydecanoyl thioester dehydrase

The nucleotide sequence of the fabA gene encoding beta-hydroxydecanoyl thioester dehydrase, a key enzyme of the unsaturated fatty acid synthesis pathway of Escherichia coli, has been determined by the dideoxynucleotide sequencing technique. Most of the sequence was obtained by sequencing intragenic insertions of the transposon, Tn1000, isolated in vivo. A synthetic primer complementary to a portion of the inverted repeat sequences at the ends of the transposon was used to prime DNA synthesis into the flanking fabA sequences. The gene is composed of 516 nucleotides (171 amino acid residues) encoding a protein with a molecular weight of 18,800. Approximately half of the derived amino acid sequence was confirmed by automated Edman sequencing of peptides obtained by cyanogen bromide cleavage. The active site histidine residue (His-70) has been identified by analysis of the peptides labeled by reaction with 14C-labeled 3-decynoyl-N-acetylcysteamine, a specific mechanism-activated inhibitor. A cysteine residue (Cys-69) adjacent to the active site histidine may play the role in catalysis previously assigned to a tyrosine residue. We also report a simplified purification process for the dehydrase beginning with extracts of a brain which greatly overproduces the enzyme.