Calpainopathy presenting as foot drop in a 41 year old

Mutations in the gene encoding muscle-specific calpain 3 protease cause limb girdle muscular dystrophy type 2A. Calpainopathy is characterised by progressive symmetrical atrophy of pelvic, scapular and trunk muscles with an elevated creatine kinase. Most patients develop symptoms in childhood and lose the ability to walk by the age of 40 years. We describe a man who presented with foot drop at the age of 41 years, together with neurophysiological, histopathological and genetic data. This is the first report of calpainopathy presenting as foot drop, and widens the phenotype associated with this disease.

Chronic lymphocytic leukemia (CLL) coexistent with HIV: An increasing association?

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Background: In the era of highly active antiretroviral therapy (HAART) HIV-seropositive patients are living longer. With improvements in overall survival the frequency and pattern of malignancies seen in these patients are changing. CLL is the most common leukemia in Western countries, yet very little has been published regarding HIV coexistent with CLL. Therefore, the aim of this study was to evaluate the clinicopathological findings and outcome of HIV-associated CLL in a series of cases. Methods: Cases of HIV-associated CLL/small lymphocytic leukemia (SLL) were collected from the authors’ archives and published case reports (using PubMed search). Information regarding patient demographics (age, gender), mode of HIV acquisition, HAART use, immunosuppression (HIV Viral load [VL], CD4+ cell count), clinical presentation, pathology, and outcome were abstracted and analyzed. Results: A total of 6 patients were identified (4 personal cases, 2 published reports) with a median patient age of 60 years (range, 50–76), 5 of whom were male. Five were homosexual and 1 heterosexual. Five patients were on HAART. Immunologic parameters available for 4 patients showed a median CD4+ count of 930 cells/mm3 (range, 396–1374) and mean HIV VL of 2,103 copies/ml (range, <75–5,297). Persistent lymphocytosis was noted in 5 cases and 4 patients had persistent/progressive lymphadenopathy. CLL/SLL was diagnosed by lymph node biopsy (n = 1) and/or flow cytometry (n = 5). Two patients remained well without treatment and 4 required therapy due to either hemolytic anemia, CLL- induced renal failure, pancytopenia, or hypogammaglobulinemia with recurrent infections. One individual died of renal failure and two from infectious complications. Conclusions: CLL/SLL may occur in association with HIV infection in the elderly without significant concomitant immunosuppression. CLL-related complications in our small series were frequent (67%), including mortality (50%). Additional cases of CLL/SLL are anticipated as HIV-infected patients in the HAART era are reported to be living longer. The association between HIV and CLL is deserving of further attention and we encourage clinicians to report their findings.

No significant financial relationships to disclose.

Novel regulatory function for NHERF-1 in Npt2a transcription

Several lines of evidence show that sodium/hydrogen exchanger regulatory factor 1 (NHERF-1) regulates the expression and activity of the type IIa sodium-dependent phosphate transporter (Npt2a) in renal proximal tubules. We have previously demonstrated that expression of a COOH-terminal ezrin binding domain-deficient NHERF-1 in opossum kidney (OK) cells decreased expression of Npt2a in apical membranes but did not affect responses to parathyroid hormone. We hypothesized that NHERF-1 regulates apical membrane expression of Npt2a in renal proximal tubule cells. To address this hypothesis, we compared regulation of Npt2a expression and function in NHERF-deficient OK cells (OK-H) and wild-type cells (OK-WT). In OK-H cells, phosphate uptake and expression of Npt2a protein in apical membranes were significantly lower than in OK-WT cells. Transient transfection of green fluorescent protein-tagged Npt2a cDNA into OK-H cells resulted in aberrant localization of an Npt2a fragment to the cytosol but not to the apical membrane. OK-H cells also exhibited a marked decrease in Npt2a mRNA expression. As demonstrated by luciferase assay, Npt2a promoter activity was significantly decreased in OK-H cells compared with that shown in OK-WT cells. Transfection of OK-H cells with human NHERF-1 restored Npt2a expression at both the protein and mRNA levels and regulation by parathyroid hormone. Expression of NHERF-1 constructs with mutations in the PDZ domains or the ezrin binding domain in OK-H cells suggested that the PDZ2 domain is critical for apical translocation of Npt2a and for expression at the mRNA level. Our data demonstrate for the first time that NHERF-1 regulates Npt2a transcription and membrane insertion.

Mitochondrial transport proteins of the brain

In this study, cellular distribution and activity of glutamate and gamma-aminobutyric acid (GABA) transport as well as oxoglutarate transport across brain mitochondrial membranes were investigated. A goal was to establish cell-type-specific expression of key transporters and enzymes involved in neurotransmitter metabolism in order to estimate neurotransmitter and metabolite traffic between neurons and astrocytes. Two methods were used to isolate brain mitochondria. One method excludes synaptosomes and the organelles may therefore be enriched in astrocytic mitochondria. The other method isolates mitochondria derived from all regions of the brain. Immunological and enzymatic methods were used to measure enzymes and carriers in the different preparations, in addition to studying transport kinetics. Immunohistochemistry was also employed using brain slices to confirm cell type specificity of enzymes and carriers. The data suggest that the aspartate/glutamate carriers (AGC) are expressed predominantly in neurons, not astrocytes, and that one of two glutamate/hydroxyl carriers is expressed predominantly in astrocytes. The GABA carrier and the oxoglutarate carrier appear to be equally distributed in astrocytes and neurons. As expected, pyruvate carboxylase and branched-chain aminotransferase were predominantly astrocytic. Insofar as the aspartate/glutamate exchange carriers are required for the malate/aspartate shuttle and for reoxidation of cytosolic NADH, the data suggest a compartmentation of glucose metabolism in which astrocytes catalyze glycolytic conversion of glucose to lactate, whereas neurons are capable of oxidizing both lactate and glucose to CO(2) + H(2)O.

Natural killer cell receptor expression in patients with severe and recurrent Herpes simplex virus-1 (HSV-1) infections

Herpes simplex virus-1 (HSV-1) is an important human pathogen which in a minority of people causes severe infections. In immunocompetent hosts the infection is self limiting. However, a small minority of people have frequent attacks. As NK cells have been implicated in host protection against HSV-1, the aim of this study was to compare NK cell receptor expression in healthy controls and in patients suffering from recurrent HSV-1 reactivations using monoclonal antibodies against NK cell receptors and 3 colour flow cytometry. Eighteen patients were recruited into the study and the results were compared to a control group. The results obtained showed that overall there was no statistical difference between patient and control groups in the expression of the NK cell receptors. There were however, individuals in the patient group (in particular, two members of one family) with significantly reduced level of activating receptors compared to the control group.

Pancreatic cancer in breast cancer patients: Incidence and relation with hormone receptor status

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Background: There has been a long-standing interest in the role of estrogens in pancreatic tumors and several reports regarding the expression of hormone receptors in pancreatic tumors and the relation between estrogen stimulation and the development of pancreatic cancer have been inconsistent . This raised questions about the increased risk of pancreatic cancer among breast cancer survivors and the possible role of antihormonal therapy in the prevention and treatment of these malignancies. Methods: The Tumor registry at the Ochsner Clinic Foundation in New Orleans was queried to identify new cases of pancreatic cancer among patients previously diagnosed with breast cancer. This was done by matching data on pancreatic and breast cancer diagnosed between January 1996 and January 2006. For each case of pancreatic cancer, data was collected from the initial breast cancer pathology report, this included : Cancer type, Grade, Estrogen Receptor status, Progesterone Receptor, HER- 2 Receptor status , BRCA gene mutation and cancer stage on diagnosis. Clinic notes and radiology reports were also reviewed to determine the presence of risk factors for pancreatic cancer, the interval of time between the two diagnosis and the stage of breast cancer at the time of diagnosis of pancreatic cancer. Results: A total of 2,669 breast cancer cases were reviewed and 5 cases of pancreatic cancers were found among patients with a previous diagnosis of breast cancer. In all these cases the breast cancer tumor was positive for Estrogen and Progesteron receptor and negative for Her2 overexpression. The incidence of pancreatic cancer in this subgroup of patients (Breast cancer, ER+,PR+, HER2-) was 1% much higher than the incidence in the general female population. Conclusions: In our experience patients with breast cancer might have a higher risk of developping pancreatic cancer. This is especially true for patients whose tumors over-express the estrogen and progesterone receptors and which do not over-express the Her2 receptor. Further studies are needed to evaluate the overall incidence of pancreatic cancer in this population and to determine the role of anti-hotmonal therapy in the prevention of these cancers.

No significant financial relationships to disclose.

Wittgenstein's neurophenomenology

Wittgenstein, despite being considered an analytical philosopher, has been quoted extensively by neurologists like Oliver Sacks. This paper explores how Wittgenstein, despite suggesting that science was antithetical to philosophy, made observations relevant to cognitive neuroscience. His work on the inner and the outer, the relation between language and sensation or perception, and on the embodied nature of emotion and its communication, is important for an understanding of neurological impairment beyond our experience. In some of his enigmatic short writing his insights are pertinent to patients' experience, say of pain, Capgras' Syndrome and spinal cord injury. He also made observations on movement sense, will and action. He did not engage in empirical science, nor obtain data in any conventional sense. But his genius was not confined to abstract philosophy. His powers of observation and introspection led him to explore lived experience in new ways, some of which are only now being approached empirically. The method of science, he once wrote, leads philosophy into complete darkness. Had he lived today, one hopes that even he might have changed his mind.