EEG in Creutzfeldt-Jakob disease.

Electroecenphalography (EEG) is an integral part of the diagnostic process in patients with Creutzfeldt-Jakob disease (CJD). The EEG has therefore been included in the World Health Organisation diagnostic classification criteria of CJD. In sporadic CJD (sCJD), the EEG exhibits characteristic changes depending on the stage of the disease, ranging from nonspecific findings such as diffuse slowing and frontal rhythmic delta activity (FIRDA) in early stages to disease-typical periodic sharp wave complexes (PSWC) in middle and late stages to areactive coma traces or even alpha coma in preterminal EEG recordings. PSWC, either lateralized (in earlier stages) or generalized, occur in about two-thirds of patients with sCJD, with a positive predictive value of 95%. PSWC occur in patients with methionine homozygosity and methionine/valine heterozygosity but only rarely in patients with valine homozygosity at codon 129 of the prion protein gene. PSWC tend to disappear during sleep and may be attenuated by sedative medication and external stimulation. Seizures are an uncommon finding, occurring in less than 15% of patients with sCJD. In patients with iatrogenic CJD, PSWC usually present with more regional EEG findings corresponding to the site of inoculation of the transmissible agent. In genetic CJD, PSWC in its typical form are uncommon, occurring in about 10%. No PSWC occur in EEG recordings of patients with variant CJD.     

Molecular genetic diagnosis in X chromosome-linked retinitis pigmentosa

Retinitis pigmentosa (RP) is the most common hereditary dystrophic disease of the retina. About 10% of the affected families show the X-linked trait. The close link observed between the gene locus (RP2) and a polymorphic DNA marker (DXS7) on the proximal short arm of the X-chromosome permits an indirect genotype diagnosis and can be helpful in carrier detection and genetic counseling. A case is presented in which the carrier risk of a female consultant dropped from 50% a priori to less than 2% by the use of clinical findings and DNA analysis.     

Fusion of bone marrow-derived stem cells with cardiomyocytes in a heterologous in vitro model.

OBJECTIVE: Recent studies have demonstrated that transplanted bone marrow-derived stem cells (BMCs) possess a broad differentiation potential and are able to form new cardiomyocytes. However, the identity of BMCs as true cardiomyocytes is still ambiguous. Therefore, we investigated the fate of transplanted fluorescence labeled BMCs and cardiomyocytes in co-culture. METHODS: For cell tracking we used two different fluorescent probes, Vybrant/DiO and Vybrant/DiI. BMCs were taken from human sternal marrow, purified using a Ficoll-gradient-centrifugation, treated with 5-azacytidine and stained with Vybrant/DiO. Furthermore, isolated spontaneous beating cardiomyocytes of neonatal rats (CM) were labeled with Vybrant/DiI. Thereafter, the BMCs were transplanted into CM-cultures and investigated on day 1, 4, 7, 14 and 28 using two-color fluorescence phenotyping by laser-scanning-cytometry (LSC). Two-color positive cells were harvested by patch-clamp technique and beta-MHC mRNA expression was analyzed by single-cell PCR. RESULTS: Two different morphological phenotypes were observed by LSC. First, isolated DiO labeled BMCs without contact or with direct cell contact to DiI labeled CMs. Second, some BMCs and CMs were double positive for DiO/DiI spontaneously forming hybrids. This population increased by 18% from day 1 to 4 and decreased only slightly until day 28. Additionally, few two-color positive cell formations expressed both human and rat specific beta-MHC mRNA as well as only human beta-MHC mRNA indicating that cell-fusion and transdifferentiation has occurred. CONCLUSION: These observations provide in vitro evidence for spontaneous cell fusion and transdifferentiation of BMCs in co-culture, raising the possibility that the observed phenomenons may contribute to development or maintenance of these cell types.     

Tracheal agenesis. A case report

A case of tracheal agenesis, a rare foregut malformation, is described. This malformation is combined with a tracheo-oesophageal fistula, furthermore with rectal and anal atresia, cardiac malformations, dysplastic kidneys, wedge-shaped vertebrae, and cerebellar hypoplasia. Since a tracheo-oesophageal fistula is a possible component of the VACTERL Association [(V) vertebral defects, (A) anal atresia, (C) cardial malformations, (T) tracheo-(E)-oesophageal fistula, (R) renal or (L) limb malformations], similar cases are reviewed from the literature and their relationship to this association is discussed.     

Effects of a new pteridine derivative on urinary sodium, potassium and magnesium excretion in conscious saline-loaded rats.

1. Two recently synthesized pteridine derivatives (RPH 3036; RPH 3038) were tested in conscious saline-loaded rats and showed natriuretic and antimagnesiuretic properties but hardly reduced potassium excretion. 2. In the same model a dose-response curve was performed for RPH 3036. ED50 and Emax values were calculated for the natriuretic (ED50 = 13.4 mumol kg-1; Emax = 1.08 mmol kg-1) and antimagnesiuretic (ED50 = 11.3 mumol kg-1; Emax = -0.099 mmol kg-1) properties of RPH 3036. There were no significant changes of potassium and calcium excretion. 3. After a single dose of RPH 3036 (100 mumol kg-1) the time course of electrolyte excretion was analysed over 6 h. RPH 3036 did not show any significant effects on renal potassium and calcium excretion whereas a pronounced decrease (P less than 0.01) in renal magnesium excretion was evident during the 6 h. A moderate increase of sodium excretion was observed only after 3, 5 and 6 h. 4. A selective reduction of magnesium secretion in the late distal tubule and collecting duct was proposed as a possible mechanism of action of RPH 3036. This would explain the fast onset of action as well as the lack of antikaliuretic and anticalciuretic effects. The high selectivity of RPH 3036 makes it potentially valuable for the future investigation of renal magnesium transport.     

Frontotemporal dementia and parkinsonism linked to chromosome 17 with the N279K tau mutation

We present a case of frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP‐17) harboring the N279K mutation in the MAPT gene from the family known as pallido‐ponto‐nigral degeneration (PPND). This 49‐year‐old man was followed for 17 years. He presented at age 41 years with left leg stiffness and en‐bloc turning. During the course of his illness he developed a constellation of symptoms including parkinsonism, pyramidal signs, vertical gaze palsy, dysphagia, dystonia, personality and cognitive dysfunction, weight loss and mutism. Gross neuropathological examination showed mild atrophy of the cerebral cortex, hippocampal formation, amygdala, thalamus, subthalamic nucleus and depigmentation of the substantia nigra. Microscopy revealed neuronal loss and gliosis in the same regions. Tau immunohistochemistry showed pretangles, numerous threads, grain‐like structures and oligodendroglial tau‐positive inclusions (“coiled bodies”). In the spinal cord the tau pathology was more abundant in gray than white matter. Pretangles and threads were present in the anterior and, to a lesser extent, in the posterior horns. FTDP‐17 should be suspected in patients with a history of familial parkinsonism combined with behavioral and cognitive changes, onset before age 65 years and an aggressive clinical course.