Effects of sorbent suspension dialysis on plasma amino acid levels in cirrhotic patients with refractory hepatic encephalopathy

In cirrhotic patients, plasma amino acid levels are severely deranged. A decreased ratio of branched-chain to aromatic amino acids (Fischer ratio) has been implicated in the pathogenesis of hepatic encephalopathy. In this prospective study, we investigated the effects of extracorporeal detoxification on amino acid levels using a sorbent suspension dialysis system. Twenty patients with documented cirrhosis and hepatic encephalopathy grade II-III not responding to standard treatment were randomized to receive either six hours of sorbent dialysis and standardized conventional medical treatment or ongoing medical treatment alone. In contrast to previous uncontrolled studies, no significant effect on amino acid levels, Fischer ratio or clinical grade of hepatic encephalopathy was detected in either treatment group. In conclusion, a 6-hour treatment with sorbent dialysis did not significantly influence plasma levels of amino acids and did not ameliorate the clinical grade of hepatic encephalopathy.     

Space-based inhibition of return in children with spina bifida

Inhibition of return (IOR) refers to an increase in time to react to a target in a previously attended location. Children with spina bifida meningomyelocele (SBM) and hydrocephalus have congenital dysmorphology of the midbrain, a brain region associated with the control of covert orienting in general and with IOR in particular. The authors studied exogenously cued covert orienting in 8- to 19-year-old children and adolescents (84 with SBM and 37 age-matched, typically developing controls). The exogenous cue was a luminance change in a peripheral box that was 50% valid for the upcoming target location. Compared with controls, children with SBM showed attenuated IOR in the vertical plane, a deficit that was associated with midbrain dysmorphology in the form of tectal beaking but not with posterior brain volume loss. The data add to the emerging evidence for SBM deficits in attentional orienting to salient information.     

Culex restuans (Diptera: Culicidae) relative abundance and vector competence for West Nile Virus

The abundance and vector competence of Culex restuans Theobald and Culex pipiens L. were compared to determine the relative importance of these species as West Nile virus (WNV) vectors in the northeastern United States. Abundance was estimated from egg raft collections at 12 sites in Albany, Suffolk, and Richmond counties, New York, during July, August, and September 2002 and 2003. Cx. restuans was more abundant than Cx. pipiens in both urban and rural areas, comprising 86% of 1,623 egg rafts collected. Vector competence for WNV was estimated after feeding on an artificial bloodmeal and in vitro transmission assays. The vector competence of the two species for WNV was similar, but the dynamics of infection seems to be mosquito species dependent. These findings suggest an important role for Cx. restuans in WNV transmission cycles in New York.     

Endogene Natriuretische und Ouabain-ähnliche Faktoren

Summary The existence of an endogenous natriuretic hormone and ouabain-like factors (OLF) has been postulated for many years. This postulate was based on our original observation that a small M.W. fraction in the serum after acute expansion of the extracellular fluid volume (ECFV) not only exhibited natriuretic activity but also inhibited the Na-K-ATPase enzyme in vitro similar to ouabain. Since then, numerous studies confirmed the presence of OLFs in serum, urine, cerebrospinal fluid, and various organs including the heart and hypothalamus. Some of these OLFs are well-known endogenous compounds, such as free unsaturated fatty acids, which inhibit in vitro transmembranous sodium transport, Na-K-ATPase and³H-ouabain binding to its membrane receptor or crossreact with digoxin antibodies. Chemically yet undefined OLFs of potentially hypothalamic origin were detected in various models of experimental and clinical hypertension and are suggested to play a pathophysiological role especially in salt- and volume-dependent forms of hypertension. Our results show that OLFs isolated from the urine of salt-loaded healthy subjects strongly enhance basal and vasopressin-stimulated release of calcium in vascular smooth muscle cells and platelets similar to the effects we had observed with endothelin. This urine fraction also exhibits natriuretic activity which increases in parallel with sodium intake. Further chromatographic separation and amino acid analysis confirmed the peptidic nature (M.W.<1000) of the natriuretic factor(s). However, the two biological activities, namely natriuretic and ouabain-like activities, reside in distinct and chemically different compounds. In face of the previous discovery of the atrial natriuretic peptides (ANP) it is of special interest that very recent observations strongly suggest a natriuretic factor of non-cardiac origin to play an important role in the natriuresis that follows ECFV expansion. In addition, numerous experimental data point to an interaction between the ANP and OLF systems. They should stimulate once again the final identification of these yet unknown endogenous natriuretic and ouabain-like factors.

Die in dieser übersicht zitierten eigenen Untersuchungen wurden von der Deutschen Forschungsgemeinschaft, Bonn, dem Ministerium für Wissenschaft und Forschung des Landes Nordrhein-Westfalen (FA-2914, FA-8871, IVA6-402-046-87), Düsseldorf, und der Konrad-Adenauer-Stiftung, Bonn, unterstützt     

Modulation of a subthreshold calcium current by the neuropeptide FMRFamide in Aplysia neuron R15

1. The effect of the endogenous neuropeptide FMRFamide (Phe-Met-Arg-Phe-amide) on the Aplysia bursting pacemaker neuron R15 was studied. Brief local applications of FMRFamide, both on R15 somata in situ, and on R15 somata that were isolated and maintained in primary cell culture, cause a hyperpolarization of the membrane potential and a suppression of spontaneous bursting or beating pacemaker activity. 2. Two-electrode voltage-clamp experiments revealed that FMRFamide decreases the amplitude of an inward current, which activates with depolarization starting at a membrane potential less depolarized than the threshold for action potentials. Previous studies have established that this subthreshold inward current is carried by calcium and is essential for the generation of bursting pacemaker activity in Aplysia neurons. The effect of FMRFamide on the subthreshold inward current of R15 is blocked by divalent cation calcium channel blockers, such as cobalt and manganese, and is unaffected by changing the external concentration of potassium or chloride ions, or addition of blockers of the calcium-activated potassium current, such as external tetraethylammonium or internal EGTA. 3. The subthreshold calcium current of R15 is also decreased by dopamine and by an unidentified synaptic neurotransmitter. These substances mimic and occlude the action of FMRFamide on the subthreshold calcium current, suggesting that all three transmitters converge to affect the same population of calcium channels in neuron R15. 4. The subthreshold calcium current is enhanced by neurotransmitters that elevate cyclic AMP in R15, including serotonin, and the Aplysia neuropeptide egg-laying hormone (ELH). Likewise, the effect of FMRFamide on the subthreshold calcium current is enhanced by serotonin, ELH, and a cyclic AMP analog, suggesting that FMRFamide and cyclic AMP have antagonistic actions on the same population of calcium channels in neuron R15. 5. We conclude that the suppression of spontaneous bursting or beating pacemaker activity in neuron R15 by FMRFamide is due to a decrease in the subthreshold calcium current. The subthreshold calcium current in R15 is a common target for modulation by many different transmitters, acting via several distinct molecular mechanisms.     

Focal pulmonary edema. Correlation with perfusion lung scan

Pulmonary embolism is diagnosed by a mismatched perfusion-ventilation lung scan. The probability is increased further when there is an associated "hot spot" in the perfusion study caused by focal pulmonary edema.     

Maintenance ECT: A Survey of Practice (1986)

A questionnaire on the use of maintenance or continuation ECT was mailed to 173 practitioners of ECT. Of 86 respondents, 51 reported they used maintenance therapy, and 35 did not. Users came from 24 states, with five states accounting for more than half. Of practitioners giving maintenance ECT, each treated a median of three patients annually between 1981 through 1984, with a range from zero to "thousands." Frequency of treatments is determined empirically, with most treatments given monthly. Memory impairment is the most commonly cited risk. Depression is the diagnosis in 90% of the patients, with schizoaffective, schizophrenic, and manic patients equally comprising the remainder of the patients. The longest series reported for any one patient is 2,400 treatments.     

"Clear cell" atypical fibroxanthoma

An 87-year-old man with extensive solar damage presented with a 2-month history of a dome-shaped, crusted lesion on the dorsum of the left hand. Microscopically, the tumor consisted of fascicles of spindle cells with bizarre nuclei and clear, vacuolated cytoplasm. Histochemical, immunohistochemical, and ultrastructural features supported the diagnosis of atypical fibroxanthoma. There was no evidence of metastatic disease. The lesion was completely excised, and there has been no recurrence in 3 months of observation. This unusual "clear cell" variant of atypical fibroxanthoma must be distinguished from other clear cell tumors, such as metastatic renal cell carcinoma, clear cell eccrine carcinoma, and clear cell sarcoma (malignant melanoma) of soft parts. Although atypical fibroxanthoma is usually cured by complete surgical excision, metastases have been reported.     

Adult-onset autosomal dominant limb-girdle muscular dystrophy

We describe a kindred with a rare autosomal dominant myopathy limited to the limb-girdle muscles, beginning insidiously any time from the late second through the sixth decades and followed by slow progression. Pelvifemoral precedes scapulohumeral weakness, and proximal appendicular involvement antedates limited distal paresis. Expressivity varies and includes an asymptomatic myopathy (preclinical or subclinical) and a nonmanifesting carrier state that extends well into the eighth decade. A variety of nonspecific changes are present in muscle on light, enzyme histochemical, and electron microscopic examination; of these changes, "rimmed" or autophagic vacuoles are the most characteristic. We identified one very similar previously reported genealogy. The similarities between the two unrelated families clearly establish this dystrophic process as a distinct genetic entity; their differences suggest genetic heterogeneity.     

The Yale algorithm. Special workshop--clinical

The assessment of causality in drug-event associations depends on the setting and purpose of such an assessment. Epidemiologists are primarily interested in population-based inferences about whether a given drug can cause a certain adverse drug reaction (ADR), and if so, how often it does so. Pharmaceutical industries and regulatory agencies are also concerned with population-based risks, but in addition must worry about individual cases. Clinicians are primarily interested in the individual, ie, whether a given drug did cause a certain adverse event in a particular patient. The authors describe an algorithm that provides specific, detailed criteria for ranking the probability that an observed untoward clinical manifestation was caused by a given drug. The criteria are subdivided into six axes of decision strategy with a built-in scoring system that ordinally ranks the probability of an adverse drug reaction as definite, probable, possible, or unlikely. To illustrate the use of the algorithm, the authors assess a reference case of pancreatitis occurring after administration of methyldopa.