Isozymes of aldolase

A new method of starch-gel electrophoresis using a technique of staining dependent on enzyme activity has been employed to demonstrate the isozymes of aldolase from a variety of human, rat, and frog tissues. Five of these isozymes were detected in man, seven in the rat, and at least four in the frog. The abilities of these isozymes to cleave fructose-1 ,6-diphosphate and fructose-1-phosphate were compared.

Cerebrospinal fluid plasminogen activator inhibitor-1: a prognostic factor in posthaemorrhagic hydrocephalus

Intraventricular fibrinolytic enhancement with plasminogen activators is an experimental treatment for posthaemorrhagic hydrocephalus, but some infants do not respond. The objectives of this study were to investigate whether plasminogen activator inhibitor-1 is detectable in normal or posthaemorrhagic neonatal cerebrospinal fluid and whether higher neonatal cerebrospinal fluid concentrations of plasminogen activator inhibitor-1 are associated with failure of fibrinolytic therapy. Cerebrospinal fluid samples from 7 controls and 16 infants with posthaemorrhagic hydrocephalus (15 treated with exogenous fibrinolytic agents) were analysed for plasminogen activator inhibitor-1. Plasminogen activator inhibitor-1 was not detectable in any of the control samples but was detectable in all but one of the posthaemorrhagic samples, and at significantly higher levels in the treatment failures (median 94 ng ml(-1)) than in the treatment successes (median 25 ng ml(-1)). High levels of plasminogen activator inhibitor-1 in the cerebrospinal fluid are predictive of, and provide a plausible biological explanation for, failure of intraventricular fibrinolytic therapy.

Defining the Occurrence and Influence of Alpha-Delta Sleep in Chronic Fatigue Syndrome

BACKGROUND

Patients with chronic fatigue syndrome (CFS) present a disordered sleep pattern and frequently undergo polysomnography to exclude a primary sleep disorder. Such studies have shown reduced sleep efficiency, a reduction of deep sleep, prolonged sleep initiation, and alpha-wave intrusion during deep sleep. Deregulation of the 2-5A synthetase/RNase L antiviral pathway and a potential acquired channelopathy are also found in a subset of CFS patients and could lead to sleep disturbances. This article compiles a large sleep study database on CFS patients and correlates these data with a limited number of immune parameters as it has been thought that RNase L could be associated with these sleep disturbances.

METHODS

Forty-eight patients who fulfilled 1994 Centers for Disease Control and Prevention criteria for CFS underwent extensive medical evaluation, routine laboratory testing, and a structured psychiatric interview. Subjects then completed a complaint checklist and a two-night polysomnographic investigation. RNase L analysis was performed by gel electrophoresis using a radiolabeled 2',5'-oligoadenylate trimer. Basic descriptive statistical parameters were calculated.

RESULTS

Patients experienced a prolonged sleep latency, showed a low sleep efficiency index, and had a low percentage of slow wave sleep. The present alpha-delta intrusion correlated with anxiety; no correlations appeared, however, between alpha-delta sleep and immunologic parameters, including RNase L.

CONCLUSIONS

The main findings are 1) validation of sleep latency problems and other sleep disturbances as already suggested by several authors; 2) alpha-delta intrusion seems associated with anxiety; and 3) elevated RNase L did not correlate with alpha-delta sleep.

Cost-Effectiveness Model of Topical Treatment of Mild to Moderate Psoriasis Vulgaris in Germany

BACKGROUND

Psoriasis vulgaris requires lifelong treatment associated with considerable health cost. Studies showed that a combination of a steroid and a vitamin D(3) analogue is more effective than both compounds in monotherapy.

OBJECTIVE

To determine the cost-effectiveness of a fix calcipotriol/betamethasone combination (Daivobet/Dovobet/Taclonex) compared to a morning/evening non-fix calcipotriol/betamethasone combination in psoriasis treatment.

METHODS

A Markov model (discrete-time stochastic process based on transitions between health states) with 2 treatment arms (Daivobet/Dovobet/Taclonex vs. non-fix calcipotriol/betamethasone) over a 48-week time period was developed. The effectiveness criterion was the number of days with clearance or marked improvement. Clinical and health resource utilisation data were derived from randomised studies.

RESULTS

Treatment with Daivobet/Dovobet/Taclonex showed a higher cost-effectiveness compared to the non-fix combination, even when assuming a maximum compliance for the twice daily non-fix combination and varying the effectiveness of Daivobet/Dovobet/Taclonex by 10%.

CONCLUSION

Psoriasis treatment with a fix calcipotriol/betamethasone combination is more cost-effective than a non-fix morning/evening combination.

Degree of agreement in plasma fibrinogen among two functional and one immunonephelometric assays

The purpose of this study was to assess the interchangeability of the nephelometric (immunoassay), von Clauss, and optical (derived) fibrinogen assays. When the nephelometric assay was compared with either of the two functional assays (199 samples) and when the von Clauss and optical methods were compared (879 samples), Pearson and intraclass correlations were .96 to .97. However, there were statistically significant biases (P < .001); the mean ratios of nephelometric to functional assay values were 1.05 to 1.07, and the mean optical to von Clauss assay ratio was 1.05 (data analyzed as logs and expressed as antilogs). The 95% limits of agreement demonstrated that 5% of the ratios for the von Clauss and optical methods were outside the 0.83 to 1.32 range. Analyses restricted to cases with a fibrinogen value of less than 2.0 g/L resulted in somewhat greater biases and higher upper limits of agreement. Laboratorians need more than correlations to make informed judgments regarding the interchangeability of these methods.

Plasminogen activator inhibitor-1: defining characteristics in the cerebrospinal fluid of newborns

We measured plasminogen activator inhibitor-1 levels in the cerebrospinal fluid and plasma of newborns with and without posthemorrhagic hydrocephalus. We found that plasminogen activator inhibitor-1 levels in the cerebrospinal fluid of healthy newborns are <10 mg/mL but are greatly elevated in patients who have posthemorrhagic hydrocephalus and correlate directly with cerebrospinal fluid D-dimer and protein levels.

Influence of hexacyanoferrate(II) based treatments upon the elimination of heavy metal traces in wine. I. The case of lead

An investigation was undertaken to determine whether the wine treatments for elimination of iron and copper used in Western Europe--with tetrapotassium hexacyanoferrate(II): K4[Fe(CN)6]--and in the United States--with iron(II) and potassium hexacyanoferrate(II) ('Fessler compound')--are suitable for lowering the concentration of lead to within legal limits. In both series of experiments the decrease in lead concentrations remained very poor. It was concluded that the treatments using hexacyanoferrates lowered lead levels but not sufficiently to reduce completely lead contamination in wines.

T-kininogen, processing and functions

Studies are presented which indicate that T-kininogen, the acute phase kininogen of the rat, could be a healing protein because of its properties as a cysteine protease inhibitor. Evidence is also presented that mRNA of T-kininogen synthesis may be a function of interleukin 6 production. A regulatory mechanism is postulated by which SH cofactors could determine if T-kinin is released or whether the T-kininogen molecule would remain intact. Evidence is also presented that T-kinin acts through kinin B2 receptors. No specific binding of bradykinin or T-kinin could be detected in rat heart preparations.

Natural killer cytotoxicity in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a multi-site clinical assessment of ME/CFS (MCAM) sub-study

BACKGROUND

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a multisystem illness characterized by substantial reduction in function accompanied by profound unexplained fatigue not significantly relieved by rest, post-exertional malaise, and other symptoms. Reduced natural killer (NK) cell count and cytotoxicity has been investigated as a biomarker for ME/CFS, but few clinical laboratories offer the test and multi-site verification studies have not been conducted.

METHODS

We determined NK cell counts and cytotoxicity in 174 (65%) ME/CFS, 86 (32%) healthy control (HC) and 10 (3.7%) participants with other fatigue associated conditions (ill control [IC]) from the Multi-Site Clinical Assessment of ME/CFS (MCAM) study using an assay validated for samples shipped overnight instead of testing on day of venipuncture.

RESULTS

We found a large variation in percent cytotoxicity [mean and (IQR) for ME/CFS and HC respectively, 34.1% (IQR 22.4-44.3%) and 33.6% (IQR 22.9-43.7%)] and no statistically significant differences between patients with ME/CFS and HC (p-value = 0.79). Analysis stratified on illness domain measured with standardized questionnaires did not identify an association of NK cytotoxicity with domain scores. Among all participants, NK cytotoxicity was not associated with survey results of physical and mental well-being, or health factors such as history of infection, obesity, smoking, and co-morbid conditions.

CONCLUSION

These results indicate this assay is not ready for clinical implementation and studies are needed to further explore immune parameters that may be involved in the pathophysiology of ME/CFS.

Cognitive assessment in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a cognitive substudy of the multi-site clinical assessment of ME/CFS (MCAM)

Introduction

Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) experience cognitive problems with attention, information processing speed, working memory, learning efficiency, and executive function. Commonly, patients report worsening of cognitive symptoms over time after physical and/or cognitive challenges. To determine, monitor, and manage longitudinal decrements in cognitive function after such exposures, it is important to be able to screen for cognitive dysfunction and changes over time in clinic and also remotely at home. The primary objectives of this paper were: (1) to determine whether a brief computerized cognitive screening battery will detect differences in cognitive function between ME/CFS and Healthy Controls (HC), (2) to monitor the impact of a full-day study visit on cognitive function over time, and (3) to evaluate the impact of exercise testing on cognitive dysfunction.

Methods

This cognitive sub-study was conducted between 2013 and 2019 across seven U.S. ME/CFS clinics as part of the Multi-Site Clinical Assessment of ME/CFS (MCAM) study. The analysis included 426 participants (261 ME/CFS and 165 HC), who completed cognitive assessments including a computerized CogState Brief Screening Battery (CBSB) administered across five timepoints (T0-T4) at the start of and following a full day in-clinic visit that included exercise testing for a subset of participants (182 ME/CFS and 160 HC). Exercise testing consisted of ramped cycle ergometry to volitional exhaustion. The primary outcomes are performance accuracy and latency (performance speed) on the computerized CBSB administered online in clinic (T0 and T1) and at home (T2-T4).

Results

No difference was found in performance accuracy between ME/CFS and HCs whereas information processing speed was significantly slower for ME/CFS at most timepoints with Cohen's d effect sizes ranging from 0.3-0.5 (p < 0.01). The cognitive decline over time on all CBSB tasks was similar for patients with ME/CFS independent of whether exercise testing was included in the clinic visit.

Conclusion

The challenges of a clinic visit (including cognitive testing) can lead to further cognitive deficits. A single short session of intense exercise does not further reduce speed of performance on any CBSB tasks.