Is genotype determination useful in predicting the clinical phenotype in lysosomal storage diseases?

Understanding the relationship between genotype and clinical phenotype will clearly aid in the prognosis, treatment and counselling of patients with lysosomal storage diseases (LSDs). This, however, will require the establishment of widely accepted indices with which to score the severity of LSDs, as these diseases are characterized by their marked clinical heterogeneity. Even in the complete absence of a functional enzyme, presentation may be variable, depending on the patient's genetic background and on a range of epigenetic and environmental factors. Further difficulties in predicting disease severity and progression from the genotype arise from the rarity of these disorders, the low enzyme levels required for a normal phenotype and the relative lack of understanding of the pathophysiology of LSDs.     

The analgesic action of dexmedetomidine--a novel alpha 2-adrenoceptor agonist--in healthy volunteers.

The analgesic efficacy of dexmedetomidine (DEX)--a novel alpha 2-adrenoceptor agonist--was studied in man. Single intravenous doses of fentanyl (FEN; 2 micrograms/kg), DEX (0.25, 0.50 and 1.0 micrograms/kg) and placebo were administered to 5 healthy male volunteers in a double-blind, crossover study in randomized order. The analgesic effect of the different treatments was measured by determining the time course of pain threshold with dental dolorimetry and by quantitating subjective pain induced by a standard ischemic pain stimulus on the upper arm using a visual analogue scale (VAS). The drugs were generally well tolerated. FEN and DEX both had analgesic effects on ischemic pain, which was seen as a statistically significant decrease in subjective VAS ratings. FEN appeared to be more effective than DEX; the difference was not, however, statistically significant. Neither of the drugs affected the pain threshold measurements.     

Isolation and characterization of hot particles from Chernobyl fallout in southwestern Finland

Three types of activity composition have been found in airborne hot particles that were transported long distances from the Chernobyl accident. Their characterization is based on the analysis of single particles isolated from Pinus Sylvestris needles. The average activity of the particles was 130 Bq at the time of the accident. The most common type of particle contains the radioactive species 141Ce, 144Ce, 95Zr and 95Nb; the second type includes 103Ru and 106Ru along with the previous isotopes; and the third contains 103Ru and 106Ru only. Cesium-134 and -137 were present only in very small amounts. The activity composition of the Chernobyl reactor core fuel was similar to the composition of the first and second type particle; apparently the core fuel was only partially volatilized. The main bulk composition of the particles is shown to be U. The average aerodynamic size of the identified hot particles is 10 microns. The particles are rectangular or pentagonal in shape.     

Need-adapted treatment of new schizophrenic patients: experiences and results of the Turku Project.

This article describes a psychotherapeutically oriented approach to schizophrenia developed especially to meet the needs of the community psychiatric field. Because of the heterogeneous nature of the schizophrenic psychoses, the authors emphasize that these patients should always be treated based on case-specific premises. The main principles of the need-adapted approach are: 1. The therapeutic activities are planned and carried out flexibly and individually in each case so that they meet the real and changing needs of the patients as well as of their family members. 2. Examination and treatment are dominated by a psychotherapeutic attitude. 3. The different therapeutic activities should support and not impair each other. 4. The process quality of therapy is clearly perceived. A family-centred initiation of the treatment is especially emphasized for both diagnostic and therapeutic reasons. The positive experiences of this led the Finnish national programme for the treatment and rehabilitation of schizophrenic patients to recommend the establishment of family- and environment-oriented acute psychosis teams (APT) in the mental health districts. In later phases of treatment, the significance of individual psychotherapy is increased. The preliminary results of the approach are presented and compared with an earlier sample of patients.     

Heart rate variability derived from exercise ECG in the detection of coronary artery disease

The diagnostic performance of heart rate variability (HRV) analysis from exercise ECG in the detection of coronary artery disease (CAD) is unknown. Bicycle exercise ECG recordings from The Finnish Cardiovascular Study (FINCAVAS) of angiography-proofed CAD patients (n = 112) and a patient group with a low likelihood of CAD (n = 114) were analyzed. HRV parameters (SDNN, RMSSD, Poincaré SD1 and SD2) were calculated from 1 min segments before exercise, during exercise and after exercise. All the parameters were in addition calculated from heart rate (HR)-corrected RR-interval segments. The ST-segment depressions in each stage were also determined. The diagnostic performance of the parameters was evaluated with the area under the receiver operating characteristic (ROC) curve method. The uncorrected HRV parameters showed the best diagnostic performance in the recovery segments but the correlation with HR was also high (SDNN: 0.758/-0.64, RMSSD: 0.747/-0.60; area under the ROC/correlation coefficient). The HR correction decreased the correlation and the diagnostic performance in recovery segments (SDNN: 0.515/-0.12, RMSSD: 0.609/0.20). The diagnostic performance of ST-level at its best was higher than any of HRV parameters (ST-level: 0.795/0.36). According to the results, the HR correction decreased the diagnostic performance of the recovery phase. The HRV parameters calculated from 1 min segments of exercise test ECG were not as capable as traditional ST-segment analysis. In conclusion, the HRV analysis from exercise or recovery phase seems to be inadequate in the detection of CAD.     

Aminoglycoside nephrotoxicity: modeling,simulation, and control

The main constraints on the administration of aminoglycosides are the risks of nephrotoxicity and ototoxicity, which can lead to acute, renal, vestibular, and auditory toxicities. In the present study we focused on nephrotoxicity. No reliable predictor of nephrotoxicity has been found to date. We have developed a deterministic model which describes the pharmacokinetic behavior of aminoglycosides (with a two-compartment model), the kinetics of aminoglycoside accumulation in the renal cortex, the effects of aminoglycosides on renal cells, the resulting effects on renal function by tubuloglomerular feedback, and the resulting effects on serum creatinine concentrations. The pharmacokinetic parameter values were estimated by use of the NPEM program. The estimated pharmacodynamic parameter values were obtained after minimization of the least-squares objective function between the measured and the calculated serum creatinine concentrations. A simulation program assessed the influences of the dosage regimens on the occurrence of nephrotoxicity. We have also demonstrated the relevancy of modeling of the circadian rhythm of the renal function. We have shown the ability of the model to fit with 49 observed serum creatinine concentrations for a group of eight patients treated for endocarditis by comparison with 49 calculated serum creatinine concentrations (r(2) = 0.988; P < 0.001). We have found that for the same daily dose, the nephrotoxicity observed with a thrice-daily administration schedule appears more rapidly, induces a greater decrease in renal function, and is more prolonged than those that occur with less frequent administration schedules (for example, once-daily administration). Moreover, for once-daily administration, we have demonstrated that the time of day of administration can influence the incidence of aminoglycoside nephrotoxicity. The lowest level of nephrotoxicity was observed when aminoglycosides were administered at 1:30 p.m. Clinical application of this model might make it possible to adjust aminoglycoside dosage regimens by taking into account both the efficacies and toxicities of the drugs.     

Creatine kinase: reassessment of optimal concentrations for adenosine-5'-diphosphate and magnesium

Whereas univariate studies led to an European agreement for the choice of optimal reagent concentrations of 2 mmol/L for ADP and 10 mmol/L for Mg2+ for determining creatine kinase (EC 2.7.3.2) activity in serum, whatever its isoenzyme pattern, the results of our bivariate study led us to recommend higher optimal concentrations: 4.1 to 4.7 mmol/L for ADP and 22 mmol/L for Mg2+. The zone of maximal activity was in fact a broad plateau such that more than 99% of maximal enzyme activity was attained at ADP concentrations between 3 and 5 mmol/L and Mg2+ concentrations between 17 and 26 mmol/L. Under these new conditions the maximum activity measured was modestly increased (about 10%) over the previously recommended method but the assay could be expected to be more resistant to the variations of ADP and Mg2+ concentrations. It may become necessary to modify the European recommended method.     

Biochemical diagnosis of hepatic glycogen storage diseases: 20 years French experience.

French experience of 242 cases of liver glycogenoses is reported. Screening tests based on serum biochemical data and glucagon tolerance tests are briefly reviewed. The diagnosis of types I glycogen storage disease (GSD) was ascertained in 73 patients' liver biopsies by measurement of glycogen content and by studying the glucose-6-phosphatase system. Liver biopsies were also required at the beginning for the diagnosis of other hepatic GSDs; later on, the possibilities of diagnosis using peripheral blood cells were investigated. Eighty-four cases of type III GSD were confirmed by measurement of debranching enzyme activity and glycogen content using either liver biopsies (78 cases) and/or erythrocytes (37 cases); enzyme determination was also performed in leukocytes and/or fibroblasts for 18 patients. Twenty-four cases of type VI GSD underwent liver biopsies, and the diagnosis could be confirmed using mononuclear or polymorphonuclear cells for 11 of these patients. Sixty-one patients were identified as type IX GSD; phosphorylase kinase deficiency was demonstrated in erythrocytes for all patients, and a liver biopsy was analyzed for 26 of these cases. From this experience, the possibilities of diagnosis of liver GSD using peripheral blood cells are emphasized.     

Perceived exertion and rehabilitation with arm crank in elderly patients after total hip arthroplasty: a preliminary study

This preliminary study examined, in a restricted randomized trial, the effects of a 6-week arm-crank rehabilitation training program in elderly osteoarthrosis patients after total hip arthroplasty, first on physiological and perceptual responses and second on physical function. Two groups of patients were studied: a training group (N = 7, mean age = 74.9 yr, standard deviation [SD] = 5.0 yr) who followed a training program in addition to traditional rehabilitation, and a control group who followed traditional rehabilitation only (N = 7 mean age = 75.4 yr, SD = 5.1 yr). At the beginning of the training program, the heart rate and the perceived exertion were not significantly correlated during the exercise session. However, at the end of the training program, five patients had a significant heart rate/perceived exertion relationship (p < 0.05). Furthermore, positive effects of the arm-crank rehabilitation training program were observed on cardioventilatory and functional responses in the training group compared with the control group. These results suggest that after an habituation period, most of our elderly osteoarthrosis patients experienced physical sensations that were connected to physiological responses. Therefore, perceived exertion could be useful in these patients to regulate exercise intensity, especially at the end of and after the rehabilitation period.