Improved Memory and Lower Stress Levels in Male Mice Co-Housed with Ovariectomized Female Mice

Aggressiveness, expressed by fighting, is a frequent problem in group-housed laboratory male mice and results in increased stress, injury, and death. One way to prevent fighting is by pairing the male mice with ovariectomized female mice to provide a compatible companion. However, the effect of these housing conditions remains unclear. Therefore, we aimed to evaluate behavior and stress levels in two different housing conditions, pair-housed with an ovariectomized female and group-housed with other males. Behavioral tests were performed to assess stress and anxiety-like behavior. Moreover, the corticosterone levels in plasma were measured by ELISA. Based on home cage behavior assessment, pair-housed male mice showed no signs of fighting, not even after isolation and regrouping. Our results also showed that the pair-housed males had a better memory and demonstrated less anxiety-like behavior. Subsequently, the pair-housed male mice had a larger reduction in corticosterone levels compared to group-housed males. Overall, pair-housing reduced anxiety-like behavior and stress levels in male mice compared to standard group-housing.

TLCD1 and TLCD2 regulate cellular phosphatidylethanolamine composition and promote the progression of non-alcoholic steatohepatitis

The fatty acid composition of phosphatidylethanolamine (PE) determines cellular metabolism, oxidative stress, and inflammation. However, our understanding of how cells regulate PE composition is limited. Here, we identify a genetic locus on mouse chromosome 11, containing two poorly characterized genes Tlcd1 and Tlcd2, that strongly influences PE composition. We generated Tlcd1/2 double-knockout (DKO) mice and found that they have reduced levels of hepatic monounsaturated fatty acid (MUFA)-containing PE species. Mechanistically, TLCD1/2 proteins act cell intrinsically to promote the incorporation of MUFAs into PEs. Furthermore, TLCD1/2 interact with the mitochondria in an evolutionarily conserved manner and regulate mitochondrial PE composition. Lastly, we demonstrate the biological relevance of our findings in dietary models of metabolic disease, where Tlcd1/2 DKO mice display attenuated development of non-alcoholic steatohepatitis compared to controls. Overall, we identify TLCD1/2 proteins as key regulators of cellular PE composition, with our findings having broad implications in understanding and treating disease.

The regulation of cellular phosphatidylethanolamine (PE) acyl chain composition is poorly understood. Here, the authors show that TLCD1 and TLCD2 proteins mediate the formation of monounsaturated fatty acid-containing PE species and promote the progression of non-alcoholic steatohepatitis.

Transient changes of sensory nerve functions in uraemia

The neurophysiological parameters (conduction velocity, amplitude and rise time of the compound action potential) of two sensory nerves of the lower limb (N. suralis and peronaeus superficialis) were determined bilaterally in five patients. Measurements were carried out at least twice in each subject during a time of great metabolic change. Two patients were recovering from acute renal failure (a single haemodialysis had to be performed on one of them) and three were under chronic maintenance haemodialysis. In the case of the haemodialysis patients, measurements were performed on two successive days, before and after one haemodialysis session. All the neurophysiological parameters showed significant improvement in successive measurements. In one patient the follow-up after acute renal failure revealed a delayed deterioration of the nerve functions, but after one year the values were normal. From the results it seems probable that an acute metabolic disturbance may cause transient inhibition of nerve functions without morphological changes in the nerve fibres.

Serum free beta-HCG and alpha-fetoprotein levels in IVF, ICSI and frozen embryo transfer pregnancies in maternal mid-trimester serum screening for Down's syndrome

BACKGROUND

The aim of this study was to compare the maternal mid-trimester free beta-HCG and alpha-fetoprotein (AFP) levels in pregnancies conceived by assisted reproduction technology and spontaneous pregnancies in Down's syndrome screening. The influence of the number of embryos transferred and the amount of gonadotrophins used on the marker levels was also evaluated.

METHODS

The study population consisted of 58 IVF, 32 ICSI and 26 frozen embryo transfer (FET) singleton pregnancies. The levels of beta-HCG and AFP were compared with the control group of 6548 singleton spontaneous pregnancies.

RESULTS

The false positive rate (FPR) in the Down's syndrome screening was 19% overall in assisted reproductive technology pregnancies, being highest (30.8%) in the FET group. The free beta-HCG multiples of the median (MoM) values were statistically significantly elevated only in the FET group (1.33 MoM; P = 0.012). A positive correlation between the number of embryos transferred and the marker levels was observed in the IVF group. No correlation was found between the amount of gonadotrophin medication used and the marker levels.

CONCLUSIONS

The present data confirm that the overall FPR in the serum screening for Down's syndrome in assisted reproduction pregnancies is high, resulting in unnecessary invasive procedures.

TEAC-Health--research-based recommendations for European certification of health telematics services

Health Telematics services are now a major part of health care delivery, and of citizens' health behaviour, and will rapidly develop further in scope and significance. However, despite their pivotal position in care and treatment, they are unregulated--unlike all other aspects of health care services. This anomaly is potentially putting the citizen at risk, and also underpinning good clinical practice as clinicians are uncertain of the integrity of specific health telematics tools. The TEAC-Health project, funded by the European Commission, has studied the issues, and produced evidence-based recommendations.

Frequency and clinical outcome of potentially harmful drug metabolic interactions in patients hospitalized on internal and pulmonary medicine wards: focus on warfarin and cisapride

Drug metabolic interactions present potential risks in patient care, but their frequency and relative importance as a clinical problem remains unclear. To assess the frequency and clinical outcome of potentially harmful drug metabolic interactions in hospitalized patients, the authors performed a survey of the medication data of patients treated on internal and pulmonary medicine wards in a university hospital. The database was searched for concomitantly administered drug pairs that would, according to Hansten and Horn's drug interaction database, carry a high risk for a clinically harmful metabolic drug interaction. Coadministrations involving warfarin or cisapride were subjected to further analysis regarding clinical outcome. A total of 142 patients were exposed to 150 interactions with potentially harmful clinical outcome, resulting in a frequency of 0.9% (95% CI 0.7% to 1.0%). Inhibition of warfarin metabolism by metronidazole produced significant overanticoagulation as evidenced by elevated international normalized ratio values, whereas inducers (rifampicin and phenobarbital) of warfarin metabolism significantly reduced the efficacy of warfarin. One case of minor bleeding and one case of clavicular vein thrombosis were detected as possible consequences of disturbed anticoagulation. The coadministration of cisapride and erythromycin significantly prolonged the corrected QT (QTc) interval and was associated with clinical symptoms of cardiac arrhythmias. Coadministration of cisapride with fluconazole or miconazole was not associated with prolongation of the QTc interval or cardiac sequelae. Evaluations of patient materials are needed to assess the clinical relevance of metabolic drug interactions.

Reminders of drug effects on laboratory test results

Drug effects on laboratory test results are difficult to take into account without an online decision support system. In this study, drug effects on hormone test results were coded using a drug-laboratory effect (DLE) code. The criteria that trigger the reminders were defined. To issue reminders, it was necessary to write a computer program linking the DLE knowledge base with databases containing individual patient medication and laboratory test results. During the first 10 months, 11% of the results from hormone samples were accompanied by one or more DLE reminders. The most common drugs to trigger reminders were glucocorticoids, furosemide, and metoclopramide. Physicians facing the reminders completed a questionnaire on the usefulness of the reminders. All respondents considered them useful. In addition, DLE reminders had caused 74% of respondents to refrain from additional, usually performed examinations. In conclusion, drug effects on laboratory tests should always be considered when interpreting laboratory results. An online reminder system is useful in displaying potential drug effects alongside test results.

Imaging end-stage kidney disease in adults. Low-field MR imaging with magnetization transfer vs. ultrasonography

PURPOSE

To 1) assess the potential of magnetization transfer (MT)-weighted MR imaging to improve the often poor visibility of native kidneys in patients with a renal transplant; and 2) compare low-field MR imaging and ultrasonography (US) for imaging these fibrotic kidney remnants.

MATERIAL AND METHODS

Seventy-two native kidneys of 36 patients were prospectively evaluated with US and MR. In low-field (0.1 T) MR imaging, T1-, T2- and MT-weighted sequences were used. MT-weighted images were compared with T2-weighted images in their ability to delineate the kidneys from their surroundings whereas US and MR were compared for detection of renal cysts and possible solid tumors.

RESULTS

MT-weighted images proved superior to conventional T2-weighted images in producing contrast between the kidney remnants and their fatty surroundings. Although US revealed a few small renal cysts that were not seen at MR images, no statistical difference was found between the two modalities in this respect.

CONCLUSION

MT imaging, due to its unique protein-specific signal depression, offers significantly improved visualization and delineation of end-stage kidneys. US, because its better availability and cost-benefit ratio, remains the method-of-choice compared to low-field MR imaging in detecting cysts in multicystic kidneys. MR investigation is helpful in selected patients and may be used as an alternative.

Maternal midtrimester serum AFP and free beta-hCG levels in in vitro fertilization twin pregnancies

We aimed to compare the levels of alpha-fetoprotein (AFP) and free beta-human chorionic gonadotrophin (beta-hCG) levels as multiples of the median (MoM) values between spontaneous and in vitro fertilized (IVF) twin pregnancies. The control group of spontaneous singleton pregnancies was used for calculating the gestational age specific median levels of the values. Within a cohort of 19 310 pregnancies, 145 twin pregnancies were identified. The data were collected from Down syndrome (DS) screening programmes in four University catchment areas in Finland between 1994-98. Maternal midtrimester serum marker levels were measured across gestational weeks 14-18. There were no fetal chromosome anomalies in either of the twin groups or the singleton group. Serum AFP of 145 and beta-hCG values of 39 spontaneous twin pregnancies were compared to the values of 6548 singleton pregnancies. In IVF twins 30 AFP and 29 beta-hCG values were compared to the levels of the control group. Both AFP and beta-hCG values were twice as high in the spontaneous twin pregnancies (medians 2.18 and 1.83 MoM respectively) as in the singleton group (medians 1.00 and 1.00 MoM respectively). In IVF twin pregnancies beta-hCG levels were higher (median 2.20 MoM) than in spontaneous twins (p=0.08), whereas no significant difference was found in AFP levels (2.30 MoM). In conclusion, the higher levels of beta-hCG levels in IVF twin pregnancies should be considered in DS screening to avoid high false positive rates.

Why certification of medical software would be useful?

Human drugs and medical devices have to be approved by the health authorities before they can enter the market. For medical software this is not needed. The main argument to resist all attempts to regulate medical software has been that it is impossible to guarantee that software is error-free. This is true of all software. However, in medical software the correctness of medical knowledge is at least as important as the correctness of the code itself. The medical contents of the software could usually be evaluated but the end-users do not have the time or possibilities to do so. The Internet makes it possible to provide commercial services designed by non-professionals. For health care, there are already several commercial services on the net. Since there is no quality assurance or regulation of medical software anyone can sell medical software on the net. Even if physicians were cautious enough not to use untested software, there is a possibility that patients do. In Finland, where over 10% of the population is using the Internet at least weekly, the problem is real. It is impossible to remove poor services from the net and therefore, it is essential to guide the users to use high quality services. The paper discusses different aspects of evaluation of medical software.

Approaches for certification of electronic prescription software

The proper management of drug treatment is essential, since adverse drug reactions are common reasons of hospitalisations. Expenditure on drug therapy has also been growing faster than any other aspect of health care in many countries. Savings and quality improvements in drug treatment could be achieved with computerised prescribing. In this paper, the architecture of an electronic prescription system is described in the light of software certification and registration. An electronic prescription system is an example of a system supporting shared care and therefore it should be person based, integrated, secure and confidential and data should be shared among health care institutions. The system architecture shares the idea of a virtual patient record and a smart card will be used as a key to prescription data located on the network. The certification and registration of medical software is a difficult and costly procedure. Ensuring the quality of software can be based on; certification of development process, voluntary evaluation, and post-market surveillance. Voluntary evaluation practice would be a precious tool for both the customers and software developers, and it would also be an invaluable source of information in terms of developing new software.

A medication database--a tool for detecting drug interactions in hospital

OBJECTIVE

Drug interactions may lead to life-threatening injuries. More often, however, they lead to slow recovery, induce slight symptoms or result only in potential injury. Therefore, clinicians are not always aware of using potentially interacting drug combinations. An on-line alarming system of potential drug interactions was developed in Turku University Central Hospital. In the present study, we utilised the system to find out the incidence and nature of potential drug interactions occurring in a representative hospital patient population.

METHODS

Computerised anatomical therapeutic chemical (ATC)-coded patient medication data of 2547 patients, treated in two internal medicine wards, were combined with an ATC-coded rule base of drug interactions. All potential drug interactions in the study population were searched for.

RESULTS

A total of 326 potentially serious drug interactions were detected in the study population. The number of patients in this group was 173, i.e. 6.8% of all patients had one or several drug combinations which might have led to serious clinical consequences. Concomitant use of calcium and fluoroquinolones (decreased absorption) was the most common mistake (66 prescriptions).

CONCLUSIONS

Potentially inappropriate drug combinations seem to occur frequently. Structured and coded medication data can be utilised efficiently to detect potential drug interactions in hospital. Computerised online monitoring and automatic alarming of potentially hazardous drug combinations might help clinicians to prescribe more safely, but further development of the system is needed to avoid unnecessary alarms.

Visualization of clinical data with neural networks, case study: polycystic ovary syndrome

In medicine, the use of neural networks has concentrated mainly on classification problems. Clinicians are often interested in knowing what a patient's status is compared with other similar cases. Compared with biostatistics neural networks have one major drawback: the reliability of the classification is difficult to express. Therefore, clear visualization of the measurements can be more helpful than the calculated probability of a disease. The self-organizing map is the most widely used neural network for data visualization. Although, visualization can be attached to almost any feed-forward network as well. In this paper, we describe a topology-preserving feed-forward network and compare it with the self-organizing map. The two neural network models are used in a case study on the diagnosis of polycystic ovary syndrome, which is a common female endocrine disorder characterized by menstrual abnormalities, hirsutism and infertility.

Serum phospholipase A2 in patients with multiple organ failure

Multiple organ failure (MOF) is the most common cause of death in the surgical intensive care unit. We studied the relation of MOF to changes in the concentration of group II phospholipase A2 (PLA2) in serum. Altogether, 215 surgical intensive care patients with multiple injuries, diffuse peritonitis, or sepsis and control patients, who were at a high risk for postoperative sepsis after various surgical interventions, were included in the present prospective study. The clinical performance of the MOF score and the concentrations of group II PLA2 and C-reactive protein (CRP) in serum were studied using receiver operating characteristic (ROC) curves. The group II PLA2 level was considerably above normal in all groups of patients during the first week of observation. There was a highly significant difference in group II PLA2 levels between patients with severe infections (peritonitis and sepsis) and the other patients studied (multiple injuries and elective surgery) (ROC 0.931, P < 0.0001). The concentration of group II PLA2 had a significant positive correlation to the CRP level and body temperature, which indicates that group II PLA2 is an acute phase reactant and that the determination of group II PLA2 is a useful measurement to diagnose severe infections. It was concluded that the concentration of group II PLA2 in serum effectively predicts lethal MOF in patients with multiple injuries after the second day (ROC 0.739, P < 0.01) and in patients with diffuse peritonitis after the fourth day (ROC 0.750, P < 0.02).

Ability of two new thyrotropin (TSH) assays to separate hyperthyroid patients from euthyroid patients with low TSH

We evaluated the ability of new thyrotropin (TSH) assays to separate hyperthyroid (n = 50) patients from clinically euthyroid subjects with low TSH values (nodular goiter, n = 20, and nonthyroidal illness, n = 22). Only patients whose serum TSH was &lt; 0.1 mIU/L by immunoradiometric assay were included. We used a new immunofluorometric method based on time-resolved fluorescence (TR-IFMA) and a new immunochemiluminometric assay (ICMA) to measure TSH in serum. Although the differences between the hyperthyroid patients and the euthyroid patients differed from each other by both methods (P = 0.0012 for TR-IFMA and P &lt; 0.0001 for ICMA), there was no cutoff point that could definitely separate the groups. Thus, it is not possible to draw any definite conclusions on whether a patient is hyperthyroid or not, solely on the basis of TSH concentration measured with these new TSH assays.

Ability of two new thyrotropin (TSH) assays to separate hyperthyroid patients from euthyroid patients with low TSH

We evaluated the ability of new thyrotropin (TSH) assays to separate hyperthyroid (n = 50) patients from clinically euthyroid subjects with low TSH values (nodular goiter, n = 20, and nonthyroidal illness, n = 22). Only patients whose serum TSH was < 0.1 mIU/L by immunoradiometric assay were included. We used a new immunofluorometric method based on time-resolved fluorescence (TR-IFMA) and a new immunochemiluminometric assay (ICMA) to measure TSH in serum. Although the differences between the hyperthyroid patients and the euthyroid patients differed from each other by both methods (P = 0.0012 for TR-IFMA and P < 0.0001 for ICMA), there was no cutoff point that could definitely separate the groups. Thus, it is not possible to draw any definite conclusions on whether a patient is hyperthyroid or not, solely on the basis of TSH concentration measured with these new TSH assays.

Inductive learning of thyroid functional states using the ID3 algorithm. The effect of poor examples on the learning result

The ID3 algorithm for inductive learning was tested using preclassified material for patients suspected to have a thyroid illness. Classification followed a rule-based expert system for the diagnosis of thyroid function. Thus, the knowledge to be learned was limited to the rules existing in the knowledge base of that expert system. The learning capability of the ID3 algorithm was tested with an unselected learning material (with some inherent missing data) and with a selected learning material (no missing data). The selected learning material was a subgroup which formed a part of the unselected learning material. When the number of learning cases was increased, the accuracy of the program improved. When the learning material was large enough, an increase in the learning material did not improve the results further. A better learning result was achieved with the selected learning material not including missing data as compared to unselected learning material. With this material we demonstrate a weakness in the ID3 algorithm: it can not find available information from good example cases if we add poor examples to the data.

Using the ID3 algorithm to find discrepant diagnoses from laboratory databases of thyroid patients

Rare cases are a central problem when an expert system is constructed from example cases with machine learning techniques. It is difficult to make a decision support system (DSS) to cover all possible clinical cases. An inductive learning program can be used to construct an expert system for detecting cases that differ from routine cases. The ID3 algorithm and the pessimistic pruning algorithm were tested in this study: a DSS was built directly from the data of patient records. A decision tree was generated, and the cases misclassified by the decision tree as compared with the classifications of a clinician were listed on a checklist, which formed the feedback to the clinician. In clinical situations about 5-10% of functional thyroid disorders may be misclassified. At this error level, the method found over 90% of the errors with a specificity of 95%. In simple medical classification tasks this dynamic self-learning system can be used to create a DSS that can assist in the quality control of clinical decision making.

Autonomic neuropathy and vibration exposure in forestry workers

The variation in heart rate (HRV) at rest and during deep breathing (6 cycles a minute) of 88 professional lumber jacks was studied using a computer technique. The traditional indexes of HRV (CV, CVS, MEAN) were calculated and the spectral components of the HRV were also computed. There was a significant difference (p less than 0.001) between the HRV indexes during the deep breathing test in those with the shortest (CV = 10.1 +/- 1.1) and those with the longest (CV V 6.2 +/- 0.4) exposures to vibration. The values of the HRV indexes decreased with age, but multiple regression analysis showed that the total exposure time to vibration had an independent negative association with the HRV. There were significant differences in all the frequency bands (frequency related power, FRP) of the heart rate between those with the longest and those with the shortest exposures. The HRV during a deep breathing test is associated with the activity of the parasympathetic nervous system and is decreased in autonomic neuropathies. Our results suggest that prolonged exposure to the vibration caused by a chain saw has a negative effect on the parasympathetic activity and thus causes autonomic dysfunction.

Effects of haemodialysis on heart rate variability in chronic renal failure

The influence of haemodialysis (HD) on the heart rate variability (HRV) was investigated in nine non-diabetic patients on maintenance haemodialysis. The R-R intervals were measured in recordings during spontaneous quiet breathing and during controlled deep breathing before and after a single HD session. The HRV was expressed as the standard deviation of the mean R-R interval in 3 min ECG recordings. Heart rate variability is the irregularity in the heart rate mainly caused by autonomic control mechanisms. The long-term HRV during quiet breathing was statistically significantly (p less than 0.05) higher after the HD than before. The HRV in the intermediate frequency range of 0.075-0.125 Hz was also significantly increased by the HD. This suggests that some metabolic agents interfering with the heart rate regulation are removed by the haemodialysis, and as a result a better function of the autonomic cardiac control is achieved in uraemic patients.

Persistence of antibodies to pneumococcal vaccine in patients with chronic renal failure

Antibody response to the 14-valent pneumococcal capsular polysaccharide vaccine was measured by the enzyme-linked immunosorbent assay (EIA) in 17 renal allograft recipients, 29 azotemic, 11 hemodialysis, and 33 control patients. The IgG, IgM, and IgA antibodies were measured against six pneumococcal antigen types 1, 3, 4, 6A, 8, and 19F. The control patients had the best antibody responses in the IgG and IgA antibody classes and the renal allograft recipients in the IgM class. The renal allograft recipients had significantly stronger antibody responses than the azotemic and hemodialysis patients. The hemodialysis patients had significantly weaker antibody responses than the control patients and the renal allograft recipients, and they also lost their antibodies most rapidly. Thus, the hemodialysis patients and probably some azotemic patients should be considered for revaccination.

Serum cysteine proteinase inhibitors with special reference to kidney failure

Serum levels of proteins reactive in radioimmunoassay with an antiserum prepared in rabbits against purified human spleen neutral cysteine proteinase inhibitor (NCPI) was determined in 70 healthy controls and from 80 patients suffering from suspected or proven kidney failure. The values varied from less than 0.2 mg/l in normal sera to levels over 2 mg/l in some patient sera. Serum level of NCPI was found to roughly correlate with serum creatinine values. However, there were sera with high NCPI levels which did not have increased serum creatinine values. In sera with high NCPI levels subjected to double radial immunodiffusion two precipitin lines, one completely and the other partially identical to NCPI were registered. After fractionating of serum proteins with gel chromatography on Sephadex G 100, two protein peaks of immunological similarity to purified NCPI were found: one low molecular weight (MW around 12,000) and one high molecular weight (MW around 100,000). The low molecular weight NCPI-like material appeared to inhibit human cathepsin B and papain and is thus free serum NCPI. alpha-Cysteine proteinase inhibitor did not increase with serum creatinine as did NCPI.

Influenza vaccination in patients with chronic renal failure

27 patients with chronic renal failure (CRF), 12 of whom were on maintenance hemodialysis, and 40 healthy control individuals were immunized with a split-type influenza vaccine containing A/Victoria/75 (H3N2), A/USSR/77 (H1N1), B/Hong Kong/73 antigens; 2 doses were given 4 weeks apart. Antibody responses were determined by the single radial hemolysis (SRH) technique. After immunization a significant rise (increase in SRH greater than or equal to 2 mm) was measured to A/Victoria in 11 (73%) azotemic and in 11 (92%) hemodialyzed patients and in 35 (88%) controls. To B/Hong Kong a significant antibody rise was observed in 10 (67%) azotemic, in 11 (92%) hemodialyzed and in 27 (68%) control individuals. The mean prevaccination and postvaccination antibody titers in patients with CRF, either azotemic or hemodialyzed, were significantly lower than in healthy control individuals to both A/Victoria and B/Hong Kong antigens (p less than 0.001). On the other hand the mean antibody rises after vaccination were of the same magnitude in all groups. The patients on maintenance hemodialysis had lower prevaccination antibody titers but the postvaccination mean titers were slightly higher than in the azotemic patients. No adverse reactions to the vaccination or deterioration of the renal function were observed; thus we recommend an annual vaccination of patients with CRF.

Plasma lipids on chronic uraemic and transplantation patients

We studied the concentrations of total cholesterol, HDL-cholesterol and triglyceride in the plasma in renal (n = 48) patients. In undialyzed uraemic patients (mean serum creatinine value 439 mumol/l) the plasma cholesterol level was somewhat higher (6.47 mmol/l) than in the control (n = 27) group (5.67 mmol/l). HCL-cholesterol was lower (1.02 mmol/l vs 1.49 mmol/l) and the triglycerides higher (2.07 mmol/l vs 1.07 mmol/l) than in the control group. In dialyzed patients the cholesterol level (5.88 mmol/l) was lower but the triglyceride level higher (2.58 mmol/l) than in undialyzed patients. Renal transplantation corrected the lipid variables to a certain degree (plasma cholesterol 5.55 mmol/l, plasma HDL-cholesterol 1.27 mmol/1 plasma triglycerides 1.15 mmol/l) but HDL-cholesterol remained still somewhat lower than in the control group. No "critical level" of renal function at which the changes of lipoprotein metabolism arise, could be demonstrated, and it seems that e.g. HDL-cholesterol is low already when the diagnosis of renal insufficiency is made.

Does transient blocking of axonal conduction occur in uraemic neuropathy?

In uraemic and other patients with neuropathies, motor unit spike intervals were analysed using a special computer program to detect prolonged intervals of twice the normal duration, so-called "double intervals." These may have different causes--trigger failure, double discharge, or a transient fall in the firing rate of coactive motor units. There was not sufficient evidence that transient conduction blockings will occur in the main axon in uraemic neuropathies.

Yersinia enterocolitica infection complicated by glomerulonephritis

A case of mild glomerulonephritis in a 24-year-old man with clinical and immunohistological findings associated with Yersinia enterocolitica serotype 3 infection is described. The role of IgA in the pathogenesis of glomerulonephritis associated with mucosal infection is briefly discussed. Although attempts to demonstrate Y. enterocolitica 3 antigen in the biopsy specimen were unsuccessful, the glomerular deposits of immunoglobulins and complement suggest immune pathogenesis.

Statistical variation of nerve conduction velocity. An analysis in normal subjects and uraemic patients

The maximal nerve conduction velocity (NCV) of 6 sensory nerves (N. radialis, suralis and peronaeus superficialis, bilaterally) was determined in 88 normals and 59 uraemic patients. When the effect upon nerve conduction velocity of age and temperature was removed through partial correlations, it became possible to verify the negative correlation between the height of the patient and NCV. This explained as much as 35% of the remaining variance in males. There were also other significant differences in the nerve functions between the sexes. A set of "statistical corrections" (grouping of NCV's according to the subject's sex, computing of the average NCV's of an individual, and height-, age- and temperature normalization of single or mean NCV values) substantially decreased the variability of NCV. At the same time, the sensitivity of NCV measurement in the early diagnosis of nerve dysfunction caused by uraemia was increased. It is suggested that the results of NCV measurements should not only be reported as rough, absolute data, but also as normative values, taking into account the known physiological determinants.

The protein binding of diazepam and N-demethyldiazepam in patients with poor renal function

The plasma protein binding of diazepam and of its main metabolite, N-demethyldiazepam, was measured in patients with renal disease and in healthy volunteers by ultracentrifugation. The total and non-protein bound concentrations of diazepam and N-demethyldiazepam, and the concentration of unconjugated oxazepam in the plasma were determined by gas chromatography after an oral 10 mg dose of diazepam. In the volunteers 98% of diazepam and N-demethyldiazepam were bound to the plasma proteins. In patients with renal disease the corresponding values were 92% and 95%, respectively. In the patients with renal disease no correlation could be found between the percent protein binding of diazepam or N-demethyldiazepam in the plasma and the serum creatinine concentration. Considerable variations in diazepam concentrations at 1 and 24 hours and in N-demethyldiazepam concentrations at 24 hours were found in the patients with renal disease. In contrast to the volunteers, 5 patients out of 28 with renal disease had measurable amounts of unconjugated oxazepam in the plasma. The deficient ability of the plasma proteins of patients with renal disease to bind diazepam may increase its clinical effect.

Serum levels and half-life of sotalol in chronic renal failure

The elimination of sotalol was studied in 25 patients with chronic renal failure. All patients were given a single 160 mg dose of sotalol orally and their sotalol serum levels were determined after 4, 6, 8, 10 and 12 hours. The elmination of sotalol was distinctly slower as the serum creatinine concentration rose. The half-lives, calculated graphically, were in lenear ratio to the serum creatinine values (r = 0,91; p less than 0.001). In accordance with the results, it is probable that sotalol accumulates in chronic renal insufficiency. Since beta-blockers may impair renal function, even in therapeutic concentrations, the dosage of sotalol, in particular, must be reduced in patient with kidney disease.