Neuraxial analgesia is not associated with an increased risk of post-partum relapses in MS

Background:

Obstetrical analgesia remains a matter of controversy because of the fear of neurotoxicity of local anesthetics on demyelinated fibers or their potential relationship with subsequent relapses.

Objective:

To assess the impact of neuraxial analgesia on the risk of relapse during the first 3 months post-partum, with a focus on women who experienced relapses during pregnancy.

Methods:

We analyzed data of women followed-up prospectively during their pregnancies and at least 3 months post-partum, collected in the Pregnancy in Multiple Sclerosis (PRIMS) and Prevention of Post-Partum Relapses with Progestin and Estradiol in Multiple Sclerosis (POPARTMUS) studies between 1992–1995 and 2005–2012, respectively. The association of neuraxial analgesia with the occurrence of a post-partum relapse was estimated by logistic regression analysis.

Results:

A total of 389 women were included, 215 from PRIMS and 174 from POPARTMUS. In total, 156 women (40%) had neuraxial analgesia. Overall, 24% experienced a relapse during pregnancy and 25% in the 3 months post-partum. Women with a pregnancy relapse were more likely to have a post-partum relapse (odds ratio (OR) = 1.83, p = 0.02), independently of the use of neuraxial analgesia. There was no association between neuraxial analgesia and post-partum relapse (OR = 1.08, p = 0.78).

Conclusion:

Neuraxial analgesia was not associated with an increased risk of post-partum relapses, whatever multiple sclerosis (MS) activity during pregnancy.

Phenotypic spectrum of Charcot-Marie-Tooth disease due to LITAF/SIMPLE mutations: a study of 18 patients

BACKGROUND AND PURPOSE

Charcot-Marie-Tooth (CMT) 1C due to mutations in LITAF/SIMPLE is a rare subtype amongst the autosomal dominant demyelinating forms of CMT. Our objective was to report the clinical and electrophysiological characteristics of 18 CMT1C patients and compare them to 20 patients with PMP22 mutations: 10 CMT1A patients and 10 patients with hereditary neuropathy with liability to pressure palsies (HNPP).

METHODS

Charcot-Marie-Tooth 1C patients were followed-up in referral centres for neuromuscular diseases or were identified by familial survey. All CMT1A and HNPP patients were recruited at the referral centre for neuromuscular diseases of Pitié-Salpêtrière Hospital.

RESULTS

Two phenotypes were identified amongst 18 CMT1C patients: the classical CMT form ('CMT-like', 11 cases) and a predominantly sensory form ('sensory form', seven cases). The mean CMT neuropathy score was 4.45 in CMT1C patients. Motor nerve conduction velocities in the upper limbs were significantly more reduced in CMT1A than in CMT1C patients. On the other hand, the motor nerve conduction velocity of the median nerve was significantly lower in CMT1C compared to the HNPP group. Distal motor latency was significantly more prolonged in CMT1A patients compared to the CMT1C and HNPP groups, the latter two groups having similar distal motor latency values. Molecular analysis revealed five new LITAF/SIMPLE mutations (Ala111Thr, Gly112Ala, Trp116Arg, Pro135Leu, Arg160Cys).

CONCLUSIONS

Our study delineates CMT1C as mostly a mild form of neuropathy, and gives clinical and electrophysiological clues differentiating CMT1C from CMT1A and HNPP. Delineating phenotypes in CMT subtypes is important to orient molecular diagnosis and to help to interpret complex molecular findings.

Impact of perioperative immunosuppressive medication on surgical outcome in Crohn's Disease (CD)

INTRODUCTION

Patients with Crohn's disease [CD] carry an 80 - 90 % lifetime risk of undergoing surgery. Many of these patients are on immunosuppressive medication at the time of surgery. The aim of this study was to evaluate the effect of immunosuppression on the surgical outcome in CD patients.

METHODS

We retrospectively analyzed 484 consecutive abdominal operations for CD from 1995 to 2008 for surgical complications.

RESULTS

A total of 241 operations (= 49.8 %) were performed under perioperative immunosuppression (corticoids and thiopurine). The overall complication rate was 18.6 %, the major complication rate was 8.7 % and the anastomotic leakage rate was 3.3 %. No differences were observed between patients without immunosuppression compared to those with immunosuppression. Patients with colo-rectal resections showed a higher complication rate than patients with small bowel resection independently of immunosuppression.

CONCLUSION

Nearly 50 % of the patients undergoing abdominal surgery for CD are receiving immunosuppressive medication during surgery. However, perioperative immunosuppression with corticoids, thiopurine or the combination of both does not significantly alter the surgical complication rate. Therefore the decision of a required surgery should not be delayed due to the fact that the patient is under immunosuppressive medication.

[Telemedicine and fibrinolysis in Franche-Comté]

INTRODUCTION

The aim of our study was to compare the efficacy and safety of intravenous thrombolysis of cerebral ischemia as it has been established in a distant hospital (DH) through telemedicine tools or in neurovascular unit of the University Hospital of Besançon.

METHOD

Our work was conducted retrospectively at the University Hospital of Besançon from 1 January 2003 to December 31, 2009.

RESULTS

Fibrinolysis was introduced at the university hospital in 98/161 patients (61%) and a DH in remote 63/161 patients (39%). A favorable neurological outcome (Rankin 0/1) was observed in 27/98 patients (27.5%) treated at University Hospital and in 25/63 (39.5%) patients in a DH. There was no significant difference between the two subgroups. Symptomatic hemorrhagic transformation occurred in 5/98 (5%) patients treated at University Hospital and in 1/63 (1.5%) patients treated in DH. There was no significant difference between the two subgroups.

CONCLUSION

Our study shows that fibrinolysis remotely using the tools of telemedicine has, from 2003 to 2009, in Franche-Comté deal effectively and without risk of a significant proportion of patients.

Cardiac involvement is frequent in patients with the m.8344A>G mutation of mitochondrial DNA

BACKGROUND

Cardiac complications, such as myocardial disease and arrhythmias, are frequent and may be severe in patients with mitochondrial disease. We sought to determine the prevalence and the prognostic value of cardiac abnormalities in a series of patients carrying the m.8344 A>G mutation.

METHODS

We retrospectively collected data concerning a cohort of patients carrying the m.8344A>G mutation. Patients systematically underwent neurologic examination, muscular biopsy, measurement of forced vital capacity, and cardiac evaluation including electrocardiogram, echocardiography, and 24-hour ambulatory electrocardiogram at diagnosis. Neurologic and cardiac evaluations were repeated during follow-up at least every 2 years.

RESULTS

Eighteen patients (mean age 39.3 +/- 17.3 years, 10 women) from 8 families were investigated. Mean follow-up duration was 5.0 +/- 2.7 years. Cardiac abnormalities were identified at diagnosis in 8 patients (44.4%, age 39.1 +/- 17.7 years), including dilated cardiomyopathy in 4, Wolff-Parkinson-White syndrome in 3, incomplete left bundle branch block in 1, and ventricular premature beats in 1. Two additional patients developed left ventricular dysfunction during follow-up and 2 patients died due to heart failure. Subgroup analyses identified early age at disease onset as the only factor significantly associated with myocardial dysfunction.

CONCLUSIONS

We identified a high prevalence of ventricular dysfunction and Wolff-Parkinson-White syndrome. Myocardial involvement was associated with an increased risk of cardiac death due to heart failure, suggesting that cardiac investigations should be systematically considered in patients carrying the m.8344A>G mutation.

First observation of a tetra-anionic metal cluster, Al(n)(4-)

The production of aluminum cluster tetra-anions, and thus the first observation of a tetra-anionic metal cluster in the gas-phase, is reported. The aluminum cluster polyanions were generated by use of the "electron-bath technique." The smallest tetra-anion observed was Al(215) (4-), containing 14% fewer atoms than expected from classical estimates of the tetra-anion appearance size.

Should a single centre for the assay of biochemical markers of nutritional status be mandatory in multicentric trials?

Clinical trials to identify patients at risk and to assess new therapeutic agents in the nutritional field are often single-site. The principal advantage of mounting a multicentric trial is that patient accrual is much quicker. Albumin, transthyretin, and C-reactive protein are frequently used biochemical markers of nutritional and inflammation status. However, the different techniques, reagents, and calibrators used to measure these markers introduce wide variations in values among laboratories. This study was carried out as part of a prospective multicentric study in chronic respiratory disease patients to evaluate variability and comparability of results among laboratories for these biochemical markers, and to determine whether centralization is necessary. Thirty enrolled laboratories provided their own range of reference values for those proteins a nd were then requested to process two control samples C1 and C2 blind. The results showed a broad dispersion of values for albumin and transthyretin. In 7% of laboratories, results of albumin for C2 (mean, all techniques: 39.1+/-3 g/l) were <35 g/l, the threshold value indicating a potential risk of malnutrition. When only laboratories using immunonephelemetry were considered, the results were satisfactory (CV<10% for all proteins). Given the possible incorrect classification of patients at risk, measurement should be made per site only if all participants use an immunonephelometric method. Otherwise, a centralizing assay of these biological markers should be considered.

Sorption mechanisms of zinc to calcium silicate hydrate: sorption and microscopic investigations

Knowledge of the binding mechanisms of heavy metals to cement minerals is essential for the prediction of the long-term leachability of secondary building materials and cement-stabilized wastes containing heavy metals. In this study, the sorption of Zn(II) to calcium silicate hydrate (C-S-H(I)) in pre-equilibrated aqueous suspensions has been investigated as a function of time (up to 87 d), pH (11.7, 12.48, and 12.78) and Zn(II) concentration (4.8-4800 microM). Electron probe microanalysis (EPMA) was performed in order to determine where Zn(II) was bound. At high Zn(II) concentrations (>1000 microM), the precipitation of beta2-Zn-(OH)2 (< pH 12) and calcium zincate (Zn2Ca(OH)6 x 2H2O, > pH 12) was observed. Surface precipitation could not be discerned. At lower concentrations, it was found that the sorption process was initially very rapid with over 50% sorbed within 30 min but that the sorption continued more slowly to at least 87 d. The data could be interpreted in terms of the Freundlich isotherm up to a Si:Zn(II)sorbed atomic ratio of approximately 6:1. Zinc was observed by EPMA to incorporate into the C-S-H(I) particles but did not appear to substitute for Ca or Si. The incorporation of Zn(ll) in the interlayer of C-S-H(I) or sorption to internal surfaces of crystalline appear to be the most probable mechanisms for the observed Zn(II) sorption to C-S-H(I).

Sorption mechanisms of zinc to calcium silicate hydrate: X-ray absorption fine structure (XAFS) investigation

In this study, X-ray absorption fine structure (XAFS) spectroscopy has been used to further elucidate the binding mechanisms of Zn(II) to calcium silicate hydrate (C-S-H), the quantitatively most important cement mineral. Such knowledge is essential for the assessment of the longterm behavior of cement-stabilized waste materials. XAFS spectra of the Zn(II) equilibrated with C-S-H(I) for up to 28 days are best modeled by tetrahedral coordination of Zn(II) by four O atoms in the first atomic shell. Beyond the first coordination shell, data analysis of more highly concentrated samples suggests the presence of two distinct Zn distances and possibly the presence of an Si shell. On the basis of the comparison with a set of reference compounds, this coordination environment can be reasonably related to the structure of hemimorphite, a naturally occurring zinc silicate, and/or the presence of gamma-Zn(OH)2. At the lowest Zn uptake, the above fitting approach failed and data could be described best with a Zn-Si and a Zn-Ca shell. Previous work has been able to show that Zn(II) diffuses into the C-S-H(I) particles and does not form discrete precipitates, so the findings appear to confirm the incorporation of Zn(II) in the interlayer of C-S-H(I).

["MELAS" (A3243G) mutation of mitochondrial DNA: a study of the relationships between the clinical phenotype in 19 patients and morphological and molecular data]

Nineteen patients were found to harbor the mitochondrial DNA A3243G mutation associated with MELAS syndrome (Mitochondrial myopathy, Encephalopathy, Lactic Acidosis and Stroke-like episodes). Eight of them had presented with stroke-like episodes and therefore had a clinical diagnosis of MELAS syndrome. The other 11 patients had no strokes and presented with generally less severe multisystemic disease. In the two groups, we compared muscle morphology, biochemical activities of muscle respiratory chain, and genetic characteristics: proportion and tissue distribution of the mutation, sequence of the 22 transfer RNA genes of the mitochondrial DNA. The proportion of mutant mtDNA in muscle was always greater than in blood. The number of patients in the two groups was too low to reach significant values. However, the patients with a MELAS syndrome presented with more severe respiratory chain abnormalities and with a proportion of the A3243G mutation that was both higher and more uniformly distributed among tissues. For symptoms others than stroke-like episodes, we did not observe any correlation with the level of mutant mtDNA in muscle. The analysis of the 22 tRNA sequences did not show differences between the two groups, and no co-inherited modifying tRNA genes could explain the variability of severity in our patients.

[Cavernous sinus lymphoma mimicking Tolosa-Hunt syndrome]

INTRODUCTION

Tolosa-Hunt syndrome is characterized by painful ophthalmoplegia due to idiopathic granulomatous inflammation of the cavernous sinus. Steroid therapy dramatically reverses the symptoms and clinical signs. Because they also may respond to steroids, tumors such as lymphoma and meningioma and orbital tumors can make differential diagnosis difficult.

EXEGESIS

We report the case of a 78-year-old male patient in whom systemic lymphoma associated with inflammation of the cavernous sinus was uncovered by painful, gradually progressing, ophthalmoplegia mimicking Tolosa-Hunt syndrome.

CONCLUSION

When faced with a clinical picture suggestive of the existence of Tolosa-Hunt syndrome clinical workup is mandatory and should lead to diagnosis of exclusion.

[Progressive multifocal leukoencephalopathy an chronic lymphocytic leukemia]

INTRODUCTION

Progressive multifocal leukoencephalopathy is a demyelinating disease resulting from an opportunistic infection of the central nervous system by JC papovavirus. It mostly occurs in patients with an underlying immunosuppressive disorder. In the era of acquired immunodeficiency syndrome it is observed with increasing frequency.

EXEGESIS

We report the case of a non-HIV-infected patient who presented chronic lymphocytic leukemia with progressive multifocal leukoencephalopathy uncovered by both imaging and the presence of JC virus in the cerebrospinal fluid.

CONCLUSION

Due to the lack of specific treatment, the disease is still rapidly progressive and fatal.

[Ischemic cerebral vascular accident and zoster infection]

Herpes zoster is uncommonly followed by cerebral infarction. The pathophysiological mechanism remains uncertain. Outcome is favorable after early specific treatment. We report the case of a 70-year-old woman who developed right hemiparesis with aphasia 15 days after thoracic herpes zoster. The herpes zoster induced cerebral vasculitis was hypothesized as no other etiology could be identified after detailed assessment of the cerebral infarction including brain MRI and cerebrospinal fluid study, and as the clinical course responded to antiviral therapy.

Nutritional and clinical efficacy of ornithine alpha-ketoglutarate in severe burn patients

Ornithine alpha-Ketoglutarate (OKG) displays anabolic and anticatabolic properties in situations of stress. However, studies including both biological and clinical end points are scarce. In this prospective, randomized and double-blind study, 60 patients who had undergone severe burns (20-60% of body surface area) received either ornithine alpha-ketoglutarate (20 g/day) or an isocaloric placebo, for 21 days, starting mean 4 days after injury. In the OKG group, nitrogen balance reached positive values at d5 and stabilized at higher levels vs controls (P< 0.05 or less from day 3 to day 21), resulting in a strongly positive cumulated nitrogen balance at day 21 (mean +/- SEM, OKG group: +127 +/- 13;

CONTROL GROUP

-63 +/- 18g nitrogen). As measured at day 21, transthyretin and RBP levels were higher in the OKG group (respectively 259 +/- 9 vs 161 +/- 10, and 45 +/- 1 vs 33 +/- 1 mg/l, P< 0.001). Body weight loss was counteracted at d21 in the OKG group (-2.6% vs -6.3%, P< 0.001). Assessment of the quality of wound healing using objective scoring showed better performances in the OKG group (P< 0.05). The results suggest that improvement in nutritional parameters observed during the treatment of burn-injured patients with ornithine a-ketoglutarate allows better clinical recovery.

Is alpha-ketoisocaproyl-glutamine a suitable glutamine precursor to sustain fibroblast growth?

BACKGROUND

Glutamine is considered an essential nutrient for cellular growth.

AIM

To test the suitability of alpha-ketoisocaproyl-Gln (Kic-Gln) as a new glutamine (Gln) precursor to sustain human fibroblast growth.

METHODS

[3H] thymidine uptake into cellular DNA of human fibroblasts. Extracellular and intracellular amino acid patterns were determined with peptides and acylated compounds.

RESULTS

L-alanyl-L-glutamine (used here as a recognized Gln precursor) promoted DNA synthesis, while N-acetyl-L-glutamine (used here as a negative control since it is known to be a poor Gln precursor) and alpha-ketoisocaproyl-glutamine had no effect. Alanyl-glutamine progressively gave rise to free glutamine in the growth medium. In contrast, glutamine supplied in acylated form was poorly available and did not appear in free form in the medium. In addition, only alanyl-glutamine increased intracellular glutamine and glutamate levels. In contrast, Kic-Gln was able to sustain net protein synthesis as judged by total protein content and reduced intracellular levels of most essential amino acids.

CONCLUSION

Kic-Gln appears to be a poor extra-cellular precursor of Gln to sustain cell growth.

Vascular complication involving the conus medullaris or cauda equina after vertebral manipulation for an L4-L5 disk herniation

A case of injury to the cauda equina or conus medullaris after lumbar vertebral manipulation is reported. In contrast to all other previously reported cases, no migrated disk fragment was demonstrated. Similar to experience at the cervical spine, lumbar vertebral manipulation may carry a risk of vascular injury. The neurological manifestations in our patient were consistent with compression of the Desproges-Gotteron artery by a small L4-L5 disk herniation.

Pharmacokinetic assessment of an oligopeptide-based enteral formula in abdominal surgery patients

The specific effect of the molecular form of the nitrogen supply (oligopeptides and whole proteins) on amino acid kinetics during enteral feeding after surgery has not been assessed previously. In a prospective, randomized study, patients having undergone esophagectomy or gastrectomy for cancer received jejunal infusions of oligopeptide-based or whole-protein-based complete formulas (OPD and WPD, respectively) during two 9-h periods on 2 consecutive days in a crossover design. The OPD and WPD had identical energy compositions and amino acid profiles. Amino acid peripheral bioavailability (measurements of area under the curve of arterial blood concentrations), amino acid arteriovenous differences, and insulin and glucagon responses were measured. Amino acid peripheral bioavailability was higher (leucine: 54%, P < 0.01; essential amino acids: 48%, P < 0.01; total amino acids: 53%, P < 0.02) and peripheral appearance of amino acids was more homogeneous (variation around the calculated plateau of plasma leucine was 39% for OPD and 78% for WPD, P < 0.001) with the OPD than with the WPD. With the OPD, insulin stimulation was faster and plasma concentrations of leucine and insulin were correlated (r = 0.77, P < 0.01). The OPD led to a higher amino acid peripheral bioavailability than the corresponding WPD. These results could be useful for a better definition of clinical indications of semi-elemental diets.

Cost-utility in CNS drug trials

This paper considers some of the theoretical and practical problems of conducting cost-utility analyses alongside clinical trials. In order to measure utilities of different health states in a clinical trial a number of critical assumptions have to be made. Some of these assumptions are questionable on a theoretical level, others empirically invalid. The practical problems of measuring utilities are discussed. The standard gamble is shown to be the most validated method of utility measurement, but still based on very strong assumptions. The standard gamble instrument is also costly and difficult to administer in clinical trials. Other instruments are found to be less valid than the standard gamble. It is concluded that although cost-utility analysis seems relevant in some instances, investigators should avoid this assessment of utility and instead measure cost-effectiveness, cost-benefit and quality of life.

Leucine kinetics are different during feeding with whole protein or oligopeptides

To determine if the molecular form of nitrogen intake affects protein metabolism during feeding, 12 normal volunteers received, by continuous nasogastric infusion, a protein or a peptide-based diet. Leucine kinetics (oral [13C]leucine and intravenous [2H3]leucine) were measured during the following three consecutive periods: first carbohydrates and lipids alone, then with either whole casein or oligopeptides in a randomized crossover design, with these two latter periods being isonitrogenous, isocaloric, and of identical amino acid compositions. Leucine concentration, turnover, oxidation, and nonoxidative disposal increased during nitrogen administration (all P < 0.01) and were higher with oligopeptides than with casein (242 +/- 44 vs. 188 +/- 31 mumol/l; 2.75 +/- 0.45 vs. 2.23 +/- 0.31; 1.14 +/- 0.19 vs. 0.82 +/- 0.22 mumol.kg-1.min-1, all P < 0.001; 1.64 +/- 0.32 vs. 1.44 +/- 0.33 mumol.kg-1.min-1, P < 0.05, respectively). Endogenous leucine production was less inhibited by oligopeptides than by casein (0.82 +/- 0.41 vs. 0.38 +/- 0.31 mumol.kg-1.min-1, P < 0.001), whereas splanchnic extractions were similar. Finally, leucine balance was more positive with casein than with oligopeptides (P < 0.001). In conclusion, the response of leucine kinetics to feeding is modified by the molecular form of nitrogen intake, with the oligopeptides inducing a higher oxidation and protein synthesis and a lesser inhibition of protein breakdown.

[Open therapeutic trial of anti-T CD4 monoclonal antibody in multiple sclerosis]

Twenty-one patients with active multiple sclerosis (16 progressive and 5 recurrent forms) were treated with murine monoclonal anti-T CD4/BF5 antibodies in an open trial. Tolerance was relatively good; 11 patients had side effects including facial swellings, skin eruptions and trembling which occurred only at the first infusion. Treatment had to be stopped in one female patient. Nine months after initiating treatment, no relapse had occurred in any of the 5 patients with a recurrent form and improvement was observed in 3 patients with a progressive form. At the end of the treatment period, there was a clear drop in the number of CD3+ cells and particularly in CD4+ cells, a decrease which was less after one month. All the patients who had side effects showed an increased level of serum IL6 and alpha TNF. These findings demonstrate that this type of long-term treatment is possible in patients with multiple sclerosis and suggest that in another trial it would be important to evaluate the effect in recurrent forms.

Ornithine alpha-ketoglutarate and glutamine supplementation during refeeding of food-deprived rats

The aim of this study was to compare the efficiency of ornithine alpha-ketoglutarate (OKG) and glutamine supplementation in an experimental model of denutrition that provides well-characterized disturbances of amino acid patterns. Male Wistar rats (187 +/- 11 g; five in each group) were starved for 3 days and then refed for 7 days with an oral diet (192 kcal kg-1.day-1 and 2.25 g of nitrogen kg-1.day-1), supplemented with 0.19 g of nitrogen kg-1.day-1 in the form of OKG, glutamine, or casein (control group). Food deprivation induced a fall in most tissue amino acids, with the notable exception of muscle leucine and liver glutamate, which increased by 43% (p < .01), and 11% (p < .05), respectively. The main effect of OKG was seen in the viscera, with a normalization of most amino acid pools (including proline and branched-chain amino acids) in the small bowel and liver. The main effect of glutamine was observed in the muscle, with a normalization of the glutamine and leucine pools. We conclude that, in this model and with the doses used, OKG and glutamine act in different target tissues, ie, splanchnic areas and muscle, respectively.

Analysis of the tissue distribution and inheritance of heteroplasmic mitochondrial DNA point mutation by denaturing gradient gel electrophoresis in MERRF syndrome

MERRF (Myoclonic Epilepsy and Ragged-Red Fibres) syndrome is one of the maternally inherited diseases for which a mitochondrial DNA (mtDNA) point mutation has recently been identified. The mutation is always heteroplasmic, that is normal and mutant mtDNA coexist within the same individual. We studied mtDNA heteroplasmy in two families with MERRF syndrome, using a denaturing gradient gel electrophoresis technique that avoids the errors in the evaluation of wild/mutant mtDNA ratios caused by restriction enzyme cutting in the situation of amplification of a heteroplasmic DNA. In two patients, the proportion of muscle mutant mtDNA was in agreement with the severity of muscle mitochondrial proliferation, energy defect and fibre type I predominance. In nine patients from three generations of one family, mutant mtDNA proportion in leukocytes was in relative agreement with the clinical severity of the disease. Transmission of mutant mtDNA through these three generations did not show any tendency toward homoplasmy. Homogeneity of the mutant mtDNA proportion among different tissues from one patient was demonstrated in brain, liver, muscle and heart but a possibility of divergence of the mutant mtDNA proportion during mitosis was documented in cultured skin fibroblasts.

Genetic biochemical and pathophysiological characterization of a familial mitochondrial encephalomyopathy (MERRF)

Myoclonic epilepsy with ragged-red fibers (MERRF) syndrome is a neuromuscular disorder characterized by mitochondrial myopathy and progressive myoclonus epilepsy. A heteroplasmic A to G transition mutation in the mitochondrial encoded tRNA(Lys) gene at nucleotide pair 8344 has been suggested to be linked to the MERRF-syndrome. We have investigated biochemically and histochemically muscle biopsies and studied the mitochondrial genomes of hair, blood and muscle tissue of a family including three cases of MERRF-syndrome as well as unaffected relatives within the maternal lineage. Sequence analysis of the mtDNAs, performed after amplification by the polymerase chain reaction (PCR), confirmed the A to G transition mutation in the tRNA(Lys) gene at position 8344. The additional point mutation at nucleotide pair 750 in the 12 S rRNA gene, which was also found by Shoffner et al. (1990), however, was absent in all investigated tissues. Quantitative analysis of the percentage of mutated mtDNA by mispairing PCR (Seibel et al., 1990) revealed variable contents in different tissues and individuals, including unaffected family members. Mitochondrial protein synthesis in cultured fibroblasts from MERRF patients revealed diminished incorporation of 35S-methionine into lysine-containing peptides.

Action of enterally administered ornithine alpha-ketoglutarate on protein breakdown in skeletal muscle and liver of the burned rat

Several studies concerning burn patients have shown that supplementation of enteral nutrition with ornithine alpha-ketoglutarate (OKG) favorably modifies protein metabolism. Therefore, the effect of OKG administration on muscular and hepatic protein catabolism was evaluated in burned rats. Four groups of six rats were used. Two groups were scalded by immersion of the dorsum in water at 90 degrees C for 10 seconds and then starved for 24 hours. Controlled enteral nutrition was then administered in three boluses daily (Osmolite, 210 kcal/kg/d, 1.2 g N/kg/d); one group was supplemented with OKG (5 g/kg/d, ie, 0.68 g N/kg/d), while the other group received an equivalent amount of nitrogen in the form of glycine. One group of healthy control rats received Osmolite supplemented with glycine and the last group was fed ad libitum. The animals were killed after 2 days of nutrition. Protein catabolism was assessed in vitro by measuring the amount of valine (liver catabolism) and phenylalanine (muscle catabolism) released into the incubation medium of isolated tissues. Tissular and serum glutamine were also assayed. Burn injury induced muscle hypercatabolism without affecting hepatic catabolism. The administration of OKG limited both muscle weight loss and muscle protein hypercatabolism and significantly improved the muscle glutamine pool. These results demonstrate the nitrogen-sparing effect of OKG in muscle in hypercatabolic states.

Efficiency of enteral nitrogen support in surgical patients: small peptides v non-degraded proteins

In a prospective study, 12 intensive care patients, after abdominal surgery, received three alternate six-day courses of two enteral diets with identical nitrogen (0.3 g N/kg per day) and energy (60 kcal/kg per day) supply. The protein hydrolysate (PH) diet contained enzyme-hydrolysed casein and lactoserum (60% small peptides), while the non-degraded protein (NDP) diet contained a nitrogen source of similar amino acid composition, but in the form of non-degraded proteins. The patients were randomised to receive either PH-NDP-PH or NDP-PH-NDP. Parameters reflecting protein metabolism were assessed in the plasma, urine, and stomal effluent on days 1, 6, 12, and 18, three hours after stopping the nutrition (t0), and one hour after restarting it (t1). Comparisons of t1 and t0 values showed that 13 amino acids (including the eight essential amino acids) increased significantly with the protein hydrolysate diet, but only two increased with the non-degraded protein diet. Similarly, with protein hydrolysate, insulin-aemia at t1 was significantly higher than at t0 and correlated with plasma leucine, phenylalanine, alanine, and lysine concentrations. In addition, significant improvements in plasma albumin, transferrin, and retinol binding protein concentrations were seen with protein hydrolysate, together with a significant decrease in the plasma phenylalanine/tyrosine ratio and urinary 3-methylhistidine excretion. We conclude that in patients in intensive care after abdominal surgery enteral support containing small peptides is more effective than an equivalent diet containing whole proteins in restoring plasma amino acid and protein levels.

Food intake, body and heart composition, and heart rate in T3 plus atenolol-treated rats

Thyroid hormones and beta-blockers both affect energy balance and the heart. The interaction of 3,5,3'-triiodothyronine (T3) and the beta-blocker atenolol on some cardiac and energy balance parameters was therefore investigated. Stock-fed male Wistar rats (approximately 400 g) received 5 micrograms (expt 1) or 1.5 micrograms (expt 2) T3.100 g body wt-1.day-1 for 3 wk, with or without atenolol. In expt 3, rats were overfed with a "cafeteria" diet before and during the experiment and otherwise treated as in experiment 2. Compared with stock-fed (expt 1 and 2) or overfed (expt 3) controls, T3 caused an increase in food intake in experiments 1 and 2 but not in experiment 3. There was a large loss of body fat in all experiments, disproportionately greater than the body weight loss. Protein loss was significant only in experiment 1 and negligible in cafeteria rats. Heart rate and weight were increased, although heart composition remained unchanged. Atenolol, in a dose that abolished T3-induced tachycardia, did not modify any of the other T3 effects investigated, including the hypertrophy of the heart. These results indicate that T3-induced tachycardia can be abolished by concomitant treatment with a beta-blocker without altering parameters connected with energy balance, whereas protein loss caused by T3 can be attenuated by lowering the dose of T3 used and can be further blunted by dietary manipulation (cafeteria overfeeding).