Effect of exogenous and endogenous ketones on respiratory exchange ratio and glucose metabolism in healthy subjects

This study examined the effect of exogenous ketone bodies (KB) on oxygen consumption (V̇o2), carbon dioxide production (V̇co2), and glucose metabolism. The data were compared with the effects of endogenous ketonemia during both, a ketogenic diet or fasting. Eight healthy individuals [24.1 ± 2.5 yr, body mass index (BMI) 24.3 ± 3.1 kg/m2] participated in a crossover intervention study and were studied in a whole-room indirect calorimeter (WRIC) to assess macronutrient oxidation following four 24-h interventions: isocaloric controlled mixed diet (ISO), ISO supplemented with ketone salts (38.7 g of β-hydroxybutyrate/day, EXO), isocaloric ketogenic diet (KETO), and total fasting (FAST). A physical activity level of 1.65 was obtained. In addition to plasma KB, 24-h C-peptide and KB excretion rates in the urine and postprandial glucose and insulin levels were measured. Although 24-h KB excretion increased in response to KETO and FAST, there was a modest increase in response to EXO only (P < 0.05). When compared with ISO, V̇o2 significantly increased in KETO (P < 0.01) and EXO (P < 0.001), whereas there was no difference in FAST. V̇co2 increased in EXO but decreased in KETO (both P < 0.01) and FAST (P < 0.001), resulting in 24-h respiratory exchange ratios (RER) of 0.828 ± 0.024 (ISO) and 0.811 ± 0.024 (EXO) (P < 0.05). In response to EXO there were no differences in basal and postprandial glucose and insulin levels, as well as in insulin sensitivity. When compared with ISO, EXO, and KETO, FAST increased homeostatic model assessment β-cell function (HOMA-B) (all P < 0.05). In conclusion, at energy balance exogenous ketone salts decreased respiratory exchange ratio without affecting glucose tolerance.NEW & NOTEWORTHY Our findings revealed that during isocaloric nutrition, additional exogenous ketone salts increased V̇o2 and V̇co2 while lowering the respiratory exchange ratio (RER). Ketone salts had no effect on postprandial glucose metabolism.

Low selenium intake is associated with risk of all-cause mortality in kidney transplant recipients

BACKGROUND

Deficiency of the essential trace element selenium is common in kidney transplant recipients (KTR), potentially hampering antioxidant and anti-inflammatory defence. Whether this impacts the long-term outcomes of KTR remains unknown. We investigated the association of urinary selenium excretion, a biomarker of selenium intake, with all-cause mortality; and its dietary determinants.

METHODS

In this cohort study, outpatient KTR with a functioning graft for longer than 1 year were recruited (2008-11). Baseline 24-h urinary selenium excretion was measured by mass spectrometry. Diet was assessed by a 177-item food frequency questionnaire, and protein intake was calculated by the Maroni equation. Multivariable linear and Cox regression analyses were performed.

RESULTS

In 693 KTR (43% men, 52 ± 12 years), baseline urinary selenium excretion was 18.8 (interquartile range 15.1-23.4) μg/24-h. During a median follow-up of 8 years, 229 (33%) KTR died. KTR in the first tertile of urinary selenium excretion, compared with those in the third, had over a 2-fold risk of all-cause mortality [hazard ratio 2.36 (95% confidence interval 1.70-3.28); P < .001], independent of multiple potential confounders including time since transplantation and plasma albumin concentration. The most important dietary determinant of urinary selenium excretion was protein intake (Standardized β 0.49, P < .001).

CONCLUSIONS

Relatively low selenium intake is associated with a higher risk of all-cause mortality in KTR. Dietary protein intake is its most important determinant. Further research is required to evaluate the potential benefit of accounting for selenium intake in the care of KTR, particularly among those with low protein intake.

Impact of one-day fasting, ketogenic diet or exogenous ketones on control of energy balance in healthy participants

BACKGROUND & AIMS

Oral ketone supplements may mimic the beneficial effects of endogenous ketones on energy metabolism as β-hydroxybutyrate has been proposed to increase energy expenditure and improve body weight regulation. Therefore, our objective was to compare the effects of a one-day isocaloric ketogenic diet, fasting and supplementation with ketone salts on energy expenditure and appetite perception.

METHODS

Eight healthy young adults (4 women, 4 men, age 24 ± 3 years, BMI 24.3 ± 3.1 kg/m²) participated in a randomized cross-over trial with four 24 h-interventions in a whole room indirect calorimeter at a physical activity level of 1.65: (i) total fasting (FAST), (ii) isocaloric ketogenic diet (3.1% energy from carbohydrates (CHO), KETO), (iii) isocaloric control diet (47.4% energy from CHO, ISO), and (iv) ISO supplemented with 38.7 g/d ketone salts (exogenous ketones, EXO). Effects on serum ketone levels (15 h-iAUC), energy metabolism (total energy expenditure, TEE; sleeping energy expenditure, SEE; macronutrient oxidation) and subjective appetite were measured.

RESULTS

Compared to ISO, ketone levels were considerably higher with FAST and KETO and little higher with EXO (all p > 0.05). Total and sleeping energy expenditure did not differ between ISO, FAST and EXO whereas KETO increased TEE (+110 ± 54 kcal/d vs. ISO, p < 0.05) and SEE (+201 ± 90 kcal/d vs. ISO, p < 0.05). CHO oxidation was slightly decreased with EXO compared to ISO (-48 ± 27 g/d, p < 0.05) resulting in a positive CHO balance (p < 0.05). No differences between the interventions were found for subjective appetite ratings (all p > 0.05).

CONCLUSION

A 24 h-ketogenic diet may contribute to maintain a neutral energy balance by increasing energy expenditure. Exogenous ketones in addition to an isocaloric diet did not improve regulation of energy balance.

CLINICAL TRIAL REGISTRATION

NCT04490226 https://clinicaltrials.gov/.

Urinary Copper Excretion Is Associated with Long-Term Graft Failure in Kidney Transplant Recipients

INTRODUCTION

In chronic kidney disease, proteinuria increases urinary copper excretion, inducing oxidative tubular damage and worsening kidney function. We investigated whether this phenomenon occurred in kidney transplant recipients (KTRs). In addition, we studied the associations of urinary copper excretion with the biomarker of oxidative tubular damage urinary liver-type fatty-acid binding protein (u-LFABP) and death-censored graft failure.

METHODS

This prospective cohort study was performed in the Netherlands between 2008 and 2017, including outpatient KTR with a functioning graft for longer than 1 year, who were extensively phenotyped at baseline. Twenty-four-hour urinary copper excretion was measured by inductively coupled plasma mass spectrometry. Multivariable linear and Cox regression analyses were performed.

RESULTS

In 693 KTR (57% men, 53 ± 13 years, estimated glomerular filtration rate [eGFR] 52 ± 20 mL/min/1.73 m2), baseline median urinary copper excretion was 23.6 (interquartile range 11.3-15.9) µg/24 h. Urinary protein excretion was positively associated with urinary copper excretion (standardized β = 0.39, p < 0.001), and urinary copper excretion was positively associated with u-LFABP (standardized β = 0.29, p < 0.001). During a median follow-up of 8 years, 109 (16%) KTR developed graft failure. KTR with relatively high copper excretion were at higher risk of long-term graft failure (hazard ratio [HR]: 1.57, 95% confidence interval [CI]: 1.32-1.86 per log2, p < 0.001), independent of multiple potential confounders like eGFR, urinary protein excretion, and time after transplantation. A dose-response relationship was observed over increasing tertiles of copper excretion (HR: 5.03, 95% CI: 2.75-9.19, tertile 3 vs. 1, p < 0.001). u-LFABP was a significant mediator of this association (74% of indirect effect, p < 0.001).

CONCLUSION

In KTR, urinary protein excretion is positively correlated with urinary copper excretion. In turn, higher urinary copper excretion is associated with an independent increased risk of kidney graft failure, with a substantial mediating effect through oxidative tubular damage. Further studies are warranted to investigate whether copper excretion-targeted interventions could improve kidney graft survival.

Plasma Copper Concentration Is Associated with Cardiovascular Mortality in Male Kidney Transplant Recipients

Kidney transplant recipients (KTR) are at increased risk of cardiovascular mortality. We investigated whether, in KTR, post-transplantation copper status is associated with the risk of cardiovascular mortality and potential effect modification by sex. In this cohort study, plasma copper was measured using mass spectrometry in extensively-phenotyped KTR with a functioning allograft >1-year. Cox regression analyses with the inclusion of multiplicative interaction terms were performed. In 660 KTR (53 ± 13 years old, 56% male), the median baseline plasma copper was 15.42 (IQR 13.53-17.63) µmol/L. During a median follow-up of 5 years, 141 KTR died, 53 (38%) due to cardiovascular causes. Higher plasma copper was associated with an increased risk of cardiovascular mortality in the overall KTR population (HR 1.37; 95% CI, 1.07-1.77 per 1-SD, p = 0.01). Sex was a significant effect modifier of this association (P_interaction = 0.01). Among male KTR, higher plasma copper concentration was independently associated with a two-fold higher risk of cardiovascular mortality (HR 2.09; 95% CI, 1.42-3.07 per 1-SD, p < 0.001). Among female KTR, this association was absent. This evidence offers a rationale for considering a sex-specific assessment of copper's role in cardiovascular risk evaluation. Further studies are warranted to elucidate whether copper-targeted interventions may decrease cardiovascular mortality in male KTR.

Dietary lithium intake, graft failure and mortality in kidney transplant recipients

BACKGROUND & AIMS

Long-term high dose lithium therapy in bipolar disorder is known to adversely affect kidney function. However, recent animal studies revealed that low amounts of lithium are beneficial for the kidney when it is damaged by exposure to nephrotoxic compounds, inflammation, or oxidative stress. This study aimed to investigate whether urinary lithium excretion, reflecting dietary lithium intake, is associated with adverse long-term kidney graft outcomes and patient survival.

METHODS

Urinary lithium concentration was measured using inductively coupled plasma-mass-spectrometry in 642 stable kidney transplant recipients. Graft failure was defined as start of dialysis or re-transplantation, and kidney function decline was defined as doubling of serum creatinine.

RESULTS

Median [interquartile range] urinary lithium excretion was 3.03 [2.31-4.01] μmol/24 h. Urinary lithium excretion was associated with energy, plant protein and water intake. During a median follow-up of 5.3 [4.5-6.0] years, 79 (12%) KTR developed graft failure and 127 (20%) KTR developed kidney function decline. Higher urinary lithium excretion was associated with lower risk of graft failure (hazard ratio [95% confidence interval]: 0.54 [0.38-0.79] per log2 μmol/24 h) and kidney function decline (HR [95% CI]: 0.73 [0.54-0.99] per log2 μmol/24 h). These associations remained independent of adjustment for potential confounders and in sensitivity analyses. There was significant effect modification by use of proliferation inhibitors (P = 0.05) and baseline eGFR (P < 0.001), with higher urinary lithium excretion being more protective in KTR not using proliferation inhibitors and in KTR with lower baseline eGFR. Furthermore, higher urinary lithium excretion was associated with reduced risk of all-cause mortality (HR [95% CI]: 0.64 [0.49-0.83]; P = 0.001).

CONCLUSION

Dietary lithium intake may be a potentially modifiable-yet rather overlooked-risk factor for adverse long-term kidney graft outcomes and patient survival.

Minerals and Trace Elements in 990 Beverages and Their Contribution to Dietary Reference Values for German Consumers

Beverages are an integral part of human nutrition, yet little is known about their contribution to daily intakes of minerals and trace elements in German consumers. Using inductively coupled plasma-mass spectrometry, we determined the concentration of five minerals and six trace elements in beverage samples (n = 990, assigned to different beverage groups) collected throughout Germany. For a calculation of their relative contribution to the mineral supply, available beverage consumption data was combined with our quantitative analysis to calculate the average contribution of beverage groups to meet the respective dietary reference values currently used in Germany, Austria and Switzerland (D-A-CH region). Based on their presence in beverages and their consumption, the top three minerals are phosphorous, calcium and magnesium, and they, therefore, may reasonably contribute to the reference values. Among the trace elements, beverages mostly contributed to the manganese supply, whereas at the same time, concentrations of iron, cobalt and copper were low across all tested groups. Our study provides an overview of the assumed mineral and trace element intake via beverages in Germany and may, thus, serve as a foundation for a mineral and trace element database of beverages that needs to be expanded in the future.

Boron Intake and decreased risk of mortality in kidney transplant recipients

Purpose

In a search for potentially modifiable factors to improve long-term outcome among kidney transplant recipients (KTR), we hypothesized that boron exposure is associated with improved long-term outcome in KTR.

Methods

We determined 24 h urinary boron excretion using inductively coupled plasma mass spectrometry as a measure of boron exposure in 693 stable KTR (57% male, mean age 53y), enrolled in the TransplantLines Food and Nutrition Biobank and Cohort Study. Dietary intake was assessed using validated food-frequency questionnaires.

Results

Linear regression analyses showed that dietary intake of fruit, wine and nuts were key determinants of boron excretion. In addition, boron excretion was negatively correlated with homocysteine and inflammatory parameters. In total, 73 (32%), 47 (20%) and 30 (13%) KTR died among the lowest, middle and highest tertiles of 24 h urinary boron excretion, respectively (P_log-rank < 0.001). Cox regression analyses showed that high boron excretion was strongly associated with lower risk of mortality, independent of age, sex, estimated glomerular filtration rate and history of cardiovascular disease (HR per doubling: 0.51, 95% CI: 0.40 to 0.66, P < 0.001).

Conclusion

Boron may be an overlooked target to improve long-term survival among KTR and potentially other patients, likely through pathways other than inflammation or the methionine-homocysteine cycle that were previously suggested. Interventional trials are warranted to confirm the potential of dietary boron supplementation in KTR and other patient populations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02702-0.

Boron Contents of German Mineral and Medicinal Waters and Their Bioavailability in Drosophila melanogaster and Humans

SCOPE

Boron is a trace element that naturally occurs in soil, making mineral and medicinal water important contributors to overall intake. Thus, in a systematic screening, the mean boron concentrations of 381 German mineral and medicinal waters are determined.

METHODS AND RESULTS

Boron concentrations in mineral and medicinal waters are analyzed by inductively coupled mass spectrometry (ICP-MS). Highest boron values find in waters from the southwest of Germany. The boron content of the waters is positively correlated with the concentration of most other analyzed bulk elements, including calcium, potassium, magnesium, and sodium. Mineral waters with either low (7.9 µg L^-1 ), medium (113.9 µg L^-1 ), or high (2193.3 µg L^-1 ) boron content are chosen for boron exposure experiments in fruit flies (Drosophila melanogaster) and humans. In flies, boron-rich mineral water significantly increases boron accumulation, with the accumulation predominantly occurring in the exoskeleton. In humans, serum boron and 24-h urinary boron excretion significantly increase only in response to the intake of boron-rich mineral water.

CONCLUSION

Overall, the current data demonstrate that mineral and medicinal waters vary substantially in the content of boron and that boron-rich mineral water can be used to elevate the boron status, both in flies and humans.

The Multiple Sclerosis Inventory of Cognition for Adolescents (MUSICADO): A brief screening instrument to assess cognitive dysfunction, fatigue and loss of health-related quality of life in pediatric-onset multiple sclerosis

OBJECTIVE

Screening for cognitive impairment (CI), fatigue and also Health-related quality of life (HRQoL) in patients with pediatric-onset multiple sclerosis (POMS) is of utmost importance in clinical practice. The aim of this study was to establish a new and validated pediatric screening tool "MUSICADO" that is easy to use and time economical.

METHODS

106 patients with POMS aged 12-18 years and 210 healthy controls (HCs) stratified for age and education underwent neuropsychological testing including a screening test "Multiple Sclerosis Inventory of Cognition" for adults and 8 standardized cognitive tests and established scales to assess fatigue and HRQoL.

RESULTS

The phonemic verbal fluency task (RWT "s-words"), the Trail Making Test A (TMT-A), and the Digit Span Forward discriminated significantly between patients and HCs (p = 0.000, respectively) and showed the highest proportion of test failure in patients (24.5%, 17.9%; 15.1%, respectively). Therefore, they were put together to form the cognitive part of the "MUSICADO". After applying a scoring algorithm with balanced weighting of the subtests and age and education correction and a cut-off score for impairment, 35.8% of patients were categorized to be cognitively impaired (specificity: 88.6%). Fatigue was detected in 37.1% of the patients (specificity: 94.0%) and loss of HRQoL in 41.8% (specificity 95.7%) with the screening version, respectively.

CONCLUSION

The MUSICADO is a newly designed brief and easy to use screening test to help to early identify CI, fatigue, and loss of HRQoL in patients with POMS as cut scores are provided for all three items. Further studies will have to show its usability in independent samples of patients with POMS.

Lithium-Rich Mineral Water is a Highly Bioavailable Lithium Source for Human Consumption

SCOPE

Lithium is an important trace element in human nutrition and medicine. Mineral and medicinal waters may represent a significant source of dietary lithium intake.

METHODS AND RESULTS

The lithium concentration of 360 German mineral and 21 medicinal waters is determined. Based on a systematic screening, three different mineral waters exhibiting low (1.7 µg L^-1 ), medium (171 µg L^-1 ), and high lithium (1724 µg L^-1 ) concentrations are chosen for an acute bioavailability study in male healthy volunteers. In Germany, a north-east to south-west gradient of analyzed lithium concentrations is observed in the 381 tested waters. The lithium concentration in the water is significantly correlated with its sodium (r = 0. 810), potassium (r = 0.716), and magnesium (r = 0.361), but not with its calcium concentration. In a randomized cross-over trial, volunteers (n = 3×10 each) drink 1.5 L of the respective mineral waters, and lithium concentrations in serum and urine are monitored over 24 h. Consumption of the mineral waters with a medium and high lithium content results in a dose-dependent response in serum lithium concentrations and total urinary lithium excretion.

CONCLUSION

Lithium-rich mineral and medicinal waters may be an important and highly bioavailable lithium source for human consumption.

[Orthopaedic Treatment for Patients with Myelomeningocele]

BACKGROUND

Due to prenatal diagnostic and folic acid prophylaxis less children with myelomeningocele are now being born. But they become older and need increasingly more orthopaedic care. The orthopaedic care is aimed at the improvement or the preservation of function.

METHOD

In this review the current knowledge from the literature and our approach are presented. This is done in the context of the functional aspects within certain periods of life. Treatment Concept: In the first two years of life, the mobility of MMC children is supported by physiotherapy and orthoses irrespective of the level of the lesion. Afterwards, the optimal orthoses are chosen depending on the muscle power, emerging bone deformities, associated CNS malformation, shunt revisions, obesity and limitations in perception as well as the child's motivation. At school age, it is paramount to encourage independence. Orthotic treatment should be continued as long as the children benefit from it. Orthopaedic operations serve the orthosis fitting and the avoidance of pressure sores. Pathological fractures are common. They should be rapidly recognised in order to avoid further bony deformities.

CONCLUSION

The aim of any orthopaedic treatment consists of the avoidance of musculoskeletal deformities in order to support the patient's self employment.

One- and Two-Dimensional Variable-Temperature13C MAS NMR Studies on the Adsorption of Methane on Zeolite HY

We present a13C MAS NMR study on the adsorption of methane on HY zeolite. These investigations were carried out at temperatures ranging from 295 K to 135 K and at loadings up to 105 methane molecules per unit cell. Up to three signals appear in the13C MAS NMR spectra. From the dependence of their intensities and chemical shifts and results of1H PFG NMR measurements of diffusion it could be concluded that they are due to gaseous methane in the void space above the zeolite powder, to methane adsorbed in the large cavities of the HY zeolite and to methane in the pores formed by neighbouring crystallites.

Self-reported health-related quality of life in children and adolescents with myelomeningocele

The aim of the study was to investigate self-reported health-related quality of life (HRQOL) in children and adolescents with myelomeningocele (MMC) and to examine the impact of clinical impairments and limitations in activities of daily living (ADL). Fifty patients (28 females, 22 males) between 8 and 16 years of age (mean age 12y 1mo [SD 2y 4mo]) with MMC from three German paediatric centres and their mothers completed standardized measures on HRQOL (KINDL-R) and limitations in ADL (Childhood Health Assessment Questionnaire). Lesion level was thoracic in nine, sacral in 25, and lumbosacral in 11 patients. Twenty-one patients were community walkers, 17 were able to walk in the home, and seven used a wheelchair. Two-thirds had health problems related to the central nervous system causing current difficulties (eight patients had a shunt, six had hydrocephalus, and 10 had a tethered cord). Patients in the study group reported diminished overall HRQOL compared with norm data, specifically in the dimensions of emotional well-being, self-esteem, and peer relations. Adolescents reported diminished HRQOL in the dimension of peer relations. Most medical parameters as well as limitations in ADL were not significantly associated with HRQOL. Our findings confirm the results of studies which dispute a linear inverse association between condition severity and HRQOL and emphasize the importance of peer relations in young patients with MMC.

Does mini-incision donor nephrectomy improve quality of life in living kidney donors?

BACKGROUND

Living kidney donation helps to avoid or reduce the time period of dialysis and on waiting lists in patients requiring a new organ. Mini-incision donor nephrectomy (MIDN) shows to result in better clinical outcome in comparison with traditional open donor nephrectomy (ODN). This study was performed to evaluate the impact of different surgical procedures on the quality of life (QoL) in patients that underwent donor nephrectomy.

METHODS

The aim of the study was to detect differences in QoL assessed with the Short Form-36 Version 2 (SF-36v2) questionnaire between MIDN (n = 34) and ODN (n = 36). Furthermore, the development of QoL from prior to surgery until one yr afterwards, as well as outcomes of QoL in comparison with norm-based scores was investigated.

RESULTS

Sixty-one of 70 patients, which is 87% (MIDN: 86%, ODN: 88%) resent a whole set questionnaires. QoL was similar at all time-points (prior to surgery, one wk, three months and one yr) in both groups. A tendency of better QoL in MIDN (Bodily Pain) after one wk was detectable (p = 0.075). Physical Component Summaries (PCS) significantly decreased from prior to surgery until one wk after surgery (p = 0.001) and improved significantly until three months (MIDN: p = 0.006, ODN: p = 0.001) and also until one yr after surgery (p = 0.002). Mental Component Summaries (MCS) were stable throughout the whole investigated time period. In comparison with norm-based scores, MIDN (p = 0.005) and ODN (p = 0.001) showed significantly higher PCS prior to, lower scores one wk after (p = 0.001), similar scores three months after and better scores (MIDN: p = 0.023, ODN: 0.015) one yr after surgery. Mental Component Scores were similar in both prior to and one wk after surgery. After three months and one yr scores were significantly better in MIDN (three months: p = 0.049, one yr: p = 0.037) and ODN (three months: 0.020, one yr: 0.073).

CONCLUSION

Quality of life after living donor nephrectomy is not influenced by the surgical technique. Nevertheless the standardized instrument of the SF-36v2 Health Survey is a useful, practicable and universally interpretable tool to gain and estimate recovery from surgical procedures in the perioperative period and its development thereafter.

Mammalian target of rapamycin is activated in human gastric cancer and serves as a target for therapy in an experimental model

The mammalian target of rapamycin (mTOR) has become an interesting target for cancer therapy through its influence on oncogenic signals, which involve phosphatidylinositol-3-kinase and hypoxia-inducible factor-1alpha (HIF-1alpha). Since mTOR is an upstream regulator of HIF-1alpha, a key mediator of gastric cancer growth and angiogenesis, we investigated mTOR activation in human gastric adenocarcinoma specimens and determined whether rapamycin could inhibit gastric cancer growth in mice. Expression of phospho-mTOR was assessed by immunohistochemical analyses of human tissues. For in vitro studies, human gastric cancer cell lines were used to determine S6K1, 4E-BP-1 and HIF-1alpha activation and cancer cell motility upon rapamycin treatment. Effects of rapamycin on tumor growth and angiogenesis in vivo were assessed in both a subcutaneous tumor model and in an experimental model with orthotopically grown tumors. Mice received either rapamycin (0.5 mg/kg/day or 1.5 mg/kg/day) or diluent per intra-peritoneal injections. In addition, antiangiogenic effects were monitored in vivo using a dorsal-skin-fold chamber model. Immunohistochemical analyses showed strong expression of phospho-mTOR in 60% of intestinal- and 64% of diffuse-type human gastric adenocarcinomas. In vitro, rapamycin-treatment effectively blocked S6K1, 4E-BP-1 and HIF-1alpha activation, and significantly impaired tumor cell migration. In vivo, rapamycin-treatment led to significant inhibition of subcutaneous tumor growth, decreased CD31-positive vessel area and reduced tumor cell proliferation. Similar significant results were obtained in an orthotopic model of gastric cancer. In the dorsal-skin-fold chamber model, rapamycin-treatment significantly inhibited tumor vascularization in vivo. In conclusion, mTOR is frequently activated in human gastric cancer and represents a promising new molecular target for therapy.

Lower limb muscle activity in ambulatory children with cerebral palsy before and after the treatment with Botulinum toxin A

Purpose: The study investigated the effect of Botulinum toxin A on the gait and lower limb muscle activity of ambulatory CP children. Methods: 19 spastic diplegic and 4 left hemiparetic CP children were injected with a mean dose of 23.5 units of Botulinum toxin A/kg body weight into the gastrocnemius and hamstring muscles. Muscle tone and gait analysis including the kinesiological electromyogram of the shank and thigh muscles were assessed before and four weeks after injection and compared with the help of a multivariate analysis (p < 0.05). Results: Botulinum toxin A caused a definite reduction of plantarflexor, knee and hip hypertonia in 21 children, resulting in a more plantar grade and erect gait in 17 children four weeks after injection. Gait analysis showed a statistically significant improvement in peak ankle dorsi-flexion and knee extension during stance, and the length of the force point of action under both feet increased. Electromyography revealed sig-nificantly less co-contraction of the lower leg muscles, due to a more phasic instead of a tonic activity of the tibialis anterior muscle, and an improved activation pattern of the left rectus and biceps femoris muscles. Conclusions: The present study demonstrated that the injection of Botulinum toxin A resulted in a more mature muscle activation pattern of CP children. Most of the children walked more plantigrade and erect, the functional gait parameters, however, did not change.

A common mutation (epsilon1267delG) in congenital myasthenic patients of Gypsy ethnic origin

OBJECTIVE

Mutation analysis of the acetylcholine receptor (AChR) epsilon subunit gene in patients with sporadic or autosomal recessive congenital myasthenic syndromes (CMS).

BACKGROUND

The nicotinic AChR of skeletal muscle is a neurotransmitter-gated ion channel that mediates synaptic transmission at the vertebrate neuromuscular junction. Mutations in its gene may cause congenital myasthenic syndromes. A recently described mutation in exon 12 of the AChR epsilon subunit (epsilon1267delG) disrupts the cytoplasmic loop and the fourth transmembrane region (M4) of the AChR epsilon subunit.

METHODS

Forty-three CMS patients from 35 nonrelated families were clinically classified as sporadic cases of CMS (group III according to European Neuromuscular Centre consensus) and were analyzed for epsilon1267delG by PCR amplification and sequence analysis.

RESULTS

The authors report the complete genomic sequence and organization of the gene coding for the epsilon subunit of the human AChR (accession number AF105999). Homozygous epsilon1267delG was identified in 13 CMS patients from 11 independent families. All epsilon1267delG families were of Gypsy or southeastern European origin. Genotype analysis indicated that they derive from a common ancestor (founder) causing CMS in the southeastern European Gypsy population. Phenotype analysis revealed a uniform pattern of clinical features including bilateral ptosis and mild to moderate fatigable weakness of ocular, facial, bulbar, and limb muscles.

CONCLUSIONS

The mutation epsilon1267delG might be frequent in European congenital myasthenic syndrome patients of Gypsy ethnic origin. In general, patients (epsilon1267delG) were characterized by the onset of symptoms in early infancy, the presence of ophthalmoparesis, positive response to anticholinesterase treatment, and the benign natural course of the disease.

Occurrence of polychlorinated terphenyls (PCTs) in indoor particulate matter

In the course of a routine investigation concerned with polychlorinated biphenyl (PCB) contamination of dust collected in classrooms of a junior high school, a group of electron capture detector (ECD)-sensitive compounds with high boiling points were found in addition to PCBs. Using gas chromatographic-mass spectrometric techniques, these compounds were identified as polychlorinated terphenyls (PCTs). Additional measurements indicated that the PCTs were present only in particulate matter collected from the tops of fluorescent light frames but not in air samples obtained concomitantly in the classrooms. Attempts to identify the PCT emission source were unsuccessful. A survey of the literature revealed that PCTs are ubiquitously distributed environmental contaminants, although no data on their indoor occurrence have been reported to date. In view of the toxic effects of PCTs, which seem to be as important as those of PCBs, further attention should be given to the possible presence of PCTs in indoor environments.

Comparison of three immunoassays for diagnosing sensitization to latex in children with spina bifida

As natural rubber latex (latex) has become more widespread in our environment, physicians have become increasingly aware of the problem of possible allergic reactions. Many fatal and near-fatal incidents have been reported (mainly during surgery) (1-3) and data has been published on groups frequently exposed to latex, such as patients with spina bifida (4-9), healthcare professionals (10-12) and occupationally exposed persons (13). The incidence of latex allergy in children seems to be increasing (14). Tests are therefore needed which can reliably detect sensitization to latex. Our aim was to compare the diagnostic accuracy of three commercial immunoassays for measuring specific IgE in serum to latex.

Risk factors for latex allergy in patients with spina bifida

OBJECTIVE AND METHODS

In order to study risk factors for latex allergy in patients with spina bifida, we investigated 165 patients with spina bifida (mean age 9 years). Besides answering a questionnaire, patients underwent skin-prick testing and determination of specific serum IgE to latex as well as a screening test for specific IgE to environmental allergens. A total of 80 patients (49%) were sensitized to latex according to the presence of specific IgE to latex.

RESULTS

Skin-prick tests (SPT) with high ammonia latex milk were performed in 81 of our patients with spina bifida and were positive in 36 patients (46%). Concordance of SPT with specific IgE in serum was good. Nineteen out of 165 patients suffered from a clinically relevant latex allergy: five patients had a history of systemic reactions to latex (e.g. severe bronchospasm, anaphylactic reactions), mostly during surgery. Fourteen patients reported clinical symptoms while inflating a balloon; all these 19 patients were sensitized to latex. Number of operations ranged from one to 26 (mean 5 operations). Concentration of specific IgE to latex in serum correlated well with increasing numbers of operations. Some 32/76 patients (41%) with spina bifida who were sensitized to latex showed an atopic disposition, while 21 out of 81 latex-negative patients (26%) were atopic. Of 300 consecutive sera (mean age of patients 9 years) sent to our laboratory for routine determination of specific IgE, 144 (48%) were positive in terms of specific IgE to environmental allergens, of which 247144 (17%) were sensitized to latex.

CONCLUSIONS

From our data we conclude that in order to minimize risk of severe systemic clinical reactions, all patients with spina bifida should be screened for their individual risk of latex allergy to plan preventive measures before operations. Main risk factors for latex allergy seem to be: more than five operations, atopic predisposition, history of clinical symptoms while inflating a balloon, and a sensitization with a CAP-class of > or = 4.

Valproate (VPA) metabolites in various clinical conditions of probable VPA-associated hepatotoxicity

Of a cohort of 470 epileptic patients in whom valproate (VPA) serum metabolites had been measured, 170 subjects without symptoms or signs of hepatic side effects were chosen as a reference group to establish the usual metabolic pattern. A wide interindividual variation of VPA metabolite concentrations was noted. Infants receiving VPA monotherapy and comedication with other antiepileptic drugs (AEDs) showed lower concentrations of the potential hepatotoxin 4-ene-VPA than did older children. In 11 patients with early symptoms and signs of possible fatal VPA-associated hepatotoxicity, the following spectrum of benign clinical conditions was observed: unusually severe side effect during initiation of VPA therapy (1 patient), high VPA dosage (2 patients), reversible impairment of coagulation with bleeding manifestations in association with a slight increase in transaminase levels (1 child), and reversible liver dysfunction associated with febrile illness (7 patients). Reversible or irreversible fulminant liver failure had occurred in 5 children. Three of the 4 children with a fatal outcome had massive lactic acidosis. In all patients with probable VPA-associated hepatotoxicity, some aspects of VPA metabolism differed distinctly from that of the reference group, but the inter-individual profile of metabolites varied considerably, even in the subgroup of 4 children who died. Impairment of VPA beta-oxidation and increase of metabolites of alternative metabolic pathways (omega- and omega 1-hydroxylation, dehydrogenation reactions) were the most frequent findings. Increased values of 2-n-propyl-4-pentenoic acid metabolite of VPA (4-ene-VPA), could be detected only in 1 of the 5 patients with fulminant liver failure and in one other child with a slight hepatic dysfunction, indicating that this VPA metabolite is not the decisive hepatotoxin or indicator of hepatotoxicity. Because we cannot distinguish between benign and life-threatening hepatic adverse reactions on the basis of VPA metabolites, all identified changes are considered secondary to an as-yet-unknown primary metabolic event. The most toxic compound could be VPA itself, which may unmask an inborn or an acquired metabolic defect in the processing of fatty acids.

[Irreversible valproate-associated liver failure]

A very severely retarded infant with a Dandy-Walker malformation was treated with valproate since the age of 6 months on account of infantile spasms. Three weeks after start of therapy dexamethasone was applied additionally because valproate was ineffective. Seventy-six days after initiation of valproate therapy the infant died with the clinical signs of fulminant valproate-associated hepatotoxicity despite the discontinuation of valproate. In combination with a febrile otitis media the child had been periodically restless and lethargic during the last week prior to liver coma. Activity of liver enzymes remained within normal limits up to two days before coma occurred. Analysis of valproate metabolites by gas chromatography/mass spectrometry yielded unusually high concentrations of the di-unsaturated metabolite E,E-2,3'-dien-valproate before and during liver failure. The concentrations of the main metabolites E-2-en-valproate und 3-keto-valproate remained within the usual range found during valproate therapy at steady state. The oxydation products 4-en-valproate and E-2,4-dien-valproate which are formed by alternative pathways and are considered to be hepatotoxic were detected in very low concentrations only. The application of carnitine, of antioxidants thought to improve the capacity of the free radical scavenger system (selen, vitamin E), and of N-acetylcysteine which can detoxify reactive drug metabolites could not prevent the fatal outcome.

[High-grade tracheomalacia and tracheal stenosis in congenital esophageal atresia with lower esophagotracheal fistula (Type III b)]

Stenosis and malacia of the trachea wall can provoke chronic stridor and/or chronic bronchitis, but usually stenosis and malacia only exist separately. The finding of an infant born with atresia of the oesophagus and a lower tracheoesophageal fistula which was cured by surgery on the 1st day of life are discussed. During the following 8 months we observed persistent stridor, chronic cough and (4-times) relapsing episodes of respiratory insufficiency ("nearly-sudden-infant-death-syndrome"/NSIDS) due to gastrooesophageal reflux (GER with aspiration) and severe tracheomalacia combined with tracheostenosis and bacterial infections (Pseudomonas aeruginosa). The strategy of therapy for GER and for the tracheal abnormality are discussed.

Identification of the functional promoter regions in the human gene encoding the myosin alkali light chains MLC1 and MLC3 of fast skeletal muscle

The human gene encoding the alkali myosin light chains (MLC) 1 and 3 of fast skeletal muscle has been isolated. Two separate start sites for transcription have been identified by S1 analysis of muscle RNA. The nucleotide sequences of both proximal promoter regions have been determined and compared to the corresponding gene regions of other species. Several conserved promoter elements were located within 140 nucleotides upstream of the mRNA cap site, whereas further upstream no homologous sequences were found. Unidirectional 5' deletion mutants of both MLC promoters were used to direct bacterial chloramphenicol acetyltransferase activity in transient transfection assays of muscle and nonmuscle cells. Approximately 120 nucleotides of the MLC1 promoter and 80 nucleotides of the MLC3 promoter were sufficient for the transcriptional activation in primary myotubes and to a lower degree also in fibroblasts and hepatocytes. The preferential expression in muscle cells was not dependent on the conserved MLC consensus sequence, CCTTTTATAG, but it absolutely required the CCAT box or the CAT-like box in the MLC1 and MLC3 promoters, respectively. The weak activity of the MLC1 promoter was markedly enhanced in myotubes when DNA from the 3' gene flanking sequence was included in the chloramphenicol acetyltransferase constructs.

The alkali light chains of human smooth and nonmuscle myosins are encoded by a single gene. Tissue-specific expression by alternative splicing pathways

Human smooth muscle and nonmuscle cells express closely related myosin alkali light chains which are different from the isoforms present in striated muscle tissues. To date no information on the amino acid sequence of these mammalian nonstriated muscle isoforms has been available. We have isolated full-length cDNA clones encoding the nonmuscle (lym4) and smooth muscle (GT6) myosin light chains (MLCs) from cultured human lymphoblasts and heart aorta smooth muscle cells, respectively. Here we present the complete nucleotide sequences for both cDNA clones, together with the deduced amino acid sequences for the peptides. Both cDNAs contain the same open reading frame for 151 amino acids with 5 amino acid differences located in the C terminus. These differences are encoded by a block of 44 nucleotides which is present only in the smooth muscle (SM) mRNA. To identify the human gene coding for the two MLC isoforms, we have isolated and sequenced the nonmuscle (NM)/SM MLC gene, together with several intronless pseudogenes. A single functional gene was found containing 7 exons which are utilized for the coding information of the SM MLC mRNA. In contrast, the NM MLC mRNA does not contain sequences encoded by exon 6 which corresponds to the 44 nucleotides expressed in SM mRNA. This genomic configuration suggests that both the smooth muscle and nonmuscle MLCs in man are generated from the identical primary transcript by alternative splicing pathways taking place in a tissue-dependent manner.

A novel human myosin alkali light chain is developmentally regulated. Expression in fetal cardiac and skeletal muscle and in adult atria

We have isolated cDNA recombinant phages encoding the embryonic isoform of the myosin alkali light chain (MLC1emb) from a human fetal skeletal muscle library. The cDNA clones were detected by their weak cross-hybridization to a human MLC1F and MLC3F cDNA clone. Nucleotide sequence analysis of the complete cDNA (GT14) revealed an open reading frame for 197 amino acids. The derived protein sequence constitutes the first structural information on this myosin isoform of any organism. Remarkable structural similarities to other alkali MLC polypeptides, particularly to those of the slow-muscle type, are evident. Under conditions of high stringency, the GT14 clone hybridized to an abundant mRNA species in fetal ventricular muscle and adult atrial muscle, whereas in fetal skeletal muscle only a very weakly hybridizing mRNA component was detected. These mRNAs were indistinguishable by size and the thermal stability of their hybrids formed with the DNA insert of clone GT14. We therefore conclude that identical mRNA is expressed in these tissues, presumably transcribed from the same gene. According to its pattern of mRNA expression, the novel MLC isoform described here was designated as "embryonic and atrial myosin light chain" (MLC1emb/A) in reference to its developmental stage-specific and tissue-specific appearance in embryonic skeletal muscle, fetal ventricle and adult atrium.

Alkali myosin light chains in man are encoded by a multigene family that includes the adult skeletal muscle, the embryonic or atrial, and nonsarcomeric isoforms

A set of cDNA clones coding for alkali myosin light chains (AMLC) was isolated from fetal human skeletal muscle. Nucleotide sequence analysis and RNA expression patterns of individual clones revealed related sequences corresponding to (i) fast fiber type MLC1 and MLC3; (ii) the embryonic MLC that is also expressed in fetal ventricle and adult atrium (MLCemb); and (iii) a nonsarcomeric MLC isoform that is found in all nonmuscle cell types and smooth muscle. The AMLC gene family in man comprises unique copies for MLC1, MLC3 and MLCemb, and multiple copies for the nonsarcomeric MLC genes. The gene coding for MLC1 and MLC3 is located on human chromosome 2.

The prognostic value of EEG patterns in epilepsies with infantile spasms

By scoring EEG patterns (hypsarrhythmia = 10, absence of sleeping patterns = 10, focal epileptic discharge = 5, general-treatment or in whom infantile spasms never disappeared even during ACTH. A low voltage EEG did not have any ending ACTH therapy free of seizures showed lower scores compared to those infants relapsing after the end of ACTH treatment or in whom infantile spasms never disappeared even during ACTH. A low voltage EED did not have any prognostic significance. Using EEG scores it might be possible to separate non-responders and responders after 3 weeks of ACTH therapy, thus shortening ACTH treatment in non-responding infants.

The repeated sequences (incB) preceding the protein E gene of plasmid mini-F are essential for replication

At the XhoI site (45.08F) of plasmid mini-F a deletion of 649 bp was generated employing exonuclease Bal31. By this deletion nucleotide sequences functioning as origin II and the four 19 bp direct repeats constituting the incB region in front of the E protein gene were removed from the plasmid. Analysis of proteins radioactively labelled in Escherichia coli mini-cells indicated that all mini-F encoded proteins are expressed. However, the plasmid carrying the deletion was not capable of replicating from the primary origin (origin I, 42.6F). Recently a smaller deletion at the XhoI site (45.08F) of about 300 bp, removing only the region functioning as origin II and replicating from origin I, was described by Tanimoto and Iino (1984, 1985). The data presented suggest that the incB repeats are essential for the initiation of replication from origin I, and possibly also from origin II, and seem not to be engaged in the autoregulation of E protein expression.