Berries vs. Disease: Revenge of the Phytochemicals

Secondary metabolites and phytochemicals in plant-based diets are known to possess properties that inhibit the development of several diseases including a variety of cancers of the aerodigestive tract. Berries are currently of high interest to researchers due to their high dietary source of phytochemicals. Black raspberries (BRB), Rubus occidentalis, are of special interest due to their rich and diverse composition of phytochemicals. In this review, we present the most up-to-date preclinical and clinical data involving berries and their phytochemicals in the chemoprevention of a variety of cancers and diseases. BRBs possess a variety of health benefits including anti-proliferative properties, anti-inflammatory activity, activation of pro-cell-death pathways, modulation of the immune response, microbiome modulation, reduction in oxidative stress, and many more. However, little has been done in both preclinical and clinical settings on the effects of BRB administration in combination with other cancer therapies currently available for patients. With the high potential for BRBs as chemopreventive agents, there is a need to investigate their potential in combination with other treatments to improve therapeutic efficacy.

Ethics in pre-ART genetics: a missed X-linked Menkes disease case

Assisted reproductive technology (ART) has experienced dramatic progress over the last 30 years, and gamete donation is routine in fertility clinics. Major advances in genetic diagnostics are part of this development due to the ability to analyze multiple genes or whole genomes fast and to an affordable prize. This requires knowledge and capability to evaluate genetic variants correctly in a clinical setting. Here we report a Menkes disease case, born after ART, where genetic screening and variant scoring failed to identify an egg donor as carrier of this fatal X-linked disorder. The gene variant is a deletion of a single base pair leading to a frameshift and premature termination of the protein, predicted to result in no or severely diminished function. The variant would be classified as likely pathogenic (class 4) and should be readily detectable by molecular genetic screening techniques. We wish to highlight this case to prevent future similar cases. IVI Igenomix has developed and embarked on an ambitious screening program to detect and prevent a large number of inherited severe childhood disorders in ART pregnancies. The company has recently achieved ISO 15189 certification with competence to evaluate and deliver timely, accurate, and reliable results. Failure to identify a pathogenic variant in the ATP7A gene leading to birth of two boys with Menkes disease invokes the required procedures to screen and detect disease-causing gene variants. This calls for ethical and legal considerations in ART diagnostics to prevent fatal errors like the present.

Can tibio-femoral kinematic and kinetic parameters reveal poor functionality and underlying deficits after total knee replacement? A systematic review

BACKGROUND

Extensive efforts have been made to understand joint kinematics and kinetics in total knee arthroplasty (TKA) in subjects with satisfactory outcomes during daily functional activities and clinical tests, but it remains unclear whether such movement characteristics hold the potential to indicate the underlying aetiology of unsatisfactory or bad TKA outcomes.

PURPOSE

To investigate which kinematic and kinetic parameters assessed during passive clinical tests and functional activities of daily living are associated with poor functionality and underlying deficits after total knee replacement.

METHODS

We focused on studies characterizing the kinematic or kinetic parameters of the knee joint that are associated with poor clinical outcome after TKA. Seventeen articles were included for the review, and kinematic and kinetic data from 719 patients with minimal follow up of 6 months were extracted and analyzed.

RESULTS

Passive posterior translation at 90°flexionexhibited good potential for differentiating stable and unstable TKAs. Anterior-posterior (A-P) translation of the medial condyle at 0-30° and 30-60° flexion, A-P translation of the lateral condyle at 60-90°during closed chain exercises, as well asknee extension moment during stair ascent and descent, knee abduction moment during stair descent, knee internal rotation moment and plantar flexion moment during walking, 2ndpeak ground reaction force during stair ascent and walkingshowed the greatest promise as functional biomarkers for a dissatisfied/poor outcome knee after TKA.

CONCLUSION

In this study, we systematically reviewed the state-of-the-art knowledge of kinematics and kinetics associated with functional deficits, and found 11 biomechanical parameters that showed promise for supportingdecision making in TKA.

[Long and short QT syndromes : Emergency treatment and secondary prophylaxis]

Long QT syndrome (LQTS) is a rare inherited or acquired channelopathy associated with a relevant mortality if left untreated. Therapy can reduce the sudden cardiac death (SCD) rate significantly. Of 17 subtypes, LQTS1-3 are the most common. Clinical presentation ranges from asymptomatic patients to torsade de pointes (TdP) and SCD. Emergency therapy includes defibrillation, administration of magnesium, betablockers and temporary pacing and sedation. Secondary prevention is based on betablocker therapy and implantation of an implantable cardioverter-defibrillator (ICD), if appropriate. Short QT syndrome (SQTS) is a rare channelopathy that manifests as SCD in 34%. So far 250 cases with mutations in 8 genes have been reported. ICDs are the only reliable protection against SCD. Drug therapy is based on hydroquinidine. Further therapeutic options exist for certain subtypes of both diseases. Patients should be referred to specialized centers.

A 37-year-old Menkes disease patient-Residual ATP7A activity and early copper administration as key factors in beneficial treatment

Menkes disease (MD) is a lethal disorder characterized by severe neurological symptoms and connective tissue abnormalities; and results from malfunctioning of cuproenzymes, which cannot receive copper due to a defective intracellular copper transporting protein, ATP7A. Early parenteral copper-histidine supplementation may modify disease progression substantially but beneficial effects of long-term treatment have been recorded in only a few patients. Here we report on the eldest surviving MD patient (37 years) receiving early-onset and long-term copper treatment. He has few neurological symptoms without connective tissue disturbances; and a missense ATP7A variant, p.(Pro852Leu), which results in impaired protein trafficking while the copper transport function is spared. These findings suggest that some cuproenzymes maintain their function when sufficient copper is provided to the cells; and underline the importance of early initiated copper treatment, efficiency of which is likely to be dependent on the mutant ATP7A function.

Garlic diallyl disulfide and diallyl trisulfide mitigates effects of pro-oxidant induced cellular stress and has immune modulatory function in LPS-stimulated porcine epithelial cells

The objective of the current study was to determine if garlic-derived diallyl disulfide (DADS) and diallyl trisulfide (DATS) could mitigate oxidative and endotoxin stress, using an intestinal porcine epithelial cell (IPEC-J2) model. The experiment was arranged as a 2 × 2 × 2 factorial of DADS + DATS (0 or 18 µM), pro-oxidant stressor (hydrogen peroxide at 0 or 100 µM), and endotoxin stressor (lipopolysaccharide [LPS] at 0 or 10 µg/mL) with 8 replicates per treatment. Cells were incubated with DADS + DATS for 18 h, LPS for 6 h, then with hydrogen peroxide for 3 h. Gene expression was measured by RT-PCR for cytokines, interleukin 8 (IL-8) and tumor necrosis factor α (TNF-α), and tight junction proteins, claudin 1 (CL-1), occludin (OC), and zonula occludens 1 (ZO-1). Trans-epithelial electrical resistance (TEER), the antioxidant enzyme catalase, and apical secretion of IL-8 protein into the incubation medium was also measured. There was an increase ( < 0.01) in TNF-α and IL-8 gene expression due to LPS, although there was no effect of hydrogen peroxide or DADS + DATS. Furthermore, there was a tendency for an increase ( = 0.08) in ZO-1 gene expression due to DADS + DATS. Treatment with DADS + DATS and hydrogen peroxide did not affect TEER, although there was a decrease ( = 0.02) in TEER with LPS incubation. Treatment of cells with hydrogen peroxide reduced catalase activity ( < 0.01), which was restored with pre-incubation of DADS + DATS ( < 0.10). There was an increase ( < 0.01) in IL-8 secretion due to LPS, which was further augmented ( < 0.01) by pre-incubation with DADS + DATS. Based on the results from the current study, DADS + DATS can ameliorate oxidative effects of hydrogen peroxide, as well as alter IL-8 secretion in LPS-treated IPEC-J2 cells.

Ability of garlic-derived diallyl disulfide and diallyl trisulfide supplemented by oral gavage to mitigate effects of an acute postweaning feed and water deprivation event in nursery pigs

Compounds in garlic have been shown to contain anti-inflammatory, antioxidant, and immune modulatory properties that may be able to mitigate the effects of nursery pig stressors. The objective of the current experiment was to determine if oral gavage of garlic-derived diallyl disulfide (DADS) and diallyl trisulfide (DATS) could mitigate the effects of a 24-h postweaning feed + water deprivation event in nursery pigs. Pigs (6.0 ± 0.05 kg and 21 d old) were allotted to 4 treatments in a randomized complete block design at weaning with 8 replicate pens per treatment that consisted of with or without a 24-h postweaning feed + water deprivation event and with or without an oral gavage containing 3.6 mg DADS + DATS/kg BW. Growth performance and morbidity were recorded throughout the experiment, and on 1, 6, and 21 d after weaning, 1 pig per pen was selected, blood was collected, the pig was euthanized, and a segment of the distal ileum was subsequently excised for morphological and gene and protein expression measurements. Mucosal gene expression was conducted by reverse transcription PCR for immune, antioxidant, and cellular integrity markers. Furthermore, activity of mucosal superoxide dismutase was measured by colorimetric assay. Immediately following the feed + water deprivation event, there was a decrease ( < 0.01) in growth performance and an increase ( = 0.01) in serum cortisol. The feed + water deprivation event tended ( = 0.10) to decrease ileal villus height and supplementation of DADS + DATS by oral gavage increased ( = 0.03) villus height 1 d after weaning. Supplementation of DADS + DATS by oral gavage decreased ( = 0.03) and tended to decrease ( = 0.08) gene expression of on 6 and 21 d after weaning, respectively. Furthermore, at 1 d after weaning, ileal mucosa SOD activity was decreased ( = 0.01) by the feed + water deprivation and increased ( = 0.04) by oral supplementation of DADS + DATS. Expression of the tight junction genes and were reduced ( ≤ 0.05) due to the feed + water deprivation event 1 d after weaning. Results from the current study show that an acute feed + water deprivation event can impact growth performance, intestinal characteristics, and antioxidant status in nursery pigs, which can be partially mitigated by oral supplementation of garlic compounds DADS + DATS.

SASOP treatment guidelines for psychiatric disorders: Eminence or evidence based?

-

Growth, serum biochemistry, complement activity, and liver gene expression responses of Pekin ducklings to graded levels of cultured aflatoxin B1

A 14-d study was conducted to evaluate the effects of cultured aflatoxin B1 (AFB1) on performance, serum biochemistry, serum natural antibody and complement activity, and hepatic gene expression parameters in Pekin ducklings. A total of 144 male Pekin ducklings were weighed, tagged, and randomly allotted to 4 dietary treatments containing 4 concentrations of AFB1 (0, 0.11, 0.14, and 0.21 mg/kg) from 0 to 14 d of age (6 cages per diet; 6 ducklings per cage). Compared with the control group, there was a 10.9, 31.7, and 47.4% (P < 0.05) decrease in cumulative BW gain with 0.11, 0.14, and 0.21 mg of AFB1/kg of diet, respectively, but feed efficiency was not affected. Increasing concentrations of AFB1 reduced cumulative BW gain and feed intake both linearly and quadratically, and regression equations were developed with r(2) ≥0.73. Feeding 0.11 to 0.21 mg of AFB1/kg reduced serum glucose, creatinine, albumin, total protein, globulin, Ca, P, and creatine phosphokinase linearly, whereas serum urea N, Cl, alkaline phosphatase, and aspartate amino transferase concentrations increased linearly with increasing AFB1 (P < 0.05). Additionally, 0.11 to 0.21 mg of AFB1/kg diets impaired classical and alternative complement pathways in the duckling serum when tested by lysis of rabbit, human type O, and horse erythrocytes, and decreased rabbit and horse agglutinins (P < 0.05). Liver peroxisome proliferator activated receptor α (PPARα) expression was linearly downregulated by AFB1 (P < 0.01). Results from this study indicate that for every 0.10 mg/kg increase in dietary AFB1, cumulative feed intake and BW gain decrease approximately 230 and 169 g per duckling from hatch to 14 d; and that AFB1 at very low concentrations can significantly impair liver function and gene expression, and innate immune dynamics in Pekin ducklings.

Efficiency of hydrated sodium calcium aluminosilicate to ameliorate the adverse effects of graded levels of aflatoxin B1 in broiler chicks

The objective of this study was to evaluate the efficiency of a hydrated sodium calcium aluminosilicate (HSCAS) adsorbent to ameliorate the adverse effects of 0.5 to 2 mg of aflatoxin B1 (AFB1)/kg in broiler chicks. The study consisted of 8 dietary treatments, including 4 concentrations of AFB1 (0, 0.5, 1, and 2 mg/kg) with or without HSCAS (0.5%) fed to 8 replicate cages per diet (6 males chicks per cage) from 0 to 21 d of age. Cumulative feed intake, BW gain (P < 0.0001), and G:F (P = 0.004) of birds fed the 2 mg of AFB1/kg of diet were significantly lower in comparison with birds fed 0 to 1 mg of AFB1/kg. Relative liver weight was increased in the 2 mg of AFB1/kg group (P < 0.0001). Dietary HSCAS improved cumulative BW gain (main effect P = 0.06), particularly from 14 to 21 d of age (P = 0.037). Dietary HSCAS also reversed the increase in relative liver weight for birds fed AFB1 (P = 0.019). Dietary AFB1 negatively affected major serum parameters (albumin, total protein, globulin, phosphorus, glucose, alkaline phosphatase, and creatine phosphokinase), whereas supplementation with HSCAS partially alleviated the affected serum biochemistry. In addition, serum complement activity and liver gene expression were negatively affected by 2 mg of AFB1/kg. The HSCAS supplement increased the liver expression of catalase and superoxide dismutase (P < 0.05). Results from this study indicate that dietary supplementation with HSCAS can effectively improve BW gain and partially ameliorate aflatoxicosis for broiler chicks fed AFB1-contaminated feeds.

Psychosis and relapse in bipolar disorder are related to GRM3, DAOA, and GRIN2B genotype

OBJECTIVE

Dysfunction in glutamate signalling is thought to play a role in the pathophysiology of bipolar disorder (BD). There is evidence of associations between single nucleotide polymorphisms (SNPs) in GRM3, GRIN2B, and DAOA genes and the diagnosis of BD. In this pilot study, we investigated the frequency of SNP variants in these 3 genes within South African population groups, and assessed interactions between genes and phenotypes of BD disease severity.

METHOD

Multiplex SNaPshotTM PCR was used to genotype 191 case and 188 control samples. Cases comprised of 191 individuals in a South African cohort of mixed ancestry and Caucasians, with BD Type 1. Phenotypes of BD disease severity were: age of onset, number of illness episodes, number of hospitalisations for depression or mania and history of psychotic symptoms.

RESULTS

There were no significant difference in SNP allele frequencies between cases and controls. In the case-only analysis, the GRM3 rs6465084 heterozygote was associated with a 4-fold increased risk of lifetime history of psychotic symptoms, and the specific variants within the gene pair, DAOA and GRIN2B, had a significant interaction with the number of hospitalisations for mania, with lowest admission rates associated with both pairs of ancestral alleles.

CONCLUSION

In BD, variations in glutamatergic genes may influence phenotypes related to the severity of illness. Speculatively, newly derived genes associated with various evolutionary advantages, may also increase the risk for more severe BD. These preliminary findings deserve validation in a larger cohort.

Parallel preparation of densely packed arrays of 150-nm gold-nanocrescent resonators in three dimensions

Metallic nanostructures show interesting optical properties due to their plasmonic resonances, and when arranged in three-dimensional (3D) arrays hold promise for optical metamaterials with negative refractive index. Towards this goal a simple, cheap, and parallel method to fabricate large-area, ordered arrays of 150-nm gold nanocrescents supporting plasmonic resonances in the near-infrared spectral range is demonstrated. In this process hexagonally ordered monolayers of monodisperse colloids are prepared by a simple floating technique, and subsequently the individual particles are size-reduced in a plasma process and used as a shadow mask with the initial lattice spacing. The resulting two-dimensional array of plasmonic resonators is coated with a transparent silica layer, which serves as a support for a second layer prepared by the identical process. The mutual orientation of the nanostructures between the individual layers can be freely adjusted, which determines the polarization-dependent absorption of the array and opens the possibility to introduce chirality in this type of 3D metamaterial. The iteration of this simple and efficient methodology yields 3D arrays with optical features as sharp as those of the individual nanocrescents, and shows strong potential for large-scale production of high-quality optical metamaterials.

Studies of craniofacial development in rotating bioreactors

Several studies in our laboratory assessed the effect of 3-D culture in various rotating bioreactors on craniofacial development. Initially, mouse first branchial arches were cultured. Molar and incisor development occurred in both upper and lower jaws, but maxilla development was deficient because no brain was present. In a second study using excised whole heads, the oral epithelia fused and teeth did not develop. External structure of the face was obliterated, although internally, eye development was excellent. To preserve both internal spaces and external face structure, subsequent experiments used heads encapsulated in alginate. Teeth developed in these heads, though some interior components were necrotic. Additional experiments used older embryos, with already initiated structures, and less concentrated alginate. Orientation and unreserved identification of structures remain unresolved issues. Future studies will identify structures of interest using transcription factors unique to these structures at particular stages of fetal development.

Impaired energy metabolism and abnormal muscle histology in mut- methylmalonic aciduria

The authors report a 27-year-old man with B12-responsive mut- methylmalonic aciduria associated with pure muscle symptoms. Two mutations were found in the methylmalonyl-CoA mutase gene. An exercise test showed a reduced maximal workload and reduced oxygen uptake, and a muscle biopsy showed subsarcolemmal accumulation of mitochondria and normal respiratory chain enzyme activities. These findings may be caused by inhibition of mitochondrial energy metabolism by methylmalonate or its metabolites.

Congenital cataract, muscular hypotonia, developmental delay and sensorineural hearing loss associated with a defect in copper metabolism

Deficiencies of different proteins involved in copper metabolism have been reported to cause human diseases. Well-known syndromes, for example, are Menkes and Wilson diseases. Here we report a patient presenting with congenital cataract, severe muscular hypotonia, developmental delay, sensorineural hearing loss and cytochrome-c oxidase deficiency with repeatedly low copper and ceruloplasmin levels. These findings were suggestive of a copper metabolism disorder. In support of this, the patient's fibroblasts showed an increased copper uptake with normal retention. Detailed follow-up examinations were performed. Immunoblotting for several proteins including ATP7A (MNK or Menkes protein), ATP7B (Wilson protein) and SOD1 showed normal results, implying a copper metabolism defect other than Wilson or Menkes disease. Sequence analysis of ATOX1 and genes coding for proteins that are known to play a role in the mitochondrial copper metabolism (COI-III, SCO1, SCO2, COX11, COX17, COX19) revealed no mutations. Additional disease genes that have been associated with cytochrome-c oxidase deficiency were negative for mutations as well. As beneficial effects of copper histidinate supplementation have been reported in selected disorders of copper metabolism presenting with low serum copper and ceruloplasmin levels, we initiated a copper histidinate supplementation. Remarkable improvement of clinical symptoms was observed, with complete restoration of cytochrome-c oxidase activity in skeletal muscle.

Xenon, a modern anaesthesia gas

Xenon is an interesting anesthetic as it appears to lack negative inotropicy and vasodilatation, giving great advantages to both patients with limited cardiovascular reserve or those who require hemodynamic stability. It has low toxicity and is not teratogenic. Xenon gives rapid induction and recovery, due to its low blood/gas partition coefficient (0.15), and has a MAC of 63%. Several vitro studies showed that Xenon may protect neural cells against ischaemic injury. Its low blood solubility can take to diffusion hypoxia if Xenon is not substituted by 100% oxygen at the end of anesthesia. It has been shown that, compared to other anesthetic regimens, Xenon anesthesia produces the highest regional blood flow in the brain, liver, kidney and intestine. In conclusion, the most important positive effects of Xenon are cardiovascular stability, cerebral protection and favourable pharmacokinetics. Negative points are high cost and the limited number of ventilators supplying Xenon.

Minimum alveolar concentration (MAC) of xenon in intubated swine

BACKGROUND

The minimum alveolar concentration (MAC) is a traditional index of the hypnotic potency of an inhalational anaesthetic. To investigate the anaesthetic as well as the unwanted effects of xenon (Xe) in a swine model, it is useful to know MAC(Xe).

METHODS

The study was performed using ten swine (weight 27.8-35.4 kg) anaesthetized with halothane and Xe 0, 15, 30, 40, 50 and 65% in oxygen. With each Xe concentration, various concentrations of halothane were administered in a step-by-step design. For each combination, a supramaximal pain stimulus (claw clamp) was applied and the appearance of a withdrawal reaction was recorded. The MAC(Xe) with halothane was calculated using a logistic regression model.

RESULTS

During stable ventilation, haemodynamics and temperature, MAC(Xe) value was determined as 119 vol. % (95% confidence limits 103-135).

CONCLUSION

MAC(Xe) in swine was calculated by extrapolation of a logistic regression model. Its theoretical value is 119 vol. %.

Heterologous production of bacteriocins by lactic acid bacteria

Over the last two decades, bacteriocins produced by lactic acid bacteria (LAB) have been the subject of considerable research and industrial interest due to their potential as food biopreservatives. The development of heterologous expression systems for such antimicrobial compounds may offer a number of advantages over native systems, such as facilitating the control of bacteriocin gene expression or achieving higher production levels. In addition, the heterologous production by food-grade LAB offers an attractive method for overcoming some of the adverse situations that may affect the effectiveness of some bacteriocins in food systems. Construction of multibacteriocinogenic strains or acquisition of antimicrobial properties by industrial strains are further objectives that can be achieved through the use of heterologous gene expression systems. The development of new biotechnological tools and recent advances in LAB genetics account for the escalating number of studies dealing with heterologous production of bacteriocins by such hosts. This paper reviews the literature published on the subject and compares the different experimental strategies that have been used up to the present for this purpose.

X-linked recessive Menkes disease: carrier detection in the case of a partial gene deletion

X-linked recessive Menkes disease is a lethal disorder of copper metabolism, caused by defects in the ATP7A gene. About 15% of the mutations causing Menkes disease are partial gene deletions. We have previously demonstrated carrier diagnosis of deletions in heterozygotes by Southern blot analysis. As this technique is very time-consuming alternative methods are obviously of high value. Multiplex polymerase chain reaction (PCR), reverse transcription PCR (RT-PCR) and spanning the deletion on genomic DNA can all be used for detection of partial gene deletions in male patients, but only spanning of the deletion can be applied for carrier detection. Simple multiplex PCR is not applicable for carrier detection because the normal allele of ATP7A will be PCR amplified thus masking the deletion. Here, we demonstrate, in addition to spanning of the deletion on genomic DNA, carrier detection based on the use of a previously unrecognized polymorphism in intron 13 of ATP7A in combination with previously identified intragenic polymorphic markers. We show that these intragenic markers can be used for carrier detection, not only indirectly by determining segregation of the disease related allele but also directly if located within the deleted region. We demonstrate determination of the carrier status of 21 at-risk carriers.

X-linked recessive Menkes disease: identification of partial gene deletions in affected males

Menkes disease is an X-linked recessive lethal disorder of copper metabolism, caused by defects in the ATP7A gene. Partial gene deletions comprise about 15% of the mutations causing Menkes disease. We have previously demonstrated identification of partial ATP7A deletions in patients by Southern blot analysis. In the present study, we report the use of three fast and reliable polymerase chain reaction (PCR)-based methods for the identification of partial ATP7A deletions in Menkes disease patients. First we demonstrate the use of multiplex PCR, a fast method for identification and rough localization of partial gene deletions, in which two exons of ATP7A are coamplified. Second, we present PCR amplification of genomic DNA across the deletion junctions, a method enabling identification of the deletion breakpoints and hence the exact size of the deletion. Finally, application of reverse transcription PCR (RT-PCR) for identification and localization of gene deletions at the cDNA level is demonstrated. By studying the mutation at the cDNA level the predicted effect of the mutation on the amino acid sequence and consequently the protein structure and function can be inferred. We demonstrate characterization of partial gene deletions in five patients, and in three of these we were able to determine the breakpoint sequences.

Disturbed copper transport in humans. Part 2: mutations of the ATP7B gene lead to Wilson disease (WD)

Mutations in the Wilson disease gene ATP7B, a P-type ATPase, are responsible for copper accumulation in the liver and other organs leading to Wilson disease (WD, OMIM 277900). Clinical manifestations of Wilson disease (WD) include chronic liver disease, acute hepatic failure or neuropsychiatric diseases. Since potent medical treatments are available to prevent disabling residual symptoms, early diagnosis is crucial. To demonstrate the clinical course and genetic findings, a male patient with a novel mutation in the ATP7B gene, a 10 base pair insertion in exon 6 (1927ins 10), and a second missense mutation in exon 13 (P992L) is reported. The patient presented with signs of chronic liver disease at the age of 10 years. Clinical findings included hepatomegaly, elevated liver enzymes and coagulopathy. A combination treatment with the copper chelating agent D-penicillamine and zinc acetate was started leading to normalization of liver function and no appearance of neurological signs or Kayser-Fleischer ring after 7 years follow-up. Truncating mutations of the ATP7B gene (insertions, deletions, nonsense mutations) leading to gross loss of C-terminal parts of the protein, thereby probably completely destroying the protein function, may correlate with a hepatic phenotype and early onset as seen in the patient presented.

Disturbed copper transport in humans. Part 1: mutations of the ATP7A gene lead to Menkes disease and occipital horn syndrome

Mutations of the ATP7A gene (OMIM 300011) lead to the Menkes disease (MD, OMIM 309400) involving impaired brain development, neurological degeneration, connective tissue abnormalities, and high lethality in early infancy. Occipital horn syndrome (OHS, OMIM 304150), a milder phenotype, is also caused by ATP7A gene mutations. In MD patients, an early copper-histidine treatment may prevent the neurological impairment and prolong survival leading to an OHS phenotype. To demonstrate the genotype/phenotype correlation, two male patients are reported with different ATP7A gene mutations and several phenotypes. In the first patient with the MD phenotype, a mutation within the exon 20 (Gln1288Ter) was found producing a stop codon just prior to the highly conserved ATP binding domain. The OHS phenotype of the second patient was caused by a splice site mutation involving the position +6 of intron 6 within a copper binding domain. Small amounts of correctly spliced ATP7A transcript were sufficient to develop the milder OHS phenotype in this patient (OMIM 30001.0006). In conclusion, mutations of the copper transporting P-type ATPase ATP7A gene cause distinct human diseases showing some genotype/phenotype correlation and implications for treatment.

Cytochrome c oxidase deficiency due to mutations in SCO2, encoding a mitochondrial copper-binding protein, is rescued by copper in human myoblasts

Mutations in SCO2, a cytochrome c oxidase (COX) assembly gene, have been reported in nine infants with early onset fatal cardioencephalomyopathy and a severe COX deficiency in striated muscle. Studies on a yeast homolog have suggested that human Sco2 acts as a copper chaperone, transporting copper to the Cu(A) site on the Cox II subunit, but the mechanism of action remains unclear. To investigate the molecular basis of pathogenesis of Sco2 defects in humans we performed genetic and biochemical studies on tissues, myoblasts and fibroblasts from affected patients, as well as on a recombinant human C-terminal Sco2 segment (22 kDa), bearing the putative CxxxC metal-binding motif. Recombinant Sco2 was shown to bind copper with a 1:1 stoichiometry and to form homomeric complexes in vitro, independent of the metal-binding motif. Immunohistochemistry using antibodies directed against different COX subunits showed a marked tissue-specific decrease in the Cox II/III subunits that form part of the catalytic core, consistent with the differential tissue involvement, but a more uniform distribution of Cox Vab, a nuclear-encoded subunit. Sco2 was severely reduced in patient fibroblasts and myoblasts by immunoblot analysis. Patient fibroblasts showed increased (64)Cu uptake but normal retention values and, consistent with this, the copper concentration was four times higher in Sco2-deficient myoblasts than in controls. COX activity in patient myoblasts was completely rescued by transduction with a retroviral vector expressing the human SCO2 coding sequence, and more interestingly by addition of copper-histidine (300 microM) to the culture medium. Whether the latter is accomplished by the very low residual levels of Sco2 in the patient cells, direct addition of copper to the Cu(A) site, or by another copper-binding protein remains unknown. Whatever the mechanism, this result suggests a possible therapy for the early treatment of this fatal infantile disease.

Homozygosity (E140K) in SCO2 causes delayed infantile onset of cardiomyopathy and neuropathy

OBJECTIVE

To report three unrelated infants with a distinctive phenotype of Leigh-like syndrome, neurogenic muscular atrophy, and hypertrophic obstructive cardiomyopathy. The patients all had a homozygous missense mutation in SCO2.

BACKGROUND

SCO2 encodes a mitochondrial inner membrane protein, thought to function as a copper transporter to cytochrome c oxidase (COX), the terminal enzyme of the respiratory chain. Mutations in SCO2 have been described in patients with severe COX deficiency and early onset fatal infantile hypertrophic cardioencephalomyopathy. All patients so far reported are compound heterozygotes for a missense mutation (E140K) near the predicted CxxxC metal binding motif; however, recent functional studies of the homologous mutation in yeast failed to demonstrate an effect on respiration.

METHODS

Here we present clinical, biochemical, morphologic, functional, MRI, and MRS data in two infants, and a short report in an additional patient, all carrying a homozygous G1541A transition (E140K).

RESULTS

The disease onset and symptoms differed significantly from those in compound heterozygotes. MRI and muscle morphology demonstrated an age-dependent progression of disease with predominant involvement of white matter, late appearance of basal ganglia lesions, and neurogenic muscular atrophy in addition to the relatively late onset of hypertrophic cardiomyopathy. The copper uptake of cultured fibroblasts was significantly increased.

CONCLUSIONS

The clinical spectrum of SCO2 deficiency includes the delayed development of hypertrophic obstructive cardiomyopathy and severe neurogenic muscular atrophy. There is increased copper uptake in patients' fibroblasts indicating that the G1541A mutation effects cellular copper metabolism.

An mtDNA mutation, 14453G-->A, in the NADH dehydrogenase subunit 6 associated with severe MELAS syndrome

We report a novel point mutation in the gene for the mitochondrially encoded ND6 subunit of the NADH:ubiquinone oxidoreductase (complex I of the respiratory chain) in a patient with MELAS syndrome. The mutation causes a change from alanine to valine in the most conserved region of the ND6 subunit. The patient was heteroplasmic for the mutation in both muscle and blood, but the mutation was not detected in the patient's mother. A marked reduction of complex I activity was found in the patient's muscular tissue. This is the first report of a mutation in the ND6 subunit causing MELAS. Our data confirm the genetic heterogeneity in mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome, and confirms that MELAS can be caused by mutation in polypeptide-coding mtDNA genes.

Multisystem disorder associated with a missense mutation in the mitochondrial cytochrome b gene

Mitochondrial cytochrome b mutations have been reported to have a homogenous phenotype of pure exercise intolerance. We describe a novel mutation in the cytochrome b gene of mitochondrial DNA (A15579G) associated with a selective decrease of muscle complex III activity in a patient who, besides severe exercise intolerance, also has multisystem manifestations (deafness, mental retardation, retinitis pigmentosa, cataract, growth retardation, epilepsy). The point mutation is heteroplasmic in muscle (88%) and leukocytes (15%), and changes a highly conserved tyrosine to cysteine at amino acid position 278.

Cosmix-plexing: a novel recombinatorial approach for evolutionary selection from combinatorial libraries

The efficiency of existing combinatorial biological library methods has been moderate in terms of the success rates, the affinities of the ligands selected and the time and effort involved in trying to optimize the initial leads. Although mimicking natural evolution, existing strategies take little notice of the importance of recombination within a selected population to generate increased diversity. We present an overview of our recent progress which has resulted in the successful development of such a strategy, which we designate cosmix-plexing. We incorporate recombination as a central feature in obtaining high success rates and high affinities, even for short monomer peptides, in a very short time. The method uses type II restriction enzymes to re-assort small hypervariable DNA cassettes from an intermediate pre-selected population (e.g. from a phagemid display library), while maintaining the original open-reading frame. Since, in the naive library, each cassette contains all possible combinations of the polypeptide sequences it encodes, much longer regions can be optimized than was possible with methods which depend on a simple selection from the naive library. Short peptides can now be rapidly selected, which exhibit the same, or higher, specificity and affinity for a defined target molecule, than (say) an antibody or even the natural ligand.

Characterization of the hCTR1 gene: genomic organization, functional expression, and identification of a highly homologous processed gene

The human hCTR1 gene was originally identified by its ability to complement a yeast mutant deficient in high-affinity copper uptake (Zhou, B., Gitschier, J., 1997. A human gene for copper uptake identified by complementation in yeast. Proc. Natl. Acad. Sci. USA 94, 7481-7486). Here, we have determined the DNA sequence of the exon-intron borders of the hCTR1 structural gene and report that the coding sequence is disrupted by three introns, all of which comply with the GT/AG rule. Furthermore, human fibroblasts, transfected with hCTR1 cDNA, were shown to have a dramatically increased capacity for (64)Cu uptake, indicating that the hCtr1 protein is functional in copper uptake in human cells. In contrast, no evidence was found for involvement of the hCTR2 gene product in copper uptake. Finally, we have identified a highly homologous processed pseudogene, hCTR1psi, which was localized to chromosome 3q25/26. The processed gene was found to be transcribed, but due to a frame shift mutation, it only had the potential to encode a truncated protein of 95 amino acid residues, and cells transfected with hCTR1psi DNA showed no increase of (64)Cu uptake.

Similar splice-site mutations of the ATP7A gene lead to different phenotypes: classical Menkes disease or occipital horn syndrome

More than 150 point mutations have now been identified in the ATP7A gene. Most of these mutations lead to the classic form of Menkes disease (MD), and a few lead to the milder occipital horn syndrome (OHS). To get a better understanding of molecular changes leading to classic MD and OHS, we took advantage of the unique finding of three patients with similar mutations but different phenotypes. Although all three patients had mutations located in the splice-donor site of intron 6, only two of the patients had the MD phenotype; the third had the OHS phenotype. Fibroblast cultures from the three patients were analyzed by reverse transcriptase (RT)-PCR to try to find an explanation of the different phenotypes. In all three patients, exon 6 was deleted in the majority of the ATP7A transcripts. However, by RT-PCR amplification with an exon 6-specific primer, we were able to amplify exon 6-containing mRNA products from all three patients, even though they were in low abundance. Sequencing of these products indicated that only the patient with OHS had correctly spliced exon 6-containing transcripts. We used two different methods of quantitative RT-PCR analysis and found that the level of correctly spliced mRNA in this patient was 2%-5% of the level found in unaffected individuals. These findings indicate that the presence of barely detectable amounts of correctly spliced ATP7A transcript is sufficient to permit the development of the milder OHS phenotype, as opposed to classic MD.

Enhanced production of pediocin PA-1 and coproduction of nisin and pediocin PA-1 by Lactococcus lactis

The production and secretion of class II bacteriocins share a number of features that allow the interchange of genetic determinants between certain members of this group of antimicrobial peptides. Lactococcus lactis IL1403 encodes translocatory functions able to recognize and mediate secretion of lactococcin A. The ability of this strain to also produce the pediococcal bacteriocin pediocin PA-1, has been demonstrated previously by the introduction of a chimeric gene, composed of sequences encoding the leader of lactococcin A and the mature part of pediocin PA-1 (N. Horn, M. I. Martínez, J. M. Martínez, P. E. Hernández, M. J. Gasson, J. M. Rodríguez, and H. M. Dodd, Appl. Environ. Microbiol. 64:818-823, 1998). This heterologous expression system has been developed further with the introduction of the lactococcin A-dedicated translocatory function genes, lcnC and lcnD, and their effect on bacteriocin yields in various lactococcal hosts was assessed. The copy number of lcnC and lcnD influenced production levels, as did the particular strain employed as host. Highest yields were achieved with L. lactis IL1403, which generated pediocin PA-1 at a level similar to that for the parental strain, Pediococcus acidilactici 347, representing a significant improvement over previous systems. The genetic determinants required for production of pediocin PA-1 were introduced into the nisin-producing strain L. lactis FI5876, where both pediocin PA-1 and nisin A were simultaneously produced. The implications of coproduction of these two industrially relevant antimicrobial agents by a food-grade organism are discussed.

Expression, purification and copper-binding studies of the first metal-binding domain of Menkes protein

The cDNA, coding for the first metal-binding domain (MBD1) of Menkes protein, was cloned into the T7-system based vector, pCA. The T7 lysozyme-encoding plasmid, pLysS, is shown to be crucial for expression, suggesting that the protein is toxic to the cells. Adding copper to the growth medium did not affect the plasmid stability. MBD1 is purified in two steps with a typical yield of 12 mg.L-1. Menkes protein, a P-type ATPase, contains a sequence GMXCXSC that is repeated six times, at the N-terminus. The paired cysteine residues are involved in metal binding. MBD1 has only two cysteine residues, which can exist as free thiol groups (reduced), as a disulphide bond (oxidized) or bound to a metal ion [e.g. Cu(I)-MBD1]. These three MBD1 forms have been investigated using CD. No major spectral change was seen between the different MBD1 forms, indicating that the folding is not changed upon metal binding. A copper-bound MBD1 was also studied by EPR, and the lack of an EPR signal suggests that the oxidation state of copper bound to MBD1 is Cu(I). Cu(I) binding studies were performed by equilibrium dialysis and revealed a stoichiometry of 1 : 1 and an apparent Kd = 46 microM. Oxidized MBD1, however, is not able to bind copper. Different copper complexes were investigated for their ability to reconstitute apo-MBD1. Given the same total copper concentration CuCl43- was superior to Cu(I)-thiourea (structural analogue of metallothionein) and Cu(I)-glutathione (used at fivefold higher copper concentration) although the latter two were able to partially reconstitute apo-MBD1. Cu(II) was not able to reconstitute apo-MBD1, presumably due to Cu(II)-induced oxidation of the thiol groups. Based on our results, glutathione and/or metallothionein are likely candidates for the in vivo incorporation of copper to Menkes protein.

[Extracorporeal liver assist devices in acute liver failure]

The acute liver failure (ALF) is a complex syndrome resulting from loss of synthetic and metabolic functions of the liver. Despite recent advances in intensive care medicine patients with severe ALF have a very high mortality and the orthotopic liver transplantation still remains the only proven effective treatment of ALF. Numerous attempts have been made to improve survival by using various extracorporeal support techniques, but none of these therapeutic approaches was able to increase the survival rate. Liver support systems based on detoxification procedures only could not influence the deleterious course of the disease. It is certain that an ideal liver support system should be capable to fulfil the liver's essential synthetic and metabolic functions as well as detoxification and excretion. Over the last years the development of hybrid liver assist devices has aimed at replacing these liver functions and therefore might give an advantage over earlier systems based on detoxification techniques only. This article gives a short review of the various liver support systems and focuses then on the hybrid liver support systems, their construction and the remaining problems after the first clinical applications.

Post-translational modification of nisin. The involvement of NisB in the dehydration process

The lantibiotic nisin is an antimicrobial peptide produced by Lactococcus lactis. As with all lantibiotics, nisin contains a number of dehydro-residues and thioether amino acids that introduce five lanthionine rings into the target peptide. These atypical amino acids are introduced by post-translational modification of a ribosomally synthesized precursor peptide. In certain cases, the serine residue, at position 33 of nisin, does not undergo dehydration to Dha33. With native nisin this partially processed form represents about 10% of the total peptide, whereas with the engineered variants, [Trp30]nisin A and [Lys27,Lys31]nisin A, the proportion of peptide that escapes full processing was found to be to approximately 50%. This feature of nisin biosynthesis was exploited in an investigation of the role of the NisB protein in pre-nisin maturation. Manipulation of the level of NisB was achieved by cloning and overexpressing the plasmid-encoded nisB gene in a range of different nisin-producing strains. The resulting fourfold increase in the level of NisB significantly increased the efficiency of the dehydration reaction at Ser33. The final secreted product of biosynthesis by these strains was the homogenous form of the fully processed nisin (or nisin variant) molecule. The results presented represent the first experimental evidence for the direct involvement of the NisB protein in the maturation process of nisin.

Mutation spectrum of ATP7A, the gene defective in Menkes disease

Our knowledge about Menkes disease (MD) has expanded greatly since its description in 1962 as a new X-linked recessive neurodegenerative disorder of early infancy. Ten years later a defect in copper metabolism was established as the underlying biochemical deficiency. In the beginning of 1990s efforts were concentrated on the molecular genetic aspects. The disease locus was mapped to Xq13.3 and the gene has been isolated by means of positional cloning. This was the beginning of a series of new findings which have greatly enhanced our understanding of copper metabolism not only in human, but also in other species. This review will focus on the molecular genetic aspects of Menkes disease and its allelic form occipital horn syndrome. The mutations will be compared briefly with those described in the animal model mottled mouse, and in Wilson disease, the autosomal recessive disorder of copper metabolism.

Accumulated experience with prenatal diagnosis of Menkes disease by neutron activation analysis of chorionic villi specimens

Since 1983, prenatal diagnosis of Menkes disease has been carried out by determining Cu in samples of chorionic villi from the fetus by means of radiochemical neutron activation analysis. Concentrations of Cu in chorionic villi from male fetuses later confirmed to have Menkes disease were invariably higher than previously reported values for normal controls. Out of 240 samples analyzed in the period 1983-1998, there were 71 from female fetuses that could be carriers of the Menkes genetic defect without suffering from the disease. Increased concentrations of Cu in these samples could not be attributed to the presence of this genetic defect, but might result from sporadic contamination of the samples before analysis. Such contamination also may occur in samples from male fetuses and thus raise the level of Cu in small, but normal specimens into the range characteristic of Menkes disease. In spite of a strict protocol for taking samples without contamination, a total of four false positives were reported during the period of investigation; no false negatives have occurred.