Tissue engineering of bone: effects of mechanical strain on osteoblastic cells in type I collagen matrices

The aim of the present study was to investigate the effect of cyclic uniaxial mechanical strain on a human osteoblastic precursor cell line (hFOB 1.19) in three-dimensional type I collagen matrices. Cell seeded collagen constructs were mechanically stretched by a daily application of cyclic uniaxial strain using a special motor-driven apparatus and compared to unstretched controls. Expression of genes involved in cell proliferation and osteoblastic differentiation as well as matrix production were investigated by analyzing the mRNA of histone H4, core binding factor 1, alkaline phosphatase, osteopontin, osteocalcin, and collagen type I (Col I) up to a cultivation period of 3 weeks using real-time PCR. Cyclic stretching of cell seeded Col I matrices at a magnitude occurring in healing bone increased cell proliferation and slightly elevated the expression of nearly all investigated genes over unstrained controls at various time points. It was concluded that mechanical load promotes the proliferation and differentiation of osteoblastic precursor cells in a Col I matrix and that the application of mechanical stimuli may have a beneficial effect on in vitro tissue formation.

Modulation of DNA repair processes by arsenic and selenium compounds

Nickel, cadmium, cobalt and arsenic compounds are well known carcinogens to humans and experimental animals. In addition to the induction of mainly oxidative DNA damage, they interfere with nucleotide and base excision repair (BER) at low, non-cytotoxic concentrations. In case of arsenic, an inactivation of DNA repair has also been observed for the trivalent and pentavalent methylated metabolites, with the strongest effects exerted by MMA(III) and DMA(III). As potential molecular targets, interactions with so-called zinc finger proteins involved in DNA repair and/or DNA damage signaling have been identified. For example, arsenite suppresses poly(ADP-ribosyl)ation at extremely low, environmentally relevant concentrations. Also, Fpg and XPA involved in BER and NER, respectively, are inactivated by arsenite, MMA(III) and DMA(III). Nevertheless, an interaction with the zinc finger structures of DNA repair proteins may also occur by essential trace elements such as certain selenium compounds, which appear to exert anticarcinogenic properties at low concentrations but may compromise genetic stability at higher concentrations.

Interference by toxic metal ions with zinc-dependent proteins involved in maintaining genomic stability

Metal ions are essential components of biological systems; nevertheless, even essential elements may have toxic or carcinogenic properties. Thus, besides As(III) and Cd(II), also Ni(II) and Co(II) have been shown previously to disturb different types of DNA repair systems at low, non-cytotoxic concentrations. Since some metals exert high affinities for SH groups, we investigated whether zinc finger structures in DNA-binding motifs of DNA repair proteins are potential targets for toxic metal ions. The bacterial formamidopyrimidine-DNA glycosylase (Fpg protein) involved in base excision repair was inhibited by Cd(II), Cu(II) and Hg(II) with increasing efficiencies, whereas Co(II), As(III), Pb(II) and Ni(II) had no effect. Furthermore, Cd(II) still disturbed enzyme function when bound to metallothionein. Strong inhibition was also observed in the presence of phenylselenyl chloride, followed by selenocystine, while selenomethionine was not inhibitory. Regarding the mammalian XPA protein involved in the recognition of DNA lesions during nucleotide excision repair, its DNA-binding capacity was diminished by Cd(II), Cu(II), Ni(II) and Co(II), while Hg(II), Pb(II) and As(III) were ineffective. Finally, the H(2)O(2)-induced activation of the poly(ADP-ribose)polymerase (PARP) involved in DNA strand break detection and apoptosis was greatly reduced by Cd(II), Co(II), Ni(II) and As(III). Similarly, the disruption of correct p53 folding and DNA binding by Cd(II), Ni(II) and Co(II) has been shown by other authors. Therefore, zinc-dependent proteins involved in DNA repair and cell-cycle control may represent sensitive targets for some toxic metals such as Cd(II), Ni(II), Co(II) and Cu(II), as well as for some selenium compounds. Relevant mechanisms of inhibition appear to be the displacement of zinc by other transition metals as well as redox reactions leading to thiol/disulfide interchange.

Clinical implementation of RNA sequencing for Mendelian disease diagnostics

BACKGROUND

Lack of functional evidence hampers variant interpretation, leaving a large proportion of individuals with a suspected Mendelian disorder without genetic diagnosis after whole genome or whole exome sequencing (WES). Research studies advocate to further sequence transcriptomes to directly and systematically probe gene expression defects. However, collection of additional biopsies and establishment of lab workflows, analytical pipelines, and defined concepts in clinical interpretation of aberrant gene expression are still needed for adopting RNA sequencing (RNA-seq) in routine diagnostics.

METHODS

We implemented an automated RNA-seq protocol and a computational workflow with which we analyzed skin fibroblasts of 303 individuals with a suspected mitochondrial disease that previously underwent WES. We also assessed through simulations how aberrant expression and mono-allelic expression tests depend on RNA-seq coverage.

RESULTS

We detected on average 12,500 genes per sample including around 60% of all disease genes-a coverage substantially higher than with whole blood, supporting the use of skin biopsies. We prioritized genes demonstrating aberrant expression, aberrant splicing, or mono-allelic expression. The pipeline required less than 1 week from sample preparation to result reporting and provided a median of eight disease-associated genes per patient for inspection. A genetic diagnosis was established for 16% of the 205 WES-inconclusive cases. Detection of aberrant expression was a major contributor to diagnosis including instances of 50% reduction, which, together with mono-allelic expression, allowed for the diagnosis of dominant disorders caused by haploinsufficiency. Moreover, calling aberrant splicing and variants from RNA-seq data enabled detecting and validating splice-disrupting variants, of which the majority fell outside WES-covered regions.

CONCLUSION

Together, these results show that streamlined experimental and computational processes can accelerate the implementation of RNA-seq in routine diagnostics.

Interaction of selenium compounds with zinc finger proteins involved in DNA repair

As an essential element, selenium is present in enzymes from several families, including glutathione peroxidases, and is thought to exert anticarcinogenic properties. A remarkable feature of selenium consists of its ability to oxidize thiols under reducing conditions. Thus, one mode of action recently suggested is the oxidation of thiol groups of metallothionein, thereby providing zinc for essential reactions. However, tetrahedral zinc ion complexation to four thiolates, similar to that found in metallothionein, is present in one of the major classes of transcription factors and other so-called zinc finger proteins. Within this study we investigated the effect of selenium compounds on the activity of the formamidopyrimidine-DNA glycosylase (Fpg), a zinc finger protein involved in base excision repair, and on the DNA-binding capacity and integrity of xeroderma pigmentosum group A protein (XPA), a zinc finger protein essential for nucleotide excision repair. The reducible selenium compounds phenylseleninic acid, phenylselenyl chloride, selenocystine, ebselen, and 2-nitrophenylselenocyanate caused a concentration-dependent decrease of Fpg activity, while no inhibition was detected with fully reduced selenomethionine, methylselenocysteine or some sulfur-containing analogs. Furthermore, reducible selenium compounds interfered with XPA-DNA binding and released zinc from the zinc finger motif, XPAzf. Zinc release was even evident at high glutathione/oxidised glutathine ratios prevailing under cellular conditions. Finally, comparative studies with metallothionein and XPAzf revealed similar or even accelerated zinc release from XPAzf. Altogether, the results indicate that zinc finger motifs are highly reactive towards oxidizing selenium compounds. This could affect gene expression, DNA repair and, thus, genomic stability.

Microarray analysis of placental tissue in intrauterine growth restriction

OBJECTIVE

Besides foetal or maternal disorders, placental dysfunction is a major cause of intrauterine growth restriction (IUGR). Although numerous macro- and histopathological changes have been described, little is known about the precise aetiology and the contribution of foetal/placental genes in this disorder.

DESIGN

Placental tissues of 20 IUGR and control neonates were analysed by microarray technique. Four of the regulated genes with possible relevance in the pathogenesis of IUGR and its consequences were further studied in placentas of 27 IUGR and 35 control newborns.

RESULTS

Elevated gene expression of leptin, corticotrophin-releasing hormone (CRH), and IGF-binding protein-1 (IGFBP-1) in IUGR placentas could be confirmed in the larger group by real-time PCR, whereas prolactin showed no significant difference. Accordingly, protein expression of leptin and IGFBP-1 depicted by Western blot was elevated in IUGR, prolactin was not different. Birthweight standard deviation score (SDS) correlated negatively to leptin, IGFBP-1, and CRH, whereas placental weight correlated only to IGFBP-1. Leptin correlated negatively to gestational age of IUGR patients and positively to placental score, a marker of severity of impaired foeto-placental circulation.

CONCLUSIONS

As confirmed in a large group of IUGR and control samples, the up-regulated factors leptin, IGFBP-1, and CRH may serve as candidate genes for the prediction of subsequent metabolic consequences in IUGR newborns. These three factors may not only influence growth of the foetus, but might also interact with programming of its metabolic functions, which has to be determined in an ongoing study.

Catechol-O-methyltransferase inhibition attenuates levodopa toxicity in mesencephalic dopamine neurons

Inhibition of catechol-O-methyltransferase (COMT; EC 2.1.1.6) is a new therapeutic strategy in the treatment of Parkinson's disease. However, nothing is known about the effects of COMT inhibition on levodopa (L-dopa)-induced toxicity in dopamine (DA) neurons. Therefore we evaluated the effects of the selective COMT inhibitors Ro 41-0960, OR-486, and tolcapone alone and in combination with L-dopa in primary mesencephalic cultures from rat. Neither COMT inhibitor affected the growth of tyrosine hydroxylase immunoreactive (THir) cells with concentrations up to 10 microM when studied alone. However, Ro 41-0960 reduced the L-dopa-induced THir cell loss after 24 h in a dose-dependent manner, shifting the TD(50) value from 21 microM in the absence to 71 microM in the presence of 1 microM Ro 41-0960 (P <.01) without affecting survival of non-DA neurons. OR-486 and the clinically used COMT inhibitor tolcapone showed similar effects. In contrast, toxicity induced by D-dopa was not altered by COMT inhibitors. Furthermore, the primary metabolite of L-dopa formed by COMT, 3-O-methyldopa, and the methyl group donor S-adenosyl-L-methionine used by COMT did not alter THir neuron survival and L-dopa-induced toxicity, respectively, with concentrations up to 100 microM. These data demonstrate that COMT inhibition attenuates L-dopa toxicity toward DA neurons in vitro, but probably not by preventing 3-O-methyldopa production or cellular S-adenosyl-L-methionine depletion.

Placental 11beta-HSD2 gene expression at birth is inversely correlated with growth velocity in the first year of life after intrauterine growth restriction

Intrauterine growth restriction (IUGR) is associated with an increased risk for short stature and diseases in adulthood thought to be inflicted by fetal programming. We hypothesized that placental endocrine systems involved in perinatal growth might also play a role in postnatal growth after IUGR. In a prospective controlled multicenter study, placental gene expression of IGF-binding protein-1 (IGFBP-1), leptin and 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) were measured in 14 IUGR infants and 15 children born appropriate for gestational age (AGA) proven by serial ultrasound examinations. Postnatally, IUGR infants experienced a significantly higher growth velocity than AGA neonates (at 1 y: p = 0.001). Gene expression of 11beta-HSD2 at birth correlated positively with birth length (r = 0.55, p = 0.04) and inversely with growth velocity in the first year of life (r = -0.69, p = 0.01) in the IUGR, but not in the AGA group. There was no correlation between gene expression of placental IGFBP-1, leptin and birth weight, length and growth velocity during the first year of life. AGA infants showed significantly higher concentrations of cortisone in venous cord blood after birth (p = 0.02) as a surrogate of a higher 11beta-HSD2 activity in the fetoplacental unit. In conclusion, placental 11beta-HSD2 gene expression might predict postnatal growth in IUGR.

Neonatal Cholestasis - Differential Diagnoses, Current Diagnostic Procedures, and Treatment

Cholestatic jaundice in early infancy is a complex diagnostic problem. Misdiagnosis of cholestasis as physiologic jaundice delays the identification of severe liver diseases. In the majority of infants, prolonged physiologic jaundice represent benign cases of breast milk jaundice, but few among them are masked and caused by neonatal cholestasis (NC) that requires a prompt diagnosis and treatment. Therefore, a prolonged neonatal jaundice, longer than 2 weeks after birth, must always be investigated because an early diagnosis is essential for appropriate management. To rapidly identify the cases with cholestatic jaundice, the conjugated bilirubin needs to be determined in any infant presenting with prolonged jaundice at 14 days of age with or without depigmented stool. Once NC is confirmed, a systematic approach is the key to reliably achieve the diagnosis in order to promptly initiate the specific, and in many cases, life-saving therapy. This strategy is most important to promptly identify and treat infants with biliary atresia, the most common cause of NC, as this requires a hepatoportoenterostomy as soon as possible. Here, we provide a detailed work-up approach including initial treatment recommendations and a clinically oriented overview of possible differential diagnoses in order to facilitate the early recognition and a timely diagnosis of cholestasis. This approach warrants a broad spectrum of diagnostic procedures and investigations including new methods that are described in this review.

Human ultrarare genetic disorders of sulfur metabolism demonstrate redundancies in H2S homeostasis

Regulation of H₂S homeostasis in humans is poorly understood. Therefore, we assessed the importance of individual enzymes in synthesis and catabolism of H₂S by studying patients with respective genetic defects. We analyzed sulfur compounds (including bioavailable sulfide) in 37 untreated or insufficiently treated patients with seven ultrarare enzyme deficiencies and compared them to 63 controls. Surprisingly, we observed that patients with severe deficiency in cystathionine β-synthase (CBS) or cystathionine γ-lyase (CSE) - the enzymes primarily responsible for H₂S synthesis - exhibited increased and normal levels of bioavailable sulfide, respectively. However, an approximately 21-fold increase of urinary homolanthionine in CBS deficiency strongly suggests that lacking CBS activity is compensated for by an increase in CSE-dependent H₂S synthesis from accumulating homocysteine, which suggests a control of H₂S homeostasis in vivo. In deficiency of sulfide:quinone oxidoreductase - the first enzyme in mitochondrial H₂S oxidation - we found normal H₂S concentrations in a symptomatic patient and his asymptomatic sibling, and elevated levels in an asymptomatic sibling, challenging the requirement for this enzyme in catabolizing H₂S under physiological conditions. Patients with ethylmalonic encephalopathy and sulfite oxidase/molybdenum cofactor deficiencies exhibited massive accumulation of thiosulfate and sulfite with formation of large amounts of S-sulfocysteine and S-sulfohomocysteine, increased renal losses of sulfur compounds and concomitant strong reduction in plasma total cysteine. Our results demonstrate the value of a comprehensive assessment of sulfur compounds in severe disorders of homocysteine/cysteine metabolism and provide evidence for redundancy and compensatory mechanisms in the maintenance of H₂S homeostasis.

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Cystathionine γ-lyase can compensate for decreased H₂S synthesis in cystathionine β-synthase deficiency.

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Sulfide:quinone oxidoreductase deficiency is compatible with normal H₂S plasma levels under non-stressed conditions.

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Persulfide dioxygenase deficiency (ethylmalonic encephalopathy) causes the largest accumulation of H₂S among disorders of sulfur metabolism.

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Excess sulfite forms S-sulfocysteine and S-sulfohomocysteine, and interferes with vitamin B₆ metabolism.

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S-sulfocysteine correlates directly with sulfite and is a stable biomarker of sulfite accumulation.

Identification of glycoprotein gpTRL10 as a structural component of human cytomegalovirus

Human cytomegalovirus (HCMV) has a coding capacity for glycoproteins which far exceeds that of other herpesviruses. Few of these proteins have been characterized. We have investigated the gene product(s) of reading frame 10, which is present in both the internal and terminal repeat regions of HCMV strain AD169 and only once in clinical isolates. The putative protein product is a 171-amino-acid glycoprotein with a theoretical mass of 20.5 kDa. We characterized the protein encoded by this reading frame in the laboratory strain AD169 and a recent isolate, TB40E. The results from both strains were comparable. Northern blot analyses showed that the gene was transcribed with early/late kinetics. Two proteins of 22 and 23.5-kDa were detected in virus-infected cells and in cells transiently expressing recombinant TRL10. Both forms contained only high-mannose-linked carbohydrate modifications. In addition, virus-infected cells expressed small amounts of the protein modified with complex N-linked sugars. Image analysis localized transiently expressed TRL10 to the endoplasmic reticulum. Immunoblot analyses as well as immunoelectron microscopy of purified virions demonstrated that TRL10 represents a structural component of the virus particle. Immunoblot analysis in the absence of reducing agents indicated that TRL10, like the other HCMV envelope glycoproteins, is present in a disulfide-linked complex. Sequence analysis of the TRL10 coding region in nine low-passage clinical isolates revealed strain-specific variation. In summary, the protein product of the TRL10 open reading frame represents a novel structural glycoprotein of HCMV and was termed gpTRL10.

Evaluation of plasma trace element and mineral status in children and adolescents with phenylketonuria using data from inductively-coupled-plasma atomic emission and mass spectrometric analysis

BACKGROUND

Phenylketonuria (PKU) is caused by a severe phenylalanine hydroxylase deficiency; the mainstay of treatment is a low-phenylalanine diet. A diet which is so restrictive is associated with a risk of nutritional deficiencies. We investigated plasma concentrations for 46 elements, including minerals and trace elements.

METHODS

We enrolled 20 children and adolescents with PKU and 20 matched controls. Multi-elementary quantification was carried out by solution-based inductively coupled plasma atomic emission spectroscopy (ICP-AES) and ICP mass spectrometry (ICP-MS).

RESULTS

With the exception of manganese and aluminium, no significant differences were found for element levels between PKU patients and controls. As a trend, manganese levels were lower in PKU patients than in control subjects (p < 0.05) but were within the reference range. There was a positive linear relationship between manganese and tyrosine levels in subjects with PKU (r(2) = 0.2295, p < 0.05). If detectable, potentially toxic elements were only identified in ultra-trace quantities in plasma samples of either group; aluminium levels were found to be slightly higher in PKU subjects than in controls (p < 0.01).

CONCLUSION

The combination of ICP-AES and ICP-MS data is a useful diagnostic tool for element quantification at a high analytical rate and for monitoring bio-element status, e.g. in patients on a restrictive diet.

Effekte mechanischer Reize auf humane osteoblastäre Zellen in einer dreidimensionalen Kollagen-Typ-I-Matrix

BACKGROUND

The aim of the present study was to investigate the effect of mechanical strain on human osteoblastic precursor cells in a three-dimensional scaffold.

METHODS

Osteoblastic precursor cells were seeded in a collagen type I gel and mechanically stretched by daily application of cyclic uniaxial strain. The expression of histone H4, core binding factor 1, alkaline phosphatase, osteopontin, osteocalcin, and collagen type I was investigated by analysing the mRNA. Cell and matrix orientation were investigated by scanning electron microscopy.

RESULTS

Cyclic stretching increased cell proliferation. The expression of osteogenic markers was slightly increased by mechanical strain. The cells and matrix were strictly oriented in the stress direction.

CONCLUSION

The application of mechanical load might have a beneficial effect on the quality and quantity of generated bone tissue and might be a important factor in tissue engineering of bone.

Diagnostic Challenges Using a 2-Tier Strategy for Methylmalonic Acidurias: Data from 1.2 Million Dried Blood Spots

BACKGROUND

The detection of methylmalonic acid (MMA) by second-tier analysis has been shown to reduce the number of false positives in newborn screening (NBS) for genetically determined methylmalonic acidurias (MMAuria). In addition to genetic conditions, MMA is an indicator of vitamin B12 status, thus applicable to detect maternal vitamin B12 deficiency in the newborns screened.

METHODS

Biochemical and clinical follow-up data of a 7.5-year pilot study with 1.2 million newborns screened were reviewed.

RESULTS

Among 1,195,850 NBS samples, 3,595 (0.3%) fulfilled criteria for second-tier analysis of MMA. In 37 (0.003%; 1/32,000) samples, elevated concentrations of MMA were detected, resulting in diagnostic workup at a metabolic center in 21 newborns. In 6 infants (1/199,000), genetic conditions were established, 1 infant with cobalamin C deficiency (CblC) showed only a moderate elevation of MMA. The remaining 15 newborns (1/79,000) displayed significantly lower concentrations of MMA and were evaluated for maternal vitamin B12 deficiency. In 9 mothers, vitamin B12 deficiency was verified, and 6 showed no indication for vitamin B12 deficiency. Treatment with vitamin B12 normalized biochemical parameters in all 15 infants.

CONCLUSIONS

Applying a 2-tier strategy measuring MMA in NBS identified genetic conditions of MMAuria. It was possible to separate severe, early-onset phenotypes from maternal vitamin B12 deficiency. However, the detection of CblC deficiency with mildly elevated MMA interferes with impaired vitamin B12 status of unknown relevance and thus burdens possibly healthy newborns. Regarding maternal vitamin B12 deficiency, testing and supplementing mothers-to-be is preferable. This might decrease straining follow-up of newborns and improve quality and overall perception of NBS.

Effect of dietary regime on metabolic control in phenylketonuria: Is exact calculation of phenylalanine intake really necessary?

Background

A phenylalanine (Phe) restricted dietary management is required in phenylketonuria (PKU) to maintain good metabolic control. Nevertheless, five different models of dietary regimes, which differ in their accuracy of Phe documentation, are used. To investigate the effect of the dietary regime on metabolic control, a multicenter evaluation was performed.

Patients/Methods

149 patients (max. 800 mg Phe-intake/day; 108 children aged 1–9 years and 41 adolescents aged 10–15 years) could be included. They were separated according to age and dietary regime, revealed by a questionnaire on dietary habits. Dietary regimes vary from daily strict calculation of all Phe-intake (group 1) to a rather loose regime only estimating Phe-intake and including high protein food (group 5). Data were analyzed with respect to metabolic control (Phe-concentrations, Phe-concentrations above upper recommended limit during 6 months before the interview), Phe-intake (mg/day) and age (years).

Results

Median Phe-concentrations in children did not differ significantly among diet groups (group 1: 161; 2: 229, 3: 236, 4: 249, 5: 288 μmol/l, p = 0.175). However, exact daily Phe calculation led to significantly lower percentage of Phe concentrations above the upper recommended limit (group 1: 17, 2: 50, 3: 42, 4: 50, 5: 75%, p = 0.035). All included patients showed good to acceptable metabolic control. Patients on the dietary regime with the least accuracy, consuming also high protein foods, showed the poorest metabolic control. Median Phe concentrations of all other groups remained within recommended ranges, including from groups not calculating special low protein foods, fruit and vegetables and using a simplified system of recording Phe-intake.

In adolescents no significant differences among diet groups were revealed.

Conclusion

Exact calculation of Phe content of all food is not necessary to achieve good metabolic control in children and adolescents with PKU. Excluding special low protein food, as well as fruit and vegetables from calculation of Phe-intake has no impact on metabolic control. However including protein rich food into the diet and simply estimating all Phe-intake appears insufficient. The simplification of dietary regime may be helpful in enhancing acceptability and feasibility.

Newborn screening and disease variants predict neurological outcome in isovaleric aciduria

Isovaleric aciduria (IVA), a metabolic disease with severe (classic IVA) or attenuated phenotype (mild IVA), is included in newborn screening (NBS) programs worldwide. The long-term clinical benefit of screened individuals, however, is still rarely investigated. A national, prospective, observational, multi-center study of individuals with confirmed IVA identified by NBS between 1998 and 2018 was conducted. Long-term clinical outcomes of 94 individuals with IVA were evaluated, representing 73.4% (for classic IVA: 92.3%) of the German NBS cohort. In classic IVA (N = 24), NBS prevented untimely death except in one individual with lethal neonatal sepsis (3.8%) but did not completely prevent single (N = 10) or recurrent (N = 7) metabolic decompensations, 13 of them occurring already neonatally. IQ (mean ± SD, 90.7 ± 10.1) was mostly normal but below the reference population (P = .0022) and was even lower in individuals with severe neonatal decompensations (IQ 78.8 ± 7.1) compared to those without crises (IQ 94.7 ± 7.5; P = .01). Similar results were obtained for school placement. In contrast, individuals with mild IVA had excellent neurocognitive outcomes (IQ 105.5 ± 15.8; normal school placement) and a benign disease course (no metabolic decompensation, normal hospitalization rate), which did not appear to be impacted by metabolic maintenance therapy. In conclusion, NBS reduces mortality in classic IVA, but does not reliably protect against severe neonatal metabolic decompensations, crucial for favorable neurocognitive outcome. In contrast, individuals with mild IVA had excellent clinical outcomes regardless of metabolic maintenance therapy, questioning their benefit from NBS. Harmonized stratified therapeutic concepts are urgently needed.

Hereditary hyperferritinemia cataract syndrome: clinical, genetic, and laboratory findings in 5 families

BACKGROUND

The hereditary hyperferritinemia cataract syndrome (HHCS) is an autosomal dominant disorder characterized by high serum ferritin and early onset cataract. Mutations in the iron responsive element (IRE) within the 5' untranslated region of the L-ferritin (FTL) gene lead to constitutive L-ferritin synthesis resulting in hyperferritinemia. Bilateral cataract formation is caused by the intracellular accumulation of ferritin in the lens.

PATIENTS

4 children from unrelated families were referred for further exploration of hyperferritinemia which was detected during the diagnostic work-up of gastroenterological or hematological disorders. 1 patient was primarily referred for the investigation of bilateral cataract.Diagnostics included routine blood analysis, including complete blood count, iron status, liver and kidney parameters, a physical and an ophthalmological examination. Molecular genetic analysis of the FTL IRE was performed in 4 patients by PCR from genomic DNA and subsequent direct sequencing.

RESULTS

All index patients presented with isolated hyperferritinemia without iron overload and had a positive family history for early onset cataract. Age at onset and disease severity varied between different families and among family members. Molecular genetic analysis revealed point mutations within the FTL IRE.

CONCLUSION

In patients with hyperferritinemia but without any other sign of iron overload or inflammation HHCS should be considered to avoid complex and invasive procedures. Vice versa, in patients with familial inherited cataract the early serum ferritin measurement helps to avoid unnecessary diagnostics.

Homozygous familial hypercholesterolemia with severe involvement of the aortic valve-A sibling-controlled case study on the efficacy of lipoprotein apheresis

BACKGROUND

Homozygous familial hypercholesterolemia (hoFH) can cause severe atherosclerotic cardiovascular disease (ASCVD) in early infancy. Diagnosis and initiation of effective lipid-lowering therapy (LLT) are recommended as early as possible to prevent ASCVD-related morbidity and mortality.

METHODS

The clinical courses of a pair of siblings with an identical hoFH genotype, who exhibited major similarities of their clinical phenotype were analyzed in a case-control fashion including the family.

RESULTS

The older sibling was diagnosed with hoFH at the age of 4. Untreated LDL-cholesterol (LDL-C) was 17 mmol/L (660 mg/dL). LLT including lipoprotein apheresis (LA) was initiated and has been successful for 8 years now. A reduction of estimated cholesterol burden by 74% was achieved by LA and combined drug therapy including statins and ezetimibe. The efficacy of escalation of drug therapy was limited because the underlying LDL receptor (LDLR) mutation in the family resulted in substantially reduced receptor function. Treatment with proprotein convertase subtilisin-kexin type 9 (PCSK9)-antibodies failed. His younger brother died at the age of 2 years shortly after the hoFH diagnosis of the elder sibling. Postmortem examination revealed advanced aortic root atheroma and aortic valve stenosis. In the older sibling, aortic valve stenosis and insufficiency were treated at the age of 9 years with mechanical aortic valve replacement.

CONCLUSIONS

LLT including LA should be initiated as early as possible following the diagnosis of hoFH with very high LDL-C levels. With the same genotype, the phenotype of hoFH can exhibit similar patterns but outcome is substantially related to treatment.

[Is appendectomy really performed too frequently? Results of the prospective multicenter study of the Swiss Society of General Surgery]

Scientific publications and provoking criticism from the lay press have recently pointed out, that appendices may be surgically removed too frequent and without indisputable necessity. In an attempt to verify these questionable statements, the Swiss Society for General Surgery (SGAC) initiated a prospective controlled multi center trial. From September 1997 to December 1998, hundred and twenty-five institutions documented 4603 appendectomies performed due to a suspected appendicitis. Histological investigation of all specimens revealed a 7% rate of normal appendices, 7.2% for patients with national health service (NHS) and 5.9% for patients with private insurances respectively. Compared to the results of the literature, where a frequency of normal appendices around 15% is judged as standard, these results are excellent. In 17.2% of the patients (15.9% NHS and 23.6% privately insured patients) an "appendicitis perforata" was observed. This percentage remains in the range reported by other authors. The analysis of time of admission (i.e. day or night) and the delay from admission to surgery shows a distribution independent to the insurance of the patients. Therefore, the planned appendectomy for patients with private insurances does not exist. A different choice of the surgical technique could be observed depending on the insurance status. In 30.4% of the private insured patients a laparoscopic appendectomy was performed as compared to 22.6% of patients with NHS. Surprisingly, an identical median hospitalization time can be observed for both groups (laparoscopic 5.5 days, open surgery 5.5 days).

[Spontaneous vaginal rupture with prolapse of the small intestine]

Spontaneous rupture of the vaginal vault is a rare event. Patients at risk are postmenopausal. Very often they show symptoms of an enterocele or have been operated before vaginally. Treatment is always by surgery. Whether it can be done vaginally or by laparotomy, depends on the local situation. To prevent recurrence, a double closure of the lesion is necessary, often combined with colpocleisis, colpectomy, sacropexie or obliteration of the "cul-de-sac".

[Antibiotic prophylaxis in elective colon surgery: comparison of the combination of metronidazole (Flagyl)/cefazolin (Kefzol) with cefazolin alone]

In this prospective trial prevention of infectious complications after elective colonic surgery was studied. 34 patients receiving i.v. cefazolin were compared to 32 patients receiving oral metronidazol and i.v. cefazolin. No significant difference was observed concerning local wound infection, septicemia, anastomotic dehiscence or death. The rate of postoperative infection was 53% in group I, 34% in group II. No side effects of this prophylaxis were observed.