Genetic heterogeneity of heritable ectopic mineralization disorders in a large international cohort

PURPOSE

Heritable ectopic mineralization disorders comprise a group of conditions with a broad range of clinical manifestations in nonskeletal connective tissues. We report the genetic findings from a large international cohort of 478 patients afflicted with ectopic mineralization.

METHODS

Sequence variations were identified using a next-generation sequencing panel consisting of 29 genes reported in association with ectopic mineralization. The pathogenicity of select splicing and missense variants was analyzed in experimental systems in vitro and in vivo.

RESULTS

A total of 872 variants of unknown significance as well as likely pathogenic and pathogenic variants were disclosed in 25 genes. A total of 159 distinct variants were identified in 425 patients in ABCC6, the gene responsible for pseudoxanthoma elasticum, a heritable multisystem ectopic mineralization disorder. The interpretation of variant pathogenicity relying on bioinformatic predictions did not provide a consensus. Our in vitro and in vivo functional assessment of 14 ABCC6 variants highlighted this dilemma and provided unambiguous interpretations to their pathogenicity.

CONCLUSION

The results expand the ABCC6 variant repertoire, shed new light on the genetic heterogeneity of heritable ectopic mineralization disorders, and provide evidence that functional characterization in appropriate experimental systems is necessary to determine the pathogenicity of genetic variants.

GGCX mutations in a patient with overlapping pseudoxanthoma elasticum/cutis laxa-like phenotype

Pseudoxanthoma elasticum (PXE) is a multisystem disorder characterized by ectopic mineralization of connective tissues with primary manifestations in the skin, eyes and the cardiovascular system. The classic forms of PXE are caused by mutations in the ABCC6 gene encoding the ABCC6 protein, expressed primarily in the liver. Cutis laxa (CL) manifests with loose and sagging skin with loss of recoil. In 2009 we investigated a 19-year-old patient with overlapping cutaneous features of PXE and CL, together with alpha thalassaemia. Genetic analysis failed to identify pathogenic mutations in ABCC6. More recently we developed a gene-targeted panel of next-generation sequencing technology. This panel has 29 genes, 22 of which, including ABCC6 and GGCX, are associated with ectopic mineralization phenotypes. Mutation analysis in the patient identified two heterozygous GGCX mutations: c.200_201delTT in exon 2 and c.763G>A, p.V255M in exon 7. The GGCX gene encodes a γ-glutamyl carboxylase necessary for activation of blood coagulation factors in the liver. The p.V255M mutation was previously reported to result in reduced γ-glutamyl carboxylase activity in vitro, while the c.200_201delTT mutation is novel. Previous studies reported that mutations in GGCX cause overlapping PXE/CL skin phenotypes in association with or without multiple vitamin K-dependent coagulation factor deficiency. Our patient had loose redundant skin, moderate-to-severe angioid streaks and characteristic calcification of elastic structures in the mid dermis, consistent with PXE/CL overlap, but no coagulation abnormalities. Our studies expand the GGCX mutation landscape in patients with PXE-like phenotypes.

Usefulness of asthma predictive index in ascertaining asthma status of children using medical records: An explorative study

BACKGROUND

Frequent wheezing in original asthma predictive index (API) was defined by parental report of recurrent wheezing within 1 year during the first 3 years of life. The nature of frequent wheezing in children, particularly aged over 3 years, has not been studied. We aimed to assess the frequency and interval of wheezing to define frequent wheezing in ascertaining asthma for children using medical records.

METHODS

Among children who participated in a previous study (n = 427), all wheezing episodes documented in medical records were collected for children who had ≥2 wheezing episodes PLUS met one major criterion or two minor criteria of API. We compared the distribution of known risk factors for asthma between subjects having two consecutive wheezing episodes with shorter interval (≤1 year) compared to those with longer interval (1 to 3 years).

RESULTS

A total of 62 children met API at median age of 2.3 years. During follow-up period (median age: 11.3 years), a total of 198 wheezing episodes were observed. 81% of wheezing intervals were within 3 years from the earlier wheezing episode, including 60% within 1 year. Children who met API based on 1-year interval (n = 40) vs 1- to 3-year interval (n = 13) appeared to be similar in regard to the known risk factors for asthma.

CONCLUSIONS

Our exploratory study finding suggests that children who had frequent wheezing episodes with longer interval (<3 years) need to be considered to be determined as asthma cases when API is applied to retrospective medical records. Prospective studies with a larger sample size need to replicate this finding.

Does high relatedness promote cheater-free multicellularity in synthetic lifecycles?

The evolution of multicellularity is one of the key transitions in evolution and requires extreme levels of cooperation between cells. However, even when cells are genetically identical, noncooperative cheating mutants can arise that cause a breakdown in cooperation. How then, do multicellular organisms maintain cooperation between cells? A number of mechanisms that increase relatedness amongst cooperative cells have been implicated in the maintenance of cooperative multicellularity including single-cell bottlenecks and kin recognition. In this study, we explore how relatively simple biological processes such as growth and dispersal can act to increase relatedness and promote multicellular cooperation. Using experimental populations of pseudo-organisms, we found that manipulating growth and dispersal of clones of a social amoeba to create high levels of relatedness was sufficient to prevent the spread of cheating mutants. By contrast, cheaters were able to spread under low-relatedness conditions. Most surprisingly, we saw the largest increase in cheating mutants under an experimental treatment that should create intermediate levels of relatedness. This is because one of the factors raising relatedness, structured growth, also causes high vulnerability to growth rate cheaters.

Leveraging electronic health records to study pleiotropic effects on bipolar disorder and medical comorbidities

Patients with bipolar disorder (BD) have a high prevalence of comorbid medical illness. However, the mechanisms underlying these comorbidities with BD are not well known. Certain genetic variants may have pleiotropic effects, increasing the risk of BD and other medical illnesses simultaneously. In this study, we evaluated the association of BD-susceptibility genetic variants with various medical conditions that tend to co-exist with BD, using electronic health records (EHR) data linked to genome-wide single-nucleotide polymorphism (SNP) data. Data from 7316 Caucasian subjects were used to test the association of 19 EHR-derived phenotypes with 34 SNPs that were previously reported to be associated with BD. After Bonferroni multiple testing correction, P<7.7 × 10(-5) was considered statistically significant. The top association findings suggested that the BD risk alleles at SNP rs4765913 in CACNA1C gene and rs7042161 in SVEP1 may be associated with increased risk of 'cardiac dysrhythmias' (odds ratio (OR)=1.1, P=3.4 × 10(-3)) and 'essential hypertension' (OR=1.1, P=3.5 × 10(-3)), respectively. Although these associations are not statistically significant after multiple testing correction, both genes have been previously implicated with cardiovascular phenotypes. Moreover, we present additional evidence supporting these associations, particularly the association of the SVEP1 SNP with hypertension. This study shows the potential for EHR-based analyses of large cohorts to discover pleiotropic effects contributing to complex psychiatric traits and commonly co-occurring medical conditions.

Biobanks and personalized medicine

We provide a mini-review of how biobanks can support clinical genetics in the era of personalized medicine. We discuss types of biobanks, including disease specific and general biobanks not focused on one disease. We present considerations in setting up a biobank, including consenting and governance, biospecimens, risk factor and related data, informatics, and linkage to electronic health records for phenotyping. We also discuss the uses of biobanks and ongoing considerations, including genotype-driven recruitment, investigations of gene-environment associations, and the re-use of data generated from studies. Finally, we present a brief discussion of some of the unresolved issues, such as return of research results and sustaining biobanks over time. In summary, carefully designed biobanks can provide critical research and infrastructure support for clinical genetics in the era of personalized medicine.

Variations in the memory capability of nonvolatile memory devices fabricated using hybrid composites of InP nanoparticles and a polystyrene layer due to the scale-down

InP nanoparticles were formed using a solution method, and the InP nanoparticles that were embedded in a polystyrene (PS) layer were formed using the spin-coating method. The transmission electron microscopy images showed that the InP nanoparticles were randomly distributed in the PS layer. The measured capacitance-voltage (C-V) of the Al/InP nanoparticles embedded in the PS layer/PS/p-Si(100) device at 300 K showed a clockwise hysteresis of the C-V curve. Based on the C-V results, the origin of variations in the memory storage of nonvolatile memory devices that were fabricated using InP nanoparticles embedded in a PS layer due to the scale-down was described.

Characterization of antithrombotic activity of lumbrokinase-immobilized polyurethane valves in the total artificial heart

Thirty ng/mm2 lumbrokinase, a potent fibrinolytic enzyme, was immobilized in a Korean type total artificial heart (KORTAH) valve by photoreaction; polyallylamine was used as a photoreactive linker. Lumbrokinase-immobilized polyurethane valves were then fitted to the total artificial hearts of 3 healthy 50 kg lambs. In the control lamb, the valves were untreated; in one other, only valves on the right were treated; and in the remaining animal, only those on the left. Implants were in place for up to 3 days, and cardiac output was 5 L/min. To facilitate thrombus formation, low doses of heparin were administered. In the control lamb, thrombi was observed only in the inlet parts of the valves. In the other 2 experiments, thrombi formed in untreated control valves but not in lumbrokinase treated valves. The grade of thrombus formation in untreated valves was 1.06+/-1.37 versus 0+/-0 in the treated part by one-sided Student's t-test (p < 0.1). After implantation, fibrinolytic activity was only observed in treated valves by fibrin plate methods. The proteolytic activity of the treated valves was 3 times higher than that of untreated valves using the azocasein method. These data show that lumbrokinase treated polyurethane valves lead to decreased thrombus formation in vivo and that their biocompatibility is therefore greater than that of untreated valves.

Protective effect of nicotinamide and 3-aminobenzamide on islet cell damage induced by gamma-interferon and tumor necrosis factor

Mouse islet cell monolayers were damaged when cultured for five days in a medium containing 200 U/ml of recombinant murine interferon-gamma (IFN-gamma) and 300 U/ml of recombinant tumor necrosis factor (TNF). The cells formed granular clusters and ultimately floated in the medium; the floating cells proved to be dead by the trypan-blue dye-exclusion method. When 20 mM of nicotinamide or 5 mM of 3-aminobenzamide was supplemented to the medium, islet cell monolayers remained in the presence of the cytokines. 51Cr release studies showed that specific 51Cr release during five-day incubation with 200 U/ml of IFN-gamma and 300 U/ml of TNF was 30 +/- 4% (mean +/- SE). In a medium containing 20 mM of nicotinamide, together with IFN-gamma and TNF, specific 51Cr release was significantly reduced (12 +/- 3%, p less than 0.01). 3-aminobenzamide was effective at the level of 5 mM; specific 51Cr release was 2 +/- 5% (p less than 0.01). These results suggest that the mechanism by which IFN-gamma and TNF damage islet cells may be similar to that of streptozotocin and/or alloxan.

[Statistical analysis of Marfan's syndrome]

To evaluate the ocular complications of Marfan's syndrome which cause severe visual disturbance, we retrospectively investigated 104 patients (208 eyes) with Marfan's syndrome. Dislocation of the lens, the most frequent ocular manifestation, was detected in 151 eyes (72.6%). There were 33 eyes with a visual acuity 0.1 or less. In this group, we found retinal detachment in 12 eyes (36.4%) and glaucoma in 5 eyes (15.2%) as the causes of visual disturbance. Among 17 eyes with retinal detachment, 5 eyes (29.4%) had horizontally dislocated lens. On the other hand. The lens dislocation in a downward direction was found in 5 (22.7%) of 22 eyes with glaucoma. No lens dislocation in an upward direction was found in eyes with glaucoma. The incidence of retinal detachment in aphakic eyes (5/31, 16.1%) was higher than that in the phakic group (16/177, 9.0%). In only 2 (3.6%) of 56 eyes, did the lens dislocation become markedly worse during the observation period. From these data, we re-confirmed that retinal detachment and glaucoma are the most important ocular complications of Marfan's syndrome leading to severe visual disturbance. The decision to operate on the dislocated lens should be made cautiously.

Prophylactic effect of tea on pathogenic microorganism infections to humans and animals. (II). Protozoacidal effect on Toxoplasma gondii in vitro and mice

The trophozoites of Toxoplasma gondii strain (RH) obtained from the peritoneal exudate of infected mice were treated with tea in various concentrations of 0.5, 1, 3 and 5% for 0.5, 1 and 3 hours, respectively. After treatment, they were intraperitoneally inoculated into the mice to observe the protozoacidal effect of tea. The results obtained are as follows: 1) Oolong tea and green tea had stronger protozoacidal effect than black tea. 2) The lowest and effective concentration of tea tested to kill Toxoplasma was 0.5%. 3) A half hour was not enough for tea in any concentration tested to kill the parasites completely. 4) Phosphate buffer solution and normal saline were unable to destroy the protozoa, but distilled water could destroy them like tea.

Immunization of rabbits with zeolite absorbed Trypanosoma gambiense inactive vaccine

T. Gambiense was treated with natural zeolite, a very powdery mineral material which has strong absorptive capacity from the cationic exchangeable properties, and kept at 4 degrees C for 3 days. Rabbits injected with this inactivated vaccine were completely protected from a challenge inoculation of homologous viable parasites. Collected immune sera by weekly intervals from the immunized animals were tested for their ability to agglutinate trypanosomes. Serum antibodies were shown high titers 3 weeks post-inoculation, i.e., 1:512, and plateau of this titer was persistent up 3-4 weeks. For the experiment of passive protective effects of rabbit immune sera, mice were inoculated with 100 viable T. Gambiense by subcutaneous or intracerebral routes and then immediately performed two injection doses of 0.1 ml antiserum at intervals of 24 hours by subcutaneous. The protective ability was remarkable at the first to second weeks after the last immunization and then slightly decreased although a high level of agglutination titer remained in immune serum.

Prophylactic effect of tea on pathogenic micro-organism infection to human and animals. (1). Growth inhibitive and bacteriocidal effect of tea on food poisoning and other pathogenic enterobacterium in vitro

0.5% tea powder of Oolong tea, green tea and black tea, respectively added to Tryptic soy agar (TSA) plates prepared non aseptically could inhibit the growth of colonies of St. aureus and airborne bacteria, but only very few fungi colonies. 0.5% tea powder of oolong tea, green tea and black tea, respectively added to Tryptic soy agar (TSA) plates prepared non aseptically could also inhibit the colonial growth of V. cholerae, V. parahaemorrhagiae, Sal. dysenteriae, Sal. typhi, Sal. paratyphi A and B. The suspension (10(-3) approximately 10(-4)) of E. coli could inhibit the colonial growth. 3% suspension of oolong tea, green tea, and black tea, respectively could kill V. cholerae and V. parahaemorrhagiae in 30 minutes. 3% suspension of oolong tea and green tea, respectively could kill Sal. Typhi B.

Protective effect of zeolite absorbed Trypanosoma gambiense inactive vaccines on mice

Inactive T. gambiense vaccines treated with strong absorbent natural zeolite and kept at 4 degrees C for 3 days were injected into mice. After 2 weeks, 75% of the white mice which had received single injection survived, 85% of double injections survived challenge with 100 parasites separated from T. gambiense-infected mouse blood. However, the survival rats of the inoculated mice challenged after 3 weeks were 55% (one injection) and 80% (two injections) respectively. The mice were challenged 2 weeks after they were inoculated with vaccines made in the same way as mentioned above except that the prepared time was lengthened to 6 days. The total survival rates were 67.4% (one injection) and 85% (two injections) and these challenged 3 weeks after inoculation were 50% (one injection) and 80% (two injections). Mice not surviving in the experimental groups lived longer by 3--4 days than those in the controlled ones which had no survivors at all. Inactive vaccines prepared with artificial zeolite showed little protective effect on mice.

A vaccine and immune serum for ascites tumor of mice and therapy of skin tumors

Of the 16 dyes studied, methylene blue med (MBM) was found to be the least and the most immunogenic either the dye-prepared vaccine or the dye solution injected simultaneously with ascites tumor (AT) cell suspension. The effective dosages of MBM ranged from 0.2 ml of 0.1% to 0.1 ml of 1%, i.e., 0.2-1.0 mg per mouse, weighed at 15-20 gm. Rabbits immunized with MBM-prepared vaccine produced specific antibody to AT in 2-3 weeks. Antisera produced by intraperitoneal injection were more effective than those produced by subcutaneous injection. Both rabbit immune serum and MBM dye solution were found to have therapeutic value in treatment of skin tumors induced by AT cell suspensions.

An international survey of leptospiral agglutinin of dogs by RMAT

FRom 1970 through 1973, the author used RMAT to examine the canine leptospiral antibodies against 10 serotypes in 12,374 attended dogs, 1,855 stray dogs and 480 house dogs in 24 countries. Among the 10 serotypes, L. icterohaemorrhagiae and L. canicola were the most prevalent. Positive rates were in the following order: Peru 26.3%, Chile 18.4%, Turkey 17.4%, Austria 16.0%, Korea 15.0%, Cina (Taiwan) 11.4%, Japan 9.8%, Brazil 7.7%, United States 5.5%, United Kingdom 4.5%, Italy 3.5%, Germany 2.0%, and Canada 0.4%. Negative results were obtained in Australia, Dominica, Ecuador, Ethiopia, Fiji, Indonesia, Iran, Malta, Philippines, Sweden and Thailand. Positive rates on different continents were: South America 11.1%, Asia 10.1%, Europe 3.4%, North America 2.4%, Oceania and Africa (Ethiopia) 0%. Negative results were obtained against either L. icterohaemorrhagiae or L. canicola in samples from most tropical countries. Lower positive rates were seen during summer in Korea and Japan. Positive reactors were detected against other serotypes, viz., L. grippotyphosa, L. australis A, L. pyrogenes, L. bataviae, L. autumnalis, L. hebdomadis and L. javanica. Sex, physical condition and vaccination status as factors in the presence of antibodies were reviewed.

Experimental transmission of Japanese encephalitis virus by Culex tritaeniorhynchus and C. fuscocephalus

Experimental transmission of Japanese encephalitis virus from swine to baby chicks was accomplished using Culex tritaeniorhynchus and Culex fuscocephalus, two of three mosquito species in Taiwan from which the virus has been recovered in nature. Whereas neither species had become infective by the twelfth day, one of ten C. fuscocephalus and 11 of 51 C. tritaeniorhynchus were infective by the seventeenth day of extrinsic incubation as verified by viraemia in chicks fed upon by potentially infective mosquitoes. The highest transmission rate obtained was 81% for C. tritaeniorhynchus on the twenty-first day of extrinsic incubation.

An investigation of canine antileptospiral antibodies in Japan

From 1970 through 1973, blood samples of 7113 attended dogs and 1615 stray dogs in 50 cities of Japan were examined for leptospiral antibodies by RMAT on filter paper specimens. Results were as follows: 1. Prevalences of antibodies against L. icterohaemorrhagiae and L. canicola in attended dogs in 50 cities ranged from 22.5% to 0% with an average of 9.8%. Those of stray dogs in 8 cities ranged from 52.5% to 0% with an average of 21.7%. 2. 64 and 37 of 7113 attended dog sera reached positively only against either L. icterohaemorrhagiae and L. canicola, respectively. 595 of 7113 attended dog sera reacted positively against both antigens. 3. In 820 attended dog sera tested against 8 leptospiral serotypes, 57 had antibodies against L. icterohaemorrhagiae, 52 against L. canicola, 2 against L. australis A, 10 against L. pyrogenes and 2 against L. grippotyphosa. 4. The prevalence of antibodies was twice as much in male dogs as in females. The prevalence in a healthy group was only half that of a sick group. Attended dogs below 4 years old had a higher antibody prevalence than any other age. The prevalence of antibodies in summer was lower than for any other season.

Studies on the susceptibility of water buffaloes to Leptospira

Eight mature farming type, Taiwan, water buffaloes were inoculate with L. australis A while six received L. canicola. Before inoculation all animals were negative to the microscopic-agglutination test (agglutinationlysis test) using the above species as antigen. No sign of clinical leptospirosis was observed although four animals developed temperatures. Cultures made from buffalo blood, kidneys and urine and from blood of guinea pigs inoculated with kidney emulsion and urine from the inoculated buffalo were all negative for leptospiral organisms. Blood samples drawn from the water buffalo 2, 3 and 4 weeks post inoculation were negative to the microscopic-agglutination test except for one animal. Blood from the animal taken two weeks post-inoculation was positive at 1:100 dilution with L. australis A antigen but that taken at 3 and 4 weeks was negative.

Serum fractions inhibitory to the growth of Leptospires

It is known that the growth inhibitory substance of animal sera on Leptospires exists in the albumin fraction. Since the globulin fraction obtained from animal sera having growth inhibitory property may support, though variable individually, some degree of leptospiral growth, it may be added, with 5% of pooled rabbit serum, to the medium to be used for the propagation of Leptospires.

The Influence of CO(2) Supply on Colonial Formation of Leptospires

The colonial formation of three serotypes of Leptospires on Cox's solid medium was promoted by microaerophilic incubation of one to three per cent of CO(2) supplied by carbon dioxide cylinder, sodium carbonate oxalic acid, and candle method. In anaerobic incubation Leptospira pomona grew the same as with CO(2) incubation. The pH of the medium was an important influence on the rate of colonial formation of Leptospires. Addition of hemoglobin and inactivation of rabbit serum was not an essential condition for rapid colonial formation. It was found that variation in the morphology of leptospiral colonies occurred with hemoglobin from different species and individuals.