Obstructive sleep apnea in relation to beat-to-beat, reading-to-reading, and day-to-day blood pressure variability

We investigated blood pressure (BP) variability as assessed by beat-to-beat, reading-to-reading and day-to-day BP variability indices in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). In 786 hospitalized hypertensives (mean age, 53.2 years; 42.2% women), we performed 10-min beat-to-beat (n = 705), 24-h ambulatory (n = 779), and 7-day home BP (n = 445) measurements and the full overnight polysomnography. Mild, moderate and severe OSAHS were defined as an apnea-hypopnea index of 5-14, 15-29, and ≥ 30 events per hour, respectively. BP variability indices including variability independent of the mean (VIM), average real variability (ARV), and maximum-minimum difference (MMD), were compared across the OSAHS severity groups. In univariate analysis, beat-to-beat systolic VIM and MMD, reading-to-reading asleep systolic and diastolic ARV and MMD increased from patients without OSAHS, to patients with mild, moderate and severe OSAHS. This increasing trend for beat-to-beat systolic VIM and MMD remained statistically significant after adjustment for confounders (P ≤ 0.047). There was significant (P ≤ 0.039) interaction of the presence and severity of OSAHS with age and body mass index in relation to the beat-to-beat systolic VIM and MMD and with the presence of diabetes mellitus in relation to asleep systolic ARV. The association was stronger in younger (age < 50 years) and obese (body mass index ≥ 28 kg/m²) and diabetic patients. None of the day-to-day BP variability indices reached statistical significance (P ≥ 0.16). BP variability, in terms of beat-to-beat systolic VIM and MMD and asleep reading-to-reading asleep systolic ARV, were higher with the more severe OSAHS, especially in younger and obese and diabetic patients.

Effects of ant nests on soil CH4 emissions from Syzygium oblatum communities of a secondary tropical forest

Exploring the effects of ant nests on soil CH4 emissions in the secondary tropical forests is of great scientific significance to understand the contribution of soil faunal activities to greenhouse gas emissions. With static chamber-gas chromatography method, we measured the dry-wet seasonal dynamics of CH4 emissions from ant nests and control soils in the secondary forest of Syzygium oblatum communities in Xishuangbanna. We also examined the linkages of ant-mediated changes in functional microbial diversity and soil physicochemical properties with CH4 emissions. The results showed that: 1) Ant nests significantly accelerated soil CH4 emissions, with average CH4 emissions in the ant nests being 2.6-fold of that in the control soils. 2) The CH4 emissions had significant dry-wet seasonal variations, which was a carbon sink in the dry seasons (from -0.29±0.03 to -0.53±0.02 μg·m-2·h-1) and a carbon source in the wet seasons (from 0.098±0.02 to 0.041±0.009 μg·m-2·h-1). The CH4 emissions were significantly higher in ant nests than in control soils. The CH4 emissions from the ant nests had smaller dry-wet seasonal variation (from -0.38±0.01 to 0.12±0.02 μg·m-2·h-1) than those in the control soils (from -0.65±0.04 to 0.058±0.006 μg·m-2·h-1). 3) Ant nests significantly increased the values (6.2%-37.8%) of soil methanogen diversity (i.e., Ace and Shannon indices), temperature and humidity, carbon pools (i.e., total, easily oxidizable, and microbial carbon), and nitrogen pools (i.e., total, hydrolyzed, ammonium, and microbial biomass nitrogen), but decreased the diversity (i.e., Ace and Chao1 indices) of methane-oxidizing bacteria by 21.9%-23.8%. 4) Results of the structural equation modeling showed that CH4 emissions were promoted by soil methanogen diversity, temperature and humidity, and C and N pools, but inhibited by soil methane-oxidizing bacterial diversity. The explained extents of soil temperature, humidity, carbon pool, nitrogen pool, methanogen diversity, and methane-oxidizing bacterial diversity for the CH4 emission changes were 6.9%, 21.6%, 18.4%, 15.2%, 14.0%, and 10.8%, respectively. Therefore, ant nests regulated soil CH4 emission dynamics through altering soil functional bacterial diversities, micro-habitat, and carbon and nitrogen pools in the secondary tropical forests.

New-onset hypertension as a contributing factor to the incidence of atrial fibrillation in the elderly

Hypertension and atrial fibrillation are closely related. However, hypertension is already prevalent in young adults, but atrial fibrillation usually occurs in the elderly. In the present analysis, we investigated incident atrial fibrillation in relation to new-onset hypertension in an elderly Chinese population. Our study participants were elderly (≥65 years) hypertensive residents, recruited from community health centers in the urban Shanghai (n = 4161). Previous and new-onset hypertension were defined as the use of antihypertensive medication or elevated systolic/diastolic blood pressure (≥140/90 mmHg), respectively, at entry and during follow-up on ≥ 2 consecutive clinic visits. Atrial fibrillation was detected by a 30-s single-lead electrocardiography (ECG, AliveCor® Heart Monitor) and further evaluated with a regular 12-lead ECG. During a median of 2.1 years follow-up, the incidence rate of atrial fibrillation was 7.60 per 1000 person-years in all study participants; it was significantly higher in patients with new-onset hypertension (n = 368) than those with previous hypertension (n = 3793, 15.76 vs. 6.77 per 1000 person-years, P = 0.02). After adjustment for confounding factors, the hazard ratio for the incidence of atrial fibrillation was 2.21 (95% confidence interval 1.15-4.23, P = 0.02) in patients with new-onset hypertension versus those with previous hypertension. The association was even stronger in those aged ≥ 75 years (hazard ratio 2.70, 95% confidence interval 1.11-6.56, P = 0.03). In patients with previous hypertension, curvilinear association (P for non-linear trend = 0.04) was observed between duration of hypertension and the risk of incident atrial fibrillation, with a higher risk in short- and long-term than mid-term duration of hypertension. Our study showed a significant association between new-onset hypertension and the incidence of atrial fibrillation in elderly Chinese. In an elderly Chinese population with previous and new-onset hypertension, we found that the new-onset hypertension during follow-up, compared with previous hypertension, was associated with a significantly higher risk of incident atrial fibrillation. In patients with previous hypertension, curvilinear association was observed between duration of hypertension and the risk of incident atrial fibrillation, with a higher risk in short- and long-term than mid-term duration of hypertension.

Changes in the CHA2DS2-VASC score as a predictor of incident atrial fibrillation in older Chinese individuals: the AF-CATCH study

Aims

Incidence of atrial fibrillation is highly associated with age and cardiovascular co-morbidities. Given this relationship, we hypothesized that the dynamic changes resulting in an increase in the CHA₂DS₂-VAS_C score over time would improve the efficiency of predicting incident atrial fibrillation on repeated screening after a negative test.

Methods and results

We investigated in an analysis of the AF-CATCH trial [quarterly vs. annual electrocardiogram (ECG) screening for atrial fibrillation in older Chinese individuals] data, the association between the changes in the CHA₂DS₂-VAS_C score from baseline to end-of-study visit and the risk of incident atrial fibrillation. Participants without a history of atrial fibrillation and with a sinus rhythm at baseline were randomized to the annual (usual) or quarterly 30 s (intensive) single-lead ECG screening groups. During a median follow-up of 2.1 years in 6806 participants, the incidence rate of atrial fibrillation increased from 4.2 per 1000 person-years in participants with a change in the CHA₂DS₂-VAS_C score of 0 to 6.4 and 25.8 per 1000 person-years in participants with a change in the CHA₂DS₂-VAS_C score of 1 and ≥2, respectively. A change in the CHA₂DS₂-VAS_C score of ≥2 was associated with a significantly elevated risk of incident atrial fibrillation.

Conclusions

Patients with substantial changes in the CHA₂DS₂-VAS_C score were more likely to develop incident atrial fibrillation, and regular re-assessments of cardiovascular risk factors in the elderly are probably worthwhile to improve the detection of atrial fibrillation.

Registration

URL: http://www.clinicaltrials.gov; Unique identifier: NCT02990741.

Antihypertensive Treatment and Central Arterial Hemodynamics: A Meta-Analysis of Randomized Controlled Trials

Background: Antihypertensive treatment may have different effects on central arterial hemodynamics. The extent of the difference in effects between various antihypertensive drugs remains undefined.

Methods: We conducted a systematic review and meta-analysis of randomized controlled trials that explored the effects of antihypertensive agents on both central and peripheral systolic blood pressure (SBP) and pulse pressure (PP) or central augmentation index, with a special focus on the comparison between newer [renin-angiotensin-aldosterone system (RAS) inhibitors and calcium-channel blockers (CCBs)] and older antihypertensive agents (diuretics and β- and α-blockers).

Results: In total, 20 studies (n = 2,498) were included. Compared with diuretics (10 studies), β-blockers (16 studies), or an α-blocker (1 study), RAS inhibitors (21 studies), and CCBs (6 studies) more efficaciously (P < 0.001) reduced both central and peripheral SBP by a weighted mean difference of −5.63 (−6.50 to −4.76 mmHg) and −1.97 mmHg (−2.99 to −0.95 mmHg), respectively. Compared with older agents, the newer agents also more efficaciously (P < 0.001) reduced central PP (−3.27 mmHg; −4.95 to −1.59 mmHg), augmentation index (−6.11%; −7.94 to −4.29) and augmentation (−3.35 mmHg; −5.28 to –1.42 mmHg) but not peripheral PP (p ≥ 0.09). Accordingly, the newer agents reduced central-to-peripheral PP amplification significantly less than the older agents (0.11 mmHg; 0.05 to 0.17 mmHg; P < 0.001).

Conclusion: Newer agents, such as RAS inhibitors and CCBs, were significantly more efficacious than older agents in their effects on central hemodynamics.

Continuous positive airway pressure adherence and blood pressure lowering in patients with obstructive sleep apnoea syndrome and nocturnal hypertension

PURPOSE

We investigated continuous positive airway pressure (CPAP) adherence and its association with the blood pressure (BP) and pulse rate changes in patients with obstructive sleep apnoea syndrome (OSAS) and hypertension.

MATERIALS AND METHODS

In a single-blind trial, patients were randomly assigned to CPAP or sham CPAP treatment for 3 months. We performed clinic, ambulatory and home BP measurements at baseline and during follow-up. CPAP adherence was assessed as the CPAP frequency per week and time per night. Non-adherence was defined as a CPAP use for <5 days/week or <4 h/night.

RESULTS

In the CPAP (n = 26) and sham CPAP groups (n = 21), the CPAP frequency was 5.5 and 4.8 days/week (p = 0.17), respectively, and the CPAP time was 5.0 and 4.1 h/night (p = 0.03), respectively. The corresponding prevalence of non-adherence was 46.2% and 66.7% (p = 0.16), respectively. The CPAP frequency but not time tended to be associated with the changes in BP and pulse rate at 3 months of follow-up, especially home systolic/diastolic BP in the CPAP group (3.2/1.3 mmHg greater reductions per 1 day increment, p ≤ 0.01). Adherent, compared with non-adherent patients, had greater reductions in BP or pulse rate at 3 months of follow-up. In the CPAP and sham CPAP groups combined, statistical significance was achieved for the adjusted between adherence and non-adherence differences in home systolic/diastolic BP (-5.0/-3.8 mmHg) and 24-h, daytime and night-time ambulatory pulse rate (-6.2, -7.8 and -4.4 beats/min, respectively, p ≤ 0.04).

CONCLUSION

CPAP adherence was associated with the BP lowering and pulse rate slowing effects, especially the CPAP frequency.

[Epidemiological characteristics of HIV infected pregnant women and exposed infants in Guangdong province, 2014-2017]

Objective: To analyze the epidemiological characteristics of HIV-infected pregnant women and exposed infant in Guangdong province and identify the factors associated with infant HIV infection through mother-to-child transmission. Methods: National Information System for Prevention of mother-to-child HIV Transmission and Early Infant Diagnosis Information Management Platform were used to collect the individual information about HIV-infected pregnant women and exposed infants who were delivered in Guangdong from January 1, 2014 to December 31 in 2017. The differences in pregnant women's demographic data, history of pregnancy and childbirth, the utilization of mother-to-child transmission prevention services and early infant diagnosis between the infected HIV exposed infants and uninfected HIV exposed infants were compared, and univariate and multivariate logistic regression analyses were conducted to identify the factors associated with mother-to-child HIV transmission. Results: Among 349 HIV infected pregnant women, the proportions of the pregnant women whose HIV infection status were confirmed before pregnancy, during pregnancy and at or after childbirth were 30.4% (106/349), 49.6% (173/349) and 20.0% (70/349) respectively. The proportions of those with sexual partners whose HIV infection status were unknown and those receiving no antiviral treatment were 39.5% (138/349) and 13.2% (46/349) respectively. Among the HIV exposed infants, the mother-to-child transmission rate was 4.2%(15/353), the HIV exposed infants had the first or second early diagnosis tests within 44 (P(25)-P(75): 42-50) days and 96 (P(25)-P(75): 92-106) days after birth, respectively. Univariate logistic regression analysis indicated that the risk for mother-to-child HIV transmission increased in those whose HIV infection status were confirmed at or after childbirth compared with before pregnancy (OR=5.72, 95%CI: 1.52-21.61) and in the group that antiviral treatment was given to either mothers or infants compared with the group that antiviral treatment was given to both mothers and infants (OR=33.56, 95%CI: 9.04-124.55), while there was lower mother-to-child HIV transmission risk in artificial feeding group compared with breast feeding group (OR=0.07, 95%CI: 0.01-0.76). Conclusion: The risk of mother-to-child HIV transmission in Guangdong can be effectively reduced by the measures of early diagnosis, antiviral treatment and artificial feeding as well as the improvement of mother-to-child transmission prevention service.

[Current status of reproductive health and its occupational influencing factors among female medical staff in a provincial maternal and child health hospital]

Objective: To investigate the current status of reproductive health among the female medical staff in a provincial maternal and child health hospital and analyze the occupational influencing factors for reproductive health, particularly the effects of high-intensity work, work shift, chemical poisons, and physical and biological factors on reproductive health, and to provide a scientific basis for developing related intervention measures and promoting the reproductive health of professional females. Methods: A reproductive health questionnaire was designed in terms of age, type of work, professional title, education level, working hours, working strength, and the reproductive health of female staff to analyze the current status of reproductive health, working strength, and occupational hazardous factors. The female medical staff in the provincial maternal and child health hospital completed the questionnaire on the internal network of the hospital voluntarily. Results: Of all respondents, 19.46% had a history of miscarriage, 5.90% visited the hospital due to infertility, 21.31% had irregular menstruation within the last 3 months, and 30.57% had reproductive system disease; 72.28% of the investigated medical staff often worked at night, 47.25% often worked overtime (more than 3 days a week) , and 22.27% worked over 8 hours daily. The respondents who often worked overtime had a significantly higher prevalence of reproductive system disease than those who did not often work overtime (χ(2)= 58.65, P<0.01) . The respondents who often worked at night had a significantly higher rate of miscarriage than those who did not work at night (χ(2)=41.57, P<0.01) . In all respondents, 87.08% were often exposed to chemical injuries such as disinfectants, and 78.15% had contact with noise, radiation, and other physical injuries; the medical staff exposed to chemical and physical injuries had a significantly higher proportion of individuals with a history of miscarriage than the unexposed staff (χ(2)=10.04, P<0.01; χ(2)=13.30, P<0.01) . Conclusion: Much attention should be paid to the reproductive health of female medical staff in the provincial maternal and child health hospital, who have high working strength. The occupational hazard factors can be avoided by reasonably arranging the work schedule and creating a supportive environment to improve the reproductive health of female medical staff.

[Mental health problems among female staff in a provincial maternal and child health hospital: an investigation of 647 individuals]

Objective: To investigate the current status of depression and anxiety among female staff in a maternal and child health hospital, and to provide a basis for developing related prevention and intervention measures and promoting the mental health of female staff. Methods: The female staff from a provincial maternal and child health hospital completed a psycho-health questionnaire survey on Internet from June to October, 2016. The questionnaires used in the survey consisted of Patient Health Questionnaire (PHQ-9) , Generalized Anxiety Disorder Scale (GAD-7) , and Symptom Checklist-90 (SCL-90) . The distribution features of mental health problems such as depression and anxiety were analyzed according to the results: of the questionnaire survey. Results Of all female staff surveyed, 42.04% showed depression symptoms, 28.90% showed anxiety symptoms, and 26.12% showed comorbid symptoms of depression and anxiety. Moderate or severe depression (anxiety) was mainly distributed among the female staff with comorbid symptoms (90.63% and 97.01%, respectively) . There were significant differences in the distribution of moderate or severe anxiety symptoms between the medical staff and nursing staff (χ(2)= 5.81, P=0.05) and between those with intermediate and junior professional titles (χ(2)=7.99, P=0.018) . As for SCL-90 results, the total score, total average score, and scores on factors of somatization, compulsion, interpersonal sensitivity, depression, and anxiety in the female staff with comorbid symptoms, moderate or severe depression, and moderate or severe anxiety were significantly higher than the national norm (P<0.01) , while the scores on paranoid and psychotic factors were significantly lower than the national norm (P<0.01) . The numbers of cases of positive factors were significantly higher in the female staff with comorbid symptoms than in the female staff with a single symptom and asymptomatic female staff (both P<0.01) , and positive cases were mainly distributed in depression, interpersonal sensitivity, compulsion, anxiety, and somatic factors. Conclusion: The prevalence of depression and anxiety is high among female staff in the maternal and child health hospital, mainly characterized by comorbid symptoms of moderate or severe depression and anxiety. Comorbidity is accompanied by mental health problems such as interpersonal sensitivity, obsessive compulsion, and physical discomfort. Corresponding measures are needed for the prevention and intervention of mental health problems among female staff in the maternal and child health hospital.

Mutation L437P in the 2B domain of keratin 1 causes diffuse palmoplantar keratoderma in a Chinese pedigree

Diffuse palmoplantar keratoderma (DPPK) is an autosomal dominant genodermatosis characterized by uniform hyperkeratosis of the palm and sole epidermis. This disorder can be caused by mutations in the genes keratin 1, keratin 9, keratin 16, desmoglein 1 and plakoglobin. Here we present a DPPK Chinese pedigree and identify the aetiology as a novel missense mutation, L437P, located in a highly conserved helix motif in domain 2B of KRT1. Functional analysis shows that overexpression of the L437P mutant in cultured cells leads to abnormal intermediate filament networks and filament aggregation. This gain-of-function mutation highlights the role of domain 2B in mediating filament assembly.

Interleukin-6 is essential for Staphylococcal exotoxin B-induced T regulatory cell insufficiency in nasal polyps

BACKGROUND

The pathogenesis of nasal polyps is still unclear. There is increasing evidence indicating that Staphylococcal aureus (S. aureus) is associated with the formation of nasal polyps, but the mechanism has not been well documented to date.

METHODS

We stimulated cultured nasal polyps and turbinate tissues with Staphylococcal exotoxin B (SEB), detected the expression of pro-inflammatory cytokines (IL-2, IL-6, and IL-8) and T cell cytokines (IFN-gamma, IL-4, IL-5, IL-10, and IL-17) in the supernatants, and evaluated mRNA expression (T-bet, GATA-3, Foxp3, and RORgammat) and frequencies of CD4+CD25+ T regulatory cells (Tregs) in nasal tissues. We also evaluated the effects of blocking IL-6 with monoclonal antibodies to T cell profiles in cultured nasal tissues stimulated by SEB.

RESULTS

Levels of IL-6, IFN-gamma and IL-4 increased significantly in SEB-stimulated nasal polyps. Meanwhile, mRNA expressions of T-bet and GATA-3 were significantly up-regulated, while Foxp3 was inhibited and the frequencies of CD4+CD25+ Tregs were decreased after SEB stimulation. After blocking IL-6, the levels of IL-10 and Foxp3 mRNA, as well as the frequencies of CD4+CD25+ Tregs, were significantly increased, while IFN-gamma and IL-4 production and the mRNA expression of T-bet and GATA-3 were significantly inhibited.

CONCLUSIONS

SEB is able to modulate pro-inflammatory factors, T-helper type 1/Th2 profiles and suppress Treg activity in cultured nasal polyps, which were rescued by blocking IL-6 activity. Therefore, IL-6 is essential for SEB-induced Treg insufficiency in nasal polyps.

[Mutation screening of 20 candidate genes located in chromo-some 5q31-5q32 for DFNA52 locus]

Previously, we mapped the DFNA52 (OMIM: 607683) locus to an 8.8 cM interval between STR D5S2056 and D5S638 on human chromosome 5q31.1-q32 in a large consanguineous Chinese family with congenital sensorineural hearing loss. Positional candidate cloning approach was applied to analyze the candidate genes in this region. We analyzed 20 genes according to cochlear expression pattern, which were also located in the DFNA52 interval as candidate genes. Sequencing of the coding and splice site regions of these genes did not reveal any potentially pathogenic mutations segregating with the disease, implying that none of these genes are likely virulence gene for DFNA52.

Foxp3+ T regulatory cells (Tregs) are increased in nasal polyps (NP) after treatment with intranasal steroid

The pathogenesis of chronic rhinosinusitis (CRS) with nasal polyps(NP) is still poorly understood. To evaluate the role of Foxp3+ T regulatory cells (Tregs) in the pathogenesis and management of NP, we investigated the location and expression of Foxp3 in NP before and after treatment with intranasal steroid. NP specimens were obtained from 14 patients with NP before and after intranasal administration of mometasone (50 microg/day for 4 weeks). Foxp3 was detected by double immunofluorescence stain, quantitative reverse transcriptase polymerase chain reaction (RT-PCR), flow cytometry and western blot. The concentration of interleukin(IL)-10 in supernatants of homogenized tissue was measured by enzyme-linked immunosorbent assay (ELISA). We found that Foxp3 and IL-10 were downregulated in NP compared to the control mucosa (P<0.05). Foxp3 and IL-10 expression were increased significantly after intranasal steroid treatment (P<0.05). And Foxp3 was tightly correlated with IL-10 in NP (P<0.05) after treatment. These data suggest that Foxp3 is downregulated in NP and intranasal steroid attenuates the chronic inflammatory response by enhancing the expression and function of Foxp3 in NP.

Characterization of reflection intermittency in a composite granular chain

The physical factors controlling the power-law behavior of impact energy in a composite granular chain remain elusive. Based on event-driven simulations and the on-off intermittency of wave reflections, we obtain the probability distribution functions of the waiting time tau and the energy leakage DeltaE . They exhibit lognormal distributions, which together with the relationship between DeltaE and tau allow one to explain directly the power-law behavior of the confined energy. This work may be extended to higher dimensions and help us understand the complex dynamics in granular materials.

[Isolation, culture and cryopreservation of cells derived from fetal appendages]

OBJECTIVE

To investigate the optimal method for isolation, culture and cryopreservation of cells from fetal appendages, for the purpose of providing viable cells for tissue engineering, cell therapy and gene therapy.

METHODS

Trypsin dispersion method was used to isolate cells from human umbilical cord and placenta. The tissues from umbilical cord and placenta were cryopreserved with dimethylsulfoxide (DMSO) in different concentrations. Then the percentage of living cells in thawed tissues, and their micro-structure were observed and compared with fresh tissues under transmission electron microscope. The expression of cell immune phenotype before and after cryopreservation were detected with immuno-histochemistry method.

RESULTS

The percentage of living cells in human fresh umbilical cord was 67.0%, while that in cryopreserved umbilical cord was 23.4%, 55.5%, 48.8%, 31.8%, respectively in 5%, 10%, 15%, 20% of DMSO. The percentage of living cells in cryopreserved tissues was similar to that of fresh tissues when the volume percentage of DMSO was 10% (P > 0.05), and it was significantly different with that when volume percentage of DMSO was 5% and 20% (P < 0.01). The result by transmission electron microscope was coincident with the results shown above. The results were similar between placenta and umbilical cord. There was no obvious changes in immune phenotype of the tissue and cells after cryopreservation.

CONCLUSION

Cryopreservation with this method can isolate a large amount of cells from fetal appendages, with no changes in immune phenotype after cryopreservation, and the effect was best when the volume percentage of DMSO was 10%.

Crossover in the power-law behavior of confined energy in a composite granular chain

We present a numerical study of the impact energy decay in a composite granular chain containing two heavy and one light sections. We observe a marked crossover in the power-law behavior of the impact-energy decay. The average reflection frequency first increases with a decreasing acceleration, and arrives at its maximum at "crossing" time then decays almost exponentially. The analysis demonstrates that this phenomenon is related to the structural transition from compression to dilation state in both heavy-particle sections. The further calculations suggest the dependence relation of the power-law exponent (gammacb) in compression state on the mass ratio (m2/m1) and the Hertz law exponent (n) of the composite granular chain gammacb approximately (m2/m1)1/(n+1).

[Novel mutation of Y271H in EXT1 gene causes multiple exostoses]

OBJECTIVE

To explore the disease associated gene mutation of multiple exostoses by family analysis.

METHODS

Polymerase chain reaction and DNA sequencing were used to detect the mutation hot spot regions of EXT1 and EXT2 gene, while restriction fragment length polymorphism was performed to screen the mutation.

RESULTS

We found a novel heterozygous mutation c.811T ->C in EXT1 gene of patients, which resulted in the substitution of histidine for tyrosine at codon 271 in this hereditary multiple exostoses family. The mutation was not found in the unaffected family members, nor in the 100 unrelated normal individual, which was unreported before.

CONCLUSION

The novel mutation Y271H is the disease-causing mutation in the hereditary multiple exostoses family.

[Identification of the origin of marker chromosome by comparative genomic hybridization]

OBJECTIVE

To identify the origin of the marker chromosome in a patient with chromosome aberration, and to provide the precise genetic diagnosis.

METHODS

Comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH) were performed to detect the known small marker chromosome in this patient.

RESULTS

The small marker chromosome originated from chromosome 13 pter->q12.

CONCLUSION

CGH and FISH can be used to detect the small marker chromosome, which is convenient and quick in detecting the origin of small marker chromosome.

[Azoospermia factor microdeletion on Y chromosome in patients with idiopathic azoospermia or severe oligozoospermia]

OBJECTIVE

To investigate the correlation between male infertility and Y chromosome microdeletions of azoospermia factor (AZF) regions, and to establish a reliable genetic diagnosis in idiopathic infertile male patients with azoospermia or severe oligozoospermia.

METHODS

Multiplex PCR amplification of 6 sequence-tagged sites in AZF regions of the Y chromosome was examined among 100 normal karyotype male patients with azoospermia or oligozoospermia.

RESULTS

Four patients (4%) had Y chromosome microdeletions, the microdeletions of 3 patients were idiopathic azoospermic and those of the other 1 patient were secretory azoospermia.

CONCLUSION

The PCR-based Y chromosome microdeletion screening is simple and effective in the diagnosis of patients with severe male infertility. Microdeletion of Y chromosome is one of the major causes of severe dyszooospermia.

[Preimplantation genetic diagnosis of Duchenne muscular dystrophy by single cell triplex PCR]

OBJECTIVE

To detect two exons of Duchenne muscular dystrophy (DMD) gene and a gender discrimination locus amelogenin gene by single cell triplex PCR, and to evaluate the possibility of this technique for preimplantation genetic diagnosis (PGD) in DMD family with DMD deletion mutation.

METHODS

Single lymphocytes from a normal male, a normal female, two DMD patients (exon 8 and 47 deleted, respectively) and single blastomeres from the couples treated by the in vitro fertilization pre-embryo transfer (IVF-ET) and without family history of DMD were obtained. Exons 8 and 47 of DMD gene were amplified by a triplex PCR assay, the amelogenin gene on X and Y chromosomes were co-amplified to analyze the correlation between embryo gender and deletion status.

RESULTS

In the normal single lymphocytes, the amplification rate of exons 8 and 47 of DMD and amelogenin gene were 93.8%, 93.8%, and 95.3% respectively. The false positive rate was 3.3%. In the exon 8 deleted DMD patient, the amplification rate of exon 47 of DMD and amelogenin gene was 95.8%, and the false positive rate was 3.3%. In the exon 47 deleted DMD patient, the amplification rate of exon 8 of DMD and amelogenin gene was 95.8%, and the false positive rate was 0. In the single blastomeres, the amplification rate of exons 8 and 47 of DMD and amelogenin gene was 82.5%, 80.0% and 77.5%, respectively, and the false positive rate was 0.

CONCLUSION

The single cell triplex PCR protocol for the detection of DMD and amelogenin gene is highly sensitive, specific and reliable, and can be used for PGD in those DMD families with DMD deletion mutation.

[IT15 gene analysis in two pedigrees of Huntington's disease]

To investigate the relationship between the clinical features and (CAG)n trinucleotide repeats in two pedigrees of Chinese Huntington's disease (HD). Clinical and neuroimaging features, the age of disease onset and pattern of transmission of the patients were studied in the two pedigrees of HD. Genomic DNA of 42 family members was used for amplification of the (CAG)n repeats of IT15 gene by PCR. The numbers of (CAG)n were determined by electrophoresis through a 6% polyacrylamide gel and direct sequence analysis. Results showed that patients in pedigree 1 were absent of the typical triad of HD symptoms or caudate atrophy. A total of 9 (5 patients and 4 asymptomatic) out of 18 family members had 40-50 (CAG)n repeats in the IT15 gene. In pedigree 2, all the patients were characterized by a triad of symptoms, including motor disturbance, cognitive impairment and psychiatric features. Three patients and two asymptomatic relatives had more than 50 (CAG)n repeats in the IT15 gene. In conclusion, the clinical symptoms are partly determined by (CAG)n repeats in the IT15 gene. The age of onset was correlated with (CAG)n repeats over 50, and the phenomenon called "anticipation" was found to have played a role.

Association of PINK1 and DJ-1 confers digenic inheritance of early-onset Parkinson's disease

Mutations in genes encoding both DJ-1 and pten-induced kinase 1 (PINK1) are independently linked to autosomal recessive early-onset familial forms of Parkinson's disease (PD). We here report identification of a family with PD patients harboring novel heterozygous missense mutations in both PINK1 and DJ-1 genes encoding DJ-1A39S and PINK1P399L, respectively. In transfected cells, DJ-1 interacts with PINK1. PINK1P399L is less stable than the wild-type protein and is degraded via the ubiquitin-mediated proteasomal pathway. Expression of wild-type DJ-1 increased steady-state levels of PINK1, whereas expression of DJ-1A39S reduced steady-state levels of PINK1. Furthermore, co-expression of wild-type DJ-1 and PINK1 suppresses neurotoxin 1-methyl-4-phenylpyridinium (MPP(+))-induced death of dopaminergic SH-SY5Y cells. In contrast, co-expression of PD-associated DJ-1A39S and PINK1P399L significantly potentiated susceptibility of SH-SY5Y cells to MPP(+)-induced cell death. This study reports the first case of autosomal recessive PD with digenic inheritance and demonstrates that DJ-1 and PINK1 physically associate and collaborate to protect cells against stress via complex formation.

Identify female carriers and de novo mutations in deletional Duchenne/Becker muscular dystrophy families

By using multiple polymerase reaction (mPCR) and haploid analysis of 11 short tandem repeats (STRs) in dystrophin gene locus to identify female carriers in deletional DMD/BMD (Duchenne/Becker Muscular Dystrophy) families, valuable information can be gathered for prenatal diagnosis. In this article, de novo mutations were detected in two out of the four patients, and one of the four female members was identified as an obligate DMD gene carrier based on the haplotype analysis. Multiple PCR and STRs haploid linkage analysis are rapid, accurate, objective methods to identify female member status, and well suited for routine use in clinical laboratories engaged in DMD/BMD research for counseling, gene diagnosis and prenatal diagnosis. During mPCR analysis, the amplicon of exon 45 showed different electrophoresis mobility in different kinds of gels. Polyacrylamide Gels Electrophoresis (PAGE) was accurate and rapid for analyzing the products of mPCR, but the mobility of different amplicons need to be considered in data analysis.

[Hotspot of the mutations of keratin 9 gene in a diffuse palmoplantar keratoderma family]

OBJECTIVE

To identify the gene causing diffuse palmoplantar keratoderma in a Chinese pedigree.

METHODS

Four normal individuals and 3 patients in a diffuse palmoplantar keratoderma family and 10 unrelated control samples were recruited. The hotspot of the mutations of keratin 9 gene was analyzed by polymerase chain reaction and direct sequencing.

RESULTS

We found a G485A transition in ke ratin 9 gene, resulting in the substitution of glutamine for arginine at codon 162 in this diffuse palmoplantar keratoderma family. The mutation was not found in the 10 unrelated control samples and 4 normal individuals.

CONCLUSION

The mutation G485A found in keratin 9 gene is the disease-causing mutation in the diffuse palmoplantar keratoderma family.

[Genetic linkage analysis in localizing a gene of autosomal dominant familial dilated cardiomyopathy with conduction defect]

OBJECTIVE

To localize the gene of autosomal dominant familial dilated cardiomyopathy with conduction defect.

METHODS

A Chinese family which was diagnosed as dilated cardiomyopathy with conduction defect was studied. Venous blood (3 - 5 mL) from some family members was collected, and genomic DNA was extracted from the blood. Then whole genome wide scan was performed after excluding the known markers on the candidate loci (CMD1A, CMD1 E, CMD1F, and CMD1H) by two-point linkage analysis.

RESULTS

No significant evidence for linkage was found in the two point linkage analyses to the known markers in the analyzed family. And the whole genome wide scan showed the maximum LOD score reached 2.68 at marker D3S1614 ( at recombination fraction theta = 0).

CONCLUSION

The related gene in this kindred is located on 3q26 other than on CMD1A, CMD1H, CMD1E, and CMD1F.

Intracellular distribution, assembly and effect of disease-associated connexin 31 mutants in HeLa cells

Mutations in connexin 31 (Cx31) are associated with erythrokeratodermia variabilis (EKV), hearing impairment and peripheral neuropathy; however, the pathological mechanism of Cx31 mutants remains unknown. This study analyzed 11 disease-associated Cx31 variants and one non-disease-associated Cx31 variant and compared their intracellular distribution and assembly in HeLa cells and their effect on these cells. The fluorescent localization assay showed no gap junction plaque formation in the cells expressing the recessive EKV-associated mutant (L34P) and four hearing impairment-associated mutants (66delD, 141delI, R180X and E183K), significantly reduced plaque formation in the cells with five EKV-associated dominant mutants (G12R, G12D, R42P, C86S and F137L) and no obvious change in the cells with two other mutants (I141V and 652del12). Immunoblotting analysis showed that 12 mutated Cx31s, like WT-Cx31, are able to form the Triton X-100 insoluble complex; however, the quantity of Triton X-100 insoluble complex in the transfected HeLa cells varied among different Cx31 mutants. Additionally, the expression of five EKV-associated dominant mutants (G12R, G12D, R42P, C86S and F137L) caused cell death in HeLa cells. However, the five hearing impairment-associated mutants did not induce cell death. The above results suggest that disease-associated mutants gain deleterious functions differentially. In summary, disease-associated Cx31 mutants impair the formation of normal gap junctions at different levels, and the diseases associated with Cx31 mutations may result from the abnormal assembly, trafficking and metabolism of the Cx31 mutants.

[Stable suppression of beta-catenin expression in prostate cancer cell line by retrovirus mediated RNAi]

OBJECTIVE

To set up a prostate cancer cell line in which beta-catenin expression is stably suppressed and to investigate the role of Wnt/beta-catenin signaling pathway in prostate tumorgenesis.

METHODS

We select 3 sites in the complete coden sequence region of beta-catenin gene as the RNAi targets, ligated the annealed double pre-DNA strands into the retroviral vectors pSUPER-retro and transfected them into the packaging cells PA317, and then collected supernatant with retrovirus to infect DU145. After selection by puromycin and culture expansion, the stable cell clones were attained. Expression of the 2 target genes of Wnt/beta-catenin signaling pathway cyclinD1 and c-myc, was detected in the beta-catenin RNAi cells by Western blot. The effect of suppressing beta-catenin by RNAi on cell proliferation was quantified by methylthiazoletetrazolium (MTT) assay.

RESULTS

Western blotting and RT-PCR showed that the expression level of beta-catenin in the 2 stable cell clones apparently decreased. CyclinD1 and c-myc expression decreased in the beta-catenin RNAi cells. MTT showed that the cell number of beta-catenin expression suppression cell clones decreased significantly (P < 0. 05), suggesting the cell proliferation was prevented.

CONCLUSION

The beta-catenin gene stable suppression cell line was successfully established.

An improved mechanical technique for assisted hatching

BACKGROUND

Varied clinical outcomes of assisted hatching (AH) have been reported. We attempt to investigate whether the size of the zona opening created by AH is adequate for blastocyst hatching, and, if not, set up a new method to improve it.

METHODS

A new AH technique, long zona dissection (LZD), was established, and experiments were performed to compare the effects of different sizes of zona opening on complete hatching of blastocysts in mouse and human embryos in vitro.

RESULTS

The LZD technique can create a long zona slit on early embryos, even blastocysts, with the slit size beyond two-thirds of zona diameter. Compared with three-dimensional partial zona dissection, LZD can significantly enhance the hatching speed and the rate of complete hatching of mouse blastocysts (93.9%). All (100%) human blastocysts completely hatched following LZD; however, when the slit size after AH was about two-fifths of zona diameter, more of the larger inner cell masses (ICM) became trapped by the zona opening during hatching than the smaller ICM (53.3 versus 12.5%, P = 0.01).

CONCLUSIONS

Zona opening of moderate size following AH is inadequate for the completion of blastocyst hatching in vitro; in some cases, however, it can be significantly improved by LZD.

Identification of the alternative promoters of the KChIP4 subfamily

The subfamily of voltage-dependent potassium (Kv) channel interacting protein 4 (KChIP4) is made up of the auxiliary interacting protein of voltage-dependent potassium channels. In this study, the structure of four splicing variants of the human KChIP4 gene was analyzed. Three of the four isoforms of the KChIP4 gene, KChIP4.1, KChIP4.2 and KChIP4.4, were amplified from mouse and human fetal brain tissues by reverse transcription-polymerase chain reaction and then identified. Based on the bioinformatics analysis of the genomic sequences of the gene, we cloned and characterized two promoter fragments from the KChIP4 gene. One was a 325 bp fragment upstream of the 5' end of the KChIP4.1 mRNA sequence and the other was an 818 bp fragment located immediately at the 5' end of the KChIP4.4 variant. Both of them can initiate the transcription of the reporter gene in HT1080 cells and Sprague-Dawley (SD) rat fetal brain neurons, and they contain CG islands, except typical TATA boxes and CAAT boxes. This shows that the KChIP4 gene expression is regulated by an alternative promoter.

[Phenotype positioning on chromosomes in a patient with the syndrome of partial trisomy 7p21.2-->pter]

By using the techniques of human chromosome G-banding, high resolution banding and fluorescence in situ hybridization (FISH), we investigated a patient with the karyotype of partial trisomy 7p21.2-->pter. Combining with the comparative review of the clinical data in 14 cases with partial trisomy 7p syndrome from reported literatures,we searched for the correlation between the karyotype and the phenotype and between the karyotype and the associated gene in the patients with partial trisomy 7p syndrome. The results indicated that the 7p21.2-->p22 is the critical segment of partial trisomy 7p syndrome. The phenotypes of the genital malformation and the dislocation of hip joint are associated with the duplication of 7p15. The cardiac anomalies is resulted from the dysfunctions of several genes on the long arm of chromosome 7. The gene associated with the craniosynostosis may locate on the region of 7p21.2-->p21.3.

[Interaction of connexin 26 with the C-terminal of neuroendocrine specific protein]

OBJECTIVE

To screen and identify the interactive proteins with connexin 26 (Cx26) by the yeast two hybrid technique.

METHODS

The whole coding region of Cx26 (GJB2) gene was amplified from normal human genomic DNA by polymerase chain reaction (PCR). The "bait" Cx26 was then subcloned into the vector pGBKT7 plasmid of the MatchMaker Gal4 Two-Hybrid System 3 as a target to screen its interactive proteins ("prey") from the human fetal brain eDNA library by the yeast two hybrid technique. The false positive clones were discarded from the preys by one to one yeast two hybrid method between Cx26 and the preys. The DNAs of the preys were sequenced and BLAST analyzed against the GenBank, and also underwent other bioinformatics analysis.

RESULTS

The insert of one positive clone contained 145 amino acids residues that was identical to the C-terminal of the neuroendocrine specific protein (NSP) and the open reading frame of the insert was correct.

CONCLUSION

Cx26 is interacted with the C-terminal of NSP. NSP may participate in the process of Cx26 transportation, assembling the connexon, or influencing the functions of its connexons.

Anesthetic management for separation of craniopagus twins

We report the anesthetic management of a case of separation of craniopagus twins with unbalanced cross circulation and one twin with renal dysfunction. After intravenous induction, anesthesia was maintained with isoflurane inhalation and propofol infusion. Twin A survived but Twin B died after the surgery. The anesthetic problems during the operation are discussed.

Confirmation and refinement of a genetic locus for disseminated superficial actinic porokeratosis (DSAP1) at 12q23.2-24.1

BACKGROUND

Our previous study has identified two loci for disseminated superficial actinic porokeratosis (DSAP), but the genes responsible are still unknown.

OBJECTIVES

To narrow down the candidate regions and to assess candidate genes.

METHODS

A genome-wide scan and linkage analysis were carried out in a newly collected five-generation Chinese family with DSAP. In addition, six candidate genes were screened for possible DSAP-associated mutations.

RESULTS

DSAP in this family was associated with chromosome 12q. Fine mapping and haplotype construction refined the DSAP1 locus to a 4.4-cM interval. No disease-associated mutation was detected in CRY1, C4ST1, TXNRD1, HCF2, CMKLR1 or KIAA0789 genes.

CONCLUSIONS

The DSAP1 locus was localized to a 4.4-cM interval at chromosome 12q23.2-24.1. CRY1, C4ST1, TXNRD1, HCF2, CMKLR1 and KIAA0789 genes were not associated with DSAP1.

[Mapping of a pedigree with congenital nystagmus]

To investigate the relationship between X chromosome and obligatory gene of a pedigree with congenital nystagmus,we used the following markers: DXS1214, DXS1068, DXS993, DXS8035, DXS1047, DXS8033, DXS1192 and DXS1232. Genome screening and genotyping were conducted in this pedigree of congenital nystagmus, and linkage analysis by LINKAGE package was used to determine the potential location. The linkage was not found on the Xp (All LOD score <-1) but on Xq (the maximum LOD score=2). The related gene of this pedigree was located on the long arm of X chromosome. We demonstrate that Xq26-Xq28 is a common locus for CMN. It bring us closer to the identification of a gene responsible for X-linked CMN.

A new locus for autosomal dominant Charcot-Marie-Tooth disease type 2 (CMT2L) maps to chromosome 12q24

Charcot-Marie-Tooth disease (CMT) is one of the most common inherited neurological disorders with a prevalence estimated at 1/2500. The axonal form of this disorder is referred to as Charcot-Marie-Tooth type 2 disease (CMT2). Recently, a large Chinese family with CMT2 was found in the Hunan and Hubei provinces of China. The known loci for CMT1A, CMT2D, CMT1B (the same locus is also responsible for CMT2I and CMT2J), CMT2A, CMT2E, and CMT2F were excluded in this family by linkage analysis. A genome-wide screening was then carried out, and the results revealed linkage of CMT2 to a locus at chromosome 12q24. Haplotype construction and analyses localized this novel locus to a 6.8-cM interval between microsatellite markers D12S366 and D12S1611. The maximal two-point LOD score of 6.35 and multipoint LOD score of 8.08 for marker D12S76 at a recombination fraction (theta) of 0 strongly supported linkage to this locus. Thus, CMT2 neuropathy in this family represents a novel genetic entity that we have designated as CMT2L.

[A novel oligonucleotide arrays-based multiplex amplifiable probe hybridization technology]

Multiplex amplifiable probe hybridization (MAPH) has recently been developed to detect gene copy number changes in total genome in several genetic disease. Here we reported a novel oligonucleotide arrays-based multiplex amplifiable probe hybridization technology for DNA fragment copy number measurement. A set of amplifiable probes were prepared by locus-specific forward and reverse primers synthesized with the T7 and T3 promoter sites at their respective 5'-ends to the interest DNA fragments and purified by Qiagen PCR products purification kit. The set of probes were then hybridized with genome DNA immobilized on the nylon membrane. The selective probes after MAPH were collected with streptavidin coated magnetic beads and amplified by a biotin labeled universal primers. The biotinylated PCR products were then intended for hybridization to the corresponding oligonucleotide arrays consisted of 10 exons of DMD gene probes and positive,negative control probes immobilized on glass slides. After hybridization, the slides were washed by hybridization buffer and stained by streptavidin-Cy3. The hybridization fluorescence images were scanned by the ScanArray software and further quantitatively analyzed by the ImageJ software. Here we used oligonucleotide array technology to replace the agarose gel analysis for detecting the biotinylated PCR products so that extendable ability of parallel assay in our method had greatly been improved. One control female, one control male and one DMD patient were tested in this study. The results demonstrate the feasibility of high-throughput detection and relative quantification of DNA fragment copy numbers changes in total genome DNA combination of MAPH and high-density oligonucleotide arrays in single reaction.

[Silica nanoparticles modified as carriers for gene transfection]

The silica nanoparticles are modified by sodium iodine or sodium chloride with different concentration. Their ability to bind and protect plasmid DNA was demonstrated by agarose gel electrophoresis. The EGFP-N1 plasmid was transfected into HT1080 by combing silica nanoparticle. Eletromicroscope examine revealed that nanoparticle-DNA could enter into cells, these silica nanoparticles protect DNA against nuclease digestion and the GFP has an effective expression. In conclusion, these nanoparticles might be used as DNA carriers for gene transfection.

[In silicon cloning of the human TECTB gene]

The coding sequence of the mouse Tectb and chick Tectb gene were subjected to Blastn searching against the human dbEST and Htgs in NCBI. One BAC clone sequence(GenBank: AL157786) was obtained, which shows high homology to the two genes. We predicted the exons and introns in the homologous region of AL157786 using GENSCAN, MZEF and Blast 2 sequence program, and then assembled the predicted exons into the coding sequence of the human TECTB. The open reading frame of human TECTB gene is 990 bp composed of ten exons, which encodes a protein of 329 amino acids. Human TECTB gene shows 88.1% identity in 990 bp overlap with that of the mouse Tectb gene and the predicted polypeptide shows 94.2% identity in 329 as with the mouse beta-tectorin. The TECTB gene was mapped to human chromosome 10q25 by electronic-PCR.

[Genetic diagnosis and prenatal genetic diagnosis of fragile X syndrome]

In order to obtain a simple,fast,accurate and low-cost diagnosis method of fragile X syndrome, cytogenetic tests and molecular genetic tests were carried out with direct amplification of (CGG)(n) repeat sequence in 5' terminal of FMR1 gene by PCR and the cDNA sequence of FMR1 by RT-PCR from six mental retardation pedigrees. The proband of pedigree A with high expression of fragile X chromosome(35/273) was detected to be a full mutation patient of fragile X syndrome by the molecular genetic test. There is no expression of fragile X chromosome in the proband and his mother of pedigree B, which was further confirmed as a non-fragile X pedigree by the molecular genetic test. A male foetus of the pedigree C has fragile X chromosome(5/93), but the proband and his mother has no fragile X chromosome. By further detection using molecular genetic test, the male foetus is a full mutation patient of fragile X syndrome, his mother is a permutated carrier, and his brother is a mosaic patient. The proband of pedigree D has high expression of fragile X chromosome (17%), his sister also has expression of fragile X chromosome (5%). By further detection with molecular genetic test, the proband is a full mutation patient of fragile X syndrome,and his sister is a mosaic patient. The probands of pedigrees E and F of the mother were found with suspicions fragile X chromosome, being confirmed as the non-fragile X pedigrees by the molecular genetic test. The conclusion is that the analysis test with direct amplification of 5'j(CGG)n repeat sequence and cDNA sequence in FMR1 gene is simple,fast,low-cost and can be applied in screening, diagnosis and prenatal diagnosis of fragile X syndrome.

In vitro chondrogenesis of human bone marrow-derived mesenchymal progenitor cells in monolayer culture: activation by transfection with TGF-beta2

Bone marrow-derived mesenchymal progenitor cells are capable of chondrogenesis, making them a possible source of cells for cartilage tissue engineering. Because of this, we studied the effect of human transforming growth factor beta2 (TGF-beta2) on mesenchymal progenitor cell chondrogenesis in monolayer culture using gene transfection technology. A recombinant pcDNA3.1(+)/TGF-beta2 construct containing a full-length TGF-beta2 from a human placental cDNA library was created through gene cloning and DNA recombination. The construct was then lipofected into mesenchymal progenitor cells isolated from human bone marrow. RT-PCR, Western blotting, and immunohistochemistry analyses were performed to identify the expression of TGF-beta2 and cartilage-associated genes and proteins. The results showed that TGF-beta2 was expressed throughout the culture period. The transfected progenitor cells expressed and produced collagen type II and aggrecan 48 h after transfection, and the expression and synthesis were upregulated after 4 weeks. In contrast, the tested genes and proteins were not detected in non-transfected cells. This shows that transfection of pcDNA3.1(+)/TGF-beta2 into mesenchymal progenitor cells is able to provide transient and persistent expression of cartilage-specific genes and proteins, and suggests that the differentiation of human marrow-derived mesenchymal progenitor cells into chondrocytes in monolayer culture is feasible and may be induced by TGF-beta2.

A novel locus (DSAP2) for disseminated superficial actinic porokeratosis maps to chromosome 15q25.1-26.1

BACKGROUND

Disseminated superficial actinic porokeratosis (DSAP) is a chronic cutaneous disorder characterized by multiple superficial keratotic lesions surrounded by a slightly raised keratotic border. It develops in teenagers in sun-exposed areas of skin and usually follows an autosomal dominant inheritance pattern. The first locus for DSAP was localized to chromosome 12q23.2-24.1, but no gene responsible for porokeratosis has been identified to date.

OBJECTIVES

To determine whether DSAP is a genetically heterogeneous disorder and to identify the disease gene locus in a three-generation Chinese family with DSAP.

METHODS

Genetic linkage analysis was carried out in this family using 15 microsatellite markers between D12S1671 and D12S369 on chromosome 12q, followed by a genome-wide scan with 382 microsatellite markers from the autosomes.

RESULTS

Genetic linkage analysis with chromosome 12q markers suggested that the locus in this family is not linked to chromosome 12q. A genome-wide scan and fine mapping finally localized the locus for DSAP in this family to a 6.4-cM region between markers D15S1023 and D15S1030 at chromosome 15q25.1-26.1. This DSAP locus was named DSAP2.

CONCLUSIONS

The previous results and this study have shown that DSAP is a genetically heterogeneous disorder; a novel locus for DSAP, termed DSAP2, was mapped to a 6.4-cM region between markers D15S1023 and D15S1030.

Cloning of Human Myelin Protein Zero-like Genes by Bioinformatics Strategy

To clone novel myelin protein related genes, two human ESTs, which shared significant similarity with the human myelin protein zero gene, were found by the comparison of homologue between the cDNA coding region sequences of MPZ gene and the EST database of NCBI. An 801 bp EST contig was assembled, which was 100% identical with a 128 kb genomic sequence, mapped to 1q24. A 435 bp open reading frame (ORF) within the 801 bp contig was shown by computer analysis. Two primers designed according to the sequence of the contig, were coupled with the primers(lambdagt10-5 and gt10-5) on the sequences flanking cloning site of the cDNA library vector to amplify the cDNA library sequences by nested PCR. New primers, designed based on novel cDNA sequences, were used for the PCR amplification with lambdagt10-5 and gt10-5 in the same way as above. Finally, the human myelin protein zero like gene isoform I and II (MPZL1a, MPZL1b GenBank AF095727, AF092424) were cloned. Comparison of gene and protein structures between MPZL1 and MPZ revealed that MPZL1 is the second member of MPZ family. Mutation analysis of MPZL1 gene was performed in 24 Charcot-Marie-Tooth disease (CMT) families and 26 nonsyndrome deafness families, but no mutation was found.

[Translational frameshift may be occur in p11, an interaction protein of Cx31, in yeast]

Connexin 31 is a member of connexin family. The carboxy-terminal cytosolic domain of connexin 31 contains several potential phosphorylation sites. In this work, a yeast two-hybrid protein interaction screen have been used to identify proteins that bind to the carboxy-terminus of connexin 31, and the p11 protein, an unique member of S100 protein family, and one of the two subunits of the annexin II tetramer was isolated. Interestingly, from yeast two-hybrid AD's coding sequence, three different reading frames of p11 DNA sequence were found,which come from different AD plasmids. By constructing AD plasmids using p11 ORF or 5' UTR, the protein coding by p11 ORF bind to connexin 31, while polypeptides coding by three kinds of 5 UTR did not bind to connexin 31, suggesting a translational frameshift of p11 fusion protein. To construct baits by dividing connexin 31 C-terminus into two domain, the p11 binding domain of connexin 31 was found located between 206-237 codons. The plasmid Cx31CT-pGEX-4T-2 was constructed for expression and purification of GST-Cx31CT; and p11-pQE30 for expression and purification of 6xHis-p11. In vitro binding assay showed that recombinant Cx31 interacted with recombinant p11.

[Molecular clonging of the human dimethyglycine dehydrogenase-like gene (DMGDHL1) from the sarcosinemia critical region at 9q34]

Through the analysis of EST database, we obtained one human EST (GenBank: H28856) which showed significant similarity with the partial coding sequence of rat dimethylglycine dehydrogenase gene. This EST was mapped to 9q34 due to 95.6% identity with one genomic sequence (GenBank: AC002295). A pair of primers (HRP-1/HRP-2) designed on the sequence of the EST were coupled with the primers (lambda gt10-5/lambda gt10-3) on the vector flanking cloning site respectively to amplify the 5' and 3' cDNA beyond the EST. New primers designed based on novel cDNA sequence overlapped with the sequence within EST H28856 were used for amplification with lambda gt10-5 and lambda gt10-3 by the similar way as above untill a complete ORF was obtained. Finally, a 1,970 bp sequence (termed as dimethylglycine dehydrogenase like gene isoform I, DMGDHL1a) containing a 1,428 bp complete coding sequence from the live cDNA library and 1,475 bp sequence (isoform II, termed as DMGDHL1b) containing a 1,296 bp complete coding sequence from the fetas live cDNA library were obtained. Fourteen exons were identified in isoform I and the first nine exons of isoform II which shared with isoform I could be determined too. The last 105 bp cDNA sequence of isoform II could not be found in the public database, indicating a very large intron (> 123 kb) existed between exon 9 and exon 10 of isoform II. DMGDHL1 showed highly homology on both cDNA and amino acid level with rat dimethylglycine dehydrogenase (60% identity in 135 bp and 35% identity in 436 residues respectively). It was reported that human sarcosinemia gene was mapped at 9q34. Therefore it could be a good candidate gene for the sarcosinemia.

Identification of a locus for disseminated superficial actinic porokeratosis at chromosome 12q23.2-24.1

Disseminated superficial actinic porokeratosis is an autosomal dominant cutaneous disorder characterized by many uniformly small, minimal, annular, anhidrotic, and keratotic lesions. The genetic basis for this disease is unknown. Using a genomewide search in a large Chinese family, we identified a locus at chromosome 12q23.2-24. 1 responsible for disseminated superficial actinic porokeratosis. The fine mapping study indicates that the disseminated superficial actinic porokeratosis gene is located within a 9.6 cM region between markers D12S1727 and D12S1605, with a maximum two-point LOD score of 20.53 (theta = 0.00) at D12S78. This is the first locus identified for a genetic disease where the major phenotype is porokeratosis. The study provides a map location for isolation of a gene causing disseminated superficial actinic porokeratosis.

[Molecular cloning of one splicing form of human M6b cDNA]

X-linked, early onset Pelizaeus-Merzbacher disease (PMD) and part of X-linked spastic paraplegia are caused by mutation of proteolipid protein. M6b (U45955) partially cloned by Olinsky was considered as a member of PLP gene family. One novel fragment about 300 bp partially overlapped but differed in 5'part with U45955 was obtained by nested PCR. Assembly of the novel sequence with U45955 make a 1.642kb cDNA sequence with an open reading frame encoding 265 amino acids, which was verified by sequence of PCR products from brain cDNA library. The cDNA (termed M6ba) and its deduced peptide sequence showed significant similarity to murine M6b gene and protein (91.2% and 93.4% respectively). Northern blot, PCR amplification in cDNA library and EST analysis indicated that human M6b gene has at least three splicing forms. M6ba also showed significant similarity to PLP gene, they encode strongly hydrophobic protein and all their hydrophobic region are highly conserved. Gene structure analysis showed that the coding region of M6ba was composed of seven exons.