Differentiation of induced pluripotent stem cells to hepatocyte-like cells on cellulose nanofibril substrate

Differentiation of hepatocyte-like cells (HLCs) from human induced pluripotent stem cells (iPSCs) in vitro has great potential in regenerative medicine. Current protocol uses matrigel of animal origin as a substrate for the differentiation of iPSCs to HLCs. Use of an appropriate non-xenogenic substrate is very important for potential future clinical applications. Towards this goal, we used Cellulose Nanofibril (CNF) gel, a natural, non-toxic, biocompatible and biodegradable polymer in humans as a thin film substrate for the differentiation of iPSCs to HLCs. Here we demonstrated that CNF as a substrate film can efficiently differentiate human iPSCs to HLCs. We investigated the expression profile of the endoderm markers (SOX17 and CXCR4), hepatoblast markers (EpCAM and AFP) and mature hepatocyte marker (ASGPR1) by flow cytometry during the differentiation of iPSCs to HLCs on both CNF and matrigel substrates. We also tested the HLCs generated from both the substrates for the expression of hepatic markers such as A1AT, HNF4A, CYP450 isotypes by Real Time-PCR and its mature hepatocyte functions (lipid accumulation and albumin expression). Our results showed that the differentiated HLCs from both the substrates are comparable and expressed stage specific hepatocyte markers as well as functional maturity. We have demonstrated that CNF, a natural biomaterial, may be used in tissue engineering applications as a potential substrate for the differentiation of iPSCs to HLCs.

Klinefelter Syndrome: Clinical Spectrum Based on 44 Consecutive Cases from a South Indian Tertiary Care Center

BACKGROUND

Klinefelter syndrome (KFS) is the commonest chromosomal abnormality, yet remains largely underdiagnosed due to its varied clinical presentation. This study was done to understand the clinical spectrum in our population.

AIM

We intended to study the clinical characteristics of children and adults with KFS in our population. We also desired to identify any special features of Klinefelter variants.

METHODS

Forty-four patients with karyotype diagnosis of KFS during the time period 2007-2015 were included in this retrospective study. Clinical details and hormonal profile were obtained from hospital information system.

RESULTS

Our study population consisted of 17 (38.6%) participants in pediatric age group (age <18 years) and 27 (61.4%) adults. Clinical presentation prompting evaluation in the former group included cardiac anomalies (29.4%), dysmorphism (23.5%), hypogonadism (17.6%), developmental delay (11.8%), tall stature (11.8%), and cryptorchidism (5.9%). Among adults, 16 (59.2%) presented with hypogonadism and 9 (20.4%) had primary infertility. Six children (35.3%) had micropenis and four (three children, one adult) had unilateral undescended testis. Behavioral problems were detected in 19 (43.2%) subjects. Mean follicle stimulating hormone (FSH) and luteinizing hormone (LH) values were 38 IU/mL and 18 IU/mL, respectively. The classical 47 XXY karyotype was detected in 38 (86.4%) subjects and 6 (13.6%) had karyotype consistent with Klinefelter variants.

CONCLUSION

KFS was diagnosed only after 18 years of age in two-thirds of patients. Developmental delay, cardiac anomalies, behavioral abnormalities, and intellectual disabilities were the common presentations in pediatric subjects. Adults predominantly presented with hypogonadism. Individuals with Klinefelter variant karyotype sought medical attention predominantly for non-gonadal concerns.

Cardiac spectrum, cytogenetic analysis and thyroid profile of 418 children with Down syndrome from South India: a cross-sectional study

OBJECTIVE

To describe the spectrum of congenital heart disease in children with Down syndrome and their cytogenetic profile (and that of parents of those with translocation), and thyroid profile.

METHODS

A cross sectional study was conducted in 418 consecutive patients with Down syndrome attending the Department of Pediatric Genetics from a tertiary care centre in Kerala with a comprehensive Pediatric Cardiac Program, from November 2005 through April 2012. All children were offered cytogenetic analysis and were subjected to echocardiography. Parental karyotyping was offered for children with translocation type of Down syndrome. The thyroid profiles of all children were checked at the first visit and once every 6 mo during follow up.

RESULTS

Congenital heart disease was present in 256 (63.4 %) of 404 children with Down syndrome. Ventricular septal defect (72; 28.1 %) was the commonest, followed by atrio-ventricular septal defect (70; 27.3 %) and patent ductus arteriosus (43; 16.8 %). Surgical correction was accomplished in 104 (40.6 %) with excellent intermediate-term outcomes. Three hundred eighty seven of 418 children (92.6 %) underwent cytogenetic tests. The abnormalities included non-disjunction (340, 87.8 %), translocation (33, 8.5 %) and mosaicism (12, 3.1 %). Hypothyroidism was detected in 57 children (13.6 %).

CONCLUSIONS

The prevalence of congenital heart disease in children with Down syndrome in Kerala is the highest reported (63.4 %). Ventricular septal defect is the most common heart disease in the present study. The results highlight the changing attitudes of families towards the surgical correction of congenital heart disease in children with Down syndrome. Prevalence of hypothyroidism in Down syndrome in Kerala is 13.6 %.

Recurrence of Angelman syndrome in siblings: challenges in genetic counseling

The authors report a rare occurrence of two siblings with Angelman syndrome. Their karyotype revealed monosomy of chromosome 15 and a derivative chromosome 1 leading to Angelman syndrome. Their mother was a balanced translocation carrier involving chromosomes 1p and 15p. In her subsequent pregnancy, prenatal karyotype analysis was offered and the fetus was unaffected.

Variation in prevalence of chromosome 22q11 deletion in subtypes of conotruncal defect in 254 children

AIM

To determine the frequency of chromosomal aberrations particularly 22q11 deletion in Indian children ≤2 years with different types of conotruncal malformations and their association with abnormal aortic arch. Additionally, extracardiac features were also studied.

METHODS

Conventional cytogenetic and fluorescence in situ hybridization analyses were performed in 254 patients with conotruncal defects. Multivariable logistic regression analysis was performed to ascertain extracardiac features helpful in identifying high-risk patients with deletion.

RESULTS

Chromosomal abnormalities were identified in 52 (21%) children, of whom 49 (94%) showed 22q11 deletion and 3 (6%) had abnormalities of chromosome 6, 2 and X. None of the 11/254 children with tetralogy of Fallot with absent pulmonary valve showed deletion. The association of 22q11 deletion with right sidedness of the aortic arch varied with the type of conotruncal defect. The eight extracardiac features in combination showed 93.5% agreement with the presence of deletion.

CONCLUSION

The extracardiac features along with specific type of conotruncal defect and associated cardiovascular anomaly should alert the clinician for 22q11 deletion testing. However, if deletion analysis is not possible, specific extracardiac features (six dysmorphic facial features, thin long fingers and hypocalcemia) can help to identify an increased risk of 22q11 deletion in patients with conotruncal defect.

Partial trisomy 9q due to maternal 9q 17q translocation

Partial Trisomy 9q is a unique chromosomal anomaly with a distinctive phenotype. Only 5 cases have been reported in the literature till now. A large family with four affected children was studied in detail and was compared with the five previously reported cases. Determination of this novel balanced translocation in their family had helped us to offer prenatal diagnosis. This presentation is unique as even though partial trisomy 9q has been reported earlier with 9/17 translocations, our family is the first to have a translocation between q arms of chromosomes 9 and 17.

Genetic monitoring of the human population from high-level natural radiation areas of Kerala on the southwest coast of India. I. Prevalence of congenital malformations in newborns

In the densely populated monazite-bearing sands of Kerala, on the southwest coast of India, natural radiation dose rates range from 1. 0 to over 35.0 mGy per year in certain well-defined high-level natural radiation areas. As a part of the program to assess the health effects of this naturally occurring high-level natural radiation on human populations, monitoring of newborns is being undertaken to determine the incidence of congenital malformations. From August 1995 to December 1998, a total of 36,805 newborns were screened, including 212 (0.58%) stillbirths. There were 36,263 singletons, 536 (1.45%) twins, and 6 born as triplets. The overall incidence of malformations was 1.46% and was dependent on maternal age. The stillborns exhibited a very high malformation rate of 20.75% compared to 1.35% among the live births. Likewise, twins also had a higher malformation rate (2.99%) compared to singletons (1.44%). About 3.5% of the newborns originated from consanguineous marriages. Consanguinity also led to a relatively higher rate of malformations (1.97%) as well as of stillbirths (1.18%). About 92% of the deliveries took place by the maternal age of 29 years and only 1.2% among women above 34 years old. The stratification of newborns with malformations, stillbirths or twinning showed no correlation with the natural radiation levels in the different areas. Thus no significant differences were observed in any of the reproductive parameters between the two population groups based on the monitoring of 26,151 newborns from high-level natural radiation and 10,654 from normal-level natural radiation (dose rate </=1.5 mGy/year) areas of the Kerala coast.

Genetic monitoring of the human population from high-level natural radiation areas of Kerala on the southwest coast of India. II. Incidence of numerical and structural chromosomal aberrations in the lymphocytes of newborns

Cytogenetic studies using cord blood samples from newborns from high-level natural radiation areas of the Kerala coast in Southwest India have been in progress since 1986. A total of 963,940 metaphases from 10,230 newborns have been screened for various types of chromosomal aberrations. Comparison of 8,493 newborns (804,212 cells) from high-level natural radiation areas (dose rate >1.5 mGy/year) and 1,737 newborns (159,728 cells) from normal-level natural radiation areas (</=1.5 mGy/year) did not show any significant difference in the frequency of dicentrics, translocations, inversions or other types of aberrations known to be associated with radiation exposure. The cytogenetic studies were continued for constitutional anomalies using karyotype analysis, and scoring of 16,169 newborns has been completed. The overall frequency of constitutional anomalies was 4.95 +/- 0.55 per 1,000 newborns, which is comparable to the incidence reported in the literature. Within the limitations of sample size, the frequencies of total autosomal and sex aneuploids as well as structural anomalies were comparable between the high-level and normal-level natural radiation areas. A striking observation was the presence of rogue cells, the rarely occurring metaphases with a high level of chromosomal damage, which have not been reported previously among newborns.