Molecular responses of calreticulin genes to iron overload and bacterial challenge in channel catfish (Ictalurus punctatus)

Infection and inflammation are often accompanied by oxidative stress caused by the accumulation of reactive oxygen species which can be deleterious to the health of the host. Antioxidant defense mechanisms and components are crucial in limiting cellular and tissue-level damage and restoring homeostasis. In mammals, calreticulin is a 46-kDa multifunctional calcium binding protein of the endoplasmic reticulum that has many critical functions in the eukaryotic cell including regulation of intracellular calcium homoeostasis, lectin binding and chaperoning, and oxidative stress responses. In previous studies from our lab, the calreticulin gene was observed to be strongly upregulated in catfish during challenge with infectious Gram-negative bacteria. However, little is known about the function of this gene in teleost fish. The objective of this study, therefore, was to characterize the calreticulin gene from channel catfish, to determine its genomic organization, to profile its patterns of tissue expression, and to establish its potential for physiological antioxidant and immune responses in catfish after bacterial infection with Edwardsiella ictaluri and iron treatment. Our results indicate that there are at least three calreticulin related genes in the catfish genome. The three calreticulin genes are widely expressed in various tissues under homeostatic conditions and their expression showed significant upregulation following infection and/or iron level changes.     

Carbon dioxide insufflation causes upper urinary tract injury in the early period of an experimental vesicoureteral reflux model

Purpose

Ureteral reimplantation via pneumovesicum is a new aspect of vesicoureteral reflux management. We aimed to determine the effects of carbon dioxide (CO₂) insufflation on the upper urinary tract in an experimental model.

Materials and methods

Thirty New Zealand rabbits were allocated into five groups of six rabbits each. Right ureters were cannulated for CO₂ insufflation in four groups. The pressures and durations of CO₂ insufflation in the respective groups were as follows: Group A (10 mm Hg, 2 h); B (12 mm Hg, 2 h); C (10 mm Hg, 4 h); and D (12 mm Hg, 4 h) and control (E). Blood gas analysis, urea and creatinine levels were measured from renal veins and aorta. Histopathological evaluation of the renal parenchyma and ureters was scored.

Results

Significant histopathological changes were detected in the ipsilateral ureter and renal parenchyma exposed to CO₂ insufflation, predominantly observed in groups insufflated for longer durations, p < 0.05. Blood gases drawn separately from renal veins were significantly more acidotic, and serum urea and creatinine levels were increased in all the groups, p < 0.05.

Conclusions

CO₂ causes significant histopathological and biochemical changes in the early period. Long-term results are required to determine whether permanent renal injury occurs.     

Birth of a healthy infant after preimplantation genetic diagnosis by sequential blastomere and trophectoderm biopsy for β-thalassemia and HLA genotyping

Background

Preimplantation genetic diagnosis (PGD) is a widely used technique for couples at genetic risk and involves the diagnosis and transfer of unaffected embryos generated through in vitro fertilization (IVF) techniques.

Study design

For those couples who are at risk of transmitting a genetic disease to their offspring, preimplantation embryos can be selected according to their genetic status as well as human leukocyte antigen (HLA) compatibility with the affected child. Stem cells from the resulting baby's umbilical cord blood can be used for transplantation to the affected sibling without graft rejection.

Results

Here we report successful hematopoietic stem cell transplantation (HSCT) after the birth of a healthy infant, who was born after successful PGD testing with both cleavage stage and blastocyst stage biopsy for the purpose of diagnosis of β-thalassemia and HLA compatibility.

Conclusion

The specific feature of this work is not only to have the first successful HSCT achieved in Bulgaria after using preimplantation HLA typing technique, it also demonstrates how to accomplish this success via cross-border collaboration of different units, which makes the application of these sophisticated methods possible in hospitals not having the necessary equipments and expertise.     

DNA polymerase ζ generates tandem mutations in immunoglobulin variable regions

Low-fidelity DNA polymerases introduce nucleotide substitutions in immunoglobulin variable regions during somatic hypermutation. Although DNA polymerase (pol) η is the major low-fidelity polymerase, other DNA polymerases may also contribute. Existing data are contradictory as to whether pol ζ is involved. We reasoned that the presence of pol η may mask the contribution of pol ζ, and therefore we generated mice deficient for pol η and heterozygous for pol ζ. The frequency and spectra of hypermutation was unaltered between Polζ(+/-) Polη(-/-) and Polζ(+/+) Polη(-/-) clones. However, there was a decrease in tandem double-base substitutions in Polζ(+/-) Polη(-/-) cells compared with Polζ(+/+) Polη(-/-) cells, suggesting that pol ζ generates tandem mutations. Contiguous mutations are consistent with the biochemical property of pol ζ to extend a mismatch with a second mutation. The presence of this unique signature implies that pol ζ contributes to mutational synthesis in vivo. Additionally, data on tandem mutations from wild type, Polζ(+/-), Polζ(-/-), Ung(-/-), Msh2(-/-), Msh6(-/-), and Ung(-/-) Msh2(-/-) clones suggest that pol ζ may function in the MSH2-MSH6 pathway.     

Successful electrical cardioversion in a massive concentric hypertrophic cardiomyopathy with atrial fibrillation

A 59-year-old man with a known history of nonobstructive hypertrophic cardiomyopathy and chronic atrial fibrillation was admitted to our clinic with weakness, palpitation, and exertional dyspnea. Electrocardiogram showed atrial fibrillation with high ventricular rate (120 beats per minute), intraventricular conduction delay, and left ventricular (LV) hypertrophy with ST-segment depression and inverted T waves. A transthoracic echocardiogram showed massive LV concentric hypertrophy. Although there was no gradient increase in the LV outflow tract, marked turbulent flow was seen in midventricular region by colored Doppler echocardiography. On the fourth day of admission, transesophageal echocardiography was done and showed no thrombus in the left atrium. Electrical cardioversion with 100 J was applied to the patient, and atrial fibrillation was returned to sinus rhythm. His control Doppler echocardiogram revealed peak systolic resting gradient of 54 mm Hg, with an increase to 84 mm Hg at Valsalva maneuver at the LV outflow. Cardiac magnetic resonance showed concentric LV hypertrophy with a 35-mm thickness in diastole, mild scar tissue in LV anterior wall midapical segments, and right ventricle wall thickness with a 10 mm in diastole. There was no bradycardia or tachycardia in 24-hour Holter and exercise electrocardiographic testing.     

Vision,Retinal Thickness,and Foveal Avascular Zone Size After Intravitreal Bevacizumab for Diabetic Macular Edema

Introduction  

To investigate three monthly intravitreal bevacizumab (IVB) injections effects in chronic diabetic macular edema (DME).     

Same-day colonoscopy preparation with Senna alkaloids and bisacodyl tablets: A pilot study

AIM: To evaluate the efficacy of same-day bowel preparation with Senna alkaloids combined with bisacodyl tablets in routine colonoscopy procedures.METHODS: Between March and June 2013, a same-day bowel preparation was implemented in our endoscopy unit. The preparation consisted of a semi-liquid, fiber-free diet one day prior to the procedure, with two bisacodyl tablets after lunch and dinner, and 250 mL of Senna alkaloid with 1.5 L of drinking water at 6 am the day of the procedure. The quality control parameters of colonoscopy were evaluated and implemented according to the guidelines of the American Society for Gastrointestinal Endoscopy. The pre-procedure, during-procedure and post-procedure patient data were collected and analyzed: (1) pre-procedure (age, gender, comorbid diseases, colonoscopy indications, complete lack of compliance with the bowel preparation protocol); (2) during-procedure (sedation dose, duration of colonoscopy, withdrawal time, cecal intubation rate, polyp detection rate, Boston Bowel Preparation Scores and presence of foam and clear liquid); and (3) post-procedure (visual analogue scale score, pain during the procedure, patient satisfaction and premature withdrawal due to the insufficient bowel preparation).RESULTS: A total of 75 patients were included in this study with a mean age of 54.64 ± 13.29 years; 53.3% (40/75) were female and 46.7% (35/75) were male. A complete lack of compliance with the bowel preparation protocol was seen in 6.7% of patients (5/75). The mean total duration of colonoscopy was 16.12 ± 6.51 min, and the mean withdrawal time was 8.89 ± 4.07 min. The cecal intubation rate was 93.8% (61/64) and the polyp detection rate was 40% (30/75). The mean Boston Bowel Preparation Score was 7.38 ± 1.81, with the following distribution: right colon, 2.34 ± 0.89; transverse colon, 2.52 ± 0.67; left colon, 2.52 ± 0.63. The mean visual analogue scale score was 4.59 ± 1.57. Due to insufficient bowel preparation, seven patients (7/75; 9.3%) were asked to repeat the procedure. Of these, five patients had poor or modest compliance with the protocol, and two patients reported constipation. Premature withdrawal due to insufficient bowel preparation was 2.7% (2/75). The overall satisfaction with the protocol was 86.7% (65/75), with patients reporting they would prefer the same protocol in a repeat procedure.CONCLUSION: The same-day administration of Senna alkaloids appears to be a safe and effective bowel cleansing protocol for colonoscopy procedures.