Imaging of regional air distributions in porcine lungs using high-performance electrical impedance tomography system.

Electrical impedance tomography (EIT) allows functional imaging of regional lung ventilation for real-time bedside monitoring of mechanically ventilated patients. Images showing time-changes of regional air distributions in the lungs can provide valuable diagnostic information for lung protective mechanical ventilation. This paper reports in vivo porcine imaging experiments of regional lung ventilation using a 16-channel parallel EIT system. Real-time time-difference chest images of 10 animals were reconstructed during mechanical ventilations with a temporal resolution of 50 frame/s. Analyzing the images together with the airway volume-pressure information from the mechanical ventilator, we could successfully produce regional compliance images at PEEP (positive end expiratory pressure) titration. From in vivo animal experiments, we propose the method as a continuous monitoring means for LPV (lung protective ventilation).

Spironolactone, but not enalapril, potentiates hypoxia-inducible factor-1 alpha and Ets-1 expression in newborn rat kidney.

Hypoxia is regarded as an important physiological factor that controls nephrogenesis. We investigated whether the renin-angiotensin-aldosterone system (RAAS) affects hypoxia-related target genes in developing kidneys. Newborn rat pups were treated with enalapril (30 mg/kg/d) or spironolactone (200 mg/kg/d) for 7 days. Tissue hypoxia was assessed by the uptake of a hypoxyprobe-1, pimonidazole (200 mg/kg), and the expression of hypoxia-responsive genes. In the enalapril group, hypoxia-inducible factor (HIF)-1alpha, HIF-2alpha, and Ets-1 protein expression were not changed, compared to the control group. In the spironolactone group, HIF-1alpha and Ets-1 protein expression were significantly increased by immunoblots and immunohistochemistry, whereas HIF-2alpha protein expression was not changed, compared to the control group. In the enalapril group, the immunoactivity of pimonidazole was not significantly different from that of the controls. However, in the spironolactone group, pimonidazole staining demonstrated that the cortex and medulla underwent severe hypoxia. In summary, our data showed that aldosterone inhibition in the developing kidney augmented the hypoxic responses, and up-regulated the expression of key mediators of hypoxia including HIF-1alpha and Ets-1. Angiotensin II inhibition did not affect hypoxia-related alterations in the developing kidney. The components of RAAS may differentially modulate renal hypoxia and its related target genes in the developing rat kidney.

Transglutaminase 2 suppresses apoptosis by modulating caspase 3 and NF-kappaB activity in hypoxic tumor cells.

The expression of hypoxia-inducible factor-1 (HIF-1) correlates with poor clinical outcomes and confers resistance to the apoptosis of the tumor cells that are exposed to hypoxia. Presently, the mechanism underlying this phenomenon is poorly understood. In this study we provide evidence that transglutaminase 2 (TG2), an enzyme that catalyses protein crosslinking reactions, is a transcriptional target of HIF-1 to enhance the survival of hypoxic cells. We found that hypoxia induces TG2 expression through an HIF-1 dependent pathway and concurrently activates intracellular TG2. The hypoxic cells overexpressing TG2 showed resistance to apoptosis. Conversely, the hypoxic cells treated with either TG2 inhibitor or small interfering RNA (siRNA) became sensitive to apoptosis. Activation of TG2 in response to hypoxic stress inhibited caspase-3 activity by forming crosslinked multimer, resulting in insoluble aggregates. TG2 also activates nuclear factor (NF)-kappaB pathway after hypoxic stress, and thereby induces the expression of cellular inhibitor of apoptosis 2. The anti-apoptotic role of TG2 was further confirmed in vivo using xenografts in athymic mice. Our results indicate that TG2 is an anti-apoptotic mediator of HIF-1 through modulating both apoptosis and survival pathways and may confer a selective growth advantage to tumor cells. These findings suggest that the inhibition of TG2 may offer a novel strategy for anticancer therapy.

Albumin versus normal saline for dehydrated term infants with metabolic acidosis due to acute diarrhea.

UNLABELLED: To compare the efficacy of albumin to normal saline (NS) for initial hydration therapy for dehydrated term infants with severe metabolic acidosis due to acute diarrhea. STUDY DESIGN: We randomized 33 infants presenting with moderate-to-severe dehydration and metabolic acidosis (pH <7.25 or base excess (BE) <-15) into two groups, an albumin group (n=15) and a NS group (n=18). For initial hydration treatment, the albumin group received 5% albumin (10 ml kg(-1)), whereas the NS group received NS (10 ml kg(-1)). RESULT: After 3 h of treatment, both groups improved. However, the magnitude of improvement in the pH, BE and HCO(3)(-) levels were not different in comparisons between these two groups. In addition, there were no differences either in the body weight and weight gain 4 days after treatment or in the length of hospital stay. CONCLUSION: Albumin was not more effective than NS for initial hydration treatment of dehydrated term infants with metabolic acidosis due to acute diarrhea.

Transcatheter occlusion of a modified Blalock-Taussig shunt using the amplatzer vascular plug with the catheter-snare technique.

A 16-month-old boy with previous repair of a critical pulmonary stenosis had persistence of a right modified Blalock-Taussig shunt. Transcatheter occlusion of the modified Blalock-Taussig shunt was achieved using the Amplatzer vascular plug with the catheter-snare technique.

Autosomal albino chicken mutation (ca/ca) deletes hexanucleotide (-deltaGACTGG817) at a copper-binding site of the tyrosinase gene.

We compared tyrosinase cDNA sequences from a line of autosomal albino and Black Silky chickens isolated from cultured melanocytes by reverse transcription-polymerase chain reaction (RT-PCR). Both sources produce a single DNA fragment of predicted normal tyrosinase size. Direct sequencing of the PCR product showed three mutated sites in the tyrosinase gene of the albino chicken. Two silent point mutations and a deletion of six nucleotides (-deltaGACTGG) at 817 bp in the tyrosinase cDNA sequence were observed when compared with the White Leghorn and Black Silky cDNA sequences. The deduced albino chicken tyrosinase protein lacks two amino acids, aspartic acid and tryptophan. The position of these amino acids is consistent with one of the potential copper-binding sites that should be indispensable for function of the enzyme. We speculate that the six-base deletion is responsible for the inactive tyrosinase in this line of albino chickens.

Survey of the Korean population for 9 short tandem repeat loci.

The short tandem repeats with repeat units ranging from two to several nucleotides became a powerful tool in the field of forensic identification and paternity determination as well as for research in human gene mapping. Allele and genotype frequencies for 9 short tandem repeats including HUMCSF1PO, HUMTH01, HUMPLA2A1, HUMF13A01, HUMCYAR04, HUMLIPOL, HUMHPRTB, HUMCD4, and HUMFABP were determined using PCR and subsequent analysis of the PCR products by denaturing polyacrylamide gel electrophoresis followed by silver-staining. DNA samples were obtained from about 100 Korean people and amplified in a thermocycler adopting glass capillaries rather than traditional tubes. We found that the bovine serum albumin was an essential additive for the capillary PCR, presumably to coat the inner surface of the capillary which may adsorb Taq DNA polymerase. The capillary thermocycler was very effective in reducing the cycling time such that most of the amplification reactions could be finished within 30 min albeit the PCR product was less than that for the tube systems. All loci except HUMHPRTB met the Hardy-Weinberg expectations according to the exact test. The cumulative power of discrimination (PD) was 0.9999998 and the power of exclusion (POE) for the paternity test was a little low, being 0.9873989.

Ligation mediated fluorescent labeling of DNA sequencing primers.

Automated DNA sequencing utilizing fluorescently labeled primers is a proven methodology for generating quality sequence data. However, for directed primer walking strategies this necessitates synthesis and labeling of a unique primer for each sequencing reaction. Here, we describe a rapid ligation-based method of generating labeled sequencing primers. An unlabeled 5'-phosphorylated sequencing primer is ligated to a fluorescent oligonucleotide by use of a bridge primer which is complementary to portions of the previous two oligonucleotides, thus aligning them properly for ligation. The resulting fluorescent hybrid primer can be utilized directly in cycle sequencing reactions without any prior purification.

Congenital aglossia with situs inversus totalis--a case report.

Hypoglassia or aglossia is an uncommon anomaly, either of which may occur as an isolated finding or in association with other deformations, especially limb anomalies. Their genetic background is uncertain, and drug induced teratogen has not been clearly identified. We experienced a case of congenital aglossia with situs inversus in a female infant aged twelve days. Her initial complaints at admission were feeding difficulty and weight loss. In a review of literature, the association with situs inversus is very rare and only three cases have been reported until now.

Producing STR locus patterns from bloodstains and other forensic samples using an infrared fluorescent automated DNA sequencer.

Short tandem repeat (STR) analysis is increasingly being used in forensic case analysis because of the large number of STR loci in the human genome and their highly polymorphic nature. An automated DNA sequencer using high sensitivity infrared (IR) fluorescence technology was used to detect STR allele patterns from simulated forensic samples. The amplification strategy used a 19 base pair extension on the 5' end of one of the PCR primers. This sequence is identical to the sequence of a universal M13 Forward sequencing primer which is included in the amplification reaction. Allelic bands were detected by incorporation of the M13 primer-fluorescent dye conjugate into PCR products thus eliminating the need for direct conjugation of fluorescent dye to individual STR primers. By using an IR-based automated DNA sequencer and Tth DNA polymerase, polymorphic STR alleles were detected on-line rapidly and efficiently from bloodstains using only a high temperature incubation to extract DNA from blood cells. Five STR loci were also amplified using Chelex extracted DNA from simulated forensic samples. Multiplexing of three primer pairs in a single PCR mixture for amplification was accomplished using Taq polymerase. This system combines IR fluorescence chemistry and laser technology thus eliminating the need for radioactivity and the gel handling required with silver staining and fluor detection systems. Real-time detection permits immediate visualization of the data and STR alleles are displayed as familiar autoradiogramlike images that can be analyzed by computer. By loading a 64 lane gel twice and multiplexing with three primer pairs, forensic scientists can type at least three loci from 120 samples in one day.

An infrared fluorescent dATP for labeling DNA.

Near-infrared fluorescence provides a nonradioactive method of detection with high sensitivity and low background. An infrared fluorophore has been attached covalently to the nucleotide deoxyadenosine triphosphate (dATP) to provide a reagent for enzymatic labeling of various types of DNA molecules and for facilitating their detection with an automated DNA sequencing and analysis system. DNA sequencing reaction products can be labeled internally by performing limited polymerization utilizing infrared-labeled dATP (IR-dATP) as the sole source of adenine deoxynucleotide prior to a dideoxy-specific termination reaction. PCR products can be labeled fluorescently by the addition of limited quantities of IR-dATP to the amplification reaction. This latter strategy has been utilized for detection of short tandem repeat polymorphisms (STRPs) which are useful for gene mapping, genetic diagnostics, forensic analysis, and paternity testing. Restriction fragments can be labeled also by fill-in reactions of appropriate 5' overhangs. Diminutive amounts of such fluorescently labeled DNA molecules can be visualized rapidly and conveniently using infrared detection technology.