Molecular weight analysis of cow's milk antigens in neonate sera

Some food antigens (Ag) can be detected in serum immunoglobulin G (IgG) antibodies (Ab) following ingestion. These Ag may thus be essential for inducing the production of IgE or IgG antibodies, which may in turn lead to the onset of atopic diseases such as atopic dermatitis, allergic rhinitis and asthma. The molecular weights (MW) of these Ag have yet to be determined. To select samples for MW analysis of circulating food Ag, we measured the concentrations of cow's milk (CM) Ag in the sera of 88 neonates by radio-immunoassay. They were found present in 20 samples of the sera. Twelve of the samples were analyzed for Ag MW by immunoblotting. Several bands appeared for one of the samples. Their MW were < 13 000 and no native CM proteins could be detected.     

Hyperbaric oxygen stimulates cell proliferation and normalizes multidrug resistance protein-2 protein localization in primary rat hepatocytes

Hyperbaric oxygen therapy (HBO) has been used for many clinical treatments, including primary liver non-function. However, the cellular mechanism by which HBO treatment ameliorates liver function is not understood. Therefore, the purpose of this study was to elucidate this cellular mechanism using primary cultured rat hepatocytes in in vitro studies. Hepatocytes were treated with HBO at 1 day after plating, and the morphological and functional characteristics of bile canaliculi formed in cultured hepatocytes were observed by time-lapse microscopy. Multidrug resistance protein-2 localization was observed by confocal laser microscopy. In cultured hepatocytes, the labeling index in the HBO group at 2 days after treatment was significantly higher than that in the control group. In addition, the proliferating cellular nuclear antigen level in the HBO group was significantly higher than that in the control group. The contraction of the bile canaliculi in the HBO group was slower than in the control group and the dilatation of bile canaliculi in the HBO group was much larger than in the control group. Multidrug resistance protein-2 in the HBO group was localized at the apical membrane. These results show that HBO stimulates hepatocytes to proliferate and HBO normalizes multidrug resistance protein-2 localization to the apical membrane, which could dilate bile canaliculi.     

Synthesis of peptide inhibitors of human spleen fibrinolytic proteinase (SFP) and human leukocyte elastase-like proteinase (ELP)

Stereoisomers of specific substrates for SFP and ELP, Suc-L-Tyr-L-Leu-L-Val-pNA and Suc-L-Ala-L-Tyr-L-Leu-L-Val-pNA, were synthesized by the conventional solution method. Suc-L-Tyr-D-Leu-D-Val-pNA was found to be an effective and specific inhibitor of SFP and ELP. Suc-L-Tyr-L-Leu-L-Val-Pipe and Suc-L-Tyr-D-Leu-D-Val-Pipe inhibited only SFP very slightly and showed no inhibitory effect on ELP. Both Dan-L-Tyr-L-Leu-L-Val-pNA and Dan-L-Tyr-D-Leu-D-Val-pNA exhibited an inhibitory effect on both SFP and ELP.     

Role of Sympathovagal Balance in the Initiation of Idiopathic Ventricular Tachycardia Originating from Right Ventricular Outflow Tract

VT originating from the right ventricular outflow tract (RVOT) is prone to occur when sympathetic nervous activity is increased. β-Blockade is, therefore, effective in suppressing this VT. The purpose of this study was to determine the role of sympathovagal balance assessed by heart rate variability (HRV) in the spontaneous initiation of repetitive premature ventricular contractions (PVCs) and VT (five or more consecutive PVCs) arising from RVOT in seven patients without structural heart diseases. Frequency-domain measures of HRV were determined by analyzing 24-hour Holter electrocardiographic recording with the maximum entropy method over α 1,280-second period immediately before the onset of 35 single PVCs, 26 episodes of 2-4 consecutive PVCs, and 21 episodes of VT. High frequency component (HF: 0.15–0.40 Hz) was used as an index of parasympathetic activity, and the ratio of low frequency component (LF: 0.04–0.15 Hz) to HF (LF/HF ratio), as an index of sympathovagal balance. NN50(%), a time-domain variable of parasympathetic activity, was also determined. Mean RR interval and any measures of HRV did not change significantly before single PVCs. Mean RR interval shortened and HF decreased prior to repetitive PVCs and VT. The LF/HF ratio, however, increased only before the onset of VT. NN50(%) tended to decrease before repetitive PVCs and decreased significantly before VT. With propranolol (30–60 mg/day), frequency of repetitive PVCs was suppressed from 2,048 ± 1,201 to 746 ± 658/day and VT was totally abolished, but frequency of single PVCs did not change significantly. In conclusion, sympathetic predominance plays an important role in the initiation of repetitive PVCs and VT originating from RVOT in patients without structural heart diseases.     

Management of meconium aspiration syndrome by tracheobronchial lavage and replacement of Surfactant-TA

Meconium aspiration syndrome creates mechanical airway obstruction with air trapping and atelectasis. Tracheobronchial saline lavage to dislodge meconium may precipitate respiratory distress, a wet lung appearance and respiratory failure. Two case studies are reported in which meconium aspiration resulted in mechanical obstruction and displacement of surfactant and in whom tracheobronchial saline lavage and artificial surfactant replacement reversed respiratory failure.     

Evolutionary aspects of positioning and identification of vertebrate limbs

Emerging developmental studies contribute to our understanding of vertebrate evolution because changes in the developmental process and the genes responsible for such changes provide a unique way for evaluating the evolution of morphology. Endoskeletal limbs, the locomotor organs that are unique to vertebrates, are a popular model system in the fields of palaeontology and phylogeny because their structure is highly visible and their bony pattern is easily preserved in the fossil records. Similarly, limb development has long served as an excellent model system for studying vertebrate pattern formation. In this review, the evolution of vertebrate limb development is examined in the light of the latest knowledge, viewpoints and hypotheses.     

SYNTHESIS OF SUBSTRATES SPECIFIC FOR HUMAN SPLEEN FIBRINOLYTIC PROTEINASE (SFP)

Two peptide anilides, Suc-Tyr-Leu-Val-pNA (III) and Ac-Ser-His-I.eu-Val-pNA (V) were synthesized by the conventional method with the object of obtaining specific substrates for human spleen fibrinolytic proteinase (SFP). The K_cat/K_m values for hydrolysis of HI and V by SFP were 22 64 7 and 2 700, respectively. On the contrary, the K_cat/K_m values for hydrolysis of III and V by porcine pancreatic elastase were 21 and 9, respectively.