Transoesophageal echocardiographic monitoring of pulmonary venous obstruction induced by sternotomy closure during infant heart transplantation

A case of an infant receiving orthotopic heart transplantation with over-sized donor heart was reported. Left lower pulmonary venous obstruction after sternotomy closure was detected by transoesophageal echocardiography (TOE) and the decision to delay sternal closure was made and the clinical outcome was very satisfactory. The usefulness of intraoperative TOE monitoring and postoperative TOE follow-up for infant heart transplantation, especially in those cases of size mismatch, was well demonstrated.

Lack of intravenous lidocaine effects on HRV changes of tracheal intubation during induction of general anesthesia

BACKGROUND

Intravenous lidocaine has been widely used for suppressing the autonomic activation from tracheal intubation during induction of general anesthesia. Conventionally, researches of its effectiveness through assessment of heart rate and blood pressure changes obtained by common clinical methods result in the conclusions deduced of much controversy. Heart rate variability is a noninvasive measurement of autonomic regulation and is suitable for the study of this subject.

METHODS

36 ASA class I-II patients undergoing general anesthesia were divided into 3 groups. Besides induction agents, intravenous lidocaine was given 5 min before tracheal intubation in group A, 3 min before intubation in group B and nothing in group C. HRV spectral powers were measured at awake state, anesthetized state before tracheal intubation and anesthetized state after tracheal intubation by time frequency spectral analysis method and comparison was made between the three groups.

RESULTS

The HRV spectral power in high frequency (HF) and mid-frequency (MF) power bands and their ratios (MF/HF) were not significantly different among the 3 groups during the 3 observation periods.

CONCLUSIONS

There was no evidence to indicate the effectiveness of intravenous lidocaine on the autonomic regulation during tracheal intubation under the influence of induction agents used in general anesthesia.

Determination of source contributions to ambient PM2.5 in Kaohsiung, Taiwan, using a receptor model

Ambient particulates of PM2.5 were sampled at three sites in Kaohsiung, Taiwan, during February and March 1999. In addition, resuspended PM2.5 collected from traffic tunnels, paved roads, fly ash of a municipal solid waste (MSW) incinerator, and seawater was obtained. All the samples were analyzed for twenty constituents, including water-soluble ions, organic carbon (OC), elemental carbon (EC), and metallic elements. In conjunction with local source profiles and the source profiles in the model library SPECIATE EPA, the receptor model based on chemical mass balance (CMB) was then applied to determine the source contributions to ambient PM2.5. The mean concentration of ambient PM2.5 was 42.69-53.68 micrograms/m3 for the sampling period. The abundant species in ambient PM2.5 in the mass fraction for three sites were OC (12.7-14.2%), SO4(2-) (12.8-15.1%), NO3- (8.1-10.3%), NH4+ (6.7-7.5%), and EC (5.3-8.5%). Results of CMB modeling show that major pollution sources for ambient PM2.5 are traffic exhaust (18-54%), secondary aerosols (30-41% from SO4(2-) and NO3-), and outdoor burning of agriculture wastes (13-17%).

Synthesis and antitumor activity of bithienyl-pyrimidine derivatives with electrostatic binding side chains

A series of bithienyl-pyrimidines having cationic side chain have been developed as antitumor agents. This work illustrates the overwhelming importance of the bithienyl unit for efficient DNA binding. The X-ray structure of 4-(2',2"-thien-5-yl)2-chloropyrimidine was obtained for postulating the conformation of the bithienyl-pyrimidine moiety.

Expression of rat microsomal epoxide hydrolase gene during liver chemical carcinogenesis

A complementary DNA library was constructed from mRNA of rat liver induced by an initiating dose of a chemical carcinogen, diethylnitrosamine. Using a differential hybridization technique, a complementary DNA clone which is induced more than 10-fold by an acute single dose of diethylnitrosamine was identified. The DNA sequence of this clone was matched with rat microsomal epoxide hydrolase. This gene may be of great interest, since it was found to be highly expressed in neoplastic nodules and primary hepatocellular carcinomas induced by different carcinogenic regimes. The inducible high level expression of this gene becomes constitutive during the process of hepatocarcinogenesis. The gene was also found to be inducibly expressed during partial hepatectomy in a similar manner as a multidrug-resistant gene (mdr-I). No change in the transcriptional initiation site was observed in the gene expression between induced and uninduced rat livers. The 5' upstream region of the gene was characterized and some potential controlling elements for gene regulation, such as Sp-1, AP-2, and Hepatitis B virus enhancer, were found. Based on our own and published results, we hypothesize that the altered expression of this xenobiotic enzyme in nodules and cancer cells could be a result of constitutive internal stimuli which might be associated with cell growth.