[Study on Servo-null method for direct measurement of microvascular pressure by micropuncture technique]

The dynamic microvascular pressures in the mesentery of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats were measured and recorded by using the Servo-null microvascular pressure measuring system (Model 4A, IPM, Inc., San Diego, USA) with glass micropipettes whose tips were 1.0-5.0 microns in diameter and had been beveled very sharply at an angle of 25 degree. Microvascular pressures were measured in two groups of microvessels: large, 25-45 microns; small, 15-25 microns. Mean microvascular pressures (Pm) of large and small arterial microvessels in SHR were 6.0 +/- 7.0 kPa and 4.8 +/- 0.6 kPa, respectively. In WKY rats, Pm were 4.2 +/- 0.6 kPa and 3.6 +/- 0.6 kPa, respectively. Pm of comparable types of arterial microvessels in SHR and WKY rats was significantly different. No significant difference of Pm in small venous vessels was found between SHR and WKY rats.

Standardization of low attenuation area versus total lung area in chest X-ray CT as an indicator of chronic pulmonary emphysema

We examined the methods for measuring the LAA% (100 x low attenuation area/total lung area) on thoracic X-ray CT scans in order to develop a useful indicator of chronic pulmonary emphysema (CPE). First, we modified the method for calculating the LAA% to be applicable by the programming tool installed in a commercially available CT machine in order to minimize manual procedures. This new method proved to be applicable in all CT machines produced after 1987. Second, we examined the difference in the Hounsfield Unit (HU) between different CT machines using two kinds of phantoms. One phantom was composed of Styrofoam, which has a density similar to the low attenuation areas. The other phantom was composed of Styrofoam and water, which has a density similar to the lung. We proved that the difference of LAA% with the correct value was 5% at maximum among four different CT machines. Thus, the phantom developed in the present study may play an important role in the standardization of HU. Finally, the possibility of decreasing the X-ray levels was examined. Twenty-five percent of the standard electrical current provided the same LAA% in cases where the subject was an established CPE patient, whereas the LAA% was overestimated in subjects with a normal LAA% value. However, a correction using a linear regression equation may be possible in the latter cases. It may be concluded that LAA% analysis can easily be performed in many city hospital, without much investment of manual procedures or any corrections to the HU levels between different CT machines. This method may be useful as a routine follow up for CPE patients because of the smaller irradiated dose given when using a CT machine.

Molecular characterization of a novel, developmentally regulated small embryonic chaperone from Caenorhabditis elegans

Low molecular weight chaperones inhibit protein aggregation and facilitate refolding of partially denatured polypeptides in cells subjected to physical and chemical stresses. The nematode Caenorhabditis elegans provides a system amenable for investigations on roles for chaperone proteins in normal homeostasis and development. We characterized a C. elegans gene and cDNAs that encode a novel, small embryonic chaperone-like protein (SEC-1) that is composed of 159 amino acids. The central core of SEC-1 (residues 45-126) is approximately 40% identical with a corresponding segment of mammalian Hsp27 and alphaB crystallin. Expression of SEC-1 in Escherichia coli confers thermotolerance on the bacterium. SEC-1 mRNA is evident only in C. elegans oocytes and developing embryos. Translation and accumulation of SEC-1 protein is temporally coupled with a prolonged burst of intense protein synthesis and rapid mitogenesis during early embryogenesis. As the rate of protein synthesis decreases during late embryogenesis, levels of SEC-1 and its cognate mRNA decline precipitously. Induction/deinduction of SEC-1 is precisely regulated by intrinsic developmental factors rather than extrinsic stresses. In vivo injection of C. elegans oocytes with antisense oligonucleotides that complement the 5'-end of SEC-1 mRNA arrests nematode development at an early stage after fertilization. Thus, SEC-1 appears to be adapted to perform essential functions in early embryogenesis.

Alterations in H-ras1 promoter conformation during N-nitroso-N-methylurea-induced mammary carcinogenesis and pregnancy

We previously demonstrated that H-ras1 oncogene mutations detected in N-nitroso-N-methylurea (NMU)-induced mammary tumors arose as background mutations within rat mammary cells (RMCs) and that NMU promoted the outgrowth of these preexisting mutants. We have now detected a putative DNA structure in the H-ras1 promoter of RMCs in vivo that was absent in NMU-induced mammary tumor cells. Analysis of the promoter in RMCs as a function of time after exposure to carcinogens indicated that NMU, but not 7,12-dimethylbenz(a)anthracene, initiated the loss of this structure with a half-life of 7 days. Although loss of the structure was irreversible in cells that gave rise to tumors, it was restored in normal RMCs by 120 days after exposure and was present in normal RMCs of animals bearing tumors, even 1 year after NMU exposure. The structure was also abrogated in RMCs during pregnancy and restored after lactation was terminated, suggesting that reversible regulation of the structure by hormones contributed to normal RMC growth. Thus, NMU may promote abnormal RMC growth by mimicking the effects of hormones on DNA conformation. We hypothesize that the NMU-induced alterations in promoter conformation irreversibly deregulates H-ras1 expression in initiated cells, thereby increasing the phenotypic penetrance of the conditional H-ras1 mutations.

The role of a mutant CCR5 allele in HIV-1 transmission and disease progression

A 32-nucleotide deletion (delta 32) within the beta-chemokine receptor 5 (CCR5) gene has been described in subjects who remain uninfected despite extensive exposure to HIV-1. This allele was found to be common in the Caucasian population with a frequency of 0.0808, but was not found in people of African or Asian ancestry. To determine its role in HIV-1 transmission and disease progression, we analyzed the CCRS genotype of 1252 homosexual men enrolled in the Chicago component of the Multicenter AIDS Cohort Study (MACS). No infected participant was found to be homozygous for the delta 32 allele, whereas 3.6% of at-risk but uninfected Caucasian participants were homozygous, showing the highly protective role of this genotype against sexual acquisition of HIV-1. No evidence was found to suggest that heterozygotes were protected against HIV-1 infection, but a limited protective role against disease progression was noted. The delta 32 allele of CCR5 is therefore an important host factor in HIV-1 transmission and pathogenesis.

[The changes in plasma nitric oxide level in normal pregnant women and pregnancy induced hypertension]

OBJECTIVE

To investigate the relationship between nitric oxide (NO) level and pregnancy induced hypertension (PIH).

METHODS

The plasma level of NO in 36 cases of normal pregnant women (normal pregnancy group), 23 cases of PIH (PIH group), and 16 cases of non-pregnant women (control group) were measured and compared using fluorophotometry.

RESULTS

The NO level of normal pregnancy group was significantly higher than that of control group (P < 0.01), particularly in the second trimester of pregnancy. The NO level of PIH was significantly lower than that of third trimester of normal pregnancy (P < 0.01), and it decreased as the disease became severe.

CONCLUSIONS

Decreased synthesizing and releasing of NO might play an important role in pathogenesis of PIH.

[Percutaneous transluminal angioplasty for the treatment of occlusion of proximal subclavian artery]

Percutaneous transluminal angioplasty (PTA) is a well-established treatment for patients with stenosis of limb arteries. However, its efficacy for treatment of severe stenosis and occlusions of the subclavian artery is unclear. We attempted to recanalize the subclavian artery in 30 patients with severe stenosis or total occlusion of proximal subclavian artery and successful outcomes were seen in 27 cases (90%). In two patients the regional arterial thrombolysis with the PTA prcedure we used was found successful. There was no severe complications. During an average 6-month follow-up stenosis recurred in 2 patients, but the subclavian artery was recanalized by repedted PTA.

Analysis of tear fluid by CE/LIF: a noninvasive approach for glucose monitoring

Nanoliter volumes of human tear fluid were collected by means of a capillary tube without inducing tearing and were analyzed for glucose content. The tear fluid was subjected to two enzymatic reactions to generate a fluorescent compound that is proportional to the concentration of glucose in the sample. CE with laser-induced fluorescence (LIF) detection was used to monitor the fluorescent species generated, hence glucose in the tear samples. The reproducibility of the method for six different preparations was < 9% relative standard deviation (RSD). The procedure was compared with the glucose dehydrogenase method for the determination of glucose in blood before using it to determine glucose in tear fluid. Blood and tear samples were collected from six healthy human subjects. The results showed that the higher glucose content in tear samples is consistent with the higher glucose content in blood samples. The glucose concentration of the tear samples analyzed ranged from 128 to 166 microM, and that of blood ranged from 3.3 to 4.3 mM.

[Genetic polymorphism of antithrombin III in five Chinese populations]

The genetic polymorphisms of antithrombin III (AT III) in 5 Chinese populations were studied by isoelectric focusing on polyacrylamide gels followed by immunoblotting. The products of two alleles at the antithrombin III locus together with 1 AT III anodic variant and 3 cathode variants were observed. The results revealed that the predominant allele of AT III blood group system in Chinese populations was AT III *1, with frequencies between 0.9773-0.9850. Frequencies of AT III *2 ranged from 0.0091 to 0.0169. These results indicate that the polymorphic information content of AT III blood group system in Chinese populations is limited.

Structure and function of gustatory neurons in the nucleus of the solitary tract: II. Relationships between neuronal morphology and physiology

This study employed intracellular recording and labeling techniques to examine potential relationships between the physiology and morphology of brainstem gustatory neurons. When we considered the neuronal response to the four "prototypic" tastants, we were able to demonstrate a positive correlation between breadth of responsiveness and the number of dendritic branch points. An analysis of the response to eight tastants also revealed an association between dendritic spine density and the breadth of responsiveness, with more narrowly tuned neurons exhibiting more spines. Interestingly, a neuron's "best response" was a relatively poor predictor of neuronal morphology. When we focused on those neurons that responded to only one tastant, however, a number of potentially important relationships became apparent. We found that the cells that only responded to quinine were smaller than the neurons that only responded to NaCl, HCl, or sucrose. The HCl-only neurons, however, were more widespread in the rostrocaudal dimension that the neurons that only responded to NaCl. A number of additional structure-function relationships were identified when we examined the neuronal response to selected tastants. We found that neurons that responded to sucrose but not quinine, as well as neurons that responded to quinine but not sucrose, were more widespread in the mediolateral dimension than neurons that responded to both sucrose and quinine. We also discovered that the neurons that responded to NaCl, but not to NH4Cl or KCl, were larger than neurons that responded to all three salts. We believe that these results support the hypothesis that there are relationships between the structure and function of gustatory neurons in the nucleus of the solitary tract, with the data highlighting the importance of three themes: 1) the relationship between dendritic specializations and tuning, 2) the relationship between dendritic arbor orientation and response properties, and 3) the potential importance of stimulus-specific neurons.

Determination of albumin and hemoglobin adducts in workers exposed to styrene and styrene oxide

Hemoglobin and albumin adducts of the carcinogen styrene-7,8-oxide (SO) were measured in 48 workers exposed to both styrene and SO in a boat manufacturing plant. Personal exposures to both substances were measured repeatedly over the course of 1 year (styrene:0.9-235 mg/m3 with a mean of 64.3 mg/m3 for 48 subjects; S0: 13.4-525 mu g/m3 with a mean of 159 mu g/m3 for 20 subjects). Cysteine and carboxylic acid adducts of SO with hemoglobin and albumin were assayed on one or more occasions for each subject. The proteins were subjected to base hydrolysis to release styrene glycol, representing carboxylic acid-bound SO, and were then treated with Raney nickel to release 1-phenylethanol and 2-phenylethanol, representing cysteine-bound SO. These three analytes were extracted, derivatized, and analyzed by gas chromatography-mass spectrometry. No evidence was found of any exposure-related increase in hemoglobin adducts. In contrast, albumin adducts were found to increase with exposures to either styrene or SO, the latter apparently being more important. This suggests that exposure to low levels of SO in the air may be important among workers in the reinforced plastics industry. Significant levels of SO adducts of albumin and hemoglobin were also detected in proteins obtained from persons without occupational exposure to styrene or to SO. This finding opens the possibility that SO is either a dietary or an environmental contaminant or is produced endogenously.

[Direct genotyping and antenatal diagnosis of deletional alpha-thalassemia of the southeast Asian type by polymerase chain reaction technique]

OBJECTIVE

To study the gene of deletional alpha-thalassemia of the Southeast Asian type (SEA) and to perform the antenatal diagnosis.

METHODS

A new method of polymerase chain reaction technique using three primers bridging the breakpoints was carried out for carrier detection and antenatal diagnosis of deletional alpha-thalassemia of the Southeast Asian type. A DNA fragment of about 630bp in size was amplified in case of--SEA alleles, while a 224 bp fragment was amplified in samples without the deletion. Homozygotes, heterozygotes, and normal subjects could be clearly distinguished with the present method.

RESULTS

We used this method in the genotyping and antenatal diagnosis of 10 high risk pregnancies of alpha-thalassemia. 2 homozygotes, 4 heterozygotes, and 4 normal infants were found.

CONCLUSION

The present method is simple and rapid in detection of carriers and antenatal diagnosis of the alpha-thalassemia of southeast Asian type.

[The value of endoscopic ultrasonography in the diagnosis of ampullary carcinoma]

The value of endoscopic ultrasonography (EUS) for diagnosing ampullary carcinoma was assessed in 14 patients. The diagnostic accuracy, the chariacteristics of the images and the preoperative invasion of the carcinoma were studied. The results showed that: (1) The lesions were clearly demonstrated in all cases (100.0%) and the diagnostic accuracy of EUS was 78.6%, which was better than that of transabdominal ultrasonography and CT (P < 0.05), but similar to that of endoscopic retrograde cholangio-pancreatography (ERCP) (P > 0.05). Three patients with pancreatic carcinoma were misdiagnosed as ampullary carcinoma by EUS, because the carcinoma was situated at the head of the pancreas and infiltrated to the duodenal wall. (2) Hyperecho image was obtained in 81.8% of the cases and hypoecho image in 18.2% of the cases. (3) The accuracy of EUS in demonstrating the invasion of the carcinoma into the duodenal wall, common bile duct, pancreatic duct and the head of the pancreas was 83.3%, 66.7%, 50.0% and 33.3% respectively and the lymph node matastasis of the carcinoma was 100.0%.

[The study of relationship between c-erbB2 expression and cytoimmunology in ovarian carcinoma and its antisense regulation]

The relationship between c-erbB2 expression and cytoimmunology in ovarian carcinoma cell lines was studied; the synthesized and modified c-erbB2 antisense oligodeoxynucleotide was tested for its ability to reduce over-expression of c-erbB2. The results showed that over-expression of c-erbB2 in ovarian carcinoma could induce resistance to tumor necrosis factor (TNF) and lymphokine activated killer (LAK) cells but had no effect on H2O2; c-erbB2 antisense oligodeoxynucleotide could specifically reduce the over-expression of c-erbB2 and increase the sensitivity of ovarian cancer targets to lysis by TNF and LAK cells.

Cell types in the rostral nucleus of the solitary tract

The rostral subdivision of the nucleus of the solitary tract (rNST) is not laminated or otherwise organized into clearly segregated cell types. Although a variety of experimental approaches have yielded a wealth of information, the definition of cell types in this nucleus has been difficult, as reflected in the sometimes contradictory literature on morphological cell typing. The present review discusses how rNST neurons have been classified in the past and adds to the evidence that distinct neuron types exist in this nucleus. Consistencies in the literature, as well as inconsistencies among studies, are discussed. Furthermore, we have included a summary of our own results that help provide additional data relevant to cell typing. The definition of cell types in other central nervous system nuclei has helped our understanding of the organization of these nuclei and our understanding of the relationships between the morphology and function of neurons. It is hoped that this synthesis of the extant literature will facilitate the many ongoing efforts to correlate neuronal morphology and physiology in the gustatory system.

[Protective effects of methanolic extract of Oenanthe stolonifera (Roxb.) Wall. ex DC. on myocardial injury induced by ischemia and reperfusion in rats]

The methanolic extract Oenanthe stoloni fera iv, pretreatment can significantly prevent the arrhythmias induced by myocardial ischemia and reduce the myocardial infarct size in rats. It can also markedly prevent myocardial ischemia and reperfusion-induced arrhythmias. In addition, the methanolic extract of Oenanthe stoloni fera (100 mg/kg i.v.) helps significantly to decrease the MDA content and preserve the SOD activity in plasma.

Structure and function of gustatory neurons in the nucleus of the solitary tract. I. A classification of neurons based on morphological features

Prior investigations in other laboratories have provided convincing evidence that the neurons of the rostral nucleus of the solitary tract (rNST) can be grouped according to their physiological response properties or morphologic features. The present study is based on the premise that the response properties of gustatory neurons are related to, and perhaps governed by, their morphology and connectivity. In this first phase of our ongoing investigation of structure-function relationships in the rNST of the rat, we have used intracellular injection of neurobiotin to label individual physiologically characterized gustatory neurons. A total of 63 taste-sensitive neurons were successfully labeled and subjected to three-dimensional quantitative and qualitative analysis. A cluster analysis using six morphologic features (total cell volume, soma area, mean segment length, swelling density, spine density, and number of primary dendrites) was used to identify six cell groups. Subsequent analyses of variance and posthoc comparisons verified that each of these six groups differed from all others with respect to at least one variable, so each group was "typified" by at least one of the six morphologic features. Neurons in group A were found to be the smallest neurons in the sample. The cells in group B had small somata and exhibited the highest swelling density of any group. Group C neurons were distinguished by dendrites with long, spine-free branches. These dendrites were significantly longer than those of any other group except Group F. The neurons in group D had more primary dendrites than any other group. Group E neurons possessed dendrities with the lowest swelling density but the most spines of any group. The cells in group F were the largest neurons in our sample and possessed the largest somata of any group. Thus overall cell size and density of dendritic spines and swellings were found to be particularly important variables in this classification scheme. Our preliminary results suggest that the number and density of dendritic spines (as well as other morphologic features) may be related to a given neuron's most effective stimulus, indicating that it will indeed be possible to use the criteria established in the present investigation to derive structure-function relationships for gustatory neurons in the rNST.

Effect of extracellular K+ on hatching and outgrowth of mouse blastocysts in vitro

The dependence of blastocyst development on the extracellular Na+/K+ ratio was investigated in an in vitro system. Hatching and outgrowth of mouse blastocysts was enhanced at Na+/K+ ratios between 3 and 10 compared to the ratio of about 25 typical for most culture media and serum. At a Na+/K+ ratio of 2, blastocyst hatching and outgrowth were inhibited. The requirement of blastocyst development for relatively high extracellular K+ concentrations agrees with the fact that K+ concentrations in oviduct and uterine secretions are higher than in serum. The findings can also be relevant in optimizing in vitro culturing techniques for blastocysts.