A modified autowasher device for rapidly washing large numbers of EM-grids

This device consists of a siphon system and 5 or 10 grid disks, modified from the previous mode (Chen, 1973), for large numbers of grids with ultrathin sections. This method improves the ease of assembling grids onto the grid disk and also requires much less stain solution. This system only takes 5 min for one single stain washing, at a maximum of 100 grids, and also avoids stain contamination. The grid disk can also be used for immunocytochemistry work and for critical point drying of grids with biological specimens.

The crystal and molecular structure of trichosanthin at 2.6 A resolution

The crystallographic refinement of trichosanthin has been performed at 2.6 A resolution. The crystal and molecular structure of trichosanthin is described in detail in this paper. On summarizing the regularity of the amino acid sequences of eight kinds of ribosome inactivating proteins and combining with the crystal and molecular structure of trichosanthin, fifteen most conservative amino acid residues are analyzed. It is found that four most conservative polar amino acid residues Gln156, Glu160, Arg163 and Glu189 gather on the molecular surface on the boundary of the large and small domains, thus forming the active center of the protein molecule.

Cloning and expression of a novel phosphatidylethanolamine N-methyltransferase. A specific biochemical and cytological marker for a unique membrane fraction in rat liver

Phosphatidylethanolamine N-methyltransferase catalyzes the synthesis of phosphatidylcholine from phosphatidylethanolamine and is most active in liver. A cDNA for this enzyme from a rat liver cDNA library has been cloned, sequenced, and expressed in COS-1 cells, McArdle-RH7777 rat hepatoma cells, and Sf9 insect cells. The expressed protein was capable of converting phosphatidylethanolamine into phosphatidylcholine in intact COS-1 cells, which normally have very low methyltransferase activity. The calculated molecular mass of the methyltransferase protein is 22.3 kDa, which is equivalent to that of the pure protein isolated from rat liver. Comparison of the sequence of the cloned rat liver methyltransferase with the yeast phosphatidylethanolamine methyltransferase PEM2 gene product revealed 44% identical amino acids and 68% similarity in the two predicted protein sequences. A polyclonal antibody was raised against a synthetic peptide corresponding to the carboxyl-terminal region of the enzyme and was affinity purified. The antibody recognized a single protein with a molecular mass of approximately 20 kDa when either rat liver proteins or proteins derived from the transfected COS-1 cells were electrophoresed on polyacrylamide gels containing sodium dodecyl sulfate. Surprisingly, the antibody exhibited no reactivity with endoplasmic reticulum proteins, even though the major phosphatidylethanolamine methyltransferase activity resides on this subcellular organelle. Instead, the antibody specifically recognized a protein in a unique subcellular membrane fraction purified from a crude mitochondrial preparation on a Percoll gradient. Immunocytochemical examination by electron microscopy showed positive labeling only in unique regions of the hepatocytes. The data suggest that this phosphatidylethanolamine methyltransferase is a specific marker for this unique membrane fraction.

[Chemical constituents of Cistanche deserticola Y.C.Ma]

Seven compounds have been isolated from Cistanche deserticola. On the basis of spectral data (NMR, IR, MS, UV) they were identified as beta-sitosterol, daucosterol, succinic acid, triacontanol, acteoside, betaine and polysaccharose.

Correlation of intrinsic chemoresistance of non-small-cell lung cancer cell lines with HER-2/neu gene expression but not with ras gene mutations

BACKGROUND

At diagnosis, most small-cell lung cancers (SCLCs) are chemosensitive, whereas non-small-cell lung cancers (NSCLCs) are usually chemoresistant. Activation of ras genes and HER-2/neu genes (also known as ERBB2) is encountered in subpopulations of NSCLC but not in SCLC and has been linked to shortened survival. Therefore, activation of these genes may be associated with intrinsic chemoresistance in NSCLC. Studies have also suggested that the multidrug-resistant phenotype expressed by the MDR1 gene (also known as PGY1) does not correlate with the in vitro chemosensitivity of NSCLC cells or with clinical response to therapy and does not explain the spectrum of cross-resistance to drugs.

PURPOSE

The purpose of this study was to investigate the relationships between chemoresistance and the presence of ras gene point mutations and overexpression of the HER-2/neu gene in NSCLC cell lines, which indicates gene activation.

METHODS

Using a panel of 20 NSCLC cell lines established from untreated patients, we assessed the differences in HER-2/neu messenger RNA (mRNA) expression in the cell lines with or without ras mutations. We performed in vitro drug sensitivity testing by the tetrazolium-based MTT [i.e., 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H- tetrazolium bromide] assay with doxorubicin, carmustine, cisplatin, melphalan, mitomycin, and etoposide, and we determined the differences in IC50 values (i.e., the drug concentrations required to inhibit cell growth by 50%) for the cell lines.

RESULTS

We found a statistically significant correlation between the IC50 values for all six drugs and the degree of HER-2/neu gene expression in all 20 cell lines (r = .67-.86; P < .005) as well as in the subpopulation of eight cell lines with ras mutations (r = .83-.98; P < .05). The IC50 values for doxorubicin, carmustine, cisplatin, and melphalan were not significantly different in the cell lines with or without ras mutations, but the values for mitomycin and etoposide in lines with ras mutations were slightly lower than in those without ras mutations (borderline significance, P = .031). Levels of HER-2/neu expression in cell lines with ras mutations were lower than those without ras mutations, but the difference was not statistically significant.

CONCLUSION

Our findings indicate that overexpression of HER-2/neu is a marker for intrinsic multidrug resistance in NSCLC cell lines.

IMPLICATIONS

If the clinical relevance of our findings is confirmed, HER-2/neu gene expression can be used as a predictor of therapeutic failure in NSCLCs. The relationships between HER-2/neu gene expression, cell proliferation, and chemoresistance in NSCLC require further investigation.

[Diagnostic value of morphological change observed by ultrasonography from skin surface in patients with cervical esophagus carcinoma]

The ultrasonography of cervical esophagus from skin surface was performed in 35 healthy adults (HA) and 46 patients with esophageal carcinoma which consisted of upper segment (USEC, n = 24) and lower one (LSEC, n = 22) divided by the level of sternoclavicular joint. The changes of the thickness of anterior wall and the luminal dimensions in the upper region were observed before and after phonating, respectively. The wall of HA was less than 2mm in thickness and became markedly thick after phonation (P < 0.05); meanwhile the lumen was evidently dilated (P < 0.01). USEC showed an irregular wall which was more than 4mm and not altered with phonation (P > 0.05). The significant differences of the above two morphologic alterations existed between HA and USEC respectively (P < 0.05 or P < 0.01). The results of LSEC were similar to HA (P > 0.05). We, therefore, establish standards for abnormal cervical esophagus to assist in the diagnosis of cervical esophageal carcinoma.

Mechanism of cerebral vasospasm following subarachnoid hemorrhage in monkeys

This paper reviews our recent studies on the mechanism of cerebral vasospasm following subarachnoid hemorrhage (SAH) in monkeys. Middle cerebral artery (MCA) vasospasm was maximal at 7 days, resolving by 14 days, and absent at 28 days after SAH. Arterial fibrosis was not detected during vasospasm, although there was intimal hyperplasia with fibrosis 28 days after SAH. On scanning electron microscopy, smooth muscle cells from vasospastic arteries had corrugated cell membranes and appeared similar to cells contracted pharmacologically, suggesting that vasospastic smooth muscle is contracted. Morphometric analysis of arteries obtained 7 days after SAH showed no significant increases in arterial wall area of vasospastic arteries compared with normal MCAs. The results suggest vasospasm in monkeys is not due to hypertrophy, hyperplasia, or fibrosis in the arterial wall. Vasospasm may be mainly vascular smooth muscle contraction, which damages the arterial wall, leading to secondary structural changes in the arterial wall which occur after angiographic vasospasm.

Intestinal malrotation and gastric perforation in a newborn with tetralogy of Fallot: report of one case

Gastric perforation with gastrointestinal anomaly is rare in newborns. A case of Tetralogy of Fallot with both malrotation and gastric perforation is reported. Before operation, malrotation was diagnosed from the x-ray films. Laparotomy disclosed a linear perforation on the posterior wall of the gastric body. Mechanical obstruction might have played a role in this case.

Plant regeneration from Carica protoplasts

Rapidly proliferating and highly regenerable suspension cultures of somatic embryos of Carica papaya x C. cauliflora were used for protoplast isolation. On average, protoplast yield was 1.5×10(6)/g fresh weight of somatic embryos. Protoplasts were first cultured in liquid KM8P-S medium for 2 weeks and then plated in the same medium solidified with 1% agarose. About 1.4% of the protoplasts developed directly into somatic embryos. Protoplast-derived somatic embryos proliferated rapidly through direct embryogenesis on modified MS medium supplemented with 1 mg/1 ABA, and developed into plantlets upon transfer to MS medium devoid of plant growth regulators. The plantlets were successfully transplanted to soil.

Oxyntic and antral gastritis in the People's Republic of China: diagnosis and relationship to Helicobacter pylori

This study investigates the relationship between gastritis and Helicobacter pylori infection in the Chinese population. Particular focus was placed upon the grading of gastritis, using the recently developed "Sydney system." Five diagnostic procedures were used to establish H. pylori status, all of which were found to be highly sensitive and specific. Histological chronic gastritis was reported in 93/108 (86.1%) of the patients examined, H. pylori infection being present in 73/93 (78.5%), and in no patient with histologically normal mucosae. There was a relatively high incidence of idiopathic antral gastritis within the gastritic population, 20/93 (21.5%). In the H. pylori-positive group, 10/73 (13.7%) had pangastritis, 57/73 (78.1%) had pangastritis-antrum-predominant, and 6/73 (8.2%) had antral-only gastritis. The level of activity was significantly higher in the antrum; however, the distribution of bacteria between the antrum and body was not significantly different. There is a need for additional studies examining the specific topographical relationship between H. pylori, the histology, and gastroduodenal disease.

Scanning electron microscopy of normal and vasospastic monkey cerebrovascular smooth muscle cells

Normal cytoarchitecture of smooth muscle cells of monkey cerebral arteries was studied using scanning electron microscopy after removal of adventitial connective tissue by hydrolysis with HCl. Cerebral arteries were also examined after contraction in vitro with prostaglandin F2 alpha (PGF2 alpha). Anterior cerebral arteries were studied after exposure for 6 days in vivo to whole blood, oxyhemoglobin, methemoglobin, bilirubin, mock cerebrospinal fluid, or supernatant fluid from an incubated mixture of autologous blood and mock cerebrospinal fluid. Normal smooth muscle cells were spindle-shaped and oriented circumferentially around the vessel. They were often grouped into bundles of 5 to 10 cells; bundles were recognizable because cells within them were joined by multiple intercellular contacts. Groups of smooth muscle cells oriented longitudinally were present outside the circular layers of cells. The adventitial surface of muscle cells was smooth apart from fine longitudinal striations in some areas. Arteries contracted with PGF2 alpha had markedly convoluted and folded cell membranes. Muscle cells of vasospastic arteries and of arteries exposed to oxyhemoglobin and supernatant fluid appeared identical to cells contracted with PGF2 alpha. The outer surface of cells of arteries exposed to bilirubin, methemoglobin, and mock cerebrospinal fluid were normal. Marked similarity between vasospastic smooth muscle cells and smooth muscle cells from arteries contracted with PGF2 alpha suggest that smooth muscle contraction occurs during "vasospasm" due to whole blood and to intrathecal injection of oxyhemoglobin.

Transfer function analysis of the circulation: unique insights into cardiovascular regulation

We have demonstrated previously that transfer function analysis can be used to precisely characterize the respiratory sinus arrhythmia (RSA) in normal humans. To further investigate the role of the autonomic nervous system in RSA and to understand the complex links between respiratory activity and arterial pressure, we determined the transfer functions between respiration, heart rate (HR), and phasic, systolic, diastolic, and pulse arterial pressures in 14 healthy subjects during 6-min periods in which the respiratory rate was controlled in a predetermined but erratic fashion. Pharmacological autonomic blockade with atropine, propranolol, and both, in combination with changes in posture, was used to characterize the sympathetic and vagal contributions to these relationships, as well as to dissect the direct mechanical links between respiration and arterial pressure from the effects of the RSA on arterial pressure. We found that 1) the pure sympathetic (standing + atropine) HR response is characterized by markedly reduced magnitude at frequencies greater than 0.1 Hz and a phase delay, whereas pure vagal (supine + propranolol) modulation of HR is characterized by higher magnitude at all frequencies and no phase delay; 2) both the mechanical links between respiration and arterial pressure and the RSA contribute significantly to the effects of respiration on arterial pressure; 3) the RSA contribution to arterial pressure fluctuations is significant for vagal but not for sympathetic modulation of HR; 4) the mechanical effects of respiration on arterial pressure are related to the negative rate of change of instantaneous lung volume; 5) the mechanical effects have a higher magnitude during systole than during diastole; and 6) the mechanical effects are larger in teh standing than the supine position. Most of these findings can be explained by a simple model of circulatory control based on previously published experimental transfer functions from our laboratory.

Effects of ginseng stem-leaves saponins on one-way avoidance behavior in rats

Using a multiple-trial, training-to-criterion procedure, the effects of repeated administrations of ginseng stem-leaves saponins (GSLS) on learning and memory of one-way avoidance in rats were studied in shuttle-box. In acquisition, GSLS 10, 30, and 60 mg.kg-1 ip shortened the latency of avoidance in a bell-shaped manner from 1.0 +/- 0.2 s in saline rats to 0.8 +/- 0.5, 0.5 +/- 0.1, 0.8 +/- 0.2 s (d 3 learning) and from 0.9 +/- 0.2 s to 0.8 +/- 0.2, 0.7 +/- 0.1, and 0.8 +/- 0.2 s (10 x 24 h memory), and the best dose was 30 mg.kg-1. GSLS 30 mg.kg-1 ip shortened the latency of avoidance prolonged by scopolamine 0.8 mg.kg-1 sc from 5.2 +/- 1.3 s to 3.9 +/- 0.8 s (d 1 learning acquisition) and from 2.2 +/- 0.6 s to 0.8 +/- 0.3 s (3 x 24 h memory acquisition). In retention, GSLS 30 mg.kg-1 ip shortened the latency prolonged by cycloheximide 2.5 and 5 mg.kg-1 ip from 3.4 +/- 1.0 s to 1.4 +/- 0.5 s (4 h memory) and from 1.6 +/- 0.3 s to 0.9 +/- 0.2 s (24 h memory), and increased the avoidance number decreased by cycloheximide 5 mg.kg-1 from 38.1 +/- 8.8% to 72.4 +/- 10.8% (4 h memory). The results indicate that GSLS facilitated the acquisition of learning and memory in rats, and improved the scopolamine amnesia and cycloheximide amnesia.

Tension pneumocephalus following ventriculoperitoneal shunt: a case report

A case of tension pneumocephalus following suboccipital craniectomy and ventriculoperitoneal (VP) shunt surgery for obstructive hydrocephalus due to the presence of a cerebellopontine (CP) angle tumor is reported. The air entries were found on both sides of the frontal skull base. The formation of the fistula may have been either due to congenital bony defects or chronically elevated intracranial pressure. Iopamidol computed tomographic (CT) cisternogram was one of the diagnostic tools. Direct surgical repair of those bony-dural defects was mandatory in the prevention of the recurrence of the pneumocephalus.

Ischemic neuronal damage after acute subdural hematoma in the rat: effects of pretreatment with a glutamate antagonist

The ability of a competitive N-methyl-D-aspartate (NMDA) receptor antagonist (D-CPP-ene) to reduce irreversible brain damage has been examined in a rodent model of acute subdural hematoma. Acute subdural hematoma was produced by the slow injection of 400 microliters homologous blood into the subdural space overlying the parietal cortex in halothane-anesthetized rats. Brain damage was assessed histologically in sections at multiple coronal planes in animals sacrificed 4 hours after induction of the subdural hematoma. Pretreatment with D-CPP-ene (15 mg/kg) significantly reduced the volume of ischemic brain damage produced by the subdural hematoma from 62 +/- 8 cu mm (mean +/- standard error of the mean) in vehicle-treated control rats to 29 +/- 7 cu mm in drug-treated animals. These data demonstrate the anti-ischemic efficacy of NMDA antagonists in an animal model of intracranial hemorrhage in which intracranial pressure is elevated, and suggest that excitotoxic mechanisms (which are susceptible to antagonism by D-CPP-ene) may play a role in the ischemic brain damage which is observed in patients who die after acute subdural hematoma.

Correlation of the extracellular glutamate concentration with extent of blood flow reduction after subdural hematoma in the rat

The excitatory neurotransmitters glutamate and aspartate are an important factor in the causation of ischemic brain damage. The concentration of glutamate and aspartate was serially measured in extracellular fluid using in vivo microdialysis after induction of a subdural hematoma or after a sham operation in the rat. Measurements were made in the cortex underlying the hematoma and in the ipsilateral hippocampus, and these findings were correlated with regional cerebral blood flow (CBF), measured autoradiographically 2 hours after hematoma induction. In the severely ischemic cortex underlying the hematoma (mean CBF less than 25 ml/100 gm/min), glutamate and aspartate content increased more than 750% over basal levels. In individual animals the magnitude of glutamate release correlated with the extent of the focal ischemic zone under the hematoma (r = 0.907). Hippocampal glutamate levels rose 339%, yet regional CBF was preserved (114 ml/100 gm/min). This accords with focal hypermetabolism in this model, and may imply a glutamate-mediated "excitotoxic" process after subdural hematoma.

Jejunal atresia with "apple peel" deformity: report of one case

A case of jejunal atresia with "apple peel" deformity is presented. A 27-year-old woman, gravida 3, para 2, suffered from premature labor pain and vaginal bleeding at 32 weeks of gestation. Prenatal ultrasound examination revealed presence of three areas of cystic dilatation in the fetal abdomen and marked polyhydramnios, indicating a high bowel obstruction. A female baby was delivered by Cesarean section with Apgar scores of 7 and 8 at one and five minutes, respectively. Physical examination showed abdominal distention. Nasogastric tube aspiration got more than 50 ml of blood-tinged fluid. Roentgenography demonstrated a high jejunal obstruction as well as a normally rotated colon. Laparotomy disclosed proximal jejunal atresia with typical "apple peel" appearance of the distal small bowel. An end-to-end anastomosis was performed smoothly after resection of both the proximal and distal small bowels. A reduction tapering antimesenteric jejunoplasty was also done. Partial parenteral nutrition had been administered for 10 days followed by enteric feeding. The postoperative course was uneventful. Her chromosomal analysis revealed a normal karyotype of 46,XX.