[Cardiac arrest during transurethral resection of the prostate]

Due to the development of anesthetic drugs and techniques, and the progress of monitor system. The rate of cardiac arrest during anesthesia has declined during the last decades. We report two cases of sudden cardiac arrest which happened during transurethral resection of the prostate, and discuss the mechanism, treatment, and the methods of prevention.

Expression of Epstein-Barr virus in carcinomas of major salivary glands: a strong association with lymphoepithelioma-like carcinoma

To elucidate the role of Epstein-Barr virus (EBV) in salivary gland carcinomas, 56 cases of carcinomas of major salivary glands were investigated. These included 14 mucoepidermoid carcinomas, 13 adenoid cystic carcinomas, seven malignant mixed tumors, four adenocarcinomas, four salivary duct carcinomas, two acinic cell carcinomas, two undifferentiated carcinomas without lymphoid stroma, seven lymphoepithelioma-like carcinomas (LELCs), two squamous cell carcinomas, and one small cell carcinoma. EBV transcripts were examined by in situ hybridization using digoxigenin-labeled oligonucleotide antisense probe for EBV-encoded RNA 1 (EBER1) on formalin-fixed paraffin-embedded tissue sections. EBER1 was detected in the malignant epithelial cells in all seven cases of LELC, but not in any of the other carcinomas and the neighboring normal salivary gland tissue. Because all the EBV-negative cases showed satisfactory labeling with the poly d(T) probe, the negative reaction with EBER1 was unlikely to be caused by poor RNA preservation in the tissues. The seven cases of LELC, which were histologically indistinguishable from undifferentiated nasopharyngeal carcinoma (NPC), had a disease-free 4-year survival rate of 85.7%. The results suggest that LELC of the salivary gland in Taiwanese Chinese may share similar EBV-related pathogenesis with that of NPC.

Use of enzyme-linked immunosorbent assay and radioimmunoassay to determine serum and urine dexamethasone concentrations in thoroughbreds after intravenous administration of the steroid

OBJECTIVE

To develop a simple and sensitive ELISA for detection of dexamethasone in horse serum and urine.

SAMPLE POPULATION

Blood and urine samples from 3 thoroughbred mares.

PROCEDURE

A dexamethasone oxime was prepared and conjugated to hemocyanin, bovine serum albumin and to horseradish peroxidase. One- and two-step double-antibody ELISA methods, as well as a radioimmunoassay method, were performed. The one-step ELISA was used to test urine from 3 Thoroughbred mares injected with 5 mg of dexamethasone, IV.

RESULTS

The ELISA could detect dexamethasone in the range of 0.01 to 50 ng/ml, with intra- and interassay variations of 8.92 and 9.42%, respectively. Serum dexamethasone concentration reached a peak of 20 to 35 ng/ml 15 minutes after steroid administration and decreased to 1 ng/ml in 2.5 hours. Urine dexamethasone concentration 18 to 50 ng/ml 1 to 2 hours after drug administration and decreased to 1 ng/ml at 10 hours.

CONCLUSION

The developed assay is sensitive as well as simple for detecting dexamethasone in horse serum and urine, and is comparable to radioimmunoassay.

CLINICAL RELEVANCE

This method can be useful for screening samples from racehorses, because it is sensitive and does not require sample preparation or sophisticated equipment.

Etiology of lymphadenopathy in patients with AIDS in Taiwan

From 1986 to 1995, we retrospectively reviewed the records of 40 of 125 patients (32.0%) with acquired immunodeficiency syndrome (AIDS) who presented with extrainguinal lymphadenopathy. Most of the patients had an advanced stage of HIV infection with a mean CD4 lymphocyte count of 44/mm3. AIDS-defining opportunistic infections and malignancies were present in most patients and the neck region was the most common site of involvement. The etiology of lymphadenopathy was established in 26 patients. Tuberculous lymphadenitis was the most common cause, followed by lymphadenopathic Kaposi's sarcoma, benign reactive hyperplasia, cryptococcal lymphadenitis and disseminated Mycobacterium avium complex infection. Characteristic histopathologic findings were detected in 19 patients and 7 had presumptive tuberculous infections. The remaining 14 patients had no definitive etiology for their lymphadenopathy. As the causes are variable and the number of HIV/AIDS cases is increasing in Taiwan, more patients with lymphadenopathy, especially in the early stages of HIV infection will be encountered. Therefore, it is essential that diagnostic histopathologic and microbiologic studies be performed for appropriate and timely treatment.

Inter-observer variability of portal hemodynamics measured by Doppler ultrasound on three different locations of portal vein

Doppler ultrasound is a noninvasive modality for portal hemodynamic study. However, inter-observer variability has been observed. This study has investigated ways to produce less inter-observer variability. Doppler ultrasound portal vein hemodynamic studies were carried out by three well-trained specialists on 20 healthy hospital staff members. The intra-hepatic, first branch, right portal vein, the hilar portal vein, and the extra-hepatic portal vein were chosen for study. With respect to the diameter of portal veins, a significant inter-observer variability was found for the first branch right portal vein and the extra-hepatic portal vein, but not for the hilar portal vein. For maximal portal vein velocity studies, inter-observer variability was not found at any location. A significant failure rate was noted for the measurement of extra-hepatic portal vein velocity. Only 8 volunteers had complete data from all of the three investigators. A significant variability was also noted for the average velocity of extra-hepatic portal vein. We conclude that Doppler ultrasound hemodynamic studies of the hilar portal vein has the most acceptable inter-observer variability and thus should be used for longitudinal portal hemodynamic studies.

Variations of the left and middle hepatic veins: application in living related hepatic transplantation

The anatomic variations of the middle hepatic vein (MHV) and left hepatic vein (LHV) in 200 patients with normal liver function were analyzed using ultrasonography to clarify the feasibility of resecting the left lobe or left lateral segment in living subjects for living related hepatic transplantation (LRHT). The MHV and LHV form a common trunk in 70% of cases but drain independently into the inferior vena cava (IVC) in 30%. In 7% of cases, the left median vein (LMV) drains into the MHV, in 32% of cases the anterior superior segmental vein (ASSV) that drains segment 8 flows into the MHV. The distance between the two confluence points (LHV flows into MHV or IVC and LMV flows into the MHV) ranged from 0.3 cm to 2.5 cm with an average of 0.75 cm. The diameter of the LMV at the point that flows into MHV ranged from 0.3 cm to 0.9 cm. with an average of 0.61 cm. The distance from the IVC to the confluence of the MHV and LHV ranged from 0 cm to 3.5 cm with an average of 1.5 cm in those cases whose MHV and LHV presented as common trunks. Preoperative delineation of this complex venous anatomy is of paramount importance because the hepatic veins have to be transected in the cutting plane of the liver. The location of this plane is determined by the optimal graft volume required, and both the graft and the remnant liver have to retain perfect function. The venous anatomy would change the cutting plane in the living donor and the surgical method of anastomosis for the recipient.

Induction of 8-hydroxydeoxyguanosine in DNA by chromium(III) plus hydrogen peroxide and its prevention by scavengers

The capability of Cr(III) to induce DNA lesions generated by oxidative damage was investigated in this study by examining the formation of 8-hydroxydeoxyguanosine (8-OHdG) in calf thymus DNA by CrCl3 and/or H2O2 in 10 mM phosphate buffer. In the presence of 0.5 mM H2O2, the formation of 8-OHdG markedly increased with increasing CrCl3 concentration. In contrast, H2O2 or CrCl3 alone did not cause any increase in 8-OHdG level above background. The amount of 8-OHdG induced by CrCl3 plus H2O2 was time dependent; its generation increased linearly over an incubation period of 90 min. The formation of 8-OHdG was unfavorable in an acidic solution (pH < 6); the highest level of 8-OHdG was observed at pH 7-8. Scavengers of reactive oxygen species markedly inhibited the formation of 8-OHdG by CrCl3 plus H2O2; the inhibition effect was sodium azide > D-mannitol > Tris-HCl at an equal concentration. The induction of 8-OHdG by CrCl3 plus H2O2 remained unchanged in D2O. Moreover, an addition of catalase (2.2 U/ml) to the reaction mixture completely inhibited the formation of 8-OHdG by CrCl3/H2O2, whereas only 22% of that formation was inhibited by superoxide dismutase (11 U/ml). A large amount of bovine serum albumin (1.1 mg/ml) could reduce the formation of 8-OHdG by CrCl3 plus H2O2, thereby implying that Cr(III)-mediated DNA-protein crosslinks are unfavorable for 8-OHdG formation. Furthermore, ascorbate could prevent the formation of 8-OHdG by CrCl3 plus H2O2; the extent of prevention increased with increasing ascorbate concentration (10 microM-3 mM). Thus, ascorbate acts as a free radical scavenger in the CrCl3/H2O2 system. The above findings suggest that Cr(III)/H2O2 could generate oxidative damage to DNA, possibly through a Fenton-like reaction, i.e. Cr(III)+H2O2-->Cr(IV)+.OH+OH-. This study also indicates that Cr(III), previously considered as the ultimate kinetically stable species of Cr(VI) metabolites, is capable of inducing carcinogenic lesions through interaction with a cellular oxygen species.

Metabolic, hormonal, and hemodynamic changes during dopamine infusions in halothane anesthetized horses

Selected metabolites, hormones and cardiovascular variables were measured in halothane anesthetized horses during 1 hour of dopamine infusion at a rate of 5 micrograms/kg/min (low) and 10 micrograms/kg/min (high), and for 1 hour after infusion. Plasma cortisol increased twofold in the low-infusion group but did not change significantly in the high-infusion group. Plasma nonesterified fatty acids, blood glucose, blood lactate, and plasma insulin increased in the high-infusion group. There was little difference in heart rate, systolic, diastolic, and mean arterial blood pressure between the two groups. The high infusion was associated with arrhythmias in several horses, and one horse showed ventricular fibrillation and died. If metabolic and hormonal changes are used as markers of a "stress response" in anesthetized horses the results must be carefully interpreted if a sympathomimetic agent such as dopamine is administered to maintain cardiovascular stability.

Micellar electrokinetic capillary chromatography combined with immunoaffinity chromatography for identification and determination of dexamethasone and flumethasone in equine urine

A capillary electrophoresis technique was developed for the separation of synthetic glucocorticoids and the determination of dexamethasone and flumethasone in horse urine. Pretreatment of the sample using a dexamethasone affinity column resulted in low background that enabled the authors to detect levels as low as 1.1 ng/mL and 2.7 ng/mL for dexamethasone and flumethasone in horse urine, respectively. The developed method was used to detect dexamethasone in horse urine samples after the injection of a therapeutic dose of dexamethasone for up to 12 hr postinjection. The optimum conditions for capillary electrophoresis and dexamethasone elution from the affinity column are described.

Oxidative damage to DNA induced by areca nut extract

In Taiwan, people chew betel quid which contains tender areca nut with husk. In other countries, people prefer ripe and dried areca nut without husk. In this study, we compared the reactive oxygen species-induced oxidative DNA damage in isolated DNA and CHO-K1 cells between treatments with tender areca nut extract (ANE) and ripe ANE. Incubation of these two ANE preparations with isolated DNA generated 8-hydroxy-2'-deoxyguanosine (8-OH-dG) in an alkaline environment in a dose-dependent manner. Ripe ANE generated higher levels of 8-OH-dG compared to tender ANE. The addition of iron(II) (100 microM) resulted in 1.4- and 3.1-fold increases of 8-OH-dG when incubated with 1 mg/ml each of tender and ripe ANE. In testing the effect of ANE to cellular DNA, CHO-K1 cells were used for its documented sensitivity to reactive oxygen species. In CHO-K1 cells, ripe ANE was more cytotoxic than tender ANE following an 18-h incubation. The cytotoxicity to CHO-K1 cells was positively correlated with the formation of 8-OH-dG following tender (r=0.97) and ripe (r=0.91) ANE treatment. Addition of the iron chelating agent o-phenanthroline (10 and 20 microM) to cells prior to ri ANE exposure significantly increased (p<0.05) the survival of CHO-K1 cells. In addition, ripe ANE induced dichlorofluorescein-mediated fluorescence which indicated the formation of hydrogen peroxide in CHO-K1 cells. In conclusion, this study demonstrated that ANE-induced oxidative damage to isolated and cellular DNA which may result from the generation of hydrogen peroxide, and iron may serve as a catalyst in this process. Furthermore, ripe ANE generated higher oxidative DNA damage levels compared to tender ANE.

Improvement of arterial oxygenation by selective infusion of prostaglandin E1 to ventilated lung during one-lung ventilation

BACKGROUND

One-lung anesthesia provides a better surgical field for thoracic procedures but also impairs the arterial oxygenation and venous admixture. During one-lung ventilation, pulmonary vasoconstriction is assumed to be present within both ventilated and collapsed lungs. We propose that arterial oxygenation could be optimized by offsetting the vasoconstriction within the microcirculation of ventilated lung.

METHOD

In an anesthetized dog model, incremental doses of prostaglandin E1 (PGE1) were selectively infused into the main trunk of the pulmonary artery of the ventilated lung after one-lung ventilation for 60 min (PGE1 group, n = 9). Arterial oxygenation and calculated venous admixture (Qs/Qt) was also assessed in a time-course control group (Control group, n = 5). During two-lung ventilation (FIO2: 0.66), arterial PO2 and venous admixture was 44.2 +/- 3.5 kPa and 10.7 +/- 2.3%, respectively. One-lung ventilation (FIO2: 0.66) with left lung collapsed reduced arterial PO2 to 11.6 +/- 1.7 kPa and increased venous admixture to 40.7 +/- 5.8% (P<0.001). Venous O2 tension also decreased from 6.3 +/- 0.7 kPa to 5.0 +/- 0.6 kPa with a slight increase in mean pulmonary artery pressure and pulmonary vascular resistance (P<0.05).

RESULTS

During selective infusion of PGE1 at a dose of 0.04 to 0.2 mu g kg-1 min-1, there was a dose-dependent improvement in arterial PO2 with a parallel reduction of venous admixture during one-lung ventilation. Arterial PO2 increased to a maximum of 23.0 +/- 4.3 kPa, and the venous admixture decreased significantly to a minimum of 27.4 +/- 4.2% by PGE1 at a dose of 0.04-0.4 mu g kg-1 min-1 (P<0.01). PGE1 resulted in a small increase in cardiac output and decreases of pulmonary pressure and pulmonary vascular resistance at a relatively high dose of 0.4 mu g kg-1 min-1 during selective infusion (P<0.05).

CONCLUSIONS

These results suggest that a selective pulmonary artery infusion of PGE1 to the ventilated lung within the dose range of 0.04-0.4 mu g kg-1 min-1 is practical and effective to improve arterial oxygenation and reduce venous admixture during one-lung ventilation.

Differential expression of EBER1 in nontumor nasopharyngeal biopsies and nontumor component of nasopharyngeal carcinoma

The close association of Epstein-Barr virus (EBV) and nasopharyngeal carcinoma (NPC) is well documented and the expression of EBV-related latent genes has been shown in NPC. Nevertheless, the status of EBV infection in the nontumor epithelial and lymphoid cells is not known. In this study, we detected EBV in the nontumor component of NPC and nontumor nasopharyngeal biopsies by in situ hybridization using digoxigenin-labeled antisense EBER1 oligoprobe in 346 nasopharyngeal biopsies. Latent membrane protein (LMP) and ZEBRA were detected by immunohistochemistry in cases containing EBER1-positive cells. The EBV-positive epithelial and lymphoid cells were identified by immunostains for cytokeratin and lymphoid phenotypes. In the nontumor nasopharyngeal biopsies, 21 (11.7%) of 179 cases had EBV-harboring lymphocytes in the lymphoid tissue, while the overlying mucosa was all negative. LMP was demonstrated in lymphoid cells of 14 (66.7%) of these 21 samples. These EBV-positive lymphocytes were B lymphocytes by combined phenotype study. EBER1-containing metaplastic squamous cells were demonstrated in the overlying mucosa close to the tumor tissue in 14 (8.4%) of 167 NPC samples. In contrast, the respiratory epithelial cells in these cases were all negative. Two (1.2%) of these cases had EBV-positive lymphocytes in the lymphoid stroma. Four of the 346 cases had ZEBRA-positive cells. This study demonstrated that latent infection and, occasionally, active replication of EBV were present in stromal B lymphocytes in nasopharyngeal tissue with and without NPC. EBER1 was found only in the metaplastic squamous cells in the mucosa of nasopharyngeal tissues with NPC, but not in those without NPC.

Tumor angiogenesis correlates with histologic type and metastasis in non-small-cell lung cancer

This study investigated the clinico-pathologic correlation of tumor angiogenesis in non-small-cell lung cancers. Formalin-fixed, paraffin-embedded surgical specimens of 55 consecutive patients with primary non-small-cell lung cancers were examined. Included were 26 squamous cell carcinomas and 29 adenocarcinomas. Twenty-five patients had stage I disease, eight patients had stage II disease, and 22 patients had stage IIIA or IIIB disease. Among them, 28 had nodal metastasis and 27 did not. The microvessel was demonstrated by immunocytochemical staining for factor VIII and platelet endothelial cell adhesion molecules (PECAM-1). The microvessels in the areas of highest neovascularization were counted under light microscopy in 200x field by two independent observers without knowledge of clinical information. At least three separate fields were counted for each specimen. The Mann-Whitney U test was used for statistical analysis. The microvessel counts in adenocarcinoma were significantly higher than in the squamous cell carcinoma (54.4 +/- 35.65 versus 26.16 +/- 20.46 in factor VIII staining and 80.52 +/- 48.42 versus 40.04 +/- 32.33 in PECAM-1 staining; p < 0.001). The microvessel counts in patients with Stages I-II disease were significantly lower than that of stages IIIA-IIIB disease (23.63 +/- 16.21 versus 65.36 +/- 31.92 in factor VIII staining and 41.85 +/- 36.76 versus 93.00 +/- 43.08 in PECAM-1; p < 0.001). Patients with nodal metastasis had higher microvessel density than those without nodal metastasis (56.67 +/- 35.55 versus 23.44 +/- 15.77 in factor VIII staining and 86.89 +/- 46.46 versus 36.30 +/- 25.83 in PECAM-1 staining; p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

[Head injuries in children and adolescents: causes and natures]

To investigate the nature of exposure factors, and effectiveness of countermeasures in head injuries in children and adolescent of Taiwan area, we conducted a retrospective study on 820 children and adolescents with head injuries consecutively admitted to Chang Gung Memorial Hospital from January 1985 to December 1989. We analyzed the data by chart review and divided the cases into four age-groups: group A (0-4 years old), group B (5-9 years old), group C (10-14 year old) and group D (15-17 years old). The boy to girl ratio was 2.43. The largest proportions of head injuries were the adolescents in group D. The most common cause of head injury was traffic accidents (74%); while the falls were contributed the main cause in other studies. In all group A, B and D, the majority of traffic accidents were pedestrian injury; while in group D, the motorcyclists or car drivers were responsible for the accidents. Fall from height was the major cause of fall in all four age-groups, but it was fall from bicycle or during play or sports in group C. Injuries were most common in summer and clustered at afternoon in all patients. Majority of head injuries occurred outdoors. Most children and adolescents suffered from mild head injury, but there were still 203 cases with severe head injury (24%). Eighty-one cases (9.9%) were either discharged in critical condition or died at the hospital. There were no significant differences in mortality among four age-groups.

Determination of tetracycline residues in bovine milk, serum, and urine by capillary electrophoresis

A method was developed for simultaneous determination of oxytetracycline (OTC), chlortetracycline, tetracycline, and doxycycline levels in cow milk, serum, and urine by capillary electrophoresis (CE). The tetracyclines (TCs) were extracted specifically with a metal-chelating affinity column. Extracts were then applied to C18 cartridges treated with dimethyldichlorosilane, and the TCs were eluted with ethanol. Salt-free sample residues were run on CE with a diode array detector at 370 nm. A 50 cm x 75 micron uncoated capillary at 15 kV and 23 degrees C was used to separate the TCs. The run buffer contained 10 mM sodium dodecyl sulfate, 50 mM borate, and 50 mM phosphate, pH 8.5. TC peaks were identified by migration times, coinjection of standards, and diode array spectra. Limits of detection for TCs were 1.3-5.6 ng/mL, and limits of quantitation were 1.7-8.7 ng/mL in cow fluid samples. OTC appeared consistently at 13.3-13.4 min in milk, serum, and urine samples from a cow treated with OTC. OTC was further identified by coinjection of OTC standard and OTC diode array spectra. The CE method can be used to simultaneously determine 4 TC residues at low parts-per-billion levels.

The association of syndromic paucity of the interlobular bile ducts and congenital mechanical obstruction of the small intestine

Three patients with congenital mechanical intestinal obstruction and features of syndromic paucity of the interlobular bile ducts (SPILBD) are presented. Two of them have siblings with syndromic paucity of the interlobular bile ducts. Two patients had jejunoileal atresia, while the other had a meconium plug with intestinal perforation. All subjects underwent surgery for intestinal obstruction within the first 24 h of life. Progressive disappearance of the bile ductules was observed in one case. We believe that an insult such as vascular insufficiency to both bile ductal epithelium and the small intestine may be the cause of this congenital disorder.

[The incidence and mortality rates of head injuries in Kaohsiung City, Taiwan (1991-1992)]

Head injury is a leading cause of mortality, morbidity and disability in Taiwan. This study was based on data from the investigation of head injuries in Kaohsiung City, Taiwan, during the period July 1, 1991 to June 30, 1992. The 3729 cases identified represented an overall incidence rate of 267/100,000--359/100,000 for males and 170/100,000 for females. The highest incidence rate was seen in the elderly group, followed by the 20-29 year age group. The population with the highest risk was males aged 20-29 years, with an incidence rate of 585/100,000. Seventy percent of all cases were from motor vehicle-related causes, followed by falls (15.3%) and assaults (8.7%). Of the motor vehicle-related head injuries, 70.9% resulted from motorcycle accidents. The incidence rate of motor vehicle head injuries was 188/100,000--248/100,000 for males and 125/100,000 for females. At all ages motor vehicle head injuries were higher in males than in females. Mortality rates from head injuries were 26/100,000--38/100,000 for males and 14/100,000 for females. The overall case fatality rate was 10%, and 61% of all deaths occurred prior to hospitalization. The case fatality rate was highest in older age groups. Initial clinical assessment was recorded using the Glasgow Coma Scale. Eighty-one percent of the cases were considered mild, and 19% moderate to severe in degree including 367 deaths. The males and the aged not only had a higher incidence of head injuries but also had a higher proportion of more severe ones. These findings indicate that head injuries are nonrandom and likely to occur in certain types of individuals under certain circumstances.(ABSTRACT TRUNCATED AT 250 WORDS)

Rebleeding rate of various stigmata of recent hemorrhage in peptic ulcer bleeding with different severity

The stigmata of recent hemorrhage (SRH) have been used as a factor for predicting peptic ulcer rebleeding. In previous studies, the rebleeding rate of the visible vessel varied. A hypothesis had been proposed stating that the evolution of the color of the stigmata depends on the point in the healing process of the blood clot on the bleeding ulcer. This retrospective study evaluates the rebleeding rates associated with various colors of stigmata of recent hemorrhage. Of a total of 623 cases of peptic ulcer bleeding (474 male and 149 female, with a mean age of 59 years old), there were 232 gastric ulcers, 369 duodenal ulcers, and 22 stomal ulcers. Stigmata of recent hemorrhage were found in 387 cases (62%). The overall rebleeding rate for those with gastric ulcers was higher than for those with duodenal ulcers (24.2% versus 16.3%, p<0.05), especially for oozing and sentinel clots, the rebleeding rates for active bleeding, blood clots, sentinel clots, and others were 35%, 24.8%, 17%, and 11.3% respectively. The red clot of stigmata of recent hemorrhage had a slightly higher rebleeding rate than the black clot, but the difference was not statistically important. Furthermore, the 5 duodenal ulcers with white sentinel clots experienced no rebleeding. When comparing the rebleeding rates between groups with massive and minor bleeding, a significantly higher rebleeding rate was found in the massive bleeding group (50.5% versus 6.6%, p < 0.001). It can thus be seen that the different types of stigmata of recent hemorrhage represent different stages in the healing process of a bleeding ulcer. A white sentinel clot had a change of not rebleeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of the transcription factor C/EBP beta in expression of a rat pregnancy-specific glycoprotein gene

Pregnancy-specific glycoproteins (PSGs), which are the major placental proteins, and the carcinoembryonic antigens comprise a subfamily within the immunoglobulin superfamily. To understand the molecular mechanisms underlying the control of PSG expression, we characterized the promoter elements of a rodent PSG gene, rnCGM3, and showed that DNA elements at nucleotides -326 to -185 (PI) relative to the translation start site of rnCGM3 function as a promoter. The rnCGM3 PI promoter contains two placental factor binding sites, PISI and PISII. Both are transcription activation elements. In the present report, we screened a placental expression cDNA library with a rnCGM3-PISII probe (nucleotides -263 to -233) encompassing two overlapping palindromes (TGTTGCTCAACATGTTG) and demonstrated that the PISII-binding factor is C/EBP beta, a leucine zipper family of transcription factor. Gel mobility-shift and transient expression analyses showed that C/EBP beta and C/EBP isoforms, C/EBP alpha and C/EBP delta, bind to the PISII element and trans-activate rnCGM3 gene expression. Deletion of PISII from the rnCGM3 PI promoter greatly reduced the basal as well as the C/EBP-activated rnCGM3 expression. Gel supershift assays demonstrated that C/EBP beta is the placental isoform that binds to the PISII site rnCGM3. Moreover, C/EBP beta is expressed in high levels in the placenta, ovary, liver, lung, heart, and spleen, in contrast to C/EBP alpha, which is expressed primarily in the liver and only low levels in the placenta. Our results demonstrate that C/EBP beta is one of the transcription factors that positively regulate rnCGM3 expression during pregnancy.

Transposon mutagenesis and cloning of the genes encoding the enzymes of fengycin biosynthesis in Bacillus subtilis

A total of 20 Bacillus subtilis F29-3 mutants defective in fengycin biosynthesis was obtained by Tn917 mutagenesis. Cloning and mapping results showed that the transposon in these mutants was inserted in eleven different locations on the chromosome. We were able to use the chromosomal sequence adjacent to the transposon as a probe to screen for cosmid clones containing the fengycin biosynthesis genes. One of the clones obtained, pFC660, was 46 kb long. Eight transposon insertion sites were mapped within this plasmid. Among the eleven different mutants analyzed, four mutants had Tn917 inserted in regions which encoded peptide sequences similar to part of gramicidin S synthetase, surfactin synthetase, and tyrocidine synthetase. Our results suggest that fengycin is synthesized nonribosomally by the multienzyme thiotemplate mechanism.

Complex of simian virus large T antigen and p53 can bind DNA specifically

The DNA-binding activity of p53 was suggested to be abrogated by binding of large T antigen. However we demonstrate that a fraction of p53 can form a complex with large T antigen and still bind DNA specifically. In EMSA analysis, both PAb 416 and 419 anti-large-T antibodies could induce supershift on p53-DNA complex using extracts derived from two T-antigen-transformed cell lines. In EMSA-Western analysis, one of the p53-complexes was shown to contain large T antigen.

Endoscopic and image features in primary gastro-intestinal lymphoma: a 7-year experience

BACKGROUND/AIM

Primary gastro-intestinal lymphoma (PGIL) has various presentations in the gastrointestinal tract. Between 1987 and 1993, we examined 90 cases, using radiography, sonography and/or endoscopy, in an attempt to characterize the lesions of PGIL.

MATERIALS AND METHODS

Patients suffering from PGIL lesions were investigated with the combined modalities of radiology. Sonography and endoscopy. The data was reviewed retrospectively. All cases were proven by tissue histology obtained by biopsy or surgical resection.

RESULTS

We characterized seven growth patterns of PGIL: ulceration, infiltration, stricture, obstruction, erosion-like lesion, new growth (divided into 3 sub-groups: nodule, polypoid and mass) and perforation. Ulcerative lesion was found to be predominant in stomach (80.5%, P < 0.001) and duodenum (71.4%, P< 0.01) comparing with small (19.2%) and large (43.8%) bowel. The positive rate of gastric biopsy using endoscopy was 86% (31/36 biopsy cases). New growth pattern was the second main feature in PGIL, and one of the new growths, namely the mass, was predominant feature in terminal ileum (71.4%, P<0.001) and colon (62.5%, P < 0.001) when compared with stomach. Ulceration was a more frequent lesion in gastric and duodenal lymphoma. Cecal and terminal ileal lymphomas were mainly presented as new growth lesions, following the mass pattern.

CONCLUSIONS

Radiographic, sonographic, and endoscopic studies showed different patterns in PGIL. A combination of these modalities was recommended in the evaluation of various lesions of PGIL.

Ultrasonically guided needle biopsy of anterior mediastinal masses: comparison of carcinomatous and non-carcinomatous masses

Thirty-three patients with anterior mediastinal masses underwent percutaneous ultrasonically guided needle biopsy (UGNB), including ultrasonically guided aspiration biopsy (UGAB) in all 33 patients and ultrasonically guided cutting biopsy (UGCB) in 13 patients. Using UGAB alone, the diagnostic rate of anterior mediastinal masses was 52% (17/33); if both the UGAB and UGCB methods were used, the diagnostic rate could achieve 79% (26/33). If the anterior mediastinal masses were divided into carcinomatous (n = 15) and non-carcinomatous (n = 18) groups, we found that the carcinomatous group was more easily diagnosed by UGAB than the non-carcinomatous group (87% vs 22%, p < 0.01) and UGCB was more valuable and helpful than UGAB in the diagnosis of non-carcinomatous mediastinal masses (75% vs 22%). One episode of injury to the aortic wall occurred after a UGCB. Our results show that carcinomatous mediastinal masses can be easily diagnosed by UGAB, and UGCB is often necessary in the diagnosis of non-carcinomatous mediastinal masses.