Spatiotemporal control of estrogen-responsive transcription in ERα-positive breast cancer cells.

Recruitment of transcription machinery to target promoters for aberrant gene expression has been well studied, but underlying control directed by distant-acting enhancers remains unclear in cancer development. Our previous study demonstrated that distant estrogen response elements (DEREs) located on chromosome 20q13 are frequently amplified and translocated to other chromosomes in ERα-positive breast cancer cells. In this study, we used three-dimensional interphase fluorescence in situ hybridization to decipher spatiotemporal gathering of multiple DEREs in the nucleus. Upon estrogen stimulation, scattered 20q13 DEREs were mobilized to form regulatory depots for synchronized gene expression of target loci. A chromosome conformation capture assay coupled with chromatin immunoprecipitation further uncovered that ERα-bound regulatory depots are tethered to heterochromatin protein 1 (HP1) for coordinated chromatin movement and histone modifications of target loci, resulting in transcription repression. Neutralizing HP1 function dysregulated the formation of DERE-involved regulatory depots and transcription inactivation of candidate tumor-suppressor genes. Deletion of amplified DEREs using the CRISPR/Cas9 genomic-editing system profoundly altered transcriptional profiles of proliferation-associated signaling networks, resulting in reduction of cancer cell growth. These findings reveal a formerly uncharacterized feature wherein multiple copies of the amplicon congregate as transcriptional units in the nucleus for synchronous regulation of function-related loci in tumorigenesis. Disruption of their assembly can be a new strategy for treating breast cancers and other malignancies.

Increased expression of MHC class II antigens in rejecting canine lung allografts.

Expression of major histocompatibility complex class II antigens was investigated in the normal lungs and in lung allografts of mongrel dogs after single-lung transplantation. Cryostat sections were stained with an indirect immunoperoxidase technique that used B1F6 and 7.5.10.1 as anti-MHC class II monoclonal antibodies. In the normal lungs and native lungs of the recipient dogs after single-lung transplantation, only some cells of lymphoid tissue and macrophages/dendritic cells were MHC class II-positive. During acute rejection, increased infiltration with MHC class II-positive cells in perivascular, peribronchial, and interstitial areas and intraalveolar spaces was found in lung allografts. In addition, expression of MHC class II antigens was induced on the bronchial epithelium and vascular endothelium. Induced expression of MHC class II antigens on the bronchial epithelium and vascular endothelium in rejecting lung allografts was found as early as two days after single-lung transplantation. The intensity of MHC class II antigen expression on bronchial epithelium and vascular endothelium in graft lungs increased with the progression of rejection response and directly correlated with the bronchoalveolar lavage fluid (BALF) levels of biochemical markers, as tumor necrosis factor alpha, gamma-interferon (IFN-gamma), interleukin 2 (IL-2) and soluble interleukin 2 receptor (SIL-2R). Abnormal expression of MHC class II antigens on bronchial epithelium and vascular endothelium and abnormal elevation of BALF levels of the cytokines in lung allografts could be prevented by cyclosporine (CsA) treatment. Our results suggested that MHC class II antigen expression could be induced on the bronchial epithelium and vascular endothelium of canine lung allografts during acute rejection. This abnormal expression of MHC class II antigens on bronchial epithelium and vascular endothelium of graft lungs may serve as a specific index for diagnosis of lung allograft rejection when infection as an inducing factor can be excluded. Furthermore, bronchial epithelium and vascular endothelium of lung allografts have become MHC class II-positive, and are likely to be the targets for low-grade rejection, resulting in the development of bronchiolitis obliterans and occlusive vascular disease in lung allografts.

Significance of biochemical markers in early detection of canine lung allograft rejection.

To evaluate the significance of bronchoalveolar lavage fluid, levels of tumor necrosis factor-alpha (TNF), gamma-interferon, interleukin 2, and soluble IL-2 receptor in early detection of canine lung allograft rejection, bronchoalveolar lavages were performed serially in mongrel dogs before and after single lung transplantation. The dogs were divided into three groups. Group 1 (control group) consisted of one in which neither donor nor recipient dogs were treated with cyclosporine. In group 2 (CsA-pretreated group) only donors were treated with CsA orally at a single dose of 20 mg/kg/day for 3 days prior to single lung transplantation. In group 3 only recipients were treated with CsA orally at a single dose of 20 mg/kg/day for a short period of 9 days after single-lung transplantation. Marked elevation was found of TNF, IFN-gamma, IL-2, and IL-2R in BALF obtained from the grafted lungs in group 1 and group 2 dogs. The levels of these markers were significantly higher than those obtained from the normal, native lungs (P less than 0.05). Two of three recipients in group 2 had pneumonia in the native lungs on day 10 after single-lung transplantation. All markers except IFN-gamma in BALF obtained from the infected native lungs were also increased, but the titers were less than those obtained from the grafted lungs at the same time. There were significantly higher levels of TNF, IL-2, and IL-2R present in the BALF of grafted lungs of dogs in group 1 than group 2 (P less than 0.05). In group 3, BALF levels of these markers from the grafted lungs were not significantly different from those of the normal and native lungs during the period of CsA treatment after single-lung transplantation. On various days after discontinuation of CsA treatment, BALF levels of all markers began to rise. Abnormal levels of BALF markers obtained from the grafted lungs heralded the appearance of abnormalities detected by chest x-ray films. Our study suggests that serially measuring BALF levels of TNF, IFN-gamma, IL-2, and IL-2R may serve as a useful means in monitoring the immunologic status of canine lung allografts and in the early detection of lung allograft rejection. The role of BALF IFN-gamma in distinguishing lung allograft rejection from pulmonary infection needs further studies.

Usefulness of bronchoalveolar cell profile in early detection of canine lung allograft rejection.

To evaluate the value of a bronchoalveolar cell profile in the early detection of canine lung allograft rejection, bronchoalveolar lavages were done serially in mongrel dogs before and after single lung transplantation. The dogs were divided into 3 groups. In group 1, neither donor nor recipient dogs were treated with cyclosporine. In group 2, only donors were treated with cyclosporine, orally at a single dose of 20 mg/kg/day for 3 days prior to single lung transplantation. In group 3, only recipients were treated with cyclosporine (20 mg/kg/day) for 9 days after single lung transplantation. A marked increase in the number of bronchoalveolar cells and their cell differentials, and of major histocompatibility complex (MHC) class II-positive cells obtained from the grafted lungs after lung transplantation, was seen in groups 1 and 2. The changes in bronchoalveolar cell profile obtained from the rejecting grafted lungs were significantly different from those obtained from the normal and native lungs (P less than 0.05). In group 3, the bronchoalveolar cell profile obtained from the grafted lungs did not significantly differ from those present in normal and native lungs during the period of cyclosporine treatment after lung transplantation. On various days after withdrawal of cyclosporine treatment, bronchoalveolar cell profiles obtained from the grafted lungs showed similar changes to those observed in groups 1 and 2. Abnormal changes in bronchoalveolar cell profiles obtained from the grafted lungs heralded the appearance of abnormalities detected by chest X-ray films. Our results indicate that serial measurements of bronchoalveolar cell profile may serve as a useful means for early detection of canine lung allograft rejection.

Effects of nonsteroidal anti-inflammatory drugs and prostaglandins on osteoblastic functions.

It has been reported that nonsteroidal anti-inflammatory drugs (NSAIDs) suppress bone repair and bone remodeling but only mildly inhibit bone mineralization at the earlier stage of the repair process. We proposed that the proliferation and/or the earlier stage of differentiation of osteoblasts may be affected by NSAIDs. This study was designed to investigate whether NSAIDs affect the proliferation and/or differentiation of osteoblasts and whether these effects are prostaglandin (PG) mediated. The effects of PGE1 and PGE2, indomethacin, and ketorolac on thymidine incorporation, cell count, intracellular alkaline phosphatase (ALP) activity, and Type I collagen content in osteoblast-enriched cultures derived from fetal calvaria were evaluated. The results showed that both PGs and NSAIDs inhibited DNA synthesis and cell mitosis in a time- and concentration-dependent manner. However, intracellular ALP activity and Type I collagen content were stimulated at an earlier stage of differentiation in osteoblasts. These results suggested that (i) the inhibitory effect of ketorolac on osteoblastic proliferation contributes to its suppressive effects on bone repair and remodeling in vivo; (ii) PGEs and NSAIDs may be involved in matrix maturation and biologic bone mineralization in the earlier stage of osteoblast differentiation; and (iii) the effects of ketorolac and indomethacin on cell proliferation and differentiation may not be through the inhibition of the synthesis of PGE1 or PGE2.

The decrease of PKCalpha is associated with hepatic apoptosis at early and late phases of polymicrobial sepsis.

The present study investigates the relationship between the PKC-alpha and hepatic apoptosis during sepsis. Cecal ligation and puncture- (CLP) induced animal model of polymicrobial sepsis was used, with early and late sepsis referring to those animals sacrificed at 9 and 18 h, respectively, after CLP. The expressions of PKCalpha and Bcl-2 family proteins as well as poly(ADP-ribose) polymerase (PARP) cleavage were quantified to evaluate the possible factors involved in the hepatic cell death during sepsis. The apoptosis of hepatocytes under septic condition or hepatocytes treated with PKCalpha antisense was evaluated by gel electrophoresis and/or flow cytometry after Annexin-V-Fluos and propidium iodide staining. The results indicated that (1) the protein expression of membrane-associated PKCalpha was decreased at early (P < 0.05) and late (P < 0.01) sepsis; (2) the protein expressions of Bcl-2 and Bcl-xL were decreased, whereas Bax expression was increased at late sepsis; (3) the percentage of PARP cleavage was increased at early (P < 0.05) and late (P < 0.01) sepsis; (4) severe DNA fragmentation was observed at late sepsis; (5) the apoptotic cell population was increased at early and late sepsis; and (6) the percentage of apoptotic cell population in PKCalpha antisense-treated cells was significantly higher than that in untreated cells. These results suggest that inactivation of PKCalpha may play an important role in modulating hepatic apoptosis during sepsis and the apoptosis is closely associated with the alterations of Bcl-2 family proteins.

Liver protein kinases in shock: I. Endotoxin administration inactivates protein kinase a in dog liver.

Effects of endotoxin administration on protein kinase A (cAMP-dependent protein kinase) activity in dog liver were investigated. Hepatic protein kinase A was extracted and partially purified by acid precipitation, ammonium sulfate fraction, and DEAE-cellulose chromatography. Protein kinase A was eluted from DEAE-cellulose column with a linear NaCl gradient. Two peaks of protein kinase A, type I (eluted at low ionic strength) and type II (eluted at high ionic strength), were collected, and their activities were determined based on the rate of incorporation of [gamma-32P]ATP into histone. The results obtained 4 h after endotoxin administration (.5 mg/kg, intravenously) show that type I protein kinase A activity was unaffected, while type II protein kinase A activity was inhibited by 26-57%. Kinetic analysis of the data on type II protein kinase A reveals that the Vmax values for ATP, cAMP, and histone were decreased by 31, 39, and 36%, respectively; while the S.5 (substrate concentration required for half-maximal enzyme activity) values for ATP, cAMP, and histone were unaffected following endotoxin administration. These data indicate that endotoxin administration inhibits hepatic type II protein kinase A activity and the nature of inhibition is by a mechanism not competing with ATP, cAMP, and histone reactive sites. Since protein phosphorylation plays an important role in the regulation of cell metabolism and function, our finding may contribute to the understanding of hepatocellular dysfunction during endotoxin shock.

Protein kinase a activity is increased in rat heart during late hypodynamic phase of sepsis.

Changes in the activities of protein kinase A (PKA, or cAMP-dependent protein kinase) in rat heart during different cardiodynamic phases of sepsis were investigated. Sepsis was induced by cecal ligation and puncture. Experiments were divided into three groups: control, early sepsis, and late sepsis. Early and late sepsis refers to those animals killed at 9 and 18 h, respectively, after cecal ligation and puncture. Cardiac PKA was extracted and partially purified by acid precipitation, ammonium sulfate fractionation, and DEAE-cellulose chromatography. PKA was eluted from DEAE-cellulose column with a linear NaCl gradient. Two peaks of PKA, type I (eluted at low ionic strength) and type II (eluted at high ionic strength), were collected and their activities were determined based on the rate of incorporation of [gamma-32P]ATP into histone. Results obtained show that during early sepsis, both type I and type II PKA activities were unaffected. During late sepsis, type I PKA activities were stimulated by 66.7-97.7%, while type II PKA activities remained constant. Kinetic analysis of the data on type I PKA during late sepsis reveals that the Vmax values for ATP, cAMP, and histone were increased by 84.7, 66.7, and 97.7%, respectively; while the Km values for ATP, cAMP, and histone were unaltered. These data indicate that type I PKA is activated in rat heart during late hypodynamic phase of sepsis. Since kinase-mediated phosphorylation plays an important role in regulating myocardial function and metabolism, an activation of type I PKA during late sepsis may contribute to the development of altered myocardial function during hypodynamic phase of sepsis.

Protein kinase C activity is increased in rat heart during the early hyperdynamic phase of sepsis.

Changes in protein kinase C (PKC) (calcium- and phospholipid-dependent protein kinase) activity in rat heart during different cardiodynamic phases of sepsis were studied in an attempt to understand the pathophysiology of altered myocardial function during sepsis. Sepsis was induced by cecal ligation and puncture. Experiments were divided into three groups: control, early sepsis, and late sepsis. Early and late sepsis refers to those animals sacrificed at 9 and 18 h, respectively, after cecal ligation and puncture. Cardiac PKC was extracted and partially purified by ammonium sulfate fractionation and diethylaminoethyl-cellulose chromatography. PKC activity was assayed on the basis of the rate of incorporation of 32P from [gamma-32P]adenosine triphosphate into histone. The results show that during early sepsis, cytosolic PKC activity was increased by 42-73%, whereas membrane associated PKC activity was unchanged. During late sepsis, both cytosolic and membrane associated PKC activities remained unchanged. Kinetic analysis of the data on cytosolic PKC during the early phase of sepsis reveals that the Vmax (maximal velocity) values for Ca2+, phosphatidylserine, and diacylglycerol were increased by 58, 42, and 50%, respectively, with no changes in their Km (substrate concentration required for half-maximal enzyme activity) values. These data indicate that cytosolic PKC activity was activated in rat heart during the early hyperdynamic phase of sepsis. Because PKC mediated phosphorylation plays an important role in regulating myocardial contractility, an activation in cytosolic PKC may contribute to the development of a hypercardiodynamic state during the early phase of sepsis.

Liver protein kinase A activity is decreased during the late hypoglycemic phase of sepsis.

Changes in protein kinase A (PKA, or cAMP-dependent protein kinase) activity in the rat liver during different metabolic phases of sepsis were investigated. Sepsis was induced by cecal ligation and puncture (CLP). Experiments were divided into 3 groups: control, early sepsis, and late sepsis. Early and late sepsis refer to those animals killed at 9 and 18 h, respectively, after CLP. Hepatic PKA was extracted and partially purified by acid precipitation, ammonium sulfate fractionation, and diethylaminoethyl (DEAE)-cellulose chromatography. PKA was eluted from DEAE-cellulose column with a linear NaCl gradient. Two peaks of PKA, type I (eluted at low ionic strength) and type II (eluted at high ionic strength), were collected and their activities were determined on the basis of the rate of incorporation of [gamma-32-P]ATP into histone. The results show that during early sepsis, both type I and type II PKA activities remained unchanged. During late sepsis, type I PKA activity was decreased by 40.7-53.6%, whereas type II PKA activity was unaffected. Kinetic analysis of the data on type I PKA during the late phase of sepsis reveals that the Vmax (maximal velocity) values for ATP, cAMP, and histone were decreased by 40.7, 53.6, and 47.3%, respectively whereas the Km (substrate concentration required for half-maximal enzymatic activity) values for ATP, cAMP, and histone were unaltered. These data indicate that type I PKA was inactivated during the late hypoglycemic phase of sepsis in the rat liver. Because PKA-mediated phosphorylation plays an important role in the regulation of hepatic glucose metabolism, an inactivation of PKA may contribute to the development of hypoglycemia during the late phase of sepsis.

Evidence of multi-step regulation of HSP72 expression in experimental sepsis.

Heat shock proteins (Hsps) are a family of highly conserved proteins induced in response to various stresses. Hsps protect cells against subsequent lethal circumstances. Previous work from our laboratory has indicated that Hsp72 is not induced during experimental sepsis in rats, but the regulation of the induction of Hsp72 synthesis in this disease cascade has not been investigated. In the present study, we evaluated the expression of the hsp72gene, focusing on the activation and DNA-binding ability of heat shock factor 1 (HSF1), hsp mRNA accumulation, and Hsp72 synthesis in animal sepsis models induced by cecal ligation and puncture procedure. The results were compared with those of sham-treated and heat-shocked rats. It was shown that the expression of the hsp72 gene in sepsis was a multi-step process, as previously documented in in vitro studies. Hsp72 synthesis was not induced during sepsis, whereas DNA binding of HSF was detectable, suggesting that the induction of Hsp72 is blocked downstream to HSF-DNA complex formation by the metabolic alteration occurring during sepsis. The dissociation failure of the constitutive heat shock element binding factor (CHBF) from the heat shock element may play an important role in this negative regulation.

Aortico-right ventricular shunt following aortic valve replacement.

A 58-year-old man developed cardiac decompensation following aortic valve replacement as a result of an aortico-right ventricular fistula. Serial hemodynamic and electrocardiographic changes are presented. Attention is drawn to this rare complication as a cause of hemodynamic deterioration following aortic valve surgery.

CYFRA 21-1 enzyme-linked immunosorbent assay. Evaluation as a tumor marker in non-small cell lung cancer.

BACKGROUND: The CYFRA 21-1, a newly developed sandwich enzyme-linked immunosorbent assay (ELISA), was used to measure soluble cytokeratin 19 fragment in serum that is expressed in simple epithelium and its malignant counterpart. The present study was designed to investigate whether CYFRA 21-1 is a sensitive and specific tumor marker for non-small cell lung cancer. METHODS: CYFRA 21-1 assay, using two specific monoclonal antibodies (KS 19.1 and BM 19.21) for cytokeratin 19, was measured in 312 serum samples, including 164 lung cancer, 118 benign pulmonary disease, and 30 healthy individuals. The sensitivity of CYFRA 21-1 was also compared with two other markers, carcinoembryonic antigen (CEA) and squamous cell carcinoma antigen (SCC), in 164 patients with lung cancer. RESULTS: The median value of healthy individuals was 1.3 ng/mL (95th percentile 1.8). In patients with benign pulmonary diseases, the median was 1.5 ng/mL (95th percentile 2.9). There is no significant difference between sexes, smoking habit, and the subgroups of benign pulmonary disease, such as tuberculosis, pneumonia, or COPD. Using the cutoff value of 3.3 ng/mL, defined at 95% specificity for benign lung disease, the sensitivities of CYFRA 21-1 for squamous cell carcinoma (n=74), adenocarcinoma (n=54), undifferentiated large cell carcinoma (n=11), and small cell lung cancer (n=25) were 62%, 39%, 36%, and 20%, respectively. Despite the cell types, the sensitivities of CYFRA 21-1 in non-small cell lung cancer (NSCLC, n=169) were 51% (CEA 42%, SCC 20%). The sensitivity of CEA was significantly higher in patients with adenocarcinoma (58%) than other markers; while in patients with squamous cell carcinoma, CYFRA 21-1 assay has the highest sensitivity. The median level of CYFRA 21-1 in squamous cell carcinoma is significantly higher than that of other cell types (Mann-Whitney test, p<0.001). The serum level and sensitivity of CYFRA 21-1 were well correlated with staging and tumor size in squamous cell carcinoma. The CYFRA 21-1 values were measured for monitoring progression of disease in 20 patients with squamous cell carcinoma. There is significant difference in paired observation of CYFRA 21-1 level in patients with progressive disease (Wilcoxon signed-rank test, p<0.05), but no difference was observed in patients with stabilized disease (p>0.1). CONCLUSION: For patients with NSCLC, especially in squamous cell carcinoma, CYFRA 21-1 is not only a sensitive and specific tumor marker, but also may be a useful adjunctive marker for disease monitoring.

Left-to-right shunts in control of bleeding following surgery for aneurysms of the ascending aorta.

Surgical repair of complex thoracic aneurysms requiring aortic valve replacement and coronary revascularization is occasionally complicated by significant bleeding despite the experience of the surgeon. While bleeding from the mediastinal tissues and the anterior suture line is usually easily controlled, posterior bleeding may require dismantling the repair and a second bypass run. The synergism of a second bypass run and continued bleeding may result in increased mortality and/or morbidity. We recently encountered bleeding in a patient who developed ventricular dysfunction after bypass and opted to interpose a Gore-tex graft between the aneurysm wall and the right atrium with immediate hemostasis and a benign course. Subsequently we used four different shunts successfully in 9 of 33 patients. The average bleeding rate 30 minutes after protamine was 221 +/- 60 ml/minute with a range of 190 to 350 ml/minute. The initial two hour chest tube drainage averaged 880 +/- 285 ml with a range of 490 to 1300 ml. There were no re-explorations for bleeding. The shunt in the first patient has remained open without cardiac decompensation. The last patient developed heart failure and required elective repair of a leak at the descending end of an arch replacement. Our experience suggests that these shunts can be effective, particularly if posterior suture line bleeding is encountered.

Reappraisal of empyema thoracis. Surgical intervention when the duration of illness is unknown.

The timing of surgical treatment of empyema remains controversial. Traditionally, thoracotomy is performed either within three weeks of diagnosis or delayed until presumed pleurodesis occurs. Often, these patients are moribund and the duration of illness impossible to determine. We report our surgical results in seven patients with a deteriorating clinical course and multiple loculations which persisted after tube thoracostomy and would not have responded to multiple thoracostomies. Five patients required decortication. One required lobectomy for an abscess which developed on the contralateral side six weeks after discharge. There were no deaths or recurrences of empyema. Average times from surgery to tube removal and to discharge were six to 12 days, respectively. We conclude that one can safely and cost-effectively treat these patients surgically even when the duration of illness and presence of pleurodesis are unknown, and that the postoperative course will be uncomplicated.

Giant bronchoesophageal fistula: a rare complication of bronchial artery embolization.

Bronchoesophageal fistulas after bronchial artery embolization are rare. In the previous literature only 2 cases were recorded. Here we report treatment of a giant bronchoesophageal fistula on both the left and right bronchus. Our surgical treatment included fistula exclusion by esophageal diversion, and esophageal reconstruction was made by retrosternal stomach. The result was good, and the patient made a satisfactory recovery.

The surgical management of empyema thoracis in substance abuse patients: a 5-year experience.

Postpneumonic empyema (EMP) may develop in substance abuse patients, requiring prolonged hospitalization. An algorithm that provides quality care and a rational basis for timely surgical intervention would be advantageous. We report our five-year experience with EMP in substance abuse patients and present such a treatment plan. Sixty-one substance abuse patients were treated for EMP. Posteroanterior, lateral, and decubitus x-ray studies were obtained before treatment to assess fluid movement. Chest tubes were placed to drain frank pus and to obtain material for positive smears. X-ray studies and computed tomography were done 24 hours later to assess parenchymal pathology and to detect any multiple loculations. Thirty-three substance abuse patients recovered following initial tube thoracostomy and 7 after a second chest tube was introduced. Twenty-one had multiple loculations and underwent thoracotomy. Twenty of the 21 required extensive debridement or decortication, or both; 2 required lobectomy and 1 pneumonectomy. Chest tubes were removed on an average of 6 +/- 1.5 days. Average postoperative stay was 10.7 +/- 2 days. There were 2 early deaths and 1 late death and no recurrent EMP. Bacteriology findings were nonspecific and often polymicrobial. We conclude that early thoracotomy can be lifesaving in the presence of a benign clinical course.

Reconstruction of the esophagus with the left colon.

This report reviews our experience with 96 patients with benign or malignant stricture of the esophagus who underwent interposition of the left colon with or without esophageal resection from July 1982 to June 1987. There were 67 male and 29 female patients ranging in age from 8 to 80 years. Thirty-seven patients had fibrotic stricture secondary to corrosive injury of the esophagus, 42 had cancer of the esophagus, and 17 had cancer of the gastric cardia. The incidence of postoperative complications and surgical mortality, respectively, was 16.2% and 2.7% for patients with corrosive stricture of the esophagus, 35.7% and 11.9% for patients with cancer of the esophagus, and 35.2% and 5.8% for patients with cancer of the gastric cardia. Reconstruction resulted in good function in 75.6% of the patients with corrosive stricture of the esophagus, 66.6% of the patients with cancer of the esophagus, and 70.5% of patients with cancer of the gastric cardia. The morbidity and mortality were higher in the group with malignant esophageal strictures because of advanced age, poor general condition of the patient, and extent of the surgical procedure needed. Cervical anastomotic leakage was the most frequently encountered complication (13.5%), and all the poor-function results were caused by this complication. In our experience, reconstruction of the esophagus with left colon is a satisfactory method that can be accomplished with acceptable morbidity and mortality. The left colon is a durable and functional substitute.

The temporal relationship in arterial and venous prostacyclin and thromboxane activity during 24 hours of intraaortic balloon counterpulsation in dogs.

We studied the effects of intraaortic balloon counterpulsation (IABCP) on prostacyclin (PGI2) and thromboxane (TXB2) levels in dogs during 24 hours of 1:1 IABCP or a sham procedure in which the balloon was positioned but left deflated. The arterial PGI2 levels in the IABCP group increased from control values of 95 +/- 20 pg/ml to 268 +/- 95 pg/ml at 1 hour, 429 +/- 95 pg/ml at 4 hours, and 1,884 +/- 532 pg/ml at 24 hours. The arterial PGI2 levels were consistently higher in the IABCP group. Although the TXB2 measurements revealed no significant differences between groups, the IABCP group consistently had a higher level than the sham group. The platelet count in the control group decreased to 45% of baseline levels versus 55% for the IABCP group. We conclude that prolonged IABCP results in either net production of PGI2 or decreased degradation. The correlation between TXB2 and platelet counts is unclear and remains to be defined.

Sex-specific expression of N-methyl D-aspartate receptor (NMDAR) in the preoptic area of neonatal rats.

The relationship between the N-methyl-D-aspartate receptor (NMDAR) and the sex-specific neurotoxicity of L-glutamate on the preoptic area (POA) of neonatal rats was studied. The NMDAR were semiquantified by western blot analysis. The kinetic change of intracellular calcium and lactate dehydrogenase (LDH) efflux were monitored as rapid and delayed toxic signals, respectively. The results showed that: (1) the NMDAR expression in POA of male rat is higher than that of females; (2) the L-glutamate (500 microM) induced a more significant elevation of intracellular calcium in neuron derived from male rat than that from female; (3) after glutamate-treatment, the LDH efflux in neuronal culture of male rat is higher than that of females. These results suggest that the quantitative difference in NMDAR between male and female rats may contribute to the sex-specific neurotoxicity of L-glutamate on the POA of neonatal rats.