Class II transactivator regulates the expression of multiple genes involved in antigen presentation

CIITA (a major histocompatibility complex [MHC] class II transactivator) has been shown to be required for the expression of MHC class II genes in both B cells and interferon gamma-inducible cells. Here we demonstrate that CIITA not only activates MHC class II genes but also genes required for antigen presentation. Mutant HeLa cells, defective in the expression of classic MHC class II genes, invariant chain, and the newly described human histocompatibility leukocyte antigen-DM genes, were used to study the role of CIITA in the regulation of these genes. Upon transfection with CIITA cDNA, the mutant cells expressed all three genes, suggesting that CIITA is a global regulator for the expression of genes involved in antigen presentation.

B7-1 expression of Langerhans cells is up-regulated by proinflammatory cytokines, and is down-regulated by interferon-gamma or by interleukin-10

Langerhans cells (LC) act as potent antigen-presenting cells (APC) for primary and secondary T cell-dependent immune responses. LC express several costimulatory and/or adhesion molecules such as B7/BB1, which has been implicated as one of the important determinants for professional APC. Recent studies have shown that B7/BB1 antigens comprise three distinct molecules termed B7-1, B7-2, and B7-3. We have examined the regulatory properties of B7-1 expression in LC using various cytokines including interleukin (IL)-1 alpha, IL-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-10, interferon (IFN)-gamma, granulocyte/macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor (TNF)-alpha. We have demonstrated: 1) that the B7-1 expression of LC is reproducibly up-regulated by either GM-CSF, TNF-alpha, IL-1 alpha, IL-1 beta, or IL-4 in a dose- and time-dependent manner, 2) that GM-CSF exhibits the most active effect on B7-1 up-regulation in each experiment, 3) that IFN-gamma or IL-10 profoundly inhibits the B7-1 expression of LC in a dose- and time-dependent manner, and 4) that the down-regulatory ability of IFN-gamma or IL-10 neutralizes the activity of up-regulatory cytokines. The enhancing or inhibitory action of these cytokines on B7-1 expression occurs selectively because none of the cytokines consistently affects I-A expression of LC. These data suggest that the B7-1 expression of LC may be dynamically regulated by these up- and down-regulatory cytokines in normal and inflammatory epidermal microenvironment.

Application of thoracoscopy for lung metastases

Lung nodules in patients with a history of malignancy usually require tissue diagnosis that will provide prognostic information and dictate further therapy. Patients with a favorable tumor histologic condition and limited tumor burden were often considered for resection. This is usually accomplished by wedge resection through open thoracotomy when the lesions were peripheral. However, complications related to open thoracotomy often exclude poor-risk patients, especially those with impaired pulmonary function. Currently, technique of thoracoscopic resection is opening up new vistas and unimagined options for the thoracic surgeon in the management of pulmonary diseases. With the application of thoracoscopy and small incisions, it is now possible for the thoracic cavity and its contained organs to be thoroughly explored. Our recent experience with the thoracoscopic resection as a primary treatment for lung metastases is the focus of this report. Forty-seven patients with a history of malignancy and new lung metastases underwent this type of resection. Postoperatively, there is less pain, quick functional recovery, and excellent cosmetic healing. It is a safe and promising approach.

Differentiation between adenomyoma and leiomyoma with transvaginal ultrasonography

The clinical utility of transvaginal ultrasonography in the differentiation of adenomyoma from leiomyoma was evaluated in 147 patients who had been scheduled for surgery due to symptomatic uterine masses. In all subjects, ultrasonographic images obtained preoperatively were correlated postoperatively with surgicopathological findings. Pathological findings showed that 110 patients proved to have fibroids, while 30 had adenomyomata. For the diagnosis of adenomyoma, transvaginal ultrasonography attained a sensitivity of 80%, a specificity of 94.3%, a positive predictive value of 85.7% and a negative predictive value of 90.9%, compared with a sensitivity of 94.3%, a specificity of 80%, a positive predictive value of 90.9% and a negative predictive value of 85.7% for leiomyoma diagnosis. Further to assess which characteristic used in ultrasonography was useful in the differential diagnosis, five characteristics were analyzed and compared by chi 2 test. These were position, number, margin and echogenicity of the uterine masses and the presence or absence of hypoechoic spaces (lacunae). Margin, echogenicity, mass number and lacunae were significantly different between both conditions. A stepwise logistic regression procedure revealed that margin, lacunae and echogenicity were good parameters for differentiating adenomyoma from leiomyoma. If we selected the features of distinct margin and absence of hypoechoic lacunae within the masses for analysis, leiomyoma could be correctly predicted in 97% of patients.

Endothelium-dependent contraction of canine coronary artery is enhanced by crystalloid cardioplegic solution

Experiments were designed to determine whether hyperkalemic crystalloid cardioplegic solution enhances endothelium-dependent contraction of coronary arteries. Segments of canine coronary arteries (n = 8 in each group) were preserved in cold (4 degrees C) crystalloid cardioplegic solution (group 1) and physiologic solution (group 2) for 60 minutes. Segments of preserved and control (group 3) coronary arteries with or without endothelium were suspended in organ chambers to measure isometric force. Perfusate hypoxia (oxygen tension 35 +/- 5 mm Hg) caused endothelium-dependent contraction in the arteries of all three groups. However, vascular segments with endothelium of group 1 exhibited hypoxic contraction (68.5% +/- 15.3% of the initial tension contracted by prostaglandin F2 alpha 2 x 10(-6) mol/L, p < 0.05) that was significantly greater than contraction of the group 2 and group 3 segments with endothelium (26.6% +/- 5.6% and 20.6 +/- 4.4%). The hypoxic contraction in arteries of group 1 could be attenuated by NG-monomethyl-L-arginine, the blocker of endothelial cell synthesis of the nitric oxide from L-arginine. The action of NG-monomethyl-L-arginine could be reversed by L-arginine but not D-arginine. Thus after preservation with cardioplegic solution, augmented endothelium-dependent contraction, occurs by L-arginine-dependent pathway, would favor coronary vasospasm after cardiac operation.

Ipsilateral post-cast hypertrichosis and dyshidrotic dermatitis

Post-cast hypertrichosis and dyshidrotic dermatitis are not uncommon separately. Yet, the simultaneous occurrence of both conditions in an individual is rare. A patient with both localized hypertrichosis and ipsilateral dyshidrotic dermatitis following multiple fractures and cast application is reported. The clinical presentation, management, spontaneous resolution, and/or response to therapy of post-cast hypertrichosis and dyshidrotic dermatitis that occurred concurrently in an individual were similar to that described when these conditions occur independently. The acquired conditions that may be associated with localized hypertrichosis are summarized and the postulated mechanisms of pathogenesis for dyshidrotic dermatitis are reviewed. The diagnosis of post-cast hypertrichosis in this patient was suspected based upon the distribution and temporal association of the hypertrichosis to the location and placement of his cast, and confirmed by excluding other causes of acquired localized hypertrichosis. Also, the possibility that in this individual either the trauma to his bones, the cast on his arm, or both had an etiologic role in promoting the development of dyshidrotic dermatitis is suggested.

Cytotoxicity of intracameral injection drugs to corneal endothelium as evaluated by corneal endothelial cell culture

The cell culture method was used to quantitatively evaluate the cytotoxicity to porcine corneal endothelial cells by drugs in the usual concentrations of intracameral injections (ICI). Time-dependent cytotoxicity of drugs was evaluated quantitatively; dye exclusion assay by trypan blue was used as a viability assay; and cytotoxicity to corneal endothelium was tested using amphotericin-B, amikacin, colistin, sulbenicillin, and cephradine in their original, 10-fold, and 100-fold ICI concentrations. Original and 10-fold ICI concentrations of betamethasone also were used. In original and 10-fold ICI concentrations, only amphotericin-B had significant cytotoxicity. In 100-fold ICI concentrations, amphotericin-B, colistin, and sulbenicillin had significant cytotoxicity. Betamethasone had neither a cytotoxic nor a proliferative effect in its original and 10-fold ICI concentrations. A 0.1-fold ICI concentration of amphotericin-B also showed 42.75% cytotoxicity to corneal endothelium by monolayer cultured cells and the time-dependent cytotoxicity of drugs as a quantitative method is efficient and objective.

Enhancement of endothelium-dependent contraction of the canine coronary artery by UW solution

University of Wisconsin (UW) solution has been used almost routinely in the preservation of the hepatic, pancreatic, renal, and cardiac allografts. However, its effect on vascular endothelium is unknown. Experiments were designed to evaluate its effect on canine coronary endothelium. Canine coronary arteries (n = 8 in each group) were preserved in cold (4 degrees C) UW solution (group 1) and physiological solution (group 2) for 6 hr immediately after harvesting. Segments of preserved and control (group 3) coronary arteries with or without endothelium were then suspended in organ chambers to measure isometric force. Perfusate hypoxia (pO2 30 +/- 5 mmHg) caused endothelium-dependent contraction in the arteries of all 3 groups. However, vascular segments with endothelium of group 1 exhibited hypoxic contractions (107 +/- 26% of the initial tension contracted by prostaglandin F2 alpha 2 x 10(-6) mol/L, P < 0.05) that were significantly greater than those of the group 2 and group 3 segments with endothelium (25 +/- 5% and 20 +/- 4%). The hypoxic contraction in arteries of group 1 could be attenuated by NG-monomethyl-L-arginine (L-NMMA), the blocker of endothelial cell synthesis of the nitric oxide from L-arginine. The action of L-NMMA could be reversed by L-arginine but not D-arginine. Endothelium-dependent relaxation of coronary endothelium to acetylcholine and adenosine diphosphate and endothelium-independent relaxation and contraction of coronary smooth muscle were not altered by the UW solution. After preservation with the UW solution, endothelium-dependent contraction of the canine coronary arteries, occurs by L-arginine-dependent pathway, is enhanced. This augmentation by the UW solution would favor vasospasm after transplantation.

Comparison of crystal structures of two homologous proteins: structural origin of altered domain interactions in immunoglobulin light-chain dimers

The sequence and structure of a second human kappa 1 immunoglobulin light-chain variable domain, Wat, has been determined. The R-factor is 15.7% for 1.9-A data. One hundred and ninety-five water molecules were identified; 30 water molecules were located in identical positions in each of the monomers. Some of the water molecules are integral parts of the domains. This light chain is encoded by the same variable domain gene that encoded the previously characterized kappa I variable domain, Rei. Due to limited somatic mutation, the two highly homologous proteins differ in only 20 of the 108 residues. Wat crystallized in space group P6(4) while Rei crystallized in space group P6(1); in both crystals, the asymmetric unit was the noncovalent dimer. Although the basic domain structure is the same for both proteins, the relative positions of the domains within the two dimers differ. This difference is most likely accounted for by the replacement of Tyr36 in Rei by Phe in the Wat protein. Residue Tyr36 is part of the hydrogen-bonding network in the interface between the domains in Rei. Losing the hydrogen-bonding capability of residue 36 by replacement of Tyr by Phe alters the network of hydrogen bonds between the domains, resulting in a different domain-domain contact. The details of lattice contacts in the two crystals were compared. One type of contact that extends the beta-sheet of the individual domains was conserved, but because it involved different symmetry elements within the crystal, different crystal packing resulted. In the Wat crystal, one of the contacts shows an example of how a symmetrical binding site can "bind" an asymmetrical object. Further, the examination of the Wat crystal also illustrates how the different crystalline environments of the domains of the dimer results in different distributions of temperature factors for the residues within the domains.

Bowel perforation--a fatal complication following renal transplantation: a report of two cases

From May 1983 to January 1993, 162 patients received renal transplantation at Taichung Veterans General Hospital. Two patients developed bowel perforation after this surgery. One was proved at 21 days and another, at 13 days after renal transplantation. Both patients died as a direct result of the perforation. From a review of literature, the average incidence is 2.7%, and the average mortality rate is 56.5%. Because of this high mortality rate, a high clinical suspicion, prompt and adequate surgical intervention, reduction of immunosuppressive agents and effective antibiotic coverage should contribute to a decline in mortality.

Thoracoscopic management of effusive pericardial disease: indications and technique

Video-assisted thoracoscopic technique was evaluated in 28 patients who underwent operation for massive pericardial effusion. Excellent results were obtained using this newly developed approach for inspection of all pericardial surfaces as well as pleural and pulmonary disorders. No perioperative or postoperative complications ensued. Videothoracoscopy revealed positive lung malignancies in 11 patients, and these would not have been promptly diagnosed without thoracoscopy. Thoracoscopy also confirmed metastatic deposits on the pleura and diaphragm in 4 other patients. The visible nodules were proved to be metastatic adenocarcinoma. In 13 patients, thoracoscopy did not reveal malignancy, although 2 of these patients had a clinically suspected malignant lung tumor. Other indications for thoracoscopic drainage included 2 patients with impending pericardial tamponade after heart procedures and 6 patients with recurrent/loculated pericardial effusion. All of the patients showed promising and favorable postoperative courses after thoracoscopy. From our experience, video-assisted thoracoscopy was a safe and effective procedure, especially for those patients with combined pericardial effusion and abnormal pulmonary or pleural pathology in whom subxiphoid pericardial window was not clearly diagnostic at the time of operation. It was effective also in the situation with recurrent or loculated pericardial effusion which allowed localization and drainage of it. We believe that the use of videothoracoscopy to visualize the whole pericardial and pleural cavity will continue to be of great benefit to patients with combined pericardial and pleural/lung diseases.

Imaged thoracic resection of a huge mediastinal tumor--role of extended incision and the use of conventional instruments

Intrathoracic lesions are usually removed through conventional thoracotomy. The long incision and the spreading of the rib usually results in much pain and interference of chest wall mechanics. Today, with the development of imaged thoracic surgery (combination of thoracoscope and video optics), major procedures can be performed through small incisions. However, indications are greatly limited due to lack of suitable instrumentation and restricted space of the trocar channel especially when a huge intrathoracic tumor is encountered. In this selected report, we demonstrate a successful procedure using extended incision and conventional instruments in imaged resection of a huge cystic intrathoracic tumor. The procedure offers the benefit of safe, easy and fast manipulation. The patient had an uneventful postoperative course and was discharged on the fourth postoperative day.

Selective regulation of ICAM-1 and major histocompatibility complex class I and II molecule expression on epidermal Langerhans cells by some of the cytokines released by keratinocytes and T cells

Epidermal Langerhans cells (LC) are major histocompatibility complex (MHC) class II (Ia)-positive dendritic cells that act as potent antigen-presenting or accessory cells for primary and secondary T cell-dependent immune responses. Recent studies have disclosed that the morphological, functional, and phenotypic characteristics of LC are variably and drastically modulated by external stimuli both in vivo and in vitro. However, little is known of the biological significance of diverse cytokines in regulating the surface molecules of LC. To determine the regulatory properties of ICAM-1, Ia, and MHC class I (H-2K) molecules in LC, we have examined the effects of interleukin (IL)-1 alpha, IL-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-10, interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), and granulocyte-macrophage colony-stimulating factor (GM-CSF) on the expression of these molecules. Among the cytokines examined, IFN-gamma markedly and reproducibly up-regulates the expression of H-2K, but not ICAM-1, in Ia+ LC in a time- and dose-dependent manner. TNF-alpha consistently up-regulates the expression of ICAM-1, but not H-2K, in a time- and dose-dependent manner. IL-10 slightly but reproducibly inhibits the expression of ICAM-1, but not H-2K, in a time- and dose-dependent manner. IL-10 potently inhibits the TNF-alpha-induced ICAM-1 up-regulation, but not the IFN-gamma-induced H-2K up-regulation. Moreover, no cytokine consistently affects the Ia expression of LC. In addition, slight enhancing effects have been observed on H-2K expression by IL-4, and on ICAM-1 expression by IL-1 alpha, IL-1 beta, or GM-CSF. The present data suggest that the selective regulation is operative in a certain cell surface moiety of LC by various cytokines. These results further facilitate our understanding of immunobiology of LC.

Transurethral resection of the prostate among Medicare beneficiaries in the United States: time trends and outcomes. Prostate Patient Outcomes Research Team (PORT)

OBJECTIVES

The purpose of this study was to examine the epidemiology of transurethral resection of the prostate (TURP) and associated risks among Medicare beneficiaries during the period of 1984 to 1990.

METHODS

Medicare hospital claims for a 20% national sample of Medicare beneficiaries were used to identify TURPs performed during the study period. All reported rates were adjusted to the composition of the 1990 Medicare population. Risks of mortality and reoperation were evaluated using life-table methods.

RESULTS

The age-adjusted rate of TURP reached a peak in 1987 and declined thereafter. Similar trends were observed for all age groups. In 1990, the rates of TURP (including all indications) were approximately 25, 19, and 13 per 1000 for men over the age of 75, 70 to 74, and 65 to 69, respectively. The 30-day mortality following TURP for the treatment of benign prostatic hyperplasia (BPH) decreased from 1.20% in 1984 to 0.77% in 1990 (linear trend, p = 0.0001). The cumulative incidence of a second TURP among men with BPH has likewise decreased steadily over time; in this study, the average was 7.2% over 7 years (5.5% when the indication for the second TURP was restricted to BPH only).

CONCLUSIONS

The rate of TURP has been declining since 1987, conceivably due to increasing availability of alternative treatments or changes in treatment preferences of patients and physicians. Over the same period, the outcomes following TURPs have improved, perhaps due to improved surgical care and changes in patient selection.

Protection of the brain by retrograde cerebral perfusion during circulatory arrest

Hypothermic circulatory arrest is commonly used to facilitate repair of complex congenital heart defects and aortic lesions and for complex neurosurgical procedures. However, extended periods of circulatory arrest may impair cerebral metabolism and cause ischemic injury. Retrograde cerebral perfusion has been applied recently in aortic surgery to protect the brain. From January 1991 to December 1993, 29 patients underwent emergency operations to repair acute type A aortic dissection with the aid of hypothermic circulatory arrest. Six patients received hypothermic circulatory arrest without retrograde cerebral perfusion with a rectal temperature of 16.4 degrees +/- 0.9 degrees C (mean +/- standard error of the mean, group 1). Retrograde cerebral perfusion during hypothermic circulatory arrest was performed in 15 patients with a rectal temperature of 15.9 degrees +/- 0.5 degrees C (group 2) and in eight patients with a rectal temperature of 21.7 degrees +/- 0.8 degrees C (group 3). The hypothermic circulatory arrest times were 25 +/- 4, 42 +/- 4, and 63 +/- 6 minutes, respectively (p < 0.05). The cardiopulmonary bypass times were 173 +/- 5, 184 +/- 7, and 143 +/- 6 minutes, respectively (p < 0.05). All patients survived the operation and regained consciousness with no neurologic defects. Follow-up (mean 23.2, 14.5, and 5.1 months, respectively) was complete in all patients except one. This patient, from group 2, was killed in a road traffic accident 12 months after the operation. Our experience suggests that retrograde cerebral perfusion can effectively protect the brain from ischemic injury and extend the safe period of hypothermic circulatory arrest. With the aid of retrograde cerebral perfusion, prolonged circulatory arrest can probably be performed safely with moderate hypothermia.

Video-assisted thoracic surgery. The Chang Gung experience

Thoracoscopy has assumed a major role in the management of a variety of surgical diseases of the chest. This technique, which was primarily devised for diagnostic purposes, has subsequently come to be used for therapeutic applications in most centers today. In this report we review 300 cases of therapeutic thoracic procedures in which a video-assisted technique was used. We describe mainly our own experience and the basic approach strategies we found helpful in the video-assisted procedures. No complications or deaths were attributable to these procedures. Our conclusions were as follows: (1) Video-assisted thoracic surgery can be as effective therapeutically as many formal thoracotomy. (2) Excellent exposure can be obtained by the use of double-lumen endotracheal tubes. (3) Video-assisted thoracic surgery is an excellent alternative treatment for pneumothorax, blebs, and bullous disease. (4) Video-assisted thoracic surgery allows safe, complete, visually guided wedge resection of lung lesions, lobectomy, pericardiectomy, removal of mediastinal tumor, esophagectomy, and reconstruction of the thoracic esophagus. (5) Video-assisted thoracic surgery also allows management of a broad scope of other general thoracic diseases such as empyema, pleural effusion, and chest trauma (hemothorax), as well as cancer staging. (6) Video-assisted thoracic surgery will not compromise the primary diagnostic and therapeutic goals set forth for the patient. (7) Because conventional instruments and extended manipulation incisions can be used, video-assisted thoracic surgery offers the promise of expediency, safety, minimal discomfort, less postoperative pain, quick functional recuperation, excellent cosmetic healing, shortened stays in the hospital, and therefore savings in cost. Accordingly, we are now using video-assisted thoracic surgery to treat the majority of patients with surgical diseases of the chest.

Effect of rate of intracellular transport and diacytosis on cytotoxicity of hybrid toxins. Study with hybrids using hepatic asialoglycoprotein receptor-mediated endocytosis

The effects of diacytosis and intracellular transport rate on cytotoxicity of hybrid toxins were studied with conjugates of diphtheria toxin fragment A (DTA) to asialoorosomucoid (ASOR) and its reduced and carboxymethylated cyanogen bromide fragment I (RC-ASCNBr-I) in cultured rat hepatocytes. In the hepatocytes the kinetics of uptake of the conjugate of asialoorosomucoid (DTA-ASOR) and that of the conjugate of the cyanogen bromide fragment (DTA-RC-ASCNBr-I) were quite similar, but the rate of accumulation of DTA moiety into the lysosomes, as determined by Percoll density gradient centrifugation, was found to be greater for the latter than the former. However, after internalization, DTA-RC-ASCNBr-I was diacytosed to a lesser extent than that of DTA-ASOR, particularly when colchicine was present during internalization. Analysis of the subunits of DTA-ASOR internalized by the hepatocytes indicated that they were accumulated disproportionately in a time-dependent manner so that the glycoprotein moiety was accumulated progressively more than the toxin moiety. Cytotoxicity of DTA-ASOR toward the hepatocytes was 2-times as much as that of DTA-RC-ASCNBr-I. Colchicine enhanced the toxicity of DTA-RC-ASCNBr-I (33-fold) to a greater extent than that of DTA-ASOR (12-fold). The difference in enhancement by colchicine was also observed in the rate of cell intoxication by the conjugates. Both conjugates were more toxic to the hepatocytes after incubation with the cells at 18 degrees C than at 37 degrees C. In the presence of vanadate (0.2 mM), which enhanced diacytosis, toxicity of DTA-ASOR decreased by 5-fold. After incubation with the hepatocytes, a partial dissociation of DTA-ASOR was found to occur independently of the receptor-mediated endocytosis. Taken together, these results indicate that diacytosis, subunit dissociation and rapid transport of conjugate toward lysosomes affect kinetically the rate of accumulation of the conjugate into a yet unidentified compartment of toxin translocation.

Effects on anti-lipid peroxidation of Cudrania cochinchinensis var. gerontogea

From the root bark of Cudrania cochinchinensis (Lour.) Kudo et Masamune var. gerontogea (Sieb. et Zucc.) Kudo et Masamune, 3 xanthones, cudraxanthone I, 1,3,7-trihydroxy-2-(3-methylbut-2- enyl)-xanthone, and lancerin, were further isolated and characterized. It was found that pretreatment with 600 mg/kg oral dose of the EtOH root extract of Cudrania cochinchinensis var. gerontogea in mice inhibited the lipid peroxidation stimulated by FeCl2-ascorbic acid-adenosine 5'-diphosphate (ADP) mixture. For searching bioactive constituents, the isolated xanthones from this folk medicine were investigated in anti-lipid peroxidative activities in the rat liver homogenate. The results showed that most of the tested xanthones effectively exhibited anti-lipid peroxidation stimulated by (a) FeCl2-ascorbic acid mixture or (b) CCl4-nicotinamide adenine dinucleotide phosphate (NADPH) mixture. As shown by the result, gerontoxanthone C and I were more active than vitamin E.

Class II transactivator (CIITA) is sufficient for the inducible expression of major histocompatibility complex class II genes

The class II transactivator (CIITA) has been shown to be required for major histocompatibility complex (MHC) class II gene expression in B cells and its deficiency is responsible for a hereditary MHC class II deficiency. Here we show that CIITA is also involved in the inducible expression of class II genes upon interferon gamma (IFN-gamma) treatment. The expression of CIITA is also inducible with IFN-gamma before the induction of MHC class II mRNA. In addition, CIITA mRNA expression does not require new protein synthesis, although new protein synthesis is necessary for the transcription of class II. This suggests that synthesis of new CIITA protein may be essential to induce class II gene expression. We also showed that the JAK1 protein tyrosine kinase activity is required to induce the expression of CIITA upon IFN-gamma stimulation. This finding indicates that CIITA is part of the signaling cascade from the IFN-gamma receptor to the activation of class II genes. In addition, the expression of CIITA is sufficient to activate class II genes in the absence of IFN-gamma stimulation suggesting that CIITA is the major regulatory factor for the inducible expression of class II genes. Together, these data suggest that CIITA is the IFN-inducible cycloheximide sensitive factor previously shown to be required for the induction of MHC class II gene expression.

Color Doppler ultrasonography and serum CA 125 in the differentiation of benign and malignant ovarian tumors

Color Doppler ultrasonography and serum CA 125 were used to evaluate 114 adnexal tumors prior to surgery. Six patients were excluded from this study because of ovarian cancer, borderline ovarian malignancy, and tubal gestation. A total of 108 patients were eligible: 83 patients with benign and 25 patients with malignant ovarian tumors. Resistance index (RI) was used to determine the peripheral resistance of intratumoral vessels. The cutoff point for the RI was defined as 0.5. The blood flow was considered to be normal when the RI was greater than 0.5 and abnormal when it was less than 0.5. The blood flow was detected in 100% of malignant tumors and 59% of benign tumors. The initial cutoff value for CA 125 was 35 U/mL. Sensitivity, specificity, positive predictive value, and negative predictive value were compared in terms of RI, serum CA 125, and a combination of the two. Our conclusion is that the combination of RI and CA 125 gives a sensitivity of 100% and negative predictive value of 100%. If the cutoff point of CA 125 was raised from 35 to 65 U/mL, then a specificity of 100% and positive predictive value of 100% were also attained with the use of RI and CA 125 without changes in sensitivity or negative predictive value. We conclude that the combination of color Doppler ultrasonography and serum CA 125 is an effective method to differentiate benign from malignant ovarian tumors.

Acute endothelial reperfusion injury after coronary artery bypass grafting

Coronary artery endothelium exhibits functional impairment after ischemia and reperfusion. Canine left anterior descending coronary arteries were exposed to ischemia (60 minutes) followed by reperfusion (60 minutes) through a left internal mammary artery graft. In organ chamber experiments, control (left circumflex coronary artery) and reperfused (left anterior descending coronary artery) arterial segments were contracted with prostaglandin F2 alpha and exposed to hypoxia (oxygen tension = 35 +/- 5 mm Hg). Reperfused coronary rings with endothelium exhibited contractions to hypoxia that were significantly greater than contractions in control rings with endothelium (+78% +/- 8% and +14% +/- 5%, respectively; p < 0.05). This phenomenon could be blocked by NG-monomethyl-L-arginine. Electron microscopic studies showed platelet adhesion and aggregation, denudation of the endothelium and disruption of the intercellular junctions, edematous subendothelial matrix, and vesiculation of the smooth muscle cells in reperfused LAD. Swelling, vacuole formation, and loss of neurofilament occurred in the nerve fibers accompanying the vessels. These phenomena were not observed in control vessels. This study demonstrates that early after coronary artery bypass grafting, hypoxia can induce coronary vasospasm mediated by an L-arginine-dependent metabolic pathway in the endothelium. The ultrastructural changes in the coronary endothelium include platelet adhesion, aggregation, and platelet-induced contraction of coronary smooth muscle. The endothelium-dependent hypoxic coronary vasospasm and ultrastructural changes in the coronary endothelium may play an important role in the pathogenesis of myocardial ischemia and infarction after coronary artery bypass grafting.

Human dermal papilla cells and outer root sheath cells: no follicular differentiation in nude mice and chicken embryos

Human scalp specimens were incubated in 5 U/ml dispase solution at 4 degrees C overnight before the isolation of dermal papillae and follicle epithelium. This pretreatment not only facilitated the attachment and cell outgrowth of dermal papillae but also made it easier to pluck out hairs with intact follicle epithelium. The outer root sheath cells were released from the follicle epithelium and grown on a feeder layer of mitomycin C-treated human dermal fibroblasts. The subcultured outer root sheath cells were grown in a serum-free medium. When the mixtures of early-passage dermal papilla cells and outer root sheath cells were injected into the subcutis of nude mice, an epidermal cyst surrounded by layers of fibrous tissue was found in three weeks. No hair follicles were found when the mixtures were implanted onto the chorioallantoic membrane of nine-day-old chicken embryos. A keratinized mass lying on the chorionic epithelium with or without smaller similar masses in the chorioallantoic membrane was found in eight days. No hair follicle-like structure could be found. Possible factors contributing to the failure to undergo follicular differentiation in this study are discussed.

Endothelium dysfunction in cardiovascular diseases

During the past 10 years, it has become obvious that endothelium regulates vasomotion, modulates hemostasis, influences vascular permeability, and controls blood vessel growth. The role of endothelium in modulating vasomotor tone is mediated by the releasing of a number of potent vasoactive compounds, including endothelium-derived relaxing factors (one of which is either nitric oxide or a compound that releases nitric oxide), vasoactive prostaglandins, endothelium-derived hyperpolarizing factor, and a number of constricting factors (such as thromboxane A2, endothelin, superoxide anion, L-arginine-dependent products etc.). This role of the endothelium is dramatically changed by several disease processes, including diabetes mellitus, cerebrovascular disease, and so on. Abnormalities of endothelial regulation of vascular tone may contribute to a number of clinical syndromes, including atherosclerosis, hypertension, septic shock syndrome, and many others. Endothelium dysfunction, characterized by altered synthesis or release of these relaxing factors along with maintained or facilitated synthesis or release of contracting factors, can lead to various pathological conditions such as thrombosis, vasospasm, and hypertension. Better understanding of the exact nature of endothelial dysfunction, including the role played by endothelium-derived vasoactive factors, may provide a basis for novel therapies in these vasculopathies.

Surgical treatment of acute type A aortic dissection with an intraluminal sutureless graft

The surgical treatment of acute type A aortic dissection remains a great challenge to all cardiac surgeons. From January 1991 to June 1993, 21 consecutive patients (13 men and eight women, aged 34 to 74 years) underwent emergency operations to repair acute type A aortic dissection, with the aid of hypothermic circulatory arrest. The intima tear was located in the ascending aorta in 13 patients, in the aortic arch in five patients, and in the descending aorta in three patients. The dissected ascending aorta was replaced with sutureless, intraluminal vascular grafts in all 21 patients. The intima tears in the aortic arch of five patients were primarily repaired. Modified Cabrol's shunts were created in seven patients for hemostasis, and Dacron grafts were used to wrap the ascending aorta in 18 patients. Retrograde cerebral perfusion during circulatory arrest was performed on 15 patients. The circulatory arrest time was 37 +/- 10 minutes (mean +/- SD). All patients survived the operation and regained consciousness in the early postoperative period without neurologic deficit. Post-treatment follow-ups (mean, 18.2 months) were completed in all patients except one, who died 12 months after the operation as a result of a traffic accident. All of the surviving patients are doing well without any further aortic operations. Our experience suggests that surgical repair of the acute type A aortic dissection can be a simple and safe procedure if sutureless intraluminal grafts are used and hypothermic circulatory arrest and retrograde cerebral perfusion are utilized.