[Clear cell odontogenic carcinoma]

Histopathologic and immunohistochemical features of 3 cases of clear cell odontogenic carcinoma were studied. The tumors were composed of sheets or islands of clear cells separated by mature collageneous tissue. Basaloid cells were also seen in the tumors. Tumor cells showed positive reactions for epithelial membrane antigen and cytokeratin. More PCNA positive cells were seen in basaloid cells than in clear cells. Metastasis to regional lymph nodes was found in all 3 cases.

Determinants of longer duration of endotracheal intubation after adult cardiac operations

BACKGROUND

Poor pulmonary reserve is a risk factor that is used to exclude some patients from major operations. However, the value of routine spirometry in patients undergoing cardiac operations has not been widely evaluated.

METHODS

The outcomes of 586 consecutive adult patients undergoing cardiac operations were reviewed retrospectively to assess predictors of longer duration of endotracheal intubation.

RESULTS

By univariate analysis, congestive failure (p < 0.001), cardiomegaly (p = 0.002), recent myocardial infarction (p = 0.039), priority of operation (p = 0.005), previous cardiac operation (p < 0.001), and renal insufficiency (p = 0.002) increased the risk of longer endotracheal intubation. Spirometry (forced vital capacity, forced expiratory volume at 1 second, the ratio of forced expiratory volume at 1 second to forced vital capacity) did not correlate with longer endotracheal intubation. Perioperative complications, such as myocardial infarction (p < 0.001), coma, reexploration for bleeding, and reduced cardiac output (p < 0.001 each), correlated with longer duration of intubation. By multiple regression, priority of operation (p = 0.03), congestive failure (p = 0.02), and previous cardiac operation (p = 0.005) among preoperative risks and bleeding, reduced cardiac output, stroke, coma, and MB fraction of creatine kinase released postoperatively (p < 0.001 each) predicted longer duration of endotracheal intubation.

CONCLUSIONS

Postoperative cardiac function and the occurrence of complications are more significant than preoperative pulmonary function in determining the duration of endotracheal intubation after cardiac operation. Routine spirometry is probably unnecessary for most adult cardiac patients.

[Sudden deafness: stepwise regression analysis on the correlation factors with prognosis]

To further investigate the correlation factors of the prognosis and therapeutic efficiency of sudden deafness, 83 cases (91 ears) from 1993. 1 to 1996. 4 were studied with stepwise regression analysis. The results showed that the prognosis is correlate with the age, the hearing threshold levels of both speech and high frequencies, and the types of the audiometric curve, but not with the illness duration, sex, vertigo, ipsi or bilateral, recurrence, virus infection, cardiac or cerebral vascular diseases, and the medicine or the duration of the treatment. By comparing the results obtained from different statistical analysis, it was suggested that the unification of the criteria of the diagnosis and the therapeutic efficiency as well as the application of the multiple factors regression analysis are essential for the research on sudden deafness.

[Image analysis of cell nuclear morphology and DNA content in osteosarcoma of the jaws]

The measurement of nuclear morphology and quantitative analysis of nuclear DNA content were made by Interactive Image Analysis System in 47 osteosarcomas of the jaws. The results showed that with a decreased degree of differentiation, the cell nuclei of osteoblastic and chondroblastic osteosarcomas came to be large and irregular, those of fibroblastic osteosarcomas, however, to be small and round. It was revealed that high-grade osteosarcomas had increased amounts of DNA and that the mean of DNA content, proportion of hyperploid cells and tumor ploidy were found to be of important prognostic value.

Effect of beta 1 adrenergic receptor blockade on myocardial blood flow and vasodilatory capacity

The beta 1 receptor blockade reduces cardiac work and may thereby lower myocardial blood flow (MBF) at rest. The effect of beta 1 receptor blockade on hyperemic MBF is unknown.

METHODS

To evaluate the effect of selective beta 1 receptor blockade on MBF at rest and during dipyridamole induced hyperemia, 10 healthy volunteers (8 men, 2 women, mean age 24 +/- 5 yr) were studied using 13N-ammonia PET (two-compartment model) under control conditions and again during metoprolol (50 mg orally 12 hr and 1 hr before the study).

RESULTS

The resting rate pressure product (6628 +/- 504 versus 5225 +/- 807) and heart rate (63 +/- 6-54 +/- 5 bpm) declined during metoprolol (p < 0.05). Similarly, heart rate and rate pressure product declined from the baseline dipyridamole study to dipyridamole plus metoprolol (p < 0.05). Resting MBF declined in proportion to cardiac work by approximately 20% from 0.61 +/- 0.09-0.51 +/- 0.10 ml/g/min (p < 0.05). In contrast, hyperemic MBF increased when metoprolol was added to dipyridamole (1.86 +/- 0.27-2.34 +/- 0.45 ml/g/min; p < 0.05). The decrease in resting MBF together with the increase in hyperemic MBF resulted in a significant increase in the myocardial flow reserve during metoprolol (3.14 +/- 0.80-4.61 +/- 0.68; p < 0.01).

CONCLUSION

The beta 1 receptor blockade increases coronary vasodilatory capacity and myocardial flow reserve. However, the mechanisms accounting for this finding remain uncertain.

[The behaviour and treatment of myoepithelial carcinoma of salivary glands]

Nineteen cases of myoepithelial carcinoma (malignant myoepithelioma) in salivary glands were studied clinicopathologically. The clinical features are as follows: arise most frequently within the parotid glands, followed by the submandibular glands; rapidly enlarging mass with extensive invasion of the surrounding tissues in some cases; low rate of cervical lymph node metastasis but high rate of distant metastasis; very frequent recurrence after surgical excision; and poor prognosis. The carcinoma belongs to the high grade malignant tumor. It must be treated radically. The elective neck dissection is generally unnecessary. It is resistant to radiotherapy. It is possible to get rather good result in limited recurrent tumors by prompt surgery.

Differential expression of 11 beta-hydroxysteroid dehydrogenase types 1 and 2 in human placenta and fetal membranes

Two isoforms of 11 beta-hydroxysteroid dehydrogenase (11 beta HSD) are present in mammals. 11 beta HSD1 interconverts biologically active cortisol and inactive cortisone, whereas 11 beta HSD2 only converts cortisol to cortisone. Placental 11 beta HSD has been proposed to protect the fetus from high level of maternal glucocorticoids. Although bidirectional activity of 11 beta HSD has been demonstrated in homogenized human placental tissues, the tissue and cellular distribution of 11 beta HSD1 has not been resolved. In this study, the cellular localization of 11 beta HSD1 protein and levels of its messenger ribonucleic acid (mRNA) in human placenta and fetal membranes were determined by immunohistochemistry and Northern blot analysis, respectively. We found that 11 beta HSD1 immunoreactivity was present in the placental extravillous intermediate trophoblasts, chorion trophoblasts, amnion epithelial cells, and stromal cells of the decidua vera. Positive staining was also observed in the endothelium of the blood vessels in both placental villous tissue and umbilical cord. However, in contrast to previous reports of immunoreactive 11 beta HSD2 localization, 11 beta HSD1 immunoreactivity was undetectable in placental syncytiotrophoblast. Using a human 11 beta HSD1 complementary DNA as probe, a 1.5-kilobase mRNA transcript was detected in the chorion, amnion, and placental tissue, with the greatest amount in the chorion. In contrast, the 1.9-kilobase mRNA of 11 beta HSD2 was observed only in the placenta, not in the chorion and amnion. The process of labor had no significant effect on levels of 11 beta HSD1 or 11 beta HSD2 mRNA in the chorion or placenta. We conclude that there is a striking difference in the tissue localization of 11 beta HSD1 and 11 beta HSD2 expression in the late gestation human placenta and fetal membranes, which may discretely determine the accessibility of bioactive glucocorticoid to specific cell types.

Pulmonary hypertension after operations for congenital heart disease: analysis of risk factors and management

BACKGROUND

Management of pulmonary hypertension, a potentially fatal complication of operations to correct congenital heart disease, has evolved through the last 15 years. Monitoring of pulmonary arterial pressure and mixed venous saturation became available, and prophylactic use of alpha-blockers and other vasodilators increased. This study examines risk factors for morbidity and mortality from pulmonary hypertension after operations to correct congenital heart disease and evaluates the impact of management changes on outcomes.

METHODS

By means of multivariable logistic regression analysis, 880 high-risk patients with congenital heart disease (of 2484 patients undergoing cardiopulmonary bypass between January 1980 and December 1994) were analyzed to determine which were at risk for postoperative pulmonary hypertension and its associated morbidity and mortality.

RESULTS

Patients with atrioventricular canal (n = 182), truncus arteriosus (n = 47), total anomalous pulmonary venous connection (n = 90), transposition of great arteries (n = 97), hypoplastic left heart syndrome (n = 50), and ventricular septal defect (n = 414) demonstrated a higher risk of postoperative pulmonary hypertension. By multivariable logistic regression, preoperative pulmonary hypertension (p < 0.0001), absence of mixed venous saturation monitoring (p < 0.0001), and absence of prophylactic alpha-blockade (p = 0.0004) significantly increased postoperative pulmonary hypertension. Preoperative pulmonary hypertension (p < 0.001) and absence of prophylactic alpha-blockers (p = 0.0004) were significant risk factors for in-hospital death related to pulmonary hypertension. Repair at older age (except in the case of total anomalous pulmonary venous connection) was a significant risk for postoperative pulmonary hypertension (p = 0.03).

CONCLUSION

Mixed venous saturation monitoring and alpha-receptor blockade reduced the incidence of pulmonary hypertension after operations for congenital heart disease. Early definitive repair reduced morbidity and mortality from postoperative pulmonary hypertension.

Surgical management of congenital tracheal stenosis

Long-segment tracheal stenosis in infants and children is difficult to manage and can be life-threatening. Patients frequently have associated cardiac, other respiratory, or gastrointestinal anomalies that may confuse the diagnosis at initial presentation. The rarity of congenital tracheal stenosis has not allowed sufficient experience for the development of standard treatment protocol. Several surgical techniques have been described but have varying results. This article reviews the diagnosis and different surgical options for congenital tracheal stenosis and their outcomes.

Surgical management of total anomalous pulmonary venous connection. Thirty-year trends

BACKGROUND

Reports of surgical correction of total anomalous pulmonary venous connection (TAPVC) over the past 30 years indicate a general improvement in operative survival. However, prevention of late pulmonary venous obstruction continues to be a cornerstone of successful repair. The purpose of the study was to identify factors associated with improvement in perioperative mortality and to determine risk factors for death and reoperation due to pulmonary vein stenosis after repair of TAPVC.

METHODS AND RESULTS

Using univariate and multiple regression analysis, we analyzed risk of early and late mortality and need for reoperation in 105 patients operated on between April 1966 and June 1995. Despite increased frequency of neonatal repair in the most recent time period (29% in 1966 through 1985; 55% in 1991 through 1995, P < .05), operative mortality declined (13% in 1966 through 1985; 0% in 1991 through 1995). The incidence of postoperative pulmonary hypertensive episodes and death related to pulmonary hypertension decreased significantly over the study period (P < .001). Aggressive preoperative elective medical stabilization and prophylaxis of postoperative pulmonary hypertensive episodes may have contributed to this improvement. By univariate analysis, preoperative pulmonary hypertension (P < .02) and preoperative pulmonary vein obstruction (P < .01) correlated with early mortality up to 1990 but not in the past 5 years. Multiple logistic regression analysis showed that only a small pulmonary confluence associated with diffuse pulmonary vein stenosis was an independent risk factor for early (P < .001) and late (P = .01) death as well as need for reoperation (P = .007). Type of TAPVC was not a significant risk factor throughout the three decades of our experience. At a median follow-up of 87 months, late survival was 98% (93 of 95 operative survivors), and all are NYHA class I.

CONCLUSIONS

Improvements on surgical technique as well as preoperative and postoperative management account for the reduction in mortality and need for reoperation for most types of TAPVC. However, the presence of a small venous confluence and diffuse pulmonary vein stenosis remains a risk factor for adverse outcome.

Anterior pericardial tracheoplasty for congenital tracheal stenosis: intermediate to long-term outcomes

BACKGROUND

Although several techniques for the treatment of long-segment stenosis of the trachea have been reported, including slide tracheoplasty, rib grafting, and use of a pericardial patch, the optimal repair remains controversial because of a lack of midterm to long-term follow-up data.

METHODS

To assess the intermediate and long-term outcomes of patients having repair with anterior pericardial tracheoplasty, we reviewed case histories of 12 patients (1984 to present). The median age was 6.7 months (range, 1 to 98 months), and the median weight was 6.0 kg (range, 0.97 to 42 kg). All patients underwent anterior pericardial tracheoplasty through a median sternotomy during partial normothermic cardiopulmonary bypass. An average of 13 tracheal rings (range, five to 23) were divided anteriorly, and a patch of fresh autologous pericardium was used to enlarge the trachea by 1.5 times the predicted diameter for patient age and weight.

RESULTS

There was one hospital death, and all but 2 patients are long-term survivors. All but 1 current survivor remain asymptomatic, with no bronchoscopic evidence of airway obstruction or granulation on the pericardial patch. All survivors examined have normal tracheal growth and development, with a median follow-up of 5.5 years (range, 1 to 11 years).

CONCLUSIONS

Anterior pericardial tracheoplasty for congenital tracheal stenosis provides excellent results at intermediate to long-term follow-up.

A simple light-driven transmembrane proton pump

Light-induced lipophilic porphyrin/aqueous acceptor charge separation across a single lipid-water interface can pump protons across the lipid bilayer when the hydrophobic weak acids, carbonylcyanide m-chlorophenylhydrazone and its p-trifluoromethoxyphenyl analogue, are present. These compounds act as proton carriers across lipid bilayers. In their symmetric presence across the bilayer, the positive currents and voltages produced by the photogeneration of porphyrin cations are replaced by larger negative currents and voltages. The maximum negative current and voltage occur at the pH of maximum dark conductance. The reversed larger current and voltage show a positive ionic charge transport in the same direction as the electron transfer. This transport can form an ion concentration gradient. The movement of protons is verified by an unusual D2O isotope effect that increases the negative ionic current by 2- to 3-fold. These effects suggest that an interfacial pK shift of the weak acid caused by the local electric field of photoformed porphyrin cations/acceptor anions functions as the driving force. The estimated pumping efficiency is 10-30%. Time-resolved results show that proton pumping across the bilayer occurs on the millisecond time scale, similar to that of biological pumps. This light-driven proteinless pump offers a simple model for a prebiological energy transducer.

Angiotensin II and glutamate influence area postrema neurons in rat brain slices

The area postrema (AP) has been repeatedly implicated in cardiovascular regulation. Microinjection and single unit recording studies in vivo have suggested specific actions for angiotensin II (ANG) and glutamate (GLU) in controlling the excitability of AP neurons. The present study was therefore designed to examine the responsiveness of AP neurons to bath administration of these substances. Of the 133 AP neurons tested with ANG (10(-8)-10(-6) M) 40% were excited, 13% inhibited and the remainder unresponsive. The excitatory effects of ANG on AP neurons were dose-dependent. Following blockade of synaptic transmission with a low calcium high magnesium solution excitatory responses were maintained in 12 of 15 cells tested. Pretreatment of slices with the AT1 receptor antagonist losartan blocked the excitatory effects of ANG in all cells (5/5) tested. The effects of GLU on AP neurons were also examined. Of the 71 AP cells tested, 40% were excited, 10% inhibited, 8% showed excitatory responses followed by periods of inhibition while the remaining cells were unaffected. Excitatory effects of GLU were maintained in all AP neurons (7/7) tested during perfusion with low calcium, high magnesium solutions. Similar responses to NMDA were observed in four of four cells tested, suggesting these GLU actions are mediated through NMDA receptors. These data demonstrate direct excitatory actions of ANG and GLU on AP neurons which are likely mediated through the AT1 and NMDA receptors, respectively.

Evidence for ion chain mechanism of the nonlinear charge transport of hydrophobic ions across lipid bilayers

The conductivity across a lipid bilayer by tetraphenylborate anion is increased 10-fold on the photoformation of lipophilic porphyrin cations. The cations alone have negligible conductivity. This nonlinear photogenerated increase of ion conductivity is termed the photogating effect. Substitution of H by Cl in the para position of tetraphenylborate leads to a 100-fold enhancement of conductivity, whereas the dark conductivities for this and other substituted borates are the same. Moreover, the halo-substituted borates show a large enhancement of conductivity in the low concentration range (10(-8) M), whereas that of tetraphenylborate is small and space charge is negligible. The enhanced ion conductivity has great structural sensitivity to the structure of the anion, the cation, and the lipid, whereas the partition coefficient of all the borates and the concentration of photoformed cations are only slightly affected. The photogated ion transport has a twofold larger activation energy than transport in the dark. Time-resolved photocurrents and voltages demonstrate that the translocation rate of the porphyrin cation is also enhanced 100-fold by the Cl-borate anion but only 10-fold by the H-borate anion. For these reasons the nonlinear gating effect cannot be explained by electrostatics alone, but requires an ion chain or ion aggregate mechanism. Kinetic modeling of the photoinduced current with a mixed cation-anion ion chain can fit the data well. The photogating effect allows the direct study of ion interactions within the bilayer.

Surgical management of hypoplastic left heart syndrome

BACKGROUND

The treatment of infants with hypoplastic left heart syndrome has been challenging and controversial.

METHODS

To assess the operative management and intermediate-term outcome, we retrospectively analyzed our surgical experience with 50 newborns with hypoplastic left heart syndrome operated on between January 1989 and June 1995.

RESULTS

Surgical palliation with a first-stage Norwood operation was offered to 28 patients. The remaining 22 infants were initially listed for heart transplantation, and 15 underwent the operation. Ten of the 15 recipients are alive, and all are in New York Heart Association class I. Seven infants underwent a Norwood procedure after being on the list for transplantation for 12 to 42 days. A total of 34 patients underwent Norwood procedures with one operation aborted because of inoperable anatomy. Two infants who survived the first-stage Norwood operation underwent subsequent heart transplantation and are currently doing well. The 1-year mortality rate for heart transplantation was 18% (3/17) versus 50% (17/34) for the Norwood procedure. Risk factors for early mortality after a Norwood procedure include longer circulatory arrest time (> 50 minutes), preoperative acidosis (pH < 7.20), larger systemic-pulmonary artery shunt (> or = 4 mm), diminutive ascending aorta (< or = 2.0 mm), and anatomic subtype of aortic and mitral atresia. The 1-year survival rate for the Norwood procedure improved from 36% for the patients operated on during 1989 through 1992 to 75% during 1993 to mid-1995 (p = 0.005). Of the 17 survivors of a first-stage Norwood operation, 10 have undergone the second stage (bidirectional Glenn procedure), and 7 have completed a Fontan procedure. Heart transplantation results have also improved, with no deaths since 1992.

CONCLUSIONS

Both the Norwood procedure and heart transplantation have encouraging early to intermediate results in infants with hypoplastic left heart syndrome. Hypoplastic left heart syndrome should be managed selectively on the basis of cardiac morphology, donor availability, and family wishes. Development of a flexible program involving the use of both procedures may aid in the successful management of infants with hypoplastic left heart syndrome.

Chronic suppurative parotitis: a proposed classification

OBJECTIVE

To propose a practical and reasonable classification of chronic suppurative parotitis (CSP) on the basis of the various entities.

MATERIAL AND METHODS

Clinical, laboratory, sialographic, scintigraphic, histopathologic (including ultrastructural) study of recurrent parotid swellings (RPS) was performed in 291 patients over a 10-year period.

RESULTS

It is suggested that CSP should be classified into recurrent parotitis in childhood (RPC), recurrent parotitis in adults (RPA), chronic obstructive parotitis (COP) and should be differentiated from other subdivisions including subclinical Sjögren's syndrome (SCSS), chronic parotid swelling of Sjögren's syndrome and sialadenosis with retrograde infection. RPA is a continuation of recurrent parotid swelling from childhood (RPC) to adulthood. Remission can take place spontaneously in RPC and RPA so that self-conservative therapy is mainly used for reducing the parotid swellings. COP is recurrent parotid swellings and/or purulent discharge resulting from various obstructive factors. Mild COP can recover completely with the use of conservative methods, severe COP is often resistant to conservative treatment and should be treated with surgical modality or injection of methyl violet into the diseased gland. Treatment with methyl violet is considered as a convenient and practical method with a definite effect. SCSS is an autoimmune disease and should be treated as systemic disease.

CONCLUSIONS

Because there exists confusion in the nomenclature of RPS this revised classification is based on the various entities and can be used as a guide in the diagnosis and treatment of RPS.

[Histochemical and electronic microscopical studies of stellate fibrillar formations (SFF) in salivary gland tumors]

PURPOSE

To study the structure and significance of SFF in pleomorphic adenoma and myoepithelioma.

MATERIAL AND METHODS

Tow cases of each tumor were studied. Histologie and ultrathin sections were made, stained with HE, Mallory, Van Gieson, Pollak methods, and examined with light and transmission electronic microscopes. RESULTE: The SFF were proved to be formed by radial arrangement of collagen fibers, which were composed of striped fibrillae under TEM.

CONCLUSION

The structure of the SFF is understood, their existence may play a role the pathologic diagnosis.

Charge transfer across a single lipid-water interface causes ion pumping across the bilayer

The photoformation of magnesium-porphyrin cations (P+) at a single lipid bilayer-water interface can pump lipophilic borate anions completely across the lipid bilayer and causes an actual reversal of the photovoltage. The system consists of a lipid bilayer containing magnesium octaethylporphyrin, an aqueous or interfacial electron acceptor on one side, and chloro- or fluoro-substituted tetraphenylborate in both aqueous electrolyte solutions. With 1-micros pulsed illumination, an immediate positive photovoltage is observed, which decreases on the microsecond and millisecond time scales. On the time scale of seconds, as the P+ cation concentration decays in reverse electron transfer, the voltage swings negative to a value almost equal to its initial value and finally decays with a half-time (approximately 20 s) longer than the time constant of the system (approximately 5 s). Thus, an ion gradient across the membrane is formed, trapped by the nonlinear relation between ion mobility and ion concentration. Continuous light illumination confirms that negative charge moves in the direction opposite that of the initial photoinduced electron transfer. Steady-state measurements indicate an ion pumping efficiency of approximately 30%. This simple mechanism may be a progenitor of photobiological ion pumps.

[Prevention of peridural fibrosis and adhesion after laminectomy: an experimental study in rats]

An experimental study on the effectiveness of various materials including poly carboxymethylcellulose (PCMC), gelatin foam (GF), ligment (L), free fat (FF) in prevention of peridural fibrosis and adhension (PDA) was done in 144 SD rats using a total laminectomy model (L1-2). PDA was measured with a double-blind protocol at 2, 4, 8, 12 weeks postoperatively by gross anatomical appearance (blunt-dissection), microscopical evaluation, computed imaging analysis and MRI enhanced with gadolinium. The results demonstrated that the peak of PDA is within 8 weeks after operation. PCMC, as a three dimensional protective material, could effectively inhibit PDFA after laminectomy, but GF and L could not. SHA had some effect in the early stage, but not in the late period. For FF though it could effectively prevent PDA, the incision infection rate was higher, the atrophy and necrosis of FF were serious. What is more, almost all transplanted fat remained in situ extended into the spinal cord in some measure after 8 weeks postoperatively.

Prognostic significance of lymph node metastasis in surgical resection of esophageal cancer

OBJECTIVE

Although surgery is relatively successful in eradicating local tumor, post-resection five-year survival rate for esophageal cancer is still lower than 30%. Multiple factors are found to influence the long-term results after surgical treatment. However, recent investigations have focused on the significance of lymph node matastasis (LNM), which seems to be one of the most important factors leading to poor survival. Hence, the prognostic significance of LNM in surgical resection of esophageal cancer was studied.

METHODS

The rate and degree of LNM were evaluated and their prognostic significance was investigated through a retrospective study of 474 patients with esophageal cancer treated by surgery alone.

RESULTS

LNM was positive in 211 patients, with an incidence of 44.5% (211/474). A total of 5382 lymph nodes were resected and studied pathologically, among which metastasis was found in 690 nodes with an overall LNM degree of 12.8% (690/5382). The 5-year survival rate was 30.6% (145/474) in the entire series, 12.8% (27/211) in patients with LNM, and 44.9% (118/263) in those without LNM.

CONCLUSIONS

Surgery remains the first choice of treatment for carcinoma of the esophagus, and that meticulous lymph node dissection is an important practice of surgical oncology. However, in more advanced cases of this disease, surgery alone is of limited value in eradicating all cancer compromized tissue, and therefore the routine practice of extensive lymph node dissection in such cases may not be rewarding.

Surgical management of complete atrioventricular septal defects. A twenty-year experience

Creation of a competent left atrioventricular valve is a cornerstone in surgical repair of complete atrioventricular septal defects. To identify risk factors for mortality and failure of left atrioventricular valve repair and to determine the impact of cleft closure on postoperative atrioventricular valve function, we retrospectively analyzed hospital records of 203 patients between January 1974 and January 1995. Overall early mortality was 7.9%. Operative mortality decreased significantly over the period of the study from 19% (4/21) before 1980 to 3% (2/67) after 1990 (p = 0.03). Ten-year survival including operative mortality was 91.3% +/- 0.004% (95% confidence limit): all survivors are in New York Heart Association class I or II. Preoperative atrioventricular valve regurgitation was assessed in 203 patients by angiography or echocardiography and was trivial or mild in 103 (52%), moderate in 82 (41%), and severe in 18 (8%). Left atrioventricular valve cleft was closed in 93% (189/203) but left alone when valve leaflet tissue was inadequate and closure of the cleft might cause significant stenosis. Reoperation for severe postoperative left atrioventricular valve regurgitation was necessary in eight patients, five of whom initially did not have closure of the cleft and three of whom had cleft closure. Six patients had reoperation with annuloplasty and two patients required left atrioventricular valve replacement. Five patients survived reoperation and are currently in New York Heart Association class I or II. On most recent evaluation assessed by angiography or echocardiography (a mean of 59 months after repair), left atrioventricular valve regurgitation was trivial or mild in 137 of the 146 survivors (94%) examined; none had moderate or severe left atrioventricular valve stenosis. By multiple logistic regression analysis, strong risk factors for early death and need for reoperation included postoperative pulmonary hypertensive crisis, immediate postoperative severe left atrioventricular valve regurgitation, and double-orifice left atrioventricular valve. These results indicate that complete atrioventricular septal defects can be repaired with low mortality and good intermediate to long-term results. Routine approximation of the cleft is safe and has a low incidence of reoperation for left atrioventricular valve regurgitation.

Complex and rapid-cycling in bipolar children and adolescents: a preliminary study

26 subjects aged 7-18 years were studied. Diagnoses of bipolar disorders were established using the Kiddie-Schedule for Affective Disorders and Schizophrenia-Present Episode Version-1986 modified for DSM-III-R criteria and for rating the number and duration of manic and hypomanic episodes. Complex cycling patterns were observed. These included numerous brief episodes suggesting continuous rapid-cycling in 80.8% of cases. Mean age of onset was early (8.5 +/- 4.4 years). Psychotic phenomena, suicidality, hyperactivity and 'mixed mania' were highly prevalent. Data in this report provide support for complex and rapid-cycling patterns in childhood onset bipolar disorder.

Vasopressin actions on area postrema neurons in vitro

The area postrema (AP) is a circumventricular organ located on the dorsal surface of the medulla. Substantial evidence suggests that the AP is an important site involved in cardiovascular regulation. Arginine vasopressin (AVP) is thought to act at the AP to increase the sensitivity of the baroreceptor reflex. We have therefore examined the effects of AVP on AP neurons with the use of extracellular single unit recordings in vitro. Coronal medullary brain slices (thickness = 400 microns) were obtained from male Sprague-Dawley rats and maintained in oxygenated artificial cerebrospinal fluid (aCSF). The slices were perfused with AVP (10(-8) to 10(-6) M), and the effect on single AP neurons was recorded. A total of 79 AP neurons was tested of which 50 (63.3%) were excited by AVP and 5 (6.3%) were inhibited, whereas the remaining 24 (30.3%) cells were unaffected. The excitatory effects of AVP were dose dependent: firing rate increased 92.6 +/- 25.8% at 10(-8) M, 289.4 +/- 53.9% at 10(-7) M, and 456.8 +/- 113.1% at 10(-6) M, respectively. We also examined whether these effects of AVP resulted from direct actions of this peptide on AP cells by testing if responses were retained during blockade of synaptic transmission (achieved by perfusion with a low Ca(2+)-high Mg2+ aCSF) in 11 cells excited by AVP. Nine of these cells were excited by AVP during such synaptic blockade. Finally, we demonstrated that the excitatory responses of five AP cells to AVP were all totally abolished by perfusion of slices with aCSF containing the V1 antagonist ([1-beta-mercapto-beta,beta-cyclopentamethylene propionic acid,2-(O-methyl)tyrosine]-Arg8-vasopressin; Peninsula Laboratories, 10(-6) M).(ABSTRACT TRUNCATED AT 250 WORDS)

[An electron microscopic histochemical study on proteoglycans in salivary gland myoepithelioma]

Four myoepitheliomas and four parotid gland were studied histochemically be electron microscopy after stain with ruthenium red. It was found that the normal myoepithelial cells of parotid gland had no secretion function, whereas the myoepithelioma cells were capable of secreting proteoglycans and might form the myxoid region in this tumor. The authors propose that in the pathological diagnosis and differentiat diagnosis of salivary gland epithelial tumors, the appearance of the myxoid region is not only the pathological feature of pleomorphic adenoma, but also the pathological change of myoepithelioma.

CEDIA for screening drugs of abuse in urine and the effect of adulterants

The performance of the Microgenics CEDIA DAU assays for screening amphetamines, barbiturates, benzodiazepines, cocaine, opiates, phencylidine (PCP), and tetrahydrocannabinol (THC) was evaluated on the Boehringer Mannheim/Hitachi 717 in urine. Limits of detection ranged from 0.6 ng/mL for PCP, to 34.1 ng/mL for benzodiazepines. The average within run and total precision for these assays ranged from 1.3 to 7.3% for controls at cutoff concentrations, and control values at -25% and +25% of cutoffs. The rate separations by CEDIA between the negative and cutoff calibrators for all drugs were greater than corresponding EMIT II (Syva Co.) assays. The relative sensitivity and specificity of CEDIA as compared to EMIT II were 95.6 and 98.8%, respectively, on 13,535 urine samples. All positive samples, and those samples producing discordant results between the assays were confirmed by quantitative gas chromatography/mass spectrometry (GC/MS). Using SAMHSA cutoff limits (and including barbiturates and benzodiazepines at 300 ng/mL), the relative sensitivity and specificity of CEDIA vs. EMIT II were 96.7 and 98.8%, respectively. The overall sensitivity of CEDIA vs. GC/MS was 98.9% with 179 false positives, as compared to 96.2% with 189 false positives for EMIT II vs. GC/MS. The effect of adulterants added to urine to potentially invalidate screening results was also tested. CEDIA produced strong interferences for most drug assays in the presence of glutaraldehyde, detergent, and high concentrations of bleach and Drano. Minimal or selective interferences were seen with golden seal tea lemon juice, Visine, and low concentrations of bleach and Drano. Essentially no interference was observed with bicarbonate, sodium chloride, and vinegar.

[Clinical study on the feasibility of preserving vagal trunks in the surgical treatment of carcinoma of the thoracic esophagus]

The results of preserving vagal trunks in the surgical treatment of 47 patients with the carcinoma of the thoracic esophagus were discussed through a controlled study. There were 20 patients in the test group with vagus nerve being preserved (PG) and 27 in the control group (CG) with vagus nerve being routinely severed. Eighteen patients in PG and 26 in CG underwent radical resections, the remaining patients received palliative surgery. Pathological findings showed that 3 cases (15.0%) in PG and 3 cases (11.1%) in CG had cancerous invasion near the vagal trunks and/or their main branchs close to the primary cancer; and 1 case (5.0%) in PG and 3 (11.1%) in CG the vagal nerves were actually invaded by cancer cells. Determinations of basal gastric acid output (BAO) and half gastric emptying time (T 1/2) revealed that the mean value of BAO (1.93mmol/h) and T 1/2(63.51min.) of the PG were statistically different from those of 0.75mmol/h and > 105min. in CG, but similar to those of the healthy group and the preoperative control values. We consider that it is feasible to preserve vagal trunks in the operation and is beneficial in minimizing of postoperative disturbances of gastric acid output and gastric motility; but the indications of this procedure should only be limited to T1-T2 lesions in order not to jeopardize the radicality of tumor resection.

Effect of acute and long-term smoking on myocardial blood flow and flow reserve

BACKGROUND

Cigarette smoking is a major preventable risk factor for coronary artery disease and sudden cardiac death. However, the effect of acute and long-term cigarette smoking on coronary vasodilatory capacity and myocardial flow reserve has not been quantified in humans.

METHODS AND RESULTS

To examine the effect of short-term and long-term smoking, myocardial blood flow was quantified at rest and during dipyridamole-induced hyperemia (0.56 mg/kg) in 12 smokers (10 males and 2 females; mean age, 27 +/- 4 years) under baseline conditions (reflecting the effect of long-term smoking) and during short-term cigarette smoking with 13N ammonia, positron emission tomography, and a two-compartment model. Twelve sex- and age-matched nonsmokers served as control subjects. Smoking significantly increased the rate-pressure product at rest from 7525 +/- 1290 to 9160 +/- 1125 (P < .001 versus baseline), which was paralleled by a proportional increase in myocardial blood flow at rest (0.70 +/- 0.17 versus 0.88 +/- 0.17 mL.g-1.min-1; P < .05 versus baseline). In contrast, hyperemic blood flow declined from 2.23 +/- 0.35 at baseline (P = NS versus control) to 1.98 +/- 0.32 mL.g-1.min-1 during smoking (P < .01 versus baseline). Accordingly, the myocardial flow reserve declined from 3.36 +/- 0.83 in smokers at baseline to only 2.28 +/- 0.28 during smoking (P < .0001 versus baseline). Thus, myocardial blood flow and flow reserve were similar in young, long-term smokers and young, healthy nonsmokers.

CONCLUSIONS

Short-term smoking increases the coronary vasomotor tone during dipyridamole-induced hyperemia and markedly reduces the myocardial flow reserve. In contrast, long-term smoking does not attenuate the coronary vasodilatory capacity in young individuals with a relatively short smoking history. It might be speculated that the short-term reduction in the coronary vasodilatory capacity during smoking could lower the ischemic threshold in smokers with coronary artery disease and contribute to the increased risk for sudden cardiac death.

Structural and ultrastructural studies of the synovial membrane in temporomandibular joint disturbance syndrome

To gain further knowledge on temporomandibular joint disturbance syndrome (TMJDS), the synovial membranes of 7 patients and 3 cadavers were examined with light microscope and transmission electron microscope. The results showed that the synoviocytes degenerated or disappeared in TMJDS. The cytoplasm contained numerous fibrils, while the organelles diminished in number. The surface of the synovial membrane was covered with a fibrinoid material. The surface of the synovial membrane was covered with a fibrinoid material. The authors consider that these pathological changes reduce or eliminate the normal functions of the synovial membrane, which may lead to damage to the articular cartilage. The articular adhesion found sometimes in TMJDS may be related to the changes in the synovial membrane.

[The ultrastructure study of white sponge nevus in oral mucosa]

Biopsies from 7 patients with white sponge nevus were examined histologically. Two of them had family history. Light microscopic observation reveals that the epithelium was thickened; the spinous cell layers had enlarged and oedematous cells and ballon-like degeneration; the keratohyalin granules were increased in upper spinous cells; the superficial layers of epithelium exhibited parakeratosis and thickening. 3 specimens were examined by electron microscopy. The basal and parabasal cells were cylindrical. The cytoplasmic tonofilaments were aggregated into boundles. It was characteristics of keratinized epithelium. In middle and superficial stratum spinosum the tonofilaments were homogeneously distributed in the cell plasma and the electron-dense granulars were located near the cell boundary and attached to desmosomes by tonofilaments, unlike normal non-keratinized oral mucosa. Many Odland bodies with a lamellar structure and irregular in both size and shape were seen. It is concluded that this leasion have a dyskeratinized process. The characteristic features of keratinized oral mucosa in non-keratinized mucosa is appeared. The thickening of superficial layer is due to shedding disturbance relating to dysfunction of Odland bodies.

[The prognostic significance of lymph node metastasis in surgical resection of esophageal cancer]

The metastatic rate and degree of lymph node (LN) were evaluated and the relation between prognostic significance and LN metastasis (M) was analysed through a retrospective study of 474 patients undergoing resections of non-irradiated esophageal carcinoma. In patients with LNM, the LNM rate was 44.5%. A total of 5382 LNs were resected and examined pathologically. 690 of them were metastatic ones with a LNM degree of 12.8%. The 5-year survival rate of this series was 30.6% (145/474), and was 12.8% (27/211) in patients with LNM and 44.9% (118/263) in those without LNM. We concluded that surgery remains the first choice of treatment for carcinoma of esophagus, and that meticulous LN dissection is an important part of surgical oncology. This is especially true when the cancer process is reasonably localized. However, in more advanced cases of this disease, surgery alone is of limited value in eradicating all cancer compromized tissue, and therefore the routine practice of extensive LN dissection in such cases may not be rewarding.

Estimation of acute toxicity by fitting a dose-time-response surface

In acute toxicity testing, organisms are continuously exposed to progressively increasing concentrations of a chemical and deaths of test organisms are recorded at several selected times. The results of the test are traditionally summarized by a dose-response curve, and the time course of effect is usually ignored for lack of a suitable model. A model which integrates the combined effects of dose and exposure duration on response is derived from the biological mechanisms of aquatic toxicity, and a statistically efficient approach for estimating acute toxicity by fitting the proposed model is developed in this paper. The proposed procedure has been computerized as software and a typical data set is used to illustrate the theory and procedure. The new statistical technique is also tested by a data base of a variety of chemical and fish species.

Quantitative multivariate analysis of myoepithelioma and myoepithelial carcinoma

The nuclear DNA content and morphologic data of 30 surgical samples (eight normal parotid gland, 12 myoepithelioma, and 10 myoepithelial carcinoma) were analyzed by the IBAS II analysis system. The results suggest that there are relationships between tumor ploidy distribution and prognosis, and that correct pathologic diagnosis can be obtained by the IBAS image system.

[Histogenesis of pleomorphic adenoma of the salivary gland]

Six parotid pleomorphic adenomas were studied histochemically by electron microscopy after staining with ruthenium red. It was found that the myxoid region was filled with ruthenium red granules. Similar positive ruthenium red-stained intracellular granules were observed within the Golgi-derived vacuoles of the neoplastic myoepithelial cells in the myxoid region. Some cells located at the periphery of the double-layer ductal structure had the features of myoepithelial cell, they also showed similar positive ruthenium red-stained granules in the intracellular vacuoles and intercellular space. No ruthenium red-stained granules was obtained in neoplastic ductal epithelium and the mucus in ductal cavities were negative for ruthenium red stain. The observations indicate that the neoplastic myoepithelial cells in the myxoid region probably derive from the periphery of the double-layer ductal structure, they secrete the proteoglycans forming the myxoid region and play an important role in the histogenesis of pleomorphic adenoma.

Genomic structure and chromosomal localization of processed pseudogenes for human RBP-Jk

The functional gene for human recombination signal sequence-binding protein (RBP-Jk) and corresponding processed psudogenes have been isolated from various species, such as Drosophila, Xenopus, mouse, and human. Here we report the isolation of another two genomic pseudogenes of human RBP-Jk, named K2 and K7, from a cosmid library of Hela cells. The nucleotide sequences of both genes exhibited more than 95% homology to the functional human gene for RBP-Jk. Moreover, they did not contain any intron sequences and were interrupted by several stop codons in all frames. In situ hybridization demonstrated that the pseudogenes, K2 and K7, were localized at chromosomes 9p13 and 9q13, respectively. Their physical maps differed from those of the true functional gene and of the pseudogenes reported previously by Amakawa et al. (1993).

Omega-3 and omega-6 fatty acids and PGE2 stimulate the growth of normal but not tumor mouse mammary epithelial cells: evidence for alterations in the signaling pathways in tumor cells

The direct effect of omega-3 and omega-6 fatty acids on the proliferation of mouse mammary tumor cells (MTC) was examined in a serum-free cell culture system. While the EGF-induced proliferation of normal mammary epithelial cells was shown to be enhanced by omega-3 and omega-6 fatty acids and prostaglandins (PGs), a majority (75-80%) of primary mammary tumors were not stimulated by these agents. Compared to normal cells, some MTC cultures showed a higher susceptibility to inhibition by omega-3 fatty acids. The general lack of response of MTC cultures to PGE2 and cyclic adenosine monophosphate (cAMP) suggests some alterations in the cAMP-mediated pathway. However, the PGE2-induced cAMP levels and cAMP-dependent protein kinase (PKA) activities in the tumor cells were comparable to normal cells. We conclude that the proliferation of mammary tumor cells either follow a cAMP-PKA-independent pathway or have some alterations in the serine/threonine kinase mediated signaling pathway.

Basal and KCl-stimulated corticotropin-releasing hormone release from human placental syncytiotrophoblasts is inhibited by sodium nitroprusside

Human placenta synthesizes and secretes large amounts of CRH during the second and third trimesters. In the hypothalamus, nitric oxide (NO) has been reported to affect CRH release. We studied the effect of NO on the regulation of placental CRH secretion. The effect of the NO donor sodium nitroprusside (SNP) on basal and KCl-stimulated CRH release was examined in cultured human syncytiotrophoblasts. CRH secretion and intracellular concentrations of cGMP, calmodulin-dependent protein kinase (CaM-PK), protein kinase-G (PKG), protein kinase-C, and cAMP-dependent protein kinase holoenzyme were measured under basal conditions and after treatment with a depolarizing concentration of KCl and with SNP. The results showed that depolarization (3 h) increased CRH release 4-fold (from basal value of 5.16 +/- 0.65 to 19.31 +/- 4.46 fmol/10(6) cells); SNP (100 mumol/L) decreased both basal (0.42 +/- 0.21 fmol/10(6) cells) and KCl-stimulated CRH release (0.94 +/- 0.32 fmol/10(6) cells). KCl also increased the activity of CaM-PK in the cell membrane and both cytosolic and membrane PKG activity, whereas the activities of protein kinase-C and cAMP-dependent protein kinase holoenzyme were unchanged. SNP increased intracellular cGMP concentrations after 10, 60, and 180 min. Methylene blue (100 mumol/L), a guanylate cyclase inhibitor, blocked the inhibitory effects of SNP on CRH release. These results suggest that NO exerts inhibitory effects on both basal and KCl-stimulated CRH release from placental syncytiotrophoblasts through a cGMP-mediated pathway. In addition, as KCl-induced changes in the cell membrane were blocked by SNP, CaM-PK may be involved in KCl-stimulated CRH release. KCl may also sensitize the inhibitory pathway involved in the regulation of CRH release by increasing cellular PKG levels. The effects of KCl and SNP on CRH release are more complex than simple activation of CaM-PK and PKG activity, as other cellular signal transduction pathways are also modulated.

Effect of exercise supplementation during adenosine infusion on hyperemic blood flow and flow reserve

Physical stress might modulate myocardial blood flow in near-maximally dilated coronary arteries by increasing coronary perfusion pressure, myocardial contractility, and heart rate. The net effect of these changes on hyperemic blood flows has not yet been defined in humans. To quantify the effect of physical exercise on pharmacologically induced hyperemia, myocardial blood flow was measured in 11 healthy volunteers. Measurements were performed with positron emission tomographic imaging with nitrogen-13 ammonia at rest, during intravenous (i.v.) adenosine administration (140 micrograms.kg-1.min-1 over 6 minutes), and during i.v. adenosine administration plus supine bicycle exercise with a maximal workload of 125 W. Myocardial blood flow was quantified by using a previously validated graphic analysis. Heart rate, systolic blood pressure, rate-pressure product, and mean aortic blood pressures were significantly higher during combined physical and pharmacologic stress than during pharmacologic stress alone. However, myocardial blood flow decreased from 2.6 +/- 0.4 to 2.2 +/- 0.4 ml.min-1.gm-1 with the addition of physical stress (p < 0.05). This decline was associated with a significant increase in coronary vascular resistance (35 +/- 6 vs 52 +/- 13 mm Hg.ml-1.gm.min; p < 0.05). Accordingly, myocardial flow reserve declined, from 5.0 +/- 0.9 to 4.3 +/- 1.0, with exercise supplementation (p < 0.05). Exercise in addition to pharmacologic stress increases coronary vascular resistance and thus significantly decreases hyperemic myocardial blood flow and flow reserve. This decrease results most likely from an increase in extravascular restrictive forces caused by higher ventricular pressures and contractility during physical stress.

[Length method in evaluating right ventricular volume in children with congenital heart disease: a comparison with two dimensional echocardiographic method]

The accuracy and reliability of two-dimensional echocardiographic length method in right ventricular volume measurement were assessed by three-dimensional echocardiographic method in 10 normal children, 10 patients with atrial septal defect, and 10 patients with pulmonary stenosis. Their age and sex were matched. Right ventricular end diastolic, end systolic, mid-systolic volume, and ejection fraction evaluated by length method were correlated very well with the values obtained by three-dimensional echocardiographic method in normal and pulmonary stenosis group (r = 0.71-0.95, P < 0.01). In atrial septal defect group, right ventricular volume obtained by the two methods was correlated well (r = 0.86-0.95, P < 0.01). Although the correlation in right ventricular ejection fraction was lower, it was still significant. The shortening rate of X, Y, Z parameters required by length method were similar in each group: delta Z % > delta X % > delta Y %. We conclude that right ventricular volume and function could be assessed accurately by two-dimensional echocardiographic length method in children with right ventricular volume or pressor overloaded, and that right ventricular systolic pattern is similar in those situations.

Cognitive performance in a high-functioning community-dwelling elderly population

BACKGROUND

The purpose of this study was to examine the role of demographic factors as predictors of cognitive performance in a high-functioning, community-dwelling elderly population.

METHODS

The study cohort consisted of 1,192 community-dwelling subjects, who were selected to represent the highest third of an elderly population with respect to physical and cognitive functioning. A neuropsychological battery, including 5 cognitive performance subtests (confrontation naming, delayed recognition span, similarities, figure-copying, and incidental delayed recall) was administered to the subjects in their homes.

RESULTS

A summary measure of the 5 neuropsychological subtest scores, the total cognitive score, arrayed the study group across a broad range of difficulty, creating a near-normal distribution. Education, income, and race had statistically significant associations with the total score and the individual subtests. The effect of education was the most striking finding, explaining 30% of the variance in the total score. Education was most strongly related to the abstraction (partial R2 = .11) subtest, and least related to the memory subtests, delayed recognition (R2 = .02) and delayed recall (R2 = .01).

CONCLUSIONS

Demographic factors are important predictors of cognitive performance in this high-functioning cohort. Education had the strongest influence on overall cognitive performance, and particularly notable associations with subtests that depended upon the use of previously learned materials. Longitudinal follow-up, now underway, will help to determine whether high levels of education help to maintain cognitive performance with age.

Technology assessment in diagnostic imaging. A proposal for a phased approach to evaluating radiology research

RATIONALE AND OBJECTIVES

The authors propose an objective basis for critical evaluation of research trends and define and analyze a sample of radiology studies according to research phase.

METHODS

A random sample of 146 original diagnostic studies from two radiology journals was categorized according to phase, modality, and design by three physician reviewers, collated with a microcomputer database, and analyzed using an SAS program.

RESULTS

Phase 1 studies (technical evaluation) constituted 18.5% of publications: phase 2 (standardization and tissue characterization), 10.3%; phase 3 (spectrum of appearances), 40.4%; phase 4 (diagnostic efficacy), 21.2%; and phase 5 (clinical evaluation), 9.6%. Of 48 diagnostic efficacy studies, 42% were prospective (versus 35% for the total sample), 38% were controlled (median sample size, 53 [versus 30 for the total sample]). Only 27% of the 48 diagnostic efficacy studies were externally funded. Research in magnetic resonance imaging (MRI), which comprised 45% of all publications, was oriented toward phase 1 (32%) rather than phase 5 studies (0%). Phase 5 studies were the focus of 18% and 8% of ultrasound (US) and computed tomography (CT) studies, respectively. There were more prospective, controlled efficacy studies in US than in MRI or CT.

CONCLUSIONS

Analyses of research trends will be facilitated by use of a standard taxonomy which adopts a modality-based, phased approach.

[Stability of shuang huanglian aerosol]

The contents of chlorogenic acid and baicalin in shuang huanglian aerosol were determined by HPLC. The process of chemical kinetics of the aerosol was studied by constant temperature acceleration tests, and the stability of the drug predicted. The results appeared close to those from the stored sample method. pH changes during degradation of the drug were also observed.