[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.