A novel type of cell death of lymphocytes induced by a monoclonal antibody without participation of complement

A monoclonal antibody, RE2, raised by immunizing a rat with cell lysate of a mouse T cell clone, was found to directly kill interleukin 2-dependent T cell clones without participation of serum complement. Fab fragments of RE2 had no cytolytic activity, while the cross-linking of Fab fragments with anti-rat immunoglobulin reconstituted the cytotoxicity. The cytotoxicity was temperature dependent: the antibody could kill target cells at 37 degrees C but not at 0 degrees C. Sodium azide, ethylenediaminetetraacetic acid, and forskolin did not affect the cytolytic activity of RE2, while the treatment of target cells with cytochalasin B and D completely blocked the activity. This suggested that the cell death involves a cytoskeleton-dependent active process. Giant holes on the cell membrane were formed within 5 minutes after the treatment with RE2, as observed by scanning electron microscopy. There was no indication of DNA fragmentation nor swelling of mitochondria during the cytolysis, suggesting that the cell death is neither apoptosis nor typical necrosis. The antibody also killed T cell lymphomas and T and B cell hybridomas only when these cells were preactivated with concanavalin A, lipopolysaccharide, or phorbol myristate acetate. Preactivated peripheral T and B cells were sensitive to the cytotoxicity of RE2, while resting T and B cells were insensitive. These results provide evidence for a novel pathway of cell death of activated lymphocytes by membrane excitation.

[Combined effect of bleomycin and SDB-ethylenediamine, a synthetic isoprenoid, on oral squamous carcinoma cell lines and transplantable nude mouse tumors]

Combined effect of bleomycin (BLM) and N-solanyl-N, N'-bis (3, 4-di-methoxy-benzyl)-ethylenediamine (SDB-ethylenediamine), a synthetic isoprenoid was studied on 3 oral squamous carcinoma cell lines (SCCTF, SCCKN, SCCRY) and clonal cell lines from SCCRY in vitro and on transplantable nude mouse tumors. The cytotoxicity of SDB-ethylenediamine varied among those cell lines in vitro. SDB-ethylenediamine potentiated more than 2-fold the cytotoxic effect of BLM in 6 cell lines, but no distinct correlation was found between cytotoxicity of SDB-ethylenediamine and potentiation by BLM. Compared with verapamil, the cytotoxic effect of BLM was potentiated 3.9-fold by SDB-ethylenediamine in SCCTF. The growth of the transplantable nude mouse tumors (SCCRY and SCCTF) was strongly suppressed when BLM was combined with SDB-ethylenediamine. Correlation between BLM resistance and potentiation of BLM by SDB-ethylenediamine was not observed in this experiment.

[Detectability of hypervascular small hepatocellular carcinoma by dynamic spiral CT]

Thirty-one cases of small hepatocellular carcinoma (HCC) under 3 cm in diameter underwent Spiral CT with bolus injection of contrast medium (Dynamic Spiral CT). Dynamic Spiral CT was compared with CT after intra-arterial injection of iodized oil (Lipiodol-CT). The detectability of 79 nodules of small HCC on early phase images of Dynamic Spiral CT was 49.4% (32.6% for those under 1 cm in diameter, 58.3% for 1-2 cm, 91.7% for 2-3 cm). The detectability of small HCCs above the hilum of the liver was better than that below the hilum. Five lesions were detected only on delayed CT images, but not on early phase CT images. Dynamic Spiral CT is useful for detecting hypervascular small HCCs, and both early phase and delayed CT images must be obtained.

Spontaneous aortic thrombosis in a neonate with multiple thrombi in the main branches of the abdominal aorta

Spontaneous aortic thrombosis in the neonate is a rare entity with a high mortality rate. The present patient, who was diagnosed after showing haematuria and cyanosis, underwent aortic thrombectomy with a Fogarty catheter through a left thoracotomy, but died of sepsis, disseminated intravascular coagulation and multiple organ failure. Autopsy revealed multiple residual thrombi in the main branches of the abdominal aorta and necrosis of the abdominal organs despite a patent thoracoabdominal aorta. In patients with no blood flow in the main branches of the abdominal aorta on preoperative examination, removal of thrombi, including those in the main branches of the abdominal aorta, might be performed in a single, early and aggressive procedure.

Interruption of aortic arch associated with pulmonary valve stenosis

A newborn male is described who presented with interruption of aortic arch associated with ventricular septal defect and pulmonary valve stenosis. He underwent total corrective surgery and was discharged with good clinical results. The combination of significant right ventricular outflow obstruction and interruption of aortic arch is incompatible with fetal survival unless there are large collateral arteries which arise early in pregnancy. This is the first report of this combination of lesions.

Biventricular repair in cardiac isomerism. Report of seventeen cases

Ninety-three patients with cardiac isomerism were treated surgically from July 1985 to June 1991. Among them, three patients with right and 14 with left isomerism underwent biventricular repair. Ages ranged from 4 months to 41 years (mean 4.8 years). Anatomic repair was accomplished in 15 patients and functional repair with the right ventricle used as the systemic ventricle in two patients. Methods of atrial septation to separate pulmonary venous flow from systemic venous flow included atrial partition with a straight patch in seven patients, intraatrial rerouting with a tailored baffle in five, and a Mustard-type atrial switch in five. One hospital death (5.8%) and two late deaths (12%) occurred. Two patients required reoperation (12%), one reconstruction of a stenotic systemic venous connection and one mitral valve replacement because of incompetence. Surgically induced complete atrioventricular block was not observed in any of the patients. Optimal atrial septation offers the possibility of biventricular repair for patients with acceptable intraventricular structure.

Thyroid nodules: re-evaluation with ultrasound

The purpose of this study was to clarify ultrasound (US) evaluation of microcalcifications and determine whether the calcifications seen in US scans can reliably predict malignant thyroid tumors. Diagnostic accuracy of microcalcification and other various signs seen in US scans for predicting malignancy was evaluated prospectively in 259 pathologically verified thyroid nodules. Sonographic and pathologic correlation of calcifications was performed on 69 of 99 surgically removed nodules. Pathologic studies revealed that hyperechoic areas with acoustic shadowing represented mostly amorphous dense calcifications and sometimes microcalcifications, but small particles without acoustic shadowing mainly reflected microcalcifications and sometimes large amount of fibrous bands and condensed colloids. Of the various sonographic signs, microcalcification showed the highest accuracy (76%), specificity (93%), and positive predictive value (70%) for malignancy as a single sonographic sign, but its sensitivity (36%) was poor. Although sonographic microcalcification showed relatively high specificity, the accuracy of this finding for malignancy was insufficient.

Endoscopic aspiration lumpectomy of esophageal leiomyomas derived from the muscularis mucosae

OBJECTIVES

There is still much debate about the indications and best technique for endoscopy for the treatment of esophageal leiomyomas. We developed a novel technique for endoscopic aspiration lumpectomy and used it in patients with esophageal leiomyomas derived from the muscularis mucosae.

METHODS

Nine patients with esophageal leiomyomas were treated with informed consent. The indication for intervention was based on the endosonographic confirmation of a tumor originating from the 2nd layer of the esophagus. We attached a transparent cylinder to the tip of an endoscope and a snare-guide tube to the outer axis of the scope. After endoscopic suction of the tumor into the cylinder, the snare was pushed open. The tumor was grabbed at its base with the entire surrounding mucosa, and removed.

RESULTS

The overall procedure time averaged 18 minutes, and there were no complications in any of the subjects. The resected specimens were elliptical with a mean long diameter of 22 +/- 4 mm and a mean short diameter of 17 +/- 4 mm. Complete resection was possible in eight of the nine tumors that were under 2 cm in diameter. After a follow-up period of 4 to 27 months (mean 11 months), no recurrence was found in any of the completely resected cases.

CONCLUSIONS

Endoscopic aspiration lumpectomy has been proven to be a safe, effective, and less invasive procedure for small esophageal leiomyomas derived from the muscularis mucosae.

[Dynamic change of serum UFT concentration in a patient with tongue cancer complicating chronic renal failure]

To evaluate the effect of UFT as a postoperative adjuvant chemotherapeutic agent for a patient with tongue cancer complicating chronic renal failure, we measured a dynamic change of serum tegafur (FT), 5-FU and uracil concentrations in hemodialysis. When the patient administered 200 mg of UFT orally one hr before hemodialysis, serum 5 FU concentration was 0.051 micrograms/ml at the beginning of hemodialysis, then rapidly increased to 0.396 micrograms/ml at maximum one hr later and thereafter decreased to the initial level after 4 hrs, the end of hemodialysis. Even after hemodialysis, however, 5-FU maintained the effective serum concentration. On the other hand, serum FT and uracil levels showed a slight change during hemodialysis. The maximum concentrations of FT and uracil were 3.154 micrograms/ml and 0.540 micrograms/ml respectively, after 3 hrs of dialysis. We next measured serum levels of 5-FU, FT and uracil during two days without hemodialysis treatment. Although their serum levels were increased after UFT administration, those were decreased to the initial level on the next day, indicating no drug accumulation. These results suggest that UFT was safe and useful as a postoperative adjuvant chemotherapeutic agent in a cancer patient being performed hemodialysis.

Extent of aortopulmonary collateral blood flow as a risk factor for Fontan operations

Between November 1987 and January 1990, 33 patients (tricuspid atresia, 9 patients; mitral atresia, 3; single ventricle, 15; others, 6) underwent Fontan operations. The rate of blood flow returning to the heart during aortic cross-clamping was measured as an indication of the extent of development of aortopulmonary collateral arteries. Percent cardiac return (calculated by dividing the blood flow rate returning to the heart by the cardiopulmonary bypass blood flow rate and expressing the value as a percentage), were 1% to 9%, 7 patients; 10% to 19%, 11; 20% to 29%, 9; 30% to 39%, 4; 40% to 49%, 1; and 50% to 59%, 1 patient. Percent cardiac return showed a significant correlation with postoperative mean systemic venous pressure (r = 0.6, p < 0.01). In those patients in whom percent cardiac return was more than 33%, the mean systemic venous pressure after operation was high (more than 17 mm Hg), and none of these patients survived. To predict percent cardiac return preoperatively, the conventional indices of systemic ventricular volume, pulmonary artery area index, arterial blood oxygen saturation, pulmonary blood flow index, and pulmonary vascular resistance were analyzed. None of these showed significant correlation with percent cardiac return. However, all the patients who had a high percent cardiac return (more than 30%) also had both high arterial blood oxygen saturation (more than 75% in room air) and small pulmonary artery area index (less than 55%). In addition, the age at operation showed good correlation (r = 0.6, p < 0.01) to percent cardiac return.(ABSTRACT TRUNCATED AT 250 WORDS)

Upregulation of surface markers on dying thymocytes

Using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) to detect cells undergoing early apoptosis, we have defined the surface markers expressed on CD4+CD8+ thymocytes undergoing spontaneous or steroid-induced apoptosis in tissue culture. Some surface markers, e.g., CD4, CD8, and heat stable antigen, are downregulated on apoptotic thymocytes. Surprisingly, however, other markers are upregulated; this applies to T cell receptor beta/CD3, CD69, and CD25 expression. Upregulation of these markers is restricted to a discrete subset of apoptotic cells.

Implication of parathyroid hormone for the development of hypertension in young spontaneously hypertensive rats

The purpose of this study is to elucidate the role of parathyroid hormone (PTH) in the development of hypertension in young spontaneously hypertensive rats (SHR). Parathyroidectomy (PTX) or sham surgery was performed on 6-week-old male SHR, and 3 weeks later human PTH (hPTH) or saline was infused subcutaneously over 2 weeks using a minipump. PTX significantly attenuated the development of hypertension and reduced serum vitamin-D concentrations. PTX also augmented the depressor response to acetylcholine before N-nitro-L-arginine (L-NNA), although it remained unchanged after L-NNA. The cardiovascular reactivity to exogenous noradrenaline and angiotensin II was not affected by PTX. The chronic administration of hPTH reversed these effects. We conclude that PTH plays an important role in the development of hypertension, through modulating the release of endothelium-derived relaxing factor, in young SHR.

Anesthetic management of a 656-g neonate undergoing pulmonary valvotomy

We describe the successful management of a 656-g preterm infant of 29 weeks' postconceptional age undergoing closed transventricular pulmonary valvotomy. The patient had a critical pulmonary stenosis and was treated with an infusion of prostaglandin E1, which resulted in excessive pulmonary blood flow through the ductus arteriosus. The key points in anaesthetic management were maintaining an optimum balance between the systemic and pulmonary circulation and preparing for the abrupt haemodynamic change caused by valvotomy.

Time-of-flight MR angiography of portal system and collaterals in portal hypertension using a 2-DFT fast spoiled gradient recalled steady-state precession technique

MR angiographic examinations were performed in 26 patients. Approximately 30 contiguous fast spoiled GRASS images (8.1/3.1/30 degrees, TR/TE/flip angle) were acquired during single breath-holding for about 35 s, and then new images were reconstructed with maximum intensity projection technique. Spoiled GRASS images (40/12/40) of 2 to 3 slices were taken during breath-holding for about 13 s, and these processes were repeated to obtain about 30 individual images for conventional MR angiography. The new MR angiograms were compared quantitatively and qualitatively with conventional MR angiograms with arterial portography as the gold standard. The new MR angiograms could visualize blood vessels with smooth margins, and provided almost the same anatomic information about the portal vein and collateral vessels as the conventional MR angiograms. Contrast-to-noise ratios between the portal or hepatic vein and liver parenchyma were significantly higher with fast spoiled GRASS images. The new MR angiograms using fast spoiled GRASS images provided useful diagnostic mapping of the collateral venous pathways within a shorter examination time.

Induction of bleomycin resistance in a human oral squamous carcinoma cell line and characterisation of bleomycin-resistant and -sensitive clones

We examined the change of sensitivity to antitumour agents by repeated treatment with bleomycin (BLM) using two oral squamous carcinoma cell lines, SCCTF and SCCKN. SCCTF exhibited minimal sensitivity to BLM and strong heterogeneity in BLM sensitivity, whereas SCCKN was highly sensitive to BLM and showed weak heterogeneity. When SCCTF was treated continuously with low-dose BLM (0.1 microgram/ml) but not intermittently with high-dose BLM (1 microgram/ml), the BLM sensitivity was rapidly decreased to acquire drug resistance. On the other hand, SCCKN was completely killed by the same treatments. To investigate the mechanism of induction of resistance in SCCTF, BLM-sensitive and -resistant clones, TF-S and TF-R, were isolated and analysed. Consequently, TF-R showed decreased cellular accumulation and retention of BLM, increased BLM hydrolase activity and elevated DNA repair activity concomitant with increased poly(ADP-ribose) polymerase activity as compared with TF-S. Therefore, it was suggested that antitumour drug-resistant clones were selectively grown from heterogeneous tumour cell population.

Open heart operation in a young child with spherocytosis

Open heart operations on patients with hereditary spherocytosis have been reported rarely. Young children who have not yet undergone splenectomy have a high risk of intraoperative hemolysis because of the heart-lung machine and secondary renal failure. We report the case of a 15-month-old child with spherocytosis who underwent an open heart operation without serious complications as a result of careful and appropriate perioperative management.

[Growth of the hypoplastic aortic arch after arch repair for coarctation and interruption of the aorta]

Surgical treatment for a hypoplastic aortic arch associated with coarctation or interruption of the aorta is controversial. We evaluate the changes of diameter of proximal transverse aortic arch after surgery in 28 patients. Proximal transverse aortic arch in all patients was preoperatively 3.5 +/- 0.9 mm (2.5 to 7 mm), and 54 +/- 12% (36 to 84%) to the normal aortic valve dimension (n-AVD: 16.6 X BSA0.6). While postoperative proximal transverse aortic arch was 6.5 +/- 1.8 mm, and 76 +/- 12% to the n-AVD, and significantly grew more than the preoperative arch dimension (p = 0.0001). In 18 patients having two times cardiac catheterization postoperatively, proximal transverse aortic arch was 6.5 +/- 1.6 mm, and 75 +/- 13% to n-AVD on the 1st postoperative examination. On the 2nd examination, the arch was 9.9 +/- 1.9 mm, and 88 +/- 12% to n-AVD, and significantly grew with increasing years (p < or = 0.0003). We concluded that the proximal transverse aortic arch, which was more than 36% to n-AVD in diameter, if not dilated surgically, grew with increasing years after aortic arch repair.

Extraserosal invasion in advanced gastric cancer: evaluation with MR imaging

PURPOSE

To evaluate the usefulness of magnetic resonance (MR) imaging in the diagnosis of extraserosal invasion in advanced gastric cancer.

MATERIALS AND METHODS

MR imaging was performed in 48 patients with advanced gastric cancer, and the results were correlated with the histopathologic findings. Images perpendicular to the gastric wall with cancer were obtained with spoiled gradient-recalled acquisition in the steady state (GRASS). The degree of serosal invasion was classified on the basis of the appearance of a low-signal-intensity band around the lesion.

RESULTS

Advanced gastric cancer appeared as a thickened wall of high signal intensity after the administration of contrast material. A low-signal-intensity band disappeared or showed irregularity in the area of extraserosal invasion by the gastric cancer. The MR imaging-determined grade correlated with the histopathologic findings for 11 of 14 (79%) pT2 tumors, 23 of 24 (96%) pT3 tumors, and eight of 10 (80%) pT4 tumors. The overall accuracy was 88%.

CONCLUSION

Presence of a low-signal-intensity band at MR imaging is useful for the preoperative evaluation of serosal invasion.

[FIO2 and SpO2 during cardiac surgery in neonates and infants]

Fractional inspired oxygen (FIO2) applied before and after a repair or palliative procedure for cardiac defects along with SpO2 measured by pulse oximeter were reviewed from anesthetic records of 62 neonates and infants. Fentanyl was used for anesthesia, except in cases without i.v. route in which sevoflurane with nitrous oxide in oxygen was used for induction of anesthesia. FIO2 was adjusted using air and oxygen. The lower FIO2 was applied to the patients for a closure of ventricular septal defect, a reconstruction of coarctation or interrupted aortic arch, and pulmonary artery banding, while the higher FIO2 was used for systemic-to-pulmonary artery shunts and the repair of tetralogy of Fallot. In the congenital heart disease with the intracardiac shunt, the magnitude of the shunt flow and hemodynamics can be altered by changing systemic and pulmonary vascular resistance which could be induced by various ways. Since alveolar oxygen tension is a known determinant of pulmonary vascular resistance, an appropriate FIO2 should be applied to each patient with different pathophysiology. A low FIO2 should be set for the cases with nonrestrictive left-to-right shunting, since a high FIO2 may cause a torrential pulmonary blood flow. A high FIO2 is preferable for the cases with right-to-left shunting and a concomitant decreased pulmonary blood flow.

Determination of a new immunosuppressant, mycophenolate mofetil, and its active metabolite, mycophenolic acid, in rat and human body fluids by high-performance liquid chromatography

Mycophenolate mofetil, a new immunosuppressant, is a morpholinoethyl ester of mycophenolic acid. A new selective, sensitive and simple high-performance liquid chromatographic method was developed for the determination of mycophenolic acid and mycophenolate mofetil in biological samples. The preparation of samples was based on liquid-liquid extraction. The compounds were separated on a CN column using acetonitrile-0.01 M phosphate buffer (1:4, v/v) as the mobile phase. UV detection was used at wavelengths 215 and 304 nm. The detection limit was 5 ng per injection volume. This method enabled pharmacokinetic and pharmacodynamic studies in humans and rats.

A novel form of self tolerance dictated in the thymus of transgenic mice with autoreactive TCR alpha and beta chain genes

Transgenic (TG) mice with TCR alpha and beta chain genes from a CD4-dependent auto-I-Ak reactive T cell clone were generated. H-2k TG mice had a large number of thymic and splenic CD4 T cells expressing the autoreactive TCR without manifestation of autoimmunity. The cells were not anergic, as they could respond to autologous antigen presenting cells and anti-TCR antibodies in vitro to proliferate and to produce interleukins. Various degrees of down-regulation of CD2 and CD44 was observed in TG mice, indicating the presence of a defective co-stimulatory process in TG T cells. These features indicate that the self tolerance in autoreactive TCR TG mice is due not to clonal deletion and anergy but to a novel mechanism where T cells cannot sufficiently respond to normally existing self ligand in vivo. That such an in vivo unresponsiveness of autoreactive T cells is dictated in the thymus during CD4 T cell differentiation atypical form of positive selection of autoreactive T cells was suggested by the abnormal surface expression of CD69 and HSA.

Double switch operation in cardiac anomalies with atrioventricular and ventriculoarterial discordance

Since June 1987, 10 of 19 consecutive patients with atrioventricular and ventriculoarterial discordance (average age 4 +/- 2 years) had undergone a double switch operation with the morphologically left ventricle used as a systemic ventricle. There were two combinations of procedures. Atrial switch combined with arterial switch was used in two patients who had a normal pulmonary valve. Atrial switch combined with ventriculoarterial switch by Rastelli's procedure was used in eight patients with pulmonary stenosis or atresia and a large ventricular septal defect. One early death and two late deaths have occurred in a postoperative follow-up period of up to 4 years. Subsequent problems were mainly related to the results of atrial switch procedures in patients who had a small atrium because of low pulmonary flow, especially in patients with apicocaval juxtaposition. Our experience suggested that the double switch operation would open a new era of definitive surgical treatment in half of the patients with atrioventricular and ventriculoarterial discordance.