Possible involvement of phosphatidylinositol-specific phospholipase C related to pertussis toxin-sensitive GTP-binding proteins during adipocyte differentiation of 3T3-L1 fibroblasts: negative regulation of protein kinase C

Insulin/dexamethasone/methylisobutylxanthine (hormones/IBMX) induce 3T3-L1 fibroblasts to differentiate into adipocytes. Our previous study suggested that pertussis toxin (IAP)-sensitive GTP-binding protein(s) (G-protein) is involved in the process of differentiation by hormones/IBMX, accompanied by c-fos induction. Northern blotting indicated that among the IAP-sensitive G-proteins, the levels of Gi2 alpha, Go alpha, and Gi3 alpha mRNA were decreased, increased and unchanged, respectively. Gi1 alpha was undetectable and IAP attenuated the decrease in Gi2 alpha mRNA level but did not affect the change in Go alpha mRNA level during the adipocyte differentiation. These results indicate that IAP-sensitive Gi2 alpha mRNA level is decreased during adipocyte differentiation. A combination of phosphatidylinositol-specific phospholipase C (PI-PLC) and IBMX induced c-fos expression in 3T3-L1 fibroblasts similar to that induced with hormones/IBMX. c-fos induced by both stimulators was also diminished by anti-inositolglycan antibody or anti-PI-PLC antiserum. Insulin stimulated the release of inositolproteoglycan and diacylglycerol from 3T3-L1 fibroblasts, which was suppressed by IAP treatment. These findings suggested that one of the pathways of adipocyte differentiation induced by hormones/IBMX occurs via the inositolglycan-specific PI-PLC cascade coupled to IAP-sensitive G-protein(s). Both activation of glycerophosphate dehydrogenase and stimulation of insulin-dependent 2-deoxyglucose uptake induced by hormones/IBMX were enhanced in protein kinase C-depleted cells exposed to phorbol 12-myristate 13-acetate (PMA), and attenuated in IAP-treated cells. The level of a 32P-labeled 52 kDa protein in plasma membrane fractions immunoprecipitated by anti-PI-PLC antiserum was increased by PMA stimulation, abolished in PMA-treated cells, and increased in IAP-treated cells. These findings suggest that protein kinase C phosphorylates PI-PLC, resulting in a decrease in PI-PLC activity related to the signal transduction pathway of adipocyte differentiation of 3T3-L1 fibroblasts.

Hepatic myelopathy: an unusual neurological complication of advanced hepatic disease

Encephalopathy is widely known as one of the neurological complications of chronic hepatic disease. Recently, the occurrence of progressive myelopathy in patients with advanced hepatic disease has been well documented and differentiated from encephalopathy. We describe a 76-year-old man with decompensatory liver cirrhosis due to hepatitis C virus infection who suffered from progressive paraplegia. Postmortem examination revealed demyelination of the lateral column of the spinal cord, especially of the thoracic segment. No evidence of spontaneous portosystemic shunts was found. These findings suggest that the patient had been affected with hepatic myelopathy, which is a rare complication of liver cirrhosis.

[Electron microscopic and immunohistochemical studies of acute stages of severe brain injury in rats]

Few morphological studies on fluid-percussion experimental models using mechanically produced severe brain injury have been reported. This study was initiated to evaluate light and electron microscopic and immunohistochemical findings in severe brain injury models using rats. The experimental rats and the methods used were as described for a fluid-percussion model. Fluid-percussion models of traumatic brain injury produce injury rapidly by injecting fluid volumes into the epidural space of the temporal lobe. We used 5 rats which sustained various degrees of injury by high (7.0 atm), medium (5.6 atm) and low (3.5 atm) magnitudes of impact and sham control. The rats were sacrificed and perfused transcardially with buffer solution followed by 2.5% glutaraldehyde at intervals of 24 hours, 3 days, and 7 days, and there were normal and sham control groups. In this immunohistochemical study, monoclonal antibody to 70 kilodalton neurofilament subunit has been used in a standard Avidin-Biotin Complex Kit (DAKO). Microscopic findings of the animals revealed subarachnoid hemorrhage, lateral IIIrd ventricular hemorrhage, and rarefaction and petechial hemorrhage of the local contusional lesion. In the medium level injury, there was a marked petechial hemorrhage in the corpus callosum and subependymal area. In the high level injury, there was marked edema in the white matter of the ipsi and contralateral cerebral hemisphere, and multiple petechial hemorrhage in the brain stem and cerebellum. Microscopic findings in the corpus callosum, subependyma and brain stem in the vicinity of petechial hemorrhage revealed a large number of axonal swellings, but in these specimens only a few typical axonal retraction balls were seen using Bodian and immunohistochemical stains.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell surface antigen CD38 identified as ecto-enzyme of NAD glycohydrolase has hyaluronate-binding activity

An ecto-enzyme of NAD glycohydrolase induced by retinoic acid in human leukemic HL-60 cells is attributed to the molecule of leukocyte cell surface antigen CD38 (Kontani, K., et al. (1993) J. Biol. Chem. 268, 16895-16898). The cell surface antigen has an amino acid sequence homologous to Aplysia ADP-ribosyl cyclase that catalyzes the conversion of NAD to cyclic ADP-ribose with a calcium-mobilizing activity. A putative hyaluronate (HA)-binding motif which has recently been identified in CD44 antigen existed in the extracellular domain and intracellular amino terminus of CD38 antigen. CD38 antigen was indeed capable of binding to HA in a manner dependent on ionic strength. By contrast, no binding activity was found in Aplysia ADP-ribosyl cyclase. Thus CD38 antigen, like CD44 antigen characterized as a HA-receptor (or binding) protein, may function as an adhesion molecule.

[Left ventricular characteristics after Jatene operation for transposition of the great arteries with intact ventricular septum--comparative study of neonatal primary and two stage repairs]

Left ventricular characteristics in late postoperative period after the arterial switch operation (ASO) was evaluated in fifty-nine patients with transposition of the great arteries and intact ventricular septum. They included 22 neonates who underwent a neonatal ASO (Group I) and 37 patients who underwent a two-stage ASO (Group II). Group II was subdivided into two groups according to the presence or absence of aortic regurgitation in the late postoperative period as group IIa (aortic regurgitation [-], 22 patients) and group IIb (aortic regurgitation [+], 15 patients). Age at ASO ranged from 4 to 27 days (average 12.7 days) in the group I, 5 to 43 months (average 12.7 months) in the group IIa, and 4 to 54 months (average 16.3 months) in the group IIb. Postoperative follow-up period ranged from 8 to 68 months (average 25.0 months) in the group I, 12 to 74 months (average 59.0 months) in the group IIa, and 19 to 66 months (average 48.5 months) in the group IIb. Left ventricular end-diastolic volume was significantly smaller in the group I (123 +/- 19% of normal) than the group IIa (146 +/- 38 of normal) and the group IIa (183 +/- 53% of normal). And left ventricular ejection fraction was significantly higher in the group I (67 +/- 5%) than the group IIa (62 +/- 11%) and the group IIb (58 +/- 8%). Left ventricular normalized mass was significantly smaller in the group I (85 +/- 11% of normal) than the group IIa (113 +/- 14% of normal) and the group IIb (130 +/- 9% of normal).(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical analysis of MRSA pneumonia. Niigata Research Group of MRSA.ABK]

Aged or immuno-compromised patients were mostly affected, by pneumonia caused by infection of MRSA, and more than half of the cases were superinfected with glucose-nonfermentative Gram-negative rods including Pseudomonas aeruginosa. These patients were treated with a monotherapy of arbekacin (ABK) by intravenous drip administration or with a combination of ABK and imipenem/cilastatin, ceftazidime or antifungals. The clinical efficiencies were 55.6% in 11 monotherapy cases and 83.3% in combined therapy. MRSA was eradicated in 31.9% of the patients. These results are comparable with, or superior to the vancomycin therapy in the treatment of MRSA pneumonia. When MRSA is isolated from sputum of pneumonia patients, the discrimination between colonization and infection is important, but the diagnosis is very difficult in many clinical cases before the initiation of chemotherapy. The number of bacteria and the grade of inflammation should be carefully scored before starting a chemotherapy.

[Reoperation after surgical repair of atrioventricular canal defect]

Among 114 survivors who underwent total repair of atrioventricular canal defect between 1981 and 1993, 19 patients underwent reoperation for the occurrence and progression of mitral valve insufficiency (18 patients), thrombosed prosthetic valve (1 patient), and subaortic stenosis (4 patients) on one or two occasions after operation. There were 7 males and 12 females with ages at reoperation ranging from 3 months to 13.8 years (mean, 3.8 years), and was no operative but one late death. At reoperation, reparative procedures involving the readjustment of previously repaired mitral cleft and annuloplasty were successfully achieved in 6 patients who had no additional abnormalities of subvalvar apparatus. Twelve patients, who were associated with additional valvar and subvalvar lesions, needed a prosthetic valve replacement. We emphasized that surgical technique based on precise knowledge of each individual mitral and submitral anatomy is indispensable to achieve good surgical results. When the anatomy involves submitral abnormalities, careful postoperative follow-up should be recommended to take measures of the progression of mitral valve regurgitation.

[Structure and function of heterotrimeric G-proteins]

In mammals, G-protein alpha, beta, gamma polypeptides are encoded by at least 16, 4 and 7 genes, respectively. G alpha-subunits bind and hydrolyze GTP and have the sites for bacterial toxin-catalyzed ADP-ribosylation. A structural model of G alpha-subunits can be defined on the basis of similarities between G alpha and other members of the GTP-binding proteins. The resulting G alpha model specifies the spatial relationship among the guanine nucleotide binding site, the binding site of the G beta gamma-subunit complex, likely regions of effector and receptor interaction, and sites of cholera or pertussis toxin-induced modification. The architecture of the G alpha core is the same as that of p21ras. Experimental evidence from immunological, molecular genetic and biochemical studies support the G alpha model. The G alpha-subunits alone were previously thought to act on the effector enzymes; However, recent evidence indicates that the G beta gamma-dimer also plays an important part in effector activation.

Melanotic neuroectodermal tumor of infancy in the skull associated with high serum levels of catecholamine. Case report

The case of a 5-month-old boy with a left retromastoid melanotic neuroectodermal tumor of infancy is presented. The tumor extended from the subcutaneous tissue of the occiput to the cerebellar hemisphere. Histologically, the epidural part of the tumor was composed of undifferentiated neuroblasts, dense connective tissue, and glandular structures lined by melanin-containing cuboidal cells, whereas the subdural part contained differentiated neuroblasts and melanin-containing cells. The preoperative high serum levels of adrenaline, noradrenaline, vanillylmandelic acid, and neuron-specific enolase returned to normal after two operations and two cycles of chemotherapy; however, the dopamine level was mildly elevated. These data and immunohistochemical and ultrastructural findings strongly suggest that melanotic neuroectodermal tumor of infancy is derived from the neural crest.

Ventricular function after anatomic repair in patients with atrioventricular discordance

Since June 1989, 18 patients with atrioventricular discordant anomalies under 15 years of age underwent anatomic correction, or double switch operation, with 2 hospital deaths (11%). Ages ranged from 1 year 4 months to 12 years (mean 7.2 years) and body weights ranged from 7.1 to 32.5 kg (mean 20.1 kg) at operation. Visceral situs was solitus in 12 and inversus in 6. Ventriculoarterial connection was discordant in 4 and double-outlet in 14. All had associated congenital cardiac anomalies consisting of ventricular septal defect in 17, atrial septal defect in 9, pulmonary atresia in 10, pulmonary stenosis in 6, systemic tricuspid regurgitation in 9, mitral regurgitation in 6, bilateral superior venae cavae in 6, patent ductus arteriosus in 6, Wolff-Parkinson-White syndrome in 2, and congenital atrioventricular block in 1. Previous palliation had been performed 19 times in 11 patients including systemic-pulmonary shunts in 10 patients and pulmonary banding in 1 patient. Anatomic correction consisted in the Mustard procedure in 12 or the Senning procedure in 6 at the atrial level and in external conduit repair in 14, arterial switch operations in 3, or direct anastomosis between the pulmonary artery and right ventricle in 1 at the ventriculoarterial level. The arterial switch operation was indicated in patients with a normal pulmonary valve, and external conduit repair was indicated for patients with pulmonic stenosis or atresia. Anatomic right ventricular end-diastolic volume showed significant reduction from 122.2% +/- 46.3% of normal to 78.8% +/- 24.0%, mainly owing to unloading of the ventricle after the operation (p < 0.0003). Right ventricular ejection fraction remained unchanged (56% +/- 8% to 56% +/- 6%). Anatomic left ventricular end-diastolic volume and left ventricular ejection fraction remained unchanged before and after the operation: volume 134.6% +/- 50.0% of normal to 127.3% +/- 32.8% and ejection fraction from 61% +/- 8% to 56% +/- 8%. Cardiac index averaged 3.1 +/- 0.5 L/min per square meter after the operation. The double switch operation is best indicated in patients with atrioventricular discordance associated with systemic tricuspid regurgitation and/or with poor systemic right ventricular function.

Autologous blood donation elective surgery in children

Studies were made on 59 children (cardiac 42, orthopaedic 13, miscellaneous 4) scheduled for autologous blood donation before elective surgery. The donor-patients' ages ranged from 3 to 15 years (mean 9.9 years) and their weights from 13 to 70 kg (mean 34 kg). All patients received 50-100 mg of oral iron sulphate per day. As a rule, about 10% of intravascular blood volume was drawn once a week. Before surgery, an average of 720 ml of autologous blood per patient was prepared. Two patients failed to donate autologous blood because of anxiety about the procedure; however, none of the donors was deferred due anaemia associated with the phlebotomy. Of the 53 patients undergoing surgery and participating in autologous predonation, 50 (94%) were able to avoid homologous blood transfusion. 600 ml of homologous blood were transfused to each of 2 orthopaedic patients and 400 ml to 1 cardiac patient. We conclude that a predeposit autologous transfusion programme is logistically possible in small children when the patients are cooperative.

Iron and erythropoietin measurement in autologous blood donors with anemia: implications for management

BACKGROUND

The importance of autologous blood donation for elective surgery is recognized, and the method is being used at many hospitals. Not all patients are able to deposit a sufficient amount of blood before surgery because they cannot recover rapidly enough from phlebotomy-induced anemia. The ability to donate sufficient blood for autologous use was studied in patients who are particularly susceptible to phlebotomy-induced anemia.

STUDY DESIGN AND METHODS

Of 840 patients who donated blood for autologous use in elective surgery from November 1987 through May 1993, 20 with rheumatoid arthritis, 24 with iron deficiency anemia, and 37 aged 65 years and above with normocytic anemia were compared with 24 nonanemic elderly patients who donated a total of 1000 mL of blood for autologous use. Patients received iron sulfate orally and donated blood once a week until operation.

RESULTS

The amount of blood collected before surgery per control patient was more than that in others. Consequently, there was a tendency to allogeneic blood transfusion in patients with rheumatoid arthritis or elderly patients. The ferritin levels in controls and in patients with iron deficiency anemia during the donation period were almost within the normal range in spite of iron supplementation, which implied a good utilization of iron sulfate for erythropoiesis. On the other hand, the rise in ferritin levels in the elderly and in patients with rheumatoid arthritis suggested inappropriate iron availability for erythropoiesis and resulted in an increase in iron storage. Since an adequate endogenous erythropoietin response to phlebotomy-induced anemia was not observed in these patients, impaired erythropoietin production was considered one of the reasons for anemia.

CONCLUSION

Patients with iron deficiency anemia are able to continue donating blood for autologous use so long as they have sufficient iron supplementation. However, the elderly or those with rheumatoid arthritis occasionally fail to donate a sufficient volume of blood before surgery as a result of phlebotomy-induced anemia, which is caused in turn by impaired erythropoietin production.

[Reoperations of extracardiac valved conduit for congenital cardiac defects]

Fifteen of 223 patients who have had extracardiac conduit repair at the Heart Institute of Japan from January, 1970, to April, 1991, have required conduits replacement because of conduit obstruction or infection. The main causes of obstruction were degeneration of the prosthetic valve and proliferative pseudo-intima in the conduit. The interval between initial conduit repair and conduit replacement was 2.2 to 18.3 years (mean 10.5 +/- 4.4). The average pressure gradient through the conduit decreased from 74.7 +/- 42.0 mmHg preoperatively to 12.3 +/- 7.1 mmHg postoperatively (p < 0.05). There was no early and late death. We concluded that xeno-pericardial roll conduits were superior to others and that conduit replacement procedure following the extracardiac conduit repair was safe and effective.

[A case of left ventricular outflow tract obstruction after repair of ostium primum defect]

We report a 3-year-old girl with left ventricular outflow tract obstruction after repair of ostium primum defect. The girl had closure of an ostium primum defect performed at the age of 1 year. Two years later, she developed left ventricular hypertrophy with systolic ejection murmur. Echocardiography showed discrete stenosis of the left ventricular outflow tract. Cardiac catheterization showed a peak systolic gradient of 63 mmHg across the left ventricular outflow tract. At the reoperation, the fibrous tissue was excised and myectomy was done. After the operation the peak systolic gradient across the left ventricular outflow tract disappeared. Since there is a possibility of occurrence of the left ventricular outflow tract obstruction after repair of atrioventricular septal defect, long term follow up is mandatory.

[The youngest case of isolated interruption of the aortic arch without associated cardiac anomalies]

A five-month-old girl was admitted to our institute because of the systolic blood pressure gradient of 42 mmHg between upper and lower extremities. Cineangiography revealed that the brachiocephalic artery originated from ascending aorta, while the left subclavian and left vertebral arteries took their origin from the descending aorta. However, the left common carotid artery was not visualized either on the angiogram or on the digital subtraction angiogram. No other associated cardiovascular anomalies, such as patent ductus or ventricular septal defect, were found. Therefore the diagnosis of isolated interruption of the aortic arch (IAA) Celoria-Patton type C, was made. As the heart failure gradually progressed, the aortic arch reconstruction with a extended polytetrafluoroethylene graft of 10 mm in diameter under extracorporeal circulation utilizing separate ascending aortic cannulation were performed. Her postoperative course was uneventful. The majority of cases with IAA associated with cardiac anomalies require surgical intervention in the neonatal period or in infancy. However, clinical course of isolated IAA generally resembles to that of the post ductal coarctation of the aorta, and most of the isolated interruption is diagnosed in adulthood. The infant is the youngest case with isolated IAA undergone aortic arch reconstruction with success ever reported in the literature.

Effects of 3 chemical treatments on in vitro fermentation of rice straw by mixed rumen microbes in the presence or absence of anaerobic rumen fungi

Rice straw (Rs) was treated by a sodium chlorite/acetic acid mixture (Sct), ammoniation (At) and alkaline hydrogen peroxide (Athp) methods. The objective was to compare their degradation and fermentation products in the presence or suppression of anaerobic fungi. Significant differences (P < 0.01) in degradation of straws were observed during all periods of incubation with Sct having the highest digestibilities during the 48-h and 72-h incubations. The degradation of Sct straw was highest in both of the incubations with whole rumen fluid (WRF) and WRF plus cycloheximide. In sacco digestion followed the order of Sct > At > Rs > Athp. Suppressing fungal activity with cycloheximide resulted in a decrease in dry matter degradation, with concomitant decrease in total volatile fatty-acid concentration. While the suppression of fungal activity with cycloheximide depressed acetate and butyrate production, it favored an increase in propionate production.