[Effect of daily administration of oral etoposide for non-small cell lung cancer treated with concurrent radiation therapy]

The purpose of this study was to explore the effect of daily administration of oral etoposide (25 mg) for patients with non-small cell lung cancer treated with concurrent radiation therapy. Planned endpoints were response, survival and toxicity. Forty-one patients with non-small cell lung cancer were divided into 25 patients given daily oral etoposide (25 mg) with concurrent radiation therapy (ERT group) and 16 patients given radiation therapy alone (RT group). Etoposide was administrated in the morning throughout radiation therapy. The median total irradiated dose was 63.1 Gy in the ERT group and 64.0 Gy in the RT group. Twenty-four patients completed therapy in the ERT group and 16 in the RT group. Three (15%) ERT patients achieved complete response (CR) and 9 (45%) achieved partial response (PR). In the RT group, no patients achieved CR and 9 (69%) achieved PR. One-year survival was 22.6% with ERT and 23.0% with RT. The prognosis of stage III patients in the ERT group was worse than that in the RT group because radiation pneumonitis and radiation esophagitis were more severe with ERT. In conclusion, the ERT group had better local response but worse in survival than the RT group. Complications of ERT were severe enough to cause death in some patients. ERT had no clear advantage over RT.

Heterotrimeric G-protein Gq/11 localized on pancreatic zymogen granules is involved in calcium-regulated amylase secretion

The heterotrimeric G-protein Gq/11 was identified on pancreatic acinar zymogen granules and its function in calcium-regulated exocytosis was examined. Western blotting showed alphaq/11, but not alphas or alphao, to be localized to the zymogen granule membrane along with G-protein beta-subunit; all three alpha subunits were present in a plasma membrane fraction and the alphaq/11 signal was 30-fold more enriched in the plasma membrane as compared with granule membrane. Neither CCK receptors nor alpha subunits of the sodium pump, both plasma membrane markers were present on granule membranes. Immunohistochemistry of pancreatic lobules showed that alphaq/11 localized to the zymogen granule-rich apical region of acinar cells together with a much stronger signal at the basolateral plasma membrane. When the substance-P-related peptide GPAnt-2a, an antagonist of Gq/11, was introduced into streptolysin-O permeabilized acini to bypass the plasma membrane, the amylase release induced by 10 microM free calcium was potentiated in a concentration-dependent manner. By contrast, another substance-P-related peptide, GPAnt-1, an antagonist of Go and Gi, showed no effect on calcium-induced amylase release from permeabilized acini. GPAnt-2a peptide also exerted an inhibitory effect on the total GTPase activity of the purified zymogen granules and a larger inhibitory effect on the GTPase activity of the Gq/11 protein immunopurified from zymogen granules. GPAnt-1, however, did not inhibit GTPase activity of either zymogen granules or immunopurified Gq/11. These results suggest that GPAnt-2a peptide augmented calcium-induced amylase release from permeabilized acini by inhibiting GTPase activity of the Gq/11 protein on zymogen granules. We conclude that Gq/11 protein on zymogen granules plays a tonic inhibitory role in calcium-regulated amylase secretion from pancreatic acini.

[Isolation rate of Enterococcus spp. from surgical infections and their susceptibilities]

Enterococcus spp. isolated from surgical infections during the period from July 1982 to June 1995 were investigated in a multicenter study involving 19 hospitals in Japan, and the following results were obtained. 1. Though the isolation rate of Enterococcus faecalis and other Enterococcus spp. were not high from primary infections, and from postoperative infections the isolation rate of other Enterococcus spp. was also low, the isolation rate of E. faecalis was highest from postoperative infections after 1993. 2. Vancomycin (VCM) showed strongest activity against E. faecalis, and followed by those of ampicillin (ABPC), imipenem. levofloxacin (LVFX) and meropenem in this order. Against other Enterococcus spp., VCM showed strongest activity, and followed by those of ABPC and LVFX. There were no resistant strains against VCM.

Evidence that zymogen granules are not a physiologically relevant calcium pool. Defining the distribution of inositol 1,4,5-trisphosphate receptors in pancreatic acinar cells

A key event leading to exocytosis of pancreatic acinar cell zymogen granules is the inositol 1,4,5-trisphosphate (InsP3)-mediated release of Ca2+ from intracellular stores. Studies using digital imaging microscopy and laser-scanning confocal microscopy have indicated that the initial release of Ca2+ is localized to the apical region of the acinar cell, an area of the cell dominated by secretory granules. Moreover, a recent study has shown that InsP3 is capable of releasing Ca2+ from a preparation enriched in secretory granules (Gerasimenko, O., Gerasimenko, J., Belan, P., and Petersen, O. H., (1996) Cell 84, 473-480). In the present study, we have investigated the possibility that zymogen granules express InsP3 receptors and are thus Ca2+ release sites. Immunofluorescence staining, obtained with antisera specific to types I, II, or III InsP3 receptors and analyzed by confocal fluorescence microscopy revealed that all InsP3 receptor types were present in acinar cells. The type II receptor localized exclusively to an area close to or at the luminal plasma membrane. While types I and III InsP3 receptors displayed a similar luminal distribution, these receptors were also present at low levels in nuclei. The localization of InsP3 receptor was in marked contrast to the distribution of amylase, a zymogen granule content protein. In a zymogen granule fraction prepared in an identical manner to the aforementioned report demonstrating InsP3-induced Ca2+ release, immunoblotting demonstrated the presence of types I, II, and III InsP3 receptors. Ca2+ release from this preparation in response to InsP3, but not thapsigargin, could also be demonstrated. In contrast, when the zymogen granules were further purified on a Percoll gradient, InsP3 receptors were undetectable, and InsP3 failed to release Ca2+. Transmission electron microscopy performed on both preparations showed that the Percoll-purified granule preparation consisted of essentially pure zymogen granules, whereas the granules prepared without this step were enriched in granules but also contained significant contamination by mitochondria, endoplasmic reticulum, and nuclei. It is concluded that zymogen granules do not express InsP3 receptors and thus are not a site of Ca2+ release relevant to the secretory process in the pancreatic acinar cell.

Antisense src expression inhibits tyrosine phosphorylation of Shc and its association with Grb2 and Sos which leads to MAP kinase activation in U937 human leukemia cells

We constructed a recombinant plasmid which expresses antisense src RNA after dexamethasone (Dexa) treatment, and transfected it into U937 human monoblastic leukemia cells (U937-ASRC). Induction of antisense src RNA expression diminished the amounts of c-Src and its protein tyrosine kinase (PTK) activity in U937-ASRC cells. The declines in c-Src and its PTK activity subsequently reduced the proliferation of U937-ASRC cells. To elucidate the growth signal transduction pathway downstream of c-Src, tyrosine phosphorylation of Shc was examined in U937-ASRC cells treated with Dexa. The decline in c-Src by induction of antisense src RNA expression decreased the level of tyrosine phosphorylation of Shc. Immunoprecipitated c-Src directly phosphorylated immunoprecipitated Shc on tyrosine residues in vitro. The amounts of Grb2 and Sos co-immunoprecipitated with Shc were decreased after Dexa treatment. However, the amount of Sos co-immunoprecipitated with Grb2 was apparently not affected by Dexa treatment. These results indicate that Grb2 and Sos constitutively associate with each other in U937 cells. Furthermore, the level of phosphorylation on tyrosine (204) essential for MAP kinase activation was decreased after Dexa treatment. Taken together with all these findings, it is suggested that c-Src directly phosphorylates Shc on tyrosine residues, which in turn binds to Grb2 constitutively associated with Sos to form a Shc-Grb2-Sos complex, and that the complex formation is coupled with MAP kinase activation mediated by Ras activation in U937 cells.

[A successful surgical case report of impending rupture of the true thoraco-abdominal aortic aneurysm induced by thrombosed-type acute aortic dissection (Stanford type A)]

Impending rupture of the true aneurysm of the thoraco-abdominal aorta induced by acute aortic dissection (Stanford type A) is very rare, and decision making of the therapeutic plain is difficult. A 88-year-old woman manifested severe back pain with hypotension. Chest computed tomographic examination revealed a true aneurysm of the thoraco-abdominal aorta and acute thrombosed-type aortic dissection (Stanford type A) with cardiac tamponade. Under the diagnosis of impending rupture of the thoraco-abdominal aortic aneurysm induced by acute aortic dissection (Stanford type A), graft replacement of the thoraco-abdominal aortic aneurysm and pericardial drainage were successfully performed. Two months later, computed tomographic examination revealed disappearance of the thrombosed false lumen in the ascending aorta.

[Hypolipidemic action of F-1394, an acyl-CoA: cholesterol acyltransferase (ACAT) inhibitor, in high-fat diet fed beagle dogs]

In the present study, we investigated the hypolipidemic effect of F-1394, a potent and selective inhibitor of acyl-CoA: cholesterol acyltransferase (ACAT), in dogs fed with a high-fat diet consisting of regular foods, 5% cholesterol and 16% fat. The serum cholesterol levels in dogs reached the steady-state 1 week after the start of feeding of a high-fat diet and were about 2-fold greater than those in normolipidemic dogs. Graded administration of the doses of F-1394 (1-30 mg/kg/d) to the dogs fed with a high-fat diet prevented the elevation of serum cholesterol levels. In the hyperlipidemic dogs fed with a high-fat diet for 14 d before the start of the administration of F-1394, the oral administration of F-1394 at a dose of 1, 3 or 10 mg/kg/d for 21 d reduced the serum cholesterol levels in a dose-dependent manner. The estimated ID50 value was 7.2 +/- 0.3 mg/kg/d p. o. (12.1 +/- 0.5 mol/kg/d p. o.). F-1394 did not affect the body weight and no diarrhea was observed by the administration of F-1394. F-1394 at a dose of 10 mg/kg/d or more also significantly inhibited the increase of serum triglyceride levels 3 h after the feeding of high-fat diet. These results suggest that F-1394 inhibits the ACAT activity in the canine small intestine and, subsequently, the inhibition of ACAT activity contributes much to the prevention of cholesterol absorption via the gut, resulting in a decrease in serum cholesterol levels in the dogs fed with high-fat diet. Furthermore, F-1394 may also have an inhibitory effect on the triglyceride absorption via the gut, and the therapeutical use for postprandial hypertriglyceridemia is expected.

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents. Special references to bacteria isolated between July 1995 and June 1996]

Isolated bacteria from infections in general surgery during the period from July 1994 to June 1995 were investigated in a multicenter study in Japan, and the following results were obtained. One hundred and sixty-four strains were isolated from primary infections, and 202 strains were isolated from postoperative infections. From primary infections, anaerobic Gram-positive bacteria were predominant, while from post operative infections, aerobic Gram-positive bacteria were predominant. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus faecalis was the highest, followed by that of Staphylococcus aureus from postoperative infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among anaerobic Gram-negative, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order, and from postoperative infections, P. aeruginosa was the most predominantly isolated, followed by Enterobacter spp. and Klebsiella spp. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both types of infections. We noticed that MICs of cefazolin against three out of 23 strains of E. coli were higher than 100 micrograms/ml. Among anaerobic bacteria, there were many resistant strains against penicillins and cephems with MICs higher than 100 micrograms/ml, and the same trend was observed among other Bacteroides spp. and Prevotella spp.

Pathophysiological changes evoked by lipopolysaccharide administration in goats

To establish an adequate experimental model for the study of immuno-neuroendocrine mechanisms underlying the behavioral changes during the acute infection, temporal relationship of various physiological responses to endotoxin administration was examined in ovariectomized goats. Immediately after intravenous injection of 200 ng/kg of lipopolysaccharide, there were an abrupt decrease of white blood cell number and a gradual increase of rectal temperature, which were followed by elevation of plasma levels of adrenocorticotropic hormone, cortisol, glucose, free fatty acids, and then later by an increase of heart rate. The results suggest that the endotoxin administration would evoke a stereotyped cascade of, febrile, neuroendocrine and metabolic as well as autonomic response to the activation of immune systems in the ruminant species.

Rete mirabile in humans--case report

Carotid rete mirabile is a physiological vascular network between the external carotid and internal carotid systems present in some vertebrate species, but rarely observed in humans. We describe a 17-year-old girl with rete mirabile who presented with subarachnoid hemorrhage. Angiography disclosed the bilateral internal carotid arteries (ICAs) ended at the cavernous portion, and abnormal arterial networks visualized via the ICAs and the external carotid arteries in the paracavernous region. The distal ICAs were visualized via the abnormal arterial networks. After 18 years of follow-up she is leading a normal life without neurological problems. Rete mirabile in humans may present with hemorrhage or ischemic symptoms, but the prognosis appears to be good.

Effect of isoflurane on motor-evoked potentials induced by direct electrical stimulation of the exposed motor cortex with single, double, and triple stimuli in rats

BACKGROUND

The clinical application of intraoperative motor-evoked potentials (MEPs) has been hampered by their sensitivity to anesthetics. Recently, to overcome anesthetic-induced depression of myogenic MEPs, multiple stimulus setups with a paired or a train of pulses for stimulation of the motor cortex were reported. However, the effects of anesthetics on MEPs induced by these stimulation techniques are unknown.

METHODS

Bipolar electrical stimulation of the left motor cortex was carried out in 15 rats anesthetized with thiopental while the compound muscle action potentials were recorded from the contralateral hind limb. After recording of the MEP in response to the single-shock stimulation of the motor cortex, paired pulses (double pulses) or a train of three pulses (triple pulses) with an interstimulus interval of each pulse at 0.3, 0.5, 1.0, 1.5, and 2.0 ms were applied. After control MEP recording, isoflurane was administered at a concentration of 0.25 minimum alveolar anesthetic concentration (MAC), 0.5 MAC, 0.75 MAC, and 1.0 MAC, and the effects of isoflurane on the MEPs induced by single, double, and triple pulses were evaluated.

RESULTS

In all animals, distinct baseline MEPs were recorded. During the administration of 0.25 MAC and 0.5 MAC isoflurane, MEPs induced by stimulation with a single pulse could be recorded in 87% and 33% of animals, respectively, and MEP amplitude was significantly reduced in a dose-dependent manner. During the administration of 0.75 MAC isoflurane, MEPs after single-pulse stimulation could not be recorded in any animals. By stimulating with paired or triple pulses, the success rate of MEP recording and MEP amplitude significantly increased compared with those after single pulse before and during the administration of isoflurane. Both the success rate of MEP recording and MEP amplitude after double- and triple-pulse stimulation decreased significantly in a dose-dependent manner during the administration of isoflurane.

CONCLUSIONS

Application of double or triple stimulation of the motor cortex increases the success rate of MEP recording and its amplitude during isoflurane anesthesia in rats. However, these responses are suppressed by isoflurane in a dose-dependent manner.

Granular cell tumors of the breast: a report of two cases

Granular cell tumors (GCT) are rare neoplasms, and only 173 cases of benign GCT of the breast have been documented. We report herein the cases of two patients with this tumor and discuss the methods of diagnosis and treatment. The first patient was a 60-year-old woman who presented with a firm ill-defined mass in her left breast. Mammography showed a dense shadow with spicula and skin thickness, and ultrasonography revealed a hypoechoic mass with an irregular border. Radical mastectomy was performed under the wrong preoperative diagnosis of breast cancer. The second patient was a 31-year-old woman who presented with an elastic-hard mass in her left breast. Mammography showed a well-demarcated dense mass, and ultrasonography revealed a well-defined hypoechoic mass with a large depth-width ratio. Fine-needle aspiration cytology (FNAC) showed a large number of histiocytic cells with abundant granular cytoplasm. An excisional biopsy was performed, and histological examination confirmed a diagnosis of GCT. GCT is benign, but often misdiagnosed as breast cancer both clinically and radiologically. Therefore, histological examination is essential for making a correct diagnosis, while FNAC is also useful. Local resection is still the treatment of choice, and surgeons should do their utmost to avoid performing needless radical mastectomy.

Activation of protein-tyrosine phosphatase SH-PTP2 by a tyrosine-based activation motif of a novel brain molecule

BIT (a brain immunoglobulin-like molecule with tyrosine-based activation motifs) is a brain-specific membrane protein which has two cytoplasmic TAMs (tyrosine-based activation motifs). Using the Far Western blotting technique, we detected association of a 70-kDa protein with the tyrosine-phosphorylated TAMs of BIT. A mouse brain cDNA library in lambdagt11 was screened for this association, and two positive clones encoding tyrosine phosphatase SH-PTP2 were isolated. SH-PTP2 has two SH2 domains and is believed to function as a positive mediator in receptor tyrosine kinase signaling. SH-PTP2 and BIT were coimmunoprecipitated from phosphorylated rat brain lysate, and BIT was a major tyrosine-phosphorylated protein associated with SH-PTP2 in this lysate. This interaction was also observed in Jurkat T cells transfected with BIT cDNA depending on tyrosine phosphorylation of BIT. Bisphosphotyrosyl peptides corresponding to BIT-TAMs stimulated SH-PTP2 activity 33-35-fold in vitro, indicating that two SH2 domains of SH-PTP2 simultaneously interact with two phosphotyrosines of BIT-TAM. Our findings suggest that the tyrosine phosphorylation of BIT results in stimulation of the signal transduction pathway promoted by SH-PTP2 and that BIT is probably a major receptor molecule in the brain located just upstream of SH-PTP2.

Pseudoankylosis of the mandible after supratentorial craniotomy

After temporal craniotomy, pseudoankylosis of the mandible can cause difficult airway management during subsequent anesthesia. However, postcraniotomy changes in maximal mouth opening and the incidence of limited mouth opening have not been characterized. Ninety-two adult patients who underwent elective craniotomy were divided into three groups: Group A (n = 28) included patients who underwent parietal, occipital, or frontal craniotomy without incision of the temporalis muscles; Group B (n = 25) included patients who underwent temporal craniotomy; and Group C (n = 39) included patients who underwent frontotemporal craniotomy. Maximal mouth opening (interincisor gap) and the frequency of limited mouth opening (maximum mouth opening < or = 2.5 cm) were evaluated before operation and 3 days, 1 wk, 2 wk, 1 mo, and 3 mo after operation. The three groups did not differ with respect to age, sex, body weight, height, operative time, anesthetic time, or maximum mouth opening before operation. The postoperative reduction in maximal mouth opening was significantly greater in Group C than in Group B. In Group C, the incidence of limited mouth opening was 33.3% and 20.5% 2 wk and 1 mo after operation, respectively; however, limited mouth opening resolved within 3 mo in most patients. Supratentorial craniotomies separated by short intervals can increase the risk of limiting the mandibular opening, which may result in a difficult intubation. Careful preoperative assessment of the airway is mandatory if patients have previously undergone temporal or frontotemporal craniotomy.

[Usefulness of ultrasound-guided prostate biopsy in the diagnosis and treatment of localized prostate cancer]

Recently the ultrasound-guided prostate biopsy, especially random systematic biopsy, is considered more sensitive than the usual site-directed biopsy for the detection of localized prostate cancers. To confirm the usefulness of the ultrasound-guided prostate biopsy in the diagnosis and treatment of prostate cancer, we analyzed 170 cases who underwent ultrasound-guided prostate biopsy due to the abnormal findings in digital rectal examination (DRE), transrectal ultrasonography (TRUS) or serum level of prostate specific antigen (PSA). Prostate cancer was detected in 53 patients including 25 patients with metastatic lesions. Excluding the advanced prostate cancers, the positive predictive value (PPV) of DRE, TRUS and serum PSA was 3.8, 8.1, and 20.8%, respectively, when only one category showed abnormal finding in spite of normal finding of the others. Although these values were very low, it seemed necessary to apply all three tests for the detection of localized prostate cancer because the prostate biopsy was indicated by the abnormal finding of a single category in 9 cases (32%; 6/28) with localized cancers. The PPV of hypoechonic region on ultrasonography was 36%, and no cancer was demonstrated in the hypoechoic region at the transition zone, suggesting a low specificity of the hypoechoic region. Although there was no statistical association between the clinical stage and the number of positive cores or the length of cancerous tissue in the sextant biopsies, 64% of coincidence was observed between Gleason's sum of biopsy cores and that of operative specimens.

[Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents. Special references to bacteria isolated between July 1994 and June 1995]

Isolated bacteria from infections in general surgery during the period from July 1994 to June 1995 were investigated by a multicenter study in Japan, and the following results were obtained. One hundred and fifty-three strains were isolated from primary infections, and 143 strains were isolated from postoperative infections. From primary infections, both anaerobic Gram-positive and-negative bacteria were predominant, and from postoperative infections, aerobic Gram-positive bacteria were predominant. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus faecalis was highest, followed by that of Staphylococcus aureus from both types of infections. Among anaerobic Gram-positive bacteria, the isolation rate of Streptococcus intermedius was highest from primary infections, but from postoperative infections anaerobic Gram-positive bacteria was uncommon. Among aerobic Gram-negative bacteria, Escherichia coli was most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order. From postoperative infections, P. aeruginosa was most predominantly isolated, followed by Serratia marcescens and E. coli. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both types of infections. We have noticed that resistant strains against imipenem and ofloxacin were increasing among P. aeruginosa and resistant strains against cefazolin were increasing among E. coli. MICs of cefazolin against four out of 30 strains of E. coli were higher than 100 micrograms/ml, and MICs of imipenem was higher than 50 micrograms/ml against 5 out of 22 strains of P. aeruginosa.

Three-dimensional bone scintigraphy using volume-rendering technique and SPECT

Three-dimensional bone scintigraphic images were made and their usefulness and limitations discussed.

METHODS

After usual bone scan procedures, single-photon emission computed tomography (SPECT) data were taken and reconstructed into three-dimensional images. Volume rendering methods were used.

RESULTS

Three cases of three-dimensional bone scintigraphy were obtained; one of a normal patient, one of a case of transplanted kidney and incomplete fracture of the left femoral head, and one of a case of degenerative joint disease (DJD) on the left temporomandibular joint (TMJ). The three-dimensional structure of the skeletal system was depicted more clearly by the three-dimensional images than by a conventional bone scan.

CONCLUSION

Three-dimensional bone scintigraphs were thought to provide additional information for better understanding of the nature of bone lesions. Some technical improvements including automated threshold level determination and feature extraction for detecting abnormal high uptake are required before routine use can be envisaged.

Rab3D localizes to zymogen granules in rat pancreatic acini and other exocrine glands

Rab3 proteins are members of the family of Ras-like monomeric GTP-binding proteins that have been implicated in secretion in neuronal cells. Although an isoform of Rab3 has been assumed to exist in pancreatic acini, its identity has not yet been established. We now report that Rab3D is present in rat pancreatic acini and is localized to the zymogen granule membrane. Reverse transcription-polymerase chain reaction (PCR) was used with primers based on mouse Rab3D to amplify Rab3D from rat pancreas. The PCR product without primer sites consisted of 580 base pairs and was 94% identical to the mouse Rab3D cDNA sequence previously cloned from adipocytes. Western blotting with a polyclonal antiserum raised against Rab3D-specific carboxyterminal amino acids identified Rab3D in rat pancreatic acini and revealed its concentration on zymogen granule membranes. Immunocytochemistry of pancreatic lobules showed that Rab3D localized to the apical region in a pattern similar to amylase. Confocal fluorescence microscopy of lobules double immunolabeled with antibodies to Rab3D and the granule membrane marker protein glycoprotein-2 (GP-2) revealed a similar localization of these proteins to zymogen granules. Immunocytochemistry also revealed the presence of Rab3D in chief and enterochromaffin-like cells in the stomach, acinar cells in lacrimal and parotid gland, and Paneth cells in the intestine. These results show that Rab3D is expressed in rat pancreatic acini and other exocrine secretory cells. Its location implies it may be involved in regulated exocytosis.

Homozygous deletions of p16/MTS1 and p15/MTS2 genes are frequent in t(1;19)-negative but not in t(1;19)-positive B precursor acute lymphoblastic leukemia in childhood

We analyzed 60 B precursor acute lymphoblastic leukemia (ALL) primary samples and 15 cell lines for homozygous deletions of p16 and p15 genes and mutations of p16 gene. These included five cell lines and 13 primary samples with the t(1;19)(q23;pl3), and eight primary samples with the t(9;22)(q34;qll). Of 10 cell lines without t(1;19), homozygous deletion of both p16 and p15 genes was found in eight cell lines (80%), and a rearrangement of p16 in one cell line (10%). In contrast, only one (20%) of the five cell lines with t(1;19) showed homozygous deletion or rearrangement of p16/p15 gene. Thirteen of 60 (22%) primary samples demonstrated p16 gene homozygous deletion. No case with t(1;19) showed homozygous deletion of p16 gene (0/13, 0%), while cases without t(1;19) showed considerable incidence of p16 gene homozygous deletion (13/47, 28%). These results suggest that the incidence of deletions of p16 gene differs according to the subtypes of B precursor ALL. We also compared the frequency of p16 gene homozygous deletion between the patients at diagnosis and at relapse. Nine of 45 (20%) samples at diagnosis and four of 22 (18%) samples at relapse showed p16 homozygous deletions. The similarity of the rate in these two groups raises the question of the role of p16 gene in progression of B precursor ALL. Mutations were found in three of the primary cases (5%); the mutations included two nonsense mutations at codon 72 and one missense mutation at codon 98. All the mutations found in this study were heterozygous, and the clinical relevance of p16 gene mutation is yet to be determined in these case

Selective angiography of the vertebral artery in the rabbit: technical note

BACKGROUND

Selective angiography of the vertebral arteries has not been performed in rabbit models. We used a tracker-10 microcatheter for selective vertebral artery angiography.

METHODS

Five Japanese male rabbits weighing 2.0 to 2.5 kg were used. The right femoral artery was identified and an 18-gauge Teflon catheter was introduced into the iliac artery. A Tracker-10 microcatheter was introduced through the 18-gauge Teflon catheter into the right vertebral artery under fluoroscopic guidance.

RESULTS

Selective angiograms of the right vertebral artery were obtained using a bolus injection of 0.1 mL of iopamidol in all five rabbits.

CONCLUSIONS

Selective vertebral artery angiograms could be obtained via the transfemoral route with the use of Tracker-10, and intraarterial selective administration of vasodilators will be achieved using our technique.

Thrombopoietin modulates platelet activation in vitro through protein-tyrosine phosphorylation

To determine the roles of thrombopoietin (TPO) in platelet function in vitro, we examined the effects of TPO on platelet aggregation. Although several proteins in platelets were tyrosine-phosphorylated by TPO treatment, TPO alone was unable to induce platelet aggregation. However, the secondary wave of platelet aggregation induced by adenosine diphosphate (ADP) was enhanced by TPO in a dose-dependent manner. TPO in conjunction with ADP augmented tyrosine phosphorylation of platelet proteins, including tyrosine-phosphorylated proteins induced by TPO alone. Genistein inhibited protein-tyrosine phosphorylation in platelets induced by TPO with ADP and suppressed TPO-enhanced platelet aggregation. Moreover, tyrosine phosphorylation of MAP-kinases induced by TPO alone and TPO with ADP was consistent with TPO-enhanced platelet aggregation. These findings in the present study suggest that signal transduction involved in TPO-enhanced platelet aggregation is mediated in part by tyrosine-phosphorylated proteins, including MAP-kinases, in platelets through TPO-stimulated c-Mpl, TPO receptor.

Ursodeoxycholic acid corrects defective natural killer activity by inhibiting prostaglandin E2 production in primary biliary cirrhosis

We evaluated the effect of ursodeoxycholic acid on the defective natural killer activity in primary biliary cirrhosis. Administration of ursodeoxycholic acid (600 mg daily) for one month significantly increased natural killer activity in patients with primary biliary cirrhosis (P < 0.05). Ursodeoxycholic acid also enhanced the in vitro natural killer activity of lymphocytes from healthy volunteers, while other hydrophobic bile acids depressed it. Furthermore, ursodeoxycholic acid reduced the prostaglandin E2 concentration in culture supernatants of lymphocytes from healthy volunteers to a lower level than that in culture incubated with chenodeoxycholic acid (P < 0.05) or control cultures (P < 0.01). Urosdeoxycholic acid normalized the defective natural killer activity in primary biliary cirrhosis by reducing the levels of other hydrophobic bile acids and inhibiting prostaglandin E2 production, suggesting that it may be a useful immunomodulating agent for primary biliary cirrhosis.