Increased sensitivity of scid heterozygous mice to ionizing radiation

In the present study, acute effects of ionizing radiation on animal survival, bone marrow cells and fibroblast cell lines of scid homozygous, scid heterozygous and wild-type mice with the same C.B-17 genetic background were examined. The sensitivities to ultraviolet light (UV) and various chemicals, bleomycin, mitomycin C, N-methyl-N'-nitro-N-nitrosoguanidine, methyl methanosulphonate, 5-fluorouracil, 6-mercaptopurine, 4-nitroquinoline 1-oxide and potassium bromate) were also investigated. In addition, micronucleus testing of whole-body irradiated mice was performed. Scid heterozygous mice were found to be less sensitive than the homozygotes but more sensitive to ionizing radiation than wild-type mice, not only in vivo but also for bone marrow cells in vitro, suggesting partial dominance under both conditions. In contrast, there were no differences in sensitivity to UV light and various chemicals, as compared with wild-type and scid heterozygous cell lines, either in vitro or in the micronucleus test.

Contribution of tumor necrosis factor alpha and interleukin-1 alpha on the production of macrophage inflammatory protein-2 in response to respiratory syncytial virus infection in a murine macrophage cell line, RAW264.7

The production of several inflammatory cytokines, such as murine macrophage inflammatory protein-2 (MIP-2), tumor necrosis factor (TNF), and interleukin (IL)-1, was investigated in response to respiratory syncytial virus (RSV) infection in a murine macrophage cell line, RAW264.7, with special reference to mutual relation of their productions. The kinetics of MIP-2 production showed a trend for a biphasic pattern, that is, MIP-2 levels became detectable from 2 h postinfection (p.i.) and increased markedly until 8 h p.i. Thereafter, this level fell to the same level until 16 h p.i. and then increased again. TNF alpha was also detectable at 2 h p.i. and then increased sharply until 8 h p.i., when the peak level attained. Compared with the levels of MIP-2 and TNF alpha, that of IL-1 alpha/beta, especially IL-1 beta, was lower (ng versus pg/ml order). The presence of anti-TNF alpha or anti-IL-1 alpha antibody did not influence the early phase of MIP-2 production but significantly inhibited the late phase, suggesting that MIP-2 is induced by the combined effects of RSV infection via direct induction and indirectly after initial induction of TNF alpha and IL-1 alpha productions. Although RSV-infected RAW264.7 cells had no alteration in viability compared with mock-infected control, these data demonstrate that RSV is a potent inducer of inflammatory cytokines by direct induction and indirectly via the initial production of other cytokines.

Recovery of heart rate variability profile in patients after coronary artery surgery

We examined the different characteristics of heart rate variability (HRV) to define the time course of HRV profile after coronary artery surgery (CAS). Spectral analysis of HRV was performed on a 512-s segment of R-R intervals of the electrocardiogram on the preoperative day and on Postoperative Days 1, 2, 3, 4, 5, 6, 7, 14, 21, and 28. Power spectral area was divided into low (0.04-0.15 Hz; LF)- and high (0.15-0.5 Hz; HF)-frequency components. Fractal slope and sympathovagal slope of 1/f characteristics of HRV were determined in two different frequency ranges (from 0.01 to 0.15 Hz and from 0.01 to 0.5 Hz, respectively). Three recovery profiles of HRV were identified. Early HRV recovery profiles (Postoperative Days 1-6) included reduction in LF, HF, and sympathovagal slope, as well as an increase in fractal slope. Subsequent HRV recovery profiles (Postoperative Days 7-21) revealed reductions in LF, HF, and sympathovagal slope. Fractal slope became normal. Later HRV recovery profiles (Postoperative Day 28) demonstrated that all spectral components of HRV remained reduced, but sympathovagal and fractal slopes became normal. These changes in the HRV profile after CAS suggest significant postoperative alterations in cardiovascular homeostasis with significant but incomplete recovery during the first 28 postoperative days.

IMPLICATIONS

Heart rate variability reflects normal neural regulation of cardiac function. This variability remains depressed as long as 28 days after coronary artery bypass surgery, but can recover as early as 1 wk postoperatively. Despite implied loss of normal neural regulation of cardiac function, a specific correlation between depressed heart rate variability and outcomes was not performed.

Pretreatment with topical 60% lidocaine tape reduces pain on injection of propofol

We determined whether pretreatment with topical 60% lidocaine tape reduced the incidence of pain on injection of propofol compared with mixing intravenous lidocaine with propofol. In a randomized, double-blind trial, 90 patients were allocated to one of three groups: pretreatment with a bioocclusive dressing and administration of a premixed solution of propofol 180 mg and 2 mL of normal saline (Group A); pretreatment with 60% lidocaine tape and a premixed solution of propofol and normal saline (Group B); or pretreatment with a bioocclusive dressing and a premixed solution of propofol 180 mg and lidocaine 40 mg (Group C). The incidences of pain in Groups A, B, and C were 86.7%, 33.4%, and 20%, respectively. Group B and Group C had a significantly lower incidence of pain than Group A. There was no significant difference in the incidence of pain between Group B and Group C. There was no significant difference in the distribution of site of pain on injection of propofol among the three groups. Pretreatment with topical 60% lidocaine tape reduced the incidence of pain on injection of propofol similar to that of intravenous lidocaine mixed with propofol.

IMPLICATIONS

Pretreatment with topical 60% lidocaine tape reduces the pain associated with injection of propofol, a frequently used intravenous anesthetic. This approach should increase patient comfort during induction of anesthesia.

[Continuous epidural morphine for postoperative pain relief after spinal surgery--use of an epidural catheter placed at the time of surgery]

Postoperative analgesia by continuous epidural morphine infusion after spinal surgery was investigated in a retrospective study. An epidural catheter was placed by surgeons at the time of surgery. Postoperative pain was less intense and use of analgesics and sedative was less frequent in patients with continuous epidural morphine (n = 41) as compared with patients without continuous epidural morphine (n = 41). Among the patients with continuous epidural morphine, postoperative pain in patients (n = 16) with the dura opened or dural rent during surgery was less intense and the uses of analgesics and sedative was less frequent as compared with patients (n = 25) without the dural rent. There were no severe complications except for respiratory depression in a patient with chronic obstructive pulmonary disease. Our study demonstrated the ease of insertion of an epidural catheter at the time of surgery and the good quality of epidural analgesia after spinal surgery.

Studies on aromatase inhibitors. IV. Synthesis and biological evaluation of N,N-disubstituted-5-aminopyrimidine derivatives

In order to study the potency of the 5-aminopyrimidine skeleton as an aromatase inhibitor, we synthesized various N,N-disubstituted-5-aminopyrimidine derivatives and evaluated their aromatase-inhibitory activity (in vitro) and their inhibitory activity on pregnant mare serum gonadotropin (PMSG)-induced estrogen synthesis (in vivo). Compounds with the fluoro-substituted benzyl group showed potent aromatase inhibition. Among them, 5-[(4-cyanophenyl)(3,5-difluorobenzyl)amino]pyrimidine (5w, YM553) was a highly potent compound with an IC50 value of 0.038 nM for aromatase from human placenta. Its inhibitory effect was approximately four times greater than that of YM511. In addition, YM553 was a weak inhibitor of other enzymes involved in steroid hormone synthesis. These results indicate that YM553, as well as YM511 (a 4-amino-4H-1,2,4-triazole derivative), is a promising agent for the treatment of estrogen-dependent diseases.

Genetic alterations in patients with esophageal cancer with short- and long-term survival rates after curative esophagectomy

OBJECTIVE

The objective of this study was to ascertain the exact relation between specific oncogenes and long- and short-term survival rates in patients with esophageal cancer.

SUMMARY BACKGROUND DATA

Recent developments in molecular biology have shown that several oncogenes and suppressor genes are involved in the development of esophageal cancer. However, the role of these genes still is unknown.

METHODS

The clinical outcome of 84 cases of R0-resected esophageal carcinomas (from 1986-1993) and the molecular and biologic characteristics of these tumors were studied. The patients studied were divided into three groups, which were designated as follows: shortest term survivors (up to 6 months), short-term survivors (7-12 months), and long-term survivors (>5 years). These groups included 23, 17, and 44 subjects, respectively. For the genomic analysis, CyclinD1, int-2, murine double minute 2 (MDM2), retinoblastoma, p53, adenomatous polyposis coli (APC), deleted in colorectal carcinoma (DCC), and human papillomavirus were studied in these patients. The regrowth capability of primary cultures and the clinicopathologic characteristics of these patients also were analyzed.

RESULTS

The CyclinD1 and int-2 genes, which are located in the 11q13 chromosome, and the MDM2 gene were related to short survival. However, the p53 mutation and human papillomavirus infection were not related to short-term survival. The average ratio of genomic abnormalities to genes examined was higher in the shortest and short-term survival groups than in the long-term survival group. Regrowth capability in primary cultures also was related to short-term survival. Among the long-term survival patients, 7 (16%) of 44 cases suffered further cancer after esophagectomy.

CONCLUSIONS

These results suggest that the 11q13 amplicon and MDM2 may play an important role in the progression of esophageal cancer, and an accumulation of genomic abnormalities may result in poor prognosis. Careful follow-up testing for double cancer is needed in long-term survivors of esophageal cancer.

FHIT gene alterations in esophageal cancer and ulcerative colitis (UC)

FHIT (fragile histidine triad gene), a candidate tumor suppressor gene, was recently identified and cloned at chromosome 3p14.2. Alterations of this gene have been reported in a number of primary human tumors, including colorectal, esophageal, gastric and lung carcinomas. However, some reports have found no abnormalities in this gene. We investigated a total of 63 primary esophageal tumors, nine esophageal cancer cell lines and 17 ulcerative colitis-associated neoplasms (UCANs) for alterations of FHIT. In 13 esophageal tumors, we employed overlapping reverse transcriptase-PCRs (RT-PCRs) to amplify and sequence the complete open reading frame of FHIT. One of 13 primary esophageal tumors analysed by RT-PCR expressed no detectable FHIT transcript; the remaining 12 expressed normal-sized transcripts with wild-type open reading frame sequences. In an additional 50 esophageal tumors, the polymorphic microsatellite loci D3S1300 and D3S1313 were used to evaluate loss of heterozygosity (LOH) at 3p14.2. Eleven of these 50 tumors showed LOH at one or both loci. In all these 11 tumors, genomic PCR and direct sequencing of FHIT exons 5-9 was performed. This analysis revealed that none of these 11 primary esophageal tumors contained any alterations in the FHIT open reading frame or adjacent intron sequences. Finally, among 17 UCANs, the in vitro synthesized protein (IVSP) assay detected no truncated protein products, nor were there any abnormalities in size or DNA sequence of FHIT RT-PCR products. However, in six of nine esophageal carcinoma cell lines, no FHIT RT-PCR product was detectable using either of the overlapping primer sets. Genomic PCR and direct sequencing of exons 5-9, also performed in these nine cell lines, revealed wild-type sequence in eight cell lines; however, one cell line contained no exon 5 PCR product. This cell line also lacked detectable FHIT transcript. These data suggest that the open reading frame of FHIT is not important in the development or progression of most primary esophageal carcinomas or UCANs, although lack of expression of the FHIT transcript may be common in esophageal cancer-derived cell lines. The possibility of an additional tumor suppressor gene at chromosome 3p14.2 remains to be evaluated.

How are macular changes reflected in pattern visually evoked cortical potentials?

To investigate the macular contribution to the amplitude and latency of pattern visual evoked cortical potentials (PVECPs), we recorded PVECPs in patients with unilateral macular disease (retinal diseases involving the macular region) and optic neuritis. We selected patients with visual acuities better than 0.3, which is thought to be the minimum acuity to provide clearly discernible responses. The visual stimulus was a checkerboard. We varied the check size in 4 steps as 7, 14, 28, and 56 min of arc, and the contrast was 20% or 80%. The amplitude of the sinusoidal wave of steady-state VECPs (12 Hz) and the P100 component of a transient VECP (3 Hz) were measured. Significant attenuation and delay of PVECPs in the affected eye were found in the macular disease group. Macular disease may cause an increase of VECP latency. However, VECP seemed to be a more sensitive test of optic nerve disease than of macular disease, when patients had similar visual acuities.

[The effect of low-dose prostaglandin E1 on serum and urinary fluoride concentrations in patients anesthetized with sevoflurane]

We investigated the effects of low-dose prostaglandin E1 (PGE1) on serum and urinary concentrations of inorganic fluoride in 39 adult patients undergoing upper abdominal surgery. Anesthesia was maintained with a combination of N2O-O2-sevoflurane and thoracic epidural anesthesia. Twenty-two patients received infusion of PGE1 at a rate of 0.02 micrograms.kg-1.min-1 throughout surgery. Seventeen patients served as control by not receiving PGE1. Serum inorganic fluoride concentrations (FB) were determined before the induction of anesthesia and 0, 2 and 24 hours after the end of anesthesia. Urinary inorganic fluoride concentrations (FU) were determined before the induction of anesthesia, and 0, 24 and 48 hours after the end of anesthesia. These was no difference between PGE1 group and control group in anesthetic dose (MAC hours) of sevoflurane. In both groups, FB peaked at the end of anesthesia. In PGE1 group, UB peaked at the end of anesthesia, while in control group, it peaked 24 hours after anesthesia. There were differences between groups neither in FB nor in FU throughout the study period. The relationships between anesthetic dose and fluoride concentrations, however, differed significantly between the groups. In control group FB values of 0, 2 and 24 hours after anesthesia correlated positively with MAC hours, respectively, while in PGE1 group they did not. Similarly in control group, FU values of 24 and 48 hours after anesthesia correlated positively with MAC hours, respectively, while in PGE1 group, they did not. Thus in patients receiving high-dose sevoflurane, FB and FU tended to be lower in PGE1 group than in control group. In contrast, in PGE1 group, urinary excretion of fluoride during surgery correlated positively with MAC hours, while in control group, it did not. Urinary fluoride excretion during surgery was significantly greater in PGE1 group than in control group. These results suggested that PGE1 might prevent elevation of serum and urinary fluoride concentrations in patients receiving high-dose sevoflurane. This effect might result from enhanced urinary excretion of fluoride with PGE1.

[The effect of low-dose prostaglandin E1 on intra- and post-operative liver function]

We investigated the effects of low-dose prostaglandin E1 (PGE1) on intra- and post-operative liver function in 109 adult patients undergoing upper abdominal surgery. Patients were divided into 2 groups; Control group (n = 42) and PGE1 group (n = 67). In PGE1 group, PGE1 was infused throughout surgery at a rate of 0.02 microgram kg-1 min-1. In both groups, anesthesia was maintained with a combination of inhalational and thoracic epidural anesthesia. Epidural anesthesia was maintained with 1.5% lidocaine infused epidurally at a constant rate (8 +/- 2 ml.hr-1). The continuous epidural infusion of lidocaine was initiated before surgery and discontinued at the end of surgery. Preoperative and postoperative liver function was evaluated with blood chemistry examination. Intraoperative liver function was evaluated in 84 patients (33 in control group and 51 in PGE1 group) by measuring plasma lidocaine concentration. Plasma lidocaine concentration was determined 1 and 3 hours after the initiation of lidocaine infusion and 0 and 2 hours after its termination. There were no differences between the groups in doses and infusion rates of lidocaine. In both groups, lidocaine concentration increased progressively as infusion was continued. Lidocaine concentration was significantly lower in PGE1 group than in control group at the end of the infusion. In 22 patients in control group and 35 in PGE1 group who received high-dose lidocaine (> 8 mg.kg-1), lidocaine concentration remained significantly lower in PGE1 group than in control group throughout the infusion period. The difference in lidocaine concentrations between the groups increased progressively as infusion was continued, though the doses and the infusion rates of lidocaine were not different between the groups. Postoperative liver function did not differ between the groups. Because removal of lidocaine from blood to liver parallels hepatic blood flow, the lower plasma lidocaine concentration in PGE1 group indicated that hepatic blood flow was higher and liver function was better-maintained with PGE1 during anesthesia and surgery. Low dose PGE1 thus improved intraoperative liver function during upper abdominal surgery.

Biological activities of novel zaragozic acids, the potent inhibitors of squalene synthase, produced by the fungus, Mollisia sp. SANK 10294

Four novel zaragozic acids, F-10863A, B, C and D, were isolated from a culture broth of the fungus Mollisia sp. SANK 10294. F-10863 compounds contain a 4,6,7-trihydroxy-2,8-dioxyobicyclo-[3.2.1]octane-3,4,5-tricarboxyl ic acid core like previously reported zaragozic acids, but the structures of the side chains are different. Recently, it was found that F-10863A is identical to zaragozic acid D3, while the other three are novel compounds. F-10863 compounds are potent inhibitors of squalene synthase like previously reported zaragozic acids, and, furthermore, they exhibit serum cholesterol-lowering activity in vivo.

Colonoscopy for frank bloody stools associated with cancer chemotherapy

Diarrhea is a common complication of cancer chemotherapy, while bloody stool is rare. Pseudomembranous colitis has been reported as causing bloody diarrhea after chemotherapy. In this report, we describe nine consecutive patients who presented frank bloody stools within one month after cancer chemotherapy. Patients with a history of pelvic irradiation or with a previously identified colorectal tumor were excluded. Among nine patients, bleeding from tumor undetected before chemotherapy was seen in three, pseudomembranous colitis in four, ischemic colitis in one and methicillin-resistant Staphylococcus aureus enterocolitis in one. Of the three tumors, one was an adenomatous polyp and the other two were metastatic tumors. Two of the four patients with pseudomembranous colitis had not received antibiotics before the onset of colitis. Causes of bloody stools after chemotherapy were various and colonoscopy played an important role in diagnosis and prompt therapy.

[The effect of low-dose prostaglandin E1 on intra- and post-operative renal function]

We investigated the effects of low-dose prostaglandin E1 (PGE1) on intra- and post-operative renal function in 109 adult patients undergoing upper abdominal surgery. Anesthesia was maintained with a combination of thoracic epidural combined with inhalational anesthesia. Sixty-seven patients received PGE1 at a rate of 0.2 microgram.kg-1.min-1 throughout surgery. Forty-two patients, who did not receive PGE1, served as control. Pre- and post-operative renal function was evaluated with serum levels of BUN and creatinine (Cr), while intra-operative renal function was evaluated mainly with urine output and urine flow rate during anesthesia. Urinary Na excretion and creatinine clearance (Ccr) were determined during surgery in limited cases. Urine output and urine flow rate during anesthesia were greater in PGE1 group than in control group, whereas infusion volumes and infusion rates were not different between the groups. In PGE1 group, urine flow rate was greater during surgery than before surgery, while in control group, it was unchanged. Na excretion during anesthesia was also greater in PGE1 group than in control group. In control group, Na excretion and Ccr were smaller during surgery than before surgery, while in PGE1 group, they were unchanged. Postoperative serum BUN and creatinine levels were not different between the groups. Decreased Na excretion and decreased Ccr in control group indicated that renal function was depressed during surgery, whereas unchanged Ccr, unchanged Na excretion and increased urine flow rate in PGE1 group indicated that renal function was well-maintained during surgery with PGE1. Low-dose PGE1 thus prevented depression of renal function during surgical anesthesia.

Anterior decompression of foraminal stenosis below a lumbosacral transitional vertebra. A case report

STUDY DESIGN

A case of unilateral far-out foraminal entrapment of the L5 spinal nerve below a transitional vertebra is presented with a review of the literature.

OBJECTIVES

To describe management of a rare far-out foraminal stenosis below a transitional vertebra and to evaluate the surgical procedure and results.

SUMMARY OF BACKGROUND DATA

Far-out foraminal stenosis with radiculopathy caused by bony spur formation secondary to anomalous articulation between the transverse process and the sacral ala is rarely reported. Decompression at this point traditionally has been performed through a posterior approach, similar to that performed for the far-out syndrome. There are no previous reports describing anterior decompression through an extraperitoneal approach.

METHODS

The diagnosis was confirmed by computed tomography, magnetic resonance imaging, and selective radiculography. Anterior decompression was performed by resecting the bony spur using a wide muscle-splitting extraperitoneal approach.

RESULTS

Anterior decompression was performed with minimal intervention to the spine and the trunk muscles. Good relief of low back pain and sciatica was obtained.

CONCLUSIONS

Selective radiculography was the method of examination with the optimal diagnostic value for far-out foraminal stenosis. An anterior approach to the decompression of far-out foraminal stenosis below a lumbosacral transitional vertebra is a relatively simple and effective method.

Cell cycle-dependent activation of telomerase in naturally synchronized culture of a true slime mold, Physarum polycephalum

Telomeres of Physarum plasmodia did not shorten with numerous repeats of nuclear division, and an apparent activity of telomerase was detected in this organism. In naturally synchronized culture of Physarum plasmodia, an evident activation of telomerase was observed at the late S-phase, just prior to the completion of in vivo DNA replication, and the low telomerase activity was detected throughout the cell cycle. In the nuclei isolated from different phases of synchronized plasmodia, a higher activity of telomerase was also observed at late S-phase. These results clearly show the existence of a cell cycle-dependent regulatory mechanism of telomerase activity in growing, naturally synchronized cells.

Multiple types of aberrations in the p16 (INK4a) and the p15(INK4b) genes in 30 esophageal squamous-cell-carcinoma cell lines

To determine the role and mode of inactivation of the p16 and p15 genes in human esophageal tumors, we examined alterations and expression of the alpha and beta forms of the p16 gene, 5' CpG island methylation of p16 exon 1 alpha, and alterations of the p15 gene in 30 esophageal squamous-cell-carcinoma cell lines. Of 30 such cell lines examined, 28 (93%) showed aberrations of the alpha form of the p16 gene: 18 homozygous deletions, 6 point mutations and 4 hypermethylation. Methylation was exclusively observed in cell lines with the wild-type alpha form. Of the 6 point mutations, one was observed in exon 1 alpha, one in the splice acceptor site of intron 1 and the remaining 4 were in exon 2. In the beta form, 18 homozygous deletions and 3 point mutations in exon 2 were detected, but no point mutation was found in exon 1 beta. All mutations in exon 2 gave rise to premature termination codons in the reading frame of the alpha transcript, while no non-sense mutations were observed in the reading frame of the beta transcript. Among 12 cell lines without homozygous deletions of the alpha and beta forms of the p16 gene, the expected wild-type beta transcript was observed in 8 cell lines, whereas only one cell line expressed the expected wild-type alpha transcript. Homozygous deletions of the p15 gene were observed in 16 cell lines (53%), and no point mutations were detected. Twelve cell lines had alterations only in the alpha form of the p16 gene, while none showed aberrations exclusively in the p15 gene. Taken together, these results indicate that inactivation of the beta form of the p16 gene and the p15 gene are not so frequent as that of the alpha form of the p16 gene in ESC cell lines, suggesting that aberration of the alpha form of p16 gene is the primary target of 9p loss in ESC.

[The effect of low-rose prostaglandin E1 on circulation, respiration and body temperature during surgical anesthesia]

We investigated the effects of low-dose prostaglandin E1 (PGE1) on circulation, respiration, and body temperature during surgical anesthesia. We studied 109 adult patients undergoing upper abdominal operations under thoracic epidural combined with inhalational anesthesia. Patients were divided into 2 groups; Control group (n = 42) and PGE1 group (n = 67). In PGE1 group, PGE1 infusion was started at the rate of 0.02 microgram.kg-1.min-1 before the induction of anesthesia and was terminated at the end of surgery. There were no differences between the groups in demographic, anesthetic and surgical characteristics. After treatment with PGE1, arterial pressure decreased slightly but significantly, resulting in lower arterial pressure in PGE1 group than in control group before the induction of anesthesia. After the induction of anesthesia, however, arterial pressure decreased significantly in both groups, and the differences in arterial pressure between the groups were not observed any more during surgery. Heart rate was not different between the groups throughout the study period. Intraoperative urine output was greater in PGE1 group than in control group. PaO2/FIO2 ratio was not different between the groups both before and during anesthesia. Rectal temperature remained slightly but significantly lower in PGE1 group throughout surgery. Rectal-to-palm temperature gradient tended to be smaller in PGE1 group 1 hour after the induction of anesthesia. Low-dose PGE1 reduced arterial pressure. However, the difference in arterial pressure between the groups was so small that the difference disappeared during surgery. Meanwhile, low-dose PGE1 increased urine output, suggesting that renal blood flow was better-maintained with PGE1. In spite of several investigations reporting an unfavorable effect of PGE1 on PaO2, low dose PGE1 did not affect PaO2 in this study. Finally low-dose PGE1 reduced core temperature, though slightly, probably through redistribution of the body heat.

Studies on aromatase inhibitors. III. Synthesis and biological evaluation of [(4-bromobenzyl)(4-cyanophenyl)amino]azoles and their azine analogs

A series of [(4-bromobenzyl)(4-cyanophenyl)amino]azoles and their azine analogs, which have the side chain of the selective aromatase inhibitor YM511, were synthesized and evaluated for aromatase-inhibitory activity (in vitro) and for pregnant mare serum gonadotropin (PMSG)-induced estrogen synthesis inhibitory activity (in vivo). Among these aza-heterocycles, the pyrimidin-5-yl derivative (6a) was the most potent aromatase inhibitor and its in vitro inhibitory activity was comparable to that of YM511. Compound 6a also showed weak inhibitory activity on aldosterone synthesis. These data indicated that the pyrimidin-5-yl moiety is useful as a new azole fragment in place of the 4H-1,2,4-triazol-4-yl moiety of the aromatase inhibitor YM511.

Phase I-II study of irinotecan hydrochloride combined with cisplatin in patients with advanced gastric cancer

PURPOSE

A dose-escalation study of irinotecan hydrochloride (CPT-11) combined with fixed-dose cisplatin was conducted to determine the maximum-tolerated dose (MTD), dose-limiting toxicities, and objective response rate in patients with advanced gastric cancer.

PATIENTS AND METHODS

Twenty-four patients with or without prior chemotherapy were enrolled. All patients were assessable for toxicities and response. On day 1, CPT-11 was administered as a 90-minute intravenous (I.V.) infusion, which was followed 2 hours later by a 120-minute I.V. infusion of cisplatin 80 mg/m2. CPT-11 alone at the same dose was administered again on day 15. The treatment was repeated every 4 weeks until disease progression was observed. The initial dose of CPT-11 was 60 mg/m2, and was escalated in increments of 10 mg/m2 until severe or life-threatening toxicity was observed.

RESULTS

The MTD of this combination was CPT-11 80 mg/m2. At this dose level, 16.7% of patients (two of 12) had leukopenia of less than 1,000/microL, 66.7% (eight of 12) had neutropenia of less than 500/microL, and 16.7% (two of 12) had severe diarrhea of grade 4 during the first course. The dose-limiting toxicity was neutropenia. Ten patients achieved a partial response (PR), and the overall response rate was 41.7% among 24 patients (95% confidence interval, 21.9% to 61.4%).

CONCLUSION

The recommended dose and schedule is CPT-11 70 mg/m2 on days 1 and 15 and cisplatin 80 mg/m2 on day 1 every 4 weeks. This combination of CPT-11 and cisplatin, considered to be active against advanced gastric cancer with acceptable toxicity, should be further assessed in a phase II study.

Role of platelets in myocardial ischemia-reperfusion injury in dogs

We investigated the involvement of circulating platelets in myocardial ischemia-reperfusion injury in canine autoperfused heart-lung preparations using filters to deplete platelets and/or leukocytes. The left anterior descending (LAD) coronary artery was occluded for 40 min, followed by 40 min reperfusion, in 3 groups: a leukocyte-platelet-depleted (LPD) group, in which both leukocytes and platelets were depleted; a leukocyte-depleted (LD) group, in which leukocytes alone were depleted; and a control group. There were no differences in hemodynamics or arrhythmias among groups before or during coronary occlusion. After reperfusion, the maximum rate of change in left ventricular pressure during systole and diastole was significantly higher in the LPD group than in the control and LD groups. The LPD group also showed gradual recovery of regional myocardial function and a decrease in the frequency of premature ventricular contractions. The LD group showed a slight improvement in cardiac function and arrhythmias compared with the control group. Although there was no significant difference in the pulmonary arterial plasma level of thromboxane B2 at any stage among groups, the control group showed an increase after reperfusion. These results suggest that platelets are important in reperfusion injury and that the depletion of both leukocytes and platelets effectively protects against reperfusion injury.

Multiple types of aberrations in the p16 (INK4a) and the p15(INK4b) genes in 30 esophageal squamous-cell-carcinoma cell lines

To determine the role and mode of inactivation of the p16 and p15 genes in human esophageal tumors, we examined alterations and expression of the alpha and beta forms of the p16 gene, 5' CpG island methylation of p16 exon 1 alpha, and alterations of the p15 gene in 30 esophageal squamous-cell-carcinoma cell lines. Of 30 such cell lines examined, 28 (93%) showed aberrations of the alpha form of the p16 gene: 18 homozygous deletions, 6 point mutations and 4 hypermethylation. Methylation was exclusively observed in cell lines with the wild-type alpha form. Of the 6 point mutations, one was observed in exon 1 alpha, one in the splice acceptor site of intron 1 and the remaining 4 were in exon 2. In the beta form, 18 homozygous deletions and 3 point mutations in exon 2 were detected, but no point mutation was found in exon 1 beta. All mutations in exon 2 gave rise to premature termination codons in the reading frame of the alpha transcript, while no non-sense mutations were observed in the reading frame of the beta transcript. Among 12 cell lines without homozygous deletions of the alpha and beta forms of the p16 gene, the expected wild-type beta transcript was observed in 8 cell lines, whereas only one cell line expressed the expected wild-type alpha transcript. Homozygous deletions of the p15 gene were observed in 16 cell lines (53%), and no point mutations were detected. Twelve cell lines had alterations only in the alpha form of the p16 gene, while none showed aberrations exclusively in the p15 gene. Taken together, these results indicate that inactivation of the beta form of the p16 gene and the p15 gene are not so frequent as that of the alpha form of the p16 gene in ESC cell lines, suggesting that aberration of the alpha form of p16 gene is the primary target of 9p loss in ESC.

Clinical trial of prophylactic endoscopic variceal ligation for esophageal varices

Endoscopic variceal ligation is an effective therapy for variceal bleeding, and use of the method has recently been increasing. We evaluated the clinical usefulness of prophylactic endoscopic variceal ligation. Twenty-two patients with enlarged, tortuous varices and "red color signs" were selected. These patients were treated with ligation therapy alone and the varices were eradicated, i.e., reduced to small, straight varices without red color signs. Ligation therapy was withdrawn if the general condition of the patient worsened or if the varices could not be removed by suction. Follow-up endoscopy was performed every 4 months, and another ligation was performed if there were recurrent varices or variceal bleeding. The total reduction rate was 86.4%, and eradication required two sessions of therapy and 30 days of hospitalization on average. Complications included esophageal injury in 1 patient and treatment-induced bleeding in 1 patient; both complications were easily controlled. No variceal bleeding occurred after the eradication. There was no mortality due to gastrointestinal bleeding during the median follow-up period of 346 days. Prophylactic endoscopic variceal ligation made it possible to prevent fatal variceal bleeding with a minimum risk of complications, suggesting that this could be an alternative method for the prevention of first-time variceal bleeding.