Difference in Radiosensitivity Depending on the Presence and Absence of EGFR Mutations: Clinical and In Vitro Analyses

PURPOSE/OBJECTIVE(S)

For stage IV non-small cell lung cancer (NSCLC), the treatment drug is selected based on the gene mutation status. However, the dose or field of radiation therapy is not change based on the genetic status. We evaluated both clinical and in vitro data, showing that the presence or absence of epidermal growth factor receptor (EGFR) mutations affects radiosensitivity in patients with brain metastases (BM) from NSCLC.

MATERIALS/METHODS

Patients with BM from NSCLC who received whole brain radiotherapy (WBRT) were enrolled in this study. Patient characteristics are shown in the Table. EGFR mutations were observed in 13 (31.0%) patients. The prescribed dose was 30 Gy in 10 fractions (85.7%). The A549, VMRC-LCD, NCI-H1975, and HCC4006 cell lines were used for the in vitro study. EGFR mutation was negative in A549 and VMRC-LCD and positive in NCI-H1975 (exon21) and HCC4006 (exon19). After irradiation of these cell lines with 0, 2, 4, and 8 Gy, a colony formation assay was performed. DNA double-strand breaks (DSBs) were assessed 30 min and 24 h after 4 Gy irradiation using γH2AX.

RESULTS

The median follow-up period was 4 months (range, 1-35). Intracranial recurrence was observed in 14 (33.3%) patients during the follow-up period. Thirty-nine (92.9%) patients died during the follow-up period. Patients with EGFR mutation-positive tumors had significantly better intracranial control rates than those with EGFR mutation-negative tumors (p = 0.0213). A similar tendency was observed in the analysis conducted, except for the cases in which tyrosine kinase inhibitor (TKI) was administered after WBRT. In the EGFR mutation-positive group, no significant difference was observed between patients who received TKI after WBRT and those who did not (p = 0.527). In the colony formation assay, EGFR mutation-positive cell lines showed a significantly lower number of colonies formed after irradiation with 2 and 4 Gy than mutation-negative cell lines (p = 0.00018 and 0.0000291, respectively). EGFR mutation-positive cell lines had significantly more DNA-DSBs remaining 24 h after irradiation than mutation-negative cell lines (p = 0.0000000312).

CONCLUSION

Our data suggest that patients with EGFR mutation-positive NSCLC are more radiosensitive than those with negative EGFR mutations.

Deep-Inspiration Breath-Hold Stereotactic Body Radiation Therapy by Combining Spirometer-Guided Breath-Hold and a Real-Time Tumor Tracking System: A Novel Approach

PURPOSE/OBJECTIVE(S)

There are several methods used against respiratory motion (RM). Expiratory breath-hold (BH) is considered more stable and reproducible than inspiratory BH; therefore, BH with spirometry is often used for expiration. The real-time tumor tracking radiotherapy (RTRT) system is a highly effective method for reducing the margin of RM. This system ambushes and irradiates tumors during the expiratory phase when tumors move slowly. Although these methods usually involve expiration, it is advantageous to expand the lungs with inspiration to reduce the risk of adverse events. Here, we developed a new approach of performing stereotactic body radiation therapy (SBRT) under deep-inspiration BH (DIBH) by combining these two methods.

MATERIALS/METHODS

Lung tumors with respiratory motion ≥ 1 cm were included. Three or four fiducial markers were placed near the tumor via bronchoscopy. DIBH CT (CT-IN) was performed under the guidance of spirometer. The PTV was obtained by adding a 5-mm margin to the GTV delineated on CT-IN. The prescribed dose was 42 Gy in four fractions for the D95 of the PTV. An error of 2.0 mm around the planned position of the fiducial marker on CT-IN was permitted along each orthogonal axis as a gating box. In preparation for cases in which the reproducibility of DIBH is low and treatment cannot be performed, light expiration BH CT (CT-EX) was also performed, and a radiotherapy plan was prepared for the conventional RTRT system so that it could be switched at any time. Lung volumes and doses (mean dose, V20 Gy, V10 Gy, and V5 Gy) on CT-EX and CT-IN were compared.

RESULTS

Five patients underwent SBRT with DIBH, and all completed the planned irradiation course. The median treatment time per fraction was 27.86 min (range, 25.5-40.6). Four tumors were located in the left lower lobe and one in the right lower lobe. The median volume of PTV was 12.4 (range, 5.2-26.2) mL. The lung volumes and doses on CT-EX and CT-IN are shown in the Table. The lung volume on CT-IN was 1.6 times larger than that on CT-EX. The PTV-to-lung ratio on CT-IN was significantly lower than that on CT-EX. V20 Gy and V10 Gy on CT-IN were significantly lower than those on CT-EX.

CONCLUSION

SBRT with DIBH was achieved by combining the spirometer and RTRT system. This can help to eliminate concerns about reproducibility and high-speed tumor movement during inspiration, which are weaknesses of spirometer-guided breath-hold and the RTRT system, respectively, while ensuring the accuracy of the RTRT system. DIBH SBRT is a promising method that can reduce lung dose.

Transient azoospermia following rosuvastatin medication for hypercholesterolemia

The authors report a case of transient azoospermia following hydroxymethylglutaryl-coenzyme A reductase (HMGCR) inhibitor rosuvastatin medication for hypercholesterolemia. While a primary infertile couple with oligoasthenospermia was preparing for an in vitro fertilization program, the male partner had been diagnosed with hypercholesterolemia in a medical check-up and prescribed four-week oral administration of rosuvastatin. No motile spermatozoa were found in the ejaculated semen and urine on the day of follicular aspiration. Azoospermia was confirmed by reexamination in weeks 3 and 7. Spermatozoa appeared in the ejaculated semen in two weeks of drug withdrawal. In week 16, the sperm count and motility increased to the level where intracytoplasmic sperm injection was available.

Diclofenac suppository pretreatment in prevention of vasovagal reflex-associated complications for infertile women undergoing local endometrial injury

PURPOSE OF INVESTIGATION

To assess the effects of the diclofenac suppository pretreatment in prevention of vasovagal reflex-associated complications for infertile women undergoing local endometrial injury (LEI).

MATERIALS AND METHODS

Eighty-six infertile outpatients with repeated implantation failure following transfer of morphologically good embryos and/or blastocysts underwent single curettage LEI to improve the pregnancy outcome in the subsequent embryo/blastocyst transfer cycle. Of them, 35 patients chose diclofenac suppository administration prior to LEI, whereas 51 patients did not. The occurrence of palpitations, bradycardia, hypotension, presyncope, and requirement of bed rest was compared between the two groups.

RESULTS

There were no significant differences in the demographics between the two groups. The prevalence of presyncope and requirement of bed rest was significantly lower in the diclofenac suppository group than in the control group. The pregnancy outcome was similar between the two groups.

CONCLUSION

The diclofenac suppository administration is a low-cost effective method to reduce the risk of the vasovagal reflex-associated complications in infertile women undergoing LEI.

Do combined psychological stress examinations predict pregnancy outcome in an assisted reproductive technology program?

PURPOSE OF INVESTIGATION

To investigate prospectively if the pregnancy outcome in infertile women undergoing assisted reproductive technology (ART) is predictable by a combination of psychological stress examinations on the day of embryo/blastocyst transfer.

MATERIALS AND METHODS

From April 2012 to May 2012, 114 women aged 42 years old or less underwent transfer of morphologically-good embryo/blastocyst(s) in the present in vitro fertilization (IVF) center. Immediately before the transfer, salivary secretion was obtained and frozen. α-amylase and cortisol concentrations were quantified using biochemical assays. In addition, patients were asked to answer General Health Questionnaire 28 (GHQ28) and Zung's Self Rating Depression Scale (SDS) following transfer. The results were compared between the pregnant group and non-pregnant group.

RESULTS

There were no significant differences in the age of the infertile couples between the pregnant group and non-pregnant group as well as body mass index of the infertile women. The GHQ28 and SDS scores were similar between the two groups, as were the salivary α-amylase and cortisol concentrations.

CONCLUSION

This prospective study failed to demonstrate the predictivity of the pregnancy outcome by psychological stress examinations in infertile women in an ART program, even though these tests were used in combination.

Vaginal preparation with povidone iodine disinfection and saline douching as a safe and effective method in prevention of oocyte pickup-associated pelvic inflammation without spoiling the reproductive outcome: evidence from a large cohort study

PURPOSE OF INVESTIGATION

The aim of this study was to investigate if vaginal preparation procedure affects the occurrence of oocyte pickup-associated pelvic inflammation (OPU-PI) and the reproductive outcome in an in vitro fertilization (IVF) program.

MATERIALS AND METHODS

The occurrence of OPU-PI and the reproductive outcome were compared between 956 infertile patients undergoing vaginal preparation with saline douching alone versus 1,216 infertile patients undergoing a combination ofpovidone iodine disinfection and subsequent saline douching in an IVF program.

RESULTS

OPU-PI occurred in four patients (0.042%) in the saline douching alone group, whereas there were no cases in the combination group (p = 0.016). There were no significant differences in the rate of fertilization, morphologically good embryo acquisition, clinical and ongoing pregnancy between the two groups (p > 0.23).

CONCLUSIONS

This large cohort study demonstrated that a combination of vaginal povidone iodine disinfection and subsequent saline douching is more effective procedure than saline douching alone to prevent OPU-PI, without spoiling the oocyte quality.

Primary low-grade B-cell lymphoma in mucosa-associated lymphoid tissue of the lung

A 67-year-old asymptomatic woman was referred to our department for treatment for a left lung tumor. The tumor was 40 mm in diameter and was present in the left lower lobe. A primary low-grade B-cell lymphoma in the mucosa-associated lymphoid tissue of the lung was suspected after a trans-bronchial lung tissue biopsy. Systemic screening revealed no other organ involvement, and the tumor was considered to be a primary lung tumor. A left lower lobectomy with hilar and mediastinal lymph node sampling was performed. Pathological examination revealed centrocyte-like cells that expressed CD20. These cells had invaded the bronchiolar epithelium to form lymphoepithelial lesions. The pathological diagnosis was confirmed to be primary low-grade B-cell lymphoma in the mucosa-associated lymphoid tissue of the lung. The origin of this tumor type in the lung is relatively rare.

Malignant transformation of a giant cell tumor 25 years after initial treatment

The current authors report a patient in whom a malignant fibrous histiocytoma developed long after a benign giant cell tumor of bone was removed from the same site. Twenty-five years after a benign giant cell tumor of the lateral condyle of the proximal tibia had been treated by curettage and iliac bone grafting without radiotherapy, a 53-year-old woman noted progressive pain and an enlarging mass in the same area. Radiographs showed osteolytic change, whereas magnetic resonance imaging indicated a tumor arising at the site of the giant cell tumor and extending beyond the bone. Examination of an open biopsy specimen showed a high-grade malignant fibrous histiocytoma with some areas rich in giant cells. After five courses of caffeine assisted intraarterial chemotherapy, the tumor was resected with an adequate margin, and the defect was reconstructed with an implanted prosthesis of corresponding shape. The extensor mechanism of the knee was reinforced using an allograft of fascia from the tensor fascia lata muscle. The resected specimen showed a good histologic response (95% tumor necrosis) to preoperative chemotherapy. Excellent function in the knee has been regained with no evidence of disease recurrence. Caffeine potentiated chemotherapy was effective in minimizing the extent of tumor excision, in this case of high-grade malignant fibrous histiocytoma representing transformation from a benign giant cell tumor.

Chlamydia pneumoniae in coronary and iliac arteries of Japanese patients with atherosclerotic cardiovascular diseases

Recent studies suggest the association of atherosclerotic cardiovascular diseases with Chlamydia pneumoniae infection in western populations. It is of great interest whether such an association exists in Asians with their distinct genetic background. Symptomatic patients with coronary heart disease (29) or arteriosclerosis obliterans (10) who underwent directional endo-atherectomy were studied. Atherectomy specimens of coronary and iliac arteries were examined for C. pneumoniae by culture, nested PCR and immunohistochemical stain (IHC) with one Chlamydia genus-specific, two C. pneumoniae species-specific, and two C. trachomatis species-specific monoclonal antibodies. Among the 29 patients with coronary artery disease, C. pneumoniae was detected in the coronary arteries of 13 by IHC, 16 by PCR and 20 by IHC or PCR, or both. C. pneumoniae was also found in the iliac arteries of four patients by IHC, three by PCR and five by IHC or PCR, or both, of the 10 patients with arteriosclerosis obliterans. Attempts to isolate C. pneumoniae by culture were unsuccessful. The re-stenotic rate after atherectomy was higher in the C. pneumoniae-positive group than in the negative group, but not significantly so. These findings support the high incidence of C. pneumoniae in atherosclerotic lesions of symptomatic patients with coronary heart disease and arteriosclerosis obliterans in Asians.

Increased release of nitric oxide in ischemic hearts after exercise in patients with effort angina

OBJECTIVES

The aim of this study was to determine whether the release of nitric oxide (NO) from the ischemic heart increases during exercise in patients with effort angina.

BACKGROUND

Myocardial ischemia increases NO production in the canine heart, but no such increase has been demonstrated in the ischemic human heart.

METHODS

Fifteen patients with effort angina underwent supine ergometer exercise tests. All patients had severe proximal stenosis (>90%) in the left anterior descending coronary artery. The control group consisted of 17 subjects without coronary artery disease or systemic hemodynamic abnormalities.

RESULTS

Neither the lactate extraction ratio (LER) nor the difference in NO concentration between coronary venous and arterial blood (deltaVA[NO]) was affected by exercise in the control subjects. In patients with effort angina, neither variable differed from that in the control group at rest; however, exercise markedly decreased LER and significantly increased deltaVA(NO) (from 4.7 +/- 0.3 to 16.5 +/- 1.6 micromol/liter, p < 0.001) in the patient group. The extent of decrease in LER was significantly correlated with the extent of increase in deltaVA(NO) in the patients with effort angina (r2 = -0.837, p < 0.001).

CONCLUSIONS

Provocation of myocardial ischemia by exercise stress increases NO production in the hearts of patients with effort angina.

Acid-tolerance response in Helicobacter pylori and differences between cagA+ and cagA- strains

Helicobacter pylori cagA transcription and translation are maximal at pH 6 in stationary phase. The aim of this study was to determine whether H. pylori has an acid-tolerance response and whether that response is related to CagA expression, by investigating whether preexposure to pH 5 or 6 improved survival of cells subsequently exposed to pH 3. Cell number was determined after broth growth, after exposure to pH 5, 6, or 7, and then after a 30-min exposure to pH 3 without urea. H. pylori cells preexposed to pH 6 or 5 survived pH 3 exposure 100-fold better than did cells preexposed to pH 7. Cells of cagA+ strains grown at pH 6 for 48 h, which induced maximal CagA expression, were significantly more susceptible to pH 3 than were wild type cagA- strains or isogenic cagA- knockouts. Thus, H. pylori strains possess a urea-independent acid-tolerance response. Differential acid susceptibility may contribute to preferential colonization of particular H. pylori strains in specific mucus layer niches.

Appearance of a metronidazole-resistant Helicobacter pylori strain in an infected-ICR-mouse model and difference in eradication of metronidazole-resistant and -sensitive strains

We tested whether antibiotic-resistant strains appeared in vivo after the failure of treatment using the Helicobacter pylori-infected euthymic mouse model. The numbers of colonies isolated from 56 ICR mice 2 weeks after 4 days of treatment with metronidazole (3.2, 10, or 32 mg/kg of body weight) or amoxicillin (1, 3.2 or 10 mg/kg), with treatment started 4 days after H. pylori CPY2052 inoculation, were counted, and the isolated strains were tested for their sensitivities to two antibiotics to rule out the presence of antibiotic-resistant strains. One metronidazole-resistant strain was detected in a mouse treated with 10 mg of metronidazole per kg, and the MIC of metronidazole for this strain was 25 microg/ml, compared to a MIC of 1.56 microg/ml for the original strain. However, no resistant strain was detected in the amoxicillin treatment group. After the examination described above, mice challenged with a metronidazole-resistant or -sensitive strain isolated from the stomach of a mouse were treated with metronidazole or amoxicillin. The metronidazole-resistant strain was more difficult to eradicate in vivo than the sensitive strain after treatment with metronidazole but not after treatment with amoxicillin. Thus, a metronidazole-resistant H. pylori strain was selected by insufficient treatment, but no resistant strain was selected with amoxicillin. Eradication of a metronidazole-resistant H. pylori strain in vivo required a higher dosage than eradication of a metronidazole-sensitive H. pylori strain. These results may explain one of the reasons for H. pylori treatment failure.

Characterization of Helicobacter pylori dapE and construction of a conditionally lethal dapE mutant

Helicobacter pylori colonizes the human gastric mucosa and causes gastritis, ulceration, or gastric cancer. A previously uncharacterized region of the H. pylori genome was identified and sequenced. This region includes a putative operon containing three open reading frames termed gidA (1,866 bp), dapE (1,167 bp), and orf2 (753 bp); the gidA and dapE products are highly homologous to other bacterial proteins. In E. coli, dapE encodes N-succinyl-L-diaminopimelic acid desuccinylase, which catalyzes the hydrolysis of N-succinyl-L-diaminopimelic acid to L-diaminopimelic acid (L-DAP) and succinate. When wild-type H. pylori strains were transformed to select for dapE mutagenesis, mutants were present when plates were supplemented with DAP but not with lysine; orf2 mutants were selected without DAP supplementation. Consistent with the finding that GidA is essential in Escherichia coli, we were unable to obtain a gidA mutant in H. pylori despite evidence that insertional mutagenesis had occurred. The positions of gidA, dapE, and orf2 suggest that they form an operon, which was supported by slot blot RNA hybridization and reverse transcriptase PCR studies. The data imply that the H. pylori dapE mutant may be useful as a conditionally lethal vaccine.

Respiratory oxygen cost for dead space challenge is characteristically increased during exercise in patients with chronic heart failure: does it further decrease exercise capacity?

BACKGROUND

Although the work of the respiratory muscles is markedly increased during exercise in patients with chronic heart failure, the role of this abnormality in exercise intolerance is still controversial. This issue may be clarified directly by dead space challenge, as this technique increases minute ventilation. Therefore, in this study, the effects of an external dead space on exercise ventilation, gas exchange data, and exercise capacity in patients with chronic heart failure were examined.

METHODS AND RESULTS

Dead space challenge was performed by adding an external dead space to the airway in 20 patients with chronic heart failure and 10 normal subjects. Two hours after completion of the control maximal bicycle exercise, the second exercise was performed under application of an external dead space equivalent to 10% of peak tidal volume. Respiratory gas exchange data were collected during exercise. Aerobic exercise capacity was assessed from the exercise time and the time to anaerobic threshold. The sensation of exertional dyspnea was assessed using Borg's rating scale. As compared with data during the control exercise, minute ventilation was increased by approximately 25% with the external dead space throughout exercise in both groups. A parallel 20% increase in systemic oxygen uptake was observed in the heart failure group, likely reflecting an increase in respiratory muscle work. This response was not observed in the normal group. Despite an additional increase in respiratory muscle work, neither aerobic exercise capacity nor exertional dyspnea was exacerbated in the heart failure group by the external dead space.

CONCLUSIONS

Dead space challenge appears to be a unique technique that characteristically increases the work of respiratory muscles during exercise in patients with chronic heart failure. By use of this technique, it was demonstrated that an increase in respiratory muscle work is not important in reducing exercise capacity of patients with chronic heart failure.

Induction of ulceration and severe gastritis in Mongolian gerbil by Helicobacter pylori infection

Specific pathogen-free Mongolian gerbils were infected orally with Helicobacter pylori to establish a new small animal model of severe gastritis H. pylori was recovered by culture from both antrum and body over a 16-week period after a single inoculation. The number of H. pylori colonising the antrum was about 100-fold higher than in the body, and this was consistent throughout the experiment. Histological examination showed that all animals developed severe inflammation with infiltration of polymorphonuclear leucocytes and mononuclear cells into the lamina propria and submucosa of the antrum from 4 weeks after infection. From 8 weeks after infection, multifocal lymphoid follicles appeared in the lamina propria and submucosa, and micro-erosions were also observed in the epithelial layer. At 16 weeks after infection, ulceration with disruption of the lamina muscularis mucosae was observed in the antral mucosa. To determine whether H. pylori caused gastritis or not, infected gerbils were treated with amoxycillin. After the treatment, gastritis could not be seen in the gastric mucosa. Therefore, the Mongolian gerbil is a useful small animal model to study the pathogenesis of H. pylori in gastric ulceration and severe gastritis and to assess anti-H. pylori treatment.

Effect of acute dynamic exercise on circulating plasma nitric oxide level and correlation to norepinephrine release in normal subjects

Physical exercise increased the levels of the end product of nitric oxide in normal subjects. The increased nitric oxide may contribute to vasodilation during exercise.

Studies on the response of nitroglycerin oral spray compared with sublingual tablets for angina pectoris patients with dry mouth. A multicenter trial

Nitroglycerin (glyceryl trinitrate, CAS 55-63-0, NTG) administered with an oral spray may be more effective in relieving anginal pain than sublingual tablets especially when the patient's mouth is dry. In this study, the effect of a NTG oral spray (Myocor Spray) on exercise-induced angina was compared with that of a sublingual tablet in relation to the oral dryness. In 17 patients with effort angina, graded bicycle exercise was performed twice at an interval of one week. Exercise was discontinued upon the onset of moderate anginal pain. Immediately after exercise, the oral dryness was evaluated by touching the tip of the tongue with a blotting paper for a moment. Then, 0.3 mg of NTG was administered by either a squirt of spray or a sublingual tablet in a randomized crossover fashion. Exercise results were reproducible between two exercise tests. According to the extent of the wet area of the blotting paper, the subjects were divided into two groups. In 7 patients of the wet group, the remission times of chest pain and ST segment depression were not significantly different by the formulation of NTG. In 10 patients of the dry group, however, both chest pain and ST depression more rapidly recovered with use of the oral spray (p < 0.05 and p < 0.05, respectively). These results strongly suggest that the NTG oral spray is superior to the sublingual tablet in relieving anginal attacks, when the oral wetness is decreased.

In vitro evaluation of linear motor-driven total artificial heart

This paper deals with the in vitro evaluation of a newly developed linear motor-driven total artificial heart (linear TAH). The linear TAHs have been developed and evaluated in mock testing and acute animal experiments. The new linear TAH was made based on experience with acute animal experiments. The maximum static thrust of the new linear pulse motor is 146 N with exciting current of 1.69 A. The weight and the volume of this linear TAH are 1.9 kg and 560 ml, respectively. The linear TAH has a kinetic thrust of 85 to 43 N and provides the maximum flow rate of 6.8 L/min in mock circulatory testing.

Expression of the human cell surface glycoconjugates Lewis x and Lewis y by Helicobacter pylori isolates is related to cagA status

Monoclonal antibodies were used in an enzyme-linked immunosorbent assay for the detection of human Lewis immunodeterminants in the lipopolysaccharide of Helicobacter pylori. In 94 H. pylori isolates, expression of Lewis(x) (Le(x)) and Le(y) was a stable phenotypic marker independent of the growth medium and cell age; 46 (49%) of the isolates expressed both and 34 (36%) of the isolates expressed either Le(x) or Le(y); 14 (15%) were negative for both determinants. Twelve (13%) isolates expressed Le(b), 3 (3%) expressed Le(a), and 2 (2%) expressed sialyl-Le(x). H. pylori isolates positive for both Le(x) and Le(y) were predominantly cagA+ (P < 0.001) and possessed the s1 signal sequence (P < 0.05) and the m1 midregion type (P = 0.033) of vacA. Isogenic mutants of H. pylori CPY3401 were created by interruption of the cagA, picB, or ureA gene. The cagA-ablated strain (but not the picB- and ureA-ablated mutant strains) had significantly (P < 0.01) diminished expression of Le(y) compared with that of the wild-type strain; for all four strains, expression of Le(x) was similar. In conclusion, 89% of H. pylori isolates express Le determinants in their lipopolysaccharide, mimicking human cell surface glycoconjugates. Strong expression of Le(x) and Le(y) by cagA+ isolates could counterbalance their enhanced proinflammatory activities and thereby facilitate persistence.

Effect of growth phase and acid shock on Helicobacter pylori cagA expression

Helicobacter pylori strains possessing cagA are associated with peptic ulceration. To understand the regulation of expression of cagA, picB, associated with interleukin-8 induction, and ureA, encoding the small urease subunit, we created gene fusions of cagA, ureA, and picB of strain 3401, using a promoterless reporter (xylE). Expression of XylE after growth in broth culture revealed that basal levels of expression of cagA and urea in H. pylori were substantially greater than for picB. For cagA expression in stationary-phase cells, brief exposure to acid pH caused a significant increase in xylE expression compared with neutral pH. In contrast, expression of xylE in urea or picB decreased after parallel exposure to acid pH (pH 7 > 6 > 5 > 4), regardless of the growth phase. Expression of the CagA protein varied with growth phase and pH exposure in parallel with the observed transcriptional variation. The concentration of CagA in a cell membrane-enriched fraction after growth at pH 6 was significantly higher than after growth at pH 5 or 7. We conclude that the promoterless reporter xylE is useful for studying the regulation of gene expression in H. pylori and that regulation of CagA production occurs mainly at the transcriptional level.

Diagnostic utility of 20-megahertz linear endoscopic ultrasonography in early gastric cancer

BACKGROUND

Because of the widespread endoscopic treatment of early gastric cancer (EGC), accurate pretherapeutic staging of the invasion depth of EGC differentiating those limited within the mucosa from cancers invading the submucosa has become important.

METHODS

We staged the depth of tumor invasion of 47 lesions of EGC using 20 MHz linear endoscopic ultrasonography (EUS). The EUS probe was introduced via the instrument channel of a standard endoscope.

RESULTS

The accuracy of 20 MHz EUS in staging the mucosa or submucosa was 72.3%. There was 19.1% overstaging, 2.1% understaging, and 6.4% indeterminant. The principal causes of errors were inflammation associated with ulcers, benign cystic glands in the submucosal layer, and attenuation of the high-frequency ultrasound beam.

CONCLUSIONS

20 MHz EUS is useful in the pretherapeutic staging of EGC.

Distribution of inflammation and atrophy in the stomach of Helicobacter pylori-positive and -negative patients with chronic gastritis

OBJECTIVES

To investigate the extent of inflammation and atrophy in the stomach of Helicobacter pylori-positive and -negative patients with chronic gastritis.

METHODS

Endoscopy with biopsies from the lesser curvatures of the antrum, angulus, middle body, and the greater curvature of the middle body of the stomach was performed in 59 patients with histologically confirmed chronic gastritis. The extent of atrophic gastritis was assessed endoscopically as well histologically. H. pylori status was assessed by histology as well as enzyme-linked immunosorbent assay. The histological severity of chronic and acute inflammation, glandular atrophy, and intestinal metaplasia was assessed according to the Sydney system.

RESULTS

In H. pylori-positive patients, H. pylori was evenly distributed throughout the stomach when the extent of atrophic gastritis was limited to the antrum and the lesser curvature of the body, but disappeared from the antrum of patients with more extensive atrophic gastritis. The severity of acute and chronic inflammation at the greater curvature of the body increased with the extension of atrophic gastritis. In H. pylori-negative patients, the severity of chronic inflammation at the greater curvature of the body was significantly higher in patients with extensive atrophic gastritis than in those with a lesser extent of atrophic gastritis.

CONCLUSION

At the greater curvature of the body, the development of atrophy is closely associated with the increase in the severity of inflammation, which is more marked in H. pylori-positive patients.

Pharmacological effects of concomitant administration of beta-adrenoceptor blocker and agonist in normal subjects: characterization by heart rate response to exercise. Effects of beta-blocker combined with beta-agonist

The effects of a combination regimen of metoprolol and beta 1-adrenoceptor agonist denopamine on resting and exercise heart rate have been studied in 10 normal volunteers. Maximal ramp upright bicycle exercise was performed three times at 1-week intervals. Two hours before each exercise test, 5 mg metoprolol plus 20 mg denopamine, 5 mg metoprolol plus a denopamine placebo, or two placebos were orally administered in a double-blind fashion. During exercise after placebo administration, heart rate increased in parallel with the exercise intensity. Compared to the placebo values, resting heart rate was significantly decreased by an average of 10 beats.min-1 by 5 mg metoprolol, whereas it was not altered by the combination regimen. During exercise, however, both the combination regimen and metoprolol alone showed a significant negative chronotropic effect, decreasing peak exercise heart rate by an average of 14 and 21 beats.min-1, respectively. Peak oxygen uptake was also significantly decreased by both regimens. We conclude that concomitant administration of 5 mg metoprolol and 20 mg denopamine exerts an effective beta-adrenoceptor blocking action during exercise but a minimal effect at rest in normal subjects. The combination regimen appears to have a favourable pharmacological profile for beta-adrenoceptor blocker therapy in patients with chronic heart failure.

Analysis of strains of Burkholderia (Pseudomonas) cepacia isolated in a nosocomial outbreak by biochemical and genomic typing

We analyzed strains of Burkholderia (formerly Pseudomonas) cepacia isolated in a nosocomial outbreak by biochemical and genomic typing methods. One hundred isolates of B. cepacia were obtained from patients at several wards in a single hospital from March 1983 to February 1984. These isolates were classified into 12 groups by a new biochemical typing scheme on the basis of the production of six enzymes and the production of hemolytic substance and yellow pigment. Among them, 33 strains collected from the 12 groups were further characterized by DNA fingerprinting by pulse-field gel electrophoresis, ribotyping, and plasmid profile analysis. Forty-seven strains of B. cepacia of independent origins and 25 isolates from the same hospital obtained 10 years later for a follow-up study were also subjected to analysis. Both DNA fingerprinting and ribotyping clearly discriminated the isolates from different hospitals. Of interest, although the biochemical typing and plasmid profiles of the isolates obtained during 1983 to 1984 in a single hospital were variable, genomic typing identified the majority of the isolates (32 of 33 [97%]) as derivatives of a single strain. Furthermore, a follow-up study suggested the persistence of such derivatives among the isolates after a decade. These results clearly indicated that the outbreak of B. cepacia infection in the hospital was nosocomial in origin. Thus, the usefulness of genomic typing for epidemiological studies of B. cepacia infection was further demonstrated. The biochemical typing revealed the marked variability of phenotypes of B. cepacia.

Evaluation of a new bismuth-free triple therapy in nude mice and humans

OBJECTIVES

To evaluate the efficacy of a new triple therapy (amoxycillin, metronidazole, plaunotol) in eradicating Helicobacter pylori in a nude mouse model and in humans.

MATERIALS AND METHODS

In an animal study we used 215 nude mice infected with H. pylori to assess the ability of single, dual and triple therapy to eradicate H. pylori from the mouse stomach. The number of H. pylori in the mouse stomach and extent of the gastritis was assessed from 1 to 4 weeks after treatment. In a human study, we enrolled 78 H. pylori-positive patients with recurrent peptic ulcer diseases, 29 of whom were given triple therapy (amoxycillin and metronidazole for 1 week and plaunotol for 4 weeks). Patients in the control group (n = 49) were given a histamine H2-receptor antagonist. All patients were assessed 5 and 11 months after completion of therapy.

RESULTS

In the mouse model, both the number of H. pylori and the gastritis score were significantly lower in the triple therapy group than in any other treatment group assessed 1-4 weeks after completion of therapy. In the human study, the triple therapy eradicated H. pylori from the stomachs of 25 out of 29 patients (86%), compared to the control group in which none of the 49 patients were free of H. pylori in the stomach 11 months after completion of therapy. There were no reported side effects with this triple therapy. None of the H. pylori-eradicated patients showed a recurrence of peptic ulcer disease; three of the four patients whose H. pylori was not eradicated by triple therapy showed a peptic ulcer recurrence within the study period, whereas 16 out of 49 patients in the control group had a peptic ulcer recurrence.

CONCLUSIONS

This new triple therapy was effective in the eradication H. pylori, had very few side effects and greatly reduced the rate of recurrent peptic ulcers.

Detection and identification of cagA of Helicobacter pylori by polymerase chain reaction

AIM

To investigate cagA, which is linked to vacuolating cytotoxin activity of Helicobacter pylori, using molecular techniques.

MATERIALS AND METHODS

A polymerase chain reaction method was used to detect cagA from clinical isolates of H. pylori. H. pylori strain diversity was examined by DNA restriction fragment length polymorphism (RFLP) patterns with cagA as a probe.

RESULTS

The detection rate of the cagA products was significantly higher in strains from gastric ulcer patients than in those of chronic gastritis patients (78.9 versus 56.0%; P < 0.05), and RFLP patterns were different between gastric ulcer and gastric cancer strains.

CONCLUSIONS

A polymerase chain reaction method established for the detection of cagA proved to be rapid and useful. Analysis of cagA may therefore be a useful genetic technique for the study of strain diversity.

Essential role of Helicobacter pylori urease in gastric colonization: definite proof using a urease-negative mutant constructed by gene replacement

OBJECTIVE

To investigate the involvement of urease in Helicobacter pylori colonization in the nude mouse stomach by using a genetically defined urease-negative mutant.

METHODS AND RESULTS

Through electroporation-mediated gene replacement, one of the urease genes of an H. pylori strain, CYP3401, was disrupted by insertion of a kanamycin-resistance determinant to construct a stable urease-negative mutant, HPT73. Southern analysis confirmed that gene replacement was achieved. The two isogenic strains were introduced into the stomachs of nude mice, and the number of H. pylori and the histological changes in the stomachs were investigated 1 or 4 weeks after the challenge. Gastritis was present in the CPY3401-challenged stomach, from which bacteria indistinguishable from CPY3401 were successfully recovered. In contrast, no gastritis was found in the HPT73-challenged stomach, and H. pylori was not recovered from these stomachs.

CONCLUSION

H. pylori urease is essential for colonization of the nude mouse stomach.

Growth medium containing cyclodextrin and low concentration of horse serum for cultivation of Helicobacter pylori

The growth of Helicobacter pylori, a Gram-negative microaerophilic bacterium, is often difficult and requires complex media with the supplementation of 5% to 10% blood or blood derivatives. We have found that Brucella broth supplemented with 1% heated horse serum and 0.1% beta-cyclodextrin supports the good growth of H. pylori. The degree of growth and production of urease and vacuolating cytotoxin in this medium were equal to those in the medium supplemented with 5% horse serum. This medium was found to be suitable for both the routine laboratory culture and primary isolation of H. pylori from biopsy samples.

Long-term clinical effect of nilvadipine in patients with chronic heart failure: a double-blind placebo-controlled study

The long-term effect of calcium channel blockers on chronic heart failure is disappointing, probably because of reflex sympathetic activation through arterial vasodilation. However, nilvadipine may be beneficial for treatment of chronic heart failure since this drug has minimal effects on sympathetic activation. In this study, the effects of 12-week administration of nilvadipine or placebo on symptoms of heart failure and cardiac function were investigated in 23 patients with mild-to-moderate chronic heart failure in a double-blind trial. The patients were randomly assigned to either a nilvadipine group (16 mg daily) or a placebo group. Intergroup comparisons did not show significant differences in any parameters. Serious adverse effects were not observed during the study. Thus, this study failed to show any beneficial effect of nilvadipine in the long-term treatment of patients with chronic heart failure. We conclude that the long-term administration of nilvadipine (16 mg daily) is neither effective nor harmful in the treatment of patients with chronic heart failure.

A urease-negative mutant of Helicobacter pylori constructed by allelic exchange mutagenesis lacks the ability to colonize the nude mouse stomach

The urease of Helicobacter pylori has been proposed to be one of its pathogenic factors. A kanamycin resistance determinant was inserted in a cloned urease gene, and transformation-mediated allelic exchange mutagenesis was carried out to introduce the disrupted gene into the corresponding wild-type chromosomal region of a clinical isolate of H. pylori, CPY3401. The resulting mutant, HPT73, had the null activity of urease. Nude mouse stomachs were challenged with these two isogenic strains to examine the role of urease in pathogenesis. Gastritis was found in the CPY3401-challenged stomachs, from which bacteria indistinguishable from CPY3401 were recovered. There was no gastritis in the HPT73-challenged stomachs, and we could not recover H. pylori from them. These results indicated that H. pylori urease is essential for colonizing the nude mouse stomach.

Bismuth-free triple therapy for eradicating Helicobacter pylori and reducing the gastric ulcer recurrence rate

OBJECTIVES

The goals of this study were to assess the effectiveness of a new triple therapy consisting of amoxicillin and metronidazole with plaunotol in the eradication of Helicobacter pylori infection in humans, and to determine whether this treatment regimen reduces the rate of recurrence of gastric ulcer in patients infected with H. pylori, without instituting maintenance therapy with H2-receptor antagonists.

METHODS

Thirty patients with active gastric ulcer who were infected with H. pylori were first treated with omeprazole until scarring occurred. Patients then received plaunotol for 4 wk, with amoxicillin and metronidazole for 7 days.

RESULTS

This triple therapy resulted in the safe eradication of H. pylori in 26 (86.7%) of 30 patients, with no recurrence of ulcer seen during a 12-month follow-up period in patients who tested negative for the presence of H. pylori. In addition, histological inflammatory changes improved in these patients. Of the four patients with persistent H. pylori infection, in three (75%), ulcers recurred.

CONCLUSION

This new triple therapy was very effective in eradicating H. pylori in infected patients and in reducing the rate of recurrence of gastric ulcer in these patients.

Prevalence of Chlamydia pneumoniae in acute lower respiratory infection in the pediatric population in Japan

Chlamydia pneumoniae has been established as an important etiologic agent of acute respiratory tract infection in humans, especially in adults. However, there is little information available on C. pneumoniae infection in the pediatric age group. The microimmunofluorescence test and Chlamydia pneumoniae-specific polymerase chain reaction (PCR) method were applied to reveal the role of C. pneumoniae as an etiologic agent of acute lower respiratory tract infection in children in Japan. Among 136 patients aged between 2 months and 15 years with acute lower respiratory tract infection, five patients with pneumonia were found to have recent C. pneumoniae infection by the microimmunofluorescence test. C. pneumoniae-specific PCR products were detected from specimens of four patients among these five. Neither C. trachomatis nor C. psittaci infection was found in this population. These results suggest that C. pneumoniae is an important causative agent of acute childhood pneumonia and may be the most prevalent pathogen among the genus Chlamydia that causes acute lower respiratory disease in this age group in Japan.

Establishment of a small animal model for human Helicobacter pylori infection using germ-free mouse

OBJECTIVE

To understand why oral inoculation of Helicobacter pylori resulted in continuous colonization of the stomach in germ-free athymic mice, but only temporary colonization in mice that were not germ-free.

METHODS

We inoculated germ-free and "not-germ-free" euthymic mice with H. pylori and studied the resulting colonization of the stomach, comparing it against the germ-free athymic mouse model. In addition, we investigated Lactobacillus in the above-described three mouse groups.

RESULTS

H. pylori were detected in all germ-free athymic mice and all germ-free euthymic mice continuously. However, in all euthymic mice that were not germ-free, H. pylori was detected only temporarily after inoculation. Lactobacilli were detected only in the not-germ-free mouse group. The number of H. pylori in the germ-free euthymic mice was significantly lower than in the germ-free athymic mice during the period of this study after inoculation.

CONCLUSIONS

We therefore suggest that the growth of H. pylori may be suppressed by the immunological system and eradicated by Lactobacilli previously inhabiting the stomach.

[Restriction endonuclease (NotI) analysis of chromosomal DNA of Helicobacter pylori by PFGE]

With the goal of differentiating H. pylori in order to clarify its pathogenicity, we have conducted a restriction endonuclease of the chromosomal DNA of 24 strains of H. pylori employing the restriction endonucleases, NotI, CPOI, KpnI, and SmaI using pulsed-field gel electrophoresis (PFGE). With NotI, these 16 strains out of 24 strains were completely digested, and 16 clearly different electrophoretic patterns of NotI digested chromosomal DNA fragments were seen, permitting us to successfully differentiate H. Pylori. We also estimated the genome size of each strain, ranging from 1326 to 2360 kilobases. Using this method, we confirmed our previously established nude mouse model of infection with H. pylori by demonstrating that the mice were infected with the H. pylori administered in this study. Thus, we have demonstrated the digested with NotI by PFGE is an effective method for differentiating H. pylori and estimating the size of DNA of H. pylori.

Evaluation of new therapy for eradication of H. pylori infection in nude mouse model

OBJECTIVES

developing a new therapy for eradication of H. pylori by using the nude mouse model.

METHODS

By quantifying the number of colonies of Helicobacter pylori and the score of H. pylori-associated gastritis from the gastric tissue following different drug regimens in inoculated nude mice, we evaluated the effectiveness of each regimen, including a new drug, plaunotol. Drugs were administered daily for a 1-wk period, beginning 4 wk after inoculation.

RESULTS

In the examination after therapy, the number of colonies of H. pylori and the score of gastritis in the triple-therapy group were significantly lower than in any of the singly- and dual-drug groups or control group from 5 wk to the end of the study after inoculation. Inflammation of the stomach was less apparent in the treatment groups than in the control group.

CONCLUSION

With the nude mouse model, we quantitatively demonstrated that the new triple therapy is the most effective therapy for eradication of H. pylori.

Endoscopic diagnosis and resection treatment for flat adenoma with severe dysplasia

In a prospective study from 1988 to 1991, we discovered 31 flat colon adenomas in 29 patients and performed endoscopic resection of 27 of these lesions, using the strip biopsy technique. All of these lesions were safely and completely resected even in the thin walls of the colon. All 27 lesions were histologically flat adenomas confined to the mucosa, with a maximum diameter of 3-20 mm. Thirteen were identified as severe dysplasia, three as moderate dysplasia, and 11 as mild dysplasia. These lesions were more clearly defined after they were sprayed with indigo carmine endoscopically. The 13 flat adenomas with severe dysplasia were morphologically slightly depressed red lesions with elevation of the surrounding mucosa (six lesions) and flat round red lesions with no changes in the surrounding mucosa (seven lesions). Due to the high incidence of severe dysplasia found in flat adenomas, removal using strip biopsy is recommended.

Delineation of the gastric muscularis mucosae and assessment of depth of invasion of early gastric cancer using a 20-megahertz endoscopic ultrasound probe

Using a 20 MHz endoscopic ultrasound system, delineation of the gastric muscularis mucosae and estimation of the depth of malignant invasion was attempted by in vivo scanning during the process of routine endoscopic observation or in vitro scanning of excised sections of 34 early gastric cancers in 32 patients. The muscularis mucosae was visualized as a single hypoechoic layer in 16 of 32 lesions (50%) scanned in vitro. Comparison of lesions in which delineation of the muscularis mucosae was or was not possible revealed no significant differences with respect to either the thickness of the lamina propria and muscularis mucosae or with respect to the degree of inflammatory cell infiltration of the lamina propria or the conditions of the boundary between the lamina propria and the muscularis mucosae. This indicates that improvement of the operability characteristics of the ultrasonic apparatus will be needed to achieve improved delineation of the muscularis mucosae. The accuracy of invasion depth estimation of early gastric cancer was 67% (16 of 24 lesions scanned in vivo) and 73% (8 of 11 lesions) in cases in vivo where the muscularis mucosae and the tumor were delineated on the same screen. The principal factors causing erroneous staging were the presence of dilated benign glandular ducts, ulcer scars, and attenuation of the ultrasound waves.

Genetic transformation in Helicobacter pylori

Genetic transformation in Helicobacter pylori was investigated by using its chromosomal and plasmid DNAs. Six out of the eight strains exhibited the natural competence for incorporation of H. pylori chromosomal DNA, and all the strains incorporated the donor DNA efficiently by washing and concentrating the cells with a glycerol solution. The much higher frequency of transformation was obtained in each strain by means of electroporation. Electroporation experiments were also conducted by use of the recombinant DNAs consisting of the H. pylori and Escherichia coli plasmids as the donors, and the occurrence of the homologous recombination was demonstrated between the incoming H. pylori plasmid-derived region and the corresponding region of the originally residing plasmid in H. pylori.

Application of ultrasonic probes prior to endoscopic resection of early gastric cancer

The development of a new strip biopsy technique for endoscopic mucosectomy utilizing endoscopic saline injection and a double-channel endoscope permits the safe and simple resection of superficial type early gastric cancer which has been difficult to perform with conventional polypectomy techniques. Preresection assessment of the depth of invasion and postresection assessment of efficacy are important with regard to treatment of early gastric cancer, but conventional endoscopic ultrasonography employed for this purpose requires special equipment and involves intricate procedures. An ultrasonic probe which can be used endoscopically has recently been developed and is currently in the trial stage. The authors have conducted studies with respect to a 7.5 MHz radial scanning type Miniature Ultrasonic Probe as well as a 20 MHz manual linear scanning type Sonoprobe System. Experimental studies indicated that the former type is capable of delineating postresection ulcers, while the latter permitted delineation of tumors as hypoechoic images in 9 of 11 cases of early gastric cancer.