Non-telecentric two-photon microscopy for 3D random access mesoscale imaging

Diffraction-limited two-photon microscopy permits minimally invasive optical monitoring of neuronal activity. However, most conventional two-photon microscopes impose significant constraints on the size of the imaging field-of-view and the specific shape of the effective excitation volume, thus limiting the scope of biological questions that can be addressed and the information obtainable. Here, employing a non-telecentric optical design, we present a low-cost, easily implemented and flexible solution to address these limitations, offering a several-fold expanded three-dimensional field of view. Moreover, rapid laser-focus control via an electrically tunable lens allows near-simultaneous imaging of remote regions separated in three dimensions and permits the bending of imaging planes to follow natural curvatures in biological structures. Crucially, our core design is readily implemented (and reversed) within a matter of hours, making it highly suitable as a base platform for further development. We demonstrate the application of our system for imaging neuronal activity in a variety of examples in zebrafish, mice and fruit flies.

Abstract P4-02-10: Breast cancer surveillance in high-risk women with dynamic contrast-enhanced magnetic resonance imaging every 6 months: Results from a single institution study

Purpose: To develop a novel approach for early detection of breast cancer and examine molecular features of screen detected cancers in prospectively ascertained high-risk women undergoing semi-annual dynamic contrast-enhanced breast magnetic resonance imaging (DCE-MRI) for women at high genetic risk.

Background: Women with a personal or family history of breast cancer and genetic mutation carriers of BRCA1 and BRCA2 have a higher than normal risk of breast cancer. An intensified screening surveillance regimen is an early detection strategy in high-risk women. The American Cancer Society recommends annual DCE-MRI in addition to annual mammogram based off several pivotal screening studies that demonstrated improved sensitivity and cancer detection rates and decreased interval cancer rates with the addition of annual DCE-MRI. Questions remain regarding the optimal screening modality and interval regimen in these high-risk women.

Methods: Between 2004 and 2016, we assembled a prospective cohort of high-risk women undergoing semi-annual DCE-MRI and annual mammography. To be eligible, women had a lifetime breast cancer risk >20% and/or tested positive for a pathogenic mutation using a cancer gene panel including BRCA1, BRCA2, CDH1, PALB2, CHEK2 and other cancer susceptibility genes in the DNA repair pathway. Somatic mutation events in screen-detected tumors were investigated using UW-OncoPlex cancer gene panel using DNA extracted from FFPE shavings.

Results: 295 women were recruited to the study; 44% of the study participants had pathogenic mutations in BRCA1 or BRCA2 genes. At a median follow-up of 3.3 years (range 0-12 years), 3 DCIS and 13 early stage invasive breast cancers were detected, of which 14 occurred in subjects with identifiable pathogenic mutations (11 BRCA1, 2 BRCA2, 1 CDH1). The incidence rate is 1.3% in all subjects, but 3.5 % per year in BRCA1 carriers. DCE-MRI identified all 13 invasive cancers at a mean size of 0.61 cm (range 0.1-1.0 cm); none had lymph node metastasis. No interval cancers occurred. In addition, 7 of the breast cancers were detected on DCE-MRI imaging obtained at the 6 months screening interval; they would be interval cancers if only annual screening were implemented. There was very little DNA for somatic mutation testing in the majority of cases. However, as expected, there was heterogeneity in the spectrum of mutations but the most commonly somatically mutated gene in the early cancers was TP53.

Conclusions: DCE-MRI every 6 months performed well for early detection of invasive breast cancer in high-risk women, accomplishing the ultimate goal of breast cancer screening—detecting node-negative, invasive tumors less than 1 cm. Semi-annual DCE-MRI performed especially well in BRCA1 mutation carriers at risk for the most aggressive subtype of breast cancer. Further interventional studies evaluating this novel screening approach are warranted to personalize breast cancer risk assessment and prevention.

Citation Format: Whitaker K, Guindalini R, Abe H, Sheeth D, Huo D, Hong S, Churpek J, Verp M, Obeid E, Zheng Y, Amico A, Yoshimatsu T, Olopade O. Breast cancer surveillance in high-risk women with dynamic contrast-enhanced magnetic resonance imaging every 6 months: Results from a single institution study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-02-10.

Abstract PD8-05: Comparative analysis of the genomic landscape of breast cancers from women of African and European ancestry

Objectives: Paucity of data on populations of African Ancestry in clinical trials continues to limit our ability to design and implement innovative solutions to narrow the breast cancer survival gap amongst Africans, African Americans, and European Americans. We have developed a cross-continent research infrastructure to examine the spectrum of genomic alterations in breast tumors from West Africa and subsequently, to compare them to tumors from African American women and women of European Ancestry in The Cancer Genome Atlas (TCGA) database.

Methods: Consecutive women with breast cancer presenting for treatment at the University College Hospital, Ibadan and at Lagos State University Teaching Hospital, Lagos, Nigeria gave informed consent and were recruited to the West African Breast Cancer Study (WABCS) between 2013-2016. Tumor-normal pairs were subjected to exome and/or high-depth (90x) genome sequencing. High confidence somatic mutations (substitutions, insertions/deletions and structural variants) were obtained by using multiple variant callers. Furthermore, 1,089 exomic and 80 genomic breast tumor-normal pairs from TCGA were harmonized with WABCS samples, resulting in a cohort of 147 West Africans (147 exome; 40 genome), 154 African Americans (154 exome; 31 genome), and 776 Caucasians (776 exome; 43 genome).

Results: Across the exomes, genes commonly altered in breast cancer in TCGA are also altered in women of African ancestry, but the mutational spectrum is quite different, demonstrating overrepresentation of tumors with aggressive phenotypes. Overall, TP53 (65%), ERBB2 (27%), and GATA3 (17%) showed statistically significant higher alteration frequencies in West Africans and African Americans. In contrast, PIK3CA (24%) was less frequently mutated. Of note, GATA3 mutation was statistically significantly more frequent in Nigerians (39%) and African Americans (16.7%) compared to Caucasians (10.5%), in ER-positive cancers. Analysis on Structural Variants (SV), on the other hand, has shown that the genome-wide SV counts among three populations are comparable in ER-negative cancers, while Nigerians have significantly more SV counts compared to African Americans (P=0.0013) or European Americans (P=2.9x10-5) in ER-positive cancers. Similarly, genome-wide substitution patterns in ER+ and ER- cancers varied widely by race/ethnicity. In ER- cases, West Africans carried the highest proportion of canonical APOBEC-associated substitutions, particularly C>T transitions. Conversely, European Americans with ER+ disease showed a higher proportion of C>T than both West Africans (Welch t-test P = 0.044) and African Americans (Welch t-test P = 0.011). Mutation signature analyses highlighted multiple APOBEC signatures, with notable contribution differences across ancestry and ER status. A signature likely corresponding to DNA damage repair correlated with the proportion of genetic ancestry, being most prevalent in European Americans and least common in Nigerians, particularly in ER-negative cancers, with African Americans showing a degree of this signature's contribution in between the two populations (linear model adjusted for age, P=1.0x10-10).

Conclusions: Overall, our data suggests mutation spectra differences in across race/ethnicity and geography. Identification of molecular characteristics such as higher rates of HER2 enriched tumors and higher rates of GATA3 mutations in ER positive tumors are beginning to reveal the genomic basis of race-associated phenotypes and outcomes in breast cancer. Population differences in frequency and spectrum of mutations should now inform the design of innovative clinical trials that improve health equity and accelerate Precision Oncology care in diverse populations.

Citation Format: Olopade OI, Pitt JJ, Riester M, Odetunde A, Yoshimatsu T, Labrot E, Ademola A, Sanni A, Okedere B, Mahan S, Nwosu I, Leary R, Ajani M, Johnson RS, Sveen E, Zheng Y, Wang S, Fitzgerald DJ, Grundstad J, Tuteja J, Clayton W, Khramtsova G, Oludara M, Omodele F, Benson O, Adeoye A, Morhason-Bello O, Ogundiran T, Babalola C, Popoola A, Morrissey M, Chen L, Huo D, Falusi A, Winckler W, Obafunwa J, Papoutsakis D, Ojengbede O, White KP, Ibrahim N, Oluwasola O, Barretina J. Comparative analysis of the genomic landscape of breast cancers from women of African and European ancestry [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD8-05.

Abstract P6-03-17: Genomic landscape of breast cancers from women of African ancestry across the diaspora

Objectives: Of all ethnic/racial groups, age-standardized mortality rate from breast cancer is highest for African American women in the US for reasons that remain understudied. The paucity of genomic studies of breast tumors across the African Diaspora further restricts our understanding of the biology of breast cancer in underserved populations. To gain a better understanding of the genomic landscape of breast cancer in women of African Ancestry, we have developed a cross continent translational research infrastructure to examine the spectrum of genetic alterations in breast tumors from West Africa compared to the spectrum of alterations observed in tumors from African-American and other women who are predominantly white in The Cancer Genome Atlas (TCGA) dataset.

Methods: Peripheral blood and breast cancer biopsy tissues were collected from 214 patients enrolled in the West Africa Breast Cancer Study (WABCS) at the University of Ibadan/University College Hospital (UI/UCH) and at Lagos State University Teaching Hospital (LASUTH). Blood DNA as well as breast cancer tissue DNA and RNA were extracted at the Novartis Institutes for Biomedical Research (NIBR), UI/UCH, and LASUTH using a modified protocol of PAXgene Tissue DNA and RNA extraction method. Whole-exome (WES) and transcriptome (RNA-seq) sequencing were performed on the Illumina HiSeq2000 platform at NIBR. Single Nucleotide Variants (SNVs) and insertions/deletions (indels) were called using MuTect and Pindel, while Copy Number Alterations (CNAs) were called using an in-house implementation of the ABSOLUTE method. Observed mutations were compared against those reported in the TCGA dataset. ER, PR and HER2 status were determined by immunohistochemistry (IHC) at UI/UCH, LASUTH and UChicago.

Results: WES data for 95 tumors have been analyzed thus far. Genes commonly mutated in breast cancer in TCGA are also mutated in WABCS but the mutational spectrum is vastly different. TP53 (64%), MYC (31%), and GATA3 (26%), showed significantly higher alteration frequencies in WABCS and African Americans. In contrast, PIK3CA (20%), CDH1 (2%), and MAP3K1 (2%) were less frequently mutated in women of African ancestry. In addition to the high proportion with TP53 mutations, the proportion with HER2 positive subtype of 42.1% and triple-negative subtype of 37.9% suggest that tumors with the most aggressive features are overrepresented in breast cancer patients in West Africa.

Conclusions: In the first study of its kind, high throughput genomic analysis of the largest cohort of women of African ancestry has uncovered alterations in cancer genes, some of which may be amenable to treatment with targeted therapies. Furthermore, we provide evidence that population differences in frequency and spectrum of mutations should drive the design and deployment of precision medicine initiatives. Only then can we develop innovative interventions to reduce the unacceptably high rates of mortality from breast cancer in underserved and under resourced populations.

Citation Format: Olopade OI, Odetunde A, Riester M, Yoshimatsu T, Labrot E, Ademola A, Sanni A, Okedere B, Mahan S, Nwosu I, Leary R, Ajani M, Johnson RS, Sveen E, Zheng Y, Clayton W, Khramtsova G, Oludara M, Omodele F, Benson O, Adeoye A, Morhason-Bello O, Ogundiran T, Babalola C, Popoola A, Morrissey M, Huo D, Falusi A, Winckler W, Obafunwa J, Papoutsakis D, Ojengbede O, Ibrahim N, Oluwasola O, Barretina J. Genomic landscape of breast cancers from women of African ancestry across the diaspora. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-03-17.

Effect of dietary ascorbate on lipogenesis and lipolysis activities in black sea bream, Acanthopagrus schlegelii

To assess the effect of dietary ascorbate on lipid metabolism, 1-year black sea bream (Acanthopagrus schlegelii) were reared on a casein-based purified diet and an ascorbate fortified diet (1,100 mg of L: -ascorbyl-2- monophosphate-Mg/kg diet). The fortified ascorbate was effectively incorporated into the fish body and elevated muscle carnitine content. Fortifications of dietary ascorbate depressed activities of glucose-6-phosphate dehydrogenase and NADP-isocitrate dehydrogenase as lipogenic enzymes in the hepatopancreas and intraperitoneal fat body. Starvation after feeding experiment activated carnitine palmitoyltransferase as a lipolysis enzyme in the hepatopancreas in both control and vitamin C(VC) groups, while the lipolysis activity was significantly higher in VC group. These results confirmed that dietary ascorbate depressed lipogenesis and activated lipolysis, i.e., influenced the lipid metabolism of black sea bream.

Randomized phase II trial of the biweekly schedule of adjuvant chemotherapy with carboplatin plus paclitaxel versus carboplatin plus gemcitabine in patients with non-small cell lung cancer (NSCLC)

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Background: Carboplatin plus paclitaxel and carboplatin plus gemcitabine chemotherapy have shown a good response and an improved survival against advanced NSCLC. This phase II trial assessed the feasibility, safety and efficacy of a bi-weekly schedule for adjuvant chemotherapy. Methods: Patients with completely resected stage IB-IIIB NSCLC were randomized to either carboplatin (AUC3) plus paclitaxel (90mg/m2) (arm A) or carboplatin (AUC3) plus gemcitabine (1000 mg/m2) (arm B), q2w for 8 cycles within 8 weeks after surgery. The main inclusion criteria were no prior chemotherapy or radiotherapy, ECOG PS 0–1, an age of less than 80 years, and an adequate organ function. The primary endpoint was compliance, and secondary endpoints were the disease free survival (DFS) and toxicity. The patients were stratified by gender, histology (adenoca vs. non-adenoca) and disease stage. Results: Between 07/2005 and 06/2007, 76 patients were randomized and 75 were eligible (including 48 males, 27 females; median age 66 years) for intent-to-treat analysis (39 in arm A, 36 in arm B). The histologic types included adenocarcinoma (n=51), squamous cell carcinoma (n=18), large cell carcinoma (n=5), and adenosquamous cell carcinoma (n=1). The pathological stages were IB/IIA/IIB/IIIA/IIIB: 22/10/13/29/1. Twenty-one of 39 pts (54%) in arm A and 25 of 36 pts (69%) in arm B completed 8 cycles, and 59% in arm A and 81% in arm B completed ≥6 cycles. Grade 3/4 hematologic toxicities (%) in arms A/B were respectively; neutropenia 36/53, anemia 0/17, thrombocytopenia 3/0, nausea 3/3. No treatment related deaths were observed. Up to 12/2008, 11 of 39 pts in arm A and 13 of 36 pts in arm B had recurrent disease, but no significant difference was observed. Conclusions: This adjuvant bi- weekly scheduled chemotherapy in both arms resulted in a good compliance and feasible with acceptable levels of toxicity in completely resected NSCLC.

No significant financial relationships to disclose.

[Successful repair of blunt right atrial rupture; report of a case]

A 58-year-old male was compressed between 2 trucks during a traffic accident, and was brought to a local hospital with chest and back pain. Computed tomography showed pericardial effusion, and pericardiocentesis was performed. As cardiac rupture was suspected by the aspiration of blood, the patient was immediately transferred to our hospital. Pericaridocentesis was performed again with the introduction of a 7F sheath to release cardiac tamponade because the patient suddenly lost consciousness and showed respiratory arrest with shock just after arrival. After recovery from shock, the patient underwent median sternotomy. Surgery was performed without using cardiopulmonary bypass, and the rupture site in the right atrium was closed by direct surtures. The patient recovered without cardiac event and was discharged on the 46th postoperative day.

[Spontaneous pneumomediastinum]

We encountered 3 patients with spontaneous pneumomediastinum. The patients were a 14-year-old female, a 16-year-old male and an 18-year-old male. All 3 were previously healthy. They complained of chest pain or dyspnea. On admission, physical examination revealed subcutaneous emphysema. Chest computed tomography (CT) revealed pneumomediastinum and subcutaneous emphysema. All patients were treated with rest and all recovered in 7 to 9 days without any complication. Spontaneous pneumomediastinum is an uncommon, usually benign, self-limited disorder that usually occurs in young adults without any apparent precipitating factor or disease. Most patients require only conservative treatment.

Bactericidal activity of the nitroimidazopyran PA-824 in a murine model of tuberculosis

The nitroimidazopyran PA-824 has potent in vitro activity against Mycobacterium tuberculosis, a narrow spectrum of activity limited primarily to the M. tuberculosis complex, and no demonstrable cross-resistance to a variety of antituberculosis drugs. In a series of experiments, we sequentially characterized the activity of PA-824 in an experimental murine model of tuberculosis. The minimal effective dose was 12.5 mg/kg of body weight/day. The minimal bactericidal dose (MBD) was 100 mg/kg/day. When PA-824 was used as monotherapy at the MBD, it exhibited promising bactericidal activity during the initial intensive phase of therapy that was similar to that of the equipotent dose of isoniazid in humans. In combination with isoniazid, PA-824 prevented the selection of isoniazid-resistant mutants. Perhaps more importantly, PA-824 also demonstrated potent activity during the continuation phase of therapy, during which it targeted bacilli that had persisted through an initial 2-month intensive phase of treatment with rifampin, isoniazid, and pyrazinamide. Together, these data strongly support further evaluation of PA-824 in combination with first- or second-line antituberculosis drugs to determine its potential contribution to the treatment of drug-susceptible or multidrug-resistant tuberculosis, respectively.

[Right delayed traumatic diaphragmatic hernia; report of a case]

An 80-year-old woman was admitted to our hospital with abnormal shadow on chest X-ray 8 years after a chest trauma during which multiple ribs on the right side were fractured causing hemothorax. A diagnosis of right delayed traumatic diaphragmatic hernia was based on the findings on plain X-ray and multislice computed tomography. We performed surgery via thoracic approach with thoracoscopic assist. The transverse colon, liver, and omentum were dislocated into the right thoracic cavity and hardly adhered to the lung. We successfully repaired the ruptured diaphragm. The postoperative course was uneventful and the patient was discharged on the 33rd postoperative day.

[Pulmonary thromboembolism after thoracoscopic pulmonary wedge resection; report of a case]

We encountered a case of acute pulmonary embolism after lung cancer surgery. The case was a 64-year-old female. She was admitted to our hospital with an abnormal shadow on chest X-ray. There was a past history of hypopituitarism medicated with steroids. Chest computed tomography (CT) demonstrated ground glass attenuation shadow measuring 10 mm in the left upper lobe. She underwent left thoracoscopic pulmonary wedge resection due to bronchioloalveolar cell carcinoma. Postoperatively, the patient suddenly complained of chest pain and dyspnea the day after surgery. Chest CT showed left and right pulmonary arterial thromboembolism. Thrombolytic and anticoagulation therapy with urokinase and heparin sodium were immediately started. Venography demonstrated thrombus located in the vein of the bilateral lower leg region. We inserted an inferior vena cava filter to prevent aggravation of pulmonary embolism. After 11 days, CT showed completed thrombolysis in the bilateral pulmonary artery. The patient was discharged on the 25th postoperative day, and has been followed with anticoagulation therapy.

Paucibacillary tuberculosis in mice after prior aerosol immunization with Mycobacterium bovis BCG

To develop a murine model of paucibacillary tuberculosis for experimental chemotherapy of latent tuberculosis infection, mice were immunized with viable Mycobacterium bovis BCG by the aerosol or intravenous route and then challenged six weeks later with virulent Mycobacterium tuberculosis. The day after immunization, the counts were 3.71 +/- 0.10 log(10) CFU in the lungs of aerosol-immunized mice and 3.65 +/- 0.11 and 4.93 +/- 0.07 log(10) CFU in the lungs and spleens of intravenously immunized mice, respectively. Six weeks later, the lungs of all BCG-immunized mice had many gross lung lesions and splenomegaly; the counts were 5.97 +/- 0.14 and 3.54 +/- 0.07 log(10) CFU in the lungs and spleens of aerosol-immunized mice, respectively, and 4.36 +/- 0.28 and 5.12 +/- 0.23 log(10) CFU in the lungs and spleens of intravenously immunized mice, respectively. Mice were then aerosol challenged with M. tuberculosis by implanting 2.37 +/- 0.13 log(10) CFU in the lungs. Six weeks after challenge, M. tuberculosis had multiplied so that the counts were 6.41 +/- 0.27 and 4.44 +/- 0.14 log(10) CFU in the lungs and spleens of control mice, respectively. Multiplication of M. tuberculosis was greatly limited in BCG-immunized mice. Six weeks after challenge, the counts were 4.76 +/- 0.24 and 3.73 +/- 0.34 log(10) CFU in the lungs of intravenously immunized and aerosol-immunized mice, respectively. In contrast to intravenously immunized mice, there was no detectable dissemination to the spleen in aerosol-immunized mice. Therefore, immunization of mice with BCG by the aerosol route prior to challenge with a low dose of M. tuberculosis resulted in improved containment of infection and a stable paucibacillary infection. This model may prove to be useful for evaluation of new treatments for latent tuberculosis infection in humans.

Anticipatory and reflexive neck muscle activities during voluntary rapid jaw opening and passive jaw depression in humans

The characteristics of head movement during voluntary rapid jaw opening movement and passive jaw depression were investigated using accelerometers and electromyographs (EMG) on eight healthy examinees. Passive depressions were executed by means of load on the lower jaw, initiated either by examinees themselves or an experimenter. In the depression initiated by examinees, a head-extension movement that preceded the load to the lower jaw and anticipatory activities in the nuchal region of the trapezius muscle were observed. In the depression initiated by the experimenter, the anticipatory activities were not observed. In both of these cases, stretch reflexes were induced in the trapezius muscle. During voluntary rapid jaw opening, a head-extension movement nearly synchronized with the opening movement in the lower jaw acceleration, and dorsal-neck muscle activities accompanying the synchronized movement were observed. The peak timing of these neck-muscle activities preceded the latencies of the stretch-reflex activities observed in the jaw-depressed tasks, but no anticipatory activities were observed in the dorsal-neck muscles. We conclude that neither the anticipatory activities nor the reflex activities observed in the passive depressions have effects on the initial part of the dorsal-neck muscle activities, which are related to the head-extension synchronized with the voluntary lower-jaw opening movement.

Head movement properties during voluntary rapid jaw movement in humans

The purpose of this study was to determine whether the start of the synchronized head movement during mandibular movement is evoked by the peripheral reflexes following mandibular movement (i.e. stretch or trigemino-neck reflexes), or, alternatively, is started by pre-programmed central command. Head movement accompanying voluntary rapid jaw opening movement was studied using accelerometers fixed to the upper and lower incisors, as well as electromyographs (EMGs) of the neck muscles. The direction of head acceleration at the upper incisor was towards head extension at the beginning of jaw opening movement in 89.2% of all trials, opposite to the direction of lower jaw acceleration. The onset of head acceleration was later than that of the lower jaw acceleration by averages of 6.2-10.7 ms, and the onset of electromyographic activities of the sternocleidomastoid (SCM) muscle preceded that of head acceleration by an average of 12.5-24.3 ms. These findings suggest that head movement during mandibular movement is not started by peripheral reflexes but by pre-programmed central commands. This may be relevant to muscular discomfort in the neck and shoulder regions of patients with stomatognathic disorders.

Interaction of corticotropin-releasing factor and glucagon-like peptide-1 on behaviors in chicks

Both corticortropin-releasing factor (CRF) and glucagon-like peptide-1 (GLP-1) inhibit food intake of chicks, but they also produce other behaviors. The present experiments were undertaken to clarify the interaction of CRF and GLP-1 regarding their anorectic actions as well as other behaviors. In Experiment 1, birds were injected intracerebroventricularly (i.c.v.), following a 3-h fast, with either saline, 0.1 microg of CRF, 0.1 microg of CRF+0.1 microg of GLP-1 or 0.1 microg of CRF+1 microg of GLP-1, and food intake was measured for 2 h. The injection of CRF decreased food intake, and CRF injected with GLP-1 suppressed food intake for up to 2 h. Birds were treated similarly in Experiment 2 in which the doses of CRF and GLP-1 were reversed. GLP-1 strongly suppressed food intake, and this effect was augmented by coadministration of CRF. In Experiment 3, the behaviors of chicks injected with saline, CRF (0.1 microg), GLP-1 (0.1 microg) or CRF (0.1 microg)+GLP-1 (0.1 microg) were monitored for the numbers of steps, vocalization and locomotion. Chicks were excited, moved more and vocalized loudly following injection of CRF, whereas an opposite response was seen with GLP-1. The behaviors were intermediate following the coinjection of the two peptides. In conclusion, CRF and GLP-1 interact in the chick brain, but the response depends on the behavior being measured.

Intracerebroventricular injection of exendin (5-39) increases food intake of layer-type chicks but not broiler chicks

To clarify the involvement of endogenous glucagon-like peptide-1 (GLP-1) on feeding in chicks, we examined the central effect of GLP-1 antagonist, exendin (5-39) on food intake. Intracerebroventricular co-injection of exendin (5-39) with GLP-1 attenuated the anorexigenic effect of GLP-1 in layer-type chicks. Furthermore, exendin (5-39) enhanced food intake of layer-type chicks under ad libitum feeding. However, this effect was not observed in broiler chicks. Therefore, endogenous GLP-1 may be important in the regulation of feeding in layer-type chicks but not in broiler chicks.

Characterization of immortalized human chondrocytes originated from osteoarthritis cartilage

Immortalized cloned human chondrocytes isolated from a normal (Ch-4, 8, N) and an osteoarthritis patient (Ch-8-OA) were established by introduction of recombinant SV40-adenovirus vector containing SV40 early gene. These cells exhibited continuous proliferative capacity in monolayer culture and showed chondrocytic characteristics in that they were positive for alkaline phosphatase and collagen type II. When cells were treated with IL-1alpha, the growth was inhibited. IL-1alpha induced the production of IL-6, GM-CSF and TNFalpha from immortalized chondrocytes. Significantly high amounts of cytokines including IL-6, GM-CSF and TNFalpha were produced from Ch-8-OA cells, even in the absence of IL-1alpha stimulation. Interestingly, TNFalpha, exogenously added into the culture, inhibited the growth of Ch-8-OA cells. Further studies are required to clarify the different mechanisms on chondrocytes originating from osteoarthritis cartilage underlying the biological reaction to various cytokines and the production of these cytokines as compared with chondrocytes from normal cartilages. However, the novel chondrocyte cell lines established in the present study may provide researchers with a useful model for studying the pathogenesis of osteoarthritis.

Suppression of food intake induced by corticotropin-releasing factor family in neonatal chicks

Corticotropin-releasing factor (CRF), urocortin and urotensin I share amino acid sequences, and they inhibit food intake in mammals. CRF plays a potent role in decreasing food intake in avian species, but the effects of urocortin and urotensin I have not been investigated. Therefore, the effect of these three peptides on food intake in the neonatal chick was compared. In Experiment 1, birds were injected intracerebroventricularly (i.c.v.) with either 0, 0.01, 0.1 or 1 microg of urocortin following a 3-h fast, and food intake was measured for 2 h post-injection. Food intake was suppressed in a dose-dependent manner. Using a similar design in Experiment 2, the effect of urotensin I was investigated. Urotensin I appeared to suppress food intake in neonatal chicks more than urocortin did. In Experiment 3, the efficacy of CRF, urocortin and urotensin I was directly compared using one dose, 0.1 microg. The results indicated that the suppressive effect on food intake was strongest for CRF followed by urotensin I, then urocortin. These results suggest that the structure of receptors for the CRF family in chicks may be somewhat different than in mammals.

Influence on force curve exerted by jaw tapping force

The purpose of this study, which made use of visual biofeedback, was to determine how methods of regulating jaw tapping force differed depending on the strength of the tapping, using the force curve as an index. Nine healthy examinees were asked to make 30-35 jaw tapping movements, reproducing the defined target tapping force as accurately as possible. We measured the duration of the tooth contact phase, the time to peak force, the first time derivative of force (peak dF/dt), and the time to peak dF/dt. The results indicated that the duration of the tooth contact phase and the time to peak force increased with the target value (P < 0.01). As the target rose, the peak dF/dt increased significantly (P < 0.01), but the time to peak dF/dt was not significant (P=0.134). We found that the higher the target value, the greater the degree of dependency on feedback information. We also found that both the peak dF/dt and the time to peak dF/dt were determined for each examinee prior to movement.

Generation of autologous tumor-specific T cell clones from a patient with adenosquamous carcinoma of the lung

BACKGROUND

Adenosquamous carcinoma of the lung is not a common cancer, but its prognosis is worse than that of adenocarcinoma or squamous cell carcinoma. Therefore, new therapeutic strategies need to be developed to treat this type of lung cancer. Recently, vaccination using tumor antigens which are recognized by cytotoxic T lymphocytes (CTL) has been applied mainly to melanoma patients. We therefore attempted to establish T cell clones specific for autologous tumor cells (AT) from a patient with adenosquamous carcinoma in order to analyze the specific immune responses against AT.

METHODS

A lung adenosquamous carcinoma cell line was established from a resected tumor obtained from a 72-year-old patient. Regional lymph node lymphocytes were stimulated weekly with CD80-transfected AT to induce CTL. The CTL activities were assessed by a standard (51)Cr release assay and by cytokine release.

RESULTS

We succeeded in inducing an AT-specific CTL line. Using a limiting dilution method, eight T cell clones were established. AT-specific activity was observed in three CD8(+) T cell clones and one CD4(+) T cell clone out of the eight clones tested. Anti-HLA class I and anti-HLA-B/C mAbs inhibited IFN-gamma production from the AT-specific CD8(+) clones co-cultured with AT, thus indicating the restriction element to be HLA-B*5201 or HLA-Cw*1202. In contrast, the CD4(+) T cell clone recognized AT in an HLA class II-restricted manner.

CONCLUSIONS

These results are the first demonstration of a successful induction of AT-specific T cell clones from a patient with lung adenosquamous carcinoma. It may therefore supply a possible way to apply specific immunotherapy to this type of lung cancer.

Intracerebroventricular injection of agouti-related protein attenuates the anorexigenic effect of alpha-melanocyte stimulating hormone in neonatal chicks

It is well known that alpha-melanocyte stimulating hormone (alpha-MSH) inhibits feeding via melanocortin receptor-4 (MC4R) in the mammalian brain. The anorexigenic effect of alpha-MSH is attenuated by agouti-related protein (AGRP), an antagonist for MC4R. Present studies were carried out to clarify whether human AGRP (86-132) antagonizes the anorexigenic effect of alpha-MSH in broiler chicks. Intracerebroventricular injection of AGRP attenuated the anorexigenic effect of alpha-MSH. Furthermore, AGRP stimulated food intake of layer-type chicks under an ad libitum feeding condition but not broiler chicks, suggesting that the orexigenic effect of AGRP is different between two breeds. These also imply that the extent of the anorexigenic effect of endogenous alpha-MSH is different among two breeds. This may be a part of the difference in food intake between two breeds.

Amelioration of retrovirus-mediated gene transfer into hepatocellular carcinoma cells

Recombinant retroviruses are by far the most frequently used vehicle in clinical gene therapy. No serious side-effects have been reported so far in clinical gene therapy trials using recombinant retroviral systems. Low titers of recombinant retroviruses, however, have limited the usefulness of recombinant retroviruses. To improve the efficiency of retrovirus-mediated gene transfer, we previously introduced the polyomavirus early region into amphotropic PA317 cells and established a modified retroviral packaging cell line, PAMP51. We demonstrate here that recombinant retroviruses produced by PAMP51-derived retroviral producing cells have approximately 10-fold higher titers compared with those produced by conventional PA317-derived retroviral producing cells. Importantly, recombinant retroviruses produced by PAMP-derived retroviral producing cells could infect hepatocellular carcinoma cells much more efficiently and could induce much stronger expression of a lacZ reporter gene in HCC cells compared with those produced by PA317-derived ones. These results indicate that recombinant retroviruses prepared from PAMP51-derived retroviral producing cells are much more useful than those prepared from PA317-derived ones and that the use of PAMP51 retroviral packaging cells may open up new avenues for the treatment of various types of cancer including hepatocellular carcinoma.

Unfavorable prognosis of patients with non-small cell lung carcinoma associated with HLA-A2

BACKGROUND

HLA class I molecules present antigenic peptides to cytotoxic T lymphocytes and, thus, play an important role in immune surveillance. Since 1970s there have been many reports of an increased frequency of one or more HLA haplotype in association with autoimmune disease, and malignancy. We studied types of HLA class I antigens in 204 resected non-small cell lung carcinoma (NSCLC) patients and also examined its correlation with clinicopathologic features and prognosis.

METHOD

Serological typing for HLA class I antigens was performed using a microcytotoxicity test. The disease-free survival curves were calculated by the Kaplan-Meier method and then compared using the Logrank test. Multivariate analysis was carried out by Cox's proportional hazard method.

RESULTS

The difference in disease-free survival time between the HLA-A2 present group and A2 absent group was significant (P = 0.040). The 3-year disease-free survival rate of all patients was 44% in HLA-A2 present group and 66% in A2 absent group. When a comparison was made within the group with stage I, expression of HLA-A2 was the only independent factor that affected survival time by multivariate analysis (P = 0.0457).

CONCLUSIONS

Expression of HLA-A2 was considered as one of the unfavorable prognostic factors in NSCLC patients. Our results suggested expression of HLA-A2 in NSCLC patients was one of the mechanisms of escape from immune surveillance.

Intracerebroventricular injection of ghrelin and growth hormone releasing factor inhibits food intake in neonatal chicks

Growth hormone releasing factor (GRF) is known to stimulate feeding of rats. Ghrelin, a novel growth hormone (GH)-releasing acylated peptide, was recently isolated from rat stomach. It also stimulates the release of GH from the anterior pituitary through the GH secretagogue receptor (GHS-R) and feeding in the rat. We have investigated the effects of ghrelin and GRF on food intake of the neonatal chick. In Experiment 1, 0, 1.25, 2.5 and 5 microg of ghrelin were administered intracerebroventricularly (i.c.v.) to ad libitum fed birds. In Experiment 2, the effect of (i.c.v.) injection of 0, 1.25, 2.5 and 5 microg of GRF was investigated. Both peptides strongly inhibited food intake of the chick during the 2-h post-injection period. In the third experiment, 0, 0.5, 1 and 2 microg of ghrelin was injected i.c.v. in chicks previously deprived of food for 3 h. Food intake was again inhibited by ghrelin in a dose-dependent manner. These results suggest that the mechanisms for feeding of the neonatal chick through GH release are different from mammals.

[Comparisons of factors affecting voiding disorders between patients with benign prostate hyperplasia and volunteers]

PURPOSE

The prostate size and motivation to visit clinics were investigated in patients with prostate hyperplasia.

OBJECTS AND METHODS

One hundred ninety-five patients who had urinary symptoms and visited our outpatient clinic between September 1994 and October 1999 and 268 age-matched volunteers in Mitaka City who underwent a medical examination of the prostate in June 1997 were compared. International Prostate Symptom Score (IPSS), Quality Of Life Score (QOL score), residual urine volume, prostate volume and urinary flow rate were measured.

RESULTS

The prostate volume of the volunteers was 20-25 cm3 irrespective of the age. The prostate size of the outpatients was larger than that of the volunteers for every age group. IPSS and QOL score were significantly higher in the outpatients than in the volunteers. Diurnal urinary frequency and sense of residual urine contributed to the discrimination index of the two groups more significantly than the other scores. There was a significant correlation between prostate volume and residual urine volume. The score of weak urinary steam was inversely and significantly correlated with peak urinary flow rate.

CONCLUSIONS

There was no age-related enlargement of the prostate gland. The prostate gland was significantly larger in the patients than in the volunteers even in those in their fifties. Urinary frequency and sense of residual urine are important factors for men to seek and receive medical care.

Isolation and characterization of the genes up-regulated in isolated neurons by aged garlic extract (AGE)

Aged garlic extract (AGE) produces neurotrophic effects on cultured fetal rat hippocampal neurons. These studies examined the molecular events triggered by AGE that might account for a suppression of neuronal cell death. Genes differentially expressed by the addition of AGE in primary cultured hippocampal neurons isolated from fetal rat brain were screened using mRNA differential display. Four cDNA clones were significantly enhanced at their transcriptional level; they were designated as #24, #110, #153 and #155. Quantitative reverse transcription-polymerase chain reaction (RT-PCR), as well as dot-blot hybridization combined with RT-PCR, confirmed that the transcription from these four genes was elevated at least twofold, particularly the mRNA of #153, which was increased >20 times 72 h after the addition of AGE. A homology search of the respective cDNA sequences in the DNA database revealed that #153 is an alpha 2-microglobulin-related protein (alpha 2MRP) gene. The others genes were not identified. Induction of the alpha 2MRP gene expression occurred within 24 h after addition of AGE. These findings suggest a possible mechanism by which AGE may regulate gene expression and bring about a neurotrophic effect. Further, our results suggest that alpha 2MRP may function at the initial step of the molecular events triggered by AGE and play an important role in the survival of hippocampal neurons.

[Treatment and results of interstitial lung diseases in video assisted thoracoscopic lung biopsy]

In order to establish treatment of interstitial lung diseases in video assisted thoracoscopic lung biopsy, we retrospectively reviewed our experiences. The present study included 7 patients with a mean age of 46.4, range from 24 to 61, who were treated at our department from 1996 through 1999. They were 5 men and 2 women. The pathologic diagnosis was nonspecific interstitial pneumonia in 3 patients who responded to steroid therapy. Three other patients had usual interstitial pneumonia. One patient had lymphocytic interstitial pneumonia. No complications occurred. The results indicate that video assisted thoracoscopic lung biopsy is an effective and safe way to diagnose interstitial lung diseases.

Eradication of murine brain tumors by direct inoculation of concentrated high titer-recombinant retrovirus harboring the herpes simplex virus thymidine kinase gene

Implantation of retrovirus-producing cells within a tumor has been demonstrated to eliminate malignant brain tumors effectively in animal models. In our previous study, the implantation of high-titer retrovirus-producing fibroblasts into tumors resulted in highly efficient transduction in vivo. The transduced glioma cells migrated far from the implantation site, potentiating the induction of the remarkable bystander effect. It is also possible, however, that the implantation of murine fibroblast-derived virus-producing cells may induce an immune response in patients. In this study, we prepared retroviruses carrying the herpes simplex virus thymidine kinase (HTK) gene with titers of 1.4--2.5 x 10(11) colony-forming units (c.f.u.)/ml, and stereotactically inoculated only 3 microl of the HTK-bearing retroviruses into the brain tumors of mice. Following repetitive ganciclovir (GCV) intraperitoneal injection, effective killing of glioma cells in the mouse brain was observed. The transduction efficiency was nearly as high as that observed for the implantation of high-titer retrovirus-producing fibroblasts. Eighty percent of brain tumor-bearing mice were completely cured by our treatment protocol using concentrated HTK-harboring retroviruses. Our results suggest that repeated inoculations of high-titer retroviruses carrying the HTK gene followed by GCV treatment may be a promising strategy for the clinical treatment of malignant gliomas.

Prediction of pulmonary complications after a lobectomy in patients with non-small cell lung cancer

BACKGROUND

Although the preoperative prediction of pulmonary complications after lung major surgery has been reported in various papers, it still remains unclear.

METHODS

Eighty nine patients with stage I-IIIA non-small cell lung cancer (NSCLC) who underwent a complete resection at our institute from 1994-8 were evaluated for the feasibility of making a preoperative prediction of pulmonary complications. All had either a predicted postoperative forced vital capacity (FVC) of >800 ml/m(2) or forced expiratory volume in one second (FEV(1)) of >600 ml/m(2).

RESULTS

Postoperative complications occurred in 37 patients (41.2%) but no patients died during the 30 day period after the operation. Pulmonary complications occurred in 20 patients (22.5%). Univariate analysis indicated that the factors significantly related to pulmonary complications were FVC <80%, serum lactate dehydrogenase (LDH) level > or =230 U/l, and arterial oxygen tension (PaO(2)) <10.6 kPa (80 mm Hg). In a multivariate analysis the three independent predictors of pulmonary complications were serum LDH > or =230 U/l (odds ratio (OR) 10.5, 95% CI 1.4 to 77.3), residual volume (RV)/total lung capacity (TLC) > or =30% (OR 6.0, 95% CI 1.1 to 33.7), and PaO(2) <10.6 kPa (OR 5.6, 95% CI 1.4 to 22.2).

CONCLUSIONS

The above findings indicate that three factors (serum LDH levels of > or =230 U/l, RV/TLC > or =30%, and PaO(2) <10.6 kPa) may be associated with pulmonary complications in patients undergoing a lobectomy for NSCLC, even though the patient group was relatively small for statistical analysis of such a diverse subject as pulmonary complications.

[The significance of early detection for prostate cancer in mass screening]

PURPOSE

In Mitaka city, mass screening for prostate cancer was conducted for 3 years from 1995 to 1997. Clinical stages were compared between patients found by screening and those diagnosed at our clinic during the same time. The significance of serum-free prostate specific antigen (PSA) in mass screening for prostate cancer was examined.

MATERIAL AND METHODS

A prospective clinical trial was conducted on men aged 50 years or older. The primary examination consisted of taking the international prostate symptom score, quality of life score, PSA (Tandem-R) and digital rectal examination (DRE). If PSA was greater than 4.0 ng./ml and/or if DRE suggested cancer, transrectal ultrasound-guided sextant prostate biopsies were indicated.

RESULTS

Of the men screened, 23.2% (320/1375) had serum PSA greater than 4.0 ng./ml. and/or suspicious findings on DRE. Biopsy was performed in 199 of 320 (62.1%). Cancer was detected in 21 (1.5%, 21/1375). Prostate cancer was found in one case among 154 males (0.65%, 1/154) who were screened twice or more. The cancer stage found by screening was significantly earlier than that diagnosed at the outpatient clinic (Wilcoxon's rank-sum test: p = 0.0047). Receiver operating characteristics analysis showed that the optimal free PSA-to-PSA ratio was 12%. Positive predictive value increased from 18% to 50% when free PSA-to-PSA ratio was combined with PSA.

CONCLUSION

1. Cancer detection rate was 1.5% in the mass screening in Mitaka City. 2. Cancer stage found by screening was significantly earlier than that diagnosed at the outpatient clinic. 3. Free PSA determination might eliminate unnecessary biopsies in men with PSA above 4.0 ng./ml with minimal loss of cancer detection.

Benign mesenchymoma of the mediastinum

We report our recent experience of a rare case of a benign mesenchymoma in the mediastinum. A 24-year-old man was admitted to our hospital with an abnormal shadow on chest X-ray. A chest computerized tomography scan and magnetic resonance imaging showed an anterior mediastinal mass along the right border of the pericardium. The tumor was surgically resected. It was yellow on the surface, 12.5 x 10.0 x 3.8 cm in size, and 230 g in weight. The histopathological diagnosis was a benign mesenchymoma. The postoperative course was uneventful. A search of the literature revealed that a benign mesenchymoma in the mediastinum is extremely rare. It seems to be difficult to reach a definitive diagnosis preoperatively. Surgical resection can confirm the diagnosis, and is curative.

Deduced amino acid sequence and possible catalytic residues of a thermostable, alkaline cellulase from an Alkaliphilic bacillus strain

Alkaliphilic Bacillus sp. strain KSM-S237 (a relative of Bacillus pseudofirmus) produces a thermostable, alkaline endo-1,4-beta-glucanase (Egl). The entire gene for the enzyme harbored a 2,472-bp open reading frame (ORF) encoding 824 amino acids, including a 30-aminoacid signal peptide. The deduced amino acid sequence of the mature enzyme (794 amino acids, 88,284 Da) showed very high similarity to those of family 5 mesophilic, alkaline Egls from some alkaliphilic bacilli. The enzyme had a region similar to a novel cellulose binding domain proposed for an Egl (EngF) from Clostridium cellulovorans. Expression of the Bacillus Egl gene in Bacillus subtilis resulted in high carboxymethy cellulase activity (2.0 g/l) in the culture broth, concomitant with the appearance of a protein band on an SDS gel at 86 kDa. Site-directed mutagenesis delineated the importance of Arg111, His151, Glu190, His262, Tyr264, and Glu305 in catalysis and/or substrate binding of the enzyme.

[A case of familial juvenile gouty nephropathy associated with a right renal tumor]

We present a case of familial juvenile gouty nephropathy which was associated with a right renal tumor that was found incidentally. The patient was a 27-year-old woman who initially presented with acute gouty arthritis at the age of twenty years. Her mother and her sister had been attacked with acute gouty arthritis in their early twenties. Progressive deterioration in the renal function was noted in the three family members who had experienced gouty attack. Her mother was maintained on hemodialysis. As image diagnoses could not rule out malignancy in her right renal tumor, in situ non-ischemic enucleation of the right renal tumor using a microwave tissue coagulator(Microtaze) and a renal biopsy were performed. The pathological diagnosis of the renal tumor was tubulopapillary adenoma, and the renal biopsy showed minimal change in the glomeruli and tubules. The post-operative course was uneventful. The serum creatinine and creatinine clearance before and three months after the operation were 2.4 mg/dl and 2.6 mg/dl, 36.7 ml/min and 32.5 ml/min, respectively. The renal biopsy findings that glomerular and tubular changes were minimal and there was no tissue precipitation of uric acid or sodium urate, and the fact that her renal function decreased progressively despite the treatment of hyperuricemia suggested strongly that renal function might have deteriorated due to unknown factors other than hyperuricemia.

Transmission of Helicobacter pylori from challenged to nonchallenged nude mice kept in a single cage

To determine the transmission route of Helicobacter pylori, one nude mouse was challenged by H. pylori, and then raised with nonchallenged nude mice in a single cage in a sterilized environment with and without exposure to their feces. After coraising for two and four weeks, all mice were killed to determine H. pylori in the stomach, saliva, and feces and to assess gastritis grade. Natural transmission of H. pylori occurred in 50% (2/4) and 70% (7/10) of mice after two weeks and four weeks of coraising when they were exposed to their feces. H. pylori was detected not only in the stomach but also in saliva and feces by PCR of all challenged and transmitted mice. However, no transmission occurred in mice not exposed to feces of a challenged mouse, while sharing food and water in a single cage. These findings suggest that the fecal-oral transmission route is important, at least in the animal model. Serum levels of anti-H. pylori urease IgG of the H. pylori-transmitted mice increased after coraising, and gastritis was observed in the stomach of both challenged and transmitted mice. We conclude that H. pylori bacteria are transmitted through the fecal-oral route from challenged to nonchallenged nude mice, resulting in gastritis.

Metastatic pulmonary epithelioid hemangioendothelioma with peculiar radiographic features

We report a case of a pulmonary epithelioid hemangioendothelioma presenting as a solitary pulmonary nodule with subsequent systemic spread, including histologically documented gingival metastasis. Chest radiography and computed tomography at initial evaluation showed a solitary 2 cm pulmonary nodule, associated with pleural indentation and vascular convergence. The tumor later spread systemically, including multiple pulmonary nodules, bilateral pleural effusions, and gingival swelling and erosion. A biopsy of the gingival lesion showed histologic features identical to that of the lung biopsy.

Heterogeneous response patterns of alveolar macrophages from patients with lung cancer by stimulation with interferon-gamma

BACKGROUND

Macrophages are considered to play an important role in the host defense against malignant tumors. In this study, cytotoxic activity of alveolar macrophages (AM) derived from 32 patients with lung cancer was investigated.

METHODS

AM were aseptically obtained by lavage from resected lung and subsequently tested for cytolytic activity against QG56, a lung squamous cell line, following treatment with recombinant interferon-gamma (IFN-gamma).

RESULTS

In seven patients (21.9%), AM showed no cytotoxicity even though AM were incubated with IFN-gamma. In 20 (62.5%), AM showed substantial cytotoxicity in response to IFN-gamma in a dose-dependent manner. In the other five (15.6%), relatively strong cytotoxicity was observed even without preincubation with IFN-gamma. Such a heterogeneous profile of the cytotoxicity of AM might be a reflection of various activated states of AM since the potential of cytotoxicity and that of IL-1 secretion were almost parallel. Both IFN-gamma dependent and -independent cytotoxicity were partially blocked either by anti-tumor necrosis factor-alpha (TNF-alpha) antibody or by the inhibitor of nitric oxide synthesis. However, those activities were completely abrogated by both treatments. Since the supernatant of AM culture exhibited TNF-alpha-mediated but not NO-mediated cytolysis, TNF-alpha could mediate a bystander killing whereas NO acts in close contact with tumor cells.

CONCLUSION

The AM have anti-tumor cytotoxicity in lung cancer although the cytolytic potential is heterogeneous and that the tumor lysis by AM is mediated by both TNF-alpha and NO production.

Regulation of human jaw tapping force with visual biofeedback

The purpose of this study, which made use of visual biofeedback, was to determine whether jaw tapping force reproduction is related to the strength of tapping and to investigate how jaw tapping force affects the tapping movement curve. Nine healthy examinees were asked to reproduce jaw tapping force. We found that the ease and method of regulating jaw tapping force differed depending on the target force. We also found that jaw tapping force was regulated by alteration of the jaw opening distance, the duration of the tooth contact phase, the duration of the jaw closing phase, the maximum jaw opening velocity, and the maximum jaw closing velocity. However, the duration of the jaw opening phase and cycle time was not affected by force regulation under our experimental conditions.

Deduced amino-acid sequence and possible catalytic residues of a novel pectate lyase from an alkaliphilic strain of Bacillus

The nucleotide sequence of the gene for a highly alkaline, low-molecular-mass pectate lyase (Pel-15) from an alkaliphilic Bacillus isolate was determined. It harbored an open reading frame of 672 bp encoding the mature enzyme of 197 amino acids with a predicted molecular mass of 20 924 Da. The deduced amino-acid sequence of the mature enzyme showed very low homology (< 20.4% identity) to those of known pectinolytic enzymes in the large pectate lyase superfamily (the polysaccharide lyase family 1). In an integrally conserved region designated the BF domain, Pel-15 showed a high degree of identity (40.5% to 79.4%) with pectate lyases in the polysaccharide lyase family 3, such as PelA, PelB, PelC, and PelD from Fusarium solani f. sp. pisi, PelB from Erwinia carotovora ssp. carotovora, PelI from E. chrysanthemi, and PelA from a Bacillus strain. By site-directed mutagenesis of the Pel-15 gene, we replaced Lys20 in the N-terminal region, Glu38, Lys41, Glu47, Asp63, His66, Trp78, Asp80, Glu83, Asp84, Lys89, Asp106, Lys107, Asp126, Lys129, and Arg132 in the BF domain, and Arg152, Tyr174, Lys182, and Lys185 in the C-terminal region of the enzyme individually with Ala and/or other amino acids. Consequently, some carboxylate and basic residues selected from Glu38, Asp63, Glu83, Asp106, Lys107, Lys129, and Arg132 were suggested to be involved in catalysis and/or calcium binding. We constructed a chimeric enzyme composed of Ala1 to Tyr105 of Pel-15 in the N-terminal regions, Asp133 to Arg159 of FsPelB in the internal regions, and Gln133 to Tyr197 of Pel-15 in the C-terminal regions. The substituted PelB segment could also express beta-elimination activity in the chimeric molecule, confirming that Pel-15 and PelB share a similar active-site topology.