Abstract P1-15-03: Prevention of letrozole–induced bone loss using risedronate in postmenopausal women with hormone receptor positive breast cancer: A multicenter randomized clinical trial

Background

Prevention of letrozole–induced bone loss using oral risedronate has not been proved in the Japanese women. The aim of this study was to assess the effect of risedronate 17.5mg/week on bone mineral density (BMD) in postmenopausal, early breast cancer patients scheduled to receive adjuvant letrozole.

Patients and Methods

Postmenopausal women with hormone receptor–positive early breast cancer were assigned to one of two strata according to their baseline BMD T-score as being at low and high risk of osteoporosis. Patients with low risk (-2.5 ≤ T score) were randomly assigned to letrozole and risedronate (L+R) or to letrozole alone (L). Patients with high risk (-2.5 > T score) received letrozole and risedronate (L+R). Letrozole was given at a dosage of 2.5 mg/day while oral risedronate was given at 17.5mg/week. The primary end point was the change in lumbar spine (LS) BMD at 12 months. The secondary end points included change in total hip (HP) BMD and bone turnover markers.

Results

In the low risk group (N=103), treatment with L+R resulted in a significant increase in BMD at LS and at HP compared to treatment with L only at 12 months (1.8% vs -2.2%, P < 0.001, and -0.3% vs -2.9%, P = 0.001, respectively). In the L+R group, significant decreases in bone turnover makers, NTX and PINP, were recognized compared with L only at 12months (-11.1% vs. 27.5%, P<0.001, -42.3% vs. 15.2%, P<0.001, respectively). In the high risk group (N=28), treatment with L+R resulted in a significant increase in BMD at LS and prevention of decrease in BMD at HP (3.6%; 95%CI, 1.8% to 5.3%, p=0.003, 0.3%; 95%CI, -1.3% to 1.8%, p=0.47, respectively).

Estimated Percentage Change From Baseline to 6 and 12 Months in Lumbar Spine and Total Hip BMD   From Baseline to 6 MonthsFrom Baseline to 12 MonthsBMD areaRisk GroupTreatmentChange in BMD (%), 95% CIPChange in BMD (%), 95% CIPLumbar spineLow riskL+R1.7 (-1.3 to 4.7)<0.0011.8 (-2.1 to 5.7)<0.001  L-1.6 (-4.3 to 1.1) -2.2 (-5.7 to 1.3)  High riskL+R1.8 (0.4 to 3.2)0.043.6 (1.8 to 5.3)0.003Total hipLow riskL+R-0.2 (-2.7 to 2.3)0.001-0.3 (-3.2 to 2.6)0.001  L-2.2 (-5.4 to 1.0) -2.9 (-7.2 to 1.4)  High riskL+R0.1 (-1.3 to 1.6)0.610.3 (-1.3 to 1.8)0.47BMD: bone mineral density, L: Letrozole, R: risedronate

Four patients (14.3%) improved from osteoporotic region to the osteopenic region with L+R treatment. Letrozole and risedronate were well tolerable and there was no serious adeverse event including osteonecrosis of jaw.

Conclusions

At 12 months, 17.5mg/week risedronate therapy prevented bone loss in postmenopausal women with breast cancer who were receiving adjuvant letrozole, of which results were compatible with previous findings of western populations.

Citation Format: Kadoya T, Masumoto N, Shigematsu H, Emi A, Kajitani K, Kobayashi Y, Funakoshi M, Kawabuchi Y, Ohara M, Matsuura K, Noma M, Sasada T, Okada M. Prevention of letrozole–induced bone loss using risedronate in postmenopausal women with hormone receptor positive breast cancer: A multicenter randomized clinical trial. [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 P1-15-03.

The elimination of the onchocerciasis vector from the island of Bioko as a result of larviciding by the WHO African Programme for Onchocerciasis Control

The island of Bioko is part of the Republic of Equatorial Guinea and is the only island in the World to have endemic onchocerciasis. The disease is hyperendemic and shows a forest-type epidemiology with low levels of blindness and high levels of skin disease, and the whole population of 68,000 is estimated to be at risk. Control of onchocerciasis began in 1990 using ivermectin and this yielded significant clinical benefits but transmission was not interrupted. Feasibility and preparatory studies carried out between 1995 and 2002 confirmed the probable isolation of the vector on the island, the high vectorial efficiency of the Bioko form of Simulium yahense, the seasonality of river flow, blackfly breeding and biting densities, and the distribution of the vector breeding sites. It was proposed that larviciding should be carried out from January to April, when most of the island's rivers were dry or too low to support Simulium damnosum s.l., and that most rivers would not need to be treated above 500 m altitude because they were too small to support the breeding of S. damnosum s.l. Larviciding (with temephos) would need to be carried out by helicopter (because of problems of access by land), supplemented by ground-based delivery. Insecticide susceptibility trials showed that the Bioko form was highly susceptible to temephos, and insecticide carry was tested in the rivers by assessing the length of river in which S. damnosum s.l. larvae were killed below a temephos dosing point. Regular fly catching points were established in 1999 to provide pre-control biting densities, and to act as monitoring points for control efforts. An environmental impact assessment concluded that the proposed control programme could be expected to do little damage, and a large-scale larviciding trial using ground-based applications of temephos (Abate 20EC) throughout the northern (accessible) part of the island was carried out for five weeks from 12 February 2001. Following this, a first attempt to eliminate the vectors was conducted using helicopter and ground-based applications of temephos from February to May 2003, but this was not successful because some vector populations persisted and subsequently spread throughout the island. A second attempt from January to May 2005 aimed to treat all flowing watercourses and greatly increased the number of treatment points. This led to the successful elimination of the vector. The last biting S. damnosum s.l. was caught in March 2005 and none have been found since then for more than 3 years.

[Epicardial atrial pacing using an active fixation bipolar endocardial lead in children]

Good performance was observed over 10 years after implantation of bipolar epicardial atrial pacing using an active fixation bipolar endocardial lead in 3 pediatric patients with congenital heart block. The bipolar endocardial lead which was supposed to be fixed transvenously was implanted on the atrial surface by first screwing the lead's helix into the myocardium. The catheter was then laid down on the atrial surface, and both electrodes were wrapped by the atrial tissue. The good performance of this pacing lead seemed to depend on stable positioning of the electrode. This lead is superior to the commercially available, and steroid eluting epicardial bipolar pacing lead, on the point of its small size in head and body, and could be applied to dual chamber pacing in smaller children.

[African programme for onchocerciasis control (APOC): entomological aspects of Onchocerca volvulus transmission by Simulium neavei in the Basin of Sankuru (Eastern Kasai, Democratic Republic of Congo)]

As part of a study to evaluate the long-term impact of community-directed treatment with ivermectin (CDTI), baseline entomological data on the transmission of onchocerciasis in the forest zone of the Eastern Kasai Province were collected from July 1998 to January 1999. Species of the Simulium neavei complex were the only vectors found in the site during the study. Nuisance activity was low with a mean biting rate of only 32.5 bites/man/day. The mean parturity rate was 29.4%, the mean rate of infected females was 14.5% and the mean number of infective Onchocerca larvae per 1000 parous flies was 659. These findings clearly show that the S. neavei population at the study site has high vector capability and constitutes a large microfilarial reservoir. The entomological features found in the study area are consistent with a hyper-endemic zone.

[Onchocerciasis in the area of Lastourville, Gabon. Clinical and entomological aspects]

The African Programme for Onchocerciasis Control (APOC) has implemented a series of surveys aimed at evaluating the long-term impact of its activities. The region of Lastourville (Gabon) is one of the selected sites for this study. A total of 886 persons was examined for skin lesions, and 459 out of them participated in detailed ocular examinations. Blackflies were collected during one year and dissected. Although the focus was found to be hypoendemic (prevalence of nodules: 7.7%), the frequency of onchodermatitis was relatively high. The lesions of the anterior segment of the eye were rare, but the prevalence of optic nerve disease, and of choroido-retinal lesions reached 5.2 and 2.7%, respectively. The annual transmission potential (2,171 infective larvae per man) was high, when compared with the results recorded in the human population. This may be due to the presence of Onchocerca spp. of animal origin in the blackflies. These results indicate that in the area of Lastourville, though regarded as the main focus of onchocerciasis in Gabon, the disease is relatively mild.

[African Programme for Onchocerdasis Control (APOC): Onchocerca Simulium squamosum in two regions in the Republic of Cameroon]

In 1998, the African Programme for Onchocerciasis Control (APOC) decided to launch a long-term impact assessment of its operations. This paper reports the baseline entomological data collected throughout a whole year in two sites of Cameroon (Kahn and Bolo). The Simulium populations of the two study sites were characterized by parous rates of 7.2% and 33.5% respectively and infectivity by O. volvulus of 31 and 190 infective larvae per 1000 parous flies respectively The Annual Transmission Potentials (ATP) were respectively 523 and 9972 infective larvae per man and per year in Kahn and in Bolo. The Simulium populations studied in both sites, even though the ATP in Kahn is 19 times lower than that of Bolo, showed a pattern of an onchocerciasis hyperendemic zone in terms of vector capacities and entomological indices.

Programme africain de lutte contre l’onchocercose (APOC) : transmission d’Onchocerca volvulusparSimulium damnosumS. l. dans deux régions de la République Centrafricaine

Entomological baseline data were collected in the villages of Zinga and Boali-Falls in Central African Republic (CAR) in view of the long term impact assessment of community-directed treatment with ivermectin (CDTI). Morphological determinations revealed that flies caught in both sites belong to the sub-group Sou/Sq. In Boali, the nuisance was relatively high with biting rates averaging 243 bites/man/day, with a parous rate of 61.6% and a crude annual transmission potential (ATP) of 8,259 infective larvae/man/year; and the average number of infective larvae per 1,000 parous flies was 177. In Zinga, the mean biting rate was 191 bites/man/day, with a parous rate of 51.6%, a crude ATP of 3,422, and 86 infective larvae per 1,000 porous flies. In conclusion, the vectorial capacity and the entomological indices recorded are characteristic of high onchocerciasis transmission zones. However, some of the infective larvae found, maybe of animal origin, need identification to better determine the real level of endemicity.

[Cor triatriatum diagnosed in adulthood; report of a case]

Cor triatriatum is a rare congenital cardiac anomaly especially in adulthood. A 68-year-old female was diagnosed as a cor triatriatum classified to Lucas-Schmidt IA, severe degree of mitral regurgitation and atrial fibrillation. Resection of the abnormal diaphragm in the left atrium and miral valve replacement were performed. Although the reason of sudden death of this patient after discharge is unknown, surgical intervention for atrial fibrillation should have performed to prevent a thromboembolism in such cases.

[Delayed onset malignant hyperthermia after a closure of ventricular septal defect]

An 18 month-old girl was diagnosed as ventricular septal defect (VSD) with mild aortic valve prolapse. She underwent a closure of VSD. Intra-and early postoperative course was uneventful. However, 20 hours after surgery, sudden bradycardia led to cardiac arrest and strong muscle rigidity was seen. Hyperkalemia and metabolic acidosis rapidly progressed and resuscitation was failed. Extracorporeal life support and continuous hemodialysis were initiated, but the patient died with multiple organ failure on 5th postoperative day. Her clinical course supported the diagnosis of delayed onset malignant hyperthermia. Histopathological findings of muscle biopsy were consistent with rhabdomyolysis, and immunopathological stains demonstrated changes as in a Duchenne type muscular dystrophy carrier. Delayed onset malignant hyperthermia is an extremely rare complication of general anesthesia. We should be aware of this lethal condition, which occurs with a certain time lag after surgery, especially when the patient has possible background of myopathy.

[Leaflet extension technique in a congenital aortic valve regurgitation]

A 17-year-old boy who was diagnosed as congenital aortic valve regurgitation underwent the leaflet extension technique in 3 aortic leaflets using glutaraldehyde-preserved autologous pericardium. Intraoperative transesophageal echocardiography and postoperative cardiac catheter revealed grade I regurgitation and the patient has been doing well for more than 4 months after the surgery. The leaflet extension technique is considered to be an acceptable surgical treatment for aortic valve disease especially in young patients to whom valve replacement or Ross procedure might not be suitable. A careful long-term follow-up will be necessary to evaluate the durability of the leaflet extension technique with autologous pericardium.

[Right-sided infective endocarditis with a large size vegetation]

A 2-year-old boy with ventricular septal defect(VSD) had suffered from right-sided infective endocarditis with a vegetation 1.0 cm in size, involving pulmonary valve. Resection of the vegetation and partial resection of the pulmonary valve and patch closure of the VSD was performed after 3 weeks intravenous antibiotic therapy. In right-sided infective endocarditis, it is still unclear, however, which factors may be useful in predicting outcome or determining the need of surgical intervention. We recognize that following factors are the risk for need of surgical intervention. 1. persistent infection, 2. sever right-sided heart failure, 3. multiple embolic episodes, 4. infected by Staphylococcus aureus, 5. infection involving the annulus of the valve, 6. infection of prosthetic valve, 7. vegetation which is floppy and greater than 1.0 cm in size.

[Management of mediastinitis after pediatric cardiac surgery with continuous closed irrigation method]

Two cases are presented as a successful management for mediastinitis with the continuous closed irrigation method after pediatric cardiac surgery. The continuous closed irrigation method has significant advantages over conventional open irrigation method or muscle flap in pediatric cases, because the system is simple to handle and easy to wash out any infectious tissue debris without additional invasive intervention. However, adequate duration of the irrigation and subsequent antibiotic regimen is still unclear. We conclude that the continuous closed irrigation method is an effective management which is applicable to most of mediastinitis cases after pediatric cardiac surgery.

Gender issues in the community-directed treatment with ivermectin (CDTI) of the African Programme for Onchocerciasis Control (APOC)

This paper reviews the issues relating to compliance and participation among the men and women of three countries within the remit of the African Programme for the Control of Onchocerciasis (APOC): Cameroon, Nigeria and Tanzania. Project-monitoring data from 109 focus-group discussions, 6069 household-survey respondents and 89 interviews with ivermectin distributors were analysed to gain an insight into the attitudes and behaviours of men and women in relation to ivermectin treatment and their participation in the programme. Although there are no statistically significant gender differences in coverages for ivermectin treatment, culturally prescribed gender relationships influence the ways in which men and women express and experience treatment-related behaviours. Gender roles also affect participation in the programme. Decision-making in communities on the selection of distributors tends to follow socio-cultural hierarchies based upon patriarchy and gerontocracy. Relatively few ivermectin distributors (21%) are women. Although they receive less support than their male counterparts, the female distributors are just as willing to continue ivermectin distribution in the community, and they perform as well or better than men in this regard. The terms 'community-directed', 'community participation' and even 'compliance' obfuscate important gender differences that are inherent in the implementation of onchocerciasis control. Development of strategies that recognize these gender differences will have important implications for long-term adherence to treatment and for the overall quality and sustainability of the programme.

APOC's strategy of community-directed treatment with ivermectin (CDTI) and its potential for providing additional health services to the poorest populations. African Programme for Onchocerciasis Control

Since its inauguration in 1995, the African Programme for Onchocerciasis Control (APOC) has made significant progress towards achieving its main objective: to establish sustainable community-directed treatment with ivermectin (CDTI) in onchocerciasis-endemic areas outside of the remit of the Onchocerciasis Control Programme in West Africa (OCP). In the year 2000, the programme, in partnership with governments, non-governmental organizations and the endemic communities themselves, succeeded in treating 20,298,138 individuals in 49,654 communities in 63 projects in 14 countries. Besides the distribution of ivermectin, the programme has strengthened primary healthcare (PHC) through capacity-building, mobilization of resources and empowerment of communities. The community-directed-treatment approach is a model that can be adopted in developing other community-based health programmes. The approach has also made it possible to bring to the poor some measure of intervention in some other healthcare programmes, such as those for malaria control, eye care, maternal and child health, nutrition and immunization. CDTI presents, at all stages of its implementation, a unique window of opportunity for promoting the functional integration of healthcare activities. For this to be done successfully and in a co-ordinated manner, adequate funding of CDTI within PHC is as important as an effective sensitization of the relevant policy-makers, healthworkers and communities on the value of integration (accompanied by appropriate training at all levels). Evaluation of the experiences in integration of health services, particularly at community level, is crucial to the success of the integration.

The challenges of community-directed treatment with ivermectin (CDTI) within the African Programme for Onchocerciasis Control (APOC)

The principal strategy adopted by the African Programme for Onchocerciasis Control (APOC), for the control of onchocerciasis in the 19 countries of Africa that now fall within the programme's remit, is that of community-directed treatment with ivermectin (CDTI). Halfway through its 12-year mandate, APOC has gathered enough information on the main challenges to guide its activities in Phase 2. An analysis of reports and other documents, emanating from consultants, scientists, monitors and national and project-level implementers, indicates that there are three broad categories of challenge: managerial; technical; and socio-political. Under these three categories, this review identifies the most pertinent concerns that APOC must address, during Phase 2, to enhance the prospects of establishing sustainable systems for ivermectin distribution. The major challenges include: (1) maintaining timely drug-collection mechanisms; (2) integrating CDTI with existing primary-healthcare services; (3) strengthening local health infrastructure; (4) achieving and maintaining an optimal treatment coverage; (5) establishing and up-scaling community self-monitoring; (6) designing and implementing operations research locally; (7) ensuring the adequacy of community-directed distributors; (8) increasing the involvement of local non-govemmental develop organizations in the programme; (9) achieving financial sustainability; (10) implementing equitable cost-recovery systems; and (11) engaging in effective advocacy. The implications of the challenges and suggestions about how they are being (or could be) addressed are also highlighted in this brief review, which should be of value to other programmes and agencies that may be contemplating the adoption of this unique strategy.

Rapid epidemiological mapping of onchocerciasis (REMO): its application by the African Programme for Onchocerciasis Control (APOC)

One of the fundamental challenges that the African Programme for Onchocerciasis Control (APOC) has had to face is how to identify the endemic communities where its mass ivermectin-treatment operations are to be carried out in conformity with its stated objective of targetting the most highly endemic, affected and at-risk populations. This it has done by adopting a technique, known as the rapid epidemiological mapping of onchocerciasis (REMO), that provides data on the distribution and prevalence of onchocerciasis. Integration of the REMO data into a geographical information system (GIS) enables delineation of zones of various levels of endemicity, and this is an important step in the planning process for onchocerciasis control. Zones are included in (or excluded from) the APOC-funded programme of community-directed treatment with ivermectin (CDTI), depending on whether or not their levels of onchocercal endemicity reach the threshold set by APOC. This review describes the application of the REMO/GIS technique by APOC in its operations, and identifies the remaining related challenges.

Monitoring community-directed treatment programmes for sustainability: lessons from the African Programme for Onchocerciasis Control (APOC)

Community-directed treatment is a relatively new strategy that was adopted in 1997 by the African Programme for Onchocerciasis Control (APOC), for large-scale distribution of ivermectin (Mectizan). Participatory monitoring of 39 of the control projects based on community-directed treatment with ivermectin (CDTI) was undertaken from 1998-2000, with a focus on process implementation of the strategy and the predictors of sustainability. Data from 14,925 household interviews in 2314 villages, 183 complete treatment records, 382 focus-group discussions, and the results of interviews with 669 community leaders, 757 trained community-directed drug distributors (CDD) and 146 health personnel (in 26 projects in four countries) were analysed. The data show that CDD dispensed ivermectin to 65.4% of the total population (71.2% of the eligible population), with no significant gender differences in coverage (P > 0.05). Treatment coverage ranged from 60.2% of the eligible subjects in Cameroon to 76.9% in Uganda. There was no significant relationship between the provision of incentives to CDD and treatment coverage (P > 0.05). The frequency of treatment refusal was highest in Cameroon (29.2%). Although most (72.1%) of the communities investigated selected their CDD on the basis of a community decision at a village meeting, only 37.9% chose their distribution period in the same way. There is clearly a need to improve communication strategies, to address the issues of absentees and refusals, to emphasise community ownership and to de-emphasise incentives for CDD. The investigation of the 'predictor indicators' of sustainability should enable APOC to understand the determinants of project performance and to initiate any appropriate changes in the programme.

The achievements and challenges of the African Programme for Onchocerciasis Control (APOC)

The main strategy of APOC, of community-directed treatment with ivermectin (CDTI), has enabled the programme to reach, empower and bring relief to remote and under-served, onchocerciasis-endemic communities. With CDTI, geographical and therapeutic coverages have increased substantially, in most areas, to the levels required to eliminate onchocerciasis as a public-health problem. Over 20 million people received treatment in 2000. APOC has also made effective use of the combination of the rapid epidemiological mapping of onchocerciasis (REMO) and geographical information systems (GIS), to provide information on the geographical distribution and prevalence of the disease. This has led to improvements in the identification of CDTI-priority areas, and in the estimates of the numbers of people to be treated. A unique public-private-sector partnership has been at the heart of APOC's relative success. Through efficient capacity-building, the programme's operations have positively influenced and strengthened the health services of participating countries. These laudable achievements notwithstanding, APOC faces many challenges during the second phase of its operations, when the full impact of the programme is expected to be felt. Notable among these challenges are the sustainability of CDTI, the strategy's effective integration into the healthcare system, and the full exploitation of its potential as an entry point for other health programmes. The channels created for CDTI, could, for example, help efforts to eliminate lymphatic filariasis (which will feature on the agenda of many participating countries during APOC's Phase 2). However, these other programmes need to be executed without compromising the onchocerciasis-control programme itself. Success in meeting these challenges will depend on the continued, wholehearted commitment of all the partners involved, particularly that of the governments of the participating countries.

Successful surgical management of a tracheopulmonary artery fistula caused by an intratracheal expandable metal stent

We describe a boy who underwent slide tracheoplasty and relocation of the left pulmonary artery at 3 months of age to treat pulmonary artery sling with congenital tracheal stenosis. Persisting tracheal stenosis required that he have a Palmaz stent inserted on postoperative day 77. He developed massive hemoptysis after the fourth attempt to expand the stent balloon and immediate computed tomography showed a tracheopulmonary artery fistula. Using cardiopulmonary bypass, we conducted emergency surgery to successfully manage the fistula. He currently depends on mechanical ventilation.

[Usefulness of 99mTc-methoxy-isobutyl-isonitrile scintigraphy for preoperative localization of adenoma in primary hyperparathyroidism]

We evaluated the usefulness of 99mTc-methoxy-isobutyl-isonitrile (MIBI) dual phase scintigraphy for detecting hyperfunctioning parathyroid adenoma. We retrospectively reviewed 18 hyperparathyroid patients who received MIBI prior to neck exploration and compared the radiological findings of MIBI with ultrasonography (US) and magnetic resonance imaging (MRI). Fifteen patients were studied with MRI, and 17 patients were examined with US. All patients were found to have a solitary parathyroid adenoma histopathologically. MIBI correctly revealed the location of 17 adenomas among 18 confirmed tumors. In our series, there was one false-positive case that was found to have thyroid adenoma. The diagnostic sensitivity of MIBI MRI and US was 94.4%, 80% and 52.5%, respectively. The positive predictive value (PPV) was 94.4% for MIBI, 81.8% for MRI and 92.3% for US. We conclude that MIBI is useful and accurate for the preoperative localization of adenoma in primary hyperparathyroidism.

Quantitative analysis of hypertrophy in cardiac chambers in cyanotic tetralogy of Fallot

Although early total corrective repair for cyanotic tetralogy of Fallot is now safely performed at many institutions, long-term complications after surgical repair have been demonstrated. Therefore, the optimal procedure and timing for surgical treatment remain controxersial. In the present study, we conducted a quantitative analysis of the hypertrophy of all four chambers of 87 autopsied hearts of cyanotic tetralogy of Fallot and 71 normal control hearts utilizing the myocardial mass index, and evaluated the progression of lesions with advancing age. In cyanotic tetralogy of Fallot, hypertrophy of the right ventricle progresses immediately after birth, with that of the right atrium developing soon after. The left side of the heart is normal or slightly atrophied which could be corrected by sufficient palliative intervention or total corrective repair. The growth curves of both ventricles were parallel to those of normal hearts for the period studied. Pulmonary atresia, palliative operation, and total corrective repair have been shown to have some influence on the morphological characteristics of hearts of cyanotic tetralogy of Fallot.

[A case of large congenital right ventricular outflow aneurysm]

A rare case of large congenital right ventricular outflow aneurysm is reported. A 5-year-old girl had been diagnosed as having atrial septal defect and pulmonary valvular stenosis. A large cavity in front of right ventricular outflow was noticed by her follow-up echocardiography. The non-contracting cavity was confirmed as an aneurysm originating from right ventricular outflow tract by angiocardiogram. Surgical resection was performed successfully with concomitant atrial septal defect closure and pulmonary valvular commissurotomy. Histological examination revealed that the wall of the ventricular outflow aneurysm consisted of dense fibrous tissue, contained no myocardium, and the cavity was lined with endocardium. It is reported that rupture of congenital ventricular aneurysm may occur even if there is no symptom. Surgical resection will be recommended especially when increasing in size is diagnosed.

The effects of ivermectin on onchocercal skin disease and severe itching: results of a multicentre trial

OBJECTIVE

To determine the effects of ivermectin in annual, 3-monthly and 6-monthly doses on onchocercal skin p6isease (OSD) and severe itching.

METHOD

A multicentre, double-blind placebo controlled trial was conducted among 4072 residents of rural communities in Ghana, Nigeria and Uganda. Baseline clinical examination categorized reactive skin lesions as acute papular onchodermatitis, chronic papular onchodermatitis and lichenified onchodermatitis. Presence and severity of itching was determined by open-ended and probing questions. Clinical examination and interview took place at baseline and each of 5 subsequent 3-monthly follow-up visits.

RESULTS

While prevalence and severity of reactive lesions decreased for all 4 arms, those receiving ivermectin maintained a greater decrease in prevalence and severity over time. The difference between ivermectin and placebo groups was significant for prevalence at 9 months and for severity at 3 months. Differences between placebo and ivermectin groups were much more pronounced for itching. From 6 months onward, the prevalence of severe itching was reduced by 40-50% among those receiving ivermectin compared to the trend in the placebo group.

CONCLUSION

This is an important effect on disease burden as severe itching is for the affected people the most troubling complication of onchocerciasis. The difference among regimens was not significant, and the recommended regimen of annual treatment for the control of ocular onchocerciasis appears also the most appropriate for onchocerciasis control in areas where the skin manifestations predominate. The final determination of the effect on skin lesions requires a longer period of study.

Delivery systems and cost recovery in Mectizan treatment for onchocerciasis

The efficiency of on-going delivery systems and cost recovery in Mectizan (ivermectin, MSD) treatment for onchocerciasis are reviewed. The search is on for an effective system of Mectizan delivery, involving drug procurement, delivery from port to districts and distribution to eligible persons, which can be sustained by the endemic countries for many years. The mechanisms for procuring and clearing the drug at the ports, and the drug's integration into the existing delivery systems of each national health service, need to be improved. Although large-scale treatments by mobile teams or community-based methods evidently achieve high and satisfactory rates of coverage, they also incur high recurrent costs which have to be covered by external partners and are not sustainable by national health services. Cost-sharing is considered an important factor in a sustainable delivery system and community-directed treatment, in which the community shares the cost and ownership of local distribution and is empowered to design and implement it, is likely to be more cost-effective and sustainable.

Morphological changes and hypomethylation of DNA in transgenic tobacco expressing antisense RNA of the S-adenosyl-L-homocysteine hydrolase gene

S-adenosyl-L-homocysteine hydrolase (SAHH) is a key enzyme in the regulation of intracellular methylation reactions. To investigate the role of SAHH in methylation reactions and morphogenesis in planta, we have made transgenic plants expressing antisense RNA of tobacco SAHH. The transgenic plants displayed distinct morphological changes including a floral homeotic change. We hypothesized that the changes were caused by increased levels of cytokinin. In those transgenic plants, we observed that a repetitive DNA sequence appeared less methylated than controls. We speculated that altered gene expressions by the hypomethylation of DNA might be involved in the changes.

Morphological changes and hypomethylation of DNA in transgenic tobacco expressing antisense RNA of the S-adenosyl-L-homocysteine hydrolase gene

S-adenosyl-L-homocysteine hydrolase (SAHH) is a key enzyme in the regulation of intracellular methylation reactions. To investigate the role of SAHH in methylation reactions and morphogenesis in planta, we have made transgenic plants expressing antisense RNA of tobacco SAHH. The transgenic plants displayed distinct morphological changes including a floral homeotic change. We hypothesized that the changes were caused by increased levels of cytokinin. In those transgenic plants, we observed that a repetitive DNA sequence appeared less methylated than controls. We speculated that altered gene expressions by the hypomethylation of DNA might be involved in the changes.

[A case report of a fenestrated Fontan operation after bivalvation of the common atrioventricular valve in right isomerism]

The patient is a boy of five years old with asplenia, dextrocardia, right aortic arch, bilateral superior vena cavae, single atrium, common atrioventricular orifice, double outlet right ventricle and pulmonary stenosis. He underwent operations of right Blalock-Taussig shunt and right superior vena cava ligation when he was eight months old and at the age of three years old, bidirectional Glenn procedure and bivalvation of the common atrioventricular valve (CAVV) as he, then, suffered from severe regurgitation of the CAVV. The regurgitation improved from grade 3 to 1 and his recovery allowed the fenestrated Fontan operation at the age of four years and nine months. Bivalvation is an effective means for the mitigation of regurgitation of CAVV and paves the way for application of Fontan-type operation.

Successful engraftment of allogeneic CD34-enriched marrow cell transplantation from HLA-mismatched parental donors

The CD34 antigen is expressed on pluripotent stem cells and the CD34+ cell has been shown to be capable of hematopoietic reconstitution in animal and human autologous grafts. We asked if CD34+ cells could reconstitute hematopoiesis in human allogeneic transplantation from a HLA-mismatched donor. Three pediatric patients with advanced leukemia received allogeneic CD34-enriched marrow cell graft from HLA two (two patients) or three (one patient) loci-mismatched parental donors. CD34+ cell selection was performed with mouse anti-CD34 antibody 9C5 and magnetic beads coated sheep anti-mouse IgG1. 1.53 to 2.48 x 10(9) marrow cells were processed and 2.53 to 7.89 x 10(7) positively selected cells were recovered. The selected population showed 93.7 to 99.0% CD34+ cells and total recovery of CD34+ cells from the starting population was 54.6 to 62.3%. CD34+ cell selection resulted in more than 99.9% depletion of CD5+ cells from the bone marrow. The patients received 2.53 to 7.25 x 10(6) CD34-enriched cells/kg after myeloablative therapy. All patients achieved trilineage engraftment that was confirmed by various genetic markers. Acute graft-versus-host disease (GVHD) was grade 0 (two patients) or grade I (one patient), and hematological recovery was successfully achieved as follows; the days to reach granulocytes over 0.5 x 10(9)/I were 11 to 13 days, reticulocytes over 2% was 18 to 28 days, platelets over 50 x 10(9)/I was 33 to 58 days. One patient is surviving without relapse of leukemia and two patients died after either mixed hematopoietic chimerism or leukemia relapse was observed. These studies suggest that CD34+ marrow cells are capable of hematopoietic reconstitution from HLA two or three loci-mismatched donors even with the lowest dose of mature T cells.

Identification of two isoforms of mouse neuropeptide Y-Y1 receptor generated by alternative splicing. Isolation, genomic structure, and functional expression of the receptors

Two cDNA clones homologous with human neuropeptide (NP) Y-Y1 receptor have been isolated from a mouse bone marrow cDNA library. One was thought to be the cognate of the human NPY-Y1 receptor, termed Y1 alpha receptor, and the other form, termed Y1 beta receptor, differed from the Y1 alpha receptor in the seventh transmembrane domain and C-terminal tail. Analysis of the mouse genomic DNA showed that both receptors originated from a single gene. The different peptide sequences of the Y1 beta receptor were encoded by separate exons, hence, these receptors were generated by differential RNA splicing. High affinity binding of [125I]NPY to each receptor expressed in Chinese hamster ovary (CHO) cells and sequestration of [125I]NPY after binding to each receptor were observed. In the CHO cells expressing the Y1 alpha receptor, intracellular Ca2+ increase, inhibition of forskolin-induced cAMP accumulation, and mitogen-activated protein kinase (MAPK) activation were observed by stimulation of NPY, and these responses were abolished by pretreatment with pertussis toxin. Since wortmannin completely inhibited NPY-elicited MAPK activation, we speculate that wortmannin-sensitive signaling molecule(s) such as phosphoinositide 3-kinase may lie between pertussis toxin-sensitive G-protein and MAPK. In contrast, these intracellular signals were not detected in CHO cells expressing the Y1 beta receptor. Northern blots and reverse transcriptase-polymerase chain reaction analyses indicated that the Y1 alpha receptor was highly expressed in the brain, heart, kidney, spleen, skeletal muscle, and lung, whereas the Y1 beta receptor mRNA was not detected in these tissues. However, the Y1 beta receptor was expressed in mouse embryonic developmental stage (7 and 11 days), bone marrow cells and several hematopoietic cell lines. These results suggest that the Y1 beta receptor is an embryonic and a bone marrow form of the NPY-Y1 receptor, which decreases in the expression during development and differentiation.

[A case of supravalvular pulmonary stenosis with atrial septal defect]

We reported a case of supravalvular pulmonary stenosis with atrial septal defect (ASD) in 37-year-old man. Extended pulmonary arterioplasty with the technique of Doty's operation for supravalvular aortic stenosis was carried out with bovine pericardial patch. Pressure gradient between the right ventricle and the pulmonary artery reduced from 90 to 20 mmHg after this operation. Doty's technique could be modified and successfully applicable to supravalvular pulmonary stenosis.

A radioreceptor binding assay for platelet-activating factor (PAF) using membranes from CHO cells expressing human PAF receptor

A simple and reproducible radioreceptor assay (RRA) has been developed using membranes from CHO cells which can stably express human platelet-activating factor (PAF) receptor. The CHO cells expressing the PAF receptor, termed CHO.1F8, showed a significant intracellular Ca2+ response to PAF, and the same binding properties to [3H]WEB 2086, a PAF antagonist, as reported (Kd, 13.6 +/- 1.9 nM; Bmax, 2.5 +/- 0.4 pmol/mg protein (n = 6)). A competitive binding assay was done using the CHO.1F8 cell membranes and [3H]WEB 2086. The minimum detectable dose of PAF was 0.3 nM (approximately 30 pg per well) and the assay was highly specific for PAF. This method makes it possible to handle large numbers of samples rapidly and simultaneously, since the receptor membrane is prepared in advance and the binding assay can be completed within 3 h. Using this method, we have determined the production and cell association of PAF in human neutrophils.

[Citrate and ionized calcium on extracorporeal circulation in pediatric cardiac surgery]

The control of optimum concentrations of ionized calcium Ca2+ during cardiopulmonary bypass is important in maintaining cardiac function and reducing reperfusion injury. Ca2+ may be in part dependent upon the serum level of citrate Cit in use of hemodiluted prime in pediatric cardiac surgery. The purpose of this study was to ascertain fluctuations of Ca2+ during bypass in relation to Cit and to study control of optimum Ca2+. Ca2+ and Cit was measured prior to and every 10 or 20 minutes during bypass in 12 children aged 21 days to 6 years. Of 6 patients (body weight less than 6 kg) received acid-citrate-dextrose (ACD) solution 20 ml before aortic declamp to give low Ca2+ for reducing reperfusion injury. Ca2+ showed initial drop and then gradually increased as the result of decreasing Cit. Ca2+ was inversely correlated with Cit (r = 0.85, p = 0.0001). When ACD 20 ml was added, Ca2+ significantly decreased from 1.00 +/- 0.13 to 0.65 +/- 0.13 mmol/l. However, Cit remained 24.3 +/- 13.3 mg/dl at the end of bypass. In conclusion, the results of this study suggest that gradually increasing Ca2+ during bypass may be related to the rate of citrate metabolism and the use of citrate for the control of Ca2+ remains questionable.

Improvement of coronary vasomotion with eicosapentaenoic acid does not inhibit acetylcholine-induced coronary vasospasm in patients with variant angina

Impaired function of the endothelium may be a mechanism of the coronary vasospasm induced by acetylcholine. We examined whether purified eicosapentaenoic acid (EPA), a major component of fish oil, improves the coronary vasomotion in response to acetylcholine, and the effect of purified EPA on acetylcholine (ACh)-induced coronary vasospasm in 22 patients with variant angina. ACh was infused into the coronary artery both before and after 4 months of EPA treatment (EPA 1.8 g/day, n = 12). In the control group (n = 10) that did not receive EPA, the response of the coronary diameter to ACh did not change over time. In the EPA-treated group, the cholinergic response in non-spastic sites changed from vasoconstriction to vasodilation, while ACh-induced coronary vasospasm persisted at the spastic sites. Therefore, EPA treatment improved the coronary vasomotor responsiveness to ACh, but did not inhibit ACh-induced coronary vasospasm.

[Postoperative bronchial stenosis associated with IAA complex and transendoscopic resection of intrabronchial granulation]

Problem with stenosis of the left bronchus was encountered in a patient with type B interrupted aortic arch complex after the arch reconstruction and pulmonary artery banding. Bronchoscopic study disclosed the intraluminal granulation of left bronchus and transendoscopic resection of the granulation successfully relieved the stenosis and brought the patient to full recovery.

Broad resistance to plant viruses in transgenic plants conferred by antisense inhibition of a host gene essential in S-adenosylmethionine-dependent transmethylation reactions

S-Adenosylhomocysteine hydrolase (SAHH) is a key enzyme in transmethylation reactions that use S-adenosylmethionine as the methyl donor. Because of the importance of SAHH in a number of S-adenosylmethionine-dependent transmethylation reactions, particularly the 5' capping of mRNA during viral replication, SAHH has been considered as a target of potential antiviral agents against animal viruses. To test the possibility of engineering a broad type of resistance to plant viruses, we expressed the antisense RNA for tobacco SAHH in transgenic tobacco plants. As expected, transgenic plants constitutively expressing an anti-sense SAHH gene showed resistance to infection by various plant viruses. Among those plants, about half exhibited some level of morphological change (typically stunting). Analysis of the physiological change in those plants showed that they contained excess levels of cytokinin. Because cytokinin has been found to induce acquired resistance, there is also a strong possibility that the observed resistance was induced by cytokinin.

[A case of multiple liver metastasis from remnant gastric cancer responding to leucovorin.5-FU+UFT therapy]

We report a case of a 67-year-old male patient who experienced multiple liver metastasis 6 months after undergoing an operation for remnant gastric cancer. The histological classification of the cancer in gastric remnant was poorly-differentiated adenocarcinoma. The patient was treated with a low dose of LV.5-FU once a week and oral UFT as an outpatient. As a result, after 3 months of the treatment, CT showed that multiple liver lesions almost disappeared, a condition that lasted about 3 years without relapse. Toxic effects due to this treatment were temporary slight liver disfunction, mild anorexia and stomatitis. This case indicates that the regimen of LV.5-FU+UFT may be effective for multiple liver metastasis from postoperative remnant gastric cancer, enabling the patient to maintain an excellent QOL (quality of life).

[Continuous intraarterial infusion of 5-fluorouracil plus leucovorin for liver metastases from colorectal cancer]

Between September 1990 and August 1994, 11 patients (pts) with liver metastases (mets) from colorectal cancer were treated with continuous hepatic arterial infusion chemotherapy of 5-fluorouracil (FU) plus leucovorin (LV). Eight pts had non-resectable liver mets (H3: 7, H2: 1), and 3 had residual small mets after resection of major mets. Drugs were administered via an extracorporeal infusion device connected to the hepatic arterial infusion port. 5-FU and LV were given through a 5- to 7-day continuous infusion at 500-750 mg/body/day and 30 mg/body/day, respectively, with a 3- to 4-week rest period. In the recent 6 pts, cisplatin was administered as a 2-hour infusion at 25 mg/body, one or two times simultaneously. Grade 2 toxicity was noted in two pts (18%). One was stomatitis and another was uncontrolled ascites in an advanced cirrhotic pt. The response rate in the 9 evaluable pts was 67% with 6 PR and no CR. The duration of the response was 5 to 9 months. One- and two-year survival rates were 75% and 22%, respectively. These results were superior to those of the intermittent bolus injection of 5-FU plus MMC (or epirubicin) in 40 pts from 1977 to 1994. These results suggest that continuous 5-FU plus LV arterial infusion is an effective regimen in pts with liver metastases from colorectal cancer. However, the infusion with an extracorporeal device limits the pts' quality of life. Further investigation is needed for a schedule that can be practiced for a longer period.

Human 5-lipoxygenase associates with phosphatidylcholine liposomes and modulates LTA4 synthetase activity

A Ca2+ and a phosphatidylcholine (PC) as stimulatory factors to human 5-lipoxygenase (5-LO) were assessed to examine aspects of the regulatory mechanism of 5-LO. In the presence of Ca2+ (1 microM or less), PC liposomes distinctly stimulated the dual activities of 5-LO for the production of 5-HPETE from arachidonate and for its subsequent conversion to LTA4. At the same concentration of Ca2+, 5-LO was found to bind to PC liposomes. As with 5-LO activities, the binding was dependent on the range of Ca2+ concentration. The conversion ratios of 5-HPETE to LTA4 were dependent on PC liposome concentration and reached a maximum of 50% conversion. Among the four cell membrane lipids examined, PC liposomes demonstrated the highest conversion ratio of 5-HPETE to LTA4 by 5-LO. Most of the arachidonate added to the reaction mixture localized in PC liposomes. These results confirm that the intracellular increase of Ca2+ concentration causes 5-LO to associate with the cell membrane and perform an interfacial reaction. They also suggest that this binding of 5-LO to the cell membrane enhances the subsequent conversion from 5-HPETE to LTA4.

Purification and characterization of a novel enzyme, alpha-neoagarooligosaccharide hydrolase (alpha-NAOS hydrolase), from a marine bacterium, Vibrio sp. strain JT0107

A novel enzyme, alpha-neoagarooligosaccharide hydrolase (EC 3.2.1.-), which hydrolyzes the alpha-1,3 linkage of neoagarooligosaccharides to yield agaropentaose (O-beta-D-galactopyranosyl(1-->4)-O-3,6-anhydro-alpha-L-galactopyranosyl (1-->3)-D-galactose], agarotriose [O-beta-D-galactopyranosyl(1-->4)-O-3,6-anhydro- alpha-L-galactopyranosyl (1-->3)-D-galactose], agarobiose [O-beta-D-galactopyranosyl(1-->4)-3,6-anhydro-L-galactose], 3,6-anhydro-L-galactose, and D-galactose was isolated from the marine bacterium Vibrio sp. strain JT0107 and characterized. This enzyme was purified 383-fold from cultured cells by using a combination of ammonium sulfate precipitation, successive anion-exchange column chromatography, gel filtration, and hydroxyapatite chromatography, gel filtration, and hydroxyapatite chromatography. The purified protein gave a single band (M(r), 42,000) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Estimation of the M(r) by the gel filtration method gave a value of 84,000, indicating that the enzyme is dimeric. Amino acid sequence analysis revealed it to have a single N-terminal sequence that has no sequence homology to any other known agarases. The optimum temperature and pH were 30 degrees C and 7.7, respectively. The Km and maximum rate of metabolism for neoagarobiose were 5.37 mM and 92 U/mg of protein, respectively.

X-ray structure of a pokeweed antiviral protein, coded by a new genomic clone, at 0.23 nm resolution. A model structure provides a suitable electrostatic field for substrate binding

We have determined the crystal structure of alpha-pokeweed antiviral protein, a member of ribosome-inactivating proteins, at 0.23 nm resolution, by the molecular-replacement method. The crystals belong to the space group P2(1)2(1)2 with unit-cell dimensions a = 4.71, b = 11.63 and c = 4.96 nm, and contain one protein molecule/asymmetric unit based on a crystal volume/unit protein molecular mass of 2.1 x 10(-3) nm3/Da. The crystallographic residual value was reduced to 17.2% (0.6-0.23 nm resolution) with root-mean-square deviations in bond lengths of 1.9 pm and bond angles of 2.2 degrees. The C alpha-C alpha distance map shows that alpha-pokeweed antiviral protein is composed of three modules, the N-terminal (Ala1-Leu76), the central (Tyr77-Lys185) and the C-terminal (Tyr186-Thr266) modules. The substrate-binding site is formed as a cleft between the central and C-terminal modules and all the active residues exist on the central module. The electrostatic potential around the substrate-binding site shows that the central and C-terminal module sides of this cleft have a negatively and a positively charged region, respectively. This charge distribution in the protein seems to provide a suitable interaction with the substrate rRNA.

Prevalence and pathogenesis of silent myocardial ischemia following myocardial infarction

The objective of this study was to examine the prevalence and pathogenesis of silent myocardial ischemia during exercise following myocardial infarction. Exercise-induced myocardial ischemia was assessed by 201Tl-SPECT (single photon emission computed tomography) 4.5 weeks after acute myocardial infarction in 229 patients. Exercise-induced myocardial ischemia occurred in 109 patients (48%), and 72 (32%) had silent ischemia. Although the prevalence of multivessel coronary artery disease was similar between patients with silent and symptomatic ischemia, the size of reversible myocardial ischemia was larger in patients with symptomatic ischemia than in those with silent ischemia (21.3 +/- 3.0% vs 13.2 +/- 1.9% of LV, p < 0.05). The incidence of reversible ischemia remote from the infarct area was higher in patients with symptomatic ischemia than in those with silent ischemia (30% vs 17%, p < 0.10). The cause of silent ischemia after myocardial infarction may be closely related to the smaller size of reversible myocardial ischemia. Ischemia remote from, or adjacent to, the infarct area could be a factor in determining the presence or absence of pain.

Effects of continuous intravenous infusion of isosorbide dinitrate on development of tolerance to vasodilating action in human epicardial coronary arteries

This study was performed to determine the effects of long-term intravenous infusion on the coronary vasodilating actions of continuous intravenous and bolus intracoronary administration of isosorbide dinitrate (ISDN). With quantitative coronary angiography, the coronary diameter and the vasodilating response to intracoronary ISDN (1 mg) at angiographically normal segments were studied before and after intravenous administration of ISDN, 10 to 60 micrograms/min for 1 hour, 2 days, or 5 days. The vasodilating effects of intravenous ISDN were 72% +/- 13%, 65% +/- 21%, and 6% +/- 11% of the response to intracoronary ISDN in the baseline study in each group. Irrespective of the duration of intravenous infusion, subsequent intracoronary ISDN dilated coronary arteries to extent similar to that observed in each baseline study. In conclusion, significant coronary vasodilating effects of intravenous ISDN were observed after a 2-day infusion, whereas tolerance to the vasodilating effects apparently developed within 5 days of infusion. The vasodilating response to bolus intracoronary ISDN was preserved even when the vasodilating effects of intravenous ISDN were no longer present.

Improved crystals of the toxic protein MAP by protein engineering towards the host specificity

Mirabilis anti-viral protein (MAP) is a ribosome-inactivating protein from Mirabilis jalapa L. Since MAP is effective over a broad spectrum of species, the protein is difficult to express in heterologous hosts such as Escherichia coli. Recently, we obtained a MAP mutant, Y72F which exhibits a lower (1/100) activity against E. coli ribosomes while retaining almost full activity against mammalian cells [Habuka, Miyano, Kataoka, Tsuge & Noma (1992). J. Biol. Chem. 267, 7758-7760]. For the crystallographic studies, the Y72F MAP expression vector with an OmpA leading sequence was constructed and expressed in E. coli. The Y72F MAP mutant was then isolated and purified from the cell culture medium. Crystals were grown using the crystallization conditions for the native MAP crystals [Miyano et al. (1992). J. Mol. Biol. 226, 281-283]: 50% ammonium sulfate containing 50 mM ammonium citrate and 2 mM adenine sulfate, pH 5.4. The crystals belong to space group P3(1)21 (or P3(2)21) with a = b = 104.1 and c = 134.3 A. The crystals are isomorphous with the wild-type crystals but diffract to higher resolution. Imaging-plate photographs of the Y72F mutant showed sharp intense spots without the streaking observed in the native crystals.

Interfacial kinetic reaction of human 5-lipoxygenase

The kinetics of human 5-lipoxygenase were investigated in the presence of Tween 20 using a continuous spectrophotometric assay. Using the mixture at a constant molar ratio of arachidonate/Tween 20 at pH 8.0, the steady-state velocity on a varied arachidonate concentration did not follow simple Michaelis-Menten-type kinetics and double-reciprocal plot analysis gave hyperbolic curves. However, by introducing the concept of a local pH change, it was possible to analyze the kinetics as simple Michaelis-Menten type. The concept of a local pH change implies that when utilizing an acidic and amphiphilic substance as a substrate, such as arachidonate, the medium around the substrate is acidified with an increased concentration of substrate. This concept was explained rationally by two experiments. Consequently, the data were transformed according to a local pH change and analyzed according to a dual phospholipid model as has been proposed for phospholipase A2 [Hendrickson, H. S. and Dennis, E. A. (1984) Kinetic analysis of the dual phospholipid model for phosphalipase A2, J. Biol. Chem. 259, 5734-5739]. It is concluded that 5-lipoxygenase performs an interfacial reaction in the arachidonate/Tween 20 mixed micelles in the same manner as phospholipase A2. The values of Km were almost constant (about 0.07 molar fraction), even when arachidonate molar ratios were changed in the surface of the mixed micelles. The values for Ks (the association constant of the enzyme to the micelle interface) ranged over 0.21-0.48 microM. The Vmax was 25.76 mumol.min-1.mg-1. This concept of a local pH change could be used extensively with enzymes which utilize both amphiphilic and acidic substances as substrates.

Crystallization and preliminary X-ray crystallographic studies of recombinant human leukotriene A4 hydrolase complexed with bestatin

Recombinant human leukotriene A4 hydrolase complexed with bestatin, an inhibitor of metalloprotease, has been crystallized by the hanging drop vapor diffusion method using 0.1 M phosphate buffer (pH 6.5) and 50 to 54% saturated ammonium sulfate. The orthorhombic crystals belong to the space group I222 or I2(1)2(1)2(1) with unit cell dimensions of a = 273.6 A, b = 261.3 A and c = 52.9 A. They diffract beyond 2.5 A resolution and a native data set up to 3 A resolution has been collected on an imaging plate Weissenberg camera using synchrotron radiation.