Multi-Criteria Optimization and RapidPlan for Improved Organs at Risk Sparing in Treatment Planning of Malignant Pleural Mesothelioma

PURPOSE/OBJECTIVE(S)

Treatment planning for malignant pleural mesothelioma is complex and time-consuming owing to the large volume of the target as well as its overlap and proximity to critical organs. Knowledge-based planning (KBP) model using RapidPlan (RP) was previously developed and clinically tested at our institution for treatment planning of these cases that had undergone pleurectomy-decortication, and therefore had two intact-lungs. The aim of this work is to investigate if multi-criteria optimization (MCO) can further improve the RP model with respect to organ at risk (OAR) sparing without compromising target coverage.

MATERIALS/METHODS

The RP model was trained with clinically accepted plans of 57 patients that used Volumetric Modulated Arc Therapy (VMAT) with 2 partial arcs and 6 MV photons. The dose volume histogram (DVH) estimation model was trained to estimate doses to the heart, ipsilateral lung, total lung, contralateral lung, stomach, esophagus, kidneys and liver. Clinical treatment plans for 12 patients were re-planned using RP as well as a combination of RP and MCO. Application of MCO was after RP and used tradeoff exploration to navigate to the improved dose distribution on a Pareto surface. Selection of a plan that further improved OAR sparing while maintaining coverage constraints of PTV D95 and V95 ≥ 94% was made. Dosimetric parameters for clinical plans (CP), plans using RP as well as plans generated with RP and MCO were all compared for 12 new validation cases. Wilcoxon sign-rank test was used for statistical significance testing.

RESULTS

The mean heart dose was reduced from 20.9 Gy ± 3.2 Gy for CP to 17.1 Gy ± 4.2 Gy with RP and further to 13.8 Gy ± 3.3 Gy with RP and MCO. The heart V30 Gy was reduced from 23.7% ± 8% to 18.2% ± 9.4% with RP and further to 13.6% ± 5.7% with RP and MCO. The corresponding results for contralateral lung V5 Gy were 68.6% ± 14.1% with CP, 50% ± 26.3% with RP and 45.3% ± 22.8% with RP and MCO, while the mean esophagus dose was reduced from 26.5 Gy ± 3.1 Gy to 21.5 Gy ± 4.7 Gy with RP and further to 19.1 Gy ± 4.2 Gy with RP and MCO. All these dosimetric improvements were statistically significant (p<0.001). However, improvements with RP and MCO for the total lung mean and V20 Gy, liver mean, stomach mean and kidney V18 Gy were marginal over the RP. Sparing of ipsilateral lung V20 Gy was maintained at ≥ 50 cc on average for all plans. PTV D95 and V95 were both normalized at 94%.

CONCLUSION

Combination of RP and MCO significantly improved sparing of the OARs, especially the heart, contralateral lung and esophagus without compromising coverage or doses to other structures. Since doses to the heart, and contralateral lung are known to correlate with incidence of radiation pneumonitis, it would be prudent to consider planning with both RP and MCO to help determine the optimal treatment plan for the individual patient's anatomy.

Federated learning enables big data for rare cancer boundary detection

Although machine learning (ML) has shown promise across disciplines, out-of-sample generalizability is concerning. This is currently addressed by sharing multi-site data, but such centralization is challenging/infeasible to scale due to various limitations. Federated ML (FL) provides an alternative paradigm for accurate and generalizable ML, by only sharing numerical model updates. Here we present the largest FL study to-date, involving data from 71 sites across 6 continents, to generate an automatic tumor boundary detector for the rare disease of glioblastoma, reporting the largest such dataset in the literature (n = 6, 314). We demonstrate a 33% delineation improvement for the surgically targetable tumor, and 23% for the complete tumor extent, over a publicly trained model. We anticipate our study to: 1) enable more healthcare studies informed by large diverse data, ensuring meaningful results for rare diseases and underrepresented populations, 2) facilitate further analyses for glioblastoma by releasing our consensus model, and 3) demonstrate the FL effectiveness at such scale and task-complexity as a paradigm shift for multi-site collaborations, alleviating the need for data-sharing.

RADI-29. BIOLOGIC SUBTYPES OF BREAST CANCER BRAIN METS AS A PREDICTOR OF LOCAL CONTROL AFTER STEREOTACTIC RADIOSURGERY

INTRODUCTION: Brain metastases (BM) are diagnosed in approximately 15% of breast cancer (BC) patients. Biologic subtype is predictive of loco-regional recurrence following breast conserving therapy and/or mastectomy with the highest risk in the ER-/PR-/HER2- (TN) subtype. The aim of this study is to determine whether biologic subtype is predictive of local control (LC) in BC patients with BM treated with Stereotactic Radiosurgery (SRS). MATERIALS/METHODS: All patients underwent LINAC-based SRS at our institution. Patients were subdivided into three biologic subtypes: ER+/Her2- (Luminal), Her2+, and TN (Basal). Kaplan Meier method was used to estimate the overall survival (OS). Cox proportional hazard model was used to analyze association of local failure (LF) with biologic subtypes. This is an IRB-approved single center retrospective study. RESULTS: 108 BC BM in 50 consecutive patients were included in this study with a median follow up of 11.1 months. The median disease-specific GPA was 2.0, and all patients received systemic chemotherapy and/or hormonal therapy. The 12 month LC rates for the entire cohort were 85%, 87%,49% for Luminal, Her2+ and Basal, respectively, with a significantly shorter LC for the basal sub-type (p=0.014). The 12 month OS rates were 83%, 88%, 80% for Luminal, Her2+ and Basal, respectively with a no significant difference in OS among the subgroups. 24% of the lesions were treated with salvage whole brain radiation therapy. CONCLUSIONS: This study shows that in BC patients with BM treated with SRS, biologic subtype impacts LC but not OS. Consideration of radiation treatment intensification or altered fractionation to improve LC may be indicated for the TN subtype. Further multi-center studies are necessary to corroborate our results.

Off-target-isocentric approach in non-coplanar Volumetric Modulated Arc Therapy (VMAT) planning for lung SBRT treatments

PURPOSE

Volumetric Modulated Arc Therapy (VMAT) has emerged as an efficient alternative to traditional three-dimensional (3D) non-coplanar conformal (3D-NC-C) beams for lung cancer stereotactic body radiotherapy (SBRT) because of its superior dosimetric properties and native ease in planning and treatment delivery. However, patient immobilization in lung SBRT often presents challenging geometrical clearance issues in the execution of large (in excess of 180°) non-coplanar arcs. In this study, we present an off-target-isocentric, non-coplanar VMAT (OTI-NC-VMAT) technique that appears to be simple, dosimetrically robust and allows for ample patient/couch-gantry clearance. We compared this technique to a target-isocentric, non-coplanar VMAT (TI-NC-VMAT) technique and the 3D-NC-C beams for dosimetric evaluations.

METHODS

Nineteen lung cancer patients previously treated with 3D-NC-C SBRT technique at our institution were selected. For each patient, an OTI-NC-VMAT plan and TI-NC-VMAT plan were created and compared to the original 3D-NC-C treatment plan. All of the plans were created for the same prescription dose of 54 Gy total in 3 fractions, covering 95% of the planning target volume (PTV). Nine to ten non-coplanar beams were used for the 3D technique and three non-coplanar arcs were used in both the TI-NC-VMAT and OTI-NC-VMAT plans, with the couch set at ± 20° and 0°, with each arc rotation in excess of 180°. Progressive Resolution Optimizer (PRO) in Varian Eclipse version 11 was used for all of the treatment planning. Conformity Index (CI), conformity number (CN), gradient index (GI), maximum dose at 2 cm away from the PTV (D2cm), mean lung dose (MLD), V20, V5 and mean target dose (MTD) were analyzed for all of the plans. We also performed statistical analysis to examine differences in the dosimetric indices between 3D and VMAT techniques.

RESULTS

Dosimetric indices CI, CN, GI, V20 and MTD values were similar, within 5%, for all three plans: 3D-NC-C, TI-NC-VMAT and OTI-NC-VMAT. However, both types of VMAT plans were dosimetrically superior to 3D conformal plans in organ-at-risk (OAR) sparing; D2cm, MLD, and V5 values were significantly lower at 6-8%, 9-12% and 26-30% in VMAT plans, respectively. The OTI-NC-VMAT plans showed equivalent plan quality to the TI-NC-VMAT plans and exhibited robust freedom from limiting arc rotation due to potential patient/couch-gantry collision.

CONCLUSIONS

The OTI-NC-VMAT plans appear dosimetrically equivalent to TI-NC-VMAT plans for lung SBRT, while permitting large angle arc selection, free from obstructional limitations. Both OTI-NC-VMAT and TI-NC-VMAT plans were dosimetrically superior to 3D-NC-C plans in terms of organ-at-risk (OAR) sparing.

Spatial variations of multiple off-axial targets for a single isocenter SRS treatment in Novalis Tx linac system

PURPOSE

To develop a method to evaluate the positional variations of multiple off-axial targets for a single isocenter stereotactic radiosurgery (SRS) treatment in Novalis Tx linac system.Method and Materials: Five metallic ball bearing (BB) markers were placed sparsely in 3D off-axial locations (non-coplanar) inside a skull phantom as the representatives of multiple targets mimicking multiple brain metastases. The locations of the BB markers were carefully chosen to minimize overlapping of each other in a portal imaging detector plane. The skull phantom was immobilized by a frameless mask and CT scanned with a BrainLab Head&Neck Localizer using a GE Optima multi-detector CT (MDCT) scanner. The CT images were exported to iPlan treatment planning software and a multiple target PTV was drawn by combining all the contours of the BB markers. The margin of the MLC opening was selected as 3 mm expansion outward. Four non-coplanar arc beams were placed to generate a single isocenter SRS plan to treat the PTV. The skull phantom was localized to the treatment position using ExacTrac 6D Patient Positioning system. The four dynamic conformal arc beams were delivered using Novalis Tx system with portal imaging acquisition mode per 10% temporal resolution. The locations of the BB markers were visualized and analyzed with respect to the MLC aperture in the treatment plan similar to the Winston-Lutz (WL) test.

RESULTS

All the BB markers were clearly identified inside the MLC openings. The total positional errors for the MLC aperture were 0.61 ± 0.2 mm along the rotational path of the four arcs.

CONCLUSION

This study verified that the spatial deviations of multiple off-axial targets for a single isocenter SRS treatment plan is within sub-millimeter range in Novalis Tx linac system. Accompanied with the WL test, this simple test will quality-assure the spatial accuracies of the isocenter as well as the positions of multiple off-axial targets for the SRS treatment using a single isocenter multiple target treatment plan.

Highly efficient beamline and spectrometer for inelastic soft X-ray scattering at high resolution

The design, construction and commissioning of a beamline and spectrometer for inelastic soft X-ray scattering at high resolution in a highly efficient system are presented. Based on the energy-compensation principle of grating dispersion, the design of the monochromator-spectrometer system greatly enhances the efficiency of measurement of inelastic soft X-rays scattering. Comprising two bendable gratings, the set-up effectively diminishes the defocus and coma aberrations. At commissioning, this system showed results of spin-flip, d-d and charge-transfer excitations of NiO. These results are consistent with published results but exhibit improved spectral resolution and increased efficiency of measurement. The best energy resolution of the set-up in terms of full width at half-maximum is 108 meV at an incident photon energy tuned about the Ni L3-edge.

Development of a novel aspherical mirror bender for an active grating

A novel monolithic mechanical bender has been designed and fabricated to meet the requirements of an active polynomial grating in a new soft X-ray scattering and emission beamline at the National Synchrotron Radiation Research Center, Taiwan. This compact bender achieves nearly fixed center point under different bending conditions. Moreover, the compact bender can be bent to a desirable third-order polynomial surface profile to cancel the defocus and coma aberrations using two PZT actuators. Theoretical analysis reveals that the grating has unprecedented spectral resolving power. A detailed mechanical analysis has been conducted and a prototype bender was fabricated and tested. The results indicate that the performance of the bender is excellent and is therefore suitable to be used in the active grating.

VAM-1: a new member of the MAGUK family binds to human Veli-1 through a conserved domain

The MAGUKs (membrane-associated guanylate kinase homologues) constitute a family of peripheral membrane proteins that function in tumor suppression and receptor clustering by forming multiprotein complexes containing distinct sets of transmembrane, cytoskeletal, and cytoplasmic signaling proteins. Here, we report the characterization of the human vam-1 gene that encodes a novel member of the p55 subfamily of MAGUKs. The complete cDNA sequence of VAM-1, tissue distribution of its mRNA, genomic structure, chromosomal localization, and Veli-1 binding properties are presented. The vam-1 gene is composed of 12 exons and spans approx. 115 kb. By fluorescence in situ hybridization the vam-1 gene was localized to 7p15-21, a chromosome region frequently disrupted in some human cancers. VAM-1 mRNA was abundant in human testis, brain, and kidney with lower levels detectable in other tissues. The primary structure of VAM-1, predicted from cDNA sequencing, consists of 540 amino acids including a single PDZ domain near the N-terminus, a central SH3 domain, and a C-terminal GUK (guanylate kinase-like) domain. Sequence alignment, heterologous transfection, GST pull-down experiments, and blot overlay assays revealed a conserved domain in VAM-1 that binds to Veli-1, the human homologue of the LIN-7 adaptor protein in Caenorhabditis. LIN-7 is known to play an essential role in the basolateral localization of the LET-23 tyrosine kinase receptor, by linking the receptor to LIN-2 and LIN-10 proteins. Our results therefore suggest that VAM-1 may function by promoting the assembly of a Veli-1 containing protein complex in neuronal as well as epithelial cells.

Occurrence of fumonisin B1 in maize imported into Taiwan

Samples of maize imported into Taiwan during 1997-1998 were collected and analyzed for the presence of fumonisin B1 (FB1) using high performance liquid chromatography. Eight (6.8%) of 118 samples were found to contain FB1 (334-1614 microg kg(-1)). The frequency of FB1 found in maize samples imported from Australia was 20%, followed by Thailand (10%), and USA (5.1%). In analyzing the distribution pattern, it was found that 93.2% of the samples had FB1 concentrations below 100 microg kg(-1), and only 3.4% (or four samples) were in excess of 300 microg kg(-1).

Genomic organization, expression, and chromosome localization of a third aurora-related kinase gene, Aie1

We previously reported two novel testis-specific serine/threonine kinases, Aie1 (mouse) and AIE2 (human), that share high amino acid identities with the kinase domains of fly aurora and yeast Ipl1. Here, we report the entire intron-exon organization of the Aie1 gene and analyze the expression patterns of Aie1 mRNA during testis development. The mouse Aie1 gene spans approximately 14 kb and contains seven exons. The sequences of the exon-intron boundaries of the Aie1 gene conform to the consensus sequences (GT/AG) of the splicing donor and acceptor sites of most eukaryotic genes. Comparative genomic sequencing revealed that the gene structure is highly conserved between mouse Aie1 and human AIE2. However, much less homology was found in the sequence outside the kinase-coding domains. The Aie1 locus was mapped to mouse chromosome 7A2-A3 by fluorescent in situ hybridization. Northern blot analysis indicates that Aie1 mRNA likely is expressed at a low level on day 14 and reaches its plateau on day 21 in the developing postnatal testis. RNA in situ hybridization indicated that the expression of the Aie1 transcript was restricted to meiotically active germ cells, with the highest levels detected in spermatocytes at the late pachytene stage. These findings suggest that Aie1 plays a role in spermatogenesis.

Evidence of circadian rhythm of electric discharge in Eigenmannia virescens system

The gymnotid electric fish, Eigenmannia virescens, exhibits electric discharge rhythmicity both in alternate light-dark (LD; 12 h light, 12 h dark [LD 12:12]) and in constant dark (DD) conditions. It suggests that the electric discharge rhythm is under control of the circadian clock. The free-running periods (FRPs) of electric discharge rhythms at 21 degrees C in DD are greater than, but close to, 24 h. The maximum of the electric discharge in the Eigenmannia system peaks approximately at circadian time 6 (CT6) in the middle of the subjective day. The circadian oscillator in the system is temperature compensated. This original report reveals the relationship between electric discharge activity and the circadian pacemaker in Eigenmannia and provides an alternative system to investigate circadian rhythms in vertebrates.

Natural occurrence of fumonisins B(1) and B(2) in domestic maize of Taiwan

Samples of maize grown in various districts of Taiwan were collected and analyzed for the presence of fumonisin B(1) (FB(1)) and fumonisin B(2) (FB(2)) using high-performance liquid chromatography. Forty-nine (44.5%) and 2 (1.8%) of 110 samples were found to contain FB(1) (109-1148 ng/g) and FB(2) (222-255 ng/g), respectively. The frequency of detection and also the maximum FB(1) concentration were found in samples from Penton (2/2, 262 ng/g), followed by Chiayi (18/26, 264 ng/g), Tainan (8/16, 160 ng/g), Hualinen (5/14, 1148 ng/g), Taitung (7/20, 109 ng/g), and Yunlin (9/26, 361 ng/g). Of the 110 samples examined, only 2 samples from Hualinen had been detected containing FB(2). During an analysis of the distribution pattern of FB(1), it became apparent that >79% of tested samples had FB(1) concentrations <100 ng/g, whereas 2.7% (or 3 samples) contained FB(1) >300 ng/g. These results clearly illustrated that domestically produced maize for human consumption is frequently contaminated with FB(1).

Protein kinase profile of sperm and eggs: cloning and characterization of two novel testis-specific protein kinases (AIE1, AIE2) related to yeast and fly chromosome segregation regulators

We have analyzed the general protein kinase expression profile in mouse sperm and eggs. A total of 41 different kinases were identified. In this study, we describe two novel protein kinases, designated AIE1 (mouse) and AIE2 (human), which share high amino acid identities with the serine/threonine (S/T) kinase domain of yeast Ip11, fly aurora, and frog Eg2. Mutations in Ip11 and aurora have been reported to cause abnormal chromosome segregation and centrosome separation. Both AIE1 and AIE2 contain a typical S/T kinase domain (251 aa) flanked by a short polypeptide at both ends. Two other AIE-related kinases (STK-1 and IAK1/Ayk1) were also identified in mature mouse oocytes. The central kinase domain of AIE1 revealed 77.6% and 66.3% identity with that of STK-1 and IAK1/Ayk1, but much less homology was found in the sequence outside the kinase domain. Northern blot analysis revealed that both AIE1 and AIE2 are specifically expressed in testis, whereas STK-1 and IAK1/Ayk1 are expressed in many tissues rich in proliferating cells. An in vitro kinase assay showed that AIE1 can phosphorylate casein, AIE1 itself, and an uncharacterized cellular protein (p16). The kinase activity of AIE1 can be destroyed by heat inactivation. In summary, we suggest that AIE is a new member of the S/T kinase family, which may be regulated in a fashion distinct from other AIE-related kinases.

A compact mirror manipulator in the SRRC beamline

A compact mirror manipulator which has high stiffness and is easily adjustable has been developed for new beamlines at SRRC. It consists of a vertical stem to support the mirror and allows for six-axis precise positioning. The rotation adjustment is designed with a minimum of cross-coupling between adjustments. An independent support is fixed to the ground to reduce vibration from the chamber and the pump. Some performance test results in vacuum and in atmosphere, including vibration, repeatability, long-term drift etc., are described in this paper.

Mycoflora and mycotoxins in adzuki and mung beans produced in Ontario, Canada

This is the first report on the detection of fumonisin B1 (FB1) in Fusarium-infected adzuki bean (Phaseolus angularis) and mung bean (Phaseolus aureus). The infected beans had either a mouldy appearance or a distinct discoloration. Seed coats of infected adzuki beans changed from dark red to light red and those of mung beans from green to dark or brownish green. Fusarium spp. isolated from mouldy and discoloured beans included F. avenaceum, F. culmorum, F. equiseti, F. graminearum, F. moniliforme, F. oxysporum, F. solani, F. sporotrichoides and a few unidentified species. Healthy beans without any apparent discoloration and diseased beans with discoloration and mouldy appearance were analysed for mycotoxins. Diacetoxyscripenol, deoxynivalenol and T-2 toxin (T-2) were not detected in either healthy or discoloured adzuki and mung bean samples by thin layer chromatography (TLC). FB1 was detected by TLC in discoloured adzuki and mung bean samples but not in the healthy samples. TLC results were confirmed by high performance liquid chromatography (HPLC). The quantification of FB1 by HPLC revealed that discoloured adzuki and mung bean samples contained 261 +/- 43.8, and 230 +/- 21.6 micrograms g-1 of FB1, respectively. This investigation emphasizes the need for more detailed research in dealing with possible mycotoxin contamination in various foodstuffs including legumes.

The techniques of nonmuscular closure of hypopharyngeal defect following total laryngectomy: the assessment of complication and pharyngoesophageal segment

The usual method of reconstructing a hypopharyngeal defect during total laryngectomy includes pharyngeal muscle layer closure, which may result in high pharyngoesophageal pressure. We hypothesize that nonclosure of the pharyngeal muscle can reduce the pressure of the pharyngoesophageal segment which can reduce the chances of the formation of pharyngocutaneous fistulae. A technique of nonmuscular closure of a hypopharyngeal defect is presented. The differences in the rate of fistula formation and swallowing function between patients with usual and nonmuscular closure were also studied. Sixty consecutive laryngectomees were enrolled in this study. Thirty patients received usual closure after total laryngectomy, whereas the other 30 patients underwent non closure of their pharyngeal muscles. One patient (3.3 per cent) in the nonmuscular closure group and three patients (10 per cent) in the usual closure group developed a pharyngocutaneous fistula. The pharyngoesophageal pressures of the nonmuscular closure group were significantly lower than those of the usual closure group. We conclude that the technique of nonclosure of the pharyngeal constrictor muscle after total laryngectomy is relatively more simple and is not associated with a higher rate of fistula formation. Furthermore, nonclosure of the pharyngeal constrictor muscle is preferable to muscular closure because it reduces the spasm of the pharyngoesophageal segment which limits voice rehabilitation.

Occurrence of fumonisin B1 and B2 in corn-based foodstuffs in Taiwan market

Corn-based human foodstuffs purchased in Taiwan were analyzed for fumonisin B1 (FB1) and fumonisin B2 (FB2) using high-performance liquid chromatography. Fifty-two (33.9%) and 32 (20.9%) of 153 samples were found to contain FB1 (73-2395 ng/g) and FB2 (120-715 ng/g), respectively. The highest frequency of detection and also the highest FB1 concentrations were found in sweetcorn (50%, 1089 ng/g) and cornflour (50%, 608 ng/g), followed by corn snacks (33.3%, 2395 ng/g), miscellaneous corn products (33.3%, 73 ng/g), popcorn (31.8%, 1003 ng/g) and cornflakes (23.5%, 1281 ng/g). 16 corn snacks (= approximately 20.5% of the samples) had an average FB1 and FB2 content of 456 and 145 ng/g, respectively, while six sweetcorn (= 25%) samples were contaminated with an average of 400 ng/g of FB1 and 65 ng/g of FB2. Of the 22 pop-corn samples examined, 7 had an average of 347 ng/g and 116 ng/g of FB1 and FB2, respectively. During an analysis of the distribution pattern for the combined fumonisin levels of FB1 and FB2, it became apparent that more than 69% of tested samples had fumonisin concentrations below 100 ng/g, while 11.1% (or 17 samples) contained in excess of 600 ng toxins per g. These results clearly illustrated that commercially available corn-based foodstuffs for human consumption in Taiwan are frequently contaminated with FB1 and FB2.

Differentiation of Salmonella typhi strains by ribosomal RNA gene restriction patterns

Owing to the limited value of phage typing to determine the epidemiological association of Salmonella typhi (S. typhi) strains isolated from the source of typhoid fever, we analyzed ribosomal RNA (rRNA) gene restriction patterns to differentiate the independently isolated strains of identical phage type. The data showed that the restriction patterns of PstI was most polymorphic among four enzymes (BamHI, EcoRI, PstI, and SmaI) used, which revealed 13 types among 25 strains belonged to 4 phage types, 1 untypable and 2 not-determined strains. Total 25 strains of S. typhi were divided into 15 combination types by the rRNA restriction patterns with three enzymes (BamHI, PstI, and SmaI).

Identification of sucrose-regulated genes in cultured rice cells using mRNA differential display

In order to get more information about carbon metabolite regulation pathways, cloning and sequence analysis of sucrose-regulated genes from rice-suspension-cultured cells were performed. We used a new method, mRNA differential display, to screen differentially expressed genes under conditions of 3% and no sucrose in the cultured medium. Six candidate clones were identified and sequenced. Clones SI1 and SI2 were repressed by sucrose starvation, while clones SR1, SR2, SR3 and SR4 were induced by sucrose starvation. Nucleotide sequence analysis showed that clone SR2 has 94.8% homology to the salT gene, and clones SI1 and SR3 show 88.3 and 96.9% identity, respectively, to partial cDNA sequences in the GenBank database. The results suggest that mRNA differential display provides an easy and quick way to clone genes involved in the carbon metabolite regulation pathway.

Production of fumonisins by Fusarium species of Taiwan

Twenty-nine Fusarium species isolated from various sources in different districts of Taiwan were tested for their ability to produce fumonisins in corn cultures. Only Fusarium moniliforme produced fumonisin B1 (FB1) and fumonisin B2 (FB2). The finding that the other 28 Fusarium species produced neither FB1 nor FB2 is preliminary because only one strain per species was studied. The detection of FB1 and FB2 in cultures of F. moniliforme was demonstrated by TLC and HPLC, and FB1 was further confirmed by mass spectrometry. In a separate experiment, in which 38 strains of F. moniliforme were tested for fumonisins, approximately 66% (25/38) produced FB1 and/or FB2. Of the 25 strains, 14 produced only FB1 and 11 produced both FB1 and FB2, and the amounts of FB1 and FB2 produced by different strains varied greatly. This is the first report that fumonisins are found in corn cultures experimentally infected with F. moniliforme strains from Taiwan. It is safe to assume that fumonisin producing strains of F. moniliforme are widely distributed among the economic crops such as corn, rice, sugarcane, and sorghum throughout the Island.

Comparison of the profiles of seedborne fungi and the occurrence of aflatoxins in mould-damaged beans and soybeans

The average percentage of fungal infection in twenty bean and soybean lots was determined by visual inspection (24.5 and 16.8%, respectively), and by laboratory isolation (58.5 and 33.7%), respectively. The mycoflora were more diverse in bean than soybean. Bean was more susceptible to fungal infection than soybean under similar environmental and cultural conditions. The most frequently isolated fungal genera for bean and soybean were Aspergillus, Penicillium, Rhizopus, Eurotium and Curvularia. Aflatoxins were not detected in the non-infected beans and soybeans, but aflatoxins (B1, B2, G1 and G2) were detected in the infected beans but not in the infected soybeans. The absence of aflatoxin in the fungal infected soybeans is discussed.

[Seroepidemiological investigation on Japanese encephalitis in Taiwan (January 1989-December 1991)]

The hemagglutination inhibition (HI) test was used to detect sero-confirmed cases of clinically suspected Japanese encephalitis. The results revealed a total of 76 sero-confirmed cases; 24, 27 and 25 cases respectively for the year 1989, 1990 and 1991. The percentages of sero-confirmed cases with respect to reported cases were 12.97%, 12.33%, 10.04% respectively. The mean percentage was 11.64%. The mean number of sero-confirmed cases in recent three years was 25, and morbidity rate per 100,000 population was 0.125. The number of sero-confirmed cases in 1970 was 269, and morbidity rate per 100,000 was 1.86. The comparison of these two groups showed the ratio of 1:11 and 1:15. It demonstrated that the period of 50% sero-conversion of HI antibody positive pigs appeared two months earlier in the middle of May currently as against the middle of July during the years 1966-1968. The period of JE prevalence likewise shifted two months earlier to the months of May, June and July, with a peak in June in 1989-1991 as against the months of July, August and September with a peak in August in 1966-1968. There occurred a few sporadic cases in other months away from the period of major epidemic. With regard to the geographical distribution of the sero-confirmed cases in recent three years, most JE cases were detected in the Taipei basin and the Kaohsiung-Pingtung river basin. The next numerous cases were found in the terrace which extends from Taoyuan, Hsinchu and Miaoli to the central Taiwan and in the Chiayi-Tainan plain. Only four cases were reported from Ilan, Hualien and Taitung counties. During the years between 1955 and 1967, the vast majority of cases occurred among children, especially of 2-9 years of age. The next suffered group was the age group of 10-14 years. In the meanwhile, the current major group of victim was the age group of 10-14 years and its morbidity rate per 100,000 population was 0.30. The second suffered group was the age group of 20-24 years and its morbidity rate was 0.28, and the third was the age group of 0-9 years and its morbidity rate was 0.16. The percentages of sero-confirmed cases of the above each age group with respect to all sero-confirmed cases were 23.68%, 21.05%, 22.36% respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

[Results of early thoracotomy in the treatment of non-calcified solitary pulmonary nodules. Analysis of 19 cases]

We reviewed 19 patients who had undergone thoracotomy and resection of a noncalcified solitary pulmonary nodule over the past 7 years, to see if a policy of early thoracotomy was therapeutically valid. The average age of patients was 50 (range 10 to 73 years), 6 females and 13 males. All of them asymptomatic. In this study, there were 9 (47.3%) of primary bronchogenic carcinoma, the incidence was 54.5% in patients above 50 years. There were no postoperative deaths and 3 serious postoperative complications (15.7%). Post operatory followed up by all patients ranged from one to seven years. The patients with benign lesions are all well. 9 of the cases had primary lung cancer, 2 died, 3 1/2 years and 5 years after surgery. We conclude that pre-operative differential diagnostic procedure between benign and malign nodules may not always be decisive, and that an early thoracotomy in indicated every case, since the incidence of malign tumors is frequent. Very small primary lung cancers detected and treated early do not have the same poor prognosis as larger primary cancers.

Detection of serum antibody to herpes simplex virus type I by enzyme-linked immunosorbent assay (ELISA)

For setting up an Enzyme-Linked Immunosorbent Assay (ELISA) to detect antibodies to herpes simplex virus type 1 (HSV-1), the virus was propagated in Vero cells and partially purified by sonification and ultracentrifugation on 30% sucrose solution. DEAE ion-exchange column chromatography was used for purification of goat anti-human IgG serum. The anti-human IgG immune serum and alkaline phosphatase were conjugated by glutaraldehyde method. ELISA test was performed by reacting HSV-1 antigen coated in polystyrene tubes with serum specimens and enzyme-IgG conjugates. The color produced by enzyme-substrate reaction was measured on a spectrophotometer. The results obtained by the ELISA had a good agreement with those obtained by a standard neutralization procedure on 119 serum specimens tested for antibody to HSV-1.