Respiratory syncytial virus infection induces matrix metalloproteinase-9 expression in epithelial cells

Increased gelatinolytic activity was observed in respiratory syncytial virus (RSV)-infected HEp-2 cells by using zymography. The anti-matrix metalloproteinase-9 (MMP-9) antibody specifically reduced the gelatinolytic activity suggesting that the increased gelatinolytic activity was due to the MMP-9. It was also supported by the results from immunofluorescent staining, treatment of MMP inhibitors, and RSV infection of the cell clones that were transfected with plasmids to express more MMP-9 and tissue type inhibitor of metalloproteinase-1 (TIMP-1). The gelatinolytic activity of extracellular MMP-9 in RSV-infected HEp-2 cells increased 1.5 +/- 0.2 fold compared with the control (p < 0.01). Cell surface MMP-9 expression was also clearly detected by immunofluorescent staining. Treatment with 1,10-phenanthroline (0.05 mM), ethylenediamine-tetraacetate (EDTA) (1.5 mM), and penta-O-galloyl-beta-D-glucose (PGG) (3.3 microM) inhibited RSV multiplication as well as syncytia formation. Furthermore, the average syncytia size increased when the cells expressing more MMP-9 were infected by RSV. In contrast, syncytia formation was inhibited in the cells manipulated to express TIMP-1. Thus, this study concludes that although RSV infection induces MMP-9, which can enhance the syncytia formation leading to RSV multiplication and spread it can be inhibited by MMP inhibitors.

Multimodality program involving stereotactic surgery in brain tumor management

Stereotactic and image guided surgery is becoming increasingly important in the management of brain tumors. Although there are several stereotactic modalities that have been reported to be of value, it is the combination of techniques in a multimodality approach that seems to show the most promise. Both frame-based and frameless guidance may facilitate glioma resection, allowing the optimal amount of resection while permitting avoidance of surrounding eloquent areas. Not only does this optimize resection, but leaving a minimal amount of gross tumor may provide a better bed for intracavitary chemotherapy. Deep tumors may be localized and approached through a small channel. Surgical exposure may be minimized to protect uninvolved areas of the brain. There is increasing evidence that patients operated with imaging guidance have a more benign course and more rapid discharge, perhaps with a lower incidence of adverse neurological sequelae. Stereotactic conformal radiotherapy allows a higher tumor dose while sparing uninvolved brain from radiation more efficiently than conventional radiation. Residual tumor may be treated with a boost of stereotactic radiotherapy. Stereotactic instillation of radioisotope may be used to treat cystic tumors. Stereotactic insertion of cannulae or radioisotope seeds permits efficient brachytherapy. Stereotactic surgery has moved beyond a subspeciality, so that every neurosurgeon might benefit from using stereotactic techniques in brain tumor management.

Is expressed emotion a specific risk factor for depression or a nonspecific correlate of psychopathology?

Five Minute Speech Sample Expressed Emotion (FMSS-EE) was examined in families of youth with depressive disorders, nondepressed youth with attention deficit/hyperactivity disorder (ADHD), and community controls screened for the absence of depression and ADHD. Consistent with the hypothesis that FMSS-EE shows some specificity as a risk factor for depression, rates of critical EE were significantly higher among mothers of youth with depression as compared to mothers of nondepressed youth with ADHD, or mothers of controls. When both mothers' and fathers' scores were used to generate family EE ratings, rates of overall EE and critical EE were significantly higher for the depressed group than the control group, but the nondepressed ADHD group did not differ significantly from the other groups. Results support the hypothesis that critical EE in mothers shows some specificity as a risk factor or correlate of depression in youth.

Enhanced therapeutic effect of multiple injections of HSV-TK + GCV gene therapy in combination with ionizing radiation in a mouse mammary tumor model

PURPOSE

Standard therapies for breast cancer lack tumor specificity and have significant risk for recurrence and toxicities. Herpes simplex virus-thymidine kinase (HSV-tk) gene therapy combined with radiation therapy (XRT) may be effective because of complementary mechanisms and distinct toxicity profiles. HSV-tk gene therapy followed by systemic administration of ganciclovir (GCV) enhances radiation-induced DNA damage by generating high local concentrations of phosphorylated nucleotide analogs that increase radiation-induced DNA breaks and interfere with DNA repair mechanisms. In addition, radiation-induced membrane damage enhances the "bystander effect" by facilitating transfer of nucleotide analogs to neighboring nontransduced cells and by promoting local and systemic immune responses. This study assesses the effect of single and multiple courses of HSV-tk gene therapy in combination with ionizing radiation in a mouse mammary cancer model.

METHODS AND MATERIALS

Mouse mammary TM40D tumors transplanted s.c. in syngeneic immunocompetent BALB-c mice were treated with either adenoviral-mediated HSV-tk gene therapy or local radiation or the combination of gene and radiation therapy. A vector consisting of a replication-deficient (E1-deleted) adenovirus type 5 was injected intratumorally to administer the HSV-tk gene, and GCV was initiated 24 h later for a total of 6 days. Radiation was given as a single dose of 5 Gy 48 h after the HSV-tk injection. A metastatic model was developed by tail vein injection of TM40D cells on the same day that the s.c. tumors were established. Systemic antitumor effect was evaluated by counting the number of lung nodules after treating only the primary tumors with gene therapy, radiation, or the combination of gene and radiation therapy. To assess the therapeutic efficacy of multiple courses of this combinatorial approach, one, two, and three courses of HSV-tk + GCV gene therapy, in combination with radiation, were compared to HSV-tk or XRT alone and to sham-treated animals. (Treatments were repeated at 7-day intervals from the HSV-tk injection.)

RESULTS

Both single-therapy modalities reduced tumor growth by 11% compared to controls, while the combined therapy resulted in a decrease of 29%. Median survival was 36 days in the combined therapy group, compared to 33 days in the monotherapy groups and 26 days in the control group. In the metastatic model, the number of lung nodules was reduced by 59.5% after HSV-tk gene therapy, whereas radiotherapy had no effect on metastatic growth. Combined therapy led to an additional 66.7% reduction in lung colonization. Compared to controls, local tumor growth was maximally suppressed by three courses of combined therapy (51.5%), followed by two courses of combined therapy (37.2%), and three sessions of XRT alone (35.6%). Median survival was also significantly prolonged to 58 days with the three courses of combined therapy, followed by two courses, to 45 days. All other treatment groups demonstrated median survival times between 26 and 35 days, while controls had a median survival of 24 days.

CONCLUSIONS

These results indicate that multiple courses of HSV-tk therapy in combination with radiation improve the therapeutic efficacy of this approach and may provide therapeutic implications for the treatment of human breast cancer and other solid tumors.

Phase I/II trial evaluating combined radiotherapy and in situ gene therapy with or without hormonal therapy in the treatment of prostate cancer--a preliminary report

PURPOSE

To report the preliminary results of a Phase I/II study combining radiotherapy and in situ gene therapy (adenovirus/herpes simplex virus thymidine kinase gene/valacyclovir) with or without hormonal therapy in the treatment of prostate cancer.

METHODS AND MATERIALS

Arm A: low-risk patients (T1-T2a, Gleason score <7, pretreatment PSA <10) were treated with combined radio-gene therapy. A mean dose of 76 Gy was delivered to the prostate with intensity-modulated radiotherapy. Arm B: high-risk patients (T2b-T3, Gleason score >or=7, pretreatment PSA >or=10) were treated with combined radio-gene therapy and hormonal therapy. Hormonal therapy was comprised of a 4-month leuprolide injection and 2-week use of flutamide. Arm C: Stage D1 (positive pelvic lymph node) patients received the same regimen as Arm B, with the additional 45 Gy to the pelvic lymphatics. Treatment-related toxicity was assessed using Cancer Therapy Evaluation Program common toxicity score and Radiation Therapy Oncology Group (RTOG) toxicity score.

RESULTS

Thirty patients (13 in Arm A, 14 in Arm B, and 3 in Arm C) completed the trial. Median follow-up was 5.5 months. Eleven patients (37%) developed flu-like symptoms (Cancer Therapy Evaluation Program Grade 1) of fatigue and chills/rigors after gene therapy injection but recovered within 24 h. Four patients (13%) and 2 patients (7%) developed Grade 1 and 2 fever, respectively. There was no patient with weight loss. One patient in Arm B developed Grade 3 elevation in liver enzyme, whereas 11 and 2 patients developed Grade 1 and 2 abnormal liver function tests. There was no Grade 2 or above hematologic toxicity. Three patients had transient rise in creatinine. There was no RTOG Grade 3 or above lower gastrointestinal toxicity. Toxicity levels were as follows: 4 patients (13%), Grade 2; 6 patients (20%), Grade 1; and 20 patients (67%), no toxicity. There was 1 patient with RTOG Grade 3 genitourinary toxicity, 12 patients (40%) with Grade 2, 8 patients (27%) with Grade 1, and 9 patients (30%) with no toxicity. No patient dropped out from the trial or had to withhold treatment because of severe toxicity.

CONCLUSIONS

This is the first trial of its kind in the field of prostate cancer that aims to expand the therapeutic index of radiotherapy by combining in situ gene therapy. Initial experience has demonstrated the safety of this approach. There is no added toxicity to each therapy used alone. Long-term follow-up and larger cohort studies are warranted to evaluate long-term toxicity and efficacy.

Important prognostic factors in patients with skull base erosion from nasopharyngeal carcinoma after radiotherapy

PURPOSE

To evaluate the long-term outcome and prognostic factors in patients with skull base erosion from nasopharyngeal carcinoma after initial radiotherapy (RT).

METHODS AND MATERIALS

From January 1985 to December 1986, 100 patients (71 males, 29 females) with a diagnosis of nasopharyngeal carcinoma were found on computed tomography (CT) to have skull base erosion. The mean age was 41 years (range 16-66). Ninety-six patients had World Health Organization type III undifferentiated carcinoma, and 4 had type I. The metastatic workup, including chest radiography, liver ultrasound scanning, and liver function test was negative. All patients underwent external beam RT (EBRT) alone to 66-80 Gy during 6-8 weeks. A daily fraction size of 2 Gy was delivered using 60Co or a linear accelerator. No patient received chemotherapy. All patients were followed at regular intervals after irradiation. The median follow-up was 22.3 months (range 2-174). Survival of the cohort was computed by the Kaplan-Meier method. The potential prognostic factors of survival were examined. Multivariate analyses were performed using the Cox regression model.

RESULTS

The 1, 2, 5, and 10-year overall survival rate for the cohort was 79%, 41%, 27%, and 13%, respectively. However, the subgroup of patients with both anterior cranial nerve (I-VIII) and posterior cranial nerve (IX-XII) involvement had a 5-year survival of only 7.7%. A difference in the time course of local recurrence and distant metastasis was observed. Both local recurrence and distant metastasis often occurred within the first 2 years after RT. However, local relapse continued to occur after 5 years. In contrast, no additional distant metastases were found after 5 years. The causes of death included local recurrence (n = 59), distant metastasis (n = 21), both local recurrence and distant metastasis (n = 1), and unrelated causes (n = 5). After multivariate analysis, complete recovery of cranial nerve involvement, cranial nerve palsy, and headache after irradiation were found to be independent prognostic factors in this cohort.

CONCLUSIONS

We present one of the longest follow-ups of patients with nasopharyngeal carcinoma invading the skull base. Our results demonstrate the importance of cranial nerve involvement, recovery of headache, and cranial nerve palsy. These factors should be carefully evaluated from the history, physical examination, and imaging studies. A subgroup of patients with skull base involvement had long-term survival after RT alone. The findings of this study are important as a yardstick against which more aggressive strategies, such as combined radiochemotherapy and altered fractionation RT can be compared.

The potential use of intensity modulated radiotherapy (IMRT) in women with pectus excavatum desiring breast-conserving therapy

The purpose of this study was to determine if intensity modulated radiation therapy (IMRT) offers a better treatment plan compared to conventional radiotherapy for patients with pectus excavatum desiring breast-conserving therapy and to assess the feasibility of simultaneous modulated accelerated radiation therapy (SMART) boost. A patient with pectus excavatum desired breast-conserving therapy for her early stage breast cancer. She underwent lumpectomy and axillary lymph node dissection followed by chemotherapy. She was then referred for radiotherapy. A breast board (Med-Tec) with aquaplast body cast was used to limit the movement of the patient, chest wall, and breasts before planning a computed tomography (CT) scan. IMRT including dose-volume histogram (DVH) was compared to that of the conventional plan using parallel opposed tangential beams with a 15-degree wedge pair. Forty-five gray was prescribed to the whole breast to each plan, while 50 Gy was prescribed to the tumor bed using IMRT with SMART boost in 25 fractions over 5 weeks. The coverage of the whole breast was adequate for both plans. IMRT allowed a more homogeneous dose distribution within the breast at the desired dose range. With IMRT there is less volume of ipsilateral lung receiving the radiation dose that is above the tolerance threshold of 15 Gy when compared to that of the conventional plan. However, there is more volume of surrounding normal tissues (the heart, spinal cord, and contralateral breast and lung) receiving low-dose irradiation when IMRT was employed. SMART boost was feasible, allowing a mean dose of 57 Gy to be delivered to the tumor bed simultaneously along with the rest of the breast in 5 weeks. IMRT is feasible in treating early breast cancer patients with pectus excavatum by decreasing the ipsilateral lung volume receiving high-dose radiation when compared to the conventional method. SMART boost shortens the overall treatment time that may have potential radiobiological benefit.

The role of DRE in the diagnosis of prostate carcinoma

DRE has been used as a diagnostic and screening tool for prostate cancer for decades. However these are based on Western data and its local applicability has yet to be verified. We held a Prostate Health Awareness Week in August 1998 and a total of 2086 men were screened. All men aged 50 years old and above were included for the study. The subjects were evaluated on DRE findings, PSA levels and if indicated a TRUS-guided biopsy results. We concluded that DRE per se might have limited role in the screening of prostate cancer in Malaysia. Screening using DRE and PSA combined are still recognized as the most cost-effective means. Neither DRE nor PSA alone has high enough specificity for diagnosis of prostate cancer cases. Combining DRE and PSA will definitely increase the specificity significantly.

Prevalence of symptomatic BPE among Malaysian men aged 50 and above attending screening during prostate health awareness campaign

OBJECTIVE

To study the prevalence of symptomatic BPE among Malaysian men age 50 and above attending prostate health awareness campaign and to identify differences in prevalence between different ethnic groups residing within metropolitan Kuala Lumpur.

MATERIALS AND METHODS

Demographic data and the completed International Prostate Symptom Score (IPSS), maximal uroflow rate (Qmax) and prostate size of volunteers, aged 50 and above, who attended the prostate health awareness campaign were analyzed. Subjects with known prostate diseases or prostate surgery, bladder disorders and neurological disorders were excluded.

RESULTS

2086 volunteers attended the campaign. 575 men fulfilled the inclusion criteria and their demographic data, IPSS; peak flow rate and prostate volume were analysed. Overall, 18.9% and 39.6% of the men were severely and moderately symptomatic, respectively. The prevalence of moderate to severe lower urinary tract symptoms (LUTS) in Malays, Chinese and Indians were 70%, 59% and 50% respectively (p = 0.004). The commonest bothersome symptoms were nocturia (56%), frequency (50.4%) and sense of incomplete voiding (43.5%). The mean peak flow rate of the subjects was 15.4 ml/s. 20.9% and 55.2% of the subjects had peak flow less than 10 ml/sec and 15 ml/sec respectively. The mean prostate size was 25.1 cc. There is no significant difference in term of maximal flow rate and prostate size among Malays, Chinese and Indians in Malaysia. A good correlation was found between the total symptom score and the single disease-specific quality of life question (r = 0.69, p < 0.001). The correlation between IPSS and peak flow rate (r = -0.22, p < 0.001) and prostate volume (r = 0.11, p = 0.009) was weak. There was no correlation between IPSS and age (r = 0.06, p = 0.17). The prevalence of symptomatic benign prostate enlargement (BPE) was 39.3%. The prevalence increased 8% per decade from 41.7% for men aged 50 to 59 to 65.4% for men aged 70 or more. There is no significant difference in prevalence of symptomatic BPE among the three ethnic groups. The Prevalence of BPO was 15.8%.

CONCLUSION

The correlation between symptom score, maximal flow rate and prostate size was poor and one cannot predict the value of one parameter by knowing one or more of the other parameters. There is a high prevalence of LUTS suggestive of benign prostatic obstruction in the apparently healthy Malaysian aged 50 and above attending the prostate health awareness campaign.

Apoptosis and megakaryocytic differentiation during ex vivo expansion of human cord blood CD34+ cells using thrombopoietin

Thrombopoietin (TPO), the primary regulator of megakaryocytopoiesis, plays important roles in early haematopoiesis. Previously, we have demonstrated that TPO induces a characteristic pattern of apoptosis during ex vivo expansion of cord blood (CB) CD34+ cells. In this study, we have demonstrated that the TPO-induced apoptotic cells belong to the megakaryocytic (MK) lineage and that initially expanding MK progenitors declined along with the appearance of TPO-induced apoptosis. Human CB CD34+ cells were expanded in serum-free conditions with TPO. Multidimensional flow cytometry using simultaneous measurement of apoptosis and immunophenotyping showed that the TPO-induced apoptotic cells appeared in CD61+ fractions. Immunocytochemical analysis of the fluorescent activated cell-sorted fractions showed that the apoptosis-associated CD44low fraction expressed CD61. Clonogenic assay revealed 7.4 +/- 0.50-fold increase of total megakaryocyte colony-forming units (CFU-MKs) during the initial 9 d. Thereafter, the number of CFU-MKs decreased in parallel with the increase of apoptosis. When the MK colonies were subdivided according to size, the proportion of large colonies progressively decreased, while that of medium and small colonies increased. In particular, from d 6 small colonies became predominant. These results suggested that the MK progenitors matured as they expanded during ex vivo expansion with TPO and then proceeded to apoptosis.

Enhanced therapeutic effect of HSV-tk+GCV gene therapy and ionizing radiation for prostate cancer

Standard therapies for prostate cancer including radiation, prostatectomy, and hormone ablation have significant toxicities and recurrence risk. HSV-tk gene therapy may be effective in combination with radiation therapy due to complementary mechanisms and distinct toxicity profiles. Mouse prostate tumors transplanted subcutaneously were treated by either gene therapy involving intratumoral injection of AdV-tk followed by systemic ganciclovir or local radiation therapy or the combination of gene and radiation therapy. Both single-therapy modalities showed a 38% decrease in tumor growth compared to controls. The combined treatment resulted in a decrease of 61%. In addition the combined-therapy group had a mean survival of 22 days versus 16.6 days for single therapy and 13.8 days for nontreated controls. To analyze systemic anti-tumor activity, lung metastases were generated by tail vein injection of RM-1 prostate cancer cells on the same day that they were injected subcutaneously. The primary tumors were treated as before with AdV-tk followed by ganciclovir, radiation, or the combination. The number of lung nodules was reduced by 37% following treatment with AdV-tk, whereas radiotherapy alone had no effect on metastatic growth. The combination led to an additional 50% reduction in lung colonization. Primary tumors that received the combination therapy had a marked increase in CD4 T cell infiltrate. This is the first report showing a dramatic systemic effect following the local combination treatment of radiation and AdV-tk. A clinical study using this strategy has been initiated and patient accrual is ongoing.

A teleradiology case conference system

To investigate the use of teleradiology in the quality assurance programme of a multicentre radiotherapy practice, we installed image acquisition and display workstations at each of two affiliated radiation oncology clinics. A commercial diagnostic teleradiology system was successfully modified to suit the requirements of the radiotherapy subspecialty. The system allowed intersite transmission of images, access to high-resolution images from each site and, by use of laser film scanners, made accessible all types of radiation therapy image. Transmission speed and storage capacity were better than expected. Using the system, radiation oncology residents and staff reviewed 83 complex cases over eight months. Case presentation and discussion were enhanced. In the same period, 276 cases were reviewed by conference in person. Case conferences for quality assurance conducted with the teleradiology system influenced changes in treatment planning as effectively as those conducted in person. Equivalent treatment outcomes were produced. The teleradiology system facilitated quality assurance through review of patients' radiation treatments by allowing natural interactive consultation.

Intensity-modulated radiation therapy (IMRT) for prostate cancer with the use of a rectal balloon for prostate immobilization: acute toxicity and dose-volume analysis

PURPOSE

To report acute toxicity and to evaluate the relationship between dose-volume effects and acute toxicity in patients with localized prostate cancer, treated with intensity-modulated radiation therapy (IMRT).

METHODS AND MATERIALS

Acute toxicity (both lower gastrointestinal [GI] and genito-urinary [GU]) in 100 patients treated with IMRT definitively to a prescribed dose of 70 Gy were assessed using RTOG scoring criteria. A rectal balloon was used for prostate immobilization. Mean doses to seminal vesicles, prostate, bladder, and rectum were recorded. Average irradiated bladder and rectal volumes above 65, 70, and 75 Gy were assessed. A relationship between dose volume and clinical toxicity was evaluated. All patients completed the full duration of acute toxicity assessment.

RESULTS

Mean doses to the prostate and seminal vesicles were 75.8 and 73.9 Gy. This represents a moderate dose escalation. Acute GI toxicity profile was very favorable. Eleven percent and 6% of the patients had grade 1 and 2 GI toxicity, respectively, while 83% had no GI complaint. For GU complaints, 38% and 35% had grade 1 and 2 toxicity, respectively, while 27% had no complaints. There was no grade 3 or higher acute GI or GU toxicity. Mean doses to the bladder were 22.8, 23.4, and 26.1 Gy for grade 0, 1, and 2 GU toxicity, respectively (p = 0.132). There is no statistically significant relationship between acute GU toxicity and the bladder volume receiving > 65 Gy, > 70 Gy, or > 75 Gy. In evaluating acute GI toxicity, there are very few grade 1 and 2 events. No relationship was found between acute rectal toxicity and mean rectal dose or irradiated rectal volumes receiving more than 65, 70, and 75 Gy.

CONCLUSION

The findings are important with regard to the safety of IMRT, especially in reducing acute GI toxicity. Dose escalation with IMRT using a prostate immobilization technique is feasible. The findings are also important because they contribute to the clinical and dosimetric correlation aspect in the use of IMRT to treat prostate cancer. A larger cohort may be needed to determine if there is a relationship between acute GU toxicity and (a) mean bladder dose and (b) irradiated bladder volume receiving > 65 Gy, > 70 Gy, or > 75 Gy. A larger cohort of patients treated to a higher dose may be needed to show a relationship between dose volume and acute GI toxicity.

Intensity modulated radiation therapy (IMRT) following prostatectomy: more favorable acute genitourinary toxicity profile compared to primary IMRT for prostate cancer

PURPOSE

To report our initial experience on postprostatectomy IMRT (PPI), addressing acute genitourinary (GU) toxicity in comparison to primary IMRT (PI) for prostate cancer.

METHODS AND MATERIALS

From April 1998 to December 1999, 40 postprostatectomy patients were treated with intensity modulated radiation therapy (IMRT) to a median prescribed dose of 64 Gy (mean dose of 69 Gy). The Radiation Therapy Oncology Group (RTOG) scoring system was used to assess acute GU toxicity. Target volume and maximum and mean doses were evaluated. The mean doses to the bladder and irradiated bladder volume receiving >65 Gy were assessed. These were compared to those of 125 patients treated with PI to a prescribed dose of 70 Gy (mean dose of 76 Gy).

RESULTS

The acute GU toxicity profile is more favorable in the PPI group with 82.5% of Grade 0-1 and 17.5% of Grade 2 toxicity compared to 59.2% and 40.8%, respectively, in the PI group (p < 0.001). There was no Grade 3 or higher toxicity in either group. The target volume was larger in the PPI group, while the maximum and mean doses to the target were higher in the PI group. The mean dose delivered to the bladder was higher in the PPI group. The irradiated bladder volume receiving >65 Gy was significantly larger in the PI group (p < 0.001).

CONCLUSIONS

PPI can be delivered with acceptable ute GU toxicity. The larger PPI target volume may be related to the difficulty in delineating prostatic fossa. Despite a larger target volume and a higher mean dose to the bladder, PPI produced a more favorable acute GU toxicity profile. This may be related to a combination of lower mean and maximum doses and smaller bladder volumes receiving >65 Gy in the PPI group, as well as urethral rather than bladder irradiation. The findings have implications in the evaluation of IMRT treatment plan for prostate cancer, whereby the irradiated bladder volumes above 65 Gy may be more meaningful than the mean dose to the bladder. Longer term toxicity results are awaited.

Rice transposable elements: a survey of 73,000 sequence-tagged-connectors

As part of an international effort to sequence the rice genome, the Clemson University Genomics Institute is developing a sequence-tagged-connector (STC) framework. This framework includes the generation of deep-coverage BAC libraries from O. sativa ssp. japonica c.v. Nipponbare and the sequencing of both ends of the genomic DNA insert of the BAC clones. Here, we report a survey of the transposable elements (TE) in >73,000 STCs. A total of 6848 STCs were found homologous to regions of known TE sequences (E<10(-5)) by FASTX search of STCs against a set of 1358 TE protein sequences obtained from GenBank. Of these TE-containing STCs (TE-STCs), 88% (6027) are related to retroelements and the remaining are transposase homologs. Nearly all DNA transposons known previously in plants were present in the STCs, including maize Ac/Ds, En/Spm, Mutator, and mariner-like elements. In addition, 2746 STCs were found to contain regions homologous to known miniature inverted-repeat transposable elements (MITEs). The distribution of these MITEs in regions near genes was confirmed by EST comparisons to MITE-containing STCs, and our results showed that the association of MITEs with known EST transcripts varies by MITE type. Unlike the biased distribution of retroelements in maize, we found no evidence for the presence of gene islands when we correlated TE-STCs with a physical map of the CUGI BAC library. These analyses of TEs in nearly 50 Mb of rice genomic DNA provide an interesting and informative preview of the rice genome.

Properties of GST-CALM expressed in E. coli

Clathrin-coated vesicles (CCVs) are involved in protein and lipid trafficking between intracellular compartments in eukaryotic cells. CCVs are composed of clathrin and assembly proteins. The clathrin assembly protein lymphoid myeloid leukemia (CALM) gene, encodes a homologoue of the neuronal clathrin assembly protein AP180. In this study, we characterized the properties of the CALM expressed in E. coli. The molecular weight of bacterially expressed GST-CALM fusion protein was approximately 105 kD on SDS-PAGE. The CALM protein could promote clathrin triskelia into clathrin cages and could bind the preformed clathrin cage. However, 33 kD N-terminal domain of CALM could not bind pre-assembled clathrin cages, but assemble clathrin triskelia into clathrin cages. The CALM protein was bound to SH3 domain through N-terminal domain1, in vitro. The CALM protein is proteolyzed by caspase 3, caspase 8 and calpain through C-terminal domain.

The use of intensity modulated radiotherapy for the treatment of extensive and recurrent juvenile angiofibroma

These case series are presented to describe the application and advantages of intensity modulated radiotherapy (IMRT) for the treatment of extensive and/or recurrent juvenile angiofibroma. Two patients were diagnosed with recurrence at 11 and 13 months postoperatively, and one was surgically unresectable. The affected areas included the base of skull, cavernous sinus, pterygopalatine fossa, infratemporal fossa, posterior orbit and nasopharynx. Highly conformal IMRT was delivered with limited radiation doses to the optic nerves, optic chiasm, brainstem, brain, spinal cord, lens, retina, mandible, and parotid. The total dose delivered to the tumor varied from 3400 to 4500 cGy. The tumor shrunk radiographically in all three cases and there was no endoscopic evidence of disease in two cases at 15 months and 40 months. There was no acute toxicity. Late toxicity was limited to one episode of epistaxis and persistent rhinitis in one patient. In conclusion, IMRT provides several advantages over conventional radiotherapy in the treatment of recurrent juvenile angiofibroma.

Intensity modulated radiation therapy (IMRT): a new promising technology in radiation oncology

Intensity modulated radiation therapy (IMRT) is a new technology in radiation oncology that delivers radiation more precisely to the tumor while relatively sparing the surrounding normal tissues. It also introduces new concepts of inverse planning and computer-controlled radiation deposition and normal tissue avoidance in contrast to the conventional trial-and-error approach. IMRT has wide application in most aspects of radiation oncology because of its ability to create multiple targets and multiple avoidance structures, to treat different targets simultaneously to different doses as well as to weight targets and avoidance structures according to their importance. By delivering radiation with greater precision, IMRT has been shown to minimize acute treatment-related morbidity, making dose escalation feasible which may ultimately improve local tumor control. IMRT has also introduced a new accelerated fractionation scheme known as SMART (simultaneous modulated accelerated radiation therapy) boost. By shortening the overall treatment time, SMART boost has the potential of improving tumor control in addition to offering patient convenience and cost savings.

[The ice storm: an opportunity to study the effects of prenatal stress on the baby and the mother.]

Over the last several years, studies have shown that stressful experiences during the pregnancy can predict levels of neurological development, as well as cognitive and psychological functioning, during childhood and adulthood. For example, Mednick (1997) has been studying the effects of a major earthquake in China on the psychological and intellectual development of the unborn child. Twenty-three years after the quake, significant differences have been found between the earthquake group and a control group born one year later in terms of intellectual functioning, depression, and the size of certain brain regions. Less severe events, such as a divorce or job loss during the pregnancy, may also increase the risk of obstetric complications and may have an effect on the baby's neurological well being, weight and head circumference at birth. Death of the baby's father during the pregnancy and natural disasters have both been associated with increased rates of depression, schizophrenia and criminality in adulthood. Several of these same effects have been found in studies of prenatal stress in non-human primates. Many of these studies suggest that the second trimester of pregnancy is a particularly critical period during which stressful events may compromise development of the fetus. Methodological constraints limit research on prenatal maternal stress. Animal studies are able to control for pre- and postnatal environments. However, animal studies have limited generalizability to humans for whom numerous risk and protective factors are in operation. Studies of human pregnancies cannot randomly assign subjects to stress conditions. Maternal personality and temperament may be associated with characteristics of a woman's child not only through genetic transmission of personality, but possibly also through differential exposure to difficult life conditions which may, in part, be self-imposed. In addition, studies of prenatal life events in humans have severely restricted variance; very large samples of women must be screened to identify even small numbers of women who have experienced major life events during the pregnancy. Finally, follow-back studies which show an association between prenatal events and later rates of mental illness, do not include timely evaluations of actual rates of exposure to the event, nor the pregnant woman's subjective or biological reactions to the event. In this paper, we present a review of the literature on prenatal maternal stress followed by a discussion of how the January 1998 Québec ice storm could be used to study the mechanisms by which prenatal stress may influence mental health outcomes in the unborn child.

Applying the equivalent uniform dose formulation based on the linear-quadratic model to inhomogeneous tumor dose distributions: Caution for analyzing and reporting

We apply the concept of equivalent uniform dose (EUD) to our data set of model distributions and intensity modulated radiotherapy (IMRT) treatment plans as a method for analyzing large dose inhomogeneities within the tumor volume. For large dose nonuniformities, we find that the linerar-quadratic based EUD model is sensitive to the linear-quadratic model parameters, alpha and beta, making it necessary to consider EUD as a function of these parameters. This complicates the analysis for inhomogeneous dose distributions. EUD provides a biological estimate that requires interpretation and cannot be used as a single parameter for judging an inhomogeneous plan. We present heuristic examples to demonstrate the dose volume effect associated with EUD and the correlation to statistical parameters used for describing dose distributions. From these examples and patient plans, we discuss the risk of incorrectly applying EUD to IMRT patient plans.

Prenatal orogastric gene delivery results in transduction of the small bowel in the fetal rabbit

BACKGROUND

Gene therapy for meconium ileus, or other genetic diseases involving the gastrointestinal epithelium, may be possible with prenatal delivery of the CFTR gene to the gastrointestinal tract. Although minimally invasive techniques will probably be used for any future therapy of gastrointestinal disease, it is important to first test this strategy with a reliable animal model.

METHODS

The technique of orogastric fetal gene delivery was assessed using 7 pregnant rabbits (22 days' gestation n = 1, 25 days' gestation n = 4, 28 days' gestation n = 2). Four fetuses from each litter were given an adenoviral vector carrying a marker gene by instilling it into the posterior pharynx with an animal feeding needle (1 x 10(10) particles of ADV/RSV/LacZ suspended in 0.3 ml of saline), with the untreated fetuses serving as control animals.

RESULTS

There were no recoverable fetuses from the does that had surgery at 22 and 28 days (n = 3) due to maternal death (n = 2) and premature delivery (n = 1). Among the 4 does that underwent hysterotomy at 25 days of gestation, 1 underwent cesarean section 2 days after fetal gene delivery and 3 delivered at term, 5 (n = 1) or 6 (n = 2) days following gene delivery. Eleven of the 16 experimental pups and 7 untreated control animals were collected alive, and were sacrificed at delivery for study. Nine of the 11 experimental pups (82%) showed positive blue (LacZ+) nuclei in the small intestine by X-gal staining. No positive cells were found in 7/7 control animals. The presence of the reporter gene LacZ was confirmed in 8/11 (73%) virus-treated pups by PCR with 5/5 control animals negative for LacZ by PCR.

CONCLUSIONS

There was significant maternal and fetal loss related to anesthetic and husbandry issues when surgery was performed at 22 or 28 days of gestation. Based on these preliminary results, we conclude that orogastric gene delivery in the rabbit fetus at 25 days' gestation is an encouraging animal model to study fetal delivery to the gastrointestinal tract.

Distinct patterns of apoptosis in association with modulation of CD44 induced by thrombopoietin and granulocyte-colony stimulating factor during ex vivo expansion of human cord blood CD34+ cells

The insufficient number of haemopoietic stem cells (HSCs) in cord blood (CB) is the major potential limitation to widespread use of CB for marrow replacement. Cytokine-mediated ex vivo expansion has been proposed as a means of increasing the number of CB HSCs for transplantation. However, the biology of CB HSCs during cytokine-mediated ex vivo expansion, such as apoptosis or expression of adhesion molecules, has not yet been elucidated. We have investigated the patterns of apoptosis and CD44 expression on human CB CD34+ cells during ex vivo expansion. CD34+ cells isolated from human CB were cultured in a stroma-free liquid culture system with thrombopoietin (TPO), flt3-ligand (FL), stem cell factor (SCF), and/or granulocyte-colony stimulating factor (G-CSF). During the culture, for up to 5 weeks, apoptosis was measured by staining with 7-amino-actinomycin D (7-AAD) along with concurrent immunophenotyping of CD34 and CD44 with three-colour flow cytometry. In the cultures with TPO, an apoptotic fraction with down-regulated CD44 appeared from the fourth day up to the second week. G-CSF also induced apoptosis but in a different manner; the apoptotic fraction without down-regulation of CD44 appeared unremittingly for up to 5 weeks. FL did not induce apoptosis or down-regulation of CD44. These findings show that apoptosis is indeed involved in the regulation of CB CD34+ cells in ex vivo expansion and the patterns of apoptosis are dependent on the type of cytokines used. The distinct patterns of apoptosis suggest different mechanisms of TPO and G-CSF in inducing apoptosis, which still remains to be elucidated.