Case report: L5 tomita En bloc spondylectomy for oligometastatic liposarcoma with post adjuvant stereotactic ablative radiotherapy

Introduction

Tomita En-bloc spondylectomy of L5 is one of the most challenging techniques in radical oncological spine surgery. A 42-year-old female was referred with lower back pain and L5 radiculopathy with a background of right shoulder liposarcoma excision. CT-PET confirmed a solitary L5 oligometastasis. MRI showed thecal sac indentation hence wasn't suitable for Stereotactic Ablative Radiotherapy (SABR) alone. The seeding nature of sarcoma prevents the indication of separation surgery hence excisional surgery is considered for radical curative treatment. This case report demonstrates dual-staged modified TES including the utilisation of novel techniques to allow for maximum radical oncological control in the era of SABR and lesser invasive surgery.

Methods

First-stage: Carbonfibre pedicle screws planned from L2 to S2AI-Pelvis, aligned, to her patient-specific rods. Radiofrequency ablation of L5 pedicles prior to osteotomy was performed to prevent sarcoma cell seeding. Microscope-assisted thecal sac tumour separation and L5 nerve root dissection was performed. Novel surgical navigation of the ultrasonic bone-cutter assisted inferior L4 and superior S1 endplate osteotomies. Second-stage: Vascular-assisted retroperitoneal approach at L4–S1 was undertaken protecting the great vessels. Completion of osteotomies at L4 and S1 to En-bloc L5: (L4 inferior endplate, L4/5 disc, L5 body, L5/S1 disc and S1 superior endplate). Anterior reconstruction used an expandable PEEK cage obviating the need for a third posterior stage. Reinforced with a patient-specific carbon plate L4–S1 promontory.

Results

Patient rehabilitated well and was discharged after 42 days. Cyberknife of 30Gy in 5 fractions was delivered two months post-op. Despite left foot drop, she's walking independently 9 months post-op.

Conclusion

These are challenging cases require a truly multi-disciplinary team approach. We share this technique for a dual stage TES and metal-free construct with post adjuvant SABR to achieve maximum local control in spinal oligometastatic disease. This case promotes our modified TES technique in the era of SABR and separation surgery in carefully selected cases.

Radiomic Features From Diffusion-Weighted MRI of Retroperitoneal Soft-Tissue Sarcomas Are Repeatable and Exhibit Change After Radiotherapy

Background

Size-based assessments are inaccurate indicators of tumor response in soft-tissue sarcoma (STS), motivating the requirement for new response imaging biomarkers for this rare and heterogeneous disease. In this study, we assess the test-retest repeatability of radiomic features from MR diffusion-weighted imaging (DWI) and derived maps of apparent diffusion coefficient (ADC) in retroperitoneal STS and compare baseline repeatability with changes in radiomic features following radiotherapy (RT).

Materials and Methods

Thirty patients with retroperitoneal STS received an MR examination prior to treatment, of whom 23/30 were investigated in our repeatability analysis having received repeat baseline examinations and 14/30 patients were investigated in our post-treatment analysis having received an MR examination after completing pre-operative RT. One hundred and seven radiomic features were extracted from the full manually delineated tumor region using PyRadiomics. Test-retest repeatability was assessed using an intraclass correlation coefficient (baseline ICC), and post-radiotherapy variance analysis (post-RT-IMS) was used to compare the change in radiomic feature value to baseline repeatability.

Results

For the ADC maps and DWI images, 101 and 102 features demonstrated good baseline repeatability (baseline ICC > 0.85), respectively. Forty-three and 2 features demonstrated both good baseline repeatability and a high post-RT-IMS (>0.85), respectively. Pearson correlation between the baseline ICC and post-RT-IMS was weak (0.432 and 0.133, respectively).

Conclusions

The ADC-based radiomic analysis shows better test-retest repeatability compared with features derived from DWI images in STS, and some of these features are sensitive to post-treatment change. However, good repeatability at baseline does not imply sensitivity to post-treatment change.

OX40 and 4-1BB delineate distinct immune profiles in sarcoma

Systemic relapse after radiotherapy and surgery is the major cause of disease-related mortality in sarcoma patients. Combining radiotherapy and immunotherapy is under investigation as a means to improve response rates. However, the immune contexture of sarcoma is understudied. Here, we use a retrospective cohort of sarcoma patients, treated with neoadjuvant radiotherapy, and TCGA data. We explore therapeutic targets of relevance to sarcoma, using genomics and multispectral immunohistochemistry to provide insights into the tumor immune microenvironment across sarcoma subtypes. Differential gene expression between radioresponsive myxoid liposarcoma (MLPS) and more radioresistant undifferentiated pleomorphic sarcoma (UPS) indicated UPS contained higher transcript levels of a number of immunotherapy targets (CD73/NT5E, CD39/ENTPD1, CD25/IL2RA, and 4-1BB/TNFRSF9). We focused on 4-1BB/TNFRSF9 and other costimulatory molecules. In TCGA data, 4-1BB correlated to an inflamed and exhausted phenotype. OX40/TNFRSF4 and 4-1BB/TNFRSF9 were highly expressed in sarcoma subtypes versus other cancers. Despite OX40 and 4-1BB being described as Treg markers, we identified that they delineate distinct tumor immune profiles. This was true for sarcoma and other cancers. While only a limited number of samples could be analyzed, spatial analysis of OX40 expression identified two diverse phenotypes of OX40+ Tregs, one associated with and one independent of tertiary lymphoid structures (TLSs). Patient stratification is of intense interest for immunotherapies. We provide data supporting the viewpoint that a cohort of sarcoma patients, appropriately selected, are promising candidates for immunotherapies. Spatial profiling of OX40+ Tregs, in relation to TLSs, could be an additional metric to improve future patient stratification.

Treatments and Outcomes in Oligometastatic Soft Tissue Soft Sarcoma - A Single Centre Retrospective Analysis

BACKGROUND/AIM

Distinguishing true oligometastatic disease from early polymetastatic disease is vital in patients with soft tissue sarcoma as contemporary treatment strategies differ significantly. Clinical factors such as tumour biology, organ involved, number of lesions, and patient fitness influence clinical decisions.

PATIENTS AND METHODS

A retrospective search of a prospective database identified patients with new distant relapse, treated between 2009 and 2012.

RESULTS

A total of 223 patients were included, and oligometastases were diagnosed in 81 (36%) patients, which were pulmonary in just over half of cases. These were treated with local therapy in 66 of 89 cases, and 7 patients received subsequent treatment for additional oligometastases. Metastasectomy was the most common treatment modality. A total of 16/66 patients (24%) underwent active surveillance for >6 months prior to local therapy.

CONCLUSION

Patients with oligometastatic disease can experience durable disease control with timely multimodality treatment approaches for evolving metastatic disease, where disease biology allows.

Dose Reduction of Preoperative Radiotherapy in Myxoid Liposarcoma: A Nonrandomized Controlled Trial

IMPORTANCE

Currently, preoperative radiotherapy for all soft-tissue sarcomas is identical at a 50-Gy dose level, which can be associated with morbidity, particularly wound complications. The observed clinical radiosensitivity of the myxoid liposarcoma subtype might offer the possibility to reduce morbidity.

OBJECTIVE

To assess whether a dose reduction of preoperative radiotherapy for myxoid liposarcoma would result in comparable oncological outcome with less morbidity.

DESIGN, SETTING, AND PARTICIPANTS

The Dose Reduction of Preoperative Radiotherapy in Myxoid Liposarcomas (DOREMY) trial is a prospective, single-group, phase 2 nonrandomized controlled trial being conducted in 9 tertiary sarcoma centers in Europe and the US. Participants include adults with nonmetastatic, biopsy-proven and translocation-confirmed myxoid liposarcoma of the extremity or trunk who were enrolled between November 24, 2010, and August 1, 2019. Data analyses, using both per-protocol and intention-to-treat approaches, were conducted from November 24, 2010, to January 31, 2020.

INTERVENTIONS

The experimental preoperative radiotherapy regimen consisted of 36 Gy in once-daily 2-Gy fractions, with subsequent definitive surgical resection after an interval of 4 or more weeks.

MAIN OUTCOMES AND MEASURES

As a short-term evaluable surrogate for local control, the primary end point was centrally reviewed pathologic treatment response. The experimental regimen was regarded as a success when 70% or more of the resection specimens showed extensive treatment response, defined as 50% or greater of the tumor volume containing treatment effects. Morbidity outcomes consisted of wound complications and late toxic effects.

RESULTS

Among the 79 eligible patients, 44 (56%) were men and the median (interquartile range) age was 45 (39-56) years. Two patients did not undergo surgical resection because of intercurrent metastatic disease. Extensive pathological treatment response was observed in 70 of 77 patients (91%; posterior mean, 90.4%; 95% highest probability density interval, 83.8%-96.4%). The local control rate was 100%. The rate of wound complication requiring intervention was 17%, and the rate of grade 2 or higher toxic effects was 14%.

CONCLUSIONS AND RELEVANCE

The findings of the DOREMY nonrandomized clinical trial suggest that deintensification of preoperative radiotherapy dose is effective and oncologically safe and is associated with less morbidity than historical controls, although differences in radiotherapy techniques and follow-up should be considered. A 36-Gy dose delivered in once-daily 2-Gy fractions is proposed as a dose-fractionation approach for myxoid liposarcoma, given that phase 3 trials are logistically impossible to execute in rare cancers.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02106312.

Utility of Multi-Parametric Quantitative Magnetic Resonance Imaging for Characterization and Radiotherapy Response Assessment in Soft-Tissue Sarcomas and Correlation With Histopathology

Purpose: To evaluate repeatability of quantitative multi-parametric MRI in retroperitoneal sarcomas, assess parameter changes with radiotherapy, and correlate pre-operative values with histopathological findings in the surgical specimens. Materials and Methods: Thirty patients with retroperitoneal sarcoma were imaged at baseline, of whom 27 also underwent a second baseline examination for repeatability assessment. 14/30 patients were treated with pre-operative radiotherapy and were imaged again after completing radiotherapy (50.4 Gy in 28 daily fractions, over 5.5 weeks). The following parameter estimates were assessed in the whole tumor volume at baseline and following radiotherapy: apparent diffusion coefficient (ADC), parameters of the intra-voxel incoherent motion model of diffusion-weighted MRI (D, f, D*), transverse relaxation rate, fat fraction, and enhancing fraction after gadolinium-based contrast injection. Correlation was evaluated between pre-operative quantitative parameters and histopathological assessments of cellularity and fat fraction in post-surgical specimens (ClinicalTrials.gov, registration number NCT01902667). Results: Upper and lower 95% limits of agreement were 7.1 and -6.6%, respectively for median ADC at baseline. Median ADC increased significantly post-radiotherapy. Pre-operative ADC and D were negatively correlated with cellularity (r = -0.42, p = 0.01, 95% confidence interval (CI) -0.22 to -0.59 for ADC; r = -0.45, p = 0.005, 95% CI -0.25 to -0.62 for D), and fat fraction from Dixon MRI showed strong correlation with histopathological assessment of fat fraction (r = 0.79, p = 10-7, 95% CI 0.69-0.86). Conclusion: Fat fraction on MRI corresponded to fat content on histology and therefore contributes to lesion characterization. Measurement repeatability was excellent for ADC; this parameter increased significantly post-radiotherapy even in disease categorized as stable by size criteria, and corresponded to cellularity on histology. ADC can be utilized for characterizing and assessing response in heterogeneous retroperitoneal sarcomas.

Recovery of Salivary Function: Contralateral Parotid-sparing Intensity-modulated Radiotherapy versus Bilateral Superficial Lobe Parotid-sparing Intensity-modulated Radiotherapy

AIMS

To establish whether there is a difference in recovery of salivary function with bilateral superficial lobe parotid-sparing intensity-modulated radiotherapy (BSLPS-IMRT) versus contralateral parotid-sparing IMRT (CLPS-IMRT) in patients with locally advanced head and neck squamous cell cancers.

MATERIALS AND METHODS

A dosimetric analysis was carried out on data from two studies in which patients received BSLPS-IMRT (PARSPORT II) or CLPS-IMRT (PARSPORT). Acute (National Cancer Institute, Common Terminology Criteria for adverse events - NCI CTCAEv3.0) and late (Late Effects of Normal Tissue- subjective, objective, management analytical - LENTSOMA and Radiation Therapy Oncology Group) xerostomia scores were dichotomised: recovery (grade 0-1) versus no recovery (≥grade 2). Incidence of recovery of salivary function was compared between the two techniques and dose-response relationships were determined by fitting dose-response curves to the data using non-linear logistic regression analysis.

RESULTS

Seventy-one patients received BSLPS-IMRT and 35 received CLPS-IMRT. Patients received 65 Gy in 30 fractions to the primary site and involved nodal levels and 54 Gy in 30 fractions to elective nodal levels. There were significant differences in mean doses to contralateral parotid gland (29.4 Gy versus 24.9 Gy, P < 0.005) and superficial lobes (26.8 Gy versus 30.5 Gy, P = 0.02) for BSLPS and CLPS-IMRT, respectively. Lower risk of long-term ≥grade 2 subjective xerostomia (LENTSOMA) was reported with BSLPS-IMRT (odds ratio 0.50; 95% confidence interval 0.29-0.86; P = 0.012). The percentage of patients who reported recovery of parotid saliva flow at 1 year was higher with BSLPS-IMRT compared with CLPS-IMRT techniques (67.1% versus 52.8%), but the difference was not statistically significant (P = 0.12). For the whole parotid gland, the tolerance doses, D50, were 25.6 Gy (95% confidence interval 20.6-30.5), k = 2.7 (0.9-4.5) (CLPS-IMRT) and 28.9 Gy (26.1-31.9), k = 2.4 (1.4-3.4) (BSLPS-IMRT). For the superficial lobe, D50 were similar: BSLPS-IMRT 23.5 Gy (19.3-27.6), k = 1.9 (0.5-3.8); CLPS-IMRT 24.0 Gy (17.7-30.1), k = 2.1 (0.1-4.1).

CONCLUSION

BSLPS-IMRT reduces the risk of developing high-grade subjective xerostomia compared with CLPS-IMRT. The D50 of the superficial lobe may be a more reliable predictor of recovery of parotid function than the whole gland mean dose.

Induction Chemotherapy Followed by Chemo-intensity-modulated Radiotherapy for Locally Advanced Nasopharyngeal Cancer

AIMS

To determine the toxicity and tumour control rates after chemo-intensity-modulated radiotherapy (chemo-IMRT) for locally advanced nasopharyngeal cancers (LA-NPC).

MATERIALS AND METHODS

Patients with LA-NPC were enrolled in a trial to receive induction chemotherapy followed by parotid-sparing chemo-IMRT. The primary site and involved nodal levels received 65 Gy in 30 fractions and at risk nodal levels received 54 Gy in 30 fractions. Incidence of ≥grade 2 subjective xerostomia was the primary end point. Secondary end points included incidences of acute and late toxicities and survival outcomes.

RESULTS

Forty-two patients with American Joint Committee on Cancer stages II (12%), III (26%) and IV (62%) (World Health Organization subtype: I [5%]; II [40%]; III [55%]) completed treatment between January 2006 and April 2010 with a median follow-up of 32 months. Incidences of ≥grade 2 acute toxicities were: dysphagia 83%; xerostomia 76%; mucositis 97%; pain 76%; fatigue 99% and ototoxicity 12%. At 12 months, ≥grade 2 subjective xerostomia was observed in 31%, ototoxicitiy in 13% and dysphagia in 4%. Two year locoregional control was 86.2% (95% confidence interval: 70.0-94.0) with 2 year progression-free survival at 78.4% (61.4-88.6) and 2 year overall survival at 85.9% (69.3-93.9).

CONCLUSIONS

Chemo-IMRT for LA-NPC is feasible with good survival outcomes. At 1 year, 31% experience ≥grade 2 subjective xerostomia.

Optimising measles virus-guided radiovirotherapy with external beam radiotherapy and specific checkpoint kinase 1 inhibition

BACKGROUND AND PURPOSE

We previously reported a therapeutic strategy comprising replication-defective NIS-expressing adenovirus combined with radioiodide, external beam radiotherapy (EBRT) and DNA repair inhibition. We have now evaluated NIS-expressing oncolytic measles virus (MV-NIS) combined with NIS-guided radioiodide, EBRT and specific checkpoint kinase 1 (Chk1) inhibition in head and neck and colorectal models.

MATERIALS AND METHODS

Anti-proliferative/cytotoxic effects of individual agents and their combinations were measured by MTS, clonogenic and Western analysis. Viral gene expression was measured by radioisotope uptake and replication by one-step growth curves. Potential synergistic interactions were tested in vitro by Bliss independence analysis and in in vivo therapeutic studies.

RESULTS

EBRT and MV-NIS were synergistic in vitro. Furthermore, EBRT increased NIS expression in infected cells. SAR-020106 was synergistic with EBRT, but also with MV-NIS in HN5 cells. MV-NIS mediated (131)I-induced cytotoxicity in HN5 and HCT116 cells and, in the latter, this was enhanced by SAR-020106. In vivo studies confirmed that MV-NIS, EBRT and Chk1 inhibition were effective in HCT116 xenografts. The quadruplet regimen of MV-NIS, virally-directed (131)I, EBRT and SAR-020106 had significant anti-tumour activity in HCT116 xenografts.

CONCLUSION

This study strongly supports translational and clinical research on MV-NIS combined with radiation therapy and radiosensitising agents.

Dose-response analysis of parotid gland function: what is the best measure of xerostomia?

PURPOSE

To describe the dose-response relationships for the different measures of salivary gland recovery following radical radiotherapy for locally advanced head and neck squamous cell cancers (LA-HNSCC).

METHODS AND MATERIALS

Dosimetric analysis of data from the PARSPORT trial, a Phase III study of conventional RT (RT) and intensity modulated radiotherapy (IMRT) for LA-HNSCC was undertaken to determine the relationship between parotid gland mean dose and toxicity endpoints: high-grade subjective and objective xerostomia and xerostomia-related quality of life scores. LKB-NTCP parameters (TD50, m and n) were generated and tolerance doses (D50) reported using non-linear logistic regression analysis.

RESULTS

Data were available on 63 patients from the PARSPORT trial. Parotid saliva flow rate provided the strongest association between mean dose and recovery, D50=23.4 Gy (20.6-26.2) and k=3.2 (1.9-4.5), R(2)=0.85. Corresponding LKB parameters were TD50=26.3 Gy (95% CI: 24.0-30.1), m=0.25 (0.18-1.0 and n=1). LENTSOMA subjective xerostomia also demonstrated a strong association D50=33.3 Gy (26.7-39.8), k=2.8 (91.4-4.4), R(2)=0.77).

CONCLUSION

We recommend using the LENT SOMA subjective xerostomia score to predict recovery of salivation due to its strong association with dosimetry and ease of recording.

The effect of concomitant chemotherapy on parotid gland function following head and neck IMRT

PURPOSE

To determine whether concomitant chemotherapy increases the incidence of high grade xerostomia following parotid-sparing intensity-modulated radiotherapy (IMRT) in patients with locally advanced head and neck squamous cell cancer.

MATERIALS AND METHODS

The incidence of high grade (≥G2) acute (CTCAEv3.0) and late (LENTSOMA and RTOG) xerostomia was compared between patients treated with either IMRT or concomitant chemo-IMRT (c-IMRT) in 2 prospective studies. Parotid gland mean tolerance doses (D₅₀) were reported using non-linear logistic regression analysis.

RESULTS

Thirty-six patients received IMRT alone and 60 patients received c-IMRT. Patients received 65 Gy in 30 daily fractions to the primary site and involved nodal groups and 54 Gy in 30 fractions to elective nodal groups, mean doses to the parotid glands were comparable. Concomitant cisplatin 100mg/m(2) was administered on days 1 and 29 of IMRT. The incidence of ≥G2 subjective xerostomia was similar in both groups; acute-64.7% (IMRT) versus 60.3% (c-IMRT), p=0.83; late-43% (IMRT) versus 34% (c-IMRT), p=0.51. Recovery of parotid salivary flow at 1 year was higher with IMRT (64% vs 50%), but not statistically significant (p=0.15). D₅₀ for absence of parotid saliva flow at 1 year was 23.2 Gy (95% CI: 17.7-28.7) for IMRT and 21.1 Gy (11.8-30.3) for c-IMRT.

CONCLUSION

Concomitant c-IMRT does not increase the incidence of acute or late xerostomia relative to IMRT alone.

Novel targeted radiosensitisers in cancer treatment

The last few years have seen a significant increase in our understanding of the molecular pathways governing cell function in cancer. This has led to an explosive interest in novel molecularly-targeted agents and, until recently, the focus of research effort has been to combine these agents with conventional cytotoxic chemotherapy. However, following a recent trial of an anti-EGFR targeted antibody in combination with radiation, a new paradigm is emerging in which these novel agents will be combined with external beam radiotherapy (RT). In this article we review classes of novel targeted radiosensitisers that are directed at specific aspects of cell function. Such agents are aimed at either single or multiple targets (the latter is a more attractive approach in view of cross-talk between different cell signaling pathways). We review available preclinical and clinical literature with a particular focus on novel agents targeting components of the ErbB and IGF-1R family cell signaling pathways. In this model, radiosensitisers can exert their effects at the cell membrane surface by preventing receptor activation or by interfering with the function of second messengers such as the Ras/PI3K/mTOR pathway. In addition, the effects of novel DNA repair inhibitors will be considered in the context of combination strategies with signal transduction pathway blockade. Other small molecule inhibitors, such as HSP90 inhibitors, that can disrupt signaling in a number of different pathways, will also be discussed. Ultimately, through the synergistic use of these innovative molecules and RT, the therapeutic index may be enhanced by modulating cellular metabolism, proliferation, repair, angiogenesis, and apoptosis. The rapid proliferation of available targeted agents and their entry into phase I clinical trials means that this is an extremely interesting area for research in radiation oncology.

Gene transfer of the serine elastase inhibitor elafin protects against vein graft degeneration

BACKGROUND

Leukocyte infiltration and serine elastase activity lead to smooth muscle cell proliferation in association with posttransplant coronary arteriopathy and may also be involved in vein graft neointimal formation. A number of therapies have targeted cellular proliferation, but the inhibition of serine elastase-mediated extracellular matrix remodeling has not been investigated as a potential strategy to prevent neointimal formation and subsequent atherosclerotic degeneration in vein grafts.

METHODS AND RESULTS

We studied jugular vein grafts 48 hours after interposition into the carotid arteries of rabbits and demonstrated inflammatory cell infiltration and elevated serine elastase activity, a stimulus for matrix remodeling and deposition of elastin. Therefore, elastolytic activity in vein grafts was targeted through transient expression of the selective serine elastase inhibitor elafin with hemagglutinating virus of Japan liposome-mediated gene transfer. Elafin transfection reduced inflammation by 60% at 48 hours and neointimal formation by approximately 50% at 4 weeks after implantation. At 3 months, a 74% decrease in neointimal elastin deposition correlated with protection against cholesterol-induced macrophage infiltration and lipid accumulation, which were both reduced by approximately 50% in elafin-transfected grafts relative to controls.

CONCLUSIONS

Gene transfer of the selective serine elastase inhibitor elafin in vein grafts is effective in reducing the early inflammatory response. Although transient expression of elafin delays neointimal formation, it is also sufficient to cause an alteration in elastin content of the extracellular matrix, making it relatively resistant to atherosclerotic degeneration.

Suppressed smooth muscle proliferation and inflammatory cell invasion after arterial injury in elafin-overexpressing mice

Elastases degrade the extracellular matrix, releasing growth factors and chemotactic peptides, inducing glycoproteins such as tenascin, and thereby promoting vascular cell proliferation and migration. Administration of serine elastase inhibitors reduces experimentally induced vascular disease. The ability to mount an intrinsic anti-elastase response may, therefore, protect against intimal/medial thickening after vascular injury. To investigate this, we showed that wire-induced endothelial denudation of the carotid artery is associated with transient elevation in elastase activity and confirmed that this is abolished in transgenic mice overexpressing the serine elastase inhibitor, elafin, targeted to the cardiovascular system. Ten days after injury, nontransgenic littermates show vessel enlargement, intimal thickening, increased medial area and cellularity, and 2-fold increase in tenascin. Injured vessels in transgenic mice become enlarged but are otherwise similar to sham-operated controls. Injury-induced vessel wall thickening, which is observed only in nontransgenic mice, is related to foci of neutrophils and macrophages, in addition to smooth muscle cells that fail to stain for alpha-actin and are likely dedifferentiated. Our study therefore suggests that a major determinant of the vascular response to injury is the early transient induction of serine elastase activity, which leads to cellular proliferation and inflammatory cell migration.

Nitric oxide reduces vascular smooth muscle cell elastase activity through cGMP-mediated suppression of ERK phosphorylation and AML1B nuclear partitioning

Nitric oxide (NO) reduces the severity of pulmonary vascular disease in rats as do elastase inhibitors. We therefore hypothesized that NO inhibits elastase by suppressing mitogen-activated protein kinases that trans-activate AML1B, a transcription factor for elastase. We used cultured pulmonary artery smooth muscle cells in which serum-treated elastin (STE) induces a > threefold increase in elastase activity as evaluated by solubilization of [(3)H]-elastin. NO donors (SNAP and DETA NONOate) inhibited elastase in a dose-dependent manner as did a cGMP mimetic (8-pCPT-cGMP). SNAP inhibition of elastase was reversed by coadministration of a cGMP-PKG inhibitor (Rp-8-pCPT-cGMP). The STE-induced increase in phospho-ERK was suppressed by NO donors and the cGMP mimetic, and reversed by cGMP-PKG inhibitor, as was expression of AML1B and DNA binding in nuclear extracts. A concomitant increase in p38 phosphorylation was also inhibited by SNAP, but whereas MEK inhibitor (PD98059) suppressed elastase and AML1B-DNA binding, a p38 inhibitor (SB202190) did not. Our study uniquely links NO with inhibition of elastase-dependent matrix remodeling in vascular disease by suggesting a cGMP-PKG-related mechanism suppressing ERK-mediated partitioning of AML1B in nuclear extracts.

Cancer incidence in Karachi, Pakistan: first results from Karachi Cancer Registry

No cancer incidence data from Pakistan have been published in the 5 decades since independence. Incidence data for the period 1995-1997 from the population of the Karachi South district (1.7 million) are presented here. A total of 4,268 new cancer cases were registered during this period: 2,160 cases in males and 2,108 cases in females. Overall, 95.3% of the incident cases were microscopically verified. The incidence rates for all cancers combined were 80.5 per 100,000 (crude) and 136.7 per 100,000 (age- standardised rates [ASR]) for males and 91.8 (crude) and 163.2 per 100,000 (ASR) for females. In males, lung cancer (ASR 20.3) was the most frequently recorded malignancy followed by oral cavity (ASR 13.8) and larynx cancer (ASR 8.6). In females, breast was the most common site of cancer, accounting for one third of female cancers (ASR 51.7), followed by oral cavity (ASR 14.1) and ovarian cancer (ASR 10.2). Karachi reports the highest incidence of breast cancer for any Asian population, except Jews in Israel. Tobacco smoking is estimated to be responsible for 40% of cancers in males and tobacco chewing for a further substantial proportion of head and neck cancers.

Targeted overexpression of elafin protects mice against cardiac dysfunction and mortality following viral myocarditis

Serine elastases degrade elastin, stimulate vascular smooth muscle cell migration and proliferation, and are associated with myocardial damage. To evaluate the impact of elastase inhibition on cardiovascular development and disease, transgenic mice were created in which the mouse preproendothelin-1 promoter was used to target elafin overexpression to the cardiovascular system. To distinguish the transgene from endogenous elafin, constructs were made incorporating a FLAG sequence; the COOH-terminus FLAG-tagged elafin construct produced a stable, functionally active gene product and was used to create transgenic mice. Consistent with endothelin expression, abundant elafin mRNA was observed in transgenic F1 embryos (embryonic day 13.5) and in adult transgenic mice heart, trachea, aorta, kidney, lung, and skin, but not in liver, spleen, and intestine. Functional activity of the transgene was confirmed by heightened myocardial elastase inhibitory activity. No tissue abnormalities were detected by light microscopy or elastin content. However, injection of 10 plaque-forming units (PFU) of encephalomyocarditis virus resulted in death within 11 days in 10 out of 12 nontransgenic mice compared with one out of nine transgenic littermates. This reduced mortality was associated with better cardiac function and less myocardial inflammatory damage. Thus, elafin expression may confer a protective advantage in myocarditis and other inflammatory diseases.

A serine elastase inhibitor reduces inflammation and fibrosis and preserves cardiac function after experimentally-induced murine myocarditis

In viral myocarditis, inflammation and destruction of cardiac myocytes leads to fibrosis, causing progressive impairment in cardiac function. Here we show the etiologic importance of serine elastase activity in the pathophysiology of acute viral myocarditis and the therapeutic efficacy of an elastase inhibitor. In DBA/2 mice inoculated with the encephalomyocarditis virus, a more than 150% increase in myocardial serine elastase activity is observed. This is suppressed by a selective serine elastase inhibitor, ZD0892, which is biologically effective after oral administration. Mice treated with this compound had little evidence of microvascular constriction and obstruction associated with myocarditis-induced ischemia reperfusion injury, much less inflammation and necrosis, only mild fibrosis and myocardial collagen deposition, and normal ventricular function, compared with the infected nontreated group.

AML1-like transcription factor induces serine elastase activity in ovine pulmonary artery smooth muscle cells

In previous studies, we showed that induction of pulmonary artery (PA) smooth muscle cell (SMC) elastase activity by serum-treated elastin (STE) requires DNA transcription. We therefore used differential mRNA display to identify transcripts expressed coincident with elastase induction. Twenty-four individual transcripts were differentially expressed from a screen of approximately 2000 mRNA sequences. An mRNA with sequence homology to the human transcription factor AML1 was identified and subsequently cloned from ovine PA SMCs. Since AML1 binds to a consensus sequence in the promoter of neutrophil elastase, we pursued the possibility that AML1 is a candidate transcription factor for SMC elastase. We documented by immunohistochemistry that serum stimulation induces increased expression of AML1 in the nucleus of PA SMCs. We also showed that STE induction of elastase activity is associated with early expression of AML1 mRNA and protein and that AML1 consensus sequence DNA binding activity is increased in nuclear extracts of STE-treated cells. In addition, AML1 antisense oligonucleotides reduced serum induction of elastase activity. Our study thus provides the first functional evidence of AML1 transcriptional activity related to elastase genes and offers novel insights into the broader biological significance of AML1 in nonmyeloid cells.

Nucleolin and heterogeneous nuclear ribonucleoprotein C proteins specifically interact with the 3'-untranslated region of amyloid protein precursor mRNA

The central nervous system deposition by neurons and glia of beta A4 amyloid protein is an important contributing factor to the development of Alzheimer's disease. Amyloidogenic cells overexpress amyloid precursor protein (APP) mRNAs suggesting a transcriptional or post-transcriptional defect may contribute to this process. We have previously shown that APP mRNAs display regulated stability which is dependent on a 29-base element within the 3'-untranslated region (UTR). This domain specifically interacted with several cytoplasmic RNA-binding proteins. We have purified these APP RNA-binding proteins from a human T-cell leukemia and demonstrate that five cytoplasmic proteins of 70, 48, 47, 39, and 38 kDa form the previously observed APP RNA protein complexes. Amino acid sequence analyses showed that the 70-, 48-, and 47-kDa proteins were fragments of nucleolin and that the 39- and 38-kDa proteins were heterogeneous nuclear ribonucleoprotein (hnRNP) C protein. Northwestern and Western blot analyses of purified material further confirmed these data. Nucleolin protein is known to shuttle between the nucleus and cytoplasm but hnRNP C has not been reported within the cytoplasm. This report of sequence specific, mRNA binding by nucleolin and hnRNP C suggests that these proteins participate in the post-transcriptional regulation of APP mRNA through 3'-UTR, site-specific interactions.

Danger to the popliteal artery in high tibial osteotomy

We report a case in which the popliteal artery was divided during upper tibial osteotomy performed with the knee in 90 degrees of flexion. This position is believed to allow it to fall safely back from the tibia, but we could find no published confirmation. We used duplex ultrasonography in ten healthy volunteers to measure the distance from the popliteal artery to the posterior surface of the tibia at various degrees of flexion of the knee. Our results showed that in 12 of 20 knees the popliteal artery was closer to the tibia in 90 degrees of knee flexion than in full extension. Surgeons performing upper tibial osteotomy should be aware that flexing the knee does not protect the popliteal artery from injury.

Danger to the popliteal artery in high tibial osteotomy

We report a case in which the popliteal artery was divided during upper tibial osteotomy performed with the knee in 90 degrees of flexion. This position is believed to allow it to fall safely back from the tibia, but we could find no published confirmation. We used duplex ultrasonography in ten healthy volunteers to measure the distance from the popliteal artery to the posterior surface of the tibia at various degrees of flexion of the knee. Our results showed that in 12 of 20 knees the popliteal artery was closer to the tibia in 90 degrees of knee flexion than in full extension. Surgeons performing upper tibial osteotomy should be aware that flexing the knee does not protect the popliteal artery from injury.

Post-transcriptional regulation of the p53 tumor suppressor gene during growth-induction of human peripheral blood mononuclear cells

Regulation of p53 gene expression at the post-transcriptional level was investigated during growth induction of human peripheral blood mononuclear cells (PBMCs). Freshly isolated PBMCs, which are in the Go phase of the cell cycle, were shown to express low levels of p53 mRNA that was rapidly degraded with a half life of 1 h. The rapid decay of p53 mRNA in quiescent PBMCs was dependent on global protein synthesis as treatment with cycloheximide resulted in stabilization of the p53 message. PBMCs were stimulated to enter the cell cycle by treatment with a combination of the mitogenic lectin phytohemagglutinin (PHA) and phorbol ester (TPA). Progressive stabilization of the p53 message occurred in PBMCs during growth induction. By 24 h of incubation in the presence of PHA and TPA, the half life of p53 mRNA was 6 h and p53 mRNA steady state levels were increased 4.5 to 5.0-fold. p53 protein was not detected in quiescent PBMCs, but was readily detected in PBMCs stimulated for 24 h with PHA and TPA. Stabilization of p53 mRNA was observed in PBMCs treated with either PHA or TPA, but to a lesser degree than when PHA and TPA were used as co-stimulants. These results indicate that differential degradation of p53 messenger RNA occurs in quiescent vs mitogen stimulated PBMCs and suggest that post-transcriptional regulation importantly contributes to increased p53 mRNA steady state levels as PBMCs enter the cell cycle.

Subfeature speckle interferometry

A novel speckle technique, subfeature speckle interferometry, is introduced that relies on the amplitude interference of two independent speckle patterns, originating from coherent illumination, by use of an optical system that produces interferometric quality interference fringes on a scale comparable with the speckle correlation length. Examples are given for in-plane translation, sample tilt, and temperature measurement (strain). A temperature measurement accuracy sigma = 0.92 degrees C is realized. In contrast to traditional full-field speckle crosscorrelation techniques, this technique requires only a small number of detector elements with minimal signal processing and is compatible with many real-time sensor applications.

Amyloid precursor protein mRNA stability is controlled by a 29-base element in the 3'-untranslated region

In the accompanying paper (Zaidi, S. H. E., Denman, R., and Malter, J. S. (1994) J. Biol. Chem. 269, 24000-24006) we demonstrate that in tumor and normal cells, multiple cytosolic proteins interact with a 29-base sequence in the 3'-untranslated region of amyloid precursor protein (APP) mRNA. These data suggested that APP gene expression may be modulated by regulated APP mRNA decay. We have investigated this prediction by measuring the decay rates of APP mRNA in resting and mitogen-treated peripheral blood mononuclear cells and H4 and K562 tumor cell lines. In resting peripheral blood mononuclear cells, APP mRNA decayed with a half-life of 4 h. Under these conditions, the activity of APP mRNA-binding proteins was not detectable. After activation, binding protein activities were induced, and APP mRNA decay was blocked with a half-life of > 12 h. In log phase neuronal or lymphoid tumor cell lines, binding activity was constitutively present and APP mRNA displayed a half-life of > 12 h. Protein synthesis inhibition by cycloheximide had no effect on APP mRNA decay in normal or tumor cells. Transfected wild type or mutant APP mRNAs that lacked the 29-base region were stable (t1/2 > 10 h) in K562 tumor cells. Therefore, we conclude that the 29-base region functions in cis to destabilize APP mRNA in resting, normal cells. Upon activation APP mRNA-binding proteins are induced, interact with the 29-base region, and likely participate in stabilization of the mRNA.

Multiple proteins interact at a unique cis-element in the 3'-untranslated region of amyloid precursor protein mRNA

Growing evidence suggests that Alzheimer's disease results from dysregulated production and deposition of beta-amyloid in the central nervous system. beta-Amyloid is derived from proteolytic processing of one of multiple amyloid precursor protein (APP) isoforms. The production of APP in many somatic tissues and tumor cell lines provides a more accessible model to study the regulation of APP gene expression. Recent data suggest that APP mRNAs accumulate in activated lymphocytes and neuronal tumor lines. We are interested in defining the contribution of alterations in stability to changes in steady-state APP mRNA levels in these model systems. Herein we demonstrate by mobility shift assay that the 3'-untranslated region of APP RNAs which contain a contiguous 29-base region interacts in vitro with multiple mRNA-binding proteins found in cytosolic lysates prepared from normal and transformed human cells. UV cross-linking of radiolabeled APP RNAs to cytosolic protein extracts followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis identified six distinct RNA-protein complexes of 42, 47, 65, 73, 84, and 104 kDa. Competition assays with APP, AU-rich, or irrelevant RNAs demonstrated that binding was specific and in some cases preferential for AU- or U-rich sequences by which we tentatively place the binding site of the proteins along the 29-base region. APP mRNA-binding proteins were constitutively active in all tumor lines examined as well as at diminished levels in whole human brain cytosolic lysates. The core element is AU-rich and highly conserved between human and some murine APP mRNAs. In the accompanying paper (Zaidi, S. H. E. and Malter, J. S. (1994) J. Biol. Chem. 269, 24007-24013) we show that this 29-base element in the 3'-untranslated region regulates the stability of APP mRNA. Cumulatively these data suggest that steady-state APP mRNA levels are modulated by cytosolic protein-RNA interactions.

Pattern of leucocyte acid phosphatase reaction in T-cell lymphoblastic leukaemia

Acid phosphatase (AP) reaction is a specific cytochemical marker for T-cell lymphoblastic leukaemia (T-ALL). Twenty six cases of ALL were diagnosed as T-ALL employing cytochemical profiles including AP and sheep red blood cell rosettes. Three district patterns of AP reaction were observed. On one end of the spectrum, 100% of the positive blasts showed the classical dot-like reaction while on the other 100% showed a scattered reaction. Between the two a mixed pattern was observed with 30-80% of the positive blasts showing the dot-like reaction while the rest showed scattered pattern. Dot-like pattern showed L1 morphology, high counts and low SRBC rosettes while scattered showed L2 morphology, low counts and high SRBC rosettes. The pattern observed in our series differs from the dot-like reaction observed in T-ALL in the western series. We recommend that this pattern must be borne in mind when employing AP reaction for T-ALL diagnosis (JPMA 42: 151, 1992).

Unilateral proptosis in E.N.T. practice

Seventeen cases of unilateral proptosis aged 11-54 years are presented. The proptosis was due to mucormycosis in 7, ethmoid polyposis in 4, malignancy in 4, and one each due to Ringert's tumour and fibrous dysplasia. Surgery was performed in all cases with the aim of total extirpation of disease and orbital repositioning. The surgical approaches included transverse maxillary osteotomy, transantral ethmoidectomy, modified lateral rhinotomy, and orbital decompression. There was one fatality, and two recurrences. Three cases showed satisfactory and eleven excellent results.

A study of H2 receptor antagonists in the treatment of chronic intractable pharyngitis

In a controlled study of 75 patients suffering from chronic pharyngitis: 30 were treated with H2-receptor antagonist, 30 with H1-receptor antagonist, local decongestants and antiseptic gargles: and 15 treated with alum, salt or Dispirin gargles acted as controls. Best response was obtained with the first mode of treatment, raising the possibility of role of the H2-receptors in causing chronic pharyngitis. The difference was highly significant (P less than 0.001).

Hepatocellular carcinoma in Karachi

The present study defines the clinical presentation and examines possible aetiological factors in the occurrence of hepatocellular carcinoma in Karachi, Pakistan. Histologically proven cases of hepatocellular carcinoma (n = 366) were seen over 16 years. The maximum frequency occurred in the age range 51-60 years (range: 8-98 years), and the male to female ratio was 2.5:1. The place of birth, place of longest stay and various addictions did not have any association with the occurrence of liver carcinoma. Only three cases had a history of liver cancer in their immediate relatives. The main presenting features were right hypochondrial mass (85%) and pain (79%). The liver size did not correlate with the duration of illness. alpha-Fetoprotein titres were more than 200 ng/mL in 62% of cases. Using a reverse passive haemagglutination assay method, HBsAg and anti-HBc positivity were 32% and 60%, respectively. Antigen figures rose to 60% when radio-immunoassay was used; 41% of cases were anti-delta positive (EIA). Aflatoxin contamination varied between 10% and 17% in various localities of Karachi, suggesting an association of liver cancer with HBsAg and aflatoxins. Histopathologically 73% were trabecular, and 2.5% were mixed hepatocholangiocarcinomas. Follow-up was available in 45% of cases. All except two (1.2%) died within 6 months.

Anthropological study of the mastoid air cell system in Pakistani races

This is an anthropological study of the development of the mastoid process in the four ethnic groups of Pakistani races: Turko-Iranian, Indo-Aryan, Scytho-Dravidian, and Aryo-Dravidian. Cephalometric studies have established that the majority of Pakistanis are brachio to ultra-brachiocephalic (Cephalic Index 82-x). Radiological evaluation of normal mastoids and their planimetric measurements show that the mastoid process is smaller (Av: 10.24 sq.cm. +/- 0.8) than the Caucasian Western races (Av: 12-15 sq.cm.). Neither combined approach tympanoplasty, nor mastoid obliteration technique may be required, nor technically possible in a small mastoid. Natural epithelization of a small 'peanut size' mastoidectomy cavity does not justify these procedures. A modified radical mastoidectomy and tympanoplasty reconstruction provides a satisfactory result in chronic discharging ears.

Noise levels and the sources of noise pollution in Karachi

The menace of noise is a by-product of civilization and its hazards are well known. Noise levels were measured in Karachi, at different places and at different times of the night and day, using an Amplaid noise meter. The leg for Karachi came to 80 dB (A), the General Noise Index x (G.N.I.) to 460, and the noise pollution level (N.P.L.) to 99 dB (A). These values are significantly higher (P less than 0.01) than the available international data. The sources of noise production were indentified as, the road traffic, human activity, industrial and civil works, mechanical and engineering workshops. The most noticeable sources of noise pollution in Karachi, are the autorickshaws, trail motor bikes and the fag horns of public transport (JPMA 39-62, 1989).

Assessment of occupational benzene exposure in petrol filling stations at Rangoon

An occupational health survey was conducted on workers, who inhale petrol fumes which contain low concentrations of benzene, at petrol filling stations in the city of Rangoon, Burma. To evaluate the exposure to benzene, urinary phenol (which is a principal metabolite of absorbed benzene) was measured in workers at petrol filling stations and in a control group of healthy male adults. The survey revealed that the urinary phenol content of workers exposed to petrol fumes was significantly higher than that of workers who were not exposed.

High aspect-ratio holographic photoresist gratings

Holographic gratings with periods as small as 700 nm, rectangular profiles with linewidths of <120 nm, and depths of 1.2 microm (aspect ratio of 10) have been formed using positive photoresist on Si substrates and visible laser exposure (488 nm). Similar aspect ratios have been achieved at a 400-nm period using 334-nm exposing radiation. A simple exposure and development model, which accounts for the large aspect ratios and predicts the grating fabrication limits, is presented.

Spirometry and flow-volume curves in healthy, normal Pakistanis

Previous studies have indicated that lung volumes in healthy, normal Pakistani adults are smaller than measurements reported in comparable healthy European populations; in order to confirm these findings and to examine the relationship of maximal expiratory flow rates to lung volumes, we studied 250 non-smoking healthy subjects (116 men and 114 women) between the ages of 18 and 65 years. The population sample was drawn from urban and rural areas of Pakistan, with low levels of air pollution. The results indicate that the forced vital capacity (FVC) and forced expired volume in 1 second (FEV1) were lower in the Pakistani population compared to European populations and North American populations of European descent. These data are in conformity with previous studies; however, in Pakistani men the effects of age on FVC and FEV1 were slight so that, after the fourth decade, the FVC and FEV1 values are very comparable between the European and Pakistani populations. Amongst Pakistani women, on the other hand, FVC and FEV1 remained lower than in their European counterparts throughout adult life. Maximal expiratory flow rates amongst the men did not correlate with age, and these values were very similar to those reported in age-matched European populations. In women, however, there was a significant correlation of maximal flow rates with age and height, and the maximal expiratory flows were decreased compared to European populations. These data indicate that in Pakistani men pulmonary mechanics may be different to their European counterparts, allowing for higher maximal expiratory flows at any given lung volume.

Experimental bagassosis: role of infection

The pathological lesions of bagassosis have been reproduced in guinea pigs given bagasse fibers along with low doses of actinomycete spores. In the early stages, interstitial infiltration with lymphocytes and macrophages as seen in humans was noted. Later, small interstitial bagasse granulomas composed of foreign body giant cells, fibroblasts, and lymphocytes developed, some of which had a laminated appearance. Lymph node changes consistent with an immunological reaction were observed. Actinomycetes alone showed occasional areas of pneumonitis and bagasse alone small granulomas consisting of foreign body giant cells and bagasse fibers. Finally, the combined effect of dust and actinomycetes produced interstitial fibrosis composed of thick reticulin fibers and occasional collagen fibers, which persisted to the end of the experiment. Bagasse alone and actinomycetes alone produced only thin reticulin fibers. It has been suggested that bagassosis is due to the synergistic action of bagasse fibers and Micropolyspora faeni and that in the pathogenesis of the syndrome an immunological component may be involved.