TB and interstitial lung disease: a systematic review and meta-analysis

INTRODUCTION

To determine the frequency of TB among patients with interstitial lung diseases (ILDs).

METHODS

We performed a comprehensive search in the PubMed/Medline, EMBASE and Scopus databases up to 1 August 2023 of studies reporting on the prevalence of TB among patients with ILDs.

RESULTS

Twelve studies comprising 3,817 patients with ILD were found: the pooled prevalence of TB among ILD patients was 11.0% (95% CI 5.4-21.0). In the subgroup analysis, the TB rate among patients with silicosis and idiopathic pulmonary fibrosis (IPF) was respectively 35.6% (95% CI 32.6-38.8) and 4.4% (95% CI 3.6-5.3) (P = 0.00). The frequency of TB among ILD patients was higher in high TB burden countries than in low/intermediate-burden countries: 26.3%, 95% CI 17.7-37.3 vs. 4.9%, 95% CI 3.3-7.2; P = 0.00.

CONCLUSIONS

This study shows the frequency of TB among ILD patients. The meta-analysis reveals a significantly increased prevalence of TB among ILD patients with silicosis compared to IPF, and among individuals in high TB burden countries than in those with low/intermediate burden. The study results can help physicians and policymakers make efficient decisions for prompt screening and anti-TB treatment initiation in ILD patients..

Characterization of Radiographic and Molecular Changes in Mouse Brain after FLASH Irradiation

PURPOSE/OBJECTIVE(S)

Despite refinements in treatment platforms such as incorporation of high-resolution imaging and real time motion tracking, the amount of radiation dose delivered safely to a particular tissue type is limited by both tissue intrinsic and extrinsic factors. FLASH radiotherapy (RT), delivery of relatively high radiation dose at dose rates several orders of magnitude higher than that of conventional (CONV) dose-rates, may change that paradigm due to normal tissue sparing characteristics of FLASH RT. Our Radiation Oncology Physics division developed a novel FLASH kV x-ray cabinet system for preclinical laboratory research. Here we utilize this technology to establish optimal radiation parameters for FLASH effect in brain tissue of a murine model. A range of total radiation dose and dose rates that are considered to be within the window for FLASH effect are being investigated. We have identified several measurable and clinically meaningful toxicity outcomes, including radiation necrosis and blood brain barrier integrity, to assess FLASH effects in brain tissue.

MATERIALS/METHODS

A high-capacity rotating anode x-ray tube was implemented for FLASH irradiation, operating at 150 kVp with 0.025 mm Cu added filtration. A custom 3D printed immobilization tool was designed to reproducibly position animals for stereotactic irradiation of the brain. Dose and dose rate measurements were performed with calibrated radiographic film in kV solid water. Conventional dose rate irradiations were delivered using a standard laboratory irradiator (SARRP) operating at the same kVp and filtration. The depth-dose gradients in solid water were compared between the irradiators. Healthy 8-week-old C57BL6J mice were then irradiated with graded doses of FLASH and CONV x-rays (10- 60 Gy) using a single 1-cm wide AP field. Dose was prescribed to the center of the brain, at a depth of 3.25 mm. RT-induced necrosis is being monitored by serial biweekly MR imaging using a 7-T preclinical MRI machine. Histopathological changes will be assessed through H&E staining of harvested brain at 3-months post-irradiation (n = 5 per arm). FITC-Dextran infusion will be performed prior to necropsy to assess blood-brain barrier integrity.

RESULTS

Animal setup for stereotactic FLASH brain irradiation was reproducible to within 0.5mm. Measured dose rates were 75.6 Gy/s for FLASH and 3.8 Gy/min for conventional irradiations. At 5-mm depth in solid water, the PDDs agreed to within 4% between SARRP and FLASH Irradiator. Biweekly T1 post and T2 weighted image acquisition is currently underway. Histology and FITC-Dextran data will be presented when available.

CONCLUSION

We have successfully designed a high-precision platform to study x-ray FLASH effects in mice brain model. Evaluation of dose window for brain FLASH effect and molecular mechanisms of this phenomenon is an important step in the potential translation of FLASH RT for brain irradiation.

A Molecular Approach to Characterize the Effects of Fluence, Fluence Rate and LET on Radiation Damage

PURPOSE/OBJECTIVE(S)

Effects of fluence, fluence rate and LET on radiation damage are not resolved using traditional methods of measuring energy deposited by ionization events. The deficiency led to the use of empirical RBE factors in the clinical applications of particle therapy. The use of ionization dosimetry is similarly challenged when applied to development of radiation treatment at ultrahigh (FLASH) dose rate. This study reports a molecular method using plasmid DNA as a more comprehensive model for radiation dosimetry than ionization measurements.

MATERIALS/METHODS

Aqueous solutions of purified supercoiled plasmid DNA, pUC19 (2686 bp), were prepared at different scavenging conditions and injected into 5x5x1 mm3 wells as detector elements. Irradiated samples were analyzed using base excision repair enzymes (Nth and Fpg) and gel electrophoresis to measure yields for DNA single and double strand breaks (SSB and DSB), and clustered lesions. The low LET characteristics of conventional radiation treatment was modeled using orthovoltage 150 kVp x-rays to deliver 2-110 Gy at 90 and 0.5 Gy/s. Higher LET irradiations in the range of 2 - 14 keV/μm were facilitated by measurements in the pristine Bragg peak region using synchrotron-produced 142.2 MeV protons to deliver dose at 2 - 160 Gy at 600 and 1 Gy/s. The DNA wells were inserted into a solid water equivalent phantom for proton irradiation. Only 4 wells could be positioned in the short Bragg peak region in water (∼ 2 cm). To alleviate the uncertainties due to rapidly varying dose and LET distributions, we innovated the use of a 3% water density (i.e., Styrofoam) medium to extend the Bragg peak region from 2 cm to 20 cm, enabling the placement of 20 well containers.

RESULTS

Quantity and quality of molecular damage in the plasmid DNA model varies with fluence, fluence rate and LET of radiation. At high fluence (> 30 Gy) of low-LET radiations, the yields of DNA SSB and non-DSB clustered lesions depend on the fluence rate. These yields decrease by two times between ultrahigh and conventional dose rate irradiation. At a given fluence and fluence rate, the yields for the formation of DNA DSB and non-DSB clustered lesions increase linearly with LET. The low-density phantom allows significant (∼ 10 folds) increase in the number of sampling points and more accurate sample positioning at specific LET compared to water-equivalent phantom. Monte-Carlo track structure simulation of yields for different DNA lesions is being developed to model the molecular damage. In parallel, approaches to improve the sensitivity of the measurements to dose are being investigated.

CONCLUSION

Our results suggest that a molecular-based approach can be used to differentiate the effects of fluence, fluence rate, and LET on radiation damage. The approach demonstrates the potential to improve on the modeling of radiation effects in biological systems than using measured ionization energy. Correlation of the molecular changes to biological outcome for in vitro and in vivo systems are under investigation.

Preclinical Intraoperative FLASH Radiotherapy

PURPOSE/OBJECTIVE(S)

Intraoperative radiation therapy (IORT) is a method of delivering high radiation doses to an internal target with low dose to adjacent organs. Most organs at risk can often be moved out of the radiation field, so dose is usually limited by in-field vascular and/or nerve structures. It is known that ultra-high (FLASH) dose rate (>40 Gy/s) radiation reduces normal tissue toxicity compared to conventional, while preserving tumor control. We hypothesize that FLASH radiation can increase the dose tolerance of vascular and nerve structures, thus permitting for dose escalation in IORT. Here, we present a novel platform using orthovoltage x-rays to study FLASH effects in preclinical IORT. The experimental setup and dosimetry of the system have been established for FLASH irradiation of the abdominal aorta in rats to investigate dose tolerance.

MATERIALS/METHODS

A 150 kVp rotating anode x-ray source with a 75-kW generator was used to deliver FLASH and conventional irradiation. A 3D printed immobilization platform was designed to reproducibly place a surgically exposed rat abdominal aorta at 55mm SSD. A 3-mm thick lead collimator with a 10mm x 10mm aperture was placed into a flange adapter, which docks into the immobilization platform. Phantom and in vivo dosimetry were performed using both calibrated radiographic film and thermoluminescent dosimeters (TLD). Anesthetized 2-month-old Wistar rats underwent laparotomy to expose the abdomen for irradiation. A 10x12x1 mm3 tungsten plate was placed under the aorta to reduce spinal cord dose. Animals were then docked into the irradiator using the immobilization platform. Radiation dose in the range of 20 - 50 Gy were delivered to the abdominal aorta at FLASH and conventional dose-rates. Following treatment, animals undergo MR angiography every two months for 6 months, at which a histological evaluation of aorta wall will be performed.

RESULTS

The FLASH dose rate measured at the aorta wall in a rat carcass was 49.7 ± 1.2 Gy/s distal to the collimator. Dose measurements between the films and TLDs showed an agreement within ±3%. Positional uncertainty mainly depends on the visual localization of the aorta on the collimator window, which is verified before irradiation. Vertical uncertainty is less than 1 mm, which is important given the rapid dose fall off of the system. Eight animals went successfully through the procedure, are healthy and currently being follow up with MR angiography. More animals are being treated for meaningful statistical results. MR angiography and IORT are performed on different days to avoid longer times under anesthesia, which initially resulted on mortality. Results of the MR angiography and histological analysis will be presented.

CONCLUSION

The proposed platform has been successfully utilized for precision setup for FLASH IORT in a preclinical laboratory setting. Evaluation of FLASH effects in IORT setup will be an important step in the potential translation of FLASH IORT, where only one high-dose fraction can be delivered.

Effectiveness of postoperative oral administration of cephalexin and metronidazole on surgical site infection among obese women undergoing cesarean section: a randomized, double-blind, placebo-controlled, parallel-group study-phase III

BACKGROUND

Cesarean section (CS) is the most frequently performed surgery in the United States. Compared to vaginal delivery, CS has a higher risk of maternal and neonatal mortality, morbidities, and complications, among which surgical site infection (SSI) is the most common. We aimed at evaluating the effectiveness of postoperative oral administration of cephalexin and metronidazole on SSI among obese women undergoing CS.

METHODS

We conducted a randomized, double-blind clinical trial comparing the prophylactic effect of oral cephalexin and metronidazole vs cephalexin and placebo on SSI following CS among obese women. who had received preoperative prophylactic cephalosporin antibiotics. The study was conducted at the Ommolbanin Hospital, affiliated with Mashhad University of Medical Sciences from April 2019 to February 2020.

RESULT

The participants were randomized into the intervention group (n = 210) and the control group (n = 210). At week-1 follow-up, the outcomes were significantly lower in the intervention group as compared to the control group in terms of fever (9% vs 19%, p = 0.003), abnormal discharge from the incision (serous: 8.6% vs 10.5%, purulent: 2.9% vs 16.7%, p < 0.001), incision separation (1% vs 7.1%, p = 0.001), and cellulitis (4.8% vs 13.3%, p = 0.002). At week-2 follow-up, there were no patients in the intervention group with fever, abnormal discharge from the incision, incision separation, or cellulitis and there was a statistically significant difference for fever, abnormal discharge from the incision, and incision separation between the two groups (p < 0.001, p = 0.001, p = 0.014, respectively).

CONCLUSION

Post-operative administration of cephalexin and metronidazole for 48-h post-cesarean delivery among obese women, in addition to the standard pre-operative prophylaxis, reduced the overall rate of surgical site infection and wound infection symptoms in a 2-week follow-up. Trial registration The study protocol was approved by the Iranian Registry of Clinical Trials (IRCTID: IRCT20200608047685N2) on 2021-03-15.

BMI modifies the effect of HDL on outcomes after coronary artery bypass grafting surgery

Background

While the important role of both high-density lipoprotein cholesterol (HDL-C) and body mass index (BMI) in the prognosis of coronary artery disease (CAD) is well known, the impact of BMI on the association between HDL-C and cardiovascular outcomes remains unclear.

Purpose

In this regard, we aimed to investigate whether BMI can modify the correlation between HDL-C levels and outcomes in patients who underwent coronary artery bypass grafting (CABG).

Methods

The present registry-based cohort study included patients who underwent isolated, elective, and first time CABG with 18≤BMI&lt;35 kg/m2. The median follow-up period was 76.62 (75.71–77.52) months. The participants categorized into three groups based on BMI: 18.5≤BMI&lt;25 kg/m2, 25≤BMI&lt;30 kg/m2, and 30≤BMI&lt;35 kg/m2. The Cox proportional hazards models and Restricted Cubic Splines (RCS) in the Cox models were applied to evaluate the association between HDL-C and all-cause mortality and occurrence of major adverse cardio-cerebrovascular events (MACCE) in different BMI categories.

Results

From 2006 to 2016, a total of 17309 patients (73% male, mean age 66.17±9.98) were included. Compared to other groups, diabetes, hypertension, dyslipidemia, and family history of coronary disease were more prevalent in patients with 30≤BMI&lt;35 kg/m2 (P&lt;0.05). Cox proportional hazards models did not show a significant correlation between each 1 mg/dl increase in HDL-C and risk of all-cause mortality and MACCE. In contrast, the results of RCS in the Cox models demonstrated a non-linear relationship between HDL-C and outcomes in patients with 30≤BMI&lt;35 kg/m2, with higher levels of HDL-C, were paradoxically associated with a higher risk of all-cause mortality and MACCE in this BMI category. In the 3D presentation of the association between BMI, HDL-C and all-cause mortality, the highest risk of all-cause mortality was seen in low levels of HDL-C (HDL-C &lt;20 mg/dl) and low or very high levels of BMI.

Conclusions

Very high HDL-C levels could be associated with a higher risk of adverse outcomes after CABG, in patients with 30≤BMI&lt;35 kg/m2. These findings suggest a role of obesity in the function and properties of HDL-C thereby, it seems necessary to consider the concomitant conditions such as BMI when evaluating the risk of cardiovascular events.

Funding Acknowledgement

Type of funding sources: None.

The effect of essential oil of rosemary on eccentric exercise-induced delayed-onset muscle soreness in non-active women

Muscle soreness is a problem associated with physical activities. Recently, the medicinal herbs are strategies to prevent muscle soreness. The present study aims were to determine the effect of rosemary essential oil on the responses of lactate dehydrogenase, creatine kinase (CK), lymphocytes, neutrophils, muscle swelling (MS) and muscle pain (MP) following eccentric leg curl exercise in non-active women. 24 non-active females voluntarily participated in this study and were randomly assigned into three groups: rosemary dose 1 (RD1) (n=8; 0.25 ml), rosemary dose 2 (RD2) (n=8; 0.5 ml) and placebo (n=8; 0.5 ml olive oil). Participants in supplement groups consumed the desire amounts of rosemary essential oil every 8 h per day for 14 days. Then, the eccentric leg curl exercise was performed. The supplementation continued until 72 h after exercise. The serum variables, as well as, MS and MP were measured before, 24, 48 and 72 h after exercise. Data were analysed using repeated measure analysis of variance and P≤0.05 considered as significant. The results showed that rosemary significantly decreases CK in RD2 compared with placebo and RD1 48 h after exercise. There was no other significant difference in other serum variables. In conclusion, the present study showed a beneficial effect of rosemary on 48-h post-exercise serum CK concentration (a muscle damage indicator).

On the removal of hexavalent chromium from a Class F fly ash

Coarse and fine samples of a Class F fly ash obtained from commercial combustion of Illinois bituminous coal have been exposed to two long-term leaching tests designed to simulate conditions in waste impoundments. ICP-AES analysis indicated that the coarse and fine fly ash samples contained 135 and 171mg/kg Cr, respectively. Measurements by XAFS spectroscopy showed that the ash samples originally contained 5 and 8% of the chromium, respectively, in the hexavalent oxidation state, Cr(VI). After exposure to water for more than four months, the percentage of chromium as Cr(VI) in the fly-ash decreased significantly for the coarse and fine fly-ash in both tests. Combining the XAFS data with ICP-AES data on the concentration of chromium in the leachates indicated that, after the nineteen-week-long, more aggressive, kinetic test on the coarse fly ash, approximately 60% of the Cr(VI) had been leached, 20% had been reduced to Cr(III) and retained in the ash, and 20% remained as Cr(VI) in the ash. In contrast, during the six-month-long baseline test, very little Cr was actually leached from either the coarse or the fine fly-ash (<0.1mg/kg); rather, about 66% and 20%, respectively, of the original Cr(VI) in the coarse and fine fly-ash was retained in the ash in that form, while the remainder, 34% and 80%, respectively, was reduced and retained in the ash as Cr(III). The results are interpreted as indicating that Cr(VI) present in Class F fly-ash can be reduced to Cr(III) when in contact with water and that such chemical reduction can compete with physical removal of Cr(VI) from the ash by aqueous leaching.

Non-DSB clustered DNA lesions induced by ionizing radiation are largely responsible for the loss of plasmid DNA functionality in the presence of cisplatin

The combination of cisplatin and ionizing radiation (IR) increases cell toxicity by both enhancing DNA damage and inhibiting repair mechanisms. Although the formation of cluster DNA lesions, particularly double-strand breaks (DSB) at the site of cisplatin-DNA-adducts has been reported to induce cell death, the contribution of DSB and non-DSB cluster lesions to the cellular toxicity is still unknown. Although both lesions are toxic, it is not always possible to measure their frequency and cell survival in the same model system. To overcome this problem, here, we investigate the effect of cisplatin-adducts on the induction of DSB and non-DSB cluster DNA lesions by IR and determine the impact of such lesions on plasmid functionality. Cluster lesions are two or more lesions on opposite DNA strands with a short distance such that error free repair is difficult or impossible. At a ratio of two cisplatin per plasmid, irradiation of platinated DNA in solution with (137)Cs γ-rays shows enhancements in the formation of DNA DSB and non-DSB cluster lesions by factors of 2.6 and 2.1, respectively, compared to unmodified DNA. However, in absolute terms, the yield for non-DSB cluster lesions is far larger than that for DSB, by a factor of 26. Unmodified and cisplatin-modified DNA were irradiated and subsequently transformed into Escherichia coli to give survival curves representing the functionality of the plasmid DNA as a function of radiation dose. Our results demonstrate that non-DSB cluster lesions are the only toxic lesions present at a sufficient frequency to account for the loss of DNA functionality. Our data also show that Frank-DSB lesions are simply too infrequent to account for the loss of DNA functionality. In conclusion, non-DSB cluster DNA damage is known to be difficult to repair and is probably the lesion responsible for the loss of functionality of DNA modified by cisplatin.

Synthesis of wide band gap nanocrystalline NiO powder via a sonochemical method

A sonochemistry-based synthesis method was used to produce nanocrystalline nickel oxide powder with ≈ 20 nm average crystallite diameter from Ni(OH)(2) precursor. Ultrasound waves were applied to the primary solution to intensify the Ni(OH)(2) precipitation. Dried precipitates were calcined at 320°C to form nanocrystalline NiO particles. The morphology of the produced powder was characterized by transmission electron microscopy. Using sonochemical waves resulted in lowering of the size of the nickel oxide crystallites. FT-IR spectroscopy and X-ray diffraction revealed high purity well-crystallized structure of the synthesized powder. Photoluminescence spectroscopy confirmed production of a wide band-gap structure.

Rietveld analysis of the effect of annealing atmosphere on phase evolution of nanocrystalline TiO2 powders

The structural evolution of nanocrystalline TiO2 was studied by X-ray diffraction (XRD) and the Rietveld refinement method (RRM). TiO2 powders were prepared by the sol-gel technique. Post annealing of as-synthesized powders in the temperature range from 500 degrees C to 800 degrees C under air and argon atmospheres led to the formation of TiO2 nanoparticles with mean crystallite size in the range of 37-165 nm, based on the Rietveld refinement results. It was found that the phase structure, composition, and crystallite size of the resulting particles were dependent on not only the annealing temperature, but also the annealing atmosphere. Rietveld refinement of the XRD data showed that annealing the powders under argon atmosphere promoted the polymorphic phase transformation from anatase to rutile. Field emission scanning electron microscopy (FESEM) was employed to investigate the morphology and size of the annealed powders.

Serum level of matrix metalloproteinase-3 in patients with oral lichen planus

BACKGROUND

Oral Lichen planus (OLP) is a chronic lesion of the oral mucosa with unknown origin. Basement membrane changes are common in OLP and may be mediated by proteases such as matrix metalloproteinase (MMPs) and mast cell chymase. The aim of our study was to evaluate the level of serum MMP-3 in OLP com-pared to normal individuals and assess its clinical significance.

METHODS

Thirty four serum samples from patients diagnosed with OLP (12 males, 22 females, age: 42.2±10.8 years) and 34 serum samples from healthy control subjects (11 males, 23 females, age: 42.5±13.3 years) were collected and MMP-3 concentration was measured by ELISA.

RESULTS

The serum MMP-3 level in OLP patients was higher (21.64±24.31 ng/ml) compared with healthy con-trols (16.52±23.63 ng/ml), but showed no statistically significant difference. A statistically significant difference was demonstrated between the two types of OLP, being more pronounced in the erosive/atrophic form 6).

CONCLUSION

The different clinical appearances of OLP are associated with significant differences in MMP-3 serum level.

The Wound Healing Effects of Iloprost in Patients with Buerger's Disease: Claudication and Prevention of Major Amputations

BACKGROUND

This study analyzes the therapeutic effects of intravenous infusion of iloprost in wound healing, healing of the amputation stump wound, improvement in intermittent claudication and prevention of major amputation in patients with Buerger's disease.

METHODS

In a prospective study, 19 patients with known Buerger's disease, received intravenous iloprost infusion, 6 hours per day for 10 days. Iloprost with a dose of 0.5-2 ng/kg/min according to the patients' tolerance and using cardiac monitoring during the whole infusion period was administered for 6 hours/day using saline solution. Patients with larger wounds underwent simultaneous transmetatarsal or Ray amputation of the involved toe(s). All patients were discharged after 10 days. Patients were followed to detect their healing changes.

RESULTS

Nineteen patients, 19-55 years old received 0.5-2 ng/kg/min iloprost intravenously for 6 hours/day for 10 days. During this period, there was relative improvement in resting pain, but no significant amelioration was noticed in wound healing. In a 2 years follow-up, 14 patients showed a complete healing of the amputation stump and increased distance of walking without any pain. Some previous candidates of major amputation did not need amputation anymore. Five patients (26%) did not respond to therapy.

CONCLUSION

Although Buerger's disease patients who were under iloprost therapy, may not show significant changes in wound healing during treatment and at discharge, late results have proved that iloprost infusion is promising in improving wound healing and claudication and preventing major amputations.

Latex gloves allergy in dental workers, Iran

Dermal-respiratory reactions to latex glove is a common problem and sometimes life threatening. Some of the health related past histories such as hand dermatitis, atopy and food allergy increase the probability of these reaction. The purpose of this study was to evaluate reactions to latex gloves amongst dental workers in military dental health centers. In this cross-sectional descriptive survey, dental workers with minimum three months length of employment and most often use of latex gloves were asked to fill standard questionnaire regarding latex related clinical manifestation and personal medical history and predisposing factors. Those with clinical problems did Skin Prick Test (SPT). In this study 330 personnel were assessed. The mean age and length of employment was 31.6 and 8 years, respectively. The most occupation was dentistry. A total of 232 subjects (70.3%) reported latex gloves-allergic symptoms. 72 (21.8%) of persons have history of atopy and food allergy was seen in 114 (34.5%). 63 (19.1%) of subjects reported history of hand dermatitis. All of these had positive regression with allergic responses. Among 73 (34%) symptom positives, 28 (38%) had positive result of SPT. In this survey, the prevalence of allergic reactions is higher than similar studies, which may be due to type of gloves, lack of preemployment assessments and other factors. Because of relationship between allergic reactions to latex gloves and some medical histories, it seems to be necessary for preemployment evaluation and periodic health surveillance of dental workers.

Determination of organophosphorus pesticides in water samples by single drop microextraction and gas chromatography-flame photometric detector

In this paper we have developed single drop microextraction (SDME) with modified 1.00 microl microsyringe, followed by gas chromatography with flame photometric detector (GC-FPD) for determination of 13 organophosphorus pesticides (OPPs) in water samples. By using a 1.00 microl microsyringe the repeatability of drop volume and injection were improved, because of using maximum volume of microsyringe and no dead volume. On the other hand, the modification of needle tip caused increasing cross section of needle tip and increasing adhesion force between needle tip and drop, thereby increasing drop stability and achieving a higher stirrer speed (up to 1700 rpm). The method used 0.9 microl of carbon tetrachloride as extractant solvent, 40 min extraction time, stirring at 1300 rpm and no salt addition. The enrichment factor of this method ranged from 540 to 830. The linear ranges were 0.01-100 microg/l (four orders of magnitude) and limits of detection were 0.001-0.005 microg/l for most of analyte. The relative standard deviation (RSD%) for 2 microg/l of OPPs in water by using internal standard was in the range 1.1-8.6% (n = 5). The recoveries of OPPs from farm water at spiking level of 1.0 microg/l were 91-104%.

Evaluation of the percutaneous intramyocardial injection for local myocardial treatment

Therapeutic angiogenesis requires the induction of new blood vessel formation for the treatment of peripheral vascular and coronary artery disease. Efficacious application of this new therapy requires optimizing multiple factors, including the therapeutic agent, dosing, frequency of administration, and delivery modality. In this study, a helical needle drug infusion catheter was applied for optimal application of percutaneous intramyocardial delivery (PIMD). (125)Iodine-labeled albumin was injected by PIMD into the left ventricle myocardium in eight swine. After 1 hr, PIMD resulted in a high concentration of radiolabel at the treatment site; 16.4% +/- 2.1% of delivered and 81.4% +/- 2.6% of the total cardiac activity was concentrated at the site of delivery. The depth of needle penetration correlated with the myocardial retention of delivered protein. The myocardial retention of radiolabel in animals with shallow injections was 10.1% +/- 0.8%, compared to 18.9% +/- 3.3% retention after deep injections. The specific activity at the treatment site (radioactive counts per gram of tissue) was 115 +/- 36, 226 +/- 55, and 47 +/- 10 times higher compared to liver, lung, and kidney, respectively. Continuous coronary sinus and aortic blood sampling indicates that within 15 min following intramyocardial injection, a significant amount of nonretained protein is found within the coronary sinus. This study defines some of the parameters that can affect optimal application of PIMD and demonstrates that PIMD is a safe and efficient method for local drug delivery.

Cloning of an immunoglobulin family adhesion molecule selectively expressed by endothelial cells

To gain fundamental information regarding the molecular basis of endothelial cell adhesive interactions during vascular formation, we have cloned and characterized a unique cell adhesion molecule. This molecule, named endothelial cell-selective adhesion molecule (ESAM), is a new member of the immunoglobulin superfamily. The conceptual protein encoded by cDNA clones consists of V-type and C2-type immunoglobulin domains as well as a hydrophobic signal sequence, a single transmembrane region, and a cytoplasmic domain. Northern blot analysis showed ESAM to be selectively expressed in cultured human and murine vascular endothelial cells and revealed high level expression in lung and heart and low level expression in kidney and skin. In situ hybridization analysis indicated that ESAM is primarily expressed in the developing vasculature of the embryo in an endothelial cell-restricted pattern. Epitope-tagged ESAM was shown to co-localize with cadherins and catenins in cell-cell junctions. In aggregation assays employing ESAM-expressing Chinese hamster ovary cells, this novel molecule was shown to mediate cell-cell adhesion through homophilic interactions. The endothelial cell-selective expression of this immunoglobulin-like adhesion molecule coupled with its in vitro functional profile strongly suggests a role in cell-cell interactions that is critical for vascular development or function.

Selective regional myocardial infiltration by the percutaneous coronary venous route: A novel technique for local drug delivery

Recent advances in the treatment of heart disease, in particular cardiovascular gene therapy and therapeutic angiogenesis, highlight the need for efficient and practical local delivery methods for the heart. We assessed the feasibility of percutaneous selective coronary venous cannulation and injection as a novel approach to local myocardial drug delivery. In anesthetized swine, the coronary sinus was cannulated percutaneously and a balloon-tipped catheter advanced to the anterior interventricular vein (AIV) or middle cardiac vein (MCV). During balloon occlusion, venous injection of radiographic contrast caused regional infiltration of targeted myocardial regions. Complete AIV occlusion had no impact on LAD flow parameters. Videodensitometric analysis following venous injection showed that radiographic contrast persisted for at least 30 min. Selective regional myocardial infiltration is feasible by this approach, targeting selected myocardial beds, including the apex, anterior wall, septum, and inferoposterior wall. This novel technique has potential application for local myocardial drug or growth factor delivery. Cathet. Cardiovasc. Intervent. 51:358-363, 2000.

Intrapericardial delivery of fibroblast growth factor-2 induces neovascularization in a porcine model of chronic myocardial ischemia

Therapeutic angiogenesis is a novel approach to the treatment of myocardial ischemia based on the use of proangiogenic growth factors to induce the growth of new blood vessels to supply the myocardium at risk. This study was designed to assess the safety and efficacy of a single intrapericardial injection of basic fibroblast growth factor (FGF-2) in a porcine model of chronic myocardial ischemia. Yorkshire pigs underwent ameroid placement around the left circumflex coronary artery. At 3 weeks, animals were randomized to receive a single intrapericardial injection of either saline (n = 10), 3 mg of heparin (n = 9), 3 mg of heparin + 30 microgram of FGF-2 (n = 10), 200 microgram of FGF-2 (n = 10), or 2 mg of FGF-2 (n = 10). Coronary angiography, microsphere flow, magnetic resonance functional, and perfusion imaging were performed before and 4 weeks after treatment, at which time histologic analysis was also performed on 3 animals in each group. In ischemic pigs, FGF-2 treatment resulted in significant increases in left-to-left angiographic collaterals and left circumflex coronary artery blood flow. These benefits were accompanied by improvements in myocardial perfusion and function in the ischemic territory, as well as histologic evidence of increased myocardial vascularity without any adverse effects. Not one of these benefits was seen in saline- or heparin-treated ischemic animals. A single intrapericardial injection of FGF-2 in a porcine model of chronic myocardial ischemia results in functionally significant myocardial angiogenesis, without any adverse outcomes. This mode of FGF-2 administration may prove to be a useful therapeutic strategy for the treatment of patients with ischemic heart disease.

Determination of kinetic isotope effects for nucleoside hydrolases using gas chromatography/mass spectrometry

Kinetic isotope effects are widely used to determine the transition state of chemical and enzymatic reactions. Radioactive isotopes are used most often to determine these kinetic isotope effects. However, stable isotopes offer a number of advantages over the use of radioactive isotopes. These advantages include ease of handling and disposal along with increased safety in the laboratory. [1'-(13)C]Inosine and [1'-(2)H]inosine kinetic isotope effects were determined using a gas chromatograph in conjunction with a mass selective detector for nucleoside hydrolase, a purine-metabolizing enzyme. Three ion pairs were used to determine kinetic isotope effects. These ion pairs were 158/159, 187/188, and 217/218. The average isotope effects for all ion pairs were 1.021 +/- 0.006 for [1'-(13)C]inosine and 1.113 +/- 0.008 for [1'-(2)H]inosine. The transition state consistent with these isotope effects is also consistent with the transition state proposed by Schramm and Horenstein using radioactive substrates.

Intracoronary and intravenous administration of basic fibroblast growth factor: myocardial and tissue distribution

Therapeutic angiogenesis using various heparin-binding growth factors is a promising treatment for ischemic heart disease. Single dose intracoronary (IC) or i.v. delivery are most practical for clinical use. This study was designed to investigate the myocardial and tissue deposition of basic fibroblast growth factor (bFGF) after IC and i.v. administration in normal and chronically ischemic animals. Twenty-four Yorkshire pigs were used (12 normal and 12 ischemic animals) with IC and i.v. administration of 125I-bFGF (25 microCi) combined with cold bFGF (30 microg) and heparin (3 mg). Tissue and myocardial distribution was determined at 1 and 24 h by measuring 125I-bFGF specific activity and by organ and light level autoradiography. The liver accounted for the majority of 125I-bFGF activity at 1 h (37.6 +/- 17.1% for IC and 42.1 +/- 17.7% for i.v. delivery), with a reduction to 2.8 +/- 1.5% for IC and 1.5 +/- 0.9% for i.v. delivery by 24 h. Total cardiac specific activity at 1 h was 0.88 +/- 0.89% for IC and 0.26 +/- 0.08% for i.v. administration (p =.12) and decreased to 0.05 +/- 0.04% (p =.05, versus 1 h) and 0. 04 +/- 0.01% (p <.001, versus 1 h) at 24 h, respectively. IC but not i.v. delivery resulted in higher deposition in ischemic than normal myocardium. IC delivery resulted in enhanced bFGF deposition only in myocardial territories subtended by the infused artery. Intravenous delivery compares favorably with IC delivery with a 3- to 4-fold reduction in myocardial deposition at 1 h and with similar solid organ deposition. The less invasive nature of i.v. delivery, its potential for repeat administration, and its applicability to a larger population may offset its resultant reduced myocardial deposition. Efficacy studies are ongoing.

Diminished expression of the alpha 5 beta 1 integrin (fibronectin receptor) by invasive clones of a human follicular thyroid cancer cell line

Altered adhesion plaques have been observed in transformed cell lines and are associated with enhanced metastatic potential. The prototypical adhesion plaque is formed by alpha 5 beta 1 fibronectin receptors (FnRs) interacting with the cellular actin network. We have found differences in the actin networks of noninvasive (FTC-133) and invasive (FTC-236, FTC-238) clones of a human follicular thyroid cancer cell line. Furthermore, thyroid-stimulating hormone (TSH) induces stress fibers in FTC-133. In order to investigate differences in adhesion plaques, expression of fibronectin (FN) and its receptor by these cells was analyzed. For these studies FTC-133, FTC-236, and FTC-238 were cultured in serum-depleted DME-H21 medium for 24 hours before the addition of TSH 30 mU/ml. No quantitative differences were noted in FN expression on Western blot in either the conditioned medium or cellular extracts. Western blots and immunohistochemical studies indicated that TSH induced secretion of FN only in FTC-133. Flow cytometry with an alpha 5 antibody demonstrated a 52% and 45% reduction (p < 0.01) in expression of FnR by FTC-236 and FTC-238, respectively, compared to FTC-133; this finding was supported by immunohistochemistry results. TSH treatment did not alter FnR expression. From these studies, we conclude that invasive clones of FTC decrease their expression of FnRs without changing their expression of FN. Furthermore, TSH treatment may promote FN secretion by FTC-133, although it does not seem to affect FnR or absolute FN expression. The diminished expression of FnR adhesion plaques may enhance metastatic potential in some follicular thyroid cancers.