<Superscript>124</Superscript>I-L19-SIP for immuno-PET imaging of tumour vasculature and guidance of <Superscript>131</Superscript>I-L19-SIP radioimmunotherapy

Purpose  The human monoclonal antibody (MAb) fragment L19-SIP is directed against extra domain B (ED-B) of fibronectin, a marker of tumour angiogenesis. A clinical radioimmunotherapy (RIT) trial with ¹³¹I-L19-SIP was recently started. In the present study, after GMP production of ¹²⁴I and efficient production of ¹²⁴I-L19-SIP, we aimed to demonstrate the suitability of ¹²⁴I-L19-SIP immuno-PET for imaging of angiogenesis at early-stage tumour development and as a scouting procedure prior to clinical ¹³¹I-L19-SIP RIT. Methods   ¹²⁴I was produced in a GMP compliant way via ¹²⁴Te(p,n)¹²⁴I reaction and using a TERIMO™ module for radioiodine separation. L19-SIP was radioiodinated by using a modified version of the IODO-GEN method. The biodistribution of coinjected ¹²⁴I- and ¹³¹I-L19-SIP was compared in FaDu xenograft-bearing nude mice, while ¹²⁴I PET images were obtained from mice with tumours of <50 to ∼700 mm³. Results   ¹²⁴I was produced highly pure with an average yield of 15.4 ± 0.5 MBq/μAh, while separation yield was ∼90% efficient with <0.5% loss of TeO₂. Overall labelling efficiency, radiochemical purity and immunoreactive fraction were for ¹²⁴I-L19-SIP: ∼80 , 99.9 and >90%, respectively. Tumour uptake was 7.3 ± 2.1, 10.8 ± 1.5, 7.8 ± 1.4, 5.3 ± 0.6 and 3.1 ± 0.4%ID/g at 3, 6, 24, 48 and 72 h p.i., resulting in increased tumour to blood ratios ranging from 6.0 at 24 h to 45.9 at 72 h p.i.. Fully concordant labelling and biodistribution results were obtained with ¹²⁴I- and ¹³¹I-L19-SIP. Immuno-PET with ¹²⁴I-L19-SIP using a high-resolution research tomograph PET scanner revealed clear delineation of the tumours as small as 50 mm³ and no adverse uptake in other organs. Conclusions   ¹²⁴I-MAb conjugates for clinical immuno-PET can be efficiently produced. Immuno-PET with ¹²⁴I-L19-SIP appeared qualified for sensitive imaging of tumour neovasculature and for predicting ¹³¹I-L19-SIP biodistribution. Bernard M. Tijink and Lars R. Perk contributed equally to this article.     

Percutaneous absorption and skin distribution of [14C]flutrimazole in mini-pigs.

The percutaneous absorption and skin distribution of a skin cream containing 1% 14C-labelled 1-[(fluorophenyl) (4-fluorophenyl) phenylmethyl]-1H-imidazole (flutrimazole, UR-4056, CAS 119006-77-8) was studied in minipigs. The same dose of flutrimazole was administered i.v. and topically (as a cream) on scarified skin according to a crossover protocol. Samples of urine and faeces were taken at various intervals after administration, and radioactivity was measured. The percentage of radioactivity accumulated in urine after topical and intravenous administration were 1.46% and 41.7%, respectively. In faeces, the percentage of radioactivity observed was 6.0% after intravenous administration, and none was detected after topical application. In order to study the distribution and penetration of [14C]flutrimazole, the cream was applied to intact and scarified skin. At various intervals after administration, skin samples were taken. The samples for the autoradiographic studies were cut transversely, and for the measurement of the levels of radioactivity at different skin depths, slices were cut parallel to the cutaneous layers. The results obtained indicate that [14C]flutrimazole penetrates quickly into the different epidermic layers and is retained mainly in the strata spinosum, granulosum and basale. The stratum basale possibly acts as a selective barrier preventing the penetration of the compound into the dermis. The percentage of radioactivity in the stratum corneum is lower than that detected in all the other epidermic layers taken together. The stratum corneum offers low resistance to penetration by the flutrimazole, which very probably crosses the epidermic strata by a transcellular route.     

MEK Activation Suppresses CPT11-Induced Apoptosis in Rat Intestinal Epithelial Cells Through a COX-2-Dependent Mechanism

Resistance to chemotherapeutic agents is one of the distinct features of cancer cells. We evaluate the role of activated MEK-ERK signaling in Camptotecin/irinotecan (CPT-11)-induced cell death using constitutively activated MEK1-transfected normal rat intestinal epithelial cells (IEC-caMEK cells). A CPT-11-induced inhibitory concentration of 50% was determined by WST assay. Apoptosis was evaluated by DNA staining and fragmented DNA analysis. Protein expressions were analyzed by western blotting. We also examined the role of cyclooxygenase-2 in the cell systems. IEC-caMEK cells possessed survival advantages compared to control cells. Apoptosis was remarkably suppressed in IEC-caMEK cells. Western blot analysis revealed increased expression of Bcl-2, Bcl-xL, Mcl-1, and COX-2 and decreased expression of Bak in IEC-caMEK cells. The COX-2 selective inhibitor ameliorated the antiapoptotic nature of IEC-caMEK cells. MEK activation suppressed CPT-11-induced apoptosis in IEC-caMEK cells via a COX-2- dependent mechanism. Therefore, MEK-ERK signaling may contribute to the drug-resistant nature of cancer cells.     

Reduced shear stress and disturbed flow may lead to coronary aneurysm and thrombus formations

BACKGROUND: With Kawasaki disease it is important to clarify the mechanisms of coronary artery aneurysm and thrombus to avoid acute myocardial infarction. The authors tested the hypothesis that shear stress is reduced at coronary branching sites and in coronary artery aneurysms, and that this reduction of shear stress can promote formation of coronary artery aneurysms and thrombus. METHODS: The subjects were 111 children with Kawasaki disease with left coronary artery aneurysms, classified into three groups: giant coronary artery aneurysm (n= 28, diameter of coronary artery >8 mm), aneurysm (n= 44, diameter of coronary artery =8 mm), and normal-appearing coronary (n= 39). Averaged peak flow velocity (APV), flow patterns and shear stress were measured and calculated at normal-appearing coronary vessels, left coronary artery branching sites and intra-coronary aneurysm using flow wire, and coronary angiography. Also, presence and appearance of thrombus were detected by intravascular ultrasonography. RESULTS: The authors found that 90.3% of the coronary artery aneurysms occurred at major left coronary branching sites. APV and shear stress were significantly decreased in giant coronary artery aneurysms (APV, 7.1 +/- 2.1 cm/s; shear stress, 3.8 +/- 2.1 dyne/cm(2)) and at the left coronary artery branching site (APV, 9.1 +/- 1.2; shear stress, 1+/-+/-.2 3.0). In total, 20 of 24 thrombi were detected only in giant aneurysm, and all patients exhibited disturbed flow pattern in their giant coronary artery aneurysms. CONCLUSIONS: Reduced shear stress and disturbed flow pattern may lead to coronary artery aneurysm and thrombus formation.     

Can the gracilis replace the anterior cruciate ligament in the knee? A biomechanical study

Purpose

The purpose of this study was to determine whether a four-strand gracilis-only construct possesses the biomechanical properties needed to act as an anterior cruciate ligament (ACL) reconstruction graft.

Methods

This was a pilot study with 32 cadaver specimens. The biomechanical properties of three types of grafts were determined using validated tensile testing methods: patellar tendon (BTB), both hamstring tendons together (GST4) and gracilis alone (G4).

Results

The maximum load at failure of the G4 was 416.4 N (±187.7). The GST4 and BTB had a maximum load at failure of 473.5 N (±176.9) and 413.3 N (±120.4), respectively. The three groups had similar mean maximum load and stiffness values. The patellar tendon had significantly less elongation at failure than the other two graft types.

Conclusions

The biomechanical properties of a four-strand gracilis construct are comparable to the ones of standard grafts. This type of graft would be useful in the reconstruction of the anteromedial bundle in patients with partial ACL ruptures.

     

Racial Disparities in Erectile Dysfunction among Participants in the California Men's Health Study

IntroductionThe burden of erectile dysfunction (ED) among different racial and ethnic groups is unclear, in part, because prior studies have not included all four major racial and ethnic groups in the same population‐based sample.AimTo determine the prevalence and odds of ED among all four major racial and ethnic groups after adjustment for demographic, medical, socioeconomic, and lifestyle characteristics.MethodsThis cross‐sectional study was conducted using data from men, aged 45–69 years, without a diagnosis of prostate cancer (N = 78,445), who completed questionnaires as part of the California Men's Health Study, a large multiethnic cohort study with detailed demographic, medical and, socioeconomic data.Main Outcome MeasureErectile dysfunction measured by a previously validated four‐level response question.ResultsThe overall prevalence of ED by age category was 13%, 24%, and 44% for men aged 45–49 years, 50 and 59 years, and 60–69 years, respectively. In a multivariable model, relative to white men, Hispanic (OR 1.05, 95% CI 0.99, 1.12), Asian (OR 1.1, 95% CI 1.02, 1.19), and other men (OR 1.13, 95% CI 1.06, 1.1.21) had increased odds of moderate‐severe ED, while black men were less likely to report moderate to severe ED (OR 0.86, 95% CI 0.81, 0.92). Black (OR 0.54, 95% CI 0.48, 0.61) and Asian men (OR 0.91, 95% CI 0.80, 1.04) were less likely to have severe ED after adjustment for age, socioeconomic status, medical co‐morbidities, and lifestyle characteristics.ConclusionThese data demonstrate that the prevalence of ED among different racial and ethnic groups is likely the result of complex phenomena and depends upon the interplay of socioeconomic, demographic, medical, cultural, and lifestyle characteristics. After accounting for these factors, these data suggest that Asian and black men are less likely to have severe ED relative to white men. Smith JF, Caan BJ, Sternfeld B, Haque R, Quesenberry CP, Jr, Quinn VP, Shan J, Walsh TJ, Lue TF, Jacobsen SJ, and Van Den Eeden SK. Racial disparities in erectile dysfunction among participants in the California men's health study.     

Autoregressive analysis of cardiac RR intervals in preterm and full-term infants

For the purpose of obtaining information on the maturation process of the autonomic nervous system in pre- and full-term infants, polygraphs were recorded during sleep from a total of 52 appropriate-for-dates infants at a conceptional age of 28–41 weeks. The 104 RR interval time series was calculated by auto-regressive (AR) and component analysis. Histograms of damping frequencies obtained were divided into two frequency bands: low frequency fluctuations (LF) of less the 0.1 cycle/beat (c/b) and high frequency fluctuations (HF) of more than 0.15 c/b. Total power and LF power decreased with increases in the conceptional age or postnatal age at a significance level of 0.01, respectively. In addition, the HF amount of bio-informing activity increased (P< 0.001) and the damping time of HF also increased (P <0.01). From these results, it was speculated that the activity of the sympathetic system decreases with increases in conceptional or postnatal age. It was also speculated that increased regularity and oscillatory duration in HF might be caused by the development of the reciprocal response of respiration to heart rate variation.