Galectin-3 and Autophagy in Renal Acute Tubular Necrosis.

Acute kidney injury (AKI) is a public health burden with increasing morbidity and mortality rates and health care costs. Acute tubular necrosis (ATN) is the most common cause of AKI. Cisplatin (CIS) is a platinum-based chemotherapeutic agent used in the treatment of a wide variety of malignancies such as lung, breast, ovary, testis, bladder, cervix, and head and neck cancers. Autophagy plays an important role in AKI. Galectin-3 (Gal-3) is significantly increased in renal tubules in AKI; however, its role in autophagy is not well understood. Male C57B6/J and B6.Cg-Lgals3 /J Gal-3 knockout (KO) mice were used to induce AKI using a CIS mouse model of ATN. Renal Gal-3 and autophagy proteins' expression were measured using standard histologic, immunofluorescent, and enzyme-linked immunosorbent assay techniques. The data were presented as the mean ± S.E. Statistically significant differences (p < 0.05) were calculated between experimental groups and corresponding control groups by one-way analysis of variance. There was a significant increase in renal concentrations of Gal-3 in the Gal-3 wild-type CIS-treated mice when compared with sham control mice. There were significantly higher concentrations of renal LC3B, ATG13, Ulk-1, Beclin, ATG5, ATG12, ATG9A, and p-AMPK in the CIS-treated Gal-3 KO mice than in the Gal-3 wild-type CIS-treated mice. Further, there were significantly higher concentrations of mTOR, p- NF-κB, beta-catenin, and p62 in the kidneys of the Gal-3 wild-type CIS-treated mice than in the Gal-3 KO CIS-treated mice. Our findings affirm the connection between Gal-3 and autophagy, revealing its central role as a connector with prosurvival signaling proteins. Gal-3 plays a pivotal role in orchestrating cellular responses by interacting with prosurvival signal pathways and engaging with autophagy proteins. Notably, our observations highlight that the absence of Gal-3 can enhance autophagy in CIS-induced ATN.

Neonatal AKI: An update.

Neonatal acute kidney injury (AKI) is a common complication, especially in the neonatal intensive care unit, that is associated with long term consequences and poor outcomes. Early detection and treatment is critical. Currently, neonatal AKI is defined with urinary markers and serum creatinine, with limitations on early detection and individual treatment. There have been numerous biomarkers and risk factor scores that have been studied for their ability to predict neonatal AKI. To move towards personalized medicine, neonatal AKI must be categorized into phenotypes and subphenotypes that fully encapsulate the diverse causes and specific treatments. This review aims to advance our understanding of neonatal AKI detection through the use of biomarkers, subphenotypes, and phenotypes to move towards personalized treatment strategies.

Galectin-3 Possesses Anti-Necroptotic and Anti-Apoptotic Effects in Cisplatin-Induced Acute Tubular Necrosis.

BACKGROUND/AIMS: Acute kidney injury (AKI) is a public health burden with increasing morbidity, mortality and health care cost. It is associated with increased risk for the development of chronic kidney disease and death. Acute tubular necrosis (ATN) is the most common cause of AKI. Apoptosis and tissue necrosis play an important role in ATN. Galectin 3 (GAL-3), a beta galactoside binding lectin, is known to have a role in inflammation, apoptosis and oxidative stress but its role in cisplatin induced acute tubular necrosis is not clearly elucidated. METHODS: Male C57B6-J and C57BL-6 -GAL-3 knock-out mice were used to induce ATN using cisplatin mouse model of acute tubular necrosis. GAL-3 expression, apoptotic, necrotic and necroptotic proteins in kidneys were measured using standard histologic, immunohistochemical, and enzyme-linked immunosorbent assay techniques. Data were presented as mean ± S.E. Statistically significant differences (p<0.05) was calculated between experimental groups and corresponding control groups by one-way analysis of variance. RESULTS: There was a significant increase in GAL-3 in kidneys of cisplatin treated GAL-3 wild mice when compared with its control mice. In addition, there were significant higher percentage of ATN, higher levels of plasma urea and creatinine, and higher levels of cathepsin B and cathepsin D, in kidneys of cisplatin-treated GAL-3 KO mice than cisplatin-treated GAL-3 wild mice. Likewise, there were significant higher levels of necroptosis proteins RIPK1, RIPK3, and MLKL in kidneys of cisplatin-treated GAL-3 KO mice than cisplatin-treated GAL-3 wild mice. Moreover, there were significant higher levels of kidney pro-apoptotic proteins; cleaved caspase-3, cleaved PARP, TRAIL and FAS in cisplatin treated GAL-3 KO mice when compared with cisplatin treated GAL-3 wild mice. CONCLUSION: GAL-3 can affect cell survival and death through its interaction with necroptotic, apoptotic and pro-survival proteins in renal tubules during cisplatin-induced acute tubular necrosis.

Comparison of performances of loop-mediated isothermal amplification, XPERT MTB/RIF and BACTEC MGIT in the diagnosis of childhood tuberculosis.

AIM: Key to the successful management of paediatric pulmonary tuberculosis (PTB) lies in the early detection and proper treatment. We evaluated the performances of modern diagnostic tests: loop-mediated isothermal amplification (LAMP-IS6110), Xpert MTB/RIF (Cepheid) and mycobacteria growth indicator tube (BACTEC MGIT 960 culture) against a modified version of international consensus diagnostic definition (i.e. composite reference standard (CRS)). METHODS: A cross-sectional analytical study was conducted in a tertiary care hospital in North India from July 2016 to December 2017 involving 100 children <14 years with suspected PTB. Respiratory specimens (sputum, gastric lavage and/or bronchoalveolar lavage) were collected and subjected to LAMP-IS6110, Xpert MTB/RIF and BACTEC MGIT 960 culture assay. RESULTS: Fifty-five children had confirmed and probable TB according to the CRS (prevalence = 58.5%). The sensitivity of BACTEC MGIT 960 culture, Xpert MTB/RIF and LAMP-IS6110 assay was 14%, 9.1% and 10.91%, respectively, when compared against the predefined CRS. The specificity for all these tests was 100%. When compared with BACTEC MGIT 960 culture as the gold standard, the LAMP-IS6110 assay and Xpert MTB/RIF assay had the sensitivity of 85.71% (95% CI: 42.13-99.64%) and 71.43% (95% CI: 29.04-96.33%), respectively. The specificity of both assays was 100%. CONCLUSIONS: We noted that LAMP-IS6110 performed better than Xpert MTB/RIF (Cepheid) in terms of sensitivity when compared against BACTEC MGIT 960 culture as reference standard, though specificity of both the tests was comparable. The diagnostic performance of BACTEC MGIT 960 culture was better than LAMP-IS6110 and Xpert MTB/RIF in paediatric PTB, when compared against CRS.

Galectin-3: A Cardiomyocyte Antiapoptotic Mediator at 24-Hour Post Myocardial Infarction.

BACKGROUND/AIMS: Galectin 3 (GAL-3) is a beta galactoside binding lectin that has different roles in normal and pathophysiological conditions. GAL-3 has been associated with heart failure and was linked to increased risk of death in a number of studies. GAL-3 was found to be up regulated in animal models of heart failure as well as myocardial infarction (MI). The objective of his study is to test if high GAL-3 after myocardial infarction has a protective role on the heart through its anti-apoptotic and anti-necrotic functions. METHODS: Male C57B6/J mice and GAL-3 knockout (KO) mice were used for permanent ligation of the left anterior descending artery of the heart to create infarction in the anterior myocardium. Heart and plasma samples were collected 24 hours after the induction of MI and were used for immunohistochemistry, Tunnel procedure, electron microscopy and enzyme linked immunosorbent assay (ELISA). RESULTS: Our results show that the significant increase in GAL-3 levels in the left ventricle at 24-hour following MI is associated with significant lower levels of pro-apoptotic proteins; cytochrome c, Bax, annexin V, cleaved caspase-3 and a higher levels of anti-apoptotic protein Bcl2 in GAL-3 wild MI group than GAL-3 KO group. We also have identified the anti-apoptotic activity of GAL-3 is mediated through a significant increase in Akt-1, NF kappa-B and beta- catenin proteins. In addition, we have identified the antiapoptotic activity is mediated through a significant lower levels of cathepsin-D protein. CONCLUSION: We conclude that the increased levels of GAL-3 at 24-hour following MI regulate antiapoptotic mechanisms in the myocardium that will shape the future course of the disease. We also identified that the anti-apoptotic mechanisms are likely mediated through interaction of GAL-3 with Akt-1, NF kappa-B, beta- catenin and cathepsin D proteins.

Efficacy of galcanezumab in patients with episodic migraine and a history of preventive treatment failure: results from two global randomized clinical trials.

BACKGROUND AND PURPOSE: The efficacy of galcanezumab, a monoclonal antibody for migraine prevention, has been demonstrated in two pivotal trials in patients with episodic migraine. METHODS: EVOLVE-1 and EVOLVE-2 were identical phase 3, randomized, double-blind, placebo-controlled studies in patients with episodic migraine. Mean migraine headache days per month at baseline was 9. Patients were randomized 2:1:1 to monthly injections of placebo, galcanezumab 120 mg/240 mg during the 6-month double-blind treatment period. Key efficacy outcomes were assessed in subgroups amongst patients for whom, previously, for efficacy and/or safety/tolerability reasons (i) one or more (≥1) preventives failed, (ii) two or more (≥2) preventives failed and (iii) preventives were never used, or used but not failed (no prior failure). RESULTS: In an integrated analysis of EVOLVE studies, galcanezumab 120 mg/240 mg versus placebo led to larger overall mean (SE) reductions in monthly migraine headache days across 6 months in patients with prior preventive failures (P < 0.001): ≥1 failure: 120 mg: -4.0 (0.4); 240 mg: -4.2 (0.5); placebo: -1.3 (0.4); ≥2 failures: 120 mg: -3.1 (0.7); 240 mg: -3.8 (0.8); placebo: -0.5 (0.6). Similar results were observed amongst patients with no prior failure, but the placebo response was larger: 120 mg: -4.7 (0.2); 240 mg: -4.5 (0.2); placebo: -3.0 (0.2) (P < 0.001 versus placebo). Significant improvements were observed with galcanezumab versus placebo for ≥50% and ≥75% reduction in monthly migraine headache days. CONCLUSION: In patients with episodic migraine treated with galcanezumab, those with ≥1 or ≥2 prior preventive failures had significantly larger improvements, versus placebo, in efficacy outcomes. Similar results were observed in patients with no prior failure, with a larger placebo response.

Molecular epidemiology of methicillin resistant staphylococcus aureus colonizing the anterior Nares of school children of Udupi Taluk.

CONTEXT: Community associated methicillin resistant Staphylococcus aureus (CA-MRSA) cause serious skin and soft tissue infections including necrotizing fasciitis and necrotizing pneumonia. Production of Panton Valentine Leucocidine (PVL) toxin is implicated in its enhanced virulence. A variant of epidemic MRSA-15 (EMRSA-15) which produces PVL toxin has been isolated and characterized by pulsed-field gel electrophoresis (PFGE) method from the Indian population both in hospital and community settings. AIMS: Identify the epidemiological type of MRSA colonizing the anterior nares of school children in Udupi taluk. SETTINGS AND DESIGN: The study population included children of the age group of 5-16 years belonging to the Udupi taluk of Karnataka, India. A total of 1503 children were screened for MRSA colonization during July 2009 to December 2010. MATERIALS AND METHODS: PVL assay, Staphylococcal Cassette Chromosome (SCC) mec typing and PFGE typing were carried out with all the MRSA isolates. STATISTICAL ANALYSIS USED: Frequency distribution of different variables was assessed by SPSS. RESULTS: Among the 1.1% of MRSA, 58.8% (10/17) of isolates were positive for pvl and 41.7% (7/17) were identified as SCC mec type IV. PFGE patterns of all the strains were identical with Indian variant EMRSA-15; however they were different from classical EMRSA-15 in 3-4 bands. CONCLUSIONS: The Indian variant EMRSA-15 gains much epidemiological relevance owing to the acquisition of pvl gene. In spite of low prevalence of nasal colonization of MRSA, emergence of the virulent Indian variant EMRSA-15 in our community is a worrisome fact to be reckoned with.

Necrotizing fasciitis caused by a variant of epidemic methicillin resistant Staphylococcus aureus -15.

We report a case of necrotizing fasciitis (NF), caused by community-acquired epidemic methicillin resistant Staphylococcus aureus 15 (EMRSA 15). The patient had a prolonged recovery period following treatment with antibiotics and surgical debridement of the infected part. Molecular characterization revealed that the isolate carried Staphylococcal Cassette Chromosome mec (SCC mec) type IV harboring Panton-Valentine Leucocidin (pvl) gene and having accessory gene regulator (agr) type I. The isolate was positive for enterotoxin gene cluster (egc). Pulsed field gel electrophoresis patterns revealed that the isolate belonged sequence type 22, which is an Indian variant of EMRSA 15, reported earlier.

Biophysical evaluation of two red-shifted hypocrellin B derivatives as novel PDT agents.

Two novel cyclohexane-1,2-diamino and N,N dimethyl amino-propyl substituted hypocrellin B derivatives, abbreviated as CHA2HB and DMAHB, respectively were synthesized. These derivatives exhibited enhanced absorption in phototherapeutic window. Photodynamic action of these derivatives, investigated using optical and electron spin resonance methods, depended on both Type I and Type II mechanisms. Gel electrophoresis indicated 1O2/O2(.-) mediated DNA damage. CHA2HB displayed 20 fold increase in light dependent cytotoxicity on colon cancer cell line (HCT 116) than the well-known hypocrellin B (HB). The light induced, LD(50) values for CHA2HB and DMAHB were found to be 0.1 microM and 1.5 microM, respectively. The singlet oxygen generating efficiency followed the order HB>CHA(2)HB>DMAHB. But, the enhanced red absorption as well as the hydrophilicity renders the CHA2HB a better photodynamic therapeutic agent.

Role of Shigella infection in endometriosis: a novel hypothesis.

Endometriosis is the presence of endometrial cells and stroma at ectopic sites outside the uterine cavity. The natural history of endometriosis is uncertain, its etiology unknown, the clinical presentation inconsistent, diagnosis difficult and the treatment poorly standardized. It causes significant morbidity due to pelvic pain and infertility among 15-25% of women during their reproductive age. The benign disease causes peritoneal inflammation, fibrosis, adhesions and ovarian cysts but displays features of malignancy, like neo-vascularization, local invasion and distant metastasis. Mechanical, hormonal, immunological, environmental and genetic factors have been implicated in its etiology but provide inconclusive explanations. Present study was carried out on ectopic and eutopic endometriotic tissue specimens collected during laproscopy/laprotomy from cases of endometriosis. mRNA was isolated from the tissues and converted to cDNA by RT and subsequently subjected to differential display Polymerase Chain Reaction using seven sets of arbitrary primers. A unique band was identified only in the ectopic endometriotic tissue, which was sequenced. BLAST search results revealed sequence homology to shigella bacterial DNA leading us to hypothesize that infection may be playing a role in the etiology of endometriosis. This is the first report implicating the role of bacterial infection in the etiology of endometriosis. Shigella is known to invade the mucosa of the colon through the feco-oral route causing Shigellosis. The pathogenesis of shigellosis involves inflammation, ulceration, haemorrhage, tissue destruction and fibrosis of the colonic mucosa resulting in abdominal pain and diarrhoea/dysentery, this is similar to the pathogenesis of endometriosis which also involves inflammation, haemorrhage, tissue destruction and fibrotic adhesions of the pelvic peritoneum resulting in abdominal pain and infertility. The non-motile shigella bacteria invade the deeper mucosal layers by travelling from cell to cell of colonic epithelium, reaching the lamina propria of the colonic mucosa. We propose that, by the same mechanism, the bacteria travel across the colon wall to reach the outer peritoneal surface of the colon, which is in close proximity to the posterior uterine surface in the Pouch of Douglas, the site which incidentally happens to be the commonest site of early endometriosis. Our hypothesis therefore proposes that shigella or shigella-like organisms may be the trigger for the initiation of immunological changes in the pelvic peritoneum causing endometriosis. Once the endometrial cells are implanted at ectopic sites they are sustained by hormones and angiogenic factors. Hence "Infection hypothesis" provides a novel explanation for the etiopathogenesis of endometriosis.

Association of progesterone receptor gene polymorphism (PROGINS) with endometriosis, uterine fibroids and breast cancer.

Endometriosis, uterine fibroids and breast cancer are female health disorders associated with a great deal of morbidity. Since all these disorders are hormone responsive, our present study has been carried out to identify the association of 306bp Alu insertion polymorphism in intron 7 of progesterone receptor gene (PROGINS). DNA was isolated from the blood samples of 445 Asian Indian women, which included 100 endometriosis, 80 fibroids and 157 cases of breast cancer along with 108 age matched normal healthy women as controls. PROGINS polymorphism was assessed by PCR followed by agarose gel electrophoresis. Results showed that T2 allele frequency is 5%, 10% and 14.6% in endometriosis, uterine fibroids and breast cancer, as compared to 5.5% in controls. This indicates that PROGINS can be considered as a predisposing risk marker for breast cancer but not for endometriosis and uterine fibroids.

Further studies on the clinical efficacy of Solanum xanthocarpum and Solanum trilobatum in bronchial asthma.

The clinical efficacy of two herbs S. xanthocarpum and S. trilobatum in a dose of 300 mg tds for 3 days was investigated in mild to moderate bronchial asthma. Their effect was compared with standard bronchodilator drugs, salbutamol (4 mg) and deriphylline (200 mg). The respiratory function was assessed by measuring the peak expiratory flow rate (PEFR) using a mini peak flow meter. In addition, improvement in lung function was assessed by physical examination (rhonchi and crepitation) and other symptoms such as cough, breathlessness and sputum. S. xanthocarpum and S. trilobatum produced a progressive improvement in the ventilatory function of asthmatic individuals over 3 days. The scores for rhonchi, cough, breathlessness and sputum were decreased by these drug treatments. The improvement in PEFR and the reduction in other symptom scores clearly indicate a bronchodilator effect, a decrease of oedema and secretions in the airway lumen. The response to these herbs can be considered to be equivalent to that of deriphylline but less than salbutamol. No untoward effects were reported during the study. The present study further confirms the traditional use of these herbs in bronchial asthma.

Successful therapy of a human lung cancer xenograft using MAb RS7 labeled with residualizing radioiodine.

We have recently reported that a radioiodinated, DTPA-appended peptide, designated IMP-R1, is a residualizing iodine label that overcomes many of the limitations that have impeded the development of residualizing iodine for clinical use. In this study the potential of 131I-IMP-R1-RS7, an internalizing anti-EGP-1 monoclonal antibody, was evaluated by performing preclinical therapy studies in nude mice bearing Calu-3 human non-small cell carcinoma of the lung xenografis. Elimination of 6 of 9 established tumors (mean tumor volume=0.3 cm(3)) was observed using a single dose of 350 microCi/mouse of 131I-IMP-R1-RS7, with all animals tolerating the dose. At the same dose and specific activity of 131I-RS7, labeled using the conventional chloramine-T method, there were four deaths, and one complete remission in nine treated mice. At the maximum tolerated dose of conventionally 131I-labeled RS7, 275 microCi, mean stable disease for approximately 5 weeks was observed, with no complete responses. Specificity of the therapeutic effect was shown in an isotype-matched control experiment, where 131I-IMP-R1-RS7 was markedly more effective than the (131)I-IMP-R1-labeled control antibody. These studies demonstrate that (131)I-IMP-R1-RS7 provides a therapeutic advantage in comparison to conventional 131I-labeled RS7, as predicted by the increased tumor accretion observed previously in targeting studies. A direct comparison of the maximum tolerated doses of (131)I-IMP-R1-RS7 (350 microCi) and 90Y-DOTA-RS7 (105 microCi) was performed in this tumor model using large established tumors (mean tumor volume=0.85 cm(3)). Anti-tumor efficacy and toxicity of the two treatments were comparable.

Radioimmunotherapy of a human lung cancer xenograft with monoclonal antibody RS7: evaluation of (177)Lu and comparison of its efficacy with that of (90)Y and residualizing (131)I.

UNLABELLED: Tumor targeting and therapeutic efficacy of (177)Lu-labeled monoclonal antibody (mAb) RS7 (antiepithelial glycoprotein-1) was evaluated in a human nonsmall cell lung carcinoma xenograft model. The potential of (177)Lu-labeled RS7 was compared with that of RS7 labeled with (90)Y and a residualizing form of (131)I. METHODS: A 1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid (DOTA) conjugate of RS7 was used for radiolabeling with (177)Lu-acetate or (88/90)Y-acetate. Biodistribution and therapy studies were conducted in nude mice with subcutaneous Calu-3 xenografts. Therapy studies were performed using the maximal tolerated doses (MTDs) of (90)Y-DOTA-RS7 (3.9 MBq [105 microCi]) and (177)Lu-DOTA-RS7 (10.2 MBq [275 microCi]) and compared with the data obtained using the MTD (13.0 MBq [350 microCi]) of a residualizing form of (131)I-RS7. RESULTS: Radiolabeling of RS7-DOTA conjugate with (177)Lu-acetate was facile. (177)Lu-DOTA-RS7 displayed biodistribution results that were nearly identical to that of the (88)Y analog in a paired-label study. The mean percentage injected doses per gram (%ID/g) for (177)Lu-RS7 and (88)Y-RS7 (in parentheses) in tumor were 38.3 %ID/g (39.1 %ID/g), 63.0 %ID/g (66.0 %ID/g), 63.0 %ID/g (65.8 %ID/g), and 34.0 %ID/g (34.9 %ID/g) on days 1, 3, 7, and 14, respectively. Elimination of established tumors, with an initial mean tumor volume of 0.24 cm(3), was shown using doses of (177)Lu-DOTA-RS7 ranging from 5.6 to 9.3 MBq (150--250 microCi) per nude mouse, with no significant difference in response rate noted between the doses in this range. Specificity of the therapeutic effect was shown in an isotype-matched control experiment, in which (177)Lu-DOTA-RS7 was markedly more effective than the (177)Lu-DOTA control antibody. A comparison of the therapeutic efficacies of (177)Lu-DOTA-RS7 and (90)Y-DOTA-RS7, using mice with established tumors with an initial mean tumor volume of 0.85 cm(3), indicated similar tumor growth inhibition and similar tumor regrowth profiles. The therapy data were similar to those obtained with residualizing (131)I-RS7 obtained at the same time. CONCLUSION: (177)Lu-RS7 is an effective radioimmunoconjugate for radioimmunotherapy. With its radiophysical properties similar to those of (131)I, coupled with its facile and stable attachment to mAb, (177)Lu promises to be an alternative to (131)I, and a complement to (90)Y, in radioimmunotherapy.

Radionuclides linked to a CD74 antibody as therapeutic agents for B-cell lymphoma: comparison of Auger electron emitters with beta-particle emitters.

UNLABELLED: We demonstrated previously that human B-cell lymphomas were effectively and specifically killed in vitro by an antibody to CD74 (LL1) linked to (111)In or other Auger electron emitters. This study was intended to more accurately compare the potency and specificity of 3Auger electron emitters, (111)In, 67Ga, and 125I, and to evaluate beta-particle emitters, 131I and 90Y. The unique property of LL1 is its high level of intracellular uptake. METHODS: Raji B-lymphoma cells were incubated with serial dilutions of the radiolabeled Abs for 2 d and then monitored for cell growth by 2 assays: a cell counting assay and a clonogenic assay. The uptake of radioactivity per cell was monitored at various time points, and the radiation dose was calculated using published S values for radioactivity located in the cytoplasm. Both specific and nonspecific toxicity were evaluated. RESULTS: The beta-particle emitters had considerably higher levels of nonspecific toxicity than the Auger electron emitters, but both 131I and 90Y, and particularly 131I, still had high levels of specificity. Both of these results were consistent with dosimetry calculations. Relative to the delivered disintegrations per cell, 131I and 67Ga were the most potent of the radionuclides tested, with 125I and (111)In being significantly weaker and 90Y being intermediate. The high potency of 67Ga, together with its low nonspecific toxicity, caused this radionuclide to have the highest specificity index. CONCLUSION: When delivered by Ab LL1, both Auger electron and beta-particle emitters can produce specific and effective toxicity. The choice of the optimal radionuclide for therapy may depend on the ease and efficiency of labeling, the specific activity obtained, the nature of the tumor being targeted, and other factors, but the high specificity indices of the Auger electron emitters may be an advantage.

Targeting human cancer xenografts with monoclonal antibodies labeled using radioiodinated, diethylenetriaminepentaacetic acid-appended peptides.

A new nonmetabolizable peptide approach to the production of residualizing radioiodine was evaluated in nude mice bearing xenografts of human lung adenocarcinoma (Calu-3) and B-cell lymphoma (Ramos). Monoclonal antibodies (MAbs) RS7 (anti-epithelial glycoprotein-1) and LL2 (anti-CD22) were radioiodinated using the thiol-reactive diethylenetriaminepentaacetic acid-D-peptide adducts IMP-R1 and IMP-R2. 125I-IMP-R1- and 125I-IMP-R2-labeled MAbs were compared to the MAbs iodinated by the conventional chloramine-T approach, (111)In, and 131I-dilactitoltyramine (DLT). In vivo biodistribution studies demonstrated a significant improvement in the tumor accretion of radiolabel using the 125I-IMP-R1 labeled MAbs compared with the conventionally iodinated antibodies. For example, at day 7, the percentage of injected dose per gram of tissue in Calu-3 was 7.9 +/- 4.1% and 18.1 +/- 7.9% (P < 0.05) for the conventional 131I- and 125I-IMP-R1-RS7, respectively, and tumor:nontumor ratios were 2.6-4.5-fold higher with the 125I-IMP-R1-RS7. It is estimated that 131I-IMP-R1-RS7 would deliver a dose to tumor (at the estimated maximum tolerated dose) 3.9 times greater than conventional 131I-labeled RS7, 1.4 times greater than 90Y-labeled RS7, and 0.7 times that of 131I-DLT-labeled RS7. Tumor accretion of 125I-IMP-R2-RS7 was also improved compared with conventionally iodinated antibody. However, this label also caused a large increase in kidney accretion. Similar improvements in tumor accretion and tumor:nontumor ratios were observed when 125I-IMP-R1-LL2 was used in the Ramos model. IMP-R1 offers a practical and useful residualizing radioiodine label because labeling efficiency is at least 10 times greater than that of the residualizing label DLT, without MAb aggregation. Structural modifications can be envisioned for further improvements in radioiodine incorporation, specific activity, and tumor dosimetry, and efforts along these lines are under way.

A pilot study on the clinical efficacy of Solanum xanthocarpum and Solanum trilobatum in bronchial asthma.

Solanum xanthocarpum and Solanum trilobatum are widely used to treat respiratory diseases in southern Indian traditional medicine (Siddha). A pilot study was undertaken to investigate the clinical efficacy and safety of a single dose of the above herbs in mild to moderate bronchial asthma. The respiratory functions (FVC, FEV1, PEFR and FEF25-75%) were assessed by using a spirometer prior to and 2 h after oral administration of 300 mg powder of whole plant of either S. xanthocarpum or S. trilobatum. Standard bronchodilator drugs, salbutamol (4 mg) and deriphylline (200 mg) were used for comparison. Treatment with either S. xanthocarpum or S. trilobatum significantly improved the various parameters of pulmonary function in asthmatic subjects. However, the effect was less when compared to that of deriphylline or salbutamol. No untoward effects were reported during the study. The results of the present study confirm the traditional claim for the usefulness of these herbs in bronchial asthma. More detailed studies are required to investigate the mechanism of action and therapeutic utility of S. xanthocarpum and S. trilobatum.

Cytotoxicity with Auger electron-emitting radionuclides delivered by antibodies.

We investigated the in vitro cytotoxic potential of Auger electron-emitting radionuclides delivered to the cytoplasm or, more specifically, to lysosomes, via antibodies. The antibody (Ab) used was LL1, which is specific for CD74, an epitope of the major histocompatibility complex (MHC) class II antigen invariant chain, Ii, present on the cell surface. It is taken up in large amounts, approximately 10(7) Ab molecules per cell per day, and delivered to lysosomes. The radioisotopes tested included (111)In, 99mTc and 125I. With sufficient specific activity, approximately 10 mCi/mg Ab, all of these isotopes were potent cytotoxic agents. 125I was active only if a "residualizing" form was used, meaning a form that is trapped within cells after catabolism of the Ab to which it was conjugated (conventional oxidative iodination produces a non-residualizing label). The conjugates of (111)In and 99mTc used are known to be residualizing. One hundred percent cell kill in vitro was obtained with (111)In and 125I, under conditions in which a non-reactive control Ab, conjugated in the same way, produced no significant toxicity. 99mTc was also potent and specific, but appeared somewhat less active than the other isotopes under the conditions evaluated. Although few Abs are accreted by cells at the same rate as LL1, it may be possible to use other Abs to deliver similar amounts of radioactivity, if Abs with higher specific activity can be produced. Such conjugated radioisotopes may be useful for attacking tumor cells in vivo, particularly for single cells or micrometastases.

Labeling of monoclonal antibodies with diethylenetriaminepentaacetic acid-appended radioiodinated peptides containing D-amino acids.

The optimal use of radioiodinated internalizing monoclonal antibodies (mAbs) for radioimmunotherapy necessitates the development of practical methods for increasing the level of retention of 131I in the tumor. Lysosomally trapped ("residualizing") iodine radiolabels that have been previously designed are based mostly on carbohydrate-tyramine adducts, but these methods have drawbacks of low overall yields and/or high levels of mAb aggregation. We have developed a method using thiol-reactive diethylenetriaminepentaacetic acid (DTPA)-peptide adducts wherein the peptides are assembled with one or more D-amino acids, including D-tyrosine. Two such substrates, R-Gly-D-Tyr-D-Lys[1-(p-thiocarbonylaminobenzyl)DTPA], referred to as IMP-R1, and [R-D-Ala-D-Tyr-D-Tyr-D-Lys]2(CA-DTPA), referred to as IMP-R2, wherein R is 4-(N-maleimidomethyl)cyclohexane-1-carbonyl, were synthesized by preparing functional group-protected peptides on a solid phase, selectively derivatizing the lysine side chain with 1-(p-isothiocyanatobenzyl)DTPA or DTPA dianhydride (CA-DTPA), deprotecting other functional groups, and finally derivatizing the peptide's N-terminus so it contained a maleimide group. Radioiodinations of the peptides followed by conjugations to disulfide-reduced mAbs, carried out as a one-vial procedure, resulted in 32-89% overall yields, at specific activities of 1.8-11. 1 mCi/mg, with less than 2% aggregation. Two internalizing mAbs, LL2 (anti-CD 22 B-cell lymphoma mAb) and RS7 (an anti-adenocarcinoma mAb which targets EGP-1 antigen), labeled with this procedure exhibited a 2-3-fold better cellular retention in Ramos and Calu-3 tumor cell lines, in vitro, respectively, compared to the same mAbs radioiodinated with the chloramine-T method. The rationale for the new approach, syntheses, radiochemistry and in vitro data are presented.