Spatiotemporal atmospheric in-situ carbon dioxide data over the Indian sites-data perspective

In the current study, atmospheric carbon dioxide (CO2) data covering multiple locations in the Indian subcontinent are reported. This data was collected using a dedicated ground-based in-situ network established as part of the Geosphere-Biosphere Programme (CAP-IGBP) of the Climate and Atmospheric Processes of the Indian Space Research Organisation (ISRO). Data are collected over Ponmudi, Ooty, Sriharikota, Gadanki, Shadnagar, Nagpur, and Dehradun during 2014-2015, 2017-2020, 2012, 2011-2015, 2014-2017, 2017 and 2008-2011, respectively. The atmospheric CO2 generated as part of the CAP-IGBP network would enhance the understanding of CO2 variability in different time scales ranging from diurnal, seasonal, and annual over the Indian region. Data available under this network may be interesting to other research communities for modeling studies and spatiotemporal variability of atmospheric CO2 across the study locations. The work also evaluated the CO2 observations against the Model for Interdisciplinary Research on Climate version 4 atmospheric chemistry-transport model (MIROC4-ACTM) concentrations.

Tissue-targeted and localized AAV5-DCN and AAV5-PEDF combination gene therapy abrogates corneal fibrosis and concurrent neovascularization in rabbit eyes in vivo

PURPOSE

Corneal fibrosis and neovascularization (CNV) after ocular trauma impairs vision. This study tested therapeutic potential of tissue-targeted adeno-associated virus5 (AAV5) mediated decorin (DCN) and pigment epithelium-derived factor (PEDF) combination genes in vivo.

METHODS

Corneal fibrosis and CNV were induced in New Zealand White rabbits via chemical trauma. Gene therapy in stroma was delivered 30-min after chemical-trauma via topical AAV5-DCN and AAV5-PEDF application using a cloning cylinder. Clinical eye examinations and multimodal imaging in live rabbits were performed periodically and corneal tissues were collected 9-day and 15-day post euthanasia. Histological, cellular, and molecular and apoptosis assays were used for efficacy, tolerability, and mechanistic studies.

RESULTS

The AAV5-DCN and AAV5-PEDF combination gene therapy significantly reduced corneal fibrosis (p < 0.01 or p < 0.001) and CNV (p < 0.001) in therapy-given (chemical-trauma and AAV5-DCN + AAV5-PEDF) rabbit eyes compared to the no-therapy given eyes (chemical-trauma and AAV5-naked vector). Histopathological analyses demonstrated significantly reduced fibrotic α-smooth muscle actin and endothelial lectin expression in therapy-given corneas compared to no-therapy corneas on day-9 (p < 0.001) and day-15 (p < 0.001). Further, therapy-given corneas showed significantly increased Fas-ligand mRNA levels (p < 0.001) and apoptotic cell death in neovessels (p < 0.001) compared to no-therapy corneas. AAV5 delivered 2.69 × 107 copies of DCN and 2.31 × 107 copies of PEDF genes per μg of DNA. AAV5 vector and delivered DCN and PEDF genes found tolerable to the rabbit eyes and caused no significant toxicity to the cornea.

CONCLUSION

The combination AAV5-DCN and AAV5-PEDF topical gene therapy effectively reduces corneal fibrosis and CNV with high tolerability in vivo in rabbits. Additional studies are warranted.

Toxicological effects of ocular acrolein exposure to eyelids in rabbits in vivo

Acrolein is a highly reactive volatile toxic chemical that injures the eyes and many organs. It has been used in wars and terrorism for wounding masses on multiple occasions and is readily accessible commercially. Our earlier studies revealed acrolein's toxicity to the cornea and witnessed damage to other ocular tissues. Eyelids play a vital role in keeping eyes mobile, moist, lubricated, and functional utilizing a range of diverse lipids produced by the Meibomian glands located in the upper and lower eyelids. This study sought to investigate acrolein's toxicity to eyelid tissues by studying the expression of inflammatory and lipid markers in rabbit eyes in vivo utilizing our reported vapor-cap model. The study was approved by the institutional animal care and use committees and followed ARVO guidelines. Twelve New Zealand White Rabbits were divided into 3 groups: Naïve (group 1), 1-min acrolein exposure (group 2), or 3-min acrolein exposure (group 3). The toxicological effects of acrolein on ocular health in live animals were monitored with regular clinical eye exams and intraocular pressure measurements and eyelid tissues post-euthanasia were subjected to H&E and Masson's trichrome histology and qRT-PCR analysis. Clinical eye examinations witnessed severely swollen eyelids, abnormal ocular discharge, chemosis, and elevated intraocular pressure (p < 0.001) in acrolein-exposed eyes. Histological studies supported clinical findings and exhibited noticeable changes in eyelid tissue morphology. Gene expression studies exhibited significantly increased expression of inflammatory and lipid mediators (LOX, PAF, Cox-2, and LTB4; p < 0.001) in acrolein-exposed eyelid tissues compared to naïve eyelid tissues. The results suggest that acrolein exposure to the eyes causes acute damage to eyelids by altering inflammatory and lipid mediators in vivo.

Characterization of C-X-C chemokine receptor type 5 in the cornea and role in the inflammatory response after corneal injury

C-X-C chemokine receptor type 5 (CXCR5) regulates inflammatory responses in ocular and non-ocular tissues. However, its expression and role in the cornea are still unknown. Here, we report the expression of CXCR5 in human cornea in vitro and mouse corneas in vivo, and its functional role in corneal inflammation using C57BL/6J wild-type (CXCR5^+/+) and CXCR5-deficient (CXCR5^-/-) mice, topical alkali injury, clinical eye imaging, histology, immunofluorescence, PCR, qRT-PCR, and western blotting. Human corneal epithelial cells, stromal fibroblasts, and endothelial cells demonstrated CXCR5 mRNA and protein expression in PCR, and Western blot analyses, respectively. To study the functional role of CXCR5 in vivo, mice were divided into four groups: Group-1 (CXCR5^+/+ alkali injured cornea; n = 30), Group-2 (CXCR5^-/- alkali injured cornea; n = 30), Group-3 (CXCR5^+/+ naïve cornea; n = 30), and Group-4 (CXCR5^-/- naïve cornea; n = 30). Only one eye was wounded with alkali. Clinical corneal evaluation and imaging were performed before and after injury. Mice were euthanized 4 h, 3 days, or 7 days after injury, eyes were excised and used for histology, immunofluorescence, and qRT-PCR. In clinical eye examinations, CXCR5^-/- mouse corneas showed ocular health akin to the naïve corneas. Alkali injured CXCR5^+/+ mouse corneas showed significantly increased mRNA (p < 0.001) and protein (p < 0.01 or p < 0.0001) levels of the CXCR5 compared to the naïve corneas. Likewise, alkali injured CXCR5^-/- mouse corneas showed remarkably amplified inflammation in clinical eye exams in live animals. The histological and molecular analyses of these corneas post euthanasia exhibited markedly augmented inflammatory cells in H&E staining and significant CD11b + cells in immunofluorescence (p < 0.01 or < 0.05); and tumor necrosis factor-alpha (TNFα; p < 0.05), cyclooxygenase 2 (COX-2; p < 0.0001), interleukin (IL)-1β (p < 0.0001), and IL-6 (p < 0.0001 or < 0.01) mRNA expression compared to the CXCR5^+/+ mouse corneas. Interestingly, CXCR5^-/- alkali injured corneas also showed altered mRNA expression of fibrotic alpha smooth muscle actin (α-SMA; p > 0.05) and angiogenic vascular endothelial growth factor (VEGF; p < 0.01) compared to the CXCR5^+/+ alkali injured corneas. In summary, the CXCR5 gene is expressed in all three major layers of the cornea and appears to influence corneal inflammatory and repair events post-injury in vivo. More studies are warranted to tease the mechanistic role of CXCR5 in corneal inflammation and wound healing.

Corneal fibrosis abrogation by a localized AAV-mediated inhibitor of differentiation 3 (Id3) gene therapy in rabbit eyes in vivo

Previously we found that inhibitor of differentiation 3 (Id3) gene, a transcriptional repressor, efficiently inhibits corneal keratocyte differentiation to myofibroblasts in vitro. This study evaluated the potential of adeno-associated virus 5 (AAV5)-mediated Id3 gene therapy to treat corneal scarring using an established rabbit in vivo disease model. Corneal scarring/fibrosis in rabbit eyes was induced by alkali trauma, and 24 h thereafter corneas were administered with either balanced salt solution AAV5-naked vector, or AAV5-Id3 vector (n = 6/group) via an optimized reported method. Therapeutic effects of AAV5-Id3 gene therapy on corneal pathology and ocular health were evaluated with clinical, histological, and molecular techniques. Localized AAV5-Id3 gene therapy significantly inhibited corneal fibrosis/haze clinically from 2.7 to 0.7 on the Fantes scale in live animals (AAV5-naked versus AAV5-Id3; p < 0.001). Furthermore, AAV5-Id3 treatment significantly reduced profibrotic gene mRNA levels: α-smooth muscle actin (α-SMA) (2.8-fold; p < 0.001), fibronectin (3.2-fold; p < 0.001), collagen I (0.8-fold; p < 0.001), and collagen III (1.4-fold; p < 0.001), as well as protein levels of α-SMA (23.8%; p < 0.001) and collagens (1.8-fold; p < 0.001). The anti-fibrotic activity of AAV5-Id3 is attributed to reduced myofibroblast formation by disrupting the binding of E-box proteins to the promoter of α-SMA, a transforming growth factor-β signaling downstream target gene. In conclusion, these results indicate that localized AAV5-Id3 delivery in stroma caused no clinically relevant ocular symptoms or corneal cellular toxicity in the rabbit eyes.

Time-dependent in situ structural and cellular aberrations in rabbit cornea in vivo after mustard gas exposure

An array of corneal pathologies collectively called mustard gas keratopathy (MGK) resulting from ocular exposure to sulfur mustard (SM) gas are the most prevalent chemical warfare injury. MGK involves chronic ocular discomfort that results in vision impairment. The etiology of MGK remains unclear and poorly understood primarily due to a lack of scientific data regarding structural and cellular changes in different layers of the cornea altered by mustard vapor exposure in vivo. The goals of this study were to (a) characterize time-dependent changes in different layers of corneal epithelium, stroma, and endothelium in live animals in situ by employing state-of-the-art multimodal clinical ophthalmic imaging techniques and (b) determine if SM-induced acute changes in corneal cells could be rescued by a topical eye drop (TED) treatment using in an established rabbit in vivo model. Forty-five New Zealand White Rabbit eyes were divided into four groups (Naïve, TED, SM, and SM + TED). Only one eye was exposed to SM (200 mg-min/m³ for 8 min), and each group had three time points with six eyes each (Table-1). TED was topically applied twice a day for seven days. Clinical eye examinations and imaging were performed in live rabbits with stereo, Slit-lamp, HRT-RCM3, and Spectralis microscopy system. Fantes grading, fluorescein staining, Schirmer's tests, and applanation tonometry were conducted to measure corneal haze, ocular surface aberrations, tears, and intraocular pressure respectively. H&E and PSR staining were used for histopathological cellular changes in the cornea. In vivo confocal and OCT imaging revealed significant changes in structural and morphological appearance of corneal epithelium, stroma, and endothelium in vivo in SM-exposed rabbit corneas in a time-dependent manner compared to naïve cornea. Also, SM-exposed eyes showed loss of corneal transparency characterized by increased stromal thickness and light-scattering myofibroblasts or activated keratocytes, representing haze formation in the cornea. Neither naive nor TED-alone treated eyes showed any structural, cellular, and functional abnormalities. Topical TED treatment significantly reduced SM-induced abnormalities in primary corneal layers. We conclude that structural and cellular changes in primary corneal layers are early pathological events contributing to MGK in vivo, and efficient targeting of them with suitable agents has the potential to mitigate SM ocular injury.

Effects of Regular/Dilute Proparacaine Anesthetic Eye Drops in Combination with Ophthalmic Antibiotics on Corneal Wound Healing

Purpose: Topical, local anesthetic eye drops in conjunction with antibiotics are commonly used to reduce ocular pain and treat patients in emergency clinics; however, their effects on corneal healing are poorly understood. This study examined whether regular or diluted proparacaine eye drops given in combination with common ophthalmic antibiotics affect corneal wound healing parameters using in vitro and in vivo models. Methods: Primary human corneal fibroblasts generated from donor corneas and New Zealand white rabbits were used. Regular (0.5%) and diluted (0.05%) proparacaine eye drops, twice daily for 3 days, were applied to cultures and rabbit eyes, with or without ophthalmic antibiotics (polymyxin B sulfate and trimethoprim). Trypan blue, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT), and scratch wound assays measured cellular viability, proliferation, and migration, respectively, in vitro. Slit lamp biomicroscopy, tonometry, fluorescein eye test, hematoxylin and eosin (H&E) staining, and 4',6-diamidino-2-phenylindole (DAPI) immunofluorescence were used for in vivo studies. Results: Both regular and diluted proparacaine affected wound healing response in the cornea in vitro and in vivo in a time-dependent manner. Adjunct antibiotic treatments had additive effects characterized by reduced corneal fibroblast viability, proliferation, and migration in vitro and corneal epithelial recovery in vivo. Regular proparacaine with antibiotics showed most pronounced effects on corneal wound healing parameters, and diluted proparacaine without antibiotics had minimal negative effects in vitro and in vivo. Conclusions: Both methods of regular (0.5%) and diluted (0.05%) proparacaine topical application to the cornea are safe, but impede corneal wound healing in vitro and in vivo. Adjunct antibiotic treatments had additive negative effects on corneal wound repair.

Decorin regulates collagen fibrillogenesis during corneal wound healing in mouse in vivo

A characteristic rigid spatial arrangement of collagen fibrils in the stroma is critical for corneal transparency. This unique organization of collagen fibrils in corneal stroma can be impacted by the presence and interactions of proteoglycans and extracellular matrix (ECM) proteins in a corneal microenvironment. Earlier studies revealed that decorin, a leucine-rich proteoglycan in stroma, regulates keratocyte-collagen matrix assembly and wound healing in the cornea. This study investigated the role of decorin in the regulation of stromal fibrillogenesis and corneal transparency in vivo employing a loss-of-function genetic approach using decorin null (dcn^-/-) and wild type (dcn^+/+) mice and a standard alkali-injury model. A time-dependent ocular examinations with Slit lamp microscope in live animals assessed corneal clarity, haze, and neovascularization levels in normal and injured eyes. Morphometric changes in normal and injured dcn^+/+ and dcn^-/- corneas, post-euthanasia, were analyzed with Masson's Trichrome and Periodic Acid-Schiff (PAS) histology evaluations. The ultrastructure changes in all corneas were investigated with transmission electron microscopy (TEM). Injury to eye produced clinically relevant corneal haze and neovascularization in dcn^-/- and dcn^+/+ mice while corneas of uninjured eyes remained clear and avascular. A clinically significant haze and neovascularization appeared in injured dcn^-/- corneas compared to the dcn^+/+ corneas at day 21 post-injury and not at early tested times. Histological examinations revealed noticeably abnormal morphology and compromised collagen levels in injured dcn^-/- corneas compared to the injured/normal dcn^+/+ and uninjured dcn^-/- corneas. TEM analysis exhibited remarkably uneven collagen fibrils size and distribution in the stroma with asymmetrical organization and loose packing in injured dcn^-/- corneas than injured/normal dcn^+/+ and uninjured dcn^-/- corneas. The minimum and maximum inter-fibril distances were markedly irregular in injured dcn^-/- corneas compared to all other corneas. Together, results of clinical, histological, and ultrastructural investigations in a genetic knockout model suggested that decorin influenced stromal fibrillogenesis and transparency in healing cornea.

Long-Term Safety and Tolerability of BMP7 and HGF Gene Overexpression in Rabbit Cornea

Purpose

Tissue-targeted localized BMP7+HGF genes delivered into the stroma via nanoparticle effectively treats corneal fibrosis and rehabilitates transparency in vivo without acute toxicity. This study evaluated the long-term safety and tolerability of BMP7+HGF nanomedicine for the eye in vivo.

Methods

One eye each of 36 rabbits received balanced salt solution (group 1, naïve; n = 12), naked vector with polyethylenimine-conjugated gold nanoparticles (PEI2-GNP; group 2, naked-vector; n = 12), or BMP7+HGF genes with PEI2-GNP (group 3, BMP7+HGF; n = 12) via a topical delivery technique. Safety and tolerability measurements were performed by clinical biomicroscopy in live rabbits at predetermined time intervals up to 7 months. Corneal tissues were collected at 2 months and 7 months after treatment and subjected to histology, immunofluorescence, and quantitative real-time PCR analyses.

Results

Clinical ophthalmic examinations and modified MacDonald-Shadduck scores showed no significant changes in corneal thickness (P = 0.3389), tear flow (P = 0.2121), intraocular pressure (P = 0.9958), epithelial abrasion, or ocular abnormality. Slit-lamp, stereo, confocal, and specular biomicroscopy showed no signs of blepharospasm chemosis, erythema, epiphora, abnormal ocular discharge, or changes in epithelium, stroma, and endothelium after BMP7+HGF therapy for up to 7 months, as compared with control groups. Throughout the 7-month period, no significant changes were recorded in endothelial density (P = 0.9581). Histological and molecular data were well corroborated with the subjective clinical analyses and showed no differences in the naïve, naked-vector, and BMP7+HGF groups.

Conclusions

Localized BMP7+HGF therapy is a safe, tolerable, and innovative modality for the treatment of corneal fibrosis.

Translational Relevance

Nanoparticle-mediated BMP7+HGF combination gene therapy has the potential to treat corneal fibrosis in vivo without short- or long-term toxicity.

Six-Month In Vivo Safety Profiling of Topical Ocular AVV5-Decorin Gene Transfer

Purpose

A significant remission of corneal fibrosis and neovascularization in rabbit eye in vivo was observed from a tissue-selective localized adeno-associated virus (AAV)5–Decorin (Dcn) gene therapy. This study sought to investigate 6-month toxicity profiling of this gene therapy for the eye in vivo using a rabbit model.

Methods

A small epithelial scrape followed by corneal drying was performed unilaterally in 12 rabbit eyes and either AAV5–Dcn (n = 6) or naked vector (n = 6) was delivered topically using a cloning cylinder technique. Contralateral eyes served as naïve control (n = 6). Safety and tolerability measurements in live rabbits were performed periodically until month 6 using multimodel clinical ophthalmic imaging tools—a slit lamp, stereomicroscope, and HRT3-RCM in vivo confocal microscope. Thereafter, corneas were excised and subjected to hematoxylin and eosin staining, Mason trichome staining, propidium iodide nuclear staining, and quantitative real-time polymerase chain reaction analyses.

Results

Clinical eye examinations based on the modified Hackett–McDonald ocular scoring system, and in vivo confocal imaging of the cornea showed no signs of ocular toxicity in rabbit eyes given AAV5–Dcn gene transfer vs control eyes (P > 0.05) through 6 months after treatment. The histologic and molecular analyses showed no significant differences in AAV5–Dcn vs AAV naked or naïve control groups (P > 0.05) and were in accordance with the masked clinical ophthalmic observations showing no abnormalities.

Conclusions

Topical tissue-targeted localized AAV5–Dcn gene therapy seems to be safe and nontoxic to the rabbit eye in vivo.

Translational Relevance

AAV5–Dcn gene therapy has the potential to treat corneal fibrosis and neovascularization in vivo safely without significant ocular toxicity.

The functional role of decorin in corneal neovascularization in vivo

Our earlier decorin (Dcn) gene overexpression studies found that the targeted Dcn gene transfer into the cornea inhibited corneal angiogenesis in vivo using a rabbit model. In this study, we tested the hypothesis that anti-angiogenic effects of decorin in the cornea are mediated by alterations in a normal physiologic balance of pro- and anti-angiogenic factors using decorin deficient (Dcn^-/-) and wild type (Dcn^+/+) mice. Corneal neovascularization (CNV) in Dcn^-/- and Dcn^+/+ mice was produced with a standard chemical injury technique. The clinical progression of CNV in mice was monitored with stereo- and slit-lamp microscopes, and histopathological hematoxylin and eosin (H&E) staining. Protein and mRNA expression of pro- and anti-angiogenic factors in the cornea were evaluated using immunofluorescence and quantitative real-time PCR, respectively. Slit-lamp clinical eye examinations revealed significantly more CNV in Dcn^-/- mice than the Dcn^+/+ mice post-injury (p < 0.05) and AAV5-Dcn gene therapy significantly reduced CNV in Dcn^-/- mice compered to no AAV5-Dcn gene therapy controls (p < 0.001). H&E-stained corneal sections exhibited morphology with several neovessels in injured corneas of the Dcn^-/- mice than the Dcn^+/+ mice. Immunofluorescence of corneal sections displayed significantly higher expression of α-smooth muscle actin (α-SMA) and endoglin proteins in Dcn^-/- mice than Dcn^+/+ mice (p < 0.05). Quantitative real-time PCR found significantly increased mRNA levels of pro-angiogenic factors endoglin (2.53-fold; p < 0.05), Vegf (2.47-fold; p < 0.05), and Pecam (2.14-fold; p < 0.05) and anti-angiogenic factor Vegfr2 (1.56-fold; p < 0.05) in the normal cornea of the Dcn^-/- mice than the Dcn^+/+ mice. Furthermore, neovascularized Dcn^-/- mice corneas showed greater increase in mRNA expression of pro-angiogenic factors endoglin (4.58-fold; p < 0.0001), Vegf (4.16-fold; p < 0.0001), and Pdgf (2.15-fold; p < 0.0001) and reduced expression of anti-angiogenic factors Ang2 (0.12-fold; p < 0.05), Timp1 (0.22-fold; p < 0.05), and Vegfr2 (0.67-fold; p > 0.05) compared to neovascularized Dcn^+/+ mice corneas. These gene deficience studies carried with transgenic Dcn^-/- mice revealed decorin's role in influencing a physiologic balance between pro-and anti-angiogenic factors in the normal and injured cornea. We infer that the functional deletion of Dcn promotes irregular corneal repair and aggravates CNV.

Glutathione is a potential therapeutic target for acrolein toxicity in the cornea

Toxic and volatile chemicals are widely used in household products and previously used as warfare agents, causing a public health threat worldwide. This study aimed to evaluate the extent of injury and mechanisms of acrolein toxicity in the cornea. Primary human corneal stromal fibroblasts cultures (hCSFs) from human donor cornea were cultured and exposed to acrolein toxicity with -/+ N-acetylcysteine (NAC) to study the mode of action in the presence of Buthionine sulphoximine (BSO). PrestoBlue and MTT assays were used to optimize acrolein, NAC, and BSO doses for hCSFs. Cell-based assays and qRT-PCR analyses were performed to understand the acrolein toxicity and mechanisms. Acrolein exposure leads to an increased reactive oxygen species (ROS), compromised glutathione (GSH) levels, and mitochondrial dysfunction. The TUNEL and caspase assays showed that acrolein caused cell death in hCSFs. These deleterious effects can be mitigated using NAC in hCSFs, suggesting that GSH can be a potential target for acrolein toxicity in the cornea.

Role of inhibitor of differentiation 3 gene in cellular differentiation of human corneal stromal fibroblasts

Purpose

Inhibitor of differentiation (Id) proteins are helix-loop-helix (HLH) transcriptional repressors that modulate a range of developmental and cellular processes, including cell differentiation and cell cycle mobilization. The inhibitor of differentiation 3 (Id3) gene, a member of the Id gene family, governs the expression and progression of transforming growth factor beta (TGFβ)-mediated cell differentiation. In the face of mechanical, chemical, or surgical corneal insults, corneal keratocytes differentiate into myofibroblasts for wound repair. Excessive development or persistence or both of myofibroblasts after wound repair results in corneal haze that compromises corneal clarity and visual function. The objective of this study was to investigate whether Id3 overexpression in human corneal stromal fibroblasts governs TGFβ-driven cellular differentiation and inhibits keratocyte to myofibroblast transformation.

Methods

Primary human corneal stromal fibroblast (h-CSF) cultures were generated from donor human corneas. Human corneal myofibroblasts (h-CMFs) were produced by growing h-CSF in the presence of TGFβ1 under serum-free conditions. The Id3 gene was cloned into a mammalian expression vector (pcDNA3 mCherry LIC cloning vector), and the nucleotide sequence of the vector constructs was confirmed with sequencing as well as through restriction enzyme analysis. The Id3 mammalian overexpression vector was introduced into h-CSFs using a lipofectamine transfection kit. The expression of Id3 in selected clones was characterized with quantitative real-time PCR (qRT-PCR), immunocytochemistry, and western blotting. Phase contrast microscopy and trypan blue exclusion assays were used to evaluate the effects of the transfer of the Id3 gene on the hCSF phenotype and viability, respectively. To analyze the inhibitory effects of the Id3 gene transfer on TGFβ-induced formation of h-CMFs, expression of the mRNA and protein of the myofibroblast marker alpha smooth muscle actin (α-SMA) was examined with qRT-PCR, western blotting, and immunocytochemistry. Student t test, analysis of variance (ANOVA), and Bonferroni adjustment for repeated measures were used for statistical analysis.

Results

The results indicate that Id3 overexpression does not alter the cellular phenotype or viability of h-CSFs. Overexpression of the Id3 gene in h-CSF cells grown in the presence of TGFβ1 under serum-free conditions showed a statistically significant decrease (76.3±4.3%) in α-SMA expression (p<0.01) compared to the naked-vector transfected or non-transfected h-CSF cells. Id3-transfected, naked-vector transfected, and non-transfected h-CSF cells grown in the absence of TGFβ1 showed the expected low expression of α-SMA (0-5%). Furthermore, Id3 overexpression statistically significantly decreased TGFβ-induced mRNA levels of profibrogenic genes such as fibronectin, collagen type I, and collagen type IV (1.80±0.26-, 1.70±0.35- and 1.70±0.36-fold, respectively; p<0.05) that a play role in stromal matrix modulation and corneal wound healing. Results of the protein analysis with western blotting indicated that Id3 overexpression in h-CSF cells effectively slows TGFβ-driven differentiation and formation of h-CMFs. Results for subsequent overexpression studies showed that this process occurs through the regulation of E2A, a TATA box protein.

Conclusions

Id3 regulates TGFβ-driven differentiation of h-CSFs and formation of h-CMFs in vitro. Targeted Id3 gene delivery has potential to treat corneal fibrosis and reestablish corneal clarity in vivo.

A Novel Topical Ophthalmic Formulation to Mitigate Acute Mustard Gas Keratopathy In Vivo: A Pilot Study

Purpose

This pilot study investigated the in vivo therapeutic potential and tolerability of a multimodal ophthalmic formulation, topical eye drops (TED), for acute mustard gas keratopathy (MGK) using a rabbit model.

Methods

Twenty New Zealand White rabbits were used. Only right eyes of 18 rabbits (oculus dexter [OD]) received single sulfur mustard gas (SM) vapor injury, whereas contralateral eyes were left untreated or received TED for tolerabilty evaluation. Two rabbit eyes received no treatment and served as age-matched naive control. The four groups were: Naive (oculus sinister [OS] untreated eyes; n = 9); TED (OS treated only with TED BID for 3 days; n = 9); SM (OD exposed to SM vapor; n = 9); and SM+TED (OD exposed to SM+TED BID for 3 days; n = 9). Ocular examination in live rabbits were performed utilizing slit-lamp biomicroscopy, Fantes grading system, fluorescein staining, Schirmer's tests, pachymetry, and applanation tonometry. Cellular and molecular changes in rabbit corneas were assessed after humane euthanasia on day-3 and day-7 with histopathological and real-time polymerase chain reaction PCR techniques.

Results

TED to rabbit eyes was found tolerable in vivo. SM-exposed eyes showed significant increase in Fantes scores, central corneal thickness (CCT), Schirmer's test, epithelium-stroma separation, and corneal edema. TED mitigated clinical symptoms by reducing corneal edema, Fantes scores, CCT, and Schirmer's test. Further, TED decreased SM-induced corneal haze, inflammatory and profibrotic markers, transforming growth factor-TGF-β1 and cyclooxygenase-2COX-2, and damage to corneal structure, including epithelial-stromal integrity.

Conclusions

The developed multimodal eyedrop formulation, TED, has potential to mitigate acute MGK effectively in vivo.

Translational Relevance

TED is effective against MGK.

A rabbit model for evaluating ocular damage from acrolein toxicity in vivo

Acrolein is a highly reactive and volatile unsaturated aldehyde commonly used for producing scores of commercial products. It has been recognized as a chemical weapon since its use during World War I, and more recently, in Syria. Acrolein exposure causes severe eye, skin, and lung damage in addition to many casualties. In the eye, it causes severe pain, eyelid swelling, corneal burns, and vision impairment. Very little information is available about how acrolein damages the cornea and causes vision loss. At present, the lack of clinically relevant animal models limits evaluation of acrolein toxicity and mechanisms specific to the eye. We aim to standardize the mode of delivery and exposure duration of acrolein, damaging the rabbit eye in vivo as an ocular injury model for studying the toxicity of acrolein and developing medical countermeasures. Rabbit eyes were exposed to two modes of delivery (topical and vapor) for different durations (1-5 minutes). Clinical ophthalmic examinations with a slit lamp, stereomicroscope, fluorescein dye, pachymeter, tonometer, and tearing examinations in live rabbits were performed at various times up to 4 weeks. Corneas were histologically diagnosed for transparency, fibrosis, collagens, and neovascularization. Our study successfully established an in vivo rabbit model for evaluating acrolein toxicity to the eye, accounting for different modes and durations of exposure.

Linear Polyethylenimine-DNA Nanoconstruct for Corneal Gene Delivery

PURPOSE

This study investigated the efficiency and potential toxicity of a linear 22-kDa polyethylenimine (PEI)-DNA nanoconstruct for delivering genes to corneal cells and the effects of PEI nitrogen-to-DNA phosphate (N:P) ratio on gene transfer efficiency in vitro and in vivo.

METHODS

A gel retardation assay, zeta potential measurement, bright-field microscopy, transfection with green fluorescent protein (GFP), immunofluorescence, and enzyme-linked immunosorbent assay (ELISA) were used to characterize the physicochemical and biological properties and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH), and reactive oxygen species (ROS) assay for cytotoxicity of the linear PEI-DNA nanoconstruct using in vitro cultured primary human corneal fibroblast and in vivo mouse models.

RESULTS

Of the several evaluated N:P ratios, the highest gene transfection efficiency achieved without any notable cytotoxicity was observed at an N:P ratio of 30:1 (N:P 30). In vivo gene transfer studies revealed substantial GFP gene delivery into the corneas of mice 3 days after a single 5-min topical application without any significant adverse ocular effects. Slit-lamp biomicroscope ophthalmic examination of the mouse exposed to the linear PEI-DNA nanoconstruct showed no evidence of hyperemia (redness), corneal edema, ocular inflammation, or epiphora (excessive tearing).

CONCLUSIONS

The 22-kDa linear PEI-DNA nanoconstruct is an efficient and well-tolerated vector for corneal gene therapy in vitro and in vivo and could be used as a platform for developing novel gene-based nanomedicine approaches for corneal diseases.

Novel Combination BMP7 and HGF Gene Therapy Instigates Selective Myofibroblast Apoptosis and Reduces Corneal Haze In Vivo

Purpose

We tested the potential of bone morphogenic protein 7 (BMP7) and hepatocyte growth factor (HGF) combination gene therapy to treat preformed corneal fibrosis using established rabbit in vivo and human in vitro models.

Methods

Eighteen New Zealand White rabbits were used. Corneal fibrosis was produced by alkali injury. Twenty-four hours after scar formation, cornea received topically either balanced salt solution (BSS; n = 6), polyethylenimine-conjugated gold nanoparticle (PEI2-GNP)-naked plasmid (n = 6) or PEI2-GNP plasmids expressing BMP7 and HGF genes (n = 6). Donor human corneas were used to obtain primary human corneal fibroblasts and myofibroblasts for mechanistic studies. Gene therapy effects on corneal fibrosis and ocular safety were evaluated by slit-lamp microscope, stereo microscopes, quantitative real-time PCR, immunofluorescence, TUNEL, modified MacDonald-Shadduck scoring system, and Draize tests.

Results

PEI2-GNP–mediated BMP7+HGF gene therapy significantly decreased corneal fibrosis in live rabbits in vivo (Fantes scale was 0.6 in BMP7+HGF-treated eyes compared to 3.3 in −therapy group; P < 0.001). Corneas that received BMP7+HGF demonstrated significantly reduced mRNA levels of profibrotic genes: α-SMA (3.2-fold; P < 0.01), fibronectin (2.3-fold, P < 0.01), collagen I (2.1-fold, P < 0.01), collagen III (1.6-fold, P < 0.01), and collagen IV (1.9-fold, P < 0.01) compared to the −therapy corneas. Furthermore, BMP7+HGF-treated corneas showed significantly fewer myofibroblasts compared to the −therapy controls (83%; P < 0.001). The PEI2-GNP introduced >10⁴ gene copies per microgram DNA of BMP7 and HGF genes. The recombinant HGF rendered apoptosis in corneal myofibroblasts but not in fibroblasts. Localized topical BMP7+HGF therapy showed no ocular toxicity.

Conclusions

Localized topical BMP7+HGF gene therapy treats corneal fibrosis and restores transparency in vivo mitigating excessive healing and rendering selective apoptosis in myofibroblasts.

Targeted AAV5-Smad7 gene therapy inhibits corneal scarring in vivo

Corneal scarring is due to aberrant activity of the transforming growth factor β (TGFβ) signaling pathway following traumatic, mechanical, infectious, or surgical injury. Altered TGFβ signaling cascade leads to downstream Smad (Suppressor of mothers against decapentaplegic) protein-mediated signaling events that regulate expression of extracellular matrix and myogenic proteins. These events lead to transdifferentiation of keratocytes into myofibroblasts through fibroblasts and often results in permanent corneal scarring. Hence, therapeutic targets that reduce transdifferentiation of fibroblasts into myofibroblasts may provide a clinically relevant approach to treat corneal fibrosis and improve long-term visual outcomes. Smad7 protein regulates the functional effects of TGFβ signaling during corneal wound healing. We tested that targeted delivery of Smad7 using recombinant adeno-associated virus serotype 5 (AAV5-Smad7) delivered to the corneal stroma can inhibit corneal haze post photorefractive keratectomy (PRK) in vivo in a rabbit corneal injury model. We demonstrate that a single topical application of AAV5-Smad7 in rabbit cornea post-PRK led to a significant decrease in corneal haze and corneal fibrosis. Further, histopathology revealed lack of immune cell infiltration following AAV5-Smad7 gene transfer into the corneal stroma. Our data demonstrates that AAV5-Smad7 gene therapy is relatively safe with significant potential for the treatment of corneal disease currently resulting in fibrosis and impaired vision.

Human-wildlife conflict: proximate predictors of aggression between humans and rhesus macaques in India

Macaques live in close contact with humans across South and Southeast Asia, and direct interaction is frequent. Aggressive contact is a concern in many locations, particularly among populations of rhesus and longtail macaques that co-inhabit urbanized cities and towns with humans. We investigated the proximate factors influencing the occurrence of macaque aggression toward humans as well as human aggression toward macaques to determine the extent to which human behavior elicits macaque aggression and vice versa. We conducted a 3-month study of four free-ranging populations of rhesus macaques in Dehradun, India from October-December 2012, using event sampling to record all instances of human-macaque interaction (N = 3120). Our results show that while human aggression was predicted by the potential for economic losses or damage, macaque aggression was influenced by aggressive or intimidating behavior by humans as well as recent rates of conspecific aggression. Further, adult female macaques participated in aggression more frequently than expected, whereas adult and subadult males participated as frequently as expected. Our analyses demonstrate that neither human nor macaque aggression is unprovoked. Rather, both humans and macaques are responding to one another's behavior. Mitigation of human-primate conflict, and indeed other types of human-wildlife conflict in such coupled systems, will require a holistic investigation of the ways in which each participant is responding to, and consequently altering, the behavior of the other.

The impact assessment of Diwali fireworks emissions on the air quality of a tropical urban site, Hyderabad, India, during three consecutive years

Diwali is one of the largest festivals for Hindu religion which falls in the period October-November every year. During the festival days, extensive burning of firecrackers takes place, especially in the evening hours, constituting a significant source of aerosols, black carbon (BC), organics, and trace gases. The widespread use of sparklers was found to be associated with short-term air quality degradation events. The present study focuses on the influence of Diwali fireworks emissions on surface ozone (O3), nitrogen oxides (NO x ), and BC aerosol concentration over the tropical urban region of Hyderabad, India during three consecutive years (2009-2011). The trace gases are analyzed for pre-Diwali, Diwali, and post-Diwali days in order to reveal the festivity's contribution to the ambient air quality over the city. A twofold to threefold increase is observed in O3, NO x , and BC concentrations during the festival period compared to control days for 2009-2011, which is mainly attributed to firecrackers burning. The high correlation coefficient (~0.74) between NO x and SO2 concentrations and higher SO2/NO x (S/N) index suggested air quality degradation due to firecrackers burning. Furthermore, the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation-derived aerosol subtyping map also confirmed the presence of smoke aerosols emitted from firecrackers burning over the region. Nevertheless, the concentration level of pollutants exhibited substantial decline over the region during the years 2010 and 2011 compared to 2009 ascribed to various awareness campaigns and increased cost of firecrackers.

Patterns and determinants of dyslipidaemia in 'Young' versus 'Not so Young' patients of coronary artery disease: a multicentric, randomised observational study in northern India

AIMS

The aims of the study were to ascertain difference in lipid levels of 'Young' onset of coronary artery disease (CAD) (≤ 45 years) vs. 'Not so Young' onset of CAD (≥ 55 years) among north Indians and also to investigate determinants of 'dyslipidaemia' in CAD patients.

METHODS

This was a prospective, multicentric, randomised, observational study carried in eight centres of UP, India. All blood investigations were performed employing a central laboratory.

RESULTS

Out of a total 435 patients studied, 218 were in the 'young group' (YG) and 235 were in the 'Not so Young Group' (NSYG). Dyslipidaemia was more common in YG as evident by significantly higher levels of total cholesterol, triglycerides, low- and very low-density lipoprotein cholesterol as compared to NSYG. Diabetes, hypertension, urban lifestyle, and family history of CAD were found to be important determinants of dyslipidaemia in YG.

CONCLUSION

We conclude that lipid levels among north Indians are significantly higher in younger patients with CAD when compared with elderly.

Anti-allergic effects of probiotic Dahi through modulation of the gut immune system

BACKGROUND/AIMS

The alarming increase in allergy in the last few decades demands the development of new anti-allergic prevention strategies, and consumption of functional foods (i.e. probiotic Dahi, which has already been proven to enhance immunity by modulation of the gut mucosal immune system) may be one of them. In the present study, we evaluated anti-allergic effects of a Dahi (yogurt) containing probiotic Lactobacillus acidophilus, L. casei and normal Dahi culture Lactococcus lactis biovar diacetylactis (named probiotic Dahi) on ovalbumin induced allergy in mice.

METHODS

Allergy was induced by injecting (i.p.) ovalbumin at 0 and 14 days. Animals were fed with standard diet (control), milk, control Dahi or probiotic Dahi for 21 days. Total and ovalbumin-specific IgE, cytokines and lymphocyte proliferation index were examined after 7, 14 and 21 days.

RESULTS

Feeding of probiotic Dahi completely suppressed the elevation of total and ovalbumin-specific IgE in the serum of ovalbumin-injected mice. Similarly, splenocytes collected from mice fed with probiotic Dahi entirely lost the total and ovalbumin-specific IgE production property during in-vitro culture. Production of T helper (Th)-1 cell-specific cytokines, i.e. interferon -γ and interleukin (IL)-2, increased, while Th2-specific cytokines, i.e. IL-4 and IL-6, decreased in the supernatant of cultured splenocytes collected from mice fed with probiotic Dahi compared to the other groups. Moreover, ovalbumin-stimulated lymphocyte proliferation was strongly suppressed by feeding of probiotic Dahi in comparison to milk and control Dahi.

CONCLUSIONS

Results of the present study indicate that probiotic Dahi suppressed ovalbumin-induced allergic consequences characterized by decreasing levels of total and ovalbumin-specific IgE and lymphocyte proliferation and skewed ovalbumin-induced Th2-specific immune response towards Th1-specific response.

Epigenomic derangement of hepatic glucose metabolism by feeding of high fructose diet and its prevention by Rosiglitazone in rats

BACKGROUND

The high consumption of fructose leads to the increasing incidence of insulin resistance by several unknown mechanisms. Hepatic glucose metabolism may also be an important target of fructose-induced-metabolic alterations.

AIM

The aim of present study was to investigate alterations in hepatic glycogenolysis, glycogenesis and gluconeogenic fluxes by feeding of 21% high fructose diet and the effects of Rosiglitazone treatment to prevent these derangements in rats.

METHODS

Rats were maintained on normal chow and high fructose diet with or without Rosiglitazone for 8 weeks and various biochemical and gene expression measures were estimated.

RESULTS

The feeding of high fructose diet impaired glucose, insulin and pyruvate tolerance tests and increased blood HbA(1c), insulin, triglyceride, free fatty acids and homeostasis model assessment after 8 weeks. In addition, high fructose diet feeding increased expression of phosphoenol-pyruvatecorboxykinase, glucose-6-phosphatase, sterol regulatory element binding proteins-1 and fatty acid synthase through enhanced expression of fork-head receptor, peroxisome proliferator activated receptor-gamma-co-activator 1 and cAMP reactive element binding protein. The treatment with Rosiglitazone inhibited all these derangements, i.e. hepato-lipogenic and gluconeogenic effects of high fructose diet feeding in rats.

CONCLUSIONS

Together these findings suggest that high fructose diet induced hepatic gluconeogenic and lipogenic rate, and increased circulating triglycerides and free fatty acids, which may be the major risk factors for glucose intolerance, hyperglycemia and insulin resistance in rats. In such situations high fructose flux also induces transcriptional cascade of gluconeogenic enzymes through the modulation of various associated transcriptional factors.

Dahi containing probiotic Lactobacillus acidophilus and Lactobacillus casei has a protective effect against Salmonella enteritidis infection in mice

Salmonella enteritidis infection has received attention during recent years owing to its high prevalence worldwide. In the present study, the protective effect of probiotic dahi (curd) supplemented with Lactobacillus acidophilus and L. casei against Salmonella enteritidis infection in mice is investigated. Seven days pre-feeding with probiotic dahi significantly increased anti-S. enteritidis sIgA (secretary IgA) antibodies and lymphocyte proliferation in S. enteritidis infected mice. IL-2, IL-6 and IFN-gamma production were significantly increased in supernatant of cultured splenocytes collected from mice pre-fed with probiotic dahi, while IL-4 levels were not changed significantly. Moreover, activities of beta-galactosidase and beta-glucuronidase, and counts of S. enteritidis in intestine, liver and spleen were decreased, whereas total lactobacilli in faeces were increased in mice pre-fed with probiotic dahi. Pre-feeding of probiotic dahi for 7 days was more effective than 2 days pre-feeding. Thus, the results indicate that, pre-feeding with probiotic dahi ameliorated S. enteritidis infection by stimulating specific and non-specific immune response. Above all, it lowered colonization of gastrointestinal tract as well as translocation of S. enteritidis.

Antidiabetic effect of probiotic dahi containing Lactobacillus acidophilus and Lactobacillus casei in high fructose fed rats

OBJECTIVE

We investigated the effect of low-fat (2.5%) dahi containing probiotic Lactobacillus acidophilus and Lactobacillus casei on progression of high fructose-induced type 2 diabetes in rats.

METHODS

Diabetes was induced in male albino Wistar rats by feeding 21% fructose in water. The body weight, food and water intakes, fasting blood glucose, glycosylated hemoglobin, oral glucose tolerance test, plasma insulin, liver glycogen content, and blood lipid profile were recorded. The oxidative status in terms of thiobarbituric acid-reactive substances and reduced glutathione contents in liver and pancreatic tissues were also measured.

RESULTS

Values for blood glucose, glycosylated hemoglobin, glucose intolerance, plasma insulin, liver glycogen, plasma total cholesterol, triacylglycerol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, and blood free fatty acids were increased significantly after 8 wk of high fructose feeding; however, the dahi-supplemented diet restricted the elevation of these parameters in comparison with the high fructose-fed control group. In contrast, high-density lipoprotein cholesterol decreased slightly and was retained in the dahi-fed group. The dahi-fed group also exhibited lower values of thiobarbituric acid-reactive substances and higher values of reduced glutathione in liver and pancreatic tissues compared with the high fructose-fed control group.

CONCLUSION

The probiotic dahi-supplemented diet significantly delayed the onset of glucose intolerance, hyperglycemia, hyperinsulinemia, dyslipidemia, and oxidative stress in high fructose-induced diabetic rats, indicating a lower risk of diabetes and its complications.

Effect of Dahi containing Lactococcus lactis on the progression of diabetes induced by a high-fructose diet in rats

The antidiabetic effect of dahi was observed on high-fructose-induced diabetic rats. The fasting blood glucose, glycosylated haemoglobin, insulin, free fatty acids and triglyceride levels of the dahi fed group animals were significantly lower than those of the control group (p<0.05). The imparity of the glucose tolerance test was also delayed by one week in the dahi-fed animals.

Effect of Skim Milk and Dahi (Yogurt) on Blood Glucose, Insulin, and Lipid Profile in Rats Fed with High Fructose Diet

In the present study, the effect of skim milk and the fermented milk product named dahi (yogurt) on plasma glucose, insulin, and lipid levels as well as on liver glycogen and lipid contents in rats fed with high fructose diet has been investigated. Rats were fed with high fructose diet (21%) supplemented with skim milk, dahi (10 g/day each), or no milk product (control group) for 6 weeks. After 6 weeks of high fructose diet administration, the plasma glucose became significantly higher in control animals (246 mg/dL), whereas it was lower in skim milk (178 mg/dL)- and dahi (143 mg/dL)-fed rats. The glucose tolerance became impaired at the third week of feeding of high fructose diet in control animals, whereas in skim milk- and dahi-fed animals achievement of glucose intolerance was delayed until the fourth and fifth week, respectively. Blood glycosylated hemoglobin and plasma insulin were significantly lower in skim milk (10% and 34%, respectively)- and dahi (17%, and 48%, respectively)-fed animals than those of the control group. Plasma total cholesterol, triglycerides, low-density lipoprotein-cholesterol, and very-low-density lipoprotein-cholesterol and blood free fatty acids were significantly lower in skim milk (13%, 14%, 14%, 19%, and 14%, respectively)- and dahi (22%, 33%, 30%, 33%, and 29%, respectively)-fed animals as compared with control animals. Moreover, the total cholesterol, triglyceride, and glycogen contents in liver tissues were also lower in skim milk (55%, 50%, and 36%, respectively)- and dahi (64%, 27%, and 4%, respectively)-fed animals as compared with control animals. In contrast, high-density lipoprotein-cholesterol in plasma was higher in skim milk (14%)- and dahi (29%)-fed animals as compared with control animals. These results indicate that skim milk and its fermented milk product, dahi, delay the progression of fructose-induced diabetes and dyslipidemia in rats and that these may be useful as antidiabetic food supplements that can be included in daily meals of the diabetic as well as normal population.

Antioxidative and hypocholesterolemic effect of Lactobacillus casei ssp casei (biodefensive properties of lactobacilli)

BACKGROUND

A positive correlation between an individual's cholesterol level and development of CHD has been suggested. Low levels of high-density lipoprotein cholesterol (HDL-C) and high levels of low-density lipoprotein cholesterol (LDL-C) are important risk factors and oxidation of LDL has been implicated as an initiator of atherosclerosis.

AIM

Attempts are being made worldwide for the search of effective antioxidants that can prevent oxidation of LDL. Role of fermented milk and culture containing dairy products as effective antioxidants and their potential hypocholesterolemic effect is the focus of research. Keeping this in view, the various lactobacilli cultures were screened for their in vitro antioxidative activity. Lactobacillus casei ssp casei showing maximum antioxidative activity was selected for carrying out in vivo studies.

SETTINGS AND DESIGN

Six groups of Wistar albino rats were fed on diets containing 20% fresh or oxidized soybean oil supplemented with 5% lyophilized culture or fermented milk prepared using L. casei ssp casei for a period of 90 days. The plasma was separated in different lipoprotein fractions and analyzed for cholesterol content and thiobarbituric acid reactive substances (TBARS).

RESULTS

The cholesterol levels were less in plasma of groups fed on fermented milk by 2-11% and by 15-25% in groups fed on lyophilized culture as compared to group fed on skim milk. The levels of TBARS were lower in the LDL fraction of plasma in rats fed on fermented milk or culture than the control group fed on skim milk.

CONCLUSIONS

The results depict the cholesterol-lowering and antioxidative potential of Lactobacillus casei ssp casei for their application as dietary adjunct.

Some unusual and severe forms of adverse drug reactions: a call for setting adverse drug reaction monitoring centres

Thirty four patients aged 14 to 65 years (18 males and 16 females) admitted to the University Hospital with various unusual and severe forms of adverse drug reactions were studied. It comprised of toxic epidermal necrolysis in 8 patients, systemic vasculitis in 7 of which 3 patients had gangrene of fingers and/or toes, severe erosive gastritis in 9 patients, Stevens-Johnson syndrome in 7 patients, thrombocytopenic purpura in 2 patients and generalised convulsions in 1 patient. Various drugs responsible for causing these adverse drug reactions included antibacterials, antimalarials, anticonvulsants, antituberculars and nonsteroidal anti-inflammatory drugs. Most of the patients recovered. However, 5 of the 8 patients having toxic epidermal necrolysis died of which 2 patients had developed tetanus as a preterminal event. In view of ongoing addition of newer drugs to the therapeutic armamentarium and an increasing incidence of various unusual and severe forms of adverse drug reactions, it is our contention that a separate adverse drug reaction monitoring cell should be established in every hospital setting.

A cluster of cases of severe cardiotoxicity among kala-azar patients treated with a high-osmolarity lot of sodium antimony gluconate

In India, sodium antimony gluconate is the drug of choice for kala-azar. Due to increasing unresponsiveness to this drug in the current epidemic that began in the early 1970s, daily doses of 20 mg/kg/day for 30 days or more is recommended as opposed to the 10 mg/kg/day dose for 6-10 days used in the past. Of the 130-150 patients treated annually at our center with locally made sodium antimony gluconate, serious cardiotoxicity has occurred in less than 10%. During April 1995 at the University Hospital in Varanasi, we encountered life-threatening cardiotoxicity after 3-28 days of therapy in each of the eight patients being treated with a new lot of this drug made by a different manufacturer. Of the eight patients, six each developed congestive heart failure and/or prolongation of the corrected QT interval (QTc), and three died as a direct consequence of drug-induced toxicities. In three instances, the life-threatening complications occurred with a cumulative dose of less than 300 mg/kg. In patients with prolonged QTc, ventricular premature beats and ventricular tachycardia were recorded; in one patient, the ventricular tachycardia progressed to torsade de pointes, culminating in ventricular fibrillation and death. Since switching to different lots of this drug, we have not seen further clustering of dangerous cardiotoxicity. The antimony content of the implicated drug was comparable with that in lots from other manufacturers that did not show overt toxicity, but the osmolarity was approximately 300 mOsm/L higher. The simple technique of measuring of osmolarity may help identify inappropriately manufactured drug.

Short-course, low-dose amphotericin B lipid complex therapy for visceral leishmaniasis unresponsive to antimony

BACKGROUND

Visceral leishmaniasis (kala-azar) is a worldwide, disseminated intracellular protozoal infection for which prolonged, conventional therapy with pentavalent antimony has become increasingly less effective.

OBJECTIVE

To determine the efficacy and minimal effective dose of short-course therapy with amphotericin B lipid complex in visceral leishmaniasis.

DESIGN

A randomized, open-label study.

SETTING

Inpatient kala-azar treatment unit in the state of Bihar in northeast India, where visceral leishmaniasis is endemic.

PATIENTS

60 patients with active infection who had not responded to or who had relapse after receiving conventional (> 30 days) treatment with pentavalent antimony.

INTERVENTION

Intravenous amphotericin B lipid complex was given once daily for 5 consecutive days by 2-hour infusion. Patients were randomly assigned to receive 1, 2, or 3 mg/kg of body weight per day (total doses of 5, 10, or 15 mg/kg, respectively).

MEASUREMENTS

Clinical and parasitologic responses (the latter were measured by parasite density score of the splenic aspirate) were determined 14 days after treatment. Definitive responses were assessed 6 months after treatment according to clinical outcomes and findings on examination of bone marrow aspirate.

RESULTS

All 60 patients responded to 5 days of treatment. Fourteen days after therapy, all patients had parasite-free splenic aspirates and were considered to have an apparent clinical and parasitologic response. Six months after therapy, definitive responses were documented in 16 of 19 (84% [95% Cl, 60% to 97%]), 18 of 20 (90% [Cl, 68% to 99%]), and 21 of 21 (100% [Cl, 84% to 100%]) patients who received total doses of 5, 10, and 15 mg/kg, respectively.

CONCLUSION

Short-course therapy with low-dose amphotericin B lipid complex is effective for visceral leishmaniasis and is an important therapeutic alternative in the management of this serious intracellular protozoal infection.

Intracardiac hydatid cyst and sudden death in a child

Left ventricular hydatid cyst was diagnosed in a 4-year-old boy by echocardiography. The patient did not respond to oral mebendazole therapy and had a sudden death, probably due to rupture of the cyst. The occurrence of cardiac hydatid cyst and its life threatening complications are rare and have not been reported in children.

Adverse effects of oral amiodarone therapy

Oral amiodarone was administered to 38 patients (25 males, 13 females) with mean age of 43.6 years. Ventricular and supraventricular arrhythmias were present in 30 and 8 patients respectively. Amiodarone was given as 400-1200 mg/day for 1-2 weeks as loading dose and then it was maintained as 100-600 mg/day. The mean duration of therapy was 12.4 months. Adverse effects were noted in 21 (55.3%) cases. The commonest adverse effects observed were asymptomatic corneal microdeposits followed by gastrointestinal, cardiac, neurological and cutaneous disturbances. The drug was withdrawn in 2 (5.3%) patients because of nausea and vomiting. One patient died of pulmonary infiltrations. It is concluded that adverse effects are common with amiodarone but are tolerated well, making this drug an excellent choice for treatment of cardiac arrhythmias.

Cor-triatriatum with atrial septal defect and bicuspid aortic valve diagnosed by cross-sectional echocardiography

We report a rare case with a combination of cor-triatriatum, large secundum atrial septal defect and bicuspid aortic valve. The diagnosis was made by cross-sectional echocardiography. A defect was present between proximal (accessory) left atrial chamber and right atrium decompressing the accessory left atrial chamber. The large left to right shunt resulted in severe pulmonary arterial hypertension.

Intracellular nuclease activities of buffalo rumen bacterial population

Nuclease activities of the predominantly bacterial population obtained from buffalo rumen were investigated. Optimum temperature for hydrolysis of both DNA and RNA was 50 degrees C whereas DNAase activity was observed to be stable up to 50 degrees C, a decrease in RNAase activity was observed even after 40 degrees C. Two pH optima, one at 5.5 and the other at 7.5, were recorded for hydrolysis of DNA. RNAase activity was maximum between pH 6.0 to 7.0. Whereas DNAase activity was stable near its optimum pH, RNAase activity was stable between pH 7.0 to 8.5. Mn2+ ions stimulated DNAase activity. It was strongly inhibited by Hg2+, Zn2+, Pb2+ and Ag+. RNAase activity was stimulated by Mg2+ ions and was strongly inhibited by Hg2+, Cu2+, Zn2+ and Ag+. Cysteine hydrochloride and 2-mercaptoethanol stimulated DNAase activity. The activity was strongly inhibited by N-ethylmaleimide, 4-chloromercuribenzoate, 8-quinolinol, iodoacetic acid and 1,10-phenanthroline. RNAase activity was stimulated by cysteine hydrochloride, reduced glutathione and 2-mercaptoethanol and was strongly inhibited by 4-chloromercuribenzoate, 8-quinolinol and 2,2'bipyridyl.