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Carew EO, Patel J, Garg A, Houghtaling P, Blackstone E, Vesely I. Effect of specimen size and aspect ratio on the tensile properties of porcine aortic valve tissues. Ann Biomed Eng 2003; 31:526-35. [PMID: 12757197 DOI: 10.1114/1.1568116] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The measurement of mechanical properties of biological tissues is subject to artifacts such as natural variability and inconsistency in specimen preparation. As a result, data cannot be easily compared across laboratories. To test the effects of variable specimen dimensions, we systematically modified the size and aspect ratio (AR) of porcine aortic valve tissues and measured their stiffness and extensibility. We found that: (i) as the AR of circumferential specimens increased from 1:1 to 5:1, their stiffness increased by 36% (p < 0.001) and their extensibility decreased by 21% (p < 0.001); (ii) as the AR of radial specimens increased from 0.8:1 to 4:1, their stiffness increased by 36% (p < 0.001) and their extensibility decreased by 34% (p < 0.001); (iii) as the size of circumferential specimens was reduced from 128 to 32 mm2 at fixed AR (2:1), their stiffness decreased by 6 (p = 0.05), and their extensibility increased by 17% (p < 0.001); and (iv) as the size of radial specimens was reduced from 72 to 32 mm2 at fixed AR (2:1), their stiffness decreased by 7% (p = 0.03) and their extensibility increased by 16% (p = 0.005). Thus, as specimens of constant length became narrower, they became stiffer and less extensible, and as specimens of fixed aspect ratio became smaller, they became less stiff and more extensible. Statistical models of these trends were predictive and can thus be used to integrate materials test data across different laboratories.
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Ayyagari A, Agarwal J, Garg A. Antibiotic associated diarrhoea: infectious causes. Indian J Med Microbiol 2003; 21:6-11. [PMID: 17642966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Nearly 25% of antibiotic associated diarrhoeas (AAD) is caused by Clostridium difficile, making it the commonest identified and treatable pathogen. Other pathogens implicated infrequently include Clostridium perfringens, Staphylococcus aureus, Klebsiella oxytoca, Candida spp. and Salmonella spp. Most mild cases of AAD are due to non-infectious causes which include reduced break down of primary bile acids and decrease metabolism of carbohydrates, allergic or toxic effects of antibiotic on intestinal mucosa and pharmacological effect on gut motility. The antibiotics most frequently associated with C. difficile associated diarrhoea are clindamycin, cephalosporin, ampicillin and amoxicillin. Clinical presentation may vary from mild diarrhoea to severe colitis and pseudomembranous colitis associated with high morbidity and mortality. The most sensitive and specific diagnostic test for C. difficile infection is tissue culture assay for cytotoxicity of toxin B. Commercial ELISA kits are available. Though less sensitive, they are easy to perform and are rapid. Withdrawal of precipitating antibiotic is all that is needed for control of mild to moderate cases. For severe cases of AAD, oral metronidazole is the first line of treatment, and oral vancomycin is the second choice. Probiotics have been used for recurrent cases.
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Abstract
AIMS Familial partial lipodystrophy, Dunnigan variety (FPLD), is an autosomal dominant disorder due to missense mutations in the lamin A/C gene and is characterized by gradual loss of subcutaneous fat from the extremities and trunk, fat accumulation in the head, neck and intra-abdominal areas, insulin resistance and its metabolic complications. We studied autopsy findings in two patients with FPLD to determine fat distribution and organ involvement. RESULTS Patient 1, a 66-year-old woman with the R482Q mutation, had diabetes mellitus, dyslipidaemia, and coronary artery disease and died suddenly. Autopsy confirmed the typical body fat distribution and further revealed excess fat deposition in the subpectoral regions extending to the axillae, in the axillary lymph nodes and in the retroperitoneum. Atherosclerotic vascular disease including old infarcts of the myocardium, temporal lobe and kidneys were noted. Severe amyloidosis of the pancreatic islets and grouped muscle atrophy of the quadriceps and diaphragmatic muscles were present. Patient 2, a 29-year-old woman belonging to a pedigree with the R62G mutation, died of hyperlipidaemia-induced acute pancreatitis. Autopsy of patient 2 revealed extensive pancreatitis, hepatic steatosis and polycystic ovaries. CONCLUSIONS Our study confirms typical body fat distribution and describes new sites of excess fat deposition. Our data show predisposition to atherosclerosis and polycystic ovaries and suggest that pancreatic amyloidosis may underlie development of hyperglycaemia in FPLD patients.
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Morris BS, Garg A, Jadhav PJ. Tuberous sclerosis: a presentation of less-commonly encountered stigmata. AUSTRALASIAN RADIOLOGY 2002; 46:426-30. [PMID: 12452918 DOI: 10.1046/j.1440-1673.2002.01098.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The protean manifestations of the tuberous sclerosis complex have lent this condition to extensive review in textbooks and in the medical literature. This condition generally presents by virtue of its neurological manifestations. Osseous stigmata, when encountered, are generally asymptomatic and do not require specific treatment owing to their benignity. We present the case of a young man with a slowly enlarging facial swelling for whom cosmetic surgery was considered. The swelling, present since childhood, had in time assumed disfiguring proportions. In what was hitherto considered an isolated facial deformity, a skull radiograph followed by CT revealed neurological stigmata of tuberous sclerosis. A large cerebellar hamartoma, proliferative soft tissue in the scalp adjacent to focal hyperostosis of the calvarium and the accompanying hemifacial changes seen in this patient constitute less commonly described features of tuberous sclerosis.
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Rathod K, Garg A, Chavhan G, Rathod N. Computed tomography as a diagnostic tool in acute renal cortical necrosis. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2002; 50:1451-2. [PMID: 12583485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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Ye J, Garg A, Calhoun C, Feingold KR, Elias PM, Ghadially R. Alterations in cytokine regulation in aged epidermis: implications for permeability barrier homeostasis and inflammation. I. IL-1 gene family. Exp Dermatol 2002; 11:209-16. [PMID: 12102659 DOI: 10.1034/j.1600-0625.2002.110303.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Acute disruption of the cutaneous permeability barrier with either solvents or tape-stripping stimulates a homeostatic metabolic response in the subjacent nucleated layers of the epidermis that results in a rapid restoration of normal permeability barrier function. When the aged epidermal permeability barrier is stressed, it reveals a diminished capacity for recovery, in comparison to young epidermis, analogous to other organs in the aged when stressed. Although the signals that regulate this homeostatic response by the epidermis have not yet been resolved, acute permeability barrier disruption stimulates release of prestored IL-1alpha, and increased production of potentially regulatory cytokines, including IL-1alpha and TNFalpha in the epidermis. In these studies, we addressed the hypothesis that cytokine dysregulation explains the permeability barrier abnormality in aged epidermis, assessing the regulation of IL-1 and TNF signaling in aged vs young mice. To determine whether the IL-1 family of cytokines plays a key role in the permeability barrier abnormality of the aged, permeability barrier recovery rates were compared in transgenic mice lacking the functional IL-1 type 1 receptor vs wild-type mice at various ages. Knockout of the IL-1 type 1 receptor exacerbates the defect in permeability barrier homeostasis that is seen in age-matched, wild-type counterparts. Furthermore, the sluggish permeability barrier recovery in aged epidermis is associated with, and at least in part attributable to, altered expression of the IL-1 family of cytokines and receptors both under basal conditions and after acute barrier perturbations. Whereas modulations in cytokine expression with epidermal permeability barrier perturbation are qualitatively similar in aged epidermis, they greatly differ quantitatively. In contrast, examination of TNFalpha mRNA and protein basally, and following barrier perturbation revealed no alterations in aged epidermis. Together, these results show that selective alterations in the IL-1 family of cytokines occur with aging and that defects in IL-1 signaling may contribute to the epidermal permeability barrier abnormality of aged skin.
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Garg A, Aggarwal BB. Nuclear transcription factor-kappaB as a target for cancer drug development. Leukemia 2002; 16:1053-68. [PMID: 12040437 DOI: 10.1038/sj.leu.2402482] [Citation(s) in RCA: 351] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2001] [Accepted: 01/21/2002] [Indexed: 11/09/2022]
Abstract
Nuclear factor kappa B (NF-kappaB) is a family of inducible transcription factors found virtually ubiquitously in all cells. Since its discovery by Sen and Baltimore in 1986, much has been discovered about its mechanisms of activation, its target genes, and its function in a variety of human diseases including those related to inflammation, asthma, atherosclerosis, AIDS, septic shock, arthritis, and cancer. Due to its role in a wide variety of diseases, NF-kappaB has become one of the major targets for drug development. Here, we review our current knowledge of NF-kappaB, the possible mechanisms of its activation, its potential role in cancer, and various strategies being employed to target the NF-kappaB signaling pathway for cancer drug development.
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Morris BS, Varma R, Garg A, Awasthi M, Maheshwari M. Multifocal musculoskeletal tuberculosis in children: appearances on computed tomography. Skeletal Radiol 2002; 31:1-8. [PMID: 11807585 DOI: 10.1007/s00256-001-0439-y] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2001] [Indexed: 02/02/2023]
Abstract
PURPOSE AND PATIENTS The incidence of skeletal tuberculosis (TB), which once accounted for a majority of cases of extrapulmonary tuberculosis, has fallen significantly in recent years with the advent of effective drug therapy. Disseminated bone involvement in TB is very uncommon but it may still occur in countries where TB is endemic. We present the imaging findings of four children ranging in age from 2 to13 years, each of whom had multiple osseous stigmata of tuberculous infection. They presented to us over a period of 9 months. RESULTS AND CONCLUSION Three of four children had calvarial lesions, with involvement of the bony orbit in one, and large abscesses were present in the chest wall and the mediastinum of another. Lesions along the dorsal spine were demonstrated in three cases, two of which showed epidural extensions. Bone lesions in the thoracic cage accompanying those in the spine were also seen in two children, one of whom had a solitary destructive focus in a rib distant from the site of vertebral involvement. Bone lesions involving the first metacarpal in one case and the scapular wing in two others are also described. The diagnosis in each of the cases was confirmed by the identification of epitheloid giant cells and caseous necrosis or tubercle bacilli in fine needle aspirates or on tissue culture studies.
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Garg A, Garg S, Zaneveld LJ, Singla AK. Chemistry and pharmacology of the Citrus bioflavonoid hesperidin. Phytother Res 2001; 15:655-69. [PMID: 11746857 DOI: 10.1002/ptr.1074] [Citation(s) in RCA: 520] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Hesperidin, a bioflavonoid, is an abundant and inexpensive by-product of Citrus cultivation. A deficiency of this substance in the diet has been linked with abnormal capillary leakiness as well as pain in the extremities causing aches, weakness and night leg cramps. No signs of toxicity have been observed with the normal intake of hesperidin or related compounds. Both hesperidin and its aglycone hesperetin have been reported to possess a wide range of pharmacological properties. This paper reviews various aspects of hesperidin and its related compounds, including their occurrence, physical and chemical properties, analysis, pharmacokinetics, safety and toxicity and the marketed products available. A special emphasis has been laid on the pharmacological properties and medicinal uses of these compounds.
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Panagariya A, Jain RS, Gupta S, Garg A, Sureka RK, Mathur V. Herpes simplex encephalitis in North West India. Neurol India 2001; 49:360-5. [PMID: 11799408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
All patients admitted with provisional diagnosis of an encephalitic illness over a period of 30 months, were studied. Special investigations included CSF analysis, EEG, CT scan and MRI. Herpes simplex virus (HSV) antibody estimation in CSF and blood was done simultaneously using ELISA. Patients with diagnosis of cerebral venous thrombosis, cerebral malaria, tubercular meningitis etc, who resembled herpes simplex encephalitis (HSE), were excluded systematically with relevant investigations. 28 patients showed electroencephalographic, serologic and/or neuroradiological evidence of herpes simplex encephalitis. Males were affected more than females. Age ranged from 4 years to 65 years. Main clinical features included altered sensorium (100%) and seizures (89%). Serological test for HSV antibody in CSF and blood was positive in 14 patients. Fronto-temporal localisation was seen in EEG of 18 patients. CT and MRI were fairly characteristic with bilateral asymmetric fronto-temporal lesions. Patients with mild disease and who reported earlier responded well to treatment with acyclovir. Mortality was higher if treatment was delayed or if the disease was severe. Delayed treatment even in less severe cases produced neurological deficit in many survivors. Despite limitations of non-availability of CSF-PCR and serial estimation of HSV antibodies, the study is an attempt to highlight the value of high index of suspicion of HSE on clinical grounds, systematically excluding cases with different aetiologies resembling HSE and planning early antiviral therapy to reduce both mortality and morbidity associated with this fatal disease.
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Court-Brown CM, Garg A, McQueen MM. The epidemiology of proximal humeral fractures. ACTA ORTHOPAEDICA SCANDINAVICA 2001; 72:365-71. [PMID: 11580125 DOI: 10.1080/000164701753542023] [Citation(s) in RCA: 453] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
We present a 5-year prospective study of the epidemiology of 1,027 proximal humeral fractures. These fractures, which tend to occur in fit elderly persons, have a unipolar age distribution and the highest age-specific incidence occurs in women between 80 and 89 years of age. The commonest was the B1.1 impacted valgus fracture, found in one-fifth of the cases in this series, a type that is not included in the Neer classification. We used both Neer and AO classifications. The AO classification proved to be more comprehensive because in the Neer classification, half of the fractures are minimally displaced and almost nine-tenths fall into only three categories. In the AO classification, the B1.1, A2.2, A3.2 and A1.2 sub-groups comprise over half of all proximal humeral fractures, while the AO type C fractures occur in only 6%. We suggest that the literature does not adequately reflect the spectrum of proximal humeral fractures.
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Sachdev HP, Mahajan SC, Garg A. Improving antibiotic and bronchodilator prescription in children presenting with difficult breathing: experience from an urban hospital in India. Indian Pediatr 2001; 38:827-38. [PMID: 11520993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
OBJECTIVE To evaluate the relative frequency of other conditions that share a clinical overlap with pneumonia as defined by the WHO case management algorithm and to determine the possibility of refining the antibiotic and bronchodilator prescription on the basis of simple clinical features. DESIGN Prospective observational. SETTING Urban tertiary care center. METHODS Two hundred children, between the ages of 6 months to 5 years, presenting with difficult breathing (as defined by WHO algorithm) were prospectively evaluated for the diagnosis and the need for bronchodilator and antibiotic therapy (clinician s diagnosis). An additional independent blinded evaluation of the chest X-rays was done by a radiologist after the study (radiologist-aided diagnosis). On the basis of reliable predictors (sensitivity > 70% and specificity > 70%) of antibiotic and bronchodilator prescription, irrespective of the exact diagnostic category, two viable modifications of WHO case management algorithm emerged, which were compared by paired proportion test. RESULTS Acute asthma was the predominant condition (46% or 54%), pneumonia alone was rare (10%), co-existence of pneumonia with wheeze (bronchospasm) was more frequent (22% or 15%) and often diagnoses not related to the respiratory system were documented (18% or 17%). All the subjects in whom a preceding history of cough was not elicited had non-respiratory illnesses. An audible wheeze was appreciated in only 44 of the 150 cases (29.3%) with an auscultable wheeze. The two alternatives represented a significant (p < 0.0001) improvement over the WHO algorithm preventing inappropriate usage of both antibiotics and bronchodilators, primarily by restricting over-prescription of the former (14% and 26.5% for proposed algorithms 1 and 2, respectively) and under-utilization of the latter (40%). The performance of the alternative algorithms for the radiologist-aided diagnosis was marginally better for over-prescription of antibiotics (16.2% and 30.9% for proposed algorithms 1 and 2, respectively). CONCLUSION It is feasible to amalgamate simple clinical features (history of: (i) previous similar episode of cough and difficult breathing, and (ii) fever) in the WHO case management algorithm to significantly refine the antibiotic (95% CI range 7% to 33%) and bronchodilator (35%; 95% CI 27% to 43%) prescription.
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Court-Brown CM, Garg A, McQueen MM. The translated two-part fracture of the proximal humerus. Epidemiology and outcome in the older patient. THE JOURNAL OF BONE AND JOINT SURGERY. BRITISH VOLUME 2001; 83:799-804. [PMID: 11521917 DOI: 10.1302/0301-620x.83b6.11401] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We have undertaken a five-year prospective study of 126 translated two-part fractures of the proximal humerus and present an analysis of the epidemiology and of the factors which affect outcome in elderly patients. The fracture has a unimodal age distribution and rarely affects adults under the age of 50 years. Analysis showed that patients with two-part translated fractures of the surgical neck tended to be independent and relatively fit, despite the fact that their mean age was 72 years. Outcome was determined by the age of each patient and the degree of translation on the initial anteroposterior radiograph. Surgery did not improve the outcome, regardless of the degree of translation.
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Abstract
We have undertaken a five-year prospective study of 126 translated two-part fractures of the proximal humerus and present an analysis of the epidemiology and of the factors which affect outcome in elderly patients. The fracture has a unimodal age distribution and rarely affects adults under the age of 50 years. Analysis showed that patients with two-part translated fractures of the surgical neck tended to be independent and relatively fit, despite the fact that their mean age was 72 years. Outcome was determined by the age of each patient and the degree of translation on the initial anteroposterior radiograph. Surgery did not improve the outcome, regardless of the degree of translation.
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Woolf A, Alpert HR, Garg A, Lesko S. Adolescent occupational toxic exposures: a national study. ARCHIVES OF PEDIATRICS & ADOLESCENT MEDICINE 2001; 155:704-10. [PMID: 11386962 DOI: 10.1001/archpedi.155.6.704] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND While many previous studies describe workplace-associated injuries in adolescents, few focus on toxic exposures. Such incidents are unlikely to be reported to either federal or state agencies. However, poison control centers often get called about these poisonings and might serve as a resource for monitoring their occurrence. OBJECTIVE To describe the frequency and severity of job-related toxic exposures involving adolescents, the specific toxic agents involved, and trends over time. METHODS Occupational toxic exposures occurring in the United States between 1993 and 1997 were analyzed using the Toxic Exposure Surveillance System database compiled by the American Association of Poison Control Centers. Contingency tables with the chi(2) statistic were used to test bivariate associations. Logistic regression was performed to investigate trends over time. RESULTS Of 301 228 workplace toxic exposures reported over 5 years, 8779 (3%) involved adolescents younger than 18 years. The most common agents involved were alkaline corrosives (13.2%), gases and fumes (12.0%), cleaning agents (9.7%), bleaches (8.3%), drugs (7.4%), acids (7.2%), and hydrocarbons (6.9%). The injuries were rated as severe in 14.2% of exposures, life-threatening in 0.3%, and there were 2 deaths. The proportionate frequency of occupational exposures occurring among adolescents vs adults increased over time (odds ratio, 1.003; P<.001). CONCLUSIONS Adolescent occupational toxic exposures are an underrecognized hazard in the United States. Poison control center experience can be used to fill a gap in the surveillance of such injuries.
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Abstract
The sphenomandibular ligament, which is derived from the sheath of Meckel's cartilage, is a fibrous structure that passes between the spine of the sphenoid bone and the lingula of the mandible. Although anatomical texts provide basic descriptions of this structure, there are few published reports of the extent of its variability or its possible clinical implications. The aim of this study was to provide a detailed description of the nature and extent of anatomical variability in the sphenomandibular ligament of seven human cadavers. Dissections of sagittally sectioned heads were performed using a medial approach that involved displacement of the tongue and mucosal tissues in the oral cavity and oropharynx, then reflection of the medial pterygoid muscle. The ligaments ranged in shape from thin bands that descended for a short distance from the spine of the sphenoid to broad bi-concave ligaments with prominent insertions. The mylohyoid nerve was seen to pass behind the ligament in all specimens, emerging from the postero-inferior border of the mandibular attachment before running into the mylohyoid groove on the medial surface of the ramus. Lying in the pterygomandibular space, the ligament was surrounded by fascia, both structures presenting potential barriers to the diffusion of local anaesthetic solution if injected medially. The appearance of the lingula also varied, and did not seem to reflect the size of attachment of the ligament, suggesting an alternative explanation of lingula morphology, perhaps related to a continuation of the mylohyoid ridge and anterior border of the mylohyoid groove.
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Deol PS, Mishra NK, Gupta V, Gaikwad SB, Garg A, Singh N. Post-Traumatic Cavernous Fistula Fed by Persistent Trigeminal Artery: Treatment by GDC Embolisation. Interv Neuroradiol 2001; 7:47-50. [PMID: 20663331 DOI: 10.1177/159101990100700107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2001] [Accepted: 02/15/2001] [Indexed: 11/17/2022] Open
Abstract
SUMMARY A case of traumatic persistent pnmltlve trigeminal artery (PPTA) cavernous sinus fistula treated with GDC embolisation is reported. Because of the small lumen of PP TA, posteriorly directed course and flow contribution from the posterior circulation, balloon embolisation via the carotid system was not considered appropriate. The fistula was successfully closed by GDC embolisation.
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Wasczcak MD, Wang Y, Garg A, Geiger WE, Kang SO, Carroll PJ, Sneddon LG. Syntheses and structural and electrochemical characterizations of vanadatricarbadecaboranyl analogues of vanadocene and the structural characterization of the [Li(CH(3)CN)2+](6-CH(3)-nido-5,6,9-C(3)B(7)H(9-) tricarbadecaboranyl anion. J Am Chem Soc 2001; 123:2783-90. [PMID: 11456964 DOI: 10.1021/ja003757z] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A single-crystal X-ray determination of the [Li(CH(3)CN)(2)(+)](6-CH(3)-nido-5,6,9-C(3)B(7)H(9)(-)) salt has shown that the 6-CH(3)-nido-5,6,9-C(3)B(7)H(9)(-) tricarbadecaboranyl anion has a nido-cage geometry based on an octadecahedron missing the unique six-coordinate vertex. The resulting six-membered open face is puckered, with two of the cage carbons (C6 and C9) occupying the low-coordinate cage positions above the plane of the four remaining atoms (C5, B7, B8, and B10). The Li(+) ion is centered over the open face and is solvated by two acetonitrile molecules. The reactions of the 6-CH(3)-nido-5,6,9-C(3)B(7)H(9)(-) anion with various vanadium halide salts, including VCl(4), VCl(3), and VBr(2), each resulted in the isolation of the same five paramagnetic products (2-6) of composition V(CH(3)-C(3)B(7)H(9))(2). X-ray crystallographic determinations of 2-5 showed that the complexes consist of two octadecahedral VC(3)B(7) fragments sharing a common vanadium vertex and established their structures as commo-V-(1-V-4'-CH(3)-2',3',4'-C(3)B(7)H(9))(1-V-2-CH(3)-2,3,4-C(3)B(7)H(9)) (2), commo-V-(1-V-5'-CH(3)-2',3',5'-C(3)B(7)H(9))(1-V-4-CH(3)-2,3,4-C(3)B(7)H(9)) (3), commo-V-(1-V-5'-CH(3)-2',3',5'-C(3)B(7)H(9))(1-V-2-CH(3)-2,3,4-C(3)B(7)H(9)) (4), and commo-V-(1-V-2-CH(3)-2,3,4-C(3)B(7)H(9))(2) (5). These complexes can be considered as tricarbadecaboranyl analogues of vanadocene, (eta(5)-C(5)H(5))(2)V. However, unlike vanadocene, these complexes are air- and moisture-stable and have only one unpaired electron. The five complexes differ with respect to one another in that they either (1) contain different enantiomeric forms of the CH(3)-C(3)B(7)H(9) cages, (2) have a different twist orientation of the two cages, or (3) have the methyl group of the CH(3)-C(3)B(7)H(9) cage located in either the 2 or 4 position of the cage. Subsequent attempts to oxidize the compounds with reagents such as Br(2) and Ag(+) were unsuccessful, illustrating the ability of the tricarbadecaboranyl anion to stabilize metals in low oxidation states. Consistent with this, both the electrochemical oxidation and the reduction of 2 were much more positive than those of the same oxidation state changes in vanadocene. The one-electron reduction of 2 is a remarkable 2.9 V positive of that of Cp(2)V.
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Kalla G, Garg A, Kachhawa D. Chemical peeling--glycolic acid versus trichloroacetic acid in melasma. Indian J Dermatol Venereol Leprol 2001; 67:82-4. [PMID: 17664715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Melasma continues to be a therapeutic challenge. 100 patients of melasma not responding to conventional depigmenting agents were divided into 2 groups, one treated with 55-75% glycolic acid (68 patients) and the other with 10-15% trichloroacetic acid (32 patients). Applications were made after every 15 days and response assessed clinically along with relapse or hyperpigmentation after 3 month follow up period. More than 75% improvement was seen in 30%, and 50-75% improvement in 24% patients. Response with TCA was more rapid as compared to GA. Chronic pigmentation responded more favourably to TCA. Relapse and hyperpigmentation was more-25% in TCA as compared to 5.9% GA. Sun exposure was the most important precipitating factor followed by pregnancy and drugs.
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Kao JS, Garg A, Mao-Qiang M, Crumrine D, Ghadially R, Feingold KR, Elias PM. Testosterone perturbs epidermal permeability barrier homeostasis. J Invest Dermatol 2001; 116:443-51. [PMID: 11231319 DOI: 10.1046/j.1523-1747.2001.01281.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Although there are no known gender-related differences in permeability barrier function in adults, estrogens accelerate whereas testosterone retards barrier development in fetal skin, and male fetuses demonstrate slower barrier development than female littermates. Moreover, prenatal administration of the androgen receptor antagonist, flutamide, equalizes developmental rates in male and female fetuses. Therefore, we evaluated the effects of changes in testosterone on barrier homeostasis in adult murine and human skin. Hypogonadal mice (whether by castration or by treatment with systemic flutamide) displayed significantly faster barrier recovery at 3, 6, and 12 h than did controls, and testosterone replacement slowed barrier recovery in castrated mice. Moreover, testosterone directly effects the skin, as topical flutamide also accelerated barrier recovery in normal male mice. These findings appear to be of physiologic significance, since prepubertal male mice (age 5 wk) displayed accelerated barrier recovery in comparison with adult postpubertal (11 wk) males. These studies also appear to be relevant for humans, as a hypopituitary human subject demonstrated repeated changes in barrier recovery in parallel with peaks and nadirs in serum testosterone levels during intermittent testosterone replacement. Mechanistic studies showed that differences in epidermal lipid synthesis do not account for the testosterone-induced functional alterations. Instead, epidermal lamellar body (LB) formation and secretion both decrease, resulting in decreased extracellular lamellar bilayers in testosterone-replete animals. These studies demonstrate that fluctuations in testosterone modulate barrier function, and that testosterone repletion can have negative consequences for permeability barrier homeostasis.
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Rathod KR, Narlawar RS, Garg A, Lolge S. Percutaneous conservative management of emphysematous pyelonephritis. J Postgrad Med 2001; 47:66. [PMID: 11590300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
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247
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Panagariya A, Garg A. Lacunar syndromes due to small haemorrhagic lesions. INDIAN JOURNAL OF MEDICAL SCIENCES 2001; 55:47-52. [PMID: 11480397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
OBJECTIVE To study the frequency, clinical presentations and prognostic aspects of haemorrhagic lacunar syndromes. MATERIAL AND METHODS 375 patients of cerebrovascular accidents admitted in neurology wards over 2 years were studied. Based on CT findings, 114 patients were diagnosed as intra cerebral haemorrhage (ICH). They were assessed in detail by careful history and examination of neurological status. Coagulation studies, MRI and angiography were done in selected cases. RESULTS In 17 (15%) patients, size of hematoma was < 2 cms as seen in CT scan. The sites of these small haemorrhages were in basal ganglia (6 patients), internal capsule (3 patients), thalamus (5 patients) and pons (3 patients). Depending on their location they presented as pure motor stroke, pure sensory stroke, ataxic hemiparesis, sensorimotor stroke and clumsy hand-dysarthia syndrome. Three patients showed interesting phenomena like transient ischemic attack caused by bleed or previous disease showing improvement after bleed. Prognosis of these small ICH was excellent with 100% survival rate and lesser disability as shown by good functional recovery. CONCLUSIONS Haemorrhagic lacunar syndromes are not just the statistical curiosities but could have significant prognostic bearing.
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Tewari SC, Chatterji RS, Varghese SJ, Prasad B, Garg A. MALAKOPLAKIA OF LUNG IN AN IMMUNOCOMPROMISED PATIENT. Med J Armed Forces India 2001; 57:63-5. [PMID: 27365584 DOI: 10.1016/s0377-1237(01)80097-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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249
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Garg A, Vinaitheerthan M, Weatherall PT, Bowcock AM. Phenotypic heterogeneity in patients with familial partial lipodystrophy (dunnigan variety) related to the site of missense mutations in lamin a/c gene. J Clin Endocrinol Metab 2001; 86:59-65. [PMID: 11231979 DOI: 10.1210/jcem.86.1.7121] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The lamin A/C (LMNA) gene has recently been reported to be mutated in familial partial lipodystrophy, Dunnigan variety (FPLD). We found mutations within exon 8 of LMNA (R482Q, R482W, and G465D) in 12 families with typical FPLD and in exon 11 (R582H) in 1 atypical family. To investigate phenotypic heterogeneity, we compared body fat distribution, using anthropometry and whole body magnetic resonance imaging, and metabolic parameters in women with atypical and typical FPLD. Compared with women with typical FPLD, the two sisters with atypical FPLD had less severe loss of sc fat from all the extremities and trunk and particularly from the gluteal region and medial parts of proximal thighs. Both types had similar excess of fat deposition in the neck, face, intraabdominal, and intermuscular regions. Women with atypical FPLD tended to have lower serum triglyceride and higher high density lipoprotein cholesterol concentrations. As exon 11 of LMNA does not comprise part of the lamin C-coding region, the R582H mutation affects only lamin A protein. Therefore, a unique phenotype of atypical FPLD may result from disrupted interaction of lamin A with other proteins and chromatin compared with typical FPLD, in which interaction of both lamins A and C may be disrupted.
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Garg A, Chren MM, Sands LP, Matsui MS, Marenus KD, Feingold KR, Elias PM. Psychological stress perturbs epidermal permeability barrier homeostasis: implications for the pathogenesis of stress-associated skin disorders. ARCHIVES OF DERMATOLOGY 2001; 137:53-9. [PMID: 11176661 DOI: 10.1001/archderm.137.1.53] [Citation(s) in RCA: 193] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND A large number of skin diseases, including atopic dermatitis and psoriasis, appear to be precipitated or exacerbated by psychological stress. Nevertheless, the specific pathogenic role of psychological stress remains unknown. In 3 different murine models of psychological stress, it was recently shown that psychological stress negatively impacts cutaneous permeability barrier function and that coadministration of tranquilizers blocks this stress-induced deterioration in barrier function. OBJECTIVES AND METHODS The relationship between psychological stress and epidermal permeability barrier function was investigated in 27 medical, dental, and pharmacy students without coexistent skin disease. Their psychological state was assessed with 2 well-validated measures: the Perceived Stress Scale and the Profile of Mood States. Barrier function was assessed simultaneously with the stress measures at periods of presumed higher stress (during final examinations) and at 2 assumed, lower stress occasions (after return from winter vacation [approximately 4 weeks before final examinations] and during spring vacation [approximately 4 weeks after final examinations]). RESULTS The subjects as a group demonstrated a decline in permeability barrier recovery kinetics after barrier disruption by cellophane tape stripping, in parallel with an increase in perceived psychological stress during the higher vs the initial lower stress occasions. During the follow-up, presumed lower stress period, the subjects again displayed lower perceived psychological stress scores and improved permeability barrier recovery kinetics, comparable to those during the initial lower stress period. Moreover, the greatest deterioration in barrier function occurred in those subjects who demonstrated the largest increases in perceived psychological stress. CONCLUSION These studies provide the first link between psychological status and cutaneous function in humans and suggest a new pathophysiological paradigm, ie, stress-induced derangements in epidermal function as precipitators of inflammatory dermatoses.
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