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Kotloff KL, Wasserman SS, Russ K, Shapiro S, Daniel R, Brown W, Frost A, Tabara SO, Shah K. Detection of genital human papillomavirus and associated cytological abnormalities among college women. Sex Transm Dis 1998; 25:243-50. [PMID: 9587175 DOI: 10.1097/00007435-199805000-00005] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND OBJECTIVES Human papillomavirus (HPV) is strongly implicated in the etiology of cervical neoplasia; however, the frequency, rate, and predictors of neoplastic progression are unknown. GOAL To measure the type-specific prevalence of cervical HPV and the rate of development of cytological abnormalities among a cohort of college women and to elucidate factors associated with acquisition of HPV DNA and progression to cytological abnormalities. STUDY DESIGN Women 18 to 40 years of age seeking routine gynecologic care at a university health center were enrolled in a cross-sectional study with prospective, longitudinal follow-up of a subset of women. Demographic and behavioral data were collected using a written questionnaire. HPV DNA was detected in cervical scrapes by polymerase chain reaction using L1 consensus primers and a generic and 25 type-specific probes, and cervical cytological abnormalities were identified by Papanicolaou's (Pap) smear. RESULTS HPV DNA was detected in 35% of the 414 women in the cross-sectional study; 66% of infections were with intermediate or high cancer risk HPV types. Multiple lifetime sex partners was an independent predictor of prevalent infection. Longitudinal analysis of 205 women showed that detection was transient (HPV DNA absent at follow-up) in 38% of the 84 women who were HPV-positive at enrollment. Persistent detection of the same HPV type at > or = 2 visits occurred in 14% of women and was significantly more common when intermediate or high cancer risk types were present. After 16 months of observation, 9% of HPV-infected women developed low-grade squamous intraepithelial lesions (SIL) and 5% developed high-grade SIL; the risk of incident SIL was 7.8-fold higher among women who had persistent HPV detection with the same type. CONCLUSIONS It was concluded that cervical HPV infection is highly prevalent among college women. Although most infections are caused by intermediate of high cancer risk types, few women (5%) developed high-grade SIL during 16 months of observation.
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Brook I, Yocum P, Shah K. Aerobic and anaerobic bacteriology of concurrent chronic otitis media with effusion and chronic sinusitis in children. ARCHIVES OF OTOLARYNGOLOGY--HEAD & NECK SURGERY 2000; 126:174-6. [PMID: 10680868 DOI: 10.1001/archotol.126.2.174] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To correlate the aerobic and anaerobic microbiologic findings of concurrent chronic otitis media with effusion and chronic maxillary sinusitis. METHODS Cultures were obtained from 32 children with concurrent chronic otitis media with effusion and maxillary sinusitis who underwent tympanostomy tube placement. RESULTS A total of 42 isolates, 24 aerobic and 18 anaerobic, were recovered from 30 patients; 27 were isolated from both sites, 4 from the ear only, and 11 from the sinus only. The most common isolates were Haemophilus influenzae (9 isolates), Streptococcus pneumoniae (n = 7), Prevotella species (n = 8), and Peptostreptococcus species (n = 6). Microbiological concordance between the ear and sinus was found in 22 (69%) of culture-positive patients. CONCLUSION The concordance in recovery of organisms in more than two thirds of the patients illustrates the common bacterial etiology between chronic otitis media with effusion and chronic sinusitis in children.
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Armamento-Villareal R, Aguirre L, Napoli N, Shah K, Hilton T, Sinacore DR, Qualls C, Villareal DT. Changes in thigh muscle volume predict bone mineral density response to lifestyle therapy in frail, obese older adults. Osteoporos Int 2014; 25:551-8. [PMID: 23892583 PMCID: PMC3903658 DOI: 10.1007/s00198-013-2450-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 06/14/2013] [Indexed: 12/14/2022]
Abstract
UNLABELLED We studied the relationships among strength, muscle mass, and bone mineral density (BMD) with lifestyle change. Lifestyle therapy consisted of exercise, diet, and diet plus exercise. Diet was by caloric restriction to induce and maintain a weight loss of 10 % from baseline body weight. Exercise attenuated weight loss-induced muscle and bone losses. Exercise improved strength despite muscle loss in patients on diet and exercise. Changes in strength did not correlate with changes in BMD. However, changes in thigh muscle volume correlated with, and predicted changes in hip BMD. INTRODUCTION Losses of hip BMD and lean body mass are major complications of lifestyle therapy in frail, obese older adults; however, the contribution of mechanical strain loss from muscle loss is poorly defined. We determined the effect of changes in thigh muscle volume and muscle strength on BMD in frail, obese older adults undergoing lifestyle therapy aimed at intentional weight loss with or without exercise. METHODS One hundred seven obese older adults were randomized to control, diet, exercise, and diet-exercise groups for 1 year. Thigh muscle volume was measured by magnetic resonance imaging, BMD by DXA, knee strength by dynamometry, total strength by one-repetition maximum (1-RM), and bone markers by immunoassay. RESULTS Thigh muscle volume decreased in the diet group (-6.2 ± 4.8 %) and increased in the exercise group (2.7 ± 3.1 %), while it was not significantly different from the control in the diet-exercise group. Changes in hip BMD followed similar pattern as those in thigh muscle volume. Knee extension and flexion increased in the exercise group (23 ± 20 %; 25 ± 19 %) and diet-exercise group (20 ± 19 %; 20.6 ± 27 %) but were unchanged in the control and diet groups. Changes in thigh muscle volume correlated with changes in hip BMD (r = 0.55, P = <0.001) and were an independent predictor of changes in hip BMD (β = 0.12, P = 0.03) in the multiple regression analyses after accounting for demographic factors and changes in weight and physical activity. There were no correlations between BMD changes and knee strength, 1-RM, and sclerostin changes. CONCLUSIONS Changes in thigh muscle volume predict hip BMD changes in obese older patients undergoing lifestyle therapy. The effect of exercise in attenuating thigh muscle loss when added to diet may in part account for the reduction in weight loss-induced bone loss in the diet-exercise group.
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Randomized Controlled Trial |
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Abstract
Between October, 1985 and May 1987, 29 children (mean age 22 +/- 22 months, range 2-54 months) with AIDS or ARC developed acute respiratory illness. The initial diagnostic procedure was flexible fiberoptic bronchoscopy, with bronchoalveolar lavage (BAL). BAL was positive for Pneumocystis carinii in 14 and for respiratory syncytial virus, Staphylococcus aureus, and Escherichia coli in 3 additional patients. Subsequent lung tissue analysis and/or clinical course suggested no false negative lavages. Complications possibly related to the procedure occurred in two patients. We find BAL an effective diagnostic technique in these patients, offering a less invasive alternative to open lung biopsy.
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Kumar RG, Shah K, Dubey RS. Salinity induced behavioural changes in malate dehydrogenase and glutamate dehydrogenase activities in rice seedlings of differing salt tolerance. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2000; 156:23-34. [PMID: 10908802 DOI: 10.1016/s0168-9452(00)00224-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The activities of malate dehydrogenase in whole tissue extract (NAD(+)-MDH) as well as in mitochondrial (NAD(+)-MDH) and chloroplastic (NADP(+)-MDH) preparations of aminating (NADH-GDH) and deaminating(NAD(+)-GDH) glutamate dehydrogenases were studied in two sets of rice cultivars differing in salt tolerance grown under moderate (7 dS m(-1)) and high (14 dS m(-1)) NaCl salinity levels. A contrasting response to salinity on enzyme activities was found between the sensitive and tolerant cultivars during a 5-20-day growth period of study. NaCl salinity in situ caused increase in all three MDH activities in salt tolerant cvs. CSR-1 and CSR-3 whereas in salt sensitive cvs. Ratna and Jaya 16-100% inhibition in activities was noted. Chloroplastic MDH was extremely sensitive to NaCl. In seedlings of salt tolerant cultivars concomitant increase in both aminating and deaminating GDH activities was observed with increase in salinity level, whereas in sensitive cultivars under higher salinity level decrease in GDH activity was noted. Under in vitro conditions NaCl concentration in the range 1-1000 mM caused gradual inhibition in MDH activity. With 400 mM NaCl in vitro, complete loss of mitochondrial and chloroplastic MDH activities was observed. GDH activity increased with increasing concentration of NaCl up to 200 mM NaCl and other salts in vitro and was inhibited thereafter. However 800 mM NaCl caused complete loss of deaminating GDH activity from sensitive cultivar but not from tolerant cultivar. Results suggest varying behaviour of MDH and GDH in two sets of rice cultivars differing in salt tolerance and that inhibition in the activities of dehydrogenases in salt sensitive rice cultivars due to salinity may be one of the possible reasons for decreased growth of rice plants under saline conditions.
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Kazlow PG, Shah K, Benkov KJ, Dische R, LeLeiko NS. Esophageal cryptosporidiosis in a child with acquired immune deficiency syndrome. Gastroenterology 1986; 91:1301-3. [PMID: 3758622 DOI: 10.1016/s0016-5085(86)80031-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Oral Candida and Candida esophagitis are common findings in patients with the acquired immune deficiency syndrome. The intestinal protozoan, Cryptosporidium, is known to cause gastrointestinal symptoms in these patients. We report a 2-yr-old child with acquired immune deficiency syndrome, who had oral candidiasis, dysphagia, and vomiting. Upper gastrointestinal endoscopy and esophageal biopsy led to a diagnosis of esophageal cryptosporidiosis. We recommend upper gastrointestinal endoscopy as a diagnostic tool in selected patients with acquired immune deficiency syndrome. This is in contradistinction to a previous report that concludes that endoscopy is not necessary in this setting.
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Case Reports |
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Ray-Chaudhuri A, Shah K, Porter RJ. The oral management of patients who have received radiotherapy to the head and neck region. Br Dent J 2014; 214:387-93. [PMID: 23619856 DOI: 10.1038/sj.bdj.2013.380] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/07/2012] [Indexed: 01/22/2023]
Abstract
Several thousand patients are diagnosed annually with head and neck cancer (HANC) in the United Kingdom. This represents a significant proportion of all cancers that are diagnosed and a common treatment modality for this is radiotherapy to the head and neck region. Radiotherapy can be highly successful in managing HANC but also has several side-effects in the oral cavity and associated structures. These sequelae present considerable short and long-term problems for dental professionals involved in the care of HANC suffers.
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Journal Article |
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Shah K. Research in brief: what do medical students know about autism? AUTISM : THE INTERNATIONAL JOURNAL OF RESEARCH AND PRACTICE 2001; 5:127-33. [PMID: 11706861 DOI: 10.1177/1362361301005002003] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although recent research indicates the importance of early recognition and intervention for children with autism, it is clear that many families remain very dissatisfied with the diagnostic process. In order to improve this situation, it is essential that primary care practitioners, such as GPs, are fully aware of the core symptoms of autism. The present study reports on autism awareness amongst 250 medical students at different stages of their training. Differences between first-year and fourth-year students were compared with respect to their knowledge of various aspects of autism, including diagnosis, cause, symptomatology, treatment and outcome. Fourth-year students were significantly more likely to respond correctly to questions related to diagnostic criteria and core symptoms. However no significant differences were found between first-year and fourth-year students for other aspects, such as possible causes, IQ profiles, prognosis and treatment. These findings suggest that more emphasis needs to be placed on teaching medical students about autism if diagnosis and access to intervention are to be improved.
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Bergeron C, Naghashfar Z, Canaan C, Shah K, Fu Y, Ferenczy A. Human papillomavirus type 16 in intraepithelial neoplasia (bowenoid papulosis) and coexistent invasive carcinoma of the vulva. Int J Gynecol Pathol 1987; 6:1-11. [PMID: 3032817 DOI: 10.1097/00004347-198703000-00001] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Tissues from two cases of bowenoid papulosis of the vulva with coexistent invasive squamous cell carcinoma were evaluated for the presence of human papillomaviruses (HPVs) and for nuclear DNA content. In both cases, HPV type 16 and nuclear aneuploidy were found in bowenoid papulosis as well as in invasive carcinoma. Patterns of hybridization suggested that the viral genome was integrated into the cellular genome in both bowenoid papulosis tissues as well as in invasive carcinoma tissues. These observations suggest that lesions designated as bowenoid papulosis may have invasive cancer potential. The term vulvar intraepithelial neoplasia seems to be more appropriate for HPV-16-containing aneuploid, intraepithelial lesions of the vulva.
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Case Reports |
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Brook I, Shah K. Bacteriology of adenoids and tonsils in children with recurrent adenotonsillitis. Ann Otol Rhinol Laryngol 2001; 110:844-8. [PMID: 11558761 DOI: 10.1177/000348940111000908] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Adenoids and tonsils electively removed from 25 children with a history of recurrent group A beta-hemolytic streptococci (GABHS) adenotonsillitis were cultured for aerobic and anaerobic bacteria. Two hundred twenty-four organisms (112 aerobes and facultatives, 110 anaerobes, and 2 Candida albicans) were isolated from the tonsils, and 229 (111 aerobes and facultatives and 118 anaerobes) were isolated from the adenoids. Mixed infection was present in all instances, with an average of 9.1 isolates per specimen. The predominant aerobes were Streptococcus sp, Haemophilus influenzae, and GABHS, and the prevalent anaerobes were Peptostreptococcus, Prevotella, and Fusobacterium spp. Beta-lactamase-producing bacteria were detected in 72 isolates recovered from 22 tonsils (88%) and in 74 isolates recovered from 21 adenoids (84%). Discrepancies in the organisms recovered were found between the tonsils and adenoids. Of the aerobic isolates, 20% were isolated only in tonsils and 18% only in adenoids. Of the anaerobes, 20% were found only in tonsils and 26% only in adenoids. This study demonstrates a polymicrobial aerobic-anaerobic flora in both adenoids and tonsils, and discrepancies in recovery of pathogens such as GABHS. The adenoids may serve as a potential source of tonsillitis caused by GABHS.
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Shah K, Vasileva D, Karadaghy A, Zustiak SP. Development and characterization of polyethylene glycol–carbon nanotube hydrogel composite. J Mater Chem B 2015; 3:7950-7962. [DOI: 10.1039/c5tb01047k] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Polyethylene–glycol–carbon nanotube composite was developed where carbon nanotubes altered the hydrogel mechanical and physical properties and aided neuronal cell viability.
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Scherl MP, Som PM, Biller HF, Shah K. Recurrent infiltrating lipoma of the head and neck. Case report and literature review. ARCHIVES OF OTOLARYNGOLOGY--HEAD & NECK SURGERY 1986; 112:1210-2. [PMID: 3755996 DOI: 10.1001/archotol.1986.03780110086014] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Lipomatous tumors with intramuscular infiltration are uncommon in the head and neck. Oral lipomas have been recorded in the literature; however, infiltration and recurrence have rarely been documented. We describe a case of an oral lipoma that did not have microscopic characteristics of malignancy, lipoblastomatosis, or atypia, but which showed intramuscular invasion and recurred twice after surgery. Although certain characteristics distinguish our case from congenital lipomatosis, the clinical picture is quite similar. Lipomas with intramuscular invasion uniformly tend to recur when they are not widely resected, whether in the trunk and extremities or in the head and neck. These lesions can rapidly enlarge and infiltrate local tissues, and they require wide resection with an attempt at preservation of important structures. Preoperatively, computed tomographic analysis allows a lipoma to be diagnosed by its low attenuation, and a grossly infiltrating tumor can be distinguished from the ordinary well-encapsulated lesion.
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Case Reports |
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Brook I, Yocum P, Shah K, Feldman B, Epstein S. Aerobic and anaerobic bacteriologic features of serous otitis media in children. Am J Otolaryngol 1983; 4:389-92. [PMID: 6140881 DOI: 10.1016/s0196-0709(83)80044-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Aspirates of serous ear fluids from 57 children were examined for aerobic and anaerobic bacteria. Bacterial growth was noted in 23 patients (40 per cent). Aerobic organisms only were recovered in 13 aspirates (57 per cent of the culture-positive aspirates); anaerobic bacteria in four (17 per cent); and mixed aerobic and anaerobic bacteria in six (26 per cent). A total of 45 bacterial isolates were recovered, accounting for 2.0 isolates per specimen (1.4 aerobes and 0.6 anaerobe). There were a total of 31 aerobic isolates, including Hemophilus influenzae (eight isolates), Staphylococcus aureus and Streptococcus pneumoniae (five of each), and Staphylococcus epidermidis and alpha-hemolytic streptococcus (four of each). Fourteen anaerobes were recovered, including anaerobic gram-positive cocci and Bacteroides melaninogenicus (five isolates each) and Propionibacterium acnes (three isolates).
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Shah K, Ouyang X, Besser RS. Microreaction for Microfuel Processing: Challenges and Prospects. Chem Eng Technol 2005. [DOI: 10.1002/ceat.200407140] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Dekhne AS, Shah K, Ducker GS, Katinas JM, Wong-Roushar J, Nayeen MJ, Doshi A, Ning C, Bao X, Frühauf J, Liu J, Wallace-Povirk A, O'Connor C, Dzinic SH, White K, Kushner J, Kim S, Hüttemann M, Polin L, Rabinowitz JD, Li J, Hou Z, Dann CE, Gangjee A, Matherly LH. Novel Pyrrolo[3,2- d]pyrimidine Compounds Target Mitochondrial and Cytosolic One-carbon Metabolism with Broad-spectrum Antitumor Efficacy. Mol Cancer Ther 2019; 18:1787-1799. [PMID: 31289137 PMCID: PMC6774887 DOI: 10.1158/1535-7163.mct-19-0037] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/05/2019] [Accepted: 07/03/2019] [Indexed: 01/06/2023]
Abstract
Folate-dependent one-carbon (C1) metabolism is compartmentalized into the mitochondria and cytosol and supports cell growth through nucleotide and amino acid biosynthesis. Mitochondrial C1 metabolism, including serine hydroxymethyltransferase (SHMT) 2, provides glycine, NAD(P)H, ATP, and C1 units for cytosolic biosynthetic reactions, and is implicated in the oncogenic phenotype across a wide range of cancers. Whereas multitargeted inhibitors of cytosolic C1 metabolism, such as pemetrexed, are used clinically, there are currently no anticancer drugs that specifically target mitochondrial C1 metabolism. We used molecular modeling to design novel small-molecule pyrrolo[3,2-d]pyrimidine inhibitors targeting mitochondrial C1 metabolism at SHMT2. In vitro antitumor efficacy was established with the lead compounds (AGF291, AGF320, AGF347) toward lung, colon, and pancreatic cancer cells. Intracellular targets were identified by metabolic rescue with glycine and nucleosides, and by targeted metabolomics using a stable isotope tracer, with confirmation by in vitro assays with purified enzymes. In addition to targeting SHMT2, inhibition of the cytosolic purine biosynthetic enzymes, β-glycinamide ribonucleotide formyltransferase and/or 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase, and SHMT1 was also established. AGF347 generated significant in vivo antitumor efficacy with potential for complete responses against both early-stage and upstage MIA PaCa-2 pancreatic tumor xenografts, providing compelling proof-of-concept for therapeutic targeting of SHMT2 and cytosolic C1 enzymes by this series. Our results establish structure-activity relationships and identify exciting new drug prototypes for further development as multitargeted antitumor agents.
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Research Support, N.I.H., Extramural |
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Nelson MD, Zhou E, Kiontke K, Fradin H, Maldonado G, Martin D, Shah K, Fitch DHA. A bow-tie genetic architecture for morphogenesis suggested by a genome-wide RNAi screen in Caenorhabditis elegans. PLoS Genet 2011; 7:e1002010. [PMID: 21408209 PMCID: PMC3048373 DOI: 10.1371/journal.pgen.1002010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Accepted: 01/04/2011] [Indexed: 11/19/2022] Open
Abstract
During animal development, cellular morphogenesis plays a fundamental role in determining the shape and function of tissues and organs. Identifying the components that regulate and drive morphogenesis is thus a major goal of developmental biology. The four-celled tip of the Caenorhabditis elegans male tail is a simple but powerful model for studying the mechanism of morphogenesis and its spatiotemporal regulation. Here, through a genome-wide post-embryonic RNAi-feeding screen, we identified 212 components that regulate or participate in male tail tip morphogenesis. We constructed a working hypothesis for a gene regulatory network of tail tip morphogenesis. We found regulatory roles for the posterior Hox genes nob-1 and php-3, the TGF-β pathway, nuclear hormone receptors (e.g. nhr-25), the heterochronic gene blmp-1, and the GATA transcription factors egl-18 and elt-6. The majority of the pathways converge at dmd-3 and mab-3. In addition, nhr-25 and dmd-3/mab-3 regulate each others' expression, thus placing these three genes at the center of a complex regulatory network. We also show that dmd-3 and mab-3 negatively regulate other signaling pathways and affect downstream cellular processes such as vesicular trafficking (e.g. arl-1, rme-8) and rearrangement of the cytoskeleton (e.g. cdc-42, nmy-1, and nmy-2). Based on these data, we suggest that male tail tip morphogenesis is governed by a gene regulatory network with a bow-tie architecture. Morphogenesis is a process in which cells change their shape and position to give rise to mature structures. Elucidation of the molecular basis of morphogenesis and its regulation would be a major step towards understanding organ formation and functionality. We focus on a powerful model for morphogenesis, the four-celled tail tip of the C. elegans male, which undergoes morphogenesis during the last larval stage. To comprehensively determine the components that regulate and execute male tail tip morphogenesis, we performed a genome-wide RNAi screen. We identified 212 genes that encode proteins with roles in fundamental processes like endocytosis, vesicular trafficking, cell–cell communication, and cytoskeletal organization. We determined the interactions among several of these genes to reconstruct a first draft of the genetic network underlying tail tip morphogenesis. The structure of this network is consistent with the "bow-tie architecture" that has been proposed to be universal and confers evolvability and robustness to biological systems. Bow-tie networks have a conserved core which is linked to numerous input and output components. Many components of the network underlying tail tip morphogenesis in C. elegans are conserved all the way to humans. Thus, understanding tail tip morphogenesis will inform us about morphogenesis in other organisms.
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Research Support, U.S. Gov't, Non-P.H.S. |
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Shah K, Wu H, Rana TM. Synthesis of uridine phosphoramidite analogs: reagents for site-specific incorporation of photoreactive sites into RNA sequences. Bioconjug Chem 1994; 5:508-12. [PMID: 7533002 DOI: 10.1021/bc00030a005] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The synthesis of three new photoactive RNA phosphoramidites, 5-bromouridine, 5-iodouridine, and O4-triazolouridine, is reported. The 5' OH of bromouridine and iodouridine were protected as dimethoxytrityl ether using dimethoxytrityl chloride and pyridine. Selective protection of 2' OH was achieved as the corresponding tert-butyldimethylsilyl ether. Protected ribonucleosides were converted to phosphoramidites using 2-cyanoethyl N,N-diisopropylchlorophosphoramidite. O4-Triazolouridine phosphoramidite monomer was prepared in one step from uridine phosphoramidite. These phosphoramidites were used to incorporate photoprobes at any chosen sites in the RNA sequences during chemical syntheses. The modified monomers were incorporated into RNA oligomers with coupling yields > 98%. After chemical synthesis, O4-triazolouridine was converted to 4-thiouridine by the addition of thiolacetic acid during standard deprotection methods. The extent of thiation and incorporation of modified nucleotides into RNA sequences were confirmed by nuclease digest, HPLC, and gel electrophoresis.
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Bonagura VR, Siegal FP, Abramson AL, Santiago-Schwarz F, O'Reilly ME, Shah K, Drake D, Steinberg BM. Enriched HLA-DQ3 phenotype and decreased class I major histocompatibility complex antigen expression in recurrent respiratory papillomatosis. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1994; 1:357-60. [PMID: 7496977 PMCID: PMC368263 DOI: 10.1128/cdli.1.3.357-360.1994] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Respiratory papillomas, caused by human papillomaviruses, are benign tumors that recur following removal. We evaluated immune function and major histocompatibility complex (MHC) phenotype and expression in these patients. MHC-independent immune function appeared normal. The frequency of peripheral blood MHC class II phenotypes was highly enriched for DQ3 and DR11, one split of DR5. Class I MHC antigen expression on papilloma tissue was markedly reduced. Together, these phenomena may facilitate papillomavirus evasion of the cellular immune response.
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research-article |
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Cook JV, Kyriou JC, Pettet A, Fitzgerald MC, Shah K, Pablot SM. Key factors in the optimization of paediatric X-ray practice. Br J Radiol 2001; 74:1032-40. [PMID: 11709469 DOI: 10.1259/bjr.74.887.741032] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Justification of radiological requests, standardization of procedures and optimization of protection measures are key principles in the protection of individuals exposed to ionizing radiation for diagnostic purposes. Nowhere is this more pertinent than in the imaging of children and, following the recent introduction of the Ionising Radiation (Medical Exposure) Regulations, there is now a regulatory requirement for diagnostic radiology departments to demonstrate compliance with these principles. A study was undertaken to compare all aspects of paediatric radiological practice at two specialist and two non-specialist centres. An initial study involved analysis of nearly 3000 patient doses. The second phase of the project involved assessment of referral criteria, radiographic technique and approximately 100 radiographs at each centre by two consultant paediatric radiologists. While all radiographs were found to be diagnostically acceptable, major differences in technique were evident, reflecting the disparity in experience between staff at the specialist and non-specialist centres. The large number of sub-optimum films encountered at the latter suggests that there is a need for specific training of less experienced radiographic and clinical staff.
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Heselmeyer K, du Manoir S, Blegen H, Friberg B, Svensson C, Schröck E, Veldman T, Shah K, Auer G, Ried T. A recurrent pattern of chromosomal aberrations and immunophenotypic appearance defines anal squamous cell carcinomas. Br J Cancer 1997; 76:1271-8. [PMID: 9374370 PMCID: PMC2228157 DOI: 10.1038/bjc.1997.547] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Squamous cell carcinomas of the anus are rare neoplasias that account for about 3% of large bowel tumours. Infections with human papillomaviruses are frequently detected in these cancers, suggesting that pathogenic pathways in anal carcinomas and in carcinomas of the uterine cervix are similar. Little is known regarding recurrent chromosomal aberrations in this subgroup of squamous cell carcinomas. We have applied comparative genomic hybridization to identify chromosomal gains and losses in 23 cases of anal carcinomas. A non-random copy number increase of chromosomes 17 and 19, and chromosome arm 3q was observed. Consistent losses were mapped to chromosome arms 4p, 11q, 13q and 18q. A majority of the tumours were aneuploid, and most of them showed increased proliferative activity as determined by staining for Ki-67 antigen. p53 expression was low or undetectable, and expression of p21/WAF-1 was increased in most tumours. Sixteen cancers were satisfactorily tested for the presence of HPV by consensus L1-primer polymerase chain reaction; nine were HPV positive, of which eight were positive for HPV 16.
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Blegen H, Einhorn N, Sjövall K, Roschke A, Ghadimi BM, McShane LM, Nilsson B, Shah K, Ried T, Auer G. Prognostic significance of cell cycle proteins and genomic instability in borderline, early and advanced stage ovarian carcinomas. Int J Gynecol Cancer 2000; 10:477-487. [PMID: 11240718 DOI: 10.1046/j.1525-1438.2000.00077.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Disturbed cell cycle-regulating checkpoints and impairment of genomic stability are key events during the genesis and progression of malignant tumors. We analyzed 80 epithelial ovarian tumors of benign (n = 10) and borderline type (n = 18) in addition to carcinomas of early (n = 26) and advanced (n = 26) stages for the expression of Ki67, cyclin A and cyclin E, p21WAF-1, p27KIP-1 and p53 and correlated the results with the clinical course. Genomic instability was assessed by DNA ploidy measurements and, in 35 cases, by comparative genomic hybridization. Overexpression of cyclin A and cyclin E was observed in the majority of invasive carcinomas, only rarely in borderline tumors and in none of the benign tumors. Similarly, high expression of p53 together with undetectable p21 or loss of chromosome arm 17p were frequent events only in adenocarcinomas. Both borderline tumors and adenocarcinomas revealed a high number of chromosomal gains and losses. However, regional chromosomal amplifications were found to occur 13 times more frequently in the adenocarcinomas than in the borderline tumors. The expression pattern of low p27 together with high Ki67 was found to be an independent predictor of poor outcome in invasive carcinomas. The results provide a link between disturbed cell cycle regulatory proteins, chromosomal aberrations and survival in ovarian carcinomas.
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Finer S, Robb P, Cowan K, Daly A, Shah K, Farmer A. Setting the top 10 research priorities to improve the health of people with Type 2 diabetes: a Diabetes UK-James Lind Alliance Priority Setting Partnership. Diabet Med 2018; 35:862-870. [PMID: 29485717 PMCID: PMC6032840 DOI: 10.1111/dme.13613] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/22/2018] [Indexed: 11/28/2022]
Abstract
AIMS To describe processes and outcomes of a priority setting partnership to identify the 'top 10 research priorities' in Type 2 diabetes, involving people living with the condition, their carers, and healthcare professionals. METHODS We followed the four-step James Lind Alliance Priority Setting Partnership process which involved: gathering uncertainties using a questionnaire survey distributed to 70 000 people living with Type 2 diabetes and their carers, and healthcare professionals; organizing the uncertainties; interim priority setting by resampling of participants with a second survey; and final priority setting in an independent group of participants, using the nominal group technique. At each step the steering group closely monitored and guided the process. RESULTS In the first survey, 8227 uncertainties were proposed by 2587 participants, of whom 18% were from black, Asian and minority ethnic groups. Uncertainties were formatted and collated into 114 indicative questions. A total of 1506 people contributed to a second survey, generating a shortlist of 24 questions equally weighted to the contributions of people living with diabetes and their carers and those of healthcare professionals. In the final step the 'top 10 research priorities' were selected, including questions on cure and reversal, risk identification and prevention, and self-management approaches in Type 2 diabetes. CONCLUSION Systematic and transparent methodology was used to identify research priorities in a large and genuine partnership of people with lived and professional experience of Type 2 diabetes. The top 10 questions represent consensus areas of research priority to guide future research, deliver responsive and strategic allocation of research resources, and improve the future health and well-being of people living with, and at risk of, Type 2 diabetes.
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Shah K, Daniel R, Madden D, Stagno S. Serological investigation of BK papovavirus infection in pregnant women and their offspring. Infect Immun 1980; 30:29-35. [PMID: 6254883 PMCID: PMC551272 DOI: 10.1128/iai.30.1.29-35.1980] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Paired sera from 150 pregnant women and 387 umbilical cord sera were tested for BK virus (BKV) antibodies. The hemagglutination inhibition, neutralization, and indirect immunofluorescence tests were employed for the detection of antibodies. Treatment of serum with anti-gamma Fc and tests of immunoglobulin M (IgM) fractions for antibodies were utilized as required to detect and validate the presence of virus-specific IgM. The BKV antibody prevalence in the sera collected at the time of the first prenatal visit was 75% by hemagglutination inhibition and 91% by neutralization tests. A total of 95% of the women had antibodies by at least one of the three serological tests. Five of 100 women with normal pregnancies exhibited BKV activity during pregnancy as evidenced by a greater than fourfold rise in BKV hemagglutination inhibition antibody titers and acquisition of BKV-specific IgM. The antibody rise occurred in the younger women and appeared to be a result of reactivation of the virus rather than of primary infection. Two instances of possible recent BKV infections were identified. BKV-specific IgM was not detected in any of the 387 umbilical cord sera which included three specimens from infants born to mothers with definite or probable BKV activity during pregnancy and 50 specimens with IgM levels of > 20 mg/100 ml. The results indicate that few women in the child-bearing age are nonimmune to BKV and that, although reactivation of infection occurs in pregnancy, congenital transmission of the virus either does not occur or is rare.
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Shah K, Varna VP, Sharma U, Mavalankar D. Does vitamin D supplementation reduce COVID-19 severity?: a systematic review. QJM 2022; 115:665-672. [PMID: 35166850 PMCID: PMC9383458 DOI: 10.1093/qjmed/hcac040] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/04/2022] [Accepted: 02/05/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The evidence regarding the efficacy of vitamin D supplementation in reducing severity of COVID-19 is still insufficient. This is partially due to the lack of primary robust trial-based data and heterogeneous study designs. AIM This evidence summary, aims to study the effect of vitamin D supplementation on morbidity and mortality in hospitalized COVID-19 patients.Design: Evidence summary of systematic reviews. METHODS For this study, systematic reviews and meta-analysis published from December 2019 to January 2022 presenting the impact of vitamin D supplementation on COVID-19 severity were screened and selected from PubMed and Google scholar. After initial screening, 10 eligible reviews were identified and quality of included reviews were assessed using AMSTAR and GRADE tools and overlapping among the primary studies used were also assessed. RESULTS The number of primary studies included in the systematic reviews ranged from 3 to 13. Meta-analysis of seven systematic reviews showed strong evidence that vitamin D supplementation reduces the risk of mortality (Odds ratio: 0.48, 95% CI: 0.346-0.664; P < 0.001) in COVID patients. It was also observed that supplementation reduces the need for intensive care (Odds ratio: 0.35; 95%CI: 0.28-0.44; P < 0.001) and mechanical ventilation (Odds ratio: 0.54; 95% CI: 0.411-0.708; P < 0.001) requirement. The findings were robust and reliable as level of heterogeneity was considerably low. However the included studies were of varied quality. Qualitative analysis showed that supplements (oral and IV) are well tolerated, safe and effective in COVID patients. CONCLUSION The findings of this study show that vitamin D supplementation is effective in reducing the COVID-19 severity. Hence, vitamin D should be recommended as an adjuvant therapy for COVID-19.However, more robust and larger trials are required to substantiate it further.
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Morley MJ, Shah K, Bradshaw CM, Szabadi E. DSP4 and Herrnstein's equation: further evidence for a role of noradrenaline in the maintenance of operant behaviour by positive reinforcement. Psychopharmacology (Berl) 1988; 96:551-6. [PMID: 3149780 DOI: 10.1007/bf02180039] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The effect of the selective noradrenaline neurotoxin DSP4 on steady-state operant behaviour was examined using a quantitative behavioural paradigm based on Herrnstein's (1970) equation, which defines a hyperbolic relationship between steady-state response rate and reinforcement frequency in variable-interval schedules. Eleven rats received injections of DSP4 (two doses of 50 mg/kg, intraperitoneally), and 12 rats received injections of the vehicle alone. The rats were trained to steady state in a series of six variable-interval schedules of sucrose reinforcement, affording scheduled reinforcement frequencies of 4-360 reinforcers per hour. Herrnstein's equation was fitted to the data obtained from each rat and to the averaged data obtained from the two groups. The value of KH (the parameter expressing the reinforcement frequency needed to maintain the half-maximal response rate) was higher in the DSP4-treated rats than in the control rats; the value of Rmax (the parameter expressing the maximum response rate) did not differ significantly between the two groups. At the end of the behavioural experiment the rats were sacrificed for determination of the concentrations of catecholamines in the brain by high-performance liquid chromatography. The levels of noradrenaline in the parietal cortex, hippocampus and cerebellum of the DSP4-treated rats were less than 20% of those of the control rats. The results provide further evidence that central noradrenergic neurones are involved in the maintenance of operant behaviour by positive reinforcement.
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