Biomedical subjects
Publications and source records attributed to A Lal.
Retroperitoneal plexiform neurofibroma is a rare finding in neurofibromatosis type I, or von Recklinghausen's disease. A case of retroperitoneal plexiform neurofibroma mimicking psoas abscesses is reported here with its CT and MRI findings.
Summary Intraductal pancreatic calculi are a rare association in patients with choledochal cyst (CC). Reported herein is a retrospective analysis of the data on pancreatic calculi in 37 patients (10 children and 27 adults) who underwent endoscopic retrograde cholangiopancreatography (ERCP) for CC over a period of 15 years. Five patients (one child and four adults) were identified as having intraductal pancreatic calculi. Three had type I and two had type IV CC. Four underwent cyst excision. No intervention was carried out for the pancreatic calculi. There was no evidence of pancreatic insufficiency on follow up and none had recurrence of abdominal pain. One patient died of cholangitis, which was the initial presenting problem. Intraductal pancreatic calculi associated with CC, although uncommon, are not rare and are not always symptomatic.
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PURPOSE: To evaluate the various radiological abnormalities in patients with proven esophageal tuberculosis. MATERIAL AND METHODS: The case records of 23 patients with proven esophageal tuberculosis were evaluated retrospectively for various radiological abnormalities. Twenty-two patients had secondary involvement of esophagus in the form of direct extension of mediastinal and pulmonary tuberculosis or spinal tuberculosis. Only 1 patient had primary involvement of the esophagus with no evidence of disease elsewhere. The diagnosis was confirmed by endoscopic and CT-guided biopsy/aspiration cytology in 7 and 6 cases, respectively. Diagnosis was made on the basis of surgical biopsy of lymph node and autopsy in 1 patient each. In the remaining 8 patients the diagnosis was based on radiological and endoscopic findings and the response to antituberculous treatment. RESULTS: Chest radiography (CXR) was abnormal in 65% patients. While the findings were non-conclusive for esophageal tuberculosis, characteristic lesions of tuberculosis in lungs or spine were suggestive of tuberculous etiology. In 15 patients, CT of the chest confirmed the corresponding CXR findings and also showed additional findings of mediastinal lymphadenopathy when CXR was normal. Fourteen patients showed mediastinal lymphadenopathy on CT of the chest. In all these patients, more than one group of lymph nodes was involved. The characteristic hypodense center of lymph nodes suggestive of tuberculosis was seen in 12 patients. Radiological abnormalities seen in barium swallow examination were extrinsic compression, traction diverticula, strictures, sinus/fistulous tracts, kinking and pseudotumor mass of esophagus in decreasing order of frequency. The middle third of the esophagus was found to be the most frequent site of involvement.
BACKGROUND: A prototype paediatric propofol target-controlled infusion (TCI) system, the 'Paedfusor' has been developed. This system incorporates a paediatric pharmacokinetic data set and algorithm specific for children in a Graseby 3500 anaesthesia syringe driver. In this study we have evaluated the accuracy of the Paedfusor TCI system in children who underwent either cardiac surgery or cardiac catheterization procedures. METHODS: Twenty-nine children aged 1-15 yr were investigated. General anaesthesia was provided using propofol administered by the Paedfusor system. Accuracy of the system was evaluated by obtaining up to 9 arterial samples for measurement of propofol concentration both during anaesthesia and in the recovery period. Measured arterial propofol concentrations were then compared with values calculated by the Paedfusor. RESULTS: The predictive indices of median performance error (MDPE), and median absolute performance error (MDAPE) of the Paedfusor system were found to be 4.1% and 9.7%, respectively and the median value for wobble was 8.3%. These values are much better than those found with the adult 'Diprifusor' system. CONCLUSION: The Paedfusor performance was found to be within the accepted limits for use as a TCI system.
Hepatoblastoma, a childhood tumor of the liver, is composed of epithelial and mesenchymal elements in varying proportions and at various stages of differentiation. The epithelial element recapitulates the stages of hepatocyte development from the primitive blastema through embryonal hepatocytes to fetal hepatocytes. The blastemal or undifferentiated cells have been postulated to represent neoplastic hepatocyte progenitor cells. In this study, we examine the immunophenotype of the various epithelial cells of hepatoblastoma with special emphasis on the small undifferentiated cell component and compare it with that of adult hepatocytes and hepatic stem (oval) cells. Putative stem cells in the liver can express all of the following markers: alpha-feto protein, CK19 (OV-6), chromogranin A, Bcl-2, HepPar-1, and alpha1 microglobulin. The latter, like alpha-feto protein, is a plasma protein synthesized by hepatocytes. Both alpha1 microglobulin and HepPar-1 are expressed in fetal liver cells as early as 7 weeks of intrauterine life. They are also expressed in hepatocellular carcinoma and in hepatocytic cell lines derived from normal fetal or adult liver. Formalin-fixed, paraffin-embedded archival tissues from 10 predominantly epithelial hepatoblastomas were immunostained with antibodies directed against CD 34, alpha1 microglobulin, Bcl-2, HepPar 1, and CK19 using the avidin-biotin-peroxidase method. The undifferentiated small cell component did not express any of the markers studied, namely, Bcl-2, HepPar-1, alpha(1) microglobulin, CD34, or CK19. Hepatocyte-like cells were alpha1 microglobulin- and HepPar-1-positive, with the intensity of staining correlating with the degree of hepatocytic differentiation. Bcl-2 expression was restricted to areas of ductular differentiation. CK19 was detected in foci that showed duct formation. The small cells of hepatoblastoma did not express HepPar-1, Bcl-2, CK19, alpha1 microglobulin, or CD34, markers that characterize the immunophenotype of hepatic stem cells ("oval" cells). Thus, this observation raises the following questions: (1) is "hepatoblastoma" a misnomer? (2) is the expression of tumor antigens dysregulated in hepatoblastoma? (3) does the liver have two different types of progenitor cells, oval cells and blastemal cells, with differing immunophenotypes? and (4) do the blastemal cells, rather than oval cells, represent the more primitive progenitor cells of the liver?
OBJECTIVE: To compare the quality and funding source of studies concluding a negative economic impact of smoke-free policies in the hospitality industry to studies concluding no such negative impact. DATA SOURCES: Researchers sought all studies produced before 31 August 2002. Articles published in scientific journals were located with Medline, Science Citation Index, Social Sciences Citation Index, Current Contents, PsychInfo, Econlit, and Healthstar. Unpublished studies were located from tobacco company websites and through internet searches. STUDY SELECTION: 97 studies that made statements about economic impact were included. 93% of the studies located met the selection criteria as determined by consensus between multiple reviewers. DATA EXTRACTION: Findings and characteristics of studies (apart from funding source) were classified independently by two researchers. A third assessor blind to both the objective of the present study and to funding source also classified each study. DATA SYNTHESIS: In studies concluding a negative impact, the odds of using a subjective outcome measure was 4.0 times (95% confidence interval (CI) 1.4 to 9.6; p = 0.007) and the odds of not being peer reviewed was 20 times (95% CI 2.6 to 166.7; p = 0.004) that of studies concluding no such negative impact. All of the studies concluding a negative impact were supported by the tobacco industry. 94% of the tobacco industry supported studies concluded a negative economic impact compared to none of the non-industry supported studies. CONCLUSION: All of the best designed studies report no impact or a positive impact of smoke-free restaurant and bar laws on sales or employment. Policymakers can act to protect workers and patrons from the toxins in secondhand smoke confident in rejecting industry claims that there will be an adverse economic impact.
Although Cryptosporidium has been found worldwide in molluscan shellfish from waters contaminated with human and animal feces, little or no related environmental data have been obtained. In the present study, oysters ( Crassostrea virginica) were collected eight times over 3 years from seven sites in the Chesapeake Bay or its tributaries, with accompanying data on water temperature, salinity, rainfall, and streamflow. Oyster gill washings were examined by immunofluorescence microscopy for Cryptosporidium oocysts. Of 1,590 oysters collected, 19.6% had detectable oocysts. Of 53 collections, oocysts were detected 81% of the time. The time when the greatest percentage of oysters at most sites had detectable oocysts coincided with the time of greatest weekly and monthly rainfall, greatest streamflow into the Bay, and lowest water temperatures. In 28% of 53 collections, C. parvum genotypes 1 and 2 and C. baileyi were identified by PCR and gene sequencing. Oocyst infectivity was confirmed from 37.5% of 40 collections by initiating C. parvum genotype 2 infections in mice.
The method of resonant ultrasonic spectroscopy (RUS) was evaluated for bovine bone and compared with the traditional wave transmission ultrasound method. In RUS, the resonance structure of a cubic or rectangular specimen is scanned. For some low-damping materials, a single measurement yields sufficient resonant frequencies to determine all of the anisotropic elastic constants. Bone has a high viscoelastic damping at ultrasonic frequency. Consequently, resonance peaks of a cubic specimen tend to overlap. Therefore, the usual RUS method must be modified for application to bone; even so, one cannot obtain all the elastic constants. Concurrent studies with transmission ultrasound were conducted. Results were used to generate a map of the elastic moduli vs position along the bone axis. Stiffness was greatest in the mid part of the bovine femur.
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Researchers working collaboratively in Brazil and the United States have assembled an International Database of Cancer Gene Expression. Several strategies have been employed to generate gene expression data including expressed sequence tags (ESTs), serial analysis of gene expression (SAGE), and open reading-frame expressed sequence tags (ORESTES). The database contains six million gene tags that reflect the gene expression profiles in a wide variety of cancerous tissues and their normal counterparts. All sequences are deposited in the public databases, GenBank and SAGEmap. A suite of informatics tools was designed to facilitate in silico analysis of the gene expression datasets and are available through the NCI Cancer Genome Anatomy Project web site (http://cgap.nci.nih.gov).
We report a 45-year-old man who presented with localized skeletal involvement as the initial manifestation of hairy cell leukemia (HCL) without abnormal peripheral blood counts, splenomegaly or posterior iliac crest bone marrow involvement. The patient presented with pain in the left thigh. A plain radiograph was normal, but a magnetic resonance imaging (MRI) of this region showed a marrow-based lesion occupying the left femur neck, left proximal femur and both greater trochanters. Histological and immunophenotypic examination revealed a focal infiltrate of HCL. Skeletal involvement by HCL without co-existing bone marrow involvement should be included in the differential diagnosis of bone marrow lesions where metastatic tumor is the foremost consideration.
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BACKGROUND: Perforation and fistulae, though uncommon, are serious complications of gastrointestinal tuberculosis. Patients with acute tuberculous perforation are subjected to surgery, whereas localized perforation and fistulae with subtle clinical signs are detected by barium contrast examination. There has been no report on radiological series regarding the incidence of perforation and fistulae, detected by barium contrast studies. MATERIAL AND METHODS: A retrospective analysis of barium contrast studies of 684 proven cases of gastrointestinal tuberculosis seen over a period of 15 years was done to detect the incidence of perforation and fistulae. RESULTS: Fifty-two patients (7.6%) with localized perforation and fistulae were seen. Twenty-eight patients had evidence of perforation, and 24 patients showed fistulae formation. The most common site of perforation and fistulae was the small bowel followed by the colon. Associated abnormalities noted were ulcerations, strictures, nodular filling defects and extrinsic compression. CONCLUSION: Perforation and fistulae along with other associated abnormalities of the gastrointestinal tract are suggestive of tuberculosis, particularly in a population predisposed to tuberculous infection.
BACKGROUND: The presence of hypoxic regions within solid tumors is associated with a more malignant tumor phenotype and worse prognosis. To obtain a blood supply and protect against cellular damage and death, oxygen-deprived cells in tumors alter gene expression, resulting in resistance to therapy. To investigate the mechanisms by which cancer cells adapt to hypoxia, we looked for novel hypoxia-induced genes. METHODS: The transcriptional response to hypoxia in human glioblastoma cells was quantified with the use of serial analysis of gene expression. The time course of gene expression in response to hypoxia in a panel of various human tumor cell lines was measured by real-time polymerase chain reaction. Hypoxic regions of human carcinomas were chemically marked with pimonidazole. Immunohistochemistry and in situ hybridization were used to examine gene expression in the tumor's hypoxic regions. RESULTS: From the 24 504 unique transcripts expressed, 10 new hypoxia-regulated genes were detected-all induced, to a greater extent than vascular endothelial growth factor, a hypoxia-induced mitogen that promotes blood vessel growth. These genes also responded to hypoxia in breast and colon cancer cells and were activated by hypoxia-inducible factor 1, a key regulator of hypoxic responses. In tumors, gene expression was limited to hypoxic regions. Induced genes included hexabrachion (an extracellular matrix glycoprotein), stanniocalcin 1 (a calcium homeostasis protein), and an angiopoietin-related gene. CONCLUSIONS: We have identified the genes that are transcriptionally activated within hypoxic malignant cells, a crucial first step in understanding the complex interactions driving hypoxia response. Within our catalogue of hypoxia-responsive genes are novel candidates for hypoxia-driven angiogenesis.
We have analyzed 75 isolates of Plasmodium falciparum, collected in Venezuela during both the dry (November) and rainy (May-July) seasons, with a range of genetic markers including antigen genes and 14 random amplified polymorphic DNA (RAPD) primers. Thirteen P. falciparum stocks from Kenya and four other Plasmodium species are included in the analysis for comparison. Cross-hybridization shows that the 14 RAPD primers reveal 14 separate regions of the parasite's genome. The P. falciparum isolates are a monophyletic clade, significantly different from the other Plasmodium species. We identify three RAPD characters that could be useful as "tags" for rapid species identification. The Venezuelan genotypes fall into two discrete genetic subdivisions associated with either the dry or the rainy season; the isolates collected in the rainy season exhibit greater genetic diversity. There is significant linkage disequilibrium in each seasonal subsample and in the full sample. In contrast, no linkage disequilibrium is detected in the African sample. These results support the hypothesis that the population structure of P. falciparum in Venezuela, but not in Africa, is predominantly clonal. However, the impact of genetic recombination on Venezuelan P. falciparum seems higher than in parasitic species with long-term clonal evolution like Trypanosoma cruzi, the agent of Chagas' disease. The genetic structure of the Venezuelan samples is similar to that of Escherichia coli, a bacterium that propagates clonally, with occasional genetic recombination.
OBJECTIVE: To evaluate compliance with a legislative ban on smoking inside restaurants by comparing smoking in Sydney restaurants (where it is legally banned) with smoking in Melbourne restaurants (not subject to a legal ban). DESIGN AND PARTICIPANTS: Unobtrusive observational study of restaurant patrons, and interviews with restaurant staff, carried out by 159 volunteers. SETTING: 78 Sydney restaurants with smoke-free indoor environments (as required by legislation) and 81 Melbourne restaurants not subject to legislation preventing smoking. The study took place from 20-31 October 2000. INTERVENTION: Legislation to ban smoking in indoor areas of restaurants was introduced in New South Wales in September 2000 (about six weeks before our study). OUTCOMES: Observed incidents of smoking inside restaurants; staff attitudes to the ban; customer satisfaction as indicated by comments to staff; staff perceptions of restaurant patronage. RESULTS: No restaurant patrons were seen smoking in 78 Sydney restaurants during 156 hours of observation of 2,646 diners, compared with 176 smokers among 3,014 Melbourne diners over 154 hours of observation. Thirty-one per cent (24/78) of Sydney restaurants had experienced smokers attempting to smoke indoors after the legislation was introduced; 6% (5/78) reported instances of smokers refusing to stop smoking when asked; 79% (62/78) of restaurants had received favourable comments from patrons about the smoke-free law; 81% (63/78) of restaurant staff interviewed either supported or strongly supported the law. Since introduction of the legislation, 76% of restaurants reported normal trade, 14% increased trade, and 9% reduced trade. CONCLUSIONS: Smoke-free restaurants do not require "smoking police" to enforce bans, present few ongoing difficulties for staff, attract many more favourable than unfavourable comments from patrons, and do not adversely affect trade.
Submicroscopic evidence of persistent minimal residual disease (MRD) in first remission bone marrow samples from children with acute lymphoblastic leukaemia (ALL) indicates a high risk of clinical relapse. Since microscopic evidence of leukaemic lymphoblasts is often present in the peripheral blood in the weeks before clinical presentation at diagnosis or relapse, peripheral blood may be used instead of bone marrow to detect MRD in ALL patients. We examined a median of 0.165 microg (from 1.0-2.0x10(4)cells) genomic DNA from archived peripheral blood smears collected 8-16 months prior to clinical relapse in eight children with ALL for evidence of MRD. We used the polymerase chain reaction and primers designed to identify clonal antigen receptor gene rearrangements. Among the seven patients with bone marrow relapse, MRD was detected at a median of 1.2 months (0-8 months) prior to clinical relapse, indicating that MRD in the peripheral blood may be a late event in the course of leukaemic relapse. A prospective MRD study in ALL patients analysing larger numbers of peripheral blood cells will be needed to evaluate the utility of peripheral blood over bone marrow for MRD testing in childhood ALL.