Computed tomography virtual bronchoscopy: normal variants, pitfalls, and spectrum of common and rare pathology.

A broad spectrum of pathologies that involve the laryngotracheobronchial airway and imaging plays a crucial role in evaluating these abnormalities. Computed tomography with virtual bronchoscopy has been found to be very helpful in defining the location, extent, and nature of these lesions, and is increasingly being used even in patients with contraindications for fiberoptic bronchoscopy and laryngoscopy. Ionizing radiation, associated with virtual bronchoscopy, can be minimized by using low-dose multidetector computed tomography and hybrid iterative reconstruction techniques. Furthermore, retrospectively generated virtual bronchoscopy from a routinely acquired computed tomography data set eliminates additional cost and radiation. In the future, virtual bronchoscopy assisted with advanced navigational techniques will broaden the diagnostic and therapeutic landscape. This article presents the characteristic features of common and rare laryngotracheobronchial pathologies seen with virtual bronchoscopy.

Genetic enhancement of host plant-resistance of the Lalat cultivar of rice against bacterial blight employing marker-assisted selection.

To incorporate durable resistance against bacterial blight, a major disease rice, three resistance genes, xa 5, xa13 and Xa21, from IRBB 60 were transferred through marker-assisted backcrossing using RG 556, RG 136 and pTA248 markers linked to the three genes to supplement the Xa4 gene present in Lalat, a popular rice cultivar. Effective selection enabled the transfer in three back-crosses and a generation of selfing and background selection employing morphological and grain quality traits and molecular markers, led to >90 % recovery of the recurrent parental genome. The gene pyramids exhibited high levels of resistance against the pathogen in multi-location evaluation trials conducted over several locations of bacterial blight in India. IL-2 (CRMAS2621-7-1), a gene pyramid, was identified as being promising for several endemic regions of bacterial blight and was released as Improved Lalat in one of the identified regions. The success of the study demonstrates the vast potential of marker-assisted selection for gene stacking and recovery of the parental genome with high precision.

Residues of the minimal sequence of G0S2 collectively contribute to ATGL inhibition while C-and N-terminal extensions promote binding to ATGL.

The protein encoded by the G0/G1 switch gene 2 (G0S2) is a potent inhibitor of adipose triglyceride lipase (ATGL) and thus an important regulator of intracellular lipolysis. Since dysfunction of lipolysis is associated with metabolic diseases including diabetes and obesity, inhibition of ATGL is considered a therapeutic strategy. G0S2 interacts with ATGL's patatin-domain to mediate non-competitive inhibition, however atomic details of the inhibition mechanism are incompletely understood. Sequences of G0S2 from higher organisms show a highly conserved N-terminal part, including a hydrophobic region covering amino acids 27 to 42. We show that predicted G0S2 orthologs from platypus, chicken and Japanese rice-fish are able to inhibit human and mouse ATGL, emphasizing the contribution of conserved amino acid to ATGL inhibition. Our site directed mutagenesis and truncation studies give insights in the protein-protein interaction on a per-residue level. We determine that the minimal sequence required for ATGL inhibition ranges from amino acids 20 to 44. Residues Y27, V28, G30, A34 G37, V39 or L42 within this sequence play a substantial role in ATGL inhibition. Furthermore, we show that unspecific interactions of the N-terminal part (amino acids 20-27) of the minimal sequence facilitate the interaction to ATGL. Our studies also demonstrate that full-length G0S2 shows higher tolerance to specific single amino acid exchanges in the hydrophobic region due to the stronger contributions of unspecific interactions. However, exchanges of more than one amino-acid in the hydrophobic region also result in the loss of function as ATGL inhibitor even in the full-length protein.

Patients with inflammatory bowel disease may have a transforming growth factor-beta-, interleukin (IL)-2- or IL-10-deficient state induced by intrinsic neutralizing antibodies.

Ulcerative colitis (UC) and Crohn's disease (CD) are considered to be immunologically mediated disorders that share certain features with murine models of colitis. Whether any of these models are physiologically relevant to the human condition remains controversial. The hypothesis is that increased amounts of antibodies neutralizing transforming growth factor (TGF)-beta, interleukin (IL)-2 or IL-10 create a relative immunodeficient state in inflammatory bowel disease (IBD) that predisposes to disease. To evaluate this, serum samples from patients with UC or CD and from normal healthy individuals were studied by enzyme-linked immunosorbent assays. Antibodies recognizing TGF-beta were most prevalent in UC (P<0.01); anti-IL-10 antibodies were elevated in CD (P<0.05), while anti-IL-2 antibodies were the same for all three groups. Importantly, the percentage of IBD patients with at least one of the antibody levels greater than any control value was 30% for UC and 33% for CD. To verify the presence of these antibodies, immobilized TGF-beta was exposed to UC sera and the attached proteins identified by Western blot assay. The proteins proved to be exclusively immunoglobulin (Ig) G. To evaluate the neutralizing activity of these antibodies, cytokine-specific IgG from subjects in each group of patients was incubated with TGF-beta, IL-2 or IL-10 before addition to a bioassay with changes in viability determined by a colorimetric analysis. Antibodies from most individuals in all three groups neutralized the action of each cytokine. This study shows that about one-third of IBD patients may have a relative deficiency of TGF-beta, IL-2 or IL-10 due to an increase in neutralizing antibodies in their sera.

Non-response to infliximab may be due to innate neutralizing anti-tumour necrosis factor-alpha antibodies.

Infliximab is a chimeric anti-tumour necrosis factor (TNF)-alpha antibody that is therapeutic in many patients with inflammatory bowel disease. What causes certain patients not to respond is unknown. The question posed is whether innate anti-TNF-alpha antibodies play any role in the response to infliximab. Blood was drawn prior to the initial dose of infliximab. Serum anti-TNF-alpha antibodies were quantitated by enzyme-linked immunosorbent assay (ELISA). Affinity-purified anti-TNF-alpha antibodies were isolated from serum immunoglobulin G using TNF-alpha-coated beads. The ability of these antibodies to induce apoptosis of macrophages was measured by annexin and propidium iodide staining. Changes in TNF receptor type 2 (TNFR2) expression and release were determined by immunofluorescence and ELISA respectively. TNF-alpha-neutralization was assessed by the reversal of the lytic actions of TNF-alpha on WEHI cells. The amounts of innate anti-TNF-alpha antibodies in the serum from infliximab responders versus non-responders were the same. Apoptosis of monocytes increased with infliximab and by several of the purified anti-TNF-alpha antibodies, but these findings did not vary with the patients' responses to infliximab. Effects of the anti-TNF-alpha antibodies on the expression of TNFR2 on monocytes and their release of soluble TNFR2 did not vary with the patients' responses to infliximab. However, the neutralizing capacity of these antibodies differed, with responders having antibodies that reduced only 47 +/- 4% of the TNF-alpha activity while those from non-responders reduced 70 +/- 5% of the TNF-alpha activity (P < 0.01). Non-responders have innate anti-TNF-alpha antibodies with greater neutralizing activity than antibodies from responders. Any TNF-alpha-mediated disease process would be neutralized by intrinsic antibodies, so that the disease is likely to be driven by non-TNF-alpha-mediated events.

Coronary artery dissection with rupture of aortic valve commissure following type A aortic dissection: the role of 64-slice MDCT.

A rare case of bilateral coronary artery dissection with rupture of aortic valve commissure following type A aortic dissection is described. 64-slice multidetector computed tomography (MDCT) was able to demonstrate both this findings along with involvement of other neck vessels. TEE demonstrated the severity and mechanisms of aortic valve damage and assisted the surgeon in valve repair. MDCT has played an invaluable role in the diagnosis of the abnormal details of such life-threatening vascular complications.

Isolation and characterization of a colonic autoantigen specifically recognized by colon tissue-bound immunoglobulin G from idiopathic ulcerative colitis.

Patients with idiopathic ulcerative colitis (UC) have a colonbound antibody (CCA-IgG) that reacts with colon tissue extracts. We have partially characterized a colonic protein that is specifically recognized by CCA-IgG. CCA-IgG was eluted from operative colon specimens from 10 patients with UC. A colon tissue-bound IgG was similarly eluted from six patients with Crohn's colitis, two with ischemic colitis, and one with diverticulitis. Purified serum IgG from patients with Crohn's disease, from normal subjects and a patient with myeloma were also used as additional controls. For detection of antigen(s), tissue extracts were prepared from 26 specimens of colon (UC, 12; Crohn's disease, 6; normal, 4; other controls, 4), 8 specimens of human normal stomach, duodenum, ileum, and liver (2 each). Tissue extracts were also prepared from rats and mice, including germ-free rat colons and rat's fetal colons. Immunorecognition of CCA-IgG to the tissue extracts was examined by affinity-column chromatography and by transblot analysis. Tissue-extracted proteins were electrophoresed in SDS-polyacrylamide gel, transferred to nitrocellulose sheet, and probed with iodinated CCA-IgG, colonic IgG from other inflammatory bowel disease patients, UC serum IgG, and control serum IgG. Although many proteins were present in colon tissue extracts, 9 of 10 CCA-IgG consistently recognized a protein of 40 kD. None of the nine IgG preparations from colon specimens of patients with Crohn's colitis and other colonic inflammatory diseases reacted with the 40-kD protein. Five of six symptomatic UC serum IgG and none of eight control serum IgG reacted with the 40-kD protein. The 40-kD protein was present in all colon specimens and it appeared to be organ specific. It was absent in mouse and rat tissues, including colon. The 40-kD protein is not actin and nor a part of the Ig molecule. These results suggest that the 40-kD protein is a colonic "autoantigen" that may initiate a specific IgG antibody response in UC.

Immunohistochemical changes in morphologically involved and uninvolved colonic mucosa of patients with idiopathic proctitis.

Alterations in secretory component, IgA, IgG, and IgM were studied by immunofluorescent techniques in mucosal biopsy specimens obtained at colonoscopy from inflamed and grossly uninvolved colonic mucosa from 12 patients with idiopathic proctitis. Parotid-salivary secretory component and IgA and serum immunoglobulins were also investigated. Decreased secretory IgA was observed in the epithelium of all grossly involved rectal mucosa and in 40% of proximal normal mucosa. Salivary secretory IgA was not diminished. These observations suggest that a local immune defect may be pathogenetically related to idiopathic proctitis.

K-ras mutations and cell kinetics in Helicobacter pylori associated gastric intestinal metaplasia: a comparison before and after eradication in patients with chronic gastritis and gastric cancer.

BACKGROUND: Helicobacter pylori related gastric intestinal metaplasia (IM) is considered to be a precancerous lesion. AIMS: To identify the effects of H pylori eradication on K-ras mutations, cell kinetics in IM and histological changes in patients with and without gastric cancers in a one-year prospective study. METHODS: Patients included group A (n = 39), chronic gastritis, and group B (n = 53), intestinal-type early gastric cancer patients who had all undergone endoscopic mucosal resection (n = 25) or surgical resection (n = 28). K-ras codon 12 mutations in IM were examined, followed by DNA sequencing analysis. Proliferating and apoptotic cells were detected with anti-Ki-67 antibody and using the TUNEL method, respectively. RESULTS: The incidence of K-ras mutations in the cancer was only 3.8%. The mutant K-ras in IM was observed more frequently in group A (46.2%) than in group B patients (1.9%) (p<0.005). After eradication, the K-ras mutations significantly declined to 12.8% in group A (p<0.005). The mutation pattern of K-ras codon 12 before eradication was that GGT was mainly changed to AGT (50%) in group A. AGT transformation was not affected by treatment. Apoptosis in IM showed an increase after H pylori eradication in both groups (p<0.05 in group A) although no histological improvement in IM was observed. The monocyte score was significantly higher in group A than in group B (p<0.05); the score improved significantly after eradication. CONCLUSIONS: K-ras mutations in IM do not always play a role in gastric carcinogenesis but cell kinetics, especially apoptosis, in IM may contribute to it. There are early events in K-ras mutations which are influenced by H pylori infection; some mutations may also be selected by eradication. These unstable K-ras mutations in IM may be related to lymphocyte infiltration caused by H pylori infection.

Acetylation polymorphism of sulfapyridine in patients with ulcerative colitis and Crohn's disease.

Sulfapyridine (SP) is one of the main metabolites of salicylazosulfapyridine (sulfasalazine) that is used extensively in the management of inflammatory bowel disease. One hundred and twenty-two patients with ulcerative colitis or Crohn's disease were studied, including 21 new, untreated patients and 101 previously treated patients. Patients were studied for at least one year during active disease and remission. It was shown that sulfapyridine shares the same acetylation polymorphism as sulfadimidine. The acetylation capability of each patient as determined in serum and urine was constant irrespective of dose (2 to 8 gm/day) and state of disease. A single study of serum can determine acetylator phenotype in patients on sulfasalazine therapy without using any other drug for this purpose and may help ascertain dosage and assess side effects.

Immunofluorescence assay using Crohn's disease tissue-injected athymic nude mouse lymph nodes in the diagnosis of inflammatory bowel diseases.

Sometimes, even after extensive investigative efforts, the diagnosis of inflammatory bowel disease remains in doubt. The accurate diagnosis is important if appropriate therapy is to be instituted. A simple indirect immunofluorescence assay that tests the patient's serum against lymphoid tissues from athymic nude (nu/nu) mice receiving injections of filtrates of Crohn's disease tissue is proposed. Eighty percent of serum samples from patients with active, symptomatic Crohn's disease give positive results of immunofluorescence when tested with these lymphoid tissues. The false-positive rate has been very low (less than 10 percent). Because this assay is fairly sensitive and least invasive, it was used for the clarification of many puzzling cases that were seen at the Albert Einstein College of Medicine over the past three years. Ten of these cases were selected for illustration and discussion and are presented in this report.

Desensitization of patients with inflammatory bowel disease to sulfasalazine.

Seventeen patients with ulcerative colitis and three patients with Crohn's disease exhibited different side effects during sulfasalazine therapy. Eighty percent of these patients belonged to slow acetylator phenotypes. All side effects except skin rash were associated with a mean serum total sulfapyridine concentration of 62.9 +/- 17.4 micrograms/ml and free sulfapyridine concentration of 42 +/- 9.5 micrograms/ml. All patients were successfully desensitized, which allowed them the benefit of continued sulfasalazine therapy for prevention of relapses.

Antibody-dependent cell-mediated cytotoxicity in serum samples from patients with ulcerative colitis. Relationship to disease activity and response to total colectomy.

A group of six medically treated patients with ulcerative colitis were followed for up to 30 months along with eight additional patients who underwent proctocolectomy. Patients were examined frequently, and serum samples were collected for antibody-dependent cell-mediated cytotoxicity studies. Clinically active disease was substantiated by history, physical examination, laboratory investigations, proctoscopy and, when feasible, by rectal and/or colonic biopsy specimens. During active clinical disease, serum samples from patients with ulcerative colitis showed antibody-dependent cell-mediated cytotoxicity of 16.5 +/- 1.6 percent (range 8.2 to 25.8 percent). During remission of the disease, serum samples from the same patients demonstrated a mean antibody-dependent cell-mediated cytotoxicity value of 5.9 +/- 1.3 percent (range 0.4 to 11.1 percent) (p less than 0.01). In the eight patients who underwent proctocolectomy, mean preoperative antibody-dependent cell-mediated cytotoxicity value was 19.5 +/- 2.3 percent (range 4.1 to 38.6 percent). One month after proctocolectomy, antibody-dependent cell-mediated cytotoxic activity decreased by 72 +/- 11 percent of the preoperative value (p less than 0.001). These findings reveal a positive correlation between the antibody-dependent cell-mediated cytotoxicity with RPMI-4788 and clinical activity of ulcerative colitis, and support the hypothesis that the antibody being studied has direct relation to the presence of the ulcerative colitis colon in situ.

Phenotype of Barrett's esophagus and intestinal metaplasia of the distal esophagus and gastroesophageal junction: an immunohistochemical study of cytokeratins 7 and 20, Das-1 and 45 MI.

The pathogenesis of short segment Barrett's esophagus (SSBE) and intestinal metaplasia (IM) of the gastroesophageal junction (IMGEJ) are poorly understood. Also, these conditions are difficult to distinguish from one another based solely on endoscopic and pathologic criteria. Therefore, the aim of this study was to evaluate the immunophenotypic features of SSBE and IMGEJ and to compare the results with lesions of known etiologies: long segment BE (LSBE) caused by reflux disease and Helicobacter pylori-induced IM of the gastric antrum (IMGA). Routinely processed mucosal biopsy specimens from 11 patients with LSBE, 17 with SSBE, 10 with IMGEJ, 16 with IMGA, 17 with a normal nonmetaplastic GEJ, and 7 patients with a normal gastric antrum were immunohistochemically stained with monoclonal antibodies to: Das1, an antibody shown to react specifically with colonic goblet cells; 45M1, an antibody that recognizes the M1 gastric mucin antigen; and cytokeratin (CK) 7 and 20, antibodies that have previously been reported to show specific staining patterns in BE versus IMGA. Also evaluated was nonintestinalized mucinous epithelium from LSBE, SSBE, and also the normal GEJ and gastric antrum. LSBE, SSBE, and IMGEJ showed similar prevalences of Das1 (91% versus 88% versus 100%) and 45M1 reactivity (100% versus 100% versus 100%), and a similar pattern of CK7/20 reactivity (diffuse strong CK7 staining of the surface and crypt epithelium, and strong surface and superficial crypt CK20 staining) (91% versus 94% versus 90%). In contrast, although 45M1 reactivity in IMGA (93%) was similar to that of the other three groups, IMGA showed a significantly lower prevalence of Das positivity (13%, p < 0.001), and only a 14% prevalence of the CK7/20 staining pattern that was predominant in the other three groups (p < 0.001). Das1, 45M1, and CK7/20 staining were similar in nonintestinalized "cardia-type" mucinous epithelium from LSBE, SSBE, and the GEJ, but all were distinct from the normal gastric antrum. In summary, the immunophenotypic features of SSBE and IMGEJ are similar and closely resemble those seen in classic LSBE, but are distinct from IMGA. This may indicate that IM in LSBE, SSBE and at the GEJ have similar biologic properties. Based on our data, SSBE and IMGEJ cannot be distinguished on the basis of their immunophenotype.

Clinical pharmacokinetics of sulphasalazine.

Sulphasalazine consists of 5-aminosalicylic acid and sulphapyridine both linked together by an azo bond. Sulphasalazine is clearly useful in long-term management of ulcerative colitis and may be useful in Crohn's disease. The absorption, metabolism and excretion of sulphasalazine is similar in volunteers and patients with ulcerative colitis or Crohn's disease. Sulphasalazine serves as a vehicle to deliver its possible active components, 5-aminosalicylic acid and sulphapyridine, to the colon in higher concentrations than could be achieved by oral administration of either one alone. Sulphasalazine reaches the colon mostly unchanged and is split by gut bacteria at the azo linkage, releasing 5-aminosalicylic acid and sulphapyridine. 5-Aminosalicylic acid may act locally and is not absorbed to any great extent. On the contrary, sulphapyridine is mostly absorpbed from the colon and may act both locally, during mucosal absorption, and systemically. A positive correlation exists between serum total sulphapyridine concentration and both therapeutic efficacy and toxicity. Sulphapyridine metabolism is largely determined by inherited acetylator phenotype, either slow or fast. Slow acetylators have higher levels of free sulphapyridine and lower levels of acetylated sulphapyridine than fast acetylators, and are likely to have more toxic symptoms on equivalent doses of sulphasalazine. Therapeutic effects of sulphasalazine in ulcerative colitis and Crohn's disease correlate with serum concentrations of total sulphapyridine (20 to 50 microng/ml), and toxicity with total sulphapyridine concentration greater than 50 microng/ml. Side-effects are mostly observed among slow acetylators. In long-term therapy of ulcerative colitis doses of 2 to 3g/day of sulphasalazine are most likely to sustain remissions and avoid toxicity. During therapy with sulphasalazine, determination of acetylator phenotype and total sulphapyridine concentration can guide effective dosage and avoid side-effects. A single serum sample for free and acetylated sulphapyridine concentrations is sufficient for this purpose.

Epithelial deposits of immunoglobulin G1 and activated complement co-localize with the "M(r) 40kD" putative auto-antigen in ulcerative colitis.

In conclusion, the "M(r) 40kD" antigen is expressed on the apical face of colonic enterocytes often in spatial relation to immune complexes in active UC, apparently targeting an IgG1-mediated autoimmune attack. Thus, our findings support the notion that an autoimmune response to the "M(r) 40kD" antigen, with local production of specific IgG1, is a possible immunopathological mechanism(s) in UC.

Ultrasound guided intrauterine transfusion.

Intrauterine transfusion was performed on 12 occasions in 9 Rh-sensitizedwomen. Under constant real-time ultrasound guidance, a 17G Touhy needle was negotiated through a placenta-free area and advanced into the foetal abdomen to reach the peritoneal cavity. After confirming the position of the needle, either by aspiration of foetal ascitic fluid or by injecting air into the peritoneal cavity, an epidural catheter was passed through the needle and the transfusion was accomplished. This procedure was successful in 11 (91%) of the 12 instances. In one patient the needle could not be placed in the foetal peritoneal cavity despite repeated. attempts; she developed pyrexia and went into spontaneous labour. The neonatal survival rate was 22% (2/9). The ultrasound guided technique not only eliminates the risk of radiation hazards, but also helps in precise placement of the needle in the uterus and foetal peritoneal cavity, which makes intrauterine transfusion safe.

Ultrasound in obstructive jaundice.

One hundred and twenty-five consecutive patients with obstructive jaundice were prospectively studied by ultrasonography to determine the level and cause of obstruction. These were diagnosed precisely in 80 (72%) and 52 patients (41.6%) respectively. The results were compared with cholangiography. The final diagnosis was established at surgery (97 cases) and fine needle aspiration cytology (28 cases). While US is an excellent screening modality in distinguishing obstructive and non-obstructive jaundice, cholangiography is still the gold standard for determining the precise anatomic level and cause of obstruction.

Pharmacotherapy of inflammatory bowel disease. Part 1. Sulfasalazine.

Published studies suggest that sulfasalazine is effective in treating mild to moderate attacks of ulcerative colitis. Its usefulness in severe attacks has not been adequately tested. Published reports also justify the use of sulfasalazine to prevent recurrence of ulcerative colitis. It is not clear how long maintenance therapy should be continued, but evidence to date favors prolonged treatment in the absence of side effects. In treatment of Crohn's disease, sulfasalazine has been shown to be effective when disease involves the colon or the colon and small intestine. Maintenance therapy does not prevent relapse. Recent studies have indicated that 5-aminosalicylic acid (5-ASA) may be the therapeutic moiety of sulfasalazine, and sulfapyridine (SP) may be related to most of the side effects. Therefore, research is under way to develop a product that contains 5-ASA without the sulfonamide component and that is capable of reaching the colon without being absorbed in the upper small intestine.

Anatomical variation of pulmonary venous ostium and its relationship with atrial arrhythmia in the Saudi population.

PURPOSE: To assess the anatomical variation of the ostial pattern of pulmonary veins observed on coronary computed tomography (CT) angiogram and to estimate the relationship of atrial arrhythmia with similar ostial variants in the Saudi population. MATERIALS AND METHODS: Thin-section (0.625 mm) contrast enhanced CT scans of 151 consecutive patients obtained over a span of a two-year period (January 2009-January 2011) for the diagnosis of ischemic heart disease, aortic regurgitation, infective endocarditis, aortic aneurysm, fibrosing mediastinitis, and pericardial defect. The retrospective study was focused on the identification of the number of venous ostia on either side of the left atrium and the drainage patterns of pulmonary veins. The frequency of each pattern was tabulated, and significance of their relationship with atrial arrhythmias was assessed with the X(2) and Fisher's exact tests. RESULTS: Out of 151 patients analyzed, 26 patients (17.2%) had anatomical variation of the pulmonary venous ostia. Atrial arrhythmia was recorded in 16 of 26(61.5%) patients (p = 0.000). The association of higher anatomical variation of pulmonary venous ostia was recorded as higher (p = 0.034) in the female group (n = 15, 57.7%). CONCLUSION: The association between anatomically varied venous ostia and atrial arrhythmia was significant (p = 0.000) with a significantly higher anatomical variation of pulmonary venous ostia in the female Saudi population (p = 0.034).