Two vs One Forward View Examination of Right Colon on Adenoma Detection: An International Multicenter Randomized Trial.

BACKGROUND & AIMS: Second forward view (SFV) examination of the right colon (RC) in colonoscopy was suggested to improve the adenoma detection rate (ADR), but multicenter data to inform its routine use remain limited. We performed an international multicenter randomized trial comparing SFV vs a standard single forward view examination of the RC on adenoma detection. METHODS: Asymptomatic individuals undergoing screening or surveillance colonoscopies from 6 Asia Pacific regions were invited for study. A forward view examination of the RC was first performed in all patients, followed by randomization at the hepatic flexure to either SFV examination of the RC and standard withdrawal examination from the hepatic flexure to rectum, or a standard withdrawal colonoscopy (SWC) examination from the hepatic flexure to rectum. The primary outcome was RC ADR. RESULTS: Between 2016 and 2019, there were 1011 patients randomized (SFV group, 502 patients; SWC group, 509 patients). Forty-five endoscopists performed the colonoscopies. The RC ADR was significantly higher in the SFV group than in the SWC group (27.1% vs 21.6%; P = .042). The whole-colon ADR was high in both groups (49.0% vs 45.0%; P =.201). The SFV examination identified 58 additional adenomas in 49 patients (9.8%), leading to a change in surveillance recommendations in 15 patients (3.0%). The median overall withdrawal time was 1.5 minutes longer in the SFV group (12.0 vs 10.5 min; P < .001). Older age, male sex, ever smoking, and longer RC withdrawal time were independent predictors of right-sided adenoma detection. CONCLUSIONS: In this multicenter trial, SFV examination significantly increased the RC ADR in screening and surveillance colonoscopies. Routine RC SFV examination should be considered. ClinicalTrials.gov ID: NCT03121495.

Adenoma detection rates in colonoscopies for positive fecal immunochemical tests versus direct screening colonoscopies.

BACKGROUND AND AIMS: Recent guidelines propose higher adenoma detection rate (ADR) benchmarks for colonoscopies performed for positive results for fecal immunochemical tests (FIT), but this is based on low-quality evidence. We aimed to compare ADR, advanced ADR (AADR), and number of adenomas per colonoscopy (APC) in direct screening colonoscopy (DSC) versus FIT-positive colonoscopy (FITC) in a multicenter Asia-Pacific cohort to justify differential targets. METHODS: Asymptomatic average-risk patients ≥50 years of age who underwent screening colonoscopy directly or as follow-up for positive OC-Sensor FIT results were identified from 8 sites across the Asia-Pacific region. Overall, sex-specific ADR, overall AADR, and overall APC were compared between the 2 screening methods. Multivariable logistic regression was performed to adjust for confounding by differences in patient characteristics. Linear regression was used to correlate ADR with APC and to propose APC benchmarks. RESULTS: A total of 2901 (mean age, 60.1 years; 57% men) individuals had DSC, and 2485 (mean age, 62.8 years; 57% men) underwent FITC. Overall ADR (53.6% vs 37.5%; odds ratio [OR], 1.93; P < .001), male-specific ADR (61.6% vs 44.6%; OR, 2; P < .001), female-specific ADR (43.2% vs 28.2%; OR, 1.94; P < .001) and overall AADR (29.9% vs 4.9%; OR, 8.2; P < .001) in FITC were significantly higher than the corresponding values for DSC. Differences remained significant after adjustment for patient characteristics. ADR was strongly and positively correlated to APC, with an ADR of 45% and 35% correlating to an APC of ∼1 and ∼0.65. CONCLUSIONS: Results from this international multicenter cohort study provide early evidence that newly proposed higher ADR targets are justified as quality indicators for FITC.

Lung retinoid metabolism and signaling in chronic obstructive pulmonary disease.

There are a number of sites that are required for the production and/or action of all-trans retinoic acid (ATRA). In particular, interruption of different components of the chain of trafficking and metabolism has been associated with cancers arising in numerous organs of the body. Preliminary work suggests that such interruptions may be a factor in lung disorders induced by the smoke exposure. The active metabolite of retinoid, ATRA offers a therapeutic strategy to protect against functional abnormality in the lung, including chronic obstructive pulmonary disease (COPD). This review deals with the lung retinoid metabolism and mediators of retinoid trafficking and signaling with special emphasis on their roles in health and disease.

Addition of thiopurines can recapture response in patients with Crohn's disease who have lost response to anti-tumor necrosis factor monotherapy.

BACKGROUND AND AIM: Anti-tumor necrosis factor (TNF) antibodies are effective in maintaining remission in Crohn's disease. However, a significant proportion of patients lose response to these agents with time. This study aimed to determine whether the introduction of a thiopurine in patients who have lost response to anti-TNF monotherapy results in regained response. METHODS: Five patients (four males; aged 22-38 years) with active Crohn's disease, who had an initial response to anti-TNF therapy but had lost response, were commenced on azathioprine or mercaptopurine at standard doses while continuing anti-TNF therapy. All had previously failed thiopurine therapy prior to starting anti-TNF treatment. RESULTS: All patients experienced improved clinical symptoms within 2-6 months, with benefit sustained over a mean follow-up of 19 months. Two patients with an elevated C-reactive protein at the time of thiopurine addition demonstrated a fall in C-reactive protein. Colonoscopy before and after thiopurine addition in four patients showed improvement in all, with mucosal healing achieved in two. No adverse effects of treatment were noted. CONCLUSIONS: Addition of a thiopurine in patients who have lost response to anti-TNF monotherapy is an effective strategy to recapture response even if the patient has previously failed thiopurine therapy. Thiopurines may reduce immunogenicity or act synergistically with anti-TNF therapy.

Oral Microbiome of Crohn's Disease Patients With and Without Oral Manifestations.

BACKGROUND AND AIMS: Microbiome dysbiosis is associated with inflammatory destruction in Crohn's disease [CD]. Although gut microbiome dysbiosis is well established in CD, the oral microbiome is comparatively under-studied. This study aims to characterize the oral microbiome of CD patients with/without oral manifestations. METHODS: Patients with CD were recruited with age-, gender- and race-matched controls. Potential confounders such as dental caries and periodontal condition were recorded. The oral microbiome was collected using saliva samples. Microbial DNA was extracted and sequenced using shotgun sequencing. Metagenomic taxonomic and functional profiles were generated and analysed. RESULTS: The study recruited 41 patients with CD and 24 healthy controls. Within the CD subjects, 39.0% had oral manifestations with the majority presenting with cobblestoning and/or oral ulcers. Principal coordinate analysis demonstrated distinct oral microbiome profiles between subjects with and without CD, with four key variables responsible for overall oral microbiome variance: [1] diagnosis of CD, [2] concomitant use of steroids, [3] concomitant use of azathioprine and 4] presence of oral ulcers. Thirty-two significant differentially abundant microbial species were identified, with the majority associated with the diagnosis of CD. A predictive model based on differences in the oral microbiome found that the oral microbiome has strong discriminatory function to distinguish subjects with and without CD [AUROC 0.84]. Functional analysis found that an increased representation of microbial enzymes [n = 5] in the butyrate pathway was positively associated with the presence of oral ulcers. CONCLUSIONS: The oral microbiome can aid in the diagnosis of CD and its composition was associated with oral manifestations.

Ectopic gut colonization: a metagenomic study of the oral and gut microbiome in Crohn's disease.

BACKGROUND: This study aims to characterize, the gut and oral microbiome in Asian subjects with Crohn's disease (CD) using whole genome shotgun sequencing, thereby allowing for strain-level comparison. METHODS: A case-control study with age, sex and ethnicity matched healthy controls was conducted. CD subjects were limited to well-controlled patients without oral manifestations. Fecal and saliva samples were collected for characterization of gut and oral microbiome respectively. Microbial DNA were extracted, libraries prepared and sequenced reads profiled. Taxonomic diversity, taxonomic association, strain typing and microbial gene pathway analyses were conducted. RESULTS: The study recruited 25 subjects with CD and 25 healthy controls. The oral microbe Streptococcus salivarius was found to be enriched and of concordant strains in the gut and oral microbiome of Crohn's disease subjects. This was more likely in CD subjects with higher Crohn's Disease Activity Index (184.3 ± 2.9 vs 67.1 ± 82.5, p = 0.012) and active disease status (Diarrhoea/abdominal pain/blood-in-stool/fever and fatigue) (p = 0.016). Gut species found to be significantly depleted in CD compared to control (Relative abundance: Median[Range]) include: Faecalibacterium prausnitzii (0.03[0.00-4.56] vs 13.69[5.32-18.71], p = 0.010), Roseburia inulinivorans (0.00[0.00-0.03] vs 0.21[0.01-0.53], p = 0.010) and Alistipes senegalensis (0.00[0.00-0.00] vs 0.00[0.00-0.02], p = 0.029). While Clostridium nexile (0.00[0.00-0.12] vs 0.00[0.00-0.00], p = 0.038) and Ruminococcus gnavus (0.43[0.02-0.33] vs 0.00[0.00-0.13], p = 0.043) were found to be enriched. C. nexile enrichment was not found in CD subjects of European descent. Microbial arginine (Linear-discriminant-analysis: 3.162, p = 0.001) and isoprene (Linear-discriminant-analysis: 3.058, p < 0.001) pathways were found at a higher relative abundance level in gut microbiome of Crohn's disease. CONCLUSIONS: There was evidence of ectopic gut colonization by oral bacteria, especially during the active phase of CD. Previously studied gut microbial differences were detected, in addition to novel associations which could have resulted from geographical/ethnic differences to subjects of European descent. Differences in microbial pathways provide possible targets for microbiome modification.

Estrogen regulates the expression of retinoic acid synthesis enzymes and binding proteins in mouse skin.

Topical 17-beta-estradiol (E2) regulates the hair cycle, hair shaft differentiation, and sebum production. Vitamin A also regulates sebum production. Vitamin A metabolism proteins localized to the pilosebaceous unit (PSU; hair follicle and sebaceous gland); and were regulated by E2 in other tissues. This study tests the hypothesis that E2 also regulates vitamin A metabolism in the PSU. First, aromatase and estrogen receptors localized to similar sites as retinoid metabolism proteins during mid-anagen. Next, female and male wax stripped C57BL/6J mice were topically treated with E2, the estrogen receptor antagonist ICI 182,780 (ICI), letrozole, E2 plus letrozole, or vehicle control (acetone) during mid-anagen. E2 or one of its inhibitors regulated most of the vitamin A metabolism genes and proteins examined in a sex-dependent manner. Most components were higher in females and reduced with ICI in females. ICI reductions occurred in the premedulla, sebaceous gland, and epidermis. Reduced E2 also reduced RA receptors in the sebaceous gland and bulge in females. However, reduced E2 increased the number of retinal dehydrogenase 2 positive hair follicle associated dermal dendritic cells in males. These results suggest that estrogen regulates vitamin A metabolism in the skin. Interactions between E2 and vitamin A have implications in acne treatment, hair loss, and skin immunity.

Uptake of all-trans retinoic acid-containing aerosol by inhalation to lungs in a guinea pig model system--a pilot study.

Systemic therapies with retinoic acid (RA) can result in toxic side effects without yielding biologically effective levels in target tissues such as lung. The authors adapted a PARI LC Star nebulizer to create a tubular system for short-term inhalation treatment of guinea pigs using a water-miscible formulation of all-trans RA (ATRA) or vehicle. Based on the initial average weight, animals received an estimated average ATRA doses of either 0.32 mg·kg(-1) (low dose, 1.4 mM), or 0.62 mg·kg(-1) (medium dose, 2.8 mM), or 1.26 mg·kg(-1) (high dose, 5.6 mM) 20 minutes per day for 6 consecutive days. This system led to a rise of ATRA levels in lung, but not liver or plasma. Cellular lung levels of retinol, retinyl palmitate, and retinyl stearate also appeared to be unaffected (245.6 ± 10.7, 47.4 ± 3.4, and 132.8 ± 7.7 ng·g(-1) wet weight, respectively). The application of this aerosolized ATRA also induced a dose-dependent protein expression of the cellular retinol-binding protein 1 (CRBP-1) in lung, without apparent harmful side effects.

Cyclic nucleotide-gated ion channels in rod photoreceptors are protected from retinoid inhibition.

In vertebrate rods, photoisomerization of the 11-cis retinal chromophore of rhodopsin to the all-trans conformation initiates a biochemical cascade that closes cGMP-gated channels and hyperpolarizes the cell. All-trans retinal is reduced to retinol and then removed to the pigment epithelium. The pigment epithelium supplies fresh 11-cis retinal to regenerate rhodopsin. The recent discovery that tens of nanomolar retinal inhibits cloned cGMP-gated channels at low [cGMP] raised the question of whether retinoid traffic across the plasma membrane of the rod might participate in the signaling of light. Native channels in excised patches from rods were very sensitive to retinoid inhibition. Perfusion of intact rods with exogenous 9- or 11-cis retinal closed cGMP-gated channels but required higher than expected concentrations. Channels reopened after perfusing the rod with cellular retinoid binding protein II. PDE activity, flash response kinetics, and relative sensitivity were unchanged, ruling out pharmacological activation of the phototransduction cascade. Bleaching of rhodopsin to create all-trans retinal and retinol inside the rod did not produce any measurable channel inhibition. Exposure of a bleached rod to 9- or 11-cis retinal did not elicit channel inhibition during the period of rhodopsin regeneration. Microspectrophotometric measurements showed that exogenous 9- or 11-cis retinal rapidly cross the plasma membrane of bleached rods and regenerate their rhodopsin. Although dark-adapted rods could also take up large quantities of 9-cis retinal, which they converted to retinol, the time course was slow. Apparently cGMP-gated channels in intact rods are protected from the inhibitory effects of retinoids that cross the plasma membrane by a large-capacity buffer. Opsin, with its chromophore binding pocket occupied (rhodopsin) or vacant, may be an important component. Exceptionally high retinoid levels, e.g., associated with some retinal degenerations, could overcome the buffer, however, and impair sensitivity or delay the recovery after exposure to bright light.

The retinoic acid synthesis gene ALDH1a2 is a candidate tumor suppressor in prostate cancer.

Prostate cancer is the most common cancer among men in the United States, and aberrant DNA methylation is known to be an early molecular event in its development. Here, we have used expression profiling to identify novel hypermethylated genes whose expression is induced by treatment of prostate cancer cell lines with the DNA methyltransferase inhibitor 5-Aza-2'-deoxycytidine (5-aza-dC). Of the 271 genes that were induced by 5-aza-dC treatment, 25 also displayed reduced expression in primary prostate tumors compared with normal prostate tissue, and the decreased expression of only one gene, aldehyde dehydrogenase 1 family, member A2 (ALDH1a2), was also associated with shorter recurrence-free survival. ALDH1a2 encodes an enzyme responsible for synthesis of retinoic acid (RA), a compound with prodifferentiation properties. By immunohistochemistry, we observed that ALDH1a2 was expressed in epithelia from normal prostate but not prostate cancer. Using bisulfite sequencing, we determined that the ALDH1a2 promoter region was significantly hypermethylated in primary prostate tumors compared with normal prostate specimens (P = 0.01). Finally, transfection-mediated reexpression of wild-type ALDH1a2 (but not a presumptive catalytically dead mutant) in the prostate cancer cell line DU145 resulted in decreased colony growth (P < 0.0001), comparable with treatment with either 5-aza-dC or RA. Taken together, our findings implicate ALDH1a2 as a candidate tumor suppressor gene in prostate cancer and further support a role of retinoids in the prevention or treatment of prostate cancer.

Endoscopic and Histological Mucosal Healing in Ulcerative Colitis in the First Year of Diagnosis: Results from a Population-based Inception Cohort from Six Countries in Asia.

BACKGROUND AND AIMS: Mucosal healing is associated with improved long-term clinical outcomes in patients with ulcerative colitis. This population-based study assessed endoscopic and histological mucosal healing within the first year of diagnosis. METHODS: Consecutive patients diagnosed with ulcerative colitis from six countries in Asia were prospectively enrolled. Clinical demographics, blood markers and inflammatory activity were assessed at baseline. Mayo score and Nancy index were used to assess endoscopic and histological activities, respectively. Clinical, endoscopic and histological evaluations were repeated at 1 year. Logistic regression was performed to identify predictors of mucosal healing. RESULTS: Of 433 ulcerative colitis patients, 202 [46.7%] underwent colonoscopy at 1 year. In total, 68 [38.2%] achieved endoscopic mucosal healing and 35 [23.1%] achieved histological mucosal healing. On multivariate analysis, an elevated erythrocyte sedimentation rate [ESR] at diagnosis (odds ratio [OR], 0.332; 95% confidence interval (CI), 0.133-0.830; p = 0.018) was a significant negative predictor of endoscopic mucosal healing at 1 year, while histological features of ulceration [OR, 0.156; 95% CI, 0.028-0.862; p = 0.033] and being an ex-smoker [OR, 0.067; 95% CI, 0.005-0.965; p = 0.047] were significant negative predictors of histological healing at 1 year. Both endoscopic and histological mucosal healing were associated with less steroid use [p < 0.001 and p = 0.001, respectively] and hospitalization [p = 0.002 and p = 0.01, respectively]. CONCLUSIONS: Mucosal healing was achieved in fewer than half of patients with ulcerative colitis in the first year of diagnosis. An elevated ESR predicted less likelihood of endoscopic mucosal healing, while histological features of ulceration and being an ex-smoker at diagnosis predicted less likelihood of histological healing.

Loss of gastrokine-2 drives premalignant gastric inflammation and tumor progression.

Chronic mucosal inflammation is associated with a greater risk of gastric cancer (GC) and, therefore, requires tight control by suppressive counter mechanisms. Gastrokine-2 (GKN2) belongs to a family of secreted proteins expressed within normal gastric mucosal cells. GKN2 expression is frequently lost during GC progression, suggesting an inhibitory role; however, a causal link remains unsubstantiated. Here, we developed Gkn2 knockout and transgenic overexpressing mice to investigate the functional impact of GKN2 loss in GC pathogenesis. In mouse models of GC, decreased GKN2 expression correlated with gastric pathology that paralleled human GC progression. At baseline, Gkn2 knockout mice exhibited defective gastric epithelial differentiation but not malignant progression. Conversely, Gkn2 knockout in the IL-11/STAT3-dependent gp130F/F GC model caused tumorigenesis of the proximal stomach. Additionally, gastric immunopathology was accelerated in Helicobacter pylori-infected Gkn2 knockout mice and was associated with augmented T helper cell type 1 (Th1) but not Th17 immunity. Heightened Th1 responses in Gkn2 knockout mice were linked to deregulated mucosal innate immunity and impaired myeloid-derived suppressor cell activation. Finally, transgenic overexpression of human gastrokines (GKNs) attenuated gastric tumor growth in gp130F/F mice. Together, these results reveal an antiinflammatory role for GKN2, provide in vivo evidence that links GKN2 loss to GC pathogenesis, and suggest GKN restoration as a strategy to restrain GC progression.

Microsomal triglyceride transfer protein expression in adipocytes: a new component in fat metabolism.

Microsomal triglyceride transfer protein (MTP) is a carrier of triglyceride essential for the assembly of apolipoprotein (apo)B-containing lipoproteins by the liver and the small intestine. Its role in triglyceride transfer in tissues that do not secrete lipoproteins has not been explored. In particular, MTP would seem to be a candidate for a role in triglyceride metabolism within the adipocyte. To test this hypothesis, we probed adipocytes for the presence of MTP. Immunohistochemical and biochemical studies demonstrate MTP in adipocytes from brown and white fat depots of mice and human, as well as in 3T3-L1 cells. Confocal microscopy revealed MTP throughout 3T3 cells; however, MTP fluorescence was prominent in juxtanuclear areas. In differentiated 3T3 cells MTP fluorescence was very striking around lipid droplets. In vitro lipid transfer assays demonstrated the presence of triglyceride transfer activity within microsomal fractions isolated from rat adipose tissue. In addition, quantitative rtPCR studies showed that MTP expression in mouse white fat depots was approximately 1% of MTP expression in mouse liver. MTP mRNA in differentiated 3T3 cells was approximately 13% of liver expression. Our results provide unequivocal evidence for the presence of MTP in adipocytes and present new possibilities for defining the mechanisms by which triglyceride is stored and/or hydrolyzed and mobilized.

Risk of Major Abdominal Surgery in an Asian Population-based Crohn's Disease Cohort.

BACKGROUND: Crohn's disease (CD) is increasing in incidence and prevalence in Asia, but there is a paucity of population-based studies on risk factors for surgery in Asian patients with CD. This will be useful to identify patients who may benefit from top-down treatment. This study describes the rates of abdominal surgery and identifies associated risk factors in Singaporean patients with CD. METHODS: This was a retrospective observational study. The medical records of Singaporeans diagnosed with CD from 1970 to 2013 were reviewed from 8 different hospitals in Singapore. The cumulative probability of CD-related abdominal surgery was estimated using the Kaplan-Meier method. The logistic regression model was used to assess associations between independent risk factors and surgery. RESULTS: The cohort of 430 Singaporean patients with CD included 63.5% Chinese, 11.9% Malay, and 24.7% Indians, with a male to female ratio of 1.6; median follow-up was 7.3 years (range, 2.9-13.0 yr) and median age at diagnosis 30.5 years (range, 19.5-43.7 yr). One hundred twelve patients (26.0%) required major abdominal surgery: the cumulative risk of surgery was 14.9% at 90 days, 21.2% at 5 years, 28.8% at 10 years, 38.3% at 20 years, and 50.6% at 30 years from diagnosis. Of the surgical patients, 75.0% were Chinese, 10.7% Malays, and 14.3% Indians; 21.4% underwent surgery for inflammatory disease, 40.2% for stricturing disease, and 38.4% for penetrating disease. Age at diagnosis (A2 17-40 yr, OR: 2.75, 95% confidence interval [CI], 1.14-7.76), ileal disease (L1 location, OR: 2.35, 95% CI, 1.14-5.0), stricturing (B2 OR: 6.09, 95% CI, 3.20-11.8), and penetrating behavior (B3 OR: 21.6, 95% CI, 9.0-58.8) were independent risk factors for CD-related abdominal surgery. Indian patients were less likely to require surgery (OR: 0.40, 95% CI, 0.19-0.78). CONCLUSIONS: Age at diagnosis, L1 location, B2, and B3 disease behavior are independent risk factors for abdominal surgery. Interestingly, despite a higher prevalence of CD in Indians, a smaller proportion of Indian patients required surgery. These findings suggest that both environmental and genetic factors contribute to the risk of surgery in Asian patients with CD.

Hair cycle-specific immunolocalization of retinoic acid synthesizing enzymes Aldh1a2 and Aldh1a3 indicate complex regulation.

Retinoic acid has long been known to alter skin and hair growth but an exact mechanism is unclear. This study was performed to examine the sites of endogenous retinoic acid synthesis in the cycling hair follicle to better understand the role retinoic acid plays in this process. Retinal dehydrogenases (Aldh1a1, 2, and 3, formerly Raldh 1, 2, and 3) are the enzymes responsible for the last step in retinoic acid synthesis. Immunohistochemistry was performed on adult C57BL/6J mouse skin sections with antibodies against Aldh1a2 and Aldh1a3. Aldh1a2 expression was seen primarily in the outer root sheath and basal/spinous layer during all stages of the hair cycle, and in the bulge during anagen and early catagen, whereas Aldh1a3 expression was primarily in the dermal papilla, pre-cortex, and hair shaft during mid-late anagen. The expression patterns of these two similar retinoic acid synthesizing enzymes at specific follicular sites suggest that they mediate and are regulated by different epithelial proliferation and differentiation signaling pathways.

Estrogen directly induces expression of retinoic acid biosynthetic enzymes, compartmentalized between the epithelium and underlying stromal cells in rat uterus.

Estrogen (E2) has been shown to induce the biosynthesis of retinoic acid (RA) in rat uterus. Here we examined whether E2 could directly induce the enzymes involved in this process by using the ovariectomized rat. A retinol dehydrogenase that we have previously described, eRolDH, and the retinal dehydrogenase, RalDH II, were found to have markedly increased uterine mRNA levels within 4 h of E2 administration, independent of the prior administration of puromycin. eRolDH and RalDH II and their mRNAs were also increased in uteri of rats during estrus. This indicated that RA biosynthesis in rat uterus is directly controlled by E2 and provides a direct link between the action of a steroid hormone and retinoid action. We also examined the cell-specific localization of RalDH II by immunohistochemistry. The enzyme was observed in the stromal compartment, particularly in cells close to the uterine lumenal epithelium. eRolDH was observed only in the lining epithelial cells. Taken together with the previous observations of cellular retinol-binding protein and cellular retinoic acid-binding protein, type two also being expressed in the lumenal epithelium, we propose that RA production is compartmentalized, with retinol oxidation occurring in the lumenal epithelium and subsequent oxidation of retinal to RA occurring in the underlying stromal cells.

Identification, immunolocalization, regulation, and postnatal development of the lipocalin EP17 (epididymal protein of 17 kilodaltons) in the mouse and rat epididymis.

Several lipocalins are present in the mouse epididymis and are thought to play a role in sperm maturation by transporting lipophilic molecules. We have previously reported that two lipocalin genes, mERABP (mouse epididymal retinoic acid binding protein), and mEP17 (mouse epididymal protein of 17 kDa), derived from an ancestral gene, are specifically expressed in the epididymis. In the present study, a polyclonal antibody was raised against a recombinant protein to investigate the presence and the regulation of mEP17. mEP17 was detected in the supranuclear region of the principal cells of the initial segment, the clear cells of the caput epididymidis, and the lumen of the mid/distal caput but not of the distal epididymis. Initial segment and caput tissue extracts were subjected to HPLC separation. After electrophoresis of the immunoreactive mEP17-enriched fractions, the immunoreactive band was analyzed by mass spectrometry to identified mEP17 unambiguously. After two-dimensional electrophoresis, mEP17 appeared as a train of five 22-kDa spots with a range of pI (isoelectric point) from 5.8-6.7. N-glycanase digestion gave rise to a single spot of 17 kDa and pI 6, the predicted mass and pI. During ontogeny, mEP17 was detected as early as 3 wk of age and increased afterward. After bilateral orchiectomy, mEP17 disappeared 2 d after surgery and was not restored after testosterone replacement. After unilateral orchiectomy, mEP17 levels decreased only in the orchiectomized side. After cryptorchidism or busulfan treatment, mEP17 levels were either greatly diminished or not detected. This suggests that mEP17 is dependent on testicular factor(s) that may have a germ cell origin. Altogether, our data demonstrate that mEP17 spatial expression, regulation, and fate are different from that of the highly related mouse epididymal retinoic acid binding protein. This suggests that these two related proteins exhibit distinct functions in the mouse epididymis.

Gastric metastases of oral carcinoma resulting from percutaneous endoscopic gastrostomy placement via the introducer technique.

INTRODUCTION. Tumour cell implantation is a rare complication in patients with head and neck cancers, who have undergone percutaneous endoscopic gastrostomy (PEG) tube placement. It has not been reported in patients who underwent a PEG insertion via the radiological or introducer technique. We describe a novel case presentation of metastatic disease in a patient who underwent PEG placement via the introducer (Russell) technique which, to the best of our knowledge, has not not previously been described. CASE PRESENTATION. The patient was a 37-year-old Malay woman who developed metastatic squamous cell carcinoma deposits in her stomach and liver one month after a gastrostomy tube was removed following the completion of treatment for oropharyngeal carcinoma. CONCLUSION. Previous authors have advocated the use of alternative PEG insertion technique apart from the 'pull' technique to minimise the risk of tumour implantation from head and neck cancers. Our case report suggests that this risk is not totally eliminated when the PEG tube is inserted via the introducer technique.

Retinoid metabolism is altered in human and mouse cicatricial alopecia.

C57BL/6 mice develop dermatitis and scarring alopecia resembling human cicatricial alopecias (CAs), particularly the central centrifugal CA (CCCA) type. To evaluate the role of retinoids in CA, the expression of retinoid metabolism components were examined in these mice with mild, moderate, or severe CA compared with hair cycle-matched mice with no disease. Two feeding studies were conducted with dams fed either NIH 31 diet (study 1) or AIN93G diet (study 2). Adult mice were fed AIN93M diet with 4 (recommended), 28, or 56 IU vitamin A g(-1) diet. Feeding the AIN93M diet to adults increased CA frequency over NIH 31 fed mice. Increased follicular dystrophy was seen in study 1 and increased dermal scars in study 2 in mice fed the 28 IU diet. These results indicate that retinoid metabolism is altered in CA in C57BL/6J mice that require precise levels of dietary vitamin A. Human patients with CCCA, pseudopelade (end-stage scarring), and controls with no alopecia were also studied. Many retinoid metabolism proteins were increased in mild CCCA, but were undetectable in pseudopelade. Studies to determine whether these dietary alterations in retinoid metabolism seen in C57BL/6J mice are also involved in different types of human CA are needed.