Pancreatic cysts: Diagnostic accuracy and risk of inappropriate resections

BACKGROUND

Pancreatic cystic neoplasms (PCN) frequently undergo surgery, given malignant potential. Pancreatic cyst surgery is associated with significant rates of morbidity and mortality. It is crucial to accurately characterize these lesions pre-operatively to avoid unnecessary surgery in patients with benign pancreatic cysts.

AIM

We aimed to assess the correlation between pre-operative (pre-op) diagnosis based on imaging and clinical presentation, and post-operative (post-op) diagnosis based on histopathology in patients undergone pancreatic cyst surgery.

METHODS

From January 2000 to January 2012, we randomly selected 2000 patients with ICD-9 code 211.6 and 577.2. Amongst these we identified 281 patients undergone pancreas surgery. Patients with no pre-op imaging or non-cyst indication for surgery were excluded (n = 107). Imaging details, demographics, pre-operative physician diagnosis and histopathologic details of pancreatic cysts were recorded in 174 patients.

RESULTS

There was a discrepancy between the pre- and post-operative pancreatic cyst diagnosis in 54 (31%) patients. There was no difference in the proportion of various imaging studies (CT, EUS or MRI) between patients with a correct and patients with an incorrect pre-op diagnosis. The pre-op diagnosis was confirmed at pathology in 87.5% of the presumed SCNs, in 80% of the presumed pseudocysts, in 73.3% of the presumed BD-IPMNs, in 66.7% of the presumed MD/mixed-IPMNs and in 53.6% of the presumed MCNs. The accuracy of the pre-operative diagnosis of presumed MCN was significantly lower compared to the non-MCN cysts (53.6% vs. 75%; p = 0.037). Fourteen percent of resections were performed for asymptomatic benign cysts, preoperatively suspected to be potentially pre-malignant cysts.

CONCLUSION

In nearly 1 out of 3 patients undergone pancreas cyst surgery, there is a discrepancy between pre- and post-op diagnosis. Pre-op diagnosis of presumed MCN is more likely to be incorrect, compared to the other cysts.

Associations of Telomere Length and Diabetes with Pancreatic Cancer

Risk for pancreatic cancer increases strongly with older age, and diabetic conditions have been consistently associated with pancreatic cancer, although the temporal relation between diabetes and pancreatic cancer remains uncertain. Telomeres are complexes of proteins and hexameric DNA repeats that cap and protect the ends of chromosomes. Telomere length decreases with subsequent cell divisions and the length of telomeres in peripheral blood leukocytes (PBL) has been observed to be shorter with older age, and shorter among cases of several cancer types than in controls. We conducted a hospital-based case-control study with 500 cases of pancreatic cancer, and 1,000 controls without pancreatic cancer (500 diabetic and 500 non-diabetic). We examined associations between PBL telomere length and pancreatic cancer status using generalized additive models (GAM), adjusting for age, body mass index, and gender. We observed significant heterogeneity in the association between PBL telomere length and pancreatic cancer by fasting blood glucose status (P < 0.003). Among those with impaired fasting blood glucose (>100 mg/dL) there was a continuous inverse association between pancreatic cancer and telomere length in the GAM adjusted for age, body mass index, sex, and cigarette smoking status. The adjusted odds ratio for pancreatic cancer comparing the 10th percentile of telomere length (4,184 bp) to the 90th percentile (7,823 bp) was 3.21 (95% C.I. 1.87, 5.52). In contrast, no significant association was found between telomere length and pancreatic cancer status among those with normal fasting blood glucose (OR = 0.67; 95% C.I. 0.39, 1.05; comparing 10th to 90th percentiles). We did not find strong evidence for effect modification of the relation between PBL telomere length and pancreatic cancer by age, gender, or cigarette smoking status. Shorter telomeres in peripheral blood may portend higher risk for pancreatic cancer among those with impaired fasting blood glucose, or may indicate cases who are more likely to have tumors that result in diabetes.

Human follicular fluid levels of endothelins in relation to oocyte maturity status

The levels of endothelins 1 and 2 (ET-1 and ET-2) have been examined in 415 follicular fluids of 57 women participating in the IVF-ET programme in the University Women's Hospital, Marburg, in relation to the morphological appearance ("maturity") and fertilizability of harvested oocytes as well as to the levels of inhibin, FSH, IGF-1, estradiol and progesterone. Follicular aspiration was done transvaginally in all patients after down regulation with nafareline and ovarian stimulation using urofollitropin and menotropin. Ovulation was induced by hCG. ETs were measured by RIA using commercial kits supplied by Peninsula Laboratories, Belmont, CA. For FF samples, ET-1 and ET-2 RIAs were revalidated. Immunoreactive ET-1 was detectable in all follicular samples, the average level being 18.5 +/- 11.8 pg/ml, ET-2 was present only in 67.5% of the samples, the average level being 13.6 +/- 16.3 pg/ml. There was no significant difference in the average levels of ET-1 in the fluids of small, medium and large follicles. However, there was a significantly higher level of ET-2 in the fluids of medium compared to large follicles and there was a negative correlation of the ET-2 levels to the volume of the follicle (p < 0.01) which suggests that ET-2 could play a role during the maturation of the ovarian follicles. Unlike ET-1, the mean concentrations of ET-2 were significantly higher in the fluids with oocytes which could be fertilized and cleaved than in those with oocytes which did not fertilize or cleave, thus indicating a role for ET-2 in the process of oocyte maturation. No correlations of ET levels were found with the levels of inhibin, FSH, estradiol and progesterone. However, ET-2 levels significantly correlated with the levels of IGF-1 (p < 0.001) indicating a possible synergistic effect of endothelins and IGF-system. In conclusion, this study is further evidence for a physiological role of the ETs in the human ovary.

Microarray Technologies for Gene Transcript Analysis in Pancreatic Cancer

Pancreatic cancer is a devastating condition that is most often characterized by a poor prognosis. Microarray technologies are promising screening methods for the identification of potential markers for early diagnosis and chemotherapeutic intervention. In this article, we review the current state of pancreatic cancer research as it relates to the measurement of gene transcript levels by DNA microarray analysis.

Thioredoxin-interacting protein deficiency disrupts the fasting-feeding metabolic transition

Through a positional cloning approach, the thioredoxin-interacting protein gene (Txnip) was recently identified as causal for a form of combined hyperlipidemia in mice (Bodnar, J. S., A. Chatterjee, L. W. Castellani, D. A. Ross, J. Ohmen, J. Cavalcoli, C. Wu, K. M. Dains, J. Catanese, M. Chu, S. S. Sheth, K. Charugundla, P. Demant, D. B. West, P. de Jong, and A. J. Lusis. 2002. Positional cloning of the combined hyperlipidemia gene Hyplip1. Nat. Genet. 30: 110-116). We now show that Txnip-deficient mice in the fed state exhibit a metabolic profile similar to fasted mice, including increased levels of plasma ketone bodies and free fatty acids, decreased glucose, and increased hepatic expression of peroxisome proliferator-activated receptor-gamma coactivator-1alpha, phosphoenolpyruvate carboxykinase, glucose-6-phosphatase, and acyl-CoA oxidase. Dramatic differences in the expression of key metabolic enzymes were also observed in other tissues, and the fat-to-muscle ratio of Txnip-deficient mice was increased by approximately 40%. We demonstrate an effect of Txnip on the redox status, as the Txnip-deficient mice in the fed state had a significant increase in the ratio of NADH to NAD(+). Surprisingly, we observed that Txnip-deficient mice and wild-type mice had similar levels of thioredoxin activity, suggesting that the effects of Txnip deficiency may be mediated in part by other interactions. These results indicate a role for Txnip in the metabolic response to feeding and the maintenance of the redox status.

A role for leukotriene antagonists in atopic dermatitis?

Atopic dermatitis is a chronic, relapsing skin condition that affects over 2% of the population. The pathophysiology of this disease is not completely understood, but immunologic abnormalities and the subsequent release of inflammatory mediators play a central role. Treatment with glucocorticoids has long been the standard of care, but their use is limited by their adverse effect profile. Leukotrienes (LTB4, LTC4, LTD4, and LTE4) are metabolites of arachidonic acid produced through the 5-lipoxygenase pathway. They play an important role in inflammatory and atopic conditions. LT modulating agents have been used with success in asthma. Recently, there has been increased interest in the potential utility of LT antagonists in atopic dermatitis. In vitro and in vivo data have demonstrated that LTs may play a key role in atopic dermatitis. The 2 different types of LT-modulating agents are 5-lipoxygenase inhibitors and LT receptor antagonists. Since the 5-lipoxygenase inhibitor acts at an earlier step in the LT synthetic pathway, it has the ability to alter the production of all the LTs, including LTB4, while the receptor antagonists target only the cysteinyl LTs, LTC4, LTD4, and LTE4. This reduction of LTB4 activity may point to a therapeutic advantage in using LT synthesis inhibitors as opposed to LT receptor antagonists for atopic dermatitis. Clinical evidence of the use of LT agents in atopic dermatitis is limited, but initial results have been promising and these agents may one day serve as corticosteroid-sparing treatments for atopic dermatitis.

Solution-phase, parallel synthesis and pharmacological evaluation of acylguanidine derivatives as potential sodium channel blockers

Solution-phase synthesis of various acylguanidine derivatives and the evaluation of a small library of compounds as potential sodium channel blockers are described.

Phosphorylation of MAP4 affects microtubule properties and cell cycle progression

In human cells, MAP4, a microtubule-associated protein ubiquitously expressed in proliferating cells, has been shown to undergo in vivo phosphorylation. Two phosphorylation sites, serines 696 and 787, lie within the proline-rich region of its microtubule-binding domain. To test the hypothesis that phosphorylation at these sites influences microtubule properties or cell cycle progression, we prepared stable cell lines that inducibly express versions of MAP4 in which phosphorylation of these two serines was prevented by their replacement with alanine, lysine, or glutamate residues (AA-, KK-, or EE-MAP4). All non-phosphorylatable mutant forms of MAP4 expressed in mouse Ltk- cells were localized to MT arrays that were unremarkable in appearance. Expression of non-phosphorylatable mutants of MAP4 did not affect cell doubling time; however, expression of some mutants altered progression into or through cell division. Interactions of mutant MAP4 with MTs were examined in vitro. KK mutant MAP4 bound MTs more avidly than its wild-type counterpart, WT-MAP4. In vivo MT polymer also differed among the mutants: MTs in cells expressing the KK- and AA-MAP4 forms were more resistant to nocodazole depolymerization than those in cells expressing EE- or WT-MAP4 forms. Our results demonstrate that phosphorylation alters MAP4 properties and suggest a raison d'être for phosphorylation of the MAP4 microtubule-binding domain during cell cycle progression.

The efficiency of simian foamy virus vector type-1 (SFV-1) in nondividing cells and in human PBLs

Current retroviral vectors based on murine leukemia virus (MuLV) are unable to efficiently transduce nondividing cells. Lentiviruses, such as the human immunodeficiency virus 1 (HIV-1) are efficient at transducing nondividing, growth-arrested, and post-mitotic cells, but due to complex safety considerations, they may have limited potential for human clinical gene transfer. For this reason, alternatives to MuLV and HIV-1 vectors need to be explored. In this paper, we have found that simian foamy virus vector (SFV-1) containing a CMV-LacZ expression cassette is able to efficiently transduce multiple cell types of various species that include epithelial, lymphoid, and hematopoietic-derived human cell lines and fibroblast cell lines of several species. Previously it was reported that foamy virus replication is cell cycle dependent (P. D. Bieniasz, R. A. Weiss, and M. O. McClure, 1995. J. Virol. 69, 7295-7299). However, others studies demonstrated nuclear import of viral DNA in arrested cells (A. Saibi, F. Puvion-Dutilleul, M. Schmid, J. Peries, and H. d. The 1997. J. Virol. 71, 1155-1161). Here, we show efficient LacZ transduction by SFV-1 vectors in several chemically arrested cell lines and terminally differentiated human neurons. SFV-1 vector can transduce cell lines arrested in G1/S phase of the cell cycle by aphidicolin treatment with similar efficiencies to that of dividing cells. The terminally differentiated human neural cell line, NT2N, was transduced with 30-50% efficiency, corroborating our data obtained with the arrested cell lines. To further examine whether the SFV-1 vector can efficiently deliver a gene into clinically important cells for gene therapy, we transduced primary human peripheral blood cells (PBLs) in the presence and absence of phytohemagglutanin (PHA) stimulation. We observed 81% transduction efficiency in non-stimulated PBLs and 87% in PHA-stimulated PBLs with vector infection carried out twice in 8 hours intervals at a multiplicity of infection of 1. Together, these data indicate that SFV-1 based retroviral vectors may provide a safe, efficient alternative to current onco- and lentiviral vectors for gene transfer in cells from a broad spectrum of lineages across species boundaries.

Lipid peroxidation and antioxidant enzymes in coronary and peripheral artery disease

There is a strong co-relation in between the levels of blood lipids in patients of different subgroups of CAD, however this is not present in the case of subgroups of patients in PAD. Moreover levels of MDA and antioxidant enzymes are also significantly altered in the subgroups of CAD but the correlation is weak in that of PAD. Thus these values may serve as a clinical support for experimental data and supplementary information regarding atheromatous disease.

Detection of malingering through the use of raven's standard progressive matrices

Raven's Standard Progressive Matrices (SPM) has been suggested to assist in the detection of malingering, and a putatively validated formula method for defining genuine and fake performances is available In the present study, 47 normal individuals were asked to fake cognitive impairment on the SPM; a day later, their genuine performances were obtained. As expected, the genuine performances were significantly superior to the faked performances: however, the formula method failed to distinguish between the two. The present study used logistic regression analysis to model genuine and faked performances; the method resulted in a 74.5% accurate classification. It is concluded that, while the SPM may be useful in certain cases, it cannot reliably detect malingering.

Isolation of differentially expressed genes in hypertensive pulmonary artery of rats

Pulmonary artery remodeling is a complex biological process, and a key molecular mechanism regulating this process is selective up- and downregulation of genes. We used reverse transcriptase-polymerase chain reaction (RT-PCR) differential display in a rat model of hypoxic pulmonary hypertension to identify selectively expressed genes relevant to pulmonary artery remodeling. We characterized the pattern of gene expression in hypertensive and normal arteries. Eight differentially expressed cDNAs were selected, isolated, and characterized. Homology searches identified 4 previously identified genes and 4 novel genes that were not further characterized. The known genes were beta-glucoronidase, hemeoxygenase-2 (HO-2), glycerol-3-phosphate dehydrogenase, and cytoplasmic gamma-actin. Each of the 4 known genes was relevant to processes involved in pulmonary artery remodeling. We conclude that mRNA differential display was informative in identifying genes coding for products directly involved in pulmonary artery remodeling.

D4 dopamine receptor-mediated phospholipid methylation and its implications for mental illnesses such as schizophrenia

Previous studies have shown D2-like dopamine receptor involvement in the regulation of phospholipid methylation (PLM), while others have documented impaired methionine and folate metabolism in schizophrenia. Utilizing [14C]formate labeling in cultured neuroblastoma cell lines, we now show that D4 dopamine receptors (D4R) mediate the stimulatory effect of dopamine (DA) on PLM. The effect of DA was potently blocked by highly D4R-selective antagonists and stimulated by the D4R-selective agonist CP-226269. DA-stimulated PLM was dependent upon the activity of methionine cycle enzymes, but DA failed to increase PLM in [3H]methionine labeling studies, indicating that a methionine residue in the D4R might be involved in mediating PLM. A direct role for MET313, located on transmembrane helix No. 6 immediately adjacent to phospholipid headgroups, was further suggested from adenosylation, site-directed mutagenesis and GTP-binding results. A comparison of PLM in lymphocytes from schizophrenia patients vs control samples showed a four-fold lower activity in the schizophrenia group. These findings reveal a novel mechanism by which the D4R can regulate membrane composition. Abnormalities in D4R-mediated PLM may be important in psychiatric illnesses such as schizophrenia.

cis-Acting sequences required for simian foamy virus type 1 vectors

We have constructed a series of vectors based on simian foamy virus type 1 (SFV-1) to define the minimum cis-acting elements required for gene transfer. To characterize these vectors, we inserted the coding sequence of the bacterial lacZ gene linked to the cytomegalovirus immediate-early gene promoter. Introduction of a deletion mutation in the leader region between the 5' long terminal repeat and the start of the gag gene at position 1659 to 1694 completely abrogated gene transfer by the SFV-1 vector. Deletion of 39 nucleotides from position 1692 to 1731 in the leader region resulted in a significant reduction in the transducing-particle titer. Furthermore, we have identified a second cis-acting element located at the 3' end of the pol gene between position 6486 and 6975 to be critical for SFV-1 vector transduction. These results identify the two important cis-acting elements required for SFV-1 vector construction, and the finding of a cis-acting element in the pol gene is unique among retroviruses.

MAP4 is the in vivo substrate for CDC2 kinase in HeLa cells: identification of an M-phase specific and a cell cycle-independent phosphorylation site in MAP4

We reported previously that cdc2 kinase decreased the microtubule-stabilizing ability of a major HeLa cell microtubule-associated protein, MAP4, by phosphorylation in vitro [Ookata, K., et al. (1995) J. Cell Biol. 128, 849-862]. An important question raised by this study is whether MAP4 is indeed phosphorylated by cdc2 kinase at mitosis in vivo. We present here evidence that cdc2 kinase is the major M-phase MAP4 kinase, and, further, we identify two phosphorylation sites within the proline-rich domain of MAP4. Metabolic 32P labeling showed the increased phosphorylation of MAP4 at mitosis. A specific inhibitor of cdc2 kinase, butyrolactone I, inhibited phosphorylation of MAP4 both in mitotic HeLa cells and in the mitotic HeLa cell extract. The phosphopeptide map analysis revealed the high similarity of in vivo labeled mitotic MAP4 to that phosphorylated by cdc2 kinase in vitro. Ser-696 and Ser-787, both of which lie within SPXK consensus sequences for cdc2 kinase, were identified as phosphorylation sites in the proline-rich region of MAP4 in vivo and in vitro. Immunoblotting with antibodies that recognize the phosphorylation state of Ser-696 or Ser-787 showed that Ser-787 in the SPSK sequence was specifically phosphorylated at mitosis while Ser-696 in the SPEK sequence was phosphorylated both at mitosis and in interphase. These results suggest that cdc2 kinase directly regulates microtubule dynamics at mitosis through phosphorylation of MAP4 at a number of sites, including Ser-787.

Biphasic activation of p21ras by endothelin-1 sequentially activates the ERK cascade and phosphatidylinositol 3-kinase

Endothelin-1 (ET-1) induces cell proliferation and differentiation through multiple G-protein-linked signaling systems, including p21ras activation. Whereas p21ras activation and desensitization by receptor tyrosine kinases have been extensively investigated, the kinetics of p21ras activation induced by engagement of G-protein-coupled receptors remains to be fully elucidated. In the present study we show that ET-1 induces a biphasic activation of p21ras in rat glomerular mesangial cells. The first peak of activation of p21ras, at 2-5 min, is mediated by immediate association of phosphorylated Shc with the guanosine exchange factor Sos1 via the adaptor protein Grb2. This initial activation of p21ras results in activation of the extracellular signal-regulated kinase (ERK) cascade. We demonstrate that ET-1 signaling elicits a negative feedback mechanism, modulating p21ras activity through ERK-dependent Sos1 phosphorylation, findings which were confirmed using an adenovirus MEK construct. Subsequent to p21ras and ERK deactivation, Sos1 reverts to the non-phosphorylated condition, enabling it to bind again to the Grb2/Shc complex, which is stabilized by persistent Shc phosphorylation. However, the resulting secondary activation of p21ras at 30 min does not lead to ERK activation, correlating with intensive, ET-1-induced expression of MAP kinase phosphatase-1, but does result in increased p21ras-associated phosphatidylinositol 3-kinase activity. Our data provide evidence that ET-1-induced biphasic p21ras activation causes sequential stimulation of divergent downstream signaling pathways.

Inhibition of FIV replication by a ribozyme that targets the Rev response element

The feline immunodeficiency virus (FIV) Rev protein and its cognate sequence the Rev response element (RRE) are essential for virus replication. Thus, the inhibition of either Rev or RRE function can significantly inhibit FIV replication. In the present study, we constructed a ribozyme that targets the RRE sequence and determined its ability to inhibit FIV replication. The RRE ribozyme cleaved the target molecule both in vitro and in FIV-infected cells. Furthermore, FIV replication was reduced significantly in the presence of the RRE ribozyme. FIV provides a good animal model system with which to develop novel antiviral strategies for the human immunodeficiency virus.

Overexpression of full- or partial-length MAP4 stabilizes microtubules and alters cell growth

To investigate the in vivo functions of MAP4, a microtubule-associated protein expressed almost ubiquitously in vertebrate cells, we prepared stably transfected clonal mouse Ltk- cell lines expressing full-length MAP4 (L-MAP4 cells) or its MT-binding domain (L-MTB cells). Although transfectants showed no dramatic defect in morphology, organellar distribution, or level of MT polymer, as compared to naive Ltk- cells or L-MOCK cells (transfected with vector alone), MTs in L-MAP4 and L-MTB cells showed greater stability than those in control cells, as monitored by the level of post-translationally detyrosinated alpha-tubulin and by a quantitative nocodazole-resistance assay. In vivo, the MT-binding domain of MAP4 stabilized MTs less potently than full-length MAP4, in contrast to the equivalent efficacy demonstrated in studies of in vitro MT polymerization (Aizawa et al. (1991), J. Biol. Chem. 266, 9841–9846), L-MAP4 and L-MTB cells grew significantly more slowly than control cells; this growth inhibition was not due to mitotic arrest or cell death. L-MAP4 and L-MTB cells also exhibited greater tolerance to the MT-depolymerizing agent, nocodazole, but not to the MT-polymerizing agent, Taxol. Our results demonstrate that MAP4 and its MT-binding domain are capable of MT stabilization in vivo, and that increasing the intracellular level of MAP4 affects cell growth parameters.

Expression of mRNA for ovarian steroid-stimulating factor (apolipoprotein A-I and apolipoprotein A-I-like protein) in human granulosa cells

Sequential chromatography of human follicular fluid (hFF) on Sephadex G-50, Q-Sepharose and finally Cibracon Blue yielded a protein molecule which biologically had a stimulating effect on steroid secretion (SSF) by ovarian granulosa cells in vitro. SDS-gel electrophoresis followed by blotting on PVDF membrane of the biologically active fraction revealed 3 bands of ca. 28, 27 and 24 kDa. The N-terminal sequence of the 3 bands corresponded completely with that of apolipoprotein A-I. In view of this, it was of interest to examine whether human ovary expresses apo A-I. Using specific primers for apo A-I and apo A-I-like protein (ALP; Richardson et al., 1996), we could demonstrate the presence of mRNA for apo A-I as well as ALP in the granulosa cells. The expression of ALP was found to be much higher than that of apo A-I. Like hFF-protein, purified apo A-I could also stimulate steroid secretion by human granulosa cells incubated in the presence of cholesterol. The functional role of ovarian apo A-I/ALP may be speculated as a transport molecule for steroid precursors.

Comparison of the effects of the M1-receptor antagonist telenzepine and the CCK-receptor antagonist loxiglumide on the pancreatic secretory response to intraduodenal tryptophan in dogs

In six conscious dogs with chronic gastric and pancreatic fistulas we compared the action of different doses (20.25 to 81.0 nmol/kg/h) of the muscarinic M1-receptor antagonist telenzepine, the cholecystokinin (CCK) antagonist loxiglumide (2.5 to 10.0 mg/kg/h) and several combinations of both drugs on the pancreatic secretory response to intraduodenal perfusion of graded loads of tryptophan (0.37-10.0 mmol/h) given against a background of secretin (20.5 pmol/kg/h i.v.). Except for 20.25 nmol/kg/h telenzepine, all tested doses of telenzepine and/or loxiglumide decreased the 180-min integrated bicarbonate response to tryptophan by 55 to 119%. Except of 20.25 nmol/kg/h telenzepine and/or 2.5 mg/kg/h loxiglumide, all tested doses of telezepine and/or loxiglumide inhibited the tryptophan stimulated integrated pancreatic protein responses by 54 to 88%. While telenzepine mainly inhibited the bicarbonate and protein response to the lower loads of tryptophan (0.37-1.1 mmol/h), loxiglumide decreased the response to all loads of tryptophan. The inhibition evoked by the combinations of telenzepine and loxiglumide was not significantly greater than that by single infusion of either drug. The CCK plasma levels basally and in response to tryptophan were not significantly altered by telenzepine and/or loxiglumide. These findings indicate that (1) both enteropancreatic cholinergic reflexes and the hormone CCK are mediators of the protein response to intraduodenal trytophan (2) enteropancreatic cholinergic reflexes are probably the dominant mediators of the response to low amounts of tryptophan, whereas CCK is the major mediator of the response to high loads of tryptophan, (3) the two mediators seem to act independently of each other, and (4) the release of CCK by intestinal trytophan is not influenced by telenzepine or loxiglumide.

Does Crohn's disease need differentiation from tuberculosis?

Crohn's disease (CD) and tuberculosis (TB) of the gastrointestinal tract pose major diagnostic problems for clinicians where these conditions coexist. Clinically and radiologically, the diseases are similar. In the West, TB is considered in the differential diagnosis of all suspected cases of CD, particularly among Asian migrants. Earlier age of presentation, perianal disease and enteric fistulae favour a diagnosis of CD. Aphthoid ulceration, pseudopolyps and filiform mucosa at endoscopy are suggestive of CD and a negative tuberculin test us useful. The final diagnosis depends largely on histopathology and the presence or absence of acid fast bacilli. Tuberculosis is more common in developing countries and intestinal TB frequently coexists with pulmonary tuberculosis. TB is known to affect all age groups and fistulous communication, although uncommon, does occur. In addition to radiology and endoscopy, laparotomy may be required to establish the diagnosis. In developing countries, CD is uncommon and remains largely a diagnosis of exclusion. A trial of anti-tuberculosis therapy may often be prescribed before definitely diagnosing CD. The development of molecular biology techniques had led to a revival of interest in mycobacteria as a possible aetiological agent in CD. DNA from Mycobacterium paratuberculosis and Mycobacterium kansaii have both been identified in CD cases but the significance of this finding has not been established. However, in the near future polymerase chain reaction will become increasingly useful in differentiating CD from intestinal TB because it allows the amplification and identification of very small quantities of mycobacterium DNA.

Teratogenicity and transplacental pharmacokinetics of 13-cis-retinoic acid in rabbits

No embryotoxic or teratogenic effects, considered to be treatment related, were observed in rabbits after daily oral doses of 3 mg/kg of 13-cis-retinoic acid (13-cis-RA) from Day 8 to Day 11 of gestation. In contrast, treatment with 15 mg/kg/day significantly increased the rate of fetal resorptions (22%) and 13 out of 68 surviving fetuses (16%) were malformed. Pharmacokinetic studies with both dosing regimens of 13-cis-RA in pregnant rabbits showed that on Day 11 of gestation, high concentrations of parent compound, 13-cis-RA, and its major metabolite, 13-cis-4-oxoRA, existed in maternal plasma. Much lower concentrations were found for all-trans-4-oxoRA and all-trans-RA. The area under the concentration-time curve (AUC) of all-trans-RA following the 15 mg/kg/day dosing regimen of 13-cis-RA was only 1.2% that of parent compound 13-cis-RA. At this dose, embryo levels of 13-cis-RA, 13-cis-4-oxoRA, and all-trans-4-oxoRA were 2.5-, 4.7-, and 3.6-fold higher by AUC comparison (24-hr period of Day 11) compared with the dose of 3 mg/kg. However, embryo levels of all-trans-RA were virtually identical at both doses and were, in fact, somewhat lower than endogenous concentrations measured in untreated rabbit embryos. In contrast to mice, where isomerization from 13-cis- to all-trans-RA was suggested to be crucial for the teratogenic action of 13-cis-RA, we found that the teratogenic action of 13-cis-RA (15 mg/kg/day) in rabbits is characterized by increased whole embryo concentrations of 13-cis-RA, 13-cis-4-oxoRA, and all-trans-4-oxoRA, but not of all-trans-RA.

[Pathophysiologic concepts and protective possibilities in experimental pancreatic lesions]

Experimental pancreatic lesions can be induced by a number of different procedures, e.g. pancreatic hyperstimulation, intraductal application of bile acids, feeding choline deficient diet, obstruction of pancreatic duct, or reducing pancreatic blood flow. The pathogenetic mechanisms leading to pancreatic lesions include basolateral enzyme secretion, acinar cell polarisation defect, intracellular activation of proteases, and the production of free radicals and other active metabolites. The importance of these individual mechanisms in the production and progression of different experimentally-induced pancreatic lesions remains speculative. These pathogenetic concepts have inspired the study of a number of substances likely to protect the pancreas and prevent the pancreatic lesions. This paper gives an overview of the pathogenetic concepts of development of and protection against experimental pancreatic lesions produced in animal models. Special mention has been made of an animal model of pancreatic lesion produced by immunosuppressives.

Alcohol and gastric acid secretion in humans

The secretory response of gastric acid to pure ethanol and alcoholic beverages may be different because the action of the non-ethanolic contents of the beverage may overwhelm that of ethanol. Pure ethanol in low concentrations (< 5% vol/vol) is a mild stimulant of acid secretion whereas at higher concentrations it has either no effect or a mildly inhibitory one. Pure ethanol given by any route does not cause release of gastrin in humans. Alcoholic beverages with low ethanol content (beer and wine) are strong stimulants of gastric acid secretion and gastrin release, the effect of beer being equal to the maximal acid output. Beverages with a higher ethanol content (whisky, gin, cognac) do not stimulate gastric acid secretion or release of gastrin. The powerful stimulants of gastric acid secretion present in beer, which are yet to be identified, are thermostable and anionic polar substances. The effect of chronic alcohol abuse on gastric acid secretion is not as predictable. Chronic alcoholic patients may have normal, enhanced, or diminished acid secretory capacity; hypochlorhydria being associated histologically with atrophic gastritis. There are no studies on the acute effect of alcohol intake on gastric acid secretion in chronic alcoholic patients. The acid stimulatory component of beer and wine needs to be characterised and its possible role in the causation of alcohol induced gastrointestinal diseases needs to be investigated.

Isolation of luteinising hormone receptor binding inhibitor from bovine corpus luteum

A luteinising hormone receptor binding inhibitor (LHRBI) has been purified from bovine corpus luteum (CL). Steroid-free extract of the CL was subjected to successive chromatographies on Sephadex G-50, Q-Sepharose, Orange A dye and metal chelate affinity columns followed by high performance-reverse phase and gel filtration columns. Purification was monitored by the ability of the fractions to inhibit the binding of 125I-human chorionic gonadotropin (hCG) to porcine granulosa cells in vitro. The final isolate showed an 8000-fold enrichment of activity. It was also capable of inhibiting porcine granulosa cell secretion of estradiol and progesterone (P) in vitro. Administration of LHRBI into follicle-stimulating hormone (FSH)-stimulated, immature rats strongly inhibited the ovarian ovulatory response to hCG as revealed by decreased P levels and the number of ova released. The M(r) of LHRBI as assessed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis was ca. 15 kDa and the pI was between 5.0 and 5.5.

Radiological appearance of pancreatic calculi in tropical versus alcoholic chronic pancreatitis

Tropical and alcoholic forms of chronic pancreatitis differ in their clinical, aetiological and epidemiological features. We compared the radiological appearances of pancreatic calculi seen on plain roentgenogram of the abdomen of 89 patients with tropical calcific pancreatitis (TCP) and 32 patients with alcoholic calcific pancreatitis (ACP) seen in Madras, Southern India. While TCP was characterized by the frequent occurrence of large, discrete, dense calculi, patients with ACP had typically small, speckled calculi with irregular, hazy margins. The calculi in TCP resembled those described for hereditary pancreatitis. This is the first report comparing the radiological appearances of TCP and ACP patients seen at the same centre.

Faecal chymotrypsin assay in tropical and alcoholic chronic pancreatitis

Faecal chymotrypsin (FCT) levels were estimated in a group of patients with tropical chronic pancreatitis (TCP) and compared with patients with alcoholic chronic pancreatitis (ACP), 'gastrointestinal' controls and 'healthy' subjects. Exocrine pancreatic insufficiency as assessed by low faecal chymotrypsin levels (less than 5.8 mu/g) were present in 85.7 per cent of TPC and 84.6 per cent of ACP patients. Mean FCT levels as well as the distribution of FCT values were similar in TCP and ACP patients and significantly lower than the two control groups (P less than 0.001). There was also no difference with respect to mean FCT levels between subgroups of TCP patients with and without diabetes and those with and without calcification. Faecal chymotrypsin assay is a simple test for diagnosis of chronic pancreatitis in gastroenterological centres in tropical countries.

Plasma glucagon responses in tropical fibrocalculous pancreatic diabetes

Plasma insulin and glucagon responses to a glucose load were measured in a group of patients with fibrocalculous pancreatic diabetes (FCPD) and compared with patients with noninsulin-dependent diabetes mellitus (NIDDM) and control subjects. Both diabetic groups had markedly diminished insulin responses but the differences between FCPD and NIDDM groups were not significant. In control subjects, in response to the glucose load, plasma glucagon levels decreased while they increased in NIDDM patients. In FCPD patients there was no significant change in glucagon levels in response to the glucose load. The study shows that FCPD patients lack pancreatic alpha-cell responses to a glucose load. This may play a role in protecting these patients against ketosis.

Fibrocalculous pancreatic diabetes and obesity

Fibrocalculous pancreatic diabetes (FCPD) is a form of diabetes secondary to chronic pancreatitis that is found in tropical countries. Most patients with FCPD are lean and many are frankly undernourished. Four patients with FCPD who were obese are reported in this paper and this is the first report of obesity in FCPD patients.

Exocrine pancreatic function in tropical fibrocalculous pancreatic diabetes

Exocrine pancreatic function was studied by fecal chymotrypsin test in three groups of diabetic patients seen in southern India. Exocrine pancreatic insufficiency, as shown by low fecal chymotrypsin levels, was seen in 87.5% of patients with fibrocalculous pancreatic diabetes (FCPD), in 23.5% of insulin-dependent diabetes mellitus patients, and in 4.5% of non-insulin-dependent diabetes mellitus patients. There was no correlation between fecal chymotrypsin levels and serum amylase, serum lipase, age, body mass index, duration of diabetes, fasting plasma glucose, or glycosylated hemoglobin levels. The fecal chymotrypsin test is a useful additional investigation for the diagnosis of FCPD found in tropical countries.

Young v adult cirrhotics: a prospective, comparative analysis of the clinical profile, natural course and survival

In order to assess the frequency and profile of cirrhosis in the young, 169 consecutive patients with cirrhosis were studied. Sixty three (37%) patients of less than or equal to 35 years age were defined as young and the remaining 106 (63%) patients (greater than 35 years) as adult cirrhotics. Men predominated significantly (p less than 0.01) in the young cirrhotic group. The aetiology, the frequency of positive hepatitis B markers and initial clinical presentation were similar in the two groups. During the follow up period (30.6 +/- 29.7 months for the young and 25.8 +/- 21.7 months for the adult group), except for abdominal distension and pedal oedema which occurred significantly more often in the adult compared with the young cirrhotics, no difference was noted in the two groups. Twenty seven (39.7%) deaths (40% as a result of hepatic failure and 52% due to variceal bleeding) occurred in the young and 47 (44.3%) deaths (63.8% because of hepatic failure and 26% because of variceal bleeding) occurred in the adult cirrhotics during the follow up (difference NS). The five year survival (61.9% v 55.7%) and the probability of survival within the same Child's grade of liver disease were comparable. In both the groups, however, the probability of survival was significantly higher in Child's A compared with Child's B and C and in Child's B compared with Child's C grade of liver disease. Survival was not influenced by sex of the patient and aetiology of cirrhosis. Results of this prospective study indicate that cirrhosis is not uncommon in young adults. The aetiology, clinical presentation, natural history of the disease and the survival rates in young cirrhotics do not differ significantly from adult cirrhotics.

Intravariceal versus paravariceal sclerotherapy: a prospective, controlled, randomised trial

Fifty four consecutive patients with oesophageal variceal bleeding were randomised to undergo intravariceal (28 patients) or paravariceal (26 patients) sclerotherapy, every three weeks. Intravariceal technique was found significantly (p less than 0.01) more effective in controlling active variceal bleeding than the paravariceal technique (91% v 18.7% respectively). The mean (+/- SD) time taken for variceal eradication by intravariceal sclerotherapy (15.4 +/- 5.3 weeks) was significantly (p less than 0.001) less than paravariceal (26.8 +/- 6.6 weeks) technique. The number of sclerotherapy sessions needed with intravariceal technique were also significantly less. Rebleeding was seen in 38.5% patients after para and 14.3% after intravariceal injections (NS). Except for retrosternal pain, which occurred more often (p less than 0.01) with paravariceal technique, there was no difference in the incidence of other complications or mortality between the two groups. Variceal recurrence was seen in seven patients (25%) in the intra and one (3.9%) patient in the paravariceal group (p less than 0.01) after a mean follow up of 29.4 +/- 9.1 weeks. Intravariceal sclerotherapy was superior to paravariceal in the control of active variceal bleeding and for total variceal obliteration, but was associated with a higher variceal recurrence.

Regulators of steroid secretion and inhibin activity in human ovarian follicular fluid

Inhibin activity from human follicular fluid was purified by successive chromatographies on Sephadex G-50, DEAE-Biogel A and orange A dye matrix. Inhibin activity was associated only with the protein(s) that bound to orange A (OrA-2). Daily injection of OrA-2, 1 h prior to hMG into 10-day-old female rats for 4 days caused a significant inhibition of hMG-induced estradiol secretion. In vitro, OrA-2 dose-dependently inhibited the amounts of estradiol secreted by porcine granulosa cells during a 3-h incubation. Orange A-unbound proteins, on the other hand, induced a dose-dependent increase in estradiol as well as progesterone secretion by porcine granulosa cells in vitro. Separation of stimulator from the inhibitor by orange A chromatography led to an increase in the relative inhibin activity (25-50-fold) as well as aromatisation-suppressing activity (60-fold). The results indicate a possible local action of hFF inhibin to regulate aromatisation activity.

On the identity of bovine seminal plasma inhibin

In light of current discussions on multiple forms of inhibin, it was thought of interest to ascertain the identity of the postulated 'iso-hormones' of bull seminal plasma inhibin (Chari et al., 1978). By subjecting the biologically active fraction, obtained by Sephadex G-100 gel filtration of bull seminal plasma acetone powder, to extensive dialysis in distilled water adjusted to pH 5.8, it was possible to remove the bulk of inert protein as a precipitate. The resulting active preparation could be readily fractionated by preparative iso-electric focusing in the pH range 4.0-6.5 yielding 2 distinct homogeneous peptides, alpha and beta, capable of suppressing hCG-induced uterine weight increase in immature mice, in a 'reversed Steelman-Pohley' assay design. However, of these, alpha alone was able to suppress post-castrational serum gonadotropin rise in appropriate animal models. This peptide is highly acidic in nature (iso-electric point congruent to 2.2) and has a molecular weight (Mr) of 18200 and a Stokes radius of 1.90 nm. On the basis of currently available evidence, it is concluded that the molecule consists of a single peptide chain.

Oocyte maturation as regulated by follicular factors

Follicular fluid (FFl), obtained from 24 women treated with clomiphene/hCG in an in vitro fertilization program, was characterized with respect to steroid hormone levels and oocyte maturation inhibitor (OMI) activity. Three FFl samples apparently were derived from cystic follicles and contained low steroid levels and no OMI activity in an in vitro rat oocyte assay. The remaining 21 follicles contained normal preovulatory steroid levels and mature and generally fertilizable oocytes. In 7 of these follicles the FFl (at 50% concentration) significantly inhibited rat oocyte meiosis, while 14 exerted no OMI activity. The results confirm earlier work on porcine and human FFl, suggesting that the putative OMI activity declines with follicular maturation.

Simplification of the method of in vitro fertilization: sonographic measurements of follicular diameter as the sole index of follicular maturity

As a simplification of the in vitro fertilization (IVF) procedure, repeated sonographic scanning of follicular diameters in stimulated cycles was performed, until the largest visible follicle reached a mean diameter of at least 20 mm, at which time human chorionic gonadotropin (hCG) was administered. Follicle puncture was performed either guided by sonography or by laparoscopy 34-36 hr after the hCG injection, and following insemination oocytes were cultured for 48-60 hr before embryo transfer (ET). Serum levels of luteinizing hormone (LH), prolactin (PRL), and estradiol-17 beta (E2) at the time of hCG injection as well as follicular fluid levels of follicle stimulating hormone (FSH), LH, and PRL as well as progesterone (P), testosterone (T), and E2 at the time of puncture were determined in retrospect using specific radioimmunoassay (RIA). It was found that the knowledge of a single value of LH or E2 in serum should have been of little additional value for the decision to give hCG in all stimulation models used: clomiphene + hCG, human menopausal gonadotropin (hMG) + hCG, and clomiphene + hMG + hCG. The concentrations of the three steroids measured in follicular fluid were, in a high proportion of the follicles, within a normal range in all stimulation models. The group receiving clomiphene + hMG + hCG appeared promising through its higher proportion of estrogenic follicles. It is concluded that sonographic measurement of follicular diameters may be used as the sole index of follicular maturity in an IVF program.(ABSTRACT TRUNCATED AT 250 WORDS)

[Sex hormones and fertility following portacaval anastomosis in rats]

Portocaval anastomosis (PCA) in the normal male rat causes profound alterations in testicular morphology and function and in plasma levels of sex steroids as well as of gonadotropins. Testicular atrophy is accompanied by a significant decrease of plasma testosterone (0.03 ng/ml versus 0.99 ng/ml) and an increase of estradiol (76.2 pg/ml versus 39.7 pg/ml) and estrone (68. pg/ml versus 45.5 pg/ml). Plasma levels of gonadotropins (LH, FSH) and prolactin are lowered too (LH: 15 ng/ml versus 28.5 ng/ml, FSH:119 versus 182 ng/ml, prolactin:53 versus 109 ng/ml). The altered sex hormone metabolism is reflected in marked changes of the morphology and nucleic acid content of the metabolizing organs i.e. liver, gonades and kidney. The results of this study are consistent with the hypothesis that portosystemic shunt per se plays an important role in the pathogenesis of the disturbed metabolism of sex hormones observed in patients with liver cirrhosis and portal hypertension.

In vitro inhibition of rat oocyte meiosis by human follicular fluid fractions

We studied the effect of low molecular weight fractions of human follicular fluid (FF1) on rat oocyte meiosis and progesterone secretion by the granulosa cells. Steroid-free FF1 extracts were filtered through Sephadex G50 gel. One highly retarded fraction was obtained (GF-3), which was either used for testing or further purified by filtration on Sephadex G10, the G10-3 fraction of which was used for experiments. The GF-3 and G10-3 fractions of FF1 inhibited (in a dose-dependent and reversible manner) meiosis of isolated rat oocytes during a 4-h culture. Similarly treated fractions of serum had no effect. The inhibition was not abolished by ether extraction, trypsin treatment, heating to 56 degrees C for 1 h or boiling for 5 min, whereas heating to 105 degrees C for 18 h decreased the effect. Gonadotropin-stimulated progesterone secretion by cumulus and mural granulosa cells was also dose-dependently and reversibly inhibited by the GF-3 fractions. Our results confirm those obtained in earlier studies on porcine oocyte maturation inhibitor (OMI).

Inhibition of progesterone secretion in cultured human granulosa cells by a low molecular weight fraction of human follicular fluid

Previous studies demonstrated that a low molecular weight peptide fraction (G10-3) from human follicular fluid (FFl) could inhibit steroidogenesis by rat granulosa cells in vitro. In the present study this FFl fraction was tested upon human granulosa cells. The G10-3 fraction (less than 1000 mol wt) was obtained by sequential gel filtration on Sephadex G50 and G10 of a steroid-free extract of a pool of human FFl collected from various-sized follicles at different stages of the menstrual cycle. Human granulosa cells were obtained from large, healthy follicles in the mid- to late follicular phase of eight patients, and cultured for 4-6 days in the absence or presence of G10-3. In all cases G10-3 produced a dose-dependent inhibition of basal progesterone secretion and, when tested, also of FSH-stimulated progesterone secretion. Inhibition of progesterone secretion appeared to be greater in cells obtained from less mature follicles as compared to cells obtained from follicles that were periovulatory. The results suggest the presence of a low molecular weight luteinizing inhibitor in human FFl.