Epidermal growth factor and transforming growth factor-alpha stimulate the proliferation of mouse uterine stromal cells

Growth factors produced in the uterine endometrium are considered to be involved in the proliferation of the mouse uterine stromal cells induced by estradiol-17beta (E(2)) and progesterone (P). The effect of epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha), one of EGF-related growth factors, on the proliferation of mouse uterine stromal cells was studied in a serum-free culture. The growth of the uterine stromal cells was measured by MTT assay. EGF was found to increase the number of uterine stromal cells in a dose-dependent manner. The DNA-replicating cells were investigated using the immunocytochemical detection of bromodeoxyuridine (BrdU)-labeled cells. EGF and TGF-alpha increased the percentage of BrdU-labeled cells in a dose-dependent manner. Administration of the combination of E(2) (10(-9) M) and P (10(-7) M) for 2 days increased the percentage of BrdU-labeled cells 2.3-fold. The stimulatory effect of EGF, TGF-alpha and the combination of E(2) and P on DNA replication in the uterine stromal cells was repressed by RG-13022 (10(-5) M, the inhibitor of the EGF receptor tyrosine kinase). RT-PCR analysis of EGF-receptor-, TGF-alpha-, and EGF-mRNA was carried out in the cultured uterine stromal cells, and revealed the expression of those mRNAs. These data supported the hypothesis that uterine endometrial stromal growth induced by sex steroids required the EGF family of ligands such as EGF and TGF-alpha, both produced in the stromal cells, acting for DNA synthesis through EGF receptors.     

Gene expression and the physiological role of transforming growth factor-alpha in the mouse pituitary

Transforming growth factor-alpha (TGF-alpha), a member of the epidermal growth factor (EGF) family, is produced within the mouse anterior pituitaries. However, the cell types of TGF-alpha-expressing cells and the physiological roles of TGF-alpha within mouse pituitary glands remain unclear. The aim of the present study was to localize TGF-alpha mRNA-expressing cells, and to clarify the involvement of TGF-alpha in estrogen-induced DNA replication in mouse anterior pituitary cells. Northern blot analysis demonstrated TGF-alpha mRNA expression in adult male and female mouse anterior pituitaries. In situ hybridization analysis of the pituitaries in these mice showed that TGF-alpha mRNA-expressing cells in the anterior pituitary are round, oval, and medium-sized. TGF-alpha mRNA was colocalized in most of the growth hormone (GH) mRNA-expressing cells, while only some of the prolactin (PRL) mRNA-expressing cells. DNA replication in the anterior pituitary cells was detected by monitoring the cellular uptake of a thymidine analogue, bromodeoxyuridine (BrdU) in a primary serum-free culture system. Estradiol-17beta (E2) and TGF-alpha treatment increased the number of BrdU-labelled mammotrophs, indicating that E2 and TGF-alpha treatment stimulates the DNA replication in mammotrophs. Immunoneutralization of TGF-alpha with anti-TGF-alpha-antibodies nullified the E2-induced increase in DNA replication. RT-PCR analysis of TGF-alpha mRNA expression in ovariectomized female mice revealed that E2 increases TGF-alpha mRNA levels. These results indicate that the TGF-alpha produced primarily in the somatotrophs mediates the stimulatory effects of estrogen on the DNA replication of pituitary cells in a paracrine or autocrine manner.     

Quantitative analysis of flagellar movement in hyperactivated and acrosome-reacted golden hamster spermatozoa

Caudal epididymal spermatozoa of golden hamsters were incubated in capacitation medium. Their movement patterns changed as they became hyperactivated and underwent the acrosome reaction. To understand the basic mechanism by which changes in movement pattern are brought about, digital image analysis was carried out on the flagellar movements recorded with a video system. The degree of flagellar bending increased with incubation time, especially in the proximal midpiece. The hyperactivated spermatozoa had remarkably asymmetrical flagellar waves of large amplitude because either the bends in the same direction as the hook of the head (referred as the "pro-hook bend") or the bends in the opposite direction to the hook of the head (referred as the "anti-hook bend") extremely increased their curvature; whereas, the acrosome-reacted spermatozoa had relatively symmetrical flagellar waves of large amplitude because both the pro- and anti-hook bends remarkably increased their curvature. Beat frequency significantly decreased while wavelength of flagellar waves increased after hyperactivation and further after the acrosome reaction. These results suggest that both extreme pro- and anti-hook bends are essential in the acrosome-reacted spermatozoa even though beat frequency decreased markedly.     

Distinct roles of Smad2-, Smad3-, and ERK-dependent pathways in transforming growth factor-beta1 regulation of pancreatic stellate cellular functions

Pancreatic stellate cells (PSCs) play a major role in promoting pancreatic fibrosis. Transforming growth factor-beta(1) (TGF-beta(1)) regulates PSC activation and proliferation in an autocrine manner. The intracellular signaling pathways of the regulation were examined in this study. Immunoprecipitation and immunocytochemistry revealed that Smad2, Smad3, and Smad4 were functionally expressed in PSCs. Adenovirus-mediated expression of Smad2, Smad3, or dominant-negative Smad2/3 did not alter TGF-beta(1) mRNA expression level or the amount of autocrine TGF-beta(1) peptide. However, expression of dominant-negative Smad2/3 inhibited PSC activation and enhanced their proliferation. Co-expression of Smad2 with dominant-negative Smad2/3 restored PSC activation inhibited by dominant-negative Smad2/3 expression without changing their proliferation. By contrast, co-expression of Smad3 with dominant-negative Smad2/3 attenuated PSC proliferation enhanced by dominant-negative Smad2/3 expression without altering their activation. Exogenous TGF-beta(1) increased TGFbeta(1) mRNA expression in PSCs. However, PD98059, a specific inhibitor of mitogen-activated protein kinase kinase (MEK1), inhibited ERK activation by TGF-beta(1), and consequently attenuated TGF-beta(1) enhancement of its own mRNA expression in PSCs. We propose that TGF-beta(1) differentially regulates PSC activation, proliferation, and TGF-beta(1) mRNA expression through Smad2-, Smad3-, and ERK-dependent pathways, respectively.     

Distribution of virulence-associated genes in Vibrio mimicus isolates from clinical and environmental origins

Distribution of virulence-associated genes in Vibrio mimicus was studied including the toxin genes ctxA, tdh, st and vmh and the genes necessary for regulation of toxin production, toxR, toxS, toxT, tcpA and tcpP. Approximately half of clinical V. mimicus isolates possessed one or more genes encoding V. cholerae enterotoxic factors such as ctxA, tdh and st. All of the clinical and environmental isolates possessed vmh encoding V. mimicus hemolysin (VMH). The ctxA encoding cholera toxin was detected in only 2 strains, 5% of the clinical isolates. Furthermore, there were very few strains possessing tcpP and toxT needed for the expression of ctxA. These results may suggest that VMH is a more important pathogenic factor than well recognized toxins such as cholera toxin (CT) in V. mimicus infection.     

Flight capability and fatty acid level in triacylglycerol of long-distance migratory adults of the common cutworm, Spodoptera litura

The larvae of Spodoptera litura were reared on an artificial diet, and the flight capability, and triacylglycerol (TG) level plus its fatty acid composition in 3-day-old sexually mature and non-fed adults were compared. In males, during 3 hr of tethered flight, the levels of abdominal TG and its fatty acid components did not change. But thereafter the TG and fatty acids, significantly unsaturated fatty acids in TG declined in their levels with the prolongation of flight, unsaturated fatty acids being exhausted preceding saturated fatty acid decline. When males were tested by tethered flight for 20 hr, some could fly for nearly the whole period, and were judged to be able to fly for approximately 24 hr, depending on the level of residual TG. Fatty aids in TG decreased in females similarly to males during tethered flight and some females with fully developed ovaries deposited eggs after 12 hr of flight similarly to non-flown individuals, which supports the long-distance flight capability even in sexually mature females. These results are discussed with regard to the overseas migration of this moth.     

Endogenous indole-3-acetic acid and ethylene evolution in tilted<Emphasis Type="Italic"> Metasequoia glyptostroboides</Emphasis> stems in relation to compression-wood formation

Eight-year-old Metasequoia glyptostroboides seedlings were tilted at a 45° angle to induce compression-wood formation on the lower side of the stems. After 2 weeks of treatment, half of the seedlings were sampled and the remaining half were tilted to the opposite orientation to exchange the upper and lower sides and were kept for 2 more weeks until sampled. Cambium-emitted ethylene was analyzed by gas chromatography with flame-ionization detection. Endogenous indole-3-acetic acid (IAA) was measured by gas chromatography-mass spectrometry. Tracheid production and compression-wood formation were determined by light microscopy. Anatomical studies showed that tracheid production was promoted and compression-wood tracheids always developed on the gravitationally lower side of tilted stems in both the original tilting and the subsequent reverse-tilting periods. These were accompanied by an increase in IAA content in and an accelerated ethylene-evolution rate from the cambial region of the same side.     

Recurrent peptic ulcers in patients following successful Helicobacter pylori eradication: a multicenter study of 4940 patients

Objective. Although curative treatment of Helicobacter pylori infection markedly reduces the relapse of peptic ulcers, the details of the ulcers that do recur is not well characterized. The aim of this study is to describe the recurrence rate and specific features of peptic ulcers after cure of H. pylori infection. Methods. This was a multicenter study involving 4940 peptic ulcer patients who were H. pylori negative after successful eradication treatment and were followed for up to 48 months. The annual incidence of ulcer relapse in H. pylori‐cured patients, background of patients with relapsed ulcers, time to relapse, ulcer size, and site of relapsed ulcers were investigated. Results. Crude peptic ulcer recurrence rate was 3.02% (149/4940). The annual recurrence rates of gastric, duodenal and gastroduodenal ulcer were 2.3%, 1.6%, and 1.6%, respectively. Exclusion of patients who took NSAIDs led annual recurrence rates to 1.9%, 1.5% and 1.3%, respectively. The recurrence rate was significantly higher in gastric ulcer. Recurrence rates of patients who smoked, consumed alcohol, and used NSAIDs were significantly higher in those with gastric ulcer recurrence compared to duodenal ulcer recurrence (e.g. 125 of 149 [83.9%] relapsed ulcers recurred at the same or adjacent sites as the previous ulcers). Conclusions. Curative treatment of H. pylori infection is useful in preventing ulcer recurrence. Gastric ulcer is more likely to relapse than duodenal ulcer. Recurrent ulcer tended to recur at the site of the original ulcers.