Evaluation of sensitization to the crude extract of Dermatophagoides farinae and its derived allergens, Der f 2 and Zen 1, in dogs with atopic dermatitis in Southern Brazil

BACKGROUND

Atopic dermatitis is associated with the production of IgE antibodies against environmental allergens and allergens of the house dust miteDermatophagoides farinae are frequently implicated in the disease.

OBJECTIVES

We aimed to observe the allergen-specific IgE against crudeD. farinae, Der f 2 and Zen 1 in dogs with atopic dermatitis and report if these dogs are in contact with material that could shelter mite allergens.

METHODS

100 dogs with clinical diagnosis of atopic dermatitis were included after exclusion of other forms of pruritic skin disease and dogs that already received specific or non-specific immunotherapy. These dogs were of different breeds and ages and they were presented at a veterinary teaching hospital and a private service of veterinary dermatology, both located in Curitiba, Southern Brazil. At the time of anamnesis, some questions were applied to know the possibility of these dogs having had contact with furniture and textile material which could shelter house dust mites. Sera samples were obtained and further analyzed by ELISA assay to measure serum IgE levels against these allergens with an established cut-off of 0.200 IgE optical density.

RESULTS

The allergen-specific IgE positivity against crudeD. farinae (92 %) and Zen 1 (77 %) was higher than Der f 2 (56 %). There was a correlation in sensitization to crude D. farinae and Zen 1 that was not observed between crude D. farinae and Der f 2 and Der f 2 and Zen 1. The sensitization to D. farinae and its allergens was associated with an unrestricted exposition to furniture and textile material. CONCLUSION & CLINICAL RELEVANCE: dogs with atopic dermatitis are frequently sensitized to D. farinae and its allergens, Der f 2 and Zen 1, may be considered major allergens in these dogs. Zen 1 may be the main allergen responsible for the sensitization to crude D. farinae.

Duodenogastric reflux induced by endoscopic submucosal dissection

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD) may cause excessive duodenogastric reflux (DGR) in a similar manner to distal gastrectomy, particularly after antral resections. We aimed to examine the occurrence of DGR after ESD.

PATIENTS AND METHODS

Patients with gastric neoplasm for whom ESD was indicated were categorized according to lesion site: the antral group (lower [L] stomach, n = 46) and the nonantral group (upper or middle [U or M] stomach, n = 49). Endoscopy was performed before ESD, the day after ESD, and 3 months after ESD, and the fasting bile acid concentration (BAC) in the gastric juice was analyzed.

RESULTS

BAC values showed significant interaction between time point and group, although this association differed in the antral and nonantral groups. BACs on the day after ESD were higher in the antral group than in the nonantral group, but not the pre-ESD and 3 months post-ESD levels. In the antral group only, fasting BACs increased significantly the day after ESD and decreased to baseline levels 3 months post-ESD. There was also a correlation between BAC and lesion location in the antral subgroups, with significantly higher BACs found the day after ESD in patients with lesser curvature lesions.

CONCLUSIONS

ESD of lesions in the antral lesser curvature may lead to a transient early increase in DGR. However, ESD does not result in long-term DGR, a factor that is known to increase the risk of carcinogenesis following gastrectomy.

MAGE-A protein and MAGE-A10 gene expressions in liver metastasis in patients with stomach cancer

Tumour samples from 71 patients with stomach cancer, 41 patients with liver metastasis (group A) and 15 patients each in stages II–IV (group B) and stage I (group C) without liver metastasis were analysed. MAGE-A protein expression was evaluated by immunohistochemistry using a 6C1 monoclonal antibody and MAGE-A10 mRNA expression was detected by highly sensitive in situ hybridisation using a cRNA probe. Expressions of MAGE-A protein and MAGE-A10 mRNA in group A were detected in 65.9 and 80.5%, respectively. Both protein and gene showed significantly higher expression in group A than those in groups B (6.7, 26.7%) and C (0, 0%) (P=0.0003, P=<0.0001, respectively). MAGE-A10 mRNA expression in liver metastasis was found in eight (88.9%) out of nine patients. The concordant rate between MAGE-A family protein expression and MAGE-A10 mRNA expression in the primary sites was 81.7% (P<0.0001). MAGE-A10 gene expression was associated with reduced survival duration. The results of this study suggest that MAGE-A10 is a possible target in active immunotherapy for advanced stomach cancer.

Chemopreventive effect of celecoxib in gastric cancer

COX (cyclooxygenase) is one of the key enzymes involved in the synthesis of a variety of prostaglandins (PGs), some of which have been strongly linked to inflammation. One of its two well-known isoforms, COX-2, is an inducible enzyme whose induction and expression is dynamically regulated by growth factors, mitogens, and tumor promoters. Several animal and clinical studies have reported the chemopreventive effect of celecoxib, a selective COX-2 inhibitor; and in particular, a few studies have shown that celecoxib prevents the development of gastric cancer. Administration of celecoxib also showed increases in cardiovascular risk and disruption of renal physiology. Therefore, studies hoping to clarify how selective COX-2 inhibitors modulate gastric cancer must keep in mind that coxibs have also been linked to serious cardiovascular events and disruption of renal physiology.

Monocyte chemoattractant protein 1 and macrophage cyclooxygenase 2 expression in colonic adenoma

BACKGROUND AND AIMS

Cyclooxygenase 2 (COX-2) expression in subepithelial macrophages of colorectal adenoma has been suggested as the first in a series of steps leading to colorectal tumorigenesis. We tested the hypothesis that chemokines released from human colorectal adenoma epithelium might be involved in COX-2 expression in macrophages of the lamina propria.

METHODS

Endoscopic samples of sporadic colorectal adenomas were tested by enzyme linked immunosorbent assay for chemokines involved in macrophage chemotaxis. Localisation of adenoma macrophage chemoattractant protein 1 (MCP-1) and COX-2 were determined by immunohistochemistry. The effects of MCP-1, in the presence or absence of celecoxib, on COX-2 expression, and prostaglandin (PG) E(2) and vascular endothelial growth factor (VEGF) release, were examined in human macrophages isolated from peripheral blood.

RESULTS

MCP-1 levels were markedly higher in adenoma with mild-moderate dysplasia (129.7 (19.9) pg/mg protein) and severe dysplasia (227.9 (35.4) pg/mg protein) than in normal colonic mucosa (55.8 (4.2) pg/mg protein). Other chemokine levels, macrophage inflammatory proteins (MIP)-1alpha and MIP-1beta, and the chemokine regulated on activation of normal T cell expressed and secreted (RANTES) did not vary significantly between adenoma and normal mucosa. MCP-1 levels in both adenoma and normal colonic mucosa increased significantly three hours after tissue cultivation in vitro. MCP-1 immunoreactivity was restricted to the adenoma epithelium, with no reactivity seen in adjacent normal epithelial cells. MCP-1 stimulated COX-2 expression and PGE(2) and VEGF release in human macrophages. Celecoxib, a selective COX-2 inhibitor, inhibited MCP-1-induced PGE(2) and VEGF release in macrophages. Addition of exogenous PGE(2) reversed this inhibitory effect on VEGF release, suggesting that MCP-1 in adenoma epithelial cells might be involved in COX-2 expression and subsequent macrophage activation.

CONCLUSIONS

MCP-1 in colorectal adenoma epithelial cells might be involved in macrophage migration and COX-2 expression, leading to the subsequent development of colonic adenoma.

Preventive therapy for non-steroidal anti-inflammatory drug-induced ulcers in Japanese patients with rheumatoid arthritis: the current situation and a prospective controlled-study of the preventive effects of lansoprazole or famotidine

BACKGROUND

There is a lack of evidence for the efficacy of preventive medications for peptic ulcers (PUs) among long-term users of non-steroidal anti-inflammatory drugs (NSAIDs) in Japan.

AIM

To estimate the preventive effect by normal dose, not high-dose histamine-H2 receptor antagonists (H2RA) for NSAID-induced ulcers.

METHODS

We designed two different studies to assess the efficacy of anti-ulcer agents in rheumatoid arthritis (RA) in patients treated over a long term with NSAIDs. An investigative survey divided patients into those not taking anti-ulcer agents (non-medication group); those taking mucosal protective agents (mucosal protectant group), H2RA (H2RA group), proton pump inhibitors (PPI group), or a prostaglandin E1 analog (PG) (PG group). The second study compared prospectively the preventive effects of either famotidine 20 mg bd (famotidine group) or lansoprazole 15 mg daily (lansoprazole group) in patients with PU scars.

RESULTS

The prevalence of PU in the H2RA group was significantly lower compared to the mucosal protectant group (P < 0.05), and the mucosal protectant group was not significantly different to the non-medication group. The prospective study revealed that the PU onset rate of the famotidine group was 8% (1/13), and lansoprazole group was 15% (2/13), indicating no significant differences between the two.

CONCLUSIONS

In Japan, normal-dose H2RA is expected to be a new PU preventive treatment strategy in patients requiring long-term NSAID therapy.

Implications of corpus gastritis, atrophy and cyclooxygenase in the development of gastric erosions after curing Helicobacter pylori infection

BACKGROUND

Helicobacter pylori eradication decreases recurrence of peptic ulcers with marked improvement in histological inflammation, but gastric mucosal injuries may be developed even after eradication.

PURPOSE

To investigate the mechanisms responsible for the development of gastric erosions after eradication, we analysed the relationship between clinicopathological risk factors and the occurrence of gastric erosion after curing H. pylori infection.

PATIENTS

Sixty patients underwent endoscopy before, and 3, 6 and 12 months after the completion of H. pylori eradication.

METHODS

Risk factors associated with the development of gastric erosions after eradication were assessed by multivariate analysis, and cyclooxygenase-1 and -2 immunoreactivity was histologically examined in the gastric mucosa before and after eradication.

RESULTS

The cumulative prevalence of gastric erosions after H. pylori eradication was 38.3% within 1 year. Using multivariate analysis, corpus gastritis scores (inflammation score+activity score), corpus atrophy scores and an age of more than 50 years were found to be independent factors associated with the development of gastric erosion after eradication with odds ratios of 7.39, 0.13 and 5.00, respectively. Cyclooxygenase-2 immunoreactivity of the corpus was decreased for the non-erosion group after eradication, but not for the erosion group.

CONCLUSIONS

Severe gastritis or less severe atrophy in oxyntic glands but not in pyloric glands before eradication may be involved in the development of gastric erosions after curing H. pylori infection.

Identification of peptides containing T-cell epitopes of Japanese cedar (Cryptomeria japonica) pollen allergen (Cry j 1) in dogs

Japanese cedar (Cryptomeria japonica, CJ) pollen has been known to cause atopic dermatitis in dogs in Japan. However, since the mechanism of the CJ antigen recognition is not well understood in dogs, it is difficult to develop effective immunotherapy for atopic dermatitis caused by sensitization to CJ pollen. In order to aim at development of a peptide immunotherapy, we tried to identify T-cell epitopes of a major allergen of CJ pollen, Cry j 1, in dogs sensitive to CJ pollen allergen. Peripheral blood mononuclear cells (PBMCs) obtained from 22 dogs experimentally sensitized to CJ pollen allergen and 5 atopic dogs sensitive to CJ pollen allergen were used for mapping of T-cell epitopes of Cry j 1 using 35 kinds of synthesized overlapping peptides of Cry j 1. Reactive peptides were identified based on the results of blastogenic responses of PBMCs against the peptides when the stimulation indices were beyond 2.0. Three reactive peptides were identical in a relatively high population of experimental dogs, which were Nos. 8 (p71-90) (41%), 10 (p91-110) (50%), and 11 (p101-120) (41%). It was considered that these synthesized peptides should contain T-cell epitopes of Cry j 1 in the dogs. However, there were no reactive peptides identical among the five atopic dogs spontaneously sensitive to CJ pollen. The population of dogs experimentally sensitized to CJ pollen antigen will be used in order to investigate effects of a peptide immunotherapy using the reactive peptides. The results in atopic dogs sensitive to CJ pollen antigen will also provide useful information on necessity to develop a tailor-made immunotherapy using reactive peptides in each dog.

Monocyte chemoattractant protein 1 (MCP-1) released from Helicobacter pylori stimulated gastric epithelial cells induces cyclooxygenase 2 expression and activation in T cells

BACKGROUND

and aims: To clarify the interaction between gastric epithelial and mucosal T cells, we examined the role of cytokines released from epithelial cells in response to Helicobacter pylori water extract protein (HPWEP) in regulating T cell cyclooxygenase 2 (COX-2) expression and activation.

METHODS

Media from MKN-28 cells incubated with HPWEP for 48 hours were added to Jurkat T cells and human peripheral T cells. C-C and CXC chemokine concentrations in MKN-28 cell media, and COX-2 expression, interferon gamma (IFN-gamma), and interleukin (IL)-4 secretions in T cells were determined by western blot analysis and ELISA methods. Distributions of COX-2 positive T cells and monocyte chemoattractant protein 1 (MCP-1) in tissue specimens with H pylori associated gastritis were determined as single or double labelling by immunohistochemistry.

RESULTS

MCP-1, IL-7, IL-8, and RANTES were detected in media from MKN-28 cells incubated with HPWEP. Media as a whole, and MCP-1 alone, stimulated COX-2 expression and peripheral T cell proliferation. Anti-MCP-1 antibody inhibited media stimulated COX-2 mRNA expression in Jurkat T cells. Media stimulated IFN-gamma but not IL-4 secretion from peripheral T cells, while MCP-1 stimulated IL-4 but not IFN-gamma secretion. Both stimulated cytokine release, and peripheral T cell proliferation was partially inhibited by NS-398, a specific COX-2 inhibitor. In mucosa with gastritis, COX-2 was expressed in T cells and MCP-1 was localised mainly in epithelial and mononuclear cells. MCP-1 levels and the intensity of COX-2 expression in tissue samples were closely related.

CONCLUSIONS

Cytokines such as MCP-1, released from gastric epithelial cells in response to HPWEP, seem to modulate T cell immune responses, at least in part via COX-2 expression.

Differential expression of secreted frizzled-related protein 4 in decidual cells during pregnancy

During pregnancy, the uterus shows marked morphological and physiological changes under the regulation of ovarian steroid. To elucidate the molecular cues of these changes, we tried to identify the transcripts differentially expressed in the pregnant rat uterus by using the suppression subtractive hybridization method. Seven independent clones were isolated and one of the up-regulated genes was secreted frizzled-related protein 4 (sFRP4). sFRP4 contains a Wnt-binding domain and belongs to the secreted frizzled protein family whose members are assumed to function as modulators of the Wnt signal. The expression level of sFRP4 mRNA reached a peak in the pregnant uterus on day 12, when uterine decidualization was almost complete in the rat. In situ hybridization histochemistry revealed that sFRP4 transcripts were observed in the decidual cells. In addition, proliferating cell nuclear antigen (PCNA)-positive cells were shown to be overlapped in decidua, suggesting that sFRP4 mRNA expression was accompanied by the late phase of decidual cell proliferation. Moreover, sFRP4 and estrogen receptor-alpha transcripts were co-localized. Furthermore, we analyzed the regulation of sFRP4 by estrogen using 17 beta-estradiol-treated ovariectomized rats. sFRP4 mRNA was detected in the uterus at 48 h after estrogen treatment, especially in endometrial stroma where PCNA-positive cells were also observed. The results in this study led us to the notion that sFRP4 mRNA may be up-regulated after estrogen treatment in the late phase of uterine cell proliferation.

Inhibition of Helicobacter pylori-induced cyclo-oxygenase-2 aggravates NSAID-caused gastric damage in Mongolian gerbils

BACKGROUND

The effect of Helicobacter pylori infection on non-steroidal anti-inflammatory drug-induced gastric mucosal injury is controversial.

AIM

To examine the effect of the interaction between H. pylori and non-steroidal anti-inflammatory drugs on gastric mucosal injury.

METHODS

Mongolian gerbils infected with H. pylori were treated with indometacin at 8 mg/kg for 2 days or 7 days. Mucosal damage was assessed by macroscopic and histological examination, and myeloperoxidase activity was measured as an index of neutrophil infiltration. The expression levels of cyclo-oxygenase proteins were determined by Western blot analysis and cyclo-oxygenase activity.

RESULTS

A 2-day course of indometacin did not cause an increase in gastric damage in H. pylori-infected Mongolian gerbils compared to uninfected gerbils, while a 7-day course of indometacin caused additive gastric damage in H. pylori-infected animals. H. pylori infection induced cyclo-oxygenase-2 expression in the stomach. Treatment with indometacin for 2 days did not significantly affect cyclo-oxygenase activity in H. pylori-infected animals, while treatment for 7 days inhibited both cyclo-oxygenase-1 and cyclo-oxygenase-2 activities. Pre-treatment with a selective cyclo-oxygenase-2 inhibitor aggravated mucosal injury in H. pylori-infected animals treated or not treated with indometacin for 2 days.

CONCLUSIONS

Our results suggest that cyclo-oxygenase-2 protein induced by H. pylori infection may be involved in the defence of the gastric mucosa against damage caused by non-steroidal anti-inflammatory drugs. Therefore, inhibition of cyclo-oxygenase-2 activity may enhance non-steroidal anti-inflammatory drug-caused gastric damage in H. pylori-infected animals.

Effect of acid suppression therapy on development of gastric erosions after cure of Helicobacter pylori infection

BACKGROUND

Helicobacter pylori eradication markedly improves histological inflammation and decreases peptic ulcer recurrence, but little is known about the subsequent development of gastric mucosal injury.

AIM

To investigate whether acid suppression treatment after eradication influences the development of gastric erosions.

METHODS

Eighty-one patients (gastritis or peptic ulcer) after successful H. pylori eradication were divided into two groups: 40 received an H2-blocker for 6 months (H2-blocker-positive) and 41 received no treatment (H2-blocker-negative). Endoscopy was performed before, and at 3 and 6 months after completion of eradication.

RESULTS

Cumulative prevalence of gastric erosions in the H2-blocker-positive group was significantly lower than in the H2-blocker-negative group, 25% vs. 42%, respectively. In the H2-blocker-negative group but not the H2-blocker-positive group, the cumulative prevalence of gastric erosions after eradication was higher in patients with less severe corpus atrophy or more severe corpus gastritis.

CONCLUSIONS

Development of gastric erosions after H. pylori eradication may be controlled by acid suppression treatment. Less severe atrophy or more severe gastritis in oxyntic glands before eradication may be involved in the development of gastric erosions. These results support the idea that recovery of acid secretion may be one of factors for development of gastric mucosal erosions after successful eradication.

Dickkopf1 is required for embryonic head induction and limb morphogenesis in the mouse

Dickkopf1 (Dkk1) is a secreted protein that acts as a Wnt inhibitor and, together with BMP inhibitors, is able to induce the formation of ectopic heads in Xenopus. Here, we show that Dkk1 null mutant embryos lack head structures anterior of the midbrain. Analysis of chimeric embryos implicates the requirement of Dkk1 in anterior axial mesendoderm but not in anterior visceral endoderm for head induction. In addition, mutant embryos show duplications and fusions of limb digits. Characterization of the limb phenotype strongly suggests a role for Dkk1 both in cell proliferation and in programmed cell death. Our data provide direct genetic evidence for the requirement of secreted Wnt antagonists during embryonic patterning and implicate Dkk1 as an essential inducer during anterior specification as well as a regulator during distal limb patterning.

Aging increases, and duodenal ulcer reduces the risk for intestinal metaplasia of the gastric corpus in Japanese patients with dyspepsia

BACKGROUND AND AIMS

The classification of gastritis by using the revised Sydney system suggests that there are two types of Helicobacter pylori-related gastritis. The aim of the present study was to examine the risk factors that might be involved in the presence of either atrophic gastritis or intestinal metaplasia of the gastric corpus of Japanese patients.

METHODS

Biopsy samples were obtained from the gastric corpus in 154 patients with dyspepsia, and the degree of atrophy or intestinal metaplasia was determined histologically. The correlation between several variables and presence of atrophy or intestinal metaplasia was evaluated by using multivariate analysis.

RESULTS

Among the 11 variables, which included age, peptic ulcer diseases and H. pylori infection, H. pylori infection was the major risk factor associated with the presence of atrophic gastritis or intestinal metaplasia of the gastric corpus. In contrast, duodenal ulcer (DU) disease reduced the risk of contracting both conditions. Age was an independent risk factor only for intestinal metaplasia of the gastric corpus. When 128 H. pylori-positive subjects were analyzed, DU and age were similarly associated with the presence of both conditions.

CONCLUSIONS

These results suggest that DU reduces the risk for contracting atrophic gastritis and intestinal metaplasia, and age is an independent risk factor for intestinal metaplasia of the gastric corpus in dyspeptic Japanese patients.

Evidence that members of the Cut/Cux/CDP family may be involved in AER positioning and polarizing activity during chick limb development

In vertebrates, the apical ectodermal ridge (AER) is a specialized epithelium localized at the dorsoventral boundary of the limb bud that regulates limb outgrowth. In Drosophila, the wing margin is also a specialized region located at the dorsoventral frontier of the wing imaginal disc. The wingless and Notch pathways have been implicated in positioning both the wing margin and the AER. One of the nuclear effectors of the Notch signal in the wing margin is the transcription factor cut. Here we report the identification of two chick homologues of the Cut/Cux/CDP family that are expressed in the developing limb bud. Chick cux1 is expressed in the ectoderm outside the AER, as well as around ridge-like structures induced by (β)-catenin, a downstream target of the Wnt pathway. cux1 overexpression in the chick limb results in scalloping of the AER and limb truncations, suggesting that Cux1 may have a role in limiting the position of the AER by preventing the ectodermal cells around it from differentiating into AER cells. The second molecule of the Cut family identified in this study, cux2, is expressed in the pre-limb lateral plate mesoderm, posterior limb bud and flank mesenchyme, a pattern reminiscent of the distribution of polarizing activity. The polarizing activity is determined by the ability of a certain region to induce digit duplications when grafted into the anterior margin of a host limb bud. Several manipulations of the chick limb bud show that cux2 expression is regulated by retinoic acid, Sonic hedgehog and the posterior AER. These results suggest that Cux2 may have a role in generating or mediating polarizing activity. Taking into account the probable involvement of Cut/Cux/CDP molecules in cell cycle regulation and differentiation, our results raise the hypothesis that chick Cux1 and Cux2 may act by modulating proliferation versus differentiation in the limb ectoderm and polarizing activity regions, respectively.

Localisation of cyclooxygenase 1 and cyclooxygenase 2 in Helicobacter pylori related gastritis and gastric ulcer tissues in humans

BACKGROUND

Prostaglandin endoperoxide synthase/cyclooxygenase (COX) is the key enzyme in gastric mucosal protection and repair but its cellular localisation in the human stomach is still unclear.

AIMS

To investigate immunohistochemically the cellular distribution of COX-1 and COX-2 proteins in the human stomach with or without gastritis or ulceration.

PATIENTS AND METHODS

Tissues were obtained by surgical resection of gastric ulcers associated with perforation (n = 9) or by biopsy from Helicobacter pylori positive patients with gastric ulcers (n = 45) and H pylori negative healthy subjects (n = 15). COX expression was detected by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR), western blotting, and light and electron microscopic immunohistochemistry.

RESULTS

COX-2 mRNA and protein were detected in gastric ulcer tissues but not in intact gastric mucosa. COX-1 mRNA and protein were detected in the intact mucosa. COX-2 immunostaining was exclusively localised in macrophages and fibroblasts between necrotic and granulation tissues of the ulcer bed. The percentage of COX-2 expressing cells was significantly higher in open than in closed ulcers, and in gastritis than in gastric mucosa without H pylori infection. COX-1 immunoreactivity localised in lamina propria mesenchymal cells was similar in various stages of ulcer disease and in intact gastric mucosa. Electron microscopic immunohistochemistry revealed both COX-1 and COX-2 on the luminal surfaces of the endoplasmic reticulum and nuclear envelope of macrophages and fibroblasts.

CONCLUSIONS

Our results showed that COX-2 protein was induced in macrophages and fibroblasts in gastric ulcers and H pylori related gastritis, suggesting its involvement in the tissue repair process.

Induction of cyclooxygenase-2 in mesothelial cells in peritonitis caused by perforated ulcers--an immunohistochemical study in humans

BACKGROUND

Increasing evidence suggests that mesothelial cells contribute to the control of inflammation in the peritoneal cavity by secreting prostaglandins. A study has shown that cyclooxygenase (COX)-2 knockout mice die partly as a result of peritonitis.

AIM

To investigate the expression and location of COX in peritonitis associated with peptic ulcer perforation.

METHODS

Gastric and duodenal tissues were collected intraoperatively from nine and four patients, respectively, and immunohistochemical staining for COX-1 and COX-2 was performed.

RESULTS

Histologically, all patients had severe peritonitis around the perforation sites, into which many inflammatory cells and fibroblasts had infiltrated, and reactive mesothelial cells exhibited hyperplastic change. The COX-1 protein was not detected, whereas COX-2 was abundant in reactive mesothelial cells near the perforation site and disappeared away from the site. Macrophages and fibroblasts around the perforation site also revealed immunostaining for COX-2.

CONCLUSIONS

Our results showed that COX-2 protein is induced in mesothelial cells, as well as in macrophages and fibroblasts, in inflamed peritoneal tissues associated with peptic ulcer perforation, suggesting involvement of COX-2 in tissue repair.

Control of vertebrate limb outgrowth by the proximal factor Meis2 and distal antagonism of BMPs by Gremlin

The mechanisms controlling growth and patterning along the proximal-distal axis of the vertebrate limb are yet to be understood. We show that restriction of expression of the homeobox gene Meis2 to proximal regions of the limb bud is essential for limb development, since ectopic Meis2 severely disrupts limb outgrowth. We also uncover an antagonistic relationship between the secreted factors Gremlin and BMPs required to maintain the Shh/FGF loop that regulates distal outgrowth. These proximal and distal factors have coordinated activities: Meis2 can repress distal genes, and Bmps and Hoxd genes restrict Meis2 expression to the proximal limb bud. Moreover, combinations of BMPs and AER factors are sufficient to distalize proximal limb cells. Our results unveil a novel set of proximal-distal regulatory interactions that establish and maintain outgrowth of the vertebrate limb.

Multiple left-right asymmetry defects in Shh(-/-) mutant mice unveil a convergence of the shh and retinoic acid pathways in the control of Lefty-1

Asymmetric expression of Sonic hedgehog (Shh) in Hensen's node of the chicken embryo plays a key role in the genetic cascade that controls left-right asymmetry, but its involvement in left-right specification in other vertebrates remains unclear. We show that mouse embryos lacking Shh display a variety of laterality defects, including pulmonary left isomerism, alterations of heart looping, and randomization of axial turning. Expression of the left-specific gene Lefty-1 is absent in Shh(-/-) embryos, suggesting that the observed laterality defects could be the result of the lack of Lefty-1. We also demonstrate that retinoic acid (RA) controls Lefty-1 expression in a pathway downstream or parallel to Shh. Further, we provide evidence that RA controls left-right development across vertebrate species. Thus, the roles of Shh and RA in left-right specification indeed are conserved among vertebrates, and the Shh and RA pathways converge in the control of Lefty-1.

A model for CD8+ CTL tumor immunosurveillance and regulation of tumor escape by CD4 T cells through an effect on quality of CTL

Understanding immune mechanisms influencing cancer regression, recurrence, and metastasis may be critical to developing effective immunotherapy. Using a tumor expressing HIV gp160 as a model viral tumor Ag, we found a growth-regression-recurrence pattern, and used this to investigate mechanisms of immunosurveillance. Regression was dependent on CD8 T cells, and recurrent tumors were resistant to CTL, had substantially reduced expression of epitope mRNA, but retained the gp160 gene, MHC, and processing apparatus. Increasing CTL numbers by advance priming with vaccinia virus expressing gp160 prevented only the initial tumor growth but not the later appearance of escape variants. Unexpectedly, CD4 cell depletion protected mice from tumor recurrence, whereas IL-4 knockout mice, deficient in Th2 cells, did not show this protection, and IFN-gamma knockout mice were more susceptible. Purified CD8 T cells from CD4-depleted mice following tumor regression had more IFN-gamma mRNA and lysed tumor cells without stimulation ex vivo, in contrast to CD4-intact mice. Thus, the quality as well as quantity of CD8+ CTL determines the completeness of immunosurveillance and is controlled by CD4 T cells but not solely Th2 cytokines. This model of immunosurveillance may indicate ways to enhance the efficacy of surveillance and improve immunotherapy.

The T-box genes Tbx4 and Tbx5 regulate limb outgrowth and identity

During embryonic development, initially similar fields can develop into distinct structures, such as the vertebrate fore- and hindlimbs. Although considerable progress has been made in our understanding of the genetic control underlying the establishment of the different limb axes, the molecular cues that specify the differential development of the fore- and hindlimbs are unknown. Possible candidates for genes determining limb identity are Pitx1, a gene whose transcripts are detected in the early hind- but not forelimb bud, and two members of the T-box (Tbx) gene family, Tbx4 and Tbx5, which are specifically expressed in the hindlimb and forelimb buds, respectively. Here we show that Tbx4 and Tbx5 are essential regulators of limb outgrowth whose roles seem to be tightly linked to the activity of three signalling proteins that are required for limb outgrowth and patterning: fibroblast growth factor (FGF), bone morphogenetic protein (BMP) and Wnt. In addition, we provide evidence that Tbx4 and Tbx5 are involved in controlling limb identity. Our findings provide insight into how similar developmental fields can evolve into homologous but distinct structures.

Spatially and temporally-restricted expression of two T-box genes during zebrafish embryogenesis

T-box genes are conserved in all animal species. We have identified two members of the T-box gene family from the zebrafish, Danio rerio. Zf-tbr1 and zf-tbx3 share high amino acid identity with human, murine, chick and Xenopus orthologs and are expressed in specific regions during zebrafish development.

Pitx2 determines left-right asymmetry of internal organs in vertebrates

The handedness of visceral organs is conserved among vertebrates and is regulated by asymmetric signals relayed by molecules such as Shh, Nodal and activin. The gene Pitx2 is expressed in the left lateral plate mesoderm and, subsequently, in the left heart and gut of mouse, chick and Xenopus embryos. Misexpression of Shh and Nodal induces Pitx2 expression, whereas inhibition of activin signalling blocks it. Misexpression of Pitx2 alters the relative position of organs and the direction of body rotation in chick and Xenopus embryos. Changes in Pitx2 expression are evident in mouse mutants with laterality defects. Thus, Pitx2 seems to serve as a critical downstream transcription target that mediates left-right asymmetry in vertebrates.

Tbx genes and limb identity in chick embryo development

Tbx-2, Tbx-3, Tbx-4 and Tbx-5 chick genes have been isolated and, like the mouse homologues, are expressed in the limb regions. Tbx-2 and Tbx-3 are expressed in anterior and posterior domains in wings and legs, as well as throughout the flank. Of particular interest, however, are Tbx-5, which is expressed in wing and flank but not leg, and Tbx-4, which is expressed very strongly in leg but not wing. Grafts of leg tissue to wing and wing tissue to leg give rise to toe-like or wing-like digits in wing and leg respectively. Expression of Tbx-4 is stable when leg tissue is grafted to wing, and Tbx-5 expression is stable when wing tissue is grafted to leg. Induction of either extra wings or legs from the flank by applying FGF-2 in different positions alters the expression of Tbx-4 and Tbx-5 in such a way that suggests that the amount of Tbx-4 that is expressed in the limb determines the type that will form. The ectopic limb always displays a limb-like Tbx-3 expression. Thus Tbx-4 and Tbx-5 are strong candidates for encoding ‘wingness’ and ‘legness’.

Immune activation in cervical neoplasia: cross-sectional association between plasma soluble interleukin 2 receptor levels and disease

In a previous study (Tsukui et al., Cancer Res., 56: 3967-3974, 1996), we observed an inverse association between degree of cervical neoplasia and interleukin (IL) 2 production by peripheral blood mononuclear cells in response to human papillomavirus (HPV) 16 E6 and E7 peptides in vitro. This suggested that a Th1-mediated cellular immune response might be important in host immunological control of HPV infection and that a lack of such a response might predispose to progression of cervical disease. To follow up on these findings, we have conducted a cross-sectional study of women with various degrees of cervical neoplasia to investigate the association between overall immune activation and cervical disease. A total of 235 women were recruited into our study; 120 of these women were participants in our previous study in which IL-2 production in response to HPV-16-specific peptides was measured. The study population included 34 women with invasive cancer, 62 women with high-grade squamous intraepithelial lesions (HSILs), and 105 women with low-grade squamous intraepithelial lesions (LSILs). In addition, 34 cytologically normal women with no past history of squamous intraepithelial lesions despite confirmed HPV-16 infection in the 5 years preceding the study were selected as controls. As our measure of overall immune activation, serum samples obtained from study participants were tested for soluble IL-2 receptor (sIL-2R) level using an ELISA method. The mean sIL-2R levels were found to increase with increasing disease severity (Ptrend = 0.0002). Among cytologically normal, HPV-exposed women, the mean receptor level in serum was 465.8 units/ml compared to 467.6 units/ml among LSIL subjects, 514.9 units/ml among HSIL subjects, and 695.5 units/ml among women with invasive cervical cancer. Similarly, the proportion of women with elevated sIL-2R levels (defined as > or = 450 units/ml) increased with increasing disease severity from 35.2% among normal study subjects to 70.6% among cancer patients (Ptrend = 0.003). Among the subgroup of subjects for whom in vitro IL-2 production in response to HPV-16-specific peptides was measured, we examined the association between in vitro IL-2 production and serum levels of sIL-2R. sIL-2R levels were higher, on average, among those women who were positive in our IL-2 production assay compared to those who were negative, but the differences did not reach statistical significance (P > 0.05). We also observed a trend of increasing sIL-2R level with increasing disease severity both in women who were positive and in women who were negative for our IL-2 production assay, but the trend was only significant among those who were negative for IL-2 production (Ptrend = 0.01). Results from our studies suggest that although the immune system of women with cervical neoplasia is nonspecifically activated as disease severity increases, the ability of those women with HSILs or cancer to mount a Th1-mediated immune response to HPV peptides appears to decrease compared to women with LSILs or normal women infected with HPV. Increased overall activation along with decreased Th1 immune response among women with increasing cervical disease severity might be explained by an increased Th2-mediated immune response, a response that we hypothesize is ineffective in controlling the viral infection and its early cytological manifestations. Future studies should directly assess Th2-mediated responses to confirm this hypothesis. Also, future efforts should be aimed at determining whether the associations observed are causally related to disease progression or an effect of the disease.

Interleukin 2 production in vitro by peripheral lymphocytes in response to human papillomavirus-derived peptides: correlation with cervical pathology

Human papillomavirus (HPV) is believed to be the major cause of cervical cancer. To investigate whether a cellular immune response, especially a T helper type 1 response, is related to the natural defense against HPV-related cervical lesions, the interleukin 2 response of peripheral blood lymphocytes in vitro to overlapping peptides from HPV-16 E6 and E7 oncoproteins was compared with the degree of cervical cytological abnormality among 140 women in a cross-sectional study. We compared 66 women diagnosed with low-grade squamous intraepithelial lesions (LSIL), 21 with high-grade squamous intraepithelial lesions (HSIL), and 28 with invasive cervical cancer with 25 women who were cytologically normal but previously HPV-16 DNA positive. The fraction showing strong interleukin 2 production against HPV-16 peptides was greatest among cytologically normal women (35%) and declined with increasing disease severity [LSIL] (20%), HSIL, (17%), and cancer patients (7%); X2 test P for the trend = 0.02], whereas the responses against a recall influenza antigen were not significantly different among groups. Our finding suggests that a T helper lymphocyte type 1 response to HPV antigens is associated with disease status. This result may reflect a targeted effect of the disease on immune function or a protective effect of the immune response against disease progression.

Transgenesis by adenovirus-mediated gene transfer into mouse zona-free eggs

Zona-free mouse eggs at the pronucleus stage were infected with a replication-defective adenovirus vector containing a nuclear-targeted lacZ gene. Exogenous beta-galactosidase activity was detected in almost all eggs at the two-cell stage. Of 27 mice that developed from infected eggs, three carried the integrated exogenous gene mediated by the adenovirus. Two of the three expressed the lacZ gene, and all three mice transmitted the adenovirus-mediated transgene to F1 progeny Southern blot analysis was consistent with single copy integration. This finding should accelerate the development of new strategies for transgenesis and assist studies on the function of cloned genes in vivo.

Molecular analysis of presentation by HLA-A2.1 of a promiscuously binding V3 loop peptide from the HIV-envelope protein to human cytotoxic T lymphocytes

P18(IIIB) is a highly immunogenic peptide from the V3 loop of the HIV-1 gp160 envelope protein that is presented promiscuously by multiple class I MHC molecules. Understanding the molecular basis for promiscuous presentation may have many practical applications. As the highly prevalent HLA-A2.1 class I molecule is known to present P18(IIIB) for recognition by cytotoxic T lymphocytes (CTL) found in peripheral blood mononuclear cells of HIV+ donors, a P18(IIIB)-specific CTL line was generated from and HLA-A2(+), HIV- donor in order to define the molecular basis for, and ultimately improve upon the binding of, this peptide to HLA-A2.1. The minimal epitope recognized by the line was a decamer, I10, with the sequence RGPGRAFVTI. Interestingly, this decamer is identical to the minimal epitope from P18(IIIB) seen by murine CTL restricted by H-2Dd. A panel of Ala-substituted peptides was employed in MHC-binding and T cell response studies to identify MHC- and TCR-binding residues. Notably, many of the agretopic and epitopic residues identified were identical to those involved in the corresponding interactions of I10 with the H-2Dd MHC molecule and murine I10-specific CTL. The I10 peptide does not contain the described HLA-A2.1 binding motif. Instead a Pro at P3, a Phe at P7 and an Ile at P10 are utilized for MHC binding. Agretopic residue similarities with the hepatitis B nucleocapsid decamer suggest that these residues may comprise an alternative motif of anchors utilized by decamers for binding to HLA-A2.1.

Gene transfer and expression in mouse preimplantation embryos by recombinant adenovirus vector

Replication-defective recombinant adenovirus, Adex4SRLacZL, was used as a vector for transferring exogenous genes in mouse zona pellucida-free eggs at the pronuclear stage. The vector contained the E. coli LacZ reporter gene under the control of the SR alpha promoter (SV40 early promoter-fused HTLV-I LTR), and the expression of the reporter gene was examined during preimplantation development in culture. Histochemical staining of the embryos for beta-galactosidase activity showed that the exogenous LacZ gene as expressed in 98% of the embryos at the morula-blastocyst stages. As in the microinjection method, the exogenous genes could be pursued from the 2-cell stage. Neither apparent morphological changes nor cytotoxic effects were observed. Both the percentages of embryos expressing reporter genes and the rate of development to the blastocyst stage were higher in the adenovirus vector-treated embryos than in the microinjected ones. These results suggest that the adenovirus vector system is a useful tool in investigating the genetic control of early mammalian development.

Production of interleukin-1 by primary cultured parenchymal liver cells (hepatocytes)

The production of interleukin-1 (IL-1) by cultured parenchymal liver cells was revealed by a biological assay with an IL-1-dependent cell line, Northern blot analysis, and in situ hybridization. Inhibition experiments on the IL-1 activity with anti IL-1 alpha antibody also support the presence of IL-1 alpha in the supernatant of cultured parenchymal liver cells. Based on these results, we discuss the possibility of IL-1 production by parenchymal liver cells in vivo.

A mutant p53 tumor suppressor protein is a target for peptide-induced CD8+ cytotoxic T-cells

Cytotoxic T-lymphocytes (CTL) recognize processed peptide fragments of any endogenous protein, after these peptides are carried to the cell surface by class I major histocompatibility molecules. Thus, a tumor antigen does not have to be expressed as an intact protein on the cell surface to be recognizable by CTL. However, mutant oncogene products have not yet been shown to be targets of CD8+ CTL. Here, we generate p53-specific CD8+ CTL by immunizing BALB/c mice with spleen cells pulsed with a peptide, corresponding to a 21-amino acid sequence encompassing a point mutation (135 Cys to Tyr) in the mutant p53 gene product from a human lung carcinoma. The mutation created a new Kd class I molecule binding motif sequence, and the determinant recognized was mapped to this motif and presented by the Kd class I molecule. The wild type peptide, without the mutation, was not recognized. Importantly, the CTL killed specifically BALB/c fibroblasts transfected with the mutant p53 gene and endogenously expressing the mutant protein, but not control fibroblasts or ones transfected with a different human mutant p53 gene. Thus, endogenously synthesized mutant p53, at levels found in tumors, can render cells targets for specific CTL, and these CTL can be generated by peptide immunization. These findings point the way toward an approach to selective immunotherapy against tumors.

Production of macrophage colony-stimulating factor by adult murine parenchymal liver cells (hepatocytes)

The activity of macrophage colony-stimulating factor (M-CSF) was found in the culture supernatant of mouse parenchymal liver cell fractions in a bone marrow colony-forming assay. The activity of an M-CSF-like substance purified by a four-step procedure was neutralized by goat anti-mouse M-CSF antiserum. M-CSF mRNA was detected in cellular RNA prepared from cultured parenchymal liver cell fractions by Northern blot analysis and also in cultured parenchymal liver cells by in situ hybridization. These results indicate that parenchymal liver cells have the capacity to produce M-CSF. We discuss the role of M-CSF in hematopoiesis, the immune response, and other biological phenomena.

[Partial purification of bone marrow cell-stimulating activity from the parenchymal liver cell supernatant]

Mouse bone marrow cell-stimulating activity has been found in the supernatants of mouse parenchymal liver cells. In order to clarify the character, we attempted to purify the activity by a four-step purification procedure involving concentration and chromatographies on DEAE-cellulose, Sephacryl S-300, and Superose 6. By DEAE-cellulose chromatography, the activity was found to be eluted stepwisely with 0.1 M (Peak 1) and 0.2 M (Peak 2) NaCl. Gel filtration revealed that the activities in Peak 1 and Peak 2 had molecular weights of 170,000 and 600,000, respectively. Both preparations of the activity finally obtained derived the cells which spread over the plastic dish from mouse bone marrow cells, but did not stimulate the proliferation of IL-3/GM-CSF dependent cell line, IC2. These results suggest the presence of the bone marrow cell-stimulating activities, which are different from GM-CSF and IL-3, in the parenchymal liver cell supernatants.

[Pharmacokinetic study of mitoxantrone]

The pharmacokinetics of mitoxantrone, an anthraquinone antitumor agent, were cooperatively investigated at 5 institutions including 4 patients with breast cancer and 3 patients with malignant lymphoma. A single dose of 10 mg/m2 was intravenously infused into 5 patients, and a 5-day schedule of repeated 4.2 mg/m2 or 3 mg/m2 was given to each of 2 patients. With single administration, the blood concentrations showed that the half-life for the alpha phase was 0.16 h, for the beta phase 1.58 h, and for the gamma phase 83.4 h. The distribution volume at steady state was 1,112 l/m2. The total body clearance was 326.8 ml/m2, showing rapid clearance from the blood. The cumulative urinary excretion in 96 h was 5.17% of the dose. With repeated administration, in one patient without third space, the pharmacokinetics were similar to those of the patients given single administration, but in the other patient with third space, lowered clearance was noted. The pharmacokinetics of mitoxantrone in the Japanese patients were nearly the same as those of European patients, and the blood concentration fitted the three-compartment model, with rapid distribution to the tissues.

Juvenile thyroid carcinoma with metastasis to the bilateral cervical lymph nodes--a case report

A case of juvenile thyroid carcinoma with metastasis to the bilateral cervical lymph nodes in a 9-year-old male is reported. The clinical picture of juvenile thyroid carcinoma is characterized by early metastasis to the lungs and cervical lymph nodes. In Europe, there have been many reports of thyroid carcinoma after radiation. However, our patient had received no radiation. Surgery consisted of subtotal thyroidectomy and right modified neck dissection. The tumor was a papillary adenocarcinoma and metastasis was seen in 24 out of 38 lymph nodes removed. The serum thyroglobulin level, determined by radioimmunoassay, was 184 ng/ml preoperatively, but by 8 months postoperatively the level fell to 48 ng/ml. No signs of recurrence have been found to date (30 months after the operation).

Re-evaluation of a possible high incidence of hypertension in hypothyroid patients

In an attempt to re-evaluate a possible high incidence of hypertension in hypothyroid patients, blood pressure was measured in 38 slightly hypothyroid patients, in 17 moderate hypothyroid patients, and in 26 severe hypothyroid patients. The data were then compared with the findings in 73 known euthyroid subjects and in 1,601 possibly euthyroid subjects. Blood pressure and incidence of hypertension increased progressively with age in known euthyroid subjects and in possibly euthyroid subjects. Similarly, blood pressure increased progressively with age in slight and moderate hypothyroid patients, but the incidence of hypertension was high in the sixth decade in slightly hypothyroid patients for some unknown reason. In contrast, blood pressure and the incidence of hypertension were low in the fifth and sixth decades in severe hypothyroid patients. This low blood pressure was elevated slightly when Sv1 + Rv5 and C/T were shifted toward normal by T4 treatment for 3 to 4 months. It is suggested that the hypothyroid state does not accelerate the development of hypertension.

Changes in hormonal activities relative to the severity of essential hypertension

Endocrine activity in patients with essential hypertension was studied by measuring the urinary excretion of catecholamines, prostaglandin E (PGE) and cyclic adenosine monophosphate (cAMP). Simultaneously, plasma renin activity, concentrations of serum sodium, potassium, blood urea nitrogen (BUN) and creatinine were determined. Systolic blood pressure and BUN increased progressively with age until the sixth decade. Urinary excretion of norepinephrine was correlated with the systolic blood pressure. In contrast, plasma renin activity and urinary excretion of PGE decreased progressively with the increase in systolic blood pressure. Although the cause of essential hypertension is not known, it is suggested that hypertension accelerates the aging process in the kidney and thus decreases renal PGE synthesis. This decrease of PGE in turn causes a reduction of plasma renin activity, possibly either by accelerating the retention of sodium and water or by failing to stimulate renin synthesis. A decrease of PGE may also potentiate the vasopressor action of norepinephrine.

Effect of thyroid hormone, actinomycin D, cycloheximide and puromycin on TRH-induced secretion of TSH, as studied by pituitary concentration of cyclic AMP and intrathyroidal colloid droplet formation

In an attempt to study the functional relation between pituitary cyclic AMP and TSH secretion in response to thyrotropin releasing hormone (TRH) or thyroid hormone administration, pituitary concentration of cyclic AMP was measured by protein binding assay after in vivo and in vitro administration of test materials (TRH, thyroxine, triiodothyronine, actinomycin D, puromycin and cycloheximide singly or in combination). Small dose of TRH apparently augmented TSH secretion as evidenced by a marked increase of intrathyroidal colloid droplet, but failed to elevate the pituitary concentration of cyclic AMP. Triiodothyronine (T3) and thyroxine (T4) blocked an increase of TSH secretion produced by TRH, but they elevated pituitary concentration of cyclic AMP in vivo and in vitro. Actinomycin D (Act D), puromycin and cycloheximide elevated pituitary cyclic AMP concentration without stimulating TSH secretion. From the data accumulated, it appears that the measurement of total anterior pituitary concentration of cyclic AMP is not useful to evaluate the activity of TSH cells in response to thyroid hormone, TRH and TRH plus thyroid hormone.

Studies on the mechanism of goitrogenic action of diphenylthiohydantoin

Diphenylthiohydantoin (DPTH) is a potent goitrogenic compound and produces goiters in rats. Like methimazole, DPTH depresses plasma T4 and T3 concentrations and elevates plasma T4 and T3 concentrations and elevates plasma TSH concentration. Unlike methimazole, however, DPTH does not suppress thyroidal radioiodine uptake and thyroid hormone synthesis, although the monoiodotyrosine to diiodotyrosine ration is elevated by DPTH. DPTH does not inhibit thyroidal radioiodine release or augment the degradation of thyroid hormone. DPTH depresses an increase of plasma T4 and T3 in thyroidectomized rats maintained on T4 or T3 by augmenting fecal excretion of hormones. In addition, DPTH decreases conversion of T4 to T3 in vitro. It is suggested that DPTH is a unique goitrogen which acts at two different extrahyroidal sites, viz. fecal loss of thyroid hormone and conversion of T4 to T3.

Comparison of prostaglandin E1 and TSH stimulation of cyclic AMP synthesis in thyroid tissues from euthyroid subjects and thyrotoxic patients

Possible differences of the mode of action of TSH and prostaglandin E1 (PGE) on the synthesis of cyclic AMP were studied in normal human thyroids (normal thyroid) and thyroids from thyrotoxic patients (toxic thyroid). TSH was less effective in toxic thyroids than in normal thyroids; whereas PGE1 was equally effective in normal thyroids and toxic thyroids. Since the basal level of cyclic AMP was the same in normal and toxic thyroids, this lower sensitivity of toxic thyroids to TSH was not due to the fact that toxic thyroids were already overactive in terms of cyclic AMP synthesis. The measurement of adenylate cyclase and phosphodiesterase activities in the plasma membranes or homogenates failed to explain this lower sensitivity of toxic thyroids to TSH. Small and large doses of T4 and T3 failed to suppress an increase of cyclic AMP produced by PGE1, in the slices and plasma membranes of normal and toxic thyroids; whereas large doses of T3 depressed an increase of cyclic AMP in response to TSH in the thyroid plasma membrane of toxic thyroids. When both TSH and PGE1 were administered simultaneously, an additive increase of cyclic AMP was found in normal thyroids and in toxic thyroids. From the data accumulated, we suggest that, although TSH and PGE1 stimulate cyclic AMP synthesis in normal and toxic thyroids, the site of action and/or mode of action of these two stimulators may possibly be different, at least in human thyroids.

Volume of sella turcica in normal subjects and in patients with primary hypothyroidism and hyperthyroidism

In an attempt to assess a possible relationship between pituitary size and TSH secretion, the volume of sella turcica was measured in 570 subjects, 26 primary hypothyroid patients, and 34 thyrotoxic patients. The volume of sella turcica, measured by a 3-dimensional approach, increased progressively with age until 20 years of age and was rather constant thereafter in normal subjects. In thyrotoxic patients, the volume of sella turcica was normal in spite of decreased plasma TSH concentration. In contrast, 81% of primary hypothyroid patients had an abnormal enlargement of the sella turcica. The magnitude of an increase of sella turcica inversely related with a decrease in serum T4 and T3 concentrations. On the other hand, the magnitude of an increase of sella turcica correlated well with an increase of circulating TSH. We suggest that an increase of sella turcica indirectly reflects an increase in pituitary size and TSH-secreting capacity, possibly due to hypertrophy and hyperplasia of TSH cells in primary hypothyroid patients.

Pituitary unresponsiveness to thyrotropin-releasing hormone in thyrotoxic patients during chronic anti-thyroid drug therapy and in rats previously treated with excess thyroid hormone

In an attempt to study pituitary-thyroid feedback control in thyrotoxic patients, TRH tests were performed in 10 thyrotoxic patients who were treated for varying intervals with propylthiouracil. Plasma TSH was undetectable before and after administration of 500 mug TRH in 7 patients (euthyroid or hypothyroid) after therapy for 1 to 4 months. Also, plasma TSH was undetectable before and after TRH in 3 patients who had been euthyroid for at least 6 months. To explore this abnormality, rats were made thyrotoxic by administering large doses of thyroxine or desiccated thyroid for 3 to 28 days. Discontinuation of thyroid hormone administration was followed by a significant but temporary fall of plasma thyroxine and triiodothyronine concentration below control levels. Duration of the low plasma thyroxine and triiodothyronine concentration was longer with the prolonged administration of thyroid hormone. Despite low plasma thyroxine and triiodothyronine concentrations, plasma TSH was below normal before and after administration of TRH. This unresponsiveness of the pituitary to TRH may be comparable to that found in thyrotoxic patients receiving antithyroid drugs for a certain period. Since this pituitary unresponsiveness to TRH in rats is due to a depletion of pituitary TSH content, it is suggested that depletion of pituitary TSH in thyrotoxic patients during antithyroid therapy is the cause of pituitary unresponsiveness to TRH.

Effect of butyldiiodohydroxybenzoate on pituitary-thyroid interplay

The effect of BHDB, an analogue of thyroxine, on the pituitary-thyroid system was studied in the rat. BHDB produced low plasma T4 and T3 concentrations similar to those produced by methimazole, but failed to elevate plasma TSH and to produce goiter because of displacement of T4 from the binding protein. Low plasma thyroid hormone concentrations were due to an increase of fecal loss of thyroid hormones. By releasing excess iodide, BHDB blocked the development of goiter produced by methimazole.