Mediastinal lymph node involvement as the initial manifestation of occult thyroid cancer in the surgical treatment of lung cancer: report of a case

A 63-year-old man was referred to our institute for the treatment of squamous cell carcinoma of the upper lobe of his right lung. A right upper lobectomy of the lung was performed with a mediastinal lymph node dissection. The postoperative pathological examination of the dissected specimens revealed one of the superior mediastinal lymph nodes to be morbid with micrometastasis of occult thyroid cancer, while no node involvement was seen due to lung cancer. A right lobectomy of the thyroid gland with a modified radical neck dissection was done 4 years later after the confirmation of the absence of any recurrent sign of lung cancer. In the resected specimen, papillary thyroid microcarcinoma was observed with several intraglandular metastases and right regional lymph node involvement. Eight months later, a new primary lung cancer developed in the left lung, and a left upper lobectomy of the lung with a mediastinal lymph node dissection was performed. At that time, the absence of mediastinal lymph node metastasis from lung cancer or thyroid cancer was confirmed. Mediastinal lymph node involvement as the initial manifestation of occult thyroid cancer in surgical treatment for lung cancer is rare, but it is important to be aware of the possibility of incidentally detecting occult thyroid cancer in surgical dissections in this area for lung cancer. The appropriate surgical treatment should be determined while carefully considering the prognosis of the lung cancer as well as that of any coexisting malignancy.

Successful removal of a primitive neuroectodermal tumor in the lung with gross extension into the left atrium

We report here the successful multi-model treatment of a 31-year-old female demonstrating a primitive neuroectodermal tumor originating in the lower lobe of the right lung with gross extension into the left atrium via the inferior pulmonary vein. The tumor was markedly reduced by combination chemotherapy consisting of vincristine, doxorubicin, cyclophosphamide, and ifosfamide. The residual tumor was completely removed through a combined left atrial resection and right middle and lower lobectomy, using a percutaneous cardiopulmonary support system.

Surgical treatment for metastatic lung tumors with incidentally coexisting lung cancer

We report four surgically resected cases of a metastatic lung tumors with incidentally coexisting lung cancer. Two patients (Cases 1 and 2) were admitted for surgical treatment for pulmonary metastases from colon cancer, and the other two (Cases 3 and 4) were for pulmonary metastases from renal cell carcinoma. In only one patient (Case 3), one lesion among the multiple shadows on the preoperative computed tomography examination was rather strongly suspected to be primary lung cancer. In three patients (Cases 1, 2 and 3), one of the resected lesions in each individual case was diagnosed as lung adenocarcinoma by an intraoperative examination using frozen sections, and was later histologically confirmed. In Case 4, one of the resected lesions was postoperatively determined to be lung adenocarcinoma. All coexisting lung cancers, treated with partial resection of the lung, were well-differentiated small-sized adenocarcinoma (T1N0), while the other lesions resected in each case were metastases from the individual cancer. Problems in preoperative diagnosis and surgical treatment for metastatic lung tumors with incidentally coexisting lung cancer are discussed.

Prevention of infection of influenza virus in DQ6 mice, a human model, by a peptide vaccine prepared according to the cassette theory

We proposed a strategy (cassette theory) in which non-binding peptides for murine major histocompatibility complex (MHC) class II molecules are introduced into a MHC-binding component to render the resultant hybrid peptides bound to the MHC and thus immunogenic in animals carrying the relevant MHC. It was shown that 46F/HA127-133/54A(18mer) peptide which was prepared by introducing hemagglutinin (HA)127-133 of influenza virus into the H-2Ab binding component induced significant T cell responses and antibodies (Ab) specific for HA127-133 in H-2Ab mice. Further we found that the H-2Ab binding component had a supermotif for human class II molecules (i.e. HLA-DQ6). In the present study, a new peptide vaccine, H3-H3, was prepared by combining 46F/HA127-133/54A(18mer) as a carrier and HA127-133 attached to the C terminus of 46F/HA127-133/54A(18mer) as a hapten and the effect of vaccine was examined in DQ6 mice which carry HLA-DQ6 alone as MHC class II molecules and thus may be regarded as a model of the DQ6 positive individuals. Since 46F/HA127-133/ 54A(18mer) induced merely Ab against HA127-133, it was assumed that H3-H3 induced mainly HA127-133 specific Ab in DQ6 mice without undesirable Ab production against the carrier. Indeed, H3-H3 elicited T cell responses and induced HA127-133 specific Ab in DQ6 mice. Furthermore, administration of H3-H3 inhibited growth of influenza virus until 9 weeks after the last immunization in DQ6 mice.

Functional characterization of the rat multispecific organic anion transporter OAT1 mediating basolateral uptake of anionic drugs in the kidney

The functional characteristics of rat organic anion transporter OAT1 were investigated using Xenopus laevis oocytes. Uptake of p-aminohippurate (PAH) by the oocytes expressing OAT1 was markedly inhibited by glutarate, alpha-ketoglutarate and probenecid, moderately inhibited by folate and methotrexate, but not inhibited by taurocholate or tetraethylammonium. Methotrexate and folate were transported by OAT1, but probenecid, a typical inhibitor of organic anion transporter, was not transported. Inhibition of PAH uptake by aliphatic dicarboxylates with various alkyl chain lengths was maximal at 5 (glutarate) and 6 (adipate) carbon atoms. OAT1-mediated PAH uptake was markedly inhibited by phorbol 12-myristate 13-acetate (PMA), phorbol 12,13-dibutyrate and mezerein, but not by 4alpha-phorbol 12,13-didecanoate. The inhibitory effect of PMA was attenuated in the presence of staurosporine, suggesting that OAT1 is regulated by protein kinase C. These results suggest that the substrate recognition of OAT1 is comparable to that of renal basolateral organic anion transporter, and the transport activity is regulated by protein kinase C.

Genetic variation of mitochondrial cytochrome b genes among the subspecies of koala, Phascolarctos cinereus

A conserved DNA region among the subspecies of koala, of mitochondrial cytochrome b gene, was employed to analyze the genetic variation among 3 available subspecies of koala. This conserved sequence, 307 bp DNA, was sequenced using polymerase chain reaction and direct DNA sequencing technique. Substitutions in the nucleotide sequences were observed, with which koalas can be divided into 3 DNA haplotypes subspecies, but the molecular data provided inconsistency with current classification of the 3 subspecies of koala.

[Surgical treatment of T3N0M0 non-small cell lung cancer]

From January 1982 to June 1995, 45 patients underwent operation at our department for T3N0M0 non-small cell lung cancer. Tumors invaded chest wall in 38 patients (parietal pleura in 17, subpleural fat tissue in 10, and rib in 11), diaphragm in 3, mediastinum in 3, and pericardium in 1. Extrapleural dissection was performed in 17 patients and en bloc resection of chest wall and lung was performed in 21. Complete resection was possible in 43 patients (96%). Operative mortality was 2.2%. The actuarial overall 5-year survival rate was 63% for the patients with parietal pleura invasion, 45% for those with subpleural invasion, 45% for those with rib invasion, and 56% for those with diaphragm, mediastinal pleura or pericardial invasion. Recurrence at the resected margin was observed in 5 patients with chest wall invasion (subpleural tissue in 3, rib in 2) and 1 with diaphragmatic invasion. In conclusion, we recommend an en bloc resection of the chest wall with enough surgical margin for peripheral tumors firmly adherent to the parietal pleura.

Fibroblast growth factor receptor-1 expression in the cortex and hippocampus in Alzheimer's disease

Localization of fibroblast growth receptor (FGFR)-1 immunoreactivity was investigated immunochemically in postmortem brain tissue of Alzheimer's disease (AD) and age-matched control cases using a rabbit polyclonal antibody and a mouse monoclonal antibody specific for FGFR-1. In control cases, FGFR-1 immunoreactivity was identified in astrocytes in white matter and in hippocampal pyramidal neurons. In AD cases, the immunoreactivity in reactive astrocytes surrounding senile plaques was increased. The pattern of FGFR-1 immunoreactivity was confirmed in selected cases by in situ hybridization for FGFR-1 mRNA. Immunoreactivity using a monoclonal antibody demonstrated a similar distribution pattern. The localization of FGFR-1 is consistent with previous reports on the involvement of FGF-1 and FGF-2 in AD.

Distinct characteristics of transcellular transport between nicotine and tetraethylammonium in LLC-PK1 cells

To clarify the mechanisms of the renal tubular secretion of nicotine, we studied transport of nicotine in the kidney epithelial cell line LLC-PK1. The transcellular transport of nicotine from the basolateral side to the apical side of the LLC-PK1 monolayers grown on membrane filters was much greater than that of tetraethylammonium. The basolateral-to-apical transport of nicotine was stimulated by lowering the pH of the apical side, accompanied by a decrease in the accumulation of nicotine. The accumulation of nicotine from the basolateral side was inhibited by unlabeled nicotine, cotinine, tetraethylammonium, cimetidine and quinidine. The uptake of nicotine across the apical membrane was inhibited by unlabeled nicotine and quinidine but not by tetraethylammonium or cimetidine. Pretreatment with p-chloromercuribenzene sulfonate caused a decrease in the transcellular transport of tetraethylammonium but not of nicotine. These results suggest that nicotine undergoes vectorial transport from basolateral side to the apical side of LLC-PK1 monolayers in a H+ gradient-dependent manner, corresponding to the secretion in the renal tubules. Nicotine transport in LLC-PK1 cells could be mediated by a transport system that is distinct from the transport system for tetraethylammonium.

KAI1/CD82 expression in nonsmall cell lung carcinoma is a novel, favorable prognostic factor: an immunohistochemical analysis

BACKGROUND

The KAI1/CD82 gene, the product of which is a member of the transmembrane-4 superfamily, is a suppressor of metastasis; as a result, it is inversely associated with tumor progression and is a favorable prognostic factor in some tumors. This study was performed to determine the prognostic value of KAI1/CD82 protein levels in nonsmall cell lung carcinoma (NSCLC). In addition, levels of KAIl/CD82 expression in metastatic lesions were determined and compared with those in primary NSCLC lesions.

METHODS

KAI1/CD82 expression in 200 NSCLC patients who underwent potentially curative surgery was immunohistochemically detected with C33, an anti-KAI1/CD82 monoclonal antibody. According to the degree of KAI1/CD82 positive cancer cells within the tumor tissue, each sample was classified as KAI1/CD82 positive, KAI1/CD82 reduced, or KAI1/CD82 negative.

RESULTS

Sixty-five samples (32.5%) were KAI1/CD82 positive, 31 (15.5%) were reduced, and 104 (52%) were negative. There was no significant association between KAI1/CD82 expression and clinicopathologic factors, but patients who were positive for KAI1/CD82 expression had significantly favorable prognoses for overall survival (P = 0.0026) and disease free survival (DFS; P = 0.0007) compared with the other groups. In particular, among patients with adenocarcinoma, similar results were even more significant. In multivariate analysis, immunohistochemical KAI1/CD82 expression in patients with NSCLC was an independent prognostic factor for overall survival and DFS; in those with adenocarcinoma, it was an even more valuable factor. In some patients with NSCLC, especially those with adenocarcinoma, KAI1/CD82 expression levels in metastatic lesions were diminished compared with levels of expression in the primary lung lesions.

CONCLUSIONS

The immunohistochemically determined level of KAI1/CD82 expression in NSCLC cells within tumor tissue appears to be a favorable prognostic factor for overall survival as well as DFS. The results of this study suggest that decreased KAI1/CD82 expression may be associated with tumor progression and enhanced metastatic potential in some patients with this disease.

Effects of troglitazone on hepatic and peripheral insulin resistance induced by growth hormone excess in rats

It is well known that short-term growth hormone (GH) administration in humans and animals induces insulin resistance and glucose intolerance. The purpose of the present study was to clarify whether troglitazone, a new insulin-sensitizing drug of the thiazolidinedione class, counteracts the insulin antagonistic effects of recombinant human (rh) GH on glucose metabolism in rats. Male Wistar rats weighing 184 to 226 g were treated either with rhGH (n = 8) or rhGH plus troglitazone (n = 8). rhGH (20 IU/kg body weight/d) was given by subcutaneous injection twice daily for 2 days. Troglitazone was given at 100 mg/kg/d orally for 5 days before and 2 days during rhGH. Saline was injected to the control rats (n = 7). Euglycemic clamp studies with an insulin infusion rate of 8 mU/kg/min were performed in these rats after an overnight fast. Hepatic glucose output (HGO), glucose infusion rate (GIR), and glucose disappearance rate (GDR) were measured. Fasting levels of plasma glucose (6.6 +/- 0.1, 6.1 +/- 0.3, 6.5 +/- 0.2 mmol/L), insulin (187.5 +/- 24.1, 206.4 +/- 24.1, 182.3 +/- 31.0 pmol/L), and serum free fatty acid (FFA) (1.58 +/- 0.18, 1.43 +/- 0.16, 1.61 +/- 0.25 mEq/L) were comparable among rats treated with rhGH, rhGH plus troglitazone, and controls, respectively. Basal HGO was also comparable among the three treatment groups. HGO was suppressed significantly during the hyperinsulinemic glucose clamp in control rats, but not in rhGH rats. When troglitazone was coadministered with rhGH, suppressibility of HGO during the glucose clamp was comparable to that of controls. GIR (13.5 +/- 4.5 v 24.1 +/- 4.1 mg/kg/min) and GDR (18.1 +/- 5.8 v 30.3 +/- 5.2 mg/kg/min) were decreased by rhGH treatment compared with control values. They returned to normal levels in rats treated with both rhGH and troglitazone (GIR, 22.4 +/- 5.9; GDR, 24.7 +/- 7.1). From these results, it is evident that rhGH treatment impaired insulin's ability to suppress HGO and stimulate peripheral glucose utilization. Troglitazone could block the insulin antagonistic effects of GH on hepatic glucose output and peripheral glucose utilization.

[Simultaneous operation of lung cancer accompanied with aortic arch aneurysm: report of a case]

We report a simultaneously operated case of a 68-year-old man with lung cancer accompanied with aortic arch aneurysm. Preoperative staging CT for lung cancer incidentally demonstrated another lesion in the para-aortic arch area, which was suspected to be rather a pleural or intrapulmonary lesion by enhanced CT and MRI. However, this lesion was intraoperatively diagnosed as a cystic small sized-aneurysm. After a left upper lobectomy with lymph node dissection for lung adenocarcinoma (T2N0) was performed, this aneurysm was tightly wrapped using PTFE felt during the course of one operation. The difficulty of peroperative diagnosis by CT and MRI for small sized-aneurysm is discussed, and surgical stragety for lung cancer accompanied with such an aortic aneurysm is also commented.

[Does induction therapy followed by surgery improve the survival rate in limited-stage small-cell lung cancer patients?]

Small-cell lung cancer (SCLC) is distinguished from non-small cell lung cancer (NSCLC) by its rapid tumor doubling time, high growth fraction, and early development of widespread metastases. Surgery alone offers the best chance for long-term survival in selected patients with stage I SCLC. Most patients with limited SCLC (stage I-IIIa) are treated with "comprehensive therapy" combined with chemotherapy, radiotherapy (thoracic radiotherapy and/or prophylactic cranial irradiation), and surgery. Although the efficacy of surgery in the control of local disease is well established, to date no report has shown better survival rates in patients who receive induction therapy when compared with patients receiving postoperative chemotherapy. However, studies of induction therapy include more patients with advanced-stage cancer than do studies of post-operative chemotherapy. Thus the final role of induction therapy followed by surgery must await the results of future prospective, randomized trials conducted by large cooperative study groups.

Immunohistochemical p53 protein status in nonsmall cell lung cancer is a promising indicator in determining in vitro chemosensitivity to some anticancer drugs

BACKGROUND AND OBJECTIVES

The tumor suppressor oncogene p53 abnormalities have been closely associated with resistance or sensitivity of cancer cells to some chemotherapeutic agents. We examined the association between p53 protein status in nonsmall cell lung cancer (NSCLC) and in vitro chemosensitivity to several chemotherapeutic agents.

METHODS

Using 146 surgically resected specimens of NSCLC, p53 status was immunohistochemically evaluated, and in vitro chemosensitivity to 5-fluorouracil (5-Fu), cisplatin (CDDP), mitomycin C (MMC), etoposide (VP-16), doxorubicin hydrochloride (ADM), and vindesine sulfate (VDS) was examined by a collagen gel-droplet embedded culture drug sensitivity test (CD-DST, Int J Oncol, 1997;11:449).

RESULTS

Sixty-five of 146 materials (45%) showed immunohistochemically abnormal p53 protein accumulation in >10% of cancer cells within the tumor tissue, being regarded as p53+, whereas 81 (55%) were to p53-, in which no or less than 10% positive immunostaining cancer cells were detected. By CD-DST, the incidence of chemosensitive, borderline, and resistant p53- materials (N=81) to 5-Fu was 37%(N=30), 14%(N=11), and 49%(N=40), whereas that of p53+ materials (N=65) was 20%(N=13), 6%(N=4), and 74%(N=48), respectively, showing that p53- materials were significantly more sensitive to 5-Fu than p53+ materials (P=0.011), especially in the adenocarcinoma type. As similar borderline association between p53 protein status and in vitro chemosensitivity was also shown in ADM (P=0.078), but not in other chemoagents.

CONCLUSIONS

Immunohistochemically detected p53 protein status in NSCLC patients may be a promising indicator in determining in vitro chemosensitivity to some anticancer drugs, especially 5-Fu and ADM.

Myoepithelioma of the lung: report of two cases and review of the literature

Myoepithelial tumors occur mainly in the salivary glands, the sweat glands or the breast, but uncommonly in the lung. Herein, we describe two cases of myoepithelioma of the lung. Both patients were 58-year-old men, in whom the tumors were located in the right-upper bronchus and in the left-upper bronchus, respectively, with endobronchial growth pattern. Surgery was performed, but metastasis occurred into the forearm and hip muscles in the former case, and into the liver in the latter. Histologically, the tumor in the former was a spindle-plasmacytoid type, and that in the latter was a plasmacytoid type in part with squamous differentiation. Based on histochemical, immunohistochemical and ultrastructural analyses, both were compatible with myoepithelioma. The clinicopathological uniqueness of this neoplasm is discussed, together with a review of reports of this disease in the literature.

Analysis of zebrafish Mhc using BAC clones

Although major histocompatibility complex (Mhc) genes have been identified in a number of species, little is yet known about their organization in species other than human and mouse. The zebrafish, Danio rerio, is a good candidate for full elucidation of the organization of its Mhc. As a step toward achieving this goal, a commercially available zebrafish BAC library was screened with probes specific for previously identified zebrafish class I and class II genes, as well as for genes controlling the proteasome subunits LMP7 and LMP2. Restriction maps of the individual positive clones were prepared and the Mhc (LMP7) genes localized to specific fragments. The total length of genomic DNA fragments with Mhc genes was approximately 1700 kilobases (kb) (200 kb of fragments bearing class I loci and 1500 kb of fragments bearing class II loci). One of the two class I loci (Dare-UCA) is closely associated with the LMP7 locus; the second class I locus (Dare-UAA) is more than 50 kb distant from the UCA locus and has no LMP genes associated with it. None of the class II genes are linked to the class I or the LMP genes. All six of the previously identified class II B genes and one of the three class II A genes were found to be present in the BAC clones; no new Mhc loci could be identified in the library. Each of the six previously identified class II B loci was found to be borne by a separate group of BAC clones. The Dare-DAB and -DAA loci were found on the same clone, approximately 15 kb apart from each other. An expansion of DCB and DDB loci was detected: the zebrafish genome may contain at least five closely related DCB and two closely related DDB loci which are presumably the products of relatively recent tandem duplication. These results are consistent with linkage studies and indicate that in the zebrafish, the class I and class II loci are on different chromosomes, and the class II loci are in three different regions, at least two of which are on different chromosomes.

Effects of troglitazone on dexamethasone-induced insulin resistance in rats

Troglitazone, a thiazolidinedione derivative, has been shown to counteract insulin resistance in obesity and non-insulin-dependent diabetes mellitus (NIDDM). To test its effects on dexamethasone-induced insulin resistance, we measured hepatic glucose production (HGP) and the insulin-stimulated glucose disposal rate (Rd) by a euglycemic-hyperinsulinemic glucose clamp technique coupled with 3-3H-glucose infusion in male Wistar rats treated with low-dose dexamethasone ([LoDex] 0.05 mg/kg/d, n = 7), high-dose dexamethasone ([HiDex] 0.1 mg/kg/d, n = 7), or dexamethasone plus troglitazone (LoDex + T, n = 8; HiDex + T, n = 6). Dexamethasone was injected subcutaneously for 4 days. Troglitazone was administered orally at 20 mg/d for 3 days before and for 4 days along with the dexamethasone treatment. The glucose clamp study was performed after an overnight fast in chronically catheterized conscious rats with a continuous insulin infusion of 57.4 pmol/kg/min. Basal HGP was comparable among the control (45.8 +/- 2.1 micromol/kg/min, n = 7), LoDex (47.9 +/- 4.7 micromol/kg/min), LoDex + T (46.0 +/- 2.6 micromol/kg/min), and HiDex + T (54.7 +/- 3.4 micromol/kg/min) groups. It increased about twofold in the HiDex group (80.1 +/- 5.2 micromol/kg/min, P < .05 v control). Under hyperinsulinemia, HGP was suppressed to a similar level in the control (11.3 +/- 8.8 micromol/kg/min), LoDex (10.2 +/- 8.4 micromol/kg/min), and LoDex + T (7.8 +/- 7.9 micromol/kg/min) groups. The suppressive effect of insulin on steady-state HGP during the clamp was impaired in HiDex (63.7 +/- 9.7 micromol/kg/min, P < .05) and HiDex + T (64.0 +/- 6.5 micromol/kg/min, P < .05). Rd decreased 27% in LoDex (81.5 +/- 5.8 micromol/kg/min, P < .05) and 36% in HiDex (71.3 +/- 9.4 micromol/kg/min, P < .05) compared with the controls (111.4 +/- 7.4 micromol/kg/min). Troglitazone prevented the decrease in Rd in LoDex + T (102.6 +/- 5.7 micromol/kg/min), but not in HiDex + T (67.0 +/- 6.4 micromol/kg/min). These results indicate that the development of peripheral insulin resistance was prevented by troglitazone in LoDex rats. Troglitazone may be a useful drug to treat steroid-induced diabetes.

Linkage of LMP, TAP, and RING3 with Mhc class I rather than class II genes in the zebrafish

The LMP2 and LMP7 genes code for subunits of the proteasome, a multimeric enzymatic complex that degrades proteins into peptides. The two subunits replace corresponding constitutively expressed subunits during the immune response. Some of the peptides generated by the proteasome in the cytosol are transported by the products of the TAP1 and TAP2 genes into the lumen of the endoplasmic reticulum and are loaded onto the assembling MHC class I molecules. In mammals, the LMP2, LMP7, TAP1, and TAP2 genes reside in the class II region of the Mhc, closely linked to the RING3 gene. In the present study we identified, cloned, and sequenced the LMP, TAP2, and RING3 genes of the zebrafish, Danio rerio. We identified variants of these genes and used them in a segregation analysis of haploid embryos derived from heterozygous mothers. The analysis revealed that in zebrafish, the LMP2, LMP7, TAP12, and RING3 loci are closely linked but, in contrast to mammals, the LMP/TAP/RING3 cluster resides not in the Mhc class II but in the class I region. We also confirmed that in the zebrafish, the class I and class II regions are not linked to each other. In this species, therefore, the LMP/TAP/RING3 genes are clustered with the class I genes on a chromosome that apparently does not contain any class II genes. The linkage of LMP/TAP/RING3/class I may be the original and the LMP/TAP/RING3/class II a derived arrangement of these genes.

Linkage of LMP, TAP, and RING3 with Mhc class I rather than class II genes in the zebrafish

The LMP2 and LMP7 genes code for subunits of the proteasome, a multimeric enzymatic complex that degrades proteins into peptides. The two subunits replace corresponding constitutively expressed subunits during the immune response. Some of the peptides generated by the proteasome in the cytosol are transported by the products of the TAP1 and TAP2 genes into the lumen of the endoplasmic reticulum and are loaded onto the assembling MHC class I molecules. In mammals, the LMP2, LMP7, TAP1, and TAP2 genes reside in the class II region of the Mhc, closely linked to the RING3 gene. In the present study we identified, cloned, and sequenced the LMP, TAP2, and RING3 genes of the zebrafish, Danio rerio. We identified variants of these genes and used them in a segregation analysis of haploid embryos derived from heterozygous mothers. The analysis revealed that in zebrafish, the LMP2, LMP7, TAP12, and RING3 loci are closely linked but, in contrast to mammals, the LMP/TAP/RING3 cluster resides not in the Mhc class II but in the class I region. We also confirmed that in the zebrafish, the class I and class II regions are not linked to each other. In this species, therefore, the LMP/TAP/RING3 genes are clustered with the class I genes on a chromosome that apparently does not contain any class II genes. The linkage of LMP/TAP/RING3/class I may be the original and the LMP/TAP/RING3/class II a derived arrangement of these genes.

New ulcerative colitis model induced by sulfhydryl blockers in rats and the effects of antiinflammatory drugs on the colitis

We tried to produce a new ulcerative colitis model in rats by topical administration of sulfhydryl blockers. After male SD rats were fasted for 24 hr, 100 microliters of 3% N-ethylmaleimide (NEM) or iodoacetamide (IA) was introduced into the colon via a Nelaton's catheter. Both NEM and IA caused severe diarrhea with rectal bleeding and decreased body weight for about 7 days. At autopsy, adhesions and dilatation of the colon and severe mucosal lesions were observed. Both the weight and myeloperoxidase activity of the colon increased markedly. Maximum changes were observed within 1-3 days followed by gradual recovery, but even on day 21, some abnormalities were still observed. The ulceration and inflammation of the colon were confirmed by histological studies. Antiinflammatory drugs such as indomethacin inhibited the inflammation of the colon by NEM, but aggravated the ulceration. These results revealed that sulfhydryl blockers instilled into the colon caused ulcerative colitis in the rat. This model may be useful in studies on the pathogenesis of ulcerative colitis and the evaluation of drugs for therapy. Furthermore, it was suggested that antiinflammatory drugs may delay the healing of colonic ulcers.

Unmasking of an unusual myelin basic protein epitope during the process of myelin degeneration in humans: a potential mechanism for the generation of autoantigens

A rabbit antiserum (anti-EP), induced against a synthetic peptide corresponding to residues 68 to 86 of guinea pig myelin basic protein, powerfully immunostained abnormal-appearing oligodendrocytic processes and cell bodies in demyelinating areas associated with multiple sclerosis plaques. However, it failed to recognize any structures in normal human, rat, or guinea pig brain. The antiserum recognized the synthetic peptide QDENPVV, which corresponds to human myelin basic protein residues 82 to 88. Immunoabsorption with this peptide eliminated immunohistochemical staining. By contrast, several commercial antibodies recognizing nearby sequences of human myelin basic protein intensely stained all myelinated structures in both normal and multiple sclerosis tissue. The unusual epitope recognized by anti-EP appears to be accessible only in areas of myelin degeneration. If insults occur that repeatedly expose a region of MBP normally sheltered from immunosurveillance, a self-sustaining immune reaction might result.

Csk overexpression reduces several monokines and nitric oxide productions but enhances prostaglandin E2 production in response to lipopolysaccharide in the macrophage cell line J774A.1

The catalytic activity of src-family protein tyrosine kinases (src-PTK) is suppressed when a C-terminal tyrosine is phosphorylated by an intracellular PTK, C-terminal Src kinase (Csk). In the present report, to study the regulatory functions of the Csk in cells of monocyte/macrophage lineage, we transfected a eukaryotic expression vector containing rat csk cDNA in a macrophage cell line, J774A.1, and examined alterations of the response to lipopolysaccharide (LPS) in the transfectants which overexpressed Csk. Csk overexpression resulted primarily in a down-regulation of Fgr activity, an src-PTK expressed in J774A.1, and hyperphosphorylation of several cellular proteins of 35, 57, 66, 97 and 120-130 kDa. Furthermore, in these Csk transfectants, production of interleukin (IL)-1alpha, IL-6, tumor necrosis factor-alpha, and nitric oxide (NO) following LPS stimulation were reduced compared with those in parental J774A.1 or J774A.1 transfected with the vector alone. The extent of reduction paralleled the amounts of Csk proteins expressed in the Csk-transfected J774A.1. The reduced NO production in these cells was associated with low levels of mRNA of inducible NO synthetase. On the other hand, an enhancement of prostaglandin E2 production was observed in the Csk-transfected J774A.1 cells upon stimulation with LPS, which appeared to result from the high level of prostaglandin-H synthetase in the transfectants. The present findings indicate that overexpression of Csk has differential effects on the regulation of production of chemical mediators and monokines, probably via modulation of signal transduction downstream of LPS-mediated signals.