Substrate modulation of osteoblast adhesion strength, focal adhesion kinase activation, and responsiveness to mechanical stimuli

Osteoblast interactions with extracellular matrix (ECM) proteins are known to influence many cell functions, which may ultimately affect osseointegration of implants with the host bone tissue. Some adhesion-mediated events include activation of focal adhesion kinase, and subsequent changes in the cytoskeleton and cell morphology, which may lead to changes in adhesion strength and cell responsiveness to mechanical stimuli. In this study we examined focal adhesion kinase activation (FAK), F-actin cytoskeleton reorganization, adhesion strength, and osteoblast responsiveness to fluid shear when adhered to type I collagen (ColI), glass, poly-L-lysine (PLL), fibronectin (FN), vitronectin (VN), and serum (FBS). In general, surfaces that bind cells through integrins (FN, VN, FBS) elicited the highest adhesion strength, FAK activation, and F-actin stress fiber formation after both 15 and 60 minutes of adhesion. In contrast, cells attached through non-integrin mediated means (PLL, glass) showed the lowest FAK activation, adhesion strength, and little F-actin stress fiber formation. When subjected to steady fluid shear using a parallel plate flow chamber, osteoblasts plated on FN released significantly more PGE2 compared to those on glass. In contrast, PGE2 release of osteoblasts attached to FN or glass was not different in the absence of fluid shear, suggesting that differences in binding alone are insufficient to alter PGE2 secretion. The increased adhesion strength as well as PGE2 secretion of osteoblasts adhered via integrins may be due to increased F-actin fiber formation, which leads to increased cell stiffness.

Frequency and clinical characteristics of dilated cardiomyopathy caused by desmin gene mutation in a Japanese population

AIMS

Dilated cardiomyopathy is partly caused by a mutation of some cytoskeletal or nuclear envelope proteins. It has been confirmed recently that a missense mutation of the gene encoding desmin, a cytoskeletal protein, can cause dilated cardiomyopathy. This study was aimed at elucidating the frequency and clinical characteristics of dilated cardiomyopathy caused by desmin mutation.

METHODS AND RESULTS

We examined 265 Japanese patients with dilated cardiomyopathy (217 sporadic cases and 48 probands of familial dilated cardiomyopathy). The exon 8 of the desmin gene, the critical region for the pathogenesis of dilated cardiomyopathy, was analysed by polymerase chain reaction, single-strand conformation polymorphism and sequencing. The same missense mutation (Ile451Met) as reported previously was detected in three patients (1.1%). All these patients were male and sporadic, and more likely to be accompanied by characteristics such as younger age at diagnosis, lower fractional shortening and ejection fraction than each mean value of sporadic cases. The chronological changes in cardiac function were inconsistent in the three patients.

CONCLUSION

The missense mutation (Ile451Met) of the desmin gene can be the genetic cause of dilated cardiomyopathy, although with very low frequency. The ages at diagnosis were younger and the cardiac function had deteriorated further than general cases of sporadic dilated cardiomyopathy.

Differential splenic migration of dendritic cells after immunologic unresponsiveness in rat hepatic allografts induced by pretransplant donor-specific transfusion

BACKGROUND

Donor dendritic cells migrate into the recipient spleen after hepatic transplantation. We previously reported that immunologic unresponsiveness to rat hepatic allografts can be induced by prior donor-specific blood transfusion (DST). We investigated the phenotype and splenic distribution of donor dendritic cells after allografting and DST.

METHODS

Donor dendritic cells were identified with anti-rat dendritic cell (OX-62) and anti-donor class II MHC (RT1B(a)) (OX-76) antibodies. The phenotype of dendritic cells was determined with antibodies to CD45RC, CD62L, and the maturation markers CD80 (B7-1) and CD86 (B7-2). The cytokine profile of sorted CD45RC(+) OX-62(+) and CD45RC(-) OX-62(+) dendritic cells was analyzed by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Pretransplant DST significantly prolonged rat hepatic allograft survival. Immunostaining revealed OX76(+)/OX-62(+) cells in the splenic red pulp of animals receiving pretransplant DST and in the white pulp of untreated animals after transplantation. The ratio of splenic CD45RC(-) OX-62(+) cells to CD45RC(+) OX-62(+) cells was significantly higher in DST recipients than in untreated animals. CD62L, CD80, and CD86 were lower on CD45RC(-) OX-62(+) than CD45RC(+) OX-62(+) cells. RT-PCR revealed that sorted CD45RC(-) OX-62(+) cells expressed interleukin (IL)-4 and IL-10. In contrast, sorted CD45RC(+) OX-62(+) cells expressed only IL-2 and interferon gamma (IFN-gamma).

CONCLUSION

Differential splenic migration of CD45RC(-) dendritic cells is associated with immunologic unresponsiveness to rat hepatic allografts.

A high-speed atomic force microscope for studying biological macromolecules

The atomic force microscope (AFM) is a powerful tool for imaging individual biological molecules attached to a substrate and placed in aqueous solution. At present, however, it is limited by the speed at which it can successively record highly resolved images. We sought to increase markedly the scan speed of the AFM, so that in the future it can be used to study the dynamic behavior of biomolecules. For this purpose, we have developed a high-speed scanner, free of resonant vibrations up to 60 kHz, small cantilevers with high resonance frequencies (450-650 kHz) and small spring constants (150-280 pN/nm), an objective-lens type of deflection detection device, and several electronic devices of wide bandwidth. Integration of these various devices has produced an AFM that can capture a 100 x 100 pixel(2) image within 80 ms and therefore can generate a movie consisting of many successive images (80-ms intervals) of a sample in aqueous solution. This is demonstrated by imaging myosin V molecules moving on mica (see http://www.s.kanazawa-u.ac.jp/phys/biophys/bmv_movie.htm).

Asymptomatic pyuria in diabetic women

The aim of the present study was to determine the prevalence of and the host factors for asymptomatic pyuria (ASP) in women with type 2 diabetes. The study included 179 type 2 diabetic women and consecutive 455 non-diabetic women attending as out-patients in 1996. Patients with symptoms of a urinary tract infection were excluded. ASP was defined as the presence of more than 10 leukocytes/high-power field in a random urine sample. Diabetic women more often had ASP than non-diabetic women (27.9 vs. 15.8%, P<0.001). The prevalence of ASP was significantly increased in patients with a duration of diabetes exceeding 15 years (0 approximately 4 years; 20.3%, 5 approximately 9 years; 24.3%, 10 approximately 14 years; 23.8%, and > or =15 years; 46.3%). No differences were evident in HbA(1C) between diabetic patients without ASP and those with ASP. Diabetic women with ASP more often had diabetic retinopathy, neuropathy, nephropathy, cerebrovascular disease, ischemic heart disease, and hyperlipidemia than those without ASP. However, no statistically significant differences were evident in the prevalence of hypertension, constipation, or dementia. As the degree of neuropathy increases, it is accompanied by an increasing prevalence of ASP (none, 21.4%; blunt tendon reflexes, 24.5%; symptomatic, 50.0%; and gangrene, 66.6%). The prevalence of ASP was significantly increased in the patients with proliferative diabetic retinopathy (none, 23.2%; background, 29.4%; pre-proliferative, 18.2%; and proliferative, 50.0%). As the degree of nephropathy increases, it is accompanied by an increasing prevalence of ASP (none, 20.0%; microalbuminuria, 31.9%; macroalbuminuria, 37.0%; and renal failure, 60.0%). Thus, the prevalence of ASP is increased in women with diabetes and increased with longer duration of diabetes but was not affected by glucose control. The incidence of ASP increases significantly as diabetic microangiopathy becomes severer.

CD3+CD56+CD8+ cells demonstrating a suppressor T cell-like function in the peripheral blood of colon cancer patients

We previously reported that HLA-unrestricted CTLs against MUC-1 were induced from colon cancer patients by stimulating peripheral blood lymphocytes (PBLs) with recombinant MUC-1 vaccinia virus (rVMUC-1). We have performed adoptive immunotherapy (AI) for two gastric and two colon cancer patients, using the rVMUC-1-stimulated T lymphocytes. A significant level of HLA-unrestricted cytotoxicity against MUC-1 was induced in the two colon cancer patients (pA and pB) during the first adoptive immunotherapy, but extremely reduced during the second AI. During the second stimulation phase, the rate of CD3+CD56+CD8+ cells were significantly increased and that of CD3+CD56-CD4+ cells were significantly decreased in the two colon cancer patients as compared to the first AI. CD3+CD56+CD8+ and CD3+CD56-CD4+ cells were isolated from the second AI of the colon cancer patient (pB) and designated as D856 and D4, respectively. The D4 cells demonstrated a high level of HLA-unrestricted CTL activity against MUC-1, but D856 cells did not. When D856 cells were mixed with D4 cells at a D856/D4 ratio of 1:3, 1:2, and 1:1 and used as effector cells, the HLA-unrestricted and MUC-1-specific CTL activity of D4 cells was suppressed in a D856/D4 ratio-dependent manner. Further, D856 cells were highly lytic for the D4 cells demonstrating HLA-unrestricted cytotoxicity against MUC-1. It is concluded that the reduction in HLA-unrestricted cytotoxicity against MUC-1 during the second AI is attributed to the D856 cells killing MUC-1-specific CTLs (D4). Thus, the CD3+CD56+ CD8+ cells seem likely to behave as a suppressor T cell.

CA19-9 epitope a possible marker for MUC-1/Y protein

It has been reported that MUC-1 molecules devoid of the tandem repeat region (MUC-1/Y) are detected preferentially in carcinoma cells and are associated with their progression. However, its clinical significance is still unknown. We constructed a mouse colon adenocarcinoma cell line (MC-38) transduced with either MUC-1/Y cDNA defecting the tandem repeat region (Y-MC-38) or MUC-1/R cDNA containing ten tandem repeats (R-MC-38). RT-PCR of mRNAs derived from Y-MC-38 cells using the specific primers to MUC-1/Y mRNAs, proved the existence of 600 bp RT-PCR products generated only from MUC-1/Y mRNAs. DF3 and CA19-9 epitopes out of the MUC-1-related tumor-associated antigens, have been reported to be involved in the prognosis of cancer patients. We examined the expression of DF3 and CA19-9 epitopes on Y-MC-38 and R-MC-38 cells. Fluorescence-activated cell sorting (FACS) analysis of R-MC-38 and Y-MC-38 cells using two monoclonal antibodies against DF3 (mAb DF3) and CA19-9 (mAb CA19-9) epitopes revealed that R-MC-38 cells expressed DF3 but not CA19-9 [DF3(+)CA19-9(-)], while Y-MC-38 cells expressed CA19-9 but not DF3 [DF3(-)CA19-9(+)]. On Western blot, a 40 kDa protein product was recognized by mAb CA19-9 but not by mAb DF3 on cell lysates of Y-MC-38 cells, whereas a 70 kDa protein product was recognized by mAb DF3 but not by mAb CA19-9 on the cell lysates of R-MC-38. Further, we analyzed the expression of MUC-1/Y mRNAs by RT-PCR on various human cancer cell lines: the gastric cancer cell line AZ521, the pancreatic cancer cell lines PANC-1 and Capan-1, the gall bladder cell line GBK-1, the breast cancer cell line MCF-7, and the colon cancer cell lines HT-29 and Colo205. HT-29 and Capan-1 cells producing the 600 bp RT-PCR product, were positive for mAb CA19-9. These results demonstrate that CA19-9 epitope is produced only on MUC-1/Y core protein, suggesting that CA19-9 epitope may be a specific marker for MUC-1/Y protein.

CD45RC gammadelta T-cell infiltration is associated with immunologic unresponsiveness induced by prior donor-specific blood transfusion in rat hepatic allografts

Little is known regarding the role of gammadelta(+) T cells in organ transplantation. We previously reported that immunologic unresponsiveness is induced by prior donor-specific blood transfusion (DST) in rat hepatic allografts. We investigated the phenotype and distribution of gammadelta(+) T cells in the hepatic allograft, spleen, and peripheral blood of recipient rats with immunologic unresponsiveness induced by DST. gammadelta(+) T cells were enumerated in allograft livers and spleens by immunostaining and in blood by flow cytometric analysis. The phenotype of gammadelta(+) T cells was determined using CD45RC isoforms derived from alternative mRNA splicing. The cytokine profile of CD45RC(+) and CD45RC(-) gammadelta(+) T cells was analyzed by reverse transcription polymerase chain reaction. The number of gammadelta(+) T cells in hepatic infiltrates in recipient rats pretreated with DST was significantly greater than in untreated animals. This correlated with significantly higher levels of gammadelta T cell receptor (TCR) mRNA in hepatic allografts of DST-treated rats as compared with untreated animals. The gammadelta(+) T cell/alphabeta(+) T-cell ratio increased in hepatic infiltrates in DST-treated recipient rats but not in untreated animals. CD45RC(-)gammadelta(+) T cells were predominantly increased in DST-treated hepatic allografts compared with untreated allografts. Most of the intestinal intraepithelial T cells were CD45RC(-)gammadelta(+). Interleukin (IL)-10 and IL-4 mRNA were detected more in CD45RC(-)gammadelta(+) T cells than CD45RC(+)gammadelta(+) T cells. CD45RC(-)gammadelta(+) T cells infiltrating liver allografts produce Th2-type cytokines and are associated with immunologic unresponsiveness induced by DST.

Immunohistochemical analysis of distribution of RON receptor tyrosine kinase in human digestive organs

The immunohistochemical distribution of RON receptor tyrosine kinase in digestive organs of both human fetus and adult, including the esophagus, stomach, duodenum, small intestine, colon, rectum, liver, gallbladder, pancreas, and spleen, was investigated semiquantitively using an affinity-purified rabbit polyclonal antibody. RON was observed to be widely distributed throughout various digestive organs and cell types in humans. The immunoreactivity for RON was observed in the epithelium of the esophagus, small intestine, colon, hepatocytes, Kupffer cells, and splenic macrophages both in the adult and the fetus, suggesting that the MSP/RON signaling pathway possesses the proper biological properties to possibly be involved in morphogenesis or differentiation of cells in these organs and cell types. Several organs differed in immunoreactivity between adult and fetus. No immunoreactive cells were found in the pancreas of adults; however, immunoreactivity was observed in acinar cells and in some of the duct or ductular cells and endocrine cells of the islet of the fetus. Similarly, immunoreactivity was not observed in gastric mucosa except in the intestinal metaplastic cells in adults; however, immunoreactivity was found in the foveolar epithelium of the stomach of the fetus. Although the biological significance of RON in malignancy is unclear, the presence of RON immunoreactivity in the fetus and it lack in the adult may indicate that RON is a oncofetal substance in human pancreas and stomach.

Systemic endothelial function is preserved in men with both active and inactive variant angina pectoris

To test the hypothesis that coronary spasm could be a coronary manifestation of systemic endothelial dysfunction and that the activity of coronary spasm could influence systemic endothelial function, we examined brachial flow-mediated, endothelium-dependent vasodilation and nitroglycerin-induced endothelium-independent vasodilation with high-resolution ultrasound in 11 men with variant angina pectoris (6 active and 5 inactive) without established coronary atherosclerosis. Endothelium-dependent vasodilation in peripheral circulation was preserved in men with active and inactive variant angina pectoris, suggesting that systemic endothelial dysfunction is not involved in either the pathogenesis or the activity of coronary spasm.

Modification of acetylcholine release by nociceptin in conscious rat striatum

Nociceptin (NOC), an endogenous ligand for the orphan opioid receptor ORL1 (ORL1), has recently been recognized as a neuropeptide. We used brain microdialysis and on-line high performance liquid chromatography (HPLC) to examine the effect of NOC on the basal outflow of acetylcholine (ACh) in the freely moving rat striatum in vivo. ACh release was reduced by nociceptin at a concentration of 10(-5) M to 79% of control release. This effect of NOC was attenuated by [Phe1Psi(CH2-NH)Gly2]nociceptin-(1-13)-NH2 (PhePsi), suggesting that NOC activates the ORL1 receptor and (PhePsi) acts as an antagonist on ORL1 in rat striatum in vivo. These findings indicate that NOC may act as a neuropeptide which inhibits ACh release in the striatum via ORL1.

Mutational analysis of the cardiac actin gene in familial and sporadic dilated cardiomyopathy

Dilated cardiomyopathy (DCM) results in part from genetic disorders. Recently, missense mutations of the cardiac actin gene have been reported to cause DCM. We studied 136 Japanese DCM cases to elucidate how frequently the gene mutations are involved in its pathogenesis. Genomic DNA samples were obtained from 136 DCM cases (107 males, 29 females), containing 30 familial DCM (5 confirmed and 25 suspected). All six exons of the cardiac actin gene were analyzed by polymerase chain reaction, single-strand conformation polymorphism, and sequencing. We detected no mutations of the disease causation previously reported (G867A or A1014G) but two silent mutations (G979C and C1018T) in exon 6 and one point mutation (T1080A) in the 3'-untranslated region. As a result of screening 128 healthy subjects, these novel silent mutations were found to be mere genetic polymorphisms, not responsible for the disease. Although some genetic polymorphisms exist in the cardiac actin gene, mutations of the gene are rarely responsible for DCM, at least in the Japanese patients.

Presence of RON receptor tyrosine kinase and its splicing variant in malignant and non-malignant human colonic mucosa

The presence of RON and its variant isoform in malignant and non-malignant human colonic tissues was examined by immunohistochemistry using paraffin-embedded sections and RT-PCR analysis followed by direct sequencing of PCR product using RNAs isolated from frozen tissues. In normal colonic mucosa, RON was uniformly expressed in crypt cells, especially in the bottom of crypta. On the other hand, the expression was distributed heterogeneously in adenomas and in colon cancer. The expression of RON was significantly related to the degree of differentiation of colon cancer and the deletion of the expression was observed in colon cancer specimens with high incidence. The RT-PCR analysis of RNA isolated from non-malignant and malignant colonic tissue revealed the presence of two RON mRNA isoforms with 432-bp and 286-bp. Direct sequencing of major product of 432-bp was revealed to be identical to that of human wild-type RON. On the other hand, major product of 286-bp was revealed to be almost identical to that of a splicing variant of RON transcript which has been found in human gastric cancer cell line, KATO-III. The results obtained in this study may indicate that both wild-type RON and its variant isoform play an important role in regulating the normal function of colonic mucosa such as differentiation and motile activity and the expression of both wild-type RON and its variant isoform could be considered to be reduced during malignancy of human colonic mucosa.

Stromelysin promoter 5A/6A polymorphism is associated with acute myocardial infarction

BACKGROUND

Rupture of the fibrous cap of an atherosclerotic plaque is a key event that predisposes to acute myocardial infarction (AMI). Matrix metalloproteinases (MMPs) may contribute to weakening of the cap, which favors rupture. Stromelysin, a member of MMP family, is identified extensively in human coronary atherosclerotic lesions. It can degrade most of the constituents of extracellular matrix as well as activating other MMPs, which suggests that it may play an important role in plaque rupture. Recently, a common variant (5A/6A) in the promoter of the stromelysin gene has been identified. The 5A/6A polymorphism could regulate the transcription of the stromelysin gene in an allele-specific manner.

METHODS AND RESULTS

To investigate the relation between the 5A/6A polymorphism in the promoter of the stromelysin gene and AMI, we conducted a case-control study of 330 AMI patients and 330 control subjects. The prevalence of the 5A/6A+5A/5A genotype was significantly more frequent in the patients with AMI than in control subjects (48.8% vs 32.7%, P<0.0001). In logistic regression models, the odds ratio of the 5A/6A+5A/5A was 2.25 (95% CI, 1.51 to 3.35). The association of 5A/6A polymorphism with AMI was statistically significant and independent of other risk factors.

CONCLUSIONS

The 5A/6A polymorphism in the promoter of the stromelysin gene is a novel pathogenetic risk factor for AMI.

Prognostic values of MUC-1 molecule expressing cytokine receptor-like epitope and DF3 in patients with gastric carcinoma

As recently reported, DF3/MUC-1 molecules having cytokine receptor-like sequences (CRL) at the extracellular region, are likely to function in signal transduction pathways. To elucidate the functional significance of CRL expressed on the DF3/MUC1 molecule, immunohistochemical localization of CRL and/or DF3 was investigated in cases of 115 patients with gastric carcinomas, treated by surgical resection. CRL was detected in 65 of 115 patients (56.5%), DF3 in 85 (73.9%), and both DF3 and CRL in 52 (45.2%). The combined immunohistochemical analysis of CRL and/or DF3, revealed that simultaneous expression of DF3 and CRL (DF3+/CRL+) significantly correlated to lymph node metastasis and to blood vessel invasion, and that patients with DF3+/CRL+-tumors survived for a significantly shorter period after surgery than did the other three groups (DF3+/CRL-, DF3-/CRL+, and DF3-/CRL-). Multivariate analysis showed independent prognostic significance for DF3+/CRL+ expression (hazard ratio [HR]=2.733, P=0.0085), and surgical cure (HR=4.334, P=0.003). To investigate the biological role of the simultaneous expression of DF3 and CRL, we constructed DF3-/CRL+ (NR-MC-38) and DF3+/CRL+ (R-MC-38) cells by transducing a mouse colon adenocarcinoma cell line MC-38 expressing neither DF3 nor CRL with MUC-1 cDNA containing ten tandem repeats (R-MC-38) or MUC-1 cDNA devoid of tandem repeats (NR-MC-38). R-MC-38 (DF3+/CRL+) cells were more invasive than NR-MC-38 (DF3-/CRL+) and MC-38 (DF3-/CRL-) cells. When these transfectants were incubated with pAb CRL, the invasiveness of R-MC-38 (DF3+/CRL+) was strikingly elevated over the case with native MC-38 (DF3-/CRL-) and NR-MC-38 (DF3-/CRL+) cells. The pAb CRL-induced invasiveness of R-MC-38 cells was inhibited by adding mAb DF3 or CRL peptides together with pAb CRL. These results suggest that an expression of DF3/MUC1 is highly associated with cell-invasiveness, and the DF3/MUC1-associated invasiveness is amplified by CRL. Thus DF3+/CRL+-MUC-1 molecule seems to be closely involved in a poor prognosis for gastric cancer patients.

Regulation of squid visual phospholipase C by activated G-protein alpha

Phospholipase C (PLC) is the key enzyme in the phototransduction cascade of invertebrate rhabdomeric photoreceptors. In addition to 130 kDa PLC, a 95 kDa protein recognized by antibody against the catalytic site of PLC was found in the squid retina. The PLC-like 95 kDa protein (95 kDa PLC) was produced from 130 kDa PLC by an intrinsic protease in the presence of calcium. The 130 kDa PLC was stimulated by the active form of Gq-class G-protein alpha (Gq alpha), but the 95 kDa PLC was not, although their PLC activity was similar. A 35 kDa fragment, the counterpart of 95 kDa PLC, was not recognized by antibodies against catalytic site or N-terminal site of the 130 kDa PLC, indicating that the cleavage site is on the C-terminal side beyond the catalytic site. In the presence of a large excess of the 35 kDa fragment, 95 kDa PLC was stimulated by Gq alpha to a similar extent as intact 130 kDa PLC. These results indicate that the C-terminal polypeptide of PLC is necessary for regulation of its enzyme activity by Gq alpha. The uncoupling of PLC from Gq alpha, caused by limited proteolysis, is therefore a candidate regulatory mechanism of the phototransduction cascade in rhabdomeric photoreceptors.

Complications and management of microwave coagulation therapy for primary and metastatic liver tumors

Microwave coagulation therapy (MCT) has been widely used, both percutaneously and directly, as effective minimal invasive therapy for liver tumors. To facilitate the use of MCT, we describe the complications we have encountered, and their possible management and prophylaxis. MCT was performed for 42 patients with hepatocellular carcinoma (HCC) and for 29 with metastatic liver tumors, following which complications developed in 14.2% and 20.6% of the HCC and metastatic groups, respectively. The complications included abscess, biloma, bleeding, hepatic failure, and dissemination of cancer cells. In the HCC group, the mean value of tumor size and the clinical stage of patients with complications were significantly larger (P = 0.006) and higher (P = 0.032), respectively, than those of patients without complications. The incidence of complications increased significantly when the tumor size was more than 4cm (P = 0.008). Abscesses and bleeding were successfully treated using percutaneous drainage and interventional angiography, respectively, but as the other serious complications were not able to be treated effectively once induced, prophylaxis is important to facilitate MCT. Transcatheter cooling of the intrahepatic bile duct during MCT and the administration of an anticancer agent into the abdominal cavity are recommended to prevent biloma and dissemination, respectively. MCT is indicated for tumors less than 4 cm in diameter to reduce the risk of complications. The prophylaxis and treatment of these complications enhance the safety of MCT.

The current status of postoperative complications and risk factors after a pulmonary resection for primary lung cancer. A multivariate analysis

OBJECTIVE

The purpose of the present study is to identify the current postoperative complications after a pulmonary resection for primary lung cancer and the associated risk factors.

METHODS

From 1988 to 1992, 291 patients with primary lung cancer, excluding T4 diseases, consecutively underwent a pulmonary resection at our institute. The observed postoperative complications were divided into non-life-threatening ones (simple arrhythmia, atelectasis, liver dysfunction, etc.) and life-threatening ones (respiratory failure, pyothorax, pneumonia, bronchopleural fistula, cardiac failure, cerebral infarction, myocardial infarction, etc.). Using logistic regression procedures, both univariate and multivariate analyses of the association between various perioperative factors and the incidence of postoperative complications were performed.

RESULTS

Non-life-threatening complications occurred in 60 patients (20.6%) while life-threatening ones occurred in 36 (12.4%), and resulted in five in-hospital deaths (1.75%). Multivariate analyses showed that an age of 70 or older, a combined resection, an abnormality on preoperative ECG, and diffusing capacity of carbon monoxide (%DLco) below 70 were all independently associated with an increased non-life-threatening morbidity. On the other hand, an age of 70 or older, the need for a pneumonectomy, and a %DLco below 70 were also independently predominant risk factors for life-threatening morbidity.

CONCLUSION

The risk factors for life-threatening morbidity therefore did not completely correspond to those for non-life-threatening morbidity. Since the mortality was quite low, even risk factors for life-threatening morbidity were not solely considered to be a contraindication for a major pulmonary resection.

Comparison of the surgical results of lobectomy with bronchoplasty and pneumonectomy for lung cancer

BACKGROUND

We retrospectively compared sleeve lobectomy (SL) and pneumonectomy (PN) for lung cancer in terms of surgical complications and postoperative disease-free survival, as well as incidence and pattern of recurrent disease.

METHODS

From 1977 to 1993. 29 patients with primary lung cancer underwent sleeve resection at our institution. The pneumonectomy group consisted of 29 cases that had been selected during the same period according to the following criteria: (1) in a tumor located in the upper lobe, there was no invasion within 1 cm from both the carina and the orifice of the middle and the lower lobe bronchus, whereas in a tumor located in the middle or lower lobe, there was no invasion within 1 cm of the orifice of the upper bronchus, (2) there was no invasion to the trunks of the pulmonary vessels, (3) there was no invasion to any other lobes, (4) a complete resection was achieved.

RESULTS

No differences were observed between the two groups regarding stage, histological population, or age. The incidence of postoperative complications was 13.7% in the SL group (2 cases each of pneumonia and arrythmia), and 24.1% in the PN group (3 bronchopulmonary fistula, 2 bleeding, 1 instance each of arrythmia and acute cardiac failure, and 2 operation-related deaths) (P < 0.05). The 3-year disease-free survival was 65.7% in SL, 58.8% in PN (no statistical significance in the log-rank test). Recurrent disease was observed in the local regions of three patients in the SL group and six patients in the PN group, and at distant organs of six patients in the SL group and seven in the PN group.

CONCLUSIONS

These findings thus suggest that as a curative treatment, lobectomy with bronchoplasty may be a safer procedure than pneumonectomy for lung cancer.

Interleukin-2 receptors in pulmonary adenocarcinoma tissue

We previously reported that the serum soluble interleukin-2 receptor (sIL-2R) level increased with the advance of disease stage in non-small cell lung cancer. The present study was thus conducted to investigate the origin of serum sIL-2R in patients with pulmonary adenocarcinoma. Fresh tumor cell suspensions were prepared from surgically resected specimens of pulmonary adenocarcinoma. They were adjusted to a cell density of 5 x 10(5)/ml and then cultured for 24 h at 37 degrees C. The culture supernatants were collected and assayed to determine the sIL-2R levels using an enzyme immunoassay. The resultant cells were thereafter cytocentrifuged onto glass slides and immunochemically stained with anti-human IL-2R alpha (CD25) monoclonal antibody. In three of six cases examined, a substantial level of sIL-2R was identified in the culture supernatants. In four cases, including those three cases with the presence of sIL-2R in the culture supernatants, various proportions of tumor cells were positively stained with the anti-IL-2R alpha antibody. Further examinations revealed that tumor cells expressed IL-2R alpha (CD25) in seven of 16 cases with pulmonary adenocarcinoma. These results thus suggested that the tumor cells did express IL-2R alpha and release sIL-2R in some cases with pulmonary adenocarcinoma.

Tumor-induced hypercalcemia and parathyroid hormone-related protein in lung carcinoma

BACKGROUND

Although lung carcinoma is the most common cause of tumor-induced hypercalcemia (TIH), the precise incidence of TIH remains obscure. Furthermore, the role of parathyroid hormone-related protein (PTHrP) has not been clearly elucidated.

METHODS

This study included 690 consecutive patients who were newly diagnosed as having lung carcinoma between 1989 and 1994 (379 adenocarcinomas, 207 squamous cell carcinomas, 75 small cell carcinomas, and 29 large cell carcinomas). All patients were treated for lung carcinoma and were also periodically monitored for their serum level of calcium (Ca). Hypercalcemia was defined as a serum Ca concentration higher than 11 mg/dL. The serum levels of PTHrP (109-141) were measured by a C-terminal-region-specific radioimmunoassay.

RESULTS

TIH was observed in 17 of 690 patients (2.5%). All 17 patients demonstrated an advanced stage of lung carcinoma (Stage III or IV), 10 squamous cell carcinomas, 5 adenocarcinomas, 1 small cell carcinoma, and 1 large cell carcinoma. In 15 patients, the serum level of C-PTHrP (109-141) was substantially high, ranging from 99 pmol/L to 890 pmol/L (normal range, 21-50.7 pmol/L). There was no significant difference in the serum PTHrP level between patients with or without bone metastasis. The reduction of tumor burden decreased both the serum level of PTHrP and that of Ca in parallel. The median survival time after diagnosis of TIH was only 27 days.

CONCLUSIONS

TIH in lung carcinoma was most likely attributable to PTHrP, and its occurrence appears to be an ominous prognostic sign.

Skip metastasis to the mediastinal lymph nodes in non-small cell lung cancer

BACKGROUND

Whether any difference exists in clinical characteristics between resected non-small cell lung cancer with either skip or ordinary mediastinal lymph node metastases (N2 disease) needs to be clarified.

METHODS

There were 110 patients with stage IIIA N2 disease. Thirty-three patients demonstrating no metastasis at the hilar nodes [skip (+) group] were compared with the other 77 patients [skip (-) group]. To investigate the extent of nodal involvement, we classified the mediastinal lymph nodes into three regions (superior, inferior, or aortic).

RESULTS

There were no significant differences regarding histologic type, T status, or the site of the primary tumors between the skip (+) and the skip (-) N2 groups. In the skip (+) group, mediastinal node metastasis was found in only one region (level 1) in 30 patients (90.9%) and in two regions (level 2) in 3 (9.1%), whereas 28 patients (36.4%) from the skip (-) group revealed mediastinal metastasis at two or three regions (level 2 or 3). The overall survival rate at 5 years after operation was 35% in the skip (+) group and 12.7% in the skip (-) group (p = 0.054). This favorable clinical outcome in the skip (+) group could be explained partially by the higher proportion of patients with level 1 metastases. Furthermore, regarding patients with level 1 disease, the skip (+) group tended to have a better prognosis than the skip (-) group (p = 0.096).

CONCLUSIONS

These results suggest that patients with skip mediastinal lymph node metastases represent a unique subgroup of N2 disease.

Tumor-induced hypercalcemia and parathyroid hormone-related protein in lung carcinoma

BACKGROUND

Although lung carcinoma is the most common cause of tumor-induced hypercalcemia (TIH), the precise incidence of TIH remains obscure. Furthermore, the role of parathyroid hormone-related protein (PTHrP) has not been clearly elucidated.

METHODS

This study included 690 consecutive patients who were newly diagnosed as having lung carcinoma between 1989 and 1994 (379 adenocarcinomas, 207 squamous cell carcinomas, 75 small cell carcinomas, and 29 large cell carcinomas). All patients were treated for lung carcinoma and were also periodically monitored for their serum level of calcium (Ca). Hypercalcemia was defined as a serum Ca concentration higher than 11 mg/dL. The serum levels of PTHrP (109-141) were measured by a C-terminal-region-specific radioimmunoassay.

RESULTS

TIH was observed in 17 of 690 patients (2.5%). All 17 patients demonstrated an advanced stage of lung carcinoma (Stage III or IV), 10 squamous cell carcinomas, 5 adenocarcinomas, 1 small cell carcinoma, and 1 large cell carcinoma. In 15 patients, the serum level of C-PTHrP (109-141) was substantially high, ranging from 99 pmol/L to 890 pmol/L (normal range, 21-50.7 pmol/L). There was no significant difference in the serum PTHrP level between patients with or without bone metastasis. The reduction of tumor burden decreased both the serum level of PTHrP and that of Ca in parallel. The median survival time after diagnosis of TIH was only 27 days.

CONCLUSIONS

TIH in lung carcinoma was most likely attributable to PTHrP, and its occurrence appears to be an ominous prognostic sign.

Alpha-fetoprotein-producing adenocarcinoma of the lung

We herein present a case of metachronous primary lung cancers, the first of which was adenosquamous cell carcinoma and the second of which was poorly differentiated adenocarcinoma. At the time the second lung cancer was detected 5 years after being operated on for the first cancer, a high level of serum alpha-fetoprotein (AFP) was noticed, but no elevation of other tumor markers was observed. In addition, no liver metastases, chronic liver diseases or other systemic abnormalities were seen either. The serum AFP level was 696 ng/ml, and the profile of lectin affinity showed a tumor-derived pattern. Two weeks after the operation, the serum AFP level decreased to a normal level. An immunohistochemical analysis confirmed that the exact origin of AFP was the tumor tissue. A specimen taken from the first lung cancer was not stained by the same procedures, which thus indicated this case to be a double primary lung cancer.

The clinical significance of serum soluble interleukin-2 receptors in lung cancer

It has been recently reported that the soluble interleukin-2 receptor (IL-2R) levels in the sera of cancer patients were higher than those of normal controls. The present study was conducted in order to clarify the clinical significance of serum soluble IL-2R in patients with lung cancer. Using commercially available EIA kits, we measured the serum levels of soluble IL-2R in 102 lung cancer patients and 18 normal controls. The serum level of IL-2R was higher than 100 pM (mean +3 S.D. in the normal controls) in 14 of 58 patients with adenocarcinoma and in 13 of 32 patients with squamous cell carcinoma. In both adenocarcinoma and squamous cell carcinoma, the mean level of soluble IL-2R was higher in advanced stages (Stages IIIA, IIIB and IV) than in early stages (Stages I and II). In contrast, no patients with small cell carcinoma exhibited a serum level of soluble IL-2R higher than 100 pM, whereas almost all of those patients were in advanced-stage diseases. These results first demonstrated that the serum level of soluble IL-2R increased in association with both the disease stage and the histological type in lung cancer.

Tracheal lipoma obstructing the right main bronchus: report of a case

Most tracheal tumors are malignant, and benign neoplasms are extremely rare. We herein report the case of a 60-year-old woman with a tracheal lipoma obstructing the right main bronchus in whom a preoperative diagnosis was not able to be established. Thus, a thoracotomy was performed followed by complete resection of the tumor including two rings of the tracheal wall. Pathologic examination confirmed that the tumor was a lipoma covered with tracheal epithelium, extending between the cartilage into the outer layer of the trachea.

Use of a pericardial fat pad flap for preventing bronchopleural fistula: an experimental study focusing on the angiogenesis and cytokine production of the fat pad

An experimental study was conducted to determine whether pericardial fat tissue could induce neovascularization and produce cytokines related to tissue repair. Neovascularization was examined using chick chorioallantoic membranes. Pieces of pericardial fat tissue, omentum, and intercostal muscle were individually placed on a number of chorioallantoic membranes and neovascularization induced by each material was assayed 6 days after the implantation. The intensity of neovascularization was in the order of pericardial fat > or = omentum > muscle. Cytokines, such as interleukin 1 (IL-1) alpha and beta, tumor necrosis factor-alpha (TNF alpha), interferon-gamma (IFN-gamma), and interleukin 6 (IL-6) were assayed in a culture supernatant of pericardial fat tissue. The latter was obtained 24 h after the addition of lipopolysaccharide (LPS) following various incubation times. All cytokines other than IFN gamma are known to play a part in tissue repair, whereas IFN gamma is negatively related to tissue repair because it inhibits fibroblast growth. The pericardial fat tissue incubated with LPS produced a certain amount of IL-1 on day 1, and TNF alpha on days 1 and 8, whereafter these values decreased to an undetectable level. Irrespective of the addition of LPS, a large amount of IL-6 was observed in the supernatant of pericardial fat tissue and it was detectable until day 29. On the contrary, INF gamma was not detected at any assay time. These observations suggest that a pericardial fat pad flap could possibly be beneficial in the prevention of bronchopleural fistula after pulmonary resection.

The first site of recurrence after complete resection in non-small-cell carcinoma of the lung. Comparison between pN0 disease and pN2 disease

In the present study, we assessed whether the pattern of postoperative recurrence of non-small-cell lung cancer differed between patients with pathologic N0 disease and those with pathologic N2 disease. We reviewed 231 patients with pathologic N0 disease and 63 with pathologic N2 disease, who had undergone a complete resection from 1980 to 1990, and investigated the first recurrence sites. Seventy-two patients with pathologic N0 disease and 52 with pathologic N2 disease were found to have had postoperative recurrence. Both pathologic N0 disease and pathologic N2 disease recur frequently in distant organs, and the ratio of distant metastasis to local recurrence did not differ between the two diseases. The brain, lung, and bone were the common initial metastatic sites in both pathologic N0 disease and pathologic N2 disease. The brain was the most frequent site of distant metastasis in patients with pathologic N0 disease, whereas, on the other hand, pulmonary metastasis was observed more frequently than brain metastasis in those with pathologic N2 disease. Despite histologic types, the presence of different patterns of initial metastatic sites between pathologic N0 and pathologic N2 diseases was observed. Our results suggest that the sites of metastasis after resection depend largely on such anatomic factors as drainage routes. Namely, in contrast to pathologic N0 disease, pathologic N2 disease has an additional drainage route, which is from the N2 nodes to the superior vena cava (pulmonary circulation). Therefore, the frequency of pulmonary metastasis may increase in patients with pathologic N2 disease.

Hepatitis B surface antigen particles of subtypes adw and adr, and compound subtype (adwr) in symptom-free carriers in Japan

Of sera from 1,878 Japanese blood donors who carried hepatitis B surface antigen (HBsAg), 420 were subtyped as adw (22.4%) and 1,443 as adr (76.8%); only 15 (0.8%) contained HBsAg of subtype ayw or ayr. Sera with HBsAg/adr had higher HBsAg titres than those with HBsAg/adw (geometric mean of haemagglutination titre: 10.1 +/- 2.4 vs. 9.7 +/- 2.4, p less than 0.01), and a higher prevalence of hepatitis B e antigen (24% vs. 13%, p less than 0.001). Carriers of HBsAg/adr progressively predominated over those of HBsAg/adw with increasing age. Of sera from 1,863 carriers of HBsAg/adw or HBsAg/adr, 182 (9.8%) contained HBsAg particles with both subtypic determinants in the w/r allele. The presence of w and r determinants on the same particles was ascertained by sandwiching them between monoclonal antibody with the specificity for w and that with the specificity for r. HBsAg particles of compound subtype (adwr) were found more often in sera with hepatitis B e antigen than those without it (145/403 [36.0%] vs. 37/1,460 [2.5%], p less than 0.001). Sera with HBsAg/adwr particles had HBsAg titres higher than those without them (12.4 +/- 1.9 vs. 9.7 +/- 2.3, p less than 0.001). HBsAg/adwr particles arise from phenotypic mixing of the S-gene product of wild-type virus and that of mutants with point mutations for subtypic changes. The results obtained indicated that HBV strains of subtype adr have a higher replicative activity than those of adw, and suggested that mutations in the S gene for subtypic changes would be associated with an active replication of hepatitis B virus.

Synthetic oligopeptides bearing a common or subtypic determinant of hepatitis B surface antigen

Two determinants of hepatitis B surface Ag (HBsAg), identified by mAb raised against polypeptide components, were characterized immunochemically. One was expressed on HBsAg irrespective of the four major subtypes, i.e., adw, adr, ayw, and ayr, whereas the other was subtypic but not identical to any of d, y, w, and r determinants. The common determinant was generated by a synthetic pentadecapeptide with a sequence of Thr-Thr-Ser-Thr-Gly-Pro-Cys-Lys-Thr-Cys-Thr-Ile-Pro-Ala-Gln representing amino acids 115-129 of the S gene product, and detected invariably in 366 HBsAg samples in sera from asymptomatic carriers in Japan. The activity of the S gene product, as well as the peptide (115-129), to bind with the mAb was not affected by alkylation alone, but was completely lost after reductive alkylation. The antigenic activity was lost when the S gene product was severed between Lys122 and Thr123 by trypsin. A microconformation maintained by the -Cys121-Cys124 bond, therefore, would be required for the common determinant. The other mAb identified an epitope of HBsAg that was mimicked by a synthetic tetradecapeptide with a sequence of Thr-Cys-Thr-Ile-Pro-Ala-Gln-Gly-Thr-Ser-Met-Phe-Pro-Ser, representing amino acids 123-136 of the S gene product. Among 16 HBsAg samples with known S gene sequences, 5 with Ile126 possessed this subtypic determinant, but the remaining 11 with Thr126 did not. The 5 hepatitis B virus genomes encoding the subtypic determinant differed less than 5.6% from each other in the entire nucleotide sequence, but by 8.0% or more from any of the other 11 genomes without the capacity to encode it.

Synthetic oligopeptides bearing a common or subtypic determinant of hepatitis B surface antigen

Two determinants of hepatitis B surface Ag (HBsAg), identified by mAb raised against polypeptide components, were characterized immunochemically. One was expressed on HBsAg irrespective of the four major subtypes, i.e., adw, adr, ayw, and ayr, whereas the other was subtypic but not identical to any of d, y, w, and r determinants. The common determinant was generated by a synthetic pentadecapeptide with a sequence of Thr-Thr-Ser-Thr-Gly-Pro-Cys-Lys-Thr-Cys-Thr-Ile-Pro-Ala-Gln representing amino acids 115-129 of the S gene product, and detected invariably in 366 HBsAg samples in sera from asymptomatic carriers in Japan. The activity of the S gene product, as well as the peptide (115-129), to bind with the mAb was not affected by alkylation alone, but was completely lost after reductive alkylation. The antigenic activity was lost when the S gene product was severed between Lys122 and Thr123 by trypsin. A microconformation maintained by the -Cys121-Cys124 bond, therefore, would be required for the common determinant. The other mAb identified an epitope of HBsAg that was mimicked by a synthetic tetradecapeptide with a sequence of Thr-Cys-Thr-Ile-Pro-Ala-Gln-Gly-Thr-Ser-Met-Phe-Pro-Ser, representing amino acids 123-136 of the S gene product. Among 16 HBsAg samples with known S gene sequences, 5 with Ile126 possessed this subtypic determinant, but the remaining 11 with Thr126 did not. The 5 hepatitis B virus genomes encoding the subtypic determinant differed less than 5.6% from each other in the entire nucleotide sequence, but by 8.0% or more from any of the other 11 genomes without the capacity to encode it.

Antigenic sites on the arginine-rich carboxyl-terminal domain of the capsid protein of hepatitis B virus distinct from hepatitis B core or e antigen

The capsid protein of hepatitis B virus (P19) is made of 183 amino acids and carries the antigenic sites of hepatitis B core antigen (HBcAg) and hepatitis B e antigen (HBeAg) on the amino-terminal domain. The carboxyl-terminal domain of P19 (amino acids 150-183) is arginine-rich (47%) and faces the interior of the nucleocapsid for the binding with DNA. Monoclonal antibody was raised against an antigenic site on this protamine-like region of P19, which was distinct from HBcAg or HBeAg sites, and the novel antigenic site(s) was provisionally designated as hepatitis B inner core antigen (HBicAg). When P19 in a low concn (150 ng/ml) was immobilized on the solid surface, HBicAg sites were preserved, while HBcAg or HBcAg sites were no longer available on it. This allowed the detection of antibodies against HBicAg (anti-HBic), by sandwiching them between immobilized P19 and anti-IgG labeled with horseradish peroxidase. Anti-HBic was detected in sera from HBsAg carriers, typically those seropositive for antibody to HBeAg. A synthetic arginine-rich decapeptide, with a sequence of Arg-Arg-Arg-Gly-Arg-Ser-Pro-Arg-Arg-Arg, representing amino acids 150-159 of P19 and conserved in the majority of reported hepatitis B virus, absorbed the activity to bind with P19 in seven (44%) out of 16 sera containing anti-HBic. These results indicate that the decapeptide carries an HBicAg epitope and the remaining amino acid sequence of the arginine-rich carboxyl terminal domain (160-183) may be responsible for the other HBicAg epitopes.

Antibodies to translation products of the pre-S1 and pre-S2 regions of the envelope gene of hepatitis B virus in fulminant hepatitis B

Sera from 11 patients with fulminant hepatitis B were tested for antibodies to translation products of the pre-S1 and pre-S2 regions of hepatitis B virus of IgM, IgA and IgG classes, as well as of IgA1, IgA2 and SIgA, with solid-phase enzyme immunoassays using native viral polypeptides. Antibodies to pre-S1 region product of IgM and/or IgA class were detected invariably in six patients who still had detectable hepatitis B surface antigen in serum at the time of clinical presentation. The remaining five patients who had lost HBsAg at presentation had antibodies to pre-S region products of various immunoglobulin classes in higher titers. The five patients with fulminant hepatitis without HBsAg had higher levels of IgA antibodies to pre-S region products than the seven patients with nonfulminant acute hepatitis B who had lost HBsAg: IgA antibody to pre-S1 region product (75.6 +/- 63.8 vs. 2.9 +/- 3.2, p less than 0.01) and IgA antibody to pre-S2 region product (28.9 +/- 25.3 vs. 4.2 +/- 6.9, p less than 0.01). IgA antibodies to pre-S1 and pre-S2 region products were invariably polymeric in fulminant hepatitis B. These findings are compatible with the hypothesis that a heightened humoral antibody response to pre-S1 and pre-S2 region products occurs early during the course of fulminant hepatitis B, participating in severe hepatic injury and early clearance of virus characteristic of this disease.

A synthetic peptide coded for by the pre-S2 region of hepatitis B virus for adding immunogenicity to small spherical particles made of the product of the S gene

Small spherical particles produced in the non-permissive phase of hepatitis B virus infection, when the viral genome is integrated into the chromosome of hosts, are rich in the product of the S gene, but poor in the product of the pre-S2 region. For the purpose of adding immunogenicity to spherical particles deficient in the pre-S2 region product, they were conjugated with a synthetic peptide of 19 amino acid residues. The peptide reproduced a hydrophilic area of the pre-S2 region product encoded by viral genomes of subtypes adr, ayw and ayr. The spherical particles supplemented with the pre-S2 peptide raised antibody to the pre-S2 region product in mice, in addition to antibody to the product of the S gene. Antibody to pre-S2 region product, prepared from sera of immunized mice by absorption with the S gene product, bound to spherical particles bearing pre-S2 region product, irrespective of adr, adw, ayw or ayr subtype, and agglutinated hepatitis B virions in immune electron microscopy. Based on the results obtained, the synthetic peptide may prove useful in adding protective efficacy to small spherical particles poor in pre-S2 region product.

A solid-phase enzyme immunoassay for the determination of IgM and IgG antibodies against translation products of pre-S1 and pre-S2 regions of hepatitis B virus

The envelope of hepatitis B virus is coded for by pre-S1, pre-S2 regions and the S gene. A method was developed to determine antibody to the product of pre-S1 region (anti-pre-S1) and antibody to the product of pre-S2 region (anti-pre-S2), either of IgM or IgG class, by a solid-phase enzyme immunoassay. For the determination of anti-pre-S1, tubular particles containing translation products of pre-S1, pre-S2 regions and the S gene were broken into constituent envelope polypeptides and immobilized on a solid support. Serums were absorbed with spherical particles containing translation products of pre-S2 region and the S gene, obtained from plasma positive for hepatitis B e antigen (HBeAg) and deprived of particles carrying pre-S1 product by an affinity column. They were then tested for the binding with tubular polypeptides fixed on a solid support, and the bound antibody representing anti-pre-S1 was detected by monoclonal antibody to human IgM/mu or IgG/gamma labeled with horseradish peroxidase. For the determination of anti-pre-S2, test serums were absorbed with spherical particles containing the product of the S gene, obtained from plasma positive for antibody to HBeAg and deprived of particles bearing pre-S2 product by an affinity column. They were then tested for the binding with polypeptides, fixed on a solid support, composed of products of pre-S2 region and the S gene. The assay was applied to the determination of anti-pre-S1 and anti-pre-S2 of IgM or IgG class in asymptomatic carriers and in persons who had recovered from infection with hepatitis B virus.

Translation products of pre-S(1), pre-S(2) regions and the S gene of hepatitis B virus: susceptibility of their antigenic activities to treatment with heat, urea, formalin or pepsin

Hepatitis B subviral particles, purified from plasma of asymptomatic carriers seropositive for hepatitis B e antigen, were treated with various conditions reported for the processing of vaccines. Thereafter, antigenic activities displayed by the translation products of pre-S(1), pre-(2) regions and the S gene were determined with monoclonal antibodies, and the reactivity for polyalbumin receptor was tested. Heating at 100 degrees C for 1.5 min and then at 65 degrees C for 10 h preserved more than 1/2 of antigenic activities representing products of pre-S(1), pre-S(2) regions and the S gene. After incubation in the presence of 8 M urea at 37 degrees C for 4 h, more than 2/3 of antigenic activities still remained. The antigenic activity of the S gene product was decreased to 2/3 and that of pre-S(2) region product to 1/3, after treatment with formalin at the final concentration of 1:4000 at 37 degrees C for 72 h, whereas the activity of pre-S(1) region product was affected drastically. Although 1/5 of the antigenic activity of the S gene product survived the digestion with pepsin for 18 h, antigenic activities of pre-S(1) and pre-S(2) region products were destroyed almost completely. Polyalbumin receptor, borne by the pre-S(2) region product, was lost by pepsin digestion also. Based on the results obtained, heating may be most appropriate for sterilizing plasma-derived hepatitis B particles for use as a vaccine, because it is reliably virucidal and would not affect the protective efficacy to an extent as the other virucidal methods would.

A synthetic peptide vaccine involving the product of the pre-S(2) region of hepatitis B virus DNA: protective efficacy in chimpanzees

The S gene encoding the major surface polypeptide of hepatitis B virus is preceded by the region pre-S(2) with a capacity to code for 55 amino acid residues. In the product of region pre-S(2), the sequence of 19 amino acid residues (amino acids 14-32 from the N terminus) representing an area of high local hydrophilicity is shared by viral strains of subtypes adr, ayw, and ayr; residue 22, phenylalanine, is replaced by leucine in a strain of the other subtype, adw. A synthetic peptide vaccine involving these 19 amino acid residues, when given to two chimpanzees, raised antibodies that bound to viral particles and protected the animals from challenge with 10(6) chimpanzee infectious doses of hepatitis B virus.

Polypeptides coded for by the region pre-S and gene S of hepatitis B virus DNA with the receptor for polymerized human serum albumin: expression on hepatitis B particles produced in the HBeAg or anti-HBe phase of hepatitis B virus infection

There are four polypeptides coded for by the region Pre-S and gene S on DNA of hepatitis B virus that carry the receptor for polymerized human serum albumin (poly-HSA), i.e., P31 and P39, as well as their glycosylated counterparts P35 and P43. With the use of monoclonal antibodies directed to Pre-S(1) sequence and Pre-S(2) sequence (bearing the receptor for poly-HSA), the content of these polypeptides, as well as their expression on the surface, was determined for hepatitis B particles of various categories. P39 and P43, carrying both Pre-S(1) and Pre-S(2) sequences, were contained abundantly in Dane and tubular particles, and to a much lesser extent in small spherical particles, all of which were purified from plasma containing hepatitis B e antigen (HBeAg). P31 and P35, carrying Pre-S(2) but not Pre-S(1) sequence, were contained comparably in these three categories of hepatitis B particles. In remarkable contrast, small spherical particles derived from plasma containing antibody to HBeAg were very low in the content of any Pre-S polypeptides. P31 and P39 showed higher activities for poly-HSA receptor than their glycosylated versions. When Dane particles were digested with trypsin, the poly-HSA receptor was deprived in parallel with the loss of antigenicity for Pre-S(2) sequence. The antigenicity for Pre-S(1) sequence was much less affected, and that for the product of gene S was virtually unchanged by the digestion.