Isolation and molecular cloning of human sorcin a calcium-binding protein in vincristine-resistant HOB1 lymphoma cells

A vincristine-resistant lymphoma cell line (HOB1/VCR1.0) that is resistant to 1.0 microM of vincristine has been established from a human immunoblastic B lymphoma cell line, HOB1. HOB1/VCR1.0 cells demonstrated the typical multidrug resistant phenotypes. Using two-dimensional gel electrophoresis, we discovered one protein with a molecular mass of 22 kDa and pI 5.7 that was overexpressed in HOB1/VCR1.0 cells. This protein was purified to the degree of apparent homogeneity by preparative isoelectric focusing and sodium dodecylsulfate-polyacrylamide gel electrophoresis. The identification of this protein with sorcin was revealed by comparing the internal amino acid sequence of three Lys-C digested peptides from the purified protein with the sequence previously determined for hamster sorcin. The complete primary structure of the human sorcin was deduced from nucleotide sequence analysis of its cDNA clones. It is composed of 198 amino acid residues with a calculated molecular weight of 21,676, and its sequence is highly similar to that of hamster sorcin (95%). Direct-binding assay with calcium showed that human sorcin is a calcium-binding protein with four 'E-F hand' structures typical of calcium-binding sites. Like the sorcin of hamster, two of the calcium-binding sites of human sorcin contain putative recognition sites for cAMP-dependent protein kinase. Southern and Northern blot analyses showed that the human sorcin gene was greatly amplified and overexpressed in resistant HOB1/VCR1.0 cells but not detected in the parental HOB1 cells. The overproduction of this protein in resistant cells implies that sorcin plays a role in expression of the resistant phenotype.

Detection of CYP2C9 polymorphism based on the polymerase chain reaction in Chinese

Cytochrome P450 (CYP) 2C9 catalyses the metabolism of a wide range of drugs. Previous studies have shown the differences in the amino acid composition among CYP2C9 variants at Cys144/Arg, Tyr358/Cys, Leu359/Ile, and Gly417/Asp. PCR-endonuclease digestion methods have been developed to detect these four possible polymorphisms. The T416-->C mutation in exon 3 of CYP2C9 (Cys144-->Arg) creates an Ava II site. In the 135 subjects we tested, all leukocyte DNA samples showed a complete Ava II digestion indicating homozygous C416 (Arg144). A Tyr358-->Cys mutation will create a Nsi I site at codon 1057-1063 in exon 7. In 40 subjects tested, all samples showed negative results. DNA sequencing on a few samples showed Tyr358Ile359. A mismatched PCR primer pair was then designed to detect codon C1061-->A (Leu359-->Ile) mutation. In 115 subjects tested, 111 samples showed a complete Nsi I digestion (Ile359) and four samples showed heterozygous results. Another mismatched PCR primer pair was used to confirm the C1061 codon in heterozygous subjects. The four heterozygous subjects showed partial digestion with endonuclease Kpn I, which confirmed the heterozygous Ile/Leu at amino acid 359. The G1236-->A mutation in exon 8 of CYP2C9 (Gly417-->Asp) creates a Hph I site. In all 46 subjects, homozygous G1236 (Gly417) was found. Most Chinese subjects actually have Arg144 Tyr358 Ile359 Gly417 in CYP2C9 as previously reported human-2. Furthermore, we found an A-->T (+12 position in intron 2) mutation in our CYP2C9 sequencing process. The mutation creates a NIa III site.(ABSTRACT TRUNCATED AT 250 WORDS)

Pathological changes of oxytalan fibers in the human gingiva of chronic periodontitis

The gingiva samples were obtained from 40 patients with chronic periodontitis after flap operation and 20 cases having healthy gingiva after ectopic wisdom tooth extraction. We investigated the oxytalan fibers by light microscopy (LM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The results demonstrated that under normal conditions numerous oxytalan fibers were widely and evenly distributed throughout the periodontal tissues. There was marked degeneration of the oxytalan fibers in chronic peridontitis. The predominant features were disintegration, fragmentation or disappearance of the oxytalan fibers under the basement membrane. Around the blood vessels, the oxytalan fibers decreased in density with fragmentation of the fibers and sometimes they disappeared almost completely. These results indicated that degeneration and destruction of the oxytalan fibers were closely correlated with the chronic periodontitis process, leading to reduced function occlusion of teeth.

Proteolysis-coupled secretion of the N terminus of apolipoprotein B. Characterization of a transient, translocation arrested intermediate

We have shown that non-hepatic Chinese hamster ovary cells (CHO) have a specific inability to translocate and secrete apolipoprotein B (apoB), leading to its complete degradation in the endoplasmic reticulum (Thrift, R. N., Drisko, J., Dueland, S., Trawick, J. D., and Davis, R. A. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 9161-9165). To gain an understanding why a protein having no predictable trans-membrane sequences can be stably integrated into the endoplasmic reticulum, we determined the topography and metabolic fate of apoB in both CHO cells and human hepatoma cells (HepG2). Using epitope-specific antibodies, we show that in microsomes from both cell types, apoB assumes a trans-membrane orientation having 69 kDa of its N terminus in the lumen and the remaining portion of the C terminus residing on the cytoplasmic surface. In both cell types, proteolytic cleavage of the translocation arrested apoB by a process that can be blocked by acetyl-leucine, leucine, norleucal, produces an 85-kDa N-terminal fragment that resumes translocation and is secreted. This same N-terminal 85-kDa fragment is also found in human plasma. These results show that sequences residing outside of the membrane spanning domain can block translocation. Moreover, our data provide compelling evidence showing that apoB undergoes an unusual transient, translocation arrest, that serves as an entrance into the intracellular degradative pathway regulating its secretion.

[Study on preserving intestinal function and the possible mechanism of hypermetabolic response following severe burn injury]

In order to approach the mechanism of hypermetabolic response following severe burn injury, a new animal model was developed with a specially bred miniswine (Guizhou species). Multiple catheterizations were applied for sampling different blood from portal, inferior mesenteric as will as jugular (central) veins. The animals were sustained with 30% III burn of TB-SA and divided randomly into early feeding group, given a complete diet beginning from 2 hours postburn (N = 6), and delayed feeding group, given the same diet initiating on 4 day postburn (N = 6). The results showed that compared with delayed feeding, early enteral feeding could strengthen the barrier function, decline the rate of translocation of bacteria and endotoxin from the gut to portal vein, reduce obviously blood TNF, CRP and catabolic-hormones, and significantly decrease REE (resting energy expenditure) and urinary 3-Mehis excretion. During the hypermetabolism (PBD7-10), the metabolic response mediated by "intestinal way" was at least 35%. The way of "intestinal tract--macrophages in liver--Hypermetabolism" is a possible mechanism of hypermetabolic response following severe burn injury, and the bacteria and endotoxin translocated from the gut, the active products (IL-1, TNF, etc) released by Kupffer's cells might be the mediating factors of the mechanism.

The role of T cell activation in anti-CD3 x antitumor bispecific antibody therapy

Anti-CD3 x antitumor bispecific Ab can retarget T cell mediated lysis in an MHC-independent fashion and prevent tumor growth in animal models. Two bispecific Ab preparations that differ in the presence or absence of Fc were compared in the 38C13 immunocompetent murine lymphoma model to evaluate how functional Fc and T cell activation impact on response to bispecific Ab therapy. Bispecific (bs) IgG contained functional Fc and was purified from hybrid-hybridoma Ab product. Bsf(ab')2 lacked functional Fc, and was genetically constructed using the leucine zipper technique. In vitro, bsF(ab')2 induced tumor cell lysis by activated T cells more effectively than bsIgG. However, bsF(ab')2 failed to induce T cell activation in the absence of tumor cells, and did so more slowly than bsIgG when tumor cells were present. In vivo, bsIgG induced nonspecific T cell activation whereas bsF(ab')2 did not. In therapy experiments, bsIgG inhibited tumor growth in mice although a single dose of bsF(ab')2 had minimal antitumor effect. BsF(ab')2 was capable of preventing tumor growth and improving survival when mice were also treated with T cell activators (IL-2 or staphylococcal enterotoxin B), or given repeated bsF(ab')2 doses. We conclude that therapeutic response to bispecific Ab was not dependent on functional Fc, but did require T cell activation. The use of bifunctional constructs that lack functional Fc therefore allows for separate manipulation of T cell retargeting and T cell activation and deserves further evaluation as a potential immunotherapy for malignancy.

The role of T cell activation in anti-CD3 x antitumor bispecific antibody therapy

Anti-CD3 x antitumor bispecific Ab can retarget T cell mediated lysis in an MHC-independent fashion and prevent tumor growth in animal models. Two bispecific Ab preparations that differ in the presence or absence of Fc were compared in the 38C13 immunocompetent murine lymphoma model to evaluate how functional Fc and T cell activation impact on response to bispecific Ab therapy. Bispecific (bs) IgG contained functional Fc and was purified from hybrid-hybridoma Ab product. Bsf(ab')2 lacked functional Fc, and was genetically constructed using the leucine zipper technique. In vitro, bsF(ab')2 induced tumor cell lysis by activated T cells more effectively than bsIgG. However, bsF(ab')2 failed to induce T cell activation in the absence of tumor cells, and did so more slowly than bsIgG when tumor cells were present. In vivo, bsIgG induced nonspecific T cell activation whereas bsF(ab')2 did not. In therapy experiments, bsIgG inhibited tumor growth in mice although a single dose of bsF(ab')2 had minimal antitumor effect. BsF(ab')2 was capable of preventing tumor growth and improving survival when mice were also treated with T cell activators (IL-2 or staphylococcal enterotoxin B), or given repeated bsF(ab')2 doses. We conclude that therapeutic response to bispecific Ab was not dependent on functional Fc, but did require T cell activation. The use of bifunctional constructs that lack functional Fc therefore allows for separate manipulation of T cell retargeting and T cell activation and deserves further evaluation as a potential immunotherapy for malignancy.

[Severe burn injury: glucose absorption and early enteral nutrition]

We investigated the changes of glucose absorption and the effect of early enteral nutrition after severe burn injury. A new animal model was developed with a specially bred miniswine (Gui Zhou species) to which multiple catheterizations were applied for sampling different blood from the portal, inferior mesenteric as well as jugular (central) veins. The animals were sustained with 30% III burns of TBSA 7 days after the catheterizations and divided randomly into early feeding (EF) group, given a complete diet beginning from 2 hours postburn, and delayed feeding (DF) group, given the same diet on 4 days postburn. After burn injury, glucose absorption was significantly decreased, but the absorption was much lower in group DF than that in group EF. However, the intestinal ability of absorbing nutrients was not attenuated greatly, and the reduction of portal blood flow was attributed to the decrease of absorption of nutrients. Early enteral feeding can increase portal blood flow obviously.

[Preserving intestinal function after severe burn injury]

To study the changes of the bowel-barrier function and its preservation, we developed a new animal model. A specially bred miniswine (Guizhou species) was used with multiple catheterizations for sampling different blood from portal, inferior mesenteric as will as jugular (central) veins. The animals were sustained with 30% III burns of TBSA 7 days after catheterization and divided randomly into early feeding (EF) group, given a complete diet beginning from 2 hours postburn (n = 6) and delayed feeding (DF) group, given the same diet initiating on 4 days postburn (n = 6). The results indicated that the bowel-barrier function was weakened significantly early postburn so that the translocation of both endotoxin and bacteria from the gut to portal vein was evidently increased. However, improving the intestinal mucosa ischemia, preserving mucosal mass and maintaining bowel-microecological balance through early enteral feeding, as revealed in this study, could enhance the barrier function, and the translocation of bacteria and endotoxin would be thus decreased to some extent.

Biochemical characterization of epidermal growth-factor receptor in Syrian hamster buccal pouch

Binding of [125I]-epidermal growth factor (EGF) to the membrane of the adult hamster buccal pouch was specific and protein concentration dependent, and was significantly higher than that of rat buccal tissue (hamster versus rat; 12.1 +/- 0.9 versus 9.77 +/- 0.22 fmol/mg protein, mean +/- SD, n = 5, p < 0.01). The higher binding was due to a higher receptor number (Bmax). Western blot analysis using anti-EGF receptor antibody revealed four immunoreactive protein bands of 170, 150, 116 and 55 kDa in hamster buccal membrane preparations. In a separate experiment, the EGF concentration in the phosphate-buffered saline extract of the hamster submandibular gland was determined by radioimmunoassay; the level was significantly much lower (p < 0.01) than that of rat or mouse (hamster, rat, mouse; 24.2 +/- 2.6, 123 +/- 17, 5950 +/- 171 ng/g wet tissue; mean +/- SD, n = 3). The findings suggest that hamster buccal pouch is particularly well suited to the study of the biological functions of oral EGF receptor.

Effect of acute ethanol treatment on epidermal growth factor receptor in the rat stomach

The present study investigated the effect of acute ethanol (ETOH) treatment on the epidermal growth factor (EGF) receptor in rat gastric mucosa using two different experimental models. In the in vitro experiments, gastric mucosal cells were incubated with 0, 0.05, 0.1, 0.25, and 0.5% ethanol in Dulbecco's modified Eagle's medium (DMEM) for 30 min and then used for the membrane preparation. The EGF receptor binding assay indicated that cells incubated in the presence of ethanol displayed a concentration-dependent increase (r = 0.85) in the 125I-EGF binding. The Western blot analysis using anti-EGF-receptor antibody revealed that ethanol in vitro caused reduction in the immunoreactivity of the major 170-kDa protein. There were also alterations in the minor protein bands (140, 120, and 50 kDa). In the in vivo experiments, rats that fasted overnight were given 1.0 ml of saline or ethanol (5, 10, or 15%) by gastric intubation 30 min before sacrifice. In comparison with the saline controls, ethanol treatment caused a decrease of the EGF receptor binding to the gastric mucosal membrane (saline: 5%: 10%; 15% ETOH, 1.46 +/- 0.18: 1.13 +/- 0.17: 1.27 +/- 0.19: 0.84 +/- 0.14, p < 0.02; mean +/- SEM, n = 9). Furthermore, the immunoblot analysis revealed concentration-dependent decrease in the intensity of the major 170-kDa protein with ethanol. The reduction in the EGF receptor binding and the impairment of the receptor protein might be due to the nonspecific damage of the gastric mucosal membrane by ethanol.

Recurrent swelling of parotid glands and Sjögren's syndrome

This study included 125 patients with chronic parotitis, and it presents in particular, a long-term clinical, laboratory, and sialographic study of 22 patients who were diagnosed as having adult recurrent sialadenitis of the parotid glands (ARSPG). Twelve of the 22 patients with ARSPG were shown to have Sjögren's syndrome (SS). These patients had recurrent parotid gland swelling for 1.5-14 years (mean, 5.2 years) before xerostomia and keratoconjunctivitis sicca occurred. Ten of the 22 patients with ARSPG did not develop SS, but did experience recurrent parotitis which extended from childhood into adulthood. The ARSPG underwent remission in seven of these patients. It is suggested that patients with ARSPG, but without a history of parotid gland swellings in childhood, should be diagnosed provisionally as having subclinical SS (SCSS).

Effects of benzo(a)pyrene and nicotine on prostaglandin synthesis in buccal pouch and submandibular glands of the Syrian hamster

Adult male Syrian hamsters were treated by swabbing the apex of the buccal pouch with corn oil (control, C), 1 mM benzo(a)pyrene (BP), nicotine (NC), or BP+NC in corn oil, twice daily, 5 days a week. After a 4-week treatment, the pouches and submandibular glands were dissected and used for the determination of endogenous prostaglandin (PG) production and studies on in vitro PG synthesis. Of the three PGs analysed (PGE2, PGF2 alpha and 6-keto-PGF1 alpha), PGE2 was predominant in the pouch and the glands. BP or NC alone had only a weak effect on PG synthesis in both tissues. However, the combination of BP and NC had a synergistic effect, causing diminished PG synthesis in both tissues. In buccal pouch, BP+NC significantly decreased the concentrations of endogenous PGE2 and PGF2 alpha (PGE2: 0.669 +/- 0.254 versus 1.698 +/- 0.460, PGF2 alpha: 0.273 +/- 0.090 versus 0.625 +/- 0.272 ng/g tissue; BP+NC versus C; mean +/- SD, n = 5, p < 0.05). Similarly significant results were also found for in vitro PG synthesis (PGE2: 0.541 +/- 0.249 versus 1.399 +/- 0.340, PGF2 alpha: 1.045 +/- 0.428 versus 2.133 +/- 0.510 ng/g tissue; BP+NC versus C; mean +/- SD, n = 5, p < 0.05). In submandibular glands, BP+NC significantly diminished the concentration of endogenous PGE2 (1.183 +/- 0.175 versus 2.379 +/- 0.488 ng/g tissue; BP+NC versus C; mean +/- SD, n = 5, p < 0.05). The synthesis of 6-keto-PGF1 alpha in both tissues, and the synthesis of PGF2 alpha in submandibular gland, were slightly decreased with all treatments.

[Adult recurrent sialadenitis of parotid gland and Sjogren's syndrome]

This paper presents clinical, laboratory and sialographic studies on 22 patients with recurrent sialadenitis of parotid glands in adults (RSPA), 103 sjögren's syndrome (SS) cases, and particularly a long term (2 approximately 24 years, mean 10 years) follow-up studies on 22 patients with RSPA. Twelve out of 22 RSPA patients developed SS. These patients had recurrent parotid swelling for 1.5 approximately 14 years (mean 5.2 years) before xerostomia and keratoconjunctivitis sicca presented. Ten of the 22 RSPA patients did not develop SS, of them 10 experienced recurrent parotitis from childhood to adulthood, and the disease underwent remission in 7 of them. It is suggested to classify RSPA patients without any history of parotid swellings in childhood tentatively as subclinical SS (SCSS).

Recurrent parotitis in adults. Report of 35 cases

Clinical, laboratory and sialographic findings were studied in 35 adult patients with recurrent parotitis. The patients were followed up for 0.5-23 years. The results showed that sialographic recovery occurred 3-5 years after disappearance of clinical symptoms. Recurrent parotitis is not a autoimmune disease, and remission may take place spontaneously, including clinical and sialographic healing. However, marked degeneration of the parotid gland or chronic obstructive parotitis may develop consequently. The differential diagnosis of recurrent parotitis in adults is also discussed.

Expression of prostaglandin E2 receptor in hamster buccal pouch: effect of benzo (a) pyrene and nicotine

Prostaglandin E2 (PGE2) plays an important role in the maintenance of oral mucosal integrity. In this study, we characterized PGE2 receptor binding in the buccal mucosa of Syrian hamster and assessed the effect of nicotine (NC) and benzo (a) pyrene (BP), the two major ingredients in cigarette smoke, on this receptor. Adult male animals were treated for 4 weeks by apical swabbing of the buccal pouch with corn oil (control, C), 1 mM NC, BP, or NC + BP in corn oil, twice a day, 5 days a week. The results obtained with the untreated group revealed the presence of a specific PGE2 receptor consisting of two binding sites (high affinity with Kd = 1.52 nM and Bmax = 37 fmol/mg protein and low affinity with Kd = 813 nM and Bmax = 1.29 pmol/mg protein). The treatment with NC, BP, and NC + BP caused a significant decrease in PGE2 receptor binding (specific binding: 10.20 +/- 0.42, 6.84 +/- 1.32**, 6.58 +/- 0.67** and 5.88 +/- 1.03** fmol/mg protein; C, NC, BP, and NC+BP, respectively; Mean +/- SD, n = 5, **p < 0.01). The data suggest that decreased receptor binding for PGE2 in the buccal mucosa may be the cause for the adverse effect of cigarette smoke on the health of oral mucosa.

[Research on hemostatic mechanism of extracts from carbonized Schizonepeta tenuifolia Brig]

It has been shown that StE can significantly shorten PT, TT, KPTT and RT of experimental animals and has an antiheparin function in the body. Meanwhile, it can significantly shorten ELT and strengthen FA. Its hemostatic action is accomplished through promoting coagulation and inhibiting fibrinolysis. 3P test and EG test were negative, it is thus impossible for a large dosage of StE to lead to DIC.

[Research on hemostatic constituents in carbonized Schizonepeta tenuifolia Brig]

It has been shown that the fatsoluble extract SeE from carbonized Schizonepeta tenuifolia has an obvious hemostatic action. In a given range of dose there is a significant linear correlation between the logarithms of its doses and the reciprocal of the bleeding and coagulating times in mice. Obvious hemostatic action was observed after mice had been administered in ip and po respectively for 0.5h and 1h. The hemostatic time of the former was 6h and the latter 12h. The LD50 of StE in po was 2.652 +/- 0.286 g/kg, while in ip 1.945 4/- 0.207 g/kg.