Alcohol and aldehyde dehydrogenases in human esophagus: comparison with the stomach enzyme activities

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) isoenzymes from surgical esophageal and gastric mucosa were compared by agarose isoelectric focusing. Two prominent ADH forms, designated mu 1 (equivalent to the recently reported mu-form) and mu 2, were expressed in all the 15 esophagus specimens studied, whereas only four of seven examined gastric specimens exhibited a weak to moderately strong mu 1-ADH activity band on the isoelectric focusing gels. pI values of the esophageal mu 1-ADH and mu 2-ADH, and the liver pi-ADH were determined to be 8.61, 8.13, and 8.90, respectively. mu-ADHs exhibited high Km for ethanol (12 mM) and low sensitivity to 4-methylpyrazole inhibition. ALDH3 (BB form) and ALDH1 were the major high- and low-Km aldehyde dehydrogenase in the esophagus, respectively. The ADH and ALDH activities were determined at pH 7.5 to be 751 +/- 78 and 29.9 +/- 3.0 nmol/min/g tissue, respectively (measured at 500 mM ethanol or at 200 microM acetaldehyde; mean +/- SEM; N = 15). The esophageal ADH activity was approximately 4-fold and the ALDH activity 20% that of the stomach enzyme. Because the presence of high activity and high Km mu-ADHs as well as low-activity ALDH1 were found in human esophageal mucosa, it is suggested that there may exist an accumulation of intracellular acetaldehyde during alcohol ingestion. This reactive and toxic metabolite may be involved in the pathogenesis of alcohol-induced esophageal disorders.

NORPLANT and the levonorgestrel IUD in Chinese family planning programmes

NORPLANT was introduced into the Chinese family planning programmes in 1984 by the Population Council. After a pilot study of 1200 cases in four centres in China, the study was expanded to 12 centres with 10,718 cases of NORPLANT and 1208 cases of NORPLANT-2 followed up for more than 6 years. The 5 years net cumulative pregnancy rates were 0.5-1.2 and the net cumulative continuation rates were around 65-72 per 100 users. There were significant differences in pregnancy rates between different groups of body weight and age, i.e. the pregnancy rates were higher in groups with body weight over 70 kg and those aged below 25 years. The age, body weight and dependence on contraceptive effectiveness of NORPLANT should be taken into account in the selection of users. Nationwide large-scale studies in provincial and country rural areas and postmarketing surveillance are being carried out. Changes in ovarian function and endometrium have been studied. Levonorgestrel IUD (LNg-IUD) was introduced into China in 1985. Comparative clinical studies on NORPLANT and LNg-IUD, pharmacokinetic and pharmacodynamic studies and endometrial studies of LNg-IUD were performed. The higher percentage (55.1%) of ovarian suppression in Chinese users of LNg-IUD may be attributed to ethnic differences among Caucasian women in their susceptibility to steroid hormones. Results showed favourable acceptance of both devices among Chinese women. The studies promoted the incorporation of new long-acting contraceptive methods into the Chinese family planning programmes.

Molecular basis of genetic variation in debrisoquin hydroxylation in Chinese subjects: polymorphism in RFLP and DNA sequence of CYP2D6

Debrisoquin hydroxylation phenotype was determined in 124 Chinese persons living in Taiwan, and two poor metabolizers were identified with a urinary metabolic ratio (MR) greater than 12.6. The other subjects, extensive metabolizers, showed a normal frequency distribution of log(MR). Most subjects (50%) showed a 44/29 kb pattern in restriction fragment length polymorphism (RFLP) analysis with use of Xba I, and 30% and 15% of the subjects exhibited a homozygous 29/29 kb and 44/44 kb pattern, respectively. Among extensive metabolizers, subjects with the 44/44 kb pattern had a significant higher log(MR) than those with the 44/29 pattern, and the log(MR) of the subjects with the 44/29 kb pattern was significantly higher than that of the subjects with 29/29 kb pattern. All nine exons and intron 3 of C gamma P2D6 were amplified with polymerase chain reaction (PCR) and sequenced for four extensive metabolizers. Two major polymorphisms were found: one at position 188 of exon 1 and the other at position 4268 in exon 9. With PCR and endonuclease digestion, polymorphisms at exon 1, intron 3, and exon 9 were investigated. Only two of 254 alleles showed a heterozygous guanine at 1934 base pairs (G1934) to adenine (A) mutation, commonly found in white poor metabolizers. Approximately 70% of alleles showed thymine at 188 base pairs (T188), and 76% showed cytosine at 4268 base pairs (C4268) instead of C188 and G4268, as is found in most white subjects. Subjects with T188 or C4268 showed a significant higher log(MR) than subjects with homozygous C188 and G4268. The C/T188, G/A1934, G/C4268, and RFLP polymorphisms may explain the interracial variations between Chinese and white subjects, as well as the genetic variations among Chinese subjects.

Estimation of the calorie requirements of burned Chinese adults

Studies of energy expenditure in 75 adult Chinese patients with burns covering between 5 and 98 per cent of the total body surface area (TBSA) gave the following formula for an optimal nutritional regimen: the daily calorie input should be 1000 x m2 (surface area) + 25 x per cent TBSA. Glucose should provide between 55 and 60 per cent of the calories, fat between 20 and 30 per cent, and protein between 15 and 20 per cent. The calorie to nitrogen ratio should lie between 150 and 170 to 1.

Microsurgical replantation of the avulsed scalp: report of six cases

This article reports the successful microsurgical replantation of six scalps avulsed for over 3 to 11 hr, after trauma and before repair, including five total and one partial avulsion. The authors believe that one key to successful replantation is effective vessel anastomoses. In the reported series, three scalps were reconstructed with two superficial temporal vessels and in five cases, with a 1:1 ratio between arteries and veins. The partially avulsed scalp was replanted successfully with only one artery and one vein. The management of postoperative complications is discussed.

[Effect of different preparations of ginger on blood coagulation time in mice]

The experiments indicate that the decoction, ether extraction and suspension liquid of roasted ginger and charcoal of ginger all can markedly shorten the blood coagulation time in mice, while the decoction, ether extraction of fresh ginger and dry ginger cannot. The decoction of ginger charcoal has stronger effect than roasted ginger in shortening the blood coagulation time in mice. The effect of decoction of ginger charcoal on blood coagulation time tends to increase when the dosage is increased.

[A 5-year interval report on study of burn metabolism and nutrition]

This paper introduces the essential experiences concerning studies of burn metabolism and nutrition in our institute in the past five years. 1. Three new and practical animal models were developed for studying gastro-enteral nutrition in burns. 2. With indirect calorimetry, resting energy expenditure (REE) of 92 burn adult patients were measured and analyzed, and on the basis of which a new formula for calculating nutritional supplement in Chinese burn adults was proposed: kcal/day = 1,000 x M2 (body surface area) + 25 x % TBSA (total burn surface area). 3. Through experimental and clinical studies, it was found that antiouperoxide agents (such as SOD, CAT), tolbutamide, glutamine and Chinese herb decoction Sizunzituang all exhibited modulating effects on postburn metabolism and nutrition, e.g. decreasing catabolism, reducing negative nitrogen balance, stimulating secretion of insulin, enhancing tissue utilization of glucose, maintaining the mass of enteral mucosa and improving functions of viscerae. 4. A new less irritating, simple and easy-to-introduce nasal-enteral nutrition tube was devised, which could pass through the pylorus easily into the duodenum usually within 6hrs without using a stylet. It would be useful in the early postburn enteral nutrition supplementation.

Sialographic changes related to clinical and pathologic findings in chronic obstructive parotitis

This paper presents the results from a study of 23 patients with chronic obstructive parotitis (COP) in whom the sialographic changes were related to the clinical and histopathologic features. The sialographic changes were divided into four types. The stimulated parotid flow rate (SPFR) was normal in sialography Type I patients, while SPFR was significantly reduced in Types II, III, and IV patients, as compared with healthy persons. The changes observed by light microscopy were irregular dilation and chronic inflammation of main and branching ducts with saliva deposits in the enlarged luminal system. Ultrastructural changes included degeneration of ductal epithelial cells, marked proliferation of periductal fibrous tissue, and moderately electron-dense deposits in the lumen of the dilated peripheral ducts. The extent of the histopathologic changes largely paralleled the severity of the sialographic changes. These findings indicate that COP is a relatively common inflammatory disease and that the sialographic classification reflects the severity of the disease.

[Sequential quantitative scintigraphy of parotid glands with chronic inflammatory diseases]

Sequential quantitative scintigraphy of parotid glands was performed in 16 cases with recurrent parotitis in childhood, 33 with chronic obstructive parotitis, 37 with Sjögren's syndrome, 4 with sialadenosis and 30 normal controls. Uptake function was normal, but excretion was retarded in recurrent parotitis in childhood. Chronic obstructive parotitis exhibited that excretion was obstructed and the uptake and excretion function between bilateral parotids was marked different. In Sjögren's syndrome, uptake was very low and excretion was heavily delayed. Sialadenosis showed that excretion was retarded and uptake function was not definitely involved. The possible mechanism of the scintigraphical features were analyzed combined with the histopathological findings.

Effect of cigarette smoking on salivary epidermal growth factor (EGF) and EGF receptor in human buccal mucosa

The mouth acts as a primary target for cigarette smoke which is associated with several oral diseases and cancer. The present study investigated the effect of cigarette smoking on salivary EGF and the buccal EGF receptor. Samples of whole saliva and buccal biopsy were obtained from 15 healthy volunteers (10 smokers and 5 non-smokers). The smokers smoked 20 or more cigarettes/day for more than 5 years. Salivary cotinine (a major metabolite of nicotine) was determined by radioimmunoassay (RIA). The salivary cotinine level was consistent with the self-reported smoking status (smokers, 106-530 ng/ml saliva; non-smokers, < 2 ng/ml saliva). As compared to the non-smokers, the salivary EGF concentration (determined by RIA) was 32% lower in those smokers whose salivary cotinine level was 250 ng/ml or higher (non-smokers, 2.21 +/- 0.16; smokers, 1.57 +/- 0.09 ng/ml saliva; mean +/- S.E.M., P < 0.01). There was no significant difference in 125I-labeled EGF binding to the buccal receptor between the two groups. However, EGF stimulated the autophosphorylation of a 170-kDa protein band in the sample of non-smokers, but not in the smokers. The immunoblot analysis using anti-EGF receptor antibody indicated that the smoking-related deficiency in EGF receptor autophosphorylation was due to the functional alteration of the receptor proteins. In conclusion, cigarette smoking reduces the salivary EGF level and impairs the function of buccal EGF receptor, which may be associated with the pathology of smoking-related oral disease.

Effect of ethanol on prostaglandin E2 receptor in rat submandibular salivary glands

The dose-dependent effects of acute ethanol treatment on the prostaglandin E2 (PGE2) receptor in submandibular salivary glands was investigated. Rat submandibular-gland segments were preincubated with Dulbecco's modified Eagle's medium in the absence and the presence of various concentrations of ethanol (0.1-5%). After incubation, membranes were prepared and assayed for PGE2 receptor binding using [3H]-PGE2. Ethanol had no effect on receptor binding at concentrations below 1%, but binding was stimulated by higher concentrations. A 30% increase in binding occurred with 2.5% ethanol and 50% with 5% ethanol. This increase was due to an alteration of the binding characteristics. Scatchard analysis of the data from the control and 5% ethanol groups revealed that the ethanol-induced increase in PGE2 receptor binding was mainly due to a 26 and 58% decrease in the dissociation constant (Kd) for the high- and low-affinity binding sites, respectively. A 31% decrease of binding capacity (Bmax) was also observed in the low-affinity binding sites. The results demonstrate that PGE2 receptor binding in submandibular glands is not altered by acute treatment with ethanol at physiological doses. The receptor binding is also relatively stable on pretreatment with 1% ethanol. It is suggested that the increase of receptor binding induced by high concentrations of ethanol may be a spontaneous response to the decrease of PGE2 synthesis in the tissues.

Cigarette smoking reduces human salivary eicosanoids

The effect of cigarette smoking on salivary eicosanoid levels was investigated in 10 smoker and 10 non-smoker volunteers. The smokers consumed an average of 20 cigarettes/day for the past 5 years or longer. The smoking status was validated by salivary cotinine level. Eicosanoids were extracted from saliva with ethanol, and the radioimmunoassay was performed to determine the concentrations of four major eicosanoids, i.e. prostaglandin E2 (PGE2), PGF2 alpha, 6-sulphidopeptide-containing leukotrienes (LTs) and 12-hydroxyeicosatetraenoic acid (12-HETE). The levels of PGE2, PGF2 alpha, and LTs were significantly lower in the saliva of smokers as compared to that of the non-smokers (1.74 +/- 0.32 vs 2.41 +/- 0.64, p = 0.006; 0.36 +/- 0.12 vs 0.54 +/- 0.18, p = 0.04; 2.24 +/- 0.96 vs 4.92 +/- 1.29, p = 0.006; mean +/- SD, ng/ml saliva). No significant differences were found in the levels of 12-HETE between the two groups. The results suggest that cigarette smoking reduces the concentrations of both the cyclooxygenase and 5-lipoxygenase products in saliva.

[Microvascular anastomosis in replantation of 6 avulsed scalps]

From 1990 to 1991, 6 avulsed scalps (total avulsing in 5, partial avulsing in 1) were replanted successfully. Follow-up for over 6 months showed that the hair of the replanted scalps grew normally in all the 6 patients. We think that the key to successful replantation is to anastomose the vessels effectively. The scalp can survive just with its superficial temporal vessels on both sides and with an artery-vein ratio of 1:1. The management of postoperative complications is discussed.

Benzo[a]pyrene and nicotine impair epidermal growth factor mediated cellular functions of buccal mucosa

This study investigated the effect of two major ingredients in cigarette smoke, benzo[a]pyrene (BP) and nicotine, on epidermal growth factor (EGF) receptor binding and EGF-mediated cellular functions in rat buccal mucosa. Rat buccal tissue was incubated in DMEM in the absence (control) and presence of 10 microM BP or nicotine for 2.5 h at 25 degrees C. There were no significant differences in [125I]EGF binding to the buccal mucosal membranes between the control and treatment groups. Protein tyrosine kinase assay showed that EGF stimulated phosphorylation of a 170-kDa protein band in the controls, but not in the BP- and nicotine-treated samples. The basal [3H]thymidine incorporations were not significantly different between the groups. Nevertheless, addition of 5 nM EGF increased [3H]thymidine incorporation by 22% in the control, but not in the BP- or nicotine-treated group. The results demonstrate that BP and nicotine change the buccal mucosal functions associated with alteration of EGF receptor.

Synthesis of hydrolytic enzymes during production of tylosin by Streptomyces fradiae

The exposure of a wild-type tylosin producing strain of Streptomyces fradiae to mutagenic agents resulted in the isolation of several tylosin over-producing strains. Examination of three mutants, T4310, 612 and 3204 showed that improved tylosin production was associated with increased hydrolytic enzyme activity and cell growth. The wild-type strain showed lower levels of hydrolytic activity including, protease, amylase, lipase and esterase activities and attained a lower cell density than the mutants.

Three years' experience with levonorgestrel-releasing intrauterine device and Norplant-2 implants: a randomized comparative study

A randomized comparative study of levonorgestrel-releasing intrauterine device (LNG-IUD) and Norplant-2 implants was carried out in 200 women for 36 months. Three thousand one hundred woman-months of use were observed with each device. Only one pregnancy occurred in users of LNG-IUD at the 12th month of use. The change in bleeding pattern was the most frequent reason for discontinuation. The discontinuation rate for irregular bleeding with Norplant-2 was 17.3 and 26.8 at 24 and 36 months, respectively, as compared to 3.3 with LNG-IUD at both 24 and 36 months. The differences were statistically significant. Removal for amenorrhea and pain only occurred in acceptors of LNG-IUD. About 20-40% of women using Norplant-2 had prolonged bleeding through 36 months. The percentage of amenorrhea in LNG-IUD was the highest (29.3%) at the end of two years of use. More than 97% of subjects reported satisfaction with the methods used by themselves.

Chronic obstructive parotitis. Report of ninety-two cases

Clinical, sialographic, and sequential quantitative scintigraphic characteristics of 92 cases of chronic obstructive parotitis (in 117 diseased parotid glands) are reported, and the treatment investigated. The cardinal feature of this disease is obstruction or retarded salivary flow resulting in recurrent swellings and retrograde infection. The main characteristic seen in sialograms is irregular dilation of the main and branching ducts. On the basis of sialographic findings, the ducts are classified into four types. This classification reflects the severity of the disease and can also be used as a guide to treatment.

Specialized collagen mRNA and secreted collagens in human glomerular epithelial, mesangial, and tubular cells

Isolated glomeruli and cultured cells were examined under nonmitogenic conditions by Northern hybridization of steady-state mRNA levels for procollagens alpha 1(I), alpha 1(III), alpha 1(IV), alpha 2(IV), beta-actin, and fibronectin. Procollagens concurrently secreted from these cells were characterized after limited pepsin digestion. Poly(A)-mRNA from freshly isolated whole porcine glomeruli was primarily type IV. For cultured glomerular and tubular epithelial cells, the collagen mRNA species were almost exclusively alpha 1(IV) and alpha 2(IV). Correspondingly, the secreted collagen was almost entirely type IV. The mRNA signals for collagens in glomerular mesangial cells included alpha 1(I), alpha 1(IV), alpha 2(IV), and less alpha 1(III). The secreted collagens were also types I and IV, with less types III and V. There were similar patterns of mRNA signal levels for the two type IV collagens and similar patterns of expression of alpha 1(I) and alpha 1(III). In situ hybridization showed the fibroblast and epithelial cell populations homogeneous in expressing the same mRNA signals seen by Northern hybridization. These findings establish the correlation of collagen mRNA and protein expression of collagens in differentiated glomerular cells in culture, under resting nonmitotic conditions.

Ethanol-induced structural and functional alterations of epidermal growth factor receptor in buccal mucosa

1. Ethanol treatment caused a 47% decrease in [125I]EGF binding to the membrane preparations of buccal mucosa resulting from the decrease of binding sites rather than the affinity of high affinity receptor. 2. The immunoblot revealed a protein band of 170 kDa in the control sample, while a barely detectable 200 kDa protein was observed in the ethanol-treated sample. 3. Protein kinase assays using [32P]ATP as probe showed an EGF-stimulated phosphorylation band of 170 kDa in the control but not in ethanol-treated sample. 4. Ethanol did not change the basal incorporation of [3H]thymidine and [35S]methionine, but caused a 38% and 57% decrease of EGF-stimulated thymidine and methionine incorporation, respectively. 5. The data suggest that EtOH decreases EGF receptor binding through modification of the receptor molecule, thereby impairing receptor kinase activity and its physiological function.

The plastid genome of Cryptomonas phi encodes an hsp70-like protein, a histone-like protein, and an acyl carrier protein

The plastid genome of Cryptomonas phi, a cryptomonad alga, contains three genes that have not previously been found in any organellar genome. Each of these genes encodes a functional class of organellar gene product not previously reported. The first gene, dnaK, encodes a polypeptide of the hsp70 heat shock protein family. The predicted amino acid sequence of the DnaK protein is 54% identical to that of the Escherichia coli hsp70 protein (DnaK), 50-53% identical to that of two nucleus-encoded mitochondrial hsp70 proteins, and 43-46% identical to that of several eukaryotic cytoplasmic members of the hsp70 protein family. The second gene, hlpA, encodes a polypeptide resembling bacterial histone-like proteins. The predicted amino acid sequence of the HlpA protein is 25-53% identical to that of several bacterial histone-like proteins, and the identity increases to 39-76% over a conserved region corresponding to the long arm that binds DNA. The third gene, acpA, encodes an acyl carrier protein, which is a key cofactor in the synthesis and metabolism of fatty acids. Its predicted amino acid sequence is 36-59% identical to that of eubacterial and plant chloroplast (nucleus-encoded) acyl carrier proteins.

Transforming growth factor-alpha binds to the epidermal growth factor receptor in gastric mucosa

The ability of transforming growth factor-alpha (TGF-alpha) to interact with the gastric mucosal epidermal growth factor (EGF) receptor was investigated using a mucosal membrane preparation. TGF-alpha inhibited specific binding of [125I]EGF to its receptor, but the IC50 for TGF-alpha was at least 100 fold greater than that observed for unlabeled EGF. Cross-linking studies revealed no attachment of [125I]TGF-alpha to EGF-receptor size components, and the unlabeled TGF-alpha was only weakly effective in inhibiting cross-linking of [125I]EGF to the 170 kDa receptor. However, when the cytosolic fraction was reconstituted with the membrane preparation, an enhancement in binding of [125I]TGF-alpha to the EGF receptor occurred in a manner dependent on the concentration of cytosolic protein. Hence the binding characteristics of TGF-alpha to the EGF receptor in gastric mucosa are different from those for EGF.

Increased microsomal irreversible binding of phenytoin by valproic acid

Phenytoin is known to be metabolized to form p-hydroxyphenyl-phenyl-hydantoin, possibly via the arene oxide intermediate. The reactive arene oxide may bind to macromolecules irreversibly and cause toxicity. In this study, valproic acid was found to increase the irreversible binding of phenytoin to rat liver microsomes at high concentrations. The effect was similar to that of TCPO and could be reversed by adding glutathione. Valproic acid may increase the hepatotoxicity of phenytoin.

Structural features of stomach aldehyde dehydrogenase distinguish dimeric aldehyde dehydrogenase as a 'variable' enzyme. 'Variable' and 'constant' enzymes within the alcohol and aldehyde dehydrogenase families

Stomach aldehyde dehydrogenase was structurally evaluated by analysis of peptide fragments of the human enzyme and comparisons with corresponding parts from other characterized aldehyde dehydrogenases. The results establish a large part of the structure, confirming that the stomach enzyme is identical to the inducible or tumor-derived dimeric aldehyde dehydrogenase. In addition, species variations between identical sets of different aldehyde and alcohol dehydrogenases reveal that stomach aldehyde dehydrogenase exhibits a fairly rapid rate of evolutionary changes, similar to that for the likewise 'variable' classical alcohol dehydrogenase, sorbitol dehydrogenase, and cytosolic aldehyde dehydrogenase but in contrast to the 'constant' class III alcohol dehydrogenase and mitochondrial aldehyde dehydrogenase. This establishes that rates of divergence in the aldehyde and alcohol dehydrogenases are unrelated to subunit size or quaternary structure, highlights the unique nature of class III alcohol dehydrogenase, and positions the stomach aldehyde dehydrogenase in a group with more ordinary features.

[Treatment and prognostic factors of epithelial ovarian carcinoma]

From 1978 to 1987, a total of 135 cases of epithelial carcinoma were treated in our hospital. 91 cases (67.4%) belonged to stage III and IV. All patients were treated with surgery plus chemotherapy. The 5-year and 10-year survival rates were 41.4% and 39.9%, respectively. COX model was used to analyse the prognostic factors, one factor analysis and multiple factors analysis were all showed that stage, residual tumor and histological type were the main prognostic factors, age was not considered to be a prognostic factor.

Treatment of malignant trophoblastic tumors. An analysis of 209 cases

From 1948 to 1985, a total of 630 cases of choriocarcinoma and invasive mole were treated in our hospital. The methods of treatment varied in different periods of time. In the third period (1972-1985), 5 Fu and/or KSM were the main therapeutic agents used in the treatment of 110 cases of choriocarcinoma and 99 cases of invasive mole. Metastases were observed in more than 90% of cases of choriocarcinoma and nearly 1/4 belonged to stage IV. The mortality of choriocarcinoma decreased from 84.3% to 32.7% after treatment and that of invasive mole from 32.4% to 8.1%. 43 of 80 patients treated with chemotherapy alone conceived after recovery, resulting in a total of 50 pregnancies including 31 term deliveries by 28 women. All the children are normal and healthy, the eldest being 11 years old now.

Impairment by ethanol of prostaglandin production in rat salivary glands

Sublingual salivary acini and submandibular tissue were incubated in DMEM medium in the presence of various concentrations (0-5%) of ethanol and the content of the three major prostaglandins, PGE2, PGF2 alpha and 6-keto-PGF1 alpha, were determined by radioimmunoassay. In In the sublingual gland, ethanol caused a decrease in PGE2 and PGF2 alpha levels, but had no effect on 6-keto-PGF1 alpha, while all three prostaglandins were affected in the submandibular gland. At 2.5% ethanol, the production of PGF2 alpha and PGE2 in sublingual gland decreased by 10% and reached maximum inhibition at 5% ethanol, at which concentration there was a 20 and 30% decrease in their levels. In submandibular gland, 2.5% ethanol caused a 20% decrease in PGE2, 30% in PGF2 alpha and 50% in 6-keto-PGF1 alpha; 40% inhibition in PGE2, 57% in 6-keto-PGF1 alpha and 65% in PGF2 alpha occurred in the presence of 5% ethanol. These findings suggest that alcohol impairs the function of salivary glands by inhibiting prostaglandin production.

Characterization of gingival epithelium epidermal growth factor receptor

The binding characteristics of gingival epithelium epidermal growth factor (EGF) receptor were investigated using epithelial cell membranes from bovine gingiva. The binding of [125I]EGF was found to be time and protein concentration dependent, reversible, and specific. Unlabeled EGF competed for [125I]EGF binding with IC50 of 0.25nM and maximum displacement of 93% at 0.81nM. Scatchard analysis of the binding data inferred the presence of two binding sites, one of high affinity (Kd = 3.3 nM and Bmax = 47.3fmol/mg protein) and the other of a low affinity (Kd = 1.6 microM and Bmax = 1.9pmol/mg protein). Crosslinking of [125I]EGF to gingival membranes followed by polyacrylamide gel electrophoresis and autoradiography revealed a receptor protein of 170kDa.

Prostaglandin E2 receptor of rat submandibular salivary glands

The binding characteristics of the PGE2 receptor were investigated in membrane preparations from these glands. Specific [3H]PGE2 binding was linear as a function of the membrane protein concentration and reached steady state by 40 min of incubation at 37 degrees C under neutral pH. Scatchard analysis of the binding data produced a curvilinear plot with a Kd of 0.18 nM and Bmax of 1.02 fmol/mg protein for the high-affinity binding sites, and a Kd of 181 nM and Bmax of 5.72 pmol/mg protein for the low-affinity binding sites. A competitive displacement study indicated that the receptor was specific for prostaglandins of the E series. The study is the first to demonstrate the presence of the PGE2 receptor in rat submandibular gland and to provide its biochemical features.

Relation between plasma atrial natriuretic peptide (ANP) and glomerular ANP receptors in 5/6 nephrectomized rats

Chronic renal failure (CRF) was induced in male wistar rats (Group I) by 5/6 nephrectomy and the sham-operated ones served as control (Group II). The results showed that in Group I, plasma atrial natriuretic peptide (ANP) levels increased progressively as the Scr was elevated. Plasma R-A rose simultaneously compared to the normal (P less than 0.001). At the 20th week after operation, urine volume and Na decreased significantly (P less than 0.05). The number of glomerular receptors decreased markedly at the 12th week (P less than 0.05) and 20th week (P less than 0.01). Our data suggest that in 5/6 nephrectomized rats, the elevation of plasma ANP level might be partly caused by the damage of glomerular ANP receptors, and the elevated plasma ANP could not play its role in diuresis, natriuresis, blood pressure depression and R-A inhibition as a result of the damage of kidney ANP receptors.

Isolation of high-Km aldehyde dehydrogenase isoenzymes from human gastric mucosa

Human stomach aldehyde dehydrogenase-3 isoenzymes were isolated by DEAE-cellulose, CM-Sephadex, and 5' AMP-Sepharose chromatographies to apparent homogeneity. The subunit of the isoenzymes was determined to be 55,000 daltons by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The kinetic constants for oxidation of various aliphatic and aromatic aldehydes were determined. The Km value for straight-chain aldehydes decreased over 9,000 fold when chain length increased from C2 to C7. The Vmax/Km value for heptaldehyde was 10-fold higher than that for benzaldehyde. NAD+ was a much better cosubstrate than NADP+. The human stomach aldehyde dehydrogenase-3 isoenzymes were insensitive to disulfiram inhibition and were not activated or inhibited by magnesium ions.

[Total saliva amount and salivary immunoglobulins in normal children]

Total saliva amount and salivary immunoglobulins are examined in 90 normal children who are divided into three groups, aged 3-5, 6-10 and 11-15 year old. The normal reference range of total saliva amount and salivary immunoglobulins are established. The amount of total saliva and IgM is higher in elder group. SIgA is very low in the children aged under ten, which may results from incomplete development of salivary gland and is much higher in children at the age of eleven to fifty, which is related to the development of salivary gland and synthesis of SIgA in salivary gland; IgG is low among all three groups and has not much changes with aging, which supports that IgG in saliva is mainly a leakage from blood into saliva.

[Comparative study of norplant-2 and levonorgestrel-releasing intrauterine devices]

Norplant-2 and Levonorgestrel-releasing IUD were studied in a randomized comparative trial for one year. Each group consisted of 100 healthy women among whom contraceptive efficacy and acceptability were studied. Only one woman with the LNG-IUD got pregnancy during the 12 months of use. Expulsion rate was 3.0 in the LNG-IUD. Removal rate for menstrual problems was 3.0 for both groups. The use-related discontinuation were 4.0 and 10.0 respectively. Irregular bleeding was the major side-effect with the two devices. Menstrual blood loss (MBL) and haemoglobin concentration were measured in thirty women at pre- and post-insertion periods. After the 1st, 6th, 12th month of use in Norplant-2 group, the mean MBL were all less than that of pre-insertion, but the differences were not significant. Among LNG-IUD users, the MBL decreased significantly after one year of use. Haemogloblin concentrations were slightly increased in both groups.

Recurrent parotitis in children. A report of 102 cases

This article presents 102 cases of recurrent parotitis in children with studies of clinical findings, sialographic manifestations, dynamic functions of the parotid gland examined with radionuclide, laboratory findings and follow-up studies of 28 cases with sialography. The following conclusions are reached: 1. Retrograde infection induced by the mumps virus and upper respiratory infection seem to play a major role in the etiology of recurrent parotitis. Familial abnormalities are potential factors. Incomplete immune functions of the children are factors related to the pathogenesis, and following growth and development of the immune system, this disease will undergo remission; 2. Sequential scintigraphy shows normal uptake and retarded excretion function of the parotid; 3. Long-term follow-up studies demonstrate that the patients are free from symptoms for many years, but the punctate dilatation in sialography may diminish, disappear, or be unchanged; and 4. If the disease is not cured in childhood, it may continue into adulthood and healing will take place eventually. Relationship with Sjogren's syndrome has not been revealed.

Comparison of the clinical performance, contraceptive efficacy and acceptability of levonorgestrel-releasing IUD and Norplant-2 implants in China

The levonorgestrel-releasing IUD (LNG-IUD, 20 micrograms/d) and the Norplant-2 implants were studied in a randomized comparative clinical trial with 200 women for one year. No pregnancy or expulsion occurred with the Norplant-2. In the LNG-IUD group, there was one pregnancy at the 12th month of use after an unnoticed expulsion. The net cumulative pregnancy and expulsion rates of LNG-IUD were 1.0 and 3.0. The removal rate due to menstrual disturbances in both LNG-IUD and Norplant-2 groups was 3.0. The use-related discontinuation rates were 9.0 and 3.0, and the continuation rates were 90.0 and 96.0, respectively. The differences were not statistically significant. Menstrual disturbance was the main side effect. It was improved after long time use, especially in the LNG-IUD group. After one year, the percentages of women with amenorrhea were 18.9 for the LNG-IUD and 8.3 for the Norplant-2. The menstrual blood loss was statistically significantly reduced in the LNG-IUD group, and blood haemoglobin concentration increased in both groups. The LNG-IUD and Norplant-2 are highly effective, safe, long-acting, and well accepted by the Chinese women.

Benzo(a)pyrene inhibits epidermal growth factor binding and receptor autophosphorylation in human placental cell cultures

Studies investigated the effects of benzo(a)pyrene (BP) treatment on epidermal growth factor (EGF) receptor binding and kinase activity in human placental cell cultures. Specific binding of 125I-EGF to cells from early gestation placentae was significantly decreased by 37 and 60% following exposure to 1 and 10 microM BP, respectively, for 24 hr. In contrast, cells cultured from term placentae showed no inhibitory effect of either concentration of BP. Specific binding of 125I-labeled insulin and insulin-like growth factors-I and -II to early gestation cells was decreased only 15-18% at 10 microM BP, which indicates that loss of membrane receptors appears to be selective for EGF. Scatchard analysis of early gestation cells revealed that BP was associated with a dose-dependent loss in the number of high affinity EGF binding sites. Evidence from cross-linking and autophosphorylation experiments confirmed that the Mr 170,000 binding protein was decreased in a dose-dependent manner following BP treatment. In comparison, term placental cells exhibit a 26% loss of EGF receptor autophosphorylation without alteration in binding following exposure to 10 microM BP. Thus, early gestation cells exhibit a BP-related down-regulation of EGF receptors, whereas term placental cells show receptor desensitization. No adverse effect of BP treatment was observed on the incorporation of [35S] methionine into proteins secreted by early gestation cells. Further experiments compared the effects of BP with the related poly-cyclic compounds beta-naphthoflavone, alpha-naphthoflavone, and 3-methylcholanthrene. In early gestation cells, EGF binding and receptor autophosphorylation were measurably decreased at 10 microM concentrations of these polycyclic compounds, but to a lesser extent than observed with BP. In term placental cells, however, EGF binding was unchanged or increased, whereas receptor autophosphorylation was decreased 10-26%. Thus, exposure of term placental cells to these polycyclic compounds leads to a dissociation between EGF binding and receptor protein kinase activity. Finally, aryl hydrocarbon hydroxylase activity was induced 20- to 200-fold in early placental cells exposed to BP, beta-naphthoflavone, and 3-methylcholanthrene. In summary, the direct effects of BP and related compounds observed on placental EGF receptors may indicate altered function of EGF in the regulation of cell growth and differentiation in the human placenta.

Characterization of epidermal growth factor receptor in rat buccal mucosal cells

1. Receptor binding for epidermal growth factor (EGF) in rat buccal mucosa was characterized. Binding of [125I]EGF to rat buccal mucosa was time, temperature, cell number and [125I]EGF concentration dependent. 2. The [125I]EGF binding was reversible and specific. Unlabeled EGF competed for binding to buccal mucosal cells with an IC50 of 1.25 nM, whereas insulin failed to compete. 3. Scatchard analysis of the binding data revealed a curvilinear plot with dissociation constants of 3.39 nM and 2.14 microM, and binding capacities of 1.23 x 10(4) and 3.38 x 10(5) receptors per cell for high and low affinity sites, respectively. 4. Crosslinking of [125I]EGF to buccal mucosa followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed one major protein with Mw 170,000 which shares similar molecular weight with other known EGF receptors from different tissues and species. 5. The study is the first report to provide biochemical parameters of the specific EGF receptors in rat buccal mucosa.

Characterization of gastric mucosal prostaglandin E2 receptor

1. The binding characteristics of gastric mucosal prostaglandin (PG) E2 (PGE2) receptor were investigated using mucosal cell membranes from rat stomach. The binding was found to be dependent upon PGE2 and membrane protein concentration, the time of incubation and the pH of the mixture, being highest at pH 3.0. 2. Scatchard analysis of the binding data revealed a curvilinear plot with high affinity binding (Kd = 2 nM; Bmax = 0.106 pmol/mg protein) and low affinity binding (Kd = 319 nM; Bmax = 2.262 pmol/mg protein) sites. 3. Competitive displacement study indicated that the receptor was specific for PGs of the E series, as PGF2 alpha and 6-keto-PGF1 alpha failed to displace the PGE2. 4. The study is the first report to provide biochemical parameters of specific PGE receptors in rat gastric mucosa.

Characterization of the epidermal growth factor receptor in the gastric mucosa

The effects of epidermal growth factor (EGF), a potent mitogen involved in mucosal protection, are mediated by specific cellular receptors. Here, we present the characteristics and binding properties of EGF receptors in the gastric mucosa. The studies were conducted using cell membranes isolated by subcellular fractionation of rat stomach mucosal scrapings. Specific binding of [125I]-EGF to the membrane preparations was assessed at room temperature for various periods of time and at different pHs. The results showed that the binding was proportional to the incubation time up to 1 h and was not affected by a pH change between 4.0 and 7.0. Scatchard analysis of the binding data infer the presence of 2 binding sites, one of high affinity (Kd = 1.34 nM, Bmax = 34 fmol/mg protein) and the other of low affinity (Kd = 484 nM, Bmax = 2.29 pmol/mg protein). Cross-linking experiments using disuccinimidyl suberate to link the [125I]-EGF to gastric membranes followed by polyacrylamide gel electrophoresis and autoradiography revealed that the major receptor for EGF was a protein of 170 kilodaltons. When the solubilized membranes were subjected to wheat germ agglutinin affinity chromatography, the purified material was found to act as substrate for EGF-stimulated phosphorylation. The major component which was labeled by the [gamma-32P]-ATP was also found to be a 170-kilodalton protein. The data are the first to provide evidence that the gastric mucosa possesses a functional EGF receptor and describe its binding characteristics.

Identification of epidermal growth factor receptor in human buccal mucosa

EGF receptor was identified and its binding characteristics were determined. Buccal mucosa was obtained from 12 healthy volunteers (6 males and 6 females) and assayed individually for [125I]-EGF binding. The specific binding of [125I]-EGF to the receptor ranged from 2.85 to 6.12 fmol/mg protein. There was no significant difference in binding between male and female (4.31 +/- 0.61 versus 3.94 +/- 0.53 fmol/mg protein; mean +/- SEM). Individual tissue homogenates were pooled for Scatchard analysis and cross-linking experiments. Scatchard analysis produced curvilinear plots with a Kd of 0.71 nM and Bmax of 0.024 pmol/mg protein for the high-affinity binding sites, and Kd of 435 nM and Bmax of 9.92 pmol/mg protein for the low-affinity binding sites. To determine the molecular weight of the EGF receptor, the [125I]-EGF and receptor complex were cross-linked by DSS and subjected to SDS-PAGE. The autoradiogram of the gel revealed one major protein band of 160K and a minor band of 170 K, characteristics shared with the EGF receptors in other tissues. The study is thought to be the first to demonstrate the presence of the EGF receptor in human buccal tissue and to show its biochemical features.

[Effect of the thromboxane synthetase inhibitor dazmegrel (UK 38,485) on skin blood flow in deep partial thickness burns]

We have previously demonstrated more rapid wound healing in deep partial thickness burn guinea-pigs treated with intramuscular injection of the lower dosage of the thromboxane synthetase inhibitor Dazmegrel. In striking contrast, systemic and topical application of larger dosage of Dazmegrel inhibited or did not improve wound healing in this study, a deep partial thickness burn model of guinea-pig was used to evaluate the effect of Dazmegrel given systemically using dosage of 3.4 mg, 10 mg and 30 mg/kg/day on dermal perfusion measured by India ink injection or by Xe-133 clearance. There was no improvement of dermal perfusion in any of the groups receiving Dazmegrel. The beneficial effect of Dazmegrel on wound healing at a dosage of 3.4 mg/kg/day was not due to improved local dermal perfusion but, rather, resulted from a systemic immune effect on the animal. The Xe-133-determined blood perfusion showed a significantly diminished blood perfusion in the burn wound at 7h post-burn, and a higher burn skin blood flow at 24h post-burn. Their finding is consistent with the report from other laboratory that microvascular perfusion in zone-of-stasis burns, immediately post-burn, gradually diminishes to nil over the next 16 hours, to be followed by reperfusion between 16 and 96 hours postburn.

Pathogenetic role of anti-vascular endothelial cell antibodies in systemic lupus erythematosus

In order to study the relationship between vascular endothelial cell (VEC) antigen system and systemic lupus erythematosus (SLE), including lupus nephritis, Terasaki's microcytotoxicity test and indirect immunofluorescence were used to detect anti-VEC antibody. VEC was identified by electron microscopy. Sera of 21 SLE patients and of 100 healthy donors were examined. Among the 21 SLE patients evaluated, 17 had kidney injury and 13 were in active stage SLE. Results showed that anti-VEC antibody was found in 76.2% of 21 SLE patients, while only 1% of the controls were positive (P less than 0.05). This antibody was detected in 84.6% of patients in active stage SLE and in 62.5% of patients in inactive stage (P greater than 0.05). In patients with and without kidney injury, it was detected in 82.4% and 50%, respectively (P greater than 0.05). These data show that anti-VEC antibody does exist in the sera of SLE patients, the presence of which is closely related to SLE onset and is independent of whether the patient is in active stage of SLE or has kidney injury. In summary, our data suggest that anti-VEC antibody may be one of the triggering factors in the vasculitis of SLE. It is proposed that renal VEC may act as a target cell which can be attacked by anti-VEC antibody to constitute an in-situ immune complex formation in the kidney, leading to lupus nephritis.

Kinetic evidence for human liver and stomach aldehyde dehydrogenase-3 representing an unique class of isozymes

Substrate and coenzyme specificities of human liver and stomach aldehyde dehydrogenase (ALDH) isozymes were compared by staining with various aldehydes including propionaldehyde, heptaldehyde, decaldehyde, 2-furaldehyde, succinic semialdehyde, and glutamic gamma-semialdehyde and with NAD+ or NADP+ on agarose isoelectric focusing gels. ALDH3 isozyme was isolated from a liver via carboxymethyl-Sephadex and blue Sepharose chromatographies and its kinetic constants for various substrates and coenzymes were determined. Consistent with the previously proposed genetic model for human ALDH3 isozymes (Yin et al., Biochem. Genet. 26:343, 1988), a single liver form and multiple stomach forms exhibited similar kinetic properties, which were strikingly distinct from those of ALDH1, ALDH2, and ALDH4 (glutamic gamma-semialdehyde dehydrogenase). A set of activity assays using various substrates, coenzymes, and an inhibitor to distinguish ALDH1, ALDH2, ALDH3, and ALDH4 is presented. As previously reported in ALDH1 and ALDH2, a higher catalytic efficiency (Vmax/Km) for oxidation of long-chain aliphatic aldehydes was found in ALDH3, suggesting that these enzymes have a hydrophobic barrel-shape substrate binding pocket. Since the Km value for acetaldehyde for liver ALDH3, 83 mM, is very much higher than those of ALDH1 and ALDH2, ALDH3 thus represents an unique class of human ALDH isozymes and it appears not to be involved in ethanol metabolism.

Localization and characterization of prostaglandin E1 receptors in rat small intestine

While prostaglandins of the E series are known to affect several small intestinal functions, their cellular mechanisms are poorly understood. The purposes of our study were to determine whether receptors for PGE are present in rat small intestine and to locate and characterize the receptor binding in the subcellular fractions. Small intestinal binding of prostaglandin E1 was significantly higher than that of prostaglandin E2. Highest receptor binding for prostaglandin E1 was found in the plasma membrane fraction of isolated small intestinal enterocytes. Curvilinearity of prostaglandin E1 binding in plasma membranes upon Scatchard analysis indicated two receptor binding sites in rat small intestine. Competitive binding studies demonstrated that receptor binding was highest for prostaglandins of the E series. These studies are the first to demonstrate specific prostaglandin E1 receptors in different subcellular fractions of rat small intestine. We suggest that receptor binding of prostaglandin E may be an important initial step in the mechanism of prostaglandin-E-induced responses in the small intestine.