Activation of transient receptor potential vanilloid subtype 1 increases secretion of the hypofunctional, transplanted submandibular gland

Hyposecretion occurs in most patients early after submandibular gland autotransplantation for severe keratoconjunctivitis sicca. Endogenous transient receptor potential vanilloid subtype 1 (TRPV1) has been recently demonstrated in rabbit submandibular glands, and activation of TRPV1 by capsaicin increases secretion in isolated glands, but the TRPV1-mediated secretory mechanism remains to be elucidated. The purpose of this study was to verify whether activation of TRPV1 by capsaicin could improve the secretion of transplanted gland and its underlying mechanism. The salivary flow of the transplanted glands was significantly decreased, and the mRNA and protein levels of TRPV1 and aquaporin 5 (AQP5) were downregulated in the transplanted glands. Topical capsaicin cream increased secretion and upregulated levels of TRPV1 and AQP5 in transplanted glands. Moreover, in cultured submandibular gland cells, capsaicin increased the mRNA expression of AQP5 and led to redistribution of AQP5 from the cytoplasm to the plasma membrane via TRPV1 activation. Capsaicin enhanced the phosphorylation of extracellular signal-regulated kinase (ERK). Preincubation of cells with PD98059, an inhibitor of ERK kinase, suppressed the capsaicin-induced mRNA expression of AQP5. In summary, the capsaicin-induced secretory mechanism involved activation of TRPV1 and upregulation of AQP5 in an ERK-dependent manner and promoted the redistribution of AQP5 in submandibular gland cells. Activation of TRPV1 may provide a new therapeutic strategy to improve submandibular gland hypofunction.

Isoproterenol improves secretion of transplanted submandibular glands

Autotransplantation of the submandibular gland is effective for severe keratoconjunctivitis sicca. However, most transplants show decreased secretion shortly after the operation, which leads to obstruction of Wharton's duct. The hypothesis that decreased catecholamine release due to denervation contributes to hypofunction in the early phase was tested in transplanted glands in rabbits. We found that salivary flow, expression of beta(1)- and beta(2)-adrenoceptor, and the maximum binding capacity were markedly decreased in the transplanted glands. Isoproterenol significantly reversed the decreased secretion, enhanced the expressions of beta(1)- and beta(2)-adrenoceptor, and ameliorated the atrophy of acinar cells. The contents of cAMP and phospho-ERK 1/2 were increased after isoproterenol treatment. These results indicate that lack of beta-adrenoceptor stimulation is involved in early dysfunction of the transplanted gland. Isoproterenol treatment moderates structural injury and improves secretory function in the transplanted submandibular gland through up-regulating beta(1)- and beta(2)-adrenoceptor expression and post-receptor signal transduction.

125I seed implant brachytherapy-assisted surgery with preservation of the facial nerve for treatment of malignant parotid gland tumors

The surgical treatment of malignant parotid gland tumors combined with (125)I seed implant brachytherapy and preservation of the facial nerve is described. Tumor and parotid gland resection with preservation of the facial nerve was carried out in 12 patients with malignant parotid gland tumors. (125)I seeds were implanted into the target area intra- or postoperatively. The extent of regional control of the tumor was followed up, and facial nerve function was evaluated. None of the patients had tumor recurrence during the follow-up period of 50-74 months (median follow-up period, 66 months). Facial nerve function had recovered to normal by 6 months postoperatively in all patients. A limited surgical resection combined with (125)I seed implant brachytherapy is therefore considered to be an alternative treatment for local control of malignant parotid gland tumors with preservation of the facial nerve.

Microvascular autologous submandibular gland transfer in severe cases of keratoconjunctivitis sicca

The objective is to evaluate the technique of microvascular autologous submandibular gland transfer for the treatment of severe keratoconjunctivitis sicca. From August 1999 to April 2002, 38 patients with severe keratoconjunctivitis sicca were treated by autologous submandibular gland transfer to the temporal region of the skull. The related vessels were anastomosed to the superficial temporal artery and vein. When the vein was too small, venous bridging was applied. Prior to cutting off the gland, the facial artery was preserved and infused with heparin in normal saline after the gland had been freed to allow inspection of the blood oozing from the three veins. This would be helpful in the selection of a relevant vein for anastomosis. Wharton's duct was transplanted to the upper lateral conjunctiva fornix, and the gland was left denervated. Postoperative scintigraphy with Tc99m pertechnetate, follow-up studies, and management of complications were performed. The transplantations were successful in 33 cases, their symptoms of xerophthalmia disappeared. The discomfort resulting from bright light and wind was also relieved. These patients could stop applying artificial tears. In five patients the transplanted glands did not survive. Epiphora occurred in eight cases. They were successfully treated by reducing the size of the graft. Obliteration of Wharton's duct took place in two cases and was treated by the reconstruction of the duct or duct orifice. Microvascular autologous submandibular gland transfer is a lasting and effective solution for severe cases of keratoconjunctivitis sicca.

Diagnosis and treatment of epithelial salivary gland tumours in children and adolescents

In a series of 2,871 epithelial salivary gland neoplasms managed in the Peking University School of Stomatology between 1974 and 1999, 86 arose in children <16 years of age (52 parotid, 12 submandibular gland, 2 sublingual gland, and 20 minor salivary gland). Considerable delay was encountered in diagnosis (benign 24 months and malignant 16 months). In this group of children, 46 tumours (53%) proved to be malignant, with an incidence in the parotid, submandibular, sublingual, and minor salivary glands of 31/52 (60%), 2/12, 0/2, and 13/20 (65%), respectively. Sixty-six of 86 neoplasms (77%) occurred in children between 10 and 16 years of age. Only six neoplasms were encountered in children of 5 years or younger, four of which were high-grade malignant tumours. Benign tumours were successfully treated by local excision with only one recurrence. Of 46 malignant neoplasms, 8 were treated palliatively; of the remainder 8 were lost to follow-up and 2 patients died of their disease.

Adenomatous ductal proliferation of the salivary gland

OBJECTIVE

The objective of this study is to report a series of patients with adenomatous ductal proliferation of the salivary gland and to investigate the nature and histogenesis of this process.

STUDY DESIGN

The histologic and immunohistochemical studies of 13 patients with adenomatous ductal proliferation of the salivary gland were performed.

RESULTS

Ten cases coexisted with other diseases, such as salivary gland tumor or chronic parotitis. Most of the lesions were limited to 1 or 2 lobules and showed prominent ductal proliferation with some acinar cell complexes. The proliferative ducts had a compact growth pattern with little stroma. Dedifferentiation of acinar cells, identified by the loss of their secretory granules and appearing similar to intercalated duct epithelium, was seen in the early stages of adenomatous ductal proliferation.

CONCLUSION

Acinar cells play a role in the histogenesis of salivary gland tumors because acinar cells clearly participate in the formation of the proliferative ducts.

Unicystic ameloblastoma: a clinicopathologic study of 33 Chinese patients

The term unicystic ameloblastoma refers to those cystic lesions that show clinical, radiographic, or gross features of a jaw cyst, but on histologic examination show a typical ameloblastomatous epithelium lining part of the cyst cavity, with or without luminal and/or mural tumor growth. To ascertain the clinicomorphologic spectrum and biologic behavior of this tumor group, the clinicopathologic features of 33 unicystic ameloblastomas from Chinese patients were studied. This series represents approximately 19% of all cases of ameloblastoma accessioned in the authors' hospital during a 15-year period. Twenty-one patients were male and 12 were female, for a total of 33 patients. The age at diagnosis ranged from 8 to 60 years (mean, 25.3 yrs) and peaked at the second and third decades (70%), Thirty tumors (91%) occurred in the mandible and three in the maxilla. Of the 29 patients with a radiographic record, an expansive unilocular radiolucency was seen in 22 cases, and was multilocular in seven cases. Microscopically, all tumors demonstrated a generally monocystic growth pattern. Eight tumors were simple cystic, 10 comprised intraluminal tumor nodules, and the remaining 15 had a conspicuous component of infiltrative tumor islands in the cyst capsule. The cystic tumor linings invariably showed, at least in part, a typical ameloblastomatous pattern that was often accompanied by epithelial areas of various histologic appearance. Follow up of 29 patients revealed no recurrence in less than 4 years of follow up, but did reveal a 35% recurrence rate at more than 4 years of follow up. The average interval to recurrence was approximately 7 years. Recurrence also appeared to relate to histologic subtypes of unicystic ameloblastoma, with those invading the fibrous wall having a rate of 35.7%, but other types having a rate of 6.7%. Despite the fact that unicystic ameloblastoma may, in general, compare favorably with its solid or multicystic counterpart in terms of clinical behavior and response to treatment, the subsets of the maxillary lesions or tumors containing invading islands in the fibrous wall could have a high risk of recurrence. Furthermore, recurrence of unicystic ameloblastoma may be long delayed, and a long-term postoperative follow up is essential to the proper management of these patients.

Endogenous fatty acid synthesis in squamous cell carcinomas of the oral cavity

We measured the synthesis of endogenous fatty acids in oral squamous cell carcinoma, its adjacent tissue, and normal oral tissues that were collected fresh from surgical specimens. The tissues were minced in Roswell Park Memorial Institute Medium 1640 (RPMI 1640) and incubated in [1(2)-(14)C] acetic acid, sodium salt ((14)CH(3)(14)CO(2)Na). Total lipids were then extracted and(14)C was measured by scintillation counter. We found that incorporation of(14)C in the total lipids of squamous cell carcinoma was significantly higher than in the other tissues.

Possible effects of the Three Gorges dam on the transmission of Schistosoma japonicum on the Jiang Han plain, China

The Three Gorges dam, under construction on the Yangtze River in China, might affect the transmission of Schistosoma japonicum on the Jiang Han plain, which is downstream of the dam. To study this possibility, the prevalence of schistosomiasis was investigated in relation to a range of malacological, hydrological and meteorological factors. The general water level in the Yangzte over a year had a marked effect on the distribution of the intermediate host (Oncomelania hupensis) and the prevalence of human schistosomiasis in that year. Disease prevalence showed significant correlations with the density of the snail hosts, the level of the water table, annual rainfall, yearly evaporation, and altitude. Once the dam is complete, the flow of water downstream will probably be maintained at a level between those currently occurring in flood and dry weather, and this may have implications for schistosome transmission. Systematic monitoring is necessary to investigate the impact of the environmental changes brought about by the dam on transmission.

[Overproduction of cholera toxin B subunit by recombinant Escherichia coli MM2 in lactate-containing medium]

The expression of ctb gene in recombinant E. coli MM2 strain is affected by temperature, pH and carbon source. High level production of cholera toxin B subunit (CTB) was investigated in lactate-containing medium which designed by experiments of orthogonal test. Upshifting temperature from 30 degrees C to 37 degrees C could increase the production of CTB by 4 fold, upshifting pH value from 7.2 to 8.4 at the later culture stage could increase the specific expression level of CTB by 2.14 fold, and adding sodium acetate increased the production of CTB by 65%. In 5 L fermentor the cell density was reached at OD600 30, and the 186.7 mg/L of CTB was obtained. The CTB in the culture supernatants was in the form of polymer like the native CTB from Sigma, and also possessed the same antigenity.

Impact of environmental change and schistosomiasis transmission in the middle reaches of the Yangtze River following the Three Gorges construction project

With the construction of the Three Gorges high dam on the Yangtze River in China in mind, a serious of ecological environmental factors that might affect the transmission of Schistosoma japonicum in Jian Han Plain were investigated by means of data collection, field surveys and observation in Hubei Province. Several ecological factors including water level of the Yangtze River; riparian water table, annual rainfall and yearly evaporation were investigated in relation to the prevalence of schistosomiasis. The results suggest that after the dam construction, middle water level flows (ie between flood flows and dry-weather flows) will persist in the flood season due to a rise in the water table. The investigation indicated that snail distribution and human schistosomiasis prevalence differed significantly between years which had typically high, middle and low typical water levels in the Yangzte. Moreover, the prevalence of the disease showed a significant linear regression relationship with density of snail intermediate hosts, water table, annual rainfall, yearly evaporation and ground altitude in the survey area. Systematic and careful monitoring and surveillance is necessary to investigate the impact of the environmental changes brought about by the dam construction on schistosomiasis transmission.

Histogenesis and development of membranous basal cell adenoma

The histogenesis of salivary gland tumors remains controversial. A histologic and immunohistochemical study was carried out on 12 cases of membranous basal cell adenoma in the salivary glands to investigate its histogenesis and development. In 4 cases, multiple focal proliferations of striated ducts in the surrounding salivary gland, which were conspicuous, allowed tracing of the development of the tumors from their origin. The earliest changes were characterized by hyperplasia of the basal cells of striated ducts. Continuous ductal proliferation led to the formation of microadenomas. The observations suggest that proliferating basal cells of striated ducts apparently participate in and play a main role in the histogenesis of some membranous basal cell adenomas of the salivary glands.

Membranous basal cell adenoma of the salivary gland: a clinicopathologic study of 12 cases

Twelve cases with membranous basal cell adenoma of the salivary gland were analysed clinicopathologically. Its histology was characterized by palisading of peripheral cells and an excessive hyaline basal membrane. The differential diagnosis involved the solid variant of basal cell adenoma, basal cell adenocarcinoma, solid subtype of adenoid cystic carcinoma and basaloid squamous cell carcinoma. Four cases had coexisting dermal cylindromas of the scalp. Screening for skin lesions of the scalp or other locations is suggested. In 8 cases, the tumors demonstrated multifocal origin. Total parotidectomy rather than superficial parotidectomy is suggested to avoid the recurrence of the tumor. One case showed malignant transformation and cervical lymph node metastases. A close follow-up after treatment is necessary.

Local excision of the parotid gland in the treatment of Warthin's tumour

The results of local excision of Warthin's tumour in the parotid gland (n = 61) (resection of the tumour together with surrounding normal gland and associated lymph nodes) were compared with those of superficial parotidectomy (n = 88) for incidence of recurrence, duration of operation, and degree of facial deformity. A subgroup of patients in each group were tested for gustatory sweating (iodine starch test) and parotid function (quantitative scintigraphy). Local excision had the following advantages over superficial parotidectomy: shorter operating time, less risk of facial nerve damage, less facial deformity, lower incidence of Frey's syndrome, and better preservation of the function of the parotid gland.

Smoking and the development of Warthin's tumour of the parotid gland

The smoking history was surveyed in 160 consecutive patients with Warthin's tumour of the parotid gland in order to investigate the relationship between smoking and the development of this tumour. Two hundred cases of middle-aged or elderly normal persons and 163 consecutive patients with pleomorphic adenoma in the parotid gland served as controls. The percentage of smoking in patients with Warthin's tumour (96.3%) was much higher than that of middle-aged or elderly normal persons (25.5%) and in patients with pleomorphic adenoma (26.4%). Moreover, the amount of smoking was greater and the smoking history was longer in patients with Warthin's tumour. When the male and female patients were analysed respectively, the same result was shown. This case-control study suggests that smoking may be one of the aetiologic factors associated with the development of Warthin's tumour.

Gas chromatographic determination of residues of thyreostatic drugs in bovine muscle tissue using combined resin mediated methylation and extraction

A method is described for the assay of residues of the thyreostatic substances 2-thiouracil, 6-methyl-2-thiouracil, 5- and 6-propyl-2-thiouracils and 6-phenyl-2-thiouracil in beef muscle at levels of quantitation down to 25 microg/kg for thiouracil and 15 microg/kg for substituted thiouracils. Analytes are extracted from the muscle matrix with acetonitrile and methylated by absorption onto a macroporous anion exchange resin followed by treatment with methyl iodide in acetonitrile at room temperature. Supercritical carbon dioxide is also a suitable derivatization solvent. Determination is carried out using gas chromatography with mass spectrometric detection. The methyl ester of 2,4,5-trichlorophenoxyacetic acid serves as an internal standard while 5-methyl-2-thiouracil is a suitable surrogate. 5-Ethyl-2-thiouracil is added to minimise losses of the analytes during the analysis. The method exhibits a linear range of 25-625 microg/kg for the substituted thiouracils and 50-1250 microg/kg for 2-thiouracil. Recovery of the analytes ranges from 50% for 6-phenyl-2-thiouracil to 90% for 2-thiouracil with coefficients of variation of less than 10%.

[Salivary duct carcinoma (clinicopathologic study of 11 cases)]

Eleven cases of salivary duct carcinoma were studied clinicopathologically. The clinical features are as follows: men outnumber women; arise most frequently within the parotid glands; rapidly enlarging mass; obvious symptoms of invading nerves; high rates of cervical lymph node and distant metastases; poor patient's prognosis. Its histologic features were shown by the various stages of development of duct carcinoma including dysplasia, carcinoma in situ, papillary, cribriorm, solid and commedo patterns. In addition to the intraductal carcinoma, there is the invasive carcinoma with obvious infiltration into the surrounding tissues. Its treatment requires the combination of radical surgery with postoperative radiotherapy.

The Saccharomyces cerevisiae SPT14 gene is essential for normal expression of the yeast transposon, Ty, as well as for expression of the HIS4 gene and several genes in the mating pathway

To investigate the role of the trans-acting transcription factor encoded by the essential SPT14 (SPT = Suppressor of Ty insertion mutations) gene, we have cloned, mapped and sequenced the gene. From the analysis of the effect of spt14 mutations on expression of various genes, we conclude that the SPT14 product has an important role in activation of Ty transcription as well as in the regulation of other genes including HIS4 and several of the a- and alpha-specific mating type genes. Similarities in the phenotypes of spt14 and spt13 mutants (suppression of Ty insertion mutations but not delta insertion mutations), lead to the suggestion that the SPT14 gene and the previously characterized SPT13/GAL11 gene might encode transcriptional regulators with related functions. Our current findings show that in contrast to SPT13/GAL11, which appears negatively to regulate Ty transcription, SPT14 plays a role in the activation of Ty transcription. Thus, despite the similarities in the suppression phenotype exhibited by spt13 and spt14 mutants, SPT13/GAL11 and SPT14 probably differ in their transcriptional roles.

[Dynamic CT and its application in the diagnosis of oral and maxillofacial tumors]

Dynamic CT was used in 26 cases with oral and maxillofacial tumors. Among them, 21 were incremental dynamic CT, 4 were single level dynamic CT, and both of them were used in 1 case. Incremental dynamic CT can show not only the extent of the tumor, but also the relationship between the tumors and carotid arteries and jugular veins. It can provide important information for design of the operation. There are four types of shape of the carotid sheath in the involved side as follows: (1) a space of fat is present between the tumor and major vessels, indicating that carotid sheath is not involved by the tumor. (2) the vessel is close to the tumor although its position and shape are normal. (3) vessel is displaced by the tumor. (4) involved jugular vein is narrower than normal, with or without displacement.

[Combined diagnosis of parotid masses]

Computed tomography (CT), ultrasonography, sialography, and 99mTc scintigraphy were applied before operation to 108 patients with parotid masses. The results of each technique and the combined study of them were compared with the pathological diagnosis. Ultrasonography was found to be a very effective diagnostic aid in determining the presence of space-occupying lesion in the parotid. CT was the best technique to provide adequately reliable informations regarding the location of the tumor and the relationship between tumor and surrounding tissues. For diagnosing the nature of tumors, ultrasonography combined with sialography was reliable. 99mTc scintigraphy was better than other techniques in diagnosis of adenolymphoma. The diagnostic accuracy of combined diagnosis (90.7%) was higher than those of ultrasonography (83%), CT (80.5%), sialography (79%), and 99mTc scintigraphy (13.9%) alone. The advantage of combined diagnosis was particularly obvious for the diagnosis of low-grade malignant tumors.