Loss of a novel mucin-like epithelial glycoprotein in oral and cervical squamous cell carcinomas.

Stratified squamous epithelia of oral and cervical mucosa express high levels of simple mucin-type O-linked carbohydrates, and these are known to undergo structural changes in relation to epithelial differentiation and neoplastic transformation. O-glycans in these epithelia are associated with the cell membrane, but the identity of the carrier molecule(s) remains largely unknown. We report here the identification of a membrane-bound M(r) 200,000-250,000 glycoprotein (gp230) that is expressed in stratified squamous epithelia of the oral cavity. Western blot analysis identified gp230 as a major carrier of simple-mucin type carbohydrate antigens in buccal nonkeratinized mucosal epithelium, suggesting that it may represent a mucin-like molecule. A monoclonal antibody PANH4 defining a protein epitope of gp230 was generated. The PANH4 epitope was localized by immunohistology to suprabasal cell layers of buccal epithelium and was also found in larynx, esophagus, vagina, and exocervix, but not in epidermis. Data showed that gp230 was distinct from MUC1 or CD44. It is interesting that in most cases gp230 was not expressed in squamous cell carcinomas of buccal and cervical mucosa. A few moderately differentiated carcinomas, mainly from cervix, expressed the gp230 epitope. The results suggest that a membrane-bound mucin-like molecule, gp230, is associated with the differentiated phenotype of normal mucosal stratified squamous epithelia and that expression of gp230 generally is lost in severe oral epithelial dysplasia and squamous cell carcinomas of oral and cervical mucosa.

Effect of preoperative oral dextromethorphan on immediate and late postoperative pain and hyperalgesia after total abdominal hysterectomy.

Dextromethorphan is a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist known to inhibit wind-up and NMDA-mediated nociceptive responses of dorsal horn neurons. Experimental and clinical studies indicate that NMDA-receptor antagonists may potentiate the effect of analgesics such as morphine, local anesthetics and NSAIDs. Results from previous clinical studies of dextromethorphan in postoperative pain are conflicting, possibly related to administration of insufficient doses of the drug. Fifty patients scheduled for non-malignant elective abdominal hysterectomy in general anesthesia were randomized to receive oral dextromethorphan 150 mg, or placebo 1 h before surgery. The patients received patient-controlled analgesia with morphine for 24 h postoperatively as the only analgesic. Patient-controlled analgesia (PCA) morphine consumption was reduced with 30% from 0-4 h after operation in patients receiving dextromethorphan compared with placebo (P=0.02); no differences were observed from 5-24 h postoperatively. There were no significant differences between groups for visual analogue scale scores at rest, during cough, or during mobilization, pressure pain detection thresholds, von Frey hair pain detection thresholds, or peak flow. At 24 h after operation, hyperalgesia to von Frey hair stimulation proximal to the surgical wound was easily detected in 23 of 25 patients receiving dextromethorphan, and in 22 of 25 patients receiving placebo, with no significant difference between groups. Pooled data from both groups showed a weak but significant correlation between the extent of hyperalgesia at 24 h after operation, and total 24 h postoperative PCA morphine consumption (Rs=0.28, P=0.05). Three months postoperatively, hyperalgesia was still detectable in 18 of 22 examined patients in the dextromethorphan group, and in 16 of 23 patients in the placebo group, without statistical differences between groups. There were no significant differences in side-effects (nausea, vomiting, sedation). In conclusion, oral dextromethorphan 150 mg reduced PCA morphine consumption immediately (0-4 h) after hysterectomy, without prolonged effects on pain or wound hyperalgesia. A positive correlation between the magnitude of wound hyperalgesia at 24 h after operation, and total 24 h postoperative PCA morphine consumption was demonstrated.

Characterization of the association of connexins and ZO-1 in the lens.

ZO-1 (Zona Occludens protein 1) has previously been shown to bind Cx43alpha1. This interaction involves the most C-terminal residues of Cx43alpha1 and the second PDZ-domain of ZO-1. The biological significance of this interaction is not well understood. The similarity of the C-terminal residues of the lens connexins Cx46alpha3 and Cx50alpha8 to Cx43alpha1 prompted us to examine if ZO-1 is expressed in the lens, and if ZO-1 interacts with lens connexins. A high level of ZO-1 expression was detected in the mouse lens. Lens connexins were shown to co-immunoprecipitate with ZO-1, and the interaction was found to involve similar domains as those previously demonstrated for the Cx43alpha1/ZO-1 interaction (Nielsen et al. manuscript in preparation). Futhermore, transient expression of Cx46alpha3 and Cx50alpha8 in cell culture showed colocalization of gap junction plaques with ZO-1, further suggesting that lens connexins interact with ZO-1. Sequence comparison suggests that a large number of connexins of the alpha subclass may interact with ZO-1. Using the lens as a system to study connexin/ZO-1 interactions may further our understanding of their biological significance in the lens, as well as in other organs.

Microfungal contamination of damp buildings--examples of risk constructions and risk materials.

To elucidate problems with microfungal infestation in indoor environments, a multidisciplinary collaborative pilot study, supported by a grant from the Danish Ministry of Housing and Urban Affairs, was performed on 72 mold-infected building materials from 23 buildings. Water leakage through roofs, rising damp, and defective plumbing installations were the main reasons for water damage with subsequent infestation of molds. From a score system assessing the bioavailability of the building materials, products most vulnerable to mold attacks were water damaged, aged organic materials containing cellulose, such as wooden materials, jute, wallpaper, and cardboard. The microfungal genera most frequently encountered were Penicillium (68%), Aspergillus (56%), Chaetomium (22%), Ulocladium, (21%), Stachybotrys (19%) and Cladosporium (15%). Penicillium chrysogenum, Aspergillus versicolor, and Stachybotrys chartarum were the most frequently occurring species. Under field conditions, several trichothecenes were detected in each of three commonly used building materials, heavily contaminated with S. chartarum. Under experimental conditions, four out of five isolates of S. chartarum produced satratoxin H and G when growing on new and old, very humid gypsum boards. A. versicolor produced the carcinogenic mycotoxin sterigmatocystin and 5-methoxysterigmatocystin under the same conditions.

Differential expression of human high-molecular-weight salivary mucin (MG1) and low-molecular-weight salivary mucin (MG2).

Two distinct mucin components of saliva, MG1 and MG2, have been identified based on chemical composition and molecular weights (high and low, respectively) in saliva. With the aim of characterizing the expression pattern of salivary mucins, we have prepared monoclonal antibodies (MAbs) directed against the peptide core of MG1 and against a synthetic peptide derived from the MG2 (MUC7) sequence. MAb PANH2 raised against partially deglycosylated MG1 stained a high-molecular-weight smear in Western blots of partially purified MG1. PANH2 binding was increased by deglycosylation with trifluoromethanesulfonic acid as well as with subsequent periodate treatment, and was eliminated by pronase treatment, strongly suggesting that MAb PANH2 was directed to a peptide epitope of MG1. MAb PANH3 raised against a synthetic peptide derived from the MG2 (MUC7) sequence reacted with the native molecule and stained a narrow smear of ca. 200,000 to 210,000 in Western blots of concentrated saliva and a lower-molecular-weight smear of trifluoromethanesulfonic-acid-treated MG2. Immunohistology on frozen sections of human salivary glands showed that MAb PANH2 selectively labeled mucous cells, whereas MAb PANH3 labeled subpopulations of serous cells. Double-direct immunofluorescence staining with PANH2 and PANH3 demonstrated that the staining patterns were non-overlapping. The development of these antibody probes will facilitate studies of mucin expression in diseases of salivary glands.

Edetate disodium-mediated chloramphenicol resistance in Pseudomonas cepacia.

The presence of edetate disodium decreased the susceptibility of a particular strain of Pseudomonas cepacia to chloramphenicol. The mechanism of this edetate disodium effect, which may be unique to this strain, remains obscure. Tests showed no enzymatic destruction by the microorganism of the chloramphenicol nor any chemical complexation of the antibiotic by the salt. The possibility does exist that edetate disodium alters the cell envelope or cytoplasmic membrane so as to block the transport of chloramphenicol to its site of action within the cell. This possibility is now under investigation.

Mutagenicity studies on complex environmental mixtures: selection of solvent system for extraction.

The mutagenic activities in the Salmonella/microsome assay of dichloromethane (DCM) and acetone extracts of complex environmental mixtures were compared. The particulate samples used in the IPCS collaborative study were Soxhlet-extracted twice with DCM followed by a third extraction with acetone. Compared with the mutagenic activity of the first extract, the third (acetone) extract of the urban particulate matter showed a relatively high mutagenic activity. In contrast to this the third extract of the diesel particulate matter contributed very little additional mutagenic activity. Furthermore, 10 filter samples of air particulates from a suburban airport area were collected for comparison of the extraction efficiency of DCM and acetone. Each sample was divided into two samples of identical size followed by extraction with acetone and DCM, respectively. No clear difference in the mutagenic activity of these extracts was observed in strains TA98 and TA98NR. It is concluded that for ambient air particulates (but not emission samples) acetone may extract some mutagenic compounds which are not extracted by DCM. The amount of these additional extractable compounds seems to depend on the composition of the sample. As DCM extracts are better suited for further fractionation and chemical analysis DCM is considered to be the best choice for a general solvent system for extraction of complex environmental mixtures.

Mutagenic activity of nine N,N-disubstituted hydrazines in the Salmonella/mammalian microsome assay.

The mutagenic activity of N,N-dimethyl-, N,N-diethyl-, N,N-dibutyl-, N,N-diisobutyl-, N,N-di(p-tolyl)-, N-ethyl-N-phenyl-, N,N-dibenzyl-, N,N-diphenyl- and N,N-diisopropylhydrazine was examined in the Salmonella/mammalian microsome assay using the strains TA1535, TA1537, TA97, TA98, TA100, TA102 and TA1530. All nine hydrazines were mutagenic in at least one tester strain, although of borderline significance for some of the compounds. The mutagenic potencies of the hydrazines varied 2-3 orders of magnitude, from very weak to moderate mutagenic activity. In general, the addition of S9 resulted in a lowering of the mutagenic activity and a lowering of the toxic properties of the hydrazines. The test results were relatively difficult to evaluate due to toxic effects of many of the test compounds on the test bacteria which may have resulted in an underestimation of the mutagenic potencies of some of the compounds. The pattern of mutagenic activity of the hydrazines in the different tester strains indicates that more than one mechanism of action may be involved in the mutagenicity.

The distribution and origin of mutagens in airborne particulates, detected by the salmonella/microsome assay in relation to levels of lead, vanadium and PAH.

At three stations in central Copenhagen, Denmark, samples of particulate matter were collected simultaneously with different contributions from automobile exhaust products. Samples were obtained at street level, 22 m above street level and within a hospital zone; 32 samples were analysed for levels of polycyclic aromatic hydrocarbons (PAH) and elements, as well as for mutagenicity towards S. typhimurium TA1538. Two classes of mutagens were quantified: a non-polar extract rich in PAH and, other promutagens, and a polar extract containing direct acting mutagens (not requiring microsomal activation). Covariances between lead and mutagenicity, and the varying distribution of the polar and non-polar mutagens at the stations, indicate that at all stations the mutagenicity of the non-polar extract is dominated by automobile exhaust products. The polar extract is relatively less influenced by primary traffic emissions; a considerable part of the activity of this extract is attributed to secondary emissions, transformed by atmospheric reactions, and primary emissions from stationary sources.

Warm or cold saline for volume preload before spinal anaesthesia for caesarean section?

In this study, we compared the effect of prophylactic administration of warm and cold saline against spinal anaesthesia induced hypotension in parturients undergoing elective caesarean section. One hundred and thirteen parturients with singleton pregnancies received an i.v. infusion of isotonic saline 20 mL x kg(- 1)during the 15 min before spinal injection followed by 10 mL x kg(- 1)during the 20 min after spinal injection. Fifty-seven patients were allocated to the warm saline group (37 degrees C) and 56 to the cold saline group (21 degrees C). Discomfort in the infusion arm was less in the warm saline group (P<0.01), whereas the incidence of shivering was similar in the two groups. Following induction of spinal anaesthesia, blood pressures were significantly higher in the cold saline infusion group compared to the warm saline group (P<0.05). However, the group mean difference in mean arterial pressure was only about 5 mmHg, and the amount of ephedrine administered and the incidence of clinical significant hypotension did not differ between groups. In conclusion, the temperature of the fluid used for i.v. preload and maintenance at caesarean section under spinal anaesthesia is not clinically important.

[Permanent central venous catheter in pediatric oncology]. / Permanente centrale venekatetre i paediatrisk onkologi.

Thirty-eight permanent central venous catheters were introduced in 28 children as part of the intensive chemotherapeutic treatment for malignant disease. These catheters were employed partly for administration of medicine and partly for sampling blood for control. The total duration of life with a catheter was 7,303 days. On an average, 27 chemotherapeutic agents were administered, 172 supplementary injections and 56 blood samples were performed via the central venous catheter per child. In the present investigation, a frequency of infection of 0.27/100 catheter days was found and an incidence of non-infectious complications resulting in removal of the catheter or adjustment of the catheter of 0.16/100 catheter days. The authors consider that employment of a permanent central venous catheter in paediatric oncology represents considerable progress and that this should be employed in all children to be submitted to prolonged treatment with cancer chemotherapy.

[Comparison of propofol and thiopentone in young and elderly patients]. / Propofol versus tiopental til unge og aeldre patienter.

Forty patients between 20 and 40 years and 39 patients between 60 and 80 years, all unpremedicated, were allocated to induction with propofol or thiopentone. The induction dose of propofol in patients between 60 and 80 years was 65% of the dose in the patients between 20 and 40 years. Administration of the induction dose of propofol was followed by an even decrease in mean arterial blood pressure of approximately 16% in young and in elderly patients. Propofol caused a more pronounced decrease in mean arterial blood pressure than thiopentone, both in young and elderly patients.