Effects of phenobarbital and 3-methylcholanthrene induction on the formation of three glucuronide metabolites of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, NNK.

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a tobacco specific carcinogen believed to be a causative agent for human lung cancer. To exert its carcinogenic potential, NNK must be metabolically activated, by alpha-hydroxylation, at either the methyl or methylene carbons adjacent to the N-nitroso group. We recently reported the presence of a glucuronide conjugate of 4-(hydroxymethylnitrosamino)-1-(3-pyridyl)-1-butanone (alpha-hydroxymethylNNK-Gluc) in the urine of Phenobarbital (PB) treated rats, and in the media of PB induced hepatocytes incubated with NNK. PB induces the alpha-hydroxylation of NNK, which generates the aglycon, as well as several UDP-glucuronosyl transferases. In the study presented here, we compared the metabolism of NNK to alpha-hydroxymethylNNK-Gluc by PB induced, 3-methylcholanthrene (3-MC) induced and control rat hepatocytes. Media was analyzed for the products of alpha-hydroxylation, N-oxidation and glucuronidation by radioflow HPLC. PB induced both N-oxidation and alpha-hydroxylation of NNK. 3-MC did not induce N-oxidation but induced alpha-hydroxylation more than 10-fold. alpha-HydroxymethylNNK-Gluc was not detected (< 0.05% total metabolites) when control hepatocytes were incubated with 1 to 100 microM NNK. When 3-MC and PB induced hepatocytes were incubated with 1-100 microM NNK alpha-hydroxymethylNNK-Gluc, expressed as the average percent of metabolites, accounted for 0.725 +/- 0.27 and 1.35 +/- 0.24% (+/-S.D.) of the NNK metabolites, respectively. The percent of NNK metabolized to alpha-hydroxymethylNNK-Gluc is small. But this glucuronide is potentially important in NNK carcinogenesis, since its formation results in the direct conjugation of an active metabolite responsible for DNA adduct formation. When PB induced rats were injected with NNK the level of NNK hemoglobin adducts, which can serve as surrogates for DNA adducts, decreased 50% compared to control rats administered NNK. Hepatic microsomal metabolism increased 2-fold and urinary alpha-hydroxymethylNNK-Gluc increased more than 10-fold in PB treated rats. One explanation for the decrease in NNK hemoglobin adducts may be a PB induced increase in the glucuronidation of alpha-hydroxymethylNNK, the metabolite responsible for adduct formation.

Effect of a surgically created disk displacement on mandibular symmetry in the growing rabbit.

PURPOSE: The purpose of this study was to evaluate the contribution of unilateral disk displacement to growth changes in the young New Zealand White rabbit. METHODS: Ten female rabbits aged 10 weeks were included in this study. The five experimental rabbits had unilateral anterior disk displacement surgery. The five controls had no surgery. The rabbits were killed at 22 weeks of age, and the mandibles hemisected and radiographed. Cephalograms were digitized and analyzed by conventional methods. RESULTS: The gross appearance showed shortening and flattening of the articulating surface in the experimental group (P < 0.05). No significant shortening and flattening was found in the control group. CONCLUSION: These observations suggest that surgically created internal derangement can produce altered growth in the mandible.

Content analysis of gay male and lesbian personal advertisements.

396 randomly selected gay and lesbian personal advertisements were analyzed for content. Analysis supported the hypotheses that the 198 men are more interested in sexuality and physical attractiveness, while the 198 women are more concerned with the personality characteristics of prospective partners.

Angle of the articular eminence in patients with temporomandibular joint dysfunction and asymptomatic volunteers.

OBJECTIVE: The purpose of this study was to compare structural variations of the temporomandibular joint anatomy between symptomatic patients with temporomandibular joint dysfunction and asymptomatic controls. STUDY DESIGN: There were 74 symptomatic patients with temporomandibular joint dysfunction, 29 asymptomatic volunteers with normal joints, and 6 asymptomatic volunteers with disk displacement with reduction included in this study. All subjects had bilateral high resolution magnetic resonance imaging scans performed in the sagittal (closed and opened) and coronal (closed) positions. All subjects had right and left full profile laminagraphs, one in the centric occlusal position, and one with the incisors edge to edge. RESULTS: Student-Newman-Keuls tests demonstrated no significant angular or linear differences for depth of the articular fossa, angle of the articular eminence, horizontal and vertical overlap of the incisor teeth, and linear condylar translation. CONCLUSION: This study concludes that there are no significant differences in angular and linear measurements in the articular fossa of asymptomatic volunteers and symptomatic subjects with temporomandibular joint dysfunction.

Comparison of linoleic acid and eicosapentaenoic acid incorporation into human breast cancer cells.

To gain some insight into the mechanisms involved in the opposing effects of linoleic acid (LA) and eicosapentaenoic acid (EPA) on the growth and invasiveness of MDA-MB-435 human breast cancer cells, the dynamics of the uptake by cells and the incorporation of [14C]LA and [14C]EPA into major lipid and phospholipid pools, as well as the effects of unlabeled EPA or LA on the uptake and distribution of [14C]LA or [14C]EPA, respectively, were examined. Cells were exposed to [14C]LA (1.28 micrograms/mL) or [14C]EPA (1.0 micrograms/mL) and unlabeled EPA or LA, respectively, at 0, 1, 4 and 16 micrograms/mL for 24 h in serum-free media. The uptake of each fatty acid (FA) was linear over time and was not affected by the presence of the opposing FA. For both FA, 80-90% was incorporated into the phospholipid fraction with the remaining 10-20% in neutral lipids. The relative distribution profile of [14C]LA among the phospholipid classes indicated a preferential incorporation into phosphatidylcholine (65%), whereas [14C]EPA was mostly found in phosphatidylethanolamine (58%). In the presence of unlabeled EPA or LA at various concentrations, corresponding dose-dependent shifts of [14C]LA or [14C]EPA from the phospholipid to the neutral lipid pool were noted, which did not alter the relative distribution of the FA among the phospholipid classes. Exogenous exposure to EPA or LA increased its content in membrane phospholipids while concurrently decreasing LA or EPA content, respectively, in a dose-dependent manner. Arachidonic acid content of membrane phospholipids remained constant.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the reproducibility of rest activity of the anterior temporal and masseter muscles in asymptomatic and symptomatic temporomandibular subjects.

There is a general assumption that temporomandibular disorders and the pain and tenderness of mastication muscles may be caused by hyperactivity. Five asymptomatic men, five asymptomatic women, and five women with temporomandibular disorders participated in this study. Multiple examinations were performed to provide information concerning the reproducibility of the rest electromyographic signals. No significant differences between groups were noted. This study supports the contention that the mean rest activity in women with pain and dysfunction is less than or equal to that of sex-matched controls.

Dietary fatty acids and breast cancer invasion and metastasis.

This review presents the evidence for the hypothesis that dietary linoleic acid and its metabolic derivative arachidonic acid enhance the metastatic process in breast cancer. Key biochemical events are eicosanoid biosynthesis and protein kinase C activation, both of which are involved in tumor cell invasion and angiogenesis. It is concluded that the utilization of appropriate dietary interventions and pharmacological inhibitors offers a promising approach to suppress metastasis.

Effects of dietary fish oil on fatty acids and eicosanoids in metastasizing human breast cancer cells.

We examined the relationships between the suppressive effects of dietary fish oil on growth and metastasis of MDA-MB-435 human breast cancer cells in female nude mice and the primary tumor phospholipid fatty acid concentrations, phospholipase A2 activity, and eicosanoid levels. Mice (n = 120) were fed a 23% (wt/wt) corn oil (CO) linoleic acid (LA)-rich diet for seven days before and after 10(6) tumor cells were injected into a mammary fat pad, and then the mice receive one of three isocaloric diets containing 23% total fat but different proportions of CO and menhaden oil (MO) (18% CO-5% MO, 11.5% CO-11.5% MO, 5% CO-18% MO) or a 23% fat diet containing 18% deodorized fish oil supplemented with tocopherol and tert-butylhydroquinone antioxidants (FAO). Primary tumor growth rate was significantly greater in mice fed the 18% CO diet than in the three diets containing higher levels of fish oil (all p < 0.05). The 18% MO diet, but not the 11.5% MO or the 18% FAO diet, suppressed the development of lung metastases compared with the 18% CO diet. Increasing the proportion of MO relative to CO in the diets produced corresponding increases in the primary tumor phospholipid eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations and reductions in LA and arachidonic acid. There was a significant positive correlation between the LA concentration in these tumors and the extent of lung metastasis (r = 0.504). Tumor phospholipase A2 activity was unaffected by dietary MO intake. Prostaglandin E2 concentration was inversely correlated with phospholipid EPA (r = -0.484) and DHA (r = -0.439), but there was no relationship with lung metastasis. Tumor leukotriene B4 and 5-hydroxyeicosatetraenoic acid levels were not reduced by dietary MO. The 18% FAO- and the 18% MO-fed mice showed similar relationships for the phospholipid fatty acids and prostaglandin E2, despite the lack of effect on metastasis. The strong correlation between phospholipid LA levels and metastasis and the lack of an association with tumor eicosanoids suggest that the 18% MO diet inhibited metastasis because dietary LA was replaced by other fatty acids.

Temporomandibular joint axiography and MRI findings: a comparative study.

Axiography may be useful in the evaluation of condyle motion and the effects of internal derangements on this motion. Fifty-one patients were selected by one investigator (RHT) to provide a representative sample of asymptomatic and symptomatic subjects for the following categories: (1) normal disk position, (2) disk displacement with reduction, (3) disk displacement without reduction and (4) disk displacement without reduction associated with degenerative joint disease. Axiography was performed by a separate investigator (KGP) in a blinded fashion. The diagnosis of the presence of internal derangement was based on the tracings only. All subjects had bilateral magnetic resonance imaging scans to evaluate for the presence or absence of internal derangement. The diagnostic sensitivity was 0.64, which indicated that axiography is marginal at identifying disease when present. The negative predictive value was 0.78, which indicated that axiography is accurate in the detection of normal disk condyle relationship.

Effect of diets containing different levels of linoleic acid on human breast cancer growth and lung metastasis in nude mice.

The purpose of the study was to determine the effect of three different levels of dietary linoleic acid (LA) intake on the growth of MDA-MB-435 human breast cancer cells in the mammary fat pads of nude mice, and their metastasis to the lungs. These diets were isocaloric, and contained different mixtures of safflower (LA-rich) and coconut (saturated fatty acid-rich) oils to provide 23% (w/w) total fat, with 2, 8, and 12% (w/w) LA. A fourth group was fed a low-fat, 5% (w/w) corn oil diet. There were 25 mice in each dietary group. A necropsy, 12 weeks after the tumor cell injections, the primary tumor weights in the 12% LA (4.1 +/- 2.7 g)- and 8% LA (3.5 +/- 1.7 g)-fed groups were significantly greater (P < 0.05) than those fed the 2% LA diet (2.5 +/- 1.5 g); they did not differ significantly from the weights of mammary fat pad tumors in the 5% corn oil-fed mice. The incidence of grossly visible pulmonary metastatic nodules was not significantly different between the 8 and 12% LA-fed mice, but was higher for both groups compared with the 2% LA-fed group (P < 0.05), with a similar trend in comparison with the 5% corn oil group. The mean total calculated volumes of the macroscopic metastases per tumor-bearing mouse were significantly greater in the 8 and 12% LA (157 +/- 250.7 and 99.1 +/- 140.0 mm3, respectively), compared with the 2% LA (23.3 +/- 51.8 mm3)- and 5% corn oil (24.5 +/- 35.1 mm3)-fed mice; all P < 0.05. Micrometastases were observed most frequently in the 5% corn oil and 2% LA dietary groups, but none of the differences were statistically significant. No differences were detected in the concentrations of prostaglandin E, leukotriene B4, or 5-hydroxyeicosatetraenoic acid in tumors from mice fed the four different diets.

Characterization of phospholipase A2 activity in MDA-MB-435 human breast cancer cells.

Phospholipase A2 (PLA2) was identified and its properties characterized in MDA-MB-435 cells, a human breast cancer cell line. Cytosolic fractions, prepared in calcium-free buffer, were assayed using arachidonyl-containing phosphatidylcholine as substrate. PLA2 activity was linear as a function of both time and protein concentration. The enzyme was shown to be calcium-dependent and to require a basic pH of 9.5-10.0 for optimal activity. Activity was predominantly found in the cytosolic fraction when cells were harvested in calcium-free buffer. Phospholipase A2 may play a key role in linoleic acid-enhanced mammary tumorigenesis and metastasis.

Temporomandibular joint sounds in asymptomatic volunteers.

Abnormalities within the temporomandibular joints often produce audible sounds. Electronic recording of joint sounds has been used as a method of staging internal derangement. This study had three objectives: first, to determine whether the characterization of temporomandibular sounds can provide a sensitive and accurate measure for the presence or absence of joint abnormalities in asymptomatic volunteers; second, to evaluate the reproducibility of the sounds, when present, with successive recordings; and third, to evaluate the sound characteristics to determine their predictability for the types of internal derangement. Fifty asymptomatic volunteers (100 joints) were evaluated with an electronic device for the presence of joint sounds. Of the patients, 24% (N = 50, five men and seven women) (16% of all joints) had one or two abnormal joints as diagnosed by magnetic resonance imaging. Forty-four percent of all joints had identifiable sounds; 50% of the sounds were produced when the condyle was located at the apex of the articular eminence. Sounds often occurred in the early opening phase of jaw movement in joints diagnosed as normal by magnetic resonance imaging. Finally, the characteristics of these events did not produce adequate separation to stage the internal derangement.

Na,K-ATPase in several tissues of the rat: tissue-specific expression of subunit mRNAs and enzyme activity.

The relative contents of Na,K-ATPase subunit mRNAs in rat renal cortex, ventricular myocardium, skeletal muscle (hind limb), liver and brain (cerebrum) were measured. Expressed per unit DNA, mRNA alpha 1 content was approximately 2-fold greater in the kidney and brain as compared to either heart, skeletal muscle or liver. The hierarchy of mRNA alpha 2 expression was brain > skeletal muscle > heart, whereas mRNA alpha 3 was restricted to brain. Beta 1 subunit mRNA content in both kidney and brain exceeded the abundance of liver mRNA beta 1 by approximately 7-fold. In all tissues examined, the combined abundances of the alpha subunit mRNAs exceeded the content of mRNA beta 1. The hierarchy of Na,K-ATPase activity expressed per unit DNA was brain > kidney > skeletal muscle = heart > liver. The sum of mRNA alpha as well as mRNA beta 1 content, expressed per g of tissue, was highest in brain and kidney. A statistically significant correlation between mRNA beta 1 content and Na,K-ATPase activity was evident.

Accuracy of clinical diagnosis for TMJ internal derangement and arthrosis.

This study investigated the accuracy of clinical examination in determining the status of the temporomandibular joint with respect to internal derangement and arthrosis. A series of 110 patients was given standard clinical examinations followed by bilateral imaging with arthrography and/or magnetic resonance imaging. There was agreement between the clinical diagnosis and the imaging finding in 95 joints (43%). In the other 125 joints (57%), the clinical diagnosis did not agree with imaging findings. There were false-positive clinical diagnoses in 39 joints and false-negative clinical diagnoses in 31 joints. In the other 55 joints the clinical diagnosis correctly indicated that the joint was abnormal but was incorrect about the stage of abnormality. On the basis of the overall diagnostic accuracy of 43%, it was concluded that a clinical examination is not reliable for determining the status of the joint in patients with signs and symptoms of temporomandibular joint internal derangement.

Prevalence of temporomandibular joint internal derangement in patients with craniomandibular disorders.

To determine the prevalence of temporomandibular joint internal derangement in patients with signs and symptoms of craniomandibular disorders, bilateral imaging was performed in a consecutive series of 115 patients with signs and symptoms of craniomandibular disorders. Ninety patients (78%) had different stages of unilateral or bilateral internal derangement, and 25 patients (22%) had normal temporomandibular joints bilaterally. Out of 230 joints, 60 showed disk displacement with reduction, 8 showed disk displacement without reduction, and 29 showed disk displacement without reduction associated with anthrosis. The study indicates that almost 80% of patients with signs and symptoms of craniomandibular disorders have different forms of internal derangement.

Temporomandibular joint sounds: correlation to joint structure in fresh autopsy specimens.

In an attempt to better understand the cause of different types of temporomandibular joint (TMJ) sounds, we recorded joint sounds from 27 fresh autopsy specimens, displayed the time frequency distribution of the sound as a three-dimensional graph, and correlated the sound character to morphologic observations at subsequent dissection. Eleven joints elicited sounds, and 16 joints were silent. All joints with sounds had different degrees of intraarticular changes. These ranged from disk displacement with reduction to displacement without reduction and arthrosis of the articular surfaces. Reciprocal clicking occurred both in joints with disk displacement with and without reduction, as well as in joints with arthrotic changes. Crepitation only occurred in joints with arthrosis and perforation. The sample was too small to demonstrate any statistically significant association between the joint sound classified as clicking or crepitation and joint structure types of joint pathosis in this small sample. A high frequency component to the sound appeared to be associated with arthrosis of the articular surfaces. It was concluded that joint sounds indicate joint abnormality but that the absence of joint sound does not exclude intraarticular pathosis.

Temporomandibular joint: improved MR image quality with decreased section thickness.

To determine if the quality of spin-echo magnetic resonance (MR) images of the temporomandibular joint (TMJ) could be improved by reducing section thickness, coronal and sagittal 3.0- and 1.5-mm MR images of the same joints were evaluated. Depiction of the disk, trabecular pattern, and cortex of the condyle was better on coronal 1.5-mm images than on 3.0-mm images (P less than .01), and 1.5-mm sagittal images were better for depiction of the trabecular pattern of the condyle than were 3.0-mm images (P less than .05). The ability of MR imaging with thinner sections to reveal more anatomic details should result in improved diagnostic accuracy.

Increased horizontal angle of the mandibular condyle in abnormal temporomandibular joints. A magnetic resonance imaging study.

The horizontal condylar angle was measured in axial magnetic resonance images of normal and abnormal temporomandibular joints (TMJs). The average condylar angle in the normal joints was 21.2 degrees. In joints with disk displacement with reduction it was 29.7 degrees; joints with disk displacement without reduction, 33.5 degrees; and in joints with degenerative joint disease, 36.5 degrees. There were statistically significant differences between all four groups. Thus the condylar angle seemed to be increasingly larger with more advanced pathologic changes related to internal derangement and degenerative disease in the joint. The reason for the larger condylar angle in the abnormal joint was unclear. Joints with a larger condylar angle might have a greater tendency for internal derangement and degenerative joint disease to develop. Another possible explanation could be that remodeling associated with internal derangement and degenerative joint disease might result in a larger condylar angle. Further studies with longitudinal observations are needed to determine whether a causal relationship exists between the changes of the joint and a large condylar angle.

Biological thiols elicit prolactin proteolysis by glandular kallikrein and permit regulation by biochemical pathways linked to redox control.

Rat glandular kallikrein (GK), a trypsin-like serine protease, cleaves rat prolactin (PRL) in vitro to novel forms detectable in vivo and likely to be of physiological significance. PRL proteolysis by GK is thiol-dependent, with thiols acting upon PRL to refold the molecule into novel conformations that are GK substrates. This study compared several natural and synthetic thiols for their ability to elicit PRL proteolysis by GK. Rat PRL was incubated with rat GK in the presence of various thiols and 0.5% Triton X-100, which enhances thiol-elicited proteolysis. Cleavage was analyzed by gel electrophoresis under reducing and nonreducing conditions. In the presence of Triton X-100, all low molecular weight thiols elicited PRL cleavage by GK. The order of potency was dithiothreitol greater than mercaptoethanol greater than lipoic acid greater than cysteamine = glutathione (GSH) = coenzyme A greater than cysteine. In the absence of Triton, however, dithiothreitol, coenzyme A, and mercaptoethanol were most effective in eliciting GK proteolysis. Triton X-100 enhanced PRL cleavage by 4-19-fold, depending upon the thiol used. Folding isomers of processed PRL observed following cleavage included disulfide-liked homodimers, oxidized monomers, reduced monomers and mixed disulfides; the folding isomers generated varied depending upon the thiol used. GSH potency in eliciting PRL proteolysis increased 10-fold in the presence of biochemical pathways shuttling reducing equivalents to GSH disulfide (GSSG). PRL cleavage by GK could be controlled by substrates, enzymes, and cofactors making up the reducing shuttle when GSSG was used. Thioredoxin (a protein disulfide oxidoreductase) potently elicited PRL proteolysis by GK in the presence of a reducing shuttle and Triton X-100.(ABSTRACT TRUNCATED AT 250 WORDS)

[Unasyn in severe hospital infections]. / Unasyn u tezkých nemocnicních infekcí.

A total 16 patients with moderate and serious surgical and urogenital infections were treated intravenously with the Unasyn IM/IV inj., combination of ampicillin and sulbactam, which is a beta-lactamase inhibitor. In this combination, sulbactam saves the ampicillin against the effects of beta-lactamases and extends the susceptibility to ampicillin of previously ampicillin-resistant strains. Clinical cure was observed in 69% of the patients, improvement in 19%, and failure in 12%. Microbiological elimination was proved in 50% of the patients, persistence in 6%, a in the rest of the patients (44%) were microbiological response unevaluable. The evaluation of subjective and objective tolerance of Unasyn IM/IV inj. was excellent. It follows from this study that the combination of ampicillin with sulbactam can be considered an effective and safe treatment of nosocomial infections, especially in the departments with an increasing rate of ampicillin-resistant strains due to production of the beta-lactamases.