Positive groin lymph nodes in superficial squamous cell vulvar cancer. A Gynecologic Oncology Group Study

The term microinvasive carcinoma is inappropriate when applied to all vulvar cancers less than or equal to 5 mm thick because approximately 50% of vulvar carcinomas are no thicker than 5 mm and 20% of those superficial tumors metastasize to the lymph nodes. The significant predictors of groin node metastases in patients with superficial vulvar cancer are tumor thickness, histologic grade (proportion of undifferentiated tumor pattern), capillary-like space involvement with the tumor, clitoral or perineal location, and clinically suspicious nodes, according to the linear logistic model analysis of clinicopathologic data in 272 women. No lymph node metastases occurred in approximately one fourth of patients with a combination of low-risk factors: no clinically suspicious nodes, negative capillary-like space, and nonmidline vulvar cancers that were either grade 1 and 1 to 5 mm thick or grade 2 and 1 to 2 mm thick. In contrast, all 10 patients with clinically suspicious nodes and grade 4 tumors had positive groin nodes. The risk of lymph node metastases is best determined by simultaneous evaluation of all risk factors rather than a single factor such as tumor thickness.

Ferritin assay in malignant pleural effusion

In order to assess the usefulness of ferritin as a tumor marker, the authors measured and analyzed pleural fluid and serum ferritin concentrations by double antibody radioimmunoassay method in 20 patients with malignant pleural effusion, and in 39 patients with benign pleural effusion. Serum ferritin levels were also measured in a control group of 20 healthy people.

The results obtained are summarized as follows: 1) Pleural fluid ferritin levels in the malignant pleural effusion group were significantly higher (p<0.001) than those of the benign pleural effusion group. 2) As one of the criteria in differentiating between malignant and benign pleural effusion, the differentiating pleural fluid ferritin level was set at 2,000 ng/ml, a specificity up to 75.0% and sensitivity of 89.7% could be obtained. 3) Serum ferritin levels in the malignant pleural effusion group were significantly higher (p<0.001) than those in the control group. 4) There was no statistically significant correlation between pleural fluid and serum ferritin levels in the malignant pleural effusion group.

From the above results, it can be concluded that it is possible to use pleural fluid ferritin levels as a tumor marker.

Agonist-induced muscarinic acetylcholine receptor down-regulation in intact rat brain cells

Intact brain cells were prepared by dissociating whole adult rat brains without the cerebellum using a sieving technique. It has been found that preincubation of these cells with the muscarinic acetylcholine receptor agonist, carbamylcholine, results in a significant reduction in the specific binding of [3H]N-methylscopolamine to the receptors after the agonist was washed away. This agonist-mediated receptor down-regulation increased with prolongation of the exposure period to the agonist, and a steady state was achieved after 3 h at 37 degrees C. This effect of agonist was concentration-dependent, reaching a 30-35% decline in subsequent ligand binding upon preincubation with 1 mM carbamylcholine for 3 h. Carbamylcholine-induced receptor down-regulation was not apparent when exposure to the agonist was performed at 15 degrees C. In addition, it was abolished when the receptors were blocked by atropine. The decline in [3H]N-methylscopolamine binding induced by agonist was reflected as a significant reduction in the receptor density with no change in receptor affinity, suggesting that 'true' receptor down-regulation takes place. Moreover, when the receptors were labeled with the lipophilic antagonist [3H]quinuclidinyl benzilate instead of the hydrophilic ligand [3H]N-methylscopolamine, the magnitude of the observed receptor down-regulation was significantly lower in case of the former than the latter. This suggests that exposure of intact brain cells to muscarinic agonists might induce a slight degree of accumulation of receptors in intracellular sites before the receptors are actually degraded. These results are discussed in relation to previous findings regarding muscarinic receptor regulation in clonal cell lines.

Studies with chymotrypsin and RNAase showing a heterooligomeric structure of the glucocorticoid receptor complex from rat liver which is stabilized by a low molecular weight factor

The glucocorticoid receptor from rat liver displays a differential sensitivity toward digestion by chymotrypsin and RNAase A that is dependent on its activation state. Unactivated (9-10 S) receptor is not digested by these enzymes, while activated 7-8 S receptor is. Chymotrypsin treatment yields an approx. 3 S form, while RNAase treatment yields a 4.9 S form that is distinct from the high-salt 4 S form. To firmly establish that the results are due to specific hydrolytic activities of the particular enzymes, we show that the chymotrypsin effect is inhibited by diisopropylfluorophosphate and not RNAasin, while the reverse is true for RNAase A. We further show that the differential sensitivity toward chymotrypsin is due to the association of a proteinase-resistant, heat-stable low molecular weight factor with the unactivated glucocorticoid receptor. When this factor is removed by warming, dialysis or molecular sieving of the receptor complex, the complex becomes sensitive to chymotrypsin. We also show that moderate chymotrypsin treatment yields a 6-7 S form of the receptor which is composed of, at least, RNA and the 4 S receptor. On the basis of these results, we propose that the 9-10 S receptor is composed of a low molecular weight stabilizing factor whose presence apparently alters the conformation of the complex such that the RNA and the RNA-binding site of the receptor are protected, a chymotrypsin-sensitive factor, RNA and the 4 S receptor itself.

Myocardial Na, K-ATPase in one-kidney, one-clip hypertensive rats

Myocardial ventricular Na, K-ATPase activity of normotensive rats was compared with that of healthy rats with chronic benign one-kidney, one-clip hypertension. The yield of protein (mg/g wet wt left plus right ventricles) in microsomal and sarcolemmal membrane fractions was the same for both normotensive and hypertensive rat ventricles. However, the yield of protein (mg/ventricle) was 26% greater in the hypertensive relative to the normotensive animals, consistent with the presence of hypertrophy, as also indicated by an increase in the ratio of ventricular to body weight and a shift in the isomyosin composition. Na, K-ATPase activity, sodium-dependent phosphorylation and ouabain binding were significantly (P less than 0.05) decreased (by 20%, 40%, and 45%, respectively) in the hypertensive rat ventricles when the data were expressed in units/g tissue wet weight. However, when expressed in units per ventricle, values in normotensive and hypertensive animals were similar. The molecular activity or turnover number of ventricular (and also renal) Na, K-ATPase activity was the same in both groups of animals. These results suggest that the decrease in myocardial specific Na, K-ATPase activity in the rat made hypertensive by removing one kidney and constricting the renal artery of the other kidney is related to the presence of cardiac hypertrophy.

Endobronchial tuberculosis: clinical and bronchofiberscopic features

The clinical and bronchofiberscopic features of endobronchial tuberculosis in 53 patients were investigated. These patients comprised 4.7% of some 1,132 subjects who had undergone flexible bronchofiberscopic examinations. The peak incidence occurred in the third and fourth decades, a secondary peak appeared in the seventh decade, a five to six times higher incidence was noted in the female than in the male. Staining for acid-fast bacilli was positive in 67.9% of the patients sputums and or specimens of bronchial washings. A barking cough was the most common chief complaint. Next in order were chest pain, production of mucus, dyspnea, hemoptysis, and fever. Twenty-three out of 53 patients showed abnormalities on their chest films.

The flexible bronchoscope revealed tuberculous lesions characterized by mucosal swelling or edema, redness, erosion, ulceration, hypertrophy with luminal narrowing, and cicartical stenosis due to whitish pseudomembrane. The left lower and upper bronchi were involved most frequently.

The majority of the patients who were suffering from a barking cough were resistant to antitussive agents but were responsive to steroid combination chemotherapy with antituberculous drugs.

In conclusion, the bronchofiberscopic approach is not only helpful in the differentiation of endobronchial tuberculosis from bronchogenic cancer but it can also be used for relieving atelectasis.

Covalent linking of poly(ethyleneglycol)-bound NAD with Thermus thermophilus malate dehydrogenase. NAD(H)-regeneration unit for a coupled second-enzyme reaction

Poly(ethyleneglycol)-bound NAD (PEG-NAD) was covalently linked to Thermus thermophilus malate dehydrogenase with a bifunctional reagent, 3,3'-(1,6-dioxo-1,6-hexanediyl)bis-2-thiazolidinethione. The covalently linked malate-dehydrogenase--PEG--NAD complex (MDH-PEG-NAD) was purified by DEAE-Sephadex column chromatography to remove unbound PEG-NAD, and fractionated by blue-Sepharose column chromatography into four preparations: MDH-PEG-NAD I, MDH-PEG-NAD II, MDH-PEG-NAD III and MDH-PEG-NAD IV. The average numbers of NAD moieties covalently bound per subunit of MDH-PEG-NAD I, MDH-PEG-NAD II, MDH-PEG-NAD III and MDH-PEG-NAD IV were 1.2, 1.2, 0.8 and 0.5, respectively, and the values were confirmed by sodium dodecyl sulfate/polyacrylamide gel electrophoresis. 60-80% bound NAD moiety of these preparations of MDH-PEG-NAD was reduced by the enzyme moiety in the presence of L-malate, and the specific activity of the enzyme moiety of the preparations was more than 80% that of the native enzyme. MDH-PEG-NAD I has the following properties. The Km value for exogenous NAD is three times that of the native enzyme. The coenzyme activity of its NAD moiety is 20-40% that of native NAD for alcohol and lactate dehydrogenases. The complex catalyzes the oxidation of L-malate in the presence of the redox system of 5-ethylphenazinium ethyl sulfate and a tetrazolium salt with a rate constant of 0.11 s-1. The coenzyme moiety of the complex can also be recycled by coupled reactions of the active site of the same complex and alcohol dehydrogenase. These results indicate that MDH-PEG-NAD works as an NAD(H)-regeneration unit for coupled reactions.

New poly(A)+RNAs appear coordinately during the differentiation of Naegleria gruberi amebae into flagellates

We have examined the nature of the requirement for RNA synthesis during the differentiation of Naegleria gruberi amebae into flagellates (Fulton, C., and C. Walsh, 1980, J. Cell Biol., 85:346-360) by looking for poly(A)+RNAs that are specific to differentiating cells. A cDNA library prepared from poly(A)+RNA extracted from cells 40 min after initiation of the differentiation (40-min RNA), the time when formation of flagella becomes insensitive to inhibitors of RNA synthesis, was cloned into pBR322. Recombinant clones were screened for sequences that were complementary to 40-min RNA but not to RNA from amebae (0-min RNA). Ten of these differentiation-specific (DS) plasmids were identified. The DS plasmids were found to represent at least four different poly(A)+RNAs based on cross-hybridization, restriction mapping, and Northern blot analysis. Dot blot analysis was used to quantify changes in DS RNA concentration. The four DS RNAs appeared coordinately during the differentiation. They were first detectable at 10-15 min after initiation, reached a peak at 70 min as flagella formed, and then declined to low levels by 120 min when flagella reached full length. The concentration of the DS RNAs was found to be at least 20-fold higher in cells at 70 min than in amebae. The changes in DS RNA concentration closely parallel changes in tubulin mRNA as measured by in vitro translation (Lai, E.Y., C. Walsh, D. Wardell, and C. Fulton, 1979, Cell, 17:867-878).

Mutations resulting in promoter-like sequences which enhance the expression of araC in Salmonella typhimurium

The araC gene in Salmonella typhimurium is autogeneously regulated. Nine non-self-regulated mutants were isolated by selecting for increased expression of an araC-lacZ fusion in the presence of a repressing AraC protein. S1 mapping experiments demonstrated that the effect of the mutations was to increase the amount of araC mRNA in the cell. The 5'-end of the major araC transcript was the same in the wild-type (wt) and mutant strains. DNA sequence analysis showed that all nine mutations occurred in the araC promoter. Two mutations were a G-to-T transversion at position -25, six were a G-to-T transversion at position -47 and one was a single bp deletion at position -83. The data suggest that the mutations have created a new RNA polymerase binding site which enhances transcription from the wt start point.

[3H]N-Methylscopolamine binding to muscarinic receptors in intact adult rat brain cell aggregates

Intact brain cell aggregates were dissociated from adult rat brains, by a simple sieving technique, and were used to study the binding characteristics of [3H]N-methylscopolamine to muscarinic acetylcholine receptors. The magnitude of binding of this ligand was related linearly to the amount of cell protein in the binding assay, with a high ratio of total to nonspecific binding. In addition, specific binding showed saturability and high affinity. Muscarinic receptor antagonists displaced specific [3H]N-methylscopolamine binding according to the law of mass-action, while it was possible to resolve displacement curves using receptor agonists into high- and low-affinity components. The results are discussed in terms of the usefulness of dissociated intact rat brain cells in studying muscarinic acetylcholine receptors in the central nervous system.

Characterization of corticosteroid receptors in natural killer cells: comparison with circulating lymphoid and myeloid cells

Lymphocytes mediating natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC) activities are relatively refractory to the changes in circulatory traffic and intrinsic function induced in other cell types by in vivo and in vitro corticosteroids (CS). To investigate if such drug resistance could be attributed to differences in the CS receptor number of affinity (Kd) of these cells, these characteristics were determined in purified populations of large granular lymphocytes (LGL), monocytes, neutrophils (PMN), and T cells. All cell types displayed a single class of CS receptor of uniform affinity; however, LGL resembled monocytes and PMN in receptor number and Kd while T cells had significantly fewer sites per cell with lower Kd. These studies suggest that the unresponsiveness of NK activity to CS is not secondary to differences in CS receptor capacity or affinity.

Chymotrypsin treatment of glucocorticoid receptor attenuates RNA-dependent inhibition of DNA binding. Evidence for a distinct RNA-binding site

Certain types of RNA can prevent the association of the rat liver glucocorticoid receptor with DNA. This inhibition of receptor binding to DNA cannot be mitigated by increasing amounts of DNA, suggesting that the RNA is not merely acting as a competitive inhibitor. Treatment of partially purified receptor with low concentrations of chymotrypsin eliminates the inhibitory effects of some RNAs without negatively affecting the DNA-binding ability of the receptor. Potent inhibitors of the receptor-DNA association, such as poly(G) and poly(X), still inhibit DNA binding of the treated receptor, although to a lesser extent than the untreated controls. However, moderate inhibitors, such as tRNA and poly(U), no longer inhibit the receptor-DNA association at low concentrations. We take these findings to suggest that RNA inhibition of DNA binding is due to the interaction of the RNA at a distinct RNA-binding site. This site may serve as a regulator site for the receptor-DNA association.

Use of intact rat brain cells as a model to study regulation of muscarinic acetylcholine receptors

Intact rat brain cells were dissociated and used to study the regulation of muscarinic acetylcholine receptors upon exposure to muscarinic receptor agonists. Incubation of cells with carbamylcholine resulted in a time-dependent decrease in subsequent [3H]N-methylscopolamine specific binding, an effect which reached a steady state after 3 hr at 37 degrees C. This effect of carbamylcholine was dependent on the concentration of the agonist in the incubation medium and was due to a reduction in the maximal binding capacity of the receptor with no decrease in the affinity of the remaining receptors. This preparation might be useful in future studies to elucidate the mechanisms underlying the regulation of muscarinic acetylcholine receptors in the central nervous system.

Crystallization and preliminary x-ray investigation of the regulatory subunit of cAMP-dependent protein kinase

Crystals of type I cAMP-dependent protein kinase regulatory subunit have been grown from solutions of ammonium sulfate. The crystals are square bipyramids, space group P4(1)2(1)2 (P4(3)2(1)2), with a = b = 106.9 +/- 0.6 A and c = 212.4 +/- 1.0 A. There are two dimers of the regulatory subunit/crystallographic asymmetric unit. The crystals are stable for 3-4 days in the x-ray beam and diffract to at least 3.5-A resolution.

Heterogeneity of binding of muscarinic receptor antagonists in rat brain homogenates

The binding properties of (-)-[3H]quinuclidinyl benzilate and [3H] N-methylscopolamine to muscarinic acetylcholine receptors have been investigated in rat brain homogenates. The binding of both antagonists demonstrated high affinity and saturability. Analysis of the binding data resulted in linear Scatchard plots. However, (-)-[3H]quinuclidinyl benzilate showed a significantly higher maximal binding capacity than that of [3H]N-methylscopolamine. Displacement of both ligands with several muscarinic receptor antagonists resulted in competition curves in accordance with the law of mass-action for quinuclidinyl benzilate, atropine and scopolamine. A similar profile was found for the quaternary ammonium analogs of atropine and scopolamine when [3H]N-methylscopolamine was used to label the receptors. However, when these hydrophilic antagonists were used to displace (-)-[3H] quinuclidinyl benzilate binding, they showed interaction with high- and low-affinity binding sites. On the other hand, the nonclassical muscarinic receptor antagonist, pirenzepine, was able to displace both ligands from two binding sites. The present data are discussed in terms of the relationship of this anomalous heterogenity of binding of these hydrophilic muscarinic receptor antagonists and the proposed M1 and M2 receptor subtypes.

Anomalous binding of [3H]N-methylscopolamine to rat brain muscarinic receptors

In the present studies, we investigated the binding properties of [3H]quinuclidinyl benzilate ([3H]QNB) and [3H]N-methylscopolamine ([3H]NMS) to muscarinic acetylcholine receptors (mAChR) in rat brain homogenates. Our results indicate that the hydrophilic receptor ligand, [3H]NMS, is able to interact with high affinity only with a fraction of the receptor sites available to the lipophilic ligand, [3H]QNB. Furthermore, displacement experiments demonstrated that while both unlabeled QNB and NMS displaced [3H]NMS binding according to the law of mass-action, NMS, but not QNB, displayed binding heterogeneity when [3H]QNB was used as a ligand. Our data suggest that the lipid solubility of a particular mAChR ligand might play an important role in determining its profile of binding to the receptor.

Isolation and characterization of mutant strains of Escherichia coli altered in H2 metabolism

A positive selection procedure is described for the isolation of hydrogenase-defective mutant strains of Escherichia coli. Mutant strains isolated by this procedure can be divided into two major classes. Class I mutants produced hydrogenase activity (determined by using a tritium-exchange assay) and formate hydrogenlyase activity but lacked the ability to reduce benzyl viologen or fumarate with H2 as the electron donor. Class II mutants failed to produce active hydrogenase and hydrogenase-dependent activities. All the mutant strains produced detectable levels of formate dehydrogenase-1 and -2 and fumarate reductase. The mutation in class I mutants mapped near 65 min of the E. coli chromosome, whereas the mutation in class II mutants mapped between srl and cys operons (58 and 59 min, respectively) in the genome. The class II Hyd mutants can be further subdivided into two groups (hydA and hydB) based on the cotransduction characteristics with cys and srl. These results indicate that there are two hyd operons and one hup operon in the E. coli chromosome. The two hyd operons are needed for the production of active hydrogenase, and all three are essential for hydrogen-dependent growth of the cell.