Intermediate filament networks: organization and possible functions of a diverse group of cytoskeletal elements

Immunofluorescence and electron microscopic observations demonstrate that intermediate filaments (IF) form cytoplasmic networks between the nucleus and cell surface in several types of cultured cells. Intermediate filaments interact with the nuclear surface, where they appear to terminate at the level of the nuclear envelope. From this region, they radiate towards the cell surface where they are closely associated with the plasma membrane. On the basis of these patterns of IF organization, we suggest that IF represent a cytoskeletal system interconnecting the cell surface with the nucleus. Furthermore, IF also appear to interact with other cytoskeletal components including microtubules and microfilaments. In the former case microtubule-IF interactions are seen in cytoplasmic regions between the nucleus and the cell membrane, whereas microfilament-IF interactions occur in the cortical cytoplasm. IF also appear to be cross-linked to each other; especially in the case of the IF bundles that occur in epithelial cells. In order to determine the molecular and biochemical bases of the organizational state of IF we have developed procedures for obtaining IF-enriched 'cytoskeletons' of cultured cells. In these preparations IF-nuclear and IF-cell surface associations are retained. Thus, these preparations have enabled us to begin to study various IF-associated structures (e.g. desmosomes) and associated proteins (IFAPs) using biochemical and immunological methodologies. To date, the results support the idea that IF and their associated proteins may comprise the cell type specific molecular infrastructure that is involved in transmitting and distributing information amongst the major cellular domains; the cell surface/extracellular matrix, the cytoplasm and the nuclear surface/nuclear matrix.

Is the hemidesmosome a half desmosome? An immunological comparison of mammalian desmosomes and hemidesmosomes

Although the mammalian epidermal basal cell hemidesmosome bears some superficial resemblance to one half of a desmosome at the ultrastructural level, examination of the structure of the electron-dense submembranous plaques of the hemidesmosome and desmosome reveals that they differ with respect to their overall morphology and dimensions. Based on these findings, we wondered whether components of the desmosome are present in the hemidesmosome. In order to determine this we prepared a number of stratified squamous epithelial tissues for indirect immunofluorescence using antibody preparations directed against known desmosome components including desmoplakin and certain glycoproteins. These antibody preparations do not show reaction with hemidesmosomes by indirect immunofluorescence criteria. We have also utilized bullous pemphigoid (BP) autoantibodies that have been shown to recognize hemidesmosomes in mammalian skin cells [Mutasim et al., J. Invest. Derm., 84:47-53, 1985]. Double label indirect immunofluorescence observations of neonatal mouse skin prepared using desmoplakin antibodies and BP autoantibodies reveal that hemidesmosomes that are stained by the BP autoantibodies are not recognized by the desmoplakin antibodies. We confirmed these findings at the ultrastructural level by indirect immunogold localization of desmoplakin antibodies and BP autoantibodies. Therefore, the hemidesmosome does not appear to be one half of a desmosome and may possess a very different molecular organization relative to the desmosome. We raise the possibility that the variability between the hemidesmosome and desmosome that we detect at the morphological and immunological level may reflect the functional differences of these two types of junctions.

Intermediate filaments and the initiation of desmosome assembly

The desmosome junction is an important component in the cohesion of epithelial cells, especially epidermal keratinocytes. To gain insight into the structure and function of desmosomes, their morphogenesis has been studied in a primary mouse epidermal (PME) cell culture system. When these cells are grown in approximately 0.1 mM Ca2+, they contain no desmosomes. They are induced to form desmosomes when the Ca2+ level in the culture medium is raised to approximately 1.2 mM Ca2+. PME cells in medium containing low levels of Ca2+, and then processed for indirect immunofluorescence using antibodies directed against desmoplakins (desmosomal plaque proteins), display a pattern of discrete fluorescent spots concentrated mainly in the perinuclear region. Double label immunofluorescence using keratin and desmoplakin antibodies reveals that the desmoplakin-containing spots and the cytoplasmic network of tonofibrils (bundles of intermediate filaments [IFB]) are in the same juxtanuclear region. Within 1 h after the switch to higher levels of Ca2+, the spots move toward the cell surface, primarily to areas of cell-cell contact and not to free cell surfaces. This reorganization occurs at the same time that tonofibrils also move toward cell surfaces in contact with neighboring cells. Once the desmoplakin spots have reached the cell surface, they appear to aggregate to form desmosomes. These immunofluorescence observations have been confirmed by immunogold ultrastructural localization. Preliminary biochemical and immunological studies indicate that desmoplakin appears in whole cell protein extracts and in Triton high salt insoluble residues (i.e., cytoskeletal preparations consisting primarily of IFB) prepared from PME cells maintained in medium containing both low and normal Ca2+ levels. These findings show that certain desmosome components are preformed in the cytoplasm of PME cells. These components undergo a dramatic reorganization, which parallels the changes in IFB redistribution, upon induction of desmosome formation. The reorganization depends upon both the extracellular Ca2+ level and the establishment of cell-to-cell contacts. Furthermore, the data suggests that desmosomes do not act as organizing centers for the elaboration of IFB. Indeed, we postulate that the movement of IFB and preformed desmosomal components to the cell surface is an important initiating event in desmosome morphogenesis.

Mononuclear leucocyte intracellular free calcium--does it correlate with blood pressure?

Abnormalities of calcium binding and calcium transport in cells from hypertensive subjects or animals have been previously described. Total cell sodium is reported to be increased in white blood cells from hypertensive subjects; thus by analogy with Blaustein's proposal for the vascular smooth muscle cell, mononuclear leucocyte cytosolic calcium might be increased via a reduction of the Na-Ca exchange. Using the fluorescent calcium indicator, quin 2, cytosolic calcium was measured in mononuclear leucocytes from 22 hypertensive and 19 normotensive subjects. There was no significant difference between the mononuclear leucocyte cytosolic calcium level in the two groups. Incubation of the cells with 10(-4) M ouabain reduced 86 rubidium (86Rb) uptake by 80% of the control value but failed to alter cytosolic calcium. These findings are consistent with a minimal role of the Na-Ca exchange in the mononuclear leucocyte and may explain why the cytosolic calcium was not increased in hypertension despite the previous reports of increased total cell sodium in white blood cells.

The organizational fate of intermediate filament networks in two epithelial cell types during mitosis

Intermediate filaments (IF) appear to be attached to the nuclear envelope in various mammalian cell types. The nucleus of mouse keratinocytes is enveloped by a cagelike network of keratin-containing bundles of IF (IFB). This network appears to be continuous with the cytoplasmic IFB system that extends to the cell surface. Electron microscopy reveals that the IFB appear to terminate at the level of the nuclear envelope, frequently in association with nuclear pore complexes (Jones, J. C .R., A. E. Goldman, P. Steinert, S. Yuspa, and R. D. Goldman, 1982, Cell Motility, 2:197-213). Based on these observations of nuclear-IF associations, it is of interest to determine the fate and organizational states of IF during mitosis, a period in the cell cycle when the nuclear envelope disassembles. Immunofluorescence microscopy using a monoclonal keratin antibody and electron microscopy of thin and thick sections of mitotic mouse keratinocytes revealed that the IFB system remained intact as the cells entered mitosis and surrounded the developing mitotic spindle. IFB were close to chromosomes and often associated with chromosome arms. In contrast, in HeLa, a human epithelial cell, keratin-containing IFB appear to dissemble as cells enter mitosis (Franke, W. W., E. Schmid, C. Grund, and B. Geiger, 1982, Cell, 30:103-113). The keratin IFB in mitotic HeLa cells appeared to form amorphous nonfilamentous bodies as determined by electron microscopy. However, in HeLa, another IF system composed primarily of a 55,000-mol-wt protein (frequently termed vimentin) appears to remain morphologically intact throughout mitosis in close association with the mitotic apparatus (Celis, J.E., P.M. Larsen, S.J. Fey, and A. Celis, 1983, J. Cell Biol., 97:1429-34). We propose that the mitotic apparatus in both mouse epidermal cells and in HeLa cells is supported and centered within the cell by IFB networks.

Antiestrogen-cytotoxic chemotherapy and bacillus Calmette-Guerin vaccination in stage II breast cancer: seventy-two-month follow-up

A prospective, randomized clinical trial of adjuvant treatment of 312 stage II breast cancer patients with use of chemotherapy, antiestrogen therapy, and immunotherapy is reported after 72 months of follow-up. The stratification of patients was based on nodal involvement and estrogen receptor (ER) assay of the primary tumors. Findings at 72 months indicate that antiestrogen therapy (tamoxifen, Nolvadex) added to chemotherapy with cyclophosphamide (Cytoxan), methotrexate, and fluorouracil (5-Fluorouracil) (CMF) resulted in significant delayed recurrence in ER-positive postmenopausal patients, ER-positive patients with four or more positive nodes, and ER-positive patients with tumors greater than 3 cm in diameter. The addition of nonspecific immunotherapy with bacillus Calmette-Guerin had no effect on disease-free survival. ER and progesterone receptor measurements in patients with primary breast cancer provide valuable prognostic information on subsequent recurrence and overall survival and should be documented in future clinical trials.

Human autoantibodies against desmosomes: possible causative factors in pemphigus

Pemphigus is a human disease that causes extensive blistering of the skin. This blistering is related to a loss of epidermal cell cohesion and is accompanied by circulating autoantibodies that stain epidermal cell surfaces, as shown by immunofluorescence microscopy. One of the major components involved in epidermal cell cohesion is the desmosome. The pathological changes that accompany pemphigus led us to determine whether the autoantibodies are specific for desmosomes. Incubation of cultured mouse keratinocytes in medium containing pemphigus antiserum leads to cell separation at cell-cell contact sites, which possess desmosomes. Tissue sections of mouse skin processed for indirect immunofluorescence, using pemphigus antiserum or a rabbit antiserum directed against components of desmosomes, show similar punctate cell-surface staining patterns within the epidermis. Cultured mouse keratinocytes possessing well-defined intermediate filament bundles (tonofilaments) and desmosomes were processed for double indirect immunofluorescence, using a monoclonal antibody directed against mouse skin keratin and either pemphigus antiserum or the desmosome antiserum. The keratinocytes exhibit a complex system of keratin-containing tonofilaments. Tonofilaments in contacting cells are separated by thin dark bands at the cell surface, which correspond precisely to desmosomal plaques seen by phase-contrast microscopy. These bands specifically stain with both pemphigus antiserum and the desmosome antiserum. Double indirect immunofluorescence of the cultured mouse keratinocytes, using pemphigus antiserum and the desmosome antiserum, reveals that the pemphigus autoantibodies stain the same areas of cell-cell contact as the desmosome antibodies. Our evidence supports the idea that pemphigus blisters form, at least in part, from a specific antibody-induced disruption of desmosomes in the epidermis.

An investigation into the type of union achieved between cast cores and Wiptam wire posts

The type of union formed between Wiptam wire posts and cast cores has been investigated. Scanning electron microscopy of sectioned 'as cast' specimens showed that the union between Wiptam posts and cast cores was predominantly mechanical in nature. Diffusion studies, however, using an X-ray Microanalysis Unit, revealed that there was evidence of diffusion of silver atoms into the post from the core. This suggests that the bonding between the two components is not merely a simple mechanical lock.

Isolation and characterization of keratin-like proteins from cultured cells with fibroblastic morphology

Intermediate filaments (IF) isolated from a variety of cultured cells, conventionally described as fibroblasts, are composed predominantely of proteins of molecular weights of 54,000 and/or 55,000. Less than 15% of the protein found in native IF preparations from these cells is composed of three to four polypeptides of molecular weights 60,000-70,000. We have investigated some biochemical and immunological properties of these proteins isolated from BHK-21 and mouse 3T3 cells. They are capable of forming paracrystals that exhibit a light/dark banding pattern when negatively stained with uranyl acetate. The dark bands are composed of longitudinally aligned approximately 2-nm-diam filaments. The center-to-center spacing between either dark or light bands is 37-40 nm. These dimensions are consistent with the secondary structure of IF polypeptides and suggest that the dark bands represent lateral alignment of alpha-helical coiled-coil domains. Immunoblotting, secondary structure, as well as amino acid composition data indicate that the 60,000-70,000-mol-wt paracrystal polypeptides are similar to keratin. Thus, polypeptides with biochemical and immunological properties of epidermal keratin are present in cells normally considered to be fibroblasts.

A highly sensitive cytochemical bioassay for plasma angiotensin II

A highly sensitive cytochemical bioassay has been developed for measuring angiotensin II in human plasma. The assay depends on the ability of angiotensin II to alter the reducing potency of the zona glomerulosa as measured by Prussian blue staining and microdensitometry. An inverse correlation between the intensity of the stain and the logarithm of concentration existed over the range 0.05-5.0 fmol/1 of angiotensin II. The limit of sensitivity of the assay in plasma was 50 fmol/1; the index of precision was 0.07 +/- 0.04 (mean +/- SD; n = 15); and the coefficient of variation of a quality control sample was 34%. The response was specific for angiotensin II; approximately 10(2) times more angiotensin III and approximately 10(6) times more ACTH was required to produce a similar effect. Angiotensin I had no significant activity. A significant inverse relationship existed between sodium intake and bioactive angiotensin II in 5 normal subjects studied on low, normal and high sodium diets. Extremely low levels of angiotensin II were detected in anephric subjects.

The role of pseudorabies virus thymidine kinase expression in trigeminal ganglion infection

The role of pseudorabies virus (PRV) thymidine kinase (TK) expression in the pathogenesis of PRV infection of mice was studied with TK-negative (TK-) mutants. Thymidine phosphorylation and arabinosylthymine inhibition of PRV replication and efficiency of plating were used to characterize TK+ and TK- PRV. In addition, a plaque autoradiography procedure was utilized to determine the TK phenotype of individual plaques. TK+ and TK- PRV replicated well in ocular tissues, while TK+ but not TK- did so in ganglion tissue. Mortality was absent after TK- PRV inoculation and widespread after inoculation of similar amounts of TK+ PRV. Latent infection in mice was not detected with either TK+ or TK- PRV. This study indicated the probable importance of PRV TK expression in acute trigeminal ganglion infection.

Genetic linkage and HLA association in congenital adrenal hyperplasia due to 21-hydroxylase deficiency

Twenty-eight families of patients with congenital adrenal hyperplasia due to 21-hydroxylase (21-OH) deficiency were studied to evaluate the specific HLA linkage relationship and HLA antigen association to the 21-OH deficiency gene. Genotype assignment, based on hormonal studies (ACTH stimulation) and HLA genotyping, correlated very well (p less than 0.01) in 23 unaffected sibs of children with 21-OH deficiency further supporting the genetic linkage of the 21-OH deficiency gene to the HLA complex. One family was informative for the placement of the 21-OH deficiency gene outside the HLA complex on the HLA-DR locus side. In this family HLA-A, B, C, DR, MT, MB, and glyoxylase typing and mixed lymphocyte culture was performed. An association of 21-OH deficiency and the HLA-A3 antigen was noted in the 28 families. This association is not secondary to the association of the 21-OH deficiency gene with HLA-BW47.

Adjuvant endocrine therapy, cytotoxic chemotherapy, and immunotherapy in stage-II breast cancer: five-year results

Five-year results of a prospective, randomized clinical trial of three treatment regimes--(a) cytoxan, methotrexate, and 5-fluorouracil (CMF); (b) CMF plus the antiestrogen drug, tamoxifen (CMFT); and (c) CMFT plus bacillus Calmette-Guerin (BCG) vaccinations--in 312 women with stage-II breast cancer are reported. Estrogen receptors (ER) were measured in all of the primary tumors. Addition of tamoxifen to CMF therapy significantly decreased the number of recurrences at five years in ER positive patients with four or more positive axillary lymph nodes. Addition of tamoxifen to CMF had no effect on disease-free survival in ER-positive patients with 1-3 positive axillary lymph nodes or in patients with ER-negative tumors. Addition of BCG vaccinations had no discernible effect on disease-free survival. ER measurements in the primary tumor provide important prognostic information regardless of treatment, with ER-positive patients having lower recurrence rates and mortality after five years. ER measurements also have predictive value for response to endocrine therapy. Further follow-up is needed to determine whether tamoxifen is delaying recurrence or preventing it in a subset of these patients.

Thymidine plaque autoradiography of thymidine kinase-positive and thymidine kinase-negative herpesviruses

Plaques formed by herpes simplex virus (HSV), pseudorabies virus, and varicella-zoster virus were studied by plaque autoradiography after [14C]thymidine labeling. Standard thymidine kinase-positive (TK+) viruses and TK- mutants of HSV types 1 and 2 and pseudorabies virus were studied, including cell cultured viruses and viruses isolated from animals. Autoradiography was performed with X-ray film with an exposure time of 5 days. After development of films, TK+ plaques showed dark rims due to isotope incorporation, whereas TK- plaques were minimally labeled. Plaque autoradiography of stock TK- viruses showed reversion frequencies to the TK+ phenotype of less than 10(-3). Autoradiography indicated that TK- virus retained the TK- phenotype after replication in vivo. In addition, it was shown that TK- HSV could be isolated from mouse trigeminal ganglion tissue after corneal inoculation of TK- HSV together with TK+ HSV. The plaque autoradiographic procedure was very useful to evaluate proportions of TK+ and TK- virus present in TK+-TK- virus mixtures.

Estrogen receptor status as a prognostic indicator for stage I breast cancer patients

The prognostic value of estrogen receptor determination was studied for 510 stage I (axillary node negative) breast cancer patients treated by mastectomy alone. Results at 60 months after mastectomy indicate that stage I patients whose tumors lack estrogen receptors fall into a significantly poorer prognostic group for both recurrence and survival than those whose tumors contain estrogen receptors. Within the postmenopausal group, estrogen receptor negative (ER -) patients are recurring more rapidly than estrogen receptor positive (ER +) patients. Within the premenopausal group, ER + patients have a recurrence rate identical to ER - patients, which is apparent only after prolonged follow-up. In contrast to postmenopausal ER + patients, premenopausal ER + patients appear to have no prognostic advantage over the ER - patients, and thus constitute a high risk group for which adjuvant endocrine therapy might prove beneficial.

Captopril in essential hypertension; contrasting effects of adding hydrochlorothiazide or propranolol

Twenty-four patients with moderate to severe hypertension were treated for four weeks with captopril, an oral inhibitor of angiotensin-converting enzyme. The fall in blood pressure with captopril alone correlated with pretreatment plasma renin activity. The effect of adding either hydrochlorothiazide or propranolol to the captopril treatment was then studied. The addition of hydrochlorothiazide to captopril produced a dose-dependent fall in blood pressure. At the higher dose of the diuretic this fall in blood pressure correlated with weight loss, suggesting that when the diuretic-induced compensatory rise in angiotensin II is prevented by captopril the fall in blood pressure becomes dependent on loss of sodium and water. In contrast, the addition of propranolol to captopril produced no further fall in blood pressure, suggesting that inhibition of angiotensin-converting enzyme prevents the blood pressure lowering effect of propranolol. This may have implications for the mechanism whereby beta-blockers alone lower blood pressure. These contrasting effects of hydrochlorothiazide and propranolol in the presence of captopril indicate that in patients whose hypertension is not controlled by captopril alone the addition of increasing doses of diuretic is likely to control the blood pressure. The addition of a beta-blocker, however, is less likely to be effective.

Density Meter Determination of Proof of Ethanol-Water Solutions: Collaborative Study

Density meter procedures and the official AOAC pycnometer method to measure proof of ethanol-water solutions in the 25-79° proof range were collaboratively studied. Measurement of proof by density meter is simpler, requires less time and smaller samples, and gives more reproducible results than the AOAC pycnometer method. Differences of —0.05 to +0.02° proof between averages of results reported for density meter and pycnometer are acceptable, considering that proof of finished alcohol products is reported to 0.1°. The density meter method has been adopted official first action.

Dynamic aspects of the supramolecular organization of intermediate filament networks in cultured epidermal cells

We have shown, by indirect immunofluorescence microscopy using an antiserum against the mouse keratin subunit K2 and by electron microscopy, that transformed (PAM) and primary (PME) mouse epidermal cells possess extensive networks of IF bundles. Following trypsinization and replating of PAM cells, IF bundles are seen to move as a continuous network from a perinuclear zone into the peripheral cytoplasmic regions. In PAM cells lysed in high-ionic-strength solutions containing Triton X-100 and DNAase-1, IF bundles appear to be closely associated with nuclear envelope remnants and, in some cases, appear to be attached to nuclear pore complexes. PME cells cultivated in low Ca2+-containing medium possess perinuclear birefringent arrays of IF bundles. Within 2 hours of switching the cells to normal Ca2+ levels, the PME IF bundle network moves towards and establishes contact with the cell surface as desmosomes form. Live cells observed by phase contrast and fixed cells observed by immunofluorescence microscopy demonstrate that desmosomes can be distinguished as dark bands separating neighboring cells. There is little difference between the major proteins seen in SDS-polyacrylamide gel profiles of isolated IF bundle networks from PME cells before and after the Ca2+ switch. Therefore, a reorganization of relatively insoluble membrane-associated protein following the Ca2+ switch may be involved in desmosome formation. The isolated IF networks from PAM cells differ in protein composition compared to the PME IF networks. This may be related to the greatly reduced number of desmosomes in PAM cells. The IF bundle system in epidermal cells appears to be involved in shape formation, shape maintenance, the establishment of desmosomes, nuclear centration, and cell-cell contact.

Microtubule-organizing centres and assembly of the double-spiral microtubule pattern in certain heliozoan axonemes

The double-spiral microtubule pattern is established by a self-linkage procedure when axopodial axonemes reassemble after cold treatment in multinucleate Echinosphaerium nucleofilum and mononucleate Actinophrys sol. Nuclei are related spatially to axoneme morphogenesis in both organisms but in rather different ways. Microtubules grow out in all directions from discrete clumps of dense material situated close to nuclei in E. nucleofilum as axonemal assembly begins. Each clump acts as a microtubule-organizing centre (MTOC) in so far as it is associated spatially with the assembly of microtubules for a single axoneme. The dense material spreads along the sides of a developing axoneme for several micrometers, where it probably promotes further microtubule assembly as the double-spiral pattern is established. Pattern is generated as microtubules that are randomly oriented to begin with become more closely juxtaposed and aligned with each other. There are indications that juxtaposition is brought about by the contractile action of a filamentous meshwork that interconnects the microtubules. Final positioning and alignment appears to be accomplished by a ‘zippering’ together of adjacent portions of microtubules that proceeds in both directions along the lengths of developing axonemes as self-linkage is effected. Considerable numbers of more or less radially oriented microtubules remain and project from the surface membrane of the single central nucleus during cold treatment of A. sol. Additional tubules assemble and become associated similarly with the nuclear envelope immediately after cold treatment. Initially these microtubules are not arranged in a double-spiral pattern, which is subsequently generated by procedures similar to those outlined above for E. nucleofilum. It is suggested that the surface of the nuclear envelope may act as an MTOC.

Relation between arterial pressure, dietary sodium intake, and renin system in essential hypertension

Forty-one patients with mild essential hypertension, 36 patients with severe hypertension, and 28 normotensive subjects were studied on a high sodium intake of 350 mmol/day for five days and low sodium intake of 10 mmol/day for five days. The fall in mean arterial pressure on changing from the high-sodium to the low-sodium diet was 0.7 +/- 1.7 mm Hg in normotensive subjects, 8 +/- 1.4 mm Hg in patients with mild hypertension, and 14.5 +/- 1.4 mm Hg in patients with severe hypertension. The fall in blood pressure was not correlated with age. Highly significant correlations were obtained for all subjects between the ratio of the fall in mean arterial pressure to the fall in urinary sodium excretion on changing from a high- to a low-sodium diet and (a) the level of supine blood pressure on normal diet, (b) the rise in plasma renin activity, and (c) the rise in plasma aldosterone. In patients with essential hypertension the blood pressure is sensitive to alterations in sodium intake. This may be partly due to some change either produced by or associated directly with the hypertension. A decreased responsiveness of the renin-angiotensin-aldosterone system shown in the patients with essential hypertension could partly account for the results.

Adjuvant therapy of stage II breast cancer: 48-month follow-up of a prospective randomized clinical trial

A prospective, randomized clinical trial of adjuvant treatment of 318 stage II breast cancer patients, using chemotherapy, the antiestrogen tamoxifen, and immunotherapy is reported at 48 months follow-up. Women whose primary tumors have no estrogen receptors fall into a significantly poorer prognostic group than those whose tumors contain estrogen receptors. None of the adjuvant regimens appeared to offer any clear-cut advantage for the estrogen receptor negative patients. Those women whose primary tumor contains estrogen receptors appear to be in a prognostically favorable group, when their treatment regimen included the antiestrogen, tamoxifen. The adjuvant use of BCG immunotherapy does not appear to offer additional benefit, but the follow-up period of these treated patients is too brief to be conclusive. A longer period of observation is needed to determine whether this systemic treatment in estrogen receptor positive patients is preventing recurrence or merely delaying it.

Interference by polar metabolites in a direct radioimmunoassay for plasma aldosterone

The CIS Aldoctk-125 kit, a direct radioimmunoassay for plasma aldosterone, has been compared with a conventional technique involving solvent extraction. Results given by these two methods were poorly correlated (r = 0.445, n = 103), the direct assay giving higher values, particularly in patients being dialysed for renal failure. When the kit was modified to include an extraction step, results correlated well with those of the standard method (r = 0.952, n = 60). These observations suggested interference form polar metabolites. The possibility that glucuronides were responsible was investigated by measuring plasma aldosterone before and after hydrolysis with beta-glucuronidase. Higher post-hydrolysis values confirmed the presence of glucuronides in plasma from normal subjects and patients with renal failure. Preliminary chromatographic studies on plasma form nine dialysis patients indicated the presence of tetrahydroaldosterone 3-glucuronide, and it is thought that this metabolite might contribute to the high values obtained with the direct assay.

Adjuvant chemotherapy, antiestrogen therapy and immunotherapy for stage II breast cancer: 45-month follow-up of a prospective, randomized clinical trial

The results of adjuvant chemotherapy (CMF), endocrine therapy (t), and immunotherapy (BCG) in 318 women who had undergone mastectomy for Stage II breast cancer are reported after 45 months of life table analysis. CMFT therapy was found to be more effective than CMF alone in increasing recurrence-free survival. This beneficial effect appears to be limited to patients with estrogen receptor-positive tumors (ER+). Patients with estrogen receptor-negative tumors (ER-) (< 3 fmol/mg) have increased recurrence rates and higher mortality.

The renin--angiotensin--aldosterone system in the maintenance of blood pressure, aldosterone secretion and sodium balance in normotensive subjects

1. Captopril given for 5 days caused a fall in blood pressure in normotensive subjects. The percentage fall in mean supine pressure was greatest on a low sodium diet (10 mmol/day), 19.6%, least on a high sodium diet (350 mmol/day), 11%, and in between on a normal sodium diet (120 mmol/day), 16.5%. 2. Captopril caused a marked fall in plasma aldosterone in normal subjects on all three sodium intakes. 3. Captopril caused an increase in sodium excretion on the normal (120 mmol/day) and low (10 mmol/day) sodium diet but not the high sodium diet. 4. These results suggest that the renin--angiotensin--aldosterone system is a normal mechanism for maintaining blood pressure and aldosterone secretion in normotensive man. The system may also be involved in the maintenance of sodium balance. 5. These results may lead to a better understanding of the role of the renin--angiotensin--aldosterone system in the maintenance or causation of high blood pressure in essential hypertension.

Granular cell tumor

The case report presented herein involves a granular cell tumor of the vulva, an uncommon site, with unusual clinical characteristics.

Antiestrogen, cytotoxic chemotherapy, and bacillus Calmette-Guerin vaccination in stage II breast cancer: a preliminary report

A prospective, randomized clinical trial of three treatment regimens: (1) Cytoxan, methotrexate, and 5-fluorouracil (CMF), (2) CMF plus the antiestrogen drug, tamoxifen (CMFT), and (3) CMFT plus bacillus Calmette-Guerin (BCG) vaccinations in women with stage 22 breast cancer is reported. All patients underwent mastectomy and estrogen receptor (ER) analysis was performed. The results of this study show that patients with ER- tumors have recurrences more rapidly and have a higher mortality rate than patients with ER+ tumors (P less than 0.0001). In ER+ patients CMFT treatment is more effective in delaying recurrence than CMF alone at 33 months (P = 0.0176). This effect appears to be occurring in both premenopausal and postmenopausal women. In ER- patients the recurrence rate is high, and there is no significant difference among the three treatment groups. In premenopausal patients treated with CMF alone, however, ER- patients recur more rapidly than ER+ patients (P = 0.0313) and suggests that the effect of CMF may be related to the suppression of ovarian function. These findings have demonstrated a significant role for the use of antiestrogen therapy in patients with state II, ER+ breast cancer.

Tuberous sclerosis presenting as chronic renal failure

A patient with tuberous sclerosis presented with cutaneous lesions and chronic renal failure from multiple renal angiomyolipomas and diffuse rena cystic disease, but without apparent significant neurologic involvement. The clinical and pathologic features of tuberous sclerosis, as well as diagnostic and therapeutic procedures useful in this disorder, are reviewed with particular emphasis on the renal features of the disease.

An in vitro study of marginal leakage associated with composite restorations using an acidified agar technique

The marginal leakage associated with a composite restorative material was examined using an in vitro method for the production of secondary caries-like lesions after the restorations had been subjected to thermal cycling. The fillings were placed in cavities with a 90 degrees cavo-surface angle with and without etching of the walls with phosphoric acid and in cavities with a bevelled margin which were also acid etched. Some degree of leakage was demonstrated in 95% of the unetched cavities while approximately half of the restorations in etched unbevelled cavities showed leakage. With the bevelled and etched group virtually no leakage occurred.

Ripper Procedure for Determining Sulfur Dioxide in Wine: Collaborative Study

Twenty-three laboratories analyzed 5 replicate wine samples according to a specified version of the Ripper direct iodometric titration for sulfur dioxide. Each sample was analyzed for (A) free S02, (B) total S02, and (C) iodine-reactive substances other than S02. Although variations of A with temperature and of A and B with time of analysis were anticipated, analysis of covariance showed no significant reduction in error when these variables were taken into account. Error did vary with S02 level and wine type, red vs white. Pooled estimates of precision (withinlaboratory error) in mg S02/L wine were, for white wine: (A) 3.3, (B) 10.4, (C) 1.9; for red wine: (A) 3.8, (B) 7.3, (C) 1.9. Pooled estimates of systematic (between-laboratory) error in mg SO2/L wine were, for white wine: (A) 2.7, (B) 16.6, (C) 2.1; for red wine: (A) 4.3, (B) 15.1, (C) 3.0. Although rapid and convenient, the Ripper method is severely limited by poor precision and large systematic error. The Ripper method is not recommended for adoption by the AOAC.

Essential hypertension: effect of an oral inhibitor of angiotensin-converting enzyme

Captopril, a specific oral inhibitor of angiotensin-converting enzyme, was given to 18 unselected patients with moderate essential hypertension. Mean blood pressure fell by 14.5% at the maximum dose given, and this fall was significantly correlated with the initial plasma renin activity. The main fall in blood pressure occurred two hours after the first dose of captopril. These results suggest that captopril effectively lowers blood pressure in patients with essential hypertension and that the renin-angiotensin aldosterone system may maintain blood pressure in essential hypertension. This does not necessarily imply that the renin-angiotensin system is the cause of the high blood pressure.

Is "idiopathic" edema idiopathic?

Ten women with "idiopathic" edema had sodium and water retention and a rapid gain in weight when their accustomed intake of diuretics was suddenly stopped. The magnitude of these changes was directly related to the levels of plasma-rening activity before withdrawal of diuretics. Nine patients became edematous. Within 10 days of stopping diuretics, plasma-renin activity and urinary aldosterone excretion decreased to normal or below and within 20 days weight-gain and edema had subsided in seven patients. But the greatest gains in weight, in three patients, were sustained beyond 20 days. Nevertheless, a year later, two of these three patients were free of edema without the use of diuretics. Intermittent edema of unknown cause in most, if not all, otherwise healthy women seems to result from their use of diuretics, abetted in some patients by self-imposed flucuation of sodium and carbohydrate intake, and does not appear to be idiopathic.

Potentiation by the injection vehicle of the teratological action of acetazolamide in rats

The high alkalinity of the injection vehicle of certain parenteral solutions of acetazolamide produces necrosis of the skin upon sc injection. The possible modification of this effect on the teratogenicity of acetazolamide was examined. Acetazolamide in a vehicle of pH 10.5 produced 36.6% fetal malformations, in a vehicle of pH 8.7, 6.1%, and in neutral suspension, 11.8%. Adrenal medullectomy or phentolamine plus the high pH acetazolamide reduced the frequency to 23.2 and 24.4%, respectively. The teratogenicity of the low pH acetazolamide was increased by epinephrine to 64.2%. The frequency of hemimelia and micromelia, and of bilateral involvement, was greater in litters exposed to the high pH acetazolamide or the epinephrine-acetazolamide combinations, and was reduced by phentolamine or adrenal medullectomy. Neither the high pH vehicle nor epinephrine produced fetal defects in the absence of acetazolamide. The biological disposition of acetazolamide was not altered by any of the treatments. Reduction of uterine blood flow may be responsible for the potentiation of teratogenicity by the high pH vehicle.

Long-term survival in bronchogenic carcinoma

In this report, we shall review the clinical and pathological features of 64 patients who survived 10 years or longer after resection for bronchogenic carcinoma. Most of these patients had either adenocarcinoma or bronchioloalveolar carcinoma. None of them had oat cell carcinoma. In many of the long-term survivors, there were pathological findings generally considered to indicate a poor chance for survival. Thus we believe that curative resection for bronchogenic carcinoma should be attempted whenever feasible to offer the patient every hope of long-term survival.