Metabolism of prostacyclin in the rabbit kidney.

In the isolated rabbit kidney perfused with Tyrode's solution, we examined the metabolism of radiolabeled prostacyclin. [9-3H]Prostacyclin was infused into the kidney and the radiolabeled products from the renal venous effluent were separated by thin layer chromatography and identified by gas chromatography-mass spectrometry. The major products were 7,9-dihydroxy-4,13-diketo-dinor-prostanoic acid and dinor-6-keto-prostaglandin F1alpha. They represented 25% and 10% of the total radioactivity, respectively. Metabolism of prostacyclin by the kidney may be an important determinant of the effects of prostacyclin on renal function.


Biosynthesis of bacterial glycogen. The nature of the binding of substrates and effectors to ADP-glucose synthase.

Kinetic studies with ADP-glucose synthase show that 1,6-hexanediol bisphosphate (1,6-hexanediol-P2) is an effective activator that causes the enzyme to have a higher apparent affinity for ATP- and ADP-glucose than when fructose-1,6-P2 is the activator. Furthermore, in the presence of 1,6-hexanediol-P2, substrate saturation curves are hyperbolic shaped rather than sigmoidal shaped. CrATP behaves like a nonreactive analogue of ATP. Kinetic studies show that it is competitive with ATP. CrATP is not a competitive inhibitor of ADP-glucose. However, the combined addition of CrATP and glucose-1-P inhibits the enzyme competitively when ADP-glucose is the substrate. In binding experiments, CrATP, ATP, and fructose-P2 appear to bind to only half of the expected sites in the tetrameric enzyme, while ADP-glucose, the activators, pyridoxal-P and 1,6-hexanediol-P2, and the inhibitor, AMP, bind to four sites/tetrameric enzyme. Fructose-P2 inhibits 1,6-hexanediol-P2 binding, suggesting competition for the same sites. Glucose-1-P does not bind to the enzyme unless MgCl2 and CrATP are present and binds to four sites/tetrameric enzyme. Alternatively, CrATP in the presence of glucose-1-P binds to four sites/tetrameric enzyme. Thus, there are binding sites for the substrates, activators, and inhibitor located on each subunit and the binding sites can interact homotropically and heterotropically. ATP and fructose-P2 binding is synergistic showing heterotropic cooperativity. ATP and fructose-P2 must also be present together to effectively inhibit AMP binding. A mechanism is proposed which explains some of the kinetic and binding properties in terms of an asymmetry in the distribution of the conformational states of the four identical subunits.


Sequence homologies of (guanosine + cytidine)-rich regions of mitochondrial DNA of Saccharomyces cerevisiae.

The nucleotide sequences of two distinct regions of mitochrondrial DNA of Saccharomyces cerevisiae are reported. The regions studied have a high content of G + C (45%) and contain closely spaced Hpa II and Hae III restriction sites. Both regions have sequences that are homologous over a lenght of 47 base-pairs. In addition, the two regions are highly palindromic. These data support certain aspects of the organization of mitochondrial DNA proposed by Prunell and Bernardi (Prunell, A., and Bernardi, G. (1977) J. Mol. Biol. 110, 53--74).


Free groin-flap transfer for skin defects associated with orthopaedic problems of the lower extremity.

Seventeen patients with full-thickness skin loss complicating orthopaedic problems of the lower part of the leg and the foot underwent free groin-flap transfer. Free flaps were used because more conventional means of coverage had failed or were deemed inappropriate. Nine patients had uncomplicated one-stage flap transfer. Three had peripheral necrosis but required no further procedures. Five patients had superficial necrosis of more than one-fourth of the flap, but split-thickness skin grafts applied to the viable subdermal portion of the flap provided an adequate surface in all but one of them. Necrosis was considered to be a result of anastomosis to scarred recipient vessels or of unexplained vessel thrombosis. It may be circumvented in part by the use of interposed vein grafts, or proximal extension of the flap along the recipient vascular tree.


Low-dose heparin for prevention of venous thromboembolism in total hip arthroplasty and surgical repair of hip fractures.

Sixty-seven hip-arthroplasty and fifty-two hip-fracture patients participated in a placebo-controlled randomized double-blind study on the effects of low-dose heparin prophylaxis in the prevention of venous thromboembolism. In this study, a positive thromboembolic event meant a positive test by: (1) daily 125I-fibrinogen scanning, (2) contrast venography on the tenth postoperative day, or (3) radionuclide perfusion lung scan in confirmation of suspected clinical pulmonary emboli. Nineteen (59.4 per cent) of thirty-two placebo-treated arthroplasty patients showed evidence of a thromboembolic event in contrast with eight (22.9 per cent) of thirty-five heparin-treated patients (p less than 0.003). Heparin-treated arthroplasty patients required mean blood transfusions of 4.7 units, contrasted with a mean 3.2-unit transfusion requirement for placebo-treated patients (p less than 0.05). The incidence of observed bleeding complications was higher among the heparin-treated patients. Of the twenty-three placebo-treated patients with fracturs, 39.1 per cent had a thromboembolic event, while 41.4 per cent of the twenty-nine who received heparin showed evidence of thromboembolism, demonstrating that low-dose heparin afforded no protection, nor did it affect the incidence of bleeding complications or transfusion requirements in fracture patients.


Freeze-dried allogeneic segmental cortical-bone grafts in dogs.

Forty-four adult male mongrel dogs were used to compare segmental cortical freeze-dried allogeneic bone grafts with fresh autogenous, freeze-dried autogenous, and fresh allogeneic segmental cortical grafts. Group I consisted of bilateral fresh autografts as external controls; Group II, a fresh autograft on one side for internal control and a freeze-dried autogenous graft on the other side to evaluate the effect of freeze-drying on repair; Group III, a fresh autograft on one side and a fresh allograft on the other side to measure the differences between autogenous and allogeneic grafts; and Group IV, a fresh autograft on one side and a freeze-dried allogeneic graft on the other to see if freeze-drying altered the repair of allogeneic grafts. The grafts were analyzed qualitatively over a six-month period by the use of interval roentgenograms to determine the times of graft-host union and the incidence of fatigue fractures. Six months after operation, the repair processes in the four groups were compared quantitatively with respect to biological repair and physical strength using torsional stress-testing, tetracycline labeling, and microradiography. The results indicate both qualitatively and quantitatively that: (1) fresh bilateral segmental cortical autografts show reproducible characteristics, so that the canine fibula furnishes a satisfactory model (Group I); (2) freeze-drying does not inhibit the repair process per se (Group II); (3) fresh allografts are rejected in varying degrees of intensity (Group III); and (4) freeze-drying does not protect cortical allogeneic grafts from such rejection (Group IV).


Unusual manifestations of pulmonary aspergillosis.

Pulmonary aspergillosis is being diagnosed with increasing frequency, particularly in larger referral centers. The spectrum of lung pathology can be classified into 3 major groups: A) non-invasive mycetoma; B) allergic bronchopulmonary aspergillosis and C) invasive aspergillosis. Five patients with pulmonary aspergillosis are presented, illustrating unusual features of each major group. Transthoracic needle aspiration biopsy was diagnostic in 3 patients. It is important to differentiate a mycetoma developing in a pre-existing cavity from a cavitating Aspergillus abscess. The radiologic appearances may be similar, but evolution of the 2 lesions is entirely different.


Synthesis and extracellular deposition of fibronectin in chondrocyte cultures. Response to the removal of extracellular cartilage matrix.

Fibronectin, the major cell surface glycoprotein of fibroblasts, is absent from differentiated cartilage matrix and chondrocytes in situ. However, dissociation of embryonic chick sternal cartilage with collagenase and trypsin, followed by inoculation in vitro reinitiates fibronectin synthesis by chondrocytes. Immunofluorescence microscopy with antibodies prepared against plasma fibronectin (cold insoluble globulin [CIG]) reveals fibronectin associated with the chondrocyte surface. Synthesis and secretion of fibronectin into the medium are shown by anabolic labeling with [35S]methionine or [3H]glycine, and identification of the secreted proteins by immunoprecipitation and sodium dodecyl sulfate (SDS)-disc gel electrophoresis. When chondrocytes are plated onto tissue culture dishes, the pattern of surface-associated fibronectin changes from a patchy into a strandlike appearance. Where epithelioid clones of polygonal chondrocytes develop, only short strands of fibronectin appear preferentially at cellular interfaces. This pattern is observed as long as cells continue to produce type II collagen that fails to precipitate as extracellular collagen fibers for some time in culture. Using the immunofluorescence double-labeling technique, we demonstrate that fibroblasts as well as chondrocytes which synthesize type I collagen and deposit this collagen as extracellular fibers show a different pattern of extracellular fibronectin that codistributes in large parts with collagen fibers. Where chondrocytes begin to accumulate extracellular cartilage matrix, fibronectin strands disappear. From these observations, we conclude (a) that chondrocytes synthesize fibronectin only in the absence of extracellular cartilage matrix, and (b) that fibronectin forms only short intercellular "stitches" in the absence of extracellular collagen fibers in vitro.


Fibroblasts and macrophages of mice with the Chediak-Higashi-like syndrome have microtubules and actin cables.

Cells of the beige mouse contain abnormally large lysosomes and show enhanced capping of concanavalin A. It has been suggested that these phenomena may be secondary to a defect in microtubule polymerization. We have examined the cytoskeleton of beige mouse cells by indirect immunofluorescence and find the number and distribution of microtubules and actin cables to be indistinguishable from those of normal control cells.


Two distinct mechanisms for redistribution of lymphocyte surface macromolecules. II. Contrasting effects of local anesthetics and a calcium ionophore.

In the previous study, lymphocyte surface molecules were separated into two subsets depending on whether capping was associated was associated with redistribution of cytoplasmic myosin. In the present study, the effects of the local anesthetic chlorpromazine and of the Ca2+ ionophore A23187 were compared. Both drugs affected the surface redistribution of immunoglobulin (Ig), Fc receptors, and the TL antigen--molecules that appear to cap by association with microfilaments--but had no effect on the Thy.1 (theta) and H2 antigens--molecules that cap slowly, apparently unlinked to microfilament function. The capping of Ig, Fc receptor, and TL was inhibited while that of H2 and theta was not. Both drugs reversed the Ig Fc receptor, and TL caps but not the H2 and theta caps. In the former group, the reversal of caps was accompanied by a parallel reversal of the myosin segregated to the cap area. The appearance of myosin after drug treatment varied: chlorpromazine resulted in a diffuse pattern similar to that of normal lymphocytes, whereas A23187 produced an array of aggregates and coarse filaments. The results are compatible with the view that two mechanisms for capping exist in the lymphocyte. The Ca2+ ionophore may affect capping of microfilament-dependent caps by producing a systemic activation of contractile proteins while chlorpromazine may act by disrupting a Ca2+-dependent link between surface complexes and the contractile proteins.


Visualization of centrioles and basal bodies by fluorescent staining with nonimmune rabbit sera.

Several sera from nonimmunized rabbits have been found which stain centrioles and basal bodies by indirect immunofluorescence in a wide variety of cell types. So far, approximately 10% of the rabbit sera that we have examined gave strong positive staining of centrioles and basal bodies. Cytoplasmic networks, mitotic spindles, and ciliary axonemes, however, remain unstained. This specific fluorescent staining of centrioles and basal bodies could not be abolished by absorption of sera with purified brain tubulin. This technique is superior to previous methods for the visualization of basal bodies and centrioles at the light microscopic level and should be useful for rapid and convenient detection of these organelles in large populations of cells.


Microfilament bundles, LETS protein and growth control in somatic cell hybrids.

Hybrid cell lines between normal rat embryo fibroblasts and TA3B mouse tumour cells, or between TA3B and BI hamster sarcoma cells, have been examined for the expression of the cell surface large external-transformation-sensitive (LETS) protein and the organization of microfilament bundles. LETS protein was detected by lactoperoxidase-catalysed radioiodination and microfilament bundles were visualized by indirect immunofluorescence with antibodies directed against actin or myosin. Hybrids which exhibited normal growth control characteristics had high levels of LETS protein and extensive microfilament bundles. Neoplastic transformation appears to be suppressed in these hybrids. Hybrids which had the growth control characteristics typical of transformed cells had reduced or zero levels of LETS protein and few microfilament bundles. These results confirm previous studies on the expression of the transformed phenotype in these hybrids and demonstrate that there is a good correlation between normal growth control and the presence of LETS protein and microfilament bundles. However, the changes in cell surface LETS protein and in the organization of microfilament bundles often appeared to be quantitative reductions rather than all-or-none effects. The magnitude of the alterations in the levels of LETS protein and in the organization of microfilaments appeared to correlate with the range of transformed characteristics exhibited by the cells. One transformed hybrid in particular, selected for growth in agar, had some surface LETS protein, some microfilament bundles and retained density-dependent inhibition of growth.


The cell surface of Trypanosoma cruzi: cytochemistry and freeze-fracture.

The ultrastructure of epimastigotes of Trypanosoma cruzi, obtained from acellular cultures, and bloodstream trypomastigotes, isolated from infected mice, were studied by thin-sectioning and freeze-fracturing techniques. Epimastigotes showed a thin (5 nm) surface coat when stained with ruthenium red, while the surface coat of trypomastigotes was more prominent (15 nm thick). Both P and E faces of the plasma membrane of T. cruzi had roughly the same number of intramembranous particles (IMP) as seen by freeze-fracture. The plasma membrane of bloodstream trypomastigotes had less IMP than epimastigotes. Several differentiations of the plasma membrane was observed. In epimastigotes a cytostome appears as a particle-poor region delimited by a pallisade-like row of adjacent IMP. Bloodstream trypomastigotes did not have a cytostome. Instead, abundant pinocytic vesicles were observed. At the base of the flagellum of epimastigotes a ciliary necklace was found. At this region, the surface coat was differentiated as long, hair-like projections after staining with ruthenium red. The flagellar membrane had less IMP than the body membrane. Clusters of IMP were present on both faces of the flagellar membrane at the flagellar-body adhesion zone of epimastigotes. Linear arrays of IMP were also seen. In bloostream trypomastigotes clusters of particles were observed both on the flagellar and cell body membranes. Our observations demonstrate the presence of considerable structural variations of the T. cruzi plasma membrane at the two stages of the life cycle studied.


Mobility of concanavalin A receptors and distribution of cytoplasmic actin in odontogenic epithelial and mesenchymal cells.

The distribution of concanavalin A (Con A) surface receptors and cytoplasmic actin in the same cell was studied in monolayer cultures of 2 odontogenic epithelial cells of different developmental age and in ecto-mesenchymal cells derived from the same tooth germ. Con A receptors were demonstrated by fluorescein-isothiocyanate-labelled Con A (FITC-Con A) and cytoplasmic actin by a specific anti-actin autoantibody (AAA) traced with a rhodamine-labelled goat anti-human globulin (R-AHG). All 3 cell types, incubated with FITC-Con A at 37 degrees C for increasing time periods, showed progressive changes in staining patterns from clusters, caps to perinuclear globules. Capping was seen in the majority of immature epithelial cells at 120--180 min, in cells of more mature epithelium at 180--240 min and in ecto-mesenchymal cells at 240--360 min. Binding of FITC-Con A to cell surfaces resulted in sequential changes in AAA staining from filamentous to an aggregated or diffuse pattern, co-capping of aggregated or diffusely stained areas with those capped by FITC-Con A, presence of aggregated or diffusely stained areas in sites similar to the perinuclear globules stained by FITC-Con A, to final re-emergence of filamentous staining. Prior treatment of cells with cytochalasin B or colchicine promoted capping in epithelial but not in ecto-mesenchymal cells while presence of either drug throughout the staining procedure inhibited capping. The results show that Con A receptors are more mobile in epithelial compared to ecto-mesenchymal cells and in immature epithelial cells compared to their more mature counterparts, and that binding and mobility of Con A receptors on the cell surface is associated with redistribution of cytoplasmic actin. The cytochalasin B and colchicine experiments suggest that both microfilaments and microtubules may have synergistic roles in the opposing functions of receptor anchorage and mobility, and that the relative receptor immobility of ectomesenchymal compared to epithelial cells may be attributed to firmer receptor anchorage to the cytoskeleton.


Carbon dioxide evolution during the cell cycle of the fission yeast Schizosaccharomyces pombe.

The rate of CO2 evolution was measured in synchronous cultures of the fission yeast Schizosaccharomyces pombe growing in a minimal medium. The rate of CO2 evolution was found to double sharply at about the time of nuclear division (0.75 of the way through the cell cycle). For the remainder of the cell cycle the rate remained constant. Addition of inhibitors of DNA synthesis or nuclear division did not affect the pattern of CO2 evolution in synchronous cultures. Similarly, in an induced synchronous culture, in which DNA synthesis, nuclear division and cell division--but not growth, were synchronized, CO2 evolution showed a continuous pattern and not the step-wise increase associated with the normal synchronous cultures. When S. pombe was grown in a complete medium, the evolution of CO2 in a synchronous cultures was shown to increase in a continuous manner but at a rate faster than the growth of the culture.


Fluorimetric detection of octopamine in high-performance liquid chromatography and its application to the assay of dopamine beta-monooxygenase in human serum.

A high-performance liquid chromatographic procedure is described for the determination of octopamine. The method, which is based on the separation on a microparticulate bonded strong cation-exchange resin and measurement of the native fluorescence, has been applied to give a sensitive assay of dopamine beta-monooxygenase (EC 1.14.17.1) activity in human serum with tyramine as the substrate. The procedure, which has been designed for use with an automatic sampler, has a detection limit of about 50 pmoles of octopamine, and the analysis time is approximately 10 min per sample.


Quantitation of chlordiazepoxide and its metabolites in biological fluids by thin-layer chromatography.

Chlordiazepoxide and its 4 major metabolites were assayed after separation by thin-layer chromatography following extraction from biological fluids. The compounds become intensely fluorescent in the presence of red, fuming nitric acid. The resulting compounds are quantitated with a spectrodensitometer with a fluorescent attachment. The sensitivity varies between 0.05 and 0.1 microgram. The coefficient of variation is 1.4% for assays in urine and 6.4% in serum.


Rapid isolation and identification of group B streptococci from selective broth medium by slide co-agglutination test.

Direct identification of group B streptococci from a selective broth medium was performed with the Phadebact streptococcus test to determine the feasibility of this technique for early detection of streptococcal colonization. Of 124 clinical isolates, 122 (98.4%) were correctly identified in less than 24 h from the selective broth medium, whereas standard cultures from blood agar plates identified, after 48 h, only 66 (53.2%). The presence of group B streptococci in mixed cultures was always detected by the Phadebact test, and no false-positive co-agglutination tests were observed in 372 cultures from which organisms other than group B streptococci were isolated.


[Leiomyomas of the duodenum (author's transl)].

The authors report a case of leiomyoma of the second part of the duodenum and note in the light of 55 cases in the literature, the main characteristics of this tumour including digestive hemorrhage, especially melena, which is the commonest mode of presentation. They compare it with other muscle tumours, e.g. sarcoma and myoid tumours. A barium meal and eventually superior mesenteric arteriography are the two main aids in diagnosis which remains by chance in 15% of cases. The volume of the tumour, the intimacy of its relations with the bile ducts influence the choice of surgery. The risk of hemorrhage and the histological uncertainty almost always lead to surgical operation.


Enzyme-linked immunosorbent assay determination of specific rubella antibody levels in micrograms of immunoglobulin G per milliliter of serum in clinical samples.

A "microgram assay" is described in which solid-phase enzyme-linked immunosorbent assay is used for the determination of specific rubella immunoglobulin G (IgG) antibody levels in micrograms per milliliter of serum. The quantitation was based on a standard curve obtained by using a reference serum, for which the specific IgG content was assayed by immunochemical purification. IgG was first purified and specific rubella antibodies were separated by an immunoadsorbent prepared by linking rubella virus antigens to Sepharose 4B. By using IgG-specific conjugate, the levels of specific rubella IgG antibodies could then be determined from clinical samples. Seronegative samples showed antibody levels less than 1 microgram/ml, whereas levels up to several hundred micrograms per milliliter were detected in some postinfection sera. The correlation between microgram antibody levels and hemagglutination inhibition titers was linear. The method offers a simple and sensitive antibody assay which could be used both for the laboratory diagnosis of acute rubella and for the evaluation of immunity.


Evaluation of routine subcultures of macroscopically negative blood cultures for detection of anaerobes.

Routine anaerobic subcultures of macroscopically negative blood culture bottles, performed within 1 day of receipt of the culture and after 5 days of incubation, were evaluated. Anaerobes were recovered from 207 (12.3%) of the total 1,688 positive cultures and, of these, 154 were only detected macroscopically, 11 only by subculture, and 42 by both procedures. In no instance was the anaerobe detected earlier with the subculture, and the time required for a definitive identification was reduced for only 10 isolates. Since the subcultures did not significantly improve the detection or early identification of anaerobes, routine anaerobic subcultures are not recommended.


Species identification of coagulase-negative staphylococci from urinary tract isolates.

A new scheme for identification of coagulase-negative staphylococci was applied to 138 consecutive urinary isolates of coagulase-negative staphylococci. The most common species were Staphylococcus epidermidis (53%), S. hominis (12%), and S. haemolyticus (10%). S. saprophyticus comprised only 5%. The disk method for antibiotic susceptibility for all species grouped together disclosed resistance most commonly to penicillin (35%), tetracycline (33%), methicillin (27%), and sulfonamide (24%). This pattern was also seen specifically with S. epidermidis. Further studies are needed to determine the incidence of species-specific antibiotic resistance and species-specific infection by site. This may be of particular interest in those patients with nosocomial infections due to coagulase-negative staphylococci.


Detection of cells producing surface antigen-specific antibody to influenza viruses.

B cells producing antibodies to influenza virus antigens were detected and quantitated by a hemolytic plaque assay. Responses of mice after primary infection and immunization with influenza viruses were measured and compared with responses after secondary immunization. The B-cell responses were specific and differentiated between A and B influenza viruses and between different subtypes of A influenza viruses. Responses to closely related influenza A virus strains of the H3N2 subtype cross-reacted but could also be differentiated. Cells secreting antibody to either of the virus surface antigens (hemagglutinin and neuraminidase) could be separately enumerated. Evidence that immunoglobulin G- secreting cells are detected in the assay without the use of facilitating anti-immunoglobulin G sera is presented.


Significance of appropriate techniques and media for isolation and identification of Ureaplasma urealyticum from clinical specimens.

Controversy over the association of Ureaplasma urealyticum with reproductive failure may be due to methods used to isolate the microorganism. U. urealyticum isolations from clinical material should be done simultaneously in broth and on Shepard's differential agar medium (A7) containing manganese sulfate. Urine sediments result in a 9% (P = 0.0002) higher rate of isolation than than cervical and urethral swabs. Primary isolations may not display standard textbook morphology. Isolated colonies may be present, but brown streaks in cervical mucus or a coalescent haze around epithelial cells in urine sediment may also be seen in areas of concentrated growth. The broth and agar media used, method of incubation, type of specimen, and method of storing specimens before culture are all factors which influence the recovery of U. urealyticum.


Selective medium for isolation of Eikenella corrodens from periodontal lesions.

The addition of 5 microgram of clindamycin per ml to a modified Todd-Hewitt growth medium permitted the ready enumeration of Eikenella corrodens from deep periodontal lesions because it allowed differential growth amongst the periodontal pocket gram-negative microaerophilic-anaerobic flora, maximized the numbers of E. corrodens in such culture, and inhibited the growth of most of the other confounding microorganisms.


Rapid test for acetyl-methyl-carbinol formation by Enterobacteriaceae.

A modified Voges-Proskauer test is described which distinguishes within 4 to 8 hours between organisms that can produce acetyl-methyl-carbinol (acetoin) from glucose fermentation and those that cannot.


Heated versus unheated sera in a microhemagglutination assay for antibodies to Treponema pallidum.

The effect of prior heating of sera on the results of the microhemagglutination assay for antibodies to Treponema pallidum was evaluated. Findings indicate that heating of sera had no significant effect on the results.


Evaluation of two commercially prepared biphasic media for recovery of fungi from blood.

Recovery of six yeast species from blood was comparable in commercially prepared brain heart infusion biphasic and Trypticase soy biphasic media. An increased recovery of 13% was noted when two bottles, each containing 5 ml of blood, were cultured, as compared to a 5-ml portion in a single culture bottle.


Extrinsic discoloration of teeth.

The majority of tooth discolorations are extrinsic in nature and appear as brown integuments. Various clinical indices and photometric techniques have been used for the evaluation of extrinsic discolorations. Smoking, tea or coffee consumption and increasing age are promoting factors and such discolorations are frequently seen in connection with oral use of antibacterial plaque-inhibiting mouthrinses. Chemical alteration of the acquired pellicle appears to be the major reason for these brown integuments.


Use of chlorhexidine gluconate and povidone iodine mouthwashes in the treatment of acute ulcerative gingivitis.

A trial was conducted to compare the effectiveness of povidone iodine and chlorhexidine gluconate with buffered peroxyborate in the treatment of acute ulcerative gingivitis. After 20 patients had entered the trial and 11 had required additional therapy with metronidazole to control their symptoms, the study was terminated. Those patients receiving peroxyborate all showed a satisfactory improvement in clinical signs and symptoms. One patient each receiving povidone iodine or chlorhexidine reported a symptomatic improvement, although gingival ulceration was still apparent at 1 week. The remaining patients all required metronidazole therapy to control their symptoms. Povidone iodine and chlorhexidine gluconate therefore cannot be recommended for the treatment of acute ulcerative gingivitis.


A comparative analgesic study of propoxyphene, fenoprofen, the combination of propoxyphene and fenoprofen, aspirin, and placebo.

Groups of 27 inpatients with moderate or severe postoperative, fracture, or somatic pain were given single oral doses of propoxyphene napsylate (P), fenoprofen calcium (F), combinations of P and F, aspirin, or placebo. The increasing rank order for effectiveness, with doses in milligrams, was placebo, P50, aspirin 650, F600, F50, P50 + F50, F200, P50 + F600, P50 + F200, P200 + F50, P200, P200 + F200, and P200 + F600. The overall analgesic response to propoxyphene in this dose range (50 to 200 mg) increased linearly with increasing doses. The fenoprofen response also increased in proportion to the dose up to 200 mg; the overall response to 600 mg was not significantly different from that to 200 mg. Propoxyphene napsylate and fenoprofen calcium had additive analgesic effects. There were no drug-related adverse reports.


Microscopic assay for the phagocytotic-collagenolytic performance (PCP index) of human gingival fibroblasts in vitro.

Using 16 human gingival fibroblasts cell lines from patients with periodontitis, Dilantin hyperplasia, and nonpathological gingiva, a microscopic assay was developed to quantitate the cells' ability to lyse collagen substrates. The method employs tissue culture chambers with one cover slip partially coated with a thin layer of undenatured fibrillar bovine collagen. The assay measures the relative numbers and sizes of holes in the collagen within defined regions of the cover slips effected by the phagocytotoc and collagenolytic performance (PCP) of the population of fibroblasts growing on the cover slip for 5 days. The effect on the PCP index by serum, heparin, prostaglandins, and endotoxin was evaluated.


The geometric theory of selection of artificial teeth: is it valid?

The study was done to determine the validity of William's geometric theory of tooth selection. The maxillary central incisors of 31 subjects were radiographed and photographed; casts were made of the maxillas; and the subjects' faces were photographed. Three dentists classified the form of the maxillary central incisors as shown by intraoral photographs, radiographs made by the parallelling technique, and casts, and also classified the form of the face from frontal-view photographs. The data collected were reduced by an electronic computer to determine if a correlation exists. There was no correlation between the form of the face and the form of the maxillary central incisors.


Etches for the microstructure of dental amalgams.

An iodized sodium hydroxide solution is suitable as an etch for conventional amalgams. In diluted form and followed by sodium thiosulfate solution, this may be used on dispersed phase, ternary and quaternary alloy amalgams for clearer results than with the cyanide method. Alternative etches are given for ternary-quaternary materials.


Considerations in the management of patients taking oral contraceptives.

Among the undesirable effects associated with the use of oral contraceptives are an increased incidence of thromboembolic events, an increased risk of myocardial infarction, and, in certain users, a significant elevation in blood pressure. An altered fibrinolytic activity may have a direct effect on the occurrence of localized osteitis, "dry sockets." It is also possible that gingival inflammation and loss of attachment may occur even under conditions of adequate plaque control. Salivary changes and alterations in the bony trabecular pattern of the mandible have been observed, but the clinical significance is as yet undetermined (Illustration).


The preformed stainless steel crown for restoration of permanent posterior teeth in special cases.

There are problems involving permanent posterior teeth for which the stainless steel crown may provide the most desirable short-term solution. In placing the crown, emphasis should be given to recognition of the wide variation of available crowns, occlusal considerations, the importance of the rubber dam, and the use of a precementation radiograph to confirm margin adaptation of the crown.


An evaluation of primary enamel pretreatments and their effects on resin retention.

The effects of various enamel pretreatments on bond strengths between primary enamel and resin were investigated. Pretreatments included: removal of the outer enamel surface, varied exposure to phosphoric acid, and the use of an organic coupling agent. Results indicated highest bond strengths utilizing acid pretreatments and an organic coupling agent.


Characterization of enamel surfaces prepared with commercial and experimental etchants.

Polished enamel surfaces were etched with various commercial and experimental etching solutions and evaluated for changes in surface profile and topography. Enamel surfaces that were exposed to solutions of phosphoric acid in a concentration between 37% and 50% for a minute gave the most suitable surfaces for retention of the polymer. Enamel surfaces that were roughened with a diamond stone were not etched uniformly. Enamel that was exposed to acid etching solutions was better protected by a polycarboxylate cement than by either calcium hydroxide or zinc phosphate.


Clinical evaluation of three acid-etch composite resin systems: two-year report.

One hundred fifty-seven fractured anterior teeth were restored with one of three acid-etch composite resin systems and were clinically and radiographically evaluated for 24 months. Of the three systems evaluated, the material activated by ultraviolet light provided the highest retention rate and clinical acceptance.


A technique for the removal of junctional epithelium from the epithelial attachment.

A technique utilizing sodium deoxycholate to remove junctional epithelial cells from the epithelial attachment zone is described. Light and electron micrographs show a similarity in size and appearance between the extracellular attachment substance in controls and the extracellular substance which remains on cementum previously in contact with junctional epithelium.


Guidelines for professional quality dentures for the financially disadvantaged.

The purpose of this project was to evaluate and report on the timing of procedures involved in complete denture service based on criteria for assessment of quality and to determine the effectiveness of a model of such a delivery system in terms of success of treatment and reduction of cost. It can be concluded that the denture care system may and can be used as a model to provide the base line reference to compare with other denture care delivery systems; the use of criteria for assessment of quality is not only efficient, but is also practical; and a complete denture treatment service of the quality defined by the criteria developed for this model can be provided to patients.


The effect of axial grooves on the resistance form of cast restorations.

Fifteen sets of castings were fabricated to machined stainless steel dies of 5 degrees, 10 degrees, and 15 degrees of taper and 3, 4, 6, 8, and 10 mm of preparation length. Each casting was loaded vertically on its sloped surface in an attempt to unseat the casting. Only the castings of 3 and 4 mm of preparation length and 10 degrees and 15 degrees taper were unseated. Two experiments were performed on these four sets of dies to test parallel proximal and parallel buccolingual grooves. Dies with grooves oriented on the proximal surfaces provided complete resistance to horizontal dislodgement, whereas dies with grooves oriented on the buccal and lingual surfaces provided only partial resistance to horizontal displacement and potential failure of the castings.


The effect of vitamin C on antigen-induced bronchospasm.

The effect of vitamin C pretreatment in preventing ragweed-induced bronchospasm was evaluated in 6 ragweed-sensitive asthmatics studied in a double-blind randomized fashion. The patients received either lactose capsules or 500 mg of ascorbic acid and were studied out of season. Antigen dose-response curves were determined prior to the administration of lactose or ascorbic acid in each individual subject and subsequently after administration of ascorbic acid or lactose. Bothe PD20FEV1 (provocation dose necessary for a 20% reduction in forced expiratory volume in 1 second) and PD35SGaw (provocation dose necessary for a 35% reduction in specific airways conductance) were determined. In none of the six patients was there a change in baseline FEV 1 (p greater than 0.70) nor the overall average baseline specific airways conductance (rho greater than  0.90). Additionally, no statistically significant difference (p greater than 0.60) was noted between log PD35SGaw vitamin C day and lactose day. Likewise, no statistically significant difference (p greater than 0.60) was evident when comparing log PD20FEV1 lactose and ascorbic acid days. Vitamin C (500 MG) HAS NO PROTECTIVE EFFECT AGAINST RAGWEED ANTIGEN-INDUCED BRONCHOSPASM.


Freud's Leonardo: psychobiography and autobiography of genius.

In his creation of a psychobiography of one genius and the hidden autobiographic analysis of another, Freud exemplifies what he described in the study: "Kindly nature has given the artist the ability to express his most secret mental impulses, which are hidden even from himself, by means of the works that he creates" (p. 107).


Ascaridoid nematodes of amphibians and reptiles: Gedoelstascaris n.g. and Ortleppascaris n.g.

Two new genera, Gedoelstascaris and Orleppascaris, are proposed for species of ascaridoid nematodes occurring in crocodilians and previously included in Dujardinascaris. Species included in Gedoelstascaris are vandenbrandeni Baylis, 1929 as type species and australiensis Baylis, 1931 (= salomonis Kreis, 1940). These species occur in Crocodylus spp. in Africa and Australia respectively and are characterised by lips with a rostral plate, without interlocking processes or dentigerous ridges, with well-developed interlabia, lobulated ventriculus, and excetory pore in front of the nerve ring. Species included in Ortleppascaris are: nigra Gedoelst, 1916 (= tasmani Ortlepp, 1932) as type species; alata Baylis, 1947: antipini Mozgovoy, 1950. These species occur in Crocodylus, Caiman and Alligator and are characterized by flat lips with alate margins, without anterior rostral plate, interlocking processes or dentigerous ridges, with weakly developed interlabia, by an irregular-shaped ventriculus, excretory pore behind or between the subventral lips, and by the presence of lateral alae or cuticular thickenings in the oesophageal region. The significance of this proposal is discussed in relation to the radiation and dispersal of ascaridoids of crocodilians.


Estrogen receptor immunocytochemistry.

Estrogen receptor activity was preserved in fixed, paraffin-embedded tissue and demonstrated by binding of estrogen which, in turn, was detected immunocytochemically. Estrogen was added to rat endocervial epithelium to protect specifically receptors during fixation. The protective estrogen was apparently lost during embedding and had to be resupplied before staining. Estradiol-mediated immunocytochemical staining was inhibited by diethylstilbestrol and nafoxidine hydrochloride.


Immunocytochemical localization of renin in the submandibular gland of the mouse.

Renin was localized in the submandibular gland of the adult mouse at light and electron microscopic levels by the unlabeled antibody enzyme method of Sternberger. At the light microscopic level, renin was confined to the granular convoluted tubule (GCT) segment of the gland with considerable variation among GCT cells in intensity of staining. Some GCT cells failed to stain for renin. The pattern of staining was the same in the gland of male and female mice, but in the glands of females GCT segments were smaller and less numerous. At the electron microscopic level, staining for renin was also confined to the GCT cells, and was localized exclusively to the secretory granules. The intensity of staining of the secretory granules within a given GCT cell varied; some cells contained only minimally reactive or negative secretory granules. All other organelles within the GCT cell, except condensing vacuoles, failed to stain.


The use of epon embedding with the Falck-Hillarp technique to preserve the serotonin-associated fluorescence of endocrine and mast cells in the rat stomach.

Epon embedding was used with the Falck-Hillarp Technique in a study of rat gastric endocrine cells in order to improve morphological resolution. The epon embedding not only produced excellent morphological results, but also resulted in the long-term preservation, now for 10 years of the serotonin-associated fluorescence in the gastric endocrine and mast cells.


Detection of tubulin and actin in various cell lines by an immunoperoxidase technique.

This paper reports on the preparation of immunsera against tubulin and actin, and the purification of anti-tubulin and anti-actin antibodies on immunoadsorbent columns. These purified antibodies were used in an indirect immunoperoxidase assay to visualize microtubules and microfilaments in various cell lines. The specificity of antibodies and the methods of cell fixation required are discussed, as well as some aspects of microtubule and microfilament organization, as visualized by this technique.


The morbidification of love between women by 19th-century sexologists.

Twentieth-century attitudes toward love between women are very different from those of previous centuries. Fiction and personal correspondence that antedate the work of Krafft-Ebing and Havelock Ellis in the late 19th century indicate that a much broader spectrum of expression of love and affection between women had been acceptable than that to which we have become accustomed. Medical science and psychology for the past 100 years have morbidified intense love relationships between women by inventing a syndrome of ills that supposedly accompany such affection, and by denying the validity or seriousness of the affection where such ills are clearly not present. The result has been that (until the lesbian-feminist movement) 20th-century women were largely forced to deny their love for other women unless they were willing to acknowledge their concomitant morbidity.


Jeremy Bentham's essay on "Paederasty". Part 2.

This is Part 2 of a transcription of Bentham's manuscript essay on "Paederasty" (1785), Part 1 of which appeared in Vol. 3, No. 4. In Part 1 Bentham argued for the decriminalization of sodomy and opposed the theories of Montesquieu and Voltaire as to its social dangers. In Part 2 Bentham speculates on its causes and alleges that the real reason such behavior is so severely punished is an irrational "antipathy" to pleasure generally and to sexual pleasure in particular. He discusses the danger of blackmail and false accusations and the punishment of lesbian acts, bestiality, and masturbation. Some miscellaneous related notes by Bentham are appended: these deal with religious fears based on the destruction of Sodom, the threat to population, the harshness of English naval law, and other topics.


Cultivation of Tuleniy virus (strain Murman) in vitro.

In vitro culturability of Murman strain of Tuleniy flavivirus isolated recently in the northern regions of the USSR was studied. Stable PS pig kidney line was found suitable as a primary sensitive cell substrate for the isolation, proliferation and serial propagation of the virus. The pronounced pathogenicity of the virus to PS cells permits the testing of its infective activity comparable with i.c. titrations on mice, VNT in vitro and the plaquing technique. PS line is suitable for the demonstration and identification of the virus antigen and/or for the study of reproduction of the virus on cellular level using the technique of immunofluorescence.


Free sugars in foods.

The values for the free sugars analysed in the samples collected for the fourth edition of McCance and Widdowson's 'The composition of foods' have been combined with values from the literature to provide some basic information on the distribution of free sugars in a range of foods.


Physician participation in state Medicaid programs.

Medicaid requires that physicians who accept Medicaid reimbursement for treating a patient agree to accept its payment as payment in full. Policy instruments under Medicaid's control are both levels of reimbursement and various administrative burdens imposed on physicians by the program. A model depicting the physician's participation decision is developed, and predictions from the comparative statics analysis are discussed. Data came from a 1975--76 survey of fee-for-service physicians. The results indicate that high fee schedules and low administrative burdens are ways to stimulate physician involvement with Medicaid patients. Results on the Medicaid policy instruments and other explanatory variables on the whole lend support to the model of physician behavior proposed earlier in the paper.


Stimulation of mitogenic responses in human peripheral blood lymphocytes by lipopolysaccharide: serum and T helper cell requirements.

Stimulation of human peripheral blood lymphocytes by lipopolysaccharide (LPS) was studied by the incorporation of 3H-thymidine. Peak stimulation occurred at 7 to 9 days over a broad range of LPS concentrations. Both Escherichia coli and Salmonella typhimurium LPS were effective mitogens with S. typhimurium having slightly higher activity. There was a strict serum requirement; pooled fresh frozen human serum was found to best support stimulation. In fetal calf serum, LPS caused a reduction in culture-induced stimulation. Cell separation procedures were employed in order to study the nature of the responding cell population. It was found that only non-T cells were stimulated by LPS, but in order for maximal stimulation to occur there was a requirement for helper T cells.


Increased spontaneous polyclonal activation of B lymphocytes in mice with spontaneous autoimmune disease.

Early in life, mice of four kinds [NZB, (NZB X NZW)F1, MRL/1, and male BXSB] with autoimmune disease spontaneously produced far more (greater than 3 S.D.) anti-hapten antibody-forming cells in spleens and greater concentrations of anti-hapten antibodies in sera than immunologically normal strains of mice (AKR, BALB/c, C57BL/6, DBA/1-J, DBA/2J, LG/J, 129, NZW, and female BXSB). This increased nonspecific antibody production by the abnormal animals' B cells correlated well with the spontaneous development of anti-single-stranded DNA antibodies, but not with serum levels of the viral envelope glycoprotein, gp70. These results suggest that the spontaneous formation of autoantibodies in mice whose immunologic disorder is manifested by a lupus-like disease may result from polyclonal activation of B cells by endogenous or exogenous B cell activators.


Genetic control of lymphocyte suppression. I. Lack of suppression in aged NZB mice is due to a B cell defect.

Con A-activated cells from old NZB mice were found capable of inhibiting the polyclonal response of cells from young NZB and BALB/c animals. Furthermore, Con A-preactivated spleen cells from young NZB and BALB/c mice did not significantly affect the response of spleen cells from old NZB mice. These results suggest that the defective suppressive activity in old NZB mice may be traced to a defect at the B cell level.


Modulation of immune response by bacterial lipopolysaccharide (LPS): multifocal effects of LPS-induced suppression of the primary antibody response to a T-dependent antigen.

Spleen cells from mice injected with 2 to 50 microgram bacterial lipopolysaccharide (LPS) have a reduced capacity to make an antibody response in vitro to trinitrophenylated sheep erythrocytes (TNP-SRBC) when tested 1 to 7 days later. Recovery is gradual, and these cells are full functional 2 weeks after in vivo LPS treatment. Unresponsiveness resides in the nonadherent splenic cell populations, and can be shown to have a suppressive cell component, which is irradiation sensitive and has somme characteristics of a thymus-derived lymphocyte (T cell). In addition, neither bone marrow-derived lymphocytes (B cells) nor T cells in the spleens of LPS-treated mice are functionally normal in their abilities to cooperate during an antibody response in vitro. LPS-B cells cooperated poorly with nylon wool-enriched T cells from normal mice but cooperated well with irradiated carrier-primed T cells or nylon wool-purified splenic T cells from carrier-primed mice. LPS-T cells have a reduced capacity to interact with normal B cells and appear to contain a suppressor cell component. These results indicate that the effects of exposure of immunocompetent cells to LPS are multifocal and can include suppression as well as stimulation of antibody formation.


Antigen-induced murine B cell lymphomas. I. Induction and characterization of CH1 and CH2.

Two unusual murine lymphomas, designated CH1 and CH2, were produced in the newly developed double congenic strain of mice, B10 H-2a H-4b p/Wts. Both tumors lack the T cell-specific antigen (thy-1), but express cell surface immunoglobulin and the H-2K, H-2D, and Ia specificities determined by the H-2a haplotype. Further studies have demonstrated that these tumors represent "early" B cells in that they express surface IgM (mu heavy and lambda light chains), but do not bear surface delta, gamma, or alpha heavy chains. CH1 and CH2 lack surface C3 receptors and results from assays for Fc receptors have proven variable. A competition radioimmunoassay directed against the gp71 group-specific antigen of Friend leukemia virus has shown that there is a murine leukemia virus associated with these tumors, however, we have been unable to establish a causal relationship between the virus and this malignancy. A comparison of the surface characteristics of these tumors with other mammalian B cell lymphomas is presented.


The mouse mutant "motheaten." II. Functional studies of the immune system.

Motheaten mice have normal levels of T lymphocytes but reduced levels of B lymphocytes. Those B cells that are present show an impaired proliferative response to B cell mitogens and no plaque-forming cell response to thymus-independent antigens. T lymphocyte function is also defective in motheaten mice, as assayed by the proliferative responses to T cell mitogens, and by the capacity to develop cytotoxic killer cells against allogeneic cells. Motheaten mice possess spleen cells capable of suppressing normal B cell responses to thymus-independent antigens. This suppressor cell is not sensitive to anti-Thy-1 antibody plus complement treatment but is partially removed by adherence on plastic. Overall, the motheaten mouse suffers a functional severe combined immunodeficiency of both B and T cells, even though these cells are present. We postulate that the inescapable lethality of the motheaten defect is due to the lack of immunocompetence during the critical developmental period before adulthood and perhaps to an autoaggressive component as well.


Specific antibodies to hemoglobin A1 (anti-Glu) and hemoglobin S (anti-Val) in the guinea pig: immunologic and structural correlations.

Like goats and sheep, guinea pigs can produce, in response to human sickle cell hemoglobin (beta6 Glu leads to Val), an antibody population (anti-Val) that will bind sickle cell hemoglobin but not normal hemoglobin HbA. Unlike goats and sheep, guinea pigs can produce in response to human hemoglobin A1 an antibody fraction, anti-Glu, that will not react with human sickle cell hemoglobin. These anti-Glu antibodies have been isolated by affinity chromatography and their specificity confirmed by fluorescence-quenching titrations. The sequence of the first 10 amino acids of the beta-chain of guinea pig hemoglobin has been determined. This sequence differs from those of both hemoglobin HbA and sickle cell hemoglobin by two residues, those at positions 5 and 6. This explains the similarity of the immunogenicity of this site on the two human hemoglobins when administered to guinea pigs. Both goats and sheep are identical to hemoglobin A1 at the beta-6 position.


B lymphocyte subpopulations separated by velocity sedimentation. II. Characterization of tolerance susceptibility.

Neonatal and adult splenic B lymphocyte subpopulations, separated by velocity sedimentation, were tested in an in vitro splenic focus assay for their susceptibility to tolerance induction with hapten-protein conjugates. At least two tolerizable B cell subsets have been defined in the neonatal spleen; one comprising the slowly sedimenting, small lymphocytes and the other comprising the very rapidly sedimenting, large lymphocytes. In addition, a rapidly sedimenting large B cell subset in the adult spleen was found to be highly susceptible to tolerance induction. It was suggested that the inability to detect this susceptibility in unfractionated adult spleen was due to the low proportion of these very large lymphocytes in the total spleen cell population. The tolerizable B cell subsets presently defined probably represent the least mature B lymphocytes detectable in the splenic focus assay.


A simple method for the preparation and storage of helper T cells.

Relatively purified populations of helper T cells free of active PFC precursors can be prepared from primed splenocytes by irradiation, hypotonic shock, and filtration over glass wool. These purified populations can be stored and helper activity recovered undiminished after up to 6 months of cryopreservation.


The use of the preparation of F(ab')2 antibody from soluble immune complexes to determine the complexed antigens.

An autoradiographic technique for the characterization of antibody specificity in soluble antigen--antibody complexes has been developed. The circulating antigen--antibody complexes are precipitated by polyethylene glycol (PEG). The antibodies are liberated as F(ab')2 from the complexes by pepsin digestion. The antibody specificity against the putative antigen was revealed by radioimmunoelectrophoresis using [125I]-F(ab')2 reagents. The method was developed by using an experimental model of C3/anti-C3 complexes.


A simple visual surface immunology test.

A new general immunology test is described which is capable of detecting protein in the 1 microgram/ml range. First an antigen is adsorbed in a small area of a glass surface. The glass is exposed to an antibody solution and the antibody will attach specifically to the antigen. Next the slide is washed, dried and sprayed lightly with plastic particles that stick to the protein layers on the glass. Now when the glass slide is exposed to an acid the antigen--antibody bonds are broken, the antibodies will leave the surface removing some of the plastic particles and leaving an easily visible spot behind.


Statistical analysis of measurement errors of binding data in the Farr technique.

A detailed statistical analysis of measurement errors in the Farr technique is performed, and approximated formulas for the error covariances are given. These formulas are then checked by means of experimental data. In particular, the analysis shows that the usually adopted linear extrapolation for the estimate of total antibody sites concentration may lead to relevant errors in the affinity distribution determination due to the low accuracy of data at high values of free hapten concentration. Conversely, this analysis may constitute the basis for implementing an optimal estimate procedure.


A rapid objective method for measuring the yeast opsonisation activity of serum.

A simple, objective semi-quantitative assay for yeast opsonisation by normal polymorphs has been developed. This depends on electronically counting the number of free unphagocytosed yeast particles on a Coulter counter. The method has been compared with the widely used microscope technique and shows excellent correlation. The sera of 112 unselected school-children gave a distribution curve consistent with 2 peaks; 7 gave values less than 2 S.D.s below the mean confirming the high incidence of this immunodeficiency.


A review of the literature of rotenone, 1,2,12,12a-tetrahydro-8,9-dimethoxy-2-(1-methylethenyl)-1-benzopyrano[3,5-b]furo[2,3-h][1]benzopyran-6(6h)-one.

The chemistry, biotransformation, pharmacology, toxicology, and carcinogenicity of rotenone have been reviewed. Further investigation of the biotransformation pathways of rotenone and other rotenoids should be undertaken. The acute and chronic toxicology, particularly at low concentration, should be determined in order to develop toxicity rating for this class of chemicals. A mutagenic study utilizing all presently available methods would add further knowledge concerning sites of action. More information is required to properly evaluate the hazards to humans from rotenone and other rotenoids. Carcinogenic studies at low concentrations with large groups of rodents must be undertaken to settle the present dilemma of carcinogenicity vs. non-carcinogenicity. Moreover, an epidemiological study of exposed workers might develop information concerning the toxicology of rotenone as well as its possible carcinogenicity to humans.


Depression of humoral immunity in rats following chronic developmental lead exposure.

Chronic pre- and postnatal exposure of CD rats to low levels of lead resulted in a marked depression in the antibody response to SRBC as well as decreased serum IgG levels. Serum IgM and IgA levels were normal. The fact that the antibody response to LPS, a thymus independent antigen, was not altered, suggested that the T-lymphocyte rather than the B-lymphocyte is affected by lead exposure. Additional significance is lent to these results when blood lead levels in treated rats were found to be similar to levels found in many children in urban areas.


Colchicine induces multiple axis formation and stalk cell differentiation in Dictyostelium discoideum.

Colchicine is shown to have several effects on the development of the pseudoplasmodia of the cellular slime mould Dictyostelium discoideum. At concentrations of 0.01 M and above culmination was prevented, while differentiation of cells into stalk cells occurred at the rear of cell masses. Essentially all cells transformed into stalk cells when slugs were left on colchicine agar for a long time. At concentrations of 0.01 M normal slug architecture was maintained while above 0.025 M pseudoplasmodia reorganized into multiple mounds. Each of these mounds developed an apparently normal discrete tip which was devoid of prespore cells as shown by immunofluorescent staining. The same effects were observed in growing cultures and in regulating slugs treated with colchicine. The data are consistent with the ideas that microtubules are involved in the maintenance of slug architecture and in the differentiation of stalk cells. The modes by which these intracellular structures may operate in these functions are discussed.


Genetic activity of trichloroethylene in yeast.

Trichloroethylene (TCE) was tested for its ability to induce both point mutation and mitotic gene conversion in diploid strain of yeast. Saccharomyces cerevisiae (strain D7) was tested for both activities in culture with and without a mammalian microsomal activation system and in the intrasanguineous host-mediated assay in mice. Strain D4 (gene conversion) was tested only in the host-mediated assay. In suspension tests with D7, TCE was toxic but not genetically active without microsomal activation. When a mouse liver 10,000 xg supernatant was included in the suspension tests, dose related increases in both mutation and gene conversion were seen at survival levels of greater than 50 percent. In the host-mediated assay, TCE induced both point mutation and gene conversion in D7 and gene conversion in D4 when recovered from the liver and kidneys after both acute and subacute dosing. Yeasts recovered from the lungs showed little, if any, increase in either point mutation or gene conversion.


The mutagenicity of saccharin impurities. I. Detection of mutagenic activity.

Sodium saccharin, ortho-toluenesulfonamide and impurities extracted from commercially produced saccharin with water and organic solvents were tested for mutagenicity with strains of Salmonella typhimurium. The organic solvent soluble impurities exhibited strong mutagenic activity for TA98 and slight activity for TA100. Mutagenic activity for S. typhimurium TA98 was demonstrated in extracts of some but not all lots of sodium saccharin produced by both Maumee and Remsen-Fahlberg processes. The significance of the mutagenic impurity to the carcinogenicity of saccharin is discussed.


Hair dye toxicity--a review.

This article reviews local and systemic effects which relate to hair dye formulation and hair dye ingredient tests and experiences in man and animals. Mutagenic and carcinogenic aspects are discussed. In a very limited way, safety and hazards of using hair dyes are interpreted for consumers.


Review of in vitro systems with potential for use in teratogenicity screening.

In this review an in vitro system is considered to be any developing tissue, organ, or organism other than mammalian embryo in situ. Before the various test systems that have been used or proposed are discussed, attention is given to the questions of whether all chemicals in the environment are in need of biological testing and what criteria should be used in making this judgment. Consideration is also given to selection of the appropriate level of rigorousness to be used in tests of different categories of chemicals. To aid in this, the characteristics of an optimal test are assembled and used as a standard for estimating the potential usefulness of the various in vitro systems. The systems discussed include bacteria and other unicellular organisms, somatic cells in culture, tissue culture, organ culture, intact invertebrate embryos (e.g., drosophila, sea urchins, sand dollars), intact lower vertebrate embryos (e.g., frogs, other amphibians, fish), cultured mammalian embryos, and incubating chick embryos. None of these are regarded as sufficiently validated in terms of comparisons with known teratogenic responses in pregnant mammals to warrant adoption as a reliable test at this time. Intact embryos of drosophila, sea urchins, amphibians, and fish are regarded as promising, but much research is needed to ascertain their predictive validity for mammals. The incubating chick embryo, however, possesses more of the essential features of the optimal system than any of the others. A tentative proposal using the chick is outlined, but it will require considerable further comparison with currently used procedures in pregnant mammals before its reliability can be fully evaluated.


DNA damage and repair in vivo.

DNA damage has been implicated in carcinogenesis, mutagenesis, and aging. DNA excision repair has been implicated as an ameliorating factor for such damage. It has been proposed that there is an error-prone post-replication repair system which is both mutagenic and carcinogenic. Assay of DNA damage and repair may thus illuminate the mechanism of carcinogenesis and serve as an indicator of the carcinogenic potential of environmental agents. DNA damage induction and repair can differ in vitro and in vivo. In order to rationally evaluate environmental health effects, it is therefore important to examine DNA damage induction and repair in vivo. An in vivo method is defined here as one in which the DNA is damaged and repaired in cells in situ in the organism. In vivo methods for studying DNA adducts and excision repair, strand-breaks and strand-break repair, post-replication repair, and photoreactivation repair, and the current state of knowledge of DNA damage induction and repair in vivo, are reviewed and evaluated.


Nonspecific resistance to bacterial infections. Enhancement by ubiquinone-8.

A lipid fraction from Escherichia coli was extracted with apolar solvents and was found to protect mice from a number of experimental bacterial infections. The benzoquinone, ubiquinone-8, was isolated from this extract by high pressure liquid chromatography and identified as such by nuclear magnetic resonance and mass spectrometry. At a dose of 25 mg/kg this substance was found to provide complete protection against otherwise lethal infections with gram-negative and gram-positive bacteria in mice. Treatment was most effective when given intravenously 24 h before infection. In comparative studies, ubiquinone-8 had a clearly higher activity than ubiquinones-4, Q6, and Q10. A highly significant increase in the clearance rate of bacteria from the blood by the spleen and the liver of treated animals, correlated well with the protective effect of ubiquinone-8. The compound stimulated the ability of mouse macrophages to incorporate sheep erythrocytes and significantly increased the number of antibody-producing cells in spleens of mice.


Effects in animals of chronic administration of spironolactone--a review.

Spironolactone, an aldosterone antagonist, has been found effective in the treatment of certain forms of hypertension, ascites, and edematous conditions. Since patients may receive daily doses of spironolactone for many years, it is important to determine the chronic effects on tissues. This study reviews the tissue changes in rats, dogs, and monkeys receiving spironolactone daily for up to two years. Dose levels were frequently in excess of 100 times the recommended human dose. The pituitary, adrenals, and kidneys of all animals showed no significant changes. Histologic changes were noted in rat livers, thyroid, and male internal genitalia. There were alterations in monkey testes and male mammary glands. This study found no evidence to suggest that spironolactone is tumorigenic or carcinogenic. Species differences in metabolism may account for the diversity of tissue observations.


Lethal graft-versus-host disease after bone marrow transplantation across minor histocompatibility barriers in mice. Prevention by removing mature T cells from marrow.

In two situations, transfer of normal unsensitized bone marrow cells into heavily irradiated H-2-identical allogeneic mice caused a high incidence of lethal chronic graft-versus-host disease (GVHD), i.e. mortality occuring between days of 20 and 80 postirradiation. Minor histocompatibility determinants appeared to be the main target for eliciting GVHD. Removing mature T cells from the marrow with anti-Thy 1.2 serum and complement before injection prevented GVHD. On the basis of adding purified T cells to T-cell-depleted marrow cells, it was concluded that contamination of the marrow with as few as 0.3% T cells was sufficient to cause a high incidence of lethal GVHD in certain situations. No GVHD was found with the injection of non-T cells (Thy 1.2-negative cells) or with tolerant T cells. Irradiated recipients of T-cell-depleted marrow cells remained in good health for prolonged periods. These mice showed extensive chimerism with respect to the donor marrow, normal numbers of T and B cells and were immunocompetent. The data provide no support for the view that chronic GVHD developing after bone marrow transplantation in man is the result of an attack by the progeny of the donor stem cells. The results imply that mature T cells contaminating marrow inocula are probably the main cause of GVHD seen in the clinical situation.


The type-specific polysaccharides of Streptococcus suis.

Streptococcus suis types 1 and 2 were subjected to digestion with lysozyme. Serologically type-specific capsular polysaccharides were isolated from the lysates by ethanol precipitation followed by Sepharose 6B chromatography. The purified type 1 polysaccharide has a Kd value of 0.074 on a Sepharose 4B column and contains galactose, glucose, N-acetyl glucosamine, N-acetyl galactosamine, and sialic acid in a molar ratio of 2.42:1.00:1.00:1.13:1.39. The type 2 polysaccharide has a Kd value of 0.185 and is composed of rhamnose, galactose, glucose, N-acetyl glucosamine, and sialic acid in a molar ratio of 1.07:3.17:1.00:0.94:1.00. A comparison is drawn between the type polysaccharides of S. suis and those of group B streptococci.


A method for teaching techniques of office surgery.

A method of instruction in basic wound repair and the teaching of suturing skills such as might be used in the office or Emergency Room is described which has been used effectively in family practice resident training. The method utilizes pigs' feet with four specific exercises and objectives accomplished: (1) stellate or Y-shaped laceration; (2) semi-circular, bevelled, flap-type laceration; (3) elliptical, excisional biopsy with "dog ear" correction; and (4) Z-plasty revision. Diagrams are provided, explicitly demonstrating proper techniques of the above exercises. A brief comment on skill evaluation concludes the paper.


An electron microscopic study of the location of peptidoglycan in group A and C streptococcal cell walls.

The morphological appearance of deproteinized Group A and C streptococcal walls after treatment by different procedures extracting teichoic acids and polysaccharides (formamide, hydrochloric acid, nitrous acid, trichloroacetic acid, sulphuric acid, sodium hydroxide and sodium deoxycholate) was compared with the content of teichoic acids and polysaccharides remaining in the treated walls. All procedures extracted teichoic acids almost completely, but polysaccharides were extracted to various degrees. The ultrastructural appearance of walls after these extractions still exhibited the triple-layered wall profile; only a reduction of thickness of the wall and of electron density of the layers occurred. There was no direct correlation between the reduction of rhamnose content and thickness of walls. The ultrastructural localization of peptidoglycan in the streptococcal walls was explored by means of the indirect immunoferritin technique using anti-peptidoglycan antibodies isolated from anti-Group A-variant antisera. Ferritin particles were bound predominantly to filamentous structures which protruded from both surfaces of peptidoglycan fragments and isolated walls. Peptidoglycan was also detected on the filamentous protrusions of whole cocci. These results contradict models of the streptococcal wall in which peptidoglycan forms the innermost layer and support a mosaic structure in which peptidoglycan forms a network of the peptidoglycan-polysaccharide complex.


Somatic O-1 antigen conversion of Salmonella typhimurium by a type B phage P221dis, hybrid between P22 and Fels 1 phages.

A type B Salmonella phage P221, derived from recombination between a type A phage P22 and a type B phage Fels 1, carries the protein coat of Fels 1 and the P22 early genes, at least the c to h21 genes. One of the P221 strains, P221dis, is dismune over P221 lysogens and co-immune with P22. Thus it carries the Im gene (the second immunity region) of P22 to establish co-immunity with P22. Since the att region and a1 gene for somatic 0--1 antigen conversion of P22 are located between the Im and c genes, the P221dis prophage attachment site and 0--1 antigen of P221dis lysogens were analysed. P221dis prophage is integrated at the attP22 site near the pro A region of the bacterial chromosomes and expresses the somatic 0--1 antigen.


Are divided doses of tricyclic antidepressants necessary?

A double blind control comparison on the effects of 50 mg of clomipramine given three times a day and 150 mg of clomipramine in a single bedtime dosage revealed no significant differences in therapeutic efficacy. Patients reported more lightheadedness and dizziness but no differences on other side effects. The theoretical basis was the long biological half-life of such tricyclic antidepressants. Advantages included ease of administration, patient compliance, and timing of sedative effect.


Intraventricular administration of amikacin for complicated Gram-negative meningitis and ventriculitis.

Four pediatric neurosurgical patients with Gram-negative meningitis and ventriculitis were treated with parenteral and intraventricular amikacin, a new aminoglycoside. The organisms infecting these patients were resistant to multiple antimicrobial drugs but were sensitive to amikacin. Treatment was continued for 14 days after cerebrospinal fluid cultures became negative. All four patients were cured and have demonstrated no nephrotoxicity, ototoxicity, or evidence of persistent infection on follow-up examination.


Aspergillus infection in a patient receiving immunosuppressive drugs.

A rare case of an indolent Aspergillus infection in a deep neck space in an immunologically compromised patient is reported. Aggressive measures were taken to identify the cause of the infection. Despite concerted antifungal therapy, the patient died.


Middle-third facial advancement: treatment considerations in atypical cases.

A systematic evaluation of facial esthetics in individuals with dentofacial and craniofacial deformities is necessary to achieve optimum results. This is especially true in deformities of the middle third of the face, as cephalometric analyses provide minimal useful information about frontal facial esthetics. Further, three-dimensional interrelations of the appearance of the forehead, nasal dorsum, globe, infraorbital, malar, and paranasal regions cannot be adequately evaluated through cephalometric examination. Many individuals with facial deformities do not have stereotyped deformities, and, therefore, the use of "standard" operations to correct apparently similar deformities will result in less than optimal results.


Review of factors contributing to dry socket through enhanced fibrinolysis.

Use of oral contraceptives and trauma during extraction are substantiated factors that contribute to dry socket. They appear to act by enhancing fibrinolytic activity in the alveolar bone followed by lysis of the clot. The influence of bacteria and antibiotics on the development and prevention of dry socket remains unclear. No convincing evidence can be found that factors such as age, sex, or nutritional status affect the incidence of dry socket.


An ultrastructural examination of the interaction between macrophages and Cryptococcus neoformans.

The interaction of mononuclear phagocytes with Cryptococcus neoformans was examined in vitro and in vivo using ultrastructural techniques. Immune serum roughens the surface of the yeast and in the first 2 hr, increases the number of organisms attaching to the macrophage surface, as well as the number of contacts between individual yeasts and the phagocyte. Contact is established by means of thin filopodia and cytoplasmic flaps. During the next few days the macrophages increase in size, and, by intimate apposition of their contiguous cell surfaces, a cellular barrier surrounds the now enclosed yeast. These events are accompanied by thinning of fungal capsule, degradation of the enclosed cryptococcus, and the formation of macrophage polykaryons. Electron cytochemical techniques for peroxidase reveal that these multinucleated cells are formed predominantly by the fusion of stimulated macrophages. Destruction of the enclosed yeast probably results from the secretion of various agents by the surrounding cells.


The pathology and pathogenesis of chronic lead nephropathy occurring in Queensland.

Many children who suffered acute lead poisoning in Queensland eventually died with contracted kidneys. In most cases the kidneys were granular and showed microscopically fibrosis, hypertensive vascular changes and "alterative glomerulitis". Clinically in these patients, hypertension and chronic renal insufficiency had always preceded death which was usually due to uraemia. In a minority of cases the kidneys showed the changes of benign hypertension but were unusually small; fibrosis and "alterative glomerulitis" were not present. Clinically these patients had had hypertension but minimal renal insufficiency and death was usually due to cerebral haemorrhage. The evidence indicates that lead caused severe damage to the kidney at the time of the lead intoxication by some mechanism other than hypertension. The sequence of events postulated comprises severe renal damage with destruction of glomeruli during childhood lead poisoning, disappearance of the destroyed tissue during childhood and adolescence, onset of hypertension in adolescence or early adult life, gradual onset and progress of chronic uraemia during which fibrosis and granularity developed. In milder cases the sequence is not complete because renal function has remained adequate.


In-vivo effects of anti-inflammatory and other drugs on granulocyte emigration in the rabbit skin collection chamber.

A method for measuring localised leukocyte mobilisation under in-vivo conditions with a plastic skin collection-chamber adapted to the rabbit ear was used for assessing the effects of anti-inflammatory and other agents on granulocyte emigration. Studies on the effect of oral drug administration to rabbits indicated that most anti-inflammatory drugs, two cystostatic agents (cyclophosphamide and colchicine), but none of the other compounds exhibiting antihistaminc, beta-adrenolytic or neuroleptic properties, significantly inhibited granulocyte mobilisation. The results after topical application of some of these agents into the chamber correlated well with those obtained after oral treatment. This technique may thus prove useful in selecting new compounds inhibiting granulocyte mobilisation in acute inflammatory reactions.


Myogenic cells in Kaposi's sarcoma: an ultrastructural study.

An ultrastructural study of a metastatic Kaposi's sarcoma in a cervical lymph node demonstrated the presence of endothelial cells, smooth muscle cells, fibroblasts and myofibroblasts. Some of these cells exhibited phagocytic activity in relation to extravasated red blood cells. The ultrastructural features favour the suggestion of an origin of Kaposi's sarcoma from pluripotential mesenchymal cells which may differentiate into more specialised cell types including endothelial, smooth muscle, fibroblastic and myofibroblastic cells.


Histological study of homografts showing delayed rejection following levan administration.

The delaying effect of continued administration of levan on mouse skin homograft rejection was found to be due mainly to inhibition of thrombotic occlusion of the nutrient blood vessels. Levan administration did not appear to affect epidermal regeneration, but it seemed to inhibit degranulation of mast cells, resorption of plasma extravasated during the operation and growth of granulation tissue. The delayed rejection caused by levan treatment was apparently caused by infiltration of the graft by activated mononuclear cells from the blood stream. The phenomenon is believed to represent a late stage of the graft rejection process, its apperance depending on the survival of the graft beyond the stage of vascular occlusion.


Current views on the mechanisms of pulmonary oedema.

Understanding of the causes of pulmonary oedema must be based on knowledge of the mechanism responsible for fluid exchange between the several compartments of the normal lung. Recent physiological studies have clarified the main features of these mechanisms. However in three areas knowledge is still incomplete--the magnitude of the hydrostatic and oncotic forces responsible for fluid movement within the lung, the means by which protein leaks across the wall of small pulmonary vessels and the routes by which fluid and protein pass between the interstitial tissues of the lung and the alveolar space. Further work is needed in these areas. On the basis of this physiological knowledge the mode of development of hydrostatic oedema, the role of lymphatics in pulmonary oedema, and the several stages of pulmonary oedema development that may culminate in alveolar flooding are now clearly understood. Knowledge is less complete about oedema due to increased vascular permeability. In some experimental models, such as alloxan, leakage is due to irreversible injury to the alveolar wall; in other models, including ANTU, oedema formation has been shown to depend upon minor and reversible changes in pulmonary vascular endothelium similar to those that cause exudate formation in areas of acute inflammation. In no instance is detailed information available of both the rate and magnitude of protein leakage and of the morphological basis of increased vascular permeability. Further work is required in this area. Present knowledge allows an adequate explanation of the changes that occur in many clinically important types of pulmonary oedema, including cardiac failure and neurogenic pulmonary oedema. Other types of oedema, notably that which may complicate traumatic shock or extrapulmonary sepsis and high altitude pulmonary oedema, are more complex and the details of their pathogenesis are still obscure.


Human colostral cells: phagocytosis and killing of E. coli and C. albicans.

Cells from human colostrum, collected from mothers within 48 hours of delivery, were examined for their capacity to phagocytose and kill Eschericia coli and Candida albicans. The phagocytic power of colostral cells was comparable to that of blood leukocytes from the same individuals. In contrast, the capacity of colostral cells to kill microorganisms was significantly less than that of blood leukocytes. Preincubation of blood leukocytes with colostrum supernatant did not reduce phagocytic indices, but reduced E. coli killing by 40% and C. albicans killing by 66%. The role of colostral cells in protecting the neonate from infection is discussed in the light of these findings.


Naloxone reversal of mild neurobehavioral depression in normal newborn infants after routine obstetric analgesia.

To investigate the presence of subtle narcotic depression following maternal narcotic analgesia, we have evaluated the effects of naloxone versus placebo in a double-blind parallel group study in 43 normal term newborn infants whose mothers had received routine narcotic analgesia within six hours prior to delivery. Infants were given either an intramuscular injection of 20 microgram/kg naloxone or 0.20 ml/kg placebo after determination of the one-minute Apgar score, and the following measurements were compared: Apgar scores at one and five minutes, capillary blood gas values at one, 60, 120, and 240 minutes, and neurobehavioral assessments at one, 4, and 24 hours. No adverse effects from naloxone were observed. Neither Apgar scores nor capillary blood gas determinations differed significantly between the two groups. Response to sound was significantly higher in the naloxone group at 24 hours. The alertness score was significantly higher for the naloxone group at one and four hours; the general assessment score for the naloxone group was significantly higher at four and 24 hours. Average scores of naloxone and placebo groups were also different at four and 24 hours of age. These data demonstrate that maternal narcotic analgesia may produce subtle changes in alertness and general behavior not reflected by Apgar scores or respiratory status, potentially reversible by administration of naloxone shortly following delivery.


Sequelae of caffeine treatment in preterm infants with apnea.

Growth, neurologic, and ophthalmologic assessments were done in 21 low-birth-weight infants given caffeine for neonatal apnea and in 21 matched control infants. Caffeine significantly decreased the need for and the duration of mechanical ventilation. No difference in growth and development was noted between the control and caffeine-treated infants. A high incidence of cicatricial retrolental fibroplasia was observed in both control (10/21) and caffeine-treated infants (7/18).


Ultrastructure of the anterior alimentary tract of infective-stage Wuchereria bancrofti (Nematoda: Filarioidea).

The anterior alimentary tract of infective-stage Wuchereria bancrofti is divided into the following segments: stoma or buccal capsule, muscular esophagus, glandular esophagus, esophageal-intestinal valve, and intestine. Invaginated external cuticle lines only the anterior stoma. External cuticle and esophageal lining are not continuous and are ultrastructurally distinct; the latter is compared morphologically to the amorphous component of elastin. The glandular esophagus is a composite structure of a stellate contractile epithelial core, surrounded by a sleeve of secretory epithelium. The glandular cytoplasm shows evidence of formation and release of dense secretory granules. At least 2 nerve cell bodies lie within the esophagus approximately 15 micrometer anterior to the esophageal-intestinal valve and their associated processes pass forward and backward through the contractile epithelium. Materials interpreted as ingested flight muscle mitochondria of the mosquito vector appear in various stages of degeneration within the intestinal lumen. It is suggested that, although simple by comparison to some other nematodes, the anterior alimentary tract of infective-stage W. bancrofti functions in the ingestion and breakdown of nutrient materials. The ultrastructure of the excretory cell likewise suggests a functional capability.


The reliability of a colorimetric test in determining gingival inflammation.

This investigation was undertaken to compare the Gindex saliva test scores with the Gingival Index scores and crevicular fluid flow scores, as proposed by Löe and Holm-Pedersen. Eighty-one patients were tested using the Gindex chemical analysis kit. Crevicular fluid was collected from the six teeth advocated by Ramfjord, followed by a clinical assessment of these teeth using the G.I. Of the original 81 subjects tested, 11 were given a prophylaxis consisting of scaling, root planing, polishing, and oral hygiene instruction; and were retested 14 days later. Results of the two-sample t test show that there were no significant differences between males and females in any of the three tested parameters. The sample was pooled and tested for multiple correlations between the G.I., crevicular fluid, and Gindex scores. Nonparametric rank correlation coefficient tests indicated a statistically significant correlation between the three parameters. A pair wise "t" test for the pre- and post-treatment sample demonstrated a significant reduction in the three parameters. A pair wise rank analysis also showed a significant reduction in the G.I., crevicular fluid, and Gindex scores.


The effect of a 1% chlorhexidine gel in the initial therapy of chronic periodontal disease.

Thirty patients took part in a 4 week 'double-blind' clinical trial. Following initial oral hygiene instruction and scaling, half the patients were instructed to brush with a 1% Chlorhexidine gel in the evenings, the other half to use placebo. A standard dentifrice was used in the morning. In both groups there was a marked improvement in all parameters recorded, and although final plaque scores showed a statistically significant difference in favor of the test group, there was virtually no difference in rate or degree of resolution of gingivitis. The use of standard dentifrice was only partially successful in preventing staining.


Bioavailability and related heart function index of digoxin capsules and tablets in cardiac patients.

A loading dose of digoxin (750 microgram) in two commercial formulations was administered to 14 patients with heart disease according to a crossover design. One formulation consisted of soft gelatin capsules containing a solution of digoxin; the other formulation was compressed tablets. All parameters investigated, i.e., serum peak height, time of the peak, area under the serum level--time curve (AUC), and area above the Q--S2I (electromechanical systole) decrease (obtained from polycardiographic evaluation), showed better bioavailability of digoxin capsules than tablets, averaging 36.3%. The better bioavailability of digoxin capsules than tablets seems to be more evident in heart disease patients than that encountered previously in healthy subjects. The AUC and the area above the Q-S2I decrease were linearly correlated only with digoxin capsules.


Antidiuretic action of intravenous and intracerebral pyrogen in conscious rabbits.

1. In conscious rabbits an i.v. infusion of 30 or 60 microgram E. coli pyrogen/kg body wt. decreased urine flow from control of 1.13 +/- 0.11 (S.E. of mean) ml./min to 0.43 +/- 0.09 ml./min while urine osmolality increased from 212 +/- 16 to 679 +/- 82 m-osmole/kg H2O. Clearances of exogenous creatine and p-aminohippurate did not change significantly. 2. Plasma antidiuretic activity (rat bio-assay) increased from control of 15.5 +/- 4.2 to 56.8 +/- 5.5 muu./ml. at the top of antidiuresis. 3. Comparable urine flow and osmolality changes were evoked by a pyrogen dose of only 0.2 microgram per animal injected into the lateral cerebral ventricle. 4. The results suggest that in the rabbit pyrogen stimulates ADH release by an unknown central mechanism.


Regulation of calcium fluxes in pancreatic islets: dissociation between calcium and insulin release.

1. The release of 45calcium from prelabelled pancreatic islets is rapidly and almost totally inhibited by lanthanum. 2. Glucose provokes an intitial fall followed by a secondary rise in 45calcium efflux. The latter rise occurs concomitantly with insulin release. Its magnitude is reduced whenever the secretory response to glucose is inhibited, e.g. in the absence of extracellular calcium, presence of Verapamil, or at high magnesium concentration. 3. However, under suitable conditions, the glucose-induced secondary rise in 45calcium efflux is not totally suppressed whilst insulin release is totally abolished. 4. Inversely, when calcium is replaced by barium in the perifusate, glucose increases insulin output without causing any obvious secondary rise in 45calcium efflux. 5. It is concluded that this secondary rise, which originates from a lanthanum-nondisplaceable calcium pool, does not correspond solely to an exocytotic release of 45calcium. It could represent, in part at least, a displacement of 45calcium from cellular sites and reflect a glucose-induced increase in the rate of calcium entry in islet cells.


Tissue response to overdenture therapy.

Patients who had received overdenture treatment provided with uniform standards were recalled and studied. Two examiners simultaneously and independently evaluated the tissue response using a variety of indices. Data comparisons were made between overlaid teeth and control teeth and between overlaid teeth as a function of time to assess any effects of the treatment. Patients who did not apply fluoride to retained tooth roots had a high incidence of caries. No other significant differences were noted between the health of overlaid teeth compared to control teeth. Patients demonstrated large variations in their ability to maintain low plaque levels and healthy tissues. Despite this, on a longitudinal basis over 2 years, patients were able to maintain plaque levels and gingival response at clinically acceptable standards.


A 2-year longitudinal study of overdenture patients. Part I: incidence and control of caries on overdenture abutments.

1. The development of caries on overdenture abutments is a significant problem. In the patients examined, a high incidence of caries was noted at each recall. While few teeth were lost due to caries (none by first recall, none by second recall, and four by third recall), many teeth can eventually deteriorate and be lost (Fig. 7). 2. Caries can develop in a short period of time as shown by the results of the initial examination (caries present 2 to 8 months after insertion of the overdenture). 3. Some patients seem to be caries susceptible, as shown by the recurrence of caries, notwithstanding caries removal from the overdenture teeth at each recall. For example, a large percentage of patients with caries at the 1-year recall also had caries at the 2-year recall. 4. Patients who were placed on fluoride solution and/or had teeth treated with silver nitrate had a significant decrease in caries when compared to those who received no treatment or were placed on a placebo. 5. Fluoride caused some irritation or burning sensation in tissues of several patients. This was relieved in several patients by a decrease in the frequency of application from daily to 2 to 3 times a week.


Improved design for the Thompson dowel semiprecision intracoronal retainer.

The new design of the dowel differs from the previous one in that the dowel is in contact with the inner shelf line at all times but is eased to enable it to rotate out from the well. The exact alignment of the two shelves is important. Incorporation of anything more than the slightest flare is discourged unless the shelves are at different heights. Finally, the lingual walls do not need to be parallel or at right angles to the axis of rotation, except where the shelves correspond perfectly and are horizontal to the tissue surface. The only requirement is that they do not diverge in the path of rotation.


Basic principles of obturator design for partially edentulous patients. Part I: classification.

A classification for partially edentulous maxillectomy dental arches is proposed. This classification is based on the frequency of occurrence of maxillary defects in a population of 123 patients.


Performance criteria in preclinical denture prosthodontics.

This article has reported on a preliminary study of selected criteria used by The University of Michigan, School of Dentistry Complete Denture Department. Self-evaluation opportunities by students and assessment of performance by instructors using objective criteria have been developed for each phase of complete denture prosthodontics and placed within a text illustrating methods to reach the desired standards. Agreement between all evaluations of the selected criteria studied occurred on 75% of the responses, while agreement by instructors experienced with criteria evaluations occurred on 81%. Further, extensive study into quality assessment must be initiated within the educational setting before valid and reliable criteria can be developed for the private sector. Additional research will be critical to peer-review mechanisms which attempt to be more than grievance committees.


An emergency hydrocolloid unit.

Except for the inconvenience of liquifying the material in some other place, the described setup is almost as convenient as a regular hydrocolloid unit. The chief disadvantage is that the small tanks will hold only about three regular tubes of material at a time.


Antimycotic denture adhesive in treatment of denture stomatitis.

The mycologic findings of Candida albicans or culturally similar yeasts in 70% of the subject sample is consistent with those of other researchers. It is, however, only one of several etiologic factors requiring concomitant study to obtain meaningful results. Use of an antimycotic denture adhesive did not prove to be effective in the treatment of denture stomatitis. Although in the trial it appeared that marginally better results were obtained with the amphotericin medicated adhesive, this could not be substantiated statistically. On retrospective testing in the laboratory, both medicated and placebo materials were found to have an inhibiting effect on the growth of C. albicans. However, it was considered that the beneficial effects noted were probably due to the adhesive and lubricant effects of the test materials in reducing denture trauma in function.


Marginal microleakage in cemented complete crowns.

An in vivo study was developed to observe the penetration of 131INa around the margins of complete crown castings cemented with zinc phosphate cement with and without the application of different protective agents, with the following results. 1. Complete crowns cemented with zinc phosphate cement showed 131INa marginal leakage differences depending on the protective material used prior to cementation. 2. The best protective agent against marginal leakage according to this study was two layers of cavity varnish applied to the margins. 3. The amount of marginal leakage can be influenced by crown adaptation and the film thickness of the cement. 4. There were no differences between test periods of 1 hour or 21 days after cementation.


Basic principles of obturator design for partially edentulous patients. Part II: design principles.

A classification for partially edentulous maxillectomy patients has been proposed, and a suggested design for each class is discussed. A simplified approach to the planning of resective surgery and a guide for the design of the maxillary obturator prosthesis have been presented.


Fabrication of interim acrylic resin removable partial dentures with clasps.

An orderly sequence of steps for construction of an interim acrylic resin partial denture has been presented. The technique allows the dentist to fabricate an effective restoration that has a definite path of insertion and removal that can be placed in the patient's mouth with little time spent on adjustment and correction. This technique may be used with heat- or cold-curing acrylic resin.