Diclophenax sodium (Voltaren) in rheumatoid arthritis: a double-blind comparison with indomethacin and placebo.

Diclophenac sodium, Voltaren, has been tested against indomethacin and placebo in a four-week double-blind between-patient trial in 182 patients with rheumatoid arhritis. The ameliorating effect of Voltaren on the usual clinical parameters was comparable to that of indomethacin, while no significant changes were observed in the placebo group. Side effects during treatment with Voltaren and indomethacin appeared mainly form the gastrointestinal tract and from CNS. While side effects from the gastrointestinal tract were similar in the two groups, side effects from the CNS appeared significantly less frequent during treatment with Voltaren than during treatment with indomethacin. No skin reactions, diarrhoea or gastrointestinal bleeding were observed in either group. Long-term studies are needed to establish the place of Voltaren in the treatment of rheumatoid arthritis.


Role of peroxide in the radioprotective action of thiols in E. coli.

The radioprotective action of cysteamine (MEA) and cysteine in E. coli is due partly to autoxidatively generated hydrogen peroxide (H2O2). This effect, which predominates at low concentrations of the thiols (1-2 mM in neutral solution), is regularly correlated with a metabolic block, measured as inhibition of RNA synthesis. In experiments with E. coli 15 (autotroph) under exponential growth in complete medium, the role of H2O2 was demonstrated by (a) a decreased radioprotective action if catalase was present in the medium; (b) a radioprotective action of H2O2 added to the medium; (c) a decreased protective action in the absence of catalytically active copper; and (d) oxygen being required for the radioprotective action to develop. At higher concentrations of the thiols, their radioprotective action, and the accompanying metabolic block, are less dependent on H2O2 generation and presumably due to a different mechanism. The radioprotective action of H2O2 is possibly related to the radioprotective action in mammals of catalase inhibitors.


Forced duction, active force generation, and saccadic velocity tests.

The forced duction test reveals information about mechanical limitations to full ocular rotation. When voluntary ocular rotation is limited, and the forced duction test is completely free, paresis of an extraocular muscle is suggested. The active force generation test and saccadic velocity measurements both provide information about the active forces available to move the globe. Active force can be felt with the forceps in the force generation test. These forces can be measured quantitatively with the calibrated Scott forceps. The saccadic velocity test measures the work an extraocular muscle performs (the eye movement) but does not measure active force directly. The force available is inferred by comparing saccadic velocity measurements to normal control values. This test is especially useful in infants and children, in whom the force duction test cannot be done without general anesthesia, and whose cooperation is insufficient to allow force generation measurements to be performed. It is likely that future improvements in instrumentation and further knowledge of basic oculomotor mechanisms will increase the value of these techniques in clinical strabismus.


Clinical detection of rejection nephropathy using 125I-labelled fibrinogen.

Using a modified fibrinogen-uptake (FUT) test, 22 patients were investigated at various intervals after kidney transplantation. Eight of the patients had developed or showed early clinical signs of acute rejection crisis at the time of measurement. Another fourteen patients formed the control group with no evidence of florid rejection process. Comparison of the 125I-fibrinogen accumulation in the renal grafts between the two mentioned groups showed clear differences with high statistical significance (p less than 0.001). Uptake of labelled fibrinogen was increased in every acute rejection transplant. Histologically the kidneys with increased accumulation of fibrinogen showed extensive deposits of fibrin in blood vessels, glomeruli, intracapillary thrombi and in the interstitium. Except for the limitations discussed in this paper we consider this test to be of a great clinical value in the diagnosis of rejection episodes.


The rate of skin allografts within the prostate.

There is good evidence demonstrating the absence of lymphatic drainage in the normal glandular prostate. In other organs, such as the brain and anterior chamber of the eye, this property is associated with an impaired response to foreign tissue antigens. We have examined the first set allograft survival of normal skin transplanted between strains of male inbred rats (Lewis leads to Fisher) to various sites including the prostate. The resulting data indicate that the prostate is not an immunologically privileged site when compared to the anterior chamber of the eye. However, prolonged first set allograft survival is seen in the prostate when compared to grafts placed orthotopically. These differences appear to be exaggerated or diminished, depending upon the particular foreign tissue used.


Fungal infections after renal transplantation.

Fungal infections occurred in 3 of 22 renal transplants (13.6%). Two patients developed rhinocerebral phycomycosis, and Rhizopus arrhizus was isolated from cultures of the nasal conchae. Both patients were treated with systemic amphotericin B. Three-and-a-half months after transplantation the third patient developed an acute ureteral obstruction secondary to infection with Aspergillus nidulans; this necessitated removal of the graft. There was no immediate mortality associated with these fungal infections but there was immediate loss of the grafts in the two patients.


Comparative studies of baculovirus granulins and polyhedrins.

Granulins and polyhedrins from five baculoviruses exhibit similar chemical and physical properties. Although similarities are demonstrated, it has been shown that each of the proteins is different and apparently specific to a given virus. The granulins and polyhedrins exhibit a major polypeptide component of an estimated molecular weight of 28,000. Alkaline protease activity has been detected in each preparation. N-terminal analyses reflect differences between granulins and polyhedrins studied: granulosis virus = Asx, and nuclear polyhedrosis virus = Glx. Two-dimensional high-voltage electrophoresis of highly purified granulin and polyhedrin preparations reveals relatedness as well as differences among the proteins as assessed by electrophoretic migration patterns.


Cardiovascular changes in sepsis.

The hyperdynamic circulation characteristic of severe sepsis is not likely due to peripheral arteriovenous shunts since in skeletal muscle, at least, capillary blood flow is increased and varies directly with cardiac index. The finding that flow is normal in some septic patients who are severely ill and close to death suggests that blood flow can no longer be considered the critical factor explaining the death of the septic patient. Clearly, the commonly accepted sequence of low blood flow, tissue hypoxia, lactacidosis, and death does not apply to all patients dying from shock. The hyperdynamic circulatory state and the metabolic changes associated with severe sepsis may be related. Skeletal muscle capillary blood flow was increased in fasting normal subjects and septic postoperative patients, both of whom were catabolic. Therefore, elevated blood flow, which is characteristic of severe sepsis, may be a response to the catabolism of body protein required for energy production. If this concept of sepsis is accepted, it follows that treatment which heretofore has been aimed at increasing blood flow and blood pressure should be redirected to therapy which provides energy substrates and alters hormonal patterns to favor anabolism.


[Allergic rhinitis in children (author's transl)].

Some of the problems within the research field of allergology are discussed. The main topic is the new treatment of allergic nasal diseases with a local glucocorticosteroid. Beclomethasone dipropionate (Beconase) can be given intranasally without any risk of systemic side-effects. The drug is found very effective in the treatment of hay fever, vasomotor rhinitis and nasal polypi in adults. In a double-blind crossover trial with 19 hay fever children, aged 8-16 years, 18 preferred the active drug, none preferred the placebo and one had no preference. It is concluded that 400 mug beclomethasone dipropionate a day is a safe and very effective treatment of nasal hay fever symptoms in children.


Vesicular exanthema of swine.

Vesicular exanthema of swine (VES) was first recognized in 1932. At the time, eradication measures and, later, quarantine procedures were instituted and extension of the disease to surrounding farms appeared to have been prevented. Between 1932 and 1936, however, seemingly unrelated epizootics continued among swine herds being fed raw garbage. In 1936, VES disappeared only to reappear in 1939. The disease was contained within California until 1952, at which time it spread to all the major swine producing areas of the United States. The disease was eradicated in 1959, through the enforcement of laws prohibiting the feeding of raw garbage to swine. Other than the association with raw garbage, a reservoir for VES virus (VESV) was never found. In 1972, a virus isolated from California sea lions--and thus named the San Miguel sea lion virus (SMSV)--proved to be distinguishable from VESV. When SMSV was injected into swine, clinical signs of vesicular exanthema developed, leading to the conclusion that, for all practical purposes, SMSV and VESV were the same. To date, 5 species of marine mammals and 2 species of terrestrial mammals, including feral swine, have been shown to possess antibodies to 1 or more of the 4 distinct SMSV serotypes. Current evidence suggests that SMSV infections occur among both terrestrial and marine mammals inhabiting the California coastal zones. This and the practice of shipping frozen meats known to contain SMSV to mink ranches in Utah point to the possibility that domestic swine in the United States are occasionally being exposed to SMSV. Although marine mammals are a source of SMSV, the primary virus reservoir is thought to be 1 or more submammalian marine species common to the southern California coastline. Such a primary reservoir presumably is the source of a new SMSV serotypes infecting marine mammals and may have been the original source of the VESV serotypes that infected swine through the intermediary of raw garbage.


Vesicular exanthema of swine and San Miguel sea lion virus.

San Miguel sea lion virus (SMSV), recently isolated from marine mammals, and vesicular exanthema of swine virus (VESV), which caused epizootics of vesicular exanthema of swine (VES) over a period of 24 years (1932 to 1956), may be the same virus. This finding is of particular interest because the source of the original VES epizootic was never identified, swine were the only known natural host of VESV, and VESV was thought to have been eradicated. The SMSV has been shown to be enzootic in 2 species of marine mammals found off the coast of California and to cause lesions in swine that are indistinguishable from those caused by VESV. Therefore, we should be alert to recognize situations in which swine might become exposed to SMSV and to consider SMSV in differential diagnoses of vesicular conditions.


Baroreflex sensitivity and carotid sinus dimensions in dogs with coarctation.

Baroreflex sensitivity (BRS) has not been assessed in coarctation, though it is diminished in renal and essential hypertension. Previous experimental studies of coarctation have dealt primarily with renal mechanisms of hypertension, and have relied on constricting the aorta in adult animals. We banded the thoracic aorta in newborn puppies, and performed studies 2 yr later. Blood pressure (BP) elevations, abundant chest wall collaterals, the absence of heart failure, and subsequent necropsy confirmed the full syndrome of natural coarctation in all dogs. Transient BP elevations were induced in conscious, unrestrained dogs with intravenous phenylephrine injections. Reflex bradycardia was quantitated by plotting each pulse interval in microseconds against BP of the preceding beat, and expressing BRS as the linear regression coefficient (slope) in ms/mmHg. Mean BRS in 10 dogs with coarctation did not differ significantly (P greater than 0.1) from 8 normal controls. Carotid sinus diameter (CSD) was also assessed. Carotid arteries were fixed in vivo by prolonged exposure to glutaraldehyde to prevent contraction, then were excised and measured in a calibrated microscope. Mean CSD in 10 dogs with coarctation was significantly greater (P less than 0.01) than in 10 control dogs. The unexpectedly normal BRS in experimental coarctation may be due to changes in CSD induced by hypertension; such changes may only develop in growing animals. Experimental studies of coarctation should use a preparation that mimics the natural lesion.


Comparison of spontaneous and positive-pressure breathing in supine normal subjects.

Distribution of ventilation (V) and perfusion (Q) was studied with 133Xe in eight supine, normal subjects comparing spontaneous breathing (SB) and intermittent positive-pressure breathing (IPPB). Tidal volume, inspiratory flow, and breathing frequency measured during SB were closely matched during automatically triggered IPPB. V and Q in the lung bases (adjacent to the diaphragm) were decreased relative to other regions during SB and further diminished by IPPB at similar volumes. During IPPB, basilar V and Q improved when tidal volume was increased; however; spontaneous hyperinflation resulted in significantly higher basilar V and Q than large tidal volumes delivered by IPPB. Thus, changes in lung volumes and gas exchange in the supine posture are attributable to impaired V and Q in the bases but not in dependent (posterior) regions. IPPB further reduces basilar V and Q, possibly due to loss of interdependence resulting from diminished respiratory muscle contraction. These findings may explain atelectasis during prolonged IPPB in supine patients. Although large tidal volumes improve basilar V during IPPB, spontaneous deep breaths are more effective and may prevent atelectasis better than IPPB at similar tidal volumes.


Quantitation of right-to-left shunting by double indicator and oxygen techniques.

An improved double indicator technique for quantitating right-to-left shunting has been validated in a canine right-heart bypass shunt model and compared to standard O2 shunt measurements in the same preparation. A bolus of dissolved sulfur hexafluoride (SF6) and indocyanine green dye (ICG) is injected into systemic venous return and a single, time-averaged arterial blood sample is collected during the initial circulation of indicators. Because of its low solubility, SF6 is eliminated essentially quantitatively from blood traversing gas-filled alveoli; correction for volatile tracer in arterial blood derived from nonshunt pathways in therefore unnecessary. ICG remains confined to the vascular space and SF6 is not lost in shunt pathways. Ratios of SF6-ICG shunt to directly measured shunt averaged 0.99 +/- 0.27 (SD) in 55 comparisons of shunts ranging from 2 to 25% of cardiac output; differences between actual and measured shunt averaged 0.5 +/- 2.9% of cardiac output. Simultaneously determined ratios of O2 shunt to directly measured shunt averaged 0.98 +/- 0.48 in 34 comparisons; differences between actual and measured shunt were 0.7 +/- 3.4% of cardiac output.


Employing electric shock with autistic children. A review of the side effects.

The use of electric shock in a punishment paradigm has continued to be a highly controversial issue in the treatment of autistic children. While the experimental literature argues for the effectiveness of the procedure for reducing maladaptive behaviors, some clinicians and researchers have expressed fear of possible negative side effects. The reported side effects of contingent electric shock were reviewed in an attempt to evaluate the validity of these fears. The review indicated that the majority of reported side effects of shock were of a positive nature. These positive effects included response generalization, increases in social behavior, and positive emotional behavior. The few negative side effects reported included fear of the shock apparatus, negative emotional behavior, and increases in other maladaptive behavior. The implication of these findings for the use of the shock procedure are discussed in terms of correct usage of the shock, therapist reservations, and alternative procedures.


Myosin-free ghosts of single fibers and an attempt to re-form myosin filaments in the ghost fibers.

With the final aim of replacing myosin in a single muscle fiber, a technique for removing myosin almost completely from single fibers was developed and an attempt to "re-form" thick filaments in the myosin-free ghosts of single fibers was made. Complete removal of myosin from single glycerol-treated rabbit psoas fibers with Hasselbach-Schneider solution was difficult. However, when skinned glycerol-treated fibers were used and 1% (v/v) Triton X-100 was added to the Hasselbach-Schneider solution, almost complete removal of myosin was possible. The myosin-free ghosts of skinned single fibers were very fragile but retained the overall structure. In the ghost fibers, Z-membranes and thin filaments remained. The ghost fibers, after irrigation with myosin, underwent contraction upon addition of Mg-ATP. In the myosin-irrigated fibers, thick filaments were re-formed in lengths from one Z-membrane to the other Z-membrane of a sarcomere, running parallel to the thin filaments. The packing of these two filaments was not good. The isometric tension developed by the irrigated fibers upon addition of mg-ATP was about 10% of the tension developed by untreated fibers. The weak tension developed by irrigated fibers is probably due to the irregular packing of the thick and thin filaments in the fibers. The ghost fibers also contracted, though only slightly, upon addition of Mg-ATP after irrigation with heavy meromyosin.


Development of a self-instructional program on pressure-controlled ventilators.

Discussed are the instructional development, materials, application, and evaluation of a program to train staff to apply pressure controlled ventilators correctly and to recognize and correct malfunctions in the apparatus. The self-instructional portion of the program requires slide sets, audiotapes, workbooks, and some of the sections require special apparatus. The rest of the program includes demonstrations, supervised practice, and experience in a recovery room. Compared to lecture technique, faculty teaching time has been reduced by half; teaching tends to be more satisfying, and the performance of students who complete the self-instructional part of the program is improved. For best results, the self-instructional materials must be supplemented with demonstrations and practice.


Stereochemistry of the formation of cysteine by O-acetylserine sulfhydrase.

The enzymatic preparation of (2S, 3R)- and (2S, 3S)-[3-3H] serine from the corresponding stereospecifically tritiated 3-P-glycerates is described. Following conversion into T-acetylserine, these substrates were used to establish the steric course of the O-acetylserine sulfhydrase reaction. The two samples of cysteine formed in this reaction were analyzed for their configuration at C-3. The results indicate that the replacement of the acetoxy by a sulfhydryl group in the O-acetylserine sulfhydrase reaction occurs with retention of configuration at carbon atom 3.


Synthesis of ribosomal proteins L7L12 in relaxed and stringent strains of Escherichia coli.

The control of the synthesis of ribosomal proteins L7L12 (which lack histidine) was examined during growth and histidine starvation of stringent and relaxed histidine mutants. Since no ribosomes are synthesized during starvation, these proteins, in both the stringent and relaxed organisms, accumulated in the supernatant and were shown to possess both biological and physical characteristics typical of normal L7L12. However, the rate and extent of synthesis of these proteins during starvation is greater in the relaxed strain than in the stringent. These data suggest that the regulation of the synthesis of these proteins, similar to that of ribosomal RNA is regulated by the stringent control system. It was also shown that during normal growth of both organisms, L7L12 is also found in the supernatant as well as on the ribosomes. The L7L12 found in the supernatant under these conditions, however, appears to be different than ribosomal L7L12.


Effect of estrogen on gene expression in the chick oviduct. Studies on the initiation of RNA synthesis on chromatin in vitro.

Studies on the effect of the temperature requirement for RNA chain initiation by Escherichia coli RNA polymerase on DNA, chromatin, and reconstituted chromatin were carried out in order to better understand the nature of the initiation process. Varying the temperature or ionic strength during preincubations had little effect on the formation of stable preinitiation complexes (RS complexes) between RNA polymerase and chromatin. This observation was in marked ocntrast to similar studies performed on native DNA and indicates that initiation sites for RNA synthesis on chromatin are different from those on double-stranded DNA and resemble more closely initiation of RNA synthesis on single-stranded DNA. These results suggest that the local unwinding of the initiation region which is required for RNA chain initiation on native DNA may not be a prerequisite for RNA initiation on chromatin. The results of studies on reconstituted chromatin devoid of different classes of chromatin proteins demonstrate that both histone and nonhistone fractions are essential in maintaining the characteristics inherent to initiation of RNA synthesis on chromatin. Removal of either moderatley lysine-rich histone or arginine-rich histone fractions led to the complete loss of the characteristic "chromatin type" initiation pattern for RNA synthesis, whereas, removing lysine-rich (Fi) histone had no effect. Single strand specific and double strand specific antibodies to DNA and a single strand specific nuclease were used as probes to examine the structure of chromatin sites for initiation of RNA synthesis. Their effects on RNA synthesis suggest that initiation sites on chromatin are not located in freely accessible single-stranded or double-stranded regions of DNA.


EcoRI endonuclease. Physical and catalytic properties of the homogenous enzyme.

A procedure for large scale isolation of Escherichia coli RI endonuclease in high yield has been developed. The purified enzyme is homogeneous as judged by polyacrylamide gel electrophoresis and analytical sedimentation. The denatured and reduced form of the enzyme has a molecular weight of 28,500 +/- 500. In solution the enzyme exists as a mixture of dimers and tetramers of molecular weights 57,000 and 114,000, respectively. We estimate the dissociation constant for tetramer to dimer transition to be less than or approximately equal to 1 x 10-7 M. Steady state kinetic analysis of the endonuclease with ColE1 DNA as substrate showed that the enzyme obeys Michaelis-Menten kinetics. At 37 degrees the turnover number is four double strand scissons per min, and the Km for ColE1 molecules is 8 x 10(-9) M. At 0 degrees the major product of endonuclease action contains only one single strand break in the RI site, and such molecules can dissociate from the enzyme. In contrast, at 30 degrees to 37 degrees, two single strand breaks are introduced into the RI sequence prior to dissociation of the enzyme. A transient enzyme-bound intermediate containing only one break in the RI site was observed in studies of a single turnover at 30 degrees. Kinetic analysis of this reaction indicates that the first break is introduced into the RI site with the first order rate constant of at least 40 min-1, while the second cleavage occurs with a rate constant of 14 min-1. Since the turnover number of the enzyme at 30 degress is only 0.72 min-1, these results indicate that the rate-limiting step is release of endonuclear from its DNA product.


The NADH dehydrogenase of the respiratory chain of Escherichia coli. I. Properties of the membrane-bound enzyme, its solubilization, and purification to near homogeneity.

The NADH dehydrogenase of the Escherichia coli respiratory chain has been identified by the following properties: (a) its location in membrane vesicles; (b) its inhibition by AMP in a fashion similar to that of the NADH oxidase; (c) its specificity for NADH, but not NADPH, with the same Km for NADH as that of the NADH oxidase; (d) its sensitivity when membrane-bound to inhibition by dicoumarol, rotenone, and 2-heptyl-4-hydroxyquinoline-N-oxide, which are also inhibitors for the NADH oxidase. The NADH-dehydrogenase of the cytosol fraction (assayed as NADH-dichlorphenolindophenol reductase activity) differs substantially from the membrane-bound activity both in substrate specificity and in the inhibitors of the reaction. The respiratory chain NADH dehydrogenase was extracted from isolated membrane vesicle preparations by solubilization in Triton X-100, and was purified in buffers containing that detergent. The purification employed chromatography on DEAE-cellulose, precipitation by 30% ethanol, and chromatography on hydroxyalapatite and DEAE-agarose. The most highly purified preparations of the enzyme were homogeneous in migration on polyacrylamide gels containing Triton X-100, at pH 9.5, where one band accounted for all of the protein and activity. Electrophoresis on polyacrylamide gels containing sodium dodecul sulfate showed 1 band of molecular weight 38,000, which accounted for over 75% of the protein on the gel. Because of requirements for either Triton X-100 or phospholipid for activity of the purified enzyme, it is difficult to estimate the level of purification achieved over isolated membrane vesicles. However, we estimate that the enzyme was purified some 30-fold over membrane vesicles, or some 300-fold over whole cells.


Stimulus-secretion coupling of glucose-induced insulin release. Metabolism of alpha- and beta-D-glucose in isolated islets.

Alpha-D-Glucose is known to exert more marked insulinotropic action than B-D-glucose. Both anomers are phosphorylated at the same rate by rat islet homogenates. The islet glucose-6-phosphate dehydrogenase displays a preferential affinity towards beta-D-glucose-6-phosphate, and this coincides with a higher sorbitol content in the islets exposed to beta-D-glucose. On the contrary, the islet phosphoglucose isomerase is stereospecific for alpha-D-glucose 6-phosphate and, hence, the concentration of glucose 6-phosphate is lower and that of the alpha-anomer to lactate and CO2 is also higher than that of beta-D-glucose. This increased glycolytic flux is associated with a more marked inhibitory action on 14Ca efflux, a more pronounced stimulation of 45Ca net uptake and a higher rate of insulin release in the islets exposed to alpha-D-glucose. The more marked insulinotropic action of alpha- as a distinct from beta-D-glucose is thus compatible with the view that glycolysis represents the key component of the sensor device through which glucose is identified in the pancreatic B-cell as a stimulus for insulin release.


Determination of ligand binding: partial and full saturation of aspartate transcarbamylase. Applicability of a filter assay to weakly binding ligands.

Carbamyl phosphate and succinate each bind to six sites in the hexameric aspartate transcarbamylase from Escherichia coli when both ligands are present in saturating concentrations. Their respective dissociation constants are 2.4 and 1400 muM. Positive homotropic interaction, shown earlier for the association of succinate with the enzyme in the presence of carbamyl phosphate (Changeux, J.-P., Gerhart, J.C., and Schachamn, H.K. (1968) Biochemistry 7, 513-538), is also found for carbamyl phosphate binding in the presence of succinate. Apparent half-of-the-sites saturation, previously described for carbamyl phosphate binding in the absence of succinate (Rosenbusch, J.P., and Griffin, J.H. (1973) J. Biol, Chem. 248, 5063-5066), also occurs when succinate binds to the enzyme in the absence of carbamyl phosphate. A second class of three low affinity sites for carbamyl phosphate could be detected in the enzyme when succinate was absent. These results indicate that aspartate transcarbamylase exists in an asymmetric state under several defined conditions. The results reported were obtained with a highly sensitive filter bonding assay, modified to allow the study of the protein-ligand interactions with dissociation constants in the millimolar range. The assay is described in detail. Its validity is demonstrated by the good correlation of the results obtained with those observed with independent methods.


45Calcium localization in islets of Langerhans, a study by electron-microscopic autoradiography.

Attempts were made to localize the sites of uptake of 45calcium in B cells of islets of Langerhans by electron-microscopic autoradiography. Despite the potential sources of error inherent in the partial loss of radioactivity during fixation, and in the relatively high energy of emission of this isotope, distribution of silver grains differed signficantly from random in all experiments. Grains were concentrated over mitochondria and to a lesser extent over storage granules. Incubation of islets in the presence of 10 mM glucose and isobutylmethyl-xanthine before fixation and autoradiography resulted in a small but not statistically significant reduction in silver grains associated with the mitochondria. These results further indicate a dominant role of mitochondria in the regulation of cytosolic calcium concentrations in pancreatic B cells.


Caffeic acid-containing medium for identification of Cryptococcus neoformans.

A new growth medium containing caffeic acid and ferric citrate is described. The pigment produced on this medium is specific for the identification of Cryptococcus neoformans and differentiates it from other cryptococci. The medium is more easily compounded and requires less time for pigment formation than the conventional Guizotia extract media. The medium is stable in the dry form as well as in the prepared form.


Clinical laboratory evaluation of the further improved Enterotube and Encise II.

The most recent improvements in the Enterotube coupled with Encise II permitted identification of routinely and abnormally reacting members of the family Enterobacteriaceae.


Immunofluorescence of yeast in urine.

A study of immunofluorescence of yeast in the urine was carried out in 18 patients with funguria in an effort to correlate gamma globulin coating with evidence of tissue invasion or as an indicator for institution of therapy. Positive immunofluorescence of yeast in urine is common but is neither indicative of upper urinary tract yeast invasion nor a useful guideline for beginning treatment.


Inhibitory effect of heparin on the Limulus test for endotoxin.

Heparin can inhibit the Limulus test for endotoxin unless 0.05 M CaCl(2) and 0.154 M NaCl are added to the lysate.


Rapid diagnosis of mumps virus infections by immunofluorescence methods.

Mumps and its complications, particularly meningoencephalitis, is an important disease problem, and more rapid diagnostic methods are desirable. A study was made of immunofluorescence methods for the early detection of mumps virus isolated in cell cultures, or adsorbed directly from clinical specimens onto guinea pig erythrocytes. A specific diagnosis could be made in hours to 2 or 3 days utilizing immunofluorescence methods, in contrast to about 6 days by standard methods. Details of the direct immunofluorescence methods are presented, to encourage wider application in clinical virology laboratories.


Six-hour pigmentation test for the identification of Cryptococcus neoformans.

Cryptococcus neoformans colonies can be identified within 6 h using paper disks containing caffeic acid and ferric citrate. Indentification is based on the development of a dark brown pigment. Saprophytic Cryptococcus species and common clinically isolated yeasts do not develop the brown color. The concentration of the reagents and the method of storage of the impregnated paper disks are critical for the rapid and specific development of the pigment.


Evaluation of reagin screen, a new serological test for syphilis.

A total of 1,020 serum and plasma specimens were tested using the Venereal Disease Research Laboratory (VDRL), Rapid Plasma Reagin (RPR) card, Reagin Screen (RST) and Fluorescent Treponemal Antibody-Absorption (FTA-ABS) tests. In 257 normal patients, all screening tests were nonreactive; the FTA-ABS test was reactive for one patient. In 588 patients with treated and untreated syphilis, the RST results were 91.7% in agreement with the VDRL and RPR results. In 175 patients with diseases that cause biological false reactions, the RST was 94% in agreement with the other screening tests. The titer of the RST was within one dilution of the corresponding VDRL titer in 91.7% of the 360 speciments tested and within one dilution of the RPR titer in 96.9% of 358 specimens quantitated by both tests.


Unclassified, citrate-positive member of the family Enterobacteriaceae resembling Escherichia coli.

Three isolates of an unclassified, oxidase-negative and citrate-positive, gram-negative bacillus belonging to the family Enterobacteriaceae were studied. With the exception of the citrate reactions, these strains most closely resembled Escherichia coli in their biochemical reactivity.


Rapid spot test for the determination of esculin hydrolysis.

Esculin hydrolysis is a useful test in the differentiation of both gram-positive and gram-negative bacteria covering a wide spectrum of aerobes, facultative anaerobes, and anaerobes. Commonly utilized methods require a minimum of 18 h of incubation in broth or agar medium and utilize the production of a brown-black compound, due to the combination of ferric ions with the hydrolysis product esculetin, as indicator. A procedure is presented that requires 15 to 30 min for completion and utilizes fluorescence loss as the indicator of hydrolysis. Esculin fluoresces at 366 nm, whereas the hydrolysis product esculetin does not. Over 1,400 strains of gram-positive and gram-negative bacteria were tested. There was 98.4% of correlation between the spot test and esculin broth and 97% correlation with the bile-esculin agar.


Convenient system for multiple screening of microbial carbohydrate metabolism.

A rapid technique for inoculating carbohydrate oxidation and fermentation media is described. This method employs 24-well tissue culture trays and a multi-inoculator. Other applications are discussed.


Comparison of the sensitivity of two methods for isolation of Mycoplasma pneumoniae.

Throat swab specimens from 1,494 Marine Corps recruits were inoculated into vials containing diphasic (broth/agar) mycoplasma medium and also onto PPLO agar plates, which were subsequently overlayed with sheep erythrocytes in saline agar. Strains of Mycoplasma pneumoniae were isolated from 89 (6%) of the specimens by one or both of the methods. Eight-one of the 89 (91%) positive specimens were cultured with diphasic medium, whereas only 42 (47%) were cultured with the overlay method (x2 = 7.44, P less than 0.01). The diphasic system for isolation of M. pneumoniae should be the method of choice in clinical and research application.


Comparison of API and Minitek to Center for Disease Control methods for the biochemical characterization of anaerobes.

Two commercially available micromethod multitest systems (API, Analytab Products, Inc., Minitek-Bioquest) were compared with conventional tests suggested by the Center for Disease Control for the identification of anaerobes. Anaerobiosis for the microsystems was achieved using GasPak system (BBL), A total of 175 anaerobes, including 158 clinical isolates and 17 reference strains, were used. Gram morphology, gas-liquid chromatography data, and biochemical reactions from the Center for Disease Control and Virginia Polytechnic Institute anaerobic manuals were used to identify the organisms. The Minitek system included a new anaerobe inoculum broth and two new disks, dextrose without nitrate and nitrate reductase disks. The percentage of correlation of 12 biochemicals using Minitek and 11 biochemicals using the API were compared with the Center for Disease Control reactions. The percentage of correlation of both positive and negative reactions with the API anaerobic strip ranged from 70.8 to 99.4% and with the Minitek from 97.1 to 100%. The microsystems were also evaluated as to the ease of use, adaptabilty to a clinical laboratory, time, and cost.


Rheumatoid factor-producing cells detected by direct hemolytic plaque assay.

Lymphocytes secreting anti-IgC antibodies, rheumatoid factors (RF), can be detected in the peripheral bloods, synovial fluids, and bone marrows of patients with seropositive rheumatoid arthritis by using a direct plaque-forming cell (PFC) assay with sheep erythrocytes sensitized with reduced and alkylated rabbit IgG hemolysin. The autospecific nature of the RF produced by RF-PFC was indicated by inhibition studies in which the order of patency was human IgG greater than rabbit IgG greater than bovine IgG. In metabolic studies puromycin, cycloheximide, and venblastine suppressed RF-PFC. Cyclic AMP and cyclic GMP were without effect. A need was recognized for using full tissue culture media during the cell separation and plaquing procedures to optimize detection of the RF-PFC. RF-PFC may appear in the blood of patients intermittently despite their continuing presence in the bone marrow. They have been found in the peripheral blood, especially during acutely exacerbating polyarticular synovitis, generalized vasculities, or generally active, aggressive disease. RF-PFC were found in synovial effusions of new or recrduescent acute synovitis. RF-PFC were observed to disappear from the peripheral circulation and the bone marrow during therapy with cytotoxic drugs. The data are consistent with the hypothesis that the appearance of RF-PFC in the peripheral blood represents an anamnestic response to transiently appearing antigen. The nature of the antigen is not specified. The bone marrow may be a site of origin of RF-PFC.


The role of lysosomal elastase in the digestion of Escherichia coli proteins by human polymorphonuclear leukocytes: experiments with living leukocytes.

Human polymorphonuclear leukocyte (PMN) elastase has been implicated in various pathological conditions. However, its physiological role remains undefined. One possible function of this enzyme may be digestion of bacterial proteins after phagocytosis. To test this hypothesis, we prepared Escherichia coli labeled with [3H]arginine and treated these bacteria with a lipid-soluble, active-site-directed chloromethyl ketone inactivator of pancreatic and granulocyte elastases (carbobenzoxy-L-glycyl-L-leucyl-L-alanine chloromethyl ketone, dissolved in methanol). Control bacteria were treated with methanol alone. When E. coli pretreated with the inactivator were incubated with solutions of porcine pancreatic elastase or with PMN granule extract, release of trichloroacetic acid-soluble radioactivity was significantly lower than in the control E. coli. Similar results were obtained when treated and control E. coli were fed to viable human PMN. In contrast, release of trichloroacetic acid-soluble radioactivity from E. coli containing [3H]thymidine was not affected by pretreatment of bacteria with elastase inactivator before feeding them to PMN, suggesting that phagocytosis of E. coli had not been inhibited by the chloromethyl ketone. When treated and control bacteria were fed to PMN, no significant difference was observed in the activity of lysosomal beta-glucuronidase recovered from post-granule supernatant fractions of homogenized leukocytes, suggesting that lysosomal degranulation had not been suppressed by the inactivator. However, elastase activity of the same fractions was depressed if the leukocytes had phagocytized chloromethyl ketone-treated E. coli, suggesting that inhibition of PMN elastase had occurred. We conclude that PMN elastase participates in digestion of E. coli proteins by human PMN.


A comparison between conventional gingivectomy and a non-surgical regime in the treatment of periodontitis.

The treatment of periodontitis by scaling and oral hygiene instruction was compared with the same regime augmented by conventional gingivectomy. The procedures were allocated randomly to contralateral sides of the maxillary arches of 28 patients. Following both regimes there was significant reduction in Plaque Index, Gingival Index, crevicular fluid and depths of pockets. There was slight gain in attachment on the non-surgical sides, and a minor loss of attachment on the surgical sides. Comparing the two regimes, over the second half of the study there was no significant difference in Plaque Index or crevicular fluid; however, on the surgical sides there was significantly greater reduction in Gingival Index and depths of pockets. Residual pockets after either technique were associated with more inflammation than where sulcus depths were less than 2 mm. Retrospective comparisons of the initial depths of pockets with the final gingival status indicated that, when initial depths of pockets had been 3 mm or over, surgical treatment was more effective than non-surgical in reducing the final values of both depths of pockets and inflammation; this finding was statistically significant for some, but not all of the parameters. Treatment of shallow pockets by either technique was more effective than the treatment of deep pockets. Final Plaque Index values of zero were associated with significantly less inflammation and pocketing than where plaque deposits could be detected.


Evaluating interactions between fenoprofen and propoxyphene: analgesia and adverse reports by postepisiotomy patients.

Groups of 30 postepisiotomy patients were administered single oral doses of fenoprofen calcium (0, 200, 400, or 600 mg acid equivalent) and/or propoxyphene napsylate (0, 50, 100, or 150 mg). The complete block design permits analysis of variance with determination of orthogonal medication contrasts. Evaluation of the analgesia scores indicates that both drugs were effective. In comparison with the appropriate placebo control, propoxyphene is associated with an increase in elicited adverse reports and fenoprofen is associated with a decrease in adverse reports. The two drugs are additive when given together.


Antiinflammatory drugs and gastrointestinal bleeding: a comparison of aspirin and ibuprofen.

Gastrointestinal blood loss provoked by short-term and long-term therapy with aspirin and ibuprofen was compared in patients with rheumatoid arthritis. Blood loss was assessed by isotope counting of four-day stool collections after infusion of 51Cr-labeled autologous erythrocytes. After two weeks on drug or after one year on drug, aspirin consistently caused more bleeding than ibuprofen.


The retentive ability of various cementing agents for polycarbonate crowns.

The following conclusions may be made within the limitations of this investigation. - A composite resin processed directly against a roughened stainless steel dye, similar in shape to a primary anterior tooth, which has been shaped to receive a polycarbonate crown, shows the highest retentive force measured in pounds per square inch (psi). - A polmethacrylate resin, when used as a cement, also shows high values, probably due to its ability to unite chemically with polycarbonated acrylic and to its low film thickness. - Composite resins of low viscosity, low film thickness, and high compressive and tensile strengths proved also to provide good retentive values and would contribute insolubility to a greater degree than the unfilled resin. - Polycarboxylate, zinc phosphate, and reinforced zinc oxide-eugenol cements are not to be recommended as agents for cementing polycarbonate crowns. - It can be recommended on the basis of retention only, composite crowns should be fabricated directly onto the tooth preparations of carious primary anterior teeth.


Semiporous reinforcing fillers for composite resins: I. Preparation of provisional glass formulations.

A conceptual means of obtaining improved bonding between filler particles and the polymeric binders of composites is presented. It involves preparing glass particles that separate into two interconnected vitreous phases when heated to an appropriate temperature, and then etching these to produce a porous surface layer. Candidate glass compositions were prepared and subjected to heat treatment in a gradient furnace. Compositions susceptible to phase separations were delineated.


Effect of brushing the teeth with a fluoride-containing and fluoridefree dentifrice on the gingiva of dogs.

The effect of brushing the teeth with a fluoride-containing or fluoridefree dentifrice on gingivitis induced by a soft diet was studied in four dogs. Changes in the gingival status were recorded at different stages of the experiment by the gingival indexes, which are a reflection of the external appearance, and by the amount of gingival fluid that is influenced by the pocket depth. The two factors appeared to be directly related although the range of the gingival index was much narrower than that of the amount of gingival fluid. No evident retardation in the improvement of the gingival condition occurred after brushing the teeth with a dentifrice that contained fluoride as compared with using a fluoridefree dentifrice or saline.


A medium for the isolation and enumeration of oral actinomycetaceae from dental plaque.

A supplemented, infusion-based medium that supports the growth of most oral Actinomycetaceae is described. The inclusion of Naf and colistin sulfate enabled actinomyces to be isolated from dental plaque in the presence of few other oral microorganisms.


The immediate overdenture.

The use of remaining roots of teeth enhances denture stability and retention. Teeth previously considered hopeless can now be used successfully as an aid in denture retention. The differential diagnosis for tooth selection and treatment is discussed, along with a step-by-step technique for constructing an immediate denture using prefabricated male and female attachments.


Laminate veneer restoration of permanent incisors.

Direct bonding of composite resins to fractured or discolored teeth has been shown to be a practical and effective method for restoring teeth. Previously, lack of uniform shade matching and excessive bulkiness of material have been associated with full veneer bonding. The ultraviolet light (Nuva-Lite) in our studies penetrates veneers as thick as 2 mm and effectively cures the filler material. We also have used cold-curing bonding materials (Concise and Adaptic) and they seem to be equally effective, although working time is shortened. We have had no clinical problems with this technique and after two years the veneers are intact (Fig 6). A technique has been presented that requires no tooth reduction, except where necessary for caries removal, or time-consuming contouring and color shading. Laminate veneers enable the dental practitioner to obtain consistent esthetics with minimal chair time. Further evaluation of this technique to restore malformed, fractured, or discolored permanent incisors is being conducted.


Silver points and gutta-percha and the role of root canal fillings.

Both gutta-percha and silver points can be used as root canal fillings with a high success rate although it is unlikely that either produces a "hermetic" seal. In the cases cited here, the canals remained dry even though they were not obturated for a considerable length of time (in one instance, for two years); this indicates that tissue fluids did not accumulate in the canals. Moreover, my findings indicate that root canal fillings are not necessary for healing. These observations indicate the need for investigation of the validity of the current concept of the role of the root canal filling in treatment.


Treatment of periodontosis by combined orthodontic and periodontal approach: report of case.

Tooth movement into a suspected area of periodontosis is possible if sufficient time is allowed for filling of the socket. This report describes a 19-year-old woman with periodontosis who had orthodontic therapy and periodontal surgery five years after the initial examination. The disease was arrested and occlusion established through the combined approach of orthodontic and periodontic treatment.


Cytotoxic testing for food allergy: evaluation of reproducibility and correlation.

Cytotoxic food tests still present conflicting opinions concerning their validity. Nine atopic patients with or without a history of food allergy were studied along with 5 nonatopic patients. All tests were conducted in a double-blind fashion with 6 determinations for each of 10 food antigens. Reproducibility of the test (5/6 positive or negative) was demonstrated with wheat, milk, yeast, chocolate, and orange. In the nonatopic group, reproducible results were obtained for wheat, egg, yeast, chocolate, and chicken. Clinical correlation with 11 foods in 7 patients was demonstrated. However, there were 46 positive tests without correlation and 2 negative tests with positive histories. Therefore, there appears to be reproducibility of the tests to only 3 foods but no apparent correlation with clinical symptoms. At the present time, cytotoxic tests offer no reliable help in establishing the diagnosis of food allergy.


An appraisal of Impregon as a deterrent of domestic fungus growth.

Impregon brand of tetrachlorsalicylanilide (TCSA) has been profferred widely as a household fungistatic agent, although its value remains unproved. To assess its effects, this agent was used as a laundry and paint additive and as a treatment for burlap rug backing; after recommended applications of Impregon, coded replicate materials were inoculated with mixed suspensions of fungus particles. No difference was evident in fungus growth points on fabric swatches washed in tap water with and without Impregon. However, growth on both of these was significantly greater than on samples laundered in tap water using only a commercial soap or liquid detergent. Fungus soiling of burlap was not clearly diminished by prescribed applications of Impregon solution 3 mo previously. Similarly, the addition of this agent to paint did not suppress fungus growth on Masonite plaques to which it had been applied. However, comparable levels of Impregon incorporated into agar media substantially inhibited spore germination. These findings suggest that the bioavailability of TCSA is insufficient to provide desired household antifungal effects when Impregon is used in accord with current recommendations.


Acute effects of terbutaline and epinephrine on asthma. Double-blind crossover placebo study.

In order to assess the efficacy and safety of subcutaneous terbutaline 0.25 mg and 0.5 mg as compared to subcutaneous epinephrine, 28 stable asthmatics were studied. After control of environmental exposures in the clinical research facility at the University Hospitals of Case Western Reserve Medical School, the patients were entered into a double-blind crossover placebo-controlled 4-day study. All of the patients showed significant responses to both doses of terbutaline and after epinephrine as compared to placebo (greater than 15% increase in FEV1). In general, the side effects experienced were similar for 0.25 mg epinephrine and 0.25 mg terbutaline. They were slightly more pronounced with 0.5 mg of terbutaline. In terms of duration of action, there was a substantial difference between the duration of effect of subcutaneous epinephrine and subcutaneous terbutaline at both dosages. No cardiovascular side effects of any significance were noted in this study with either agent. We conclude that subcutaneous terbutaline is at least as effective as epinephrine in the management of reversible bronchospasm and may be considered a drug of choice in stable asthmatics.


Clinical implications of left ventricular function in patients with acute myocardial infarction.

Correlation of left ventricular filling pressure (55 patients) with the left ventricular stroke work index (61 patients) provided a rapid means of objectively determining ventricular performance after myocardial infarction. Pressure was monitored by means of the Swan-Ganz balloon-tipped catheter and thermal indicators were used for measuring cardiac output. A hemodynamic grouping of these myocardial infarction patients on the basis of the stroke work index showed close correlation with morbidity and mortality and provided a more accurate prognostic indicator than did the commonly used clinical predictors. Serial assessment of ventricular function further aided in defining the prognosis when it was not clear on admission. Thus, the levels of normal or abnormal ventricular function and the effect of therapeutic measures can be rapidly evaluated by determining the pressures and flows in patients with acute myocardial infarction.


Quantitative immunoautoradiography at the cellular level. II. Absolute measurements using labeled standard cells as a source of reference.

A quantitative autoradiographic method is presented for determining absolute amounts of 125I-labeled compounds on the surface of individual cells. Autoradiographic evaluation of single cell radioactivity is accomplished by comparing the silver grain densities over the specimen and a radioactive standard being exposed simultaneously. In order to obtain a reference source of comparable physical properties, surface-radioiodinated human erythrocytes are used, the radioactivity of which is determined in a crystal counter. A simple enzymatic method for preparing such standard erythrocytes of very uniform label density is described. Numerous experimental advantages derived from the use of the standard are discussed and demonstrated by examples employing various exposure times and different radioactive standards. Hereby, very similar results were obtained when the number of A-antigenic sites was quantified on single erythrocytes in different experiments. The quantification of membrane-bound IgM on single human lymphocytes is shown as another application of this scheme.


An evaluation of the methods available for analysing results from migration inhibitory factor (MIF) test.

In order to illustrate the potential dangers in using some of the methods available for calculating migration inhibitory factor (MIF) activity, selected results have been analysed in a number of different ways. The weights corresponding to the migration areas were used in a single ratio expression and then in a double ratio formula to calculate migration inhibition. Conclusions from these results were made using both the arbitrary 20% inhibition to indicate MIF activity and a statistically-derived minimum percentage inhibition needed to demonstrate a significant effect. The procedure was then repeated using the square root of the weight equivalents of the migration areas. A double ratio expression was preferable to the single ratio formula as the former considered the information from all the control cultures. The degree of inhibition needed to demonstrate MIF activity varied between tests and for accurate interpretation of the results it was necessary to use a statistically derived minimum value for inhibition in each experiment. Use of the square root of the weight equivalents of migration areas in the double ratio method gave conclusions analogous to those using the actual weights. Use of the square root transformation narrowed the difference between sample means and caused a corresponding reduction in within-sample variability.


Clinical presentations and mechanisms of necrotizing angitis of the skin.

Cutaneous necrotizing angiitis may be present as either palpable purpura or less commonly as recurrent urticaria, and each clinical presentation may be associated with hypocomplementemia or a normal complement system. A variety of mechanisms may be operative in the production of necrotic vascular skin lesions that appear as similar, recognizable morphologic lesions. These mechanisms include immune complexes, cellular-type hypersensitivity reactions, and initiation or modulation by mast cells. Two cellular patterns have been recognized in the skin of patients with cutaneous necrotizing angiitis that can be correlated with the involvement of the complement system in serum. In patients with hypocomplementemia, there is an infiltrate of neutrophils that is consistent with a process involving immune complexes; in patients with normocomplementemia there are lymphocytes and activated lymphocytes consistent with participation in part by cellular mechanisms. In both the hypocomplementemic and normocomplementemic forms and as well as in a unique patient in whom the mast cell may initiate the venular damage, the mast cell, which its content of chemical mediators, has the capacity to initiate as well as modulate subacute and chronic vascular damage.


Cutaneous T-cell lymphomas: clues of a skin-thymus interaction.

The common cellular denominator of the neoplastic lymphocytes of the cutaneous lymphomas is the presence of membrane markers of T-cell identity. For this reason these disorders are grouped together as "cutaneous T cell lymphomas". These neoplastic T-cells have a characteristic tissue distribution (preferentially infiltrating the skin and sparing the bone marrow). The abnormal T-cells of the leukemic phase of these disorders produce large amounts of macrophage migration inhibitory factor, which may adversely affect macrophage mobilization, and also stimulate differentiation of B-cells into plasma cells. The antigenic properties, the usual slow rate of replication, and the circulatory route of these cells may be exploitable in the development of more specific therapeutic approaches to the management of affected patients. Although these T-cells have an affinity for the skin, the role of this organ in the proliferation and differentiation of these cells is as yet not established. Localization of the primary site(s) of proliferation awaits completion of in vivo kinetic studies. The neoplastic T-cells from such patients provide important cellular reagents for the study of diverse aspects of lymphocyte biology. They have already been used to investigate mechanisms of lymphocyte triggering, isolate histocompatibility antigens, and characterize anti-T-cell immunoglobulin from patients with systemic lupus erythematosus.


Malignant melanoma.

Recent advances in our understanding of the pathology and prognosis of malignant melanoma make possible rationally designed immunotherapeutic studies. A number of immunologic studies suggest that there may be a specific immune response to melanoma-associated antigens in patients with melanoma; however, other studies have shown lack of specificity, so this issue remains to be definitively resolved. New immunotherapeutic agents, including BCG, TF, and levamisole, among others, offer the potential for improving therapy for patients.


Transfer mechanism of melanosomes in epidermal cell culture.

The mode of melanosome transfer from melanocytes to keratinocytes in epidermal cell cultures has been examined with time-lapse cinematography and electron microscopy. A tip of a melanocyte dendrite containing melanosomes became enfolded by a recipient keratinocyte. It was then pinched off to form a cluster of melanosomes which initially seemed to be surrounded by two layers of membranes. The phagocytized dendrite was gradually decomposed and became an aggregate of melanosomes  surrounded by a single membrane of the keratinocyte. The individual melanosomes were dispersed from the aggregate into the keratinocyte cytoplasm, depending on the size of melanosomes. The larger ones were single and smaller ones were complex. The mechanism of melanosome transfer in vitro is a type of cytophagocytosis. The entire process consists of two steps: the first is a cytophagic process and the second a melanosome dispersion process. The process is influenced by various exogenous factors.


Effect of enterotoxins of Vibrio cholerae, Escherichia coli, and Shigella dysenteriae type 1 on fluid and electrolyte transport in the colon.

Experiments were designed to determine whether the enterotoxins of Vibrio cholerae, Escherichia coli, and Shigella dysenteriae type 1 alter the movement of fluid and electrolytes in the rat cecum. Net secretion of water and sodium were observed after incubation of 1.67 X10(-5) mug of purified cholera toxin (choleragen)/ml for 18 hr or of 50 mug/ml for 3 hr. The effect of choleragen on cecal transport of water and electrolytes was related to the dose. In addition, choleragen increased cecal mucosal content of adenosine 3':5'-cyclic phosphate but did not alter the histology of the cecum. The results demonstrate that the colon responds to choleragen in a manner similar to that of other tissues. In contrast, the enterotoxins of both E. coli and S. dysenteriae type 1 failed to affect cecal transport of water and electrolytes. These observations may explain several phenomena associated with the diarrhea produced by bacterial enterotoxins.


Evaluation of the safety of amantadine-HC1 and the role of respiratory viral infections in children with cystic fibrosis.

Amantadine-HC1, an antiviral drug clinically effective against most strains of influenza A virus, was evaluated in a double-blind trial in 153 children with cystic fibrosis during the initial appearance of influenza A/England/42 virus in the New England area. Infection with this variant strain of influenza virus did not reach epidemic proportions during the study, so that the effectiveness of amantadine in this study population could not be fully assessed. However, the potential symptomatic and biochemical toxicity of amantadine was carefully monitored in a pediatric population. Serologic screening by complement fixation tests indicated that respiratory viruses may be important pathogens in exacerbations of respiratory disease in patients with cystic fibrosis.


Genetic resistance to lethal flavivirus encephalitis. I. Infection of congenic mice with Banzi virus.

Adult C3H/RV mice were highly resistant and adult C3H/He mice were highly susceptible to lethal encephalitis after intraperitoneal inoculation of Banzi virus (flavivirus), but the infectivity of the virus was the same for both strains of mice. Yields of virus were similar from lymphoid tissues of C3H/He and C3H/RV adult mice, but titers of virus in the brain were significantly lower in C3H/RV mice. Lesions of encephalitis developed in both strains but remained mild and self-limiting in C3H/RV mice, whereas widespread necrosis occurred in the brains of C3H/He mice. Resistance to lethal infection after intraperitoneal inoculation developed postnatally in C3H/RV mice and did not reach significant levels until mice were at least four weeks old. Mortality rates among C3H/RV and C3H/He mice were comparable after intracerebral inoculation of virus. Yields of virus, brain lesions, and immunofluorescent staining patterns for viral antigen were similar in intracerebrally inoculated C3H/He and C3H/RV mice. Results indicate that tissues of resistant and susceptible mice in vivo can support replication of Banzi virus about equally well. Thus, genetic resistance to lethal infection with Banzi virus in these strains of mice does not seem to be solely dependent on resistance of tissues to viral replication.


Genetic resistance to lethal flavivrus encephalitis. II. Effect of immunosuppression.

Genetic resistance of C3H/RV mice to lethal infection with Banzi virus (flavivirus) was severely compromised by immunosuppression with cyclophosphamide, sublethal X-irradiation, or thymus (T-) cell depletion. The mortality rate among immunosuppressed mice was usually 100%, but average survival times were shorter for mice treated with cyclophosphamide or for X-irradiated mice (10 days) than for T-cell-depleted mice (17 days). Mice treated with cyclophosphamide had high titers of virus in brain, lymphoid tissues, pancreas, and serum. Viral antigen was widespread in brain and pancreas, and mice developed nonsuppurative meningoencephalitis and pancreatitis. Yields of virus, spread of viral antigen, and lesions in T-cell-depleted mice were similar but less severe. Mice treated with cyclophosphamide did not have detectable hemagglutination-inhibiting antibody. T-cell-depleted mice developed hemagglutination-inhibiting antibody but were not protected from lethal infection. These results indicate that genetic resistance of C3H/RV mice to Banzi virus requires immunological factors, and that T-cells play a significant role in resistance to infection with Banzi virus.


An outbreak of nosocomial infection due to multiply resistant Serratia marcescens: evidence of interhospital spread.

Interhospital spread appeared to be responsible for a large epidemic of infections due to a strain of Serratia marcescens that was resistant to all currently available parenteral antibiotics. Between April 1, 1973 and January 1, 1975, 210 patients in four geographically separate hospitals in Nashville, Tennessee, were infected with the epidemic strain; 21 patients were bacteremic and eight died. Catheter-associated urinary tract infection accounted for the majority of isolates, and broad-spectrum antibiotic exposure appeared to promote the acquisition of the epidemic strain. The serotype (O1:H7) and phage type (186) of the organism were identical in all four hospitals, but background, sensitive strains of S. marcesens yielded a variety of other serotypes. Carriage on the hands of hospital personnel was implicated as the mode of spread within the hospital and apparently was the mode of transmission between the hospitals. Antibiotic resistance was largely episomally mediated, but resistance to gentamicin, cephalothin, and colistin was not transferable.


Rapid microbiologic assay of tobramycin.

Different, rapid, plate diffusion assays of tobramycin in serum were compared with each other and with an overnight assay. These assays were done with Klebsiella edwardsii var. atlantae, which was resistant to many antibiotics. One of the rapid assays of tobramycin tested used a 1:50-1:100 dilution of an overnight culture, and results were recorded after incubation for 5 hr at 35 C. Two shorter assays were also tested with a 1:10 dilution of an overnight assay. The 5-hr assay was as reproducible and as accurate as the overnight assay. The 2.5-hr assay at 35 C proved to be an inaccurate method. Incubation of the assay at 40 C instead of 35 C resulted in more rapid growth of K. edwardsii and in the production by tobramycin of larger and sharper zones of inhibition. The 2.5-hr assay at 40 C was as reproducible and as accurate as the 5-hr and the overnight assays.


Clinical evaluation of tobramycin in urinary tract infections.

Twenty-one patients with urinary tract infections due to Pseudomonas and coli-form bacilli were treated with 80-120 mg of tobramycin per day in two daily doses. Of these patients, 14 (67%) were cured, one improved, three (14%) showed no improvement, and three (14%) showed a substitution of the original pathogen by another organism. Urine cultures demonstrated rapid sterilization in the cases in which patients responsed well, and long-term sterility persisted in at least 50% of the subjects.


A randomized, comparative study of tobramycin and gentamicin in treatment of acute urinary tract infections.

Eighty patients with urinary tract infections were randomly divided into two equal groups; one group received tobramycin, and the other received gentamicin. The daily dose of antibiotic for each group was 3 mg/kg. Mean levels in serum were 4.5 and 4.7 mug/ml, respectively, 1 hr after an intramuscular injection, and the mean duration of therapy was 6.5 days. Mean ages and sex ratios were similar in the two groups. Essentially equal numbers of patients with pyelonephritis and cystitis were assigned randomly to each group. Eradication of infection was similar in patients in the two treatment groups, and there was not a significant number of relapses or reinfections in either group. Renal function was abnormal in seven patients treated with gentamicin and in two patients treated with tobramycin. One patient in the gentamicin group developed a skin eruption. Our data suggest that tobramycin is as effective as gentamicin in the treatment of acute urinary tract infection and may be less nephrotoxic at similar doses.


Tobramycin sulfate: a summary of worldwide experience from clinical trials.

Tobramycin sulfate, a new bactericidal aminoglycoside antibiotic, has been evaluated in 3,506 patients. Its in vitro activity is similar to that of other aminoglycoside antibiotics, except that it is more active against Pseudomonas aeruginosa. Clincal studies have shown that tobramycin sulfate is well tolerated and effective in the treatment of the infections listed below when they are caused by susceptible gram-negative organisms and by staphylococci: infections of the respiratory tract (including cystic fibrosis), central nervous system, skin, soft tissue, and bone (including burns); urinary tract and intraabdominal infections; and septicemia. The overall response was satisfactory in greater than 86% of the patients. Drug-related adverse effects were reported in 3.9% of the patients, and included reactions in the nervous system in 0.6% and in the kidney in 1.5%.


Aspects of the pharmacology and toxicology of tobramycin in animals and humans.

The pharmacology and toxicology of tobramycin in animals and humans are reviewed. After intramuscular and intravenous administration, tobramycin diffuses throughout most body tissues and tissue fluids. Therapeutic concentrations can be obtained by intravitreal or intradural injections. Dogs tolerate intracisternal doses of 0.2 mg/kg without adverse reaction. The half-life of tobramycin in cochlear fluid of guinea pigs and in renal tissues of rats is significantly longer than the serum half-life in these species and is reflected in the ototoxic and nephrotoxic potential of tobramycin and other aminoglycosides. In man, the serum half-life of tobramycin is 2 hr; renal clearance, apparent volume of distribution, and recovery from urine are similar to those parameters for gentamicin. The serum half-life in neonates in prolonged (4.5-8.7 hr). Concentrations of tobramycin in serum are effectively reduced by hemodialysis, but peritoneal dialysis is less efficient in elimination of the antibiotic. Tobramycin crosses the placenta and is concentrated in the kidney and urine of the fetus.


Depressed neutrophil chemotaxis in patients with chronic renal failure and after renal transplantation.

Polymorphonuclear leukocyte chemotaxis, phagocytosis, and bactericidal ability were tested with neutrophlis from patients with chronic renal failure on conservative therapy, from others of regular peritoneal dialysis or hemodialysis, and from a group of patients who had received renal allografts. Chemotaxis was depressed in all groups. Phagocytosis was mildly impaired in the two groups on dialysis. The leukocytes of patients on conservative therapy had mildly decreased killing ability, whereas this function was normal in other groups tested. Sera from all patients, when activated with endotoxin, were poorly chemotactic to normal neutrophils, especially in those on conservative therapy and hemodialysis, but these sera functioned normally as opsonins for phagocytosis. The observed defect in chemotaxis could account, at least partly, for the frequency of bacterial infections in these patients.


Marginal neutrophil pool size in normal subjects and neutropenic patients as measured by epinephrine infusion.

The marginal granulocyte pool (MGP) was measured by epinephrine infusion in normal and neutropenic subjects. Neutrophil response curves to doses of 0.025 to 0.3 mg. in three normal subjects indicated that maximal neutrophil response was achieved by 0.1 mg. In 21 normal subjects, absolute neutrophils increased from 700 to 3,100 per microliter. The percentage increase ranged from 18 to 107 per cent of baseline. The per cent increase tended to be greater with low-normal baseline neutrophils than with high-normal neutrophils, although this relationship was not observed when increase was determined in absolute values. In neutropenic patients mean per cent increase of neutrophils was greater than observed in normal subjects, 121 vs. 50 per cent. Although the increase expressed in absolute neutrophil numbers was less in subjects with lower baseline neutrophil concentrations, there was an inverse correlation between the baseline neutrophil concentrations, there was an inverse correlation between the baseline neutrophils and the per cent increment following epinephrine. Mean increase was 200 per cent in patients with less than 200 neutrophils per microliter, compared with 61 per cent in patients with 1,000 to 1,500 neutrophils per microliter. These results indicate that circulating granulocyte pool (CGP) size may be misleading with respect to total blood neutrophils and in a sense confirm the concept of shift neutropenia, a decreased CGP and MGP as neutropenia becomes more profound suggests that shift neutropenia may be a normal physiologic methanism rather than a distinct neutropenic syndrome.


Studies on the prolonged bleeding time in von Willebrand's disease.

Three experimental models have been employed to investigate the mechanism of the prolonged bleeding time in patients with von Willebrand's disease (vWd). 1-deamino-8-D-arginine vasopressin (DDAVP), a synthetic analogue of the antidiuretic hormone, was administered to normal volunteers and patients with vWd in order to induce a short-term, endogenous increase of factor VIII procoagulant activity (VIIIAHF), factor VIII-related antigen (VIIIAGN), and Willebrand factor (VIIIVWF); and to investigate the relationship between bleeding time and plasma variations of factor VIII-associated properties. In normal subjects DDAVP administration was followed by a marked increase of VIIIAHF, VIIIAGN, and VIIIVWF; yet the bleeding time remained unchanged. The same parameters were also raised in two groups of patients with vWd. In a third group of patients with severe recessive vWd, factor VIII-associated properties, which were not measurable before the infusion, were unmodified. The bleeding time remained unchanged in all vWd patients. To investigate the effect of the exogenous increase of factor VIII-associated properties, cryoprecipitate was given to ten vWd patients before dental surgery. Despite the marked increase of VIIAHF, VIIAGN, and VIIVWF observed after the infusion, bleeding time was not shortened. Finally, in order to evaluate the hypothesis that factor VIII may exert its effect on primary hemostasis locally in the vessel wall, VIIIAGN and its relationship with the bleeding time were studied by direct immunofluorescence in gum-biopsy specimens obtained in vWd patients before cryoprecipitate infusion. No reaction could be elicited in five patients with severe, recessive vWd, whereas venules and arterioles stained positively in five patients with a moderate form of the disease. Immunofluorescence microscopy was also carried out in specimens obtained after cryoprecipitate at a time when the plasma defects were corrected but the long bleeding time was not modified; no reaction was detectable on the vessel wall of the three patients who were negative before the infusion.


Validation of the CO2 rebreathing method for measuring cardiac output in patients with hypertension or heart failure.

The CO2 rebreathing method, a noninvasive indirect Fick procedure, has been previously validated in normal subjects at supine rest and during exercise. In the present study 29 nearly simultaneous measurements of cardiac output were made by CO2 rebreathing and dye dilution in 17 patients with cardiovascular disease, 11 with hypertension, and six with congestive heart failure. Cardiac output at supine rest averaged 5.52 +/- 0.31 L. per minute by CO2 and 5.62 +/- 0.32 L. per minute by dye dilution (r = 0.93). Successive cardiac output measurements by rebreathing varied 6.0 +/- 1.1 per cent (r = 0.96) and by dye dilution, 6.5 +/- 0.9 per cent. Changes in cardiac output during exercise or after beta-adrenergic blockade were reflected by the CO2 method. It is concluded that the CO2 method provides reliable measurements of cardiac output both at rest and during exercise in patients with hypertension or congestive heart failure. Further validation of the method is needed in various disease states before it can be widely applied.


Betahistine in Ménière's disease.

The effects of betahistine hydrochloride (Serc) on the clinical features of Ménière's disease were assessed in two double-blind, placebo-controlled, cross-over clinical studies. The diagnosis was based on a peripheral, fluctuating, recruiting, cochlear (sensorineural) deafness in one or both ears, tinnitus (usually of low tone) and paroxysmal attacks of rotational vertigo. Appropriate auditory and vestibular analyses confirmed the diagnosis. Twenty-four patients were admitted to the studies after careful screening over two-and-a-half years. Twenty-two patients completed the studies, ten of whom received betahistine and placebo for eight weeks each whereas the remaining twelve were given betahistine and placebo for twelve weeks each. the dose of betahistine was the same (16 mg. t.i.d.) in both studies. Daily symptom score cards kept by all patients throughout the studies showed a statistically significant preference for betahistine over placebo with regard to vertigo (p = 0-025), tinnitus (p = 0-010) and fullness of the ear (p = 0-036). Symptom scores of deafness and vomiting indicated trends in favour of betahistine but these did not attain statistical significance. Objective measurements of deafness (mean db. loss), however, showed a highly significant improvement in favour of betahistine, when compared with placebo (p less than 0-001). Vestibular testing revealed no important difference between betahistine and placebo. No unwanted effects or adverse reactions attributable to betahistine were observed during the studies.


Abnormal luteinizing hormone response patterns to synthetic gonadotrophin releasing hormone in patients with polycystic ovarian syndrome.

Basal gonadotrophin and sex steroid levels and responses to an intravenous injection of 100 mug gonadotrophin releasing hormone (Gn-RH) have been studied in 15 patients with polycystic ovaries. Mean basal LH concentration was raised and an excessive, exaggerated and prolonged response was observed after Gn-RH treatment, but patients could further be subdivided into two functional groups on the basis of their basal LH values and LH response patterns. Evidence was also produced which suggested a breakdown in the negative feedback mechanism in these patients.


Masculinity-femininity in fathers of creative male adolescents.

This study investigated the relationship of paternal masculinity-femininity to filial creativity in a sample of high school students and their fathers. Thirty-one male high school students were identified as creative on the basis of teacher nominations and scores on the Remote Associates Test. An equal size control group of students matched on sex, educational level, grade point average, and geographical residence was formed. Fathers of both experimental and control students were administered a battery of tests which included a variety of masculinity-femininity measures. The results seem to support the general hypothesis that creativity is related to parental identification as a function of a less conventional sex-role stereotype, and the more specific hypothesis that there is a relation between paternal masculinity-femininity and filial creativity.


Inferior-border rib grafting for augmentation of the atrophic edentulous mandible.

Use of inferior-border grafting eliminates many of the problems associated with transoral onlay graft procedures. With an inferior-border graft, the graft does not bear the direct pressure of a prosthesis and allows for increase in mandibular height without as much loss of vestibule as in a transoral graft. A skin-graft vestibuloplasty is performed 6 to 12 months after rib grafting but the patient can wear a denture in the interim.


One-stage interpositional bone grafting and vestibuloplasty of the atrophic maxilla.

A technique of one-stage autogenous bone grafting and submucous vestibuloplasty for reconstruction of the atrophic maxillary alveolar ridge has been presented. The advantages are described. Use of this procedure has currently been limited; however, initial success indicates this may be a valuable technique for use in the atrophic maxilla.


Electromyography of the rectum and colon in Hirschsprung's disease.

The electromyographic activity of the large bowel was studied in patients suffering from aganglionic megacolon and in comparable normal infants and children, using of an intraluminal electrode. Graphs obtained in control children showed a basic electrical rhythm of 4-6 waves/min with bursts of high frequency spikes, 3-4/sec, superimposed on the top of the slow waves. The recordings in Hirschprung's disease showed an irregular basic electrical rhythm with waves of variable duration and no high frequency potentials, as long as the electrode was positioned in the aganglionic zone. As soon as the electrode was introduced further up into the normally innervated colon the graph became identical to that seen in the normal bowel. Intraluminal electromyography of the rectum and colon seems to be a suitable procedure to diagnose aganglionosis of the rectum and the extent of the lesion.


Further improvements in the transport of high-risk neonates.

The transport incubator used since 1972 was modified for the CPAP method (continuous positive airway pressure). A very generous indication for the use of this ventilatory assistance in the presence of very early clinical signs of respiratory distress syndrome before or during the transport into the Children's Hospital has contributed towards improving the survival rate of infants with a birth weight of 1001-1500 grams to 84,8% and for those below 1000 grams to 39,4%.


The gingival autograft and gingivectomy.

A rationale and technique for the utilization of the combined procedures of the gingival autograft and the gingivectomy technics for the purpose of pocket elimination and creation of an adequate zone of attached gingiva has been presented. It allows for the predictable and relatively atraumatic treatment of gingival problems in which there has been no deformity of the underlying osseous structures.


Effects of scleral collagen upon the healing of experimental osseous wounds.

Standardized wounds were created in the femurs of 13 female white New Zealand rabbits and implanted with autogenous scleral connective tissue, Achilles bovine tendon collagen chips and cores of cancellous autogenous bone and marrow. A blood-filed wound served as a control. The dynamics of the healing of these wounds over periods of time ranging from 12 days to 3 months was studied by routine histology, fluorescent microscopy and by radiography. Rapid healing of the control and bone implant wounds occurred but was retarded by the implantation of sclera. Collagen chips provoked an active lymphocytic response and severely impeded the healing of the experimental wounds. These experiments were discussed in light of the current interest in allogenic scleral implants in periodontal therapy.


Inhibitory effect of dioctyl sodium sulfosuccinate on pepsin activity.

The inhibitory effect of dioctyl sodium sulfosuccinate of hog pepsin activity was investigated over the pH 1.5-3.0 range. The inhibitory effect was studied using a natural substrate, hemoglobin, and a synthetic substrate, N-acetyl-L-phenylalanyl-L-diiodotyrosine. The mechanistic studies revealed that a substrate-inhibitor interaction was the major mechanism of inhibition with hemoglobin. However, some direct enzyme inhibition also was involved. With the synthetic substrate, the inhibition was due to a competition between the substrate and inhibitor molecules for the enzyme. The possible therapeutic significance of the inhibitory effect of the medicinal surfactant is discussed.


Antinauseant and antiemetic properties of bismuth subsalicylate in dogs and humans.

Laboratory and clinical investigations were carried out to determine the effectiveness of bismuth subsalicylate in allaying nausea by preventing the physical symptom of emesis. In normal conscious dogs, a bismuth subsalicylate formulation caused a dose-related reduction in the incidence of vomiting in response to an emetic dose of ipecac syrup. In normal human subjects, a bismuth subsalicylate suspension, unlike the placebo formulation, successfully subdued nausea and vomiting in 66.7 and 80% of the subjects, respectively, in response to ipecac syrup. Both findings demonstrate that bismuth subsalicylate can provide antiemetic action and that the decreases in the occurrence of emesis in humans and dogs parallels the decrease in nausea found in humans and the nausea suspected to occur prior to emesis in dogs.


[Calorimetric study of thermoregulatory mechanisms at the onset of sweating and during the menstrual cycle (author's transl)].

1 At the onset of sweating, tympanic (Tty), vaginal (Tva) and mean skin (Ts) temperature as well as the sudoral response were studied by direct and indirect calorimetry. Eight women with a normal ovulatory cycle were consecutively exposedt wice to 37 degrees C/20% rh during the follicular phase and again during the luteal phase. 2 Under our conditions, Tty may be used as an index of deep body temperature without any notable influence from ambient temperature. A weighting factor of chi = 0,7 was applied to the internal part of the body for the calculation of mean body temperature Tb. chi was determined by calorimetry, before and after the onset of sweating. 3 The onset of thermal sweating depends on a characteristic Tb corresponding to a specific caloric content of the body. Neither Tty, Tva, nor Ts, alone constitutes the specific stimulus leading to thermolysis by sweating. 4 The set point value (Tb "set") of the thermoregulatory system increases in the luteal phase, compared with that of the follicular phase. 5 Thermal regulation of the proportional control system shows a gain which is not modified during the menstrual cycle. 6 There is no relation between the shift of the set point value (Tb "set") and the increase of urine pregnandiol in the luteal phase. 7 The increase in basal body temperature and its maintenance during the post-ovulatory phase do not seem to be related to an increase in metabolic heat production.


[Discharge pattern of medullary respiratory neurones during thermal polypnea (author's transl)].

1 In "encephale isole" cats with a spinal section in C7, we have recorded the activity of 108 medullary inspiratory or expiratory neurones during normopnea or polypnea induced by local warming of the anterior hypothalamic region. The neurones were grouped according to their axon destination, their discharge pattern, and the correlation level between their unit activity and the phrenic neurogram. 2 In polypnea, 71% of inspiratory neurones remain active. Their firing rates, which increase during inspiratory discharges in normopnea, decrease during inspiratory discharges in polypnea. However, this inversion of discharge pattern is less marked than with phrenic motoneurones. 3 The reduction of activity in polypnea preferentially strikes certain types of neurones. While bulbo-spinal inspiratory neurones all remain active, the propriobulbar inspiratory neurones can be grouped into those which remain active and whose activity is well correlated with the phrenic neurogram, and those which become silent and showing a poor correlation. As a general rule, activity in polypnea and correlation (in normopnea) go together. 4 In polypnea, 56% of expiratory neurones cease discharging. This activity decrease applies to bulbo-spinal expiratory neurones (5 out of 14) and to propriobulbar expiratory neurones (20 out of 31). Among the expiratory neurones, only those with an elevated discharge firing rate and significant correlation coefficient values remain active in polypnea. At this time they generally exhibit a decreasing firing rate and emit only a few spikes in each burst. 5 The results suggest that during polypnea the genesis of the respiratory rhythm is dependent upon a different mechanism than in normopnea.


Dolder bar joint mandibular overdenture: a technique for nonparallel abutment teeth.

A mandibular overdenture technique has been presented that utilizes the Dolder bar joint attachment. Endodontically treated lower canines were retained as abutments. Two techniques for attaching the bar to teeth with divergent root canals were discussed: (1) the Schubiger screw system for those teeth with extremely divergent canals and (2) the Stutz pivots system for teeth with only slightly divergent root canals. The use of the Dolder bar joint offers periodontally involved teeth an improved crown/root ratio and splinting of the teeth. Because the bar is close to the alveolar bone, forces of mastication exert much less leverage to the teeth. Finally, the bar joint offers slight vertical and rotational movement of the denture as well as a stressbreaker action.


Articulator selection for restorative dentistry.

There are many types of articulators that can be used for making fixed restorations. While unquestionably the most accurate, the fully adjustable instrument is not feasible or necessary for many forms of simple occlusal treatment. The effects of tooth-hinge axis radius, intercondylar distance, and condylar inclination on occlusal morphology have been discussed. Guidelines have been proposed for matching the type of articulator with the extent of treatment anticipated. The use of small, nonadjustable hinge articulators is not recommended.


Interim overdentures.

The construction of an interim overdenture using existing removable partial dentures with natural tooth crowns and artificial teeth can be a simple and economical method of providing patients with dentures while tissues heal and teeth are prepared and restored. A more definite prognosis for both the patient and his remaining dentition can be established before the final overdenture is completed. The procedures necessary to provide three types of interim overdentures have been outlined. Patients tolerate this method of changing their dentitions extremely well.


Treatment planning for fixed and removable partial dentures: a periodontal view.

1. Chronic occlusal trauma of partial denture abutments may be observed in radiographs before other clinical symptoms are noticed. 2. Evaluation methods can determine when teeth are unsuitable to serve as abutments, but these methods may not be reliable to predict the capacity for some essentially normal teeth to accept additional stresses. 3. Whenever a potential abutment is tilted so that axial loading is questionable, no restoration should be made.


Characterization of gold-palladium-silver and palladium-silver for ceramic-metal restorations.

Properties, compositions, microstructures, and heat-treatment characteristics of three high-fusing white ceramic-metal alloys were studied. The materials displayed different compositions and as-cast microstructures, but similar tensile properties and heat-treatment responses. Hardness of cast specimens subjected to the porcelain firing cycle was increased by an additional 20 minute heat treatment at 1,300 degrees F.


Complete denture prosthodontics for the radiation patient.

The increased use of radiation therapy for the control of oral cancer necessitates that all dentists concerned with the rehabilitation of oral cancer patients be familiar with this treatment modality. Radiologic equipment, the rationale for their use, and the sequelae to oral treatment are discussed. Misconceptions have developed concerning the advisability of prescribing complete dentures following radiation therapy. However, clinical experience in the Maxillofacial Unit at the University of California, San Francisco, indicates that most radiation patients can wear complete dentures. The need to follow sound prosthodontic techniques is advocated, along with a few modifications related specifically to the radiation patient. Patient cooperation and meticulous care during and following the placement of dentures are stressed to minimize the risk of tissue necrosis and to preserve the well-being of the patient.


Obturator design for hemimaxillectomy patients.

The retention and stability of the obturator for the patient who has had a hemimaxillectomy are major problems. A removable partial denture with a swing-lock retentive design system will provide retention and stability due to the continuous splinting of the remaining teeth during function and a passive multiple retentive-clasp system during relaxation. However, because of the danger of the possible orthodontic action of the swing-lock system, special care should be taken when using this kind of design, and the patient should be closely observed.


The neutral zone in complete dentures.

The neutral-zone philosophy is based upon the concept that for each individual patient, there exists within the denture space a specific area where the function of the musculature will not unseat the denture and where forces generated by the tongue are neutralized by the forces generated by the lips and cheeks. The influence of tooth position and flange contour on denture stability is equal to or greater than that of any other factor. We should not be dogmatic and insist that teeth be placed over the crest of the ridge, buccal or lingual to the ridge. Teeth should be placed as dictated by the musculature, and this will vary for different patients. Positioning artificial teeth in the neutral zone achieves two objectives. First, the teeth will not interfere with the normal muscle function, and second, the forces exerted by the musculature against the dentures are more favorable for stability and retention.


A silicone rubber attachment for primary retention of partial dentures.

A technique for primary retention of removable partial dentures has been described. A soft-tissue-borne restoration provides an increase in primary retention without an increase in forces to the abutment teeth, and the restoration requires a minimal outlay of time and money.


A study of distortion and surface hardness of improved artificial stone casts.

1. The single-pour technique is as accurate as the double-pour technique except for point 6 (palatal point). Here the double-pour technique has greater accuracy. Impression material thickness over point 6 was approximately 15 mm. 2. The double-pour technique produced specimens which had superficial hardness values significantly higher than those of casts produced by the single-pour technique. 3. Specimens made with slurry water showed no greater distortion than specimens from other techniques. Surfaces of the specimens made with slurry water were significantly harder than those of specimens made with distilled water. Both types of specimens were made with the single-pour technique. 4. No significant difference in distortion was found in specimens produced with varying thickness of irreversible hydrocolloid impression material over the occlusal pins.


Constructing cast crowns to fit existing removable partial denture clasps.

A step-by-step procedure has been presented for fabrication of a cast crown to fit an existing partial denture clasp. The procedure can be accomplished in two appointments, and the patient need not be subjected to the incovenience of being without the partial denture between office visits. It is an accurate and easy technique which gives uniform results and eliminates the need for remaking an adequate removable partial denture.


Role of the general dentist in maxillofacial prosthetics.

Care of oral cancer patients requires the opinions and coordinated efforts of various consultants or therapists functioning as a multidisciplinary team to treat individual patients' physical, social, and economic problems. The modern medical concept of total treatment of the patient must include dentistry. Every dentist with interest and training in the basic principles of maxillofacial prosthetics can offer invaluable assistance in the treatment of maxillofacial patients.


The use of intraoral cores to repair complete and partial removable prostheses.

A technique has been described for repairing fractured dentures. The procedure entails use of an occlusal core to correctly position the broken pieces of the denture. This technique is also applicable for repair of removable partial dentures as well as complete dentures. When the cause of a fractured prosthesis can be traced to occlusal disharmony or poor fit, it is not expected that repairing the denture will solve the underlying cause.


Electron microscopic study of Trypanosoma cruzi periplast in tissue cultures. I. Number and arrangement of the peripheral microtubules in the various forms of the parasite's life cycle.

In an electron microscopic study, counts of peripheral microtubules were made in spheromastigotes and trypomastigotes in tissue cultures of embryonic heart muscle cells. In interphase spheromastigotes there were, at the level of the nucleus, approximately 114 microtubules; in dividing forms, there were approximately 222. In trypomastigotes, the number of microtubules varied according to the level of the section--there were fewer than 40 tubules in the pointed ends of an organism, while in the central segment the number of these elements ranged from 60 to 115. The highest number of microtubules was found in the region containing the Golgi complex. The distance between the microtubules was constant, equalling 44 nm, even at the pointed ends of a trypanosome. This suggests that the microtubules course parallel to one another. Cross sections and randomly arranged, variable length, longitudinal sections of the tubules were noted around the kinetosomes in dividing organisms.