Isolation and characterization of conditional-lethal rho mutants of Escherichia coli

Temperature-sensitive nitA (rho) mutants of E. coli were isolated; one of them was characterized as an amber mutant. These strains show the Nit phenotype (transcription of phage lambda DNA independent of the N gene) at low temperatures and are inviable at high temperatures. The mutated sites appear to be between cya and metE on the chromosome. Temperature-sensitive nitA bacteria not only permit leftward transcription of the lambda genome at a high rate in the absence of the lambda N protein, but also allow lambda growth at low temperatures. At high temperatures, phages lambda and T4 are incapable of normal development in these cells, while growth of T7 is not affected. The production of thermally unstable rho by the nitA temperature-sensitive mutant suggests that nitA is the structural gene for rho.

Function of the thin ascending limb of Henle of rats and hamsters perfused in vitro

In order too examine whether there is species difference in the function of the thin ascending limb of Henle (tALH), segments isolated from rat and hamster kidneys were perfused in vitro and compared to results obtained by identical techniques from rabbits. The net water flux and the transtubular potential difference were not different from zero. The osmotic water permeability of the rat and hamster tALH was unmeasurably small. Isotopic and electrically determined permeabilities for Cl- and Na+ were quite high in both species, with Cl- being approximately twice as permeable as Na+. Urea permeability across the tALH of both species was moderate. Solute permeability to NaCl, urea, and raffinose (10(-5) cm sec-1) of the tALH of both species was determined by measuring changes in osmolality of the collected fluid when each solute was added to the bath at the same osmolality. They were 82.2, 38.3, and 6.9, respectively. The relative permeabilities to various ions were estimated from the deflection of the transtubular potential difference when NaCl in the bathing medium was replaced by various salts. The following sequence of permeabilities was obtained across the tALH from both the rat and hamster: Cl- greater than or equal to Br- greater than or equal to SCN- greater than or equal to I- greater than or equal to Na+ = K+ greater than Li+ greater than choline+ greater than or equal to HCO3- greater than acetate- greater than or equal to cyclamate-. These data indicate that membrane characteristics of the tALH of rats and hamsters are similar to the previously published values of rabbits. The conclusion is drawn that the principle of the passive equilibrating model of the countercurrent multiplication system is operative in other mammalian species besides the rabbit.

Effect of bumetanide and furosemide on the thick ascending limb of Henle's loop of rabbits and rats perfused in vitro

Direct effects of bumetanide and furosemide on the thick ascending limb of Henle's loop (TALH) were compared by using the isolated tubules of rabbits and rats perfused in vitro. Both drugs, applied to the lumen, reversibly suppressed the lumen positive potential (PDt) of the rabbit TALH. Bumetanide also suppressed the PDt in the absence of Na+ where the NaCl of the artificial solutions was replaced by choline chloride. The efflux of 36Cl was also reduced by the addition of bumetanide to the perfusate. The dose-response analysis disclosed that bumetanide was 14 times as potent as furosemide. The onset and duration of bumetanide action was significantly longer than that of furosemide. Bumetanide also suppressed the PDt of the rat TALH when it was added to the perfusate.

Escape synthesis of RNA polymerase subunits and termination factor rho following induction of prophage lambda in Escherichia coli

Synthesis of RNA polymerase subunits and of transcription termination factor p was studied after thermoinduction of prophage lambdac1857 located at several unusual sites on the chromosome of Escherichia coli. When a lysogen carrying the prophage at the bfe gene was induced at 42 degrees C, the rate of synthesis of core polymerase subunits (alpha, beta and beta') rapidly decreased, followed by a marked increase after about 10 min. The latter increase was observed specifically in the "bfe lysogen" and not in any of the other lysogens tested. Similarly, the rate of synthesis of p factor increased appreciably in the induced ilv lysogen carrying the prophage at the ilv gene, and possibly in the bfe lysogen as well, but not in other lysogens examined. Taken together with other evidence, these results suggest that the enhanced syntheses of beta and beta' subunits of RNA polymerase and of p factor observerd represent "escape synthesis", resulting from the close linkage of the prophage genome to the respective structural genes. In contrast, omega factor synthesis was stimulated upon induction of any of the lysogens used without respect to the site of prophage location, suggesting the involvement of an entirely different mechanism.

Effect of perfusion rate on the fluxes of water, sodium, chloride and urea across the proximal convoluted tubule

Studies were undertaken to examine the mechanism whereby changes in intraluminal flow rates after reabsorption in the isolated perfused proximal tubule of the rabbit. All protocols employed the technique of in vitro perfusion of isolated segments of the proximal convoluted tubule. Stepwise elimination of d-glucose and l-alanine from an artifical perfusate stimulating ultrafiltrate decreased the unidirectional flux of sodium, transtubular potential difference, and net water absorption. Using isosmolal ultrafiltrate as the perfusate, net fluid reabsorption and the unidirectional lumen-to-bath flux of sodium and chloride decreased with a decrease in flow rate below 11 nl/min, but neither net fluid reabsorption nor the unidirectional fluxes of sodium and chloride increased further as the perfusion rate was increased above 11 nl/min. The unidirectional flux of 14C-urea was not affected by changes of perfusion rate from 1.6 to 44 nl/min. The dependence of net fluid reabsorption and unidirectional fluxes of sodium and chloride on flow rate per se, and not on intraluminal hydrostatic pressure or geometry, was established by demonstrating their decrease despite a rise in intraluminal pressure and inside diameter produced by counterpressure at the collecting end of the tubule, while flow was decreased. Ouabain decreased net fluid reabsorption to near zero at all flow rates, but ouabain had no effect on the flow-dependency of unidirectional sodium anf sodium was eliminated with a decrease in bicarbonate concentration and removal of d-glucose and l-alanine from the perfusate. Thus, the present studies demonstrate that net water and unidirectional sodium and chloride fluxes are flow-dependent. At flow rates somewhere below 11 nl/min, unidirectional fluxes decreased with decreasing perfusion rates; however, at perfusion rates greater than 11 nl/min, there was no further effect of perfusion rate on either net water absorption or the unidirectional fluxes of sodium or chloride. These effects may be partly mediated through the flow-dependent changes in the intraluminal concentration of bicarbonate, d-glucose, and 1-alanine.

Mechanism of sodium and chloride transport in the thin ascending limb of Henle

Our previous in vitro studies have disclosed that the thin ascending limb of Henle (tALH) possesses some unique membrane characteristics. In those studies we failed to demonstrated active transport of sodium chloride by the tALH, although it was shown that the isotopic permeability to sodium and chloride was unusually high. However, we did not examine the mechanisms by which the apparent high permeation of sodium chloride occurs. Thus the purpose of the present studies was to elucidate the mechanism of sodium chloride transport across the isolated tALH of the rabbit by conducting four different types of studies: (1) comparison of the observed chloride and sodium flux ratios to those predicted by Ussing's equation under imposed salt concentration gradients; (2) kinetic evaluation of chloride and sodium fluxes; (3) examination of the effect of bromide on the kinetics of chloride transport; and (4) experiments to test for the existence of exchange diffusion of chloride. In the first set of studies the predicted and the theoretical flux ratios of sodium were identical in those experiments in which sodium chloride was added either to the perfusate or to the bath. However, the observed chloride flux ratio, lumen-to-bath/bath-to-lumen, was significantly lower than that predicted from Ussing's equation when 100 mM sodium chloride was added to the bath. In the second set of experiments the apparent isotopic permeability for sodium and for chloride was measured under varying perfusate and bath NaCl concentrations. There was no statistical change in the apparent sodium permeability coefficient when the NaCl concentration was raised by varying increments from 85.5 to 309.5 mM. However, permeation of 36Cl decrease significantly with an increase in Cl from 73.6 to 598.6 mM. These events could be explained by a two component chloride transport process consisting of simple diffusion and a saturable facilitated diffusion process with a Vmax = 3.71 neq mm-1 min-1. In the third set of studies it was shown that bromide inhibits transport of chloride and that the magnitude of inhibition is dependent on chloride concentrations. The fourth set of studies ruled out the existence of exchange diffusion. In conclusion, these studies indicate that sodium transport across tALH is by simple passive diffusion, while chloride transport across tALH involves at least two mechanisms: (1) simple passive diffusion; and (2) a specific membrane interaction process (carrier-mediated) which is competitively inhibited by bromide.

Large-scale isolation of Dane particles from plasma containing hepatitis B antigen and deomnstration of circular double-stranded DNA molecule extruding directly from their cores

A method was developed to isolate, on a large scale, Dane particles from five liters of pooled plasma of asymptomatic carriers of hepatitis B antigen. It involved three successive ultracentrifugation procedures; the final preparation was more than 98% pure in Dane particles. Purified Dane particles had the density of 1.23 to 1.24 g/cm3. The concentration of nucleic acids in the preparation containing purified Dane particles was too low to be detected either by chemical or by spectrophotometric method. However, a circular double-stranded DNA molecule extruding directly from the core of Dane particles was clearly demonstrated by elelctron microscopic observations. The cores of Dane particles (hepatitis B core antigen; HBCAg) were prepared by treating the Dane particle preparation with mercaptoethanol and Nonidet P-40. They were sufficient both in purity and amounts to allow the determination of antibody to HBCAg by an immune adherence hamagglutination method.

Inhibition of intracellular multiplication of adenovirus by interaction between infected and uninfected cells

The possibility that virus multiplication may be inhibited by interaction of infected cells with uninfected cells was tested by experiments, using human adenovirus type 12 (Ad12). Permissive human cells (human embryonic kidney-HEK,KB or HeLa) were infected and seeded on uninfected or infected "nonpermissive" cell (human embryonic lung=HEL) monolayers, and virus yields or proportions of viral antigen-synthesizing cells were compared with each other. Both the virus yields and the proportions of viral antigen-positive cells were not reduced significantly when seeded on infected HEL cells, while they seeded on uninfected HEL cells both of them were reduced remarkably, compared with the yield and the proportion of controls seeded on glass. Similar results were obtained regardless of the type of permissive cells, HEK, KB, or HeLa. Similar reduction of the yield was observed when seeded on HEL cells infected with Ad12 inactivated by heat or by antiserum, and partial reduction was observed when seeded on HEL cells infected with UV-inactivated Ad12, depending on the extent of UV dosis. These experiments showed that intracellular virus multiplication may be inhibited by interaction of infected cells with uninfected cells, and this may be due to the difference in the cell surface structure.

Hepatitis B antigen-associated deoxyribonucleic acid polymerase activity and e antigen/anti-e system

Serum samples of 403 asymptomatic blood donors carrying hepatitis B surface antigen (HB5Ag) were concentrated threefold and tested for e antigen and antibody to e antigen (anti-e) by immunodiffusion. Hepatitis B antigen (HBAg)-associated deoxyribonucleic acid (DNA) polymerase activity was specifically determined by the difference in incorporation of [methyl-3H]thymidine 5' -triphosphate into DNA by an aliquot of centrifuged serum samples after it had been treated either with normal rabbit serum or with rabbit antibody to HBSAg. All of 58 serum samples containing e antigen revealed HBAg-associated DNA polymerase activity, whereas none of 96 samples containing anti-e did. In the remaining 249 samples in which neither e antigen nor anti-e was found, 62 showed specific DNA polymerase activity, although at lower levels than the samples containing e antigen.

Association of dane particles with e antigen in the serum of asymptomatic carriers of hepatitis B surface antigen

Asymptomatic carriers of hepatitis B surface antigen (HBsAg) were surveyed for serum e antigen (e Ag) and antibody to e (anti-e) by immunodiffusion. Seventeen serum samples containing e Ag and 17 containing anti-e, but with similar HBsAg titers, were tested for the presence of hepatitis B core antigen (HBcAg) by means of immune adherence hemagglutination method. HBcAg activity was detected in all of the samples containing e Ag, and the titer of HBcAg paralleled that of HBsAg in each serum. In remarkable contrast, no HBcAg activity was found in any of the serum samples containing anti-e. Dane particles were demonstrated in 14 of 17 serum samples with e Ag by electron microscopy, but in none of 17 with anti-e. Although both e Ag and HBcAg were closely associated with each other, the non-identity of e Ag and HBcAg was clearly demonstrated by a two-dimensional immunodiffusion test.

e antigen and anti-e in the serum of asymptomatic carrier mothers as indicators of positive and negative transmission of hepatitis B virus to their infants

Testing of serum samples of 23 pregnant women who were asymptomatic carriers of hepatitis B surface antigen for e antigen and antibody to e with an immunodiffusion technic identified 10 mothers with e antigen and seven with e antibody. Their babies were tested for hepatitis B surface antigen in serum at intervals for more than 12 months. In all 10 babies born to e-antigen-positive mothers hepatitis B surface antigen developed and persisted through the observation period, and all 10 elder siblings of these newborn babies were found to be asymptomatic carriers. In remarkable contrast, all seven babies born to mothers positive for antibody to e escaped antigenemia, and none of their three elder siblings carried surface antigen. On the basis of these results, e antigen may be used as an indicator of transmission, and antibody to e as that of absence of transmission of hepatitis B virus from carrier mothers to children.

A case of alcaptonuria with fatal cardiovascular disturbance

A case of alcaptonuria combined with aortic insufficiency was found in a 28-year-old male. The patient was palpitating at admission. The daily excretion of homogentisic acid was 2.0-6.0 g. Electrocardiography indicated atrial fibrillation and left ventricular hypertrophy with a ST-T change and right axis deviation. Cartilage tissues in the knee-joints showed no pigmentation. Vertebral X-ray revealed no calcification. The patient's history disclosed a family intermarriage in his grandparents. The patient's mother noticed the presence of black stains on diapers in his infancy and brown pigmentation on the skin and sclera in childhood. No kin had similar symptoms.

Rapid determination of thyroxine binding proteins of human serum

A simple method is described for determing thyroxine binding proteins in human serum by electrophoresis at pH 8.6, using cellulose acetate membrane as the supporting medium. The procedure had high reliability in sera of normal subjects, pregnant women and patients with decreased thyroxine binding capacity of thyroxine binding globulin.

Methemoglobinemia induced by chlorphenamidine

A 76-year old farmer ingested 100 g of chlorphenamidine (Galectron), a plant acaricle, for the purpose of suicide. Gastric lavage was performed and the patient survived. Methemoglobinemia was noted after emergency treatment and was still present at 20 hours after ingestion of the compound. The patient was lethargic for at least 50 hours. Moderate neutrophilic leukocytosis and kidney injury were observed.

Isolation and genetic characterization of the nitA mutants of Escherichia coli affecting the termination factor rho

Taking advantage of the Spi (sensitivity to P2 interference) phenomenon, bacterial mutants seemingly resistant to phage lambdasusNnin5, but sensitive to phage lambdaspi, were isolated from a strain of E. coli K12 carrying no nonsense suppressor and lysogenic for P2. A class of these mutants, designated nitA (N-independent transcription), is described here. Upon infection of the nitA mutants with a trp transducing phage lambdasusN7N53ptrp46 which carries the E. coli trpE and D genes in the CIII-att region of the lambda genome, formation of anthranilate synthetase (ASase, a complex protein of trp E and D gene products) was clearly demonstrated. In contrast, no ASase formation was observed in the parent nitA+ strain under the same conditions. The synthesis is subject to "turn off" control, and is completely repressed by the CI repressor of phage lambda. The nitA cells lysogenic for lambdaCI857susN7N53 are killed by thermal induction much more efficiently than the parent cells lysogenic for the same phage. The nitA mutants support the growth of lambdasusN7N53byp much better than the parent. These results suggest that the nitA mutation permits the early leftward and rightward transcription of the lambda genome in the absence of the N gene product. On the E. coli genetic map, nitA is located between ilv and metE, nearer to ilv. The mutant allele is recessive to the wild-type allele. The present evidence, together with results of biochemical investigations to be reported, suggests that nitA is a gene specifying the transcription termination factor rho.

[Myocardial sarcoidosis--pathological studies on 7 autopsy cases with particular reference to histological variations]

The present report consists of seven autopsy cases of myocardial sarcoidosis terminating in death 1 month to 5 years after the onset of symptoms. Histologically, they were classified into the following 4 types: a) diffuse nonspecific granulation, b) specific granuloma with giant cells, c) diffuse fibrosis with giant cells, and d) nonspecific fibrosis. Types a) and b) demonstrate active changes, while c) and d) are sequelae of active inflammation. Morphological changes of sarcoidosis were found not only in myocardium but also in both pericardium and endocardium. Although no final conclusions could be obtained as to whether the giant cells appearing in myocardium were of mesenchymal or myogenic origin, the authors favor the latter concept. Changes compatible to sarcoidosis found in other organs in acute cases were scarce and old. On the contrary, more active and variable changes were encountered in protracted cases. The authors consider giant cell myocarditis to be one type of sarcoidosis occurring in the heart.

Characteristics of salt and water transport in superficial and juxtamedullary straight segments of proximal tubules

The purpose of the present studies was to characterize the nature of salt and water transport out of the superficial (SF) and juxtamedullary (JM) straight segments of rabbit proximal tubules as examined by in vitro microperfusion techniques. When the perfusate consisted of a solution simulating ultrafiltrate of plasma, there were no differences between SF and JM straight tubules in either net reabsorption of fluid (SF=0.47 nl/mm per min; JM=0.56 nl/mm per min) or in transtubular potential difference (PD) (SF=-2.1 mV; JM=-1.8 mV). Removal of glucose and alanine from the perfusate had no effect on the magnitude of the PD in either straight segment. Ouabain decreased both the net reabsorptive rates and the PD. Isosmolal replacement of NaCL by Na-cyclamate (a presumed impermeant anion) in the perfusate and the bath caused an increase in luminal negativity in both segments wheras similar substitution of NaCL by choline-CL (nontransported cation) changed the PD TO NEAR ZERO. These studies, therefore, suggest that sodium is transported out of the proximal straight tubules by an active noncoupled process that generates a PD (electrogenic process). When the perfusate consisted of a solution with a high chloride concentration (resulting from greater HCO3 than CI reabsorption in the proximal convoluted tubule), different PDs in SF and JM tubules were generated: SF=+1.6 plus or minus 0.2 mV; JM=-1.3 plus or minus 0.3 mV. This difference in PD was attributed to relative differences in Na and CI permeabilities in these two segments. Electrophysiological and isotopic estimates of the chloride to sodium permeability revealed that the SF tubule is about twice as permeant to chloride than to sodium whereas the JM tubules are approximately twice as permeant to sodium than to chloride. It is concluded that the mechanism of active sodium transport in the straight segment of proximal tubule differs from that of the convoluted segment and that both the SF and JM straight segments differ from each other with respect os sodium and chloride permeability.

[A case of hypocholinesterasemia induced by trichlorfon]

A case of hypocholinesterasemia induced by ingestion of trichlorfon is presented. A female patient took 20 gm of this insecticide for the purpose of the suicide. She was brought to the hospital one hour later, and her life was saved by gastric lavage. Cyanosis on lips and nails, pupils with sluggish light reaction and fibrillary muscle twitch were observed upon arrival. Laboratory examination performed on the admission disclosed a serum cholinesterase activity of 0.3deltapH per hour. The enzyme activity was depressed to 0.05 deltapH per hour on the second day of hospitalization. The enzyme activity then increased gradually in the two subsequent weeks and the patient recovered.

A functional comparison of the cortical collecting tubule and the distal convoluted tubule

Electrical and permeability features of the distal convoluted tubule (DCT) and the cortical collecting tubule (CCT) were examined using the technique in which isolated segments of rabbit tubules were perfused in vitro. When rabbits were given a regular diet and tubules were perfused and bathed in artificial solutions simulating plasma ultrafiltrate, the potential difference (PD) was +3.7 plus or minus 1.9 mV in the CCT and -40.4 plus or minus 2.8 mV in the DCT. When rabbits were given a low sodium, high potassium diet plus i.m. deoxycorticosterone acetate (DOCA) (1 mg/kg per day), the PD in both the CCT (-30.8 plus or minus 3.9 mV) and the DCT (-33.8 plus or minus 5.5 mV) was negative. The PD in the CCT was quantitatively similar to that of diet plus DOCA when animals were given DOCA alone. The PD in both segments was inhibited by ouabain (10-minus 5 M) in the bath or by amiloride (10-minus 5 M) in the perfusate. Addition of vasopressin (200 muU/ml) to the bath caused a gradual decline of PD to zero in the CCT but failed to produce a potential response in the DCT. Osmotic water permeability was essentially zero in both segments in the absence of vasopressin. After addition of the vasopressin to the bath, osmotic water permeability in the DCT remained zero but increased to 71.9 plus or minus 25.5 X 10-minus 7 cm/s per atm in the CCT. We conclude that both segments are similar in that each possesses an electrogenic transport process but that these segments differ in that: (a) the CCT requires either exogenous or endogenous mineralocorticoid to maintain a maximal negative PD, whereas the PD in the DCT appears to be independent of mineralocorticoid effect; and (b) the CCT responds to vasopressin with a marked rise in water permeability, whereas the DCT is impermeable to water before and after addition of vasopressin.

Application of the paired label radioantibody technique to detection and subtyping of hepatitis B surface antigen

A sensitive radioimmunoassay has been developed for the detection and subtyping, in regard to w and r specificities, of hepatitis B surface antigens (HBsAg). The binding of monospecific rabbit antibodies directed to either w or r determinant, labeled with 131I and 125I, respectively, by HBsAg was determined in the same experiment, taking advantage of the fact that these specificities are in general, expressed mutually exclusively. HBsAg in the test sample were bound to solid phase guinea pig anti-HBsAg antibody tube before the test. The ratio of percentage uptake of 125I anti-r to that of 131I anti-w for 28 normal sera without antigen was 0.69 0.18. The ratio for seven sera containing HBsAg with w determinant was less than 0.1, and that for 34 with r determinant was more than 10; 100-fold difference was noted between values of w and r antigens.