Detection of experimental Chlamydia trachomatis eye infection in conjunctival smears and in tissue culture by use of fluorescein-conjugated monoclonal antibody

The immunofluorescent staining of conjunctival cytology smears with an antichlamydial monoclonal antibody is a new method for the detection of chlamydial eye infection. Using a monkey model of chlamydial eye infection, we compared the monoclonal antibody staining cytology with the established methods of Giemsa-stained cytology and chlamydial culture with cycloheximide-treated McCoy cells. Compared with either culture or monoclonal antibody-stained cytology, Giemsa cytology had a low sensitivity (30 and 24%, respectively) but was highly specific (100% in each case). Compared with culture, monoclonal antibody-stained cytology was highly sensitive (94%) but appeared to lack specificity (70%). However, examination of the changes in identification rates with time suggested that monoclonal antibody-stained cytology may be even more sensitive than culture and detect lower levels of infection. This study showed that monoclonal antibody-stained cytology of conjunctival smears might be a rapid, efficient, and inexpensive method of diagnosing ocular chlamydial infection.

Effect of bacterial secondary infection in an animal model of trachoma

In trachoma the interaction between chronic chlamydial and acute bacterial conjuntivitis has been suggested as important in determining the severity of disease and, therefore, blindness. We investigated the effect of acute conjunctival infection with each of three common human pathogens, Haemophilus influenzae, Haemophilus aegyptius , and Streptococcus pneumoniae, in a model of trachoma established in cynomolgus monkeys. Although acute conjunctivitis developed, animals with trachoma were not more susceptible to infection than other monkeys, nor did they develop more severe disease as a result of the bacterial conjunctivitis. The failure of bacterial conjunctivitis to exacerbate the experimental trachoma indicates that, in this model at least, chronically maintained chlamydial infection alone is sufficient to produce the changes characteristic of trachoma.

Low-sodium, high-potassium diet: feasibility and acceptability in a normotensive population

Sixty-nine normotensive volunteers participated in an eight-week study to test the feasibility and acceptability of two low-sodium (less than 70 mEq), high-potassium (greater than 100 mEq) diets. The diet groups differed only in the use of KCl salt substitute. Both dietary groups were able to reduce sodium and increase potassium intake compared to the control group. Urine sodium excretion decreased in the diet groups but no change was observed in potassium. Potassium chloride salt substitute was not used as recommended, suggesting its unacceptability.

Correlates of weight loss and its maintenance over two years of follow-up among middle-aged men

This paper analyzes demographic, social, psychological, and behavioral correlates of weight loss and maintenance in a group of 89 middle-aged men. Measures were collected before and after a 15-week intervention program and at 3-month and 1-year follow-up evaluations. Associations were examined through 2 years of follow-up observation. Principal findings were (a) a strong inverse relationship between prior participation in an organized weight control program and both short- and long-term weight loss; (b) a positive association between efficacy expectations and weight loss; (c) a positive association between attendance at treatment sessions and weight loss; (d) an inverse relationship between spouse attendance and weight loss; and (e) positive associations between weight loss and perceived social support, reported improvement in eating behavior, reported improvement in exercise behavior, and affirmative response to relapse episodes following treatment.

Quantitation of xylose from plasma and urine by capillary column gas chromatography

A specific and sensitive assay for quantitation of xylose from plasma and urine has been developed. Following a clean-up procedure, plasma (0.1 ml) or urine (0.2 ml) samples are concentrated and undergo two sequential derivatization steps. A methyloxime derivative is formed initially, followed by trimethylsilylation of all hydroxyl groups. The derivatized samples are quantitated by capillary column gas chromatography using flame ionization detection. Xylose and the internal standard (2-deoxy-D-ribose) have retention times of 6.5 and 5.2 min, respectively. Other monosaccharides (e.g. ribose, arabinose) do not interfere with the assay. Standard curves are linear and reproducible over a concentration range of 10-200 mg/l for plasma and 100-2000 mg/l for urine. The within-day and day-to-day percentage coefficients of variation were less than 5 and 9%, respectively, for plasma and urine.

Behavioral treatment of obesity with monetary contracting: two-year follow-up

Reported is a 2-year follow-up of a behavioral weight reduction program for men using monetary contracts of varying size and group versus individual contingencies. Although initial weight losses were large, in the absence of an effective maintenance program weight losses at two years were modest, similar to those obtained with less effective initial weight loss procedures. Group contracts were significantly more effective in producing long term loss than individual contracts. Reported behaviors associated with weight loss at 2 years are presented.

Calorie requirements in weight loss: an estimate based on self-reported food intake in middle-aged men

Twenty-eight men participating in a weight reduction program self-recorded foods eaten and calorie consumption for a 15-week period. These food records were examined to estimate calorie needs during weight loss as a function of age, entry weight, height and physical activity level. Only entry weight was significantly associated with calorie need. A predictive equation for calorie need is offered for setting individual calorie intake goals for patient-assessed calorie intake.

Effects of diet and bacitracin on growth, feed efficiency, and populations of Clostridium perfringens in the intestine of broiler chicks

Experiments were conducted to demonstrate the activity of bacitracin as a growth permittant for poultry and to further elucidate the mode of action of antimicrobial agents for that purpose. Supplementing a soybean protein and sucrose-based diet with 2.2, 11, and 55 ppm of bacitracin resulted in significant improvements in weight gain and feed efficiency of chicks fed the higher levels. In a second experiment, graded levels of bacitracin from 1.1 to 55 ppm were fed. A regression analysis of the index scores, the combined effects of both weight gain and feed efficiency, on the log of the significant dose levels of 5.5 to 27.5 ppm gave a linear response line with r = .996. Based on the equation, the ineffective level of the antibiotic was determined to be 4 ppm and the maximum effective level 31 ppm. Supplementing the soybean protein and sucrose-based diet with levels of 5.5, 16.5, and 55 ppm of bacitracin reduced the numbers of Clostridium perfringens organisms in ileal contents of chicks (all P less than .05). Chicks fed a level of 1.1 ppm, a level that did not give a growth response, had numbers of the organism present that were not significantly different from controls. Supplementing a soybean meal and corn-based diet with a level of 55 ppm of bacitracin did not significantly affect weight gain, feed efficiency, or numbers of C. perfringens in the ileum of chicks.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of the antibiotic thiopeptin on Clostridium perfringens and growth and feed efficiency of broiler chicks

Experiments were conducted to determine the potential of the antibiotic thiopeptin as a growth permittant for poultry. Thiopeptin as the semipurified antibiotic and as fermentation solids demonstrated activity against Clostridium perfringens at .03 ppm based on suppression of gas production in an anaerobic tube test. Supplementing a soybean protein and sucrose-based diet with levels of 2.2, 11, and 55 ppm of thiopeptin from each of the two sources resulted in significant improvements in weight gain and feed efficiency of chicks fed the higher levels. Computed indexes for each antibiotic treatment showed that the antibiotic as fermentation solids was slightly more active than the semipurified material at the lower levels. Supplementing the soybean protein and sucrose-based diet with 1.1, 5.5, 16.5, and 55 ppm thiopeptin reduced significantly (P less than .01) the numbers of C. perfringens organisms in ileal contents of chicks. Chicks fed 5.5, 16.5, and 55 ppm thiopeptin also had significantly fewer C. perfringens organisms in the intestine than those fed 1.1 ppm. A discussion is presented of the biological responses of thiopeptin relative to the antibiotics efrotomycin and bacitracin.

In vitro and in vivo evaluations of the antibiotic efrotomycin

Experiments were conducted to determine the potential of the antibiotic efrotomycin as a growth permittant for poultry and to further elucidate the mode of action of antimicrobial agents for that purpose. Efrotomycin as the semipurified antibiotic and as fermentation solids demonstrated excellent activity against Clostridium perfringens at .1 to .2 ppm based on suppression of gas production in an anaerobic tube test. Supplementing a soybean protein and sucrose-based diet with levels of 2.2, 11, and 55 ppm of the antibiotic, from the two sources each with two different purities, improved weight gain of chicks an average of 23% and improved feed efficiency an average of 13% at the higher levels (all P less than .01). Computed indexes for each antibiotic treatment, which represent the combined effects of both weight gain and feed efficiency, showed that a maximum response was generally obtained at the 11 ppm level and that the antibiotic as fermentation solids was slightly more active than the semipurified material. Supplementing the soybean protein and sucrose-based diet with levels of 1.1, 5.5, 16.5, and 55 ppm of efrotomycin reduced the numbers of C. perfringens organisms in ileal contents of chicks (all P less than .01). The effects were dose-related. Control chicks in this experiment averaged greater than 7.7 log10 of C. perfringens counts per gram of contents. The results of these experiments show that efrotomycin has excellent growth-permittant activity and the activity correlates with the antibacterial activity against C. perfringens.

Effects of diet, bacitracin, and body weight restrictions on the intestine of broiler chicks

Six experiments were conducted to evaluate the effects of diet, bacitracin, and body weight restrictions on the intestine of the broiler chick. Bacitracin, at levels of 11 and 55 ppm, significantly increased body weight, significantly reduced small intestine weight, but had no significant effect on liver weight of chicks fed a soybean protein and sucrose-based diet. The greatest effects were observed in the ileum where weight, moisture, length per unit of body weight, and dry matter per unit of length were all significantly reduced. The least effects were observed in the duodenum where weight and length per unit of body weight were significantly reduced and dry matter per unit of length was significantly increased. Intestinal weight, as a percent of body weight, was not significantly affected when body weight was suppressed with a high level of nicarbazin added to a practical diet, but it was significantly reduced when bacitracin was added to the semipurified diet and chicks were restricted in food intake to 70% of controls. A level of 55 ppm of bacitracin added to the practical diet had no significant effect on body weight, intestinal weight, or liver weight. As discussed, the observed changes in the intestine, due to bacitracin, are probably indirect and most likely reflect the action of the antibiotic on the intestinal microflora.

An animal model of trachoma: IV. The failure of local immunosuppression to reveal inapparent infection

Repeated inoculation with live chlamydia trachomatis is necessary to develop a model of trachoma in monkeys. However, it is not possible to reisolate chlamydia from the monkey's eye after the first 1 or 2 months of weekly reinoculation. The effect of subconjunctival steroid injections in monkeys that had received weekly inoculations with live chlamydia is reported. Despite a profound suppression of local inflammation, steroid treatment did not produce a reactivation of identifiable chlamydial infection as determined by repeated chlamydial cultures and cytologic examinations.

Reversed-phase thin layer chromatography of some common sterols

The chromatographic mobilities of 17 sterols and squalene on reversed-phase thin layer plates with four nonaqueous solvent systems is described. A degree of separation adequate to identify several of the sterols was obtained. It was possible to separate the pairs: cholestanol, epicholestanol; coprostanol, epicoprostanol; 5 beta-cholestan-3 alpha and 3 beta-ol and lanosterol, dihydrolanosterol.

An animal model of trachoma II. The importance of repeated reinfection

An animal model of chronic cicatrizing trachoma has been produced by repeated ocular inoculation with Chlamydia trachomatis serotype E, a genitally transmitted strain. We have now produced a chronic follicular conjunctivitis on cynomolgus monkeys by repeated inoculation with C. trachomatis serotype A, which has been isolated from an area of endemic trachoma. This disease was similar in all respects to that which followed infection with the serotype E strain. Cynomolgus monkeys inoculated with a single dose of serotype E of C. trachomatis strain developed an acute, self-limited follicular conjunctivitis, which was intense for 4 weeks and then slowly subsided. The organism could be reisolated only during the first 4 weeks after inoculation. On reinoculation at 15 and 30 weeks after the initial infections, these animals demonstrated only a mild and transitory clinical response, and the agent could be recovered for only up to 14 days after inoculation. In contrast, repeated weekly reinoculation with either serotype led to a chronic progressive clinical response in these animals, although after the first 6 weeks the agent was isolated only occasionally. This chronic disease was shown not to be due to hypersensitivity to the egg yolk components in which the organism was grown. These data suggest that the serotype of the chlamydial organism may not be as important in determining the clinical course of disease as is the frequency or persistence of exposure to the chlamydial agent. Although a single inoculum produced an acute follicular conjunctivitis, repeated inoculation is needed to produce the chronic disease characteristic of trachoma in this animal model.

Pet ownership in rural Northern California (El Dorado County)

Demographic and economic aspects of pet ownership were studied in 488 households in El Dorado County, California, from May to July 1971. About 60% of households owned dogs or cats, and pet ownership was most prevalent (75%) in two small residential communities in the western end of the county. Among dogs, Poodle and German Shepherd Dog were the most popular breeds; about 36% of the females in the sample were spayed, but only 6% of the males were castrated. Approximately one third of all cats had been neutered. Reported use of veterinary services was higher for dogs (79%) than for cats (53%). The results of the survey indicated pet ownership is most likely to be found in households with children, where the head of household is employed, generally confirming findings from earlier surveys in Yolo, Alameda, and Contra Costa Counties (all in northern California) and later surveys in Champaign County, Illinois, and Garland, Tex. Some community health findings were included for El Dorado County and nearby Yolo County. In these two counties, cancer was reported more frequently by adults without pets (3.9% of those greater than or equal to 65 years old) than by pet owners (1.8% of those greater than or equal to 65 years old). Among children less than 5 years old, "frequent diarrhea" was reported more commonly in homes without pets (9.5% vs 2.6%; P less than 0.01). On the other hand, pet-owning adults, 16 to 64 years of age, living in rural areas or areas with generally lower than average incomes reported "frequent headaches" (21%) more frequently than did adults without pets (17%; P less than 0.025%) who resided in the same areas.

Acid-catalyzed hydration of reduced nicotinamide adenine dinucleotide and its analogues

The rate of the primary acid modification reaction of 1,4-dihydronicotinamide adenine dinucleotide (NADH) and 1,4-dihydro-3-acetylpyridine adenine dinucleotide (APADH) and their analogues has been studied over a wide pH range (pH 1-7) with a variety of general acid catalysts. The rate depends on [H+] at moderate pH and becomes independent of [H+] at low pH. This behavior is attributed to substrate protonation at the carbonyl group (pK of NADH = 0.6). The reaction is general acid catalyzed; large solvent deuterium isotope effects are observed for the general acid and lyonium ion terms. Most buffers cause a linear rate increase with increasing buffer concentration, but certain buffers cause a hyperbolic rate increase. The nonlinear buffer effects are due to complexation of the buffer with the substrate, rather than to a change in rate-limiting step. The rate-limiting step is a proton transfer from the general acid species to the C5 position of the substrate. Anomerization is not a necessary first step in the case of the primary acid modification reaction of beta-NADH, in which beta to alpha anomerization takes place.

Free radical and ionic reaction of bisulfite with reduced nicotinamide adenine dinucleotide and its analogues

1,4-Dihydronicotinamide adenine dinucleotide (NADH) and its analogues undergo two reactions in sulfite buffers in the pH range 5.5-7.1: (1) an oxygen-mediated free-radical chain reaction which results in the oxidation of the dihydropyridine to the pyridinium salt, and (2) an ionic reaction which results in the hydration of the 5,6 double bond of the dihydropyridine. The free-radical reaction is inhibited by superoxide dismutase (indicating the involvement of superoxide radicals) and by free-radical inhibitors. The ionic reaction is not affected by free-radical inhibitors and follows the rate law: rate = [substrate] [HSO3-] (K + SIGMAK' [HA]), where HA is a general acid of hydronium ion. The occurrence of third-order terms of the type [substrate] X [HSO3-] [HA] is consistent with the formation of a reactive bisulfite-substrate complex, which undergoes general acid catalyzed hydration.

Characterization of gill (Na + K)-activated adenosine triphosphatase from chinook salmon, Oncorhynchus tshawytscha

(Na+K)-activated ATPase activity from gills of yearling spring chinook was examined using a new rapid assay method. Characterization of the enzyme activity was performed. Optimal activity was obtained at pH 7.2 in the presence of 240 mM NaCl, 120 mM KCl, 20 mM MgCl2 and 10 mM Na2ATP. Maximal inhibition of the enzyme was observed in the presence of 0.5 mM ouabain. Differential centrifugation indicated that 75% of the enzymatic activity was sedimented at 1000 x g. Only 8% of the activity was found in the microsomal pellet. Treatment with 0.1% sodium deoxycholate liberated activity from the 1000 x g pellet and elevated the activity. This treatment caused a loss of 20% of the original activity of the preparation. Statistical analysis of the sampling procedure for gill (Na+K)-activated ATPase activity indicated that there was small variation in the technique itself when compared to variation between the individual gill arches and between individual fish. Results indicate that for meaningful comparisons of groups of fish, the sampling of the gill arches must be standardized and a large number of individual fish must be sampled.

Investigation of the open ring form of nicotinamide adenine dinucleotide

In strong alkali, nicotinamide adenine dinucleotide (NAD+) undergoes a ring opening of the nicotinamide ring. The open form of NAD+, ONAD, has two pKa values at--1.9 and 11.2 and absorbs maximally at 350 nm in its acidic form, at 372 nm in its neutral form, and at 340 nm in its aniomic form. ONAD has the chemical properties expected for a Schiff base of 2-carboxamideglutacondialdehyde (CGDA) and adenosine diphosphate ribosylamine. The decomposition of ONAD has been studied over a wide range of pH. A final product of ONAD hydrolysis is the base fluorescent compound 2-hydroxynicotinaldehyde. In the pH range 10--13, CGDA can be trapped as an intermediate, which absorbs maximally at 345 nm in its anionic form and at 320 nm in its neutral form, pKa = 2.9. The yield of 2-hydroxynicotinaldehyde from ONAD has been estimated as 95% at NaOH concentrations of 5 N and above, and is postulated to result from ring closure of CGDA. The pseudobase hydroxide ring addition adduct of NAD+, psiNAD-OH, is reversibly formed from NAD+ and is the 370-nm precursor of ONAD.

Borate inhibition of yeast alcohol dehydrogenase

Yeast alcohol dehydrogenase is inhibited competitively by borate with respect to NAD+. An unusual mechanism of competitive inhibition prevails: the competition for the substrate NAD+ by borate and enzyme. The following evidence supports this conclusion. (1) Much greater inhibition is observed with respect to NAD+ as compared with NADH as substrates. (2) Borate decreases the equilibrium constant of the overall reaction in the direction of ethanol oxidation, therefore, borate enters directly into the overall reaction rather than merely decreases the effectiveness of the catalyst. (3) The Ki values for unrelated enzyme reactions are identical for NAD+. (4) Stopped-flow experiments show burst kinetics only when NAD+ and borate are not premixed. (5) The Ki value is identical with the inverse of the borate-NAD+ complexation constant. (6) The pH dependence of the inhibitor demonstrates that only the B(OH)4-species is inhibiting. These results are consistent with the preferable binding of borate to NAD+ as compared with NADH. These two binding constants were found to be equal to 2000 +/- 60 and 130 +/- 8 M-1, respectively. In contrast to the liver enzyme, the yeast enzyme does not show pre-steady-state burst reactions in the reduction of NAD+. This would indicate that the interconversion of ternary complexes is at least partially rate limiting for the yeast enzyme.

The interaction of borate and sulfite with pyridine nucleotides

The kinetics and equilibria of the borate interaction at ribose with NAD+ and NMN+ have been measured using as a chromophoric probe the perturbation effect borate has on the addition of sulfite to the 4 position of the nicotinamide ring. NAD+ and NMN+ have more favorable borate association constants than do their corresponding sulfite addition complexes. The rate of interaction of the ribose moiety with borate at low borate buffer concentration is dependent on the concentration of both borate and boric acid. At high borate concentration the rate becomes independent of borate concentration, indicating the existence of a two-step process for the interaction of NAD-sulfite with borate with a change of rate-determining step from the interaction of the ribose hydroxyl group with borate at low borate to an elimination of sulfite at high borate concentration. A linear free energy relationship with a slope of 0.94 describes an increased reactivity of the nucleotide for sulfite as the affinity of the nucleotide for sulfite increases.