Demonstration and identification of monoclonal proteins in the urine of patients with Sjögren's syndrome

Fresh sera and concentrated urine from 17 patients with primary Sjögren's syndrome (SS) were fractionated by high-resolution agarose electrophoresis to investigate the presence of monoclonal immunoglobulins or their components. Homogeneous protein bands were found in the gamma-globulin region in 47% of serum samples and 76% of urine specimens of all patients tested. These monoclonal proteins were detected more often in patients with extraglandular SS (77% in serum, 100% in the urine) than in patients with glandular SS (14% in serum, 43% in the urine). Immunofixation electrophoresis showed that the majority of these monoclonal proteins were free kappa or lambda light chains. Fractionation of unconcentrated parotid salivas from five SS patients failed to reveal the presence of monoclonal light chains or immunoglobulins. The present findings further substantiate our previous observation that a monoclonal process coexists with the polyclonal activation in SS patients.

Combined immunochemical and electrophoretic determinations of proteins in paired serum and cerebrospinal fluid samples

Albumin and immunoglobulin G were simultaneously determined in paired serum and cerebrospinal fluid samples from healthy volunteers. The albumin quotient and the IgG index were calculated to establish normal values. High-resolution electrophoresis was also performed with the same samples and the electrophoretic patterns were correlated with the numerical values to improve the reliability of the test results. Representative examples from abnormal conditions are also shown, to illustrate the increased accuracy and useful applications of this combined analysis in the diagnosis of neurological conditions.

Combined immunochemical and electrophoretic determinations of proteins in paired serum and cerebrospinal fluid samples

Albumin and immunoglobulin G were simultaneously determined in paired serum and cerebrospinal fluid samples from healthy volunteers. The albumin quotient and the IgG index were calculated to establish normal values. High-resolution electrophoresis was also performed with the same samples and the electrophoretic patterns were correlated with the numerical values to improve the reliability of the test results. Representative examples from abnormal conditions are also shown, to illustrate the increased accuracy and useful applications of this combined analysis in the diagnosis of neurological conditions.

Comparison of netilmicin and gentamicin pharmacokinetics in humans

In a crossover study, single doses of netilmicin and gentamicin were administered intramuscularly, each at 1.0 and 2.5 mg/kg. The serum concentrations, analyzed by a two-compartment open model with a first-order absorption, indicated that the pharmacokinetics of the drugs are essentially the same. Both drugs were rapidly absorbed and distributed after administration. No significant differences were observed between the two drugs in disposition half-life, rate of distribution and elimination, area under the serum concentration-time curve, urinary excretion, total body clearance, and renal clearance. After 1.0 mg/kg, the maximum serum concentration of netilmicin (5.18 microgram/ml) was only slightly lower than that for gentamicin (5.76 microgram/ml), but no difference was found after the 2.5-mg/kg dose.

Comparative nephrotoxicity of aminoglycoside antibiotics in rats

Netilmicin, gentamicin, tobramycin, amikacin, kanamycin, streptomycin, and sisomicin were given daily for 15 days to groups of rats at three dosage levels corresponding to 10, 15, or 25 times the dose recommended for humans on a weight basis. Decreased urinary osmolality and increased urinary excretion of protein and beta-N-acetyl hexosaminidase were dose-related features of nephrotoxicity. Decreased tubular resorption of glucose and phosphate were observed with the most toxic regimens after extensive renal damage had occurred. All aminoglycosides accumulated in renal tissue; however, the concentration of drug in the renal cortex at the time the rats were killed was not useful for the prediction of renal impairment. Streptomycin and netilmicin exhibited a flat dose-reponse curve with respect to histological damage, as compared with the curves for the other drugs. Results of studies of creatinine clearance and examination of renal tissue suggested the following order of increasing toxicity of the treatment regimens: (1) 0.9% NaCl and uninjected controls; (2) streptomycin; (3) netilmicin; (4) tobramycin; (5) sisomicin, amikacin, and kanamycin; and (6) gentamicin.

Measurement of resistance to experimental tuberculosis in albino mice. The immune phase

Enhanced resistance against experimental tuberculosis was acquired by albino mice after peritoneal vaccination with living BCG. Prolongation of life was used as a measure of resistance against massive intravenous challenge infection. The average degree of prolongation of life was found to be directly related to the size of the vaccinating dose. The ultimate numbers of BCG bacilli recovered from the animal's organs were also directly related to the quantity of vaccine initially administered. It appears therefore that the relative degree of antitubercular resistance achieved by immunized mice is closely related to the vaccinal population present in the animal's organs.

Temporal development of resistance to pulmonary tuberculosis in Swiss albino mice

The course of pulmonary tuberculosis was followed in control and BCG-vaccinated mice. Resistance was evaluated by determining the numbers of virulent mycobacteria recovered from the organs at various intervals after airborn infection. A limited but significant retardation of growth of challenge bacilli was observed in both pulmonary and splenic tissues of successfully vaccinated animals. This retardation was manifested chiefly during the early stages of the infection. However, the numbers of virulent organisms recovered from the organs of either vaccinated or control animals were much the same at later stages of the infection. The appearance of pulmonary immunity was related to the stage of development in vivo of the vaccinal population. Only after large numbers of vaccinal bacilli could be recovered from the tissues was heightened resistance observed.

Tuberculous morbidity in Swiss albino mice immunized with BCG

Study was made of the effect of BCG vaccination on the establishment of experimental tuberculous infection in mice. To this end, mice were infected with small quantities of virulent human bacilli administered by the respiratory route. The quantity of bacilli present for inhalation was so controlled as to permit only a finite percentage of unvaccinated animals to become infected. The relative proportion of mice infected by inhaling these small numbers of virulent bacilli was not found to be lowered by prior BCG vaccination. Thus, pulmonary tissue of immunized mice was not able to prevent the initial lodgement of virulent tubercle bacilli. The growth of virulent organisms in infected lungs, however, was significantly retarded by prior vaccination.

Lasting biological effects of early environmental influences. V. Viability, growth, and longevity

The effects of neonatal influences on the growth and longevity of mice were studied by using animals derived from a highly inbred germfree colony that had been reassociated with a microbial flora free of known pathogens. The size of the animals at weaning time could be conditioned predictably by manipulating the diet of their mothers during gestation and lactation or by shortening or lengthening the period of lactation. A deficient diet during gestation or during lactation decreased the metabolic efficiency of the adult animal, even if it was fed an optimum diet after weaning. The effect was greatest when malnutrition occurred during both pregnancy and lactation. In contrast, an optimum diet during gestation and lactation rendered the animal less susceptible to the depressing effects of nutritional deficiency during adult life. A marked and lasting growth depression could be reproducibly achieved by contaminating newborn mice orally with an unidentified enterovirus. But neonatal infection with enterobacteria or mycobacteria even though severe, did not significantly alter the growth rate. Regardless of its initial cause, the depression of the growth rate during the preweaning period persisted throughout the whole life span of the animals, even when they were placed under optimum sanitary and nutritional conditions after weaning. Agencies (nutritional or infectious) which brought about a depression of whole body weight also affected the absolute and relative sizes of the various organs, especially of the brain. By manipulating neonatal influences, it was possible to produce at will in a given colony of highly inbred mice a family of strikingly different growth curves. This could be done without causing the death of any animal or affecting longevity.

Lasting biological effects of early environmental influences. I. Conditioning of adult size by prenatal and postnatal nutrition

Newborn specific-pathogen-free mice (SPF) were separated from their mothers shortly after birth and immediately reallocated at random to foster mothers, each of which received eight young. Under these conditions, the growth rate and adult size of the young were profoundly and lastingly conditioned by some unidentified influence exerted by the foster mother. In SPF mice nursed by their own mothers, the diet of the latter during gestation and lactation, or during lactation alone, conditioned the weight of the young at weaning time, and throughout their whole life span. Lasting depression of growth has been achieved by minor alterations of the dam's diet, for example by lowering its content in magnesium, or in lysine and threonine. The growth-depressing effect so achieved persisted throughout the whole life-span of the young, even though they were given at weaning time and constantly thereafter unlimited amounts of an optimum diet. In contrast, the weight-depressing effect of a diet deficient in lysine and threonine administered to adult animals was completely and rapidly reversible when a complete diet was later substituted for the deficient one. Depression of growth resulting from nutritional experiences during gestation or lactation did not seem to affect adversely the health of the young, or to decrease their longevity. In fact, the results of two experiments in which the animals nursed by mothers on different diets, were kept undisturbed and on optimum diets throughout their whole life span, suggest that the smaller animals had a greater average life expectancy than the larger ones.

The influence of endotoxin administration on the nutritional requirements of mice

Albino mice lose weight within 24 hours following administration of bacterial endotoxin. The initial weight loss is proportional to the dose of endotoxin injected only when this dose is very small. The loss during the 1st day reaches a maximum with 10 to 30 microg of endotoxin; larger doses increase the duration of the overall effect. The rate at which mice regain weight after administration of endotoxin is markedly influenced by the composition of the diet. Recovery was rapid and complete within a few days when the animals were fed commercial pellets or a semisynthetic diet containing casein. In contrast, recovery was slow and incomplete when wheat gluten was used instead of casein in the diet. The deleterious effect of the gluten diet was less marked in older than in younger animals, probably because the latter have less exacting nutritional requirements. It was postulated that the failure of endotoxin-treated mice to regain weight when fed the gluten diet was due to the fact that this protein is low in certain amino acids. In fact, rapid and complete recovery from the weight loss uniformly occurred when the gluten diet was supplemented with proper amounts of lysine and threonine. The composition of the diet did not influence the extent of the initial loss of weight caused by endotoxin, nor did it prevent the animals from developing tolerance to this substance.