An immunohistochemical study of aspartate, glutamate, and taurine in rat kidney

Biochemical studies have revealed considerable amounts of free amino acids in the kidney. We examined the intrarenal distribution of three amino acids (aspartate, glutamate, and taurine) in the rat kidney with an immunoperoxidase method. In the renal cortex, all three amino acids were concentrated in the renal corpuscles and in the epithelia of the collecting tubules. Immunostaining of the collecting tubules was more intense in the principal cells than in the intercalated cells. The distal convoluted tubules were also immunostained with aspartate- and glutamate- specific antibodies but not with the taurine-specific antibody. In the renal medulla, the immunoreactivity specific for aspartate and for glutamate was similar; it was weak in the thick portion of the loop of Henle and strong in the collecting tubules. Immunoreactivity specific for taurine was restricted to regions within the epithelia of the thin portion of the loop of Henle and the collecting tubules. The significance of the accumulated amino acids as osmoregulatory agents is discussed.

Biochemical and morphological alterations of macrophages and spleen cells produced by antitumor polysaccharide from Acanthopanax obovatus roots

Acanthopanax obovatus polysaccharide (AOPS) administrated intraperitoneally (i.p.) resulted in the augmentation of phagocytosis and the chemiluminescence in peritoneal macrophages of mice. Binding of the third component of complement (C3) cleavage products to the receptors on peritoneal macrophages was enhanced by AOPS. The C3 conversion in human serum was increased by AOPS in vitro treatment. When given i.p., AOPS led to the enhancement of spleen weight, spleen cell number, and plaque-forming cells. It was also found that after in vivo administration AOPS not only enhanced the synthesis of DNA and protein but also promoted the mitogenic responses of spleen cells. The morphological observation of spleens indicated that AOPS augmented the transformation from lymphocytes to plasma cells. AOPS inhibited the growth of mouse solid Sarcoma-180 and prolonged the survival time significantly. These results suggest that AOPS is an effective biological response modifier and its antitumor activity is related to its immunopotentiating effects.

Isolation of 1001 new markers from human chromosome 11, excluding the region of 11p13-p15.5, and their sublocalization by a new series of radiation-reduced somatic cell hybrids

The determination of the physical map of human chromosome 11 will require more clones than are currently available. We have isolated an additional 1001 new markers in a bacteriophage vector from a somatic cell hybrid cell line that contains most of chromosome 11, except the middle of the short arm. These markers were localized to five different regions, 11p15-pter, 11p12-cen, 11q11-q14, 11q14-q23, and 11q23-qter, by a panel of previously characterized somatic cell hybrids. The region 11q11-14 harbors genes that have been shown to be important in breast cancer, B-cell lymphomas, centrocytic lymphomas, asthma, and multiple endocrine neoplasia, type 1 (MEN1). To determine the positions of the recombinant clones located there, we developed a new series of radiation-reduced somatic cell hybrids. These hybrids, together with those previously characterized, allowed us to map the 11q11-q14 markers into 11 separate segregation groups.

Growth hormone secretion in Alzheimer's disease: 24-hour profile of basal levels and response to stimulation and suppression studies

The 24-h growth hormone secretory pattern and GH response to growth hormone releasing hormone, the alpha 2-adrenoceptor agonist clonidine and the somatostatin-analogue SMS 201-995 were evaluated in 9 patients with Alzheimer's disease and 9 age- and body body-matched control subjects. The secretory profile did not differentiate between patients and controls. Both secreted the largest amount of GH during the early nighthours between 22.00-02.00, whereas the majority of daytime GH levels were below the assay's detection limit (0.4 ng/ml). No difference was found in GH response to GHRH between patients and controls. All subjects showed significantly enhanced GH secretion after GHRH. Dividing the patients into two groups according to age-of-onset (less than 60 years greater than), there was a trend toward larger GH responses to GHRH for the early-onset group. No other parameter differentiated the groups. GH levels after clonidine were blunted in all subjects but one AD patient, probably due to an age-dependent attenuation frequently observed in subjects over 45 years of age. Finally, the administration of the somatostatin-analogue did not render conclusive results, since spontaneous decline of GH concentration was already beginning 2 hours before the drug was given and continued steadily throughout the observation period. In conclusion, patients with only mild to moderate degree of Alzheimer's disease have no prominent changes in GH regulation.

Anionic sites in diabetic basement membranes and their possible role in diffusion barrier abnormalities in the BB-rat

Basement membrane anionic sites, thought to be responsible for charge selective permeability barriers, were investigated in retinal, endoneurial, and muscle capillary basement membranes and in Bruch's membrane of diabetic, and age- and sex-matched non-diabetic BB-rats using an ultrastructural quantitative histochemical technique. Six months of diabetes was associated with significant basement membrane thickening which was linearly related to a decrease in anionic site density suggesting a relative loss of proteoglycans. Calculation of anionic sites per unit length of basement membrane, reflecting their absolute number, revealed a significant loss in basement membrane, constituting part of normal blood-tissue barrier systems such as retinal and endoneurial capillary basement membranes, and the basement membrane of the retinal pigment epithelium. The absolute number of anionic sites in normally permeable microvessels, such as those of muscle and choriocapillaries, was unaltered by diabetes. We conclude that this specific loss of anionic sites in basement membranes of tissues affected by chronic diabetic complications may in part be responsible for permeability abnormalities seen in these tissues.

Synchronization of hormonal time series: analytical approaches

Comparison of the patterns of episodic secretion of two or more hormones measured simultaneously often suggests that peak levels tend to occur at around the same time. This visual impression can be misleading, however, as some peaks will occur simultaneously due to chance alone. Traditional cross-correlation methods are suitable for evaluating linkages among circadian and other smoothly varying rhythms, but are less well suited to correlating ultradian peaks. This paper proposes a method which entails identifying peaks of hormone secretion as discrete events in several different series, and counting the frequency of simultaneous and near-simultaneous peaks in temporal 'windows' of increasing width. The expected rates of random coincidences can be assessed by a variety of methods, including simulations and probability calculations. The method described utilizes simple techniques which make few assumptions about the character or stationarity of the series, comparing coincidence rates in the appropriately paired series with those in which a series in one subject is deliberately 'mismatched' with that of another subject. Using this approach, a significant excess of simultaneous peaks of luteinizing hormone (LH) and prolactin was found in normal subjects as compared with mismatched series (17% versus 6%; p less than 0.05). Hypogonadotrophic men treated with pulsatile gonadotrophin-releasing hormone (GnRH) have an even higher coincidence rate (26%). By contrast, the rate of coincidence between pulses of LH and cortisol is not significantly greater than that which would be expected due to chance.

Reduced number of anionic sites is associated with glomerular basement membrane thickening in the diabetic BB-rat

Glomerular basement membranes of diabetic and age- and sex-matched non-diabetic BB rats were studied morphometrically and ultrastructurally using a quantitative histochemical technique employing the cationic dye cuprolinic blue. Six months of diabetes resulted in a significant reduction in the density of anionic sites associated with increased thickness of the glomerular basement membrane. These findings suggest that the loss of anionic sites may be an important mechanism in the genesis of glomerular basement membrane dysfunction in diabetes.

[The effect of ginseng stem, leaf and rhizoma saponins on the formation of lipid peroxides in rats of various ages]

The effect of saponins isolated from the stem, leaf and rhizoma of panax ginseng on the formation of lipid peroxides in aged (30, 24 and 20 months) and middle-aged (14 months) wistar rats was studied with both in vivo and in vitro methods. The results showed: The formation of lipid peroxides increased with age in rats and mice: the two saponins of ginseng stem, leaf and rhizoma can obviously inhibit the lipid peroxidation in the serum (plasma) and liver homogenate of aged and middle-aged rats (p less than 0.05 and less than 0.001). The same effect was also shown in the aged LACA mouse (18 months) experiment.

Methods for assessing the linkage between pulsatile hormone profiles

Although the different anterior pituitary hormones are generally considered to be regulated independently, examination of their patterns in blood suggests that pulsatile secretion of several of these hormones may be synchronized. Traditional methods of cross-correlation analysis may not be adequate for quantifying this linkage. Since some simultaneity may arise by chance, expected rates of random coincidences must also be estimated to determine if apparent concordance rates significantly exceed those due to chance. A method of estimating linkage by counting simultaneous and near-simultaneous events within temporal 'windows' of varying width is proposed and tested against 11 series of luteinizing hormone (LH) and prolactin measurements from normal men. Rates of concordance in series drawn from different subjects rather than the same subject, or series scrambled in time, do not contain meaningful simultaneous events and so can be used to estimate the rate of random synchrony. By these standards, a clear excess of concordant prolactin and luteinizing hormone (LH) peaks was observed in normal men, suggesting significant physiological synchrony between these pulses of secretion. This method can be applied to a variety of hormonal systems.

Primate evolution of a dispersed human repetitive DNA sequence

A dispersed middle repetitive DNA sequence isolated originally from human chromosome 12 did not show homology with rodent DNA under standard conditions of Southern DNA blot analysis. The evolutionary relationship of this human repetitive DNA to that of other primates was investigated using three hybridization methods: DNA dot blot, Southern DNA blot analysis, and chromosome in situ hybridization. Homology with the human repetitive DNA was found throughout the suborder Anthropoidea, in fourteen ape and New and Old World monkey species. In addition, the human pattern of hybridization to noncentromeric regions of all chromosomes was seen. No hybridization by any of the three techniques was found in five species of the suborder Prosimii. The phenomenon of marked differences in sequence homology and copy number of dispersed repetitive DNA from closely related species has been observed in protozoans (Plasmodia), Drosophila, sea urchins, mice and the great apes (Hominoidea). We report here a similar phenomenon that may have occurred at an early stage in primate evolution.