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At least 19 recordsLinked to original sources
PubMed1992

Detection of a polymorphism within the pepsinogen C gene with PCR: construction of a linkage map around PGC from 6p11-6p21.3.

An insertion/deletion polymorphism between exons 7 and 8 of the pepsinogen C gene (PGC), previously detectable with Southern analysis, was formatted for detection with PCR. Alleles were rapidly typed by UV irradiation of ethidium bromide-stained agarose gels. Whereas Southern analysis revealed two alleles, the smaller fragments generated with PCR allowed the resolution of three alleles that were previously scored as a single allele and increased the heterozygosity of the system from 0.20 to 0.53. After a set of reference families was genotyped with the PCR-based polymorphism, a linkage map around the PGC gene on chromosome 6 was constructed. This included the HLA cluster and the highly informative D6S223 locus. PGC lies 22 cM proximal to HLA-DPB and between D6S5 and D6S4 at distances of 4.5 and 13.1 cM, respectively.

Base Sequence↗
PubMed2025

A whole-brain voxel-based analysis of structural abnormalities in PTSD: An ENIGMA-PGC study.

BACKGROUND: Patients with posttraumatic stress disorder (PTSD) exhibit smaller regional brain volumes in commonly reported regions including the amygdala and hippocampus, regions associated with fear and memory processing. In the current study, we have conducted a voxel-based morphometry (VBM) meta-analysis using whole-brain statistical maps with neuroimaging data from the ENIGMA-PGC PTSD working group. METHODS: T1-weighted structural neuroimaging scans from 36 cohorts (PTSD n = 1309; controls n = 2198) were processed using a standardized VBM pipeline (ENIGMA-VBM tool). We meta-analyzed the resulting statistical maps for voxel-wise differences in gray matter (GM) and white matter (WM) volumes between PTSD patients and controls, performed subgroup analyses considering the trauma exposure of the controls, and examined associations between regional brain volumes and clinical variables including PTSD (CAPS-4/5, PCL-5) and depression severity (BDI-II, PHQ-9). RESULTS: PTSD patients exhibited smaller GM volumes across the frontal and temporal lobes, and cerebellum, with the most significant effect in the left cerebellum (Hedges' g = 0.22, pcorrected = .001), and smaller cerebellar WM volume (peak Hedges' g = 0.14, pcorrected = .008). We observed similar regional differences when comparing patients to trauma-exposed controls, suggesting these structural abnormalities may be specific to PTSD. Regression analyses revealed PTSD severity was negatively associated with GM volumes within the cerebellum (p corrected  = .003), while depression severity was negatively associated with GM volumes within the cerebellum and superior frontal gyrus in patients (p corrected  = .001). CONCLUSIONS: PTSD patients exhibited widespread, regional differences in brain volumes where greater regional deficits appeared to reflect more severe symptoms. Our findings add to the growing literature implicating the cerebellum in PTSD psychopathology.

Humans↗
PubMed1976

Pineal gland calcification (PGC) in Ugandans. A radiological study of 200 isolated pineal glands.

Two hundred formalin-fixed pineal glands from consecutive unselected post-mortems on Ugandan Africans have been X-rayed. The degree of pineal gland calcification has been divided into four stages and it is shown that 43 per cent of all pineal glands after the age of ten years are likely to be detected in an ordinary skull X ray. This high percentage of calcification contrasts with the previously reported low figure from races other than whites. The pineal glands from females were more often calcified and heavier than those from males; however, the stalks of pineal glands from males were calcified more frequently than those of females. The average weight per decade was almost constant. In Ugandan Africans the pineal glands were significantly lighter than in Caucasians, and a possible reason for this is briefly discussed.

Adolescent↗
PubMed1992

Histochemical identification and behavior of quail primordial germ cells injected into chick embryos by the intravascular route.

The behavior of quail primordial germ cells (PGC) after injection into chick embryos by the intravascular route was examined. The quail (donor) PGC, taken from the bloodstream of quail embryos (recipient) at stage 13-14, were injected into the vitelline vessels of chick embryos (recipient) at stage 15. In the recipient embryos, the PGC of the quail and the chick were histochemically distinguished by a double-staining technique involving a lectin, from Wistaria floribunda (WFA) and the PAS reaction. One day after injection, quail PGC appeared in the prospective gonadal region of recipient chick embryos, being localized among the recipient chick PGC. This result indicates that a staining technique specific for WFA lectin is useful for identification of quail PGC and that quail PGC can be transferred by a vascular route for the production of germline chimeras.

Animals↗
PubMed1992

Gene structures of pepsinogens A and C.

Pepsinogen is an inactive precursor of pepsin, a typical aspartic proteinases, synthesized in the chief cells of gastric glands. There are two major groups of pepsinogen, namely pepsinogen A (PGA) and pepsinogen C (PGC) (or progastricsin), and each frequently has isozymogens. The relative extents of expression of the two pepsinogens vary among animal species and, moreover, their biosynthesis is known to be affected by such bioactive peptides as gastrin and secretin; however, the regulation mechanism of pepsinogen biosynthesis, hence pepsinogen gene expression is not yet clear. Therefore, it is thought to be of fundamental importance to elucidate the primary structures of the pepsinogen gene for such studies. This report describes the primary structures of human PGA and PGC genes and rat PGC gene. The organization of the genes is essentially the same; each gene was found to be separated into nine exons by eight introns of various lengths, encoding the amino acid sequence of the corresponding prepepsinogen. These results show that these genes are all derived from a common ancestral gene. The 5'-flanking region of human PGA gene, however, was different from those of human and rat PGC genes, whereas those of human and rat PGC genes were similar to each other. Thus, it is suggested that the expression of the PGA and PGC genes are somewhat differently regulated.

Amino Acid Sequence↗
PubMed1992

Monolayer properties of archaeol and caldarchaeol polar lipids of a methanogenic archaebacterium, Methanospirillum hungatei, at the air/water interface.

Monolayer studies at the air/water interface were carried out on the major tetraether (caldarchaeol-) derived phosphoglycolipid, Glcp-alpha(1-2)-Galf-beta(1-1)-caldarchaeol-phosphoglycerol (PGC-I), the major diether (archaeol-) derived glycolipid, Glcp-alpha(1-2)-Galf-beta(1-1)-archaeol (DGA-I), the major archaeol-derived phospholipids, phosphatidyl-N,N dimethylaminopentanetetrol (PPDAA) and phosphatidyl-N,N,N-trimethylaminopentanetetrol (PPTAA) and the minor caldarchaeol-derived glycolipid, Glcp-alpha(1-2)-Galf-beta(1-1)-caldarchaeol (DGC-I) isolated from the methanogenic archaebacterium, Methanospirillum hungatei. The compression isotherms obtained showed that the two tetraether lipids had molecular surface areas about twice those of the diether lipids at all surface pressures, suggesting that both polar headgroups of the tetraether lipids are anchored into the aqueous subphase, even at the collapse pressure pi c. A U-shaped hydrocarbon chain conformation thus appears to be preferred for the tetraether lipids at the air/water interface, rather than an extended chain arrangement. The compression isotherms of the two tetraether lipids PGC-I and DGC-I were very similar at pH 0, both molecules being uncharged, but at pH 5.6 or 8, PGC-I films were much more expanded than the neutral DGC-I, due to ionization of the phosphate group in PGC-I and the resulting charge-charge repulsion. Monolayers of the zwitterionic diether phospholipids PPDAA and PPTAA were much less compressible than the glycosylated lipids, PGC-I, DGC-I and DGA-I, because the latter lipids contain the more compressible diglycosyl headgroup, oriented in horizontal conformation at low surface pressures, compared to the lower compressibility of the zwitterionic headgroup in the vertical conformation, particularly at pH 0 and 5.6.(ABSTRACT TRUNCATED AT 250 WORDS)

Air↗
PubMed1992

Purified human alpha fetoprotein inhibits growth factor-stimulated estradiol production by porcine granulosa cells in monolayer culture.

Purified alpha fetoprotein (AFP) synergizes with transforming growth factor alpha (TGF alpha) and insulin-like growth factor I (IGF-I) to enhance proliferation of porcine granulosa cells (pGC) in primary culture, suggesting a role for AFP in the modulation of growth factor-mediated cell growth. TGF alpha stimulates basal estrogen production by pGC and is in fact more potent than FSH in these cells. In this study, we investigated the effects of AFP on growth factor-stimulated estradiol (E2) production by pGC. Basal production of E2 was not altered by the addition of AFP. AFP dose-dependently inhibited TGF alpha-stimulated E2 production with statistically significant inhibition observed with 2.5 micrograms/ml. We have previously shown that the mitogenic effects of AFP are maximized with TGF alpha+IGF-I. E2 production was even more sensitive to AFP inhibition when the two growth factors were combined. Human serum albumin (HSA; 10 micrograms/ml) was without effect. AFP did not interfere with the E2 RIA, affect the uptake of or display specific in vitro binding of the androgen substrate. Furthermore, human AFP and HSA did not exhibit specific in vitro binding of E2, in contrast to purified rat AFP (positive control). These data indicate that physiological concentrations of purified AFP significantly and dose-dependently inhibit growth factor-stimulated E2 production by pGC in culture. Since AFP is known to increase TGF alpha+IGF-I mediated cell growth, these data suggest that AFP may be inhibiting the differentiated function (steroidogenesis) of pGC while enhancing the proliferation of these cells.

Amniotic Fluid↗
PubMed1979

[Influence of cyclic adenosine monophosphate on the migration of primordial germ cells of the anuran Amphibians (author's transl)].

After the treatment in toto of the embryos from various species of Anura by cAMP, the number of primordial germ cells (PGC) in genital ridges is strongly reduced; the most part of the PGC are found in the endoderm. A ventral implant of agar impregnated with a solution of cAMP attracts numerous PGC in the same way as grafted chordomesoderm. The chordomesoderm itself, incubated with 3'-5' cyclic nucleotide phosphodiesterase, then grafted on to the ventral area of normal embryos attracts very few PBC compared with the non-incubated chordomesoderm. The results are analyzed and discussed along the following hypothesis: the migration of the PGC of the Anura is guided by cAMP which, diffusing from the chordomesoderm, is distributed along a concentration gradient increasing in a ventrodorsal direction. The PGC go up the gradient by a chemiotactic mechanism and reach the dorsal parts of the embryo.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1977

The origin, migration and fine morphology of human primordial germ cells.

Human primordial germ cells (PGCs) were observed ultrastructurally in stages from their endodermal to gonadal locations. Primitive PGCs in the hind-gut epithelium of the 4-week embryo, were recognized as well demarcated cells from the neighboring cells. At the time fo separation, the basal lamina of the epithelium was broken, then, through the gap so opened, the PGCs started to escape into the outer mesenchyme. In embryos at five weeks, PGCs were in the migration stage, and were found in the dorsal mesentery, at the coelomic angle and in the forming germinal ridge. In embryos at six weeks or later, almost all PGCS were accumulated in the gonad. The PGC was characterized by its large size and the large and round nucleus with conspicuous nucleolus, and by the presence of abundant glycogen particles and a considerable number of lipid droplets in the cytoplasm. Alkaline phosphatase activity was demonstrated selectively on the plasma membrane of the PGC. The shape of PGC was irregular, often had pseudopodia in PGCs in the separation and migration stages, suggesting their amoeboid movement in vivo, but was generally round or elliptic in PGCs in the settlement stage. The PGC was usually surrounded by and in close association with adjacent somatic cells.

Age Factors↗
PubMed1978

[Effects of optic nerve section in baboons on the geniculate and cortical spike activity during various states of vigilance].

Eye movement potentials during wakefulness (EMPs) and so-called spike (PGO) activities were studied in 4 adult baboons before and after optic nerve (ON) section. The latter was performed either in two stages at a 23-day interval or simultaneously. During wakefulness in the intact animal, triphasic EMPs were observed in darkness with smaller amplitude and longer duration than in the light. After section of one ON, the 3 EMP components persisted, but with a smaller amplitude of the first wave. After section of the second ON morphological changes appeared: the amplitude and duration of the potentials were intermediate between those noted in darkness and light but with an intermingled sharp spike. Geniculate EMPs reappeared 11 days after simultaneous ON section, with the same evolution as previously described. During slow wave and REM sleep, intact animals presented lateral geniculate (LG) monophasic and biphasic spikes, called spikes I and II. At the cortex, they occurred either generalized or limited to one area (anterior or posterior) and were called pontogeniculocortical spikes (PGC). After section of one ON, the pattern of occurrence of phasic activities remained identical in LG. Sharp spikes (spike III) appeared; then their occurrence increased. At the end of the second month after the second section, only spikes II and III remained, spike I disappearing, while PGC amplitude diminished. When both ONs were cut simultaneously, spike III was observed from the first day and PGC activity tended to disappear partially for 11 days. Their later evolution was similar to that noted previously. However, changes were seen earlier (the highest rate of spike III occurring at day 35). In both cases, PGC spikes at the cortex increased in amplitude and frequency of occurrence.

Animals↗
PubMed1992

Long-term proliferation of mouse primordial germ cells in culture.

Primordial germ cells (PGCs) are first identifiable as a population of about eight alkaline phosphatase-positive cells in the 7.0 days postcoitum mouse embryo. During the next 6 days of development they proliferate to give rise to the 25,000 cells that will establish the meiotic population. Steel factor is required for PGC survival both in vivo and in vitro and together with leukaemia inhibitory factor stimulates PGC proliferation in vitro. In feeder-dependent culture, PGCs will proliferate for up to 7 days, but their numbers eventually decline and their proliferative capacity is only a fraction of that seen in vivo. Here we report a further factor that stimulates PGC proliferation in vitro, basic fibroblast growth factor (bFGF). Furthermore, bFGF, in the presence of steel factor and leukaemia inhibitory factor, stimulates long-term proliferation of PGCs, leading to the derivation of large colonies of cells. These embryonic germ cells resemble embryonic stem cells, pluripotent cells derived from preimplantation embryos, or feeder-dependent embryonal carcinoma cells, pluripotent stem cells of PGC-derived tumours (teratomas and teratocarcinomas). To our knowledge, these results provide the first system for long-term culture of PGCs.

Animals↗
PubMed1975

A retesting and modification of the Philadelphia Geriatric Center Morale Scale.

The inter-item structuring of the questions in the Philadelphia Geriatric Center Morale Scale was analyzed for sample members of two studies being conducted by the Dept. of Social Gerontological Research of The Hebrew Rehabilitation Center for Aged (Boston) in an attempt to understand better the several components of the PGC battery first reported by Lawton. PGC items were subjected to principal component and Varimax factor analyses for both the original 22 items and also a reduced 17-item battery. In addition, using more recent findings of Lawton, further structural tests were performed in order to obtain the best possible configuration of items for the several reliable scale components found. The results of these cross SAMPLE ANALYSES INDICATE AN OVER-ALL LEVEL OF RELIABILITY FOR THREE OF THE ORIGINAL PGC components; and at the same time, indices of greater length and reliability resulted when these three PGC components were slightly restructured.

Aged↗
PubMed1978

The validity of 99mTc-pyridoxylideneglutamate (P.G.) cholescintigraphy as a diagnostic test for cholecystitis.

The purpose of this investigation was to determine the diagnostic value (validity) of technetium-99m-pyridoxylideneglutamate cholescintigraphy (99mTc-PGC) in patients with and without cholecystitis and to compare its validity to those of oral cholecystography (OC) and ultrasonography (US). 99mTc-PGC was applied to 50 patients with acute, subacute, and/or chronic cholecystitis with cystic duct obstruction proven histologically and operatively, and also to 27 non-diseased volunteers and 43 patients with right upper quadrant abdominal pain who subsequently were proven free of gallbladder disease. In addition, 38 patients had OC, and 31 had US performed. The results shows that the sensitivity and specificity of 99mTc-PGC were 100%. Whereas for OC the sensitivity was 87%, specificity was 100%. For US the sensitivity was 70%, and specificity was 93%. The repeatability of 99mTc-PGC, OC, and US were 100%, 97% and 81% respectively. These data show that 99mTc-pyridoxylideneglutamate cholescintigraphy is a valid diagnostic tool in the evaluation of patients with cholecystitis, and is also safe and simple.

Adolescent↗
PubMed1978

[Primary asymmetry in the distribution of primordial germ cells during colonization of gonadal buds in chick embryo].

Analysis of the numerical data obtained from a population of 529 chick embryos, selected according to their stage of development, shows that the primary distribution of PGC is asymmetric with a bias towards the left side. The kinetics of the colonisation process are in conformity with the law of logistic growth: the number of PGC settling in the germinal epithelia tends to an upper limit not exceeding the number of PGC identifiable in the anterior germinal crescent. Taking the embryo population as a whole, the degree of primary asymmetry at the end of colonisation is such that 56% of the total number PGC fixed in the gonadial primordia are found in the left epithelia.

Animals↗
PubMed1992

The angiotensin AT2 receptor stimulates protein tyrosine phosphatase activity and mediates inhibition of particulate guanylate cyclase.

The signalling mechanism and cellular targets of the AT2 receptor are still unknown. We report that angiotensin II (Ang II) inhibits basal and atrial natriuretic peptide stimulated particulate guanylate cyclase (pGC) activity through AT2 receptors in rat adrenal glomerulosa and PC12W cells. This inhibition is blocked by the phosphotyrosine phosphatase (PTPase) inhibitor orthovanadate but not by the Ser/Thr phosphatase inhibitor okadaic acid, suggesting the involvement of a PTPase in this process. Moreover, Ang II induces a rapid, transient and orthovanadate sensitive dephosphorylation of phosphotyrosine containing proteins in PC12W cells. Our findings suggest that AT2 receptors signal through stimulation of a PTPase and that this mechanism is implicated in the regulation of pGC activity. This observation is also the first example of hormonal inhibition of basal pGC activity.

Angiotensin II↗
PubMed1975

Use of combined chromatographic methods including thin-layer chromatography for analysis of complex polymer systems. Determination of the polydispersity of block copolymers of styrene and methyl methacrylate by gel permeation, thin-layer and pyrolysis gas chromatography.

A combination of gel permeation chromatography (GPC), thin-layer chromatography (TLC) and pyrolysis gas chromatography (PGC) has been used for investigations of a polymethyl methacrylate-polystyrene-polymethyl methacrylate block copolymer. Continuous distribution of the polymer (40-mg sample) was attained according to the content of the styrene and methyl methacrylate units and of the block copolymer and according to the composition of the copolymer as functions of the hydrodynamic radius of the macromolecules. The polymer was subjected to a preliminary fractionation with an analytical gel chromatograph. The fractions were investigated by TLC, which permitted the separation of the block copolymer and the homopolymers. The composition of the fractions obtained by GPC and TLC was determined by PGC. As a result, it was possible to establish the composition of the block copolymer and its ratio to polymethyl methacrylate in each fraction. This investigation was based on a combination of highly effective fractionation by chromatographic methods with precise quantitative ratios obtained from Benoit's universal calibration graph and from determinations of the composition of the polymer fractions by PGC. The mechanism of the TLC of polymers, including the appearance of artefacts that distort the results of analysis, is also discussed.

Chromatography↗
PubMed1979

Reversal of renal cortical actions of angiotensin II by verapamil and manganese.

Experiments were performed on 19 euvolemic Munich Wistar rats to examine the role of calcium in the action of angiotensin II(AII) on the glomerular microcirculation. Intravenous infusion of a mildly pressor dose of AII(N = 7 rats) led to a significant rise in mean glomerular capillary hydraulic pressure (PGC) and significant decines in glomerular plasma flow rate (QA) and the ultrafiltration coefficient (Kf). Because of these offsetting effects, single nephron GFR (SNGFR) and total kidney GFR failed to change significantly. Both afferent and efferent arteriolar resistances (RA and RE) increased during AII infusion, on average by approximately 40% and 75%, respectively. Despite continued AII infusion, addition of verapamil led to return of values for PGC, QA, Kf, RA, and RE essentially to pre-AII levels. In 7 other rats, verapamil infusion alone failed to exert significant influences on these indices. Likewise, no significant changes in these measures were observed when this same dose of AII was infused into verapamil-pretreated animals. Moreover, intrarenal arterial injection of a nonpressor dose of AII into 6 other rats also resulted in changes in PGC, QA, Kf, and RE similar to those seen during intravenous infusion, and addition of manganese abolished these effects. Since verapamil and manganese are both known to interfere with excitation-contraction coupling of smooth muscle, perhaps by inhibiting transcellular calcium transport, the present results suggest that the calcium ion may be an important cofactor required for the expression of AII action on the glomerular microcirculation, by affecting mesangial and efferent arteriolar smooth muscle contractility.

Angiotensin II↗