The influence of Rauscher leukemia virus (R-MuLV) on the differentiation of red blood cells in BALB/c mice

The influence of Rauscher Leukemia Virus infection of BALB/c mice on the differentiation of red blood cells has been investigated. Twenty-one days after infection, the total number of red blood cells in the spleen is increased 20 times in contrast to the bone marrow which is largely unaffected. The cellular composition of these hemopoietic organs has been analysed using a number of markers of erythroid maturation, i.e. heme and hemoglobin synthesis and the presence of globin messenger RNAs.These studies show that most of the blasts present in leukemic spleens are immature as judged by morphological criteria and do not contain globin mRNA, whereas the more mature blasts contain globin mRNA as determined autoradiographically by in situ hybridization to globin cDNA. The number of mature blasts, comprising about one-third of the immature ones, is both in absolute terms and per mg tissue higher than in control spleens.Pulse labelling with ⁵⁹Fe shows, that heme and hemoglobin synthesis takes place in leukemic spleens.The rate of heme synthesis in leukemic spleens, as judged by short-term incorporation of ⁵⁹Fe and ¹⁴C-glycine is intermediate between the values for spleens from anemic and control animals.After a pulse, labelled ⁵⁹Fe is first bound to non-hemoglobin proteins. After a chase, this protein-bound ⁵⁹Fe is transferred to hemoglobin as erythroid differentiation occurs in spleens of normal and anemic mice. However, this transfer of ⁵⁹Fe to hemoglobin does not occur in leukemic spleen cells during a pulse/chase in vivo.These results could mean that these immature blasts die or that the maturation is inhibited in the enlarged spleens, whereas only a minor portion differentiates in smaller basophilic erythroblasts, which mature into reticulocytes.     

Augeninnendruck während und nach körperlicher Belastung

Zusammenfassung An 50 jugendlichen Versuchspersonen beiderlei Geschlechts wurden standardisierte Belastungsversuche bis 250 Watt auf dem Fahrradergometer durchgeführt. Während und nach der körperlichen Arbeit wurde der Augeninnendruck gleichzeitig mit der Pulsfrequenz und dem Blutdruck gemessen. In drei Versuchsanordnungen konnte die Abhängigkeit der oculären Tension von Höhe und Dauer der Belastung sowie der Körperposition geprüft werden.Die unter reproduzierbaren Arbeitsbedingungen gewonnenen Ergebnisse ließen sowohl mit dem Schiötz- als auch mit der Applanationsmethode einen regelmäßigen Abfall des Augeninnendruckes erkennen. Die Korrelation zu Pulsfrequenz und Blutdruck wurde statistisch untersucht und mit den Angaben in der Literatur verglichen.

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Intraocular pressure under physical stressA methodical investigation under reproducible conditions I. Circulatory parameters

Summary Standard load tests on the bike ergometer up to 250 Watt were performed on 50 healthy individuals of both sex. Intraocular pressure, blood pressure and pulse frequency were measured during and after load test. In three experimentations interpendence of ocular tension on intensification of load and body carriage was shown. Unter reproducible conditions a regular decrease of intraocular pressure was found as well by the Schiötz as by the Applanation method. The correlation between intraocular tension, pulse frequency and blood pressure was statistical proved and the results were compared with findings of other authors.

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Auszugsweise vorgetragen auf der Berliner Augenärztlichen Gesellschaft, Dezember 1971.

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Wir möchten an dieser Stelle unserer Orthoptistin, Fräulein B. Reinhard, für die ständige und sachkundige Mithilfe danken, die sie bei den Untersuchungen geleistet hat.     

The ultrastructure of the nephrons of the desert rodent (Psammomys obesus) kidney II. Thin limbs of henle of long-looped nephrons

Long nephrons are derived from juxtamedullary glomeruli. In their descent through the outer medulla toward the inner medulla, the thin descending limbs (TDLs) of long loops of Henle are consistently excluded from the vascular bundles and occupy the interbundle region. The outer medullary segment of long TDLs (Type II epithelium) is elaborately developed with numerous cellular interdigitations. microvilli, and a cytoplasm well equipped with numerous organelles. The inner medullary segment of these long TDLs is characterized by yet another epithelium that is markedly reduced from its Type II predecessor and is designated as Type III epithelium. It is a very low, flattened epithelium with few cytoplasmic details. In a cross section of the inner medullary TDL, the Type III epithelium appears poorly interdigitated, with only two to four cell processes and their junctional complexes. Shortly before the bend of a long loop of Henle, the epithelium is again altered to one that is well-interdigitated and better equipped with cytoplasmic organelles (Type IV epithelium). It persists through the actual bend of the loop and throughout the entire thin ascending limb (TAL), until the latter's transition to the distal tubule at the level of the inner/outer medullary border. We conclude that the Type II epithelium of the outer medullary segments of long TDLs in Psammomys is suitably constructed for involvement in energized transport of solutes. The possibility for a similar role in the Type IV epithelium of the bends and TALs is not excluded by our data. However, the Type III epithelium of the inner medullary segments of long TDLs is most suitably constructed for the concentration of its luminal fluids via water extraction. A comparison between these epithelial types and their permeabilities in various species is presented.     

Characterization of the surface morphology in carboxylated methyl methacrylate-butyl acrylate emulsion copolymers

A series of carboxylated methyl methacrylate (MMA)-butyl acrylate (BuA) (weight ratio 1 : 1) copolymer latexes were prepared by emulsion polymerization with varying the nature of carboxylic acid (acrylic (AA), or methacrylic acid (MAA)), the type of emulsifier (sodium dodecyl sulfate (SDS) or nonylphenyl polyoxyethylene ether (HV25®) surfactants), or the polymerization method (batch or shot process). Results of surface characterization and rheological behavior of the latexes were found to provide information on the carboxylic acid location and the interfacial layer thickness, respectively. Stability studies against different types of electrolyte and temperature showed that the surface morphology is strongly dependent upon the nature of oligomers formed during the synthesis, especially the presence of sequences rich of poly-(carboxylic acid)s, and how they are anchored onto the particle. According to the type of emulsifier and polymerization process, stability is predominantly determined either by electrostatic or steric forces. In some cases, when surfactant HV25® is used, enhanced steric stabilization prevails.     

Reduced number of hemidesmosomes in the corneal epithelium of diabetics with proliferative vitreoretinopathy

Morphometry on transmission electron micrographs of the hemidesmosomal width was related to the length of the basal plasmalemma in corneal epithelium biopsy specimens. The basal plasmalemma length occupied by hemidesmosomes showed a mean fraction of 0.227 in eight patients undergoing cataract extraction or vitrectomy for diabetic proliferative vitreoretinopathy. In seven non-diabetic control patients of comparable age and sex undergoing cataract or pterygium surgery, 0.412 of the basal plasmalemma was covered by hemidesmosomes. A reduction in hemidesmosomes (P less than 0.001) may contribute to a weakness in the adhesion of diabetic corneal epithelium to the underlying stroma.     

Low prevalence of nonconservative mutations of serum and glucocorticoid-regulated kinase (SGK1) gene in hypertensive and renal patients.

BACKGROUND: The serum- and glucocorticoid-regulated kinase (SGK1) gene is an important mediator of aldosterone action, regulating the expression of the renal epithelial Na(+) channel. In renal failure, blood pressure (BP) is markedly salt-dependent and increases with decreasing renal function. Mutations of the SGK1 gene affecting phosphorylation could be responsible for salt-mediated increases in BP and hypertension-related progression to end-stage renal disease (ESRD). METHODS: The SGK1 gene was analysed for mutations in the exons 4, 5, 8 and 10-12, because of potential phosphorylation sites, in 591 subjects, including 311 ESRD patients (either dialysis or transplanted). In addition, an intron 6 single-nucleotide polymorphism (SNP) described previously was also investigated in this study. Genotyping was performed either by using a strategy based on single strand conformation polymorphism analysis of polymerase chain reaction (PCR) products and subsequent direct sequencing of identified gel shift variants or by using high throughput 5' nuclease allelic discrimination assay. RESULTS: Two SNPs in coding regions of SGK1 potentially influencing the phosphorylation of Sgk1 were identified. Both SNPs were synonymous. The prevalence of the first variant, a previously reported SNP at codon 240 in exon 8, did not differ between ESRD patients (16.3%) and controls (15.7%). There was no association between the SNP in exon 8 and either BP within the control population or progression of renal disease in the ESRD population. The second SNP at codon 398 in exon 12 was identified in one patient only. Intron 6 and exon 8 SNPs were in strong linkage disequilibrium, but did not show any association with either BP or renal diseases. CONCLUSIONS: Based on statistical analysis homozygosity for nonconservative mutations in the coding region of the SGK1 gene is estimated at < 1/300 000 when a white Caucasian population is considered, arguing against an important role of mutations of this coding region in hypertension and hypertension-associated progression of renal disease.     

Reduced local growth and spread but preserved pathogenicity of a DeltapurC Mycobacterium tuberculosis auxotrophic mutant in gamma interferon receptor-deficient mice after aerosol infection

We compared the growth levels and pathogenicities of the Mycobacterium tuberculosis MT103 clinical strain with those of the DeltapurC mutant strain MYC1551, which is auxotrophic for purine in wild-type and gamma interferon receptor (IFN-gammaR)-deficient mice. The DeltapurC strain MYC1551 grew initially in both wild-type and IFN-gammaR-deficient mice upon aerosol infection, but it grew much less than strain MT103 did. Despite the comparable bacterial burdens of the mice, IFN-gammaR-deficient mice succumbed to infection with DeltapurC strain MYC1551 from necrotic pneumonia within 6 weeks of those infected with MT103. In conclusion, the DeltapurC mutant MYC1551 displays reduced growth but retains pathogenicity. Therefore, the use of mutant strains of M. tuberculosis as live vaccines may not be recommended.     

Low proportion of recent human immunodeficiency virus (HIV) infections among newly diagnosed cases of HIV infection as shown by the presence of HIV-specific antibodies of low avidity

The time between human immunodeficiency virus (HIV) infection and diagnosis is mostly unknown. Two hundred five newly diagnosed patients were investigated for the duration of their HIV infection by avidity testing. Recent HIV infection was identified in 27.3% of the cases. Early diagnosis was achieved significantly less frequently in heterosexually infected persons than in other patients.