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Biomedical subjects

Z Krawczyk

Publications and source records attributed to Z Krawczyk.

At least 37 records · Page 2Linked to original sources

Expression of c-jun and Egr-1 genes in rat liver in response to partial hepatectomy, and injection of turpentine.

In rat liver stimulated by partial hepatectomy a significant expression of Egr-1 and to less extent c-jun genes was observed within 15-30 min after the surgery. The induction is transient and vanishes within one hour. Egr-1 and c-jun were also induced in liver after subcutaneous injection of turpentine, a strong inducer of acute phase response. A maximum activation of these genes was observed within 4-9 hours after administration of turpentine. Both Egr-1 and c-jun extend the list of "immediate early" genes involved in proliferative response and constitute a group of genes inducible at the beginning of acute phase response.

Acute-Phase Reaction↗

The ERE-like sequence from the promoter region of the testis specific hsp70-related gene is not estrogen responsive.

The 5'flanking region of the hsp70-related gene which is specifically expressed in rat and mouse spermatocytes contains the GGTCAnnnCGACC sequence closely resembling the palindromic consensus ERE (estrogen responsive element, GGTCAnnnTGACC). We used a transient expression assay to study whether this ERE-like sequence can transfer estrogen responsiveness either to heterologous or homologous promoters linked to a reporter CAT gene. We found that the GGTCAnnnCGACC sequence either as an isolated element or in its natural sequence context does not respond to hormone stimulation in MCF-7 and Fe33 cells. This observation points to the importance of the T-nucleotide in a right half-palindrome of ERE for ligand-dependent activation of transcription.

Animals↗

[Giant cystic kidney as the cause of mechanical ileus].

A rare case is presented of mechanical ileus caused by a giant cystic kidney. With absent symptoms from the urinary tract, the patient was operated on in emergency situation, and the diagnosis of polycystic renal degeneration in a 64-year-old female patient was made during the operation. The fact is worth stressing of sure imposition in the X-ray image of the signs of ileus and of presence of fluid within numerous renal cysts, and in case of lacking other signs this may lead to diagnostic errors.

Emergencies↗

Isolation and nucleotide sequence analysis of the rat testis-specific major heat-shock protein (HSP70)-related gene.

The isolation of a rat hsp 70-related gene which is specifically and highly expressed in testis is described together with the complete nucleotide sequence of the transcription unit (2947 bp), 5' flanking (about 1 kbp) and 3' flanking (about 0.3 kbp) regions. The sequence analysis and nuclease S1 mapping revealed that the isolated gene (referred to as the hst70 gene) represents a novel, distinct member of the hsp70 multigene family. Its transcription unit lacks introns and a single open reading frame encodes a protein of 69.5 kDa. The predicted amino acid sequence of this protein is highly similar (only four out of 633 amino acids are different) to that encoded by the mouse testis-specific hsp70.2 gene (Zakeri, Z.F., Wolgemuth, D.J. and Hunt, C.R. (1988) Mol. Cell. Biol. 8, 2925-2932). The functional significance of multiple potentially regulatory sequences (e.g. TATA-boxes, heat-shock element and estrogen receptor binding site) present in the 5' flanking region of the rat hst70 gene is discussed.

Amino Acid Sequence↗

Effect of amantadine on prolactin secretion, pituitary DNA synthesis and 3H-spiperone binding in male estrogen-treated rats.

Amantadine, a well-known antiviral agent, causing an increase in dopamine synthesis, release and the inhibition of re-uptake of noradrenaline and dopamine in central and peripheral catecholaminergic neurons, is successfully used in the treatment of Parkinson's disease. In the present paper, we have studied the effect of various doses of amantadine on in vivo prolactin secretion and the incorporation of 3H-thymidine and 3H-spiperone binding by the anterior pituitary gland of long-term diethylstilboestrol-treated male Wistar rats. Four weeks after a subcutaneous implantation of Silastic tubes containing 10 mg of diethylstilboestrol, a dramatic rise in serum prolactin levels was observed, accompanied by an increased uptake of 3H-thymidine by DNA anterior pituitary cells. Amantadine, given in the subcutaneous doses of 50, 5 and 0.5 mg/kg of body weight attenuated the stimulatory effect of stilboestrol on serum prolactin concentration in a dose-dependent fashion. On the other hand, the incorporation of 3H-thymidine into DNA pituitary cells in all the groups of amantadine-treated rats was only slightly suppressed. In an additional experiment, Scatchard analyses were performed on the in vitro 3H-spiperone binding kinetics in a dispersed anterior pituitary cell culture prepared from the pituitaries of 6-week diethylstilboestrol-treated rats. It has been found that amantadine injected in the dose of 5 mg/kg of body weight for 14 days induced a twofold decrease in the density of dopamine D2 binding sites (36.6 +/- 9.4 vs. 70.3 +/- 3.4 fmol/10(6) cells; p less than 0.02), while the apparent affinity of the receptors was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Amantadine↗

Isolation of a gene coding for a major heat shock protein HSP71 in rat.

A rat gene closely related to a human heat-inducible/cell cycle-dependent hsx70 gene was cloned from a rat genomic library. Northern blot analysis showed that it encodes a 2.5 kb transcript, one of the two heat-inducible mRNAs (2.5 and 2.7 kb) detected in rat tissues. Comparison of the known expression pattern of rat major heat shock proteins and mRNAs suggests that the isolated rat gene most probably codes for HSP71 protein.

Animals↗

Activation of the glucose-regulated gene (grp78) in regenerating rat liver is nonspecific and is related to acute phase response.

The expression pattern of the hsp70 gene family during regeneration or rat liver has been investigated. Northern blots were prepared from total RNA isolated from livers at 0 h (control), 12 h (end of prereplication phase), 24 h (maximum of DNA synthesis) and 36 h (postmitotic phase) after partial hepatectomy. Blots were hybridized with probes specific for the hsp70 (heat-inducible), hsc70 (constitutively expressed), hst70 (testis-specific) and grp78 (glucose-regulated) gene. No hsp70 and hst70 gene transcripts have been detected at any time point investigated, and only a low increase of the hsc70 mRNA level has been observed 24 h after surgery. In contrast, a significant accumulation of the transcript coded by the grp78 gene has been detected in liver remnant 12 and 24 h after partial hepatectomy. However, we observed a comparable activation of this gene in livers of sham-operated rats or in rats injected with turpentine to cause sterile inflammation. Our results indicate that the activation of the grp78 gene in liver of wounded rats (partial hepatectomy or sham operation) is presumably a part of acute-phase response.

Acute-Phase Reaction↗

Effect of age and busulphan treatment on the hsp70 gene-related transcript level in rat testes.

Northern blot analysis was used to determine the expression pattern of a testis-specific, heat shock gene (hsp70)-related transcript (hst70 RNA) in rats during sexual maturation, following administration of busulphan and in aged rats with progressive tubular degeneration. The level of the hst70 RNA in testes of rats aged 4, 7, 12, 19, 21 or 24 months decreased gradually with age. In the atrophic testes of old rats with tubules depleted of germ cells, the hst70 transcript was undetectable. Transient arrest of spermatogenesis in rats aged 2 months following injection of a single dose of busulphan (10 mg/kg) resulted in a parallel but transient decrease in the transcript level to undetectable values, followed by its reappearance after resumption of spermatogenesis. The transcript was absent from testes containing tubules depleted of spermatocytes and spermatids and reappeared when a new generation of round spermatids repopulated the seminiferous tubules. Possible expression of the hst70 gene prior to the formation of early spermatids is discussed.

Aging↗

Isolation of major heat shock protein (hsp70) gene-related sequences from rat genome.

Rat genome was assayed for the presence of hsp70 gene-related sequences. Southern blots prepared from rat DNA digested with EcoRI or HindIII restriction endonucleases were hybridized with mouse, human and fruit fly hsp70 gene probes at increasing stringencies. At the stringency which allows sequences divergent up to about 30% to form stable complexes all three probes detected 25-30 restriction fragments. Increased stringency of the hybridization reduced the number of detectable bands to a few and among them the DNA fragments hybridizing specifically either with mouse or human hsp70 gene probes were detected. Most of the genomic fragments containing hsp70 gene-related sequences were subsequently isolated by screening the rat genomic library with mouse hsp70 gene probe. 168 positive clones were plaque purified and on the basis of the restriction and hybridization pattern we deduced that inserts represented 20 different genomic regions. Partial restriction maps of all isolated genomic fragments were constructed and regions containing hsp70 gene related as well as highly repetitive DNA sequences were localized. A putative sequence rearrangement in the proximity of the hsp70 gene-related sequence was detected in one of the isolated genomic segments.

Animals↗

Expression of a testis-specific hsp70 gene-related RNA in defined stages of rat seminiferous epithelium.

Changes in the level of a testis-specific hsp70 gene-related transcript (hst70 RNA) and its cellular localization during the cycle of rat seminiferous epithelium have been investigated. Segments of seminiferous tubules at defined stages of the cycle were isolated in living condition by transillumination-assisted microdissection and the exact stages identified by phase-contrast microscopy of live cell squashes. The levels of the hst70 RNA were determined by Northern and slot blotting of whole cell lysates. High levels were found in stages XII-XIV and I to early VII of the cycle, and low levels were found in other stages, i.e., late VII (VIId) through VIII-XI of the cycle. The in situ hybridization revealed that the hst70 gene was activated in late pachytene primary spermatocytes during stage XII of the cycle, and that mRNA was then present in cells during differentiation through diakinesis, meiotic divisions, and early spermiogenesis (steps 1 through early 7). The activation of the gene coding for hst70 RNA shortly before meiotic divisions may indicate that the gene product is needed either during differentiation of late spermatocytes into spermatids or later during spermiogenesis, and that the mRNA may be stored in early spermatids.

Animals↗

A rat testis-specific hsp70 gene-related transcript is coded by a novel gene from the hsp70 multigene family.

To establish the identity of testis-specific hsp70 gene-related transcript, the expression pattern of the hsp70 gene family in testis and liver of rats subjected to whole body hyperthermia was investigated. In control liver two hsp70 gene-related transcripts of about 2.2 and 2.5 kb were detected. Increased body temperature resulted in high accumulation of 2.5 kb RNA and in the appearance of abundant amounts of another heat-induced transcript of approx. 2.7 kb. In testis of control rats only one hsp70 gene-related transcript has been identified and hyperthermia did not affect its level. This transcript migrated in 1% agarose-formaldehyde gel slightly faster than the 2.5 kb heat-induced RNA detected in liver and epididymis. The uniqueness of the testicular hsp70 gene-related transcript has been confirmed by its hybridization properties. At stringent conditions this transcript did not hybridize with a human hsp70 gene-related probe in contrast to the 2.5 and 2.7 kb heat-induced RNA species.

Animals↗

Isolation of RNA for dot hybridization by heparin-DNase I treatment of whole cell lysate.

We have developed a new procedure for the rapid preparation of undegraded total RNA from cultured cells for specific quantitation by dot blotting analysis. Pelleted cells are resuspended in hypotonic solution containing a ribonuclease inhibitor and heparin and disrupted by freeze-thaw. Heparin is employed as an agent for nuclear lysis, dissociation of chromosomal protein, and release of mRNA from rough endoplasmic reticulum. We eliminate chromosomal DNA by digestion with DNase I and denature the RNA in the lysate with formaldehyde. After centrifugation to remove debris, the supernatant is used directly for dot blotting. All manipulations are performed in the same microfuge tube and recovery of RNA is quantitative. The procedure is especially useful for processing large numbers of samples. We illustrate its versatility by analysis of specific RNAs in Drosophila, rat, and human cell lines. In reconstruction experiments, less than 80 molecules per cell of a small RNA (beta-globin) can be detected under highly stringent hybridization conditions, using only moderately labeled double-stranded plasmid DNA probes and short film exposures.

Animals↗

A hsp70-related gene is constitutively highly expressed in testis of rat and mouse.

The expression pattern of major heat shock related genes (hsp70 gene family) in various organs of mouse and rat was investigated using Northern blot analysis. Heat shock gene related transcripts were detected in total RNA by hybridization with cloned mouse hsp70 gene sequences. Cells of various organs of intact mouse and rat constitutively synthesize a 2.2 kb and a 2.5 kb RNA. Exceptionally high levels of the 2.5 kb RNA, 50-250 fold higher than in other tissues are found in testis of both rodents. The 2.5 kb RNA hybridizes strongly to an extended region of mouse hsp70 gene; it also hybridizes poorly to the Drosophila hsp70 gene. The data suggest that the 2.5 kb RNA is transcribed from a hsp70-related gene in mouse and rat.

Animals↗

Expression of hsp70-related gene in developing and degenerating rat testis.

Rat testes contain highly elevated levels of 2.5 kb RNA transcribed from a heat shock (hsp70) related gene. In the present paper northern blot analysis was used to follow the changes in the 2.5 kb transcript level during the postnatal development of rat testis and during the degeneration of the seminiferous epithelium in adult rats caused by experimental cryptorchidism. The 2.5 kb transcript was undetectable in newborn rats until the 3rd week of life. The level of the transcript reached a maximum at the 4th week and remained unchanged from that point on. Two days after the surgical translocation of the testes from the scrotum into the abdominal cavity the level of 2.5 kb transcript rapidly declined. Presented results strongly suggest that the hsp 70-like gene coding for the 2.5 kb RNA is specifically expressed in germinal cells, most probably in the spermatocytes.

Animals↗

Uptake of main fractions of labelled bleomycin by solid Ehrlich ascites tumours in mice.

Concentrations were studied of 58Co in the solid Ehrlich ascites tumour, blood, muscle and bone of male Swiss mice administered as complexed with total bleomycin commercially available and its isolated fractions A2, B2, demethyl A2, A1, A5, B4 and bleomycinic acid. The tumour/non-tumour ratios were determined 24 hrs after injection of the complexes. The ratios for fraction A2, B2 and total bleomycin were very close to each other. The remaining fractions showed lower values of the ratios. These results suggest that it is unlikely that any of the fractions studied are superior to total labelled bleomycin with respect to tumour scintigraphy.

Animals↗