Biomedical subjects

S Josephson

Publications and source records attributed to S Josephson.

At least 55 records · Page 3Linked to original sources

PubMed1987

Renal recovery after release of experimental neonatal ureteric obstruction.

Partial obstruction of the left ureter was created in 2-day-old rats and released 2 days later. The effects were studied after 1, 2, 3 or 6 weeks. The obstruction resulted in prominent hydronephrosis, but the pelvic volume returned to normal already within 1 week after the release operation. In most of the previously obstructed kidneys there were small regions with moderately widened convoluted tubules and collecting ducts and minor areas with mild chronic pyelonephritis; these lesions were similar after 1 week as after 2-6 weeks, indicating that they were permanent. Judging from the parenchymal weight difference between the right and left kidney, there was slight reduction on the previously obstructed side at the 3rd week, balanced by hypertrophy on the contralateral side. At the 6th week the parenchymal weight reduction was no longer apparent but there was still evidence of contralateral hypertrophy. Thus, early release of the partial ureteric obstruction prevented persistent ipsilateral parenchymal weight reduction, without ensuring healing of the tissue lesions. The catch-up of parenchymal weight is probably due to the fact that the release was performed before the end of the period of postnatal nephron differentiation. Interference with this period seems to be the main cause of parenchymal weight reduction in permanent neonatal partial ureteric obstruction.

Animals↗

PubMed1986

Production of specific antibodies against protein A fusion proteins.

The gene for Staphylococcal protein A was fused to the coding sequence of bacterial beta-galactosidase, alkaline phosphatase and human insulin-like growth factor I (IGF-I). The fusion proteins, expressed in bacteria, were purified by affinity chromatography on IgG-Sepharose and antibodies were raised in rabbits. All three fusion proteins elicited specific antibodies against both the inserted protein sequences and the protein A moiety. In the case of IGF-I, the protein A moiety in the fusion protein may act as an adjuvant since native IGF-I alone is a poor immunogen. The results suggest that the protein A fusion system can be used for efficient antibody production against peptides or proteins expressed from cloned or synthetic genes. To facilitate such gene fusions a set of optimized vectors have been constructed.

Alkaline Phosphatase↗

PubMed1986

Experimental partial ureteric obstruction in newborn rats. VII. Are the long term effects on renal morphology avoided by release of the obstruction?

Partial obstruction of the left ureter was created in newborn rats. The obstruction was either permanent or was released after two or seven days. The effects were studied at the age of six weeks. The permanently obstructed kidneys characteristically exhibited considerable enlargement (X 18) of pelvic volume and prominent deformation of the papilla, frequently associated with moderate widening of collecting ducts and convoluted tubuli, and focal inflammatory and degenerative lesions. The weight difference between the hydronephrotic and the contralateral, intact kidney was significantly higher than in a sham operated group, although the combined kidney weight was unchanged, indicating a reduction on the obstructed side and a compensatory contralateral hypertrophy. In the group released after seven days, the pelvic volume had returned to normal; nevertheless the parenchymal weight pattern and the histological lesions were similar to those found in animals obstructed for six weeks. In the group released after two days, the pelvic volume had normalized, and the histological changes were less prominent than in animals obstructed for seven days or six weeks. Yet there was a significant difference in parenchymal weight between the hydronephrotic and the contralateral kidney, almost entirely caused by hypertrophy on the nonobstructed side. Thus, the ureteric obstruction must be released very early to avoid parenchymal weight reduction and curb the tissue lesions. On the other hand, the resulting parenchymal damage is moderate and does not seem to progress with time.

Animals↗

PubMed1985

Efficient secretion and purification of human insulin-like growth factor I with a gene fusion vector in Staphylococci.

A novel approach for production of small polypeptides, using a staphylococcal protein A vector, is described. This system is used to express, secrete and purify human insulin-like growth factor I (IGF-I). A fusion protein consisting of protein A and IGF-I is recovered in high yield by passing the culture medium through an IgG affinity column. Using site-specific mutagenesis an acid labile asp-pro cleavage site was introduced at the fusion point between the two proteins. The protein A "tail" can thereby be removed from the affinity purified fusion protein by chemical cleavage releasing biologically active IGF-I molecules.

Escherichia coli↗

PubMed1985

Experimental obstructive hydronephrosis in newborn rats. VI. Long-term effects on glomerular filtration and distribution.

Partial obstruction of one ureter was created in newborn rats and its effects were studied after the rats matured. The obstructed pelvis was found to be considerably enlarged. The parenchymal weight was 19 per cent lower and the whole kidney glomerular filtration rate was 43 per cent lower than on the contralateral intact side (p less than 0.001); however, these figures probably include a compensatory increase on the intact side. In the central part of the cortex, the glomerular filtration rate/mg. cortex was 21 per cent lower in the hydronephrotic kidney (p less than 0.02), but there was no intracortical redistribution. The glomerular density in this region was 24 per cent higher on the hydronephrotic side (p less than 0.001), because the glomeruli were crammed together in the distended cortex. No redistribution of glomeruli was found. The results are discussed and compared with previous findings from our laboratory. In this model, partially obstructive uropathy was found to cause only a moderate depression, but no redistribution, of the filtration.

Animals↗

PubMed1985

Experimental obstructive hydronephrosis in newborn rats. V. Long-term effects on renal tissue solute content.

Partial obstruction of 1 ureter was created in newborn rats and its effects were studied in the adult rat. The obstructed renal pelvis was found to be about 6 times enlarged and the weight of the kidney was 85 per cent of the contralateral intact one. Despite considerable distortion of the inner medulla on the obstructed side, no loss of weight in this region was observed. The only changes observed with respect to tissue concentrations--which were significantly due to the obstruction--were increases in urea in the cortex (110 per cent) and in potassium in the inner medulla (21 per cent); thus, the changes were few and, in part, moderate. The findings are compared with previous observations of solute excretions and the pathophysiological implications are discussed. The conclusion is that although the inner medulla was considerably distorted, the solute content was far from being affected to a corresponding degree--at least not in this experimental preparation.

Animals↗

PubMed1985

Behavior therapy for panic disorder.

Eleven patients who met DSM-III criteria for panic disorder were treated with behavior therapy techniques. Seven patients had mixed phobic avoidance and none were agoraphobic; three had no phobic symptoms. Mean duration of symptoms was 3.4 years. Treatment lasted a mean of 14 weeks and consisted of 1) education about physiology and management of panic symptoms; 2) relaxation, abdominal breathing, and cognitive anxiety management skills; and 3) imaginal and in vivo exposure. Upon termination of treatment, 10 of 11 patients were panic-free and six of seven mixed phobics showed complete remission or significant improvement of phobias. Follow-up data revealed excellent stability of remission. Clinical implications for the use of behavior therapy for panic disorder and directions for future research are discussed.

Adult↗

PubMed1985

Partial ureteric obstruction in weanling rats. I. Long-term effects on the renal morphology.

Partial obstruction of one ureter was created in weanling rats (3 weeks old) and its effects were studied after 3, 6, and 9 weeks. Within 3 weeks, a considerable hydronephrosis had appeared, which did not progress with time. No effect on parenchymal weight was observed, either on the obstructed side or on the contralateral, intact one. Histological examination revealed a marked deformation of the papilla in about 25% of the hydronephrotic kidneys and evidence of chronic pyelonephritis in 40%. However, the inflammatory changes were restricted to the attenuated circumhilar 'edges' of the parenchyma, thus involving only a minor portion of the kidney. The body weight of the animals obstructed for 9 weeks was 12% lower than that of normal, sham-operated controls. In summary, the effect on the renal parenchyma of partial ureteric obstruction, created in the weanling period, was relatively discrete and less pronounced than when obstruction is performed in the neonatal period.

Animals↗

PubMed1984

Nucleotide sequence of the thioredoxin gene from Escherichia coli.

The nucleotide sequence of the thioredoxin gene from Escherichia coli was determined. The structural gene was identified on a cloned 3-kb PvuII fragment by hybridization with a synthetic oligodeoxyribonucleotide corresponding to a part of the amino acid sequence of thioredoxin. Restriction-enzyme fragments were used as templates in the dideoxy sequence method, directly and after subcloning into M13mp8. A segment of 450 nucleotides was determined using both strands, alternatively, without extensive overlaps. The sequence contains the thioredoxin coding region, a potential ribosome-binding site, and a putative promotor region. The predicted amino acid sequence differs by two inversions from the previously given thioredoxin sequence. The revised sequence is presented and the results further show that thioredoxins from E. coli B and K12 are identical.

Amino Acid Sequence↗

PubMed1984

Automatic synthesis of oligodeoxynucleotides and mixed oligodeoxynucleotides using the phosphoamidite method.

A simplified procedure for making and using the deoxynucleoside phosphoamidites (1 a-d) in the automated synthesis of oligodeoxynucleotides has been developed. The reagents prepared show good stability in solution. The reactivity of the reagents was found to be directly proportional to their concentrations, which makes it possible to synthesize mixed oligomers in desired ratios. Oligomers up to 45-mer have been synthesized using a coupling cycle of twenty min.

Chemical Phenomena↗

PubMed1984

Characterisation of the citrate synthase reaction with propionyl-CoA.

Experiments with propionyl-CoA stereoselectively deuteriated in the propionyl moiety demonstrate that the formation of (2S,3S)-methylcitric acid (1) catalysed by citrate (si)-synthase occurs with inversion of configuration in the propionyl moiety; the absolute configurations of the methylcitric acids 1 and 2 indicate a si attack on oxaloacetate. Deuterium in the pro-S position is exchanged for protium 60 times faster than deuterium in the pro-R position. Experiments with (R,S)-(2-2H1)propionyl-CoA allowed the determination of isotope effects. For the enzymatic formation of 1, a primary deuterium isotope effect kH/kD = 1.8 and a secondary alpha-deuterium isotope effect kH/kD = 0.99 were calculated; both are effects on Vmax/KM.

Acyl Coenzyme A↗

PubMed1983

An improved positive selection plasmid vector constructed by oligonucleotide mediated mutagenesis.

An Escherichia coli plasmid vector, pUN121, has been constructed which allows for positive selection of transformants harboring DNA inserts. The positive selection of transformants harboring DNA inserts. The vector is based on plasmid pTR262 (Roberts et al. Gene, 12, (1980), 123-127) in which the tetracycline resistance gene is under transcriptional control of the repressor protein coded by the phage lambda cI gene. This plasmid has been rearranged, using in vitro recombinant techniques including oligonucleotide mediated mutagenesis to yield a smaller plasmid (4.4 kb) with unique cloning sites for EcoRI, XmaI and SmaI in addition to the unique HindIII and BclI sites. The plasmid has a functional ampicillin resistance gene and the new restriction sites (EcoRI, XmaI and SmaI) when used for cloning, give rise to tetracycline resistant transformants.

Ampicillin↗

PubMed1983

Chemical synthesis and molecular cloning of a STOP oligonucleotide encoding an UGA translation terminator in all three reading frames.

We have chemically synthesized an oligonucleotide 5'd(TGATTGATTGA)3' 3'd(ACTAACTAACT)5' that encodes the translation termination codon TGA in all three reading frames. After ligation of appropriate restriction endonuclease linkers to the ends, the double-stranded oligonucleotide (STOP-oligonucleotide) was joined to the plasmid pBR322 between the EcoRI and BamHI, or HindIII and BamHI sites, and the hybrid plasmids were transformed into Escherichia coli HB101. Four different constructions were obtained: (i) EcoRI-STOP-BamHI (STOP-oligonucleotide flanked by EcoRI and BamHI linkers; pKTH606), (ii) HindIII-STOP-BamHI (pKTH601), (iii) BamHI-STOP-HindIII (pKTH604), and (iv) HindIII-STOP-POTS-BamHI (two STOP-oligonucleotides in opposite orientation; pKTH605). The inserts in pKTH606 and pKTH601 were excised and transferred to a modified plasmid constructed previously for the expression and secretion of foreign gene products from Bacillus subtilis. The resulting secretion plasmids now contain the promoter/signal sequence region of the alpha-amylase gene from Bacillus amyloliquefaciens joined to the STOP-oligonucleotide by EcoRI or HindIII linkers. Foreign genes can be cloned into these sites. The plasmids can be used to express foreign genes truncated at their C-terminal end and therefore lacking their own translation termination codon. One such plasmid has been successfully used to express the Semliki Forest virus (SFV) membrane protein E1 truncated at its C-terminus.

Bacillus subtilis↗

PubMed1983

Experimental partial ureteric obstruction in newborn rats. IV. Do the morphological effects progress continuously?

Partial obstruction of the ureter was created in newborn rats, and its effects were studied after 1, 2, 3, 6 and 9 weeks--that is, until adult age. Within 1 week, a considerable hydronephrosis had appeared. Within 2 weeks, parenchymal weight was found slightly reduced (8 per cent) on the obstructed side, and, within 3 weeks, equivalently increased on the contralateral, intact side. After these points in time, there was no further deterioration. Histological examination revealed marked deformation of the papilla and minor foci of degeneration and inflammation within 1 to 2 weeks which tended to become chronic in type after 3 to 9 weeks. Arterial hypertension was not noted. Thus, the effects of partial ureteric obstruction on the renal parenchyma are 1) discrete, 2) not in proportion to the degree of hydronephrosis, 3) fully compensated by contralateral hypertrophy and 4), after reaching an early maximum, not increasing with time.

Aging↗

PubMed1983

Experimental obstructive hydronephrosis in newborn rats. III. Long-term effects on renal function.

A partial obstruction of 1 ureter was created in newborn rats and its effects were studied in the adult rat. The obstructed pelvis was found to be considerably enlarged. Nevertheless, the GFR (glomerular filtration rate) was only slightly decreased (10 per cent), completely compensated by increase on the contralateral, non-obstructed side. The reduction in GFR was less than the reduction in number of glomeruli (19 per cent), indicating a raised filtration rate per glomerulus. Water excretion was slightly increased and potassium excretion moderately decreased; sodium and osmolar excretion were not significantly affected. There was no correlation between these changes and the degree of pelvic enlargement. Thus, in this model, in which there is no urinary tract infection or pyelonephritis, partial obstructive uropathy caused less damage to the kidney function than might have been expected.

Animals↗

PubMed1983

Isolation of cDNA sequences coding for a part of human tissue plasminogen activator.

We have isolated a cDNA sequence coding for a part of human tissue plasminogen activator. mRNA coding for tissue plasminogen activator was partially purified, copied into double-stranded cDNA, and cloned into Escherichia coli. Two sets of partially overlapping oligodeoxynucleotide mixtures corresponding to all possible coding sequences for a known portion of the tissue plasminogen activator gene were prepared. One set was used as a probe to screen cDNA containing bacterial clones and both were used as probes in hybridization against purified plasmid DNA. Of 4,200 bacterial clones examined, 1 carried a plasmid that hybridized to both sets of oligonucleotides. This plasmid contained a 370-base-pair cDNA insert, which was shown by nucleotide sequence analysis to code for the cleavage site region in the one-chain form of the human tissue plasminogen activator.

Amino Acid Sequence↗

PubMed1983

Rehydration using solutions with and without glucose before emergency abdominal surgery in children.

The metabolic effects of six different solutions used for rehydration were studied in 88 children before emergency abdominal surgery. A volume corresponding to 5% of the body weight was given i.v. during 4 h (12.5 ml . kg-1 . h-1) between admission and surgery. The different solutions were: low glucose electrolyte solution (LGE), Rehydrex 2.5%, Rehydrex 5% containing 0.9, 2.5 and 5.0% glucose, respectively, Ringer, Ringer lactate and Ringerdex (30 mmol acetate . l-1). Venous blood samples were drawn before and after rehydration and analysed for glucose, insulin, alanine, 3-hydroxybutyrate (3-HB), non-esterified fatty acids (NEFA), glycerol and base excess. Before rehydration the plasma concentrations of NEFA, glycerol and 3-HB were elevated, while that of alanine was decreased. Plasma levels of NEFA and 3-HB remained unchanged, whereas glucose and insulin decreased after rehydration with glucose-free solutions, i.e. Ringer, Ringer lactate and Ringerdex. With solutions containing glucose the concentrations of NEFA and 3-HB decreased significantly. With Rehydrex 5% hyperglycaemia and hyperinsulinaemia were observed. Rehydration using LGE and especially Rehydrex 2.5% resulted in decreased lipid mobilization and ketonaemia without concomitant marked increase of glucose and insulin. LGE and Rehydrex 2.5% thus appeared to be the most appropriate solutions in a situation where moderate dehydration had to be corrected during a short period of time before emergency abdominal surgery.

Abdomen, Acute↗

PubMed1983

The effect of experimental hydronephrosis on clearance data.

Partial obstruction of one ureter was created in newborn rats and its effects were studied in the adult rat. The obstructed renal pelvis was found to be enlarged 2-3 times. The weight of the kidney on this side was 85% of the contralateral one. Inulin clearance was measured in a way, which allowed comparison between the conventional technique and a modified technique, designed to circumvent the dilution in the enlarged pelvis. With the conventional technique, filtration was 32% of that in the contralateral kidney, whereas with the new technique true filtration of the hydronephrotic kidney was 82% (p less than 0.001). The modified technique is evaluated and the implications of the functional results are discussed.

Animals↗