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Biomedical subjects

U Berg

Publications and source records attributed to U Berg.

At least 37 records · Page 2Linked to original sources
PubMed1998

Stereochemical variations on the colchicine motif. Part 4. A remote metalation approach toward a colchicine analog with a five-membered B-ring.

Attempts to prepare a colchicine analog with a 5-membered B-ring by remote metalation of N,N-diethyl-3,4,5-trimethoxy-2-(5'-methoxy-4'-oxo-2', 5',7'-cycloheptatrienyl)-benzamide (2) led to ring contraction of the methoxytropone ring to the p-methoxycarbonylphenyl derivative (3). Dynamic 1H NMR investigations showed that the biaryl amide 2 exists as a mixture of diastereomers due to hindered rotation around both aryl-aryl and aryl-amide bonds, with rotational barriers of ca. 63 kJ mol-1. The colchicine and allocolchicine analogs 2 and 3 do not notably affect tubulin polymerization, despite the structural similarities with active analogs. The reduced tubulin binding activity of 2 and 3 may be a result of increasing steric bulk.

Colchicine↗
PubMed1998

Pediatric renal transplantation in the Nordic countries: a report of the Nordic Pediatric Renal Transplant Study Group.

The Nordic Pediatric Renal Transplant Study Group was organized in 1994 to register and follow children under 16 years of age who receive renal allografts in the Nordic countries. It comprises all transplant centers in Scandinavia, four in Sweden, three in Denmark and one each in Norway and Finland. The following report is based on 430 transplantations performed in 1982-1996. 343 were first transplants and 57 were retransplants. The mean annual incidence of renal transplantations per million children below 16 years of age was 7.4. The mean incidence of retransplantations was 1.0 and therefore the mean incidence of primary transplantations was 6.5 per million children below 16 years of age. 12% of the children were less than 2 years of age, 20% 2-5 years of age and 68% 6-15 years of age. 231 (54%) of the transplants were performed with grafts from living-related donors (LD) and 199 (46%) with cadaveric grafts (CD). 72% of the children had congenital renal disorders and 28% acquired diseases. Cyclosporine-based immunosuppressive protocols were used in all centers. Antibody induction therapy (polyclonal or monoclonal) was used by only three of the nine participating centers. The mean 1-year graft survival rate for all age groups was 88% for recipients of living-donor grafts and 78% for recipients of cadaveric donor grafts.

Adolescent↗
PubMed1997

Renal function in cyclosporine-treated pediatric renal transplant recipients in relation to gingival overgrowth.

BACKGROUND: Transplant immunosuppression using cyclosporine (CsA) leads to renal dysfunction as well as gingival overgrowth. The underlying alteration in both these lesions is characterized by an excessive accumulation of extracellular matrix components (fibrosis). To investigate the relationship between CsA-induced nephrotoxicity and gingival overgrowth, the renal function as well as the occurrence of gingival overgrowth was evaluated in pediatric renal transplant recipients: 38 boys and 30 girls, ranging in age from 2 to 20 years, who had been on a CsA-based immunosuppressive regimen for at least 12 months. METHODS: Gingival overgrowth was determined on the basis of measurements of sulcus depth and was diagnosed as positive when the probing depth was > or = 4 mm without exhibiting a loss of periodontal attachment. Renal function tests were performed using inulin and para-aminohippuric acid clearances for evaluating glomerular filtration rate, effective renal plasma flow (ERPF), and filtration fraction (FF). RESULTS: Nineteen percent of the children exhibited gingival overgrowth. The occurrence of gingival overgrowth was positively related (P<0.05) to the mean oral daily dose of CsA, the mean CsA trough blood level, and concomitant administration of nifedipine. The children who were on antihypertensive treatment exhibited lower ERPF and significantly higher FF than the normotensive children. The mean FF value was significantly higher (P<0.05) in the children with gingival overgrowth than in those without gingival overgrowth, whereas glomerular filtration rate and ERPF did not differ between the two groups. CONCLUSIONS: The study suggests that there is a positive correlation between the degree of gingival enlargement and changes in renal function expressed as filtration fraction.

Adolescent↗
PubMed1997

Renal transplantation in children less than two years old.

Twenty-one infants, 2 years old or younger, received 21 renal transplants between 1983 and 1995. Six of the transplantations were performed from 1983 to 1989, and the remaining 15 were performed from 1990 to 1995. The median age at transplantation was 16.0 months and the median body weight was 9.0 kg. Living-related donor kidneys were used in 15 cases, an adult cadaveric donor kidney was used in one case, and pediatric cadaveric donor kidneys were used in five cases. All grafts were placed intra-abdominally. The immunosuppressive therapy consisted of cyclosporine, azathioprine, and prednisolone. No prophylactic antithymocyte globulins were used. Five infants have died, one with a functioning graft and four after loss of graft function. All graft losses and deaths occurred during the first 6 months after transplantation. The 5-year patient survival and graft survival rates were 87% for recipients of living donor grafts and 44% for recipients of cadaveric grafts. The median height SD score increased from -3.7 before operation to -1.9 at 1 year, -0.7 at 3 years, and -1.1 at 5 years. The glomerular filtration rate in absolute values remained stable in all infants, whereas a reduction in glomerular filtration rate related to body surface area was seen at follow-up, 5 years after transplantation. We conclude that renal transplantation can be performed with good long-term results in children less than 2 years old.

Adult↗
PubMed1997

Epidemiology of chronic renal failure in children: a report from Sweden 1986-1994. Swedish Pediatric Nephrology Association.

In a national survey, chronic renal failure (CRF) in Swedish children was studied during the period 1986-1994; 118 children (72 boys, 46 girls) with CRF, defined as a glomerular filtration rate below 30 ml/min per 1.73 m2 body surface area, were identified. The median annual incidence of CRF was 7.7 and that of terminal renal failure (TRF) 6.4 per million children. The prevalence of preterminal renal failure decreased from 29 to 21 per million children over the study period, while the prevalence of TRF increased from 17.8 in 1986 to 38 per million children in 1994. The increase in TRF prevalence was due to a lower incidence of deaths due to uremia and a slightly increased incidence of TRF compared with an earlier study period, 1978-1985. The results point to a more active treatment of uremia in Sweden now than during the period 1978-1985. The congenital causes of CRF (renal malformations, obstructive conditions, and hereditary disorders) accounted for 67.5% of all cases, which is high compared with data from other countries. No child with non-obstructive pyelonephritis as a cause of CRF was identified. Age at detection of CRF and time from detection of CRF to TRF were studied. As a high proportion of children, 42%, reached 16 years of age without entering TRF, the value of presenting time from CRF to TRF for the remaining individuals is questionable. There were only minor differences in primary renal disease, age at presentation, and time from CRF to TRF when the study results were compared with those from 1978-1985.

Adolescent↗
PubMed1997

Effect of motile sperm count after swim-up on outcome of intrauterine insemination.

OBJECTIVE: To analyze the prognostic value of motile sperm count after swim-up in IUI with husband's sperm in a large group of subfertile couples. DESIGN: Retrospective study. SETTING: University hospital. PATIENT(S): Nine hundred two couples undergoing 3,037 treatment cycles. INTERVENTION(S): Intrauterine insemination with husband's sperm after swim-up was performed after mild ovarian stimulation with clomiphene citrate and hCG under hormonal and ultrasonographic control of follicle development. MAIN OUTCOME MEASURE(S): Pregnancy rate (PR) in correlation to motile sperm count after swim-up. RESULT(S): A nonlinear increase in PR per treatment cycle was observed with increasing numbers of motile sperm used for IUI. Insemination with < 0.8 x 10(6) motile sperm after swim-up resulted in a PR of < 1% per treatment cycle. When the motile sperm count was above this level, the PR per cycle reached a plateau of 6.9% to 10.2%, with a minor tendency for increase with higher sperm numbers. CONCLUSION(S): Strict analysis of motile sperm count after swim-up is a useful prognostic factor for PRs after IUI. There is a good chance for conception if > or = 0.8 x 10(6) motile sperm are available after appropriate selection methods. Intrauterine insemination performed with considerably higher numbers of motile sperm does not lead to a significant increase in PRs.

Adolescent↗
PubMed1997

Hyperacute rejections of two consecutive renal allografts and early loss of the third transplant caused by non-HLA antibodies specific for endothelial cells.

The immunological rejection of HLA-identical kidney transplants indicates that non-HLA antigens may also be targets for transplant rejection. Interest in the possible role of endothelial specific antigens has grown steadily over the years. Most of the studies published, regarding the association of such antibodies with rejection, have demonstrated the reactivity of endothelial antibodies also with monocytes and keratinocytes, but not with lymphocytes. Such antibodies escape detection in conventional crossmatch tests. In this paper, we present a case report of a 10-year-old girl, whose two consecutive kidney allografts, (one living and one cadaveric donor) were hyperacutely rejected in spite of the fact that she had neither been alloimmunized, nor had any HLA-specific antibodies. Endothelial cell specific antibodies were detected in vivo and in vitro after transplantation only 11 days apart, which were considered to be responsible for rejection. The third cadaveric kidney was lost within 1 week post-transplant. Immunopathological investigation of the three rejected grafts revealed deposition of IgM in the endothelium of arteries and in some glomeruli. No deposition of IgG antibodies was found. Antibodies from this patient did not react with lymphocytes, monocytes or keratinocytes. Patient serum had IgM antibodies that were specifically reactive with cultured endothelial cells, demonstrated by binding in vitro and by complement-dependent cytotoxicity of IL-beta stimulated endothelial cells. No HLA antibodies were found following the first two transplantations, but were demonstrated 1 week after the third transplantation, at the time of an acute irreversible rejection. Western blots of proteins solubilized from endothelial cell membranes, indicated that the antibodies reacted with a 97-110 kD protein. Endothelial cell antigen preparations were made from several different umbilical cord veins. Some primary cell cultures, but not all, reacted with the patient's serum. Therefore, we suggest that the target determinant might be polymorphic. These findings imply that the non-HLA endothelial cell specific molecules may function as target(s) for hyperacute antibody-mediated destruction of kidney allografts.

Antibody Specificity↗
PubMed1997

Effect of acute endurance and strength exercise on circulating calcium-regulating hormones and bone markers in young healthy males.

Physical activity plays a role in the maintenance of the skeleton but the mechanical, metabolic and hormonal mechanisms involved are largely unknown. The influence of acute endurance and strength exercise on circulating levels of calcitonin, parathyroid hormone (PTH), PTH-related peptide (PTHrP), osteocalcin, carboxyterminal cross-linked telopeptide of type I collagen (ICTP) and ionized calcium (Ca2+) was therefore evaluated. Eight healthy young males performed three exercise bouts on separate occasions: endurance exercise, i.e. cycling on a cycle ergometer for 45 min at 55% of Vo2max (E55%) and 15 min at 85% of Vo2max (E85%) and strength exercise at 85% of three repetitions maximum using a leg-press device (STR). Control experiments included the same subjects with the same time schedule but without exercise. Blood samples were taken before, immediately after exercise and during the recovery period. Hormones and bone markers were measured by use of various immunoassays. There was no obvious influence on calcitonin and PTHrP levels, whereas PTH was increased after strength exercise. ICTP and osteocalcin levels correlated positively at all times and showed regular variations. In comparison with the controls, ICTP levels showed a more pronounced decrease following physical activity whereas osteocalcin followed the same pattern as the controls except for after prolonged endurance exercise when a decrease was abolished. In conclusion, an increase in PTH after strength exercise and a pronounced decrease in ICTP after all exercise together with a relative increase in osteocalcin after prolonged endurance exercise might reflect some mechanisms involved in the positive effect of physical activity on bone mass.

Adult↗
PubMed1997

Nerve conduction and autonomic nerve function in diabetic children. A 10-year follow-up study.

In order to study the long-term development of diabetic neuropathy in children with newly diagnosed diabetes mellitus, 144 children were entered in a prospective study of nerve conduction and autonomic nervous function. Neurophysiological recordings of nerve conduction and parasympathetic function (R-R variations) were made at onset of diabetes and after 2, 5 and 10 years. Low sensory nerve conduction and autonomic dysfunction were found in approximately 25% of the children at onset of diabetes when the patients were not yet in complete remission. During years 0-2, an initial improvement of sensory conduction velocities was found. After 2 years, deteriorations in sensory and motor nerve conduction and autonomic nerve function were common and further deterioration was seen over time. A correlation was found between nerve conduction and glycaemic control.

Adolescent↗
PubMed1996

Three year results of in vitro production of bovine embryos in serum-poor bovine oviduct conditioned medium. An overview.

This paper presents a synthesis of 3 year results of in vitro production of bovine embryos in medium previously conditioned by bovine oviduct epithelial cells. In Louvain-la-Neuve, Belgium, a total of 18356 oocytes were matured and inseminated in vitro: 13967 (76%) had cleaved at 3 days post-insemination and 3593 (26%) became blastocysts using this culture system. Our data show that conditioned medium can be stored frozen for up to 3 years without significant loss of activity and is resistant to lyophilization. One single batch of conditioned medium was tested within the same period in four different laboratories and yielded variable results: 27 and 37% blastocysts/cleaved embryos in two of them and only 7 and 0% in the two others whereas in each case more than 30% blastocysts were obtained with the local reference co-culture system. In one laboratory, the batch of oil used to overlay the culture drops had a detrimental effect on the blastocyst rate in conditioned medium but not in co-culture.

Animals↗
PubMed1995

Secretion of biologically active interferon tau by in vitro-derived bovine trophoblastic tissue.

Secretion of interferon tau (IFN tau) by trophoblastic tissue has been shown to be the first embryonic signal for pregnancy recognition. Therefore we tried to derive biologically active trophoblastic tissue by in vitro techniques. Since conventional in vitro conditions for bovine embryo development were not sufficient for long-term culture, we tested more complex culture conditions, including Ménézo B2 or Buffalo rat liver (BRL) cell-conditioned medium, for their ability to support proliferation and IFN tau secretion by in vitro-derived trophoblastic tissue. IFN tau activity was determined by using a biological assay based on the inhibition of the cytopathic effect of vesicular stomatitis virus on Madin-Darby bovine kidney cells. When cultures of individual hatched blastocysts were started in 60-microliters drops of BRL cell-conditioned medium, mean IFN tau secretion (antiviral units/ml/48 h) corresponded to 1200 on Day 11 and to 5000 on Day 13 (p < 0.01). To characterize trophoblast cell-specific secretions, the inner cell mass was removed from all embryos by microsurgery on Day 13. IFN tau secretion by trophoblastic tissue increased to mean levels of > 10(5) antiviral units/ml/48 h on Day 23m, stayed high for about 1 wk, and then slowly declined to levels below 10(3) antiviral U/ml/48 h. The specificity of the cytoprotective effect of IFN tau was tested by Western blot analysis and by immunoneutralization with use of a polyclonal antiserum specific to IFN tau. Our results demonstrate that viable trophoblastic tissue can be maintained entirely in vitro and secretes high amounts of IFN tau.

Animals↗
PubMed1995

Neonatal herpes simplex: clinical findings and outcome in relation to type of maternal infection.

In 39 mothers of children with neonatal herpes simplex virus infection, maternal infection was serologically characterized retrospectively and was related to maternal clinical symptoms and to the clinical findings and outcome in the child. Thirteen mothers had a primary infection (six type 1, seven type 2), mostly with clinical symptoms. The mean age of onset of the disease of the infants was 7 days and a disseminated disease was most commonly found. Most of the type 1-infected children recovered completely, whereas all but one of the type 2-infected children died. Twenty mothers had a recurrent (2 type 1, 18 type 2) and 4 an intermediate infection (primary type 2, prior infection with type 1), mostly asymptomatic. Their children had a localized disease (of the skin-eye-mouth or the central nervous system) with onset at a mean age of 14 or 13 days, respectively. The frequency of neurological sequelae was high. Two mothers had no serological signs of herpes infection.

Age Factors↗
PubMed1994

Glomerular volume and renal function in children with different types of the nephrotic syndrome.

Glomerular hypertrophy has been suggested to be an important factor in the pathogenesis of focal glomerular sclerosis. The aim of the present study was to analyse retrospectively the renal biopsies of 58 children (0.2-16.1 years of age) with different types of the nephrotic syndrome, minimal change nephrotic syndrome (MCNS), diffuse mesangial proliferation (DMP) and focal segmental glomerulosclerosis (FSGS). Glomerular surface area was measured and glomerular volume was calculated and related to steroid responsiveness and to renal function, measured by clearances of inulin and para-aminohippuric acid. Glomerular volume correlated with body surface area (BSA) and age. Because of this, patients with FSGS and DMP were matched according to BSA and age, with corresponding MCNS patients. Glomerular volumes of FSGS and DMP patients were significantly larger than those of MCNS patients. In the MCNS patients, significant correlations were found between glomerular volumes and glomerular filtration rate and effective renal plasma flow. Steroid-dependent and steroid-resistant patients showed larger glomeruli than the steroid-responsive children. We suggest that hyperfiltration and hyperperfusion, among other factors, may contribute to glomerular hypertrophy, mesangial proliferation and glomerulosclerosis.

Adolescent↗
PubMed1994

Effect of hydrochlorothiazide and indomethacin treatment on renal function in nephrogenic diabetes insipidus.

The purpose of this study was to investigate the effects of treatment with hydrochlorothiazide and hydrochlorothiazide and indomethacin combined on renal function in four boys, two with nephrogenic diabetes insipidus and two with partial nephrogenic diabetes insipidus using the clearances of inulin and para-aminohippuric acid under water diuresis and lithium clearance. Hydrochlorothiazide reduced urine flow and lithium clearance. These effects were further potentiated by addition of indomethacin. No consistent effects on renal plasma flow or glomerular filtration rate were found. It is concluded that treatment with hydrochlorothiazide alone and hydrochlorothiazide and indomethacin combined reduces urine flow in nephrogenic diabetes insipidus by increasing proximal tubular reabsorption of sodium.

Child↗
PubMed1994

Renal scarring after acute pyelonephritis.

Seventy six children, 18 boys and 58 girls, aged 0-15.9 (median 1.0) years, with acute pyelonephritis were prospectively studied with a technetium-99m dimercaptosuccinic acid (DMSA) scan during infection and two months later. Fifty nine of these children were also studied two years after the infection. Seventeen children with a normal DMSA scan during infection or at two months after infection, or both, were not investigated by a DMSA scan at two years after acute pyelonephritis. A micturition cystourethrogram was performed in all the children after two months. Changes on the DMSA scan were found in 65 (86%) children during acute pyelonephritis, in 45 (59%) children at two months, and in 28 (37%) children at two years after infection. Vesicoureteric reflux (VUR) was found in 19 (25%) children at two months. Renal scarring was significantly correlated with the presence of gross VUR and recurrent pyelonephritis, but 62% of the scarred kidneys were drained by non-refluxing ureters. Children with scars were older at the time of acute pyelonephritis than those without scars but no difference was found between the groups with regard to duration of illness, levels of C reactive protein and maximum white cell count, glomerular filtration rate, nor renal concentration capacity at the time of infection. It is concluded that renal scarring after acute pyelonephritis in children is more common than has been previously thought. Although children with gross VUR and recurrent pyelonephritis are at the greatest risk, renal scarring is more often seen without these risk factors.

Acute Disease↗