Biomedical subjects

A Bergman

Publications and source records attributed to A Bergman.

At least 109 records · Page 6Linked to original sources

PubMed1995

Toxicity of PCB 77 (3,3',4,4'-tetrachlorobiphenyl) and PCB 118 (2,3',4,4'5-pentachlorobiphenyl) in the rat following subchronic dietary exposure.

The toxicity of 3,3',4,4'-tetrachlorobiphenyl (PCB 77) and 2,3',4,4',5-pentachlorobiphenyl (PCB 118) was investigated in rats following subchronic dietary exposure. Groups of 10 male and 10 female weanling Sprague-Dawley rats were administered PCB 77 in the diet at 0, 10, 100, 1000, or 10,000 ppb for 13 weeks. PCB 118 was administered to males in the diet at 0, 10, 100, 1000, and 10,000 ppb, while the female groups received 0, 2, 20, 200, or 2000 ppb of the congener for 13 weeks. Growth rate and food consumption were not affected by treatment. No clinical signs of toxicity were observed. Increased spleen weight occurred in male rats fed 1000 or 10,000 ppb PCB 77. Male rats receiving 10,000 ppb PCB 118 had increased liver weight and hepatic ethoxyresorufin O-deethylase (EROD) activity. Increased hepatic EROD activity but not liver weight was observed in female rats given the 2000-ppb PCB 118 diet. Increased EROD activity was also noted in male rats given 10,000 ppb and in female groups receiving 1000 or 10,000 ppb PCB 77. Male rats exposed to 10,000 ppb PCB 77 had decreased vitamin A in the liver and lung and elevated levels in the kidney. Liver vitamin A of both 1000- and 10,000-ppb PCB 77 female groups was decreased. PCB 118 had no effects on tissue vitamin A at the levels studied. No hematological changes or serum biochemical changes were seen in any of PCB 118- and PCB 77-treated groups, nor were liver uroporphyrin levels altered. A reduction in dopamine and homovanillinic acid in substantia nigra region of the brain was observed in female rats fed 2000 ppb PCB 118, while 10,000 ppb PCB 77 was associated with an elevation in 3,4-dihydroxyphenylacetic acid in the nucleus accumbens region of male rat brains. Mild to moderate changes were observed in the liver and thyroid of rats given PCB 77 or PCB 118. PCB 118 accumulated in a dose-dependent manner in fat and to a much lesser extent in liver. In contrast, very low levels of PCB 77 residue were found in the tissues examined. Based on the above data it was concluded that NOAEL of PCB 77 is 100 ppb in diet or 8.7 micrograms/kg and that of PCB 118 is 200 ppb in diet or 17 micrograms/kg body wt/day.

Animal Feed↗

PubMed1995

Three surgical procedures for genuine stress incontinence: five-year follow-up of a prospective randomized study.

OBJECTIVE: Our purpose was to evaluate and compare the long-term results of the Kelly plication, modified Pereyra needle suspension, and Burch urethropexy for the treatment of stress urinary incontinence in women. STUDY DESIGN: One hundred twenty-seven consecutive women underwent surgery at the gynecologic urology division at Women's Hospital, Los Angeles County-University of Southern California Medical Center between January 1986 and June 1987. The only indication for surgery was stress urinary incontinence. Women with previously failed antiincontinence procedures were excluded. Fifty-three patients were premenopausal and 74 postmenopausal. History, physical examination, urethocystoscopy, cotton swab test, filling cystometry, urethral pressure profile at rest and on cough, and uroflowmetry were performed preoperatively, 3 months, 1 year, and 5 years postoperatively. The subjects and surgeons were randomly allocated to one of three surgical procedures: group 1 had anterior colporrhaphy with Kelly plication, group 2 had modified Pereyra needle urethropexy, and group 3 had Burch urethropexy. One hundred seven women were available after 1 year, and 93 were the subjects of the 5-year evaluation. Fisher exact text, chi 2, t test, and paired t test were used for statistical analysis. RESULTS: The results of the 1-year postoperative evaluation has been previously published. The objective success rate for groups 1, 2, and 3 after 5 years was 37%, 43%, and 82%, respectively, and the difference was statistically significant. The drop in the success rate in 4 years was 26%, 22%, and 7% for groups 1, 2, and 3, respectively. Urodynamically all three procedures significantly increased the abdominal pressure transmission to the urethra, when successful. Ninety-one percent of women after the Burch procedure had a negative cotton swab test after 5 years compared with 46% for the Pereyra and 30% for the Kelly procedures. CONCLUSIONS: In our hands the Burch urethropexy has a higher cure rate that holds over time when compared with the modified Pereyra needle suspension and the Kelly plication. The lower incidence of the positive cotton swab test in women after Burch urethropexy may be proof of a better anatomic suspension of the bladder neck.

Adult↗

PubMed1995

Interferon as an adjuvant treatment for genital condyloma acuminatum.

OBJECTIVE: To evaluate the effect of alpha-interferon as an adjuvant to laser or fluorouracil treatment in patients with recurrent genital human papillomavirus (HPV) infection. METHODS: Sixty-two females and 21 males were treated for recurrent HPV infection, with either fluorouracil (Efudex 5%) cream or laser ablation of the lesions. Half of the patients were then randomly treated with adjuvant alpha-interferon, to the lesions for patients treated with fluorouracil, or beneath areas previously treated by laser, once a week, for 8 weeks. The other half of the patients did not receive interferon adjuvant. Evaluation of both groups was done using colposcopy and acetic acid, to assess recurrence rates up to 1 year after treatment. RESULTS: Of the 83 patients followed for 1 year, colposcopy revealed recurrent anogenital lesions in 3 of 45 receiving interferon, compared with 9 of 38 patients treated without adjuvant interferon. CONCLUSION: Interferon is effective as adjuvant treatment in controlling the recurrence of genital HPV.

Adolescent↗

PubMed1995

A cohort study comparing laparoscopic-assisted vaginal hysterectomy and extrafascial hysterectomy.

STUDY OBJECTIVE: To compare extrafascial hysterectomy (TAH) and laparoscopic-assisted vaginal hysterectomy (LAVH). DESIGN: Consecutive women scheduled for hysterectomy, who entered one group or the other based on personal preference. SETTING: A university-affiliated women's hospital. PATIENTS: Thirty-seven women with benign gynecologic pathology. INTERVENTIONS: Eighteen underwent TAH and 19 had LAVH. All were followed for 6 months postoperatively. MEASUREMENTS AND MAIN RESULTS: The duration of LAVH was significantly longer than that of TAH; estimated blood loss was significantly higher for TAH; and the duration of use of narcotic analgesics, length of hospital stay, and length of time to resumption of routine working activity were significantly shorter after LAVH. No difference was found in the two groups with respect to Q-Tip test preoperatively and 6 months after surgery. CONCLUSIONS: We believe LAVH is a valid and safe alternative to TAH in selected patients. The two procedures do not alter the mobility of the bladder neck on short-term follow-up. Additional prospective studies are necessary to confirm our data.

Activities of Daily Living↗

PubMed1995

Population structure, fitness surfaces, and linkage in the shifting balance process.

Wright first introduced the idea that random genetic drift and classical mass-action selection might combine in such a way as to allow populations to find the highest peak in complicated adaptive surfaces. His theory assumes large but structured populations, in which mating is spatially local. If gene flow is sufficiently low, and the subpopulations (demes) are small enough, they will be subject to genetic drift. Distant demes drift independently, allowing many independent searches of the adaptive surface to take place. A deme that has shifted to a higher peak can, by emigration, cause the rest of the demes to shift to the higher peak. The probability of this shift depends on the migration rate. Previous studies have concluded that very little migration is necessary to effect the shift in adaptive peaks that characterizes the last phase of Wright's Shifting Balance Process (SBP). Here we present the results of a computer study that investigates the roles of dispersal distance, the degree of epistasis in the fitness surface, and recombination on the shifting balance process. In particular, we measure their effect on the population's mean fitness. We show that over a range of dispersal distances the advantage of the SBP is a monotonically increasing function of the amount of epistasis. Our results show that the extent of dispersal that results in the greatest effect of the SBP in increasing mean fitness depends on the extent of epistasis. Finally, for low levels of epistasis, higher recombination performs better, while for intermediate levels, lower recombination results in a greater advantage of the SBP.

Adaptation, Biological↗

PubMed1995

Contact urticaria with anaphylactic reactions caused by occupational exposure to iridium salt.

This paper presents the case of a non-smoking and non-atopic male, exposed to iridium chloride at work, who developed respiratory tract symptoms and contact urticaria. Application of iridium salt to normal skin caused contact urticaria. An iridium chloride prick test showed a positive reaction and a scratch test produced anaphylactoid reactions. Platinum salt allergy was excluded through prick testing with hexachloroplatinate solution. There is no previous report describing a case where an individual has a positive prick test reaction to iridium salts and simultaneously a negative one to platinum salts. The results are interpreted as immediate-type hypersensitivity (Type I allergy?) to iridium salt. The route of sensitization was probably through the airways. Further testing showed that iridium salt allergy could persist for at least 18 months after exposure ceases. 14 employees at the same factory were prick tested with iridium and platinum salts with negative results. Prick testing is recommended as a method of first choice when investigating a person with suspected iridium salt allergy.

Adult↗

PubMed1995

Histopathology of postpartum placental sites in mink (Mustela vison) exposed to polychlorinated biphenyls or fractions thereof.

Polychlorinated biphenyls (PCB) cause reproductive failure in mink. Ovulation and nidation occur, but the fetuses die during gestation. The toxicity of different chlorinated biphenyl (CB) congeners differs markedly. Dioxin-like congeners with no (0-ortho CBs) chlorine in the ortho position to the biphenyl bond are considered to be highly toxic. Altogether, 13 groups of 10 female mink (Mustela vison) were exposed to PCB or CB fractions thereof during the reproductive season of 1988 and 1989. In 1988, one group of mink received 2 mg/day of Clophen A50 and five groups received single fractions thereof or synthetic 0-ortho CB in their diet. In 1989, one group received 1.64 mg/day of Aroclor 1254 and six groups received combinations of fractions thereof. The daily amounts of the fractions administered per animal were equivalent to those present in 2 mg of Clophen A50 or 1.64 mg of Aroclor 1254. After administration for 3 months in both experiments, the animals were killed 5 days after parturition. Histological examination focused on the placental sites. The most involuted placental sites were those of early fetal death in primiparous, non-whelping animals in the 1989 experiment. The least involuted placental sites, displaying a hyperplastic and pleomorphic uterine luminal epithelium, in which proliferating cell nuclear antigen (PCNA) was present, were those of late fetal death in biparous, non-whelping animals in the 1988 experiment. The survival of the fetoplacental unit was related to PCB exposure. The histology of the placental sites seemed only to be related to the survival time of the fetuses and to the number of former reproductive seasons.

Animals↗

PubMed1995

Genuine stress urinary incontinence with low urethral pressure. Five-year follow-up after the Ball-Burch procedure.

OBJECTIVE: To evaluate long-term results of the Ball-Burch procedure in women with genuine stress incontinence (GSI), low urethral pressure type. STUDY DESIGN: Sixty women with a clinical and urodynamic diagnosis of GSI, low urethral pressure type, underwent the Ball-Burch procedure between May 1987 and February 1988. They were evaluated preoperatively and one and five years after surgery. The urogynecologic workup consisted of a history, physical examination, urine culture, neurologic examination, urethrocystoscopy, cotton swab test, urethrocystometry, urethral profilometry and uroflowmetry. Forty-eight women were available at the one-year follow-up, and 32 of the 48 (66.7%) were available after five years; the mean age at the time of surgery was 58.7 years and mean parity, 2. Twenty-seven women were premenopausal and 33 postmenopausal; at the five-year follow-up all but 2 were postmenopausal. All postmenopausal women received estrogen replacement therapy prior to urodynamic evaluation. Cure was defined as absence of loss of urine by history (subjective) and during urodynamic evaluation (objective). The t test and paired t test were used for statistical analysis. RESULTS: Forty-two of 48 women (87.5%) were cured after one year, and 27 of 32 (84%) were cured after five. There was a statistically significant difference between the preoperative and five-year follow-up values for the swab test, maximum urethral closure pressure and pressure transmission ratio at the proximal and mid urethra. Twenty-six of 29 patients with a negative swab test at the one-year follow-up were cured after five years, resulting in a predictive value of 89% for cure after a negative test. CONCLUSION: In our series the Ball-Burch procedure was an effective surgical treatment for patients with GSI and low urethral pressure. The swab test, when negative one year after surgery, was predictive of a successful long-term outcome.

Adult↗

PubMed1995

[Preliminary studies on the retention of hydroxylated PCDF metabolites in rat blood].

We recently reported that certain hydroxylated PCB (OH-CB) metabolites were selectively retained in blood of rats experimentally dosed with PCB (Aroclor 1254), and also in blood of seals and humans environmentally exposed to PCBs. We also showed that metabolism in vivo of polychlorinated dibenzofurans (PCDFs) gave rise to a large number of hydroxylated PCDF (OH-CDF) metabolites, excreted in faeces, after oral administration to rats of PCDFs mixture (1, 2, 7, 8-tetraCDF 14%, 2, 3, 7, 8-tetraCDF 35%, 1, 2, 3, 7, 8-pentaCDF 48%). These results suggest that OH-CDFs could be present in blood. In the present study, potential retention of OH-CDF metabolites in blood (serum) was investigated in a female Wistar rat exposed to the PCDFs mixture. Serum was analyzed for the methylated OH-CDFs by gas chromatography (GC) and GC-mass spectrometry. Two major metabolites were determined in serum 1 day after oral administration. These were identified to be 3-OH-2, 4, 7, 8-tetraCDF (A) and 3-OH-2, 4, 7, 8, 9-pentaCDF (B) by comparison with synthesized reference compounds. 3-OH-2, 4, 7, 8-tetraCDF and 1, 2, 3, 7, 8-pentaCDF, respectively, via 3, 4(6, 7)-epoxide intermediate and subsequent NIH-shift of the 3(7)-chlorine to the 4(6)-position. The amounts of 3-OH-2, 4, 7, 8-tetraCDF and 3-OH-2, 4, 7, 8, 9-pentaCDF in the serum (5.72 g) analyzed accounted for 0.018% of 2, 3, 7, 8-tetraCDF and 0.003% of 1, 2, 3, 7, 8-pentaCDF dosed, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Hormonal influence on the urinary tract.

This article describes the hormonal changes in the female and the effect of these changes on the urinary tract. Current concepts in hormone replacement therapy as it relates to incontinent, estrogen-deficient women are discussed, along with the relationship between collagen and estrogen. Finally, the authors assess the published research on the effect of estrogen on incontinence.

Atrophy↗

PubMed1995

Diagnostic considerations in coexisting bladder and urethral leiomyomata. A case report.

BACKGROUND: Leiomyomata of the lower urinary tract in women are rare. Coexisting urethral and bladder leiomyomata have never been reported before. CASE: A 45-year-old woman, gravida 6, para 5, abortus 1, presented with a one-year history of increasing frequency, nocturia and hesitancy of up to 10-15 minutes at times. An intravenous pyelogram showed an extrinsic mass at the bladder neck. Urethrocystoscopy revealed a regular bulge at the level of the bladder neck on the right side without involvement of the bladder mucosa. Ultrasound showed a 5 x 4.7 x 4-cm mass of heterogeneous echogenicity, posterior to the bladder and anterior to the lower uterine area, with a normal-appearing uterus. The patient underwent surgery for vaginal excision of the tumor. Two separate masses were found at surgery. One small, firm, solid, 2-cm mass was found on the posterior proximal aspect of the urethra, and a larger, soft, 3 x 3-cm mass was found on the posterior lower aspect of the bladder. The masses clearly arose from the urethra and bladder, respectively. Rapid frozen section revealed smooth muscle cells consistent with leiomyomata. Both leiomyomata were entirely resected. CONCLUSION: Lower urinary tract leiomyomata should always be considered in the differential diagnosis of an anterior vaginal mass in premenopausal women.

Female↗

PubMed1994

Urinary ascorbic acid--HPLC determination and application as a noninvasive biomarker of hepatic response.

A high-performance liquid chromatograph (HPLC) procedure has been developed for the determination of rat urinary ascorbic acid, a major metabolite of the hepatic glucuronic acid pathway. The presence of EDTA and HCl effectively inhibited degradation of ascorbic acid during the collection of urine specimens. The reliability of the procedure was demonstrated by its high recovery (90%), specificity (characteristic absorption maximum and discrimination from isoascorbic acid), and reproducibility (2-3% coefficient of variation). The usefulness of this assay as an indicator of hepatic response was demonstrated in preliminary experiments where increases in urinary ascorbic acid excretion were detected in male rats treated with PCB 126 (3,3',4,4',5-pentachlorobiphenyl) or PCB 105 (2,3,3',4,4'-pentachlorobiphenyl). The HPLC measurement also showed that the two PCB congeners differed markedly in their potency in stimulating urinary ascorbic acid excretion. For example, 10 micrograms/kg bw/day of PCB 126 was sufficient to cause a fourfold increase in urinary ascorbic excretion while 5000 micrograms/kg bw/day of PCB 105 was required for a sevenfold increase. In response to the administration of PCB 105 or PCB 126, urinary ascorbic acid appeared to increase to the same extent as increases in hepatic ethoxyresorufin O-deethylase (EROD) and UDP-glucuronosyltransferase (UGT) activities, and to a much higher extent than changes in liver weight and hematological and serum clinical chemical parameters. The sensitivity and specificity, the ease in obtaining timed specimens, and the noninvasive nature make this assay a useful biomarker of hepatic response in dose-finding and various acute and chronic studies.

Animals↗

PubMed1994

Renal effects of human atrial natriuretic peptide in patients after major vascular surgery.

The effects were studied postoperatively of an infusion of atrial natriuretic peptide (ANP) 7.5 pMol.kg-1.min-1 on renal function and haemodynamics in seven patients who had been operated with insertion of an abdominal aortic graft. Urine flow, glomerular filtration rate (GFR), renal plasma flow (RPF) and excretion of electrolytes and osmoles were measured for three periods of 20 minutes during infusion of ANP, in the morning of the day after surgery. Haemodynamic studies were conducted, and serum levels of ANP, catecholamines and plasma renin activity were measured. ANP levels increased from 52 to approximately 250 pMol.L-1 during ANP infusion and decreased after infusion to a level equal to baseline. GFR increased from 92 mL.min-1 by 58, 20 and 21%, respectively. RPF was unchanged. Urine flow rate increased from 1.99 mL.min-1 by 81, 151 and 173%, respectively. Fractional clearances of sodium, chloride and osmoles were increased during the second and third ANP periods whereas fractional potassium clearance did not change during the study. There were no changes in catecholamine levels or plasma renin activity during the study. Heart rate, mean arterial pressure and calculated systemic and pulmonary vascular resistance did not change whereas reductions occurred in cardiac index, mean pulmonary artery pressure, pulmonary artery wedge pressure and mean right atrial pressure. We conclude that infusion of ANP also in the postoperative situation increases GFR, diuresis and sodium excretion.

Adult↗

PubMed1994

Biochemical composition of collagen in continent and stress urinary incontinent women.

This study was designed to assess the relationship between the amount of collagen type III in the pelvic supportive tissues and stress urinary incontinence (SUI) with or without pelvic relaxation. Fourteen women agreed to participate in the study: 6 had stress urinary incontinence and pelvic relaxation (group 1); 4 had no pelvic relaxation and no sign or symptoms of SUI (group 2); 4 had pelvic relaxation without SUI (group 3). All patients underwent gynecologic surgical procedures for benign pathology and at that time biopsies were taken from perineal skin, uterosacral ligaments and round ligaments of the uterus. Collagen type III content was measured in the specimens and compared between the groups. Each subject preoperatively underwent complete urodynamic workup. A t test was used for the statistical analysis. Collagen type III content was significantly reduced (p < 0.05) in the specimens from patients with SUI (group 1) as compared independently with each of the other two groups (groups 2 and 3). Tissues from women without SUI (groups 2 and 3) had a similar content of collagen type III. These findings suggest that women with SUI show an altered collagen profile in the skin, the uterosacral, and the round ligaments. This seems unrelated to secondary damage of the supportive tissues and degree of pelvic relaxation.

Adult↗

PubMed1994

Selective retention of hydroxylated PCB metabolites in blood.

Polychlorinated biphenyls (PCBs) are important environmental contaminants, and their toxicity to wildlife and humans are of major concern. PCBs form persistent and abundant metabolites, PCB methyl sulfones, that accumulate in biota. We now report that certain hydroxylated PCB metabolites show a strong and selective accumulation in mammalian blood. Plasma from experimentally PCB-dosed rats and blood from environmentally exposed grey seals (Halichoerus grypus) and humans were analyzed. Among all possible hydroxylated metabolites of PCB that may be formed, only a few, dominated by 4-OH-2,3,5,3',4'-pentachlorobiphenyl and 4-OH-2,3,5,6,2',4',5'-heptachlorobiphenyl, were found in the blood samples. All identified compounds have a structure with the hydroxy group in a para or meta position, with chlorine atoms on vicinal carbon atoms. The concentrations of hydroxylated PCB in the blood were almost in the same range as the most persistent PCB congeners both for seals and humans.

Adult↗

PubMed1994

Accuracy of double contrast barium enema and sigmoideoscopy in the detection of polyps in patients with diverticulosis.

The sensitivity between double contrast barium enema (DCBE) and sigmoideoscopy in diagnosing neoplastic lesions in the sigmoid colon was compared in patients with diverticulosis. In 52 patients with severe diverticulosis (> or = 15 diverticulas) the DCBE detected one out of 4 polyps found by sigmoideoscopy. In the remaining 54 patients with mild diverticulosis (< 15 diverticulas) DCBE detected 7 out of 10 polyps found by sigmoideoscopy. Successful bowel preparation did not influence the outcome of the DCBE. Sigmoideoscopy was incomplete in 17 (16%) of the patients; females were more difficult to examine than males (p = 0.012), as were those with a previous pelvic operation (p = 0.032). We conclude that neither DCBE nor sigmoideoscopy alone is sufficient to detect all neoplastic lesions in the sigmoid colon in patients with sigmoid diverticulosis of the colon.

Adult↗

PubMed1993

Relative tumour promoting activity of three polychlorinated biphenyls in rat liver.

The relative tumour promoting activity of three structurally and toxicologically diverse polychlorinated biphenyls (3,4,5,3',4'-penta- 2,3,4,3',4'-penta- and 2,4,5,2',4',5'-hexachlorobiphenyl) was measured in an initiation/promotion assay in nitrosodiethylamine-initiated female Sprague-Dawley rats. The congeners under study were administered by once-weekly subcutaneous injections for 20 weeks. Evaluation of the development of gamma-glutamyl transpeptidase (GGT)- and glutation transferase P (GST-P)-positive hepatic foci showed that all congeners promoted altered hepatic foci, although 3,4,5,3',4'-pentachlorobiphenyl was far more potent. The volume fraction of the liver occupied by GGT-positive tissue in the 3,4,5,3',4'-pentachlorobiphenyl-treated animals (100 micrograms/kg per week) was 23%, while the volume fractions of altered liver tissue in the rats treated with 2,3,4,3',4'-pentachlorobiphenyl (5000 micrograms/kg per week) and 2,4,5,2',4',5'-hexaCB (20,000 micrograms/kg per week) were 1.2 and 2.3, respectively. The enhancement of GGT- and GST-P-positive foci was accompanied by an increased incidence of histological changes in the livers.

Animals↗

PubMed1993

The evolution of interference: reduction of recombination among three loci.

Crossover events along chromosomes do not occur independently, but influence the probability of other nearby events. The most common interaction between nearby crossover events is inhibitory: a crossover event tends to reduce the probability of other such events nearby, and this is called positive interference. A crossover event may increase the probability of events nearby, and this rare phenomenon is called negative interference. In this paper, we use numerical methods to investigate how interference among three loci would evolve if it were under the genetic control of a fourth, selectively neutral locus. We first discuss the effect of interference on the overall rate of recombination among the three loci, and then show that, under a variety of conditions, interference evolves in the same way as would be predicted based upon its effect on the overall rate of recombination. That is, the overall rate evolves in the same direction as would the rate at a locus that controls recombination between two loci directly. We then check for the existence of viability-analogous Hardy-Weinberg equilibria in the four-locus model of interference modification.

Crossing Over, Genetic↗