The relationship between sperm nuclear DNA fragmentation, mitochondrial DNA fragmentation, and copy number in normal and abnormal human ejaculates

BACKGROUND

While it is common to clinically evaluate sperm nuclear DNA fragmentation, less attention has been given to sperm mitochondrial DNA. Recently, a digital PCR assay has allowed accurate estimation of the proportion of fragmented mtDNA molecules and relative copy number.

OBJECTIVES

To determine the correlation of classical sperm parameters, average mtDNA copies per spermatozoon and the level of mtDNA fragmentation (SDF-mtDNA) to that of nuclear DNA fragmentation (SDF-nDNA), measured as the proportion of global, single-strand DNA (SDF-SSBs) and double-strand DNA breaks (SDF-DSBs). To determine whether the level of nuclear and mitochondrial DNA fragmentation and/or copy number can differentiate normozoospermic from non-normozoospermic samples.

MATERIALS AND METHODS

Ejaculates from 29 normozoospermic and 43 non-normozoospermic were evaluated. SDF was determined using the sperm chromatin dispersion assay. mtDNA copy number and SDF-mtDNA were analyzed using digital PCR assays.

RESULTS

Relative mtDNA copy increased as sperm concentration or motility decreased, or abnormal morphology increased. Unlike SDF-mtDNA, mtDNA copy number was not correlated with SDF-nDNA. SDF-mtDNA increased as the concentration or proportion of non-vital sperm increased; the higher the mtDNA copy number, the lower the level of fragmentation. Non-normozoospermic samples showed double the level of SDF-nDNA compared to normozoospermic (median 25.00 vs. 13.67). mtDNA copy number per spermatozoon was 3× higher in non-normozoospermic ejaculates (median 16.06 vs. 4.99). Although logistic regression revealed SDF-Global and mtDNA copy number as independent risk factors for non-normozoospermia, when SDF-Global and mtDNA copy number were combined, ROC curve analysis resulted in an even stronger discriminatory ability for predicting the probability of non-normozoospermia (AUC = 0.85, 95% CI 0.76-0.94, p < 0.001).

CONCLUSION

High-quality ejaculates show lower nuclear SDF and retain less mtDNA copies, with approximately half of them fragmented, so that the absolute number of non-fragmented mtDNA molecules per spermatozoon is extremely low.

Addendum to: The relationship between sperm nuclear DNA fragmentation, mitochondrial DNA fragmentation and copy number in normal and abnormal human ejaculates

BACKGROUND

While the kinetics of human sperm nuclear DNA fragmentation (SDF-nDNA) following ejaculation have been described, the dynamics and relationships of mitochondrial DNA copy number per spermatozoon (mtDNAcn) and fragmentation (SDF-mtDNA) remain unexplored.

OBJECTIVES

To compare post-ejaculatory kinetics of mtDNAcn, SDF-mtDNA and SDF-nDNA, global, single-strand DNA breaks (SDF-SSBs) and double-strand DNA breaks (SDF-DSBs) in normozoospermic and non-normozoospermic samples.

MATERIALS AND METHODS

28 normozoospermic and 43 non-normozoospermic ejaculates were evaluated at 0, 6, 24 and 48 h of incubation in vitro. SDF-nDNA was determined by sperm chromatin dispersion (SCD) assays. mtDNAcn and SDF-mtDNA were analysed by dPCR.

RESULTS

SDF-nDNA-global values increased as a consequence of quadratic SDF-SSBs and linear SDF-DSBs kinetics. Non-normozoospermic samples showed a slower SDF-global rate between 6-24 h, due to lesser SSBs production. Regarding SDF-DSBs, non-normozoospermic samples exhibited a faster initial increase rate, followed by a slower final increment. The mtDNAcn median value decreased linearly, being 3.2× higher in non-normozoospermics at all time points; mtDNAcn in both cohorts reduced to half of the baseline by 48 h. mtDNAcn was identified as a risk factor for discriminating non-normozoospermia, a finding that was further strengthen when combined with SDF-Global or SDF-DSBs values. SDF-mtDNA frequencies were identical, increasing over time correspondingly in both cohorts. The mtDNA fragmentation rate was initially fast, decreasing progressively with time for both cohorts; half of the initially unfragmented copies were fragmented after 48 h. Rates of mtDNAcn loss and SDF-mtDNA increase were only marginally correlated with the rates of nuclear fragmentation.

CONCLUSION

mtDNA fragmentation and loss occur post ejaculation. Their dynamics are likely to be associated with different and/or uncoupled mechanisms to that which cause nuclear DNA fragmentation. Our results indicate that while mtDNA fragmentation is not influenced by the sperm quality, the number of copies of sperm mtDNAcn can potentially serve as a risk factor for predicting non-normozoospermia.

POS0624 RHEUMATOID ARTHRITIS AND ORAL MICROBIOME RELATED TO PERIODONTAL DISEASE

Background

Rheumatoid Arthritis (RA) is a prevalent systemic autoimmune disease with an unknown etiology. Its onset has been related with chronic immune activation.1 Oral microbiome (OM) could be one trigger for this beginning, due to its implication in periodontal disease (PD) and chronic gum inflammation.2

Objectives

To correlate OM species potentially harmful and RA disease activity.

Methods

During a 6-month period (June to December 2021), RA patients (from the daily practice in a Rheumatology Department) and healthy controls were recruited. Healthy controls proceed from outpatient Orthopaedic Surgery Department (with no autoimmune diseases). A specialized odontologist made an oral evaluation and took samples. OM was assessed by a semiquantitative reactive-chain protein. Species evaluated were Porphyromonas gingivalis, Tanerella forthsytia, Treponema denticola, Prevotella intermedia y Aggregatibacter actinomycetemcomitans (PerioPOC, Austria).

Results

237 RA patients and 83 healthy controls were recruited. 100% RA patients have, at least, one oral germ, as opposed to healthy controls (57.8%, p<0.001). P. gingivalis was present in 60.2% RA patients treated with biological therapies, most of them anti-TNF. No healthy patients were carriers of P. gingivalis. 41% RA patients had the association of T. denticola and P. gingivalis, regardless of therapies used. The association of T. denticola, T. forsythia and P. gingivalis was also frequent. No relationship between biological therapies used and germs were found (p<0.12). The coexistence of P. gingivalis and T. forsythia increases exponentially the risk of having a severe PD (x5, Figure 1). This is influenced also by higher age and smoking status. As well, this association was observed more frequently in RA patients versus healthy controls (x2.5).

Conclusion

RA is related with OM, regarding healthy controls. P. gingivalis is more frequent in RA patients that needed biological therapies. These therapies seem to not influence the presence of OM, being frequent the association of several species (symbiosis) causing PD. An OM and PD examination in RA patients could be beneficial to assess disease development and response to treatments, mainly if an eradication protocol is developed (based on local hygiene and periodontal treatment).

References

[1]Smolen JS, et al. Rheumatoid Arthritis. Nat Rev Dis Primers. 2018.

[2]R Bodkhe, B Balakrishnan, V Taneja. The role of microbiome in rheumatoid arthritis treatment. Ther Adv Musculoskelet Dis. 2019;11:1759720.

Disclosure of Interests

None declared

A synchrotron computed tomography dataset for validation of longitudinal tensile failure models based on fibre break and cluster development

We performed in-situ tensile tests on two carbon fibre/epoxy composites with continuous scanning using synchrotron computed tomography (CT). Both composites were cross-ply laminates, and two specimens were tested for each composite. The voxel size was sufficiently small to recognize individual fibres and fibre breaks. For each test, 16-19 volumes were reconstructed, cropped down to the 0° plies and analysed to track fibre break and cluster development. This dataset provides the last CT volume before failure for each of the four specimens as well as the individual fibre break locations in all reconstructed volumes. These data are then plotted against predictions from six state-of-the-art strength models. The target is that these data become a benchmark for the development of new models, inspiring researchers to set up refined experiments and develop improved models.

Antibiotic toxicity on human spermatozoa assessed using the sperm DNA fragmentation dynamic assay

Sperm DNA fragmentation (SDF) dynamic assays were piloted on 4 fresh ejaculates to examine the possible sperm toxicity of three common antibiotics, ciprofloxacin, doxycycline and ampicillin, incubated at a concentration estimated to be reached in semen in vivo, and 100×, for 24 h. SDF was assessed in terms of single-strand DNA breaks (SSBs) and double-strand DNA breaks (DSBs). Low and high concentrations of ciprofloxacin and high concentration of doxycycline significantly increased the SDF rate, due to sperm containing SSBs. Ampicillin did not affect SDF dynamics at any dose. Based on these results, the effect of antibiotics on the global-SDF dynamics was further examined in 21 ejaculates assessed at 0, 4 and 6 h. Ciprofloxacin increased the rate of SDF at the low concentration in 17 from 21 subjects; the high concentration resulted in a stronger effect in all individuals. A significant increase in the rate of SDF in 17 ejaculates was also noted when spermatozoa were incubated with the high concentration of doxycycline. The dynamic SDF assay is a rapid and sensitive tool to evidence sperm toxicity. Ciprofloxacin should be avoided when it is necessary to preserve sperm quality for reproductive purposes and as additive in semen diluents.

Association of accelerated dynamics of telomere sequence loss in peripheral blood leukocytes with incident knee osteoarthritis in Osteoarthritis Initiative cohort

Osteoarthritis (OA) is a chronic degenerative joint disease, being the main cause of laboral inability. Decreased telomere size in peripheral blood leukocytes (PBL) has been correlated with age-related pathologies, like knee OA. In a dynamic approach, telomere-qPCR was performed to evaluate the relative percentage of PBL telomere loss after a 6-year follow-up, in 281 subjects from the prospective osteoarthritis initiative (OAI) cohort. A radiological Kellgren-Lawrence (KL) grade ≥ 2 was indicative of knee OA. Individuals with knee OA at recruitment (n = 144) showed a higher PBL telomere loss after 6 years than those without knee OA at baseline (n = 137; p = 0.018). Moreover, individuals that developed knee OA during the follow-up (n = 39) exhibited a higher telomere loss compared to those that remained without OA (n = 98; p < 0.001). Logistic regression analysis showed that PBLs telomere loss was not significantly associated with knee OA at recruitment, but behaves as an independent risk factor associated with incidence after follow-up (OR: 1.043; p = 0.041), together with maximum KL grade (OR: 3.627; p = 0.011), body mass index-BMI (OR: 1.252; p < 0.001) and WOMAC-index (OR: 1.247; p = 0.021), at recruitment. The telomere decay in PBLs is faster in individuals with incident knee OA, possibly reflecting a systemic-global accelerated aging that enhances the cartilage degeneration.

Design of a digital-PCR assay to quantify fragmented human mitochondrial DNA

Digital PCR (dPCR) has been adapted to quantify the proportion of mitochondrial DNA (mtDNA) molecules without and with double-strand DNA breaks (DSBs). This is based on a break-apart approach of two differentially labeled target sequences distantly located in the circular DNA molecule. When the two targets amplify in separated reaction partitions, the original mtDNA molecule should be fragmented by two DSBs at least, each in a different segment between targets. When both targets amplify in the same partition, it must correspond to a circular or linear mtDNA molecule. These two possibilities may be distinguished through a restriction endonuclease (RE) induced unique DSB within a DNA segment between the targets. After RE-digestion, separation of both target signals in different partitions must indicate the presence of a previous linear mtDNA molecule. Otherwise, joint amplification in the same partition would correspond to an initial circular mtDNA that has been linearized by the endonuclease. The procedure was validated by assaying different proportions of mtDNA fragmented by in vitro digestion with REs, evidencing a perfect accordance between the expected theoretical values and dPCR quantification. Samples from peripheral blood cells, cellular and extracellular DNA from the U2OS cell line, as well as cells incubated with ethidium bromide to induce mtDNA depletion, were evaluated. The technique may be of interest to complement the studies of mtDNA in relation to aging and human disease, as well as to assess possible adverse effects of certain drugs that could be related to affectation of mtDNA.

POS0581 PERIODONTAL DISEASE IN RHEUMATOID ARTHRITIS: RESULTS FROM A COHORT AT TREATMENT WITH BIOLOGICAL, CLASSICAL AND TARGETED SYNTHETIC DMARDs

Background:

Periodontal disease (PD) has been widely studied in the pathogenesis of rheumatoid arthritis (RA). As well, its relationship with severity and disease activity, has also been investigated with ambiguous results. It has been suggested that the improvement of oral health could enhance disease activity scores.1 PD prevalence worldwide stands around 60% in older adults (>65 years) and its frequency increases with aging.2

Objectives:

To asses oral health in RA patients and to identify predictors of PD in this population.

Methods:

Patients diagnosed of RA at treatment with biological, classical or targeted synthetic disease modifying anti-rheumatic drugs (b/cs/tsDMARDs) in the aforementioned hospital during 2020 performed a dental review with a specialized periodontal odontologist. Oral health patterns were given for all patients, following criteria of American Academy of Periodontology, and reevaluation of disease activity was made 2 months later.

Clinical, demographic and treatment data were collected from participants.

Univariable logistic regression was performed to identify predictors of PD. Variables with p<0.20 were selected for multivariable analysis.

Stata 15.1 was used to perform statistical analysis.

Results:

81 patients were recruited. 82.72% were female. Mean age was 56.17 years (SD 14.15) and mean time since diagnosis was 15.58 years (SD 8.17). 25% were current or past smokers. 21 patients had comorbidities (arterial hypertension the most frequent). 66.67% were rheumatoid factor (RF) positive and 72.73% anti-citrullinated peptide autoantibody (ACPA) positive. Median erythrocyte sedimentation rate (ESR) was 12 mm (IQR 6;23) and mean C-reactive protein (CRP) was 0.48 mg/dl (SD 1.18). Mean disease activity score (DAS28-VSG) at the testing time was 2.62 (SD 1.21) and after 2 months was 2.39 (SD 0.97). 96.30% of patients were at treatment with csDMARDs, 64.20% with glucocorticoids, 96.30% with bDMARDs and 6 patients with tsDMARDs.

Univariable analysis identified higher age, at least one autoantibody positive and ESR/CRP as potential predictors of medium/severe PD (p<0.20). Multivariable testing including these variables pointed out higher age, lower ESR and at least one autoantibody positive (OR 1.09 [CI95% 1.04-1.14] p=0.001, OR 0.18 [CI95% 0.04-0.95] p=0.044 and OR 0.94 [CI95% 0.88-1.00] p=0.042, respectively) as predictors of medium or severe PD (≥3 mm interdental clinical attachment loss).

Univariable analysis identified higher age, the presence of any comorbidity and anti tumour-necrosis factor alpha treatment (anti-TNF) as potential predictors of severe PD (p<0.20). Multivariable testing including these variables pointed out higher age (OR 1.15 [CI95%1.02-1.30] p=0.026) as predictor of severe PD (≥5 mm interdental clinical attachment loss).

Conclusion:

Periodontal disease is still an extended health problem among the entire population. Its prevalence in RA is increased, therefore higher age and RF or ACPA positive are risk factors for developing severe PD. This analysis might suggest that an aggressive management of PD could implement better responses in DAS28. Also anti-TNF treatment could delimit a “penumbra” group of patients at risk of developing severe PD, where intensive manage could modify the final outcome.

References:

[1]C O Bingham, M Moni. Periodontal disease and rheumatoid arthritis: the evidence accumulates for complex pathobiologic interactions. Curr Opin Rheumatol. 2013;25(3):345-353.

[2]P Carvajal. Periodontal disease as a public health problem: the challenge for primary health care. Rev Clin Periodoncia inplantol. 2016;9(2):177-183.

Disclosure of Interests:

None declared

POS0582 RHEUMATOID ARTHRITIS AND ORAL MICROBIOME: PREDICTORS OF DISTURBANCES AND ITS IMPLICATIONS. RESULTS FROM A COHORT AT TREATMENT WITH cs/b/tsDMARD

Background:

Oral microbiome (OM) seems to be significant in the pathogenesis of some immune-mediated diseases, such as rheumatoid arthritis (RA), psoriasis or inflammatory bowel disease.1 Some microorganisms, as Porphyromonas gingivalis have been related with the production of autoantibodies. Also it has been suggested that composition of OM could change RA disease course, being more difficult-to-treat and having higher disease activity scores.2

Objectives:

To identify which variables could predict the appearance of altered OM and its implications in clinical practice.

Methods:

Patients were recruited if they were diagnosed of RA and were at active treatment (biological, classical or targeted synthetic disease modifying anti-rheumatic drugs [b/cs/tsDMARDs]). Patients performed a dental review with a specialized odontologist that made an OM test (semiquantitative PCR), and oral health standards were instructed (following criteria of American Academy of Periodontology). Recruitment was made during 2020 in the Clinical University Hospital in Santiago de Compostela, Spain. Disease activity reevaluation was made 2 months later.

Treatment, demographic and clinical data were collected from participants.

Univariable logistic and linear regression were performed to identify predictors of OM. Variables with p<0.20 were selected for multivariable analysis.

Stata 15.1 was used to perform statistical analysis.

Results:

47 patients were selected of whom 40 were female. Mean age was 55.43 years (SD 14.42). 30.77% were current or ex-smokers. Mean time since RA diagnosis was 14.89 years (SD 8.47). 63.83% were anti-citrullinated peptide autoantibody (ACPA) positive and 70.21% were rheumatoid factor (RF) positive, letting only 6 patients double negative. 46.81% had moderate/severe periodontal disease (PD). 32.61% of patients had any comorbidity. Mean DAS28 at the OM test was 2.67 (SD 1.28) and after 2 months 2.37 (SD 1.03). Mean C-reactive protein (CRP) was 0.64 mg/dl (SD 1.48) and median erythrocyte sedimentation rate (ESR) was 13 mm (IQR 7;27). All patients were under glucocorticoid treatment, 46 with bDMARD, 1 with tsDMARD and 46 with csDMARD. Treponema denticola was detected in 44.68% of patients, P. gingivalis in 29.79%, Actinomyces spp in 8.51%, Tanerella forsythia in 36.17% and Prevotella intermedia in 25.53%. Only 15 patients were full-negative for OM test.

Univariable analysis identified RF positive, double autoantibody positive (RF and ACPA) and moderate/severe PD as potential predictors of the presence of at least one oral microorganism (p<0.20). Multivariable testing pointed out moderate/severe PD as predictor of the presence of at least one oral microorganism (OR 22.91 [CI95% 2.38-220.4] p=0.007).

Univariable analysis identified higher age, presence of any comorbidity, RF positive, higher CRP, treatment with anti-tumour necrosis alpha (aTNF) and moderate/severe PD as potential predictors of the presence of multiple species in OM (p<0.20). Multivariable testing pointed out moderate/severe PD as predictor of the presence of multiple species in OM (ß 0.39 [95%CI 0.19-0.58] p=0.000).

Conclusion:

Oral microbiome is closely related with periodontal disease, added to our results, a relationship between OM and disease activity has been exposed. In this analysis the role of OM and autoantibody profile is manifest, as being double positive or RF positive is associated with the presence of altered OM. Also patients with high acute-phase reactants, active disease and under aTNF treatment could delineate a specific RA population under risk of altered OM, where intensive strategies for changing oral microbiome could have any repercussion in the disease course.

References:

[1]Chen, B., Zhao, Y., Li, S. et al. Variations in oral microbiome profiles in rheumatoid arthritis and osteoarthritis with potential biomarkers for arthritis screening. Sci Rep8, 17126 (2018).

[2]R Bodkhe, B Balakrishnan, V Taneja. The role of microbiome in rheumatoid arthritis treatment. Ther Adv Musculoskelet Dis. 2019;11:1759720.

Disclosure of Interests:

None declared

DNA fragmentation of human spermatozoa: Simple assessment of single- and double-strand DNA breaks and their respective dynamic behavioral response

BACKGROUND

Procedures to detect sperm DNA fragmentation (SDF), like the sperm chromatin dispersion (SCD) test, determine the "global" SDF without discriminating between spermatozoa with single-strand DNA breaks only (SDF-SSBs) and those containing double-strand DNA breaks (SDF-DSBs).

OBJECTIVES

(a) To validate a test to distinguish human spermatozoa with massive DSBs (DSB-SCD assay), (b) to study the baseline SDF-SSBs and SDF-DSBs, and (c) to assess their dynamics in vitro.

MATERIALS AND METHODS

(a) SDF-DSBs were determined by visualization of diffused DNA fragments from spermatozoa lysed under non-denaturing conditions. This was validated by in vitro incubation with DNase I and the comet assay. (b) Baseline SDF-DSBs and SDF-SSBs were determined in ejaculates from 95 males. (c) Their dynamic appearance was studied in samples untreated or exposed to hyperthermia, acidic pH, nitric oxide released by sodium nitroprusside (SNP), and the metabolic energy inhibitors 2-deoxy-D-glucose and antimycin A.

RESULTS

(a) DNase I and comet assay experiments confirmed that the assay successfully determined SDF-DSBs. (b) The higher the SDF of the semen sample, the higher the frequency of SSBs, whereas DSBs behaved independently. Abnormal samples showed higher SDF than normozoospermic, the difference being only significant for SDF-SSBs. (c) During the first hours of incubation, the linear rate of increase in SDF-SSBs was 3.7 X higher than that of SDF-DSBs. All hazardous agents accelerated the SDF rate when compared to untreated spermatozoa, primarily being associated with SDF-SSBs. SNP treatment was the most damaging, rapidly inducing spermatozoa with SSBs which progressively evolved to DSBs. Remarkably, this phenomenon was also evidenced after acute SNP exposure, revealing cryptic sperm damage.

CONCLUSION

The DSBs-SCD is an easy complement for SDF assessment. The dynamic study of SSBs and DSBs may improve the evaluation of sperm quality in clinical settings, particularly "unmasking" the presence of non-specific cryptic sperm damage that might otherwise go undetected.

Simple and Fast Detection of Resistance to Antibiotic Inhibitors of Protein Synthesis in Gram-Negative Pathogens Through Evaluation of Mitomycin C-Induced Cell Elongation

Increasing the resistance of Gram-negative pathogens to antibiotics that inhibit protein synthesis is of great concern. In life-threatening situations, an early detection of antibiotic resistance may improve patient outcome. A rapid assay for the identification of antibiotic resistance to gentamicin, tobramycin, and tigecycline has been designed and tested in clinical strains of Acinetobacter baumannii, Pseudomonas aeruginosa, and the Enterobacteriaceae Escherichia coli and Klebsiella pneumoniae. Exponentially growing cultures were incubated with 0.5 mg/L mitomycin C (MMC) for 2 hr (10 mg/L for A. baumannii), which induced significant cell enlargement as visualized under the microscope. Addition of the appropriate antibiotic dose 15 min before the addition of MMC prevented elongation when the strain was susceptible to the antibiotic, thereby inhibiting protein synthesis. Cell enlargement was not precluded in the antibiotic resistant strains, where protein synthesis had not been successfully inhibited. In comparison with the standard dilution-based antibiogram, the sensitivity of the assay was 100% and the specificity ranged between 96.0% and 100%. Results were obtained after 2 hr and 45 min from exponentially growing cultures. The procedure is easy, reliable, and demonstrates the suitability of the evaluation of simple morphological changes, which are protein synthesis dependent, for the rapid detection of antibiotic resistance.

Rapid Detection of Antibiotic Resistance in Gram-Negative Bacteria Through Assessment of Changes in Cellular Morphology

Rapid antimicrobial susceptibility testing has the potential to improve patient outcomes and reduce healthcare-associated costs. In this study, a novel assay based on bacterial cell elongation after exposure to an antibiotic (ceftazidime) was evaluated for its ability to rapidly detect resistance in Gram-negative bacteria. The assay was used to detect resistance in a large collection of strains containing 320 clinical isolates of Acinetobacter baumannii, 171 clinical isolates of Klebsiella pneumoniae, and 212 clinical isolates of Pseudomonas aeruginosa, and the results were compared to those obtained using standard antimicrobial susceptibility testing methods. The assay identified ceftazidime-resistant strains with 100% sensitivity and 100% specificity for A. baumannii, 100% sensitivity and 97.2% specificity for K. pneumoniae, and with 82.3% sensitivity and 100% specificity for P. aeruginosa. Importantly, results were obtained in 1 hour 15 minutes from exponentially growing cultures. This study demonstrates that changes in cell length are highly correlated with phenotypic antibiotic susceptibility determined using standard susceptibility testing methods. This study therefore provides proof-of-concept that changes in cell morphology can be used as the basis for rapid detection of antibiotic resistance and provides the basis for the development of novel rapid diagnostics for the detection of antibiotic resistance.

Falling incidence and prevalence of hepatitis A in northern Spain

The prevalence of hepatitis A virus antibodies was studied using a commercial ELISA method. 2,214 subjects were included, 1,211 in 1992 and 1,003 during 1986-87. In 1992 the seroprevalence rates among subjects 1-9, 10-19, 20-29 and 30-39 years old were 2.4%, 21%, 57.6% and 87.5% respectively, as compared with 7.7%, 37.9%, 80.6% and 98.1% respectively, in a similar group of subjects studied 5 years earlier (p < or = 0.001). The reported number viral hepatitis cases declined from 35.0 per 100,000 people in 1984 to 8.9 per 100,000 in 1992. Concurrently, the age when contracting the disease rose. The mean age for patients acquiring hepatitis A was 15.5 in 1986-88 and 20.1 in 1991-92. The decline in incidence and prevalence of HAV infection indicates a progressive and continuous decrease in HAV circulation in this geographical area.

Hemodynamic effects of chronic 4'epi-adriamycin administration

Adriamycin (ADM) is an effective antineoplastic drug. However, the amount of ADM that can be administered must be limited because of the risk of developing a severe dose-dependent cardiomyopathy. 4'Epi-adriamycin (4'ADM) is a new anthracycline analog with similar antineoplastic properties as ADM, but with perhaps less cardiac toxicity. To determine myocardial performance after a chronic treatment with 4'ADM, we studied 17 patients (mean age 36.6 years) suffering from lymphomas by means of 24-hour ambulatory ECG, x-ray, M-mode echocardiogram, and rest-exercise gated radionuclide ventriculography (RNV), performed prior to and 2 months after the end of the treatment. Pretreatment and post-treatment shortening fractions, basal pretreatment and post-treatment ejection fractions, and postexercise pretreatment and post-treatment ejection fractions, were tested for correlation with individual 4'ADM doses and pretreatment with ADM. No association was noted among them, showing the lack of correlation between doses and impairment of ventricular performance. 4'ADM doses ranged from 400 to 1100, x 748 +/- 174 mg/m2; all noninvasive studies including RNV were normal. No correlation was found between 4'ADM doses and RNV (Pearson's correlation coefficient, p = ns). No deterioration of ventricular performance could be demonstrated. Conversely, the basal pretreatment ejection fraction changed from 56.17 +/- 7.6% to 61.52 +/- 8.3% in post-treatment (p less than 0.0001). Surprisingly, the post-exercise pretreatment ejection fraction also increased from 55.47 +/- 7.7% to 63.35 +/- 10% in post-treatment (p less than 0.03). The shortening fraction changed from 35.47 +/- 4.8% to 36.47 +/- 4.2% after 4'ADM treatment (ns). No impairment of cardiac function could be shown in patients previously treated with ADM or radiotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of testicular torsion on contralateral testis and the production of antisperm antibodies in rabbits

It has been previously shown that unilateral testis torsion can cause disruptive anatomic changes in the contralateral testis of rats. This study was conducted to duplicate these findings in rabbits and analyze their serum for the production of the immunoglobulin G class of antisperm antibodies and determine whether the proposed immune response demonstrated by contralateral anatomic testis changes was mediated by these antibodies. New Zealand white rabbits were divided into 8 groups. One had a sham operation, 1 had testis biopsy, 3 groups had ligation of the right testicular vessels with subsequent orchiectomy in 2 groups at 36 and 72 hours, and 3 groups had 720-degree torsion of the right testis. Half of the animals were sacrificed after 4 weeks and the other half after 8 weeks. Contralateral histology was analyzed in all rabbits and only those with torsion showed abnormal tubular architecture and defective spermatogenesis. Detorsion at 36 hours and 96 hours did not protect against contralateral testis damage. No animal whose vessels were ligated, no matter what treatment protocol was employed, showed contralateral damage. All rabbit sera were tested for the presence of immunoglobulin G antiserum antibodies against a control rabbit that was a known antibody former, using an enzyme-linked immunosorbent technique. No experimental animal had detectable levels of antisperm immunoglobulin G when compared to controls. Three male rabbits who were converted to antisperm antibody formers by injection of sperm did not show anatomic changes in their testes.