[Arthroscopic biceps tenodesis with a «relaxed» technique.Clinical and radiological results of a prospective cohort]

INTRODUCTION

in the treatment the long head of the biceps tendon (LHBT) pathology, the «relaxed tenodesis» is an arthroscopic articular suprapectoral tenodesis that seeks to lower the tension on the LHBT, and therefore, theoretically avoid persistent pain.

OBJECTIVE

to assess clinical and radiological results of «relaxed» tenodesis in a prospective cohort of patient with work related illness.

MATERIAL AND METHODS

prospective cohort, 54 shoulders with «relaxed» tenodesis performed with an intra-articular interference screw by the same surgeon, from October 2014 to 2018, in a level 1 trauma center. Demographic, clinical, functional and radiologic results were analyzed. On 6 months follow-up, a sonographic and clinical assessment was performed.

RESULTS

mean age 49 ± 9, mean follow-up 16 ± 4 months. The main diagnosis was a rotator cuff tear in 79%, primary biceps pathology in 10% and other pathologies in 11%. At the end of follow-up, the cohort showed active anterior elevation 157.7 ± 22.7, external rotation 47 ± 16.6, median internal rotation T12, Constant Score 83 ± 12.05 points, subjective shoulder value 83 ± 12.97% and pain visual analogue scale 1.4 ± 1.7 points. One patient had a biceps tear and two had cosmetic arm asymmetry. On ultrasound 98% had the LHBT in situ and 10% had inflammatory changes on the bicipital groove. There were complications in 21% of the sample.

CONCLUSIONS

«relaxed biceps tenodesis» is a technique that shows good clinical, functional and sonographic results, with low failure rate.

P-080 Intrauterine insemination (IUI) success rates in patients with suboptimal total processed motile sperm count (TPMSC) using a second consecutive semen sample

Study question

Is it effective to request a second consecutive semen sample in patients with less than 1 million TPMSC in a first semen sample for IUI?

Summary answer

In men with TPMSC under one million, the issuing of a second consecutive sample reached pregnancy rates similar to those published for IUI.

What is known already

IUI offers a comparable cumulative live birth rate in 3-4 cycles compared to IVF and can be preferred as a cost-effective first-line treatment in mild male factor or unexplained infertility. The quality of the processed semen sample is an important factor for the IUI success.

The WHO recommends an abstinence period to ensure best quality of semen samples. However, it has been observed that when men with moderate male factor who are unable to meet the minimum requirements for IUI are asked to produce a second sample better counts are obtained; questioning the time correlation between abstinence and semen quality.

Study design, size, duration

This was a retrospective study conducted in the reproductive medicine unit of a private hospital in Chile between July 2015 and March 2021. All patients who underwent IUI in the study period that had an TPMSC less than 1 million in the eyaculate and to whom a second consecutive sample was requested were included.

Participants/materials, setting, methods

118 patients who underwent 140 IUI cycles were included in the study. All the patients with an PMSC under 1 million at the time of the IUI were requested a second consecutive semen sample within an hour or two from the previous eyaculate. The second samples were processed and used for insemination. The primary outcome was pregnancy rate. The secondary outcomes were semen quality (TPMSC of first and second semen samples).

Main results and the role of chance

Between 2015 and 2021 there were 140 IUI cycles in which a second consecutive semen sample was requested, including 118 patients. Overall 17 pregnancies were achieved. The pregnancy rate per cycle was 12,14% and the pregnancy rate per patient was 14,4%. The live birth rate per patient was 10,2%.

Regarding the sperm sample analysis, the median TPMSC of the first semen sample was 261.437. The median PMSC of the second consecutive sample was 7.315.000. 126 patients had an TPMSC of 0 in the first semen sample while only 9 patients had an IMSC of 0 in the second sample. In five cases a third consecutive sample was requested of which 4 patients had their cycles canceled because they did not meet the target PMSC. One patient had an TPMSC of 1.687.000 in the third sample.

Finally, of the 118 patients who did not meet the requirements for IUI with the first sample, only 19 cycles were canceled.

Limitations, reasons for caution

The study has the limitation of being a retrospective and descriptive study with no contol group. Also the group is heterogeneous because it includes patients with different female factors for infertility.

Wider implications of the findings

In developing countries and low-income settings the IUI remains a more accessible alternative in patients with infertility. Routinely recollecting a second semen sample in men with TPMSC <1 million would reduce cycle cancellation rates due to not achieving an optimal TPMSC, reaching pregnancy rates similar to those published for IUI.

Trial registration number

Not applicable

Environmental factors associated With Toxoplasma gondii Exposure in Neotropical Primates of Costa Rica

The apicomplexan parasite Toxoplasma gondii (T. gondii) has been found in more than 350 species of homoeothermic vertebrates in diverse climates and geographic areas. In most animals, T. gondii produces mild or asymptomatic infection. However, acute and hyperacute toxoplasmosis is associated with high mortality rates observed in Neotropical primates (NP) in captivity. These primates are distributed in 20 countries across the Americas, and although infection has been reported in certain countries and species, toxoplasmosis in the wild and its impact on NP population survival is unknown. Differences among species in exposure rates and disease susceptibility may be due in part to differences in host behavior and ecology. Four species of NP are found in Costa Rica, i.e., howler (Alouatta palliata), spider (Ateles geoffroyi), capuchin (Cebus imitator), and squirrel monkeys (Saimiri oerstedii). This study reports NP exposure to T. gondii using the modified agglutination test in 245 serum samples of NP (198 wild and 47 from captivity) from Costa Rica. Associations of serostatus with environmental (forest cover, annual mean temperature), anthropogenic (human population density), and biological (sex) variables in howler and capuchin monkeys were evaluated. The seroprevalence among wild NP was 11.6% (95% CI = 7.7–17.34), compared with 60% in captive monkeys (95% CI = 44.27–73.63), with significant differences between species (X² = 20.072; df = 3, p = 0.000164), suggesting an effect of behavior and ecology. In general, antibody titers were low for wild NP (<1:128) and high for captive NP (>1:8192), suggesting higher exposure due to management factors and increased life span in captivity. Seropositivity in howler monkeys was positively related to forest cover and inversely related to annual rainfall. For capuchins, annual rainfall was inversely related to seropositivity. Surveillance of T. gondii exposure in NP in captivity and in the wild is required to understand drivers of the infection and develop novel strategies to protect them.

Self-organization and energy of superparamagnetic nets

Superparamagnetic filaments assemble, building one-layered aggregates due to the screening effect inherited from the dipole interaction potential in a colloidal blend. The magnetic energy of rectangular and irregular ribbons is computed to obtain their mean length at thermodynamic equilibrium, in good agreement with experimental measurements.

A qPCR Targeted Against the Viral Replication Origin Designed to Quantify Total Amount of Filamentous Phages and Phagemids

Filamentous bacteriophages are widely used in phage display technology. The most common quantification method is lysis plaque formation test (PFT). This technique has several disadvantages, and only quantifies infective phages and is not effective when phagemids are used. We developed a qPCR method directed against the M13 replication origin, which detects between 3.3 × 10³ and 3.3 × 10⁸ viral genome copies with a linearity of R ²  = 0.9998. Using this method we were able to observe a difference of approximately ten more phages than with the PFT. This difference was not due to the presence of a free genome, which suggests the presence of non-infective particles. Using a DNaseI treatment, we observed the presence of 30% to 40% of unpackaged genome in recombinant phage modified in PIII or PVIII. The qPCR method with a DNase I treatment is an efficient method to quantify the total amount of filamentous phages.

Brucellosis caused by the wood rat pathogen Brucella neotomae: two case reports

Background

Brucellosis is a chronic bacterial disease caused by members of the genus Brucella. Among the classical species stands Brucella neotomae, until now, a pathogen limited to wood rats. However, we have identified two brucellosis human cases caused by B. neotomae, demonstrating that this species has zoonotic potential.

Cases presentation

Within almost 4 years of each other, a 64-year-old Costa Rican white Hispanic man and a 51-year-old Costa Rican white Hispanic man required medical care at public hospitals of Costa Rica. Their hematological and biochemical parameters were within normal limits. No adenopathies or visceral abnormalities were found. Both patients showed intermittent fever, disorientation, and general malaise and a positive Rose Bengal test compatible with Brucella infection. Blood and cerebrospinal fluid cultures rendered Gram-negative coccobacilli identified by genomic analysis as B. neotomae. After antibiotic treatment, the patients recovered with normal mental activities.

Conclusions

This is the first report describing in detail the clinical disease caused by B. neotomae in two unrelated patients. In spite of previous claims, this bacterium keeps zoonotic potential. Proposals to generate vaccines by using B. neotomae as an immunogen must be reexamined and countries housing the natural reservoir must consider the zoonotic risk.

High Prevalence of Multidrug-Resistant Community-Acquired Methicillin-Resistant Staphylococcus aureus at the Largest Veterinary Teaching Hospital in Costa Rica

Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen associated with severe infections in companion animals present in the community, and it is diagnosed in animals admitted to veterinary hospitals. However, reports that describe the circulation of MRSA in animal populations and veterinary settings in Latin America are scarce. Therefore, the objective of this study was to determine the prevalence and investigate the molecular epidemiology of MRSA in the environment of the largest veterinary teaching hospital in Costa Rica. Preselected contact surfaces were sampled twice within a 6-week period. Antimicrobial resistance, SCCmec type, Panton-Valentine leukocidin screening, USA type, and clonality were assessed in all recovered isolates. Overall, MRSA was isolated from 26.5% (27/102) of the surfaces sampled, with doors, desks, and examination tables most frequently contaminated. Molecular analysis demonstrated a variety of surfaces from different sections of the hospital contaminated by three highly related clones/pulsotypes. All, but one of the isolates were characterized as multidrug-resistant SCCmec type IV-USA700, a strain sporadically described in other countries and often classified as community acquired. The detection and frequency of this unique strain in this veterinary setting suggest Costa Rica has a distinctive MRSA ecology when compared with other countries/regions. The high level of environmental contamination highlights the necessity to establish and enforce standard cleaning and disinfection protocols to minimize further spread of this pathogen and reduce the risk of nosocomial and/or occupational transmission of MRSA.

Epidemiology of bovine brucellosis in Costa Rica: Lessons learned from failures in the control of the disease

Brucellosis, caused by Brucella abortus is a major disease of cattle and a zoonosis. In order to estimate the bovine brucellosis prevalence in Costa Rica (CR), a total 765 herds (13078 bovines) from six regions of CR were randomly sampled during 2012-2013. A non-random sample of 7907 herds (532199 bovines) of the six regions, arriving for diagnoses during 2014-2016 to the Costa Rican Animal Health Service was also studied. The prevalence estimated by Rose Bengal test (RBT) ranged from 10.5%-11.4%; alternatively, the prevalence estimated by testing the RBT positives in iELISA, ranged from 4.1%-6.0%, respectively. However, cattle in CR are not vaccinated with B. abortus S19 but with RB51 (vaccination coverage close to 11%), and under these conditions the RBT displays 99% specificity and 99% sensitivity. Therefore, the RBT herd depicted in the random analysis stands as a feasible assessment and then, the recommended value in case of planning an eradication program in CR. Studies of three decades reveled that bovine brucellosis prevalence has increased in CR. B. abortus was identified by biochemical and molecular studies as the etiological agent of bovine brucellosis. Multiple locus variable-number tandem repeat analysis-16 revealed four B. abortus clusters. Cluster one and three are intertwined with isolates from other countries, while clusters two and four have only representatives from CR. Cluster one is widely distributed in all regions of the country and may be the primary B. abortus source. The other clusters seem to be restricted to specific areas in CR. The implications of our findings, in relation to the control of the disease in CR, are critically discussed.

Self-assembly processes of superparamagnetic colloids in a quasi-two-dimensional system

Superparamagnetic colloids gather depending on the magnitude of the magnetic field applied, forming chains and ribbons in a quasi-two-dimensional chamber. The results presented in this work are in good agreement with recent experimental multistable data for the mean length of the aggregates in thermodynamic equilibrium.

The fern cavitation catapult: mechanism and design principles

Leptosporangiate ferns have evolved an ingenious cavitation catapult to disperse their spores. The mechanism relies almost entirely on the annulus, a row of 12-25 cells, which successively: (i) stores energy by evaporation of the cells' content, (ii) triggers the catapult by internal cavitation, and (iii) controls the time scales of energy release to ensure efficient spore ejection. The confluence of these three biomechanical functions within the confines of a single structure suggests a level of sophistication that goes beyond most man-made devices where specific structures or parts rarely serve more than one function. Here, we study in detail the three phases of spore ejection in the sporangia of the fern Polypodium aureum. For each of these phases, we have written the governing equations and measured the key parameters. For the opening of the sporangium, we show that the structural design of the annulus is particularly well suited to inducing bending deformations in response to osmotic volume changes. Moreover, the measured parameters for the osmoelastic design lead to a near-optimal speed of spore ejection (approx. 10 m s(-1)). Our analysis of the trigger mechanism by cavitation points to a critical cavitation pressure of approximately -100 ± 14 bar, a value that matches the most negative pressures recorded in the xylem of plants. Finally, using high-speed imaging, we elucidated the physics leading to the sharp separation of time scales (30 versus 5000 µs) in the closing dynamics. Our results highlight the importance of the precise tuning of the parameters without which the function of the leptosporangium as a catapult would be severely compromised.

Testicular adrenal rest tumors and Leydig and Sertoli cell function in boys with classical congenital adrenal hyperplasia

CONTEXT

Infertility observed in adult males with congenital adrenal hyperplasia (CAH) has been associated with testicular adrenal rest tumors (TART) that may originate during childhood.

OBJECTIVE

Our objective was to describe the prevalence of TART and Sertoli and Leydig cell function in a group of boys aged 2-10 yr with CAH and to compare prevalence with that of a control group.

DESIGN

From August 2005 to January 2007, 19 patients with classical CAH (CAH group) were referred from seven endocrinology centers.

METHODS

We studied 19 subjects in the CAH group and, as a control group, 13 boys from the community that did not have testicular diseases. A complete physical exam was performed. High-resolution ultrasound was used to determine TART prevalence. Inhibin B and anti-Müllerian hormone were used as Sertoli cell markers. The ratio between basal testosterone levels and testosterone levels 72 h after beta-human chorionic gonadotropin (5000 U/m2) treatment [(T72- T0)/T0] was used to evaluate Leydig cell response.

RESULTS

CAH and control groups were comparable in chronological age (5.9 vs. 5.6 yr; P = 0.67) and bone age/chronological age ratio (1.09 vs. 1.03; P = 0.09). TART prevalence was four of 19 (21%) in the CAH group. Lower values for inhibin B (49.2. vs. 65.2 pg/ml; P = 0.018), anti-Müllerian hormone (70.1 vs. 94.2 ng/ml; P = 0.002), and (T72- T0)/T0 (5.6 vs. 13.6; P < 0.01) were observed in the CAH group.

CONCLUSION

TART in prepubertal males with classic CAH could be found during childhood. We also report differences in markers of gonadal function in a subgroup of patients, especially in those with inadequate control.

[Prevalence of serum antibodies for the bacterium Brucella sp. in a tropical human population]

Prevalence of serum antibodies for the bacterium Brucella sp. in a tropical human population. Brucellosis is a systemic bacterial disease that can last years if not treated properly. The laboratory diagnosis is made by serological tests or isolation of the agent. We studied the prevalence of antibodies against Brucella sp. in inhabitants of rural communities of Cartago, Costa Rica, who are dedicated mainly to dairy cattle activities. We analyzed 714 representative samples with the Rose Bengal plate agglutination test (RBT) and the standard agglutination test in microplate (SAT). The overall prevalence was 0.87%. No seroconversion was demonstrated for seropositive individuals. Even though 71% of the population mentioned consuming non-pasteurized milk, no statistically significant association was found (1.09 %, IC 0.30-2.77) between milk consumption and the presence of antibodies suggestive of infection by Brucella sp. As a brucellosis high-risk population, the absence of symptoms in the population agrees with the observed titers of antibodies, suggesting a low previous exposure to the agent.

Colonization of mutans streptococci in Costa Rican children from a high-risk population

PURPOSE

The aim of the study was to determine the colonization of mutans streptococci (MS) in dental biofilm and saliva of children from a high-risk population with low socioeconomic status from San José, Costa Rica.

METHODS

A total of 68 healthy babies from 8 to 20 months of age (mean age=13 months), with caries-free status and cariogenic feeding habits (eg, nursing bottle- or breast-feeding on demand) were examined. Children divided in two groups (<13 months and 14-20 months). Samples from dental biofilm and saliva from each subject were processed and plated in blood agar (BA) and Mitis-Salivarius-Bacitracin agar (MSB) to determine MS percentage. Statistical analysis included the analysis of variance test, and stratification by age of MS levels.

RESULTS

Detectable MS levels in dental biofilm and saliva were found in 75% and 72% of children, respectively. Counts higher than 20000 colony forming units (CFU) per ml were found in 4% of saliva and in 35% of biofilm samples. The two groups showed significant differences in MS levels for dental biofilm (P=.036) and saliva (P=.009). Children older than 17 months presented higher MS levels (P<.05). Analysis by MS levels (<0.1%; 0.1-1.0%;>1.0% of MS) The two groups showed an insignificant association with increasing mean age. MS density was associated with mean number of erupted primary molars.

CONCLUSIONS

Mutans streptococci colonization of dental biofilm and saliva from high caries risk infants is associated with age and dental development.

Improvement of reproductive performance in crossbred zebu anestrous primiparous cows by treatment with norgestomet implants or 96 h calf removal

The aim of the present study was to compare the effect of norgestomet implants (NI) and calf removal (CR) for 96 h on estrus induction and first service fertility in crossbred zebu primiparous anestrous cows after 120 days postpartum. A total of 152 cows in a tropical environment were allotted to three experimental groups: CR for 96 h (n = 51), NI for 9 days plus 500 IU of PMSG at implant removal (n = 51) and a control group (CG) without treatment (n = 50). Estrous rate (%) and mean interval to first estrus (days) were 50.9 and 26.3+/-6.8; 60.7 and 13.8+/-6.8; 16.0% and 61.8+/-5.9 days for groups CR, NI and CG, respectively. CR and NI were statistically similar, however, both groups were different (P < 0.01) when compared with CG. Calving interval to first service and to conception were: CR: 151.2+/-8.4 and 157.8+/-21.4; NI: 145.2+/-8.5 and 150.9+/-21.3; CG: 186.8+/-7.3 and 201.0+/-18.5. A difference (P < 0.01) was found in both intervals when comparing the CR and NI with CG, with longer intervals for cows in the CG group. First service conception rates were 61.5, 67.7 and 62.5% for groups CR, NI and CG, respectively, and were not different (P > 0.05). These results demonstrate the efficacy of NI + PMSG or temporary CR for 96 h in inducing a fertile estrus and shortening the interval to estrus and to conception in primiparous crossbred anestrous zebu cows in the tropics.

Comparison of the antibody response in adult cattle against different epitopes of Brucella abortus lipopolysaccharide

The comparison of serological responses in a sample of adult, vaccinated and held-infected bovines with Brucella abortus is reported. Indirect enzyme immunoassav (EIA) titration curves and Western blotting tests for smooth-type lipopolysaccharide (S-LPS), rough-type LPS (R-LPS) and lipid A were performed. In the initial screening of sera, an overall prevalence of 20.5% was found, which corresponds to a country with a high incidence of brucellosis. End-point EIA titres against LPS antigens from vaccinated and field-infected cows were not significantly different. However, the absorbance values in the titration curves were significantly higher for S-LPS as compared with the other antigens. A high correlation coefficient (r = 0.933) was obtained when the titres to R-LPS versus lipid A were compared. Western blotting reactions of vaccinated and held-infected animals were indistinguishable. S-LPS, R-LPS and lipid A epitopes were recognized in a heterogeneous manner. In general, the number of bovines that reacted against LPS was higher in the field-infected group, with a stronger binding to S-LPS. Based on our observations, the vaccinated and field-infected bovines are capable of producing similar antibody responses to the Brucella main outer surface antigen, LPS. It should be emphasized that the humoral response of cattle to Brucella LPS contains significant amounts of antibodies to other antigenic moieties of this important surface molecule, which may contribute to the immunity to brucellosis.

Modulation of the susceptibility of human erythrocytes to snake venom myotoxic phospholipases A(2): role of negatively charged phospholipids as potential membrane binding sites

Cerrophidion (Bothrops) godmani myotoxins I (CGMT-I) and II (CGMT-II), Asp-49 and Lys-49 phospholipases A(2) (PLA2s), which drastically differ in enzymatic activity, were devoid of direct hemolytic effects on erythrocytes (RBC) from different species despite the fact that enzymatically active CGMT-I was able to hydrolyze RBC membrane phospholipids and disrupt liposomes prepared from RBC lipids. Human RBC did not become susceptible to the toxins after treatment with neuraminidase or after altering membrane fluidity with cholesterol or sublytic concentrations of detergent. Unlike normal RBC, significant hemolysis was induced by CGMT-II and another similar Lys-49 isoform, B. asper MT-II (BAMT-II), in RBC enriched with phosphatidylserine (PS). Hemolysis was greater in RBC preincubated with pyridyldithioethylamine (PDA), a potent inhibitor of aminophospholipid transport. RBC enriched with phosphatidic acid (PA) also became susceptible to the myotoxins but was unaffected by PDA. Cells enriched with phosphatidylcholine (PC) remained resistant to the action of the toxins. BAMT-II also induced damage in black lipid membranes prepared with PS but not PC alone. When RBC binding of BAMT-II was measured by enzyme-linked immunosorbent assay, it was observed that PS- and PA-enriched erythrocytes were always able to capture more toxin than normal and PC-enriched RBC. This effect was significantly improved by PDA (in the case of PS) and it was observed either in the presence or in the absence of calcium in the medium. These data suggest that negatively charged lipids in the outer leaflet of cell membranes constitute myotoxic PLA2 binding sites. The scarcity of anionic phospholipids in the outer leaflet of RBC could explain their resistance to the action of these PLA2s.

Substance abuse and criminal recidivism: a prospective study of adolescents

Studies of substance abuse among delinquents have shown mixed results on criminal recidivism. The present study evaluates personality traits associated with substance abuse and recidivism among delinquent boys, and prospectively determines the extent to which these factors are predictive of criminal recidivism. 134 incarcerated boys (x = 15.9 +/- 1.1) completed the Weinberger Adjustment Inventory and the Substance Abuse Screening Inventory. Youth were prospectively followed for up to 4.5 years following release. Among incarcerated delinquents, personality traits are predictive of a positive substance abuse screen and recidivism. A trend indicating a possible interaction between personality and treatment is observed. If these findings are replicated, personality traits may play a role in predicting substance abuse as well as individual delinquent responses to treatment.

[In vitro immunosuppressive effect of low density lipoproteins]

BACKGROUND

Immune cells participate in the formation of atheromatous plate, however little is known about the effects of native or oxidatively modified lipoproteins on these cells.

AIM

To study the effects of lipoproteins on in vitro mononuclear cell proliferation.

MATERIAL AND METHODS

Peripheral blood mononuclear cells were obtained from 10 patients with type 2 diabetes mellitus (aged 52 +/- 9 years old with a disease duration of 8.2 +/- 5.7 years and a mean glycosilated hemoglobin of 9.3 +/- 2.2%) and 10 non diabetic healthy controls (aged 50.3 +/- 7.1 years old). These were stimulated with phytohemagglutinin (PHA) alone or in the presence of native LDLS, malondialdehyde modified LDLs or glycated LDLs. Proliferation was measured as 3H-thymidine incorporation and expressed as Stimulation Index (SI).

RESULTS

SI of patients and healthy subjects, after PHA stimulation were similar: (57.5 +/- 29.8 and 61.1 +/- 23.5) respectively LDLs did not induce proliferation in neither group. Native LDLs produced a 98% inhibition of PHA induced proliferation. Malondialdehyde modified and glycated LDLs caused a 50% inhibition. The suppressive effect was maintained when lipoproteins were incorporated to culture media 60 min prior or after PHA stimulation.

CONCLUSIONS

Lipoproteins inhibit in vitro PHA induced peripheral blood mononuclear cell proliferation both in diabetic and in non diabetic subjects.

A polyisoprenylated benzophenone from Cuban propolis

A novel polyisoprenylated benzophenone (1) has been isolated from an ethanol extract of Cuban propolis. Its structure has been determined using high-field 2D NMR techniques. Compound 1 showed significant antimicrobial and antifungal activity against a variety of bacteria and yeasts.

[Immune response against modified low-density lipoproteins in patients with non-insulin-dependent diabetes mellitus]

BACKGROUND

Diabetes mellitus is a risk factor for atherosclerosis. Low density lipoproteins are considered a key factor in the formation of atheroma and the immune system has an important contribution to this process.

AIM

To quantify the immune response against modified low density lipoproteins in patients with non insulin dependent diabetes mellitus.

MATERIAL AND METHODS

LDLs obtained from blood of healthy subjects, were glycated or altered with malondialdehyde and used as antigens. Serum autoantibodies against these LDLs were measured by ELISA in 22 patients with non insulin dependent diabetes mellitus aged 46 to 67 years old and 13 healthy controls aged 41 to 65 years old. Basal and LDL stimulated tumor necrosis factor a production in vitro, by peripheral leukocytes of diabetics and controls was also measured.

RESULTS

The ratio of glycated LDL/native LDL antibodies was higher in diabetics than in controls (9.37 +/- 2.72 and 0.41 +/- 0.11 respectively p < 0.05) and the ratio of MDA modified LDL/native LDL antibodies was not significantly different (8.64 +/- 3.83 and 2.14 +/- 1.26 respectively, NS). Tumor necrosis or production by leukocytes was higher in diabetics than in controls in basal conditions (53.3 +/- 15.3 and 26.9 +/- 14.7 arbitrary units (a.u.) respectively), when stimulated with native LDL (46.5 +/- 5 and 24.3 +/- 9.4 a.u. respectively), when stimulated with malondialdehyde modified LDL (50 +/- 16.2 and 24.4 +/- 7.7 a.u. respectively) or when stimulated with glycated LDL (38.3 +/- 8.8 and 14.4 +/- 7.5 a.u. respectively).

CONCLUSIONS

Diabetic patients have an enhanced immune response against low density lipoproteins, factor that could contribute to the accelerated atherogenesis of this disease.

Heterogeneity of Brucella abortus lipopolysaccharides

This work demonstrates that Brucella lipopolysaccharide (LPS) preparations are a family of related molecules which display heterogeneity not only at the level of the O polysaccharide, but also at the core oligosaccharide and the lipid A. Sodium dodecyl sulphate/polyacrylamide gel electrophoresis and Western blotting showed that LPS from Brucella strains displayed molecular weight and antigenic heterogeneity. Smooth-type LPS (S-LPS) from B. abortus demonstrated three broad high-molecular-weight bands corresponding to S-LPS, and a low-molecular-weight band corresponding to O antigen lacking rough-type LPS (R-LPS). B. abortus R-LPS displayed four bands in increasing proportions as the molecular weight diminished. Immunodetection on high-performance thin-layer chromatography (HPTLC) with monoclonal antibodies (mAb) showed that R-LPS displayed three diffuse bands. HPTLC of O polysaccharide revealed two fast migrating bands recognized by antibodies. Gel chromatography and HPTLC analysis of core oligosaccharides from R-LPS demonstrated molecular weight heterogeneity as well as heterogeneous banding pattern, with no obvious correspondence between the two profiles. Immunodetection of lipid A on HPTLC plates revealed two major and three minor bands. Reactivity with mAbs suggested that regardless of the lipid A heterogeneity the basic structure of lipid A backbone is maintained.

[Significance of human leptospirosis in Mexico. Detection of Leptospira antibodies in a blood donor population]

The presence of specific serum antibodies has been used as a diagnostic test for human leptospirosis. The presence of these antibodies in humans is indicative of an active natural infection. Its detection after exposure denotes the presence of immunity. Serum samples from 206 adult blood donors were analyzed with a microscopic agglutination assay against 7 serovars of Leptospira interrogans. A total of 7% were positive with the following serovar distribution; shermani 53%, canicola 33%, pyrogens 20%, pomona 13% and icterohaemorrhagiae 6%. The highest frequency of seropositivity was found in the 20 year to 39 age group. These results in asymptomatic individuals show that leptospirosis is a frequent zoonosis in Mexico.

Immunochemical identification of Brucella abortus lipopolysaccharide epitopes

Sera from Brucella abortus-infected and -vaccinated bovines recognized four lipopolysaccharide (LPS) determinants: two in the O-polysaccharide (A and C), one in the core oligosaccharide from rough Brucella LPS (R), and one in lipid A (LA). From 46 different hybridomas secreting monoclonal antibodies (MAbs) against various LPS moieties, 9 different specificities were identified. Two epitopes, A and C/Y, were present in the O-polysaccharide. Two epitopes were found in the core oligosaccharide (R1 and R2) of rough Brucella LPS. MAbs against R1 and R2 epitopes reacted against LPS from different rough Brucella species; however, MAbs directed to the R2 epitope also reacted against enterobacterial LPS from deep rough mutants. Three epitopes (LA1, LA2, and LA3) were located in the lipid A backbone. Different sets of MAbs recognized two epitopes in the lipid A-associated outer membrane protein (LAOmp3-1 and LAOmp3-2). LPS preparations from smooth brucellae had small amounts of rough-type LPS. Although LPS from rough brucellae did not show smooth-type LPS in western blots (immunoblots), two hybridomas generated from mice immunized with rough B. abortus produced antibodies against smooth B. abortus LPS. Results are discussed in relation to the structure and function of B. abortus LPS and to previous findings on the epitopic density of the molecule.

[Persistent microalbuminuria in insulin-dependent diabetics and cardiovascular risk factors]

A possible association of cardiovascular risk factors and early diabetic nephropathy was investigated in 32 patients. Microalbuminuria (radioimmunoassay), total and HDL cholesterol and triglycerides (enzymatic methods), glycosylated hemoglobin (colorimetric methods), Apo A1 and B (immunonephelometric) and LDL were measured. Microalbuminuria was present in 28% of patients. Compared to subjects with no microalbuminuria they had increased levels of cholesterol (200.2 +/- 13.5 (SE) vs 168.6 +/- 9.4 mg/dl, p < 0.025) and LDL cholesterol (171.9 +/- 14.1 vs 137.4 +/- 9.1 mg/dl, p < 0.025). Systolic blood pressure was also higher in patients with microalbuminuria (127.8 +/- 3.9 vs 114.5 +/- 2.8 mmHg, p < 0.01). Microalbuminuria was correlated to the level of diastolic blood pressure (r = 0.74, p < 0.025). Thus, persistent microalbuminuria in insulin dependent diabetic patients is associated to cardiovascular risk factors which may explain the increased cardiovascular morbidity and mortality in these patients.

[Tuberculosis and diabetes mellitus: a longitudinal-retrospective study in a teaching hospital]

We analyzed 1529 diabetic patients seen between 1959 and 1982 at a teaching hospital in Concepción, Chile. 116 of them were insulin dependent diabetics. Gestational diabetes was excluded. The 10 year actuarial risk of acquiring tuberculosis was 24.2% for insulin-dependent diabetics and 4.8% for the rest (p less than 0.001). The risk of the diabetic population as a whole was 5.9% compared to 0.8% for the population at large. Thus, diabetics are a high risk group for tuberculosis, especially insulin-dependent patients whose risk is about 38 times higher than the general population under 40 years of age.

[Spermatogonia types in tepezcuintle (Cuniculus paca). Ultrastructural study]

Ultrastructural studies of different types of spermatogonia by thin section techniques and transmission electron microscopy showed that Cuniculus paca has two types of Type A spermatogonia (A-O and A-1). Samples were taken at different stages of the cycle in the seminiferous tubule epithelium presented a similar pattern as those of other rodents. Type B spermatogonia are similar to those of the rat, the difference being that the heterochromatic zones are larger and more numerous. Both characteristics differentiate them from preleptotenic spermatocytes.