GRACE score predicts systemic inflammation in patients with acute coronary syndrome

Background

New insights of inflammation CANTOS (1) and COLCOT (2) demonstrated the importance of blocking inflammation in CAD for major outcomes, but only in patients with systemic inflammation. The GRACE score is a readily available tool that uses a variety of items none related to inflammation per se. Many studies have emphasised the importance of inflammation, however, most markers are not readily available in the clinic setting.

Purpose

Determine if GRACE score may reflect systemic inflammation measured by WBC, hsCRP, albumin, IL-1β, IL-6, IL-8, and IL-10.

Methods

77 patients with NSTEMI/STEMI were enrolled at time of hospital admission, all patients had <24 h of the initial symptom, were >18 years old and received no therapy before the samples were obtained. Patients with pregnancy or in postpartum period, infectious, autoimmune, hepatic, or neoplastic diseases were excluded; as well as patients with current or previous dialysis, transplant, episodes of acute or chronic heart failure, and previous ACS.

WBC, hsCRP and troponin I, IL-1β, IL-6, IL-8, IL-10, were measured. Low rank regression splines, a predefined analysis of IL-1β + hsCRP/ IL-1β + IL-6 / IL-6 + hsCRP vs GRACE score was performed, adjusted by sex, type of ACS, hypertension, and diabetes. A p<0,05 was set as significant.

Results

GRACE score significantly correlated with IL-1β (ρ=0.352), IL-6 (ρ=0.465), IL-8 (ρ=0.325), IL-10 (ρ=0.31), WBC (ρ=0.428), hsCRP (ρ=0.46), and albumin (ρ=−0.538). In low rank regression splines WBC had a positive correlation with GRACE score (F=45.52 p<0.001; fig 1B) with inflection in scores >150. hsCRP also significant (F=21.54 p<0.001; fig 1C). IL-1β, IL-6 and IL-10 had a positive linear regression (F=7.32; F=8.36; F=5.32 p<0.02; respectively; fig 1 D,E,G); and IL-8, had a positive non-linear association (F=6.54 p=0.003; fig 1F). Finally, albumin had a negative relationship (F=29.68 p<0.001; fIg 1A), with inflection point in GRACE>125.

Analysis of log-IL-1 β + log-hsCRP vs GRACE (df= 2.07 and 4.9, F=12.84 and 23.23; p<0.001; fig 2A) and log- IL-1β + log-IL-6 vs GRACE (df= 2.23 and 6.53, F= 12.98 and 16.87, p<0.001; fig 2B) showed that the presence of a proportional increase in the variables correlates with higher GRACE scores. Lastly, log-hsCRP + log-IL-6 vs GRACE the F=18.18 and 2.8 with a p<0.001 and 0.07, respectively (fig 2C).

Conclusion

Our data suggest that a higher GRACE score reflect higher systemic inflammation and correlates with various cytokines that could be inferred non directly, IL-1, IL-6, IL-8 and IL-10. This open new avenues for personalized cardiology based in practical tools, possibly identifying patients that get the most benefit of the new anti-cytokine or anti-inflammatory interventions.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Instituto Nacional de Cardiología Ignacio Chávez Figure A. Low rank regression splinesFigure B. Low rank regression splines

The presence of IFL3/4 rs12979860 C allele influences the in vitro IP-10 production by mononuclear cells from patients with systemic lupus erythematosus

OBJECTIVE

To explore whether the IFNL3/4 rs12979860 genotype may influence serum levels or production of interferon-inducible protein-10 (IP-10) by peripheral blood mononuclear cells from patients with systemic lupus erythematosus (SLE).

METHODS

Sixty-six patients with SLE and 22 healthy blood donors (controls) were included. The IFNL3/4 rs12979860 polymorphism was genotyped by real-time polymerase chain reaction. IP-10 levels in sera supernatants of IFNα stimulated peripheral blood mononuclear cells were measured by enzime-linked immunosorbent assay.

RESULTS

Allelic frequencies were CC (29%), CT (52%) and TT (20%) in SLE, and CC (32%), CT (41%) and TT (27%) in healthy controls. Median serum IP-10 levels were higher in SLE patients than in controls (190.8 versus 118.1 pg/ml; p < 0.001), particularly in those with high disease activity (278.5 versus 177.2 pg/ml; p = 0.037). However, serum IP-10 levels were not influenced by IFNL3/4 genotypes. Higher IP-10 production by peripheral blood mononuclear cells was found in both SLE patients (median 519.3 versus 207.6 pg/ml; p = 0.012) and controls (median 454.0 versus 201.7 pg/ml; p = 0.034) carrying the IFNL3/4 C allele compared with carriers of the T allele.

CONCLUSIONS

Although IFNL3/4 rs12979860 allele C does not appear to influence serum IP-10 levels in SLE, it plays an important role in the production of IP-10 by peripheral blood mononuclear cells after IFNα stimulation.

Enhanced survival from CLP-induced sepsis following late administration of low doses of anti-IFNγ F(ab')2 antibody fragments

OBJECTIVE

To assess the impact of different doses of anti-interferon gamma (anti-IFNγ) F(ab')2 fragments, administered prophylactically, on survival and on serum concentration of cytokines in a murine model of sepsis induced by cecal ligation and puncture (CLP). We further explore the impact of therapeutic administration of the most protective dose on survival.

SUBJECTS AND TREATMENT

Balb/c mice were prophylactically treated by the intraperitoneal route with anti-IFNγ initiated 2 h before CLP and every 24 h for a total of five times in each of the following doses: 0.01, 0.1, or 1 mg/kg. Sham and control groups received sterile saline solution in a similar scheme.

METHODS

Serum tumor necrosis factor (TNF), interleukin (IL)-1β, IL-6, IL-10 and IFNγ were measured at 3, 24 and 48 h after CLP by ELISA. Survival curves were compared using a Mantel-Haenzel method.

RESULTS

Significant prophylactic protection was found only with 0.01 mg/kg, in association with regulation of IL-1β and IL-10 concentrations. As therapy, anti-IFNγ fragments were protective only when initiated 24 h after CLP.

CONCLUSIONS

Delicate modulation of IFNγ at the correct timing, even when the septic process has begun, is an exciting alternative to explore in the treatment of sepsis.

LPS pretreatment by the oral route protects against sepsis induced by cecal ligation and puncture. Regulation of proinflammatory response and IgM anti-LPS antibody production as associated mechanisms

OBJECTIVE

To explore the efficacy of prophylactic oral lipopolysaccharide (LPS) in sepsis induced by cecal ligation and puncture (CLP).

MATERIAL

Male Balb/c mice. LPS serotype O55: B5

TREATMENT

Mice were treated every 4 days for a total of 5 times with 50 mug of LPS by intraperitoneal (IP) or oral (O) routes. Treatment was stopped one week prior to CLP. Control (C) groups received the vehicle orally, and sham (S) groups were used as reference.

METHODS

Histopathology was performed to determine inflammation in liver and lung. Serum cytokines were measured by ELISA, and TNFalpha tissue expression by RTPCR. Antibodies against LPS were measured by ELISA.

RESULTS

Administration of LPS by the oral route significantly increased survival (p<0.05) of mice in association with a reduction of Kupffer cells in liver, pulmonary edema in lung, shorter or delayed TNFalpha expression in target organs, a trend to decreased IFN gamma and increased IL-10 serum levels, and a notable increase in the production of specific IgM anti-LPS antibodies.

CONCLUSIONS

LPS by oral route protected against CLP. The underlying mechanisms could be the modulation of the proinflammatory response and an increased production of IgM anti-LPS antibodies.

Anti-tumor necrosis factor α F(ab')2 antibody fragments protect in murine polymicrobial sepsis: Concentration and early intervention are fundamental to the outcome

BACKGROUND

Negative results are frequent using anti-TNFalpha antibodies in sepsis models and clinical trials.

METHODS AND RESULTS

Different prophylactic doses of anti-TNFalpha F(ab')2 antibody fragments were compared for the prevention of death by sepsis induced by cecal ligation and puncture (CLP) in mice. High (10 mg/kg) and very low (0.01 and 0.1 mg/kg) concentrations of anti-TNFalpha antibody fragments were not the most adequate for treating polymicrobial sepsis, since they did not significantly improve survival. To the contrary, intermediate doses (1 mg/kg) significantly protected the challenged animals. Protective activity was also observed when administration of the antibody fragments was initiated early (up to 30 min) after CLP.

CONCLUSIONS

These results suggest that in processes where excessive production of cytokines is involved, the aim should be to return them to their physiologically acting range but not to inhibit their production. The timing of initiating therapy should also be considered in order to maximize the possible benefits.

Mechanical deformation inhibits IL-10 and stimulates IL-12 production by mouse calvarial osteoblasts in vitro

The skeleton is continuously remodelled throughout life, a process that is orchestrated by cells of the osteoblast lineage. Remodelling involves a complex network of cell-cell signalling involving systemic hormones, locally produced cytokines, growth factors and the mechanical environment of the cells. Here, we report on the effect of mechanically-induced strain on the synthesis by mouse calvarial osteoblasts in monolayer culture of IL-10 and IL-12, two cytokines that inhibit osteoclast formation in bone marrow cultures; IL-10 also suppresses osteoblast differentiation suggesting a role for both cytokines in bone physiology. A tensile strain was applied to the cells intermittently for 6s, every 90s, for 2-96h. After 2-h culture, supernatants from deformed cells contained significantly less IL-10 than control cultures. In contrast, mechanical deformation had a stimulatory effect on IL-12 synthesis; however, by 48h both had returned to control levels. These data suggest that IL-10 and IL-12 can be added to the growing list of mechanical stress-responsive genes. The down-regulation of IL-10 and stimulation of IL-12 further suggests that the initial response of the cells to mechanical deformation was an osteogenic one.

CD4+ TCRalphabeta T cells are critically involved in the control of experimental murine cysticercosis in C57BL/6J mice

Taenia crassiceps cysticerci develop in the peritoneal cavity of BALB/cAnN mice and, to a lesser extent, in C57BL/6J mice. The mechanisms involved in the immunity to this murine cysticercosis seem to be mainly mediated by T cells. To gain further insight into the mechanisms of cysticercal immunity, the susceptibility of mice deficient in different immunologically relevant genes was compared with that of the respective wild type. Mice were classified according to the parasite load and survival after infection: highly susceptible (HS), with an increased parasite load and mortality rate (CD4-/-, TCRalpha-/-, TCRbeta-/-, RAG1-/-), susceptible, with only increased parasite load (TCRdelta-/-, BALB/cAnN), and relatively resistant, with a lower number of parasites (CD8-/-, WT). Neither specific proliferative response nor Th2 cytokine or antibody responses were observed in HS mice. These data strongly suggest that CD4+TCRalphabeta+ T cells have a critical role in the control of T. crassiceps murine cysticercosis.

The impact of a clinical training unit on integrated child health care in Mexico

This study had two aims: to describe the activities of a clinical training unit set up for the integrated management of sick children, and to evaluate the impact of the unit after its first four years of operation. The training unit was set up in the outpatient ward of a government hospital and was staffed by a paediatrician, a family medicine physician, two nurses and a nutritionist. The staff kept a computerized database for all patients seen and they were supervised once a month. During the first three years, the demand for first-time medical consultation increased by 477% for acute respiratory infections (ARI) and 134% for acute diarrhoea (AD), with an average annual increase of demand for medical care of 125%. Eighty-nine per cent of mothers who took their child for consultation and 85% of mothers who lived in the catchment area and had a deceased child received training on how to recognize alarming signs in a sick child. Fifty-eight per cent of these mothers were evaluated as being properly trained. Eighty-five per cent of primary care physicians who worked for government institutions (n = 350) and 45% of private physicians (n = 90) were also trained in the recognition and proper management of AD and ARI. ARI mortality in children under 1 year of age in the catchment area (which included about 25,000 children under 5 years of age) decreased by 43.2% in three years, while mortality in children under 5 years of age decreased by 38.8%. The corresponding figures for AD mortality reduction were 36.3% and 33.6%. In this same period, 11 clinical research protocols were written. In summary, we learned that a clinical training unit for integrated child care management was an excellent way to offer in-service training for primary health care physicians.

Taenia crassiceps cysticercosis: a role for prostaglandin E2 in susceptibility

Several biological factors are involved in susceptibility and resistance to murine cysticercosis. A substantial body of evidence implies prostaglandins as potent regulators of immune responses during parasitic diseases. Here we evaluated the role played by prostaglandin E2 in cysticercosis. Mice were treated in vivo with prostaglandin E2 or with indomethacin (a prostaglandin E2 synthesis inhibitor) before infection. Parasite growth was enhanced by prostaglandin treatment, which provoked poor Con-A responses, low Th1-type cytokines secretion, and high levels of IL-6 and IL-10. In contrast, mice receiving indomethacin showed a reduction in parasite load parallel to a strong Con-A response and high levels of IL-2 and IFN-gamma, concomitantly with a decrease in IL-4, IL-6 and IL-10 production. Indirect in vitro studies suggest that an important source of prostaglandin E2 production could be related to host's adherent cells. However, prostaglandin E2 from parasite origin cannot be discarded.

Susceptibility to Trypanosoma cruzi is modified by a previous non-related infection

Helminth infections are frequently massive, chronic and strong inductors of Th2-type cytokines. This implies that infection by such parasites could alter the susceptibility to subsequent infections by other pathogens, particularly intracellular parasites. We therefore explored whether a persistent infection, caused by Taenia crassiceps cysticerci, in BALB/c mice could affect susceptibility to a later infection by Trypanosoma cruzi. We found that the presence of the cysticerci indeed modified the immune response and the susceptibility to T. cruzi, and that these modifications depended on the time-course evolution of the initial infection. Coinfection with the protozoan in the early stages of the helminth infection, induced a delay on the onset of parasitaemia, early specific production of IFN-gamma and high specific production of IL-4. A significant increase in susceptibility to T. cruzi was observed only when mice were coinfected in late stages when the helminth load is greater and a Th2 type response against it is predominant. The in vitro specific response to T. cruzi antigens was then characterized by low levels of both IFN-gamma and IL-4. These findings suggest that chronic helminth infections could potentially have a significant influence over the immune response and hence susceptibility to other pathogens.

Th1-type cytokines improve resistance to murine cysticercosis caused by Taenia crassiceps

Resistance and susceptibility to different parasitic diseases have been associated with the predominance of Th1- or Th2-type immune responses. In experimental murine cysticercosis a Th1 response seems to be involved in resistance, whereas Th2 activity is associated with heavy parasite intensities. To test this notion the roles of Th1- and Th2-type cytokines in infected mice were studied after treatment with anticytokine monoclonal antibodies or with recombinant murine cytokines during early stages of infection. Mice receiving anti-interleukin 10 (IL-10) carried lower parasite intensities than did control mice and developed a strong Th1-type response, whereas mice receiving anti-interferon gamma (IFN-gamma) showed a dramatic increase in susceptibility. Treatment with recombinant cytokines confirmed these results; mice receiving IFN-gamma and IL-2 showed low parasite numbers, whereas IL-10 induced a significant increase in parasite loads. Thus, the Th1-type immune response plays a fundamental role in protection against Taenia crassiceps cysticercosis, whereas Th2, at least through IL-10, favors parasite establishment.

A clinical training unit for diarrhoea and acute respiratory infections: an intervention for primary health care physicians in Mexico

In Tlaxcala State, Mexico, we determined that 80% of children who died from diarrhoea or acute respiratory infections (ARI) received medical care before death; in more than 70% of the cases this care was provided by a private physician. Several strategies have been developed to improve physicians' primary health care practices but private practitioners have only rarely been included. The objective of the present study was to evaluate the impact of in-service training on the case management of diarrhoea and ARI among under-5-year-olds provided by private and public primary physicians. The training consisted of a five-day course of in-service practice during which physicians diagnosed and treated sick children attending a centre and conducted clinical discussions of cases under guidance. Each training course was limited to six physicians. Clinical performance was evaluated by observation before and after the courses. The evaluation of diarrhoea case management covered assessment of dehydration, hydration therapy, prescription of antimicrobial and other drugs, advice on diet, and counselling for mothers; that of ARI case management covered diagnosis, decisions on antimicrobial therapy, use of symptomatic drugs, and counselling for mothers. In general the performance of public physicians both before and after the intervention was better than that of private doctors. Most aspects of the case management of children with diarrhoea improved among both groups of physicians after the course; the proportion of private physicians who had five or six correct elements out of six increased from 14% to 37%: for public physicians the corresponding increase was from 53% to 73%. In ARI case management, decisions taken on antimicrobial therapy and symptomatic drug use improved in both groups; the proportion of private physicians with at least three correct elements out of four increased from 13% to 42%, while among public doctors the corresponding increase was from 43% to 78%. Hands-on training courses thus seemed to be effective in improving the practice of physicians in both the private and public sectors.

The quality of private and public primary health care management of children with diarrhoea and acute respiratory infections in Tlaxcala, Mexico

In Tlaxcala, Mexico, 80% of the children who died from diarrhoea or acute respiratory infections (ARI) in 1992-1993 received medical care; in more than 70% of cases it was provided by a private general practitioner (GP). The present study evaluated the quality of case management by private and public GPs to children under five years of age with diarrhoea and ARI. During the clinical observation, the treatment and counselling given to the mother were assessed with the WHO guidelines as reference standard. A total of 41 private and 40 public GPs were evaluated for the management of diarrhoea, and 59 private and 40 public GPs for the management of ARI. For diarrhoea, half of the private GPs gave inadequate rehydration therapy, 63% gave incorrect advice on diet, 66% and 49% made an incorrect correct decision in the prescription of antimicrobial and symptomatic drugs, respectively. Public GPs generally performed better in diarrhoea management: 7% gave inadequate rehydration therapy, 13% gave wrong advice on diet, 3% made a wrong decision in the prescription of symptomatic drugs and 28% gave a wrong decision in antimicrobial prescription. In the management of ARI, 66% and 58% of private GPs made a wrong decision in the prescription of antimicrobial and symptomatic drugs, respectively, compared to 30% and 20% of public GPs, respectively. Counselling to the mother given by both private and public GPs was considered inadequate in most cases of diarrhoea and ARI. These results clearly show that private doctors, as important providers of medical care, need to be included in the strategies to improve the quality of care of children with diarrhoea and ARI. Future research needs to address the determinants of the clinical practice of private doctors in countries like Mexico.

Shift from an early protective Th1-type immune response to a late permissive Th2-type response in murine cysticercosis (Taenia crassiceps)

In early stages of experimental murine cysticercosis caused by Taenia crassiceps, there is a clear but transient Th1-type immune response (characterized by high levels of interleukin [IL]-2, interferon-gamma, concanavalin A, and antigen specific response, delayed-type hypersensitivity, and immunoglobulin [Ig]G2a antibodies) that associates with a low rate of parasite reproduction. As time of infection progresses an energic and more permanent Th2-type response follows (characterized by high levels of IL-4, IL-6, IL-10, IgG2b, and IgG1 antibodies) that in turn associates with an increment in the rate of parasite reproduction. The sequential activation of Th1-type and Th2-type responses in murine cysticercosis would appear to favor progressively parasite reproduction, explaining the long time residence and the massive parasite intensity reached in chronic infections.

Antibiotic use in a periurban community in Mexico: a household and drugstore survey

In developing countries, antibiotics are the most common drugs sold, and some data suggest that they are frequently misused. In order to describe the pattern of antibiotic use in a periurban community in Mexico City, 1659 randomly-selected households were visited and an interview with the housewife was carried out. Six local drugstores also were selected at random. A social worker made six visits to each pharmacy, observed the events during the purchase of the drug and applied a structured questionnaire to the customer immediately after the transaction. Of 8279 individuals, 425 (5%) said that they had used at least one antimicrobial in the preceding 2 weeks and antibiotics were the majority (29%) of the drug sales. The main perceived reasons for drug use were acute respiratory tract ailments and gastroenteritis. Interviewees reported that antibiotic therapy was given in 27% of respiratory diseases and in 37% of all diarrheal episodes. The drugs most commonly reported were: penicillins, erythromycin, metronidazole, neomycin, cotrimoxazole and tetracyclines. While self-medication and drug purchases without medical prescription were common, the majority of antibiotics were prescribed by a physician. Approximately two thirds of individuals using an antibiotic said they had used it for less than 5 days and 72% of the purchases were for insufficient quantities of drugs. Our data suggest that antibiotics are frequently misused and they support the need to assess the determinants of self-medication, health-seeking behavior and physician prescribing practices. The need for effective educational programs to improve prescribers' decisions is stressed.

A role for 17-beta-estradiol in immunoendocrine regulation of murine cysticercosis (Taenia crassiceps)

In experimental murine cysticercosis caused by Taenia crassiceps, parasite reproduction is favored by thymectomy or by orchidectomy, and restricted by ovariectomy. Hormonal reconstitution experiments showed that 17-beta-estradiol increases parasite numbers whereas 5-alpha-dihydrotestosterone was ineffective. Parasite numbers decreased with increments in cellular immunity but were insensitive to antibody levels. A possible immunoendocrinological interaction involving estrogen as a depressor of cellular immunity is envisaged in the control of cysticercosis.

[Immune response or tolerance. Cellular selection by the thymus]

There is currently a very active research on the mechanisms that give rise to the cell selection of lymphocyte precursors by the thymus. This selection is basic for the process of formation of the repertoire of T cells with which an organism is potentially capable of developing an immune response to a foreign antigen, and not doing so when encountering its own antigens. This work pretends to detail some recent advances in the knowledge of the process by which cells are positively or negatively selected by the thymus, to give rise to the T cell repertoire of an individual.

Antibiotic misuse in diarrhea. A household survey in a Mexican community

A survey of 1659 households in a periurban community in Mexico City was carried out to assess the frequency of and risk factors for inappropriate antimicrobial therapy in acute diarrhea. The housewife was interviewed to obtain information of the occurrence of diarrhea or use of an antibiotic in the previous 2 weeks by any member of the family. An antibiotic was used in 37% or 287 diarrheal episodes although only in 5% of all episodes was this therapy indicated, based on the presence of gross blood in stools. Patients seen by a physician were 6 times more likely to be treated with an antibiotic compared to those who did not consult a physician (p < 0.001). Self-medication was associated with a higher risk of using an inadequate drug or dose (in 72% of treated episodes) and of following treatment for less than 5 days (in 66% of treated episodes). Other risk factors significantly and independently associated with antibiotic misuse were: an increased number of stools (odds ratio [OR] = 1.21; 95% confidence interval [CI] = 1.04, 1.41), bloody diarrhea (OR = 19.04; 95% CI = 2.52, 160.90) and family crowding (OR = 2.07; 95% CI = 1.17, 3.63). These findings support future community-oriented educational interventions aimed at improving physician prescribing practices and patient compliance behavior in order to achieve a more rational use of antibiotics.

Thymus-related cellular immune mechanisms in sex-associated resistance to experimental murine cysticercosis (Taenia crassiceps)

The role of sex, thymus, and cellular immune mechanisms in mouse resistance to experimental cysticercosis with Taenia crassiceps was studied in male and female susceptible mice treated with cyclophosphamide, as well as in mice neonatally thymectomized and passively transferred with T-enriched lymphoid cells. High doses of cyclophosphamide increased delayed hypersensitivity and resistance of mice of both sexes without affecting antibody production. Neonatal thymectomy diminished resistance in both sexes but depressed delayed hypersensitivity in females only, without significantly affecting antibody response in either sex. Passive transfer of T-enriched lymphoid cells to thymectomized mice restored resistance to control levels without greatly affecting delayed hypersensitivity. Thus, our results indicate that cell-associated immune mechanisms are implicated in resistance to murine cysticercosis with T. crassiceps. Because neonatal thymectomy nearly equalized the intensity of infection of female and male mice, it is argued that the thymus is importantly involved in the interaction between gonads and the immune system in the control of this cysticercosis.

[Antibiotic consumption in a community of Mexico City. II. Survey of purchases at pharmacies]

In developing countries, antibiotics are the most common sales of drugs and it has been suggested that their irrational use leads to the emergence of resistant bacteria. In order to assess the purchase of antimicrobials in a peri-urban community in Mexico City six local drug stores were randomly selected. A social worker made five visits to each pharmacy and she observed the events during the purchase of the drug and applied a structured questionnaire to the customer immediately after the transaction. Antibiotics were the majority (29%) of the drug sales. Of all purchasers of an antibiotic 43% did it without medical prescription and 72% answered that a physician had influenced on the purchase. Duration of the antibiotic therapy was specified in one out of three prescriptions that were examined and only in 28% of the sales the purchase was enough for a treatment duration of more than four days. More information, from similar surveys in drug stores in other settings, is needed to support the reinforcement of actions to control the sales of antibiotics in the community.

[The use of antibiotics in a community of Mexico City. I. A household survey]

Based on previous community-oriented studies an irrational use of antibiotics, particularly in developing countries, has been suggested. In order to describe the pattern of antibiotic use in a periurban community in Mexico City, 1659 randomly selected households were visited and an interview to the housewife was carried out. Of 8279 individuals 425 (5%) had used at least one antimicrobial in the preceding two weeks. Main perceived reasons for drug use were: respiratory tract ailments (58%) and acute diarrhea (25%). Antibiotic therapy was given in 27% of respiratory diseases and in 37% of all diarrheal episodes. Most commonly used drugs were: penicillins (43%), erythromycin (13%), metronidazole (9%), neomycin (6%), cotrimoxazole (6%) and tetracyclines (6%). While self-medication was common (19%) the majority of antibiotics were prescribed by a physician (81%). Approximately two thirds of individuals using an antibiotic did it for less than five days. Our data suggest a frequent misuse of antibiotics and support the future assessment, in this community, of physician prescribing practices, the determinants of self-medication as well as the impact of this drug use on the selection of resistant bacterial strains.

Cohort study of intestinal infection with campylobacter in Mexican children

A cohort of 179 children under 5 years of age from a low-income urban community was followed up for a year to determine the incidence of symptom-producing and of diarrhoea-free campylobacter intestinal infections, and thus their illness-to-infection ratio. 66% of all children had at least one campylobacter infection, one-third of these being associated with diarrhoea. The annual incidence of all campylobacter infections was 2.1 episodes per child. The incidence was inversely related to age (r = -0.78 p less than 0.02). The illness-to-infection ratio, which in infants younger than 6 months was 1:2, was negatively associated with age (r = -0.7, p less than 0.02). Only symptom-producing infections occurring early in life seemed to protect against subsequent infections.

Reliable serology of Taenia solium cysticercosis with antigens from cyst vesicular fluid: ELISA and hemagglutination tests

New levels of reproducibility and sensitivity have been achieved in the detection of anticysticercus antibodies in human sera by using cysticercus vesicular fluid as the source of antigens for both ELISA and hemagglutination assays. Reproducibility both between tests on a serum and between similar sera was significantly improved over typical results using antigens from whole parasite extracts. Sera collected from uninfected individuals in endemic areas gave somewhat elevated values over those collected in nonendemic areas. This necessitated the use of a higher threshold in endemic areas to avoid false positives. With the threshold appropriate for a nonendemic area, both ELISA and hemagglutination were sensitive enough to detect infection in 95% of cases. With the threshold value for sera from an endemic area, these sensitivities were reduced to 80%-90%. A prominent 103-Kd protein of vesicular fluid, not related to antigen B, elicited the strongest antibody response in neurocystercotic patients.