Rare Oral Crohn's Disease: A Case Report

Crohn's disease is an inflammatory granulomatous and chronic disease characterized by inflammation of the gastrointestinal mucosa with extra-intestinal manifestations. Oral lesions seem to occur as specific lesions like lip swelling, cobblestone or tag lesions, or nonspecific lesions like ulcers. The present case report describes an orofacial Crohn's disease case, a rare presentation of Crohn's disease, managed with infliximab. Oral Crohn's disease refers to the spread of manifestations of Crohn's disease and could precede other signs. Physicians have to be aware of oral mucosal changes. The treatment options are based on the use of corticosteroids, immune-modulators and biologics. The best plan and therapy to control oral Crohn's disease requires early and precise diagnosis.

Prevalence of pulmonary tuberculosis among respiratory symptomatic subjects in an out-patient primary health unit

SETTING

Out-patient primary health unit (OPHU) in Rio de Janeiro City, Brazil.

OBJECTIVE

To evaluate the impact on the detection of tuberculosis (TB) cases of reducing the time of respiratory symptoms from 'cough > or = 3 weeks' to 'cough > or = 1 week' as a criteria for TB case finding among individuals visiting an OPHU for any other reason.

DESIGN

Cross-sectional study.

RESULTS

During the period of the study, 10.7% (765/ 7174) of subjects reported cough > or = 1 week. Among 542 subjects enrolled in the study with cough > or = 1 week, 15 (2.7%) cases were diagnosed with pulmonary tuberculosis (PTB, 2767/100000). The probability of detecting TB in the OPHU setting among subjects seeking care for respiratory symptoms was significantly higher than among those presenting to the OPHU for other reasons (OR 31.5, 95% CI 4.1-241.9; P < 0.0001). The probability of identifying TB among patients seeking care due to respiratory symptoms was not influenced by the duration of cough (P = 0.7).

CONCLUSION

These findings suggest that the screening criteria for TB case finding of cough for less than the usual 3 weeks among patients who attend a health facility due to respiratory symptoms in settings with a high prevalence of TB may significantly improve the proportion of TB cases diagnosed.

Oxacillin- and mupirocin-resistant Staphylococcus aureus: in vitro activity of silver sulphadiazine and cerium nitrate in hospital strains

Nasal carriage is an important reservoir of oxacillin-resistant Staphylococcus aureus (ORSA). Mupirocin is a topical drug used to remove S. aureus from nares. However, isolates resistant to mupirocin have been reported all over the world. Silver sulphadiazine (SSD) is a topical agent, which when associated with cerium nitrate (CN), has been shown to be useful in the treatment of burn infections and could be an alternative drug for patient decolonization. Susceptibility to oxacillin in 203 S. aureus isolates was evaluated by the agar diffusion test, while the agar diffusion and agar dilution methods were used for mupirocin. A PCR-multiplex method was performed to detect the mecA and ileS-2 genes. Minimum inhibitory concentration (MICs) to SSD and CN, used alone or in association, were determined by the agar dilution method. One hundred and sixty-three (80.3%) strains were oxacillin-resistant, and 37 (18.2%) were mupirocin resistant. The MIC of SSD alone or in association with CN was 64 microg/mL, while for CN alone was 2048 microg/mL for all isolates. SSD presented anti-staphylococcal activity at concentrations (64 microg/mL) much lower than those commonly used in commercial preparations (10 mg/g) and had good activity against mupirocin-resistant strains, showing that this drug could be used for nasal decolonization in ORSA carries.

Genomic characterization of oxacillin-resistant Staphylococcus epidermidis and Staphylococcus haemolyticus isolated from Brazilian medical centres

Studies on the genetic diversity of oxacillin-resistant coagulase-negative staphylococcal (CNS) isolates are important for the control and prevention of infections. The present study evaluated the clonal diversity of oxacillin-resistant Staphylococcus epidermidis (ORSE) and Staphylococcus haemolyticus (ORSH) strains, isolated from patients in nine Brazilian medical centres by using pulsed-field gel electrophoresis (PFGE) after digestion of bacterial DNA using SmaI. PFGE analysis of ORSE (N=44) and ORSH (N=25) strains showed the presence of 29 restriction profiles clustered in 16 PFGE types, and 21 distinct profiles in 15 PFGE types, respectively, indicating a large genetic diversity among isolates of both of these species. Among the ORSE isolates, 23 (52%) strains belonged to two predominant PFGE types (named A and B), which were observed in most of the hospitals assessed, indicating the spread of these PFGE types in hospitals located in Rio de Janeiro. The spread of PFGE types of ORSH was also detected in some of the hospitals investigated. The results show that PFGE is a suitable tool for epidemiological studies of oxacillin-resistant CNS, and can be used as a basis for infection control procedures for these multiresistant organisms.

Agar gel immunodiffusion test (AGID) evaluation for detection of bovine paratuberculosis in Rio de Janeiro, Brazil

AIMS

The aim of this study is to evaluate the AGID serological test for detection of antibodies anti-Mycobacterium paratuberculosis and its possible adoption as diagnostic method in our field conditions.

METHODS

Bovine serum samples from dairy herds in Rio de Janeiro State, Brazil, were screened for the presence of antibodies against Myco. paratuberculosis using three different ELISA tests. A panel of 48 randomly selected sera were evaluated by an Agarose Gel Immunodiffusion (AGID) test using Protoplasmatic Paratuberculosis Antigen (PPA). AGID results were compared to the standards--the results of the three ELISA tests, and the specificity and sensitivity were calculated.

RESULTS

From 48 sera tested for AGID, 14 (29.17%) were positive and 34 (70.83%) were negative. AGID sensitivity was 57% with two false-positive reactions, and specificity was 92.5% with nine false-negative results. The positive predictive value was calculated in 85.7% for a confidence interval of 95%.

SIGNIFICANCE AND IMPACT OF THE STUDY

Due to its low sensitivity and specificity rates, AGID test has shown to be unsatisfactory as a screening diagnostic method for subclinical herd infection, but it can be useful as a confirmatory test for clinical suspect animals.

Evaluation of Etest strips for rapid susceptibility testing of Mycobacterium tuberculosis

In this study, our objective was to evaluate Etest strips containing exponential gradients of isoniazid (INH), rifampin (RIF), and streptomycin (STR) for susceptibility testing of Mycobacterium tuberculosis. M. tuberculosis isolates were tested for antimicrobial susceptibilities by the standard proportion method using Löwenstein-Jensen (LJ) medium and by the Etest. The MICs determined by the Etest were obtained at 5, 7, or 10 days. In some strains with Etest-discrepant results, radiometric susceptibility testing (BACTEC) was performed to determine a consensus result. M. tuberculosis concordance between the two methods was 97% (86 of 89 isolates) for RIF, 96% for INH (84 of 87 isolates), and 80% (61 of 76 isolates) for STR. Most of the MICs determined by the Etest were easy to interpret and readable within 5 days. Results correlated well with those obtained by the LJ proportion and BACTEC methods for INH and RIF. However, a high proportion of false-sensitive and false-resistant results were observed, most often for STR. We also observed that variations in the inoculum size of M. tuberculosis isolates affected the MICs to a substantial degree. These discrepancies, along with the expense of the media, the Etest strips, and the specialized equipment required (CO2 incubator), make this method less useful in developing countries.

Mycobacterium tuberculosis typing: usefulness of DRE-PCR to confirm cross-contamination in the mycobacteriology laboratory of a general reference hospital for AIDS

In this study two molecular typing methods, a simple double repetitive element PCR-based assay and the standardized restriction fragment length polymorphism (RFLP), were used to confirm cross-contamination in the mycobacteriology laboratory. Clinical specimens from 12 patients, submitted for acid-fast bacilli stain smear and processed for culture in Lowenstein-Jensen on the same day, resulted in positive bacterioscopy (+++) and confluent growth only for one of the patients. The specimens from all the other patients but two were smear-negative and culture-positive, with one or two colonies. None of them had clinical symptoms and radiological findings for active tuberculosis (TB). The suspicion of false-positive cultures arose when a health care worker who had had a PPD skin test conversion, claimed to be healthy and had no TB symptoms, was found to have a positive sputum culture. DRE-PCR demonstrated that all nine cultures typed belonged to one cluster, further confirmed by RFLP. Although DRE-PCR has been found to be poorly reproducible, it has enough discriminatory power to be useful for rapid epidemiological investigation in selected settings.

[Relationship between serological diagnosis (ELISA) and severity of pulmonary tuberculosis in children]

Forty eight children from 0 to 13 years old were submitted to the enzyme-linked immunosorbent assay (ELISA) serological test with a view to detect anti PPD IgG antibodies, for diagnosis of pulmonary tuberculosis and to establish the relationship between immune response and radiological gravity of pulmonary tuberculosis (mild, moderate and severe). There were 29 children with pulmonary tuberculosis and 19 children without tuberculosis. The median ELISA optical density were: 0.098 in children with primary complex (mild); 0.092 in children with pneumonic pattern (moderate) and 0.134 in children with miliary tuberculosis (severe). These data show higher positive serological test results in severe forms of pulmonary tuberculosis (p = 0.0007).

The use of Ag85 complex as antigen in ELISA for the diagnosis of bovine tuberculosis in dairy cows in Brazil

Several enzyme-linked immunosorbent assay (ELISA) methods have been investigated to evaluate their performance in the diagnosis of tuberculosis in cattle. Increased production of antibodies to the proteins of antigen 85 complex (Ag85) after experimental and natural infection in cattle shows that they are strongly immunogenic in vivo. The purpose of this study was to evaluate the use of Ag85 as an antigen in ELISA for the diagnosis of bovine tuberculosis in dairy cows in Brazil. The test groups consisted of 46 serum samples from intradermal tuberculin test (ITT)-positive animals (Group A) and 46 samples from ITT-negative animals (Group B). Group C comprised 12 samples from a tuberculosis-free herd and was the control group of the study. Samples were tested in an ELISA using Ag85 as antigen. Differences between the mean ODs of groups A and B and A and C were significant (P < 0.01), but no significant difference (P > 0.05) was observed between groups B and C. The sensitivity of the ELISA using Ag85 was 91.3% (42/46) and its specificity was 94.8% (55/58). These results were not significantly different (P > 0.05) from those observed in a previous study of an ELISA using purified protein derivative (PPD). We concluded that, although Ag85 can be used as antigen for ELISA tests in the diagnosis of bovine tuberculosis with good sensitivity and specificity rates, no significant advantages were observed in relation to the ELISA using PPD that could justify the purification and utilization of Ag85 as a single antigen in routine methods of diagnosis.

Genotypic patterns of multiple isolates of M. tuberculosis from tuberculous HIV patients

We investigated whether the recurrence of tuberculosis in HIV-infected patients is due to an exogenous reinfection or relapses after antituberculosis chemotherapy. We reviewed clinical information on 32 patients at a Rio de Janeiro hospital from whom multiple Mycobacterium tuberculosis isolates were taken. All isolates were analysed by DRE-PCR fingerprinting technique, and those with identical DRE-PCR patterns were analysed by the RFLP method. Twenty patients had M. tuberculosis simultaneously isolated from different organs. These patients and nine others with sequential positive cultures after 2 months of therapy showed stable DRE-PCR and RFLP patterns. One patient's isolate became resistant to isoniazid, but the molecular pattern remained unchanged despite the development of drug resistance. In three patients, the DRE-PCR patterns of the isolates changed dramatically. Clinical and microbiological evidence was consistent with active tuberculosis caused by a new strain of M. tuberculosis. The exogenous reinfection of the three patients was not due to an outbreak, but the isolates from each patient showed unique patterns.

RFLP patterns and risk factors for recent tuberculosis transmission among hospitalized tuberculosis patients in Rio de Janeiro, Brazil

Isolates of Mycobacterium tuberculosis from 120 tuberculosis patients seen in the 12 months ending September 1994 at 2 tertiary-care centres in Rio de Janeiro were characterized by IS6110 restriction fragment length polymorphism (RFLP) analysis. Ninety-seven patients (81%) had isolates with unique RFLP patterns, while 23 patients (19%) had isolates that belonged to 11 different RFLP cluster patterns. The strains from the latter patients were distributed among 1 group of 3 patients and 10 groups of 2 patients each. The cluster-pattern strains were not associated with gender, age, HIV infection, type of residence, living in shelter, homelessness or previous history of tuberculosis. However, clustering was strongly associated with multidrug resistance (P = 0.006). These data suggest that recent exogenous transmission may be important for the development of new cases of multidrug-resistant disease in patients attending tertiary-care centres in Rio de Janeiro, Brazil.

Mycobacterium tuberculosis lipid antigens: use of multi-antigen based enzyme immunoassay for free and complex dissociated antibodies

OBJECTIVE

To test the sensitivity and specificity of four lipid antigens of Mycobacterium tuberculosis: BDA-TDA, DAT, SL-I, and PIMs, adsorbed in the same microplate well, to detect reactive IgG by enzyme-immunoassay (EIA) from plain serum (MA-EIA) and dissociated immune complexes (ICMA-EIA).

DESIGN

IgG antibodies against four antigens, placed in the same microplate well, were evaluated in serum from 155 tuberculous (TB) cases non-infected with the human immunodeficiency virus (HIV): 78 patients with positive bacilloscopy and culture, 33 patients with positive culture and 44 patients diagnosed by clinical and radiological criteria; and from 211 HIV negative control subjects: 32 patients with other pulmonary diseases, 100 healthy people and 79 close contacts.

RESULTS

MA-EIA had an overall sensitivity and specificity of 61% (94/155) and 95% (200/211), respectively. We further examined whether the dissociation of immune complexes increases the number of positive reactions in those initially found to be seronegative (SN). The subset of 112 (76 controls and 36 TB) MA-EIA SN samples tested using ICMA-EIA yielded an overall sensitivity and specificity of 83% and 100%. The ICMA-EIA results improved the overall sensitivity from 61 to 80% without changing specificity.

CONCLUSION

These preliminary results suggest that MA-EIA followed by ICMA-EIA, for SN samples, might serve as a fast, cheap, and easy method for the diagnosis of TB in less than 48 hours.

Predictive value of the acid fast smear for detection of Mycobacterium tuberculosis in respiratory specimens in a reference center of HIV/AIDS in Rio de Janeiro, Brazil

In order to evaluate the predictive value of acid fast bacilii (AFB) smear for the diagnosis of Mycobacterium tuberculosis in respiratory specimens in a setting with a high prevalence of AIDS and an unknown prevalence of nontuberculous mycobacteria (NTM), we retrospectively examined specimens cultured for mycobacteria between 1 September 1993 and 30 September 1994 and medical records of patients with positive culture in a General Hospital, AIDS reference in Rio de Janeiro, Brazil. Seventy three per cent (1517/2077) of samples were respiratory specimens and mycobacteria were recovered from 20.6% (313/1517) of these. M. tuberculosis was identified in 94.2% (295/313) and NTM in 5.8% (18/313). The yield of positive AFB smear and of positive culture was 6.1% (93/1517) and 20.6% (313/1517), respectively. The positive predictive value (PPV) of AFB for M. tuberculosis was 98.4% in expectorated sputum and 96.4% in bronchoalveolar lavage. Forty four percent (130/295) of specimens with positive culture for M. tuberculosis and 66.7% (12/18) for NTM were from patients HIV positive. The conclusion was that in our study population, the PPV of AFB for M. tuberculosis in respiratory specimens was high and the prevalence of NTM was low despite the high prevalence of HIV positive.

Evaluation of an ELISA-PPD for the diagnosis of bovine tuberculosis in field trials in Brazil

Bovine tuberculosis is a major health problem in Brazil. The intradermal tuberculin test is the standard test for its detection, but it can lack both sensitivity and specificity. The purpose of this study was to evaluate a bovine enzyme-linked immunosorbent assay- (ELISA - PPD) under field conditions in Brazil. A total of 1632 animals from 13 dairy farms were tested with the intradermal tuberculin test (ITT). Two hundred and seven cows gave a positive reaction, which represents 12.7 per cent of the cattle studied. The sensitivity and specificity rates to ITT were 87.7 per cent and 95.2 per cent, respectively. From the 1632 animals 15 per cent of each herd (220 in total) were selected to be tested by the ELISA. Differences between mean optical density (OD) of the control group, ITT -positive and ITT -negative groups were all significant (P<0.01). The sensitivity rates to ELISA - PPD were 86.7 per cent, while specificity was 90.6 per cent. The use of ELISA - PPD is suggested for situations where the investigation of the whole herd is more important than the individual testing of each cow. In addition, the ELISA - PPD can also be helpful when a collective diagnosis is desired to elucidate clinical suspicions of disease, or in the first steps of a control program, for identification of foci.

Comparison between a gamma-IFN assay and intradermal tuberculin test for the diagnosis of bovine tuberculosis in field trials in Brazil

Bovine tuberculosis is a major problem in Brazil. The intradermal tuberculin test is the standard test for detection of bovine tuberculosis in Brazil but can lack both sensitivity and specificity. The purpose of this study was to compare a bovine gamma-IFN assay with the tuberculin test under field conditions in Brazil. A total of 1632 animals from 13 dairy farms were tested using the single cervical tuberculin test (SCTT). Among those animals, about 15% of each herd, 220 in total, represented a high-risk group and were selected to be tested using the gamma-IFN test. Of the 1632 animals tested, 207 presented significant reactions representing 12.7% of the cattle studied. In the selected group the number of animals positive by the gamma-IFN assay was 126/220 (57.3%) and the total number of reactive cows on SCTT was 106/220 (48.2%). The real number of infected cattle, following standards, was 120/220 (54.5%). From these results the relative sensitivity rate of gamma-IFN test was 100% including the false-positive results and 88.3% for the SCTT--a significant (P < 0.01) difference in favour of the gamma-IFN test of 11.7%. The gamma-IFN assay also identified some positive animals 60-120 days earlier than the SCTT. In conclusion, we believe that the gamma-IFN assay can be used alone or in combination with the SCTT, as a valuable tool for the control of bovine tuberculosis in the Brazilian national herd.

Mycobacteremia in patients with the acquired immunodeficiency syndrome

BACKGROUND

Bacillemia is a key event in the pathogenesis of tuberculosis. Although current evidence indicates that Mycobacterium tuberculosis bacteremia is rare in patients seronegative for the human immunodeficiency virus, it has been increasingly reported in patients with the acquired immunodeficiency syndrome (AIDS).

OBJECTIVE

To determine clinical and laboratory characteristics of patients with AIDS and tuberculosis with and without bacillemia.

METHODS

Fifty patients with AIDS with clinical suspicion of disseminated mycobacterial disease were prospectively selected. Three consecutive blood samples were collected for culture using a standardized protocol.

RESULTS

Mycobacterium was isolated from any body site in 42 patients (84%). Bacillemia was detected in 30 (71.4%) of these 42 patients: 11 (28.2%) caused by Mycobacterium avium-intracellulare complex and 19 (71.8%) caused by M tuberculosis. Blood culture was the only method used to confirm the diagnosis in 5 (15%) of the 33 tuberculosis cases. Tuberculosis in patients with AIDS developed with nonspecific insidious symptoms, a remarkable elevated alkaline phosphatase level, and without the classic miliary radiological pattern. We could demonstrate 2 previously unrevealed clinical characteristics of bacteremic tuberculosis in patients with AIDS: a shift to the left in the white blood cell count and abdominal lymph node enlargement. In patients with tuberculosis, the in-hospital mortality rate was higher among patients with bacillemia, although the posttreatment survival rate was comparable.

CONCLUSIONS

Blood culture is a valuable tool to confirm the clinical diagnosis of disseminated tuberculosis in patients with AIDS and can distinguish patients with characteristic clinical findings and outcome. Abdominal ultrasonography may be an additional helpful tool to identify these patients.

Surgical site infection: rates, etiology and resistance patterns to antimicrobials among strains isolated at Rio de Janeiro University Hospital

A 6-month prospective surveillance was conducted in the Department of General Surgery of the Rio de Janeiro University Hospital. Postoperative infections were classified according to CDC criteria. This study reports a significant rate (16.9%) in surgical infections detected by surveillance in a series where 45% of surgical interventions were classified as clean. The majority (52.7%) was apparent only after patient discharge from the hospital. Bacterial cultures were obtained from 42 out of 55 infected wounds. Staphylococcus aureus was the most frequently found pathogen (33.9%), followed by Escherichia coli (20.3%). With the exception of S. aureus isolates, multiresistance was found in 66% of coagulase-negative staphylococci and 60% of gram-negative bacteria. This study showed that community surveillance associated with hospital surveillance is necessary in order to determine accurate rates of surgical site infections, and also showed that the emergence of multiresistant bacterial strains was common among isolates of surgical infections.

Incidence surveillance of wound infection in hernia surgery during hospitalization and after discharge in a university hospital

A six-month prospective incidence surveillance of wound infection was conducted in the department of general surgery of the Rio de Janeiro University Hospital. Postoperative infections were classified according to Centers for Disease Control criteria. This study reports a rate of 14.04% in surgical infections limited to herniorrhaphy and detected by surveillance. The majority (87.50%) of them were only apparent after hospital discharge. Fourteen out of 16 patients (88.60%) were not deemed to be at risk for surgical infections. Staphylococcus aureus was the most important pathogen associated with infection. This report shows that community surveillance is necessary to determine accurate rates of hospital-acquired infection and will help establish prevention and control policies in Brazil.

Association between an early humoral response to Mycobacterium tuberculosis antigens and later development of tuberculosis in human immunodeficiency virus-infected individuals

OBJECTIVE

To evaluate the association between an early humoral response to Mycobacterium tuberculosis antigens and the later development of tuberculosis (TB) disease in human immunodeficiency virus (HIV)-infected individuals.

METHODS

Using an ELISA test, IgG antibodies against 4 M. tuberculosis antigens--purified protein derivative (PPD); 2,3 diacyl trehalose (DAT); a lipooligosaccharide (LOS) and a trehalose dicarboxylic acid bis N,N-dioctadecylamide (BDA.TDA)--were measured in sera from 25 HIV-infected tuberculous patients and 52 HIV-infected persons without TB.

RESULTS

With the DAT and LOS antigens, a positive result in sera obtained in the 12 months preceding the onset of TB was significantly associated with later development of TB. Using the BDA.TDA antigen, the same association was observed in sera collected during the 6 months before the diagnosis of TB. No significant association was found with the PPD antigen.

CONCLUSIONS

These results suggest that specific antibody markers may be useful to evaluate the risk of active TB in HIV-infected individuals, and a helpful indicator for preventive treatment.

Follow-up of patent and subpatent parasitemias and development of muscular lesions in mice inoculated with very small numbers of Trypanosoma cruzi

A sequential analysis of patent and subpatent parasitemias, mortality, and histopathology during acute Chagas' disease experimentally produced by inoculation of 10 or 100 bloodstream forms of Trypanosoma cruzi Y strain in susceptible mice was carried out. Parasites were searched for comparatively using three different methods: direct counting, Ficoll-MI density flotation, and hemoculture. Ficoll-MI density flotation promptly discriminated with high reproducibility subpatent parasitemic states not detected in the blood samples analyzed by direct counting. Despite the high proportion of supposedly uninfected animals and depending on the postinfection time, the majority of the mice had bloodstream parasites at the subpatent level detected by Ficoll-MI, and all of them had muscular lesions during the acute phase. All Ficoll-MI-negative blood samples from infected mice were also negative by hemoculture. Normal mouse blood purposely contaminated with parasite quantities ranging from 200 to 2000/ml was tested comparatively by density flotation and hemoculture and showed frequencies of reisolation varying from 25 to 100%. Overall, these data showed that inoculum as low as 10 infective forms of Y strain is able to induce acute Chagas' disease in susceptible mice and that a subpatent parasitemic state of 600-1000 forms/ml is a common finding. The use of Ficoll-MI to detect subpatent parasitemia is discussed.

IgM immunoglobulins reacting with the phenolic glycolipid-1 antigen from Mycobacterium leprae in sera of leprosy patients and their contacts

For the first time in Brazil it was investigated the occurrence of IgM anti-PGL-1 in the sera of household contacts of leprosy patients using the ELISA methodology. The sera of the multibacillary patients showed significantly more immuno-reactivity than from the paucibacillary patients. It was observed a high subclinical infection incidence among household contacts (19.4%). The percentage of leprosy development was 5% (1/21) among the seropositive contact group. This finding suggests that serology could be useful as prognostic test, but for better definition is necessary to test a population from endemic area for long period time.

Absorption of Mycobacterium bovis BCG administered by the oral route

The action of gastric and duodenal juices on BCG as well as on its absorption and its distribution in the organs after intragastric administration in mice were studied. A significant decrease in BCG oxygen uptake and a moderate loss of viability were found after 2 h treatment with gastric juice. Using duodenal juice, a marked decrease of respiration and a notable fall in viability were observed. Labelling of BCG with carbon-14 was accomplished using [14C]glycerol as a precursor of mycobacterial lipids. Similar levels of radioactivity were recovered in organs of mice 24 h after intragastric administration of 14C-BCG, sonicated 14C-BCG and [14C]glycerol. The level of 14C-BCG remained stable from 6 to 24 days, while sonicated 14C-BCG and [14C]glycerol defined a biological decay process. Studies of biological decay from the small intestine and liver indicated that the absorptive process started rapidly and reached its highest level at 24 h, declining thereafter according to the complexity of the material given to mice. However, living bacilli were not cultured from organs of mice given single doses of unlabelled BCG. Therefore, judging from the above data it may be concluded that the majority of BCG bacilli absorbed intact were not alive.

Mechanisms of immunological eradication of a syngeneic guinea pig tumor: participation of a component(s) of recipient origin in the expression of systemic adoptive immunity

The effects of carrageenan and trypan blue on the expression of adoptive immunity to the syngeneic guinea pig line 10 hepatoma were investigated. Adoptive immunity was assessed by observing dermal tumor growth in recipients of immune cells and by bioassays in which tumor challenge sites were transplanted into secondary hosts. Carrageenan abrogated transferred immunity in treated animals as evidenced by dermal tumor growth and by development of fatal ascites tumors in peritoneal cavities of the secondary hosts. Trypan blue, on the other hand, did not abrogate transferred immunity in treated animals. However, the i.p. bioassay revealed the presence of line 10 cells in the tumor challenge sites 10 days after adoptive transfer. In vitro and in vivo exposure of immune spleen cells to carrageenan or trypan blue had no significant effect on the subsequent adoptive transfer, indicating that the inhibitory activity of these agents cannot be attributed to direct toxicity to immune lymphoid cells. Tumor challenge sites taken from carrageenan or trypan blue-treated animals 5 days after adoptive transfer failed to grow progressively when transplanted s.c. into secondary hosts. This observation suggests the presence of immune cells at tumor challenge sites. Thus, the inhibitory effects were unlikely due to interference with recirculation of the i.v.-transferred immune cells. Adoptive immunity was not influenced in guinea pigs that received a lethal dose of irradiation (500 rads). These results demonstrate that a recipient component(s) sensitive to carrageenan and trypan blue but resistant to radiation is essential to the expression of adoptive immunity.

Mechanisms of immunological eradication of a syngeneic guinea pig tumor. II. Effect of methotrexate treatment and T cell depletion of the recipient on adoptive immunity

The influence of methotrexate on the development of immunity to the line 10 hepatoma was studied in guinea pigs. Chronic methotrexate treatment had no apparent effect on the ability of immune guinea pigs to suppress the growth of inoculated tumor cells. In contrast, the same methotrexate regimen inhibited the development of tumor immunity if started before the 8th day after immunization with a vaccine containing viable line 10 cells admixed with Bacillus Calmette-Guérin (BCG) cell walls. Thus, methotrexate selectively inhibited the afferent limb of the immune response. In adoptive transfer experiments, methotrexate-treated recipient guinea pigs were capable of being passively sensitized with immune spleen cells, indicating that the primary cell-mediated immune response of the recipient was not required for adoptive immunity. The contribution of recipient T cells in adoptive immunity was further investigated in guinea pigs deleted of T cells by thymectomy, irradiation, and bone marrow reconstitution. Despite demonstrable deficiency in T lymphocyte reactions, "B" animals were fully capable of rejecting tumors after transfer of immune cells. These results suggest that the expression of adoptive immunity was independent of recipient T cell participation. In addition, sublethal irradiation of immune spleen cells prior to adoptive transfer abolished their efficacy. Proliferation of transferred immune cells in the recipient may be essential for expression of adoptive immunity.

Mechanisms of immunologic eradication of a syngeneic guinea pig tumor. I. Quantitative analysis of adoptive immunity

Adoptive immunity against a syngeneic hepatoma (line-10) of Sewall-Wright inbred strain 2 guinea pigs was analyzed by a two-dimensional titration of iv transferred immune lymphoid cells versus intradermal tumor challenges. Tumor resistance increased exponentially as a function of the number of immune lymphoid cells transferred. Within the tumor challenge doses analyzed, suppression of tumor growth mediated by the transferred immune lymphoid cells appeared to be independent of the primary immune response in the recipient. Quantitatively, rejection of a given number of tumor cells reflected the number of transferred immune cells and was independent of the presence of the same tumor at other skin sites. There was no evidence indicating that transferred immune cells were attracted specifically to the tumor inoculation site. The number of tumor cells that could be rejected at a skin site by adoptive immunity was greater than the estimated number of immune lymphoid cells present at the challenge site.