Delayed hypersensitivity to cefazolin: report on a case involving lymphocyte transformation studies with different cephalosporins.

BACKGROUND: A cell-mediated immunopathogenic mechanism has been demonstrated in only a few cases of cutaneous reactions to systemically administered cephalosporins. OBJECTIVE: The aim was to investigate the pathogenic mechanism of a maculopapular rash experienced by a subject during cefazolin therapy. METHODS AND RESULTS: Prick, intradermal, and patch tests were carried out using penicillin determinants, ampicillin, amoxicillin, cefazolin, cephalothin, cefuroxime, ceftazidime, and ceftriaxone. Those tests for penicillin G and its determinants, as well as for ampicillin and amoxicillin, were negative. The patient displayed patch-test and delayed intradermal-test positivity to all the cephalosporins tested. No specific immunoglobulin E antibodies were found for penicillins or cefazolin. The lymphocyte-transformation-test results were negative for all the penicillins tested and showed a positive concentration-effect curve for cefazolin, ceftazidime, and ceftriaxone at concentrations up to 50 microg/mL. At 100 microg/mL the responses decreased with all the cephalosporins tested. Challenges with penicillin G and amoxicillin were well tolerated, but the challenge with cefazolin was positive. CONCLUSIONS: The data of this case demonstrate delayed hypersensitivity to cefazolin. Patch tests and delayed-reading intradermal tests can be a simple and effective means of diagnosing this type of reaction. Both in vivo and in vitro studies indicate that the responses were directed toward a determinant shared by all cephalosporins, but not by penicillins. The concentration of the cephalosporins used for the in vitro lymphocyte stimulation was critical, because at the concentrations normally used to test other beta-lactams the response decreased. This phenomenon may be attributable to an immunosuppressive, rather than toxic, effect.

Absence of regular alpha2(I) collagen chains in colon carcinoma biopsy fragments.

The extracellular matrix (ECM) is known to play an active role in numerous biological processes such as differentiation, apoptosis and cancer. Extensive alterations of epithelial basement membranes and of interstitial ECM are known to occur during the progression of most invasive carcinomas. Collagen, which represents the major component of the interstitial ECM, is primarily involved in the stromal changes at the site of tumor cell invasion. We have previously described the occurrence in breast and colon cancer ECM of an oncofetal form of collagen, characterized by an acidic chain distinct from those of type I and III collagen. In the present paper, we bring evidence that alpha2(I) collagen chains in colon cancer tissues expressing the acidic chains, are either overmodified or absent, both as protein and as regular mRNA transcripts. The results obtained strongly suggest that: i) the disorganisation of the collagen architecture and the phenomenon of fibril dispersion, which accompanies the lysis of basement membrane, is not only due to the enzymatic degradation of the collagen fibres, but presumably also to changes of the collagen molecules deposited in the stroma; ii) the neosynthesis of collagen occurring at tumor-host interface is deeply deregulated, and therefore to be considered the result of altered collagen gene expression correlated with the tumor progression, rather than as a mere defensive reaction of the host cells.

Two aromatic residues regulate the response of the human oxytocin receptor to the partial agonist arginine vasopressin.

We investigated the mechanisms that regulate the efficacy of agonists in the arginine-vasopressin (AVP)/oxytocin (OT) receptor system. In this paper, we present evidence that AVP, a full agonist of the vasopressin receptors, acts as a partial agonist on the oxytocin receptor. We also found that AVP becomes a full agonist when two aromatic residues of the oxytocin receptor are replaced by the residues present at equivalent positions in the vasopressin receptor subtypes. Our results indicate that these two residues modulate the response of the oxytocin receptor to the partial agonist AVP.

Cell-cell and cell-collagen interactions influence gelatinase production by human breast-carcinoma cell line 8701-BC.

We previously produced evidence that the human mammary-carcinoma cell line 8701-BC expresses several metalloproteinases (MMP-1, -2, -9, and -10) and their tissue inhibitors). In order to obtain a better understanding of the environmental control over gelatinolytic activities, we have tested the enzyme production of 8701-BC cells, at time intervals after plating on different collagen substrates, i.e., types I, III, IV, V and OF/LB, used as films in culture dishes. Proteinase activities, released in the conditioned culture media, were tested by zymography on SDS-PAGE, and by quantificative analyses, using 14C carboxymethylated transferrin as substrate in a liquid incubation medium. Enzymatic activities varied with time and were inversely related to cell densities, with minimum values at cell confluence. The enzymatic activity was positively supported by collagen substrates, with a maximal increase in activity when OF/LB collagen was used. In addition to the known MMPs, we found a proteinase with an M(r) of about 20 kDa, which displayed higher activity at 48 hr after cell plating and gradually decreased with cell increment. In contrast to the other MMPs, this proteinase is inhibited by soybean trypsin inhibitor, but it does not display a complete identity with trypsin, since it does not digest casein and is not inhibited by other serine proteinase inhibitors.

Onco-fetal/laminin-binding collagen from colon carcinoma: detection of new sequences.

We have recently identified an oncofetal-laminin binding collagen (OF/LB) composed of three alpha chains, with the apparent molecular mass of about 100 kDa each, but bearing different pI. One of the chains appears markedly acidic in a bidimensional electrophoretic system, where the NEPHGE is used as first dimension separating gel, while the two more basic chains have similar migration as alpha 1(III) and alpha 1(I) collagen chains, respectively. Sequence analyses have been performed on CNBr-peptides, derived from pepsinized triple helical molecules and on tryptic fragments obtained after in gel digestion of the acidic band. The research of sequence homology with computerized databases indicated that the acidic chain represents a gene product distinct from either type I, type III and other known collagen chains, while the identity of the other two chains remains to be fully determined.

Substâncias hepatotóxicas em pingas nacionais / Hepatotoxic substances in national brandy

O objetivo do trabalho foi observar se há em pingas nacionais substâncias tóxicas, além do etanol, em níveis considerados de risco para dano, principalmente hepático. Foram determinadas em amostras de 8 pingas as concentraçöes de ferro, cobre, zinco (método por absorçäo atômica) e etanol, acetaldeído, n-propanol, acetato de etila, isobutanol e álcool isoamílico (método cromatografia em fase gasosa e espectrometria de massas). Os níveis de ferro estavam acima dos limites permissíveis em duas pingas, amostras números 1 e 8 (respectivamente 0,57mg/L e 0,38mg/L). Esses níveis podem ser considerados prejudiciais se essas bebidas forem consumidas em quantidades elevadas durante longos períodos e, especialmente, se houver, como alguns autores admitem, efeito sinérgico entre etanol e ferro. Os resultados obtidos justificam prosseguir esse estudo preliminar

[Hepatotoxic substances in Brazilian rum]. / Substâncias hepatotóxicas em pingas nacionais.

The purpose of this study was to investigate whether Brazilian "pingas" (liquor distilled from sugar cane) contain toxic agents other than ethanol at levels which might risk consumers health, especially regarding liver damage. We have studied 8 different "pingas" in which the levels of iron, copper and zinc were measured through an atomic absorption method, and the levels of ethanol, acetaldehyde, n-propanol, ethyl acetate, isobutane, and isoamylic alcohol were measured through gas chromatography and mass spectrometry. Iron levels were higher than those allowed in two liquors, samples 1 and 8 (respectively 0.57 mg/L and 0.38 mg/L). Such levels may be considered deleterious to health if these liquors are consumed in great amounts and during large periods, especially if a synergistic interaction between alcohol and iron exists, as accepted by some authors. Our findings warrant that further studies be performed.

A new form of tumor and fetal collagen that binds laminin.

Human breast and colon carcinoma tissues contain a form of collagen, not described before, composed of alpha 1 chains of similar size (approximately 100 kDa) but different charge. The three constitutive chains, separated by two-dimensional electrophoresis, are a unique acidic component, undetectable in other collagen types, with an apparent isoelectric point of 4-5, and two more basic components displaying the same electrophoretic behavior as alpha 1(III) and alpha 1(I), respectively. The acidic chain is structurally distinct from alpha 1(I) and displays a cyanogen bromide-derived fragment of similar size to CB5(III). This collagen in its native state is resistant to trypsin and metalloproteinase 3, while it is fully degraded by metalloproteinases 1 and 9. Moreover, this collagen appears able to bind to laminin, as tested by affinity chromatography. The biological significance of our data is related to the finding of this collagen form not only in the tumor tissue tested but also in embryonic-fetal tissues (bovine skin and intestine and human umbilical cord). For its peculiar laminin-binding ability and occurrence in tumoral and embryonic-fetal tissues, we propose to temporarily term this new collagen form OF/LB collagen (onco-fetal, laminin-binding collagen). The presence of OF/LB collagen during development and cancer, and its absence in normal adult tissues, make this protein a potential stromal marker of malignancy.

Iron, copper and alpha 1-antitrypsin deficiency in the liver of cirrhotic and schistosomotic patients.

While a number of studies investigated iron and copper storage or alpha 1-antitrypsin (A1AT) deficiency in the liver of patients with cirrhosis, we did not find any similar study in schistosomotic patients reported in literature. We investigated the storage of both metals and the A1AT deficiency in the liver of 72 cirrhotic and 27 schistosomotic patients (5 with the hepatointestinal and 22 with the hepatoesplenic form of the disease). Forty-four patients with cirrhosis were also alcoholic, and 28 were not. Iron storage was detected in 23 patients with cirrhosis (31.9%); among these 16 (36.3%) were alcoholic and 7 (25.0%) non-alcoholic (the difference was not statistically significant). Thirteen (56.5%), 5 (21.7%) and 5 (21.7%) patients presented I-grade, II-grade, and III-grade iron storage, respectively. Copperstorage was detected in 24 cirrhotic patients (33.3%), 15 being alcoholic (34.0%) in contrast with 9 non-alcoholic patients (32.1%), a statistically non-significant difference. A1AT deficiency was observed in 2 patients with cirrhosis (2.8%), one with history of alcoholism. HBsAg and HBcAg in hepatic tissue were detected in 5 cirrhotic patients (6.9%), three of them with a history of alcoholism. Iron and copper storage and A1AT deficiency were observed in 3 patients with cirrhosis (12.5%), while iron storage and A1AT deficiency were found in 2 additional patients with cirrhosis (2.8%). The authors underline that neither iron nor copper storage nor A1AT deficiency was found in any schistosomotic patient. The authors discuss the possible importance of these data.

Microbiological study of HIV-related periodontitis.

The subgingival microbiota in 14 persons with HIV-periodontitis was examined. Subgingival plaque samples were collected with paper points, transported in VMGA III, and plated on anaerobic enriched brucella blood agar and various selective media. HIV-periodontitis sites revealed Actinobacillus actinomycetemcomitans, Wolinella recta, Peptostreptococcus micros, and Bacteroides intermedius, each averaging 7% to 16% of the cultivable subgingival flora in positive patients. High levels of spirochetes also were detected in diseased sites with phase-contrast microscopy. Low levels of Candida albicans or enteric Gram-negative rods were recovered in the subgingival flora in 7 HIV-periodontitis patients or Bacteroides fragilis, Fusobacterium necrophorum, Fusobacterium varium, and Eubacterium aerofaciens were recovered in 8 patients. These findings suggest that the major components of the subgingival microbial flora in HIV-periodontitis are similar to those associated with adult periodontitis in systemically healthy persons. However, HIV-periodontitis lesions also may contain organisms which are rarely found in common types of periodontitis. The etiological significance of specific periodontal organisms in HIV-periodontitis awaits further longitudinal study.