HLA class II molecules on monocytes regulate T cell proliferation through physical interaction in the CD3 activation pathway

HLA class II molecules are involved in the OKT3-induced T cell activation, since monoclonal antibodies (mAb) to monomorphic determinants of class II antigens are able to inhibit T cell proliferation. This effect involves several of the events leading to T cell activation and proliferation, i.e. interleukin (IL) 1, IL 6 and IL2 secretion and IL2 receptor expression. The main target of the inhibition is represented by monocytes, and the interference of anti-class II mAb in the direct interaction of monocytes with T cells is likely to play a relevant role in the inhibition mechanism. To test this hypothesis, we investigated in the present study the effect of anti-class II mAb on the proliferation of T cells stimulated with mAb OKT3 in the presence of paraformaldehyde-treated monocytes. We show that the inhibition of proliferation is specific and dose dependent, and seems to involve particular class II epitopes. Addition of fixed monocytes to inhibited T cell cultures restores proliferation to a moderate extent, only if monocytes are added within the first 12 h of culture, suggesting that class II antigens or spatially related molecules deliver signals concurrently with the mitogenic stimulus. The blocking capability of anti-class II mAb was not restricted to the CD4+ or the CD8+ T cell subsets, suggesting that, under inhibitory conditions, these mAb affect other structures on the T cell surface, relevant to the monocyte-T cell interaction.

Immunogenicity of anti-idiotypic antibodies and of their F(ab')2 fragments

Within the idiotype/anti-idiotype network, immunoglobulins act alternatively as reactive molecules and as antigens. To investigate the antigenic properties of immunoglobulins, we evaluated the immunogenicity in rabbits of three murine monoclonal anti-idiotypic antibodies and of their F(ab')2 fragments. These antibodies, bearing the internal image of a human melanoma antigen, may be useful in view of a human therapeutic application. The effect was evaluated as specific anti-anti-idiotypic response, related to the immunogenicity of the idiotypic epitopes in the combining sites of the immunoglobulins, and as total anti-murine immunoglobulin response, which represents the recognition of all the immunological determinants of the molecule. The results showed that the administration of the F(ab')2 fragments results in either higher or similar degrees of anti-anti-idiotypic immunization, compared to those induced by the whole immunoglobulins. Nevertheless, when anti-anti-idiotypic immunogenicity was increased, the anti-murine response did not increase proportionally. This suggests that the use for in vivo administration of F(ab')2 fragments is more convenient than the use of their original molecules, since this results, at least, in a similar or eventually in an increased specific immunogenicity, while the possibility of aspecific recognition is reduced.

Inhibition by anti-HLA class II monoclonal antibodies of monoclonal antibody OKT3-induced T cell proliferation. Studies at the mRNA level

mAb to monomorphic determinants of HLA class II Ag have been shown to inhibit monocyte-dependent OKT3-induced T cell proliferation, indicating that MHC class II molecules play a regulatory role also in Ag nonrestricted, CD3-induced T cell proliferation. This effect involves several steps in the process of T cell activation and proliferation, including IL-1 beta, IL-6, and IL-2 secretion and IL-2R alpha expression. In the present study, we analyzed the effect of an anti-HLA class II mAb (Q5/6) on the mRNA expression of genes related to monocyte and T cell activation. mRNA levels for early (early c-myc, c-fos) and late (late c-myc, N-ras, c-myb) genes involved in T cell activation were determined as well as mRNA levels for IL-1 beta, IL-6, IFN-gamma, IL-2, and IL-2R alpha. The kinetics of mRNA induction for ICAM-1 was also investigated. The results show that in T lymphocytes the expression of c-fos and early c-myc mRNA was unaffected by mAb Q5/6, whereas the c-myb and N-ras mRNA levels were strongly diminished as well as those of IL-2, IL-2R alpha, and IFN-gamma mRNA. An early increase of ICAM-1 mRNA was partially inhibited. In monocytes, a marked reduction of IL-1 beta and IL-6 mRNA was found. It is concluded that the HLA class II determinant involved in the inhibition mechanism can be engaged in the control of IL-1 beta and IL-6 mRNA levels and constitute an accessory signal up-regulating IL-2 and IL-2R alpha gene activation, through a pathway not affecting c-myc and c-fos expression.

Inhibition by anti-HLA class II monoclonal antibodies of monoclonal antibody OKT3-induced T cell proliferation. Studies at the mRNA level

mAb to monomorphic determinants of HLA class II Ag have been shown to inhibit monocyte-dependent OKT3-induced T cell proliferation, indicating that MHC class II molecules play a regulatory role also in Ag nonrestricted, CD3-induced T cell proliferation. This effect involves several steps in the process of T cell activation and proliferation, including IL-1 beta, IL-6, and IL-2 secretion and IL-2R alpha expression. In the present study, we analyzed the effect of an anti-HLA class II mAb (Q5/6) on the mRNA expression of genes related to monocyte and T cell activation. mRNA levels for early (early c-myc, c-fos) and late (late c-myc, N-ras, c-myb) genes involved in T cell activation were determined as well as mRNA levels for IL-1 beta, IL-6, IFN-gamma, IL-2, and IL-2R alpha. The kinetics of mRNA induction for ICAM-1 was also investigated. The results show that in T lymphocytes the expression of c-fos and early c-myc mRNA was unaffected by mAb Q5/6, whereas the c-myb and N-ras mRNA levels were strongly diminished as well as those of IL-2, IL-2R alpha, and IFN-gamma mRNA. An early increase of ICAM-1 mRNA was partially inhibited. In monocytes, a marked reduction of IL-1 beta and IL-6 mRNA was found. It is concluded that the HLA class II determinant involved in the inhibition mechanism can be engaged in the control of IL-1 beta and IL-6 mRNA levels and constitute an accessory signal up-regulating IL-2 and IL-2R alpha gene activation, through a pathway not affecting c-myc and c-fos expression.

Influence of subinhibitory concentrations of loracarbef (LY 163892) and daptomycin (LY 146032) on bacterial phagocytosis, killing and serum sensitivity

The aim of this study was to evaluate whether pre-exposure of bacteria to a subinhibitory concentration (sub-MIC) of loracarbef (LY 163892) or daptomycin (LY 146032) could modify bacterial susceptibility to serum bactericidal activity and to phagocytosis and killing by murine peritoneal macrophages and by human polymorphonuclear leucocytes. Escherichia coli, Haemophilus influenzae type b and Staphylococcus aureus grown in the presence of one quarter the MIC of loracarbef, and S. aureus exposed to one quarter the MIC of daptomycin were phagocytosed and killed in numbers significantly higher than non-exposed bacteria. Pre-exposure to loracarbef resulted in increased susceptibility of E. coli and H. influenzae type b to the bactericidal activity of antiserum, but exposure to loracarbef or daptomycin did not modify serum sensitivity of S. aureus. Loracarbef treatment and antiserum enhanced phagocytosis and killing of E. coli and H. influenzae type b to a greater extent than either antibiotic treatment or antiserum alone. These data indicate that loracarbef and daptomycin at sub-MIC enhance the susceptibility of bacterial pathogens to cellular and host defence mechanisms.

Monoclonal antibody OKT3-induced T cell proliferation: differential role of HLA class II determinants expressed by T cells and monocytes

Monoclonal antibodies (MAb) to monomorphic determinants of HLA Class II antigens inhibit monocyte-dependent T cell proliferation induced by MAb OKT3 to a different extent, suggesting a differential regulatory role of the corresponding determinants in T cell proliferation. To elucidate the mechanism(s) underlying this pattern, the MAb CR10-343 and Q5/6 with high inhibitory effect and MAb CR11-462 and CR12-356 with low inhibitory effect were characterized. Cross-inhibition studies showed that the four MAb recognize distinct determinants. The determinants recognized by MAb CR10-343 and CR12-462 are spatially close. The determinants recognized by the four MAb appear to be functionally independent in MAb OKT3-induced T cell proliferation, since the inhibitory effect of the combination of MAb CR10-343 and Q5/6 and of the MAb CR11-462 and CR12-356 was additional but not synergistic. To compare the functional activity of HLA Class II determinants expressed by monocytes and by activated T cells in MAb OKT3-induced T cell proliferation, the effect of the four MAb on MAb OKT3-induced T cell proliferation in a monocyte-dependent and in a monocyte-free system was studied. Dose-response and proliferation kinetics studies showed that the four MAb display a similar inhibitory effect on MAb OKT3-induced T cell proliferation in a monocyte-free system. These results suggest fine differences in the role played by monocyte- and T cell-bound HLA Class II determinants in the regulation of MAb OKT3-induced T cell proliferation. This functional heterogeneity may enhance the flexibility of HLA Class II antigens to mediate cell-cell interactions involved in the proliferative response to a variety of mitogenic stimuli.

Intracellular activity of cefamandole and aztreonam against phagocytosed Escherichia coli and Staphylococcus aureus

The intracellular activity of cefamandole and aztreonam against phagocytosed Escherichia coli and cefamandole against phagocytosed Staphylococcus aureus was studied using a sensitive and standardized method of murine peritoneal macrophages. Cefamandole and aztreonam exerted an intracellular antibacterial activity against E. coli which was greater than their extracellular one. With concentrations of both antibiotics up to 16 x MBC a dose-dependent decrease of the initial number of intracellular E. coli which ranged from 32% to 90% was observed. However, similar antibiotic concentrations above the MBC affected the viability of extracellular E. coli by only 20% to 30%. The intracellular antibacterial activity of both antibiotics against E. coli was further enhanced by immune serum. Cefamandole at 4 x the MBC did not affect the survival of intracellular S. aureus, but killed 41% of extracellular bacteria by 1 h and 99% after 3 h. The intracellular activity of both antibiotics against E. coli was also maintained in NaF-pulsed macrophages which have an impaired oxidative metabolism. The data suggest that both cefamandole and aztreonam possess an intracellular antibacterial activity against E. coli that seems at least in part due to a positive cooperation of antibiotics with the O2-independent microbicidal system of macrophages.

Structure of (+-)-6-methyl-6,12-methano-6H,12H,13H-[1]benzopyran[4,3-d] [1,3]benzodioxocin-13-one

A derivative of warfarin, racemic C19H14O4, Mr = 306.32, monoclinic, Cc, a = 9.594 (2), b = 20.437 (4), c = 7.793 (2) A, beta = 109.94 (3) degree, V = 1436.4 (11) A3, Z = 4, Dx = 1.416 g cm-3, lambda(CuK alpha) = 1.5418 A, mu = 7.742 cm-1, F(000) = 640, T = 293 K, final R = 0.053 for 1224 observations. The title molecule, formed by spontaneous dehydration of 2'-hydroxy-warfarin, is a cyclic ketal in which the side-chain phenyl is disposed pseudoaxially and is linked through a 2'-oxygen to the ketal carbon in a fixed cis 1,3-diaxial configuration. Two dihydropyran rings are formed; one fused with the benzopyran ring adopts an e,f-diplanar conformation, the other is a chroman and is in a similar conformation.

Kinetics of phagocytosis and killing of E. coli by murine macrophages in presence of different serum preparations

In this study we evaluated the kinetics of phagocytosis and killing of E. coli by thioglycollate-elicited murine peritoneal macrophages and the role of specific antibodies and complement present in different serum preparations in modulating these processes. In our system phagocytosis of E. coli by macrophage monolayer was exponential for 180 min. The killing activity was high in the first 30-60 min and then virtually ceased. The least phagocytosis and killing occurred in presence of heat-inactivated fetal calf serum (HFCS). These activities were 2-fold increased in presence of normal mouse serum (NMS) or heat-inactivated newborn calf serum (HNCS) and were highly stimulated in presence of immune mouse serum (IMS). IMS without complement was less efficient in enhancing phagocytosis and killing by macrophages. However when IMS or HNCS were deprived of specific antibodies their activity was remarkably reduced. When macrophages containing phagocytized bacteria were reincubated with different sera, multiplication of intracellular E. coli occurred with HFCS, NMS or antibody-deprived IMS or HNCS. In contrast, a significant decrease in the survival of intracellular bacteria was seen in presence of IMS, HNCS or complement-deprived IMS. The results indicated that specific bacterial antibodies play a major role in the phagocytic process and in the activation of killing mechanisms. However optimal macrophage activity resulted from the presence of both specific antibodies and complement.

Immunosuppressive therapy of HBsAg-positive chronic active hepatitis in childhood: a multicentric retrospective study on 139 patients

We analyzed retrospectively the effect of immunosuppressive therapy in 139 children with HBsAG-positive chronic active hepatitis (CAH) observed in four liver units in Italy from 1974 to 1982. All children had been observed for at least 12 months. Of these 139 patients, 38 were treated with steroids (prednisolone or prednisone from 1 to 2 mg/kg daily), 78 with combination therapy (prednisolone or prednisone 1 mg/kg daily in combination with azathioprine, 2 mg/kg daily) and 23 were not treated. The outcome of the disease was assessed by evaluating clinical, biochemical, and histological parameters on the basis of preselected criteria. Untreated patients deteriorated more frequently than those treated with steroids (34.8% versus 13.2%, p less than 0.05) or those receiving combination therapy (34.8% versus 10.3%, p less than 0.01). Remission or improvement was observed more frequently in steroid-treated and combination-treated patients than in the untreated ones (p less than 0.001 and p less than 0.01, respectively). At the end of the study, only one untreated patient had died of liver failure. Remission was observed in about 10% of patients in the two groups of treatment, but in the untreated one, this event never occurred. Although this study is retrospective and presents some shortcomings, the data clearly indicate that steroid and combination therapy are not deleterious, and are possibly helpful, to children with HBsAg-positive CAH.(ABSTRACT TRUNCATED AT 250 WORDS)

Prognostic significance of circulating immune complexes in a long-term follow-up of breast cancer patients

The purpose of the present study was to investigate the prognostic value of circulating immune complexes (CIC) in surgically treated breast cancer patients as compared with other well-known prognostic factors. CIC of IgG and IgM classes were determined by a C1q immunoenzymatic assay in serum samples of 122 patients before mastectomy and 51 of them were found positive for IgG. The other class of CIC was virtually absent. No relevant differences of distribution of other prognostic parameters such as estrogen and progesterone receptors, histological grading, nodal and menopausal status were found according to CIC levels. Level of IgG CIC was affected by surgical removal of the tumor since significant reduction of it was observed 2 weeks after mastectomy; however, this reduction did not show prognostic significance. The patients included in the present study were subjected to a 7-year follow-up; eventually a significant association was observed between preoperative IgG CIC and relapse of the disease. Patients with positive values of immune complexes relapsed more frequently than those with negative values. Serial determinations of IgG CIC were carried out within the 24 months following mastectomy and statistically evaluated for their prognostic use. No significant association was found between increase of IgG CIC level and relapse of the disease.

Inhibition by anti-HLA class II monoclonal antibodies of monocyte-dependent T cell proliferation induced by monoclonal antibody OKT3

The inhibitory effect of monoclonal antibodies (mAb) to monomorphic (locus-restricted and locus-shared) and polymorphic determinants of HLA class II antigens on the monocyte-dependent proliferation of T cells stimulated with mAb OKT3 has been studied. The effect appears to be specific, dose dependent, is not mediated by the Fc portion of mAb and reflects their interaction with the corresponding determinants. The anti-HLA class II mAb do not have to be present in the culture throughout the incubation period, but are essential in early phases of mAb OKT3 T cell activation. Both monocytes and T cells are the targets of the inhibition exerted by the anti-HLA class II mAb. Their inhibitory effect involves several steps in the sequence of events which leads to T cell proliferation, including interleukin (IL) 1 and 2 secretion, and IL2 receptor expression.

Presence of endotoxemia and its relationship to liver dysfunction in patients with typhoid fever

Twenty-one patients with typhoid fever were studied to evaluate the presence of endotoxin in peripheral blood and its relationship to the incidence and features of hepatic dysfunction which may occur during this disease. The limulus test for endotoxin was positive in the plasma samples of all patients prior to treatment. Liver dysfunction, as assessed by fasting and postprandial serum bile acid levels and by standard biochemical tests, occurred in 90% of patients. In seven, the injury was purely cholestatic (elevation of postprandial serum bile acid levels, alone); in 12, it was of mixed cholestatic-hepatocellular type (elevation of both serum bile acids and aminotransferase levels). After recovering, the limulus test was negative and liver function tests returned to normal values in all patients. The results demonstrate that endotoxemia is present in patients with typhoid fever. In addition, since endotoxin can impair bile secretion, our results suggest that endotoxin may have a pathogenetic role in the development of liver injury during typhoid fever.

Treatment of chronic active hepatitis with either prednisolone or corticotrophin: a controlled trial

A total of 54 patients hospitalized for chronic active hepatitis were randomly treated, 29 with prednisolone (maintenance dose 15 mg/day) and 25 with depot synthetic corticotrophin (maintenance dose 1 mg/week, i.m.) and were followed up for 6 to 24 months or longer. In this series, young males predominated, the incidence of serum HBsAg positivity approached 80% in both treatment and no patient had initial evidence of cirrhosis or had autoimmune associated diseases. With either drug SGOT levels showed a decrease during the initial 12 months of therapy (p less than 0.05); initial jaundice, when present, had disappeared by the 3rd month of treatment. With both treatments globulins and gamma-globulins decreased significantly after 12 to 24 months of therapy. Serum HBsAg persisted in all but two cases. Serum liver biopsies showed the following evolutions of histological activity: 12 cases (22%) improved to the "inactive phase" (8 with prednisolone and 4 with corticotrophin); 19 (35%) improved to a lesser extent (8 with prednisolone and 11 with corticotrophin); 17 (32%) remained unchanged (11 with prednisolone and 6 with corticotrophin); 6 (11%) worsened (2 with prednisolone and 4 with corticotrophin). Morphological features of cirrhosis appearently developed in 15 patients (8 treated with prednisolone and 7 with corticotrophin) of whom 7 achieved improvement of histological aggressiveness concurrently. Differences between treatments were not significant. Side effects suggesting drug discontinuation occurred only in 6 cases.

[Bronchiolitis. Our clinical experience in the 4 years from 1981 to 1984]

The clinical experience of 661 children with bronchiolitis is reported in four-years period to gain a better understanding of diagnosis and pathogenesis of bronchiolitis. Upper airways infections, expiratory dyspnea, clear sound by chest percussion, vesicular rales and whistling by chest auscultation, air trapping on the chest radiography were considered as essential data of diagnosis. It was found in 595 patients: expiratory dyspnea, air trapping, vesicular r. and whistling in 85% and whistling only in 15%; hypoxemia in 20% combined with hypercapnic acidosis in 10%; normoxemia in 80% combined with hypocapnia in 54%; hyperlactemia in 64% combined with an increment in the serum of CPK in 50% and of GPT in 30%; virus were cultured in 27%, adenovirus and RSV were identified in 90%. Instead it was found in 66 patients: air trapping but no difficult breath, with normal chest auscultation; crisis of cyanosis or paleness-cyanosis chilly sweat in 80% were motive of admission. The clinical and/or radiological features of "air trapping" were considered as essential symptoms and signs of bronchiolitis. The insufficient systemic perfusion was considered as a frequent occurrence and as cause for sudden respiratory and circulatory emergency.

Effect of beta-lactam antibiotics at subinhibitory concentrations on the phagocytosis of Staphylococcus aureus by the perfused rat liver

We evaluated whether the exposure of Staphylococcus aureus to a subinhibitory concentration of penicillin and cefamandole could modify its susceptibility to rat serum factors and to the phagocytic activity of the isolated and perfused rat liver. Control or sub-MIC treated bacteria were added to the circulating medium which contained homologous serum, and the disappearance of bacteria from the perfusate and their recovery in the liver was determined during the 10 min experimental time. Sub-MIC treated bacteria were more susceptible to the bactericidal activity of serum present in the perfusate. However, the clearance rate of bacteria by the liver was decreased for penicillin-treated organisms and unchanged for cefamandole-treated bacteria. The data suggest that beta-lactam antibiotics at sub-MIC levels may modify S. aureus susceptibility to host defense mechanisms.

HLA and prognostic factors in primary breast cancer

A group of 157 women with primary breast cancer (BC) were typed for HLA antigens, and gene frequencies were compared to those of 327 control healthy individuals. Diagnosis of BC was made for all patients on surgical mastectomy specimens; histologic grading, estrogen (ER) and progesterone (PgR) receptors were determined on all primary tumors. Typed antigens included the majority of the specificities controlled by the HLA-A, -B and -C loci, according to the 8th International Histocompatibility Testing Workshop recommendations. No significant discrepancy in their frequencies was found in the undivided sample as compared to controls. The analysis of HLA gene frequency was extended to subsets of patients identified by the following prognostic features: (a) age at tumor diagnosis (pre-menopause vs. post-menopause); (b) receptor status (presence vs. absence of ER and PgR); (c) mammary gland dysplasia (presence vs. absence); (d) histologic grade (grade 3 vs. grades 1 and 2 combined); (e) time to relapse before or after 24 months following mastectomy). A moderate deviation from normal of some genes was found in several subsets, often affecting only one of the antithetical subgroups (feature present vs. feature absent). In the instance of B5, the increase in frequency of the gene in one of the subset pair (ER + subjects) was balanced by a decrease of the same gene in the counterpart (ER-subjects). Increased frequencies were found for the B7 gene in the following prognostic groups: (a) lack of ER (0.08); (b) lack of PgR (0.09); (c) absence of mammary dysplasia (0.075); (d) histologic grade 3 (0.10); and (e) premenopause (0.12), the last two showing significant divergence from normal. When features (d) and (e) on the one hand and (a), (b), (d) and (e) on the other were combined, B7 reached frequencies of 0.18 (p less than 5 X 10(-4] and of 0.29 (p less than 5 X 10(-6], respectively.

Liver disease in hemophiliacs: etiological and biochemical data on 159 cases from our geographical area

A total of 159 hemophiliacs (149 treated) from our geographical area were screened in 1983 for serological evidence of HBV infection and biochemical evidence of liver disease. All were asymptomatic. HBsAg was detected in 16 cases (10%); anti-HBs and anti-HBc in 106 (67%); 19 (12%) subjects were susceptible to HBV. The HBV infection rate evaluated in 70 patients followed-up from 1980 to 1983 was 28% per year. The cumulative risk of HBV infection as well as the rate of seroconversion to HBV increased with increasing age and with increasing frequency of treatment given during the last 12 months. Anti-delta was detected in the serum of 5 (28%) out of 13 HBsAg-positive cases. Follow-up data showed that in 61% of subjects with liver dysfunction, hepatic damage could not be accounted for by HBV infection. AST and/or gamma-globulin increase was detected in 80% of patients. Abnormalities were more pronounced in HBsAg-positive cases and among them in subjects carrying anti-delta. Further follow-up studies are needed to clarify the long-term prognosis of liver disease in hemophiliacs.

["Minimal" viral pneumopathies and respiratory virosis in Campagna in 1978: pathology for research]

High frequency of bronchilitis, 70% of 1117 infants with respiratory infections, and clinical, radiological and laboratory features concerning partial tension of haematic gases, haematic lactate, enzymic activities of serum (CK, GPT, GOT) in 31 infants hospitalized with symptoms of shock in course of respiratory infections apparently affecting the upper respiratory tracts, are reported. This minimal respiratory pathology, evidenced in 3% of 1117 infants, defined as "minimal" viral pneumopathy, can be brought out trough a shock: lactacidosis, combined in half the cases with an increase of serum levels of CK and GPT and with normal PaO2 was ascertained in 87% of the cases. Three groups of bronchiolitis can be differentiated by haemogasanalytic monitoring: 1st group with a "serious" respiratory functional damage (hipercapnia hypoxemia), 14%. 2nd group with a "moderate" damage (normocapnia-hypoxemia), 20%. 3rd group with a "sligth" damage (hypocapnia-normoxemia), 66%. Decompensated shock is considered as a frequent occurrence and it is referred to the widespread involvement of the pulmonary circulation caused by the immunity-flogistic process.

[Bactericidal activity of the serum against Staphylococcus aureus grown in the presence of subinhibitory doses of cefamandole and gentamicin]

Growth of S. aureus in the presence of subinhibitory concentrations of cefamandole alone (at 1/5 the MIC) or with gentamicin (both at 1/5 the MIC) produced large, globular cells with reduced viability (50%) as compared to untreated bacteria. Gentamicin (1/5 the MIC) did not modify bacteria and also reduced viability of inoculum (57% vs. controls). Cefamandole treated bacteria were more susceptible to the rat serum bactericidal activity then control bacteria. The growth of S. aureus in the presence of cefamandole plus gentamicin did not modify further bacterial susceptibility to serum opsonins. The data suggest that even at subinhibitory concentrations cefamandole may exert an antibacterial effect by acting in cooperation with serum factors.

[Effect of amphotericin B on phagocytosis and intracellular killing of E. coli by rat liver perfused in vitro: preliminary results]

Using isolated and perfused rat livers we found an inhibitory effect on intracellular killing of hepatic macrophages versus E. coli, in presence of therapeutic levels of amphotericin B (5 micrograms/ml). Since an interference of this antibiotic with phagocytic functions of human neutrophils has also been reported, we suggest that amphotericin B may exert a toxic effect on intraphagocytic microbicidal function, possibly by an interaction with membrane sterols.

Immunosuppressive therapy in chronic active hepatitis (CAH). A multicentric retrospective study on 867 patients. A report from a study group for CAH of the Italian Association for the study of the liver

We retrospectively reviewed the clinical, biochemical and histological features of 867 patients with biopsy-proven CAH observed in 12 Italian Liver Units for at least one year. Either HBsAg positive or HBsAg negative patients (473 and 394 patients, respectively) were left untreated, or were treated with one of the following regimens: a) prednisolone or prednisone 10 to 30 mg daily, referred to as Steroids; b) azathioprine 50 to 100 mg daily; c) prednisolone or prednisone 10 to 20 mg daily associated with azathioprine 50 to 100 mg daily, referred to as Combination. The outcome was evaluated on the basis of clinical, biochemical and histological parameters. Among the 473 patients with HBsAg positive CAH those treated with combination, as compared to those untreated, more frequently, improved (P less than 0.001), and less frequently deteriorated (P less than 0.001). Under Steroids or Azathioprine improvement was more frequent than in untreated patients, but deterioration was not prevented. The results were similar among the 394 HBsAg negative patients. The data indicate that combination is effective in treating either HBsAg positive CAH or HBsAg negative CAH.

Increased phagocytosis and killing of Escherichia coli treated with subinhibitory concentrations of cefamandole and gentamicin in isolated rat livers

Our purpose was to study whether treatment of Escherichia coli with subinhibitory concentrations of either cefamandole or gentamicin could change bacterial susceptibility to the serum bactericidal effect and to the phagocytic and killing activity of the rat liver reticuloendothelial system. Bacteria were grown overnight with 1/5 or 1/10 of the MIC of each antibiotic. At one-fifth of the MIC, cefamandole induced filamentous elongated bacteria whose viability was decreased by 75%. The susceptibility of control and antibiotic-treated bacteria to serum was tested by measuring the survival of organisms exposed to different concentrations of rat serum in vitro. Susceptibility of bacteria to hepatic macrophage activity was tested by following the hepatic clearance of bacteria after they were added to the perfusate of the isolated rat liver. E. coli treated with subinhibitory concentrations of cefamandole or gentamicin appeared somewhat more resistant to the lytic activity of serum at a concentration of 4%, but not at 20%. Bacteria treated with 1/5 or 1/10 of the MIC of cefamandole or with 1/5 of the MIC of gentamicin were significantly more susceptible to phagocytosis and to the bactericidal activity of liver macrophages. Cefamandole appeared more potent than gentamicin in inducing these effects. The results suggest that subinhibitory levels of antibiotics may alter bacterial cell surface (cefamandole) or may impair the expression of antiphagocytic material (gentamicin), thus favoring phagocytosis and killing by macrophages. Our study provides evidence that antibiotics at subinhibitory concentrations may cooperate with host defence mechanisms against bacterial infections.

[Sensitivity of bacteria exposed to subinhibitory concentrations of antibiotics to the action of serum and liver phagocytes]

Incubation of E.coli and S. aureus with subinhibitory concentration (1/5 MIC) of cefamandole modified bacterial morphology and resistance to host defence mechanisms. In fact, cefamandole induced filamentous forms of E. coli, when added to the perfusing medium of the isolated rat liver system, were phagocytized at a much fortes rate then control bacteria, but appeared less sensitive to serum bactericidal activity. In contrast, S.aureus, after exposure to the antibiotic, was more sensitive to the bactericidal activity of serum then controls, while treated and untreated cells were phagocytized at the some rate. The data suggest that even at low doses some antibiotics may alter bacterial structure and increase their susceptibility to host factors.

Focused encephalography

Focused encephalography is a diagnostic procedure performed after computed tomography (CT) that can be specifically focused on diagnostic problems not solved by CT. The authors have used the procedure in 20 cases, and it has proved to be quick, risk-free, and without serious side effects. It provides useful supplementary diagnostic information, and can be especially helpful when CT is not available or when the CT scanner is an early-generation model.

Decreased phagocytic and bactericidal activity of the hepatic reticuloendothelial system during chronic ethanol treatment and its restoration by levamisole

The effect of chronic ethanol feeding (3 weeks) on the phagocytic and the bactericidal activity of hepatic RES versus viable Escherichia coli was studied using the isolated rat liver perfused with a serum-containing medium. Controls or ethanol-fed animals were used as liver or serum donors. The bactericidal activity of serum from ethanol-fed rats was similar to controls and accounted for the disappearance of nearly one-tenth of the bacterial inoculum from the system. When control livers were perfused with a medium containing serum from ethanol-fed animals, phagocytosis was comparable to controls while intracellular killing was greatly reduced. When livers were isolated from ethanol-fed rats, phagocytosis was significantly depressed and no killing occurred, irrespective of the source of serum. Levamisole was able to restore the macrophage activity depressed by ethanol. Our data indicate that the direct effect of ethanol on hepatic macrophages plays a major role in reducing the bactericidal activity of hepatic RES, although alterations of serum factors may contribute to an ineffective preparation of bacteria for intracellular killing.

Right brachial angiography with compression. Review of the literature

A technique for performing right brachial angiography by compressing the right anterior-inferior part of the neck is proposed, as a result of studying the left carotid circulation without puncturing the left carotid artery. A success was obtained in about 75% of cases. The success of the technique depends mainly on the anatomical nature of the innominate artery. When the technique is successful both left carotid arteries in the neck and their intracranial branches can be satisfactorily visualized. In some cases visualization of the left vertebral artery was also obtained. Attention is drawn also on the increased diagnostic possibilities of studying the vessels in the neck with a greater dilution of the contrast medium.

Endotoxemia in a series of 104 patients with chronic liver diseases: prevalence and significance

Endotoxemia, measured by Limulus amebocyte lysate (LAL) assay, was found to be present in 34 (46%) out of 72 patients with liver cirrhosis and in 7 (22%) out of 32 patients with chronic active hepatitis (CAH). In cirrhotics, no difference in the alteration of liver function tests and renal function was found between the two groups. However, 18 months mortality was higher in the group with endotoxemia in respect to the group without endotoxemia (p less than 0.05). In CAH patients, the Limulus-positive group showed a higher level of serum gamma-globulins, compared to the Limulus-negative group (p less than 0.005). Moreover, CAH patients with a positive LAL test showed marked histological activity and bridging necrosis more frequently than those with a negative test. This suggests that in these patients the appearance of endotoxemia may indicate a more advanced stage of the disease.

Treatment of chronic active hepatitis (CAH): a retrospective review of 130 patients

The authors review the course of disease in 130 patients (87 HBsAg-positive and 43 HBsAg-negative) with chronic active hepatitis (CAH) observed in the last six years. Patients were treated with prednisone (36 HBsAg-positive an 8 HBsAg-negative), azathioprine (7 HBsAg-positive and 12 HBsAg-negative) or a combination of prednisone and azathioprine (23 HBsAg-positive and 14 HBsAg-negative), or remained untreated (21 HBsAg-positive and 9 HBsAg-negative). Among HBsAg-positive patients improvement was observed in 54% of the 66 patients treated, and in none of the 21 untreated patients (P less than 0.001). Treatment did not modify the course of the disease in HBsAg-negative patients with CAH; this is probably related either to the small number of patients in each treatment group, or to geographical differences. Furthermore treatment was not effective in patients older than 40 years, whether HBsAg-positive or HBsAg-negative. Three out of 87 HBsAg-positive patients, and two out of the 43 HBsAg-negative patients had died by the end of the observation period irrespective of treatment. Full remission with clearance of HBsAg was observed only in one patient after 4 years of treatment with steroids.

[Transport of cytidinediphosphocholine in different biological models. II - Transport of (5 3H, Met 14C) cytidinediphosphocholine in isolated and perfused rat liver]

The uptake of double labeled CDP-choline by isolated and perfused rat liver has been investigated. The time course of CDP-choline uptake is different for 3H and 14C, showing the existence of the degradation process of the molecule. The identification and characterization of CDP-choline and its metabolites, in the perfusate and in the hepatic extract are performed by high pressure liquid chromatography.

[Effect of levamisole on changes in the of hepatic RES induced by chronic ethanol poisoning]

Hepatic RES is depressed in chronic alcholic intoxication and we have previously observed a significant reduction of killing of E.coli by the Kupffer cells of the isolated rat liver. In the present study rats treated with ethanol for 3 weeks, were given levamisole and then the clearance of E. coli, by the isolated liver, was followed. Levamisole 10mg/kg i.p. for 3 days, restored the depression of intracellular killing induced by ethanol. At the dosage of 2,5 mg/kg of levamisole this effect was not present. Changes of humoral factors were not involved in the phenomenon because sera from untreated anaimals were present in the perfusate for all sets of experiments.

HBsAg carriers among blood donors in Italy; a retrospective survey of data from 189 blood banks

Data of occasional or periodic blood donors from 189 banks scattered throughout Italy were retrospectively surveyed for the period between 1974 and 1977. The prevalence of HBsAg positive subjects (PHA or RIA) among occasional donors during 1975-1977 was about 3% with no appreciable annual variation. The rate of HBsAg positivity in southern Italy (i.e. Campania, 4.32%) was higher than in northern Italy (i.e. Trentino, 0.30%). Only 0.27% of the occasional donors showed both HBsAg positivity and elevated serum transaminases levels. Among periodic donors the rate of infection, as indicated by the appearance of HBsAg in serum subsequent to the last donation, was approximately 0.5% per year. Only one-tenth of the periodic donors who acquired HBsAg also had hypertransaminasemia.

[Hepatic clearance of Escherichia coli during chronic alcoholic intoxication]

The effects of chronic ethanolic intoxication on the phagocytic and bactericidal activity of the hepatic reticuloendothelial system against viable Escherichia coli were examined using be in vitro perfused at liver system. Livers were isolated from control and ethanol treated animals (3 week) and perfused with a red cell-free medium containing 4% homologous serum from control rats. After addition of E. coli (2 X 10(7) cell/ml) to the perfusing medium hepatic clearance of bacteria was measured by determining the recovery of viable cells in the perfusate, liver and bile after 30 min experimental time. Livers from ethanol treated animal showed a slightly lower phagocytic activity respect control animals, but were not able to kill phagocytized bacteria (20% intraphagocytic killing occurred in control livers). Our date suggest that the higher susceptibility toward infections with gram negative bacteria during chronic ethanol intoxication might be mediated by a impairment of functional activity of hepatic macrophages which may be independent of changes in serum opsonins.

Enhanced phagocytosis and bactericidal activity of hepatic reticuloendothelial system during endotoxin tolerance

The effects of tolerance to Escherichia coli endotoxin on the phagocytic and bactericidal activity of the hepatic reticuloendothelial system against viable E. coli were examined using ex vivo perfused rat livers. Livers were isolated from control and endotoxin-tolerant rats and perfused with a medium containing 5% homologous serum from either control or tolerant rats. After the addition of the E. coli (2 x 10(7) cells per ml) to the perfusate, the hepatic clearance of the bacteria was followed for 30 min. The highest activation of the hepatic reticuloendothelial system was observed when serum from tolerant animals was added to the perfusate. Under these conditions phagocytosis was 47% (12% in controls), and 37 to 38% of the bacteria were killed (5% in controls). This activation was less when livers obtained from tolerant rats were perfused with serum from controls or with saline only. The data suggests that, during endotoxin tolerance, humoral factors play an important role in the activation of the hepatic reticulendothelial system, although a direct stimulation of Kupffer cells also occurs. The enhancement of phagocytosis by tolerant serum did not require the presence of homologous antibodies and involved the activation of the alternative complement pathway, since it was lost after removal of factor B activity. On the other hand, stimulation of intracellular killing required both complement and specific antibodies. The data suggest a role of endotoxin in the activation of humoral and cellular mechanisms involved in the host resistance to gram-negative bacterial infection.

[Incidence of cryoglobulinemia in a series of cases of chronic liver diseases]

The prevalence of cryoglobulinaemia in a series of patients with chronic liver disease from the Campania area has been studied. The series included: 14 cases of chronic persistent hepatitis (CPH), 70 cases of chronic active hepatitis (CAH) and 113 cases of liver cirrhosis. Liver function tests were carried out on the serum of each patient and cryoglobulines were studied. Liver biopsy was carried out when indicated. About a third of the patients were under the effect of previous treatment with anti-inflammatory steroids and-or azathioprine. Cryoglobulines were found in 4 of the 197 patients (2%); of type IgG in 3 cases: 1 of CAH, HBsAg negative and 2 of inactive cirrhosis of which one with HbsAg in the serum; of type IgM in 1 case of CAH, HBsAg negative. The data are discussed on relation to other reported data.

[Incorporation of S-adenosylmethionine in the isolated and perfused rat liver. Preliminary study]

The uptake of labeled S-adenosylmethionine (SAM) by isolated and perfused rat liver has been compared to that of methionine: the rate of incorporation of the amino acid exceeds by about three times that of the sulfonium compound. S-Adenosylmethionine transport system shows saturation kinetics with an apparent Km of 59,5 microM and is energy-dependent, as demonstrated by the inhibition by 2,4-dinitrophenol.

Clearance of viable salmonella typhi Ty 2 and Staphylococcus aureus by the isolated rat liver in the absence of serum factors

The clearance of S. typhi Ty 2 and of a S. aureus strain by the isolated rat liver perfused in vitro with a synthetic serum free perfusate was studied. Bacteria were added to the perfusate at the initial concentration of 1x10(8) cells/ml. During perfusions the perfusate was sampled; after 30 min bile and liver samples were obtained and used for viable bacterial counts. After 30 min the amount of bacteria phagocytized greatly differed from one strain to the other: 30% for S. typhi Ty 2 and 100% for S. aureus. The end amount of viable bacteria recovered in the isolated liver was 7% for S. typhi Ty 2 and 80% for S. Aureus, thus indicating that for the latter strain greater clearance was not associated with an equally fast intracellular death.