Continuous versus intermittent administration of ceftazidime in experimental Klebsiella pneumoniae pneumonia in normal and leukopenic rats

Experimental Klebsiella pneumoniae pneumonia was used to study the influence of cyclophosphamide-induced leukopenia on the relative therapeutic efficacy of continuous and intermittent (6-h intervals) administration of ceftazidime. The antimicrobial response was evaluated with respect to the calculated daily dose that protected 50% of the animals from death (PD50) until 16 days after the termination of a 4-day treatment. When ceftazidime was administered intermittently to leukopenic rats, the PD50 was 24.37 mg/kg per day, 70 times (P less than 0.001) the PD50 of 0.35 mg/kg per day for normal rats. Continuous administration of ceftazidime to leukopenic rats resulted in a PD50 of 1.52 mg/kg per day, four times (P less than 0.001) the PD50 of 0.36 mg/kg per day for normal rats. Continuous administration of ceftazidime in daily doses that protected 100% of normal and leukopenic rats from death resulted in serum levels of 0.06 and 0.38 micrograms/ml, respectively, whereas the MIC for the infecting K. pneumoniae strain was 0.2 micrograms of ceftazidime per ml. The effect of the duration of ceftazidime treatment by continuous infusion on the therapeutic efficacy in relation to the persistence of leukopenia was then investigated in leukopenic rats. The administration of 3.75 mg of ceftazidime/kg per day for 4 days protected all leukopenic rats from death, provided the circulating leukocytes returned at the end of antibiotic treatment. When leukopenia persisted for 8 days this ceftazidime treatment schedule resulted in the mortality of rats (P less than 0.05). However, when ceftazidime treatment was continued for 8 days, until the return of the leukocytes, there was no significant mortality (P greater than 0.05).

[Infections caused by coagulase-negative Staphylococci in immunocompromised patients]

Coagulase-negative staphylococci are important members of the normal aerobic microflora of human skin and mucous membranes. Normally they are not pathogenic for men. But the increase in patients with implanted plastic foreign bodies or intravascular catheters had led to a dramatic change. In these patients, coagulase-negative staphylococci are the predominant organisms causing septicemia. Special pathomechanisms are involved in the colonization of polymers by staphylococci leading to a "plastic infection". Intravascular catheters are also important factors in the origin of septicemia in premature neonates and in patients with malignant diseases, especially under cytostatic therapy. Premature or suppressed opsonophagocytosis mechanisms are responsible for the origin and maintainance of septicemia.

Acute myelomonocytic leukemia: an unusual variant with both granulocytic and monocytic esterases in the leukemic cells

By using the combination of alpha-naphthyl butyrate esterase and chloroacetate esterase for cytochemical detection of monocytes and granulocytes, respectively, we examined and identified five adult patients with acute myeloid leukemia whose leukemic cells often (20 to 30%) had the characteristics of both monocytes and granulocytes. All five patients were men, 23 to 82 years of age. Two patients had manifestations of preleukemia. One of these two patients had received treatment for lymphoma for 12 months before acute myelomonocytic leukemia was diagnosed. One patient had gum hypertrophy, and two had leukemia cutis. At the time of initial examination, four patients had blood leukocyte counts higher than 80,000/mm3 and one had leukopenia. Four patients received chemotherapy; three responded temporarily but died within 1 year after the myelomonocytic leukemia had been diagnosed. The patient with leukopenia has remained in complete remission for 2 years. With more frequent use of double esterase stains for classification of acute myeloid leukemias, this variant of acute myelomonocytic leukemia should be detected more often and its clinical behavior should be better understood.

Corynebacterium JK: a cause of nosocomial device-related infection

Ten cases of serious infection due to antibiotic-resistant Corynebacterium JK are reported. Five infections occurred in patients with hematologic malignancy and granulocytopenia, an association previously reported. Five additional nosocomial infections occurred in patients without underlying disease previously reported to be associated with JK. Nine of the 10 infections were nosocomial in origin and were associated with plastic devices that had been inserted into the patients. JK organisms were isolated from a variety of sources from an additional 40 uninfected patients. Although the majority of clinical isolates of Corynebacterium JK were contaminants, our experience suggests that as many as 20% of isolations are associated with serious nosocomial infections. Isolation of Corynebacterium JK--particularly in blood cultures--from patients with indwelling catheters or other devices is highly suggestive of the presence of a serious nosocomial infection.

Biocompatibility of haemodialysis membranes

Haemodialysis is widely used as a method of treatment for renal failure; it relies on diffusion across a semipermeable membrane. The exposure of blood to the membrane is associated with a rapid transient fall in white cells, activation of the complement system and a fall in arterial oxygenation. The interrelationship between these phenomena, their dependence on the type of membrane used and their clinical implications are reviewed and discussed.

Immunohistological study of histiocytic necrotizing lymphadenitis

Immunohistological study of 18 cases of histiocytic necrotizing lymphadenitis (HNL) demonstrated numerous helper/inducer cells (OKT-4) and suppressor/cytotoxic cells (OKT-8) with activation (Tac) and proliferation (OKT-9) markers, and histiocytes (lysozyme, alpha-1 anti-chymotrypsin, OK-M1) in the affected areas. However, B cells (B-1), NK cells (Leu-7 and Leu-11), complement proteins and receptor (C4 and C3d receptor), and neutrophils (chloroacetate esterase) were scanty or absent in these foci. Activity of NK cells was also decreased in the peripheral blood of 2 cases examined. The results suggest that HNL might be induced by the abnormal T cell-histiocyte response against some causative agents which induce a similar reaction of delayed hypersensitivity type.

Gastrointestinal colonization and septicaemia with Pseudomonas aeruginosa due to contaminated thymol mouthwash in immunocompromised patients

An outbreak of septicaemia with Pseudomonas aeruginosa amongst adult men with haematological malignancy involved eight patients on the same ward during a period of 5 weeks. The strains isolated from blood cultures from seven patients were indistinguishable by conventional typing methods. Thymol mouthwash which had been made up and distributed in communal jugs was found to be contaminated with the epidemic strain and was the likely source for this outbreak. A high rate of gastrointestinal colonization with the epidemic strain was found in the patients receiving the contaminated mouthwash. Only those patients with prolonged severe leucopenia developed septicaemia. Communal medications are an unnecessary hazard, particularly in oncology wards.

The surgical management of fungal pulmonary infections in children with acute myelogenous leukemia

Infections are the primary cause of complications and death in patients with acute myelogenous leukemia. Current aggressive treatment protocols have improved patient survival but produce extended periods of profound neutropenia during which the patients are particularly susceptible to opportunistic infections. Candida and Aspergillus species are the most common of the fungi causing invasive infections in these patients. In a group of 77 previously untreated children with acute myelogenous leukemia begun on treatment from March 1976 to June 1984, four patients developed localized fungal infections of the lung. These initially appeared as pulmonary infiltrates on chest roentgenograms during periods of severe neutropenia (three during remission induction and one after intensive consolidation therapy). Endobronchial cultures failed to identify the infectious organism in all cases. Computerized axial tomography best defined the cavitary nature of the lesions in 2 patients. All four patients underwent surgical resection, both to establish a diagnosis (three patients) and as part of therapy. There was no operative morbidity. The organisms involved were Aspergillus (2), Torulopsis (1), and Penicillium (1). Three patients were cured of their fungal infections. The fourth patient failed to enter remission and died of a cerebral fungal abscess that developed shortly after thoracotomy. We report these cases to encourage early surgical intervention in leukemics with a localized pulmonary process consistent with a fungal infection. Resection of the primary focus obviates the risk of life threatening pulmonary hemorrhage or dissemination of the fungus and allows for early reinstitution of chemotherapy which is vital to these patients' survival.

Alcoholism, leukopenia, and pneumococcal sepsis

Pneumococcal bacteremia is associated with a high morbidity and mortality, especially when leukopenia is present. To define further the possible factors associated with death in pneumococcal bacteremia, we reviewed all cases at 2 hospitals over a 1-yr period. Overall, increased mortality was associated with women (p = 0.009), nosocomial acquisition of the disease (p = 0.001), the presence of leukopenia (p = 0.00002) or thrombocytopenia (p = 0.025), shock (p = 4 X 10(-8)), and adult respiratory distress syndrome (p = 2 X 10(-7)). Leukopenic and nonleukopenic patients were compared further to ascertain factors that may predispose to leukopenia. Alcoholism was the only associated condition correlating with the presence of leukopenia (p = 0.036), and alcoholism and leukopenia occurred in a group of younger men. We conclude that the association of alcoholism, leukopenia, and pneumococcal sepsis is a distinct clinical entity seen in younger patients and is associated with a very high mortality.

[Septicemia in leukemia and malignant lymphoma. Incidence pathogens--causes]

Septicemia occurred in 81 (= 23.9%) of 339 patients with leukemias an malignant lymphomas during 1979-1984/VI. In leukemias the acute forms and in malignant lymphomas the high malignant forms were mostly affected. The frequency of gramnegative bacterias (46 = 56.8%) was higher than that of gram-positive bacterias (32 = 39.5%) and of fungus (3 = 3.7%). The frequency of septicemia in leukemias (alone) between 1966-1977 was 13.9%, between 1979-1984/VI 30%. In this comparison septicemias caused by gram-negative bacterias and fungus decreased, whereas gram-positive septicemias increased. The focus of septicemia remained unknown in 30 cases, Pneumonias and the urinary tract were the most common source, followed by the skin. All patients were under cytostatics and therefore leukopenic, most of them received corticosteroids simultaneously and were thus immunosuppressed. A combination of granulocytopenia less than 1,000 mm3 with hypogammaglobulinemia less than 10 rel.% were mostly found in acute leukemias and in chronic lymphatic leukemia. 41.5% of febrile episodes from all groups of these diseases were of non-microbic origin (local or septic) an thus possibly symptom of activity of the underlying disease.

Pro-inflammatory flavonoids which are inhibitors of prostaglandin biosynthesis

Catechin dimers induce a large long-lasting oedema when injected in the paw of the rat. This oedema is not inhibited by methysergide, promethazine, indomethacin, phenidone, bromophenacyl bromide and colchicine. It is not modified in rats made leukopenic by methotrexate. It is slightly delayed in Brown Norway rats which were kallikrein-kininogen deficient. Similarly catechin dimers induce the formation of a large peritoneal exudate in the rat. The exudate contains insignificant levels of leucocytes and 5-hydroxytryptamine. It contains kinins but its PG content is very low. The exudate does not activate (14C)-arachidonic acid into PG. Catechin dimers induce kinin formation in rat plasma "in vitro". They inhibit the formation of PG and HETE-like compounds from (14C)-arachidonic acid by rat peritoneal cells "in vitro". Catechin dimers administered at sub-irritant doses reduced carrageenan-induced oedema. Catechin dimers at low doses have an anti-inflammatory effect which may depend on PG synthesis inhibition. At larger doses, they induce inflammatory responses which occur with almost complete lack of participation of PG.

Role of granulocytes and monocytes in the prevention and therapy of experimental Staphylococcus epidermidis endocarditis in rabbits

Rabbits with endocarditis caused by Staphylococcus epidermidis were studied to determine the parts played by granulocytes and monocytes in the prevention or outcome of therapy with cloxacillin. Both monocytes and granulocytes influenced prophylaxis with cloxacillin. The amount of cloxacillin needed to prevent infection in 50% of the rabbits was significantly less in control rabbits than in those selectively depleted of monocytes, as it was also in rabbits selectively depleted of monocytes compared with those that had both granulocytopenia and monocytopenia. Granulocytes strongly potentiated the effect of cloxacillin during prophylaxis, whereas the contribution of monocytes was merely additive. Monocytes also contributed to the effect of therapy with cloxacillin, partially via a cloxacillin-independent mechanism and partially by potentiation of the effect of cloxacillin. Granulocytes did not appear to affect cloxacillin therapy. Results of this study suggest that currently used regimens for prophylaxis and treatment of S. epidermidis endocarditis may need to be adjusted for neutropenic patients.

Prophylaxis of Pseudomonas aeruginosa infections in leukopenic mice by a combination of active and passive immunization

Mice rendered leukopenic with cyclophosphamide and then challenged with viable Pseudomonas aeruginosa were used to determine the protective efficacy of active immunization against exotoxin A and of passive immunization with human antiserum to Escherichia coli J5, a rough mutant of Escherichia coli O111:B4. Neither treatment alone provided a greater degree of protection than its respective control. However, the combination of these treatments produced a moderate, yet consistent, increase in the survival of infected immunosuppressed mice.

Use of discriminative models of Pseudomonas aeruginosa bacteremia in granulocytopenic rats for testing antimicrobial efficacy

The efficacy of single agent and combination antibiotic therapy was evaluated in rats with severe granulocytopenia and Pseudomonas aeruginosa infection using animal survival, rates of bacteremia and the emergence of resistant organisms as criteria. In this model end points following single agent therapy with imipenem/cilastatin and the synergistic combination of moxalactam plus amikacin were comparable. At a high bacterial challenge dose, equivalent results were obtained using single agent therapy with either piperacillin or ticarcillin. Results were also similar following therapy with piperacillin or ticarcillin in synergistic combination with amikacin. At a lower bacterial challenge dose, aminoglycoside therapy was superior to therapy with the beta-lactams. Therapy with the in vitro synergistic double beta-lactam combination of ceftazidime plus piperacillin was no more effective than therapy with the individual compounds. Results from these studies in this discriminative animal model have in part been used to formulate prospective clinical antibiotic studies in granulocytopenic cancer patients.

Delayed phase of hematoporphyrin-induced phototoxicity: modulation by complement, leukocytes, and antihistamines

We have investigated the role of complement, leukocytes, and histamine in the delayed phase of hematoporphyrin-induced phototoxicity in guinea pigs. The phototoxic response was quantified by the accumulation of intravenously injected [125I]bovine serum albumin in the skin. There was a greater than 6-fold increase in the vascular response at the completion of irradiation, which subsided partially to reach a plateau of twice the preirradiation level between 0.5 h and 12 h. At 18 h, the vascular responsiveness returned to the baseline value. The 7 h timepoint was selected in this study to evaluate the modulation of the delayed phase. In complement-depleted guinea pigs, as well as in leukopenic animals, the enhancement in the vascular response was significantly suppressed (p vs control, less than 0.0001 and 0.0022, respectively). Cimetidine, when administered prior to irradiation, significantly suppressed the phototoxic response (p vs control, 0.0365). The combination of diphenhydramine and cimetidine, administered 6 h after the induction of phototoxicity, also suppressed the vascular response (p vs control, less than 0.0001). These data indicate that the expression of the delayed phase of hematoporphyrin-induced phototoxicity, similar to the early phase, requires the presence of an intact complement system, leukocytes, and histamine.

Multiple drug-resistant Corynebacteriaceae: in vitro and in vivo (murine) studies

Five multiple-drug-resistant (MDR) Corynebacterium isolates, which differed in several biochemical traits, were sensitive to rifampin, vancomycin and ciprofloxacin; ciprofloxacin was more active than enoxacin and norfloxacin. The MDR Corynebacterium isolates uniformly were resistant against fresh human serum, but varied in susceptibility to fresh, defibrinated human blood. In combined blood plus antimicrobial drug assays, vancomycin was more active than rifampin, which in turn was more active than ciprofloxacin. Outbred NMRI mice essentially were resistant against the MDR Corynebacterium isolates, as were mice pretreated with cyclophosphamide (leukopenia), type II Carrageenan (blockade of macrophages), or zymosan (depletion of complement), or with the combination of cyclophosphamide plus zymosan. However, mice pretreated with cyclophosphamide plus type II Carrageenan proved somewhat more susceptible.

Epidermodysplasia verruciformis associated with Bowen's carcinoma, B lymphocytopenia and decreased immune functions

A case of epidermodysplasia verruciformis associated with Bowen's carcinoma, persistent B lymphocytopenia and decreased immune functions is reported. Human papilloma virus 5 (HPV-5) DNA was shown to be associated with the DNA from the tumor tissue by Southern blot hybridization using P-labeled HPV DNA sequences cloned on plasmid vectors. The associated Bowen's carcinoma in our case may be caused by multiple-factor relationships which include (a) an oncogenic potential of infected virus; (b) an inherited abnormality in immune function, and (c) the decreased immune function resulting from the viral infection itself. A marked B lymphocytopenia appears to be associated with persistent viral infection.

Pulmonary leukostasis in fatal human pneumococcal bacteremia without pneumonia

An asplenic man developed fulminant pneumococcal bacteremia without pneumonia. He died of irreversible shock within 24 h. Autopsy revealed extensive pulmonary vascular leukostasis. This condition has been described in laboratory animals after intravascular challenge with endotoxin, gram-negative bacilli, and gram-positive organisms including pneumococci. This case illustrates that death in pneumococcal disease can occur in the absence of pneumonia and may be attributable to cardiovascular collapse. We present a proposed mechanism based on activation of complement and release of vasoactive mediators.

Fungal infections in hematological neoplastic disease: the possibility of chemoprophylaxis

Immunoelectrosmophoresis (IEOP) was used to detect antigens of Candida albicans in the sera of 90 patients with hemolymphoblastosis. A higher percentage of sensitive results occurred in patients with acute myeloid leukemia; moreover, most of the serologically positive patients showed severe leukopenia and neutropenia (WBC less than 1000/microliter; neutrophils less than 200/microliter). According to the results of IEOP assays, a prophylactic treatment with standard dosages of amphotericin B or myconazole was instituted in positive cases. Treatment schedules were randomized in order to assess the effect of each drug. The therapy resulted in serological negativity in 60% of the patients treated with amphotericin B and 57% of those who were given myconazole.

Suppressor T cell chronic lymphocytic leukaemia associated with red cell hypoplasia

A case of T cell chronic lymphocytic leukaemia (CLL) with red cell hypoplasia and neutropenia is reported. WBC was 10.0 X 10(9)/l with 78% being T lymphocytes. These T lymphocytes were positive for Fc gamma receptor and had OKT8 and Leu 2a antigens on the cell surfaces. They suppressed both erythroid and granulocyte-macrophage colony formation in normal bone marrow cultures and suppressed immunoglobulin production by normal B lymphocytes in vitro. Though the myeloid cells were preserved in the bone marrow and the values of serum immunoglobulins were within normal limits, it can be estimated from these results that red cell hypoplasia and neutropenia were partially due to the suppression of haemopoietic precursor cells by leukaemic T lymphocytes.