Fractionation and characterization of the immunosuppressive substance in crude extracellular products released by Streptococcus intermedius.

The noncytotoxic immunosuppressive substance detected in crude extracellular products of Streptococcus intermedius (CEP-SI) was fractionated by two steps of preparative isoelectric focusing in sucrose gradients using ampholytes of pH range from 3.5 to 6 and 4 to 5, respectively. The in vitro and in vivo suppressor effects of the most highly purified fraction of CEP-Si, designated fraction 3' (F3'EP-Si), corresponded well with those of the original CEP-Si. F3'EP-Si was sensitive to the effects of alpha, gamma, and delta chymotrypsin, trypsin, and heating. It contained approximately 1% of the total amount of protein found in the original CEP-Si, corresponding to a single band on analytical isoelectric focusing, stainable by Coomassie Blue and of isoelectric point of 4.25. The absorption spectrum of F3'EP-Si had a maximum at 260 nm but its biological activity was resistant to deoxyribonuclease and ribonuclease A and it did not contain material stainable by methylene blue. It was also resistant to neuraminidase and did not contain material stainable by periodic acid schiff. We conclude that the substance responsible for the suppressor activity of CEP-Si is a protein of molecular weight approximately 90,000, which adheres to Sephadex of cellulose acetate and forms complexes with other, nonactive constituents of CEP-Si.

Rosiglitazone versus bedtime insulin in the treatment of patients with conventional oral antidiabetic drug failure: a 1-year randomized clinical trial.

This study was conducted to evaluate the efficacy and tolerability of rosiglitazone in the treatment of patients with secondary oral antidiabetic drug (OAD) failure and to directly compare its use with bedtime insulin. A total of 112 Chinese patients with type 2 diabetes and conventional OAD failure were recruited. Patients were randomly assigned to treatment with rosiglitazone or bedtime isophane insulin; they continued to take their original oral antidiabetic drugs. Glycemic index, other clinical profiles, and tolerability were assessed during treatment and 1 y after add-on treatment was provided. Among the 112 patients, mean age (+/-SD) was 58.2+/-11.0 y (median, 58 y; range, 37 to 84 y). Both rosiglitazone (n=56) and insulin (n=56) significantly improved fasting glucose (2.4 and 3.7 mmol/L, respectively) and hemoglobin A1c concentrations (1.1% and 1.3%, respectively). Both therapies increased body mass index after 1 y of treatment (0.9 and 0.8 kg/m2, respectively). Only rosiglitazone increased high-density lipoprotein cholesterol concentrations (0.1 mmol/L). Four patients (7.1%) who were given rosiglitazone developed adverse effects (2, ankle edema, and 2, gastrointestinal disturbance). Six insulin-treated patients (10.7%) described adverse effects (5, early morning hypoglycemia, and 1, anxiety). Investigators concluded that in Chinese patients with type 2 diabetes and secondary conventional OAD failure, 1 y of treatment with rosiglitazone or bedtime insulin added to the regular regimen resulted in similar improvements in glycemic control. Rosiglitazone was also associated with improved high-density lipoprotein cholesterol levels. The addition of rosiglitazone may offer a safe and effective alternative to bedtime insulin treatment.

Evaluation of four methods for separation of lymphocytes from normal individuals and patients with cancer and tuberculosis.

An optimal technique was sought for lymphocyte recovery from normal and chronic diseased individuals. Lymphocytes were separated by four techniques: Plasmagel, Ficoll--Hypaque, a commercial semiautomatic method, and simple centrifugation using blood drawn from ten normal individuals, ten cancer patients, and ten tuberculosis patients. The lymphocyte mixture obtained after using each method was analyzed for percent recovery, amount if contamination by erythrocytes and neutrophils, and percent viability. The results show that the semiautomatic method yielded the best percent recovery of lymphocytes for normal individuals, while the simple centrifugation method contributed the highest percent recovery for cancer and tuberculosis patients. The Ficoll-Hypaque method gave the lowest erythrocyte contamination for all three types of individuals tested, while the Plasmagel method gave the lowest neutrophil contamination for all three types of individuals. The simple centrifugation method yielded all viable lymphocytes and thus gave the highest percent viability.

Isolation of soluble immune complexes by affinity chromatography using staphylococcal protein A--Sepharose as substrate.

This report describes a technique for the general isolation of immune complexes, based on a combination of gel filtration and affinity chromatography. The first step is the preparation of a globulin-enriched fraction by precipitation with ammonium sulfate at 50% saturation, or of an immune-complex-enriched fraction by precipitation with 5% polyethylene glycol 6000. The enriched fraction is then subfractionated by gel filtration in Ultrogel AcA 34. The immune complexes elute close to the void volume in the macroglobulin peak, separated from monomeric IgG molecules. This peak (sometimes subdivided into two fractions) is then submitted to affinity chromatography on a protein A--Sepharose cooumn. Most immune complexes contain IgG molecules and therefore bind to the column. Almost no protein is bound when normal serum is fractionated according to this method, and no immunoglobulins are detectable in the acid-eluted fraction from the protein A--Sepharose column. In two patients with soluble immune complexes in their sera we eluted immunoglobulin-containing fractions from the column; in one, these fractions had high rheumatoid factor titers; and in the second, with a clinical diagnosis of systemic lupus erythematosus, a similar fraction contained RNA.

Persistent bacteremia due to coagulase-negative staphylococci in low birth weight neonates.

During a 6-month period in 1987, 13 low birth weight neonates without indwelling central intravascular catheters had persistent (positive blood cultures for greater than or equal to 6 days) coagulase-negative staphylococcal bacteremia despite adequate antibiotic therapy. Daily blood cultures remained persistently positive for a mean of 13 days (range 6 to 25 days). This group of infants was compared with other low birth weight infants with similar birth weights and nonpersistent coagulase-negative staphylococcal bacteremia, defined as two or more positive blood cultures accompanied by supporting clinical manifestations of sepsis. During this period, coagulase-negative staphylococcal represented 29% of all bacteremias, and 33% of coagulase-negative staphylococcal bacteremias were persistent. Other than soft tissue abscesses, none of the infants with persistent coagulase-negative staphylococcal bacteremia had a defined focus of infection. Abdominal distention (P = .001) and thrombocytopenia (P less than .03) occurred significantly more frequently in the patients with persistent coagulase-negative staphylococcal bacteremia than in those with nonpersistent bacteremia. Of the 13 patients with persistent coagulase-negative staphylococcal bacteremia, 2 received methicillin and 11 received vancomycin. No antibiotic tolerance to either antibiotic could be demonstrated. Serum concentrations of vancomycin far exceeded the minimum bactericidal concentration in all cases in which vancomycin was prescribed. No in vitro differences could be demonstrated between persistent and nonpersistent coagulase-negative staphylococcal strains for slime production, biotype, proteins from modified whole cell lysates developed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and opsonophagocytosis by adult neutrophils in the presence of pooled human sera. Additionally, plasmid profile analysis and phage typing revealed no common strain causing the persistent bacteremia.(ABSTRACT TRUNCATED AT 250 WORDS)

Light chain proteinuria and cellular mediated immunity in rifampin treated patients with tuberculosis.

Light chain proteinuria was found in 9 of 17 tuberculosis patients treated with rifampin. Concomitant assay of cellular mediated immunity in these patients using skin test antigen and a lymphokine in vitro test provided results that were different. Response to Varidase skin test antigen was negative for all eight tuberculosis patients tested, but there occurred a hyper-responsiveness of the lymphocytes of these eight patients to phytomitogen (PHA-P). as well as of those of seven other tuberculous patients. This last finding may be related to time of testing and/or endogenous serum binding of rifampin which could have inhibited mitogen activity for the lymphocyte.

Use of fluoroquinolones as prophylactic agents in patients with neutropenia.

BACKGROUND: The use of fluorinated quinolone antibiotics to selectively decontaminate the gastrointestinal tract is a reasonable alternative to prevent infection in neutropenic patients. The fluoroquinolones represent ideal antibiotics with which to achieve the principles of selective decontamination by allowing colonization of anaerobes to inhibit the adherence, colonization and proliferation of potentially pathogenic aerobic flora. OBJECTIVE: This report describes the prophylactic use of fluoroquinolones in neutropenic patients. RESULTS: The majority of studies of fluoroquinolone prophylaxis in neutropenic patients have shown a reduction in documented Gram-negative bacterial infections. However, Gram-positive infections, particularly those with viridans streptococci, present a major impediment to the use of single agent prophylaxis with a quinolone. CONCLUSION: Prophylaxis with fluoroquinolones in neutropenic patients was found to be advantageous, but it must be balanced against the risk of Gram-positive infections and the potential for antibiotic resistance.

Cefotaxime and aminoglycoside treatment of meningitis caused by gram-negative enteric organisms.

We reviewed cases of Gram-negative enteric bacillary meningitis in infants and children treated with cefotaxime at Texas Children's Hospital from January, 1984, through June, 1989. Seventeen of 20 children had an underlying condition predisposing to the development of meningitis. The etiologic organisms in these 20 children (2 days to 12 years old; median, 12 days old) were Klebsiella sp, 9; Escherichia coli, 4; Enterobacter cloacae, 3; Citrobacter diversus, 2; other, 2. With the exception of one isolate of Acinetobacter, all isolates were susceptible to cefotaxime. In addition to cefotaxime 17 children received an aminoglycoside intravenously. Children with meningitis caused by Klebsiella sp. or non-Klebsiella organisms received cefotaxime for 31 +/- 14 and 37 +/- 17 days, respectively. Aminoglycosides were administered for 16 +/- 10 days in both groups. Five children in each group also received intraventricular doses (1 to 25) of an aminoglycoside (9) or colistimethate (1). The mean durations of positive lumbar, ventricular cerebrospinal fluid or brain abscess cultures were 5.8 +/- 4.7 and 7.2 +/- 5.0 days after start of therapy in the Klebsiella and non-Klebsiella meningitis patients, respectively. Only three children were normal at the time of discharge or follow-up. Gram-negative enteric meningitis remains difficult to treat despite the excellent in vitro activity of cefotaxime against Gram-negative enterics, in part as a result of the predisposing conditions resulting in the development of this infection.

Pseudomonas aeruginosa cellulitis and ecthyma gangrenosum in immunocompromised children.

Pseudomonas aeruginosa skin infections are generally considered to be secondary manifestations of disseminated disease. A retrospective analysis of all cases of P. aeruginosa skin infections seen at St. Jude Children's Research Hospital since 1962 revealed 16 episodes of the infection (ecthyma gangrenosum, 8 episodes, 7 patients; cellulitis, 8 episodes, 7 patients) in which blood cultures were uniformly negative for P. aeruginosa. All cases were identified while the patients were receiving ambulatory care. Five episodes developed while the patients' neutrophil counts were greater than 1 x 10(9) cells/liter. Eight patients had acute lymphoblastic leukemia, 2 had acute myeloid leukemia, 2 had aplastic anemia, 1 had transient agranulocytosis and 1 had cyclic neutropenia. There were no solid tumor patients. Although patients received different antibiotic combinations, all had resolutions of their lesions without fatal complications. Patients diagnosed as having cellulitis required a mean of 9.2 days of treatment with intravenous antibiotics, as compared with 17.8 days for those with ecthyma gangrenosum (P less than 0.05 by the Wilcoxon test). These observations show that P. aeruginosa skin infections can develop in the absence of bacteremia in immunocompromised children.

Fungal susceptibility testing.

The utility of antifungal susceptibility testing has not been broadly determined. Thus, susceptibility testing of fungal isolates is not recommended on a routine basis. For instance, susceptibilty testing may be considered for some Candida species and for patients with Pseudallescheria boydii infections. Testing of yeasts for susceptiblity to azoles is of particular value due to their variability in response to these agents. It may also be important to test the susceptibility of new fungal organisms not previously identified or known to cause human disease because in these situations there are no clinical reports of efficacy to guide the choice of antifungal therapy.

Adenovirus infection after pediatric bone marrow transplantation.

Retrospective analysis of 206 patients undergoing 215 consecutive bone marrow transplants (BMT) at St Jude Children's Research Hospital between November 1990 and December 1994 identified 6% (seven male, six female) with adenovirus infection. The affected patients had a median age of 7.9 years (range 3-24 years) at time of transplantation. Although transplants were performed for hematologic malignancies, solid tumors or nonmalignant conditions, only patients with hematologic malignancies had adenoviral infections. Adenovirus was first detected at a median of 54 days (range -4 to +333) after BMT. Adenovirus developed in eight of 69 (11.6%) patients receiving grafts from matched unrelated or mismatched related donors, in four of 52 (7.7%) receiving grafts from HLA-matched siblings, and in one of 93 (1.1%) receiving autografts. The most common manifestation of adenovirus infection was hemorrhagic cystitis, followed by gastroenteritis, pneumonitis and liver failure. The incidence of adenovirus infection in pediatric BMT patients at our institution is similar to that reported in adult patients. Using univariate analysis, use of total body irradiation and type of bone marrow graft were significant risk factors for adenovirus infection. Only use of total body irradiation remained as a factor on multiple logistic regression analysis.

An optimized quality control procedure for hematology analyzers with the use of retained patient specimens.

The authors propose guidelines for the use of retained patient specimens for the quality control of multichannel hematology analyzers. They demonstrate that control limits for patient specimen replicates may be derived from the long-term standard deviations (s) of commercial whole blood controls. They then use computer stimulation of the Coulter multichannel hematology instrument to determine power functions of various procedures using retained specimens. These power functions show that the use of three patient specimens and +/- 2 s limits are optimal for the detection of systematic error. They recommend that three different, previously analyzed normal range specimens be periodically analyzed, e.g., at eight-hour intervals. The differences between the current and original measurements should then be calculated and compared with their +/- 2 s limits. If at least two of the three differences for any directly measured parameter exceed the +/- 2 s limits, there will be a high probability of significant analytic error. Because the power functions of the derived red blood cell parameters, hematocrit, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration demonstrate relatively low error detection capabilities, the authors recommend that these parameters not be monitored with the retained patient specimen procedure.

Current concepts in the pathogenesis and management of brain abscesses in children.

Brain abscesses represent the most frequent intracranial suppurative process occurring in children. Improved bacteriologic techniques for isolating anaerobic microorganisms have shown that anaerobes play a major role in brain abscesses in conjunction with aerobic organisms such as alpha-streptococci. Computerized tomography has improved the diagnosis of brain abscesses and has changed the management in certain circumstances. Although surgical drainage still remains the definitive treatment modality, conservative medical management with serial CT scans has been successful. Still, the mortality and morbidity of brain abscesses remain substantial.

Experimental model of chronic serum sickness. Relationships between proteinuria, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and glomerular and extraglomerular renal pathology.

The evolution of proteinuria in rabbits with experimentally induced chronic serum sickness was followed up longitudinally by analytical and quantitative assays. The results suggest that sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) is a more sensitive index of kidney malfunction than are total-protein assays or the quantitation of albumin and lysozyme. In some rabbits that showed abnormal proteinuria by SDS-PAGE, no histologic evidence of pathologic damage or of deposition of immune complexes in the kidneys was found. This suggests that SDS-PAGE may detect functional alterations at early stages of kidney damage when the lesions are either undetectable or reversible. In one rabbit that was killed after normalization of the proteinuria, immunofluorescence tests indicated deposition of C3, IgG, and fibrinogen, but there was no histologic evidence of kidney damage.

Management of anorectal/perineal infections caused by Pseudomonas aeruginosa in children with malignant diseases.

The role of operation for anorectal infections associated with perineal gangrene and cellulitis in children with myelo-suppression from cancer chemotherapy is unclear. We evaluated anorectal/perineal infections caused by Pseudomonas aeruginosa in 16 children with malignant diseases seen over 27 years. In 12 of 16 patients, leukemia was the underlying malignancy (ALL 10, AML 2), and in 13 of 16, severe neutropenia (absolute neutrophil count less than 500/mm3) was present at diagnosis. Cultures of the lesions showed multiple organisms in 14 of 16 patients with Escherichia coli, Klebsiella species, and Enterococcus being the most frequent coexisting organisms. All positive blood cultures grew P aeruginosa exclusively. Of three patients with necrotizing infections, two had complete resolution with medical treatment alone; the other patient who developed this problem while on terminal care died. In none of the 16 patients was a major operation (debridement or diversion) performed. Five patients died, three of whom were considered terminally ill when the anorectal infections occurred. Four of the five deaths occurred before 1974. Since then, only 1 of 7 patients died. Excluding the three terminally ill patients, the success rate of medical therapy alone is 85% (11/13). The antibiotic regimen should include an aminoglycoside in synergistic combination with anti-Pseudomonas penicillin. These results suggest that operative management may have no role in the management of anorectal infections caused by P aeruginosa in children with cancer.