Bifidobacterial supplementation reduces the incidence of necrotizing enterocolitis in a neonatal rat model.

BACKGROUND & AIMS: Neonatal necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease of premature infants partly caused by intestinal bacterial proliferation. Because bifidobacteria are thought to reduce the risk for intestinal disturbances associated with pathogenic bacterial colonization, we hypothesized that exogenous bifidobacterial supplementation to newborn rats would result in intestinal colonization and a reduction in the incidence of neonatal NEC. METHODS: Newborn rat pups were given Bifidobacterium infantis (10(9) organisms per animal daily), Escherichia coli, or saline control and exposed to the NEC protocol consisting of formula feeding (Esbilac; 200 cal. kg(-1). day(-1)) and asphyxia (100% N(2) for 50 seconds followed by cold exposure for 10 minutes). Outcome measures included stool and intestinal microbiological evaluation, gross and histological evidence of NEC, plasma endotoxin concentration, intestinal phospholipase A(2) expression, and estimation of intestinal mucosal permeability. RESULTS: Bifidobacterial supplementation resulted in intestinal colonization by 24 hours and appearance in stool samples by 48 hours. Bifidobacteria-supplemented animals had a significant reduction in the incidence of NEC compared with controls and E. coli-treated animals (NEC, 7/24 B. infantis vs. 19/27 control vs. 16/23 E. coli; P < 0.01). Plasma endotoxin and intestinal phospholipase A(2) expression were lower in bifidobacteria-treated pups than in controls, supporting the role of bacterial translocation and activation of the inflammatory cascade in the pathophysiology of NEC. CONCLUSIONS: Intestinal bifidobacterial colonization reduces the risk of NEC in newborn rats.

Diagnostic and therapeutic technology assessment. Transjugular intrahepatic portosystemic shunt (TIPS).

OBJECTIVE: To provide clinicians with a technology assessment of the safety and effectiveness of the use of a transjugular intrahepatic portosystemic shunt (TIPS) for reducing portal hypertension and its associated complications of esophageal varices and ascites. PARTICIPANTS: A literature review and a Diagnostic and Therapeutic Technology Assessment (DATTA) survey questionnaire were mailed to 72 physicians with expertise in gastrointestinal or abdominal surgery or interventional radiology and a special interest in liver disease or esophageal varices. These panelists had been nominated to the DATTA panel by appropriate specialty societies and medical schools. A total of 54 panelists (75%) responded. EVIDENCE: Assessment was based on the expert opinion of the panelists, as well as on published scientific literature (available as of January 2, 1995). Published studies were identified by a MEDLINE search using the terms transjugular intrahepatic portosystemic shunt, TIPS, and transjugular and by review of the references cited in these primary sources. CONSENSUS PROCESS: The respondents completed a DATTA survey questionnaire; the survey results were tabulated, analyzed, and interpreted by an American Medical Association staff physician. CONCLUSIONS: The safety of TIPS was considered to be established in the acute control of bleeding from esophageal varices in patients who had failed sclerotherapy. The safety of TIPS was considered to be promising for long-term control of bleeding from esophageal varices. In patients with end-stage liver disease and esophageal varices who are liver transplant candidates, the use of TIPS was considered to be an established therapy. The effectiveness of TIPS was considered to be (1) established in the acute control of bleeding in patients who failed sclerotherapy; (2) promising for long-term control of bleeding from esophageal varices; and (3) established in patients with end-stage liver disease and esophageal varices who are candidates for liver transplants.

Iron uptake by Bifidobacterium thermophilum protoplasts.

Protoplasts of Bifidobacterium thermophilum were prepared by a combination of lysozyme and protease digestion, and ferrous iron uptake studies were carried out. Little, if any, iron was internalized by the protoplasts, although large amounts of iron were bound to the protoplast surface. This binding was much greater than that of intact cells, which prefer to internalize iron by an energy-dependent process. It was also found that the binding of iron by protoplasts of cells grown in an iron-deficient medium was much more extensive than that of cells grown in an iron-sufficient medium. Soluble and particulate fractions of protoplasts were prepared by grinding them in a glass homogenizer, and the particulate fraction was also subjected to iron binding studies. The amount of iron bound was the same as that in intact protoplasts, indicating that the particulate fraction membrane fragments bound iron on their outer surface only. Nevertheless, when iron-preloaded cells were protoplasted and their surface cleared of iron, their particulate fraction contained considerable amounts of iron, indicating that the inner surface of the membranes is capable of binding iron as long as the cell is intact. The amount of iron so bound was dose-dependent on the amount of iron entering the cell. The failure of the outer and inner surface iron pools to mix was confirmed by the fact that when iron-preloaded protoplasts were incubated with additional iron, only the latter (surface-bound) was elutable with nonradioactive 2 mM FeSO4. It is concluded that increasing bifidobacterial iron load increases the amount of iron bound to the inner surface of the membrane; the procedure, which is effective in forming bifidobacterial protoplasts, destroys their iron transport mechanism while uncovering surface iron-binding sites; and that such iron-binding sites may be of significance in the cellular iron metabolism processes.

The incidence and distribution of Mycoplasma fermentans (incognitus strain) in the Chicago AIDS autopsy series: an immunohistochemical study. Chicago Associated Pathologists.

Mycoplasma incognitus is a recently described organism that was originally isolated by Shyh-Ching Lo from spleen and Kaposi's sarcoma (KS) tissue of patients with AIDS. The mycoplasm has since been found in selected AIDS autopsy cases in which there were tissues with unexplained areas of necrosis. Mycoplasma incognitus is now known to be closely related to Mycoplasma fermentans. In order to determine the incidence and distribution of M. fermentans/M. incognitus in an unselected series, we performed a retrospective immunohistochemical study of 42 HIV-positive autopsies from the Chicago AIDS autopsy series. One case (2.4%) was found to be positive. The patient was a 27-year-old white male homosexual who had no evidence of Kaposi's sarcoma nor of any other neoplastic disorder and who died of Pneumocystis carinii pneumonia. Antigen was present in the macrophages of the patient's spleen, liver, and bone marrow but was not associated with areas of necrosis. All other tissues sampled from this case (brain, heart, testis, lymph nodes) were negative. In the remaining autopsies, organs of the reticuloendothelial system as well as other randomly selected tissues (e.g., lung, heart, testis, pancreas) were screened and found to be negative. Tissues from several non-AIDS autopsies were also found to be nonreactive for M. fermentans/M. incognitus. We conclude that M. fermentans/M. incognitus is not a common agent found in the Chicago AIDS population; that it may be identified in tissue without morphologic abnormality; and that it is not randomly present in non-AIDS autopsies.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of oxoid signal with nonradiometric BACTEC NR-660 for detection of bacteremia.

The Oxoid Signal (Oxoid U.S.A. Inc., Columbia, Maryland) system was compared with the nonradiometric BACTEC NR-660 (Johnston Laboratories, Towson, Maryland) system for detection of bacteria in 2714 blood cultures. The volume of blood collected into 20 ml blood-collection tubes containing sodium polyanetholsulfonate (SPS) (Becton Dickinson, Vacutainer Systems, Rutherford, New Jersey) ranged from 10 to 20 ml with an average of 15 ml. Subsequently, equal volumes of blood were inoculated into each system. A total of 250 organisms was isolated (9.6%), of which 149 (5.5%) were considered significant while 111 isolates from 98 cultures (3.6%) were contaminants. Of the significant isolates 32.9% were aerobic Gram-negative rods, 53.0% aerobic Gram-positive cocci, 5.4% anaerobes, 7.4% yeasts, and two isolates of Neisseria meningitidis. Ninety-five isolates were recovered in both systems, 29 by Bactec only and 25 by Signal only. Of the isolates recovered there were no significant differences in detection between the two systems with the exception of anaerobes (p less than 0.005). The median detection times for many of the most commonly isolated organisms--Enterobacteriaceae, streptococci, and Staphylococcus aureus--were very similar in both systems, ranging from 14 to 21 hours. With the remaining organisms recovered, the median times in hours for BAC-TEC and Signal, respectively, were 31 and 47 for Staphylococcus epidermidis, 48 and 60 for Bacteroides, 39 and 168 for yeast, and 16.5 and 168 for N. meningitidis. Oxoid Signal compares favorably with the BACTEC system. Its main advantages are: (1) it requires no instrumentation; (2) it is characterized by ease of detection; and (3) it uses a single-bottle system.(ABSTRACT TRUNCATED AT 250 WORDS)

The Chicago AIDS autopsy study: opportunistic infections, neoplasms, and findings from selected organ systems with a comparison to national data. Chicago Associated Pathologists.

The Chicago acquired immunodeficiency syndrome (AIDS) autopsy study evaluated the first 38 AIDS autopsies through January 1, 1985 from 14 participating institutions in the Chicago area. A complete analysis of neoplasms and opportunistic infections from this material as well as a discussion of pathologic features that may be associated only with human immunodeficiency virus (HIV) infection is presented and compared with national data. Among the neoplasms nodular Kaposi's sarcoma was present post-mortem in only 15.8% of cases as compared with a national autopsy incidence of approximately 50%. This figure was highly significant (Z = -5.439 where significance occurs at more than +/- 1.96) and indicates that the Chicago AIDS population is distinct from the national AIDS population in terms of Kaposi's sarcoma. There were no parallel differences in possible cofactors to account for this lower incidence in Chicago. Inflammatory Kaposi's sarcoma was present in 3 cases but did not approach the near 100% figure reported by others. A discussion of this entity and possible reasons for confusion in its diagnosis are discussed. Chicago continues to have a low incidence of AIDS for a large metropolitan area (308 cases/million population) and a continuing low incidence of nodular Kaposi's sarcoma reported clinically. We hypothesize that either some as yet unidentified agent, not generally present in the Chicago population at risk for AIDS, is responsible for the initiation of Kaposi's sarcoma or that the particular HIV-1 isolate in Chicago is not associated with this malignancy.

Transport of ferrous iron and lactate production in Bifidobacterium bifidum var. pennsylvanicus.

Initial rates of ferrous iron transport into Bifidobacterium bifidum var. pennsylvanicus were measured at low and high iron concentrations. The low affinity system (LAFIUS) had an apparent Km of 167 microM, the high affinity system (HAFIUS) had a Km of 50 microM. Iron removal from preloaded bifidobacteria revealed the existence of a labile and an inert iron pool in the bacterial cells. Iron uptake by the bifidobacteria was associated with lactate production, though lactate production could continue without iron uptake. Cessation of iron uptake and lactate production was not because of an exhaustion of any nutrient nor the accumulation of fermentation end products in the medium. It was apparently the result of an inactivation of the cellular enzyme machinery without replacing it through normal biosynthetic processes.

Campylobacter pylori gastritis in the acquired immunodeficiency syndrome.

Campylobacter pylori has been associated with gastritis, duodenitis, and duodenal ulceration in the immunocompetent individual. It has been described within the superficial mucus layer, in interepithelial junctions, and occasionally in the microcanaliculi of epithelial cells, but never in the lamina propria. We describe a case of invasive C. pylori in a patient with the acquired immunodeficiency syndrome and discuss its clinical presentation and histopathological findings.

Ferrous iron uptake by Bifidobacterium bifidum var. pennsylvanicus: the effect of metals and metabolic inhibitors.

Ferrous iron uptake studies in Bifidobacterium bifidum var. pennsylvanicus were carried out in a well-defined salt solution termed "modified Hanks solution" at both high iron concentrations (LAFIUS conditions) and low concentrations (HAFIUS conditions). Various divalent metals, Mn2+, Zn2+, Ni2+ and Cu2+, inhibited iron uptake under HAFIUS conditions in a non-competitive manner, and in a pseudo-competitive manner under LAFIUS conditions. Cr2+ had no effect. Co2+ inhibited iron uptake competitively under HAFIUS conditions. Metabolic affectors that inhibited iron uptake both under HAFIUS and LAFIUS conditions were: tetraphenylphosphonium chloride, diethylstilbesterol, vanadate, carbonylcyanide-m-chlorophenyl-hydrazone, and a mixture of valinomycin and nigericin. Substances that stimulated iron uptake were KCl, valinomycin, and nigericin. Iron uptake under LAFIUS conditions in piperazine-buffered modified Hanks solution was higher than that in the acetate-buffered solution, and acetate inhibited iron uptake in the piperazine buffer. HAFIUS showed no difference. It is concluded that iron uptake in bifidobacteria is driven by an ATPase-dependent proton-motive force and that both the pH gradient and membrane potential are involved in this process. Mn2+, Zn2+, Ni2+, and Cu2+ may be transported via LAFIUS, but not HAFIUS. HAFIUS may transport only Co2+ in addition to Fe2+.

Cat scratch disease. Identification of bacteria in seven cases of lymphadenitis.

A retrospective study of lymph node biopsy specimens from nine patients with the clinical findings and histologic features of cat scratch disease was undertaken to determine whether the recent report by Wear et al. that pleomorphic bacteria are present in the lymph nodes of cat scratch disease could be confirmed. In seven of our nine cases, pleomorphic bacteria were demonstrated with the Warthin-Starry (WS) silver stain. These were gram-negative with the Brown-Hopps tissue Gram stain and were almost at the limit of microscopic resolution. Lymph node specimens from 13 additional patients with nonspecific lymphadenitis who had neither clinical nor histologic findings of cat scratch disease were studied similarly; in none of these were bacteria demonstrated with the WS silver stain. After examining the distribution of the organisms and the related morphologic features in cat scratch disease, we conclude that demonstration of pleomorphic, gram-negative, WS-positive bacteria in the appropriate clinical and histologic setting can firmly establish the diagnosis of cat scratch disease.

Mechanisms of ferric and ferrous iron uptake by Bifidobacterium bifidum var. pennsylvanicus.

Iron uptake studies in Bifidobacterium bifidum var. pennsylvanicus were carried out using ferric citrate at iron concentrations above 0.01 mM and pH 7, ferrous iron at concentrations less than 0.01 mM at pH 5. Two ferric iron transport systems were distinguished: the temperature-insensitive polymer, and the temperature-sensitive monomer uptake. Both showed a saturation phenomenon. The transport of ferrous iron at concentrations below 0.01 mM was temperature-dependent, and its affinity for iron was higher than that of a system operating at iron concentrations higher than 0.01 mM. The use of various metabolic inhibitors indicated that ferrous iron transport at pH 5 at both high and low iron concentrations was mediated by transport-type ATPase. Proton gradient dissipators abolished ferrous iron uptakes as well as the ferric monomer uptake. Uptake of the ferric polymer was insensitive to metabolic inhibitors. The functional significance of the various types of iron transport systems may be related to the nutritional immunity phenomenon.

Case report: blastomycosis causing sciatic neuritis.

A patient presented with pain in the right lower back, radiating down the right leg. Initial pelvic X-rays did not reveal any lesion. A follow up computerized tomography (CT) scan and technitium scan showed a sharply lytic lesion of the right ilium extending to the right sacroiliac joint. Open biopsy revealed a granulomatous inflammation with many budding yeast from consistent with Blastomyces dermatitidis. Subsequent culture confirmed this identification. There was no other site of fungal infection. Two courses of Amphotericin B (each to 2 g total dose) failed to eradicate this infection. The patient is now responding to Ketoconazole.

Demonstration of lactoferrin in tumor tissue from two patients with positive gallium scans.

We have detected lactoferrin in tumor tissue from a patient with Hodgkin's disease and a patient with Burkitt's lymphoma. Both patients had radiogallium scans demonstrating increased uptake in the tumor tissue subsequently found to contain lactoferrin. Tissue assay for lactoferrin was performed by the indirect immunofluorescence method. Control splenic tissue showed either slight lactoferrin content or none.