The purification and activities of an alkaline protease of Aspergillus clavatus from Nigerian poultry feeds

Optimal growth and extracellular protease production by Aspergillus clavatus Des. was recorded at 30 degrees C and between days 5 and 7 of the 8-day incubation period. Purification of this enzyme was achieved by a combination of ultrafiltration, alcoholic precipitation and fractionation on DEAE-cellulose and Sephadex-G.200. A single peak of an alkaline protease was subsequently obtained with a 9-fold increase in specific activity and a final recovery value of 26.2%. The enzyme had optimal activity at 37 degrees C and a pH of 7.8. The enzyme did not degrade leucine amide, hippurylphenylalanine and hippurylarginine indicating lack of exo-protease activity. However, endo-protease activity led to a rapid hydrolysis of gelatin with optimal activity at 40 degrees C and pH 7.8. The high incidence of A. clavatus on Nigerian poultry feeds vis-a-vis the potential health risks posed to farm animals is discussed.     

The nature and occurrence of registration errors in the emergency department

Research into the nature and occurrence of medical errors has shown that these often result from a combination of factors that lead to the breakdown of workflow. Nowhere is this more critical than in the emergency department (ED), where the focus of clinical decisions is on the timely evaluation and stabilization of patients. This paper reports on the nature of errors and their implications for patient safety in an adult ED, using methods of ethnographic observation, interviews, and think-aloud protocols. Data were analyzed using modified "grounded theory," which refers to a theory developed inductively from a body of data. Analysis revealed four classes of errors, relating to errors of misidentification, ranging from multiple medical record numbers, wrong patient identification or address, and in one case, switching of one patient's identification information with those of another. Further analysis traced the root of the errors to ED registration. These results indicate that the nature of errors in the emergency department are complex, multi-layered and result from an intertwined web of activity, in which stress in the work environment, high patient volume and the tendency to adopt shortcuts play a significant role. The need for information technology (IT) solutions to these problems as well as the impact of alternative policies is discussed.     

The occurrence of cyclic AMP in aging cultures of the fungus Aspergillus ornatus

The presence of endogenous cAMP was demonstrated in mycelial mats of Aspergillus ornatus Raper grown on cellulose xanthate membranes overlying a defined agar medium. Using a competitive binding assay cAMP was detected in 30 separate samples. Purification techniques increased the apparent cAMP concentration in excess of eight times the level observed in crude extracts. Cyclic AMP was only slightly detectable in extracts treated with phosphodiesterase. The concentration of endogenous cAMP as measured in purified extracts declined by approximately 60% in non-growing aging mycelial mats. Although there is an apparent age-related decline in endogenous cAMP levels and the activity of the tryptophan inducible enzyme, 2,3-dihydroxybenzoic acid carboxylyase (EC 4.1.1.46), (OPCA carboxylyase), the addition of 10(-3) M cAMP and/or 0.1% tryptophan to the culture medium did not increase OPCA carboxylyase activity in the fungus.     

Contemporaneous occurrence of allergic bronchopulmonary aspergillosis, allergic Aspergillus sinusitis, and aspergilloma.

BACKGROUND: The clinical categories of Aspergillus-related respiratory disorders usually remain mutually exclusive. The coexistence of allergic bronchopulmonary aspergillosis (ABPA) with aspergilloma is uncommon, whereas concurrent ABPA and allergic Aspergillus sinusitis (AAS) is rare. The association of these 3 clinical entities has previously been documented only once in a patient who had earlier been operated on for an aspergilloma before the diagnoses of ABPA and AAS were established. OBJECTIVE: To describe an adult in whom ABPA, AAS, and aspergilloma were diagnosed simultaneously. METHODS: Spirometry, radiography, computed tomography, skin allergy testing with Aspergillus antigens, serum precipitins against Aspergillus, total and specific IgE, functional endoscopic sinus surgery, and fungal culture were performed. RESULTS: A 26-year-old man who had asthma and rhinitis since childhood presented with hemoptysis. Serial chest radiographs revealed transient pulmonary infiltrates and an aspergilloma. Computed tomography of the thorax confirmed the aspergilloma and showed bilateral central bronchiectasis along with patchy infiltrates. Strong bands of precipitins were detected against Aspergillus fumigatus, and intradermal testing with Aspergillus antigens elicited strong type I and III hypersensitivity reactions. Specific IgE and IgG antibodies against A fumigatus were positive, and total IgE levels were significantly elevated. Peripheral blood eosinophilia was also detected. Sinus involvement was confirmed on computed tomography, and pathologic material obtained by functional endoscopic sinus surgery demonstrated allergic mucin that contained fungal elements. In addition, A fumigatus was cultured. CONCLUSIONS: ABPA, AAS, and aspergilloma can occur simultaneously in the same patient.     

Human endogenous retroviruses: nature, occurrence, and clinical implications in human disease.

Retroviral diagnostics have become standard in human laboratory medicine. While current emphasis is placed on the human exogenous viruses (human immunodeficiency virus and human T-cell leukemia virus), evidence implicating human endogenous retroviruses (HERVs) in various human disease entities continues to mount. Literature on the occurrence of HERVs in human tissues and cells was analyzed. Substantial evidence documents that retrovirus particles were clearly demonstrable in various tissues and cells in both health and disease and were abundant in the placenta and that their occurrence could be implicated in some of the reproductive diseases. The characteristics of HERVs are summarized, mechanisms of replication and regulation are outlined, and the consistent hormonal responsiveness of HERVs is noted. Clear evidence implicating HERV gene products as participants in glomerulonephritis in some cases of systemic lupus erythematosus is adduced. Data implicating HERVs as etiologic factors in reproductive diseases, in some of the autoimmune diseases, in some forms of rheumatoid arthritis and connective tissue disease, in psoriasis, and in some of the inflammatory neurologic diseases are reviewed. The current major needs are to improve methods for HERV detection, to identify the most appropriate HERV prototypes, and to develop diagnostic reagents so that the putative biologic and pathologic roles of HERVs can be better evaluated.     

Screening of Aspergillus species for occurrence of lectins and their characterization

Ten species of Aspergillus were screened for occurrence of lectins. Each of the species was investigated for the occurrence of extracellular, surface-bound and intracellular lectin activities. As many as four species namely, Aspergillus niger, Aspergillus versicolor, Aspergillus rugulosus and Aspergillus nidulans, were found to possess intracellular lectin activities, while none of the species showed extracellular or surface-bound lectin activities. Each of the lectin was characterized with respect to blood group and carbohydrate specificities. All the lectins were found to agglutinate human erythrocytes, irrespective of their blood group and pig erythrocytes. However, they did not show agglutination with sheep or goat erythrocytes. Of the various carbohydrates tested, all lectins were found to be specific for inulin, mucin, asialofetuin, N-acetyl galactosamine, melibiose, D-ribose, L-fucose, D-arabinose, D-sucrose and D-mannitol. The minimum inhibitory concentration of each of the specific sugars was also determined. The lectins were partially purified using ammonium sulfate precipitation technique. Each of the lectin was found to be precipitated at 40-50% saturation of ammonium sulfate, yielding about 80% of lectin activity.     

Further screening of Aspergillus species for occurrence of lectins and their partial characterization

Fifteen species of Aspergillus were screened for occurrence of lectins. Nine of them (A. sydowii, A. candidus, A. allahabadi, A. terricola, A. ficuum, A. sparsus, A. carneus, A. pulvinus and A. aculeatus) were found to possess lectin activity. None of the species elaborated lectin in culture supernatant. All the lectins agglutinated rat, pig and rabbit erythrocytes. A. sydowii, A. candidus, A. allahabadi, A. terricola, A. ficuum, A. sparsus, A. carneus and A. aculeatus lectins agglutinated all human type erythrocytes equally, while A. pulvinus lectin specifically agglutinated human type A and O erythrocytes. Neuraminidase and protease treatment to erythrocytes substantially augmented lectin titres manyfold. Lectins showed specificity to mucin and asialofetuin and all of them were specific to L‐arabinose except that of A. carneus. Lectins from A. sydowii, A. ficuum, A. sparsus and A. carneus displayed remarkable specificities to D‐xylose. Maximum lectin activity was expressed by 11 day old cultures of A. sydowii (titre 32), A. ficuum (titre 64) and A. sparsus (titre 1024). Lectins from A. aculeatus, A. candidus and A. terricola were expressed by 7–10 days, 6–9 days and 5–11 days old cultures, respectively. A. allahabadi cultures exhibited maximum lectin activity (titre 32) after 8–10 days of cultivation. A. carneus and A. pulvinus expressed optimal titres of 32 and 8, respectively on the 9^th day. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The nature and incidence of lysogeny in Mycobacterium fortuitum.

Ten of 28 strain of Mycobacterium fortuitum (ranae) were found to be associated with bacteriophage; three were pseudolysogenic, one liberated a phage that lysed a sensitive indicator strain, two liberated morphologically complete phages that did not lyse any of the strains used in this study and four liberated morphologically defective phages. The lysogenic and defectively lysogenic strains showed anomalies in cultural, biochemical and antigenic properties and in susceptibility to superinfecting phages. In view of the high frequency of lysogeny found in M. fortuitum, the role of bacteriophage in the variation of properties, including pathogenicity, of mycobacteria of greater clinical importance merits further consideration.     

The occurrence of arrhythmias in hospitalized asthmatic patients.

Twenty-four hour continuous ECG monitoring was performed on 20 patients hospitalized for asthma to evaluate the occurrence of potentially dangerous arrhythmias. Most patients (19/20) had sinus tachycardia on admission; premature ventricular contractions (PVCs) were present in 4; 1 had angina associated with runs of increased sinus tachycardia. With improvement in PaO2 and FEV1, the heart rate decreased in 17 patients and fewer PVCs were present in 2. Arrhythmias were not a serious problem in the patients studied.     

The immunoglobulin nature of Russell bodies.

Although Russell bodies have been widely regarded as aggregates of immunoglobulin (Ig) their true nature remains controversial. This report reinvestigates the Ig reactivity of Russell bodies using an immunoperoxidase technique to detect IgG, IgA, IgM, kappa and lambda light chains and J chain on formalin fixed paraffin embedded tissue. Both intracellular and extracellular Russell bodies stained for Ig heavy and light chain determinants. Generally staining was most intense at the surface of these structures although many appeared to have detectable Ig determinants within the Russell body cores. The results suggest that Russell bodies, irrespective of size or site, are associated with intact Ig molecules.     

The nature of neoplastic cell membranes.

The ultrastructural analysis of malignant neoplastic tissues has revealed a variety of cellular modifications, none of them common to all tumors studied. Among the constituents of cancer cells, the cell surface displays more commonly significant structural alterations. The most frequent ones are: (1) increased thickness of the carbohydrate-containing surface coat, (2) relative absence of cell contacts, (3) increased mobility of carbohydrate surface receptors, (4) diminished number of subplasmalemmal microfilaments, and (5) increase in intramembranous particles revealed by the freeze-fracture technique. Some of the above modifications correlate with the degree of invasiveness of certain human carcinomas, and could, therefore, be used to assess the future evolution of these tumors. Up to the present time, electron microscopy has revealed that the modifications of the genome of neoplastic cells induced by physical, chemical or biological agents are mainly expressed as quantitative morphological changes of cell surface components. These structural modifications may be operative in the establishment of the abnormal cell surface properties characteristic of neoplastic cells.     

The composition and nature of cuticular proteins in parasitic copepods.

1. The protein components of the cuticle of the two parasitic copepods Pennella elegans and Caligus savala were studied electrophoretically and histochemically. 2. The amino acid composition and the chemical nature of the proteins of the cuticle in the two species were also studied. 3. The fast-moving protein fractions found in the cuticle of C. savala were absent in the cuticle of P. elegans. 4. The similarities and differences in the protein components of the cuticle and their relations to the functions of the cuticle in both species are discussed.