[Accurate localization and successful treatment of 23 cases of migrating pharynx and cervical esophageal foreign bodies].

Objective: To explore clinical features, diagnosis, localization, and therapeutic strategy of migratory pharyngeal and cervical esophageal foreign bodies. Methods: A total 23 cases of pharyngeal and cervical esophageal migratory foreign bodies were admitted between January 2015 and December 2021. There were 14 females and 9 males with the age ranged from 35 to 82 (55.0±12.7)years. In all the cases, esophageal CT was taken to confirm the esophageal foreign body. Multiplanar reconstruction (MPR) was performed to locate the foreign body from the horizontal, coronal and sagittal dimensions as well as the corrected reconstructed MPR. According to the location of the foreign body, appropriate surgical method was selected.The symptoms, complications, types of foreign body, positioning, surgical methods, and relevant information were recorded.Data were analyzed using the descriptive method and SPSS 25.0 software. Results: The clinical symptoms of 23 migrating esophageal foreign bodies included pharyngodynia (20/23), foreign body sensation (6/23), hoarsenss (1/23), difficulty in turning neck(1/23), difficulty in opening mouth (1/23), fever (7/23), poor appetite (1/23), and abdominal pain (1/23). The foreign bodies included 19 fish bones, 2 wires, 1 embroidery needle and 1 chicken bone. There were 9 cases (39.1%) of foreign bodies located in extraluminal cervical esophagus, 2 cases (8.7%) of foreign bodies located in the muscular layer of the cervical esophagus and 12 cases (52.2%) of foreign bodies located in pharynx. Twenty-one cases of foreign bodies were removed by cervical lateral incision, in which 11 were removed by cervical lateral incision directly, 10 by the second lateral cervical incision after the foreign bodies were accurately located by MPR and/or corrected MPR, 1 foreign body was removed by incision of the pharyngeal mucosa under suspension laryngoscope, 1 foreign body was removed by tracheoscopy. Compared with patients with intraluminal foreign bodies (n=308) treated in the same period, intake of fishbone [19 (19/23) vs. 133 (82.6% (43.2%, 133/308), OR=7.31] and first visit was more than 24 hours [20(87.0%, 20/23) vs. 77(25.0%, 77/308),OR=17.2] were the significant risk factors of migratory esophageal foreign bodies. Conclusions: MPR and the corrected MPR can accurately locate the migrating pharyngeal and cervical esophageal foreign bodies, by providing more intuitive imaging evidence for doctors, which provide imaging basis for formulation of surgical programs. Foreign bodies in pharyngeal and cervical esophagus need to be treated as soon as possible, otherwise they are easy to migrate, leading lead to serious complications.

Influence of a bearing-wastewater phenolic compound (3,4-dimethylphenol, 3,4-DMP) treatment on Ca2+ homeostasis and its related cytotoxicity in human proximal renal tubular epithelial cells.

A lot of phenolic compounds are widespread in industrial effluents and they are considerable environmental pollutants. Being a compound commercially available, the effect of a bearing-wastewater phenolic compound 3,4-dimethylphenol (3,4-DMP) on Ca2+ homeostasis and its related physiology has not been explored in cultured human kidney cell models. The aim of this study was to explore the effect of 3,4-DMP on [Ca2+]i and viability in HK-2 human proximal renal tubular epithelial cells. In terms of Ca2+ signaling, 3,4-DMP (5-100 µM) induced [Ca2+]i rises only in HK-2 cells and Ca2+ removal reduced the signal by 40%. In Ca2+-containing medium, 3,4-DMP-induced Ca2+ entry was inhibited by 20% by a modulator of store-operated Ca2+ channels (2-APB), and by a PKC activator (PMA) and inhibitor (GF109203X). Moreover, 3,4-DMP-induced Mn2+ influx suggesting of Ca2+ entry. In Ca2+-free medium, inhibition of PLC with U73122 abolished 3,4-DMP-induced [Ca2+]i rises. Furthermore, treatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin abolished 3,4-DMP-evoked [Ca2+]i rises. Conversely, treatment with 3,4-DMP abolished thapsigargin-evoked [Ca2+]i rises. Regarding to cell viability, 3,4-DMP (60-140 µM) killed cells in a concentration-dependent fashion in HK-2 cells. Chelation of cytosolic Ca2+ with BAPTA-AM partially reversed cytotoxicity of 3,4-DMP. Collectively, our data suggest that in HK-2 cells, 3,4-DMP-induced [Ca2+]i rises by evoking Ca2+ entry via PKC-sensitive store-operated Ca2+ entry and PLC-dependent Ca2+ release from the endoplasmic reticulum. 3,4-DMP also caused cytotoxicity that was linked to preceding [Ca2+]i rises. Our findings provide new insight into the cytotoxic effects of 3,4-DMP and the possible mechanisms underlying these effects.

The role of innate lymphoid cells in nasal inflammation and cancer.

OBJECTIVE: The innate lymphoid cells (ILCs) are a recently discovered type of innate immune cell. The functions of these cells resemble different T-cell subtypes. These cells play important roles in local injury, inflammation, pathogen infection, or tumours. However, there have been few studies focusing on the role of ILCs in nasal diseases. MATERIALS AND METHODS: We reviewed the literature about the roles of ILCs in nasal inflammation, tissue remodeling, and cancer. RESULTS: The ILCs represent a newly identified family of innate immune cells. These cells play important roles in inflammation, immune responses, tissue remodeling, and cancer immunity. The ILCs, especially ILC2s, play important roles in CRSwNP and AR. ILC2s may be involved in the pathogenesis of eosinophilic inflammation in non-allergic nasal diseases, such as non-allergic CRSwNP and non-allergic rhinitis. ILCs also play pro-tumor or anti-tumor roles in cancer immunity for head and neck cancer. CONCLUSIONS: LC2s may be a useful therapeutic target for CRSwNP and AR. ILCs may also represent new therapeutic targets to activate anti-tumor immunity in head and neck cancer.

Role of local allergic inflammation and Staphylococcus aureus enterotoxins in Chinese patients with chronic rhinosinusitis with nasal polyps.

OBJECTIVE: To investigate the role of local allergic inflammation and Staphylococcus aureus enterotoxins in chronic rhinosinusitis with nasal polyps. METHODS: This study included 36 patients with chronic rhinosinusitis with nasal polyps and 18 controls. Total immunoglobulin E, eosinophil cationic protein, staphylococcal enterotoxin types A and B specific immunoglobulin E, staphylococcal enterotoxin types A and B, and myeloperoxidase levels were determined. RESULTS: Four patients with chronic rhinosinusitis with nasal polyps had a local allergy. All chronic rhinosinusitis with nasal polyps patients tested negative for staphylococcal enterotoxin types A and B specific immunoglobulin E. The chronic rhinosinusitis with nasal polyps group had significantly elevated staphylococcal enterotoxin types A and B levels in the supernatant. Fourteen patients belonged to the eosinophilic chronic rhinosinusitis with nasal polyps group and the others were characterised as having non-eosinophilic chronic rhinosinusitis with nasal polyps. CONCLUSION: Local allergy may play a role in chronic rhinosinusitis with nasal polyps, independent of staphylococcal enterotoxin superantigens. Staphylococcal enterotoxins may be important in the pathogenesis of chronic rhinosinusitis with nasal polyps; however, their roles as superantigens were not confirmed in this study. In Chinese subjects, chronic rhinosinusitis with nasal polyps usually manifests as a neutrophilic inflammation.

Role of atopy in chronic rhinosinusitis with nasal polyps: does an atopic condition affect the severity and recurrence of disease?

BACKGROUND: The role of atopy in chronic rhinosinusitis is unclear: it is particularly controversial in chronic rhinosinusitis with nasal polyps. METHODS: A prospective study of 210 patients with chronic rhinosinusitis with nasal polyps was performed. Patient demographics, visual analogue scale scores, Lund-Kennedy endoscopy scores, Lund-Mackay computed tomography scores, serum total immunoglobulin E levels, serum eosinophil cationic protein (ECP) levels and Phadiatop test findings were analysed. RESULTS: There were no significant differences in age, sex, visual analogue scale score, Lund-Mackay computed tomography score, total serum immunoglobulin E level, serum ECP level or Phadiatop test results between patients with primary and recurrent chronic rhinosinusitis with nasal polyps. A total of 99 patients (47 per cent) had positive atopy tests. No significant differences in sex, visual analogue scale score, Lund-Kennedy endoscopy score, Lund-Mackay computed tomography score or recurrence rates were found between atopic and non-atopic patients; however, atopic patients were significantly younger than non-atopic patients. Atopy status did not correlate with disease severity. CONCLUSION: There was no association between atopy status and either disease severity or recurrence in patients with chronic rhinosinusitis with nasal polyps, although atopic patients were younger than non-atopic patients.

The role of hypoxia inducible factor in nasal inflammations.

OBJECTIVE: Hypoxia-inducible factor (HIF) is considered an important transcription factor due to its roles in glycolysis, angiogenesis, cell differentiation, apoptosis, and other cellular pathways. It takes the role in various physiological and pathological states, such as solid tumors, vascular injury, and atherosclerotic lesion progression. In recent studies, HIF is found as a master regulator of body inflammation and immunity, not only in hypoxia but also in normoxia. Nasal inflammation has a close relationship with anoxia. But the role of HIF in nasal inflammation is still unclear. MATERIALS AND METHODS: We searched the Pubmed using the key words: "Hypoxia-inducible factor" and "nasal" or "Hypoxia-inducible factor", and reviewed the related articles. RESULTS: HIF is composed of HIF-α and HIF-ß subunits. HIF-a is an adjusting relational subunit, which is divided into three subtypes: HIF-1a, HIF-2a, and HIF-3a. HIF-1a is the key component and best understood. HIF-1a can be activated under hypoxic conditions or by various cytokines and growth factors. HIF-1α accumulation is critical for sustaining human allergic effector cell survival and function. The level of HIF-1a is increased in the patients with allergic rhinitis and become a new therapeutic target. HIF-1a also plays an important role in the pathogenesis of CRS and polyp formation. Some research found that the expression of HIF-1α was increased in CRS with polyps. CONCLUSIONS: HIF-1a takes an important role in allergic rhinitis and chronic sinusitis. It will be a key therapeutic target of these diseases in the future.

Effect of germination temperature on characteristics of phytase production from barley.

The effects of germination temperature on the growth of barley seedlings for phytase production were studied at 15, 20 and 25 degrees C for 6-10 days. The growth rate of the barley seedlings was increased as the germination temperature was increased. The initial rate of total protein production was closely coupled to that of the barley growth, and the rate of total protein production tended to increase as the germination temperature was increased. SDS-PAGE analysis of total protein from the barley seedlings showed time-dependent appearance and disappearance of protein bands. Although no significant phytase activity was detected at zero time of germination, a significant increase in phytase activity up to 7.9-fold occurred during the first several days of germination then decreased. Phosphate production (viz. phytate degradation) in the barley seedlings occurred rapidly at the beginning of germination. However, the rate of production continued to decrease with further germination. A time lag of about 1-2 days between the rate of total protein production and that of phytase production was observed. Unlike the extent of total protein production, that of phytase production was similar irrespective of germination temperature. Partial purification of a crude enzyme extract by hydrophobic interaction chromatography resulted in two phytase fractions (PI and PII). Zymogram analysis demonstrated that PI had two bands with molecular masses of about 66 and 123 kDa while PII had one band corresponding to a molecular mass of about 96 kDa. The optimal temperature for PI was found to be 55 degrees C, while it was 50 degrees C for PII. The enzyme fraction PI had a pH optimum at 6.0, whereas the optimum pH for PII was found to be 5.0. Addition of 0.1% (v/v) Tween 80 was found to increase enzyme activity significantly (i.e., 167% for PI and 137% for PII). Phytate in cereals including barley, rice, corn and soybean degraded effectively by the treatment of the barley phytases.

An improved method to illuminate and record a phytase assay in SDS-PAGE zymogram gels.

Experimentation at the Lethbridge Research Center in Alberta, Canada using cross-polarized transmitted light to photographically record a staining technique on zymograms has proved to be successful with both color and black and white films. It has been possible to obtain the desired visible contrast without compromising the intensity of the enzyme activity bands. Increasing numbers of such PAGE gels are being submitted for photographic recording when it is believed that the image will be used for records, publication, scientific posters or AV presentations.

The effects of sequential inoculation of mixed rumen protozoa on the degradation of orchard grass cell walls by anaerobic fungus Anaeromyces mucronatus 543.

The effects of protozoa on the degradation of plant cell walls (CW) during different growth stages of the fungus Anaeromyces mucronatus have been investigated. Since fungi show a marked lag in their in vitro cultures and many protozoa rapidly die during a prolonged incubation time, the effects of protozoa may vary according to the growth phase of the fungi. Therefore, the approach adopted was (i) to inoculate CW with fungus monoculture, (ii) to inoculate CW with fungus-protozoa coculture, or (iii) to sequentially inoculate fungal cultures that had been grown in CW for 24 (initial stage of growth), 48, and 72 h (late stage of growth) with mixed protozoa. When a fungus was associated with protozoa, a growth phase dependent effect was observed. Ruminal protozoa adversely affected the growth and activity when introduced in the initial growth stage of A. mucronatus, but a synergetic interaction was detected when added to late growth stage cultures. Although there is no immediate explanation for these results, the data suggested that protozoa can engulf the fungal zoospores, which are in ruminal fluids and (or) attached to small feed particles, but cannot engulf the fungal thallus that is tightly attached to feed particles by a rhizoidal system. Our data indicated that the protozoa did not influence cellulolysis by the fungi in exponential and (or) stationary phase, but they had a marked inhibitory effect on fungi that were in lag phase. Inhibition during lag phase could result from the protozoal predation of fungal zoospores that had failed to attach to substrates.

3(2H)-Benzofuranones and chromanes from liquid cultures of the mycoparasitic fungus Coniothyrium minitans.

Two 3(2H)-benzofuranones and three chromanes were isolated from the mycoparasitic fungus Coniothyrium minitans. Their structures and absolute stereochemistry were determined by spectroscopic methods.

The catalytic domain of a Piromyces rhizinflata cellulase expressed in Escherichia coli was stabilized by the linker peptide of the enzyme.

Analysis of a carboxymethyl-cellulase clone isolated from the cDNA library of the ruminal fungus, Piromyces rhizinflata 2301, revealed that the clone encoded a polypeptide containing a cellulase catalytic domain, designated CelAcd. CelAcd was flanked by a 28-amino acid linker peptide at the N-terminus and linked to a dockerin domain by a 7-amino acid linker at the C-terminus. CelAcd showed homology with the family 5 of glycosyl hydrolases. CelAcd plus the linker peptides at both termini (designated CelcdN'C') was expressed in Escherichia coli and the purified enzyme was characterized. The feature of particular interest of CelcdN'C' was its bifunctional endo- and exo-glucanase activity, demonstrated by its ability to hydrolyse carboxymethyl cellulose (CMC) and pNP-beta-D-cellobioside. Furthermore, CelcdN'C' exhibited relatively high ability to degrade both microcrystalline Avicel and filter paper. CelcdN'C' also showed activity against barley beta-glucan, Lichenin and oat spelt xylan. The optimal activity conditions for CelcdN'C' with CMC as the substrate were pH 5.5 and 50 degrees C. Fifty percent of the enzyme activity was lost when CelcdN'C' was treated at 55 degrees C for 10 min. CelcdN'C' retained more than 10% enzyme activity after being heated under 90 degrees C for 10 min. Deletion of the N-terminal flanking linker of CelcdN'C' (the resulting protein was designated CelcdC') did not alter the enzymatic function of the catalytic domain. However, the thermal stability of CelcdC' was dramatically reduced. We conclude that the N-terminal flanking linker of CelAcd stabilizes the enzyme protein.

Purification and characterization of a cellulase from the ruminal fungus Orpinomyces joyonii cloned in Escherichia coli.

A cellulase from the ruminal fungus Orpinomyces joyonii cloned in Escherichia coli was purified 88-fold by chromatography on High Q and hydroxyapatite. N-terminal amino acid sequence analyses confirmed that the cellulase represented the product of the cellulase gene Cel B2. The purified enzyme possessed high activity toward barley beta-glucan, lichenan, carboxymethyl cellulose (CMC), xylan, but not toward laminarin and pachyman. In addition, the cloned enzyme was able to hydrolyze p-nitrophenyl (PNP)-cellobioside, PNP-cellotrioside, PNP-cellotetraoside, PNP-cellopentaoside, but not PNP-glucopyranoside. The specific activity of the cloned enzyme on barley beta-glucan was 297 units/mg protein. The purified enzyme appeared as a single band in SDS-polyacrylamide gel electrophoresis and the molecular mass of this enzyme (58000) was consistent with the value (56463) calculated from the DNA sequence. The optimal pH of the enzyme was 5.5, and the enzyme was stable between pH 5.0 and pH 7.5. The enzyme had a temperature optimum at 40 degrees C. The K(m) values estimated for barley beta-glucan and CMC were 0.32 and 0.50 mg/ml, respectively.

The impact of a clinic-based literacy intervention on language development in inner-city preschool children.

OBJECTIVE: To determine the effect of a clinic-based literacy intervention on the language development of preschool children. METHODS: A convenience sample of families presenting to 2 urban pediatric clinics for well-child care met the following criteria: the family was Latino or black and English- or Spanish-speaking; the child was 2 to 5.9 years old, with no neurodevelopmental disability, at a gestational age of 34 weeks or more, and not attending kindergarten. Participants at the first clinic (intervention group) were exposed to a literacy support program, based on Reach Out and Read (ROR), during the previous 3 years. At the second clinic (comparison group), a similar program started 3 months before the study. Parent-child reading activities were measured using the READ Subscale of the StimQ. Language development was measured using the One-Word Expressive and Receptive Picture Vocabulary Tests, and was performed in the child's primary language. RESULTS: A total of 122 study participants (49 interventions and 73 comparisons) met inclusion criteria and completed all measures. Intervention and comparison families were similar for most sociodemographic variables. Intervention families reported reading together with their children approximately 1 more day per week. Intensity of exposure to ROR (measured by total number of contacts with the program) was associated with increased parent-child reading activities, as measured by the StimQ-Read Subscale (r = 0.20). Intervention children had higher receptive language (mean: 94.5 vs 84.8) and expressive language (mean: 84.3 vs 81.6). After adjusting for potential confounders in a multiple regression analysis, intervention status was associated with an 8.6-point increase (95% confidence interval [CI]: 3.3, 14.0) in receptive language (semipartial correlation [SR]coefficient = 0.27), and a 4.3-point increase (95% CI: 0.04, 8.6) in expressive language (SR = 0.17). In a similar multiple regression, each contact with ROR was associated with an adjusted mean 0.4-point increase (95% CI: 0.1, 0.6) in receptive score, and an adjusted mean 0.21-point increase (95% CI: 0. 02, 0.4) in expressive score. CONCLUSIONS: ROR is an important intervention, promoting parental literacy support and enhancing language development in impoverished preschool children. Integration of literacy promoting interventions such as these into routine pediatric health care for underserved populations can be recommended.

Directed evolution to produce an alkalophilic variant from a Neocallimastix patriciarum xylanase.

The catalytic domain of a xylanase from the anaerobic fungus Neocallimastix patriciarum was made more alkalophilic through directed evolution using error-prone PCR. Transformants expressing the alkalophilic variant xylanases produced larger clear zones when overlaid with high pH, xylan-containing agar. Eight amino acid substitutions were identified in six selected mutant xylanases. Whereas the wild-type xylanase exhibited no activity at pH 8.5, the relative and specific activities of the six mutants were higher at pH 8.5 than at pH 6.0. Seven of the eight amino acid substitutions were assembled in one enzyme (xyn-CDBFV) by site-directed mutagenesis. Some or all of the seven mutations exerted positive and possibly synergistic effects on the alkalophilicity of the enzyme. The resulting composite mutant xylanase retained a greater proportion of its activity than did the wild type at pH above 7.0, maintaining 25% of its activity at pH 9.0, and its retention of activity at acid pH was no lower than that of the wild type. The composite xylanase (xyn-CDBFV) had a relatively high specific activity of 10128 micromol glucose x min(-1) x (mg protein)(-1) at pH 6.0. It was more thermostable at 60 degrees C and alkaline tolerant at pH 10.0 than the wild-type xylanase. These properties suggest that the composite mutant xylanase is a promising and suitable candidate for paper pulp bio-bleaching.

Effects of Tween 60 and Tween 80 on protease activity, thiol group reactivity, protein adsorption, and cellulose degradation by rumen microbial enzymes.

Microbial enzymes extracted from mixed ruminal microorganisms were incubated for 2 h with casein and Tween 60 or Tween 80 at 10 concentrations ranging from 0 to 2.0% (vol/vol) to determine the effects of these nonionic surfactants on protease activation and thiol reactivity (unmasking of thiol groups). Rate and extent of protein adsorption to cellulosic substrate (barley straw) was measured in the presence of 0, 0.05, 0.10, 0.25, and 0.50% (vol/vol) Tween 80. Degradation of cellulose by a rumen bacterial fraction was measured over 48 h of incubation with and without Tween 60 or Tween 80 at 0.25% (vol/vol). Maximum accelerations of protease activity achievable with Tween 60 and Tween 80 (calculated from a Michaelis-Menten kinetics model) were 99.2 and 166.8%, respectively. Concentrations of Tween 60 and Tween 80 at which half the maximal velocities were attained were 0.28 and 0.20% (vol/vol), respectively. Tween 80 increased (P < 0.05) the rate and extent of adsorption of microbial protein to barley straw, and the effect was related to concentration of Tween 80 up to 0.10% (vol/vol). Initial rates of cellulose degradation with no surfactant, 0.25% Tween 60, or 0.25% Tween 80 were 0.60, 0.87, and 1.04 micrograms/ml per h, respectively. These nonionic surfactants were effective for enhancing rumen microbial protease and cellulase activities. Thus, further study is warranted to determine their potential for improving ruminant feeding.

Localization of phytase in Selenomonas ruminantium and Mitsuokella multiacidus by transmission electron microscopy.

The localization of phytase (myo-inositol-hexaphosphate phosphohydrolase) in the ruminal bacteria, Selenomonas ruminantium JY35 and Mitsuokella multiacidus 46/5(2), was determined with transmission electron microscopy. Phosphate produced from the enzymatic dephosphorylation of the calcium salt of phytic acid is precipitated as calcium phosphate. The calcium is then replaced with lead to produce electron-dense lead phosphate. This deposition of lead phosphate localized phytase in S. ruminantium JY35 and M. multiacidus 46/5(2) to the outer membrane, and confirmed intracellular expression of the enzyme in Escherichia coli pSrP.2, the recombinant clone which possesses the gene (phyA) encoding phytase (phyA) in S. ruminantium.

Intraruminal supplementation with increasing levels of exogenous polysaccharide-degrading enzymes: effects on nutrient digestion in cattle fed a barley grain diet.

The effects of supplying increasing ruminal doses of exogenous polysaccharide-degrading enzymes (EPDE) on rumen fermentation and nutrient digestion were studied using eight ruminally cannulated heifers, four of which were also duodenally cannulated, in a replicated Latin square. The heifers were fed a diet of 85.5% rolled barley grain and 14% barley silage (DM basis), and once daily they were given intraruminal doses of 0 (Control), 100, 200, or 400 g of a preparation containing polysaccharide-degrading enzymes. Enzyme treatment decreased ruminal pH (linear, P<.001) and increased ammonia N (quadratic, P<.001) concentration. The ruminally soluble fraction and effective degradability of feed DM in situ were increased (quadratic response, P<.001) by enzyme treatment. Ruminal administration of EPDE increased ruminal fluid carboxymethylcellulase and xylanase activities linearly (P<.001) and beta-glucanase activity quadratically (P<.01), decreased (quadratic response, P<.05) ruminal fluid viscosity, and did not affect (P>.05) ruminal fluid amylase activity. Elevated levels of fibrolytic activities in the rumen resulted in increased (quadratic, P<.001) carboxymethylcellulase, xylanase, and beta-glucanase (P<.01) activities in duodenal digesta. Duodenal amylase activity and reducing sugar concentration were also increased (quadratic responses, P<.001 and P<.05, respectively) by EPDE. Xylanase activity of fecal DM was increased linearly (P<.05) with increasing ruminal EPDE levels. Apparent digestibilities of DM, crude protein, and NDF were not affected by EPDE supplementation. Enzyme treatment did not affect (P>.05) urinary excretion of allantoin and uric acid, or concentrations of glucose and urea in blood.

Characterization of a Neocallimastix patriciarum xylanase gene and its product.

A xylanase gene (xynC) isolated from the anaerobic ruminal fungus Neocallimastix patriciarum was characterized. The gene consists of an N-terminal catalytic domain that exhibited homology to family 11 of glycosyl hydrolases, a C-terminal cellulose binding domain (CBD) and a putative dockerin domain in between. Each domain was linked by a short linker domain rich in proline and alanine. Deletion analysis demonstrated that the CBD was essential for optimal xylanase activity of the enzyme, while the putative dockerin domain may not be required for enzyme function.

A novel staining method for detecting phytase activity.

Differential agar media for the detection of microbial phytase activity use the disappearance of precipitated calcium or sodium phytate as an indication of enzyme activity. When this technique was applied to the study of ruminal bacteria, it became apparent that the method was unable to differentiate between phytase activity and acid production. Strong positive reactions (zones of clearing around microbial colonies) observed for acid producing, anaerobic bacteria, such as Streptococcus bovis, were not corroborated by subsequent quantitative assays. Experimentation revealed that acidic solutions generated false positive results on the selected differential medium. Empirical studies undertaken to find a solution to this limitation determined the false positive results could be eliminated through a two step counterstaining treatment (cobalt chloride and ammonium molybdate/ammonium vanadate) which reprecipitates acid solubilized phytate. This report discusses the application of the developed two step counterstaining treatment for the screening of phytase producing ruminal bacteria as well as its use in phytase zymogram assays.

Pneumonia in HIV-infected patients: a case-control survey of factors involved in risk and prevention.

OBJECTIVE: To assess the factors that increase or decrease the risk of pneumonia with particular attention to immunization with pneumococcal and influenza vaccines in a group of HIV-infected persons. DESIGN: A retrospective, case-control study based on information entered into a standard database and the medical record. SETTING: Patients attending a referral clinic specializing in AIDS/HIV care at a public hospital. PATIENTS: Among over 2000 subjects entered into a database in 8 years, 127 incidents of pneumonia were identified from the record. These cases were matched with 127 CD4 cell count matched, concurrent controls. INTERVENTIONS: None. MAIN OUTCOME MEASURE: The principal hypothesis was that chart review would find a decreased frequency of pneumococcal immunization in the pneumonia cases compared with matched controls. RESULTS: Pneumococcal immunization was associated with a reduction of the risk of pneumonia by nearly 70%. The effect was seen even when immunization was given with a CD4 cell count of less than 100/mm3. Injection drug users and African-Americans had a twofold increased risk of pneumonia. CONCLUSION: The study provides data to support the current recommendation for pneumococcal immunization of all HIV-infected persons. Although this conclusion could lead to renewed enthusiasm for increasing pneumococcal immunization rates in HIV-infected persons, it must be recognized that the study is observational and ascertainment bias cannot be excluded.