Isolation, characterization, and experimental infection of Streptococcus gallolyticus subspecies pasteurianus from commercial turkeys with acute septicemia: a pilot study.

Streptococcus gallolyticus (SG) is a Gram-positive cocci found as commensal gut flora in animals and humans. SG has emerged as a cause of disease in young poults between 1 and 3 wk of age. SG is associated with septicemia resulting in acute mortality with no premonitory signs in turkeys. Three SG isolates were obtained from clinical field cases of acute septicemia of commercial turkeys and used in three independent experiments. In Experiment 1, embryos were inoculated 25 d of embryogenesis with varying concentrations of SG1, SG2, or SG3. In Experiment 2, day of hatch, poults were inoculated with varying concentrations using different routes of administration of SG1, SG2, or SG3. In Experiment 3, day of hatch, poults were inoculated with only isolate SG1 using different paths. Poults were randomly selected for necropsy on d 8 and d 15 and sampled to collect spleen, heart, and liver for SG on d 21, the remaining poults were necropsied and cultured. Samples were plated on Columbia nalidixic acid and colistin agar (CNA) (40°C, 18-24 h). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) confirmed suspect colonies. Data were analyzed using the chi-square test of independence, testing all possible combinations to determine significance (P < 0.05). Weight data were subjected to ANOVA using JMP with significance (P < 0.05). No differences were found in BW or BWG on d 0, 8, 15, or 22. Splenomegaly, focal heart necrosis, and pericarditis were observed in all groups in experiments 1 through 3. In Experiment 3, only airsacculitis was observed in a negative control in separate isolation (P > 0.05). On d 21 of Experiment 3, increased (P < 0.05) recovery of SG from spleens were observed in co-housed negative controls, as well as poults challenged by oral gavage (P > 0.05 for d 7 and d 14). These results confirm numerous previous studies indicating that SG subsp. pasteurianus is a primary infectious microorganism that causes septicemia in young poults.

Mutations in LOXHD1 gene can cause auditory neuropathy spectrum disorder.

Objectives: The aim of this paper was to study the auditory phenotype of three related children with sensorineural hearing loss (2 sisters and their cousin) following genetic analysis revealing mutations in LOXHD1. Methods: Genetic testing was conducted on three related children. They were assessed with a standard clinical test battery including distortion otoacoustic emissions, auditory brainstem responses and audiometry. Results: We identified heterozygous variants in LOXHD1 in a family of Irish/German and Italian/Irish ancestry with autosomal recessive auditory neuropathy spectrum disorder (ANSD). Mutations in LOXHD1 (MIM #613072) have been linked to an autosomal recessive nonsyndromic hearing loss (DFNB77), mapped to the locus 18q12-q21. All three subjects had evidence of some, albeit few, functioning cochlear hair cells as revealed by the presence of a cochlear microphonic and/or partial otoacoustic emissions early in life. Conclusion: To our knowledge, this is the first association between LOXHD1 mutations and ANSD in two patients who have been successfully managed with cochlear implants.

The isolation and characterization of right-side-out plasma membrane vesicles from barley aleurone cells.

Examination of organelle- and membrane-specific processes such as signal transduction necessitates the use of plasma membrane vesicles with cytoplasmic side-in orientation. We are interested in the structural identity and subcellular localization of in vivo [32P]phosphoric acid ([32Pi])-labeled phosphoinositides, including the recently discovered phosphatidyl-scyllo-inositol, for signal transduction studies. In the first part of this investigation, plasma membrane vesicles from barley aleurone cells were isolated employing the aqueous polymer (Dextran and polyethylene glycol) two-phase partition method. The membrane vesicles that partitioned into the upper and lower phases of the aqueous polymer two-phase system were characterized and the purity of the vesicles ascertained by assaying for two marker enzymes, K+-stimulated, Mg2+-dependent adenosine triphosphatase (EC 3.6.1.3, ATPase), localized in the plasma membranes, and cytochrome c oxidase, localized in the mitochondria. Inhibitors for ATPases such as azide, molybdate, and vanadate were used to distinguish between plasma membrane-associated and intracellular membrane-associated ATPases. These inhibitor studies suggest that the plasma membrane preparation contained about 7% of intracellular membrane vesicles and the intracellular membrane fraction contained about 6% of plasma membrane vesicles. Orientation of the plasma membrane vesicles was ascertained by measuring the latent ATPase activity. These latency studies suggest that about 95% of the plasma membrane vesicles were of cytoplasmic side-in orientation. In the second part of this investigation, intracellular distribution and in vivo [32Pi] labeling of phosphoinositides in the plasma membranes and intracellular membranes were investigated. Preferential accumulation of [32Pi]-labeled phosphatidyl-myo-inositol monophosphate (myo-PIP) and phosphatidyl-myo-inositol bisphosphate (myo-PIP2) was observed in the plasma membrane. However, scyllo-phosphatidylinositol (scyllo-PI) was detected in both the plasma membrane and the intracellular membranes. The cellular concentration of myo-phosphoinositides was determined, and, after 24 h of labeling with [32Pi], the ratio of radiolabel in myo-PI, PIP, and PIP2 paralleled the relative concentrations in aleurone cells.

Biosynthesis and localization of phosphatidyl-scyllo-inositol in barley aleurone cells.

A novel isomer of phosphatidylinositol (PI), phosphatidyl-scyllo-inositol, was characterized in the aleurone cells of barley seeds. In this investigation, the subcellular localization of scyllo-PI and the relative rates of biosynthesis and accumulation of [32P]phosphoric acid ([32Pi])-labeled scyllo- and myo-phosphoinositides in the plasma membrane and intracellular membrane pools were investigated. About 25% of the [32Pi]-labeled phospholipids were present in plasma membrane and 75% in intracellular membranes. Incorporation of [32Pi] into scyllo-PI was greater than into myo-PI in both the plasma membranes and intracellular membranes at all time points investigated, thus suggesting a higher rate of biosynthesis; however, the data do not preclude reduced breakdown of labeled scyllo-PI as a contributing factor. In vitro studies were conducted to investigate the presence of cytidinediphosphate diacylglycerol (CDP-DG):scyllo-inositol 3-phosphatidyltransferase (scyllo-PI synthase) and to optimize enzymatic activity. The inclusion of nonionic detergents (Brij 58 and Triton X-100) effected significant enhancement in the biosynthesis of scyllo-PI, whereas anionic, cationic, and zwitterionic detergents had little or no effect. This is the first evidence for CDP-DG:scyllo-inositol 3-phosphatidyltransferase activity.

Microinvasion in low malignant potential tumors of the ovary.

The presence of microinvasion (Mi) has not previously been investigated in nonserous low malignant potential (LMP) tumors of the ovary. In serous LMP tumors (SLMP), Mi has not worsened the prognosis compared with usual SLMP in previous reports. In a retrospective clinicopathologic review of 126 cases of serous and mucinous LMP (MLMP) tumors of the ovary, the authors identified 14 cases with Mi: seven of 72 SLMP, four of 44 mucinous intestinal LMP (MILMP), and three of 10 mucinous müllerian LMP (MMLMP). Tumors with Mi resembled usual LMP histologically except for small foci (up to 0.2 cm) in the stroma consisting predominantly of single cells or small clusters of cells, sometimes in a cribriform pattern. In SLMP-Mi, the cells had eosinophilic cytoplasm, and the stromal reaction was minimal/absent. In MILMP-Mi and MMLMP-Mi, nuclear staining was paler; the stroma often showed a fibrous reaction or edema, especially in MILMP-Mi. All 14 patients had follow-up (2.2 to 18.6 years) and were without evidence of disease. Careful screening of both mucinous and serous ovarian LMP can show Mi. Mi foci should be distinguished from true stromal invasion, pseudoinvasion, endothelial cells, decidual cells and histiocytes, and pseudomyxoma in mucinous LMP. Mi does not seem to worsen prognosis in MLMP and SLMP tumors of the ovary.

Ovarian mucinous tumors of low malignant potential: a clinicopathologic study of 54 tumors of intestinal and müllerian type.

We have reviewed 44 mucinous intestinal (MI) and 10 mucinous mullerian (MM) tumors of low malignant potential (LMP) seen at The George Washington University Medical Center. As previously reported by Rutgers and Scully, MMLMP tumors occurred in younger women, were generally smaller and more frequently bilateral, had a papillary rather than multicystic appearance, and lacked goblet cells. All patients with MMLMP tumors were recurrence-free at last follow-up, including three whose tumors were microinvasive. Patients with MILMP tumors also all did well regardless of tumor grade, with the exception of a single patient with bilateral grade 1 ovarian tumors, an appendiceal villous adenoma, and pseudomyxoma peritonei. Microinvasion was also seen in four of these tumors, none of which recurred. Review of the literature suggests that MILMP tumors without stromal invasion but with either prominent cell stratification or marked nuclear atypia may have a worse prognosis than those lacking these features, but probably largely because of a correlation with higher stage disease. We believe that tumors of this sort should not be diagnosed as "noninvasive carcinomas," but should be sectioned more extensively for evidence of stromal invasion and subjected to careful staging. If the tumor is still noninvasive and in stage I after these procedures, the likelihood of treatment failure appears to be in the range of 1-3%.