Responses in the rumen microbiome of Bos taurus and indicus steers fed a low-quality rice straw diet and supplemented protein.

Bos indicus typically perform better than Bos taurus when consuming a low-quality diet; however, the response to supplementation is generally greater in B. taurus. The underlying mechanisms supporting these responses have not been fully elucidated. Characterization of differences in rumen prokaryotic populations and their functional role in the two subspecies may provide additional insight. Ten cannulated steers (5 Angus and 5 Brahman) were used in concurrent 5 × 5 Latin squares. Animals were offered ad libitum access to rice straw (4.7% CP). Treatments consisted of an unsupplemented control diet and two levels (50 or 120 mg N/kg BW) of isonitrogenous supplements (30% CP), that were either high (H; 74%) or low (L; 26%) in undegradable intake protein. Rumen samples were collected at 0 and 4 h postfeeding and separated into liquid and solid fractions. Rumen bacterial taxa were sequenced utilizing a Roche 454 platform based on the 16s rRNA gene. At 97% sequence similarity, 97,826 operational taxonomic units were identified, which included 24 phyla, 108 families, and 255 genera. Analysis included SAS PROC mixed model, QIIME, and PICRUSt. Across all samples, Bacteroidetes and Firmicutes accounted for 65% and 28% of total bacterial abundance, respectively. The families Prevotellaceae (P = 0.05) and Ruminococcaceae (P = 0.004) and the genera Prevotellaceae (family; P = 0.003) within the phyla Bacteroidetes differed significantly in relative abundance with added protein when compared to the control. Consistent differences in the relative abundance of family and genus taxa between B. indicus and B. taurus suggest roles the symbiotic rumen microbiome may have in the capacity of B. indicus to utilize low-quality forage over a range of supplement types and levels including (Prevotella, Ruminococcus [family], Sphingobacteriaceae [family], Bacteroidales [order], Pontibacter, Bacteroides, Succiclasticum, Barnesiella, and Xylanibacter). Overall bacterial community diversity differences across parameters were limited. Rice straw is recalcitrant to bacterial digestion because of high levels of silica in the epidermis making this straw more resistant to bacterial attachment. Thus, this analysis represents the bacterial diversity and function of the rumen under conditions depleted CP, recalcitrant fiber matrix and restricted digestibility which appear to limit the microbial population to those capable of attaching and digesting complexed structural carbohydrates, resulting in reduced plasticity, and more evenness in diversity across parameters.

Premature apoptosis of Chlamydia-infected cells disrupts chlamydial development.

The obligate intracellular development of Chlamydia suggests that the bacteria should be vulnerable to premature host cell apoptosis, but because Chlamydia-infected cells are apoptosis resistant, this has never been able to be tested. We have devised a system to circumvent the apoptotic block imposed by chlamydial infection. When the proapoptotic protein Bim(S) was experimentally induced, epithelial cells underwent apoptosis that was not blocked by chlamydial infection. Apoptosis during the developmental cycle prevented the generation of infectious bacteria and caused transcriptional changes of bacterial genes and loss of intracellular ATP. Intriguingly, although apoptosis resulted in destruction of host cell structures and of the Chlamydia inclusion, and prevented generation of elementary bodies, Bim(S) induction in the presence of a caspase inhibitor allowed differentiation into morphologically normal but noninfectious elementary bodies. These data show that chlamydial infection renders host cells apoptosis resistant at a premitochondrial step and demonstrate the consequences of premature apoptosis for development of the bacteria.

Essiac and Flor-Essence herbal tonics stimulate the in vitro growth of human breast cancer cells.

BACKGROUND: People diagnosed with cancer often self-administer complementary and alternative medicines (CAMs) to supplement their conventional treatments, improve health, or prevent recurrence. Flor-Essence and Essiac Herbal Tonics are commercially available complex mixtures of herbal extracts sold as dietary supplements and used by cancer patients based on anecdotal evidence that they can treat or prevent disease. In this study, we evaluated Flor-Essence and Essiac for their effects on the growth of human tumor cells in culture. METHODS: The effect of Flor-Essence and Essiac((R)) herbal tonics on cell proliferation was tested in MCF-7, MDA-MB-436, MDA-MB-231, and T47D cancer cells isolated from human breast tumors. Estrogen receptor (ER) dependent activation of a luciferase reporter construct was tested in MCF-7 cells. Specific binding to the ER was tested using an ICI 182,780 competition assay. RESULTS: Flor-Essence and Essiac herbal tonics at 1%, 2%, 4% and 8% stimulated cell proliferation relative to untreated controls in both estrogen receptor positive (MCF-7 and T47D) and estrogen receptor negative (MDA-MB-231 and MDA-MB-436) cell lines. Exposure to the tonics also produced a dose-dependent increase in ER dependent luciferase activity in MCF-7 cells. A 10(-7) M concentration of ICI 182,780 inhibited the induction of ER dependent luciferase activity by Flor-Essence and Essiac, but did not affect cell proliferation. CONCLUSION: Flor-Essence and Essiac Herbal Tonics can stimulate the growth of human breast cancer cells through ER mediated as well as ER independent mechanisms of action.

Selective interference with pacemaker activity by electrical dental devices.

OBJECTIVE: We sought to determine whether electromagnetic interference with cardiac pacemakers occurs during the operation of contemporary electrical dental equipment. STUDY DESIGN: Fourteen electrical dental devices were tested in vitro for their ability to interfere with the function of two Medtronics cardiac pacemakers (one a dual-chamber, bipolar Thera 7942 pacemaker, the other a single-chamber, unipolar Minix 8340 pacemaker). Atrial and ventricular pacemaker output and electrocardiographic activity were monitored by means of telemetry with the use of a Medtronics 9760/90 programmer. RESULTS: Atrial and ventricular pacing were inhibited by electromagnetic interference produced by the electrosurgical unit up to a distance of 10 cm, by the ultrasonic bath cleaner up to 30 cm, and by the magnetorestrictive ultrasonic scalers up to 37.5 cm. In contrast, operation of the amalgamator, electric pulp tester, composite curing light, dental handpieces, electric toothbrush, microwave oven, dental chair and light, ENAC ultrasonic instrument, radiography unit, and sonic scaler did not alter pacing rate or rhythm. CONCLUSIONS: These results suggest that certain electrosurgical and ultrasonic instruments may produce deleterious effects in medically fragile patients with cardiac pacemakers.

Sindbis virus DNA-based expression vectors: utility for in vitro and in vivo gene transfer.

Several DNA-based Sindbis virus vectors were constructed to investigate the feasibility and potential applications for initiating the virus life cycle in cells transfected directly with plasmid DNA. These vectors, when transfected into mammalian cells, have been used to produce virus, to express heterologous genes, and to produce infectious vector particles. This approach involved the conversion of a self-replicating vector RNA (replicon) into a layered DNA-based expression system. The first layer includes a eukaryotic RNA polymerase II expression cassette that initiates nuclear transcription of an RNA which corresponds to the Sindbis virus vector replicon. Following transport of this RNA from the nucleus to the cytoplasm, the second layer, autocatalytic amplification of the vector, proceeds according to the Sindbis virus replication cycle and results in expression of the heterologous gene. The Sindbis virus DNA vectors expressed reporter genes in transfected cells at levels that were comparable to those of in vitro-transcribed RNA replicons and were approximately 10-fold higher than the levels produced by conventional RNA polymerase II-dependent plasmids in which the promoter and reporter gene were linked directly. Reporter gene expression was also observed in rodent muscle following injection with Sindbis virus DNA vectors. In a second application, packaged vector particles were produced in cells cotransfected with complementing replicon and defective helper DNAs. The Sindbis virus-derived DNA vectors described here increase the utility of alphavirus-based vector systems in general and also provide a vector with broad potential applications for genetic immunization.

Differentiation of pathogenic Escherichia coli strains in Brazilian children by PCR.

A PCR technique to differentiate pathogenic enteric Escherichia coli strains in a field setting was evaluated. Among 76 children with acute diarrhea, this technique identified 12 children (16%) with enterotoxigenic E. coli, 6 (8%) with enteropathogenic E. coli, and 1 (1%) with enteroinvasive E. coli infection. Compared with the conventional assays, the PCR method proved to be simpler, more rapid, and inexpensive and therefore suitable for application in a developing-country field setting.

Neuropsychological impairment in Duchenne muscular dystrophy.

Fourteen younger (ages 6 to 10 years) and 11 older (ages 11 to 16 years) Duchenne Muscular Dystrophy (DMD) patients were tested with the WISC-R and neuropsychological language, visual-motor, and motor tasks. Older boys had an average IQ; younger boys were in the low average IQ range. Younger DMD boys were inferior to the older DMD group on tasks requiring some language and attentional-organizational skills, but not on visual-motor tasks. Older DMD boys were inferior on motor tasks. Results suggest that the reported low cognitive skills in DMD patients are not fixed or global, but reflect selective deficits in the younger boys. Possible bases for age differences in performance are discussed.

A prevalence survey of infections in a combined acute and long-term care hospital.

A prevalence survey of infections among 572 acute and long-term care patients in the Albany Veterans Administration Medical Center was conducted in September 1979. Presence of infection was determined by patient examination and chart review. Urine specimens from 94% of patients were cultured. The total number of clinically significant infections was 178; 117 were nosocomial (20.5 per 100 patients). The prevalence rate of nosocomial infections was highest on the Intermediate Service (long-term medical care) followed by the Surgical and Medical Services. Sites with the highest nosocomial infection rates were urinary tract (10.7), skin and subcutaneous tissues (5.1), and surgical wounds (3.0) per 100 patients. Nosocomial infections increased with age and length of hospital stay which partially explained the higher rate on the Intermediate Service. Patients using condom drainage and Foley catheters showed similarly high rates of bacteriuria. Antimicrobial drug use was 17% for acute care patients and 4% for long-term and psychiatry patients. Excepting Providencia stuartii urinary tract infection confined to the Intermediate Service, the bacterial isolates and their antibiotic susceptibilities were similar for the acute and long-term care services.

The prevalence survey as an infection surveillance method in an acute and long-term care institution.

A point prevalence survey of infections was done in 22 patients areas at the Albany VA Medical Center between September 17 and 28, 1979. The study was designed by a consultant epidemiologist, two infectious disease physicians, a biostatistician, two infection control nurses, a microbiologist, and a clinical pharmacist. A 16-page worksheet was designed for rapid and complete data collection, with computer codes and programming cross references incorporated. A total of 572 patients were seen and evaluated for signs and symptoms of infection; cultures were taken if indicated, and charts were reviewed. Urine cultures were obtained in 95% of patients. Data available for analysis will allow for a description of the characteristics of the patient population, identification of the most prevalent sites of infection and causative organisms, an analysis of antimicrobial agent use, and a description of the risk factors and their interactions that may influence the acquisition of infection.

Cleft palate velopharyngeal musculature in a five-month-old infant: a three dimensional histological reconstruction.

The structure of the velar muscles in a five-month-old infant with a cleft of the secondary palate was studied using the Plexiglas reconstruction method based on serial histological sections. The right side was sectioned horizontally and the left side in the coronal plane. Sections were projected at a magnification of 18, and muscle fibers and bone and mucosal surfaces were drawn on Plexiglas sheets. Each reconstruction was divided into representative levels which were described in detail. The three-dimensional reconstructions vividly demonstrated the anterior insertion of the levator, palatopharyngeus, and uvular muscles, and the abnormal anterior position of the velar muscles generally. The levator muscle appeared to be in a position to obstruct the auditory tube during muscle contraction. The palatoglossus muscle evidently received a substantial contribution of muscle fibers from levator as well as from some fibers originating from the pterygoid hamulus. A bundle of muscle fibers from the tensor muscle did not pass around the pterygoid hamulus but coursed anteriorly to insert on the maxillary tuberosity. The results provided fresh support for the case of intravelar surgical reorientation of the abnormally inserted muscles.