Prevalence of Alcaligenes faecalis in North Carolina broiler flocks and its relationship to respiratory disease

In order to assess the role of Alcaligenes faecalis in respiratory disease of broilers, a study was conducted to determine the prevalence of this bacterium in North Carolina broilers and to determine the relationship of A. faecalis infection to clinical disease. Our studies showed that A. faecalis is prevalent in North Carolina commercial broilers during the winter months. Bacteriological examination of turbinates and tracheas revealed that almost 40% of individual birds between 35 and 45 days of age yielded positive cultures; 62% of tested flocks were infected. When present, A. faecalis was usually the predominant bacterium isolated. Furthermore, because of a higher frequency of A. faecalis isolation in broiler flocks with respiratory disease (75% vs. 29% in flocks without respiratory diseases), these studies suggest a causal relationship between this bacterium and clinical respiratory disease.     

Experimental reproduction of enteritis in bobwhite quail (Colinus virginianus) with Cryptosporidium and reovirus

Five-day-old bobwhite quails were inoculated with reovirus and Cryptosporidium previously isolated from the intestinal contents of young, commercially raised bobwhite quails experiencing severe enteritis. Quails inoculated with reovirus alone did not develop clinically apparent disease, infection was localized principally in the intestinal tract, and no lesions were detected. Quails inoculated with Cryptosporidium, alone or with reovirus, developed severe enteritis with high mortality and marked growth depression. Cryptosporidia caused blunting of intestinal villi and provoked a mononuclear cell response in the lamina propria. The severity of intestinal lesions correlated with numbers of parasites. An apparent synergistic effect in dually infected quails was indicated by enhanced Cryptosporidium oocyst shedding, greater numbers of cryptosporidia in the intestinal tracts, and systemic reovirus infection. In addition, multifocal liver necrosis was detected in dually infected quails but was absent in quails infected with only reovirus or Cryptosporidium. The results suggest that Cryptosporidium promoted systemic spread of reovirus, and reovirus intensified Cryptosporidium infection, but no significant synergistic effect on mortality or weight gain was detected. The most important agent in the naturally occurring acute enteritis of bobwhite quails was Cryptosporidium.     

Comparison of biopsy samples obtained using standard endoscopic instruments and the harmonic scalpel during laparoscopic and laparoscopic-assisted surgery in normal dogs

Objectives— To compare tissue specimens of canine abdominal organs collected by standard techniques (ST) and harmonic scalpel (HS) and to determine the effect of each technique on wound healing.
Study Design— Experimental.
Animals— Twelve dogs.
Methods— Paired biopsy samples (ST, HS) were collected from liver, spleen, adrenal gland, pancreas, stomach, jejunum, and bladder using laparoscopic or laparoscopic-assisted methods. Hemorrhage at biopsy sites was assessed (present or absent). Specimens were evaluated for diagnostic quality and histologic changes. Dogs were necropsied at 4 or 14 days postoperatively.
Results— HS incision caused less frequent hemorrhage of all organs except spleen. HS specimens had more coagulation necrosis than ST specimens, but both techniques yielded specimens that were sized similarly and were of diagnostic quality. At necropsy, HS biopsy sites of the stomach, jejunum, bladder, adrenal gland, and pancreas were more hyperemic than ST sites. There were more adhesions at jejunal and pancreatic ST biopsy sites. HS biopsy sites had more coagulation necrosis at days 4 and 14 postoperatively. Differences in fibrin deposition, inflammation, and fibrosis were present at biopsy sites of some organs at days 4 or 14 and in comparisons between days 4 and 14.
Conclusions— Diagnostic quality biopsy specimens were obtained with HS and ST. Although HS-induced gross and histologic changes during the first 2 postoperative weeks, no clinical complications were observed.
Clinical Relevance— Both HS and ST can yield specimens with minimal hemorrhage and HS resulted in no apparent postoperative problems in normal dogs. Although HS caused more inflammation and adhesions at biopsy sites of the pancreas, adrenal gland, and jejunum, no clinical complications occurred.     

A systematic survey of loss-of-function variants in human protein-coding genes

Genome-sequencing studies indicate that all humans carry many genetic variants predicted to cause loss of function (LoF) of protein-coding genes, suggesting unexpected redundancy in the human genome. Here we apply stringent filters to 2951 putative LoF variants obtained from 185 human genomes to determine their true prevalence and properties. We estimate that human genomes typically contain ~100 genuine LoF variants with ~20 genes completely inactivated. We identify rare and likely deleterious LoF alleles, including 26 known and 21 predicted severe disease-causing variants, as well as common LoF variants in nonessential genes. We describe functional and evolutionary differences between LoF-tolerant and recessive disease genes and a method for using these differences to prioritize candidate genes found in clinical sequencing studies.