Construction and evaluation of cDNA libraries for large-scale expressed sequence tag sequencing in wheat (Triticum aestivum L.).

A total of 37 original cDNA libraries and 9 derivative libraries enriched for rare sequences were produced from Chinese Spring wheat (Triticum aestivum L.), five other hexaploid wheat genotypes (Cheyenne, Brevor, TAM W101, BH1146, Butte 86), tetraploid durum wheat (T. turgidum L.), diploid wheat (T. monococcum L.), and two other diploid members of the grass tribe Triticeae (Aegilops speltoides Tausch and Secale cereale L.). The emphasis in the choice of plant materials for library construction was reproductive development subjected to environmental factors that ultimately affect grain quality and yield, but roots and other tissues were also included. Partial cDNA expressed sequence tags (ESTs) were examined by various measures to assess the quality of these libraries. All ESTs were processed to remove cloning system sequences and contaminants and then assembled using CAP3. Following these processing steps, this assembly yielded 101,107 sequences derived from 89,043 clones, which defined 16,740 contigs and 33,213 singletons, a total of 49,953 "unigenes." Analysis of the distribution of these unigenes among the libraries led to the conclusion that the enrichment methods were effective in reducing the most abundant unigenes and to the observation that the most diverse libraries were from tissues exposed to environmental stresses including heat, drought, salinity, or low temperature.

Osseous reaction to implanted ZOE retrograde filling materials in the tibia of rats.

The osseous reaction of IRM and EBA cement were studied utilizing an intraosseous implant technique in rats. Samples of IRM, EBA cement, and amalgam were placed into polyethylene tubes and subsequently introduced surgically into rat tibias. Specimens of each were evaluated histologically after 7, 14, 21, 56, and 100 days. The IRM and amalgam samples demonstrated essentially complete healing at 56 days. The EBA cement samples displayed a slightly greater inflammatory response up to the 56-day interval; however, they also showed complete healing by 100 days. A favorable osseous reaction was seen with both of these zinc oxide-eugenol materials.

Preliminary investigation of the histological effects of laser endodontic treatment on the periradicular tissues in dogs.

This study was conducted to determine the biological effects on the periradicular tissues of Nd:YAG laser endodontic treatment in dogs. Twelve vital teeth (24 roots) of two mongrel dogs were randomly selected to receive conventional or Nd:YAG laser endodontic treatment. Endodontic therapy was performed on the second, third, or fourth, right or left, mandibular premolars. The teeth were evaluated radiographically and histologically at 1, 15, and 30 days after endodontic treatment. The remaining teeth served as untreated controls. The results of this study revealed laser treatment causes cell necrosis in the periodontal ligament 1 day after treatment. Conventionally prepared teeth displayed no evidence of cell necrosis in the periodontal ligament. At 15 days posttreatment, both the laser and conventionally treated teeth showed increased size and numbers of osteocytes and osteoclasts in the periradicular bone. Additionally, laser-treated teeth showed signs of initial bone resorption. At 30 days posttreatment, conventionally treated teeth began to return to normal morphology. The laser-treated teeth exhibited ankylosis, cemental lysis, and major bone remodeling.

Evaluation of the antibacterial effects of intracanal Nd:YAG laser irradiation.

Fifty canals of extracted single-rooted teeth were prepared to a size 50 master apical file, sterilized in ethylene oxide, and inoculated with a known quantity of Bacillus stearothermophilus spores. Five groups of 10 canals each were used. The control group received no treatment. The four treatment groups were exposed to pulsed Nd:YAG laser radiation or 0.5% NaOCl alone and in combination. The root canals were flushed with sterile distilled water to recover spores, and serial dilutions were incubated on blood agar and the number of colony-forming units recovered was determined. Analysis of the data indicated a 2-log reduction in colony-forming units among the four treatment groups as compared with the controls; however, no significant differences were observed among the treatment groups. In none of the treatment groups were the root canals sterilized.

Thermal effects of continuous wave CO2 laser exposure on human teeth: an in vitro study.

The thermal effects of continuous wave carbon dioxide laser irradiation on human teeth were investigated. Internal temperature changes were monitored by means of electrical thermistors implanted within the pulp chambers of 20 extracted, unerupted human molar teeth. One-hundred test exposures at various powers and durations were obtained. Linear regression/correlation analysis of the data suggests a direct relationship between the independent variable, exposure energy (joules), and the dependent variable, internal temperature, under the conditions of this study.

Prevalence and morphologic features of apical deltas in the canine teeth of dogs.

Prevalence and morphologic features of the apical delta in the canine teeth of dogs were determined to assist clinicians in the endodontic treatment of these teeth. Eighty-two canine teeth from mixed-breed dogs were cleared and dyed to outline root canal ramifications. Apical deltas were classified according to location in the dental arch, number of ramifications, and vertical extent of these ramifications from the apical terminus. A classification system was devised to aid in identification and treatment of the delta. Recommendations were made regarding indications for conventional and/or surgical endodontic therapy depending on the type of delta encountered. Apical deltas were detected in 69.5% of the canine teeth studied. Surgical endodontic intervention should be seriously considered when the delta is found to extend a distance > 1 mm from the apical terminus.

Acute pancreatitis in a low alcohol-consuming community.

The case records 50 patients with abdominal pain and hyperamylasemia were studied in detail. Ten cases of gallstone induced hyperamylasemia, in which no evidence of pancreatitis was found at operation, were excluded. The etiological factors in the remaining group of forty cases of acute pancreatitis, in a community practicing alcohol abstinence, were reviewed. Both alcoholic and idiopathic pancreatitis were insignificant factors in the etiology of acute pancreatitis. Eighty percent of cases of acute pancreatitis were due to biliary tract disease. A younger age-group and female preponderance, as well as biochemical evidence of cholestasis, was observed in this group. An inverse relationship between preoperative serum amylase levels and the severity of the disease was noted. A more aggressive diagnostic work-up is, however, warranted to identify these cases, for which early surgery is advocated. There was no mortality in operated cases of biliary pancreatitis.

Gall-bladder interposition: a rare anomaly of the extrahepatic ducts.

Abnormalities in bile ducts pattern occur frequently enough to merit importance during cholecystectomy. A patient with anomalous insertion of both hepatic ducts into the gall-bladder with the cystic duct replacing the common bile duct is described. This case, and related anomalies of the bile ducts, are sufficiently important for us to ascertain their location and pattern prior to removal of the gall-bladder. Inadvertent injury to a normal or aberrant bile duct can result in morbidity and even mortality. Knowledge of the embryogenesis of these anomalies helps in the understanding of the location and pattern of these malformations. Almost all of these unusual bile duct arrangements can be recognised by following the rules of meticulous dissection and accurate knowledge of these anatomical aberrations.

Eosinophilic enteritis with perforation.

A case of eosinophilic granuloma of the gastrointestinal tract with free perforation is described. The authors believe this is the first such case to be published. The patient, a 60-year-old woman, had no history of allergy. At laparotomy, 100 ml of pus was aspirated. A 42-cm section of small bowel, containing multiple punched-out ulcers, was excised. The mucosa and submucosa of the operative specimen were edematous; there was a moderate inflammatory infiltrate containing numerous eosinophils and neutrophils. The lesion appeared to represent a local reaction to some antigen with resultant eosinophilic infiltration.

Rational approach to therapy in splenic abscess.

Intrasplenic abscess is an uncommon but potentially lethal condition. Seven cases of splenic abscess were seen between 1985 and 1988. There are no specific clinical findings; symptoms and signs of fever, abdominal pain and tenderness were present in all seven cases but were only helpful in diagnosing splenic abscess in three cases. Computed tomographic scanning probably at present offers the most direct way of evaluating the spleen and making an early diagnosis. Splenectomy was done in three cases and antibiotics were used in four cases with equally successful results. Contrary to the prevalent opinion, we believe that medical management is an important addition to the surgeon's armamentarium and offers a viable alternative in selected cases of splenic abscess. A successful outcome is dependent on a high degree of clinical alertness, an aggressive diagnostic approach and prompt effective treatment.