The Effect of pH on Spore Germination, Growth, and Infection of Strawberry Roots by Fusarium oxysporum f. sp. fragariae, Cause of Fusarium wilt of Strawberry.

Previous work has shown that raising the pH of acidic soil to near neutrality can reduce the incidence of Fusarium wilt. The basis for this effect has not been established. The present study assessed effects of pH on spore germination, growth, and infection of strawberry roots by Fusarium oxysporum f. sp. fragariae, the cause of Fusarium wilt of strawberry. There was not a significant effect of pH (5 versus 7) on the rate of spore germination at either 20 or 25°C for any of the three tested isolates (one representative of each clonal lineage of F. oxysporum f. sp. fragariae found in California). Likewise, pH did not have a significant effect on fungal growth at 20°C. At 25°C, two isolates grew faster at pH 7 than at pH 5. Growth of the third isolate was unaffected by the difference in pH. For the strawberry cultivar Albion, the frequency of root infection was significantly higher for plants grown in acidified soil (near pH 5) than for plants grown in soil near neutrality. The higher frequency of root infection in acidified soil was associated with a lower level of microbial activity, as measured by hydrolysis of fluorescein diacetate.

The Population of Fusarium oxysporum f. sp. fragariae, Cause of Fusarium Wilt of Strawberry, in California.

The objectives of this study were to investigate the structure of the population of Fusarium oxysporum f. sp. fragariae in California and to evaluate methods for its detection. Fifty-nine isolates of F. oxysporum f. sp. fragariae were obtained from diseased strawberry plants and their identity was confirmed by pathogenicity testing. The full nuclear ribosomal intergenic spacer (IGS) and elongation factor 1-α gene (EF-1α) were amplified by polymerase chain reaction (PCR) and sequenced to elucidate phylogenetic relationships among isolates. IGS and EF-1α sequences revealed three main lineages, which corresponded to three somatic compatibility groups. Primers designed to detect F. oxysporum f. sp. fragariae in Japan amplified a 239-bp product from 55 of 59 California isolates of F. oxysporum f. sp. fragariae and from no nonpathogenic isolates of F. oxysporum. The sequence of this PCR product was identical to the sequence obtained from F. oxysporum f. sp. fragariae isolates in Japan. Intensive sampling at two locations in California showed results of tests based on PCR and somatic compatibility to be in agreement for 97% (257 of 264) of isolates tested. Our findings revealed considerable diversity in the California population of F. oxysporum f. sp. fragariae, and indications that horizontal gene transfer may have occurred.

Diagnostic yield of percutaneous, ultrasound-guided, fine needle aspirates of the gastrointestinal wall: a retrospective analysis of 152 samples.

OBJECTIVES: The aim was to assess the technical success of percutaneous ultrasound-guided fine needle aspirates of gastrointestinal wall lesions and evaluate predictors of success. Secondary aims included comparing the cytological diagnosis with histopathology, evaluating the utility of concurrent locoregional lymph node cytology and assessing the procedure's complication rate. MATERIAL AND METHODS: Gastrointestinal wall cytology from 75 dogs and 70 cats obtained between 2018 and 2023 were reviewed and categorised as successful (resulting in a diagnostic cytology report) and accurate (resulting in the correct diagnosis when compared to histopathology). Unsuccessful fine needle aspirates, not submitted for cytology, were not recorded. Variables recorded included animal signalment, lesion and lymph node's appearance on ultrasound, size, location, number of smears submitted and experience of the ultrasonographer. RESULTS: One hundred and fifty-two reports were analysed. Eighty-eight (58%) were successful: three normal epithelium, 21 inflammatory processes and 64 neoplasms. Variables associated with increased technical success included description of a mass, higher number of slides submitted and thickness of gastrointestinal lesion on ultrasound. Comparison with histopathology, performed for 17 lesions, showed discrepancies in eight, complete agreement in seven and partial in two. Eighty-four loco-regional lymph nodes were sampled, of which, 67 were successful (80%) and 52 brought additional clinical information (supporting GI wall cytology or diagnosing neoplasia not identified on GI wall cytology). No complication strictly attributable to gastrointestinal wall sampling was reported but when possibly related, death of the patient occurred in 2.5% of cases. CLINICAL SIGNIFICANCE: Ultrasound-guided fine needle aspirate of gastrointestinal wall had moderate accuracy and was unsuccessful in 42% of cases, but technical success increased when sampling mass lesions, thicker intestinal layers and submitting more slides.

Congenital ocular motor apraxia with autosomal dominant inheritance.

PURPOSE: To document congenital ocular motor apraxia in five first-degree relatives. METHODS: Case series. Five family members with a history of horizontal head thrusting had neuro-ophthalmologic evaluation. Magnetic resonance imaging of the brain was obtained in the proband. RESULTS: Four siblings (one boy and three girls) had congenital ocular motor apraxia. The father had head thrusting as a child and displayed residual signs of the disorder. Magnetic resonance imaging disclosed no central nervous system abnormalities in the father. CONCLUSION: Congenital ocular motor apraxia can be inherited as an autosomal dominant trait.

Screening for tuberculosis infection among secondary school students in Minneapolis-St. Paul: policy implications.

Three students in the St. Paul Public Schools were diagnosed with active tuberculosis (TB) in late 1991 and early 1992. To define the prevalence of TB infection in St. Paul and Minneapolis, we conducted school-based screening projects in the St. Paul and Minneapolis public schools during 1992 and 1993. In St. Paul, 7,596 (74.8%) students in grades six through 12 received Mantoux tests; 268 (3.5%) were reactive. Infection rates varied significantly by country of birth, with students born outside the United States more likely to be Mantoux reactors than U.S.-born students (RR = 20.2; 95% CI = 14.9-27.3; p < 0.001). In Minneapolis, 752 (47.2%) eighth-grade students received Mantoux tests; 23 (3.1%) were reactive. As in St. Paul, infection rates varied by country of birth; students born outside the United States were more likely to have reactive Mantoux tests than students born in this country (RR = 13.2; 95% CI = 5.6-31.4; p < 0.001). We conclude that routine TB screening of school students is not warranted in Minnesota, although school-based screening targeted at the highest risk students, particularly those born outside the United States, may be a beneficial prevention strategy.

Palladium(II)-catalyzed oxidation of aldehydes and ketones. 1. Carbonylation of ketones with carbon monoxide catalyzed by palladium(II) chloride in methanol.

Unsubstituted or alkyl-substituted cyclic ketones react with PdCl2 in methanol under a CO atmosphere to give mainly acyclic diesters along with some acyclic chloro-substituted monoesters. The monosubstituted cyclic ketones, 2-hydroxy- and 2-methoxycyclohexanone, do not give ring cleavage but rather produce 2-(carbomethoxy)cyclohex-2-en-1-one. 13CO labeling experiments indicate one CO is inserted in forming the diester product so the second ester group must arise from the original ketone group. Two mechanisms are possible for the diester reaction. One involves initial Pd(II)-CO2CH3 insertion across the double bond of the enol form of the ketone while the second involves initial addition of Pd(II)-OCH3 followed by CO insertion into the new Pd(II)-carbon bond formed. Pd(II) elimination and acid-catalyzed ring cleavage produce the second methyl ester group in both routes. The chloro-substituted monoester is formed by initial Pd(II)-Cl insertion across the double bond followed by the acid-catalyzed ring cleavage. The 2-(carbomethoxy)cyclohex-2-en-1-one must result from elimination of water or methanol from the alpha-ketoester product formed by the initial methoxycarbonylation of the enol form of the ketone. As expected, the acyclic ketone, 2-decanone, formed methyl acetate and a mixture of methyl nonanoate and 1-chlorooctane as products.