Differentiation of Pathogenic Groups of Xylella fastidiosa Strains with Whole-Cell Protein Profiles.

Whole-cell protein analyses of 75 Xylella fastidiosa strains by sodium dodecyl sulfatepolyacrylamide gel electrophoresis were compared, and variations in the protein banding patterns among the strains were observed. Based on the presence, absence, or difference in intensity of 10 protein bands within the 21.5 to 45.0 kDa molecular mass range, the strains could be subdivided into four distinct pathogenic groups and two miscellaneous groups whose members were pathogenic to various different hosts. Group 1 was the Pierce's disease of grapevine pathogenic group. Although 4 of these 45 strains had hosts of origin other than grapevine, they all produced Pierce's disease symptoms. Uniform, distinct protein profiles also occurred with group 2 (elderberry leaf scorch strains), group 3 (oak leaf scorch strains), and group 4 (oleander leaf scorch strains). Groups 5 and 6 were made up of strains pathogenic to almond, blackberry, lupine, mulberry, periwinkle, elm, and plum. Thus, whole-cell protein analysis was shown to be a rapid and consistent method for identifying four pathogenic groups of X. fastidiosa strains.

First Report of Oleander Leaf Scorch Caused by Xylella fastidiosa in Florida.

During the spring of 1998, mature oleanders (Nerium oleander L.), pruned to form a 2-m-high hedge along an interstate highway in Orlando, FL, were observed declining and dying. Numerous plants along a 200-m section of highway were in various stages of decline. Symptoms began as chlorotic mottling along the edges of leaves and as the disease progressed, mottling became more severe and leaf margins became necrotic. Scorched leaves died, and symptoms spread throughout the plants, resulting in defoliation. New growth from the base of affected plants was stunted and severely mottled. Petioles and leaf midribs were taken from leaves with mottling symptoms and assayed for the presence of Xylella fastidiosa by polymerase chain reaction (PCR) and culturing on periwinkle wilt agar medium. For PCR assay, infected tissue from three plants was extracted by grinding in SCP buffer (1.0 g of trisodium citrate and 1.0 g of disodium succinate per liter, in 0.015 M phosphate buffer, pH 7.0) containing 0.02 M sodium ascorbate and 5% acid-washed polyvinylpyrrolidone. Amplification was performed with primers RST31 and RST33, as previously described, for specific detection of X. fastidiosa strains (1). A X. fastidiosa-specific amplification product was produced from all three extracts. For culturing, petioles and leaf midribs were cut into 0.5-cm sections, and sap was extracted from the tissue by squeezing with a forceps. Sap was blotted directly onto the medium and incubated at 28°C. Colonies typical of X. fastidiosa were observed after 10 to 14 days of incubation, and single colonies were transferred to fresh periwinkle wilt agar. The colonies were confirmed as X. fastidiosa by PCR assay. Two of the oleander strains were used to inoculate three red and three white 18-month-old oleanders by needle-puncture of the stem through a cloudy drop of bacterium in SCP buffer (108 CFU/ml). For controls, three red and three white oleanders were inoculated with SCP buffer alone. After 9 weeks in a screenhouse, marginal leaf mottling was observed in both the red and white oleanders inoculated with X. fastidiosa, and the bacterium was reisolated from leaves as described above, completing Koch's postulates. Control plants remained symptomless. Oleander leaf scorch caused by X. fastidiosa has been described previously in California and Texas (2). This is the first report of oleander leaf scorch in Florida and the eastern United States. References: (1) G. V. Minsavage et al. Phytopathology 84:456, 1994. (2) A. H. Purcell et al. Phytopathology 89:53, 1999.

The surgical treatment of adrenal gland tumors--incidentaloma.

Analysis of 32 patients operated on because of accidentally discovered adrenal tumors "incidentaloma" is presented. In 12 of them there was subclinical hormonal activity, in 9 of them tumors turned out to be pheochromocytoma and 3 of them were cortex adenoma. There were 20 hormonally inactive tumors, in 5 of them there were malignant lesions (4 of the cortex and 1 of the medulla). For evaluation of hormonal activity of adrenal tumors evaluation of chromogranin A and cortisol serum blood level or urine free cortisol level is recommended. For precise localization of the tumor beside USG also CT examination is of use. According to the high percentage of malignant lesions in "incidentaloma" type tumors, surgery treatment without delay is recommended. BAC or DHES in blood serum examinations were not found helpful in preoperative evaluating the lesions as benign or malignant. In case of preoperatively found subclinical hormonal hyperactivity of medulla pharmacological treatment with alpha and beta blockers in surgery preparation is recommended. Lateral extraperitoneal access for adrenalectomy is considered safe and provides good operational view. Laparoscopic procedure because of high percentage of malignant lesions in this group of patients is not justified.

Primary cerebral neuroblastoma: CT and MR findings in 12 cases.

A retrospective CT, MR, and clinical study was performed in 12 patients, five children and seven adults, with histologically proved primary CNS neuroblastoma. The CT and MR appearances of this neoplasia were more variable than generally recognized. Although seven tumors were predominantly intraparenchymal masses with calcification and cyst formation, five were intra- or juxtaventricular. CT was preferable to noncontrast MR both at initial diagnosis and follow-up for identification of calcification, recurrent tumor at surgical sites, and leptomeningeal disease. Noncontrast MR was useful primarily for localization of peri- and intraventricular lesions. We conclude that primary CNS neuroblastoma has a more variable radiographic appearance than is generally recognized, and that an intra- or periventricular epicenter is common.

Primary cerebral neuroblastoma: CT and MR findings in 12 cases.

A retrospective CT, MR, and clinical study was performed in 12 patients, five children and seven adults, with histologically proved primary CNS neuroblastoma. The CT and MR appearances of these neoplasia were more variable than generally recognized. Although seven tumors were predominantly intraparenchymal masses with calcification and cyst formation, five were intra- or juxtaventricular. CT was preferable to noncontrast MR both at initial diagnosis and follow-up for identification of calcification, recurrent tumor at surgical sites, and leptomeningeal disease. Noncontrast MR was useful primarily for localization of peri- and intraventricular lesions. We conclude that primary CNS neuroblastoma has a more variable radiographic appearance than is generally recognized, and that an intra- or periventricular epicenter is common.

CT and chest radiography are equally sensitive in the detection of pneumothorax after CT-guided pulmonary interventional procedures.

Pneumothorax is the most common complication after CT-guided pulmonary interventional procedures and should be promptly diagnosed and treated. Because it is easier to obtain CT scans than chest radiographs after CT-guided interventional procedures, it is important to know the sensitivity of CT in detecting pneumothoraces. To determine the sensitivity of CT for detecting procedure-induced pneumothoraces, we retrospectively reviewed 70 pulmonary interventional procedures performed under CT guidance. The sensitivity for detecting pneumothoraces with CT was compared with the detection rate with expiratory chest radiographs. Thirty-two (46%) of 70 procedures resulted in pneumothorax. Twenty-nine (91%) of the pneumothoraces were detected on CT scans and 27 (84%) were detected on chest radiographs. The difference between these two detection rates was not statistically significant (p less than .90). We conclude that postprocedure CT scans can replace expiratory chest radiographs for the detection of pneumothoraces after CT-directed pulmonary procedures.

A cystine-dependent inactivator of tyrosine aminotransferase co-purifies with gamma-cystathionase (cystine desulfurase).

Tyrosine aminotransferase is stable in homogenates of rat liver, but not when L-cystine or L-cysteine is added, which causes the enzyme to be reversibly inactivated due to oxidation of thiol groups. By monitoring inactivation of the aminotransferase in the presence of L-cystine, a factor responsible for this loss of activity was purified from rat liver. The factor required vitamin B6 and co-purified with gamma-cystathionase during numerous steps. Highly purified inactivating factor contained a protein that was identical in size and isoelectric point to cystathionase but also contained a dissimilar peptide that appeared to be unrelated to cystathionase. Cystathionase and the cystine-dependent inactivator shared several catalytic activities, including the hydrolysis of cystathionine, desulfuration of cystine, and desulfhydration of cysteine. During incubation of L-cysteine with the purified factor, hydrogen sulfide was generated but no inactivation of the aminotransferase occurred, suggesting that cysteine-dependent inactivation requires additional mechanisms. An insoluble inactivator of tyrosine aminotransferase that is produced during the reaction may be elemental sulfur, since colloidal suspensions of sulfur also inhibited the enzyme. Another inhibitor fractionated with high molecular weight substances; this may be protein-bound sulfane.