Streptococcus pasteurianus septicemia.

Streptococcus pasteurianus is part of the normal flora of the intestine. It has also been isolated from various infection sites. However, to date it has not been reported as a cause of fulminant septicemia and death. We report the post-mortem findings in a splenectomized hemophiliac patient with cirrhosis and concurrent human immunodeficiency virus (HIV), hepatitis B and hepatitis C infections.

The chromoplasts of Or mutants of cauliflower (Brassica oleracea L. var. botrytis).

The Or mutation in cauliflower (Brassica oleracea L. var. botrytis) leads to abnormal accumulations of beta-carotene in orange chromoplasts, in tissues in which leucoplasts are characteristic of wild-type plants. Or chromoplasts were investigated by light microscopy of fresh materials and electron microscopy of glutaraldehyde- and potassium permanganate-fixed materials. Carotenoid inclusions in Or chromoplasts resemble those found in carrot root chromoplasts in their optical activity and angular shape. Electron microscopy revealed that the inclusions are made up of parallel, membrane-bound compartments. These stacks of membranes are variously rolled and folded into three-dimensional objects. We classify Or chromoplasts as "membranous" chromoplasts. The Or mutation also limits plastid replication so that a single chromoplast constitutes the plastidome in most of the affected cells. There are one to two chromoplasts in each cell of a shoot apex. The ability of differentiated chromoplasts to divide in the apical meristems of Or mutant plants resembles the ability of proplastids to maintain plastid continuity from cell to cell in meristems of Arabidopsis thaliana mutants in which plastid replication is drastically limited. The findings are used to discuss the number of levels of regulation involved in plastid replication.

High-resolution genetic and physical mapping of the cauliflower high-beta-carotene gene Or ( Orange).

Mutation in the cauliflower gene Or causes high levels of beta-carotene to accumulate in various tissues of the plant that are normally devoid of carotenoids. To decipher the molecular basis by which Or regulates carotenoid accumulation, we have undertaken the isolation of Or by a map-based cloning strategy. Two previously isolated, locus-specific, sequence-characterized amplified region (SCAR) markers that flank Or were employed for the analysis of a large segregating population consisting of 1632 F(2) individuals, and a high-resolution genetic linkage map of the Or locus region was developed. To facilitate positional cloning, we constructed a cauliflower genomic library in a bacterial artificial chromosome (BAC) vector, using high molecular weight DNA from Or homozygotes. The BAC library comprises 60,288 clones with an average insert size of 110 kb, and represents an estimated 10-fold coverage of the genome. A BAC contig encompassing the Or locus was established by screening the library with a marker that is closely linked to Or and by identifying overlapping BAC clones by chromosome walking. Physical mapping delimited the Or locus to a 50-kb DNA fragment within a single BAC clone, which corresponds to a genetic interval of 0.3 cM.

Molecular mapping of Or, a gene inducing beta-carotene accumulation in cauliflower (Brassica oleracea L. var. botrytis).

The cauliflower (Brassica oleracea L. var. botrytis) Or gene is a semi-dominant, single-locus mutation that induces the accumulation of high levels of beta-carotene in various tissues of the plant, turning them orange. As part of a map-based cloning strategy, molecular mapping of the Or gene in the cauliflower genome was undertaken in a mapping population consisting of 195 F2 individuals. By using amplified fragment length polymorphism (AFLP) in conjunction with bulked segregant analysis, we identified 10 AFLP markers closely linked to the Or gene. Four of the most closely linked flanking markers were converted into restriction fragment length polymorphism (RFLP) markers. Mapping of these markers in the mapping population placed two of them at 0.5 cM from the Or locus on one side, while another marker flanked the Or gene at 1.6 cM on the other side. Three of these markers were also successfully converted into sequence-characterized amplified region (SCAR) markers. These PCR-based markers will be useful for a large-scale application in facilitating the positional cloning of the Or gene.

Nitrate-induced genes in tomato roots. Array analysis reveals novel genes that may play a role in nitrogen nutrition.

A subtractive tomato (Lycopersicon esculentum) root cDNA library enriched in genes up-regulated by changes in plant mineral status was screened with labeled mRNA from roots of both nitrate-induced and mineral nutrient-deficient (-nitrogen [N], -phosphorus, -potassium [K], -sulfur, -magnesium, -calcium, -iron, -zinc, and -copper) tomato plants. A subset of cDNAs was selected from this library based on mineral nutrient-related changes in expression. Additional cDNAs were selected from a second mineral-deficient tomato root library based on sequence homology to known genes. These selection processes yielded a set of 1,280 mineral nutrition-related cDNAs that were arrayed on nylon membranes for further analysis. These high-density arrays were hybridized with mRNA from tomato plants exposed to nitrate at different time points after N was withheld for 48 h, for plants that were grown on nitrate/ammonium for 5 weeks prior to the withholding of N. One hundred-fifteen genes were found to be up-regulated by nitrate resupply. Among these genes were several previously identified as nitrate responsive, including nitrate transporters, nitrate and nitrite reductase, and metabolic enzymes such as transaldolase, transketolase, malate dehydrogenase, asparagine synthetase, and histidine decarboxylase. We also identified 14 novel nitrate-inducible genes, including: (a) water channels, (b) root phosphate and K(+) transporters, (c) genes potentially involved in transcriptional regulation, (d) stress response genes, and (e) ribosomal protein genes. In addition, both families of nitrate transporters were also found to be inducible by phosphate, K, and iron deficiencies. The identification of these novel nitrate-inducible genes is providing avenues of research that will yield new insights into the molecular basis of plant N nutrition, as well as possible networking between the regulation of N, phosphorus, and K nutrition.

A novel gene mutation that confers abnormal patterns of beta-carotene accumulation in cauliflower (Brassica oleracea var. botrytis).

The Or gene of cauliflower (Brassica oleracea var. botrytis) causes many tissues of the plant to accumulate carotenoids and turn orange, which is suggestive of a perturbation of the normal regulation of carotenogenesis. A series of experiments to explore the cellular basis of the carotenoid accumulation induced by the Or gene was completed. The Or gene causes obvious carotenoid accumulation in weakly or unpigmented tissues such as the curd, pith, leaf bases and shoot meristems, and cryptically in some cells of other organs, including the roots and developing fruits. The dominant carotenoid accumulated is beta-carotene, which can reach levels that are several hundred-fold higher than those in comparable wild-type tissues. The beta-carotene accumulates in plastids mainly as a component of massive, highly ordered sheets. The Or gene does not affect carotenoid composition of leaves, nor does it alter color and chromoplast appearance in flower petals. Interestingly, mRNA from carotenogenic and other isoprenoid biosynthetic genes upstream of the carotenoid pathway was detected both in orange tissues of the mutant, and in comparable unpigmented wild-type tissues. Thus the unpigmented wild-type tissues are likely to be competent to synthesize carotenoids, but this process is suppressed by an unidentified mechanism. Our results suggest that the Or gene may induce carotenoid accumulation by initiating the synthesis of a carotenoid deposition sink in the form of the large carotenoid-sequestering sheets.

Physiological basis of reduced AL tolerance in ditelosomic lines of Chinese Spring wheat.

Aluminum tolerance was assessed in the moderately Al-tolerant wheat (Triticum aestivum L.) cultivar Chinese Spring and a set of ditelosomic lines derived from Chinese Spring. Three ditelosomic lines lacking chromosome arms 4DL, 5AS and 7AS, respectively, exhibited decreased Al tolerance relative to the euploid parent Chinese Spring based on reduced root growth in Al-containing solutions. The physiological basis of the reduced Al tolerance was investigated. Measurements by inductively coupled argon plasma mass spectroscopy of root apical Al accumulation demonstrated that two of these three lines had a decreased ability to exclude Al from the root apex, the site of Al phytotoxicity. As Al-induced malate exudation has been suggested to be an important physiological mechanism of Al tolerance in wheat, this parameter was quantified and malate exudation was shown to be smaller in all three deletion lines compared with Chinese Spring. These results suggest that the decreased Al tolerance in at least two of the three ditelosomic lines is due to the loss of different genes independently influencing a single Al-tolerance mechanism, rather than to the loss of genes encoding alternative Al-tolerance mechanisms.

Molecular physiology of zinc transport in the Zn hyperaccumulator Thlaspi caerulescens.

In this manuscript, recent research from this laboratory into physiological and molecular aspects of heavy metal (Zn) transport in the hyperaccumulating plant species, Thlaspi caerulescens is reviewed. This research is aimed at elucidating the processes that underlie the accumulation of extraordinarily high levels of Zn in the T. caerulescens shoot (up to 3% Zn dry wt.) without any associated toxicity symptom. Physiological studies focused on the use of radiotracer flux techniques (65Zn2+) to characterize zinc transport and compartmentation in the root, and translocation and accumulation in the shoot of T. caerulescens in comparison with a related non-accumulator, T. arvense. These studies indicated that Zn transport was stimulated at a number of sites in T. caerulescens, contributing to the hyperaccumulation trait. The transport processes that were stimulated included Zn influx into both root and leaf cells, and Zn loading into the xylem. The 4- to 5-fold stimulation of Zn influx into the root was hypothesized to be due to an increased abundance of Zn transporters in T. caerulescens root cells. Additionally, compartmental analysis (radiotracer wash out or efflux techniques) was used to show that Zn was sequestered in the vacuoles of T. arvense root cells which retarded Zn translocation to the shoot in this non-accumulator species. Molecular studies have focused on the cloning and characterization of Zn transport genes in T. caerulescens. Complementation of a yeast Zn transport-defective mutant with a T. caerulescens cDNA library resulted in the recovery of a cDNA, ZNT1, that encodes a Zn transporter. Sequence analysis of ZNT1 indicated it is a member of a recently discovered micronutrient transport gene family which includes the Arabidopsis Fe transporter, IRT1, and the ZIP Zn transporters. Expression of ZNT1 in yeast allowed for a physiological characterization of this transporter. It was shown to encode a high affinity Zn transporter which can also mediate low affinity Cd transport. Northern analysis of ZNT1 and its homologue in the two Thlaspi species indicated that enhanced Zn transport in T. caerulescens results from a constitutively high expression of the ZNT1 gene in roots and shoots. In T. arvense, ZNT1 is expressed at far lower levels and this expression is stimulated by imposition of Zn deficiency.

The molecular physiology of heavy metal transport in the Zn/Cd hyperaccumulator Thlaspi caerulescens.

An integrated molecular and physiological investigation of the fundamental mechanisms of heavy metal accumulation was conducted in Thlaspi caerulescens, a Zn/Cd-hyperaccumulating plant species. A heavy metal transporter cDNA, ZNT1, was cloned from T. caerulescens through functional complementation in yeast and was shown to mediate high-affinity Zn(2+) uptake as well as low-affinity Cd(2+) uptake. It was found that this transporter is expressed at very high levels in roots and shoots of the hyperaccumulator. A study of ZNT1 expression and high-affinity Zn(2+) uptake in roots of T. caerulescens and in a related nonaccumulator, Thlaspi arvense, showed that alteration in the regulation of ZNT1 gene expression by plant Zn status results in the overexpression of this transporter and in increased Zn influx in roots of the hyperaccumulating Thlaspi species. These findings yield insights into the molecular regulation and control of plant heavy metal and micronutrient accumulation and homeostasis, as well as provide information that will contribute to the advancement of phytoremediation by the future engineering of plants with improved heavy metal uptake and tolerance.

Agricultural approaches to improving phytonutrient content in plants: an overview.

Recent advances in plant molecular biology, functional genomics, and biochemistry have opened up a number of new avenues of research that will enable plant biologists to characterize, increase and modify plant content of a wide range of essential minerals and vitamins, as well as a number of secondary plant compounds that appear to play a role in improving human health and nutrition. In this review, several examples of exciting new research applying plant genomic and molecular genetic approaches to the improvement of phytonutrient content and composition in plants are presented. Research focusing on the elucidation of many of these complex biosynthetic and transport pathways in plants will require considerable resources in terms of funding, time, and personnel. As plant biologists move into interdisciplinary collaborations with nutritionists and food scientists, attention must be paid to a more complete identification and characterization of specific bioactive phytonutrients. Also, a more detailed assessment of the health-promoting properties of these compounds is needed, particularly for many of the secondary plant compounds for which clear epidemiologic and clinical data are still lacking. Finally, in order for significant progress to be made in modifying the nutrient composition of crops, a major investment must be made by funding agencies.

Idiopathic giant cell myocarditis after autologous hematopoietic stem cell transplantation and interleukin-2 immunotherapy: a case report.

BACKGROUND: Interleukin-2 (IL-2) is used in the treatment of solid tumors and hematologic malignancies. Sudden death is a rare complication of IL-2 treatment. METHODS: A patient with lymphoma underwent chemoradiotherapy myeloablation and autologous stem cell transplantation. The stem cells were cultured in IL-2 (6000 IU/mL) for 24 hours prior to infusion. After engraftment, treatment with IL-2 (1.8 x 10(6) IU/m2/day administered subcutaneously) was begun. After 4 days of treatment, the patient suddenly died. An autopsy was performed. RESULTS: Histologic examination of the myocardium revealed a diffuse, lymphocytic infiltrate with scattered, multinucleated giant cells and foci of myocardial degeneration consistent with giant cell myocarditis. The lymphocytes were predominantly CD4 positive T cells, and the majority of these cells stained with antibodies for perforin, suggesting an unusual cytolytic role for these lymphocytes. DNA end-labeling of myocardial tissue sections revealed numerous apoptotic myocytes within the lymphocytic infiltrate. CONCLUSIONS: To the authors' knowledge, this is the first report of giant cell myocarditis in association with high dose chemotherapy, transplantation, and IL-2 immunomodulation. The authors suggest that the cytokine imbalance produced by IL-2 may have initiated a preferential activation of T helper cells and an autoimmune phenomenon manifesting as giant cell myocarditis.

Chronic fibrosing pancreatitis in childhood: report of a case and literature review.

Chronic fibrosing pancreatitis in childhood is an uncommon condition of unknown etiology with a variety of clinical presentations, histopathologic features, and outcomes. The diagnosis is one of exclusion (of hereditary or secondary pancreatitis), which should include histological assessment. The histological features of this condition have been described, to our knowledge, in nine published cases. We report a case in a 13-year-old male, who presented with obstructive jaundice and subsequently had evidence of endocrine and exocrine pancreatic insufficiency, despite a surgical decompression of the pancreatic-biliary duct system.

Fine needle aspiration diagnosis of a mesenteric myelolipoma: a case report.

BACKGROUND: Extraadrenal myelolipomas are very rare tumors, with a characteristic, though nonspecific, radiologic appearance. Tissue sampling is necessary for diagnosis, and although most of these tumors are asymptomatic, surgical excision is often indicated. CASE: A 59-year-old male was found to have a large mass within the mesentery of the abdomen, incidentally discovered during an ultrasound examination for renal lithiasis. Computed tomography-guided fine needle aspiration biopsy yielded mature adipose tissue admixed with hematopoietic elements. CONCLUSION: FNA proved to be a rapid and effective modality for the diagnosis of this distinctly uncommon tumor.

The effect of combining scald resistance genes on disease levels, yield and quality traits in barley.

Pairwise combinations of genes for resistance to scald in barley were developed using linked isozyme markers to test whether such combinations conferred improved resistance to the pathogen, Rhynchosporium secalis. The resistance genes originally derived from Hordeum vulgare ssp. spontaneum. The combinations were bred into an essentially similar genetic background because the scald-susceptible, Australian barley cultivar 'Clipper' was the recurrent backcross parent in their ancestry. In field tests of the recombinants over 2 years, disease levels were lower in three of six doubly resistant lines than in backcross lines carrying a single resistance gene, which in turn were less diseased than either 'Clipper' or recombinants that lacked the marked resistance genes. All resistant lines significantly outyielded 'Clipper' but did not themselves differ significantly. Lines resistant to scald had significantly higher grain size and grain weight. Gains for malt yield of about 1 % were detected in the higher disease environment. Resistance was not accompanied by any obvious "cost" in terms of yield or quality. Protection against scald is therefore a significant requirement for new malting barley cultivars in scald-prone areas.

The reduced stability of a plant alcohol dehydrogenase is due to the substitution of serine for a highly conserved phenylalanine residue.

The zinc-binding long-chain alcohol dehydrogenases from plants and animals exhibit a considerable level of amino acid sequence conservation. While the functional importance of many of the conserved residues is known, the role of others has not yet been determined. We have identified a naturally occurring Adh-1 allele in the legume Phaseolus acutifolius with several unusual characteristics. Individuals homozygous for this allele, Adh-1 CN, possess a single isozyme starch gel electrophoretic pattern suggestive of a null allele, and exhibit ADH enzyme activity levels ca. 60% lower than the standard wild-type Adh-1F line. Interestingly, analysis of Adh-1CN homozygotes on an alternative gel system indicates that Adh-1CN does encode a polypeptide capable of forming functional homo- and heterodimers. However, the levels of ADH activity displayed by these isozymes are far lower than those observed for the corresponding wild type ADH-1F isozymes. Dialysis experiments indicate that isozymes containing the ADH-1CN polypeptide are inactivated by slightly acidic conditions, which may explain the apparent null phenotype on starch gels. Elevated temperatures cause a similar loss of enzyme activity. The deduced amino acid sequences of ADH-1CN and ADH-1F were obtained from their corresponding cDNA clones, and the only significant difference detected between the two is a single amino acid replacement substitution. Residue 144 is occupied by phenylalanine in the ADH-1F polypeptide, whereas serine occupies this position in the ADH-1CN polypeptide. The proximity of residue 144 to the catalytic zinc in the substrate-binding pocket, coupled with the fact that it is integral to a defined hydrophobic core of the ADH polypeptide, may explain the observed disruptive effect that the serine substitution has on both the activity and stability of the ADH-1CN polypeptide. It also provides an explanation for the maintenance of phenylalanine or the structurally similar tyrosine at this residue in Zn-binding long-chain ADHs.

Splenic metastasis in hairy cell leukemia.

BACKGROUND: Splenic metastasis is uncommon and usually occurs in the setting of widespread visceral metastasis. Splenic metastasis as an initial manifestation of disease and sole site of metastasis has not been reported previously. METHODS: The authors describe a patient with hairy cell leukemia (HCL) with the unexpected finding of metastatic adenocarcinoma in the spleen. Direct inspection at the time of laparotomy and subsequent radiographic studies did not show a primary or additional metastatic tumor. Eventually, he manifested evidence of pulmonary and hepatic metastases and died with fungal sepsis. RESULTS: The splenectomy specimen showed HCL and metastatic adenocarcinoma. Immunohistochemical studies showed adenocarcinoma with diffuse cytoplasmic staining for prostate-specific antigen and focally positive results with prostatic acid phosphatase antigen. Postmortem examination 9 months later showed HCL and widespread metastatic adenocarcinoma. No primary tumor was identified, and multiple tissue blocks of the prostate had negative findings for tumor. CONCLUSIONS: The immunohistologic features of the metastatic adenocarcinoma were interpreted as prostatic in origin. The pattern of isolated metastatic disease in the absence of primary tumor appears to represent another possible atypical disease presentation of prostatic cancer. Hairy cell-induced structural and immunologic alterations within the splenic microenvironment may have contributed to this unique clinical presentation.

Whole-body pathologic analysis of a patient with Thorotrast-induced myelodysplasia.

An autopsy was performed on a 72-y-old Caucasian female who had received a carotid artery injection of thorium dioxide in 1953. The body was dissected in such a manner as to provide for radiobiological evaluation as well as to determine histologically the distribution of Thorotrast in the tissues and its complications. Thorotrast was identified within the liver, spleen, lymph nodes, bone marrow, and surrounding the right carotid artery (the injection site). The cause of death was gastric hemorrhage complicating pancytopenia secondary to refractory anemia with excess of blasts (myelodysplastic syndrome).

Ultrasonographic findings of testicular microlithiasis associated with intratubular germ cell neoplasia.

Testicular microlithiasis is an uncommon condition in which calcified concretions fill the lumina of seminiferous tubules. We report the case of a twenty-three-year-old white man with a metastatic germ cell tumor and normal findings on testicular physical examination, but abnormal ultrasonography of the right testis. Orchiectomy revealed intratubular germ cell neoplasia with testicular microlithiasis. Multiple circular echogenic foci on ultrasound correlated with the histologic finding of testicular microlithiasis. Further studies are indicated for assessing ultrasonography as an adjunct for screening the population at risk for intratubular germ cell neoplasia.

Solitary bone cyst of the radius containing Liesegang's rings.

The authors describe the case of a 33-year-old man with a solitary cystic lesion of the left distal radius with central radiodensities that radiographically suggested a chondroid matrix. Curettage of the lesion revealed numerous calcospherites with a lamellar structure. This lamellar pattern is thought to be a result of alternating precipitation and diffusion of supersaturated solutions. This biochemical process has been called the Liesegang's phenomenon, and the structures have been termed Liesegang's rings. The presence of these structures in this benign lesion contributed to atypical roentgenographic and pathologic findings.