Disease, drugs, or dinner? Food histology can mimic drugs and parasites in the gastrointestinal tract.

Microscopic foreign objects are sometimes found in gastrointestinal (GI) tract specimens. Some signify important diagnostic findings, such as parasitic or bacterial organisms and some medication resins. Partially digested fruits and vegetables can also be present, and some have been described in the literature as potential mimickers of clinically important findings. While animal protein appears as skeletal muscle on histologic examination, fruits and vegetables can show a wide variation under the microscope. To our knowledge, a thorough histologic examination of commonly eaten fruits and vegetables has not been published in the pathology literature. Herein, we present key morphologic features of fruits and vegetables that might be found in GI specimens, emphasizing potential mimics of significant pathologic findings.

The interaction between irreversible electroporation therapy (IRE) and embolization material using a validated vegetal model: an experimental study.

PURPOSE: Irreversible electroporation (IRE) is a nonthermal tumor ablation technique that induces cell apoptosis while preserving extracellular architecture. Surgical clips and embolic agents may lie adjacent to, or within, the target lesion. It is unknown to date if IRE causes degradation to the embolic agents or surgical clips that may have adverse effects to patients. We aimed to examine the effects of the IRE on the morphology of various embolic agents and the effects of these agents to the ablation field using a previously validated vegetal model. METHODS: Metallic surgical clips and various metallic and nonmetallic embolic agents were inserted within the center of the tuber ablation field. Additionally, clips were inserted on the edge and outside the ablation field. One tuber was ablated as a control. Ablation settings were based on previous published experiments. Tubers were imaged with magnetic resonance imaging (MRI) 18-24 hours after ablation and the ablated field dimensions were measured. Nonmetallic embolic agents were examined microscopically by the pathologist. RESULTS: Nonmetallic agents did not affect the ablation pattern. Metallic implants, however, caused arcing of the ablation margins. There was no macroscopic or microscopic degradation to the agents after IRE. CONCLUSION: The ablation zone arced in the presence of surgical clips at the edge or outside the ablation margins; therefore, nearby critical structures may be susceptible to the effects of IRE. Furthermore, there was no physical degradation of the embolic agents or surgical clips, and this may have importance when considering IRE ablation of previously embolized lesions in vivo.

Histochemical visualization of ROS and antioxidant response to viral infections of vegetable crops grown in Azerbaijan.

Extremes of environmental conditions, such as biotic stresses, strongly affect plant growth and development and may adversely affect photosynthetic process. Virus infection is especially problematic in crops, because unlike other diseases, its impact cannot be reduced by phytosanitary treatments. The vegetable crops (Solanum lycopеrsicum L, Cucurbita melo L., Cucumis sativus L., Piper longum L., Solánum melongéna L., Vicia faba L.) showing virus-like symptoms were collected from fields located in the main crop production provinces of Azerbaijan. Infection of the plants were confirmed by Enzyme-linked immunosorbent assay using commercial kits for the following viruses: Tomato yellow leaf curl virus, Tomato mosaic virus, Tomato chlorosis virus, Melon necrotic spot virus and Cucumber mosaic virus, Bean common mosaic virus and Bean yellow mosaic virus. Generation sites of superoxide and hydrogen peroxide radicals and activities of enzymes involved in the detoxification of reactive oxygen species (catalase, glutathione reductase, ascorbate peroxidase, guaiacol peroxidase and superoxide dismutase) were examined in uninfected leaves and in leaves infected with viruses. High accumulation of superoxide and hydrogen peroxide radicals was visualized in infected leaves as a purple discoloration of nitro blue tetrazolium and 3,3'-diaminobenzidine tetrahydrochloride. It was found that the activities of APX and CAT significantly increased in all infected samples compared with non-infected ones. Dynamics of GR and Cu/Zn-SOD activities differed from those of CAT and APX, and slightly increased in stressed samples. Electrophoretic mobility profiling of APX, GPX and CAT isoenzymes was also studied.

Vegetable cells in urinary samples of patients with bricker ileal conduit.

During routine cytopathological evaluation of urines for malignant cells we have occasionally noticed vegetable cells that were only present in patients with Bricker ileal conduit. We wanted to identify the means and sources of contamination of urinary samples from these patients. During the period between May and November 2010, 637 urinary samples were routinely evaluated for malignant cells. Among them were 13 urinary samples from Bricker ileal conduit which we rescreened. We prepared all urinary samples by membrane filtration and stained them according to Papanicolaou. Subsequently, we prepared samples from ostomy adhesives made by Coloplast and by ConvaTec which are used to secure the ostomy bag onto urostomy. We also took samples from different constituents (hydrocolloids) of ostomy adhesives. On the cytopathological review, we found vegetable cells along with intestinal mucosa cells in urinary samples of seven patients with Bricker ileal conduit. With the light microscopic examination of the samples prepared from different ostomy adhesives, we found vegetable cells only in Coloplast adhesives. In preparations of hydrocolloids, we found vegetable cells only in guar gum. They were morphologically identical to those found in urine samples of patients with Bricker ileal conduit and in Sensura and Sensura Xpro (Coloplast) ostomy adhesives. We determined that the origin of vegetable cells in urines from Bricker ileal conduit is the ostomy adhesive. The vegetable cells differ from human intestinal epithelial cells regarding size, shape, and color so it is difficult to misinterpret them as dysplastic cells.

Impact of a pulsed electric field on damage of plant tissues: effects of cell size and tissue electrical conductivity.

Efficiency of pulsed electric field (PEF) induced permeabilization at 293 K in selected fruit and vegetable plant tissues (apple, potato, carrot, courgette, orange, and banana) at electric field strength (E) of 400 V·cm(-1), 1000 V·cm(-1) and pulse duration (t(p)) of 1000 µs was studied experimentally. The mean cell radius (〈r〉) was within 30 to 60 µm, and the ratio of electrical conductivities of the intact and damaged tissues (σ(i)/σ(d)) was within 0.07 to 0.79 for the studied tissues. Electroporation theory predicts higher damage for tissue with larger cells; however, the direct correlation between PEF damage efficiency and size of cell was not always observed. To explain this anomaly, a theoretical Monte Carlo model was developed and checked for parameters typical for potato tissue. The model showed a strong dependence of PEF damage efficiency and power consumption (W) on σ(i)/σ(d) ratio. The optimum value of electric field strength (E(opt)) was an increasing function of σ(i)/σ(d), and plant tissues with high σ(i)/σ(d) ratio (σ(i)/σ(d) ≈ 1) required application of a rather strong field (for example, E(opt) ≈ 3000 V·cm(-1) for σ(i)/σ(d) ≈ 0.8). However, the PEF treatment at a lower field (E ≈ 400 V·cm(-1)) allowed regulation of the selectivity of damage of cells in dependence of their size. A good qualitative correspondence between experimental data and simulation results were observed.

Vegetable cells in Papanicolaou-stained cervical smears.

Vegetable cells are unusual findings in Papanicolaou-stained cervical smears; these structures could be wrongly mistaken for abnormal human cells, worm eggs, or spores by a cytologist encountering the possibility of meeting those elements in cytological analysis. Five cervicovaginal smears showing similar vegetable cells have been detected over a 3-yr period (2002-2004) in the course of a population screening program for cancer of the uterine cervix in Modena (Italy) involving 32,500 women. According to the clinical histories of the patients, the vaginal pharmaceutical drugs or appliances used were of different types: vaginal lavages, pessaries, and vaginal creams. Following a careful investigation, the only substance that can lead to vegetal elements has been identified as polysaccharide galactomannan, which is one of the excipient present in the drugs used. The authors have identified the origin of these contaminants and the means of pollution, using cytological and pharmaceutical investigation.

Airborne fungal spores, pollen grains, and vegetable cells in routine Papanicolaou smears.

The objective was to demonstrate the presence of airborne fungal spores, pollen grains, and vegetable cells in smears and establish their significance. Microscopic examination was of smears stained by the Papanicolaou technique. We found several types of airborne spores (Alternaria, Exserohilum, Aspergillus, Cladosporium, Epicoccum, Curvularia, and Ascosmycete), pollen grains (Lilium, bullrush, Pinus, Acacia, hazelnut, and oak), and several types of vegetable cells. The existence of these structures may be due to intrinsic or to extrinsic contamination of the sample. Anemophilous fungi spores and pollen grains have been shown to possess great allergenic capacity. Pollen grains and vegetable cells may be mistaken for certain microorganisms or malignant cells.

Auxin metabolism in the root apical meristem.

Within the root meristem of flowering plants is a group of mitotically inactive cells designated the quiescent center (QC). Recent work links the quiescent state to high levels of the growth regulator auxin that accumulates in the QC via polar transport. This in turn results in elevated levels of the enzyme ascorbic acid oxidase (AAO), resulting in a reduction of ascorbic acid (AA) within the QC and mitotic quiescence. We present evidence for additional interactions between auxin, AAO, and AA, and report that, in vitro, AAO oxidatively decarboxylates auxin, suggesting a mechanism for regulating auxin levels within the QC. We also report that oxidative decarboxylation occurs at the root tip and that an intact root cap must be present for this metabolic event to occur. Finally, we consider how interaction between auxin and AAO may influence root development by regulating the formation of the QC.

Molecular characterization of cDNAs for two anionic peroxidases from suspension cultures of sweet potato.

Two cDNAs for anionic peroxidase (PODs), swpa2 and swpa3, were isolated from suspension cultures of sweet potato (Ipomoea batatas), and their expression was investigated with a view to understanding the physiological function of PODs in relation to environmental stresses. Swpa2 (whose putative mature protein product would have a pI value of 4.1) and swpa3 (4.3) encode polypeptides of 358 and 349 amino acids, respectively. The genes from which they were derived are predominantly expressed in cultured cells of sweet potato; transcripts of swpa2 were not detected in any tissues of the intact plant, and transcripts of swpa3 were detected at a low level only in the stem tissue. During cell culture, the expression patterns of the two genes differed; the level of swpa2 RNA progressively increased during cell growth, whereas that of swpa3 reached a maximum at the stationary phase and decreased on further culture. The two genes responded differently to stresses such as wounding or chilling of leaves. Swpa2 was strongly induced 48 h after wounding, but swpa3 was not affected by this treatment. The two genes were also highly expressed upon chilling (4 degrees C), but expression was reduced by prior acclimation at 15 degrees C. In addition, both genes were strongly induced immediately after treatment with ozone, and expression had decreased to the basal level 12 h after treatment. The response of these two genes to stresses such as aging, wounding, and chilling are different from those of the POD genes (swpa1 encoding an anionic product and swpn1 a neutral peroxidase) that we described previously. The responses of the two genes were also different from each other. These results suggest that the two new POD genes are involved in overcoming oxidative environmental stress, and each POD gene may be regulated by cell growth and environmental stress in different ways.

Expression of a vacuolar protein (VP24) in anthocyanin-producing cells of sweet potato in suspension culture.

VP24, an abundant protein of 24 kD, was found to accumulate in the anthocyanin-containing vacuoles of cells of sweet potato (Ipomoea batatas) in suspension culture. Light-induced expression of VP24 was analyzed by immunoblotting in three different cell lines that produced anthocyanins at different rates. The expression of VP24 was closely correlated with the accumulation of anthocyanin in these cell lines. Immunocytochemical detection of VP24 with specific antibodies on thin sections showed that VP24 was localized in the intravacuolar pigmented globules (cyanoplasts) in the anthocyanin-containing vacuoles and not in the tonoplast. No VP24 immunogold labeling was detected in the vacuoles of the cell line that does not produce anthocyanin. We suggest that VP24 may be involved in the formation of the cyanoplast via an interaction with anthocyanin, and that it may play an important role in the trapping in vacuoles of large amounts of anthocyanins that have been transported into these vacuoles.

Cloning and sequencing of a cDNA encoding alpha-glucosidase from sugar beet.

A cDNA encoding sugar beet alpha-glucosidase was cloned from a library constructed from mRNA of suspension-cultured cells. The cDNA, 3056 bp in length, had an open reading frame encoding a polypeptide of 913 amino acid residues with a molecular mass of 102,078 Da, included only one of four regions which were conserved in the alpha-amylase family of enzymes. The deduced amino acid sequence from the analysis of the cDNA contained the sequences of the proteolysis peptides and the active site region peptide of sugar beet alpha-glucosidase. The primary structure indicated relatively high homology in the range of 28.2 to 54.3% to those for other alpha-glucosidases. The highest homology was found in barley alpha-glucosidase.

Plant cell pH-static circuit mediated by fusicoccin-binding proteins.

On sugar beet protoplasts that carry two types of fusicoccin-binding sites, a pH downshift in a physiological range (7.0-6.6) markedly enhanced the efficiency of fusicoccin (FC) binding, mainly owing to increased avidity of low-affinity FC-binding sites. This may allow the FC-binding proteins to act as pH-sensitive modulators of cell activity, for instance, via plasma membrane H+-ATPase or potassium channels.

Immunolocalization of mannitol dehydrogenase in celery plants and cells.

Immunolocalization of mannitol dehydrogenase (MTD) in celery (Apium graveolens L.) suspension cells and plants showed that MTD is a cytoplasmic enzyme. MTD was found in the meristems of celery root apices, in young expanding leaves, in the vascular cambium, and in the phloem, including sieve-element/companion cell complexes, parenchyma, and in the exuding phloem sap of cut petioles. Suspension cells that were grown in medium with mannitol as the sole carbon source showed a high anti-MTD cross-reaction in the cytoplasm, whereas cells that were grown in sucrose-containing medium showed little or no cross-reaction. Gel-blot analysis of proteins from vascular and nonvascular tissues of mature celery petioles showed a strong anti-MTD sera cross-reactive band, corresponding to the 40-kD molecular mass of MTD in vascular extracts, but no cross-reactive bands in nonvascular extracts. The distribution pattern of MTD within celery plants and in cell cultures that were grown on different carbon sources is consistent with the hypothesis that the Mtd gene may be regulated by sugar repression. Additionally, a developmental component may regulate the distribution of MTD within celery plants.

Active fragments and analogs of the plant growth factor, phytosulfokine: structure-activity relationships.

Sulfated pentapeptide phytosulfokine-alpha (PSK-alpha) is the first chemically characterized peptidal plant growth factor that induces proliferation of the mesophyll cells of asparagus. To determine the active core involved in the sequence PSK-alpha, we synthesized PSK-alpha and twelve PSK-alpha analogs by the solid phase peptide synthesis and the direct sulfation to the peptide-resin using dimethylformamide-sulfurtrioxide (DMF-SO3) complex. The truncated analogs of PSK-alpha without the first and second C-terminal amino acids retained 8% and 20% of the activity of the parent pentapeptide, respectively. Deletion of the sulfate groups of Tyr1 and Tyr3 resulted in compounds with 0.6% and 4% of the activity of PSK-alpha, indicating that the sulfate group of Tyr1 is more important than that of Tyr3 for the expression of its activity. In contrast, the N-terminal truncated analog and unsulfated analog exhibited little or no activity. Thus the N-terminal tripeptide fragment H-Tyr(SO3H)-Ile-Tyr(SO3H)-OH has been identified as the active core of PSK-alpha.

Phytosulfokine, sulfated peptides that induce the proliferation of single mesophyll cells of Asparagus officinalis L.

Proliferation of dispersed plant cells in culture is strictly dependent on cell density, and cells in a low-density culture can only grow in the presence of conditioned medium (CM). No known plant hormones have been able to substitute for CM. To quantify the mitogenic activity of CM, we examined conditions for the assay system using mechanically dispersed mesophyll cells of Asparagus officinalis L. and established a highly sensitive bioassay method. By use of this method, the mitogenic activity of CM prepared from asparagus cells was characterized: it was heat-stable, susceptible to pronase digestion, and resistant to glycosidase treatment. On the basis of these results, the mitogenic activity in CM was purified 10(7)-fold by column chromatography, and two factors named phytosulfokine-alpha and -beta (PSK-alpha and PSK-beta) were obtained. By amino acid sequence analysis and mass spectrometry, the structures of these two factors were determined to be sulfated pentapeptide (H-Tyr(SO3H)-Ile-Tyr(SO3H)-Thr-Gln-OH) and sulfated tetrapeptide (H-Tyr(SO3H)-Ile-Tyr(SO3H)-Thr-OH). PSK-alpha and PSK-beta were prepared by chemical synthesis and enzymatic sulfation. The synthetic peptides exhibited the same activity as the natural factors, confirming the structure for PSK-alpha and PSK-beta mentioned above. This is the first elucidation of the structure of a conditioned medium factor required for the growth of low-density plant cell cultures.

Purification of NAD-dependent mannitol dehydrogenase from celery suspension cultures.

Mannitol dehydrogenase, a mannitol:mannose 1-oxidoreductase, constitutes the first enzymatic step in the catabolism of mannitol in nonphotosynthetic tissues of celery (Apium graveolens L.). Endogenous regulation on the enzyme activity in response to environmental cues is critical in modulating tissue concentration of mannitol, which, importantly, contribute to stress tolerance of celery. The enzyme was purified to homogeneity from celery suspension cultures grown on D-mannitol as the carbon source. Mannitol dehydrogenase was purified 589-fold to a specific activity of 365 mumol h-1 mg-1 protein with a 37% yield of enzyme activity present in the crude extract. A highly efficient and simple purification protocol was developed involving polyethylene glycol fractionation, diethylaminoethyl-anion-exchange chromatography, and NAD-agarose affinity chromatography using NAD gradient elution. Sodium dodecylsulfate gel electrophoresis of the final preparation revealed a single 40-kD protein. The molecular mass of the native protein was determined to be approximately 43 kD, indicating that the enzyme is a monomer. Polyclonal antibodies raised against the enzyme inhibited enzymatic activity of purified mannitol dehydrogenase. Immunoblots of crude protein extracts from mannitol-grown celery cells and sink tissues of celery, celeriac, and parsley subjected to sodium dodecyl sulfate gel electrophoresis showed a single major immuno-reactive 40-kD protein.

Specific, high affinity binding of chitin fragments to tomato cells and membranes. Competitive inhibition of binding by derivatives of chitooligosaccharides and a Nod factor of Rhizobium.

Suspension-cultured tomato cells have a sensitive perception system for chitin fragments with a degree of polymerization (DP) > or = 4 and react to these compounds with a transient alkalinization of their culture medium (Felix, G., Regenass, M., and Boller, T. (1993) Plant. J. 4, 307-316). A chitin fragment with DP 5 was aminated at the reducing end and coupled to t-butoxycarbonyl-L-[35S]methionine via an amidoglycine spacer. The radiolabeled chitin fragment (approximately 1000 Ci/mmol) exhibited specific, saturable, reversible binding to whole tomato cells as well as to tomato microsomal membranes with dissociation constants of 1.4 and 23 nM, respectively. Binding of the radioligand was competed by chitin fragments of different DP with IC50 values (50% inhibition of binding) that closely paralleled the concentrations inducing the alkalinization response half-maximally. Deacetylated chitooligosaccharides and N-propanoyl chitooligosaccharides were weak elicitors of the alkalinization response as well as weak competitors of radioligand binding. A lipochitooligosaccharide (Nod factor) from Rhizobium leguminosarum stimulated the alkalinization response in tomato cells half-maximally at 3 nM and competed radioligand binding to the cells with an IC50 of 8 nM. These results demonstrate the presence of a high affinity binding site for chitin fragments on the tomato cell membrane that may function as a receptor.

Voltage-dependent calcium-permeable channels in the plasma membrane of a higher plant cell.

Numerous biological assays and pharmacological studies on various higher plant tissues have led to the suggestion that voltage-dependent plasma membrane Ca2+ channels play prominent roles in initiating signal transduction processes during plant growth and development. However, to date no direct evidence has been obtained for the existence of such depolarization-activated Ca2+ channels in the plasma membrane of higher plant cells. Carrot suspension cells (Daucus carota L.) provide a well-suited system to determine whether voltage-dependent Ca2+ channels are present in the plasma membrane of higher plants and to characterize the properties of putative Ca2+ channels. It is known that both depolarization, caused by raising extracellular K+, and exposure to fungal toxins or oligogalacturonides induce Ca2+ influx into carrot cells. By direct application of patch-clamp techniques to isolated carrot protoplasts, we show here that depolarization of the plasma membrane positive to -135 mV activates Ca(2+)-permeable channels. These voltage-dependent ion channels were more permeable to Ca2+ than K+, while displaying large permeabilities to Ba2+ and Mg2+ ions. Ca(2+)-permeable channels showed slow and reversible inactivation. The single-channel conductance was 13 pS in 40 mM CaCl2. These data provide direct evidence for the existence of voltage-dependent Ca2+ channels in the plasma membrane of a higher plant cell and point to physiological mechanisms for plant Ca2+ channel regulation. The depolarization-activated Ca(2+)-permeable channels identified here could constitute a regulated pathway for Ca2+ influx in response to physiologically occurring stimulus-induced depolarizations in higher plant cells.

Mapping determinants within cucumber mosaic virus and its satellite RNA for the induction of necrosis in tomato plants.

A mutant of the WL47 satellite (WL47-sat) RNA of cucumber mosaic virus (CMV), constructed in vitro, induces lethal necrosis in tomato plants when associated with either of two subgroup II strains of CMV: LS- or WL-CMV (D. E. Sleat and P. Palukaitis, Proc. Natl. Acad. Sci. USA 87:2946-2950, 1990). The phenotype of this mutant (WLM2-sat RNA) has been examined on tomato plants, after co-inoculation with a wider range of CMV strains. Necrosis was observed when WLM2-sat RNA was associated with any of the subgroup II CMV strains tested. However, WLM2-sat RNA ameliorated the symptoms induced by subgroup I CMV strains without inducing necrosis. Inoculation with WLM2-sat RNA with pseudorecombinants formed between subgroup I and subgroup II CMV strains showed an association of the necrosis induction phenotype with RNA 2 of the subgroup II strains. In contrast to WLM2-sat RNA, infectious transcripts of the naturally necrogenic D4-sat RNA induced lethal necrosis in tomato with all CMV strains tested. Experiments involving the exchange of sequences between WLM2- and D4-sat RNAs indicated that nucleotides sequences in either of two separate regions could influence the necrosis phenotype. Thus, the subgroup-specific necrosis-inducing phenotype may be due to subtle alterations in secondary and/or tertiary structure in the satellite RNA, as well as the presence or absence of particular nucleotide sequences.