Variability in foliar essential oils among different morphotypes of Lantana species complexes, and its taxonomic and ecological significance.

The genus Lantana has many species complexes, and L. camara is one of the aggressive alien weedy species complexes; species delimitation in these complexes is a nightmare for taxonomists. We examined the diversity in the chemical composition of foliar essential oils among morphotypes of Lantana species complexes inhabiting the same ecological gradient, and its taxonomic and ecological significance. The yields of essential oils varied from 0.1 to 0.79% in foliar hydrodistillates of eleven morphotypes, and a total of 39 chemical constituents were detected by GC/MS. The quantitative and qualitative variability in the composition of essential oils among morphotypes was very high, and hence they represent chemotypes. The diversity observed in the composition of essential oils appears to be of genetic origin and thus of taxonomic value. The formation of distinct clusters and sub-clusters at high distance cluster combine values also substantiates that the patterns of distribution of chemical constituents among morphotypes can be used in delimiting species and infraspecific taxa within the species complexes. The presence of beta-caryophyllene and other such compounds, which are known to prevent herbivory, in morphotypes of Lantana species complexes suggest that these compounds may provide selective advantage to Lantana over native species in the invasion of new and disturbed habitats.

A Kunitz proteinase inhibitor from Archidendron ellipticum seeds: purification, characterization, and kinetic properties.

Leguminous plants in the tropical rainforests are a rich source of proteinase inhibitors and this work illustrates isolation of a serine proteinase inhibitor from the seeds of Archidendron ellipticum (AeTI), inhabiting Great Nicobar Island, India. AeTI was purified to homogeneity by acetone and ammonium sulfate fractionation, and ion exchange, size exclusion and reverse phase chromatography (HPLC). SDS-PAGE of AeTI revealed that it is constituted by two polypeptide chains (alpha-chain, M(r) 15,000 and beta-chain, M(r) 5000), the molecular weight being approximately 20 kDa. N-terminal sequence showed high homology with other serine proteinase inhibitors belonging to the Mimosoideae subfamily. Both Native-PAGE as well as isoelectric focussing showed four isoinhibitors (pI values of 4.1, 4.55, 5.27 and 5.65). Inhibitory activity of AeTI remained unchanged over a wide range of temperatures (0-60 degrees C) and pH (1-10). The protein inhibited trypsin in the stoichiometric ratio of 1:1, but lacked similar stoichiometry against chymotrypsin. Also, AeTI-trypsin complex was stable to SDS unlike the SDS unstable AeTI-chymotrypsin complex. AeTI, which possessed inhibition constants (K(i)) of 2.46 x 10(-10) and 0.5 x 10(-10)M against trypsin and chymotrypsin activity, respectively, retained over 70% of inhibitory activity after being stored at -20 degrees C for more than a year. Initial studies on the insecticidal properties of AeTI indicate it to be a very potent insect anti-feedant.

Centrifugal enhancement of human immunodeficiency virus type 1 infection and human cytomegalovirus gene expression in human primary monocyte/macrophages in vitro.

In an effort to facilitate the efficiency of human immunodeficiency virus type 1 (HIV-1) and/or human cytomegalovirus (HCMV) infection in primary monocyte/macrophages in vitro, the effect of low-speed centrifugation was studied. The infectivity of three strains (Bal, Ada-M, and IIIB) of HIV-1 tested was significantly enhanced by centrifugal inoculation at a force of 1500g for 60 min. Reverse transcriptase activity and HIV-1 p24 antigen in primary monocyte/macrophages infected by a centrifugal inoculation technique were detectable 3-7 days earlier and were more than 10-fold greater in magnitude (at an early stage of the infection) than those of control cells infected by the conventional inoculation technique. Examination of the cells by indirect immunofluorescence revealed higher expression of HIV-1 p24 protein in the monocyte/macrophages infected by the centrifugal inoculation technique. These differences were directly related to centrifugal inoculation and were evident up to 3 weeks after infection. Enhancement was not observed when centrifugation was carried out before or after HIV-1 infection. Centrifugal inoculation of HCMV also enhanced its immediate-early and early gene expression up to 30- to 50-fold, although neither late nuclear antigens and glycoproteins of HCMV nor infectious virus was detected in HCMV-infected monocyte/macrophage cultures. These results show that centrifugal inoculation is a useful technique for improving the efficiency of HCMV and HIV-1 infection in vitro.

Percutaneous thrombolysis and stent placement for the treatment of portal vein thrombosis after liver transplantation: long-term follow-up.

BACKGROUND: The durable use of percutaneous minimally invasive techniques for the treatment of portal venous thrombosis after liver transplant has not been widely described. This report illustrates two cases in which percutaneous thrombolysis, angioplasty, and endovascular stent placement were successfully used to treat portal vein thrombosis in patients with recent liver transplants. METHODS: Liver dysfunction was initially manifested by the elevation of liver enzymes or the development of marked ascites and confirmed in both cases by sonography and angiography. The occluded portal vein was accessed by either a transjugular transhepatic puncture or direct transhepatic catheterization. Intraportal thrombolytic infusion, angioplasty, and stent placement were accomplished without complication. RESULTS: At the most recent follow-up, portal vein patency had been maintained for 2.5 and 4.5 years. CONCLUSIONS: These results demonstrate the technical feasibility and long-term patency of angioplasty and endovascular stent placement for the treatment of portal vein thrombosis in liver transplant recipients.

A cohort study of alkaloidal cocaine ("crack") in pregnancy.

The recent dramatic increase in the use of alkaloidal cocaine ("crack") has led to concern about possible deleterious fetal effects associated with its use during pregnancy. Crack, which is not destroyed by heating, can be smoked, and delivers a large quantity of cocaine to the vascular bed of the lung, producing an effect similar to that from intravenous injection. To describe the association of crack use with pregnancy outcome, we conducted a retrospective matched cohort study of 55 women who admitted to the use of crack during pregnancy and 55 non-drug-using women who delivered during the same period. The groups were matched for age, parity, socioeconomic status, alcohol use, and presence or absence of prenatal care. A significantly larger number of women using crack delivered at 37 weeks or earlier (50.9 versus 16.4%; P = .001). Crack-exposed infants were 3.6 times more likely to have intrauterine growth retardation (P less than .006) and 2.8 times more likely to have a head circumference less than the tenth percentile for gestational age (P less than .007). Premature rupture of the membranes was 1.8 times more common in the crack group (P less than .03). Sixty percent of crack-using mothers received no prenatal care. Abnormal neurobehavioral symptoms were present in a minority of infants and were usually mild.

Bilateral mammary artery bypass and sternal dehiscence. A favorable outcome.

The efficacy of mammary artery bypass for coronary artery disease has been well established. The present retrospective series of consecutive patients was scrutinized to assess the incidence of sternal dehiscence following myocardial revascularization using the right and left internal mammary arteries. For comparison, the consecutive group of patients undergoing myocardial revascularization with unilateral internal mammary artery bypass was analyzed for similar sternal complications. In a consecutive series of patients, 277 patients underwent myocardial revascularization using the right and left internal mammary arteries for bypass. The overall operative mortality in this group of patients was 0.722 per cent. In this group there was an overall incidence of seven sternal dehiscences, both partial and complete for an incidence of 2.52 per cent. Upon analysis, it was shown that the female sex and diabetes were the conditions that most likely predisposed to the occurrence of sternal dehiscence whether partial or complete. For comparison, a consecutive group of 413 patients were analyzed for similar demographic data and results. The overall operative mortality in this group was 1.21 per cent. The overall incidence of sternal dehiscence both partial and complete, was 0.484 per cent. Both instances of sternal dehiscence occurred in diabetic patients and the data indicates, as in the bilateral internal mammary artery group, the presence of diabetes predisposed to the occurrence of this complication. The low overall incidence of sternal dehiscence in the expanded use of the mammary arteries should not deter the surgeon from aggressive use of the mammary arteries. One should use caution, however, in using bilateral mammary artery grafts in diabetics, women, and to a lesser extent, patients more than 70 years of age.

Delayed pituitary apoplexy in patient with advanced prostate cancer treated with gonadotrophin-releasing hormone agonists.

Gonadotrophin-releasing hormone agonists (GnRHAs) are used in many clinical conditions, particularly prostate cancer. There have been a few case reports of apoplexy from a previously undiagnosed pituitary tumour, occurring within hours to days of initiation of GnRHA therapy. We report a case of delayed onset pituitary apoplexy following GnRHA therapy. A 71-year-old man presented three weeks after onset of headache and vision loss. On examination, he was blind in the right eye with an intact nasal field of vision in the left eye. Two months before presentation, he had a subcutaneous GnRHA (Goserelin) implant for treatment of locally advanced prostate cancer (Gleeson 4+3). An MRI scan revealed a large sellar/suprasellar mass. His follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels were grossly elevated. A trans-sphenoidal endoscopic decompression of the pituitary tumour was performed. His vision improved post-operatively and his FSH, LH, testosterone, prostate specific antigen (PSA) levels returned to normal levels. Histopathologic studies revealed a pituitary adenoma, which stained positive for FSH and LH. The prostate cancer management was changed to an anti-androgen agent and a GnRH antagonist. This case demonstrates that pituitary apoplexy can develop up to eight weeks after the initiation of treatment for prostate cancer with GnRHAs.

Purification and biochemical characterization of a serine proteinase inhibitor from Derris trifoliata Lour. seeds: insight into structural and antimalarial features.

A potent serine proteinase inhibitor was isolated and characterized from the seeds of the tropical legume liana, Derris trifoliata (DtTCI) by ammonium sulfate precipitation, ion exchange chromatography and gel filtration chromatography. SDS-PAGE as well as MALDI-TOF analysis showed that DtTCI is a single polypeptide chain with a molecular mass of approximately 20 kDa. DtTCI has three isoinhibitors (pI: 4.55, 5.34 and 5.72) and, inhibited both trypsin and chymotrypsin in a 1:1 molar ratio. Both Dixon plots and Lineweaver-Burk double reciprocal plots revealed a competitive inhibition of trypsin and chymotrypsin activity, with inhibition constants (K(i)) of 1.7x10(-10) and 1.25x10(-10) M, respectively. N-terminal sequence of DtTCI showed over 50% similarity with numerous Kunitz-type inhibitors of the Papilionoideae subfamily. High pH amplitude and broad temperature optima were noted for DtTCI, and time course experiments indicated a gradual loss in inhibitory potency on treatment with dithiothreitol (DTT). Circular Dichroism (CD) spectrum of native DtTCI revealed an unordered structure whereas exposure to thermal-pH extremes, DTT and guanidine hydrochloride (Gdn HCl) suggested that an abundance of beta-sheets along with intramolecular disulfide bonds provide conformational stability to the active site of DtTCI, and that severity of denaturants cause structural modifications promoting inhibitory inactivity. Antimalarial studies of DtTCI indicate it to be a potent antiparasitic agent.

Crystal structure of himalayan mistletoe ribosome-inactivating protein reveals the presence of a natural inhibitor and a new functionally active sugar-binding site.

Ribosome-inactivating proteins (RIPs) are toxins involved in plant defense. How the plant prevents autotoxicity is not yet fully understood. The present study is the first structural evidence of a naturally inhibited form of RIP from a plant. Himalayan mistletoe RIP (HmRIP) was purified from Viscum album leaves and crystallized with lactose. The structure was determined by the molecular replacement method and refined at 2.8-A resolution. The crystal structure revealed the presence of high quality non-protein electron density at the active site, into which a pteridine derivative (2-amino 4-isopropyl 6-carboxyl pteridine) was modeled. The carboxyl group of the ligand binds strongly with the key active site residue Arg(162), nullifies the positive charge required for catalysis, and thereby acts as a natural inhibitor. Lectin subunits of RIPs have two active sugar-binding sites present in 1alpha- and 2gamma-subdomains. A third functionally active site has been identified in the 1beta-subdomain of HmRIP. The 1beta-site is active despite the absence of conserved polar sugar-binding residues. Loss of these residues is compensated by the following: (i) the presence of an extended site where the penultimate sugar also interacts with the protein; (ii) the interactions of galactose with the protein main chain carbonyl and amide nitrogen atoms; (iii) the presence of a well defined pocket encircled by four walls; and (iv) a favorable stacking of the galactose ring with Tyr(66) besides the conserved Phe(75). The mode of sugar binding is also distinct at the 1alpha and 2gamma sugar-binding sites.

The macrophage and HIV-1.

As described above, monocytes/macrophages from such diverse areas as the CNS, lungs, peripheral blood, cord blood, and liver are susceptible to infection by HIV-1 and may serve as reservoirs for transmitting the virus throughout the body. In contrast to lymphocytes, the chronic and low-level mode of infection that HIV-1 takes on within monocytes/macrophages allows these cells to contribute to persistent viral infection. Infection of these cells by HIV-1 can alter a variety of their immunological functions such as cytokine production, chemotaxis, accessory cell function, and microbicidal activity. Furthermore, macrophages and macrophage-related microglial cells in the brain and CSF are thought to play a critical role in the pathogenesis of CNS disease. Infection with HIV-1 in monocytes/macrophages is regulated in an autocrine manner by a panel of cytokines and other soluble factors. Most HIV-1 isolates exhibit specific tropism for monocytes/macrophages, lymphocytes, or, in some cases, both cell types; this phenomenon of tropism may be linked to structural variabilities between different isolates. While in vitro studies clearly demonstrate that the replicating cycle of HIV-1 in monocytes/macrophages differs from its replicating cycle in lymphocytes, elucidation of the role of monocyte/macrophages in mediating the severe immunosuppression characteristic of AIDS is far more from complete, and further investigation into the role of monocytes/macrophages in the immunopathogenesis of HIV-1 infection is necessary to design therapeutic approaches to control viral infection and disease progression.

Giant hyperplastic polyps in the stomach: radiographic findings in seven patients.

OBJECTIVE: We reassessed the radiographic findings of giant hyperplastic polyps in the stomach on double-contrast upper gastrointestinal examinations in seven patients. CONCLUSION: Giant hyperplastic polyps in the stomach may be manifested by distinctive findings on double-contrast barium studies, appearing as polypoid lesions with multiple lobulated components that form a conglomerate mass. Nevertheless, endoscopy and biopsy are required to rule out a polypoid carcinoma as the cause of these findings.

Hartmann's pouch: radiographic evaluation of postoperative findings.

OBJECTIVE: The purpose of this study was to determine the usefulness of contrast-enhanced radiography of the Hartmann's pouch for evaluating postoperative abnormalities. MATERIALS AND METHODS: We performed a retrospective study of 84 patients with a Hartmann's pouch who underwent contrast-enhanced radiography of the pouch during a recent 7-year period. Sixty-four patients underwent single-contrast barium studies of the pouch, 17 underwent studies with a water-soluble contrast medium, and three underwent both types of studies. The radiographic studies were reviewed to determine the types and frequency of abnormalities involving the pouch. Medical records were also reviewed to determine clinical presentation and course. RESULTS: Abnormalities of the Hartmann's pouch were detected on contrast-enhanced radiography in 16 (19%) of the 84 patients. Of the 70 patients who underwent routine contrast-enhanced radiography of the pouch, 11 (16%) had abnormalities, including diversion colitis in three, leaks in two, adhesions in two, recurrent carcinoma in two, ulcerative colitis involving the pouch in one, and a stricture in one. In both patients with clinically silent leaks, the contrast-enhanced radiography was performed 3 months or more after creation of the pouch. Of the remaining 14 patients who underwent contrast-enhanced radiography because of suspected complications involving the pouch, five (36%) had abnormalities revealed, including leaks in two, fistulas in two, and recurrent carcinoma in one. CONCLUSION: Contrast-enhanced radiography of the Hartmann's pouch revealed abnormalities of the pouch in 19% of patients, including leaks or fistulas, diversion colitis, adhesions, strictures, and recurrent tumor. Because two patients had clinically silent leaks that were detected during the late postoperative period, it may be prudent to perform these studies with a water-soluble contrast medium to avoid the problems associated with extravasation of barium into the extra- or intraperitoneal spaces.

Monokine-mediated increase in human immunodeficiency virus type 1 expression in chronically infected promonocyte- and T-cell-derived lines.

The ACH-2 cell clone derived from a human T-cell line and chronically infected with human immunodeficiency virus 1 (HIV-1) and the U1 cell clone derived from a human promonocyte cell line and also chronically infected with HIV-1 produce HIV-1 in a response to stimulation with monokine-enriched supernatants prepared from highly purified populations of peripheral blood-derived human monocytes. Monokine-mediated expression of HIV-1 in these cell lines resulted in augmented virus production reflected by increases in reverse transcriptase (RT) activity, production of p24 antigen, and synthesis of major viral proteins. Examination of the cells by electron microscopy revealed numerous HIV-1 virions in the cells treated with the supernatants. This stimulation of virus production by monokine-enriched supernatants resulted in approximately 100-fold increases in RT activity and p24 antigen expression in comparison with those in untreated U1 and ACH-2 cells. Absorption of monokine-enriched supernatants with rabbit anti-tumor necrosis factor alpha antibody removed most, but not all, of the induced HIV-1 RT activity and p24 antigen expression in U1 and ACH-2 cell lines, suggesting that tumor necrosis factor alpha in the monokine-enriched supernatants is a major factor in the induction of HIV-1 expression in these cells.

Intramural tracking: a feature of esophageal intramural pseudodiverticulosis.

OBJECTIVE: Our purpose was to determine the frequency of intramural tracking in patients with esophageal intramural pseudodiverticulosis and to characterize the morphologic features of this finding on barium studies. MATERIALS AND METHODS: A review of radiology files at two institutions revealed 30 cases of esophageal intramural pseudodiverticulosis diagnosed at esophagography. In all cases, the radiographs were reviewed retrospectively to determine the frequency and morphologic features of intramural tracking in these patients. The number and distribution of pseudodiverticula and the presence or absence of strictures or esophagitis were also noted. RESULTS: Fifteen (50%) of 30 patients with esophageal intramural pseudodiverticulosis had intramural tracking on esophagography. The tracks had an average length of 1.2 cm (length range, 0.3-7 cm) and an average width of 1.6 mm (width range, 1-4 mm). The pseudodiverticula were more numerous and had a more diffuse distribution in patients with tracking than in patients without tracking. Although patients with and without tracking had a similar frequency of strictures and esophagitis, patients with tracking were more likely to have strictures involving the upper or mid esophagus, whereas patients without tracking were more likely to have strictures in the distal esophagus. These findings indicate that intramural tracking is more likely to occur in patients with the diffuse form of esophageal intramural pseudodiverticulosis. CONCLUSION: Intramural tracking was detected on esophagography in 50% of patients with esophageal intramural pseudodiverticulosis, so this type of tracking is a more common radiographic finding than has previously been recognized. Although intramural tracking has little or no known clinical significance, it is important to be aware of this finding so that it is not mistaken for a large flat ulcer in the esophagus or for an extramural collection associated with esophageal peridiverticulitis.

Purification and characterization of four isoforms of Himalayan mistletoe ribosome-inactivating protein from Viscum album having unique sugar affinity.

Ribosome-inactivating proteins having antitumor and immunomodulatory properties constitute the active principle of widely used mistletoe therapy in Europe. This is the first report of the four isoforms of Himalayan mistletoe ribosome-inactivating proteins (HmRips) from Viscum album parasitized on wild apple inhabiting NW Himalayas. HmRips were purified by affinity chromatography and four isoforms were separated by ion-exchange chromatography. HmRip 1, 2, 3, and 4 have isoelectric points of 6.6, 6.1, 5.2, and 4.7, respectively. Disulfide linked toxin and lectin subunits of HmRip 1 and 2 isoforms have molecular weights of 28 and 34kDa while those of HmRip 3 and 4 have 28 and 32kDa. The isoforms lacked blood group specificity and showed positive activity with seven mammalian erythrocyte types but did not show any activity with avian erythrocyte type. Lectin activity of HmRips remained unchanged for a wide range of temperatures (0-65 degrees C) and pH (3-9). Unlike other type II Rips, the HmRip 1, 2, and 4 showed unique affinity towards l-rhamnose, meso-inositol, and l-arabinose while HmRip 3 has specificity to gal/galNAc. Sugar binding studies with 22 sugars also suggested that the C-4 hydroxyl of galactose might be the critical site involved in sugar binding of HmRips. Type II Rips are known to be galactoside specific and do not have affinity for l-rhamnose and meso-inositol. However, HmRip 1, 2, and 4 having equal affinity for galactose and l-rhamnose do not strictly fit into any of the four structural classes of the lectins and represent a new class of type II Rips and plant lectins.

Structure of a novel ribosome-inactivating protein from a hemi-parasitic plant inhabiting the northwestern Himalayas.

This is the first report of the structural studies of a novel ribosome-inactivating protein (RIP) obtained from the Himalayan mistletoe (Viscum album) (HmRip). HmRip is a type II heterodimeric protein consisting of a toxic enzyme (A-chain) with an active site for ribosome inactivation and a lectin subunit (B-chain) with well defined sugar-binding sites. The crystal structure of HmRip has been determined at 3.8 A resolution and refined to a crystallographic R factor of 0.228 (R(free) = 0.271). A comparison of this structure with other type II RIPs reveals the presence of distinct structural features in the active site of the A-chain and in the 2gamma sugar-binding site of the B-chain. The conformation of the side chain of Tyr110, which is a conserved active-site residue in the A subunit, is strikingly different from those observed in other mistletoe RIPs, indicating its unique substrate-binding preference. The deletion of two important residues from the kink region after Ala231 in the 2gamma subdomain of the B-chain results in a significantly different conformation of the sugar-binding pocket. A ribosome-recognition site has also been identified in HmRip. The site is a shallow cavity, with the conserved residues Arg51, Asp70, Thr72 and Asn73 involved in the binding. The conformations of the antigenic epitopes of residues 1-20, 85-103 and 206-223 differ from those observed in other type II RIPs, resulting in the distinct antigenicity and pharmacological properties of HmRip.