Adverse effects and duration of treatment of TB in Canterbury, New Zealand.

BACKGROUND Treatment of TB is often extended beyond the recommended duration. The aim of this study was to assess prevalence of extended treatment and to identify associated risk factors. We also aimed to determine the frequency and type of adverse drug reactions (ADR) experienced by this study population.METHODS We performed a retrospective cohort study of all patients treated for active TB at Christchurch Hospital, Christchurch, New Zealand, between 1 March 2012 and 31 December 2018. Data for 192 patients were collected on patient demographics, disease characteristics and treatment characteristics, including planned and actual duration of treatment and ADRs.RESULTS Of 192 patients, 35 (18.2%) had treatment extended, and 85 (46.5%) of 183 with fully drug-susceptible TB received ≥9 months treatment. The most common reasons for extension were persistent or extensive disease and ADR. Extended treatment duration was not associated with any patient or disease characteristics. We found 35 (18.2%) patients experienced at least one ADR. The most common ADRs were hepatitis, rash and peripheral neuropathy.CONCLUSION TB treatment extension beyond WHO guidelines is common. Further research is needed to guide management of those with slow response to treatment. Methods for early detection of ADR, systems to improve adherence and therapeutic drug monitoring are potentially useful strategies.

[Seperation and structure elucidation of alkaloids from Chinese drug buzhaye, Folium Microcos].

From the chloroform extracts of the dried Folium Microcos, four compounds were isolated by using repeated column chromatography on silica gel and recrystallization and their structures were elucidated by physicochemical properties and UV, MS and NMR, separately. They are N-methyl-6alpha-(deca-1', 3', 5'-trienyl)-3beta-methoxy-2beta-methylpiperidine, 6-(deca-1', 3', 5'-trienyl)-3-methoxy-2-methylpiperidine, N-methyl-6-(deca-1', 3', 5'-trienyl)-2, 3-dimethylpiperidine and N-methyl-6-(deca-1', 3', 5'-trienyl)-2-methylpiperidine, named as micropiperidine A, micropiperidine B, micropiperidine C and micropiperidine D, respectively. The latter three are new compounds.

Phytochemistry and pharmacognosy.

During the past 50 years there have been tremendous advances in chemical and biological techniques of analysis that have transformed research in pharmacognosy. The PSE has regularly held symposia of relevance to pharmacognosy and some of these are briefly reviewed in the area of natural products from higher plants. These symposia have charted the developments that link pharmacognosy with phytochemistry and illustrate the application of increasingly more sophisticated analytical techniques to the discovery of biologically active compounds. Plants have yielded clinical drugs, either as natural product molecules, or as synthetic modifications, particularly for chemotherapeutic treatment of cancer and malaria. Aspects of biotechnology, traditional medicines and herbal medicinal products are briefly discussed.

Echinacea species (Echinacea angustifolia (DC.) Hell., Echinacea pallida (Nutt.) Nutt.,Echinacea purpurea (L.) Moench): a review of their chemistry, pharmacology and clinical properties.

This paper reviews the chemistry, pharmacology and clinical properties of Echinacea species used medicinally. The Echinacea species Echinacea angustifolia, Echinacea pallida and Echinacea purpurea have a long history of medicinal use for a variety of conditions, particularly infections, and today echinacea products are among the best-selling herbal preparations in several developed countries. Modern interest in echinacea is focused on its immunomodulatory effects, particularly in the prevention and treatment of upper respiratory tract infections. The chemistry of Echinacea species is well documented, and several groups of constituents, including alkamides and caffeic acid derivatives, are considered important for activity. There are, however, differences in the constituent profile of the three species. Commercial echinacea samples and marketed echinacea products may contain one or more of the three species, and analysis of samples of raw material and products has shown that some do not meet recognized standards for pharmaceutical quality. Evidence from preclinical studies supports some of the traditional and modern uses for echinacea, particularly the reputed immunostimulant (or immunomodulatory) properties. Several, but not all, clinical trials of echinacea preparations have reported effects superior to those of placebo in the prevention and treatment of upper respiratory tract infections. However, evidence of efficacy is not definitive as studies have included different patient groups and tested various different preparations and dosage regimens of echinacea. On the basis of the available limited safety data, echinacea appears to be well tolerated. However, further investigation and surveillance are required to establish the safety profiles of different echinacea preparations. Safety issues include the possibility of allergic reactions, the use of echinacea by patients with autoimmune diseases and the potential for echinacea preparations to interact with conventional medicines.

Proton NMR lipid profile of Leishmania donovani promastigotes.

The proton nuclear magnetic resonance (NMR) lipid profile of Leishmania donovani was obtained in the one-dimensional and two-dimensional modes. Partial assignments of lipid classes and individual lipids were obtained purely from the proton NMR spectrum of the mixture. A more complete assignment and quantitative analysis was achieved by prior separation of the lipids by high pressure liquid chromatography (HPLC) followed by proton NMR analysis of the fractions. This work showed that proton NMR spectroscopy could facilitate lipid analysis and classification of various parasitic protozoa and serve as a basis for rapid studies of comparative lipid metabolism in parasites.

In vitro studies on the mode of action of quassinoids with activity against chloroquine-resistant Plasmodium falciparum.

Using the incorporation of [3H]isoleucine or [3H]hypoxanthine into acid-insoluble products as indices of protein- and nucleic acid-synthetic activity, respectively, it was shown that seven plant-derived quassinoids with differing chemical substitutions all inhibited protein synthesis more rapidly than nucleic acid synthesis in human erythrocytes infected with Plasmodium falciparum, in vitro. Five quassinoids (ailanthinone, bruceantin, bruceine B, glaucarubinone and holacanthone) were effective within 30 min at doses 10 times their 48 hr in vitro IC50 values. Chaparrin and glaucarubol differed in that they did not inhibit protein synthesis during the time course of these experiments when applied at 10 times their in vitro IC50 values. When these compounds were used at 209 and 114 times their respective IC50 values, their observed effects were identical to those of the other quassinoids studied. The time (t50) at which nucleic acid synthesis was reduced to 50% of control was directly proportional to the t50 for protein synthesis, suggesting that failure of nucleic acid synthesis is a consequence of inhibition of protein synthesis. It is concluded that in the malaria parasite, as in eukaryote models, quassinoids are rapid and potent inhibitors of protein synthesis, and that this is most likely due to effects upon the ribosome, rather than upon nucleic acid metabolism.

Comparison of the in vitro activities of quassinoids with activity against Plasmodium falciparum, anisomycin and some other inhibitors of eukaryotic protein synthesis.

Using the inhibition of incorporation of [3H]hypoxanthine as an index of viability of malaria parasites, it was shown that a chloroquine-sensitive strain of Plasmodium falciparum (T9-96) and a chloroquine-resistant strain (K1) did not differ in their sensitivities to the quassinoids ailanthinone, bruceantin and chaparrin. Similarly, there were no differences between the strains in their sensitivities to the protein synthesis inhibitors anisomycin, deacetylanisomycin, cephalotaxine, homoharringtonine, cycloheximide, puromycin and puromycin aminonucleoside. The IC50 values derived for ailanthinone and bruceantin, cycloheximide, homoharringtonine and puromycin were in the nanomolar range, whereas those for the anisomycins, cephalotaxine and the aminonucleoside of puromycin were micromolar or greater. Those drugs tested which contain an ester moiety (ailanthinone, bruceantin, anisomycin, homoharringtonine) were more active than the related drugs (chaparrin, deacetylanisomycin, cephalotaxine) that do not. Cross-resistance to inhibitors of protein synthesis appeared not to accompany resistance to chloroquine.

Proliferative activity in placentas with hydropic change and hydatidiform mole as detected by Ki-67 and proliferating cell nuclear antigen immunostaining.

Complete hydatidiform moles (CHM) and partial hydatidiform moles (PHM) represent different clinicopathologic entities. To obtain prognostic and therapeutic information about both entities, it is important that pathologic classification be as accurate as possible. The distinction of molar pregnancy and an abortus with hydropic changes (AHC) can sometimes be very difficult. The acquisition of 2 antibodies against nuclear antigens expressed in cycling cells, Ki-67 and proliferating cell nuclear antigen (PCNA), allow the study of trophoblastic proliferation in CHM, PHM, and AHC. The purpose of this study is to determine whether immunocytochemical stains can help in the distinction between those entities. All materials were obtained by curettage from 95 patients with hydropic villi evident on microscopic examination. The 95 cases included 33 cases of CHM, 42 cases of PHM, and 20 cases of AHC. In the case of the Ki-67 staining, the mean was much lower in the ACH group (8.7%) than in the PHM group (65.3%) or in the CHM group (84.6%). In the case of PCNA staining, the mean differences among the 3 groups (AHC, 23.1%; PHM, 80%; and CHM, 89.2%) were all statistically significant. On the basis of the means and the Gaussian results, it appears that the Ki-67 distribution gives a better separation among the 3 groups. In conclusion, proliferative activity is an additional useful parameter for evaluation of molar pregnancies and hydropic changes, with Ki-67 staining allowing better separation than PCNA staining does.

Intratubular germ cell neoplasia in infantile yolk sac tumor. Verification by tandem repeat sequence in situ hybridization.

The strong association of intratubular germ cell neoplasia (ITGCN) with adult germ cell testicular tumors is well known, but studies noting the absence of ITGCN in certain germ cell neoplasms such as spermatocytic seminoma, childhood teratoma, and infantile yolk sac tumor (YST) have raised the issue of whether these latter neoplasms follow a different path of tumorigenesis, accounting for their more benign behavior. A case study illustrating the association of ITGCN with infantile YST is presented to challenge this hypothesis. In addition to the usual characteristic features that included strong cytoplasmic glycogen deposits, and focal placental alkaline phosphatase immunoreactivity, the atypical intratubular germ cells manifested triploidy by in situ hybridization using as probe a telomeric tandem repeat sequence, p1-79, specific to chromosome 1. The invasive YST cells, in contrast, showed evidence of tetraploidy by both in situ hybridization and flow and image cytometric studies, excluding the possibility that the atypical intratubular germ cells represented intratubular invasion by adjacent YST. These findings challenge the belief that the infantile YST follows a different path of tumorigenesis than its adult germ cell counterpart and suggest other hypotheses that might better explain its more benign behavior.

A matter of some sensitivity.

The development of sensitive chromatographic and spectroscopic techniques for the isolation and structure determination of natural products has greatly facilitated phytochemical investigations. Chemical investigations of herbarium material have resulted in the isolation of indole, quinoline and isoquinoline alkaloids from a wide number of plants. Examples of novel natural products from higher plants are given and include alkaloids, terpenoids, phenolics and quinones. Some plants investigated have not yielded the types of constituents which would have been predicted from them. Plant tissue cultures provide alternative sources of biologically active compounds and examples investigated include Cinchona, Ailanthus, Brucea and Artemisia for antiprotozoal compounds and Datura for tropane alkaloids. Biological tests are useful for bioassay-guided fractionation of plant extracts and examples of the isolation of a series of natural products with antiprotozoal and cytotoxic activities are given. Chemical and biological investigations into the traditional medicine Dragon's blood (Croton lechleri) from S. America and a Chinese prescription for the treatment of atopic eczema are described. The use of radio-ligand binding assays for the detection of a wide range of biological activities is discussed. Sensitivity of chemical and biological techniques has greatly improved prospects for finding new drug entities from plants and for investigating traditional medicines. Basic phytochemical investigations should continue to be encouraged especially in view of the rapid loss of plant species.

Phytochemistry and medicinal plants.

A truncated history of the contribution of plants to medicine is given with reference to some of the less well known ancestors of the Harborne family. Six of the top 20 prescriptions dispensed in 1996 were natural products and the clinical use of drugs such as artemisinin, etoposide and taxol has once more focussed attention on plants as sources of novel drug entities. High through-put robotic screens have been developed by industry and it is possible to carry out 50,000 tests per day in the search for compounds which have specificity of action against a key enzyme or a subset of receptors. Bioassay-guided fractionation of plant extracts linked to chromatographic separation techniques leads to the isolation of biologically active molecules whose chemical structures can readily be determined by modern spectroscopic methods. The role of academics in the search for new drugs is discussed by reference to some of our research into natural products with activity on the central nervous system, on pain receptors, the malaria parasite Plasmodium falciparum, the wound healing properties of the sap of species of Croton (Dragon's blood), and a traditional Chinese medicine used to treat eczema. Expertise in phytochemistry has been essential for this research and the strong lead shown by Professor Jeffrey Harborne is gratefully acknowledged.

Anthranilate synthase in microorganisms and plants.

The enzymology of anthranilate synthase (EC 5.4.99.6) in microorganisms and plants is reviewed. Aminoacid sequences of the enzyme subunits in different species are compared, and the mechanism of reaction is discussed.

Bioactive anthraquinone glycosides from Picramnia antidesma spp. fessonia.

A bioactivity guided fractionation, using KB cells and brine shrimp assays, of the methanolic extract from the leaves of Picramnia antidesma yielded two known anthraquinones, aloe-emodin and aloe-emodin anthrone, and three new aloe-emodin C-glycosides, named picramnioside A, picramnioside B and picramnioside C. Structures were established by spectroscopic methods (UV, IR, mass spectrometry, 1H and 13C and 2D NMR including COSY 45, HMQC, HMBC and ROESY). CD was used to establish the absolute configuration of the picramniosides.

Plant polyphenols: biologically active compounds or non-selective binders to protein?

Twenty phenolic compounds, representatives of proanthocyanidins and gallic acid/hexahydroxyldiphenic acid esters of glucose, have been assessed for their ability to inhibit binding of specific radioligands to 16 receptors. The receptors utilized were alpha 1-, alpha 2- and beta-adrenoceptors, adenosine 1, dopamine 1 and 2, muscarinic, Ca2+ channel, sulphonylureas, 5HT1, 5HT1A, 5HT2, histamine 1, benzodiazepine, opiate and Na+/K/ATPase. These phenolic compounds failed to inhibit ligands binding to 10 of the receptors under the test conditions. The most susceptible receptors to phenolic binding were beta-adrenergic, 5HT1 and opiate. Some of the compounds tested showed selectivity for a single or for two receptors. The inhibition of binding of radioligands to receptors by the phenolic compounds cannot be explained solely in terms of phenolic-protein binding. The results indicate that the removal of tannins from plant extracts prior to screening for receptor activities may result in missing biologically active compounds with specificity of action.

Anti-leishmanial activity of neolignans from Virola species and synthetic analogues.

Surinamensin, a neolignan isolated from Virola surinamensis, 3,4,5-trimethoxy-8-[2',6'-dimethoxy-4'-(E)-propenylphenoxy]-phenylpropane, a neolignan isolated from Virola pavonis, and 25 of its synthetic analogues or correlated substances with ether linkages and their corresponding C-8 sulphur and nitrogen analogues, were tested for activity against Leishmania donovani amastigotes and promastigotes in vitro. Some were active against L. donovani promastigotes at 30 microM but inactive against intracellular amastigotes. The natural neolignan from V. pavonis was active against promastigotes at 100 microM. The highest selective activity was found in those compounds with sulphur bridges. The beta-ketosulfide (3,4-dimethoxy)-8-(4'-methylthiophenoxy)-propiophenone produced 42% inhibition of L. donovani amastigotes in the liver of BALB/c mice at 100 mg/kg given once daily for five consecutive days (P>0.05).

Terpenoids from Guarea rhophalocarpa.

Four new terpenes including, two sandaracopimaradiene diterpenoids, ent-8(14),15-sandaracopimaradiene-2alpha,18-diol, and ent8(14),15-sandaracopimaradiene-2beta,18-diol, and two lanostane triterpenoids, 23-hydroxy-5alpha-lanosta 7,9(11),24-triene-3-one, and 5alpha-lanosta-7,9(11),24-triene-3alpha,23-diol, were isolated from the methanolic extract prepared from the leaves of G. rhopalocarpa together with the known steroid stigmasterol and the coumarin, scopoletin. The isolates showed weak antiprotozoal activity against Leishmania donovani promastigotes, and Trypanosoma brucei brucei blood stream trypomastigotes, and were devoid of interesting activity towards Plasmodium falciparum. The isolates did not show significant cytotoxic activity against KB cells.

Natural products as drugs.

Higher plants, many of which are threatened with extinction, are used as sources of pharmaceuticals and as ingredients of traditional medicines and are of value in new drug discovery. Artemisinin, taxol and camptothecin are examples of natural products which are undergoing clinical and commercial development. Several natural products isolated from plants used in traditional medicine have potent antiplasmodial action in vitro and represent potential sources of new antimalarial drugs. Plant biotechnology offers the possibility of improved production methods of cultivated medicinal plants as well as alternative approaches to the production of natural products for the preparation of pharmaceuticals.

Medicinal plants in tropical medicine. 1. Medicinal plants against protozoal diseases.

The active principles obtained from some of the traditional medicinal plants which are used worldwide for the treatment of protozoal diseases are reviewed. Among the active molecules considered from recent literature are bisbenzylisoquinoline, protoberberine and indole alkaloids, sesquiterpenes, quassinoids and limonoids. This review indicates that there are many antiprotozoal natural products already known which require further scientific investigation. There is a strong possibility that other antiprotozoal compounds with novel chemical structures and potentially novel modes of action will be discovered in plants.