Ipecacuanha: the South American vomiting root

The story of ipecacuanha, derived from the plant Cephaelis, is a fascinating one. It was discovered in Brazil in the 1600s and then transported to Paris in the latter part of the same century. It was used there by the physician Helvetius on various members of the French royal court to treat the flux (dysentery) with some success. Later, in the eighteenth century, it was taken up by the physician and privateer Thomas Dover and became, with opium, a fundamental constituent of his celebrated powder, which was used widely to treat fevers and agues for the next 200 years. Progress was then delayed until the early 1800s when the School of Chemistry at Paris established that the dried root of ipecac contained two powerful alkaloids, emetine and cephaeline, that consistently caused vomiting and diarrhoea. The discovery of the pathogenic amoeba, Entamoeba histolytica, in the latter part of the nineteenth century, allowed a distinction to be made between the two main forms of dysentery (amoebic and bacillary). Emetine was shown to be active against the amoebic form of dysentery but ineffective against that caused by bacteria. Ipecacuanha, its root and the pure alkaloid emetine have now been abandoned on the grounds of toxicity. They have been replaced by safer, more effective compounds. Nevertheless, they deserve an honoured place in the history of medicine, especially in the search for an effective treatment for amoebic dysentery.

Solanaceae IV: Atropa belladonna, deadly nightshade

The Deadly Nightshade, Atropa belladonna, is a plant surrounded by myth, fear and awe. In antiquity, the Greeks and the Romans knew that it contained a deadly poison. In medieval times, it was widely used by witches, sorcerors and professional poisoners. Linnaeus later codified its remarkable properties as the genus Atropa, the Fate that slits the thin spun life and the species belladonna because of its power to dilate the pupils. In the 1830s, the pure alkaloid I-atropine was isolated from the plant. This proved to be a significant tool in the study of the autonomic nervous system leading to the identification of acetylcholine as an important neurotransmitter in mammals. When pure atropine became available, it caused a large number of deaths, whether by accident, suicide or homicide.

Efficacy of moxibustion after rolling correction in dairy cows with abomasal displacement

This study was performed to assess the efficacy of moxibustion after rolling correction in dairy cows with abomasal displacement (AD). The experimental group comprised 86 Holstein cows with left displacement of the abomasum (LDA) and right displacement of the abomasum (RDA), with a mean age of 3.8 with AD during a 2-year period. The cows were rolled for correction of AD. After the rolling procedure, moxibustion was conducted on six acupoints once a day during the course of treatment. After repositioning the abomasums, the bilateral points of BL-20, BL-21 and BL-26 were then stimulated. During the follow-up of 1 week, 67 (93.1%) of 72 LDA and 12 (85.7%) of 14 RDA cows were released as cured after moxibustion. In conclusion, moxibustion effectively treats AD following rolling correction in dairy cows.

Solanaceae III: henbane, hags and Hawley Harvey Crippen

Hyoscyamus, the henbane, is one of the drugs of the ancients. Initially used both as a poison and narcotic, it was widely adopted by witches, wizards and soothsayers as a component of their hallucinatory and flying ointments. It was also used by notorious poisoners such as Madame Voisin in France. Eventually, in the nineteenth century its active principle was isolated by Ladenburg and called l-hyoscine. It proved to be a tropane alkaloid very similar to atropine. These two alkaloids proved to be very important in the study of the parasympathetic component of the autonomic nervous system, and together with physostigmine, allowed the major neurotransmitter acetylcholine to be isolated and its mechanisms of action to be characterised. The Crippen murder case in 1910 gave hyoscine further fame, indeed, notoriety. The unassuming homeopathic doctor murdered his wife with the alkaloid and then decamped for Canada with his mistress Ethel Le Neve. The case became a worldwide sensation for several reasons: the arrest of the fugitive couple by wireless telegraphy (Marconigram) and the extensive chemical and histological evidence presented by Willcox and Spilsbury. Some authorities claim that this was the beginning of the science of forensic medicine in Britain. Hyoscine is now hardly ever used in modern therapeutics but its history from antiquity to the witches and on to Dr Crippen is both bizarre and fascinating.

The Solanaceae: foods and poisons

The plant family Solanaceae contains important foodstuffs such as the potato, tomato and aubergine, together with powerful poisons including mandrake, henbane and deadly nightshade. In the first article in this short series on the family, the history and importance of the potato are described. It was first cultivated by the Inca people in the altiplano of the Andes in prehistoric times. Then it was translocated to Europe by the Spanish invaders. Originally reviled as'peasant food', it was regarded with great suspicion as an evil plant and a potential cause of leprosy. Over several centuries it gradually became established throughout Britain, France and the continent, and in particular in Ireland, where its growth allowed the population to expand very rapidly between 1750 and 1850. In the late 1840s, nemesis arrived in the form of the potato blight and the Irish famine. The 'tatties' went black, a great hunger ensued and thousands died. Later, the causative fungus was isolated and steps were taken to avoid further similar disasters. It is not generally appreciated that potatoes can be poisonous if they are turning green or sprouting (chitting). The tuber is then producing toxic quantities of the alkaloid alpha-solanine. The clinical syndrome of potato poisoning is described briefly.

Pycnogenol induces differentiation and apoptosis in human promyeloid leukemia HL-60 cells

Pycnogenol, rich of many phytochemicals of medical value, is a commercialized nutrient supplement extracted from the bark of European coastal pine. In this study, we investigated the anti-tumor effects of Pycnogenol on HL-60, U937 and K562 human leukemia cell lines. We found that Pycnogenol inhibited cell proliferation dose- and time-dependently, and the IC(50)s of Pycnogenol on HL-60, U937 and K562 cells were 150, 40 and 100 microg/ml, respectively. When HL-60 cells were incubated with low concentrations of Pycnogenol (50, 100 and 125 microg/ml) for 24 h, a prominent G0/G1 arrest was observed, followed by gradual accumulation of sub-G0/G1 nuclei. At 48 h of treatment, 50-70% of HL-60 cells differentiated, as evidenced by morphological changes, NBT reduction, induction of NSE activity, and increases of cell surface expression of CD11b. However, results from Annexin V/PI staining, DAPI staining and DNA fragmentation assay indicated that Pycnogenol induced HL-60, U937 and K562 cell apoptosis at their respective IC(50)s after 24 h of treatments. Pretreatment of z-DEVD-fmk, a caspase-3 specific inhibitor, not only decreased caspase-3 activity but also reduced the percentage of apoptotic cells induced by Pycnogenol. This indicated that caspase-3 activation was involved in Pycnogenol induced-apoptosis. In conclusion, Pycnogenol induced differentiation and apoptosis in leukemia cells. Our data suggest that Pycnogenol could serve as a potent cancer chemopreventive or chemotherapeutic agent for human leukemia.

Changes in outcome with sphincter preserving surgery for rectal cancer in Korea, 1991-2000

AIM

To report the clinical and oncological data of patients operated on for rectal cancers 3-5 cm from the AV over a 10 year period, including the Sphincter preservation (SP) rate.

METHODS

We reviewed medical records of 304 patients with rectal cancers 3-5 cm from the AV who underwent surgical resection from January 1991 through December 2000. The 10 years were divided into three periods based on the introduction of new surgical techniques, specifically, ultralow anterior resection (ULAR) with double stapling in March 1994 and ULAR with coloanal anastomosis in April 1997. The rates of SP, complications and patient survival during these periods were compared.

RESULTS

The SP rate increased significantly over the 10 years, from 16.4% in period I (January 1991-February 1994), to 53.0% in period II (March 1994-March 1997), to 86.5% in period III (April 1997-December 2000) (p<0.001). Over time, the age of the patients increased (p=0.004), the length of the distal resection margin became shorter (p=0.005), and the rate of lymph node metastasis increased (p=0.016). The factors significantly influencing SP were the period (p<0.001) and the distance from the AV (p<0.001). Over time, morbidity did not increase, and overall and disease free survival rates did not decrease. In contrast, the overall survival of N2 cases significantly increased over time (p=0.0492).

CONCLUSION

Over 10 years, the SP rate in rectal cancers 3-5 cm from the AV was significantly increased by the introduction of the double stapling and coloanal anastomosis techniques. These surgical methods, however, had no effect on morbidity, disease free survival and overall survival rates.

Curare: the South American arrow poison

The history of curare is both curious and convoluted. A product of South American culture it emerged in the sixteenth century from the mists of antiquity at the same time as quinine, coca, and chocolate. Like quinine, at first came the extract but no plant, and later the plant but no chemical compound. It took more than 300 years and the efforts of many explorers and scientists to resolve the problem. These included Condamine, Humboldt, Brodie, Waterton, Bernard, Dale, Walker, and King. Finally, the pure compound d-tubocurarine was isolated from the liana Chondrodendron and synthesised. Its specific physiological action was blockade of the effect of acetylcholine at the neuro-muscular junction. Such a paralytic poison could be used to kill oneself or others. The bizarre plot to kill the Prime Minister, Lloyd George, during the First World War is described. Fortunately this nefarious plan was thwarted by the Secret Service!

Mutational analysis of OGG1, MYH, MTH1 in FAP, HNPCC and sporadic colorectal cancer patients: R154H OGG1 polymorphism is associated with sporadic colorectal cancer patients

MYH, OGG1 and MTH1 are members of base excision repair (BER) families, and MYH germline mutations were recently identified in patients with multiple adenomas or familial adenomatous polyposis (FAP). A total of 20 APC-negative Korean FAP patients were analyzed for OGG1, MYH and MTH1 germline mutations. A total of 19 hereditary nonpolyposis colorectal cancer (HNPCC), 86 suspected HNPCC, and 246 sporadic colorectal cancer cases were investigated for OGG1 and MYH mutations. A total of 14 R154H OGG1 polymorphisms were identified in hereditary, sporadic colorectal cancers, and normal controls. For the case-control analysis of OGG1 R154H, a total of 625 hereditary or sporadic colorectal cancer patients and 527 normal controls were screened. R154H was a rare polymorphism associated with sporadic colorectal cancer patents (OR: 3.586, P= 0.053). R154H does not segregate with cancer phenotypes. Upon examining the possibility of recessive inheritance of R154H, we could not identify any complementary mutations in OGG1, MYH or MTH1. Samples with R154H were further screened for mutations of K-ras, beta-catenin, APC, p53, BRAF and the microsatellite instability (MSI) status. Eight somatic mutations were identified in these genes and G:C to T:A transversion mutations were not dominant in samples harboring R154H. This result raises the possibility that OGG1 R154H may function as a low/moderate-penetrance modifier for colorectal cancer development.

Plants against malaria. Part 1: Cinchona or the Peruvian bark

On of the most compelling sagas in the history of medicine and therapeutics is the emergence of the Peruvian bark (Cinchona) and also of the pharmacologically active substance derived from it, quinine. Its discovery involved exploration, exploitation and secrecy, and it came, in the nineteenth century, to reflect the struggles of the major European powers for domination, territory and profit. This short history shows how the use of Cinchona enabled the exploration of dangerous malarial areas and in this way facilitated imperial expansion by the Western powers.

State of the art in studying protein folding and protein structure prediction using molecular dynamics methods

This study presents an overview of the state of the art in using molecular dynamics methods to simulate protein folding and in the end game of protein structure prediction. In principle, these methods should allow the highest level of detail possible and the highest accuracy, but they are limited by both the accuracy of the force field used in the simulation and the sampling possible in the available computer time. We describe current capabilities in running the simulations longer and more efficiently.

Molecular dynamics in the endgame of protein structure prediction

In order adequately to sample conformational space, methods for protein structure prediction make necessary simplifications that also prevent them from being as accurate as desired. Thus, the idea of feeding them, hierarchically, into a more accurate method that samples less effectively was introduced a decade ago but has not met with more than limited success in a few isolated instances. Ideally, the final stages should be able to identify the native state, show a good correlation with native similarity in order to add value to the selection process, and refine the structures even further. In this work, we explore the possibility of using state-of-the-art explicit solvent molecular dynamics and implicit solvent free energy calculations to accomplish all three of those objectives on 12 small, single-domain proteins, four each of alpha, beta and mixed topologies. We find that this approach is very successful in ranking the native and also enhances the structure selection of predictions generated from the Rosetta method.

Free-energy calculations highlight differences in accuracy between X-ray and NMR structures and add value to protein structure prediction

BACKGROUND

While X-ray crystallography structures of proteins are considerably more reliable than those from NMR spectroscopy, it has been difficult to assess the inherent accuracy of NMR structures, particularly the side chains.

RESULTS

For 15 small single-domain proteins, we used a molecular mechanics-/dynamics-based free-energy approach to investigate native, decoy, and fully extended alpha conformations. Decoys were all less energetically favorable than native conformations in nine of the ten X-ray structures and in none of the five NMR structures, but short 150 ps molecular dynamics simulations on the experimental structures caused them to have the lowest predicted free energy in all 15 proteins. In addition, a strong correlation exists (r(2) = 0.86) between the predicted free energy of unfolding, from native to fully extended conformations, and the number of residues.

CONCLUSIONS

This work suggests that the approximate treatment of solvent used in solving NMR structures can lead NMR model conformations to be less reliable than crystal structures. This conclusion was reached because of the considerably higher calculated free energies and the extent of structural deviation during aqueous dynamics simulations of NMR models compared to those determined by X-ray crystallography. Also, the strong correlation found between protein length and predicted free energy of unfolding in this work suggests, for the first time, that a free-energy function can allow for identification of the native state based on calculations on an extended state and in the absence of an experimental structure.

Changes in matrix proteoglycans induced by insulin and fatty acids in hepatic cells may contribute to dyslipidemia of insulin resistance

Insulin resistance and type 2 diabetes are associated with elevated circulating levels of insulin, nonesterified fatty acids (NEFAs), and lipoprotein remnants. Extracellular matrix proteoglycan (PG) alterations are also common in macro- and microvascular complications of type 2 diabetes. In liver, extracellular heparan sulfate (HS) PGs contribute to the uptake of triglyceride-rich lipoprotein remnants. We found that HepG2 cells cultured with 10 or 50 nmol/l insulin or 300 micromol/l albumin-bound linoleic acid changed their PG secretion. The glycosaminoglycans (GAGs) of the secreted PGs from insulin-treated HepG2 cells were enriched in chondroitin sulfate (CS) PGs. In contrast, cells exposed to linoleic acid secreted PGs with decreased content of CS. Insulin caused a moderate increase in mRNA for versican (secreted CS PG), whereas linoleic acid markedly decreased mRNA for versican in HepG2 cells, as did the peroxisomal proliferator-activated receptor-alpha agonist bezafibrate. The effects of insulin or linoleic acid on syndecan 1, a cell surface HS PG, were similar to those on versican, but less pronounced. The livers of obese Zucker fa/fa rats, which are insulin-resistant and have high levels of insulin, NEFAs, and triglyceride-rich remnants, showed increased expression of CS PGs when compared with lean littermates. These changes in PG composition decreased the affinity of remnant beta-VLDL particles to PGs isolated from insulin-treated HepG2 cells and obese rat livers. The results indicated that insulin and NEFAs modulate the expression of PGs in hepatic cells. We speculate that in vivo this exchange of CS for HS may reduce the clearance of remnant beta-VLDLs and contribute to the dyslipidemia of insulin resistance.

The Chinese medicine Bu-Zhong-Yi-Qi-Tang inhibited proliferation of hepatoma cell lines by inducing apoptosis via G0/G1 arrest

Bu-Zhong-Yi-Qi-Tang (BZYQT), a Chinese herbal medicine, inhibited the proliferation of human hepatoma cell lines (Hep3B, HepG2 and HA22T) dose-dependently. The IC50s of BZYQT on the proliferation of Hep3B, HepG2 and HA22T were 432.5+/-31.8 microg/ml, 455.4+/-24.2 microg/ml, and 2284.3+/-77.2 microg/ml respectively on day 3. However, BZYQT did not significantly inhibit the proliferation of normal human hepatocytes (Chang liver, CCL-13) at the concentration under 5,000 microg/ml. Major compounds of BZYQT, including astragaloside IV, ginsenoside Rb1 and Rg1, saikosaponin a and c, and glycyrrhizin, have been identified. To investigate the key inhibitors of BZYQT. Hep3B cells were treated with BZYQT, individual major compounds of BZYQT, and mixture of major compounds in the same ratio as present in BZYQT. Significant inhibition of proliferation was detected in BZYQT and its major compounds mixture in a comparable level. Not any individual major compound examined could suppress the proliferation of Hep3B cells. This data indicated that there could be synergistic or additive effects of the ingredients in BZYQT. BrdU incorporation, cell cycle analysis and DNA fragmentation assay revealed that BZYQT suppressed the proliferation of hepatoma cells via G0/G1 cell cycle arrest and inhibition of DNA synthesis followed by apoptosis.

An assessment of the potential use of the nematode to copepod ratio in the monitoring of metals pollution. The Chañaral case

We discuss the use of the nematode to copepod ratio in relation to determining the extent of metals impact using the Chañaral area of northern Chile, where the dumping of copper mine tailings has taken place for many years, as an example. Data were collected from 12 beaches in the area on eight occasions between January 1997 and October 1998. We find that the ratio is not a good predictor of pollution due to the generally low densities of meiofauna on impacted beaches and the absence of harpacticoid copepods from those beaches. We suggest that in the case of metal pollution the mean number of Harpacticoida per site may be a better indicator of impact stress. We rule out the use of the nematode to copepod ratio as an indicator in biomonitoring studies where metal enrichment is thought to occur.

Sensitivity of partially purified ice nucleation activity of Fusarium acuminatum SRSF 616

Factors that affect bacterial ice nucleation, including growth medium, growth phase, nutrient deprivation, and cold-temperature exposure, were investigated in the ice nucleation active (INA) fungus Fusarium acuminatum SRSF 616. Ice nucleation activity remained relatively constant throughout the growth cycle, and the cell-free culture supernatant consistently displayed higher ice nucleation activity than the hyphal pellet. Although nutrient starvation and low-temperature exposure enhance bacterial ice nucleation activity, reducing the concentration of C, N, or P in synthetischer nährstoffarmer broth (SNB) did not increase fungal ice nucleation activity, nor did exposure to 4 degrees C or 15 degrees C. From the SNB supernatant, selected INA chromatography fractions were obtained that demonstrated increased sensitivity to proteinase K and heat compared with culture supernatant. We propose that partial purification of the fungal ice nuclei resulted in removal of low-molecular-weight stabilizing factors.

2.1 and 1.8 A average C(alpha) RMSD structure predictions on two small proteins, HP-36 and s15

On two different small proteins, the 36-mer villin headpiece domain (HP-36) and the 65-mer structured region of ribosomal protein (S15), several model predictions from the ab initio approach Rosetta were subjected to molecular dynamics simulations for refinement. After clustering the resulting trajectories into conformational families, the average molecular mechanics--Poisson Boltzmann/surface area (MM-PBSA) free energies and alpha carbon (C(alpha)) RMSDs were then calculated for each family. Those conformational families with the lowest average free energies also contained the best C(alpha) RMSD structures (1.4 A for S15 and HP-36 core) and the lowest average C(alpha) RMSDs (1.8 A for S15, 2.1 A for HP-36 core). For comparison, control simulations starting with the two experimental structures were very stable, each consisting of a single conformational family, with an average C(alpha) RMSD of 1.3 A for S15 and 1.2 A for HP-36 core (1.9 A over all residues). In addition, the average free energies' ranks (Spearman rank, r(s)) correlate well with the average C(alpha) RMSDs (r(s) = 0.77 for HP-36, r(s) = 0.83 for S15). Molecular dynamics simulations combined with the MM--PBSA free energy function provide a potentially powerful tool for the protein structure prediction community in allowing for both high-resolution structural refinement and accurate ranking of model predictions. With all of the information that genomics is now providing, this methodology may allow for advances in going from sequence to structure.

Apoptosis in rheumatoid arthritis--expression of Fas, Fas-L, p53, and Bcl-2 in rheumatoid synovial tissues

Recent studies have suggested that apoptosis is one of the pathogenetic mechanisms in rheumatoid arthritis (RA). In this study, by using single and double immunohistochemical staining assays, Fas, Fas-L, p53, and Bcl-2 were measured simultaneously in RA and osteoarthritic (OA) and post-traumatic (PT) synovial tissues (ST) in order to understand the distribution of these apoptosis-related proteins. The TdT-mediated dUTP-biotin nick end labelling (TUNEL) method was performed to detect apoptotic cells. There was a significant increase of Fas, Fas-L, and p53 in RA ST, compared with OA or PT, but no significant difference of Bcl-2 expression was detected between patient groups. In RA ST, expression of Fas and p53 was detected in sub-lining layers and the majority of Fas- and p53-expressing cells were fibroblast-like synoviocytes. A positive correlation between Fas and p53 was demonstrated in RA ST. In RA ST, one-third of Fas-positive and 80% of p53-positive cells were also TUNEL-positive. These results indicate that apoptosis in RA is strongly associated with the expression of Fas and p53, but not Bcl-2.

Solid-phase microextraction for organochlorine pesticide residues analysis in Chinese herbal formulations

Solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used to determine pesticide residues in Chinese herbal formulations. Fibers coated with a 100-microm film thickness of poly(dimethylsiloxane) was used to extract 19 organochlorine pesticides (OCPs). The pesticides in the study consisted of alpha-, beta-, gamma-and delta-hexachlorocyclohexane, p,p'-DDD, p,p'-DDE, p,p'-DDT, o,p'-DDT, aldrin, dieldrin, endrin, endrin aldehyde, endrin ketone, endosulfan (I, II and sulfate), heptachlor, heptachlor epoxide, and methoxychlor. The optimal experimental procedures for the adsorption and desorption of pesticides were evaluated. The linearity was obtained with a precision below 11% RSD for the studied pesticides expect endosulfan sulfate (21%) in a wide range from 1 to 200 ng/g. Detection limits were reached at below ng/g levels. Heptachlor epoxide was determined at a calculated limit of 0.03 ng/g. Comparison between SPME and Soxhlet extraction showed that SPME has a less than one order detection limit for residue pesticide determination. The proposed method was tested by analyzing herbal formulations from a local market for OCP multiresidues. Some residues studied were detected in the analyzed samples. The results demonstrate the suitability of the SPME-GC-MS approach for the analysis of multi-residue OCPs in Chinese herbal formulations.