Do Sprouting Tree Species on Erosion-prone Sites Carry Large Reserves of Resources?

Saplings ofEuptelea polyandra were studied to determine whethertree species found on unstable hillslopes of temperate, old-growthforests in Japan carry substantial storage materials for sproutingreplacement genets, as is the case with resprouter species offire-prone areas. Concentrations (% d. wt basis) of carbohydrates(starch, sucrose, glucose and fructose) contained in roots,stems and leaves were measured in summer and winter.E. polyandrasaplings were compared with those ofQuercus serrata (a frequentlysprouting tree), and those ofMallotus japonicus andIdesia polycarpa(rarely sprouting trees) in the same forest. Total concentrationsof carbohydrates (the sum of starch, sucrose, glucose and fructose)in roots were lowest inE. polyandra in both summer and winter.In addition,E. polyandra had a lower ratio of root biomass tototal plant biomass thanQ. serrata , but similar to that ofthe non-sprouting species,M. japonicus andI. polycarpa . Onthe other hand, the total concentration of carbohydrates inthe above-ground parts were similar in the four species in bothsummer and winter. These results indicate thatE. polyandra hadless long-term storage resources to implement sprouting, inspite of its apparent effectiveness in sprouting. We proposehypotheses to explain the reason whyE. polyandra stores a relativelysmall amount of resources for sprouting. Carbohydrate concentration; Euptelea polyandra Sieb. et Zacc; ground-surface disturbance; Idesia polycarpa Maxim; Mallotus japonicus (Thunb.) Muell. Arg.; Quercus serrata Thunb.; resprouter; root dry weight ratio; soluble sugars; sprouting; starch     

Maternal smoking: greater effect on males, fetal tobacco syndrome?

We tested the recently proposed criteria for a Fetal Tobacco Syndrome (FTS) on a sample of 925 primiparous black women (including 204 smokers) and their neonates. The proposed FTS criteria included proportional growth retardation (ponderal index greater than 2.26, birth weight less than 2,500 g) in term neonates. Only 19 neonates (2%) in our study fulfilled the FTS morphometric criteria, and of these only 8 had smoking mothers. Nonetheless, the negative effect of maternal smoking on fetal growth (birth weight and length) as reported from earlier investigations was clearly evident in our own data (P less than .01). Separate analysis by fetal sex revealed that the negative effect of maternal smoking upon fetal growth is more pronounced among males than females. We concluded that fetal sex should be taken into account in studies of maternal smoking effects. As for evidence for the existence of the FTS, it remains to be proven.     

Does cigarette smoking increase time to conception?

Data are reported on the relationship between cigarette smoking and other health-related behaviours and time to conception in a population-based sample of women who acted as a control group in a case-control study of twinning. Women who continued to smoke close to the time of conception took significantly longer to become pregnant than women who never smoked or stopped smoking before the year during which they attempted to conceive. A hierarchical regression analysis performed on time-to-conception data in women who continued to smoke in the year before conception provided weak evidence for a dose-response relationship between time to conception and number of cigarettes smoked per day. No significant relationships were found between time to conception and other health-related behaviours.     

Passive smoking and lung cancer: a publication bias?

To assess the likelihood of publication bias in a recent review of the effect of passive smoking on lung cancer the evidence from the reviewed papers was visualised on a “funnel” plot. In such a plot if the relative risks from various studies are plotted according to sample size they should scatter round some underlying true value, the scatter being greatest where the studies have the lowest statistical power—thus showing a “funnel” pattern. If there is publication bias and studies with non-significant results are not being published there should be a “gap” in the plot. The logarithm of the relative risks was plotted against the standard error of the logarithm of the relative risk (which was used instead of sample size as a measure of statistical uncertainty). The resulting plot was compatible with a publication bias but only in studies on men.Further studies of passive smoking and lung cancer in men seem to be warranted.     

Does smoking affect body weight and obesity in China?

An inverse relationship between smoking and body weight has been documented in the medical literature, but the effect of cigarette smoking on obesity remains inconclusive. In addition, the evidence is mixed on whether rising obesity rates are an unintended consequence of successful anti-smoking policies. This study re-examines these relationships using data from China, the largest consumer and manufacturer of tobacco in the world that is also experiencing a steady rise in obesity rates. We focus on the impact of the total number of cigarettes smoked per day on individuals’ body mass index (BMI) and on the likelihood of being overweight and obese. Instrumental variables estimation is used to correct for the endogeneity of cigarette smoking. We find a moderate negative and significant relationship between cigarette smoking and BMI. Smoking is also negatively related to being overweight and obese, but the marginal effects are small and statistically insignificant for being obese. Quantile regression analyses reveal that the association between smoking and BMI is quite weak among subjects whose BMIs are at the high end of the distribution but are considerably stronger among subjects in the healthy weight range. Ordered probit regression analyses also confirm these findings. Our results thus reconcile an inverse average effect of smoking on body weight with the absence of any significant effect on obesity. From a policy perspective these findings suggest that, while smoking cessation may lead to moderate weight gain among subjects of healthy weight, the effects on obese subjects are modest and should not be expected to lead to a large increase in obesity prevalence rates.     

HMGB1: a smoking gun in lupus nephritis?

High-mobility group box 1 protein (HMGB1) is a prototypic alarmin that is released from activated and dying cells. Because of its proinflammatory activities, HMGB1 could mediate key events in the pathogenesis of systemic lupus erythematosus, a possibility supported by elevations of HMGB1 in patient blood and increased expression in renal biopsies. The biology of HMGB1 is complicated, however, and its activity is dependent on redox state as well as binding to other molecules such as cytokines. Defining more precisely the role of HMGB1 in lupus will require treatment studies to block the activity of this alarmin in animal models and ultimately patients.A smoking gun is probably the most dramatic and iconic evidence of a crime. The concept of the smoking gun originated in a Sherlock Holmes story and then languished until it exploded into awareness during the impeachment hearings of Richard Nixon. As now understood, a smoking gun is an incontrovertible piece of evidence to establish a crime and even identify the perpetrator. This is especially true if the gun, sulfurous fumes streaming from the barrel, resides in the hand of a suspect, the murder victim bleeding nearby.In rheumatology as in all of medicine, investigators are forever searching for the smoking guns of pathogenesis. The identification of such guns, especially when found at the crime scene (such as a kidney biopsy), can delineate the mechanism of tissue injury as well as suggest new targets of therapy. Smoking guns in medicine can be very elusive, however, and cold cases abound. Assembling a case beyond a reasonable doubt can require a multitude of in vitro and in vivo studies, including treatment trials in animal models as well as patients.In the previous issue of Arthritis Research & Therapy, Zickert and colleagues [1] provided important new evidence implicating high-mobility group box 1 protein (HMGB1) as a mediator of lupus nephritis, and the enhanced expression of HMGB1 is perhaps a smoking gun in the pathogenesis of a very complicated disease. As the data presented indicate, levels of HMGB1 are elevated in the blood of patients with lupus nephritis; furthermore, renal biopsies showed increased HMGB1 expression in the mesangium and endothelium. The elevations of HMGB1 in blood occurred in patients with different histopathological forms of lupus nephritis but, interestingly, did not vary much over time or with treatment [1].These observations are important in view of the biological properties of HMGB1. HMGB1 is a prototype alarmin and, indeed, the prime example of this class of immune mediator. In other terminology, HMGB1 is a DAMP (damage-associated molecular pattern). The immune activities of HMGB1 are perhaps surprising since HMGB1 is a nuclear molecule ubiquitously expressed in cells. In its usual location, HMGB1 can bind DNA as an architectural element for chromatin structure; once released from cells, however, HMGB1 acquires a new identity and displays potent and varied immunological activities. This release can occur during immune cell activation as well as cell death, whether apoptosis or necrosis [2].Along with other studies on systemic lupus erythematosus [3-5], the evidence for a central role of HMGB1 in lupus pathogenesis is strong but nevertheless circumstantial. One of the difficulties in making the case watertight concerns the complex biology of HMGB1. While HMGB1 has immunological activity, the extent of such activity varies significantly depending on its structure, including the redox state of cysteine (C) residues at positions 23, 45, and 106. With pure HMGB1, activity requires a C106 thiol and a C23-45 disulfide bond to induce activation of nuclear factor-kappa-B. With these modifications, HMGB1 can bind to Toll-like receptor 4 (TLR4) to stimulate responses but the oxidized form lacks such activity [6,7]. Thus, the finding of HMGB1 in the blood or tissue does not prove that it is functionally active.A further complexity concerns the manner in which HMGB1 stimulates inflammation. While active by itself depending on redox state, HMGB1 can also function in concert with cytokines such as interleukin-1 (IL-1). These complexes can stimulate responses through the cytokine receptor to dramatically boost immunostimulatory activity [8,9]. Similarly, HMGB1 can form complexes with PAMPs (pathogen-associated molecular patterns) such as lipopolysaccharide or CpG DNA to act via a TLR. Thus, the finding of high levels of HMGB1 in the blood or tissue is the beginning, not the end, of the story. In the absence of a partner in crime such as IL-1 or lipopolysaccharide, the effect of this molecule may be limited depending on the status of the cysteines [10].As is now recognized, HMGB1 emanates from cells during activation, necrosis, and apoptosis. Whereas HMGB1 from activated and necrotic cells has alarmin activity, HMGB1 released during apoptosis may lack such activity because of oxidation [7]. Since tissue injury (for example, ischemia) can lead to apoptosis and therefore HMGB1 release, the presence of extracellular HMGB1 may denote the effects of injury rather than establish the cause. In this regard, HMGB1 can be a component of immune complexes in lupus, likely reflecting its interaction with DNA that emerges from dead or dying cells [4,5]. The role of HMGB1 in nephritis as opposed to dendritic cell activation is not yet clear, although, as shown in the current study, the finding of HMGB1 in the mesangium may signify immune deposition; in this case, the activation of the complement system, rather than any direct effect of HMGB1 itself, may be the key event in inciting nephritis.HMGB1 has generated great interest as a new target of immununosuppressive therapy since, in animal models of shock and arthritis, blocking the action of HMGB1 can be strikingly beneficial [2]. Such studies are awaited in lupus. Only then will it be possible to know whether the HMGB1 gun in lupus nephritis is smoking or just smoldering.     

A smoking ban in psychiatric units: threat or opportunity?

People with severe mental illness (SMI) experience some of the worst physical health and die younger than almost any section of the population. Mental health professionals have seemed strangely indifferent to this inequality, which in other areas of health would be a national scandal. In this editorial we discuss the recently introduced smoking ban in inpatient mental health service settings, which will offer mental health services an opportunity to implement creative, evidence-based strategies to help people with SMI address smoking and nicotine addiction. In doing this, we refer to National Institute for Health and Clinical Excellence (NICE) guidance. This guidance forms the basis of national smoking policies for the general population and forms a starting point for those with SMI. Such a strategy will necessarily involve close collaboration with primary care, and we specifically examine how this might be achieved.     

Life on Jupiter?

The possibilities of life on Jupiter are discussed from the point view of life as we know it. That is, we assume that any life on Jupiter would not involve new principles foreign to us. Proteins would be a constituent as would fats and the other building blocks of living organisms on Earth. This leads us to a set of limiting parameters, such as pressure. Studies in the laboratory have shown that proteins and other essential molecules are denatured by pressures of 4000 atm and higher. Thus, we must not expect life in the great depths of the Jovian atmosphere. It could exist only at depths of several hundred kilometers in the atmosphere. Since no solid surface could possibly exist at such altitudes, any organisms present must be small enough to be buoyed up by the turbulent atmospheric currents or must fly or both. Such possibilities, however, seem to be real. The necessary nutrients to preserve life and foster growth could be furnished by the Miller-Urey type reactions of lonizing radiation on the reducing atmosphere undoubtedly present. There can, of course, be no possibility of oxygen on Jupiter, and so the life forms, if they exist, must be anaerobic. Such possibilities are real and have often been cited in connection with the origin of life on Earth.     

Heteropolypeptides on Titan?

Since hydrogen cyanide is a component of Titan's hazy atmosphere, HCN polymers might also be present by way of a low energy pathway leading initially to the synthesis of polyaminomalonitrile. Subsequent reactions of HCN with the activated nitrile groups of this HCN homopolymer would then yield heteropolyamidines, readily converted to heteropolypeptides following contact with frozen water on the surface of Titan.Similar HCN polymers in the reducing atmospheres of Jupiter and Saturn could be major contributors to the yellow-brown-orange appearance of these giant planets.Any detection of such HCN chemistry by the Voyager missions or the pending Galileo probe would constitute evidence for the hypothesis that heteropolypeptides on the primitive Earth were synthesized directly from hydrogen cyanide and water without the intervening formation of -amino acids.Paper presented at the 6th College Park Colloquium, October 1981.     

How effective is nicotine replacement therapy in helping people to stop smoking?

OBJECTIVE--To assess the efficacy of nicotine replacement therapy in helping people to stop smoking. DESIGN--Analysis of the results of 28 randomised trials of nicotine 2 mg chewing gum, six trials of nicotine 4 mg chewing gum, and six trials of nicotine transdermal patch. SUBJECTS AND SETTING--Subjects were self referred (responding to advertisements or attending anti-smoking clinics) in 20 trials and invited (general practice or hospital patients) in 20. Therapists in self referred trials were generally experienced in helping people stop smoking but not in invited trials. MAIN OUTCOME MEASURE--Efficacy was defined as difference in percentages of treated and control subjects who had stopped smoking at one year. RESULTS--Efficacy was highly significant (P < 0.001) for both gum and patch. Nicotine 2 mg chewing gum had an overall efficacy of 6% (95% confidence interval 4% to 8%), greater in self referred subjects than in invited subjects (11% v 3%). Efficacy depended on the extent of dependence on nicotine as assessed by a simple questionnaire; it was 16% (7% to 25%) in "high dependence" smokers, but in "low dependence" smokers there was no significant effect. The 4 mg gum was effective in about one third of "high dependence" smokers. The efficacy of the nicotine patch (9% (6% to 13%) overall) was less strongly related to nicotine dependence, perhaps because the patch cannot deliver a bolus of nicotine to satisfy craving. CONCLUSIONS--Both gum and patch are effective aids to help nicotine dependent smokers who seek help in stopping. Among the most highly nicotine dependent smokers (those craving a cigarette on waking) the 4 mg gum is the most effective form of replacement therapy; it could enable one third to stop. In less highly dependent smokers the different preparations are comparable in their efficacy but the patch offers greater convenience and minimal need for instruction in its use. Overall, nicotine replacement therapy could enable about 15% of smokers who seek help in stopping smoking to give up the habit.