Acupuncture to alleviate chemotherapy-induced nausea and vomiting in pediatric oncology - a randomized multicenter crossover pilot trial

BACKGROUND

We investigated whether acupuncture as a supportive antiemetic approach reduces the need for antiemetic rescue medication during highly emetogenic chemotherapy in pediatric oncology. We report on a multicenter crossover study at 5 tertiary hospitals in Germany.

PROCEDURE

Twenty-three children (13.6 y,+/- 2.9) receiving highly emetogenic chemotherapy for treatment of solid malignant tumors were included. Patients were randomly allocated to receive acupuncture treatment during either the second or third identical chemotherapy course together with standard antiemetic medication. The main outcome measure was the amount of additional antiemetic medication during chemotherapy. Secondary outcome measure was the number of episodes of vomiting per course.

RESULTS

Fourty-six chemotherapy courses with or without acupuncture were compared. The need for rescue antiemetic medication was significantly lower in acupuncture courses compared to control courses (p=0.001) Episodes of vomiting per course were also significantly lower in courses with acupuncture (p=0.01). Except for pain from needling (4/23) no side effects occurred. Patients acceptance of acupuncture was high.

CONCLUSIONS

Acupuncture as applied here seems to be effective in preventing nausea and vomiting in pediatric cancer patients.

Color-coded duplex endoscopic ultrasound of the adrenals

Imaging of the adrenals by endoscopic ultrasound (EUS) is a valuable technique for detection and localization of adrenal lesions, but endosonomorphological tumor distinction remains difficult. In this single-center study, the amount of blood flow in common adrenal lesions, such as adrenal adenomas, adrenal hyperplasia, and pheochromocytomas, was visualized by color-coded duplex EUS (CD-EUS) and was retrospectively analysed. Therefore, we reviewed our EUS database to evaluate and correlate the perfusion patterns of common adrenal lesions with histologically confirmed diagnosis, possible malignancy, and endosonomorphological features such as echogeneity, echostructure, and tumor size. CD-EUS was performed using an endosonoscope Pentax FG 32 UA with a longitudinal 7.5 MHz sector array and Hitachi EUB 525 ultrasound system. In 38 consecutive patients (male=19; female=19; age: mean 53+/-16 yr SD), perfusion patterns of 46 histologically confirmed adrenal, para- or extra-adrenal lesions of adrenal origin (adenoma: no.=20; nodular hyperplasia: no.=11; pheochromocytoma: no.=15; diameter 26+/-15 mm, range 6-70 mm) were analyzed and classified semiquantitatively as "not" (no.=24), "slightly" (no.=12), "moderately" (no.=4) or "highly" (no.=6) hypervascularized. Compared to adenomas (p=0.003) and nodular hyperplasia (p=0.047), pheochromocytomas showed a significantly higher grade of perfusion. There was no relationship between perfusion patterns and localization of pheochromocytomas (adrenal: 8; paraadrenal: 3; extra-adrenal: 4). Vascularization was not statistically associated with tumor echogeneity, echostructure, malignancy or tumor size. CD-EUS is an additional tool for adrenal endosonographic tumor distinction and seems to improve the endosonographic detection of pheochromocytomas by visualization of hypervascularization. As an overlap of perfusion patterns exists, CD-EUS findings must be interpreted in the context of clinical, laboratory and chemical results.

[Knee and shoulder arthroscopy. Positioning and thermal injuries]

Intraoperative positioning injuries during shoulder- and knee arthroscopy are rare complications and affect mainly nerves and soft tissue. Although the majority of these complications are reversible, in some cases serious negative consequences for the patient persist. This article describes the frequency of several positioning injuries including their prevention and the appropriate treatment. The legal responsibilities are illustrated as well as the importance of an intense preoperative investigation of preexisting diseases and possible risk factors. Furthermore, a review of possible thermal injuries of the patient during arthroscopy caused by e.g. electrosurgical instruments or the cold light source, is given as well as prevention strategies.

GH receptor d3 polymorphism in Dutch patients with MPHD and IGHD born small or appropriate for gestational age

OBJECTIVE

GH acts through the GH receptor (GHR). The GHR gene contains a genetic polymorphism caused by a deletion of exon 3 (d3), with high frequency in the normal population. There is a continuing controversy whether the presence or absence of the exon 3 deletion (d3+ vs. d3-) affects the effect of GH in human growth.

DESIGN, PATIENTS AND MEASUREMENTS

For 144 patients with idiopathic isolated GH deficiency (IGHD, n = 72) or multiple pituitary hormone deficiency (MPHD, n = 72), amplification of the region around exon 3 of the GHR gene was performed. Clinical data and response to GH treatment were compared between GHR d3+and d3- IGHD and MPHD patients born either small for gestational age (SGA) or appropriate for gestational age (AGA).

RESULTS

IGHD patients born SGA had a significantly higher d3+frequency (82%) than IGHD patients born AGA (35%, P = 0.006). Within the group of IGHD patients born SGA, d3- patients showed a slightly better spontaneous catch up growth before start of GH treatment than d3+ patients (1.1 +/- 1.1 SD vs. 0.6 +/- 1.1 SDS, P = 0.040) There was no difference in patients first year's response to GH treatment between GHR d3+ and d3- patients.

CONCLUSIONS

In IGHD and MPHD patients, response to GH treatment was independent of GHR genotype. GHR-d3 was significantly more frequent among IGHD patients born SGA. As we are the third to report an association between birth size and GHR d3 status, it is conceivable that the GHR-d3 might affect prenatal growth in IGHD patients by a yet unknown mechanism.

Crystal structures of the conserved tRNA-modifying enzyme GidA: implications for its interaction with MnmE and substrate

GidA is a flavin-adenine-dinucleotide (FAD)-binding protein that is conserved among bacteria and eucarya. Together with MnmE, it is involved in the addition of a carboxymethylaminomethyl group to the uridine base in the wobble position (nucleotide 34) of tRNAs that read split codon boxes. Here, we report the crystal structures of the GidA proteins from both Escherichia coli and Chlorobium tepidum. The structures show that the protein can be divided into three domains: a first FAD-binding domain showing the classical Rossmann fold, a second alpha/beta domain inserted between two strands of the Rossmann fold, and an alpha-helical C-terminal domain. The domain inserted into the Rossmann fold displays structural similarity to the nicotinamide-adenine-dinucleotide-(phosphate)-binding domains of phenol hydroxylase and 3-hydroxy-3-methylglutaryl-CoA reductase, and, correspondingly, we show that GidA binds NADH with high specificity as an initial donor of electrons. GidA behaves as a homodimer in solution. As revealed by the crystal structures, homodimerization is mediated via both the FAD-binding domain and the NADH-binding domain. Finally, a large patch of highly conserved, positively charged residues on the surface of GidA leading to the FAD-binding site suggests a tRNA-binding surface. We propose a model for the interaction between GidA and MnmE, which is supported by site-directed mutagenesis. Our data suggest that this interaction is modulated and potentially regulated by the switch function of the G domain of MnmE.

Natural course of small adrenal lesions in multiple endocrine neoplasia type 1: an endoscopic ultrasound imaging study

OBJECTIVE

Adrenal lesion is one of the features of multiple endocrine neoplasia type 1 (MEN1). This study aimed to assess prevalence, natural course and clinical relevance of small adrenal lesions without clinical symptoms, endocrine activity, or mechanical problems and thus without clear indication for surgical therapy by endoscopic ultrasound (EUS).

DESIGN AND METHODS

Forty-nine patients with familial MEN1 were studied. Twenty-seven of these with adrenal lesions were detected by EUS and at least two performed EUS examinations were included into a subgroup where changes in adrenal morphology were studied by measuring changes in the largest diameter of the dominant adrenal tumour.

RESULTS

EUS detected adrenal lesions in 36 (73%) patients: 6 (12%) plump adrenals, 17 (35%) nodular hyperplasia, 12 (24%) adenomas and 1 (2%) cyst. Bilateral adrenal lesions were detected in 17 patients and unilateral in 19 patients. A change in the largest tumour diameter was found to be for nodular hyperplasia -0.02+/-1.41% per month (range -2.56 to 4.58%) and for adenomas -0.61+/-1.95% per month (range -6.25 to 1.15%). One patient had an adrenal cyst with significant growth. There was no evidence of carcinoma or metastatic disease during the study.

CONCLUSIONS

The prevalence of adrenal lesions in MEN1 is higher than that reported earlier. Except one cystic lesion, no significant change in the tumour size was observed over a mean observation period of more than 2 years. In a typical situation, small adrenal lesions in MEN1 seem to be constant in their morphology.

Recent trends in the burden of alcohol intoxication on pediatric in-patient services in Germany

AIMS

To elicit data on alcohol intoxications requiring in-patient treatment in children and adolescents in Germany between 2000 and 2002.

DESIGN AND PARTICIPANTS

An ex-post analysis was performed to assess the number of children and adolescents (age 10-17 years) with acute alcohol intoxications requiring in-patient hospital treatment (> or =24 hours).

SETTING

22 major children hospitals in Germany.

FINDINGS

The number of acute alcohol intoxications requiring in-patient treatment increased from 227 in 2000 to 313 in 2001 (+37.9%; p*<.01) and 350 in 2002 (+10.6%; p*<.05). 10-12 year-old children comprised 2.2%, adolescents aged 13-14 years 28.6%, and adolescents aged 15-17 years 69.2% of the study population. The most significant increase was seen in adolescents aged 13-14 years (2001: +35.9%, and 2002: +19.3%; p*<.05), and 15-17 years (2001: +59.1%, and 2002: +10.1%; p*<.05). The percentage of female patients increased from 34.1% in 2000 to 41.9% in 2001 and 49.8% in 2002 (p*<.05). Mean time spent in the hospital was 1.7 days (range: 1 day-->4 days).

DISCUSSION AND CONCLUSIONS

This is one of the very few studies that provide epidemiological data on the specific issue of alcohol intoxications in children and adolescents that require in-patient treatment. Apparently, gender differences seem to play a minor role in alcohol-related hospital admissions. Our data demonstrate that excessive alcohol consumption remains an issue of concern in this age cohort.

Unintentional household poisoning in children

Despite the major reduction in fatal paediatric poisonings that has been achieved in industrialised countries over the last few decades, unintentional paediatric poisoning remains a major public health issue worldwide. In this article, we aim to provide clinicians dealing with poisoned children an overview of the problem and specific guidance on the identification and management of significant poisoning. Substances most frequently ingested by children in the developed world include household chemicals, medication, and plants. Although the great majority of such poisonings have no or limited clinical effects, it puts substantial burden on health care systems. Importantly, a few poisons can kill after ingestion of very small amounts. Unintentional poisoning in developing countries can be much more serious, following ingestion of kerosene, caustic agents, herbal remedies, insecticides or herbicides. Management of symptomatic patients involves supportive care, if available the administration of antidotes, and the removal of the offending drug from the body. Recent position papers on gastric decontamination indicate that such interventions are only rarely necessary. To further reduce the number of deaths and disabilities in the industrialised world and to begin to have an effect in the developing world, much more work is required to both identify and implement prevention strategies to reduce the number of cases of paediatric poisoning.

Hypoxia attenuates effector-target cell interaction in the airway and pulmonary vascular compartment

Leucocyte infiltration is known to play an important role in hypoxia-induced tissue damage. However, little information is available about hypoxia and interaction of effector (neutrophils) with target cells (alveolar epithelial cells, AEC; rat pulmonary artery endothelial cells, RPAEC). The goal of this study was to elucidate hypoxia-induced changes of effector-target cell interaction. AEC and RPAEC were exposed to 5% oxygen for 2-6 h. Intercellular adhesion molecule-1 (ICAM-1) expression was determined and cell adherence as well as cytotoxicity assays were performed. Nitric oxide and heat shock protein 70 (HSP70) production was assessed in target cells. Under hypoxic conditions enhanced ICAM-1 production was found in both cell types. This resulted in an increase of adherent neutrophils to AEC and RPAEC. The death rate of hypoxia-exposed target cells decreased significantly in comparison to control cells. Nitric oxide (NO) concentration was enhanced, as was production of HSP70 in AEC. Blocking NO production in target cells resulted in increased cytotoxicity in AEC and RPAEC. This study shows for the first time that target cells are more resistant to effector cells under hypoxia, suggesting hypoxia-induced cell protection. An underlying mechanism for this phenomenon might be the protective effect of increased levels of NO in target cells.

Responses of epidermal phenolic compounds to light acclimation: In vivo qualitative and quantitative assessment using chlorophyll fluorescence excitation spectra in leaves of three woody species

Chlorophyll fluorescence (ChlF) excitation spectra were measured to assess the UV-sunscreen compounds accumulated in fully expanded leaves of three woody species belonging to different chemotaxons, (i.e. Morus nigra L., Prunus mahaleb L. and Lagerstroemia indica L.), grown in different light microclimates. The logarithm of the ratio of ChlF excitation spectra (logFER) between two leaves acclimated to different light microclimates was used to assess the difference in epidermal absorbance (EAbs). EAbs increased with increasing solar irradiance intercepted for the three species. This epidermal localisation of UV-absorbers was confirmed by the removal of the epidermis. It was possible to simulate EAbs as a linear combination of major phenolic compounds (Phen) identified in leaf methanol extracts by HPLC-DAD. Under UV-free radiation conditions, shaded leaves of M. nigra accumulated chlorogenic acid. Hydroxybenzoic acid (HBA) derivatives and hydroxycinnamic acid (HCA) derivatives greatly increased with increasing PAR irradiance under the low UV-B conditions found in the greenhouse. These traits were also observed for the HCA of the two other species. Flavonoid (FLAV) accumulation started under low UV-A irradiance, and became maximal in the adaxial epidermis of sun-exposed leaves outdoors. A decrease in the amount of HCA was observed concomitantly to the intense accumulation of FLAV for both leaf sides of the three species. Judging from the logFER, under low UV-B conditions, larger amounts of HCA are present in the epidermis in comparison to FLAV for the three species. Upon transition from the greenhouse to full sunlight outdoors, there was a decrease in leaf-soluble HCA that paralleled FLAV accumulation in reaction to increasing solar UV-B radiation in the three species. In M. nigra, that contains large amounts of HCA, the logFER analysis showed that this decrease occurred in the adaxial epidermis, whereas the abaxial epidermis, which is protected from direct UV-B radiation, continued to accumulate large amounts of HCA.

Short stature and decreased insulin-like growth factor I (IGF-I)/growth hormone (GH)-ratio in an adult GH-deficient patient pointing to additional partial GH insensitivity due to a R179C mutation of the growth hormone receptor

OBJECTIVE

Genetic factors play an expanding role in understanding growth hormone (GH) disorders, therefore the German KIMS Pharmacogenetics Study was initiated with the aim of genotyping various GH-/IGF-I-axis-related genes of GH-deficient adult patients to investigate genotype:phenotype relationships and response to GH therapy.

PATIENTS AND METHODS

129 consecutively enrolled GH-deficient adult patients were genotyped for variant 1 (V1) of the alternatively spliced noncoding exons in the 5'-untranslated region and for the nine coding exons of the GH receptor (GHR) gene, which obviously play a striking role in the function of the GH-IGF-I-axis. After detection of a heterozygous, non-synonymous mutation R179C in exon 6 in one single patient with acquired GH-deficiency (GHD) in late adulthood, analysis of her clinical data followed, leading to the diagnosis of mild short stature (-1.5SD). For further endocrine evaluation, five pituitary stimulation tests (arginine) of this patient were statistically compared to stimulation tests (arginine) of ten GH-deficient control patients, retrospectively.

RESULTS

The formerly in patients with Laron syndrome and idiopathic short stature reported mutation R179C leads to an amino acid change from an arginine residue (codon CGC) to a cysteine residue (codon TGC) in position 179 of the extracellular domain of the GHR. Statistical analysis revealed significant decreased IGF-I/GH(0) ratio (p=0.004) and IGF-I/GH(max) ratio (p=0.001) of the index patient compared to the control patients, implying growth hormone resistance of the index patient at the level of the GHR, according to the detected R179C mutation.

CONCLUSIONS

This study reports on the unusual case of a patient with mild short stature, who acquired GHD in late adulthood due to a non-secreting pituitary adenoma and get additionally diagnosed for pre-existing growth hormone insensitivity due to a formerly in two short statured patients described, single, heterozygous, non-synonymous mutation in the GHR. Our findings support the theory that heterozygous mutations in the GHR gene can have mild phenotypical consequences.

Efficacy of a Monthly Compared to 3-Monthly Depot GnRH Analogue (Goserelin) in the Treatment of Children with Central Precocious Puberty

AIMS

To compare the efficacy of goserelin 10.8 mg (Zoladex LA-ZLA) administered 9-12 weekly with 3.6 mg (Zoladex-Z) given monthly in suppressing pubertal development, and effect on body mass index (BMI).

METHODS

Children with central precocious puberty (CPP) treated with Z (n = 34) or ZLA (n = 28) were studied retrospectively. Pubertal scores and BMI SDS during 24 months' treatment were compared.

RESULTS

To attain adequate pubertal suppression, more patients on ZLA than Z required increase in injection frequency (p = 0.02) and this was so for 7/8 patients with a structural aetiology for CPP on ZLA and 2/8 on Z. A greater proportion of patients on ZLA had BMI >+2 SDS before (p = 0.05), and at 18 and 24 months (p = 0.02 and 0.04). BMI SDS transiently increased during the first 6 months on ZLA (p = 0.04).

CONCLUSION

Both Z and ZLA were effective in suppressing puberty. To achieve adequate suppression, increased injection frequency was more likely with ZLA than Z, and particularly in patients with structural defects. Children with CPP had an elevated BMI at the onset of therapy and ZLA had a transient positive influence on BMI.

Cutaneous pseudolymphoma induced by Cimicifuga racemosa

We report a 56-year-old female patient who presented with asymptomatic, localized erythematous plaques on arms and legs. Histologically, the diagnosis of pseudolymphoma (PL) was confirmed. Because of menopausal complaints, the patient had been taking Remifemin(R), a phytotherapeutical agent containing a standardized extract of black cohosh (Cimicifuga racemosa) rhizome for 1 year. Six months after initial administration of this herbal drug, first skin lesions appeared which continuously increased. Withdrawal of Remifemin resulted in regression and complete remission of the lesions within 12 weeks. To the best of our knowledge, this is the first report on cutaneous PL induced by a standardized extract of C. racemosa rhizoma. Thus, though claimed to be poor in adverse effects, the potency of phytotherapeutical agents to induce uncommon cutaneous eruptions needs to be taken into careful reconsideration since the course of cutaneous PL tends to be chronic and indolent if the causative agent is not discontinued.

Natural course of small, asymptomatic neuroendocrine pancreatic tumours in multiple endocrine neoplasia type 1: an endoscopic ultrasound imaging study

Endoscopic ultrasound (EUS) enables detection and localization of pancreatic neuroendocrine tumours. Even small tumours down to a diameter of 1-2 mm can be visualized. Since such small tumours usually cannot be detected by computed tomography (ct), magnetic resonance imaging (mri) and somatostatin receptor scintigraphy (srs), and experience with EUS imaging is limited, there is no clear evidence for clinical management in multiple endocrine neoplasia type 1 (MEN1). Knowledge about the natural course of growth and metastatic distribution is mandatory to come to appropriate clinical decisions and guidelines. This prospective study was aimed to assess the natural course of small (<15 mm) neuroendocrine pancreatic tumours without clinical symptoms due to endocrine activity or mechanical problems and without clear indication for surgical therapy in MEN1 by EUS. A total of 82 asymptomatic tumours<15 mm (5.9+/-3.2 mm diameter at baseline) in 20 patients with MEN1-disease (8 female/12 male, 43+/-13 years) were studied over a period of 20+/-12 months (33.8 patient years, 106.7 tumour years) by EUS. Change in largest diameter of each tumour and annual tumour incidence rate in the patients' cohort were calculated. Increase of largest tumour diameter was found to be 1.3+/-3.2% per month, annual tumour incidence rate 0.62 new tumours per patient year. In one patient, rapid progressive pancreatic manifestation of MEN1 was observed. There was no evidence in ct and/or srs and/or mri for metastatic disease in all patients. Only 4/84 (4.8%) pancreatic tumours could be visualized by computed tomography, 5/79 (6.3%) by somatostatin receptor imaging and 4/39 (10.3%) by magnetic resonance imaging. Small asymptomatic neuroendocrine pancreatic tumours in MEN1 usually seem to grow slowly. Annual tumour incidence rate is low. However, faster growing tumours and patients with rapidly progressive disease can be observed. Risk for obvious metastatic disease from asymptomatic neuroendocrine pancreatic tumours<15 mm in MEN1 seems to be low.

Effect of propofol on seizure-like phenomena and electroencephalographic activity in children with epilepsy vs children with learning difficulties

There is an ongoing debate as to whether propofol exhibits pro- or anticonvulsant effects, and whether it should be used in patients with epilepsy. We prospectively assessed the occurrence of seizure-like phenomena and the effects of intravenous propofol on the electroencephalogram (EEG) in 25 children with epilepsy (mean (SD) age: 101 (49) months) and 25 children with learning difficulties (mean (SD) age: 52 (40) months) undergoing elective sedation for MRI studies of the brain. No child demonstrated seizure-like phenomena of epileptic origin during and after propofol sedation. Immediately after stopping propofol, characteristic EEG changes in the epilepsy group consisted of increased beta wave activity (23/25 children), and suppression of pre-existing theta rhythms (11/16 children). In addition, 16 of 18 children with epilepsy and documented EEG seizure activity demonstrated suppression of spike-wave patterns after propofol sedation. In all 25 children with learning difficulties an increase in beta wave activity was seen. Suppression of theta rhythms occurred in 11 of 12 children at the end of the MRI study. In no child of either group was a primary occurrence or an increase in spike-wave patterns seen following propofol administration. The occurrence of beta wave activity (children with learning difficulties and epilepsy group) and suppression of spike-wave patterns (epilepsy group) were transient, and disappeared after 4 h. This study demonstrates characteristic, time-dependent EEG patterns induced by propofol in children with epilepsy and learning difficulties. Our data support the concept of propofol being a sedative-hypnotic agent with anticonvulsant properties as shown by depression of spike-wave patterns in children with epilepsy and by the absence of seizure-like phenomena of epileptic origin.

Improved outcome of chronic hepatitis B after heart transplantation by long-term antiviral therapy

Chronic hepatitis B progresses to cirrhosis in the majority of immunosuppressed patients. The outcome of long-term antiviral therapy in HBV-infected organ transplant recipients is unknown. In 1996, we included 20 heart transplant (HT) recipients in a pilot trial to treat chronic hepatitis B with famciclovir. At that time, bridging fibrosis or cirrhosis was evident in 15 individuals (75%). From 1998 onwards, patients were switched to lamivudine in case of primary or secondary virological nonresponse to famciclovir. Adefovir or tenofovir became available at our centre for HT recipients in 2002. After 103 months, one patient was still on famciclovir showing a complete virological response. Sixteen patients were switched to lamivudine after 0.5-4 years of famciclovir therapy. Six of those showed a long-term response to lamivudine therapy lasting for up to 7 years. Lamivudine resistance developed in the remaining 10 patients (63%), in 4 of them successful rescue therapy (adefovir n = 3, tenofovir n = 1) could be initiated. Only one hepatocellular carcinoma developed, which was successfully treated by locoregional ablative therapy. Nine patients died (45%), with lamivudine-resistance-related liver failure as the cause of death in five cases. Significant improvement of Ishak fibrosis scores could be demonstrated in six of the seven patients with more than two sequential liver biopsies available. Long-term antiviral therapy of chronic hepatitis B can lead to regression of liver cirrhosis in patients after organ transplantation, unless viral resistance occurs. This study demonstrates the urgent need for further antivirals to overcome antiviral resistance.

Cattle with thymic lymphoma and haematoma of the ventral neck: a comparison of findings

The goal of the present paper was to establish criteria for the differentiation of thymic lymphoma and haematoma of the ventral neck in cattle. Four cattle with thymic lymphoma and seven with haematoma of the ventral neck underwent physical, haematological, biochemical and ultrasonographic examinations as well as histological evaluation of a biopsy specimen. All of the animals had firm non-painful swellings, which were no warmer than normal and extended from the pharyngeal region to the thoracic inlet. A diagnosis could not be established based on the results of physical examination and palpation of the swellings. Animals with a haematoma had a shorter history of being ill compared to those with thymic lymphoma. In patients with a haematoma, anaemia was present, the heart rate was elevated and the haematocrit was decreased, but not in cattle with thymic lymphoma. A tentative diagnosis was made on the basis of a macroscopic evaluation of the biopsy samples, which were dark red and firm in cattle with a haematoma. All cases of malignant thymic lymphoma were confirmed by histological examination of a biopsy sample. Ultrasonography did not help to differentiate between haematoma and thymic lymphoma. All animals with thymic lymphoma and three of those with a haematoma were euthanased. The four remaining animals with a haematoma were treated successfully.

Relationships between optically assessed polyphenols and chlorophyll contents, and leaf mass per area ratio in woody plants: a signature of the carbon-nitrogen balance within leaves?

Chlorophyll (Chl) and epidermal polyphenol (EPhen) contents were estimated in vivo using two optical leaf-clips, SPAD-502 and Dualex, respectively. The area-based measurements were transformed into mass-based data by taking into account the leaf dry mass per area (LMA). Measurements were performed on forest trees and on saplings grown under controlled conditions. While LMA increased with irradiance along a vertical transect in a beech canopy or in saplings grown under different and increasing irradiance levels, mass-based EPhen (EPhen(m)) increased, whereas mass-based Chl (Chl(m)) decreased. This was a signature of a gradual switch of investment from protein into polyphenol production. A similar signature was obtained in saplings grown on nitrogen-deficient soil with respect to fertilized controls. However, nitrogen effects remained moderate compared to irradiance-induced effects. EPhen(m) and Chl(m) both declined with plant ageing-induced increases in LMA, under all tested growth conditions. This was a signature of an accumulation of dry matter that diluted Chl and EPhen. The described competition between Chl and EPhen in leaves fits well with the predictions of the Protein Competition Model (PCM), that is, that the total leaf mass-based polyphenols content (Phen(t)) is controlled by the competition between protein and polyphenol biosynthetic pathways and its metabolic regulation.