Polyneuropathies--short and sweet

Complaints of sensory loss and (painful) tingling in a stocking distribution are not uncommon in primary care. These symptoms are especially troublesome while getting asleep. Characteristically, ankle tendon reflexes and vibration perception are diminished. These are the hallmarks of distal-symmetric sensory polyneuropathy (PNP), with diabetes mellitus being the most common cause in our patient population. PNP presents itself only after years of suboptimal glycemic control in diabetes type 1. In patients with type 2, symptoms of PNP can precede formal diagnosis of diabetes! In this mini-review we present an algorithm for diagnosis and management of PNP's in general practice.

Sweet's syndrome involoving the musculoskeletal system during treatment of promyelocytic leukemia with all-trans retinoic acid

Induction therapy of promyelocytic leukemia with all-trans retinoic acid is a standard therapy despite significant side-effects. The most important, the "retinoic acid syndrome", consists of a hyperinflammatory reaction with capillary leakage (edema, pleural, and pericardial effusion), infiltration of myeloid cells into internal organs and systemic signs of inflammation. We describe here two cases of another hyperinflammatory reaction during all-trans retinoic acid therapy, the Sweet's syndrome, consisting of infiltrates of the skin and internal organs by neutrophilic granulocytes. Fever, painful erythematous cutaneous plaques, prominent musculoskeletal involvement (myositis, fasciitis), a sterile pulmonary infiltration and intercurrent proteinuria characterized the clinical course of all-trans retinoic acid-associated Sweet's syndrome. Treatment with glucocorticoids led to resolution of the syndrome within 48 h. Three other cases of all-trans retinoic acid-associated Sweet's syndrome without involvement of internal organs, prominent on our cases, were published previously. Recognition of ATRA-associated Sweet's syndrome is of practical importance.

Sweet Puppies and Cute Babies: Perceptual Adaptation to Babyfacedness Transfers across Species

Infant faces are very salient stimuli. The Kindchenschema describes specific features that characterize a cute infant face. In this study we used a visual adaptation paradigm to investigate the universality of the perceptual properties of the Kindchenschema. In Experiment 1, twenty-four participants adapted to cute and less cute human infant faces and in Experiment 2, twenty-four new participants adapted to cute and less cute faces of puppy dogs. In both experiments the task was to assess the cuteness of subsequently presented human infant faces. The results revealed cuteness after-effects for human infant faces in both adaptation conditions, suggesting a common mechanism coding cuteness in human and non-human faces. This study provides experimental evidence for the universality of the well-described concept of the Kindchenschema.

Giant cellulitis-like Sweet Syndrome, a new variant of neutrophilic dermatosis

BACKGROUND Neutrophilic dermatoses comprise a wide spectrum of inflammatory diseases with overlapping features characterized histologically by the presence of an aseptic neutrophilic infiltrate in the epidermis, dermis, and/or hypodermis and are often associated with systemic inflammatory and neoplastic disorders. OBSERVATIONS We describe 3 patients with an unusual neutrophilic dermatosis characterized by relapsing episodes of fever, widespread infiltrated plaques with bullous appearance, and variable involvement of the arms, legs, abdomen, and/or trunk. Light microscopy studies showed marked edema of the papillary dermis with an inflammatory infiltrate consisting mainly of mature neutrophils. All 3 patients were morbidly obese, and workup revealed underlying cancer in 2 cases: myeloma and breast carcinoma. Management of the underlying disease resulted in long-term remission of the skin disease. CONCLUSIONS The clinicopathologic features in our 3 cases best correspond to a widespread giant cellulitis-like form of Sweet syndrome. Knowledge of this newly observed unusual variant of Sweet syndrome within the broad spectrum of neutrophilic diseases is important for its prompt and proper management.

The role of human-induced fire and sweet chestnut (Castanea sativa Mill.) cultivation on the long-term landscape dynamics of the southern Swiss Alps

Changes in fire occurrence during the last decades in the southern Swiss Alps make knowledge on fire history essential to understand future evolution of the ecosystem composition and functioning. In this context, palaeoecology provides useful insights into processes operating at decadal-to-millennial time scales, such as the response of plant communities to intensified fire disturbances during periods of cultural change. We provide a high-resolution macroscopic charcoal and pollen series from Guèr, a well-dated peat sequence at mid-elevation (832 m.a.s.l.) in southern Switzerland, where the presence of local settlements is documented since the late Bronze Age and the Iron Age. Quantitative fire reconstruction shows that fire activity sharply increased from the Neolithic period (1–3 episodes/1000 year) to the late Bronze and Iron Age (7–9 episodes/1000 year), leading to extensive clearance of the former mixed deciduous forest (Alnus glutinosa, Betula, deciduous Quercus). The increase in anthropogenic pollen indicators (e.g. Cerealia-type, Plantago lanceolata) together with macroscopic charcoal suggests anthropogenic rather than climatic forcing as the main cause of the observed vegetation shift. Fire and controlled burning were extensively used during the late Roman Times and early Middle Ages to promote the introduction and establishment of chestnut (Castanea sativa) stands, which provided an important wood and food supply. Fire occurrence declined markedly (from 9 to 5–6 episodes/1000 year) during late Middle Ages because of fire suppression, biomass removal by human population, and landscape fragmentation. Land-abandonment during the last decades allowed forest to partly re-expand (mainly Alnus glutinosa, Betula) and fire frequency to increase.

Expression of a bacterial serine acetyltransferase in transgenic potato plants leads to increased levels of cysteine and glutathione

The coding sequence of the wild-type, cys-sensitive, cysE gene from Escherichia coli, which encodes an enzyme of the cysteine biosynthetic pathway, namely serine acetyltransferase (SAT, EC 2.3.1.30), was introduced into the genome of potato plants under the control of the cauliflower mosaic virus 35S promoter. In order to target the protein into the chloroplast, cysE was translationally fused to the 5′-signal sequence of rbcS from Arabidopsis thaliana. Transgenic plants showed a high accumulation of the cysE mRNA. The chloroplastic localisation of the E. coli SAT protein was demonstrated by determination of enzymatic activities in enriched organelle fractions. Crude leaf extracts of these plants exhibited up to 20-fold higher SAT activity than those prepared from wild-type plants. The transgenic potato plants expressing the E. coli gene showed not only increased levels of enzyme activity but also exhibited elevated levels of cysteine and glutathione in leaves. Both were up to twofold higher than in control plants. However, the thiol content in tubers of transgenic lines was unaffected. The alterations observed in leaf tissue had no effect on the expression of O-acetylserine(thiol)-lyase, the enzyme which converts O-acetylserine, the product of SAT, to cysteine. Only a minor effect on its enzymatic activity was observed. In conclusion, the results presented here demonstrate the importance of SAT in plant cysteine biosynthesis and show that production of cysteine and related sulfur-containing compounds can be enhanced by metabolic engineering.

Activation of plant defense responses and sugar efflux by expression of pyruvate decarboxylase in potato leaves

When plants are infected with avirulent pathogens, a selected group of plant cells rapidly die in a process commonly called the hypersensitive response (HR). Some mutations and overexpression of some unrelated genes mimic the HR lesion and associated defense responses. In all of these situations, a genetically programmed cell death pathway is activated wherein the cell actively participates in killing itself. Here we report a developmentally and environmentally regulated HR-like cell death in potato leaves constitutively expressing bacterial pyruvate decarboxylase (PDC). Lesions first appeared on the tip of fully expanded source leaves. Lesion formation was accompanied by activation of multiple defense responses and resulted in a significant resistance toPhytophthora infestans. The transgenic plants showed a five- to 12-fold increase in leaf tissue acetaldehyde and exported two- to 10-fold higher amounts of sucrose compared to the wild-type. When plants were grown at a higher temperature, both the lesion phenotype and sucrose export were restored to wild-type situations. The reduced levels of acetaldehyde at the elevated temperature suggested that the interplay of acetaldehyde with environmental and physiological factors is the inducer of lesion development. We propose that sugar metabolism plays a crucial role in the execution of cell death programs in plants.

Nitrate Increases Membrane Stability of Potato Cells under Anoxia

Summary Potato cells (Solanum tuberosum L.), cultivated in original Murashige-Skoog (MS) medium for 5 days were subsequently transferred into {MS} media containing nitrate or ammonium as sole inorganic N source and incubated under anoxia for 24 h. With regard to lipid stability, these cells behaved differently. Although lipid hydrolysis occurred in both cases by the same mechanism, nitrate was able to postpone free fatty acid release for about 6 h compared with ammonium within the 24 h anoxia treatment. The increased membrane lipid stability of nitrate-treated cells under anoxia was correlated with a higher nitrate reduction capability and an improved energy status.