Asymmetric leaves1 mediates leaf patterning and stem cell function in Arabidopsis

Meristem function in plants requires both the maintenance of stem cells and the specification of founder cells from which lateral organs arise. Lateral organs are patterned along proximodistal, dorsoventral and mediolateral axes. Here we show that the Arabidopsis mutant asymmetric leaves1 (as1) disrupts this process. AS1 encodes a myb domain protein, closely related to PHANTASTICA in Antirrhinum and ROUGH SHEATH2 in maize, both of which negatively regulate knotted-class homeobox genes. AS1 negatively regulates the homeobox genes KNAT1 and KNAT2 and is, in turn, negatively regulated by the meristematic homeobox gene SHOOT MERISTEMLESS. This genetic pathway defines a mechanism for differentiating between stem cells and organ founder cells within the shoot apical meristem and demonstrates that genes expressed in organ primordia interact with meristematic genes to regulate shoot morphogenesis.

P element homing to the Drosophila bithorax complex

P elements containing a 7 kb DNA fragment from the middle of the Drosophila bithorax complex insert preferentially into the bithorax complex or into the adjacent chromosome regions. This ‘homing’ property is similar to that reported for the engrailed promoter (Hama, C., Ali, Z. and Kornberg, T. B. (1990) Genes Dev. 4, 1079–1093). The 7 kb fragment does not contain any known promoter, but it acts as a boundary element separating adjacent segmental domains. An enhancer-trap P element was constructed with the homing fragment and the selectable marker flanked by FRT sites. P insertions can be trimmed down by Flp-mediated recombination to just the lacZ reporter, so that the (beta)-galactosidase pattern is not influenced by sequences inside the P element. Twenty insertions into the bithorax complex express (beta)-galactosidase in segmentally limited patterns, reflecting the segmental domains of the bithorax complex where the elements reside. The mapping of segmental domains has now been revised, with enlargement of the abx/bx, bxd/pbx, and the iab-3 domains. The FRT sites in the P elements permit recombination between pairs of elements on opposite chromosomes, to generate duplications or deletions of the DNA between the two insertion sites. Using this technique, the length of the Ultrabithorax transcription unit was varied from 37 to 138 kb, but there was surprisingly little effect on Ultrabithorax function.

Restricted patterning of vestigial expression in Drosophila wing imaginal discs requires synergistic activation by both Mad and the drifter POU domain transcription factor

The Drosophila Vestigial protein has been shown to play an essential role in the regulation of cell proliferation and differentiation within the developing wing imaginal disc. Cell-specific expression of vg is controlled by two separate transcriptional enhancers. The boundary enhancer controls expression in cells near the dorsoventral (DV) boundary and is regulated by the Notch signal transduction pathway, while the quadrant enhancer responds to the Decapentaplegic and Wingless morphogen gradients emanating from cells near the anteroposterior (AP) and DV boundaries, respectively. MAD-dependent activation of the vestigial quadrant enhancer results in broad expression throughout the wing pouch but is excluded from cells near the DV boundary. This has previously been thought to be due to direct repression by a signal from the DV boundary; however, we show that this exclusion of quadrant enhancer-dependent expression from the DV boundary is due to the absence of an additional essential activator in those cells. The Drosophila POU domain transcriptional regulator, Drifter, is expressed in all cells within the wing pouch expressing a vgQ-lacZ transgene and is also excluded from the DV boundary. Viable drifter hypomorphic mutations cause defects in cell proliferation and wing vein patterning correlated with decreased quadrant enhancer-dependent expression. Drifter misexpression at the DV boundary using the GAL4/UAS system causes ectopic outgrowths at the distal wing tip due to induction of aberrant Vestigial expression, while a dominant-negative Drifter isoform represses expression of vgQ-lacZ and causes severe notching of the adult wing. In addition, we have identified an essential evolutionarily conserved sequence element bound by the Drifter protein with high affinity and located adjacent to the MAD binding site within the quadrant enhancer. Our results demonstrate that Drifter functions along with MAD as a direct activator of Vestigial expression in the wing pouch.

DEVELOPMENT OF SYMMETRY IN PLANTS

Plant development involves specification and elaboration of axes of asymmetry. The apical-basal and inside-outside axes arise in embryogenesis, and are probably oriented maternally. They are maintained during growth post-germination and interact to establish novel axes of asymmetry in flowers and lateral organs (such as leaves). Whereas the genetic control of axis elaboration is now partially understood in embryos, floral meristems, and organs, the underlying mechanisms of axis specification remain largely obscure. Less functionally significant aspects of plant asymmetry (e.g. the handedness of spiral phyllotaxy) may originate in random events and therefore have no genetic control.

Plant development: YABBYs claw to the fore

The YABBY gene family was identified recently by homology to CRABS CLAW, a gene involved in carpel and nectary development in Arabidopsis. Several of the transcription factors encoded by the YABBY genes appear to have conserved roles in specifying abaxial cell fate in leaves, floral organs and ovules.

ROUGH SHEATH2: a Myb protein that represses knox homeobox genes in maize lateral organ primordia

The regulation of members of the knotted1-like homeobox (knox) gene family is required for the normal initiation and development of lateral organs. The maize rough sheath2 (rs2) gene, which encodes a Myb-domain protein, is expressed in lateral organ primordia and their initials. Mutations in the rs2 gene permit ectopic expression of knox genes in leaf and floral primordia, causing a variety of developmental defects. Ectopic KNOX protein accumulation in rs2 mutants occurs in a subset of the normal rs2-expressing cells. This variegated accumulation of KNOX proteins in rs2 mutants suggests that rs2 represses knox expression through epigenetic means.

Adult survivors of childhood sexual abuse as patients: two case studies

Adult survivors of childhood sexual abuse comprise a high percentage of the patients seen in gastrointestinal and genitourinary clinics and are commonly found among the patient population treated by WOC nurses. The physical and emotional consequences of sexual abuse may permeate the survivor's life, but rise to the forefront only with the additional stress of an ostomy or urinary diversion. Two case studies are described involving women the authors encountered in their practices.

Axioms and axes in leaf formation?

Formation of leaves and floral organs involves down-regulation of meristem-specific homeobox genes, and de novo expression of genes for organ identity, growth and patterning. Genes required for all these aspects of organ formation have been identified. The challenge now is to establish how they interact to direct organogenesis.

The Vestigial and Scalloped proteins act together to directly regulate wing-specific gene expression in Drosophila

A small number of major regulatory (selector) genes have been identified in animals that control the development of particular organs or complex structures. In Drosophila, the vestigial gene is required for wing formation and is able to induce wing-like outgrowths on other structures. However, the molecular function of the nuclear Vestigial protein, which bears no informative similarities to other proteins, was unknown. Here, we show that Vestigial requires the function of the Scalloped protein, a member of the TEA family of transcriptional regulators, to directly activate the expression of genes involved in wing morphogenesis. Genetic and molecular analyses reveal that Vestigial regulates wing identity by forming a complex with the Scalloped protein that binds sequence specifically to essential sites in wing-specific enhancers. These enhancers also require the direct inputs of signaling pathways, and the response of an enhancer can be switched to another pathway through changes in signal-transducer binding sites. Combinatorial regulation by selector proteins and signal transducers is likely to be a general feature of the tissue-specific control of gene expression during organogenesis.

The PHANTASTICA gene encodes a MYB transcription factor involved in growth and dorsoventrality of lateral organs in Antirrhinum

The organs of a higher plant show two fundamental axes of asymmetry: proximodistal and dorsoventral. Dorsoventrality in leaves, bracts, and petal lobes of Antirrhinum majus requires activity of the PHANTASTICA (PHAN) gene. Conditional mutants revealed that PHAN is also required for earlier elaboration of the proximodistal axis. PHAN was isolated and shown to encode a MYB transcription factor homolog. PHAN mRNA is first detected in organ initials before primordium initiation. The structure and expression pattern of PHAN, together with its requirement in two key features of organ development, are consistent with a role in specifying lateral organ identity as distinct from that of the stem or meristem. PHAN also appears to maintain meristem activity in a non-cell-autonomous manner.

Ultrabithorax regulates genes at several levels of the wing-patterning hierarchy to shape the development of the Drosophila haltere

Arthropods and vertebrates are constructed of many serially homologous structures whose individual patterns are regulated by Hox genes. The Hox-regulated target genes and developmental pathways that determine the morphological differences between any homologous structures are not known. The differentiation of the Drosophila haltere from the wing through the action of the Ultrabithorax (Ubx) gene is a classic example of Hox regulation of serial homology, although no Ubx-regulated genes in the haltere have been identified previously. Here, we show that Ubx represses the expression of the Wingless (Wg) signaling protein and a subset of Wg- and Decapentaplegic-activated genes such as spalt-related, vestigial, Serum Response Factor, and achaete-scute, whose products regulate morphological features that differ between the wing and haltere. In addition, we found that some genes in the same developmental pathway are independently regulated by Ubx. Our results suggest that Ubx, and Hox genes in general, independently and selectively regulate genes that act at many levels of regulatory hierarchies to shape the differential development of serially homologous structures.

Early events in leaf development

Morphological studies of early events in leaf development have been hindered by the lack of stereotypic patterns of cell division and markers for cell identity. However, molecular genetic analysis, particularly in maize, has begun to suggest the mechanisms which partition meristematic cells into a leaf primordium, define regional identities within the primordium and direct localised growth which leads to outgrowth and flattening of the leaf. Therefore, the leaf may provide a model for pattern formation applicable to other parts of the plant.

Synaptojanin 1: localization on coated endocytic intermediates in nerve terminals and interaction of its 170 kDa isoform with Eps15

Synaptojanin 1 is an inositol 5-phosphatase with a putative role in clathrin-mediated endocytosis. Goal of this study was to provide new evidence for this hypothesis. We show that synaptojanin 1 is concentrated at clathrin-coated endocytic intermediates in nerve terminals. Furthermore, we report that synaptojanin-170, an alternatively spliced isoform of synaptojanin 1, binds Eps15, a clathrin coat-associated protein. Binding is mediated by the COOH-terminal region of synaptojanin-170 which we show here to be poorly conserved from rat to humans, but to contain in both species three asparagine-proline-phenylalanine (NPF) repeats. This motif has been found to be the core of the binding site for the EH domains of Eps15. Together with previous data, our results suggest that synaptojanin 1 can be recruited to clathrin-coated pits via a multiplicity of interactions.

Plant meristems: cell signalling keeps the balance

Genetic and molecular analysis in Arabidopsis has identified components of a putative cell signalling pathway that appears to regulate the balance between stem cell proliferation and fate specification in meristems.

Meeting patients' needs: quality care in a changing environment

Recent surveys of patients in New York and Cleveland, among other cities, indicate that there is substantial room for improvement in meeting patients' needs and preferences, particularly in the areas of emotional support, coordination of care, discharge preparation, and the involvement of family and friends. Hospitals are using a variety of techniques to improve patient care and organizational efficiency in this challenging environment. One prominent approach, reengineering, offers a means by which hospitals can integrate highly specialized departmental structures and functions by focusing on interdisciplinary teamwork and organizing the delivery of care around patients. Key elements of successful hospital reengineering efforts have included: - the involvement and commitment of senior management and other key stakeholders, particularly physicians, nurses, and union representatives; - investment in staff training and retraining, and the redesign of staff evaluation and compensation systems; - timely, unit-specific measures of patient satisfaction and the clinical quality of care; - consistent and frequent internal communication between staff and leadership; and - treatment that emphasizes communication among caregivers, patients, and their family members. Several basic issues need to be addressed if hospitals are to offer technically sophisticated medical care that is also responsive to their patients' personal needs, including: - variations among patients regarding the amount of information they want and need, and the amount of involvement they want in their care; - the means by which patients will get information about their medical care, and who will provide any additional support that may be needed by non-English-speaking or socioeconomically disadvantaged patients; and - the specific changes in medical practice and hospital processes that will promote the involvement of patients in their care.

Alteration of Chlamydia trachomatis biologic behavior in synovial membranes. Suppression of surface antigen production in reactive arthritis and Reiter's syndrome

OBJECTIVE

To investigate the biologic state of Chlamydia and its surface antigen expression in the synovial membranes of patients with Chlamydia-associated reactive arthritis/Reiter's syndrome (ReA/RS).

METHODS

Expression of chlamydial lipopolysaccharide (LPS), major outer membrane protein (MOMP), and elementary body (EB) antigens was studied by gold labeling immunoelectron microscopy on 6 synovial membrane and 2 synovial fluid (SF) pellet samples from 6 patients with Chlamydia-associated arthritis. The study findings were compared with 24-hour cultures of HeLa cells infected with Chlamydia trachomatis EB.

RESULTS

Persistent C trachomatis infection was found in all 6 synovial membrane samples from patients who had either early or chronic arthritis. The infection persisted despite antibiotic treatment, including a 1-month course of doxycycline therapy. Most persistent organisms were atypical reticulate bodies (RBs) found in both fibroblasts and macrophages. Specific, but weak, immunogold staining for all 3 antibodies was found on both intracellular RBs and extracellular EBs. In the SF samples, Chlamydia surface antigens were detected only in phagosomes containing degraded electron-dense materials.

CONCLUSION

The synovial membrane biopsies conducted in this study of Chlamydia-associated ReA/RS revealed atypical RBs with diminished MOMP and LPS expression. Such altered organisms may escape immune surveillance and contribute to disease chronicity; moreover, these organisms may be difficult to detect and treat in some ReA/RS patients.

phantastica: a gene required for dorsoventrality of leaves in Antirrhinum majus

To understand better the mechanisms that lead to dorsoventrality in the lateral organs of plants, mutants at the phantastica (phan) locus of Antirrhinum majus have been identified and characterised. The leaves, bracts and petal lobes of phan mutants show varying degrees of reduction in dorsal tissues, indicating that phan is required for establishing dorsal cell identity. Each phan mutant produces a variety of different leaf morphologies, but has a characteristic and relatively constant floral phenotype. In several different forms of phan mutant leaves and petal lobes, novel boundaries between dorsal and ventral cell types form ectopic axes of growth, suggesting that phan-dependent dorsal cell identity is required for lateral growth of the wild-type leaf and petal lobe. Comparisons between the development of wild-type and mutant petals or leaves reveal that phan acts early in development of these lateral organs. The possible role of the phan gene in evolution of different leaf forms is discussed.

Sex differences in the distribution of EEG frequencies during sleep: unipolar depressed outpatients

Sex differences in period-amplitude-analysed (PAA) sleep EEG activity were evaluated in 20 symptomatic, unmedicated, unipolar, depressed outpatients. 19/20 PAA measures showed significant gender main effects or interactions. Overall, depressed females showed a higher incidence and amplitude of fast frequency, beta activity than males, particularly in the right hemisphere. Moreover, gender effects were also evident in sleep-stage-independent analysis of PAA measures. These findings are in striking contrast to normal controls for whom only slow-frequency activity differentiates males from females. These findings suggest that sex differences are stronger in depressed patients than those observed in normals and that these effects are more pronounced than age-related changes in sleep EEG activity.

Genetic and cellular characteristics of bladder outlet obstruction

Urinary bladder outlet obstruction is a common medical problem. In order to understand the effects of outlet obstruction on bladder morphology, physiology, and pharmacology, several animal models of obstruction have been developed using a variety of species. Although there are marked differences in bladder size, capacity, compliance, physiology, and pharmacology among these species, responses to outlet obstruction have many common characteristics. This article will be separated into six areas: introduction, genetic factors mediating the response during the initial period of partial outlet obstruction and overdistension, cytostructural alterations that accompany compensated bladder function, alterations in innervation accompanying bladder hypertrophy secondary to partial outlet obstruction, alterations in calcium translocation during bladder hypertrophy, and metabolic factors involved in the response to partial outlet obstruction.

Inhibition of amine oxidase activity by derivatives that recognize imidazoline I2 sites

Nonadrenergic imidazoline binding sites (imidazoline I2 sites) have been described to be colocated with monoamine oxidase (MAO) in the mitochondrial fraction of various cell types. In the present work, the authors considered whether this colocation could be associated with a functional interplay. In rat liver membranes, [3H]-idazoxan binding to I2 receptors was competed for by naphazoline and idazoxan, which also shared a high affinity for alpha-2 adrenoceptors (alpha-2 ARs). The chemicals 2-n-heptylimidazoline (S 15430), 1-methyl-5-n-heptylimidazole (S 15674), 2-benzofuran-2-yl-imidazoline (RX 801077) and 2-(1,3-benzodioxanyl)-2-imidazoline (RX 821029) exhibited higher affinity for I2 receptors than for alpha-2 ARs. The most selective agent was S 15430 with a 150-fold higher affinity for liver I2 receptors than for adipocyte alpha-2 ARs. Moreover, [3H]-idazoxan binding was also competed for by several MAO inhibitors (MAOI) that are not imidazoline or guanidinium derivatives such as tranylcypromine, harmaline, clorgiline and pargyline. Rat liver MAO activity was not only inhibited by MAOIs but also by some imidazoline derivatives: cirazoline, naphazoline, S 15674, RX 801077 and RX 821029. Idazoxan had no effect on MAO activity; it neither inhibited MAO nor prevented the inhibition induced by other imidazolines or MAOIs. This suggested that the ligand recognition site of I2 receptors was distinct from the MAOI target site. Furthermore, some imidazolines inhibited the activity of bovine plasma amine oxidase, an enzyme that does not possess the same cofactor as MAO and is insensitive to harmaline or pargyline.(ABSTRACT TRUNCATED AT 250 WORDS)

Brisk walking and serum lipid and lipoprotein variables in previously sedentary women--effect of 12 weeks of regular brisk walking followed by 12 weeks of detraining

The purpose of this study was to examine the effectiveness of brisk walking as a means of improving endurance fitness and influencing serum lipid and lipoprotein variables in previously sedentary women. Walkers (n = 10, mean (s.e.m.) age 47.3(2.0) years) followed a programme of brisk walking (mean(s.e.m.) speed 1.76(0.03) m s-1) for 12 weeks, after which the training stimulus was withdrawn. Controls (n = 10, mean(s.e.m.) age 41.6(1.2) years) maintained their habitual sedentary lifestyle throughout. Endurance fitness was determined using laboratory measures of responses to treadmill walking. Serum lipid and lipoprotein variables were determined in venous blood (12-h fasted). Body fatness was assessed by anthropometry and dietary practice using the 7-day weighed food intake technique. Measurements were repeated after 12 and 24 weeks. Brisk walking resulted in a decrease in heart rate and blood lactate concentration during exercise, while detraining was accompanied by a reversal of these changes. Changes in body mass and the ratio of circumferences at the waist and hip did not differ between groups but the sum of four skinfolds decreased with brisk walking and increased with detraining. High density lipoprotein (HDL) and HDL2 cholesterol increased with walking and decreased with detraining but no between group changes (analysis of variance, P < 0.05) were found in other lipid and lipoprotein variables. These findings suggest that regular brisk walking can improve endurance fitness and increase HDL cholesterol concentration in sedentary women.

An outbreak of cryptosporidiosis from fresh-pressed apple cider

BACKGROUND

Recent waterborne outbreaks have established Cryptosporidium as an emerging enteric pathogen, but foodborne transmission has rarely been reported. In October 1993, an outbreak of cryptosporidiosis occurred among students and staff attending a 1-day school agricultural fair in central Maine.

DESIGN

Environmental/laboratory investigation and cohort study.

PARTICIPANTS

Attendees of the fair and their household members.

MAIN OUTCOME MEASURES

Clinical or laboratory-confirmed cryptosporidiosis. Clinical cryptosporidiosis was defined as 3 days of either diarrhea (three loose stools in a 24-hour period) or vomiting.

RESULTS

Surveys were completed for 611 (81%) of the estimated 759 fair attendees. Among attendees who completed the survey, there were 160 (26%) primary cases. Cryptosporidium oocysts were detected in the stools of 50 (89%) of 56 primary and secondary case patients tested. The median incubation period was 6 days (range, 10 hours to 13 days); the median duration of illness was 6 days (range, 1 to 16 days). Eighty-four percent of primary case patients had diarrhea and 82% had vomiting. Persons drinking apple cider that was hand pressed in the afternoon were at increased risk for cryptosporidiosis (154 [54%] of 284 exposed vs six [2%] of 292 unexposed; relative risk, 26; 95% confidence interval, 12 to 59). Cryptosporidium oocysts were detected in the apple cider, on the cider press, and in the stool specimen of a calf on the farm that supplied the apples. The secondary household transmission rate was 15% (53/353).

CONCLUSIONS

This is the first large cryptosporidiosis outbreak in which foodborne transmission has been documented. It underscores the need for agricultural producers to take measures to avoid contamination of foodstuffs with infectious agents common to the farm environment.

Community psychiatric nurse teams: intensive support versus generic care

BACKGROUND

This study evaluated whether a community psychiatric nurse (CPN) team providing a comprehensive aftercare service, using a case management approach, improves psychopathology and social functioning of the long-term mentally ill, and reduces hospital use compared with a generic CPN team.

METHOD

Patients suffering from severe and persistent mental health problems were randomised to intensive aftercare or generic care after referral to the CPN manager. Each group contained 41 patients who were assessed at baseline and at 6, 12 and 18 months by an independent research psychologist. Outcome measures included the GAS, PSE, SAS, patient and relatives' satisfaction, number of admissions, and length of stay.

RESULTS

No difference between the groups was found on any of the outcome measures, despite the much higher number of contacts of the intensive (n = 52) versus generic CPNs (n = 13) and the much greater range of interventions.

CONCLUSIONS

Intensive aftercare for people with persistent mental health problems was not found to be of greater benefit than generic CPN care. Many factors need to be considered for aftercare to be effective, including community resources, process of care, and staff training.

Olive: a key gene required for chlorophyll biosynthesis in Antirrhinum majus

Olive (oli) is a recessive nuclear mutation of Antirrhinum majus which reduces the level of chlorophyll pigmentation and affects the ultrastructure of chloroplasts. The oli-605 allele carries a Tam3 transposon insertion which has allowed the locus to be isolated. The oli gene encodes a large putative protein of 153 kDa which shows homology to the products of two bacterial genes necessary for tetrapyrrole-metal chelation during the synthesis of bacteriochlorophyll or cobyrinic acid. We therefore propose that the product of the oli gene is necessary for a key step of chlorophyll synthesis: the chelation of magnesium by protoporphyrin IX. Somatic reversion of the oli-605 allele produces chimeric plants which indicate that the oli gene functions cell-autonomously. Expression of oli is restricted to photosynthetic cells and repressed by light, suggesting that it may be involved in regulating the rate of chlorophyll synthesis in green tissues.

Brisk walking improves endurance fitness without changing body fatness in previously sedentary women

The purpose of this study was to examine the influence of brisk walking on endurance fitness and the amount and distribution of body fat in previously sedentary women. Twenty eight women [mean age (SEM): 44.9 (1.5) years] followed the walking programme for 1 year, whilst 16 acted as controls [age 44.4 (2.3) years]. Changes in endurance fitness were evaluated by measuring the oxygen uptake (VO2) at a reference blood lactate concentration of 2 mmol.l-1. Two 1.61-km field tests of walking were completed, one at maximal speed and one at a "brisk" speed, as well as a 1.61-km walk on a motorised treadmill. The amount and distribution of body fat was determined by hydrostatic weighing and anthropometry and energy intake was evaluated using the 7-day weighed food intake method. Walkers completed an average of 157 min.week-1 of brisk walking over the year. The following were increased in walkers, relative to controls: brisk walking speed [walkers 1.73 (0.05) m.s-1 vs 1.88 (0.07) m.s-1; controls 1.69 (0.05) m.s-1 vs 1.70 (0.05) m.s-1 at baseline and 12 months respectively, P < 0.01], maximal walking speed and VO2 at 2 mmol.l-1. In addition, brisk walking reduced heart rate and blood lactate concentration during stepping as well as during standard, submaximal treadmill walking. It did not modify either the amount or the distribution of body fat, despite an unchanged energy intake.

The acute effects of low-intensity exercise on plasma lipids in endurance-trained and untrained young adults

The acute effects of low-intensity exercise on plasma lipids were assessed in 22 healthy, normolipidaemic volunteers [mean age (SEM) 21.1 (0.2) years] of whom 11 were untrained and 11 endurance trained. Each subject walked for 2 h on a treadmill at a speed selected to elicit 30% [29.8 (3.9)%] of his or her maximal oxygen uptake. All subjects consumed a similar diet, i.e. 48% of energy from carbohydrate, for 2 days prior to the test. Pre-exercise, high-density lipoprotein (HDL) cholesterol concentration was higher in the trained group than in the untrained group [0.88 (0.06) mmol.l-1 vs 0.73 (0.09) mmol.l-1, P less than 0.05]. The walk elicited an increase in blood lactate concentration (P less than 0.01) but glucose homeostasis was well maintained by both groups. After 2 h of walking total cholesterol had increased by 13 (0.6)% (P less than 0.05). HDL cholesterol concentration increased by 17 (1.6)%, so that the ratio of total to HDL cholesterol was lower after the walk than pre-exercise (P less than 0.05). In the endurance-trained group HDL cholesterol concentration increased progressively, being 7.9 (2.4)% higher after 1 h and 19.7 (1.6)% higher after 2 h. A different response was evident in the untrained group where a rise after the 1st h [25.1 (2.3)%] was followed by a decrease towards pre-exercise values. These results show that one prolonged bout of low-intensity exercise modifies lipoprotein metabolism and hold out the interesting possibility that this response may differ in trained and untrained individuals.

Thyrotropin-releasing hormone selectively reverses lorazepam-induced sedation but not slowing of saccadic eye movements

To investigate preliminary reports that benzodiazepine-induced sedation may be reversed by thyrotropin-releasing hormone (TRH), we examined the effect of TRH or saline placebo on two variables which are sensitive to benzodiazepine agonists: changes in sedation and saccadic eye movements. Lorazepam 10 micrograms/kg i.v. increased self-ratings of sedation and reduced self-ratings of alertness and these changes were almost completely reversed by TRH. In contrast the slowing of saccadic eye movements by lorazepam was not reversed by TRH. The effects of TRH do not appear to be due to a direct antagonism at the benzodiazepine receptor, since flumazenil reverses changes in both variables. Moreover ligand binding studies reveal that TRH has very low affinity at this receptor. These clinical data provide the first demonstration that it is possible to distinguish between the effects of benzodiazepines on saccadic eye movements and psychological self-ratings.

Comparison between effects of interleukin-1 alpha administration and sublethal endotoxemia in primates

Interleukin (IL)-1 is an early mediator of host response to inflammation, although its contribution to individual components of the acute phase reaction is still unclear. To evaluate how the hemodynamic, metabolic, and hormonal responses to sublethal endotoxemia compare with IL-1 administration, baboons received intravenously either lipopolysaccharide (LPS) or 0.1, 10, or 100 micrograms/kg IL-1 alpha. LPS induced an early tachycardia and a fall in mean arterial pressure, as well as lacticacidemia and hypoaminoacidemia. Similar hemodynamic and metabolic changes were seen with 10 or 100 micrograms/kg of IL-1 alpha. An increase in adrenocorticotropic hormone and fall in serum iron were induced by IL-1 alpha but not by LPS. Plasma tumor necrosis factor-alpha (TNF-alpha) was not measurable after IL-1 alpha administration, whereas LPS induced a monophasic TNF-alpha response. IL-6 levels were significantly greater after LPS than IL-1 alpha administration. Histopathological lesions, similar in LPS- and 100 micrograms/kg IL-1 alpha-treated groups, were present only in the adrenal cortex. We conclude that many, but not all, of the effects of sublethal endotoxemia can be replicated by IL-1 alpha administration, and these responses are dose dependent.

The efficacy of six heel pressure reducing devices

Twenty to 90 percent of pressure ulcers are located on the heel. The purpose of this study was to evaluate the pressure exerted on the heel when the foot in both the supine and the 30 degree elevated position was placed in various heel pressure reducing devices. Interface pressures of six heel devices were measured to determine their performance. Other factors, such as body weight, height shoe size, shoe width, as well as whether the device provided leg support were examined.

Influence of brisk walking on the broadband ultrasonic attenuation of the calcaneus in previously sedentary women aged 30-61 years

The amount and type of exercise needed to maintain or increase bone density in women is unclear. The purpose of the present study was to examine the influence of brisk walking on broadband ultrasonic attenuation (BUA) values for the calcaneus in formerly sedentary women aged 30-61 years (mean 44). Twenty-five women followed the program of brisk walking for 1 year and 15 acted as controls. The walkers completed an average (SEM) of 159 (46) minutes/week of brisk walking at a speed of 1.72 (0.05) meters/second, i.e., about 16-18 km/week. Broadband ultrasonic attenuation was determined at baseline and after 1 year. Analysis of variance showed that values were increased (P less than 0.05) for the walkers relative to controls [walkers 103.3 (4.9) versus 116.1 (3.8) dB/MHz; controls 103.6 (5.5) versus 99.6 (5.4) dB/MHz]. We conclude that, in formerly sedentary women, a modest program of a widely acceptable form of exercise, brisk walking, can provoke an increase in this sensitive index of bone condition.

Operative treatment of palsy of the posterior interosseous nerve of the forearm

The cases of forty patients who were operated on consecutively for palsy of the posterior interosseous nerve were analyzed. The injury was iatrogenic in sixteen patients, traumatic in fifteen, and nontraumatic in nine. Persistent paralysis (partial or complete) was the only indication for operation. Operative neurolysis was done in twenty-three patients; interfascicular nerve-grafting, in twelve; internal neurolysis, in one; and tendon transfer, in four. An excellent or good functional result was documented for all but three patients, of whom two had had neurolysis and one, nerve-grafting.

Interface skin pressures on four pressure-relieving devices

Nurses employed in acute care hospitals frequently encounter patients who require a pressure-relieving device. It is often difficult for nurses to decide which support surface should be used to best meet a patient's need for a pressure-reducing device because of the multiplicity of products available. One of the variables studied was found not to statistically influence the effectiveness of the various pressure-relieving devices. Body build is not a consideration when determining which support surface is effective in a healthy population of subjects. The two air-flotation low air-loss beds would be defined as effective pressure-relieving devices. The interface pressure readings vary from individual to individual on various bony prominences. The population studied was that of healthy volunteers. Healthy subjects have an increased fat pad in their sacral area compared with the critically ill patient. The heel had the highest interface pressure of the five that were studied. This is a bony prominence that requires additional attention if skin integrity is to be maintained.

Lysine requirements and whole-body protein turnover in growing pigs

The influence on protein accretion and whole-body protein turnover of changing dietary protein quality while maintaining constant energy intake was studied by varying the degree of lysine supplementation of a lysine-deficient barley-based diet given to growing pigs. Measurements of nitrogen metabolism and whole-body protein turnover, using both classical and 15N end-product methods following a single dose of [15N]glycine, were made in 49-kg male pigs given diets containing 109 g lysine-deficient protein/kg supplemented to make them (1) 'deficient', (2) 'adequate' and (3) 'in excess' with respect to lysine. The 15N dose and protein intake values used to calculate amino N flux from the cumulative urinary excretion of 15N in urea and ammonia were corrected respectively for apparent digestibilities of [15N]glycine and total N determined in a separate experiment in pigs fitted with simple ileal cannulas. N retention and biological value were significantly increased by lysine supplementation of the deficient diet to the 'adequate' level, but were not further increased by the higher level of supplementation. Rates of growth paralleled these changes. The poorer biological value of the unsupplemented diet 1 was shown also in a significantly higher excretion of urea N compared with diets 2 and 3. N digestibility was not markedly influenced by the level of lysine supplementation. Both whole-body protein synthesis and degradation increased markedly on 'adequate' supplementation of the diet with lysine, but did not increase further with an excess of lysine. It is concluded that the increase in protein accretion rate observed on supplementation of the diet with lysine was due to a greater increase in the rate of protein synthesis than of degradation, rather than a decrease in degradation rate.

Non-neurogenic soft tissue tumours of the axilla: prospective review of 16 cases

Sixteen consecutive patients entered in a prospective study of non-neurogenic soft tissue tumours had lesions in the axilla. Delayed diagnosis and inappropriate biopsy prior to referral to a surgical oncologist were frequent findings. Sarcoma and fibromatosis were diagnosed in 14 cases, and the approaches used for these two diseases were fundamentally different. The functional outcome with limb salvage surgery in these patients is presented.

In situ hybridization of mRNA for beta-preprotachykinin and preprosomatostatin in adult rat dorsal root ganglia: comparison with immunocytochemical localization

In situ hybridization histochemistry was used to identify neurons in rat dorsal root ganglia that contained mRNAs encoding beta-preprotachykinin and preprosomatostatin. The distribution of these neurons was compared with the distribution of neurons containing tachykinins or somatostatin, identified using immunocytochemical techniques. Neurons labelled for beta-preprotachykinin mRNA constituted 20% of the total neuronal population and belonged to the small cell class. Neurons labelled for preprosomatostatin mRNA with either RNA or DNA hybridization probes constituted approximately 10% of the total cells and comprised a small cell group that differed in average size from the beta-preprotachykinin labelled population. The distribution of cells containing tachykinin- or somatostatin-like immunoreactive material was identical to the distribution of cells containing the respective mRNAs and, in addition, individual somata in adjacent sections contained both the mRNA precursor and the peptide. These results suggest that for these neuropeptides the sensitivity of the two methods is equivalent and the respective mRNAs and peptides are co-localized in the same neurons.