CO2 storage and release in the deep Southern Ocean on millennial to centennial timescales.

The cause of changes in atmospheric carbon dioxide (CO2) during the recent ice ages is yet to be fully explained. Most mechanisms for glacial-interglacial CO2 change have centred on carbon exchange with the deep ocean, owing to its large size and relatively rapid exchange with the atmosphere1. The Southern Ocean is thought to have a key role in this exchange, as much of the deep ocean is ventilated to the atmosphere in this region2. However, it is difficult to reconstruct changes in deep Southern Ocean carbon storage, so few direct tests of this hypothesis have been carried out. Here we present deep-sea coral boron isotope data that track the pH-and thus the CO2 chemistry-of the deep Southern Ocean over the past forty thousand years. At sites closest to the Antarctic continental margin, and most influenced by the deep southern waters that form the ocean's lower overturning cell, we find a close relationship between ocean pH and atmospheric CO2: during intervals of low CO2, ocean pH is low, reflecting enhanced ocean carbon storage; and during intervals of rising CO2, ocean pH rises, reflecting loss of carbon from the ocean to the atmosphere. Correspondingly, at shallower sites we find rapid (millennial- to centennial-scale) decreases in pH during abrupt increases in CO2, reflecting the rapid transfer of carbon from the deep ocean to the upper ocean and atmosphere. Our findings confirm the importance of the deep Southern Ocean in ice-age CO2 change, and show that deep-ocean CO2 release can occur as a dynamic feedback to rapid climate change on centennial timescales.

Intuitive eating is associated with glycaemic control in adolescents with type I diabetes mellitus.

BACKGROUND: While there have been considerable advances in the medical management of type 1 diabetes mellitus (T1DM), for many, glycaemic control remains substandard. Nutrition and eating behaviour are important additional factors to consider with regards to T1DM management and outcomes. Intuitive eating is one such factor, and has not previously been investigated in T1DM. With this in mind, we undertook a study examining the relationship between intuitive eating and glycaemic control in adolescents with T1DM. METHODS: A case-control study of adolescents with established T1DM, and age/sex matched controls was conducted. Demographic information, the Intuitive Eating Scale (IES), and HbA1c were collected. Statistical analysis was undertaken to explore associations between the IES and HbA1c as a marker of glycaemic control. RESULTS: Data on 38 adolescents with T1DM, and 39 age/sex matched controls were obtained. Those with T1DM had significantly lower (by 0.5 SD) IES scores compared to controls (p = 0.009). Higher values of both total IES and the Eating for physical rather than emotional reasons subscale were associated with lower HbA1c: HbA1c 22% lower/whole unit increase in total IES mean score, HbA1c 11% lower/whole unit increase in Eating for physical rather than emotional reasons mean score, p = 0.017 and p = 0.009 respectively. CONCLUSION: In adolescents with T1DM, there appears to be a strong association between intuitive eating, in particular the effect of emotion on eating, and glycaemic control. In addition, those with T1DM have lower scores for their intuitive eating behaviour compared to controls. Emotional eating could be a future target for screening and potentially intervening in those with T1DM, as part of a wider treatment package to improve glycaemic control. Continuing efforts are needed to fully understand the important dynamics of diabetes, adolescence, diet, emotion, and how these factors affect long term outcomes in those with T1DM.

A novel approach to antibiofilm susceptibility testing using a thermo-reversible matrix.

OBJECTIVE: Biofilm microorganisms are known to have a much higher tolerance to antimicrobials compared to their planktonic equivalents. Therefore, traditional antimicrobial susceptibility testing may not extrapolate to clinical treatment of infections of biofilm origin, and as a result, there is a need to not only develop antimicrobials with antibiofilm activity, but also suitable in vitro testing methods for their evaluation. In this study, we report on a novel method of antibiofilm testing using a thermo-reversible matrix (poloxamer 407), coupled with live/dead staining of bacteria cultured from the matrix. METHOD: Pseudomonas aeruginosa (NCIMB 8626) was cultured in medium containing poloxamer 407 at 37°C for 24 hours to generate biofilms. The preparation was cooled to liquefy the poloxamer and allow recovery of the biofilm cells, which were then stained with SYTO9 to determine viability following exposure to four antimicrobials: polyhexanide, octenadine dihydrochloride, povidone-iodine and silver carbonate. Over an 8-minute time period, fluorescence levels were spectrophotometrically measured and compared with bacterial controls, cultured in the absence of poloxamer and without antimicrobial. RESULTS: Untreated cells showed no reduction in viability over this period. Importantly, planktonic cells were more susceptible to test agents compared with those of a 'biofilm' phenotype cultured in poloxamer. Antibiofilm activity was evident for all of the test agents, with highest relative activity seen with octenadine dihydrochloride. CONCLUSION: In summary, a novel and relatively rapid approach to screen compounds for antibiofilm activity has been described. The method uses standard laboratory equipment and can be readily adapted to test a wide range of microorganisms and other antibiofilm compounds. DECLARATION OF INTEREST: This research was, in part, supported by Advanced Medical Solutions in the form of a Knowledge Transfer Project. Mr J. Nosworthy was employed by Advanced Medical Solutions. There are no other conflicts of interests to declare.

Effects of inspiratory muscle training on exercise responses in Paralympic athletes with cervical spinal cord injury.

We asked whether specific inspiratory muscle training (IMT) improves respiratory structure and function and peak exercise responses in highly trained athletes with cervical spinal cord injury (SCI). Ten Paralympic wheelchair rugby players with motor-complete SCI (C5-C7) were paired by functional classification then randomly assigned to an IMT or placebo group. Diaphragm thickness (B-mode ultrasonography), respiratory function [spirometry and maximum static inspiratory (PI ,max ) and expiratory (PE ,max ) pressures], chronic activity-related dyspnea (Baseline and Transition Dyspnea Indices), and physiological responses to incremental arm-crank exercise were assessed before and after 6 weeks of pressure threshold IMT or sham bronchodilator treatment. Compared to placebo, the IMT group showed significant increases in diaphragm thickness (P = 0.001) and PI ,max (P = 0.016). There was a significant increase in tidal volume at peak exercise in IMT vs placebo (P = 0.048) and a strong trend toward an increase in peak work rate (P = 0.081, partial eta-squared = 0.33) and peak oxygen uptake (P = 0.077, partial eta-squared = 0.34). No other indices changed post-intervention. In conclusion, IMT resulted in significant diaphragmatic hypertrophy and increased inspiratory muscle strength in highly trained athletes with cervical SCI. The strong trend, with large observed effect, toward an increase in peak aerobic performance suggests IMT may provide a useful adjunct to training in this population.

Molecular characterisation of side population cells with cancer stem cell-like characteristics in small-cell lung cancer.

BACKGROUND: Side population (SP) fraction cells, identified by efflux of Hoechst dye, are present in virtually all normal and malignant tissues. The relationship between SP cells, drug resistance and cancer stem cells is poorly understood. Small-cell lung cancer (SCLC) is a highly aggressive human tumour with a 5-year survival rate of <10%. These features suggest enrichment in cancer stem cells. METHODS AND RESULTS: We examined several SCLC cell lines and found that they contain a consistent SP fraction that comprises <1% of the bulk population. Side population cells have higher proliferative capacity in vitro, efficient self-renewal and reduced cell surface expression of neuronal differentiation markers, CD56 and CD90, as compared with non-SP cells. Previous reports indicated that several thousand SP cells from non-small-cell lung cancer are required to form tumours in mice. In contrast, as few as 50 SP cells from H146 and H526 SCLC cell lines rapidly reconstituted tumours. Whereas non-SP cells formed fewer and slower-growing tumours, SP cells over-expressed many genes associated with cancer stem cell and drug resistance: ABCG2, FGF1, IGF1, MYC, SOX1/2, WNT1, as well as genes involved in angiogenesis, Notch and Hedgehog pathways. CONCLUSIONS: Side population cells from SCLC are highly enriched in tumourigenic cells and are characterised by a specific stem cell-associated gene expression signature. This gene signature may be used for development of targeted therapies for this rapidly fatal tumour.

Dissatisfaction encodes a tailless-like nuclear receptor expressed in a subset of CNS neurons controlling Drosophila sexual behavior.

The dissatisfaction (dsf) gene is necessary for appropriate sexual behavior and sex-specific neural development in both sexes. dsf males are bisexual and mate poorly, while mutant females resist male courtship and fail to lay eggs. Males and females have sex-specific neural abnormalities. We have cloned dsf and rescued both behavioral and neural phenotypes. dsf encodes a nuclear receptor closely related to the vertebrate Tailless proteins and is expressed in both sexes in an extremely limited set of neurons in regions of the brain potentially involved in sexual behavior. Expression of a female transformer cDNA under the control of a dsf enhancer in males leads to dsf-like bisexual behavior.

Parental reactions to weight screening in young children: a randomized controlled trial.

BACKGROUND: Parental inability to recognize child overweight and physician reluctance to instigate discussion prevents behaviour change. OBJECTIVE: To evaluate parental acceptance of child overweight status following screening. METHODS: Interviewers used motivational interviewing or best practice care to discuss overweight status of 271 young children (BMI ≥ 85th ) with parents using simple traffic-light BMI charts. Follow-up sessions two weeks later (n = 251, 93%) were coded qualitatively to assess parental reactions to the information (overweight diagnosis) and how it was presented (feedback condition). RESULTS: Eight-two percent of parents rated the charts positively with few (8-10%) feeling judged. Motivational interviewing parents viewed feedback as more empathetic (relative risk, 95% CI: 4.07, 1.64-10.09), but more uncomfortable (12.2, 1.48-100.1) than best practice care parents. Overall, 65.2% of parents accepted their child was overweight, 22.1% were ambivalent and 12.7% rejected the information. Although motivational interviewing parents were less likely to accept it (OR, 95% CI: 0.49, 0.37-0.64) and more likely to be ambivalent (2.01, 1.17-3.47), the most important predictor of acceptance was a positive experience of feedback (P < 0.001). CONCLUSIONS: Simple traffic-light charts facilitate discussion of child overweight status with parents. Style of feedback is less relevant than ensuring a positive experience for parents to increase acceptance of the weight information.

Altered localization of retinoid X receptor alpha coincides with loss of retinoid responsiveness in human breast cancer MDA-MB-231 cells.

To understand the mechanism of retinoid resistance, we studied the subcellular localization and function of retinoid receptors in human breast cancer cell lines. Retinoid X receptor alpha (RXR alpha) localized throughout the nucleoplasm in retinoid-sensitive normal human mammary epithelial cells and in retinoid-responsive breast cancer cell line (MCF-7), whereas it was found in the splicing factor compartment (SFC) of the retinoid-resistant MDA-MB-231 breast cancer cell line and in human breast carcinoma tissue. In MDA-MB-231 cells, RXR alpha was not associated with active transcription site in the presence of ligand. Similarly, ligand-dependent RXR homo- or heterodimer-mediated transactivation on RXR response element or RARE showed minimal response to ligand in MDA-MB-231 cells. Infecting MDA-MB-231 cells with adenoviral RXR alpha induced nucleoplasmic overexpression of RXR alpha and resulted in apoptosis upon treatment with an RXR ligand. This suggests that nucleoplasmic RXR alpha restores retinoid sensitivity. Epitope-tagged RXR alpha and a C-terminus deletion mutant failed to localize to the SFC. Moreover, RXR alpha localization to the SFC was inhibited with RXR alpha C-terminus peptide. This peptide also induced ligand-dependent transactivation on RXRE. Therefore, the RXR alpha C terminus may play a role in the intranuclear localization of RXR alpha. Our results provide evidence that altered localization of RXR alpha to the SFC may be an important factor for the loss of retinoid responsiveness in MDA-MB-231 breast cancer cells.

Anti-GD3 monoclonal antibody analysis of childhood T-cell acute lymphoblastic leukemia: detection of a target antigen for antibody-mediated cytolysis.

We have demonstrated in previous studies significant quantitative differences in the ganglioside content of leukemia cell membranes within immunological subclasses of acute lymphoblastic leukemia (ALL): The disialoganglioside GD3 (disialolactosylceramide) is increased in lymphoblasts with a T-cell immunophenotype compared to non-T-ALL blasts. Utilizing an indirect immunofluorescence assays with a monoclonal antibody to GD3(R24), pretreatment leukemic lymphoblasts from 80 children with ALL were assayed for GD3 expression. GD3 was observed in 75% of leukemic samples in which lymphoblasts exhibited a T-cell phenotype, whereas none of the 33 non-T-ALL samples tested exhibited GD3. Correlation between the expression of GD3 and various antigenic determinants of T-cell differentiation was restricted to CD2; 75% of CD2-negative T-cell ALL blasts failed to express GD3. Anti-GD3 immunoreactivity to T-ALL samples was not restricted to R24 in that two other monoclonal anti-GD3 antibodies were similarly reactive to T-ALL blasts. In vitro incubation of T-cell lymphoblasts with the anti-GD3 antibodies, R24 and C281 and human serum resulted in significant cytotoxicity, and R24 also mediated antibody-dependent cellular cytotoxicity by normal effector cells. Cytotoxicity was specific for those T-ALL blast cell populations which reacted with anti-GD3 as assessed by immunofluorescence microscopy. Since immunoreactivity with monoclonal antibody to GD3 was exclusively observed in a large population of immunophenotypically defined T-cell leukemic lymphoblasts, these studies suggest a possible immunodiagnostic and immunotherapeutic potential for anti-GD3 monoclonal antibodies in T-cell lymphoblastic malignancies.

Family CHAOS is associated with glycaemic control in children and adolescents with type 1 diabetes mellitus.

BACKGROUND: Despite advances in the medical management of type 1 diabetes mellitus (T1DM), for many, glycaemic control remains substandard. Other factors are clearly important in determining success, or lack thereof, with diabetes management. With this in mind, we have investigated whether family CHAOS may provide a novel tool to identify when environmental confusion could impact on diabetes management and subsequent glycaemic control. METHODS: A case-control study of children and adolescents with established T1DM and age-/sex-matched controls was conducted. Demographic information, both maternal and paternal CHAOS scores, and HbA1c were collected. Statistical analysis was undertaken to explore associations between T1DM and CHAOS and between CHAOS and HbA1c. RESULTS: Data on 65 children with T1DM and 60 age-/sex-matched controls were obtained. There was no evidence of group differences for maternal CHAOS (p = 0.227), but paternal CHAOS scores were higher for the T1DM group (p = 0.041). Greater maternal and paternal CHAOS scores were both associated with higher HbA1c (p ≤ 0.027). The maternal association remained after controlling for diabetes duration, SMBG frequency, and insulin therapy. CONCLUSION: In children with T1DM, there appears to be a negative association between increased environmental confusion, as rated by CHAOS, and glycaemic control. In addition, when compared to controls, fathers of children and adolescents with T1DM appear to experience CHAOS differently to mothers. These findings contribute to the growing body of literature exploring psychosocial factors in T1DM. Continuing efforts are required to fully understand how the family and psychosocial environment interact with diabetes to impact on long-term health outcomes.

Electrical and thermal transport properties of the electron-doped cuprate Sm2-x Ce x CuO4-y system.

Electrical and thermal transport measurements were performed on thin films of the electron-doped superconductor Sm2-x Ce x CuO4-y (x = 0.13 - 0.19) in order to study the evolving nature of the charge carriers from the under-doped to over-doped regime. A temperature versus cerium content (T - x) phase diagram has been constructed from the electrical transport measurements, yielding a superconducting region similar to that found for other electron-doped superconductors. Thermopower measurements show a dramatic change from the underdoped region (x < 0.15) to the overdoped region (x > 0.15). Application of the Fisher-Fisher-Huse (FFH) vortex glass scaling model to the magnetoresistance data was found to be insufficient to describe the data in the region of the vortex-solid to vortex-liquid transition. It was found instead that the modified vortex glass scaling model of Rydh, Rapp, and Anderson provided a good description of the data, indicating the importance of the applied field on the pinning landscape. A magnetic field versus temperature (H - T) phase diagram has also been constructed for the films with [Formula: see text], displaying the evolution of the vortex glass melting lines H g (T) across the superconducting regime.

Enrichment and localization of ganglioside G(D3) and caveolin-1 in shed tumor cell membrane vesicles.

Tumor cell ganglioside shedding has been implicated in the process of tumor formation. Previously, we identified three forms of tumor ganglioside shedding: micelles, monomers and membrane vesicles. Here, we have explored the membrane vesicle form of ganglioside shedding, using a newly identified human ovarian carcinoma cell line, CABA I. These cells synthesize and express a spectrum of gangliosides, including the disialoganglioside, G(D3). Immunostaining using the monoclonal antibody R24 confirmed G(D3) expression and its presence in the plasma membrane of these cells. Cellular gangliosides were detected in the culture supernatant by HPTLC autoradiography, confirming an active shedding rate of 3% of cellular gangliosides/24 h. CABA I cell membranes also express caveolin-1, a characteristic protein marker for caveolae, which was detected by flow cytometric analysis and by Western blotting in both the cell membranes and the isolated membrane vesicles. To further define the expression of G(D3) and caveolin-1, we used immunogold electron microscopy. This revealed localization of G(D3) in small clusters in the plasma membrane as well as enrichment and localization of ganglioside G(D3) and caveolin-1 in shed membrane vesicles, with 58-78% of vesicles carrying both G(D3) and caveolin-1. Together, these results suggest that membrane vesicle shedding originates in plasma membrane domains enriched in gangliosides and caveolin-1.

Characterization of immunoglobulin and T-cell receptor gene patterns in B-cell precursor acute lymphoblastic leukemia of childhood.

Immunoglobulin (Ig) and T-cell receptor (TCR) genes were examined in the lymphoblasts of 70 children with immunophenotypically defined B-cell precursor acute lymphoblastic leukemia (ALL). The most frequent genes to rearrange were Ig heavy (H) chain (93%) and TCR delta (79%), followed by TCR gamma (49%), Ig kappa and/or lambda light (L) chain (46%), TCR alpha (46%), and TCR beta (29%). Thus, despite their putative "B-cell precursor" lineage, these leukemias manifest a remarkably high incidence of TCR gene rearrangements. While certain patterns predominate, there is considerable heterogeneity in Ig and TCR genotypes in this disease. No significant associations were found between Ig and TCR genotype and commonly used prognostic factors including age, sex, race, WBC, French-American-British (FAB) subtype, or cytogenetics. However, the lymphoblasts of three of six patients who failed to achieve initial remission had germline patterns of every Ig and TCR gene, a genotype not observed in the leukemic cells from any of the 64 patients who achieved complete remission (p2 = .0007). This study suggests that particular Ig and TCR genotypes may be of clinical relevance in childhood B-cell precursor ALL. The finding of rearranged TCR genes in a large proportion of cases raises fundamental questions about early lineage commitment and lymphocyte differentiation along B-cell and T-cell pathways.

Differentiation of a male-specific muscle in Drosophila melanogaster does not require the sex-determining genes doublesex or intersex.

A pair of muscles span the fifth abdominal segment of male but not female Drosophila melanogaster adults. To establish whether genes involved in the development of other sexually dimorphic tissues controlled the differentiation of sex-specific muscles, flies mutant for five known sex-determining genes were examined for the occurrence of male-specific abdominal muscles. Female flies mutant for alleles of Sex-lethal, defective in sex determination, or null alleles of transformer or transformer-2 are converted into phenotypic males that formed male-specific abdominal muscles. Both male and female flies, when mutant for null alleles of doublesex, develop as nearly identical intersexes in other somatic characteristics. Male doublesex flies produced the male-specific muscles, whereas female doublesex flies lacked them. Female flies, even when they inappropriately expressed the male-specific form of doublesex mRNA, failed to produce the male-specific muscles. Therefore, the wild-type products of the genes Sex-lethal, transformer and transformer-2 act to prevent the differentiation of male-specific muscles in female flies. However, there is no role for the genes doublesex or intersex in either the generation of the male-specific muscles in males or their suppression in females.

Aberrant splicing and altered spatial expression patterns in fruitless mutants of Drosophila melanogaster.

The fruitless (fru) gene functions in Drosophila males to establish the potential for male sexual behaviors. fru encodes a complex set of sex-specific and sex-nonspecific mRNAs through the use of multiple promoters and alternative pre-mRNA processing. The male-specific transcripts produced from the distal (P1) fru promoter are believed to be responsible for its role in specifying sexual behavior and are only expressed in a small fraction of central nervous system (CNS) cells. To understand the molecular etiology of fruitless mutant phenotypes, we compared wild-type and mutant transcription patterns. These experiments revealed that the fru(2), fru(3), fru(4), and fru(sat) mutations, which are due to P-element inserts, alter the pattern of sex-specific and sex-nonspecific fru RNAs. These changes arise in part from the P-element insertions containing splice acceptor sites that create alternative processing pathways. In situ hybridization revealed no alterations in the locations of cells expressing the P1-fru-promoter-derived transcripts in fru(2), fru(3), fru(4), and fru(sat) pharate adults. For the fru(1) mutant (which is due to an inversion breakpoint near the P1 promoter), Northern analyses revealed no significant changes in fru transcript patterns. However, in situ hybridization revealed anomalies in the level and distribution of P1-derived transcripts: in fru(1) males, fewer P1-expressing neurons are found in regions of the dorsal lateral protocerebrum and abdominal ganglion compared to wild-type males. In other regions of the CNS, expression of these transcripts appears normal in fru(1) males. The loss of fruitless expression in these regions likely accounts for the striking courtship abnormalities exhibited by fru(1) males. Thus, we suggest that the mutant phenotypes in fru(2), fru(3), fru(4), and fru(sat) animals are due to a failure to appropriately splice P1 transcripts, whereas the mutant phenotype of fru(1) animals is due to the reduction or absence of P1 transcripts within specific regions of the CNS.

Molecular genetic dissection of the sex-specific and vital functions of the Drosophila melanogaster sex determination gene fruitless.

A multibranched hierarchy of regulatory genes controls all aspects of somatic sexual development in Drosophila melanogaster. One branch of this hierarchy is headed by the fruitless (fru) gene and functions in the central nervous system, where it is necessary for male courtship behavior as well as the differentiation of a male-specific abdominal structure, the muscle of Lawrence (MOL). A preliminary investigation of several of the mutations described here showed that the fru gene also has a sex-nonspecific vital function. The fru gene produces a complex set of transcripts through the use of four promoters and alternative splicing. Only the primary transcripts produced from the most distal (P1) promoter are sex-specifically spliced under direction of the sex-determination hierarchy. We have analyzed eight new fru mutations, created by X-ray mutagenesis and P-element excision, to try to gain insight into the relationship of specific transcript classes to specific fru functions. Males that lack the P1-derived fru transcripts show a complete absence of sexual behavior, but no other defects besides the loss of the MOL. Both males and females that have reduced levels of transcripts from the P3 promoter develop into adults but frequently die after failing to eclose. Analysis of the morphology and behavior of adult escapers showed that P3-encoded functions are required for the proper differentiation and eversion of imaginal discs. Furthermore, the reduction in the size of the neuromuscular junctions on abdominal muscles in these animals suggests that one of fru's sex-nonspecific functions involves general aspects of neuronal differentiation. In mutants that lack all fru transcripts as well as a small number of adjacent genes, animals die at an early pupal stage, indicating that fru's function is required only during late development. Thus, fru functions both in the sex-determination regulatory hierarchy to control male sexual behavior through sex-specific transcripts and sex-nonspecifically to control the development of imaginal discs and motorneuronal synapses during adult development through sex-nonspecific transcript classes.

A comparison of mid-forehead and axillary temperatures in newborn intensive care.

OBJECTIVE: To evaluate accuracy of mid-forehead (MFH) thermometry compared with digital axilla (DAT) temperatures in infants in newborn intensive care. STUDY DESIGN: A comparative study of MFH and DAT temperatures of newborn infants receiving tertiary-level intensive care. All admissions were considered and the following exclusion criteria applied: 'in extremis', hypoxic ischemic encephalopathy or non-English-speaking parents. Foot temperatures, infant and environmental variables were measured. RESULT: In all, 783 readings were obtained in 100 infants with a birth weight range 515 to 4885 g (mean 2152 g). The between-person correlation was 0.30 (P < 0.001) and the within-person correlation was 0.52 (P < 0.001). Bland-Altman plots showed wide 95% confidence intervals in the differences between MFH and DAT measurements (-0.87 to 1.16 °C). Differences were affected by infant variables measured. MFH more accurately predicted DAT measurements in smaller neonates and were less accurate in neonates requiring Bubble Continuous Positive Airway Pressure (CPAP). CONCLUSION: MFH thermometry is not able to replace DAT temperature recording in the newborn intensive care.

Ultrastructure of mouse vallate taste buds. I. Taste cells and their associated synapses.

The ultrastructural features of murine vallate taste bud cells and their associated synapses have been examined in thin and thick sections with conventional transmission electron microscopy and high-voltage electron microscopy. Computer-assisted reconstructions from serial sections were utilized to aid in visualization of taste bud cell-nerve fiber synapses. We have classified taste bud cells on the basis of previously established criteria-namely, size of the nucleus, shape and density of chromatin, density of cytoplasm, and presence or absence of dense-cored or clear vesicles, other cytoplasmic organelles, and synaptic foci. Both dark cells and light cells are present, as well as cells with intermediate morphological characteristics. Synapses were observed from taste bud cells onto nerve fiber processes. In virtually all instances, synapses are associated with the nuclear region of the taste cell. These synapses are characterized by the presence of 40-70 nm clear vesicles embedded in a thickened presynaptic membrane separated from the postsynaptic membrane by a 16-30 nm cleft. Synapses are not unique to any particular cell type. Dark, intermediate, and light cells all synapse onto nerve fibers. Two general types of synapses exist: spot (or macular) and fingerlike. In the latter, the postsynaptic region of the neuronal process protrudes into an invagination of the taste cell membrane. Differences in synaptic morphology are not correlated with taste cell type. In some cases a single taste cell was observed to possess both macular and fingerlike synapses adjacent to one another, forming a synaptic complex onto a single neuronal process. On the basis of the presence of synaptic contacts, we conclude that both "dark" and "light" cells are gustatory receptors.

Predicted disulfide-bonded structures for three uniquely related proteins of Plasmodium falciparum, Pfs230, Pfs48/45 and Pf12.

Pfs230 is a surface protein of the gametes of Plasmodium falciparum and has been demonstrated to be a target of malaria transmission-blocking antibodies; it is an important candidate antigen for a transmission-blocking vaccine. The target epitopes of transmission-blocking antibodies against Pfs230 are almost all reduction sensitive suggesting that disulfide bonds are critical for folding the native molecule. Following the cloning of the Pfs230 gene attempts are now underway to express subunits of the protein for use in vaccine trials. It will be important to understand the disulfide-bond structure of the Pfs230 to achieve this goal. In this paper we present a model for this structure based on the observation that the Pfs230 molecule contains a series of regularly repeated cysteine-containing motifs. Four such motifs have been identified, together with a fifth cysteineless motif, which occur in the same relative order, with regular alternating omission of specific motifs, 14 times throughout the length of the protein. Each of the 14 sets of motifs contains an even number of cysteine residues (2, 4 or 6). We postulate that each set folds into a separate disulfide-bonded domain in which corresponding pairs of cysteines form an equivalent disulfide bond in every such domain. The postulated bonding arrangements in the different domains are mutually confirmatory throughout the sequence of Pfs230. We have identified two other malaria proteins, Pfs48/45 and Pf12, which share the same arrangements of motifs and conform to the same disulfide-bond structure proposed for Pfs230; no other proteins in the sequence data base share these characteristics.(ABSTRACT TRUNCATED AT 250 WORDS)

Inter-hospital transport of neonatal patients on extracorporeal membrane oxygenation: mobile-ECMO.

OBJECTIVE: To describe the equipment, personnel requirements, training, management techniques, and logistic problems encountered in the design and implementation of a mobile extracorporeal membrane oxygenation (ECMO) program. DESIGN: This is a report of a technique for the transport of patients on ECMO and a description of our retrospective case series. SETTINGS: The study was conducted at a regional referral children's hospital and ECMO unit. PATIENTS: Thirteen neonatal medical patients with acute respiratory failure were transported with mobile-ECMO. RESULTS: Over a 24-month period, we transported 13 neonatal patients with mobile-ECMO. The reason for transport with mobile-ECMO was inability to convert from high-frequency ventilation (4 of 13), patient already on ECMO (1 of 13), and patient deemed too unstable for conventional transport (8 of 13). Eleven of the 13 patients were transported from other ECMO centers. Of the 13, 9 survived. No major complications during transport were reported for any of the patients. Follow-up data were available on all nine survivors of neonatal mobile-ECMO. Eight of these had normal magnetic resonance imaging scans of the brain; the ninth had a small hemorrhage in the left cerebellum. CONCLUSION: Our limited series shows that patients can be safely transported with mobile-ECMO. This program does not replace the early appropriate transfer for ECMO-eligible patients to an ECMO center.