Smoking cessation in pregnant women using financial incentives: a feasibility study.

BACKGROUND: The high prevalence of smoking pregnant women in Dutch areas with lower socioeconomic status and the consecutively harmful exposure to tobacco to both mother and child, depicted a high need for a novel intervention. According to other studies, the utilisation of financial incentives appeared to be a promising method for smoking cessation in pregnant women. Therefore, the aim of this study was to investigate the feasibility of implementing contingent financial incentives as smoking cessation support for pregnant women in the Netherlands. METHODS: Feasibility study consisting of four developmental phases: (1) acceptability of Dutch population regarding financial-incentive-intervention by conducting an online questionnaire, (2) composing a pilot study utilising the financial-incentive-intervention in clinical practice, (3) execution of the composed pilot study and (4) evaluation of the executed pilot study utilising a mixed-methods approach. A financial-incentive-intervention, given in a contingent financial scheme (during five consequential appointments, respectively €25/€50/€100/€150/€250), if smoking abstinence was proven by the amount of cotinine in the urine of the pregnant women measured utilising a urine dipstick test. The public acceptability for the financial-incentive-intervention was assessed using 5-Likert scales. The number of pregnant women able to abstain from smoking during the pilot study and utilising the financial-incentive-intervention in clinical practice were used to assess the prosperity and practicality of the pilot study respectively. The pilot study was evaluated using a mixed-methods approach. RESULTS: In total, 55.1% of the Dutch population sample (n = 328) found a financial incentive inappropriate for smoking cessation in pregnant women, while the healthcare professionals and pilot study participants thought the financial-incentive-intervention to be a helpful approach. Eleven vouchers were given during the pilot study, and one woman completed all test points and tested negative for cotinine at the end of the pilot study. CONCLUSION: Although the financial-incentive-intervention appeared to be a promising approach for smoking cessation in pregnant women, the acceptability of the Dutch population and the number of pregnant women able to abstain smoking during this pilot study was low. Despite the limited study population, this study proved the concept of this financial-incentive-intervention to be feasible for implementation in the Netherlands. TRIAL REGISTRATION: Not applicable since this is a feasibility study prior to a trial.

Women who smoke during pregnancy are more likely to be referred to an obstetrician during pregnancy and birth: results from a cohort study.

BACKGROUND: Women who smoke during pregnancy make less use of prenatal care; the relation of smoking behavior with the use of other forms of maternal healthcare is unknown. The objective of this study is to investigate the association between women's smoking behavior and their use of healthcare during pregnancy, birth and six weeks postpartum. METHODS: We analyzed data from the Dutch Midwifery Case Registration System (VeCaS), period 2012-2019. We included women with a known smoking status, singleton pregnancies, and who had their first appointment before 24 weeks of gestation with the primary care midwife. We compared three groups: non-smokers, early stoppers (stopped smoking in the first trimester), and late- or non-stoppers (stopped smoking after the first trimester or continued smoking). Descriptive statistics were used to report maternal healthcare utilization (during pregnancy, birth and six weeks postpartum), statistical differences between the groups were calculated with Kruskal-Wallis tests. Multivariable logistic regression was conducted to assess the association between smoking behavior and referrals to primary, secondary or tertiary care. RESULTS: We included 41 088 pregnant women. The groups differed significantly on maternal healthcare utilization. The late- or non-stoppers initiated prenatal care later and had less face-to-face consultations with primary care midwives during pregnancy. Compared to the non-smokers, the early- and late- or non-stoppers were statistically signficiantly more likely to be referred to the obstetrician during pregnancy and birth. Postpartum, the early- and late- or non-stoppers were statistically signficantly less likely to be referred to the obstetrician compared to the non-smokers. CONCLUSIONS: Although the early- and late- or non-stoppers initiated prenatal care later than the non-smokers, they did receive adequate prenatal care (according to the recommendations). The results suggest that not smoking during pregnancy may decrease the likelihood of referral to secondary or tertiary care. The large population of smokers being referred during pregnancy underlines the important role of the collaboration between healthcare professionals in primary and secondary or tertiary care. They need to be more aware of the importance of smoking as a medical and as a non-medical risk factor.

[General health, healthcare costs and dental care use of elderly with differing oral status]. / Algemene gezondheid, zorgkosten en tandartsbezoek van ouderen met verschillende orale status.

Cross-sectional studies have shown that elderly with a natural dentition or implant-retained overdenture have better general health outcomes than elderly with conventional dentures. It is not known whether these findings would be confirmed in longitudinal studies of such groups of elderly. Therefore, in this study a large group of elderly (aged 75 and over) with a natural dentition (n = 143,199), an implant-retained overdenture (n = 6,503) or conventional denture (n=18,420) were followed over a period of 8 years. Elderly with conventional dentures had chronic conditions more often, used more medication and had higher healthcare costs. Remarkably, the general health outcomes of elderly with an implant-retained overdenture declined over the period of 8 years. At the time the implant-retained overdenture was placed, their general health profile seemed comparable to that of elderly with a natural dentition, but as time progressed it declined to the level of elderly with conventional dentures.

Assessing Dutch women's experiences of labour and birth: adaptations and psychometric evaluations of the measures Mothers on Autonomy in Decision Making Scale, Mothers on Respect Index, and Childbirth Experience Questionnaire 2.0.

BACKGROUND: The Mothers Autonomy in Decision Making Scale (MADM) assesses women's autonomy and role in decision making. The Mothers on Respect Index (MORi) asseses women's experiences of respect when interacting with their healthcare providers. The Childbirth Experience Questionnaire 2.0 assesses the overall experience of childbirth (CEQ2.0). There are no validated Dutch measures of the quality of women's experiences in the intrapartum period. Therefore, the aim of this study was to evaluate the psychometric properties of these measures in their Dutch translations. METHODS: The available Dutch versions of the MADM and MORi were adapted to assess experiences in the intrapartum period. The CEQ2.0 was translated by using forward-backward procedures. The three measures were included in an online survey including items on individual characteristics (i.e. maternal, birth, birth interventions). Reliability was assessed by calculating Cronbach's alphas. Mann-Whitney, Kruskal Wallis or Student T-tests were applied where appropriate, to assess discrimination between women who differed on individual characteristics (known group validity). We hypothesized that women who experienced pregnancy complications and birth interventions would have statistically lower scores on the MADM, MORi and CEQ2.0, compared with women who had healthy pregnancies and physiological births. Convergent validity was assessed using Spearman Rank correlations between the MADM, MORi and/or CEQ2.0. We hypothesized moderate to strong correlations between these measures. Women's uptake of and feedback on the measures were tracked to assess acceptability and clarity. RESULTS: In total 621 women were included in the cross sectional study. The calculated Cronbach's alphas for the MADM, MORi and CEQ, were ≥ 0.77. Knowngroup validity was confirmed through significant differences on all relevant individual characteristics, except for vaginal laceration repair. Spearman Rank correlations ranged from 0.46-0.80. In total 98% of the included women out of the eligible population completed the MADM and MORi for each healthcare professional they encountered during childbirth. The proportions of MADM and MORi-items which were difficult to complete ranged from 0.0-10.8%, 0.6-2.7%, respectively. CONCLUSIONS: The results of our study showed that the Dutch version of the MADM, MORi and CEQ2.0 in Dutch are valid instruments that can be used to assess women's experiences in the intrapartum period.

The needs of women and their partners regarding professional smoking cessation support during pregnancy: A qualitative study.

BACKGROUND: Despite the health risks of smoking, some women continue during pregnancy. Professional smoking cessation support has shown to be effective in increasing the proportion of pregnant women who quit smoking. However, few women actually make use of professional support. AIM: To investigate the needs of women and their partners for professional smoking cessation support during pregnancy. METHODS: Semi-structured interviews were held with pregnant women and women who recently gave birth who smoked or quit smoking during pregnancy, and their partners, living in the north of the Netherlands. Recruitment was done via Facebook, LinkedIn, food banks, baby stores and healthcare professionals. The interviews were recorded, transcribed and thematically analysed. RESULTS: 28 interviews were conducted, 23 with pregnant women and women who recently gave birth, and five with partners of the women. The following themes were identified: 1) understanding women's needs, 2) responsibility without criticism, and 3) women and their social network. These themes reflect that women need support from an involved and understanding healthcare professional, who holds women responsible for smoking cessation but refrains from criticism. Women also prefer involvement of their social network in the professional support. CONCLUSION: For tailored support, the Dutch guideline for professional smoking cessation support may need some adaptations. The adaptations and recommendations, e.g. to involve women and their partners in the development of guidelines, might also be valuable for other countries. Women prefer healthcare professionals to address smoking cessation in a neutral way and to respect their autonomy in the decision to stop smoking.

Measuring respect and autonomy in Dutch maternity care: Applicability of two measures.

PROBLEM: In the Netherlands there are no valid measurement tools available to measure respectful maternity care and women's autonomy. BACKGROUND: Respectful maternity care including women's autonomy during childbirth are key components of high quality care. AIM: This study aims to evaluate the applicability of the Canadian measures; the Mothers Autonomy in Decision Making (MADM) scale and the Mothers on Respect index (MORi) measures among pregnant women in the Netherlands. METHODS: We translated the measures MORi and MADM according to the WHO guidelines, adapted them to the Dutch health care system, evaluated their psychometric properties, and pilot tested before administration through an online cross-sectional survey. We assessed feasibility by calculating descriptive statistics on scores, and reliability by calculating Cronbach's alpha. The construct validity was measured by hypotheses on differences between subgroups based on maternal characteristics, pregnancy characteristics and healthcare provision. FINDINGS: Of 557 women included in the study, 83% experienced high respect and 62% experienced high autonomy. Both the MORi and MADM showed feasibility, internal consistency, and with respect to construct validity, both measures discriminated between type of care provision. Compared to women with pregnancy complications, those with a healthy pregnancy reported statistically higher MORi-scores. No differences were observed on MADM-scores. DISCUSSION: Both instruments can be used as quality of care measures aiming to improve care and thus experiences of women. CONCLUSION: The results of this study support the feasibility, reliability, and to a certain extent known group validity of the Dutch MORi and MADM measures in pregnant women.

Health and quality of life differ between community living older people with and without remaining teeth who recently received formal home care: a cross sectional study.

OBJECTIVE: To assess oral health, health, and quality of life (QoL) of care-dependent community-living older people with and without remaining teeth who recently received formal home care. MATERIALS AND METHODS: For this cross-sectional observational study, community-living older people (≥ 65 years), who recently (< 6 months) received formal home care, were interviewed with validated questionnaires and underwent an oral examination. Oral health, general health, medicines usage, frailty (Groningen Frailty Indicator), cognition (Minimal Mental State Examination), QoL (RAND 36), and oral health-related QoL (Oral Health Impact Profile-14) were assessed. RESULTS: One hundred three out of 275 consecutive eligible older people (median age 79 [IQR (Inter Quartile Range) 72-85 years] participated in the study. Thirty-nine patients had remaining teeth and 64 were edentulous. Compared with edentulous older people, older people with remaining teeth scored significantly better on frailty, QoL, physical functioning, and general health. No significant differences were seen in cognition. Dental and periodontal problems were seen in more than half of the patients with remaining teeth. Two third of the edentulous patients did not visit their dentist regularly or at all. CONCLUSIONS: Care-dependent home-dwelling older people with remaining teeth generally were less frail, scored better on physical functioning and general health and had better QoL than edentulous older people. Dental and periodontal problems were seen in approximately 50% of the elderly. CLINICAL RELEVANCE: Notwithstanding their common dental problems, frailty, health, and QoL are better in home-dwelling older people with remaining teeth. To maintain this status, we advise not only dentists, but also health care workers and governments, to encourage people to maintain good oral health.

Elderly with remaining teeth report less frailty and better quality of life than edentulous elderly: a cross-sectional study.

OBJECTIVE: To assess oral status and self-reported oral health in community-living elderly and to determine differences between relevant subgroups of oral status (remaining teeth, edentulous, implant-retained overdentures) and case complexity (robust, frail, complex care needs). SUBJECTS AND METHODS: In this cross-sectional descriptive study, 1325 Dutch community-living elderly (≥75 years of age) were asked to complete validated questionnaires on frailty, activities of daily living (ADL), complexity of care needs, and QoL. Data on oral status, self-reported oral health, dental care, general health, and medication use were assessed. Differences between relevant subgroups were determined. RESULTS: Data of 1026 (77%) elderly (median 80 years, IQR 77-84) were analyzed: 39% had remaining teeth, 51% were edentulous, and 10% had implant-supported overdentures. Elderly with complex care needs (n = 225, 22%) and frail elderly (n = 217, 21%) were more often edentulous and reported more oral problems than robust elderly (n = 584, 57%). Elderly persons with remaining teeth were less frail, had better QoL and ADL, and used fewer medicines than edentulous elderly. Elderly with implant-supported overdentures performed better on frailty and QoL than edentulous elderly with conventional dentures. CONCLUSION: Community-living elderly commonly suffer from oral health problems, in particular elderly with complex care needs. QoL, ADL, and general health are higher among community-living elderly with remaining teeth and implant-supported overdentures than in edentulous elderly.

[Peri-implant health in people aged 75 and over with an implant-retained overdenture in the mandibula]. / Peri-implantaire gezondheid bij 75-plussers met een overkappingsprothese op implantaten in de onderkaak.

The number of elderly patients with an implant-retained overdenture in the mandibula is increasing. There is, however, insufficient information on how these elderly people are functioning with their overdenture and on their peri--implant health. Therefore, a study was carried out among a group of people aged 75 and over who had been provided with an implant-retained overdenture in a general dental office, measuring their ability to manage independently, their general health and peri-implant health. The study revealed a high degree of ability to manage independently, despite the health problems affecting many over 75. The patients rated their prosthetic overdentures with an average grade of 8.9 ± 1.1. Plaque around the implant (73%) and bleeding on probing (68%) were frequently seen. However, progressive peri-implant bone loss was seldom seen. No relationship was evident between plaque-scores and the ability to manage independently. Except for oral hygiene instruction and/or professional cleaning of peri-implants, no serious interventions were necessary. It was concluded that this group of elderly people, provided with an implant-retained mandibular overdenture, are functioning well. Plaque around the implant and bleeding on probing are often present but progressive peri-implant bone loss is rare.

Construct validity of the Groningen Frailty Indicator established in a large sample of home-dwelling elderly persons: Evidence of stability across age and gender.

BACKGROUND: The primary objective of the present study was to evaluate the validity of the Groningen Frailty Indicator (GFI) in a sample of Dutch elderly persons participating in LifeLines, a large population-based cohort study. Additional aims were to assess differences between frail and non-frail elderly and examine which individual characteristics were associated with frailty. METHODS: By December 2012, 5712 elderly persons were enrolled in LifeLines and complied with the inclusion criteria of the present study. Mann-Whitney U or Kruskal-Wallis tests were used to assess the variability of GFI-scores among elderly subgroups that differed in demographic characteristics, morbidity, obesity, and healthcare utilization. Within subgroups Kruskal-Wallis tests were also used to examine differences in GFI-scores across age groups. Multivariate logistic regression analyses were performed to assess associations between individual characteristics and frailty. RESULTS: The GFI discriminated between subgroups: statistically significantly higher GFI-median scores (interquartile range) were found in e.g. males (1 [0-2]), the oldest old (2 [1-3]), in elderly who were single (1 [0-2]), with lower socio economic status (1 [0-3]), with increasing co-morbidity (2 [1-3]), who were obese (2 [1-3]), and used more healthcare (2 [1-4]). Overall age had an independent and statistically significant association with GFI scores. Compared with the non-frail, frail elderly persons experienced statistically significantly more chronic stress and more social/psychological related problems. In the multivariate logistic regression model, psychological morbidity had the strongest association with frailty. CONCLUSION: The present study supports the construct validity of the GFI and provides an insight in the characteristics of (non)frail community-dwelling elderly persons participating in LifeLines.

Deletion of small ankyrin 1 (sAnk1) isoforms results in structural and functional alterations in aging skeletal muscle fibers.

Muscle-specific ankyrins 1 (sAnk1) are a group of small ankyrin 1 isoforms, of which sAnk1.5 is the most abundant. sAnk1 are localized in the sarcoplasmic reticulum (SR) membrane from where they interact with obscurin, a myofibrillar protein. This interaction appears to contribute to stabilize the SR close to the myofibrils. Here we report the structural and functional characterization of skeletal muscles from sAnk1 knockout mice (KO). Deletion of sAnk1 did not change the expression and localization of SR proteins in 4- to 6-mo-old sAnk1 KO mice. Structurally, the main modification observed in skeletal muscles of adult sAnk1 KO mice (4-6 mo of age) was the reduction of SR volume at the sarcomere A band level. With increasing age (at 12-15 mo of age) extensor digitorum longus (EDL) skeletal muscles of sAnk1 KO mice develop prematurely large tubular aggregates, whereas diaphragm undergoes significant structural damage. Parallel functional studies revealed specific changes in the contractile performance of muscles from sAnk1 KO mice and a reduced exercise tolerance in an endurance test on treadmill compared with control mice. Moreover, reduced Qγ charge and L-type Ca(2+) current, which are indexes of affected excitation-contraction coupling, were observed in diaphragm fibers from 12- to 15-mo-old mice, but not in other skeletal muscles from sAnk1 KO mice. Altogether, these findings show that the ablation of sAnk1, by altering the organization of the SR, renders skeletal muscles susceptible to undergo structural and functional alterations more evident with age, and point to an important contribution of sAnk1 to the maintenance of the longitudinal SR architecture.

[Oral health in care-dependent elderly: an inventory in a nursing home in the north of the Netherlands]. / Mondgezondheid van kwetsbare ouderen: een inventarisatie in een verpleeghuis in Noord-Nederland.

When people grow old and dependent on care, it usually becomes increasingly difficult to maintain oral health. The aim of this study was to assess what changes have taken place during the last ten years in oral health and the need for dental care among patients who were admitted to a nursing home between 2002 and 2012. Results revealed that the number of patients with remaining teeth increased significantly, from 7.9% to 28.7%, and that the number of patients with implants increased from 0.0% to 3.2%. More than 80% of the patients had moderate to poor oral health upon arrival. Moreover, almost half of the patients were revealed to be non-cooperative for evaluation and/or treatment, especially those who had remaining teeth. The expectation is that as a result of the increasing number of care-dependent elderly with remaining teeth in combination with poor oral health, the demand for dental care for care-dependent elderly in nursing homes will increase harply in the coming years.

Physiological effects of housing density on C57BL/6J mice over a 9-month period.

The NRC has consistently recommended floor space for animals used in science and agriculture. For mice, the recommended floor space is 77.4 cm(2) (12 in(2)) for a 15- to 25-g mouse. The NRC noted that its recommendations were based on "best professional judgment" and encouraged alternatives that were data driven. As part of a continual effort of The Jackson Laboratory to ensure the health and well-being of production and research mice, while promoting cost-effective, state-of-the-art research, several density-driven studies have been conducted by lab researchers. The objectives of this study were to determine the effect of housing density on variables related to mouse physiology and air quality in cages and assess the value of specific measured variables in such studies. In the present study, we monitored C57BL/6J mice in individually ventilated cages from weaning until 9 mo of age. Housing densities were equivalent to 66.4 or 36.8 cm(2) per mouse (10.3 or 5.7 in(2)). Clinical physiological variables representing general health and well-being were measured. Hematological traits, plasma lipids, and glucose, growth, bone mineral density, and percent body fat did not differ between housing densities. In the more densely housed mice, however, adrenal glands were significantly smaller, heart rates were significantly less, and food consumption was less. Cage air microenvironment was evaluated for ammonia, carbon dioxide, temperature, and humidity in cages changed weekly or every 2 wk. The cage microenvironment remained within acceptable limits at the higher density of mice at both cage-changing frequencies. The results suggest that mice housed for as long as 9 mo at up to twice the density currently recommended by NRC show no measurable adverse effects. Continued re-evaluation of the recommendation by measuring additional relevant variables of health and general well-being, and studying additional strains of mice is warranted.

Transcriptional repression and developmental functions of the atypical vertebrate GATA protein TRPS1.

Known vertebrate GATA proteins contain two zinc fingers and are required in development, whereas invertebrates express a class of essential proteins containing one GATA-type zinc finger. We isolated the gene encoding TRPS1, a vertebrate protein with a single GATA-type zinc finger. TRPS1 is highly conserved between Xenopus and mammals, and the human gene is implicated in dominantly inherited tricho-rhino-phalangeal (TRP) syndromes. TRPS1 is a nuclear protein that binds GATA sequences but fails to transactivate a GATA-dependent reporter. Instead, TRPS1 potently and specifically represses transcriptional activation mediated by other GATA factors. Repression does not occur from competition for DNA binding and depends on a C-terminal region related to repressive domains found in Ikaros proteins. During mouse development, TRPS1 expression is prominent in sites showing pathology in TRP syndromes, which are thought to result from TRPS1 haploinsufficiency. We show instead that truncating mutations identified in patients encode dominant inhibitors of wild-type TRPS1 function, suggesting an alternative mechanism for the disease. TRPS1 is the first example of a GATA protein with intrinsic transcriptional repression activity and possibly a negative regulator of GATA-dependent processes in vertebrate development.

A new spectrin, beta IV, has a major truncated isoform that associates with promyelocytic leukemia protein nuclear bodies and the nuclear matrix.

We isolated cDNAs that encode a 77-kDa peptide similar to repeats 10-16 of beta-spectrins. Its gene localizes to human chromosome 19q13.13-q13.2 and mouse chromosome 7, at 7.5 centimorgans. A 289-kDa isoform, similar to full-length beta-spectrins, was partially assembled from sequences in the human genomic DNA data base and completely cloned and sequenced. RNA transcripts are seen predominantly in the brain, and Western analysis shows a major peptide that migrates as a 72-kDa band. This new gene, spectrin betaIV, thus encodes a full-length minor isoform (SpbetaIVSigma1) and a truncated major isoform (SpbetaIVSigma5). Immunostaining of cells shows a micropunctate pattern in the cytoplasm and nucleus. In mesenchymal stem cells, the staining concentrates at nuclear dots that stain positively for the promyelocytic leukemia protein (PML). Expression of SpbetaIVSigma5 fused to green fluorescence protein in cells produces nuclear dots that include all PML bodies, which double in number in transfected cells. Deletion analysis shows that partial repeats 10 and 16 of SpbetaIVSigma5 are necessary for nuclear dot formation. Immunostaining of whole-mount nuclear matrices reveals diffuse positivity with accentuation at PML bodies. Spectrin betaIV is the first beta-spectrin associated with a subnuclear structure and may be part of a nuclear scaffold to which gene regulatory machinery binds.

Lutheran blood group glycoprotein and its newly characterized mouse homologue specifically bind alpha5 chain-containing human laminin with high affinity.

Lutheran blood group glycoproteins (Lu gps) are receptors for the extracellular matrix protein, laminin. Studies suggest that Lu gps may contribute to vaso-occlusion in sickle cell disease and it has recently been shown that sickle cells adhere to laminin isoforms containing the alpha5 chain (laminin 10/11). Laminin alpha5 is present in the subendothelium and is also a constituent of bone marrow sinusoids, suggesting a role for the Lu/laminin interaction in erythropoiesis. The objectives of the current study were to define more precisely the molecular interactions of the extracellular and intracellular regions of human Lu and to clone and characterize a mouse homologue. To this end, complementary DNA and genomic clones for the mouse homologue were sequenced and the mouse Lu gene mapped to a region on chromosome 7 with conserved synteny with human 19q13.2. Mouse and human Lu gps are highly conserved (72% identity) at the amino acid sequence level and both mouse and human Lu gps specifically bind laminin 10/11 with high affinity. Furthermore, the first 3, N-terminal, immunoglobulin superfamily domains of human Lu are critical for this interaction. The results indicated that the cytoplasmic domain of BRIC 221-labeled human Lu gp is linked with the spectrin-based skeleton, affording the speculation that this interaction may be critical for signal transduction. These results further support a role for Lu gps in sickle cell disease and indicate the utility of mouse models to explore the function of Lu gp-laminin 10/11 interaction in normal erythropoiesis and in sickle cell disease.

Downeast anemia (dea), a new mouse model of severe nonspherocytic hemolytic anemia caused by hexokinase (HK(1)) deficiency.

A new spontaneous mutation in the A/J inbred mouse strain, downeast anemia (dea), causes severe hemolytic anemia with extensive tissue iron deposition and marked reticulocytosis. The anemia is present at birth and persists throughout life. The defect is inherited as an autosomal recessive and is transferable through bone marrow stem cells. The red cell morphology is consistent with a nonspherocytic hemolytic anemia, suggestive of a red cell enzymopathy. In linkage analysis, dea is nonrecombinant with the hexokinase-1 gene (Hk1) on mouse Chromosome 10. Expression of Hk1 is markedly decreased in dea erythroid tissues, and the transcript produced is larger than normal. Hexokinase enzyme activity is significantly decreased in dea tissues, including red cells, spleen, and kidney. Southern blot analyses revealed approximately 5.5 kb of additional sequence in the 5' portion of the dea Hk1 gene, which was identified by direct sequencing as an early transposon (ETn) insertion in intron 4. ETn insertions disrupt genes in several mouse models by a variety of mechanisms, including aberrant splicing of ETn sequences into the mRNA. We conclude that the primary gene defect in the dea mutation is in Hk1 and that dea is a model of generalized hexokinase deficiency, the first such model identified to date.

Defects in the cappuccino (cno) gene on mouse chromosome 5 and human 4p cause Hermansky-Pudlak syndrome by an AP-3-independent mechanism.

Defects in a triad of organelles (melanosomes, platelet granules, and lysosomes) result in albinism, prolonged bleeding, and lysosome abnormalities in Hermansky-Pudlak syndrome (HPS). Defects in HPS1, a protein of unknown function, and in components of the AP-3 complex cause some, but not all, cases of HPS in humans. There have been 15 inherited models of HPS described in the mouse, underscoring its marked genetic heterogeneity. Here we characterize a new spontaneous mutation in the mouse, cappuccino (cno), that maps to mouse chromosome 5 in a region conserved with human 4p15-p16. Melanosomes of cno/cno mice are immature and dramatically decreased in number in the eye and skin, resulting in severe oculocutaneous albinism. Platelet dense body contents (adenosine triphosphate, serotonin) are markedly deficient, leading to defective aggregation and prolonged bleeding. Lysosomal enzyme concentrations are significantly elevated in the kidney and liver. Genetic, immunofluorescence microscopy, and lysosomal protein trafficking studies indicate that the AP-3 complex is intact in cno/cno mice. It was concluded that the cappuccino gene encodes a product involved in an AP-3-independent mechanism critical to the biogenesis of lysosome-related organelles. (Blood. 2000;96:4227-4235)

Hereditary spherocytosis in zebrafish riesling illustrates evolution of erythroid beta-spectrin structure, and function in red cell morphogenesis and membrane stability.

Spectrins are key cytoskeleton proteins with roles in membrane integrity, cell morphology, organelle transport and cell polarity of varied cell types during development. Defects in erythroid spectrins in humans result in congenital hemolytic anemias with altered red cell morphology. Although well characterized in mammals and invertebrates, analysis of the structure and function of non-mammalian vertebrate spectrins has been lacking. The zebrafish riesling (ris) suffers from profound anemia, where the developing red cells fail to assume terminally differentiated erythroid morphology. Using comparative genomics, erythroid beta-spectrin (sptb) was identified as the gene mutated in ris. Zebrafish Sptb shares 62.3% overall identity with the human ortholog and phylogenetic comparisons suggest intragenic duplication and divergence during evolution. Unlike the human and murine orthologs, the pleckstrin homology domain of zebrafish Sptb is not removed in red cells by alternative splicing. In addition, apoptosis and abnormal microtubule marginal band aggregation contribute to hemolysis of mutant erythrocytes, which are features not present in mammalian red cells with sptb defects. This study presents the first genetic characterization of a non-mammalian vertebrate sptb and demonstrates novel features of red cell hemolysis in non-mammalian red cells. Further, we propose that the distinct mammalian erythroid morphology may have evolved from specific modifications of Sptb structure and function.

Ermap, a gene coding for a novel erythroid specific adhesion/receptor membrane protein.

Ermap (erythroid membrane-associated protein), a gene coding for a novel transmembrane protein produced exclusively in erythroid cells, is described. It is mapped to murine Chromosome 4, 57 cM distal to the centromere. The initial cDNA clone was isolated from a day 9 murine embryonic erythroid cell cDNA library. The predicted peptide sequence suggests that ERMAP is a transmembrane protein with two extracellular immunoglobulin folds, as well as a highly conserved B30.2 domain and several phosphorylation consensus sequences in the cytoplasmic region. ERMAP shares a high homology throughout the entire peptide with butyrophilin, a glycoprotein essential for milk lipid droplet formation and release. A GFP-ERMAP fusion protein was localized to the plasma membrane and cytoplasmic vesicles in transiently transfected 293T cells. Northern blot analysis and in-situ hybridization demonstrated that Ermap expression was restricted to fetal and adult erythroid tissues. ERMAP is likely a novel adhesion/receptor molecule specific for erythroid cells.