Registry-driven, community-based immunization outreach: a randomized controlled trial

OBJECTIVES

This study evaluated the effectiveness of registry-driven, community-based outreach directed toward children with immunization delays.

METHODS

A sample of 1,856 children aged 6 to 10 months was randomly assigned to receive either outreach or no intervention.

RESULTS

Children in the outreach group were more likely to receive an immunization during the observation period than children in the control group (61% vs 43%). Outreach was most effective for children with multiple risks, as measured by their immunization record; it was not effective for children whose mothers had received inadequate prenatal care.

CONCLUSIONS

Registry-driven outreach can effectively identify high-risk children and bring them to care.

Cloning, mapping and expression analysis of the sheep Wilson disease gene homologue

Copper homeostasis in mammals is maintained by the balance of dietary intake and copper excretion via the bile. Sheep have a variant copper phenotype and do not efficiently excrete copper by this mechanism, often resulting in excessive copper accumulation in the liver. The Wilson disease protein (ATP7B) is a copper transporting P-type ATPase that is responsible for the efflux of hepatic copper into the bile. To investigate the role of ATP7B in the sheep copper accumulation phenotype, the cDNA encoding the ovine homologue of ATP7B was isolated and sequenced and the gene was localised by fluorescence in situ hybridisation to chromosome 10. The 6.3 kb cDNA encoded a predicted protein of 1444 amino acids which included all of the functional domains characteristic of copper transporting P-type ATPases. ATP7B mRNA was expressed primarily in the liver with lower levels present in the intestine, hypothalamus and ovary. A splice variant of ATP7B mRNA, which was expressed in the liver and comprised approximately 10% of the total ATP7B mRNA pool, also was isolated. The results suggest that ATP7B is produced in the sheep and that the tendency to accumulate copper in the liver is not due to a gross alteration in the structure or expression of ATP7B.

High frequency hearing loss correlated with mutations in the GJB2 gene

Genetic hearing impairment affects approximately 1/2000 live births. Mutations in one gene, GJB2, coding for connexin 26 cause 10%-20% of all genetic sensorineural hearing loss. Mutation analysis in the GJB2 gene and audiology were performed on 106 families presenting with at least one child with congenital hearing loss. The families were recruited from a hospital-based multidisciplinary clinic, which functions to investigate the aetiology of sensorineural hearing loss in children and which serves an ethnically diverse population. In 74 families (80 children), the aetiology was consistent with non-syndromic recessive hearing loss. Six different connexin 26 mutations, including one novel mutation, were identified. We show that GJB2 mutations cause a range of phenotypes from mild to profound hearing impairment and that loss of hearing in the high frequency range (4000-8000 Hz) is a characteristic feature in children with molecularly diagnosed connexin 26 hearing impairment. We also demonstrate that this type of audiology and high frequency hearing loss is found in a similar-sized group of deaf children in whom a mutation could only be found in one of the connexin 26 alleles, suggesting connexin 26 involvement in the aetiology of hearing loss in these cases. In our study of the M34T mutation, only compound heterozygotes exhibited hearing loss, suggesting autosomal recessive inheritance.

A tale of two representations: the misinformation effect and children's developing theory of mind

The present research investigates representational ability as a cognitive factor underlying the suggestibility of children's eyewitness memory. The misinformation effect is used as an index of children's suggestibility, and performance on the false belief task is used as an assessment of children's representational abilities (N = 117). Analyses that considered the effect of representational ability and general memory ability on children's susceptibility to misleading information showed that differences in representational ability and general memory ability predicted participants' susceptibility to misleading information. These results demonstrate that the eyewitness memory of children who lack either multirepresentational abilities, sufficient general memory abilities, or both (i.e., most 3- and 4-year-olds) is less accurate than the eyewitness memory of children with both multirepresentational abilities and sufficient memory abilities (i.e., most 6-year-olds and adults). Thus, it appears that the earliest age at which children's eyewitness memory can be considered to be similar to that of adults is 6 years of age, when children's mental representational abilities are similar to those of adults. These results suggest that one factor underlying children's vulnerability to misleading information is the number of representations of an event that they can simultaneously hold and compare.

A simple PCR test to detect the common 35delG mutation in the connexin 26 gene

BACKGROUND

The most common form of nonsyndromic neurosensory autosomal recessive deafness, DFNB1, is caused by mutations in the connexin 26 gene (GJB2) on chromosome 13. One mutation, in which one guanosine (G) residue is deleted from a run of 6 Gs (35delG), is found in 40% to 70% of DFNB1 cases and has an expected population frequency of one in 40 to one in 100.

METHODS AND RESULTS

Polymerase chain reaction (PCR)-based tests for the 35delG mutation were developed. They are based on mismatched PCR primers that produce novel EcoRII or DdeI restriction enzyme sites depending on the number of Gs at the 35delG locus. An EcoRII site is generated in the wild-type sequence (6 Gs), but not when the 35delG mutation is present. Alternatively, a DdeI site can be generated so that this enzyme cuts the PCR product when the 35delG mutation is present, but not the wild-type sequence.

CONCLUSIONS

These tests enable a quick and reliable screen for the common 35delG mutation.

SOX14 is a candidate gene for limb defects associated with BPES and Möbius syndrome

Members of the SOX gene family encode proteins with homology to the HMG box DNA-binding domain of SRY, the Y-linked testis-determining gene. SOX genes are expressed during embryogenesis and are involved in the development of a wide range of different tissues. Mutations in SRY, SOX9 and SOX10 have been shown to be responsible for XY sex reversal, campomelic dysplasia and Waardenburg-Hirschsprung disease, respectively. It is likely that mutations in other SOX genes are responsible for a variety of human genetic diseases. SOX14 has been identified from a human genomic library and the mouse and chicken sequences obtained by polymerase chain reaction amplification. The SOX14 amino acid sequence is highly conserved across these species, suggesting an important role for this protein in vertebrate development. SOX14 is expressed in the neural tube and apical ectodermal ridge of the developing chicken limb. This is the only SOX gene known to be expressed in the apical ectodermal ridge, a structure that directs outgrowth of the embryonic limb bud. Human SOX14 is localised to a 1.15-Mb yeast artificial chromosome on chromosome 3q23, close to loci for BPES (blepharophimosis, ptosis, epicanthus inversus syndrome) and Mobius syndrome. Although SOX14 maps outside these loci, its expression pattern and chromosomal localisation suggest that it is a candidate gene for the limb defects frequently associated with these syndromes.

Cloning and expression of a DAX1 homologue in the chicken embryo

DAX1 is an unusual member of the orphan nuclear receptor family of transcription factors. Mutations in human DAX1 cause X-linked adrenal hypoplasia congenita, while abnormal duplication of the gene is responsible for male-to-female dosage-sensitive sex reversal. Based on these and other observations, DAX1 is thought to play a role in adrenal and gonadal development in mammals. As DAX1 has not previously been described in any other vertebrate, a putative avian DAX1 clone was isolated from an embryonic chicken (Gallus domesticus) urogenital ridge cDNA library. The expression profile of this cDNA was then examined during gonadogenesis. The clone included the conserved 3' ligand-binding motif identified in humans and mice but the 5' region lacked the repeat motif thought to specify a DNA-binding domain in mammals. Southern blot analysis and fluorescence in situ hybridisation mapping showed that the gene is autosomal, located on chromosome 1q. Sequence comparisons showed that the putative chicken DAX1 protein has 63 and 60% identity with the human and mouse proteins respectively over the region of the conserved ligand-binding domain. However, stronger identity (74%) exists with a putative alligator DAX1 sequence over the same region. Northern blotting detected a single 1.4 kb transcript in late embryonic chicken gonads, while RNase protection assays revealed expression in the embryonic gonads of both sexes during the period of sexual differentiation. Expression increased in both sexes during gonadogenesis, but was higher in females than in males. This is the first description of a DAX1 homologue in a non-mammalian vertebrate.

Connexin26 deafness in several interconnected families

Mutations in the connexin26 gene are the basis of much autosomal recessive sensorineural deafness. There is a high frequency of mutant alleles, largely accounted for by one common mutation, 35delG. We have studied a group of families, who had been brought together through marriages between Deaf persons, in which there are more than 30 Deaf people in four generations. We show that many of the several cases of deafness are the result of 35delG homozygosity or 35delG/Q57X compound heterozygosity at the connexin26 locus. A considerable range of audiographic phenotypes was observed. The combined effects of a high population frequency of mutant alleles, and of positive assortative marriage among the Deaf, led to an infrequently observed recessive pedigree pattern.

The origin and loss of the ubiquitin activating enzyme gene on the mammalian Y chromosome

Mammalian sex chromosomes are thought to be descended from a homologous pair of autosomes: a testis-determining allele which defined the Y chromosome arose, recombination between the nascent X and Y chromosomes became restricted and the Y chromosome gradually lost its non-essential genetic functions. This model was originally inferred from the occurrence of few Y-linked genetic traits, pairing of the X and Y chromosomes during male meiosis and, more recently, the existence of X-Y homologous genes. The comparative analysis of such genes is a means by which the validity of this model can be evaluated. One well-studied example of an X-Y homologous gene is the ubiquitin activating enzyme gene ( UBE1 ), which is X-linked with a distinct Y-linked gene in many eutherian ('placental') and metatherian (marsupial) mammals. Nonetheless, no UBE1 homologue has yet been detected on the human Y chromosome. Here we describe a more extensive study of UBE1 homologues in primates and a prototherian mammal, the platypus. Our findings indicate that UBE1 lies within the X-Y pairing segment of the platypus but is absent from the human Y chromosome, having been lost from the Y chromosome during evolution of the primate lineage. Thus UBE1 illustrates the key steps of 'autosomal to X-specific' evolution of genes on the sex chromosomes.

Prelingual deafness: high prevalence of a 30delG mutation in the connexin 26 gene

Prelingual non-syndromic (isolated) deafness is the most frequent hereditary sensory defect. In >80% of the cases, the mode of transmission is autosomal recessive. To date, 14 loci have been identified for the recessive forms (DFNB loci). For two of them, DFNB1 and DFNB2, the genes responsible have been characterized; they encode connexin 26 and myosin VIIA, respectively. In order to evaluate the extent to which the connexin 26 gene (Cx26) contributes to prelingual deafness, we searched for mutations in this gene in 65 affected Caucasian families originating from various countries, mainly tunisia, France, New Zealand and the UK. Six of these families are consanguineous, and deafness was shown to be linked to the DFNB1 locus, 10 are small non consanguineous families in which the segregation of the trait has been found to be compatible with the involvement of DFNB1, and in the remaining 49 families no linkage analysis has been performed. A total of 62 mutant alleles in 39 families were identified. Therefore, mutations in Cx26 represent a major cause of recessively inherited prelingual deafness since according to the present results they would underlie approximately half of the cases. In addition, one specific mutation, 30delG, accounts for the majority (approximately 70%) of the Cx26 mutant alleles. It is therefore one of the most frequent disease mutations so far identified. Several lines of evidence indicate that the high prevalence of the 30delG mutation arises from a mutation hot spot rather than from a founder effect. Genetic counseling for prelingual deafness has been so far considerably impaired by the difficulty in distinguishing genetic and non genetic deafness in families presenting with a single deaf child. Based on the results presented here, the development of a simple molecular test could be designed which should be of considerable help.

Genes located in and near the human pseudoautosomal region are located in the X-Y pairing region in dog and sheep

We cloned and mapped the dog and/or sheep homologues of two human pseudoautosomal genes CSF2RA and ANT3. We also cloned and mapped dog and/or sheep homologues of STS and PRKX, which are located nearby on the differential region of the human X and have related genes or pseudogenes on the Y. STS, as well as CSF2RA, mapped to the tips of the short arm of the sheep X and Y (Xp and Yp), and STS and PRKX, as well as ANT3, mapped to the tips of the dog Xp and Y long arm (Yq). These locations within the X-Y pairing regions suggest that the regions containing all these human Xp22.3-Xpter genes are pseudoautosomal in dog and sheep. This supports the hypothesis that a larger pseudoautosomal region (PAR) shared by eutherian groups was disrupted by chromosomal rearrangements during primate evolution. The absence of STS and ANT3 from the sex chromosomes in two prosimian lemur species must therefore represent a recent translocation from their ancestral PAR, rather than retention of a smaller ancestral PAR shared by mouse.

The candidate sex-reversing DAX1 gene is autosomal in marsupials: implications for the evolution of sex determination in mammals

The human X-linked DAX1 gene was cloned from the region of the short arm of the human X found in duplicate in sex-reversed Xdup Y females (E. Zanaria et al., 1994, Nature 372: 635-641). DAX1 is suggested to be required for ovarian differentiation and to play an important role in mammalian sex determination or differentiation pathways. Its proposed dose-dependent effect on sexual development suggests that DAX1 could represent an evolutionary link with an ancestral sex-determining mechanism that depended on the dosage of an X-linked gene. Furthermore, DAX1 could also represent the putative X-linked switch gene, which independently controls sexual dimorphisms in marsupial mammals in an X-dose-dependent manner (D.W. Cooper et al., 1993, Semin. Dev. 4: 117-128). If DAX1 has a present role in marsupial sexual differentiation or had an ancestral role in mammalian sex determination, it would be expected to lie on the marsupial X chromosome, despite the autosomal localization of other human Xp genes. We therefore cloned and mapped the DAX1 gene in the tammar wallaby (Macropus eugenii). DAX1 was located on wallaby chromosome 5p near other human Xp genes, indicating that it was originally autosomal and that it is not involved in X-linked dose-dependent sex determination in an ancestral mammal nor in marsupial sexual differentiation.

Shared synteny between human chromosome 10 and chromosome 1 of the marsupial tammar wallaby, Macropus eugenii

Marsupial homologs of the human chromosome 10 loci IL2RA, HK1, and PLAU have been cloned and mapped by fluorescence in situ hybridization to chromosome 1q of the tammar wallaby, Macropus eugenii. Relative distance measurements of the hybridization signals on M. eugenii chromosome 1 show that marsupial homologs of human (HSA) 10p IL2RA and 10q HK1/PLAU flank the marsupial homologs of the human 5q gene IL5 and the human 15q imprinted genes SNRPN and ZNF127. The shared synteny, therefore, does not necessarily mean that HSA 10 represents an ancestral grouping; rather, it suggests that HSA 10p and HSA 10q represent two different ancestral mammalian units which fused directly in primates and were incorporated independently into two different regions of the same chromosome in marsupials.

Comparative mapping identifies the fusion point of an ancient mammalian X-autosomal rearrangement

Previous comparisons of gene location in the three major groups of mammals (eutherians, marsupials, and monotremes) have suggested that the long arm of the human X represents the ancestral mammalian X chromosome, whereas the short arm represents an autosomal region(s) recently added to the eutherian X chromosome. To identify the fusion point of this ancient X-autosome rearrangement, we have mapped four genes, three of which map near the centromere of the human Xp, in marsupials and in a monotreme. We found that ARAF1, ALAS2, and GATA1 are located on the X chromosome in marsupials, and ALAS2 and GATA1 are also located on the X in the platypus. This implies that the proximal short arm of the human X chromosome, including the centromere, was part of the ancestral mammalian X chromosome. The fusion point between the conserved region and the recently added regions therefore maps to human Xp11.23, although gene order on the human X indicates that there has been some rearrangement of this region.

The human/mouse imprinted genes IGF2, H19, SNRPN and ZNF127 map to two conserved autosomal clusters in a marsupial

The four genes IGF2, H19, SNRPN and ZNF127 are imprinted in mouse and human. IGF2 and H19 form one conserved cluster on the distal part of mouse chromosome 7 and human chromosome 11p15.5, whereas SNRPN and ZNF127 form another on the middle of mouse chromosome 7 and on human chromosome 15q11-13. We have explored the evolution of these imprinted regions by cloning and mapping IGF2, H19, SNRPN and ZNF127 homeologues in marsupials. Specifically, we wished to determine whether the arrangements were shared in eutherian and marsupial mammals, and to determine whether they lay on autosomes, or on the X, as might be predicted by the hypothesis that imprinting evolved from X inactivation. Using fluorescence in situ hybridization, we localized the marsupial homeologues of IGF2 and H19 to the distal part of tammar wallaby chromosome 2p and the marsupial homeologues of SNRPN and ZNF127 to the middle of chromosome 1q. Thus, these genes were originally organized in two separate autosomal clusters in the therian ancestor 180 million years ago, the conservation of which may suggest a functional relationship. The autosomal location of these clusters does not suggest a recent evolutionary relationship between imprinting and X chromosome inactivation.

Localization of urokinase to focal adhesions by human fibrosarcoma cells synthesizing recombinant vitronectin

Cell surface plasminogen activators have been proposed to participate in cell migration and invasion by activating both intracellular signaling pathways and extracellular proteolysis. Urokinase-type plasminogen activator (uPA) is secreted from many cell types and localizes to focal contact areas when cells are seeded onto the plasma protein vitronectin. Induction of vitronectin synthesis during migration of neural crest cells and growth of certain tumors suggests that the de novo synthesis and deposition of vitronectin into the tissue matrix may remodel the matrix to provide an environment suitable for cell migration and (or) tumor invasion. To investigate the effects of vitronectin secretion and matrix deposition on the localization and activity of cell-associated uPA, HT-1080 fibrosarcoma cells were transfected with the Rc/CMV expression vector containing a vitronectin cDNA insert and stable cell lines expressing vitronectin were selected. Vitronectin-secreting cells were allowed to attach and spread on collagen- and fibronectin-coated substrates. Within 6 h, vitronectin was detected on the substrate; vitronectin synthesis was accompanied by the clustering of both the alpha v beta 5 vitronectin receptor and uPA into vinculin-containing focal adhesions. Although mock transfected cells formed small focal adhesions on both collagen and fibronectin, no co-localization of uPA or alpha v beta 5 to focal adhesions was evident in these cells. Vitronectin-secreting cells also exhibited decreased levels of plasminogen activation and increased levels of cell adhesion as compared with the mock transfected cells. These data demonstrate that the synthesis of vitronectin and its matrix association by transfected HT-1080 fibrosarcoma cells results in localization of uPA to alpha v beta 5 containing focal adhesions, decreased cell surface uPA activity, and an increase in cell adhesion.

Alpha v beta 5 integrin receptor-mediated endocytosis of vitronectin is protein kinase C-dependent

Previous studies have demonstrated that the alpha v beta 5 integrin receptor functions in the endocytosis and degradation of matrix-bound vitronectin by human skin fibroblasts (Panetti, T. S., and McKeown-Longo, P. J. (1993) J. Biol. Chem. 268, 11988-11993; Panetti, T. S., and McKeown-Longo, P. J. (1993) J. Biol. Chem. 268, 11492-11495). These earlier studies demonstrated that vitronectin degradation was inhibited by either antibodies to the beta 5 integrin or exogenous heparin, suggesting that both integrin receptors and cell surface heparan sulfate proteoglycans are involved in the endocytosis and degradation of vitronectin. The present study was done to define intracellular signaling pathways involved in endocytosis of vitronectin and to evaluate the relative contribution of cell surface heparan sulfate proteoglycans and the alpha v beta 5 integrin in the activation of these signaling pathways. The addition of the phorbol ester phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, to monolayers of human skin fibroblasts, increased vitronectin degradation. Staurosporine and calphostin C, inhibitors of protein kinase C, blocked internalization and subsequent degradation of vitronectin, while KT5720, an inhibitor of protein kinase A, had no effect on the degradation of vitronectin. PMA was also able to reverse the inhibition of vitronectin degradation seen when cells were pretreated with heparinase or incubated with exogenous heparin. In contrast, the inhibitory effect of either RGD peptides or anti-alpha v beta 5 antibodies on vitronectin degradation were not overcome by the addition of PMA. These data suggest that the internalization of vitronectin from the matrix is mediated by the alpha v beta 5 integrin following activation of protein kinase C.

A eutherian X-linked gene, PDHA1, is autosomal in marsupials: a model for the evolution of a second, testis-specific variant in eutherian mammals

We report the cloning and mapping of a gene (PDHA) for the pyruvate dehydrogenase E1 alpha subunit in marsupials. In situ hybridization and Southern blot analysis show that PDHA is autosomal in marsupials, mapping to chromosome 3q in Sminthopsis macroura and 5p in Macropus eugenii. Since these locations represent a region that was translocated to the p arm of the human X chromosome following marsupial/eutherian divergence, we suggest that the marsupial PDHA gene is homologous to PDHA1, the somatic eutherian isoform located on human Xp and mouse X. Only one copy of PDHA is found in marsupials, whereas a second, testis-specific, intronless form is observed in eutherian mammals. We also suggest that translocation of PDHA to the eutherian X chromosome, which is inactivated during spermatogenesis, led to the evolution of a second testis-specific locus by retroposition to an autosome.

Naming as a function of linguistic form-class and object categories

We examined whether children rely on linguistic information (i.e. mass vs. count nouns) or object category information (i.e. objects vs. substances) when they name things. A grinder test was used, in which substances (e.g. water) maintain identity through transformation but objects (e.g. a cup) do not. Thirty children aged three through six were asked if the same name could be used for the same item after transformation. The items included pairs of amorphous substances and discrete objects (e.g. water--a cup), perceptually similar discrete objects (e.g. chalk--a crayon), and food items (e.g. corn--a bean). Children accepted the same name for food, ignoring linguistic information, and for objects, relying on linguistic information. In Experiment 2, 32 children aged five through eight were asked if the same name could be used for unfamiliar hardware and food items after transformation when they were labelled by nonsense mass and count nouns. Children tended to use the same name for food, relying on perceptual information. These results are discussed in terms of the active conceptualization about names of objects in relation to object characteristics.

Marsupial Y chromosome encodes a homologue of the mouse Y-linked candidate spermatogenesis gene Ube1y

The mammalian subclass Theria consists of infraclasses Metatheria (marsupials) and Eutheria ('placentals') which diverged from each other 120-150 million years before present (Myr BP). Both infraclasses have Y chromosome-dependent testis determination but direct molecular evidence linking the Metatherian and Eutherian Y chromosomes is lacking. Comparative analyses indicate that three mammalian genes have remained Y-linked for at least 80 Myr, since the divergence of the Eutherian orders from a common ancestor. These are Zfy, a gene encoding a transcription factor of the zinc-finger type; Sry, the putative primary testis-determining gene; and Ube1y (formerly Sby or A1s9Y-1), a candidate for the mouse spermatogenesis gene Spy, encoding a ubiquitin-activating enzyme E1 homologue. Although in marspials Zfy homologues are autosomal, a Y homologue of Sry has recently been isolated. We report here the identification of a functional marsupial Y-linked homologue of the murine Ube1y gene establishing that Metatherian and Eutherian Y chromosomes diverged from a common ancestor. This extreme conservation indicates that Ube1y plays a critical role in male development.

Statistical analysis of in situ hybridization data: derivation and use of the zmax test

There are many situations in which grain distributions resulting from in situ hybridization of radioactively labeled probes to unique genes should be subjected to a statistical analysis. However, the problems posed by analysis of in situ hybridization data are not straightforward, and no completely satisfying method is currently available. We have developed a procedure in which the major and any number of minor site(s) of hybridization may be specifically located and the significance of each tested. This zmax procedure first tests the overall distribution for departure from randomness and then identifies significantly overlabeled whole chromosomes (or chromosome arms or other large segments), a process that may be repeated to pinpoint significantly overlabeled regions within these chromosomes. We describe in detail the derivation of the zmax statistic, present tables of significant zmax levels, and show with examples how zmax is used in tests of significance of in situ hybridization data.

The prevalence of mandibular dysfunction. Part I: Sex and age distribution of related signs and symptoms

This study concludes the following: 1. Mandibular dysfunction is extensive. 2. Age and sex differences are apparent with various signs and symptoms. 3. Women and younger patients tend to respond positively more often than men and older patients to questions relating to subjective TMJ and muscle symptoms. 4. Objective TMJ and occlusal signs show little age or sex differentiation. 5. Positive responses to questions regarding bruxism were more common in men. 6. Age and sex differences in the prevalence of mandibular dysfunction may be influenced by the method of investigation (anamnestic versus clinical examination) and by the signs and symptoms selected to be representative of this disorder. When compared with the findings of earlier investigations, the conclusions suggest that social, cultural, psychologic, sex, and age differences contribute to the responses to questions pertaining to mandibular dysfunction. However, this may not be an accurate reflection of the prevalence of mandibular dysfunction since the objective signs do not show the age and sex differences that the subjective symptoms indicate. Therefore, additional studies are needed to correlate all data to establish a more reliable profile of both signs and symptoms of mandibular dysfunction.

Helping minority and low-income psychotherapy patients "Tell It Like It Is"

The development and field testing of an instructional slide/cassette program entitled "Tell It Like It Is" are described. The program is a major component of a three-year study to assess the effects of patient orientation, therapist orientation, and the interaction of the two upon the psychotherapy process and outcome for working class and low income Mexican American, Black American, and Anglo American patients.