A region of human chromosome 9p required for testis development contains two genes related to known sexual regulators

Deletion of the distal short arm of chromosome 9 (9p) has been reported in a number of cases to be associated with gonadal dysgenesis and XY sex reversal, suggesting that this region contains one or more genes required in two copies for normal testis development. Recent studies have greatly narrowed the interval containing this putative autosomal testis-determining gene(s) to the distal portion of 9p24.3. We previously identified DMRT1, a human gene with sequence similarity to genes that regulate the sexual development of nematodes and insects. These genes contain a novel DNA-binding domain, which we named the DM domain. DMRT1 maps to 9p24. 3 and in adults is expressed specifically in the testis. We have investigated the possible role of DM domain genes in 9p sex reversal. We identified a second DM domain gene, DMRT2, which also maps to 9p24.3. We found that point mutations in the coding region of DMRT1 and the DM domain of DMRT2 are not frequent in XY females. We showed by fluorescence in situ hybridization analysis that both genes are deleted in the smallest reported sex-reversing 9p deletion, suggesting that gonadal dysgenesis in 9p-deleted individuals might be due to combined hemizygosity of DMRT1 and DMRT2.

Effects of phenylbutyrate on proliferation and apoptosis in human prostate cancer cells in vitro and in vivo

Phenylbutyrate (PB) is a potent differentiating agent and currently under investigation for the treatment of prostate cancer (CaP) and other malignancies. We have studied the impact of PB in vitro and in vivo on differentiation, proliferation and apoptosis in the LNCaP and LuCaP 23.1 prostate cancer xenograft models. In vitro we found that i) PB increased PSA secretion/cell, ii) inhibited cell proliferation in a time- and dose-dependent manner resulting in a cell cycle arrest in G1-phase and iii) induced apoptosis at concentrations of 2.5 mM after 3 days of treatment. In PB treated animals tumor growth stabilized or regressed. Combination of castration and PB treatment had a synergistic antiproliferative effect. The growth-inhibitory and differentiating properties and a low toxicity profile of PB provide rationale for further clinical studies in patients with CaP.

Y chromosome deletions in azoospermic and severely oligozoospermic men undergoing intracytoplasmic sperm injection after testicular sperm extraction

Y chromosome deletions encompassing the AZFc region have been reported in 13% of azoospermic men and 7% of severely oligozoospermic men. We examined the impact of these Y deletions on the severity of testicular defects in 51 azoospermic men undergoing intracytoplasmic sperm injection (ICSI) after testicular sperm extraction (TESE) and 30 men with severe oligozoospermia undergoing ICSI after ejaculation of spermatozoa. In addition, five azoospermic patients shown previously to have Y chromosome deletions underwent histological evaluation of their previously obtained testis biopsy specimens. A further 27 azoospermic men underwent TESE-ICSI, but not Y chromosome DNA testing. Ten of 51 azoospermic men (20%) who underwent TESE-ICSI and Y-DNA testing were found to be deleted for portions of the Y chromosome AZFc region. Of these 10, five had spermatozoa retrievable from the testis, and in two cases the wives became pregnant. Of the 41 azoospermic men with no Y chromosome deletion, 22 (54%) had spermatozoa retrievable from the testis, and in 12 cases (29%) the wives became pregnant. Four of 30 (13%) severely oligozoospermic patients were found to be deleted for AZFc and in three (75%) of these pregnancy was achieved. The other 26 severely oligozoospermic couples who had no AZFc deletions underwent ICSI, and 12 (46%) have an ongoing or delivered pregnancy. The embryo implantation rate was not significantly different for azoospermic (22%), oligozoospermic (16%), Y-deleted (14%) or Y-intact (18%) men. Of the total of 19 infertile men who had Y chromosome deletions, 14 had deletions within Y chromosome intervals 6D-6F, in the AZFc region. Twelve of those 14 had some spermatozoa (however few in number) in the ejaculate or testis. Five of the Y-deleted men had deletions that extended more proximally on the Y chromosome, and in none of these could any spermatozoa be observed in either ejaculate or testis. These results support the concept that, in azoospermic or oligozoospermic men with Y chromosome deletions limited to intervals 6D-6F (AZFc), there are generally very small numbers of testicular or ejaculated spermatozoa. Larger Y deletions, including and extending beyond the AZFc region and encompassing more Y genes, tend to be associated with a total absence of testicular spermatozoa. In those cases where spermatozoa were retrieved, the presence of Y deletions had no obvious impact on fertilization or pregnancy rate.

Evidence for a noise gain control mechanism in human vision

For small, brief targets incremental threshold is known to obey the de Vries-Rose law: threshold rises in direct proportion to the square-root of background intensity. We present data demonstrating a square-root law for brightness matching as well. The square-root law for brightness is obtained over the full range of scotopic vision, and the low intensity end of photopic vision. The classic theory of de Vries and Rose explains the square-root law on the basis of increased variability of the photon count as the background increases. Our brightness matching data instead indicates that the mean signal level is reduced by a factor which is inversely proportional to the standard deviation of the photon count. This result is consistent with the idea that in the retina there exists a gain control mechanism that is sensitive to the variance in the photon input, rather than to the mean illuminance. The importance of this idea to the modelling of retinal gain controls is discussed.

A novel monoclonal antibody 107-1A4 with high prostate specificity: generation, characterization of antigen expression, and targeting of human prostate cancer xenografts

Monoclonal antibodies with high specificity for prostate tissue are of interest for prostate cancer research and treatment. Reactivity and specificity of a new murine monoclonal antibody, 107-1A4, was assessed by immunohistochemistry, ELISA and indirect immunofluorescence (IDIF). 107-1A4 stained all normal and malignant prostate tissue specimens while reactivity to non-prostate tissue was limited to the tubules of the normal kidney and renal cell carcinoma. Twenty two human cell lines were included in the reactivity survey; only the immunogen prostate cancer line LNCaP reacted with 107-1A4. Seminal plasma proteins PSA, PAP, PSMA, and PSP-94 were determined not to be the 107-1A4 antigen.

LNCaP produces both putative zymogen and inactive, free form of prostate-specific antigen

BACKGROUND

Our objective was to investigate the presence of prostate specific antigen (PSA) and alpha-1-antichymotrypsin (ACT) mRNA and protein in prostate cancer cell lines, and the complexing characteristics of expressed PSA.

METHODS

RT-PCR, immunohistochemistry, and Western blots were employed. Trypsin treatment of PSA was performed to establish the possible presence of an activatable form of PSA.

RESULTS

ACT mRNA and protein were detected in LNCaP, PC-3, and DU 145 by RT-PCR and by immunohistochemistry, respectively. Only LNCaP cells were positive for PSA mRNA and protein. LNCaP expressed approximately 30% active PSA, approximately 40% putative zymogen form of PSA, and approximately 30% stably inactive PSA.

CONCLUSIONS

We have shown that the majority of PSA expressed by LNCaP cells is present in free, noncomplexed forms in the conditioned media. A portion (40%) can be activated by trypsin, while the rest is stably inactive PSA. LNCaP cells may serve as a source of the "unreactive" PSA present in prostate cancer patients' serum.

Reconstructing hominid Y evolution: X-homologous block, created by X-Y transposition, was disrupted by Yp inversion through LINE-LINE recombination

The human X and Y chromosomes share many blocks of similar DNA sequence. We conducted mapping and nucleotide sequencing studies of extensive, multi-megabase homologies between Yp and Xq21, which do not recombine during male meiosis. We confirmed and built upon previous evidence that a Yp inversion had occurred during evolution: a single contiguous segment of Xq21 is homologous to two non-contiguous segments of Yp. We precisely defined and sequenced the inversion breakpoints, obtaining evidence that the inversion was mediated by recombination between LINE-1 elements in otherwise non-homologous regions. This inversion appears to have followed a single transposition of an approximately 4 Mb segment from the X to the Y chromosome. These events jointly account for the present arrangement of Yp-Xq21 homologous sequences. Based on Southern blotting studies of primates and of humans drawn from diverse populations, we conclude that both the X-Y transposition and the subsequent, LINE-mediated Yp inversion occurred after the divergence of hominid and chimp lineages but before the radiation of extant human populations. This evolutionary scenario is consistent with our finding of 99.3 +/- 0.2% nucleotide identity between the X and Y chromosomes within the transposed region, which suggests that the transposition occurred approximately 3-4 million years ago, near the time of emergence of Homo . Comparative sequencing of the entire human X and Y chromosomes may reveal a succession of transpositions, inversions and other rearrangements underlying the complex pattern of sequence similarities between the present-day sex chromosomes. With the possible exception of cubitus valgus, phenotypic features of Turner syndrome are absent in individuals monosomic for Yp-Xq21 homologous sequences, suggesting that most of the critical 'Turner genes' are found elsewhere on the X and Y chromosomes.

A model of Weber and noise gain control in the retina of the toad Bufo marinus

We present several variations of a model of gain control in the retina of the toad Bufo marinus, and use them to fit the threshold-vs-intensity data of an actual toad ganglion cell [Donner et al. (1990). Journal of General Physiology, 95, 733-753]. Our models are based on a proposal by Donner et al. that the gain (neural spike per photon ratio) of toad ganglion cells is set by a sequence of two retinal gain control stages. The first stage consists of a Weber gain control mechanism at the level of the red rods. The second is a more proximal "noise gain" stage, which multiplies the (incremental) input signal by a factor that is inversely proportional to the standard deviation of the random ganglion cell input and, under conditions that produce the de Vries-Rose threshold law, is also proportional to the standard deviation of the photon fluctuations within the ganglion cell receptive field. We demonstrate that noise gain control arises naturally from modeling ganglion cell spike generation with either of two common types of spike generation models: integrate-and-fire models or threshold accommodation models. We simulate the process of spike generation in both types of models and show that either model can account for the basic overall shape of the toad t.v.i. curve. However, although integrate-and-fire models appropriately generate noise gain control, they cannot quantitatively fit the threshold data with realistic retinal parameters. Integrate-and-fire models also fail to account for the observed relationship between the generator potential of the ganglion cell and its spiking probability. A threshold accommodation model with realistic retinal parameters, on the other hand, can account for both the threshold data and the generator potential-spike probability relationship. When a Weber gain stage is added to the model at the photoreceptor level, the resulting two-stage gain control model is shown to account quantitatively for the ganglion cell t.v.i. curve of Bufo marinus over the full range of background levels studied by Donner et al.

A very sensitive coupled luminescent assay for cytotoxicity and complement-mediated lysis

The demand for convenient and sensitive means of measuring cytotoxicity and complement-mediated killing is likely to be increased by the recent identification of Complement Factor H, an important regulatory protein of both the classical and alternate pathways of complement, as a tumor-associated antigen. Here we describe a simple luminometric assay capable of detecting the death of approximately 0.03 nucleated human-cell equivalent or approximately 1 rabbit-erythrocyte equivalent. The assay measures the release of glyceraldehyde-3-phosphate dehydrogenase (G3PDH) from dead or damaged cells by coupling its enzymatic activity to production of ATP, which in turn is measured by well-known methods involving firefly luciferase. This is accomplished by means of a reaction series in which the activity of G3PDH is coupled with that of phosphoglycerate kinase, the next enzyme in the glycolytic pathway. As described, the assay uses inexpensive, commercially available reagents. This coupled assay was used to demonstrate that an anti-factor-H antibody is capable of enhancing complement-mediated killing of the Raji cancer cell line by > 1000%.

Noise adaptation in integrate-and fire neurons

The statistical spiking response of an ensemble of identically prepared stochastic integrate-and-fire neurons to a rectangular input current plus gaussian white noise is analyzed. It is shown that, on average, integrate-and-fire neurons adapt to the root-mean-square noise level of their input. This phenomenon is referred to as noise adaptation. Noise adaptation is characterized by a decrease in the average neural firing rate and an accompanying decrease in the average value of the generator potential, both of which can be attributed to noise-induced resets of the generator potential mediated by the integrate-and-fire mechanism. A quantitative theory of noise adaptation in stochastic integrate-and-fire neurons is developed. It is shown that integrate-and-fire neurons, on average, produce transient spiking activity whenever there is an increase in the level of their input noise. This transient noise response is either reduced or eliminated over time, depending on the parameters of the model neuron. Analytical methods are used to prove that nonleaky integrate-and-fire neurons totally adapt to any constant input noise level, in the sense that their asymptotic spiking rates are independent of the magnitude of their input noise. For leaky integrate-and-fire neurons, the long-run noise adaptation is not total, but the response to noise is partially eliminated. Expressions for the probability density function of the generator potential and the first two moments of the potential distribution are derived for the particular case of a nonleaky neuron driven by gaussian white noise of mean zero and constant variance. The functional significance of noise adaptation for the performance of networks comprising integrate-and-fire neurons is discussed.

The DAZ gene cluster on the human Y chromosome arose from an autosomal gene that was transposed, repeatedly amplified and pruned

It is widely believed that most or all Y-chromosomal genes were once shared with the X chromosome. The DAZ gene is a candidate for the human Y-chromosomal Azoospermia Factor (AZF). We report multiple copies of DAZ (> 99% identical in DNA sequence) clustered in the AZF region and a functional DAZ homologue (DAZH) on human chromosome 3. The entire gene family appears to be expressed in germ cells. Sequence analysis indicates that the Y-chromosomal DAZ cluster arose during primate evolution by (i) transposing the autosomal gene to the Y, (ii) amplifying and pruning exons within the transposed gene and (iii) amplifying the modified gene. These results challenge prevailing views of sex chromosome evolution, suggesting that acquisition of autosomal fertility genes is an important process in Y chromosome evolution.

Additional rules for the transformed up-down method in psychophysics

In a classic paper, Levitt (1971) described an adaptive procedure for estimating points on the psychometric function known as the transformed up-down method. Levitt discussed the assumptions of the method and presented a brief table with simple rules that converge to a few different points on the psychometric function. Levitt's original table contains only the simplest rules, and sparsely covers the range of the psychometric function. This paper provides a table with previously unpublished rules which cover the range of the psychometric function at 5% intervals. There is a brief review of the major issues in adaptive testing. Technical issues such as the mean length and logical construction of the new rules are discussed.

Mouse autosomal homolog of DAZ, a candidate male sterility gene in humans, is expressed in male germ cells before and after puberty

Deletion of the Azoospermia Factor (AZF) region of the human Y chromosome results in spermatogenic failure. While the identity of the critical missing gene has yet to be established, a strong candidate is the putative RNA-binding protein DAZ (Deleted in Azoospermia). Here we describe the mouse homolog of DAZ. Unlike human DAZ, which is Y-linked, in mouse the Dazh (DAZ homolog) gene maps to chromosome 17. Nonetheless, the predicted amino acid sequences of the gene products are quite similar, especially in their RNP/RRM (putative RNA-binding) domains, and both genes are transcribed predominantly in testes; the mouse gene is transcribed at a lower level in ovaries. Dazh transcripts were not detected in testes of mice that lack germ cells. In testes of wildtype mice, Dazh transcription is detectable 1 day after birth (when the only germ cells are prospermatogonia), increases steadily as spermatogonial stem cells appear, plateaus as the first wave of spermatogenic cells enters meiosis (10 days after birth), and is sustained at this level thereafter. This unique pattern of expression suggests that Dazh participates in differentiation, proliferation, or maintenance of germ cell founder populations before, during, and after the pubertal onset of spermatogenesis. Such functions could readily account for the diverse spermatogenic defects observed in human males with AZF deletions.

Stochastic retinal mechanisms of light adaptation and gain control

Under appropriate experimental conditions, the threshold intensity of a visual stimulus varies as the square-root of the background illuminance. This square-root law has been observed in both psychophysical threshold experiments and in measurements of the thresholds of individual ganglion cells. A signal detection theory developed in the 1940s by H. L. de Vries and A. Rose, and since elaborated by H. B. Barlow and others, explains the square-root law on the basis of 'noise' due to fluctuations in the number of photon absorptions per unit area and unit time at the cornea. An alternative account of the square-root law--and also other threshold-vs-intensity slopes--is founded on the assumption of physiological gain control (W. A. H. Rushton, Proc, Roy. Soc. (London) B 162, 20-46, 1965; W. S. Geisler, J. Physiol. (London) 312, 165-179, 1979). In this paper, a neural model of light adaptation and gain control is described that shows how these two accounts of the square-root law can be reconciled by a stochastic gain control mechanism whose gain depends on the photon fluctuation level. The process by which spikes are generated in a ganglion cell is modeled in terms of a stochastic integrate-and-fire mechanism; this model is used to quantitatively fit toad retinal ganglion cell threshold data. A psychophysical model is then outlined showing how a statistical observer could analyze the ganglion cell spike trains generated by 'signal' and 'noise' trials in order to statistically discriminate the two conditions. The model is also shown to account for some dynamic aspects of ganglion cell responses, including ON- and OFF-responses. The neural light adaptation model predicts that--under the proper conditions--brightness matching judgments will also be subject to a square-root law. Experimental tests of the model under superthreshold conditions are proposed.

Comparison of nucleoside transport binding sites in rabbit iris-ciliary body and cultured rabbit nonpigmented ciliary epithelial cells

The iris-ciliary body (ICB) is a site of action for topically applied antiglaucoma drugs. Moreover, adenosine has been implicated as a modulator of aqueous humor dynamics. The present study compares the binding of the nucleoside transporter probe, [3H]nitrobenzylthioinosine ([3H]NBMPR), to homogenates prepared from rabbit ICB and a cultured rabbit nonpigmented ciliary epithelial cell line (NPE) to determine whether NPE can be used as an experimental model to study the nucleoside transporter. Linear transformation of the saturation binding data revealed that [3H]NBMPR binds to a homogeneous population of binding sites with similar binding affinities (Kd = 0.3 +/- 0.1 and 0.6 +/- 0.1 nM in NPE and ICB, respectively). However, the maximal binding capacity in NPE (Bmax = 288 +/- 54 fmol/mg protein) was significantly higher than that in ICB (Bmax = 154 +/- 17 fmol/mg protein). Selected inhibitors of the nucleoside transport system and structural analogs of adenosine inhibited the binding in both homogenate preparations with a similar rank order of potency: NBMPR > DPY > CV-1808 > CHA > R-PIA > S-PIA > 2-CADO > NECA. The results suggest that NPE is a useful model which could be used for characterizing the nucleoside transporter in ICB and for the screening of nucleoside transport inhibitors as potential antiglaucoma drugs.

Effects of MaxEPA on salt-induced hypertension: relationship to [3H]nitrobenzylthioinosine binding sites

We investigated the effects of dietary MaxEPA (a major source of eicosapentaenoic acid in fish oil) supplementation on blood pressure (BP) responses and heart rate (HR) of Dahl salt-sensitive (SS) rats fed low (0.4% NaCl) and high (8.0% NaCl) sodium diets. During a four week treatment period, BP remained normotensive in rats on low salt diet but was significantly elevated in those on high salt diet, causing 50% mortality. MaxEPA diminished the BP elevation and prevented the high salt-induced mortality. HR was not affected by either salt diet alone but was reduced in the presence of MaxEPA. At the end of the treatment period, the distribution of [3H]nitrobenzylthioinosine ([3H]NBMPR) binding, a putative marker of adenosine transport and metabolism, was estimated in selected rat tissues in order to evaluate the role of the purinergic system in the BP lowering effect of MaxEPA. Maximal [3H]NBMPR binding capacity (Bmax) in the kidney and platelets were 39% and 82% lower, respectively, in rats on high salt diet than in those on low salt diet. MaxEPA significantly blunted the decrease in Bmax in the kidney but not in platelets and increased Bmax in heart (48%) of low salt group. There were no changes in dissociation constants (Kd). The results suggest that MaxEPA can attenuate salt-induced hypertension, reduce salt-induced mortality and protect the integrity of kidney NBMPR binding sites in salt-induced hypertension.

Diverse spermatogenic defects in humans caused by Y chromosome deletions encompassing a novel RNA-binding protein gene

We have detected deletions of portions of the Y chromosome long arm in 12 of 89 men with azoospermia (no sperm in semen). No Y deletions were detected in their male relatives or in 90 other fertile males. The 12 deletions overlap, defining a region likely to contain one or more genes required for spermatogenesis (the Azoospermia Factor, AZF). Deletion of the AZF region is associated with highly variable testicular defects, ranging from complete absence of germ cells to spermatogenic arrest with occasional production of condensed spermatids. We find no evidence of YRRM genes, recently proposed as AZF candidates, in the AZF region. The region contains a single-copy gene, DAZ (Deleted in AZoospermia), which is transcribed in the adult testis and appears to encode an RNA binding protein. The possibility that DAZ is AZF should now be explored.

Hopkins Symptom Checklist-25, Hmong version: a screening instrument for psychological distress

The Hopkins Symptom Checklist (HSCL-25; Mattsson, Williams, Rickels, Lipman, & Uhlenhuth, 1969) was translated into the Hmong language and administered to 159 Hmong adults, 73 nonclinical and 86 mental health clients. The instrument demonstrated internal consistency of .97 and had a split-half coefficient of .92 and test-retest reliability of .90. Mental health clients produced scores that were significantly higher than those of nonclinical participants on the Anxiety, Depression, and Total scores. Consistent with expectations, Hmong more intensely affected by the casualties of war, those currently unemployed, those older, and those with less education tended to report more symptoms of anxiety and depression. The Hmong version of the HSCL-25 provided a sensitivity of 100%, specificity of 78%, and overall accuracy of 89%, demonstrating that it is a useful screening tool for assessing general distress and anxiety problems in Hmong people.

Dimensions of suicide: perceptions of lethality, time, and agony

Two hundred ninety-one lay persons and 10 forensic pathologists rated the lethality, time, and agony for 28 methods of suicide for 4117 cases of completed suicide in Los Angeles County in the period 1988-1991. Whereas pathologists provided consistent ratings, lay persons demonstrated extreme variability and a tendency to inflate ratings of all three dimensions. Significant gender differences emerged, with females rating frequently used suicide methods more similarly to pathologists than the males did. Males who suicided used the most lethal and quickest methods whereas females selected methods varying in lethality, duration, and agony. African Americans were overrepresented in the use of the most lethal and quickest methods.

Structure and function of ribosomal protein S4 genes on the human and mouse sex chromosomes

The human sex-linked genes RPS4X and RPS4Y encode distinct isoforms of ribosomal protein S4. Insufficient expression of S4 may play a role in the development of Turner syndrome, the complex human phenotype associated with monosomy X. In mice, the S4 protein is encoded by an X-linked gene, Rps4, and is identical to human S4X; there is no mouse Y homolog. We report here the organization of the human RPS4X and RPS4Y and mouse Rps4 genes. Each gene comprises seven exons; the positions of introns are conserved. The 5' flanking sequences of human RPS4X and mouse Rps4 are very similar, while RPS4Y diverges shortly upstream of the transcription start site. In chickens, S4 is encoded by a single gene that is not sex linked. The chicken protein differs from human S4X by four amino acid substitutions, all within a region encoded by a single exon. Three of the four substitutions are also present in human S4Y, suggesting that the chicken S4 gene may have arisen by recombination between S4X- and S4Y-like sequences. Using isoform-specific antisera, we determined that human S4X and S4Y are both present in translationally active ribosomes. S4Y is about 10 to 15% as abundant as S4X in ribosomes from normal male placental tissue and 46,XY cultured cells. In 49,XYYYY cells, S4Y is about half as abundant as S4X. In 49,XXXXY cells, S4Y is barely detectable. These results bear on the hypothesized role of S4 deficiency in Turner syndrome.

The human Y chromosome: a 43-interval map based on naturally occurring deletions

A deletion map of the human Y chromosome was constructed by testing 96 individuals with partial Y chromosomes for the presence or absence of many DNA loci. The individuals studied included XX males, XY females, and persons in whom chromosome banding had revealed translocated, deleted, isodicentric, or ring Y chromosomes. Most of the 132 Y chromosomal loci mapped were sequence-tagged sites, detected by means of the polymerase chain reaction. These studies resolved the euchromatic region (short arm, centromere, and proximal long arm) of the Y chromosome into 43 ordered intervals, all defined by naturally occurring chromosomal breakpoints and averaging less than 800 kilobases in length. This deletion map should be useful in identifying Y chromosomal genes, in exploring the origin of chromosomal disorders, and in tracing the evolution of the Y chromosome.

A Hmong Adaptation of the Beck Depression Inventory

We developed the Hmong Adaptation of the Beck Depression Inventory (HABDI) and evaluated the instrument's psychometric characteristics. Also examined was the relationship between depression and demographic variables such as age, sex, length of stay in America, English-speaking ability, and social support in Hmong refugees. One hundred twenty-three Hmong living in Fresno County, between the ages of 18 and 66, participated in the study. The new measure demonstrated a high coefficient alpha (.93), and test-retest reliability (.92), and a significant mean score difference between the nondepressed and the depressed groups. Individual items were distributed evenly and correlated highly with the total depression score. The HABDI correctly identified 94% of depressed and 78% of nondepressed in the Hmong sample. The results suggest that quality of social support and years of education play important roles in buffering Hmong refugees against depression, whereas length of stay in America and number of social supports do not.

Contingency interaction analysis in psychotherapy

This article introduces (a) a computerized coding procedure that rates words and utterances in terms of emotion, cognition, and contract and (b) a contingency method of analyzing verbal interactions. Using transcripts of sessions conducted by 3 master therapists with 1 client, the rating procedure and contingency correlation analyses supported the study's hypotheses. Therapists' utterances were characterized by significantly different amounts of emotion, cognition, and contracts, indicating that communication styles varied in the relative emphasis placed on these attributes. Differences suggest that the therapists responded differently to emotional, cognitive, and contract utterances and that the client's responses were different across the 3 therapist interviews. Split halves of the interviews within therapists and within client sessions were not different, providing further evidence of reliability of the coding and contingency procedures.

Homologous ribosomal protein genes on the human X and Y chromosomes: escape from X inactivation and possible implications for Turner syndrome

We have isolated two genes on the human sex chromosomes, one on the Y and one on the X, that appear to encode isoforms of ribosomal protein S4. These predicted RPS4Y and RPS4X proteins differ at 19 of 263 amino acids. Both genes are widely transcribed in human tissues, suggesting that the ribosomes of human males and females are structurally distinct. Transcription analysis revealed that, unlike most genes on the X chromosome, RPS4X is not dosage compensated. RPS4X maps to the long arm of the X chromosome (Xq), where no other genes are known to escape X inactivation. Curiously, RPS4X maps near the site from which the X-inactivating signal is thought to emanate. On the Y chromosome, RPS4Y maps to a 90 kb segment that has been implicated in Turner syndrome. We consider the possible role of RPS4 haploinsufficiency in the etiology of the Turner phenotype.

Additional deletion in sex-determining region of human Y chromosome resolves paradox of X,t(Y;22) female

Whether a human embryo develops as a male or a female is determined by the presence of the Y chromosome. The sex-determining function lies entirely in interval 1A, inasmuch as most XX individuals with descended testes and normal male external genitalia carry this small region of the Y chromosome. We have localized an essential part of the sex-determining function to a portion of interval 1A, on the basis of the discovery of a female with a reciprocal Y;22 translocation and part of 1A deleted at the translocation breakpoint. Recently, a paradox has arisen with the report of four partially masculinized XX individuals who carry only a portion of interval 1A--a portion that does not overlap the deletion in the X,t(Y;22) female. These recent findings imply that the sex-determining function lies in the portion of 1A present in the four XX intersexes and not in the portion deleted in the X,t(Y;22) female. To explain the X,t(Y;22) individual, it was proposed that she was female because of a chromosomal position effect or delayed development of the gonadal soma. Here we report that the X,t(Y;22) female has a deletion of a second portion of interval 1A--a portion corresponding closely to that present in the XX intersexes. This resolves the apparent contradiction. Nonetheless, phenotype-genotype correlations suggest that two or more genetic elements in interval 1A may contribute to the sex-determining function of the Y chromosome. The X,t(Y;22) female lacks the ZFY gene but does not exhibit the complex phenotype known as Turner's syndrome, arguing against the hypothesis that ZFY is the Turner's syndrome gene on the Y chromosome.

Chromosomal localization of ZFX--a human gene that escapes X inactivation--and its murine homologs

The ZFY gene, found in the sex-determining region of the human Y chromosome, encodes a zinc-finger protein that may be the pivotal sex-determining signal. A closely related gene, ZFX, is found on the human X chromosome, and it may also function in sex determination. ZFX is one of a few genes on the human X chromosome that are known to escape X inactivation. We report the localization of ZFX, by meiotic linkage analysis and physical mapping, distal to POLA but proximal to DXS41 (p99-6), near the boundary of bands Xp21.3 and Xp22.1. (Our results suggest the following order of loci in Xp21-p22: cen-DMD-[GK,AHC]-DXS67 (pB24)-POLA-ZFX-[DXS41 (p99-6), DXS274 (CRI-L1391)]-DXS43 (pD2)-pter.) These findings contradict the model that escape from X inactivation is limited to genes near the short-arm telomere (i.e., in Xp22.3). Instead, escape from X inactivation is likely a property of several noncontiguous segments of the X chromosome. Curiously, in mouse, the homologous Zfx gene maps to X chromosome band D, near the center from which an X-inactivating signal is thought to spread. As judged by comparative mapping, it appears that an X-chromosomal segment that spans the ZFX and DMD genes has remained grossly intact during the divergence of mouse and human from a common ancestor. Conservation of this chromosomal segment may extent to marsupials, where homologs of the ZFX and DMD genes have been observed in proximity, but on an autosome. While autosomal homologs of ZFX have not been observed in other placental mammals, a locus derived from a processed Zfx transcript is found on mouse chromosome 10 band B3 or B4.

Mouse Zfx protein is similar to Zfy-2: each contains an acidic activating domain and 13 zinc fingers

The Zfy gene is located on the Y chromosome of placental mammals and encodes a zinc finger protein which may serve as the primary sex-determining signal. A related gene, Zfx, is similarly conserved on the X chromosome. Unlike that in most mammals, the mouse genome contains four homologous zinc finger loci: Zfy-1, Zfy-2, Zfx, and Zfa (on an autosome). We report that, in contrast to the mouse Zfy genes, Zfx is widely transcribed in embryos, newborns, and adults, both male and female. Moreover, Zfx transcripts contain long 3' untranslated sequences which are phylogenetically conserved. Zfa is a processed gene derived from Zfx. An analysis of cDNA clones demonstrated that Zfx encodes a 799-amino-acid protein that is 70% identical to the mouse Zfy-1 and Zfy-2 proteins. Zfx, Zfy-1, and Zfy-2 contain highly acidic amino-terminal domains and carboxy-terminal regions containing 13 zinc fingers. When fused to the DNA-binding domain of GAL4, the acidic domains of Zfx and Zfy-2 activated transcription in yeast cells.

Putative transcription activator with alternative isoforms encoded by human ZFX gene

The ZFY gene in the sex-determining region of the human Y chromosome encodes a protein with 13 zinc fingers, and may determine whether an embryo develops as a male or female. ZFX, a related gene on the human X chromosome, may also function in sex determination; it encodes a protein with a very similar zinc-finger domain and escapes X inactivation. ZFY and ZFX diverged from a common ancestral gene before the radiation of placental mammals, and retain a similar genomic organization. Analysis of complementary DNAs from the mouse Y-chromosomal homologues of ZFY indicates that these genes encode probable transcription activators. Here, we report that ZFX encodes a protein composed of a highly acidic amino-terminal domain, a basic putative nuclear-localization signal, and a carboxy-terminal zinc-finger domain. This combination of features, also found in the ZFY gene product, is typical of transcription activators. Alternative splicing generates ZFX transcripts encoding isoforms of 575 and 804 amino acids. These ZFX protein isoforms differ in the length of their acidic domains and may be functionally distinct.

Distal interphalangeal joint flexible implant arthroplasty

Twenty-one osteoarthritic distal interphalangeal joints in 13 patients were treated by flexible implant arthroplasty. Follow-up to 5 years showed results that were good to excellent, with only one complication, and a high degree of patient satisfaction. The procedure should be considered a good alternative to the more traditional distal interphalangeal joint arthrodesis.

ZFX has a gene structure similar to ZFY, the putative human sex determinant, and escapes X inactivation

The ZFX gene on the human X chromosome is structurally similar to the ZFY gene, which may constitute the sex-determining signal on the human Y chromosome. ZFY and ZFX diverged from a common ancestral gene, as evidenced by similarities in their intron/exon organization and exon DNA sequences. The carboxy-terminal exons of ZFY and ZFX both encode 13 zinc fingers; 383 of 393 amino acid residues are identical, and there are no insertions or deletions. Thus, the ZFY and ZFX proteins may bind to the same nucleic acid sequences. ZFY and ZFX are transcribed in a wide variety of XY and (in the case of ZFX) XX cell lines. Transcription analysis of human-rodent hybrid cell lines containing "inactive" human X chromosomes suggests that ZFX escapes X inactivation. This result contradicts the "dosage/X-inactivation" model, which postulated that sex is determined by the total amount of functionally interchangeable ZFY and ZFX proteins.

Percutaneous peritoneal lavage in blunt trauma patients: a safe and accurate diagnostic method

We reviewed the records of 395 patients seen from January 1983 through May 1988, who after sustaining blunt thoracoabdominal trauma had diagnostic peritoneal lavage (DPL) performed percutaneously by the Seldinger wire technique of Lazarus and Nelson. The test was considered grossly positive if 10 cc of blood were aspirated from the catheter immediately after its insertion into the peritoneal cavity. Microscopic criteria for positivity included more than 100,000 RBC or 500 WBC/cc of lavage return, elevated amylase or bilirubin, or the presence of vegetable fibers or bacteria. Seventy-two (18%) of the patients were true positives and 315 (80%) were true negatives. There were four false positives (1.3%) and one false negative (0.2%), giving the test a sensitivity of 99% and a specificity of 98%. Complications occurred in three patients, for a rate of 0.8%, and included catheter insertion into a large ovarian dermoid cyst, needle perforation of the ileum, and needle perforation of the sigmoid colon. This technique of DPL can consistently be performed much more rapidly than the open method. Therefore we conclude that percutaneous DPL is as accurate as, as safe as, and quicker than open DPL for determining intra-abdominal injury in blunt trauma patients.

Molecular detection of a Yp/18 translocation in a 45,X holoprosencephalic male

Prenatal diagnosis in a fetus with holoprosencephaly showed a 45,X karyotype and a suspected 18p abnormality. At birth, the fetus presented with normal male genitalia. Y chromatin was not cytogenetically detectable by Q-, G-, or G11-banding. Mosaicism for a cell line containing a Y chromosome was not observed in amniocytes, lymphocytes, or skin fibroblasts. Southern blot analysis for 11 different Y-DNA loci demonstrated the presence in the patient's genome of sequences derived from the short arm, centromeric region, and proximal long arm of the Y chromosome (intervals 1-5). The distal long arm of the Y (intervals 6 and 7) was absent. In situ hybridization with the Y-derived probe pDP105 showed silver grains over the short arm of the del(18) chromosome, suggesting a Y/18 translocation with loss of 18p and distal Yq material.

Characterization of a (Y;4) translocation by DNA hybridization

A phenotypically normal male with azoospermia was found to have a translocation between the short arm of the Y chromosome and the distal long arm of a chromosome 4. By cytogenetic analysis it could not be determined whether the translocation was reciprocal, nor whether it was balanced. In situ DNA hybridization with two pseudoautosomal and one Y-specific probe demonstrated that the breakpoint was on distal Yp and that there was Y chromosome material on 4q. Thus the translocation was reciprocal and could be characterized as t(Y;4)(pll;q32). There was no evidence for loss of Y-DNA sequences as judged by Southern blotting with Y-DNA probes. Thus the translocation may be balanced. We conclude that DNA hybridization can be used to refine considerably the cytogenetic analysis of such translocations.

The sex-determining region of the human Y chromosome encodes a finger protein

The presence or absence of the Y chromosome determines whether a mammalian embryo develops as a male or female. In humans, genetic deletion analysis of "sex-reversed" individuals has identified a small portion of the Y chromosome necessary and sufficient to induce testicular differentiation of the bipotential gonad. We report the cloning of a 230-kilobase segment of the human Y chromosome that contains some or all of the testis-determining factor gene (TDF), the master sex-determining locus. The cloned region spans the deletion in a female who carries all but 160 kilobases of the Y. Certain DNA sequences within this region were highly conserved during evolution; homologs occur on the Y chromosomes of all mammals examined. In particular, homologous sequences are found within the sex-determining region of the mouse Y chromosome. The nucleotide sequence of this conserved DNA on the human Y chromosome suggests that it encodes a protein with multiple "finger" domains, as first described in frog transcription factor IIIA. The encoded protein probably binds to nucleic acids in a sequence-specific manner, and may regulate transcription. Very similar DNA sequences occur on the X chromosome of humans and other mammals. We discuss the possibility that the Y-encoded finger protein is the testis-determining factor, and propose models of sex determination accommodating the finding of a related locus on the X chromosome. The presence of similar sequences in birds suggests a possible role not only in the XX/XY sex determination system of mammals, but also in the ZZ/ZW system of birds.

Linkage, physical mapping, and DNA sequence analysis of pseudoautosomal loci on the human X and Y chromosomes

The pseudoautosomal region of the human X and Y chromosomes is subject to frequent X-Y recombination during male meiosis. We report the finding of two pseudoautosomal loci, DXYS20 and DXYS28, characterized by highly informative restriction fragment length polymorphisms (RFLPs). The pseudoautosomal character of DXYS20 and DXYS28 was formally demonstrated by comparing their transmission to 45,X and to normal individuals. Studies of the inheritance of these loci reveal that the pseudoautosomal region, though highly recombinogenic, is subject to marked recombinational interference in male meiosis; no double recombinants were observed in 143 triply informative meioses, and the coefficient of coincidence is likely less than 0.45. In female meiosis, linkage of these pseudoautosomal RFLPs to strictly sex-linked RFLPs on the short arm of the X is readily detected; the genetic length of the pseudoautosomal region in female meiosis is at least 4 cM but not more than 18 cM. The genetic map of the human X chromosome is now defined from near the short-arm telomere to band q28 on the long arm. Locus DXYS20, which maps near the X and Y short-arm telomeres, is composed of long tandem arrays of 61-bp repeats. Occasional, seemingly random base-pair substitutions within these arrays of 61-bp repeats, in combination with marked variation in the size of the array, generate the high degree of DNA polymorphism at DXYS20.

An XXX male resulting from paternal X-Y interchange and maternal X-X nondisjunction

A 2-year-old boy was found to have a 47,XXX karyotype. Restriction-fragment-length-polymorphism analysis showed that, of his three X chromosomes, one is of paternal and two are of maternal origin. The results of Y-DNA hybridization were reminiscent of those in XX males in two respects. First, hybridization to Southern transfers revealed the presence in this XXX male of sequences derived from the Y-chromosomal short arm. Second, in situ hybridization showed that this Y DNA was located on the tip of the X-chromosomal short arm. We conclude that this XXX male resulted from the coincidence of X-X nondisjunction during maternal meiosis and aberrant X-Y interchange either during or prior to paternal meiosis.

Exchange of terminal portions of X- and Y-chromosomal short arms in human XX males

In most human 'XX males', DNA sequences normally found on Yp, the short arm of the Y chromosome, are present on Xp, the short arm of the X chromosome. To establish whether this transfer involves a terminal portion of Yp, and whether a terminal portion of Xp is lost in the process, we followed the inheritance of pseudoautosomal restriction fragment length polymorphisms in two XX-male families. One XX male apparently inherited the entire pseudoautosomal region of his father's Y chromosome and no part of the pseudoautosomal region of his father's X chromosome. The second XX male also inherited the entire pseudoautosomal region of his father's Y, but in addition inherited a proximal portion of the pseudoautosomal region of his father's X. These findings argue that XX males result from the transfer of a terminal portion of Yp onto Xp in exchange for a terminal portion of Xp (ref. 7). This implies that the testis-determining factor gene (TDF) maps distally in the strictly sex-linked portion of Yp, near the pseudoautosomal domain. The XX males described here appear to result from single (and, at least in the second case, unequal) crossovers proximal to the pseudoautosomal region on Yp and proximal to or within the pseudoautosomal region on Xp.

Familial premature ovarian failure due to an interstitial deletion of the long arm of the X chromosome

We describe a family in which four women had menstrual irregularities and a partial deletion of the long arm of the X chromosome (Xq). Three of the four women had premature ovarian failure (at the ages of 24 to 37 years). Chromosome-banding studies initially suggested that a terminal portion of Xq was deleted. However, DNA-hybridization studies showed that an interstitial portion of Xq was deleted and that the affected women had a 46,XX,del(X)(pter-q21.3::q27-qter) karyotype. These findings help clarify the role of Xq in ovarian function and indicate that the accurate description of such abnormalities requires a combination of cytogenetic and DNA-hybridization analysis.

Fetal outcome with oligohydramnios in the second trimester

Thirty-four cases of oligohydramnios in the second trimester were diagnosed by ultrasonography. Nine of these pregnancies were associated with fetal anomalies including Potter syndrome (three), atrioventricular dissociation (two), congenital absence of thyroid (one), and multiple anomalies (three). There were ten unexplained stillbirths, one demise due to abruptio placentae, eight with perinatal morbidity after premature labor or abruptio placentae, and six with live-born term infants. Although oligohydramnios in the second trimester is associated with increased perinatal morbidity, this finding is not associated with a universally poor outcome.

Pregnancy complicated by intraamniotic infection by Salmonella typhi

There are few reports of transplacental infection by Salmonella typhi. A case of a primagravida at 26 weeks' gestation with severe S typhi gastroenteritis, sepsis, and disseminated intravascular coagulation is presented. Shortly after institution of antibiotic therapy, she spontaneously aborted a previable infant. Amniotic fluid was turbid and subsequently grew S typhi.

A survey of pregnancies complicated by decreased amniotic fluid

Four hundred seventy-one patients undergoing diagnostic ultrasonography were identified as having moderately decreased amniotic fluid or oligohydramnios, and 339 of these cases were reviewed. Ninety-two of the patients were excluded from further statistical analysis because their decreased fluid was attributed to rupture of the membranes only. Of the remaining patients there was a 7% neonatal malformation rate. Decreased amniotic fluid before 27 weeks of gestation was associated with a significantly poor outcome. Of all the live births, infants of patients with oligohydramnios had lower Apgar scores at 1 minute and 5 minutes than did infants of patients with moderately decreased amniotic fluid. Of cases of patients with decreased fluid, 10% involved fetal distress during labor and in 17% meconium was present. Decreased levels of fluid were associated with an increased rate of abdominal deliveries. Preeclampsia was present in 24.7% of patients with decreased fluid. There was no correlation between the quantitative fluid amounts and the severity of the disease. In view of normative data and clinical experience, these observations suggest that the diagnosis of decreased amniotic fluid on routine ultrasonography requires a fetal scan to rule out anomalies, close antepartum observation to detect complications that may arise in the pregnancy, and delivery under conditions that allow appropriate support and intervention on behalf of the fetus.

Post-traumatic trapped dislocations of the proximal interphalangeal joint

This paper deals with the uncommon and frequently unrecognized problem of trapped dislocations of the proximal interphalangeal joint. These may be dorsal or volar. Soft tissue forming a noose, or interposed in the joint, is implicated. There is injury to one or more of the following structures: 1) extensor mechanism, 2) collateral ligament, 3) volar plate, 4) flexor tendon sheath, and 5) skin (compound dislocations). Open reduction and appropriate soft tissue repair are mandatory the essential features of diagnosis and management are discussed and four illustrative cases are presented.

Treatment of felons

The pitfalls of traditional concepts in the management of a felon are reviewed. A more rational and uniformly successful method is detailed. This consists of a midvolar, longitudinal incision of the fat pad where the majority of abscesses point. Other incisions are reserved for the few cases in which maximal tenderness is shown elsewhere. An abscess should always be drained where it points. It has not been our intent in this report to discuss the problems of extension of infection beyond the closed space of the distal fat pad or to deal with paronychias and eponychias that simulate a felon by their extension.