Detection of Streptococcus pneumoniae DNA by using polymerase chain reaction and microwell hybridization with Europium-labelled probes

The present paper describes a novel modification of polymerase chain reaction (PCR) for the detection of Streptococcus pneumoniae DNA in clinical specimens. PCR was based on the detection of a 209-base pair segment of the S. pneumoniae pneumolysin gene. For the demonstration of the amplification product, microwell hybridization with a Europium-labelled oligonucleotide probe complementary to a biotinylated strand of the PCR product was performed, and the presence of the PCR product was monitored by time-resolved fluorescence (TRF) of the Europium chelate. The sensitivity of the assay for purified S. pneumoniae DNA was 50 fg DNA corresponding to 20 genome equivalents of S. pneumoniae DNA. The efficiency of the hybridization step was monitored by using known amounts of synthetic target oligonucleotides as standards. Sensitivity of 3 x 10(8) molecules per individual reaction well was achieved with a 30-min attachment time and a 3-h hybridization time. Detection of PCR-amplified products by the microwell hybridization technique and TRF was compared to agarose gel electrophoresis in 50 middle ear fluid samples obtained from children with acute otitis media. The agarose gel and TRF detection methods identified all culture-positive samples, but both were also positive for 55% of the culture-negative samples. The results suggest that the detection of amplified PCR products by microwell hybridization using Europium-labelled oligonucleotides is a reliable method for the demonstration of the pneumolysin gene fragment. Furthermore, the method is suitable for automation and, thus, for testing high numbers of samples. The clinical significance of the PCR findings remains to be studied.

Energetics and vibrational states for hydrogen on Pt(111)

We present a combination of theoretical calculations and experiments for the low-lying vibrational excitations of H and D atoms adsorbed on the Pt(111) surface. The vibrational band states are calculated based on the full three-dimensional adiabatic potential energy surface obtained from first-principles calculations. For coverages less than three quarters of a monolayer, the observed experimental high-resolution electron peaks at 31 and 68 meV are in excellent agreement with the theoretical transitions between selected bands. Our results convincingly demonstrate the need to go beyond the local harmonic oscillator picture to understand the dynamics of this system.

Special Turku Coronary Risk Factor Intervention Project for Babies (STRIP)

BACKGROUND

Introducing nutritional and lifestyle principles to children in late infancy may permanently improve their adherence to a low-saturated fat, low-cholesterol diet, thus reducing of coronary risk factors, but worries about possible effects on growth and development have hampered such an approach.

OBJECTIVE

The Special Turku Coronary Risk Factor Intervention Project for Babies (STRIP) aimed to decrease exposure to known environmental atherosclerosis risk factors in children 7-36 mo of age.

DESIGN

Repeated, individualized counseling aimed at promoting a fat intake of 30% of energy and a 1:1:1 ratio of saturated to monounsaturated to polyunsaturated fat intake was provided (n = 540 intervention children; 284 boys). Nutrition was discussed superficially with the families of the control children (n = 522; 266 boys) and food intake was recorded at 3-6-mo intervals by use of 3-4-d food diaries. Serum lipids were measured at 6-12-mo intervals and growth was monitored regularly.

RESULTS

Fat intake of the intervention (control) children provided 29.5% (29.4%) of energy at the age of 8 mo, 26.6% (28.5%) of energy at 13 mo, 30.5% (33.5%) of energy at 24 mo, and 31. 5% (33.5%) of energy at 36 mo. The intervention children consistently consumed less saturated fat than did the control children (P: <0.0001). Recommended intakes of other nutrients (except vitamin D and occasionally iron) were reached irrespective of the amount and type of dietary fat. Serum cholesterol, non-HDL cholesterol, and HDL-cholesterol concentrations were 3-6% lower in the intervention children than in the control children. The intervention had no effect on height, weight, or head circumference gain. Fat intake did not predict children's growth patterns.

CONCLUSION

Repeated, individualized counseling in early childhood aimed at reducing consumption of saturated fat and cholesterol was effective and feasible and did not restrict growth in circumstances in which children were regularly monitored.

Fatty acid composition of serum cholesterol esters as a reflector of low-saturated-fat, low-cholesterol diet in young children: the STRIP project. The Special Turku coronary Risk factor Intervention Project

STRIP (the Special Turku coronary Risk factor Intervention Project) is an ongoing intervention trial which aims at a permanent reduction in the intake of saturated fat and cholesterol starting in childhood. A total of 75 intervention and 63 control children was studied consecutively at the ages of 7 and 13 mo, and 2, 3 and 5 y to evaluate the influence of such intervention on serum cholesterol ester (CE) fatty acid composition, a widely used biomarker of fatty acid intake. Analysis of 4-d food records showed that total intake of fat and of saturated fat increased with age in both groups of children but was constantly lower in intervention than in control children, e.g. at the age of 5 y the mean intakes of total fat and of saturated fatty acids were 31.1 E% and 33.9 E% and 12.1 E% and 14.6 E% in intervention and control children, respectively (p = 0.009 and 0.0001, respectively). Serum CE fatty acid compositions did not differ between the 2 groups at any age; the mean proportion of CE linoleic acid was 52.4% and 52.0% in 5-y-old intervention and control children, respectively. Correlation analysis showed, however, that the percentage of linoleic acid and of polyunsaturated fatty acids in CE reflected well the respective dietary intakes (r = 0.36; p = 0.0001 for both coefficients). In conclusion, CE fatty acid composition did not differ between the intervention and control groups, whereas CE linoleic and total polyunsaturated fatty acids reflected well the differences in their intakes at the individual level.

Low-saturated fat, low-cholesterol diet in 3-year-old children: effect on intake and composition of trans fatty acids and other fatty acids in serum phospholipid fraction-The STRIP study. Special Turku coronary Risk factor Intervention Project for children

OBJECTIVE

We evaluated whether replacing a proportion of saturated fat with vegetable oils in the diet of young children increases trans fatty acid intake.

STUDY DESIGN

Dietary counseling aimed to reach a dietary fat ratio of unsaturated to saturated fat of 2:1 within a total fat intake of 30% to 35% of energy (E%). Four-day food records of 813 3-year-old children were analyzed, and serum phospholipid fatty acid compositions of 25 randomly selected intervention children and 17 control children were analyzed.

RESULTS

trans fatty acid intake of the intervention and control children was small (0.8 E% and 0.6 E%, respectively; P <.001). The relative content of serum phospholipid trans 18:1 was closely similar in intervention and control children (1.0% and 0.9% of all fatty acids, respectively). Trans fatty acid intake and serum trans 18:1 correlated poorly with children's serum cholesterol and HDL cholesterol concentrations and inversely with serum phospholipid arachidonic to linoleic acid ratio (r = -0.373).

CONCLUSIONS

Trans fatty acid intake of children in Finland is minimal. Dietary intervention replacing saturated with unsaturated fatty acids is safe because it does not increase trans fatty acid intake or the relative content of trans fatty acids in the serum phospholipid fraction.

Effect of low-saturated fat, low-cholesterol dietary intervention on fatty acid compositions in serum lipid fractions in 5-year-old children. The STRIP project

OBJECTIVE

To evaluate the effect of dietary low-saturated fat, low-cholesterol intervention on fat intake and fatty acid compositions in serum cholesterol ester (CE), phospholipid (PL) and triglyceride (TG) fractions in five-year-old children.

DESIGN AND SUBJECTS

The STRIP project is a prospective, randomised intervention project in which 1062 seven-month-old infants were recruited from the well-baby clinics. 764 children participated in the 5-year follow-up; 202 of them were randomly selected for this study. Diet was assessed with 4-d dietary records. Serum CE, PL and TG fatty acid compositions were analysed with gas-liquid chromatography.

RESULTS

Saturated fat intake of intervention children (mean (confidence interval)) (girls 11.9 (11.2-12.6) % of energy intake (E%); boys 12.5 (11.9-13.1)) was lower than that of the control children (girls 14.4 (13.7-15.2) E%; boys 15.0 (14.3-15. 8) E%) (P=0.0001 for the difference between intervention and control groups). The intake of unsaturated fat differed only slightly. Dietary ratios of polyunsaturated to saturated fatty acids (PS ratios) of the intervention and control diets were 0.44 and 0.33, respectively (P=0.0001). Furthermore, serum cholesterol concentrations of the intervention and control children differed (4. 28 (4.13-4.43) mmol/L vs 4.49 (4.35-4.63) mmol/L; P=0.04). Relative proportion of saturated fatty acids in serum TG was lower (34.9% vs 36.3%; P=0.04) and that of n-6 polyunsaturated fatty acids higher (13.9% vs 12.4%; P=0.0004) in the intervention than in the control children, whereas serum CE and PL fatty acid compositions of intervention and control groups were closely similar. However, intake of linoleic acid correlated better with serum linoleic acid relative content in the CE fraction (r=0.36; P=0.0001) than in the PL (r=0.27; P=0.0002) or in the TG (r=0.23; P=0.0016) fraction.

CONCLUSIONS

Intervention resulted in decreased intake of saturated fatty acids and lowered serum total and LDL cholesterol concentrations. Of serum lipid fractions, TG fatty acid composition was the most sensitive and parallelled the findings in dietary food records.

Detection of Pneumococcus from whole blood, buffy coat and serum samples by PCR during bacteremia in mice

Whole blood, purified leukocyte fraction and serum were investigated as specimens for the detection of pneumococcal bacteremia by polymerase chain reaction (PCR) in mice. The PCR findings were compared to the blood culture results. Samples were taken from animals 3 and 12 h after intraperitoneal bacterial challenge. The pneumococcal culture was positive in 27% and 77% of blood samples at 3 and 12 h after challenge, respectively. All whole blood samples were positive by PCR at both time points. Of the buffy coat samples, two of the three pools were PCR-positive at 3 h and all pools at 12 h after bacterial challenge. In the serum sample group, only 40% of the sera were PCR-positive at 3 h, while at 12 h 90% of the samples were PCR-positive. According to these results, whole blood seems to be the best specimen for the detection of pneumococcal DNA by PCR in bacteremic mice.

Microbiological investigations

Causative diagnosis of pneumonia is problematic. The lack of a reliable gold standard for diagnosis has also made the development of new diagnostic methods for different microbes causing pneumonia difficult. Serologic methods are continuously used in the diagnosis of pneumonia caused by viruses and atypical bacteria. However, rapid diagnostic methods are urgently needed to guide clinicians to choose proper antibiotic treatment because resistant bacteria are emerging in different parts of the world.

Serum cholesterol ester fatty acids in 7- and 13-month-old children in a prospective randomized trial of a low-saturated fat, low-cholesterol diet: the STRIP baby project. Special Turku coronary Risk factor Intervention Project for children

To evaluate changes that occur in serum cholesterol ester fatty acid composition during the transition from typical infant feeding to a more adult type of nutrition, this study compared the effects on serum cholesterol ester fatty acids of breast milk or formula at the age of 7 mo with effects caused by 6-mo dietary intervention in 137 children. The intervention [Special Turku coronary Risk factor Intervention Project for children (STRIP baby project)] aimed at a reduction of saturated fat intake to 10% of energy after the age of 1 y without purposefully influencing total fat intake. Nutrient intakes were calculated from 3-d food records. At the age of 7 mo, i.e. before dietary education began, milk type markedly influenced dietary and serum cholesterol ester fatty acid composition (mean serum cholesterol ester 16:0 in breastfed vs formula-fed infants, 13.7% vs 12.0%, respectively, p < 0.001; serum cholesterol ester 18:2n-6 50.6% vs 57.6%, p < 0.001). At the age of 13 mo the calculated fat intake of the intervention and control children differed markedly but serum cholesterol ester fatty acid compositions in all children resembled closely those measured in 7-mo-old breastfed infants, e.g. at the age of 13 mo the relative proportions of 18:2n-6 were 49.9% and 51.1% in previously formula-fed intervention and control children, respectively, and 50.3% and 50.1% in previously breastfed intervention and control children, respectively. In conclusion, serum cholesterol ester fatty acid composition reflected differences in dietary fat quality (breast milk or formula) at the age of 7 mo, whereas dietary intervention as applied in the STRIP baby project had only a minimal effect.

The role of joint innervation in the pathogenesis of arthritis

Recently, an expanding body of knowledge has documented the nature and functions of receptors in joint tissues and their potential importance in preserving the smooth normal functioning of the motor-skeletal system and in amplifying the inflammatory response to joint injuries and diseases. This review summarizes the current knowledge of the anatomical and physiological substrates of these mechanisms. The distribution, morphologic and functional characteristics of joint receptors have been well described. In the past decade there has been a new appreciation of the major role played by sensory neurons in promoting regional inflammatory responses, and many of the specific neuronal mechanisms and molecules that mediate these reflexes have been identified. This knowledge promises to significantly improve the selectivity and effectiveness of pharmacologic approaches to pain, trauma and regional inflammatory disorders. Other investigations have revealed important contributions of joint receptors to motor function. These refer not to proprioception or the sense of limb position in space, but rather to a more sophisticated tailoring of muscle activity to increase joint stability and to protect joint structures from damaging loads. Whether a loss of these reflexes may play a role in the pathogenesis of osteoarthritis remains controversial. However, there is a growing consensus that a loss of these reflexes may contribute to the morbidity associated with disruption of the anterior cruciate ligament. Synovial joints are sites of major interactions between the musculoskeletal and the nervous systems. Understanding the mechanisms that activate and control these interactions will certainly offer the opportunity to develop new, more effective treatments for patients with joint disorders.

Genetic relationships of Asians and Northern Europeans, revealed by Y-chromosomal DNA analysis

We have identified a new T-->C transition on the human Y chromosome. C-allele chromosomes have been found only in a subset of the populations from Asia and northern Europe and reach their highest frequencies in Yakut, Buryats, and Finns. Examination of the microsatellite haplotypes of the C-allele chromosomes suggests that the mutation occurred recently in Asia. The Y chromosome thus provides both information about population relationships in Asia and evidence for a substantial paternal genetic contribution of Asians to northern European populations such as the Finns.

Pneumococcal capsular antigen detection after enrichment culture: an alternative to culture methods in epidemiologic research

Bacterial culture of Streptococcus pneumoniae followed by serotyping is not always feasible under field conditions. Antigen detection methods could be an alternative, but they are associated with sensitivity problems. In an effort to improve their sensitivity, we introduced an enrichment phase before antigen detection and compared the results with direct bacterial culture, using nasopharyngeal swabs from 95 children with symptoms of acute respiratory infection. Antigen detection was performed by latex agglutination and counterimmunoelectrophoresis. Streptococcus pneumoniae was found in 29 (30%) of the samples by culture, and in 42 (44%) by antigen detection after enrichment, an excess of 45% over culture findings. This excess was shown to represent true positive samples since pneumococcal DNA could be detected by polymerase chain reaction in all 15 antigen-positive, culture-negative samples. Two culture-positive samples were antigen-negative; in one of these the bacteria were nonencapsulated. We conclude that for type-specific demonstration of S. pneumoniae, detection of pneumococcal antigen after an enrichment step is a sensitive method that can be applied for epidemiologic study purposes, e.g., in vaccine trials, in areas without ready access to a good microbiology laboratory.

Milk type during mixed feeding: contribution to serum cholesterol ester fatty acids in late infancy

OBJECTIVE

To evaluate the contribution of the type of milk on serum cholesterol ester fatty acids in infants receiving mixed feeding, we analyzed 3-day dietary records and serum cholesterol ester fatty acid composition of 397 seven-month-old infants.

STUDY DESIGN

The infants received, in addition to solid food, only one type of milk: human milk (n = 218), a ready-to-use liquid formula (n = 139), a powdered formula (n = 33), or soy formula (n = 7).

RESULTS

Mean fat intakes were low and varied from 28% to 31% of energy; the milks provided 43% to 64% of the fat. The mean polyunsaturated/saturated fat ratios of solid foods were from 0.52 to 0.63 and of milks from 0.20 to 0.45. Breast-fed infants' relative serum linoleic acid (18:2n-6) concentration was low (51.2%), whereas infants fed liquid formula had low serum oleic acid (18:1n-9) in accordance with low oleic acid content in that formula. The breast-fed infants had markedly higher serum concentrations of arachidonic acid (20:4n-6) and docosahexaenoic acid (22:6n-3) than the infants fed any of the formulas.

CONCLUSION

The typical fatty acid patterns of breast- or formula-fed infants were still evident in 7-month-old infants who already received 60% to 70% of their energy from solid food. Marked differences were seen also in the relative concentrations of docosahexaenoic acid and arachidonic acid despite their small contribution in cholesterol esters.

Prospective randomized trial of low-saturated-fat, low-cholesterol diet during the first 3 years of life. The STRIP baby project

BACKGROUND

The long-term consequences of modified fat intake in early childhood are poorly known. The randomized prospective STRIP baby project evaluates the effects of repeated dietary counseling on nutrient intakes and serum lipid values in children 7 months to 3 years old.

METHODS AND RESULTS

One thousand sixty-two infants were randomized to intervention and control groups at 7 months of age. The families of the 540 intervention children were counseled to reduce the child's intake of saturated fat and cholesterol but to ensure adequate energy intake. Five hundred twenty-two control children consumed an unrestricted diet. Food records were kept, and serum lipids were measured at 5- to 12-month intervals. Intakes of saturated fat, fat as proportion of energy (E%), and cholesterol were lower in the intervention children than in control children at 13, 24, and 36 months of age. Fat intake by the intervention children decreased from 29 +/- 5 E% at 8 months of age to 26 +/- 6 E% at 13 months and then increased to 30 +/- 5 E% at 24 months and to 31 +/- 5 E% at 36 months. The control children consumed 29 +/- 4 E%, 28 +/- 5 E%, 33 +/- 5 E%, and 33 +/- 5 E% of fat at 8, 13, 24, and 36 months, respectively. The ratio of dietary poly-unsaturated to saturated fats of the intervention children was consistently higher than that of the control children (P < .0001). Baseline adjusted mean serum cholesterol concentration was lower in the intervention children than control children between 13 and 36 months (P < .0001; 95% confidence interval of the difference between the group means, -0.27 to -0.12 mmol/L). The effect was significant only in boys (95% confidence interval, -0.39 to -0.20 mmol/L in boys; -0.21 to 0.01 mmol/L in girls).

CONCLUSIONS

Repeated individualized dietary counseling markedly reduces the increase in serum cholesterol concentration that occurs in control children during the first years of life.

Dominantly and recessively inherited cornea plana congenita map to the same small region of chromosome 12

Cornea plana congenita occurs in a mild autosomal dominant (CNA1) and a more severe autosomal recessive (CNA2) form. We recently assigned a CNA2 locus to a region on chromosome 12 by linkage analysis and excluded linkage to that locus in two Finnish CNA1 families. Here we describe a Cuban pedigree in which 14 members are affected with dominantly inherited cornea plana. By linkage analysis this phenotype was mapped to the immediate vicinity of markers D12S82 and D12S351 on 12q, that is, precisely the same small region (3 cM or less) to which CNA2 previously had been assigned. Our results support the existence of at least three genetically distinct forms of cornea plana. It remains to be determined whether recessive and dominant cornea plana are caused by different mutations of a single gene or whether the region in 12q harbors two or more genes whose mutations cause corneal maldevelopment.

Effects of prospective, randomized cholesterol-lowering dietary intervention and apolipoprotein E phenotype on serum lipoprotein(a) concentrations of infants aged 7-24 mo

A high serum lipoprotein(a) [Lp(a)] concentration is associated with increased risk of coronary artery disease. Few external factors are able to markedly modify serum Lp(a) concentrations. The aim of this study was to evaluate how serum Lp(a) concentrations of infants between 7 and 24 mo of age change in a cholesterol-lowering dietary intervention, and to assess the influence of apolipoprotein (apo) E phenotypes on serum Lp(a) concentrations. The intervention children (n=394) had serum cholesterol, non-high-density-lipoprotein cholesterol, and cholesterol corrected for Lp(a)-cholesterol values (P for all <0.001) lower than those of the control children (n=390), but median serum Lp(a) concentrations at the age of 24 mo were not different from those of control children. Serum Lp(a) values differed according to the apo E phenotype as the median Lp(a) values increased from E2/2 to E3/2, E4/2, E3/3, E4/3, and to E4/4 (P for the difference=0.023, Mann-Whitney U test). Our results suggest that apo E phenotype influences serum Lp(a) concentrations noticeably, but the effect of the cholesterol-lowering dietary intervention was not significant in subjects aged 24 mo.

PCR assay for detecting Streptococcus pneumoniae in the middle ear of children with otitis media with effusion

We compared a newly developed pneumococcal polymerase chain reaction (PCR) for Streptococcus pneumoniae (Pnc) to bacterial culture in 123 middle ear effusion (MEE) samples of 123 children with otitis media with effusion (OME). For the pneumococcal PCR assay, DNA of MEE samples was purified by a QIAamp blood kit. The outer primers used amplified a 348 basepair region of the pneumolysin gene, and the inner a 208. Pnc was cultured in 14 (11%) and pneumolysin PCR was positive in 57 (46%) of the 123 MEE samples. All the culture positive samples were also PCR-positive. Both the samples with culturable Pnc and with positive pneumolysin PCR increased with shorter duration of OME and a greater number of acute otitis media during the preceding 6 months. In conclusion, pneumolysin PCR suggests pneumococcal involvement in MEE even in OMEs with no evidence of Pnc in culture, and thus offers a good diagnostic tool when a more accurate and sensitive pneumococcal diagnosis is needed.

Molecular mapping of the putative gonadoblastoma locus on the Y chromosome

Based on the high incidence of gonadoblastoma in females with XY gonadal dysgenesis or 45,X/46,XY mosaicism, the existence of a susceptibility locus on the Y chromosome (GBY) has been postulated. We attempted to map GBY by making use of a recently developed dense map of Y-chromosomal sequence-tagged sites (STSs). In two female patients with gonadoblastoma, small marker chromosomes contained portions of the Y chromosome, and a single region of overlap could be defined extending from probe pDP97 in interval 4B, which contains the centromere, to marker sY182 in interval 5E of the proximal long arm. This interval is contained in a YAC contig that comprises approximately 4 Mb of DNA. Our findings confirm the previous localization of GBY and greatly refine it. The localization of GBY overlaps with the region to which a putative growth determinant, GCY, was recently assigned.

Effect of weaning on serum lipoprotein(a) concentration: the STRIP baby study

Risk for coronary heart disease is increased in adult Caucasians with high serum lipoprotein(a) [Lp(a)] concentration. In adults the concentration is mainly regulated by genetic factors. Our previous study suggests that breast milk has a beneficial effect on serum Lp(a) concentration in infants. Now we analyzed the influence of weaning by measuring serum Lp(a) and cholesterol in 414 infants at 7, 13, 24, and 36 mo of age. At 7 mo the infants received, in addition to solid food, only breast milk (n = 148), breast milk and formula (n = 74), or formula only (n = 191). Median (range) serum Lp(a) concentrations were then 25 (< or = 12-743) mg/L, 35 (< or = 12-1188) mg/L, and 45 (< or = 12-577) mg/L in the three feeding groups, respectively (p = 0.0013). Breast milk and formula were changed to cow's milk in all infants before 12 mo of age. At 13 mo serum Lp(a) concentration had increased more in infants who were weaned from breast milk than in those who had been fed both breast milk and formula, or formula only (median increases 37, 26, and 20 mg/L, respectively; p = 0.0062). Thus the serum Lp(a) concentration was similar in all feeding groups at 13 mo. This finding was also observed at 24 and 36 mo. The increase in serum Lp(a) concentration was independent of the baseline Lp(a) level, apolipoprotein E phenotype, gender, and weight gain of the infants between 7 and 13 mo.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical features of nine males with molecularly defined deletions of the Y chromosome long arm

Deletions of the long arm of the Y chromosome have previously been associated with azoospermia and short stature. We report the results of a detailed clinical and molecular study of nine males with partial deletions of Yq. Special emphasis was laid on congenital anomalies and dysmorphic features. Some of the patients have developmental problems or distinct facial features, namely a small chin and mouth, a high arched or cleft palate, downward slanting palpebral fissures, high nasal bridge, and dysmorphic ears. As far as we know, similar facial dysmorphism has not been previously described in association with del(Yq). These features are not, however, simply correlated to the size of the deletion. In none of these patients could evidence of aberrant Xq-Yq interchange be found.

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.

Deletion mapping of stature determinants on the long arm of the Y chromosome

A gene contributing to human growth has previously been tentatively mapped to the long arm of the Y chromosome. In the present study, recently developed sequence-tagged site markers covering the entire Y chromosome were used to define deletion breakpoints in 15 males with partial deletions of Yq. By correlating the height of these individuals with their deletion breakpoints, we located a region whose presence or absence has a marked effect on stature. This critical region comprises the most proximal portion of the long arm, extending from marker sY78 in interval 4B to marker sY94 in interval 5G of the proximal long arm.