Maternal serum concentrations of bisphenol A and propyl paraben in early pregnancy are associated with male infant genital development.

STUDY QUESTION: Are maternal serum phthalate metabolite, phenol and paraben concentrations measured at 10-17 weeks of gestation associated with male infant genital developmental outcomes, specifically cryptorchidism, anogenital distance (AGD), penile length and testicular descent distance, at birth and postnatally? SUMMARY ANSWER: Maternal serum bisphenol A (BPA) concentration at 10-17 weeks of gestation was positively associated with congenital or postnatally acquired cryptorchidism, and n-propyl paraben (n-PrP) concentration was associated with shorter AGD from birth to 24 months of age. WHAT IS KNOWN ALREADY: Male reproductive disorders are increasing in prevalence, which may reflect environmental influences on foetal testicular development. Animal studies have implicated phthalates, BPA and parabens, to which humans are ubiquitously exposed. However, epidemiological studies have generated conflicting results and have often been limited by small sample size and/or measurement of chemical exposures outside the most relevant developmental window. STUDY DESIGN, SIZE, DURATION: Case-control study of cryptorchidism nested within a prospective cohort study (Cambridge Baby Growth Study), with recruitment of pregnant women at 10-17 postmenstrual weeks of gestation from a single UK maternity unit between 2001 and 2009 and 24 months of infant follow-up. Of 2229 recruited women, 1640 continued with the infancy study after delivery, of whom 330 mothers of 334 male infants (30 with congenital cryptorchidism, 25 with postnatally acquired cryptorchidism and 279 unmatched controls) were included in the present analysis. PARTICIPANTS/MATERIALS, SETTING, METHODS: Maternal blood was collected at enrolment, and serum levels of 16 phthalate metabolites, 9 phenols (including BPA) and 6 parabens were measured using liquid chromatography/tandem mass spectrometry. Logistic regression was used to model the association of cryptorchidism with serum chemical concentrations, adjusting for putative confounders. Additionally, offspring AGD, penile length and testicular descent distance were assessed at 0, 3, 12, 18 and 24 months of age, and age-specific Z scores were calculated. Associations between serum chemical levels and these outcomes were tested using linear mixed models. MAIN RESULTS AND THE ROLE OF CHANCE: Maternal serum BPA concentration was associated with offspring all-type cryptorchidism both when considered as a continuous exposure (adjusted odds ratio per log10 µg/l: 2.90, 95% CI 1.31-6.43, P = 0.009) and as quartiles (phet = 0.002). Detection of n-PrP in maternal serum was associated with shorter AGD (by 0.242 standard deviations, 95% CI 0.051-0.433, P = 0.01) from birth to 24 months of age; this reduction was independent of body size and other putative confounders. We did not find any consistent associations with offspring outcomes for the other phenols, parabens, and phthalate metabolites measured. LIMITATIONS, REASONS FOR CAUTION: We cannot discount confounding by other demographic factors or endocrine-disrupting chemicals. There may have been misclassification of chemical exposure due to use of single serum measurements. The cohort was not fully representative of pregnant women in the UK, particularly in terms of smoking prevalence and maternal ethnicity. WIDER IMPLICATIONS OF THE FINDINGS: Our observational findings support experimental evidence that intrauterine exposure to BPA and n-PrP during early gestation may adversely affect male reproductive development. More evidence is required before specific public health recommendations can be made. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by a European Union Framework V programme, the World Cancer Research Fund International, the Medical Research Council (UK), Newlife the Charity for Disabled Children, the Mothercare Group Foundation, Mead Johnson Nutrition and the National Institute for Health Research Cambridge Comprehensive Biomedical Research Centre. Visiting Fellowship (J.M.): Regional Programme 'Jiménez de la Espada' for Research Mobility, Cooperation and Internationalization, Seneca Foundation-Science and Technology Agency for the Region of Murcia (No. 20136/EE/17). K.O. is supported by the Medical Research Council (UK) (Unit Programme number: MC_UU_12015/2). The authors declare no conflict of interest.

Elevation of isoprostanes in polycystic ovary syndrome and its relationship with cardiovascular risk factors.

PURPOSE: To evaluate the plasma level of 8-isoprostanes in women with polycystic ovary syndrome. To also investigate whether there is a relationship between 8-isoprostanes and several cardiovascular risk factors. METHODS: A total of 125 women with polycystic ovary syndrome and 169 healthy women were enrolled in this case-control study. 8-Isoprostanes and different parameters were measured in all subjects. Patients were evaluated for the presence of polycystic ovary syndrome according to the Rotterdam Consensus Conference criteria. RESULTS: 8-Isoprostanes levels were significantly higher in patients with polycystic ovary syndrome (138.4 ± 104.1 pg/mL) compared with control group (68.6 ± 34.3 pg/mL) (p < 0.001). The mean of triglycerides, lipid accumulation product, C-reactive protein, homocysteine, insulin, and homeostatic model assessment for insulin resistance were significantly higher in polycystic ovary syndrome patients with high 8-isoprostanes than those with normal 8-isoprostanes (p < 0.05). The Pearson correlation analyses showed that 8-isoprostanes levels in polycystic ovary syndrome group had a positive correlation with waist circumference, triglycerides, low-density lipoprotein cholesterol, apolipoprotein B, homocysteine, insulin, homeostatic model assessment for insulin resistance. CONCLUSIONS: Patients with polycystic ovary syndrome have higher 8-isoprostanes levels and it is associated with several cardiovascular risk factors.

Anogenital distance is associated with semen quality but not reproductive hormones in 1106 young men from the general population.

STUDY QUESTION: Is anogenital distance (AGD) associated with semen quality and reproductive hormones in men from the general population? SUMMARY ANSWER: Short AGD measured from the anus to the base of scrotum (AGDAS) was associated with reduced sperm counts and morphology but not with sperm motility or reproductive hormones. WHAT IS KNOWN ALREADY: AGD is longer in males than in females. In rodents, AGD is a well-established and sensitive marker of disruption during the masculinization programming window in utero and it has been suggested to be so in humans as well. Therefore, the average AGD would be expected to be shorter in men with poor semen quality, which some studies have confirmed while others have not. STUDY DESIGN, SIZE, DURATION: This cross-sectional population-based study was of 1106 men included between 2012 and 2016. PARTICIPANTS/MATERIALS, SETTING, METHODS: Men from the general Danish population (median age 19 years), unselected with regard to fertility status and semen quality, delivered a semen sample, had a blood sample drawn, which was analyzed for concentrations of reproductive hormones, and answered a comprehensive questionnaire. They also had a physical examination performed including determination of AGD measured as the distance between anus and scrotum (AGDAS) and penis (AGDAP). Odds ratios (OR) and 95% CI were estimated for a man having abnormal semen parameters according to the World Health Organization's reference values or a low/high concentration of reproductive hormones (defined as the lowest or highest 10%) depending on AGD. AGD was categorized in four strata: ≤10th percentile, 10th-30th percentile, 30th-50th percentile and >50th percentile. MAIN RESULTS AND THE ROLE OF CHANCE: Men with the 10% shortest AGDAS had a more than doubled risk (OR: 2.19, 95% CI: 1.40-3.42) of being in the subfertile range for either sperm concentration (<15 million/mL) or sperm morphology (<4%) compared to men with AGDAS above the median (reference). Men in the 10th-30th percentile also had an increased OR of 1.48 (95% CI: 1.06-2.08) but not men in the 30th-50th percentile (OR: 1.14, 95% CI: 0.81-1.62). AGDAP was only weakly related to semen quality. AGD was not associated with testicular volume or any of the reproductive hormones. LIMITATIONS, REASONS FOR CAUTION: Limitations include the potential non-differential misclassification of reproductive outcomes based on a single semen and blood sample and some between-examiner differences in AGD measurements which introduces noise and may result in an underestimation of observed associations. WIDER IMPLICATIONS OF THE FINDINGS: Our study of men from the general population confirmed associations between AGD and semen quality, supporting the hypothesis that AGD in humans could be a marker of fetal testicular development. This suggests that the low semen quality in Danish men may partly be explained by prenatal factors. STUDY FUNDING/COMPETING INTEREST(S): The study has received financial support from the ReproUnion (L.P.); the Research fund of Rigshospitalet, Copenhagen University Hospital (N.J.); Grants R01ES016863-04 and R01ES016863-02S4; National Institute of Environmental Health Sciences (NIEHS) and National Institute of Environmental Health Sciences grant (P30ES023515) (S.S.); the European Union (Contract numbers BMH4-CT96-0314, QLK4-CT-1999-01422, QLK4-CT-2002-00603, FP7/2007-2013, DEER Grant agreement no. 212844); the Danish Ministry of Health; the Danish Environmental Protection Agency; A.P. Møller and wife Chastine McKinney Møllers foundation; and Svend Andersens Foundation. None of the funders had any role in the study design, collection, analysis or interpretation of data, writing of the paper or publication decisions. The authors have nothing to declare. TRIAL REGISTRATION NUMBER: N/A.

Autologous dental pulp mesenchymal stem cells for inferior third molar post-extraction socket healing: A split-mouth randomised clinical trial.

BACKGROUND: Since the discovery of adult mesenchymal stem cells extensive research has been conducted to determine their mechanisms of differentiation and effectiveness in cell therapy and regenerative medicine. MATERIAL AND METHODS: To assess the efficacy of autologous dental pulp mesenchymal stem cells delivered in a collagen matrix for post-extraction socket healing, a single-centre, double-blind, randomised, split-mouth, controlled clinical trial was performed. Both impacted mandibular third molars were extracted from 32 patients. Dental pulp was collected and dissociated; the resulting cell suspension, obtained by centrifugation, was incorporated into a resorbable collagen matrix and implanted in 32 experimental post-extraction sockets. Collagen matrices alone were implanted in 32 contralateral, control post-extraction sockets. Two neuroradiologists independently assessed the extent of bone repair at 6 months after the extractions. Computed tomography (CT, Philips Brilliance) and an advanced display platform (IntelliSpace Portal) was used to record extraction socket density, expressed as Hounsfield units (HU) and height (mm) of the distal interdental bone septum of the second molar. Measurements at 6 months post-extraction were compared with measurements obtained immediately after extraction. Data were analysed with the statistical program STATA 14. RESULTS: Two patients dropped out of the study. The final sample consisted of 22 women and 8 men (mean age, 23 years; range: 18-30 years). Clinical, radiological, and surgical characteristics of impacted third molars of the control and experimental groups were homogeneous. Measurements obtained by the two neuroradiologists showed agreement. No significant differences were found in the extent of bone repair during analyses of density (p=0.4203 neuroradiologist 1; p=0.2525 neuroradiologist 2) or interdental septum height (p=0.2280 neuroradiologist 1; p=0.4784 neuroradiologist 2). CONCLUSIONS: In our clinical trial, we were unable to demonstrate that autologous dental pulp mesenchymal stem cells reduce socket bone resorption after inferior third molar extraction.

Comparison of the anogenital distance and anthropometry of the perineum in patients with and without pelvic organ prolapse. / Comparación de la distancia anogenital y antropometría del periné en pacientes con y sin prolapso de órganos pélvicos.

OBJECTIVES: To determine whether there are differences in the anthropometric measures of the perineum for women with symptomatic pelvic organ prolapse who are candidates for surgery, with or without urinary incontinence, and for patients without pelvic floor dysfunction. The main objective was to measure the anogenital distance in its 2 variants: anoclitoral and anofourchette. The anogenital distance appears to be determined prenatally and is influenced by the intrauterine hormonal environment. The secondary objective was to measure the length of the genital hiatus, the perineal body and the distance between the 2 ischial tuberosities. MATERIAL AND METHODS: An observational case-control study was conducted with 58 patients. The cases (n=22) were patients with stages >II 2 in the Baden-Walker classification system. The controls were patients with normal pelvic floors. Measurements were performed with a digital calliper. The patients' tocogynecological history, lifestyle habits and risk factors were recorded. RESULTS: The case patients had a significantly shorter anogenital anofourchette distance than that of the control patients (P=.001), a significantly longer anogenital anoclitoral distance than the control patients (P=.0001) and a significantly longer genital hiatus length than the control patients (P=.02). CONCLUSIONS: This was an observational study with a small sample. We cannot determine whether the difference in these distances are caused by or are the result of this disease. Given that the anogenital distance appears to be determined prenatally, we question whether this changed distance could be a risk factor for developing pelvic floor dysfunction.

Phthalate exposure and semen quality in fertile US men.

Several experimental and observational studies have demonstrated the antiandrogenicity of several phthalates. However, there is limited evidence of an association between phthalate exposure in adult life and semen quality. The aim of this study was to examine phthalate exposure during adulthood in relation to semen quality in fertile US men. This multi-center cross-sectional study included 420 partners of pregnant women who attended a prenatal clinic in one of five US cities during 1999-2001. Nine phthalate metabolites [mono (2-ethylhexyl) phthalate (MEHP), mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono (2-ethyl-5-carboxypentyl) phthalate (MECPP)], as well as mono-n-butyl phthalate (MBP) and mono-isobutyl phthalate (MiBP), mono (three carboxypropyl) phthalate (MCPP), monobenzyl phthalate (MBzP), and monoethyl phthalate (MEP)] were measured in urine collected at the same time as the semen sample. We regressed natural log-transformed (ln) sperm concentration, ln(total sperm count), ln(total motile sperm count), percent motile spermatozoa, and percent spermatozoa with normal morphology on each of the nine natural log-transformed metabolite concentrations and on the molar-weighted sum of DEHP metabolites in separate models. We fit unadjusted models and models that adjusted for confounders determined a priori. In unadjusted models, ln(MiBP) was significantly and positively associated with motility and ln(MBzP) significantly negatively associated with ln(total sperm count). In adjusted linear models, urinary metabolite concentrations of DEHP, DBP, DEP, and DOP were not associated with any semen parameter. We found an inverse association between ln(MBzP) concentrations and sperm motility (ß = -1.47, 95% CI: -2.61, -0.33), adjusted for ln(creatinine concentration), geographic location, age, race, smoking status, stress, recent fever, time from sample collection and time to complete analysis. Several sensitivity analyses confirmed the robustness of these associations. This study and the available literature suggest that impacts of adult exposure to phthalates at environmental levels on classical sperm parameters are likely to be small.

Anogenital distance and reproductive parameters in young men.

The purpose of this study was to assess the relationship between anogenital distance (AGD) measures and semen quality and serum reproductive hormone levels in Caucasian young men from southern Spain. Two variants of AGD [from the anus to the posterior base of the scrotum (AGD(AS)) and to the cephalad insertion of the penis (AGD(AP))] were assessed in 215 university students. Semen parameters (semen volume, sperm concentration, total sperm counts, motility and morphology) and serum reproductive hormones (follicle stimulating hormone, luteinising hormone, inhibin B, testosterone, calculated free testosterone, oestradiol and sex hormone-binding globulin) were also determined. Associations between AGD measures and the semen quality and reproductive hormone levels were tested using multiple regression analyses. Overall, median sperm concentration was 44.0 × 10(6) ml(-1) (5th-95th percentiles: 8.9-129 × 10(6 ) ml(-1)), median total sperm count was 121 × 10(6) (18.0-400 × 10(6)), and mean (SD) testosterone level was 21.7 nmol/l (6.9). Mean (SD) AGD(AS) and AGD(AP) measures were 48.3 mm (11.6) and 128 mm (12.0) respectively. In the multivariable analysis, AGD measures were not associated with any semen parameters or any of the reproductive hormone levels, which is in contrast to results of studies of US young men or infertile men. Further research is warranted to confirm these findings.

Longer anogenital distance is associated with higher testosterone levels in women: a cross-sectional study.

OBJECTIVE: Animal models have suggested that anogenital distance (AGD) at birth reflects androgen levels during in utero development and predicts adult AGD. A recent study showed an association between perineal length and androgen levels in men, suggesting that serum testosterone levels in adulthood will depend on factors involved during the fetal period. The aim of this study is to assess the relationship between AGD measures and reproductive hormone levels in women. DESIGN: Cross-sectional study conducted between February and November 2011. SETTING: University-affiliated fertility clinics. POPULATION: 100 young college students. METHODS: Physical and gynaecological examinations were conducted on university students. All participants provided a blood sample for determination of reproductive hormones and completed an epidemiological questionnaire on lifestyles and gynaecological history. We used multiple linear regression analysis to examine the associations between perineal length measurements [anus-fourchette (AGDAF ) and anus-clitoris (AGDAC )] and reproductive hormone levels. MAIN OUTCOME MEASURES: Anogenital distance measurements and reproductive hormone levels. RESULTS: In the multiple linear regression analyses, AGDAF was positively associated with serum testosterone levels. Serum testosterone increased 0.06 ng/ml (95%CI 0.01, 0.10; P = 0.02) for each 1-cm increase in AGDAF . None of the measurements was associated with other reproductive hormones. CONCLUSIONS: Anogenital distance may predict normal reproductive development in women, and may be a new tool of potential clinical interest to evaluate ovarian function. Our results suggest that serum testosterone levels in adulthood may depend on factors operating in the prenatal period.

Dairy food intake in relation to semen quality and reproductive hormone levels among physically active young men.

STUDY QUESTION: Is increased consumption of dairy foods associated with lower semen quality? SUMMARY ANSWER: We found that intake of full-fat dairy was inversely related to sperm motility and morphology. These associations were driven primarily by intake of cheese and were independent of overall dietary patterns. WHAT IS KNOWN ALREADY: It has been suggested that environmental estrogens could be responsible for the putative secular decline in sperm counts. Dairy foods contain large amounts of estrogens. While some studies have suggested dairy as a possible contributing factor for decreased semen quality, this finding has not been consistent across studies. STUDY DESIGN, SIZE, DURATION: The Rochester Young Men's Study (n = 189) was a cross-sectional study conducted between 2009 and 2010 at the University of Rochester. PARTICIPANTS/MATERIALS, SETTING, METHODS: Men aged 18-22 years were included in this analysis. Diet was assessed via food frequency questionnaire. Linear regression was used to analyze the relation between dairy intake and conventional semen quality parameters (total sperm count, sperm concentration, progressive motility, morphology and ejaculate volume) adjusting for age, abstinence time, race, smoking status, body mass index, recruitment period, moderate-to-intense exercise, TV watching and total calorie intake. MAIN RESULTS AND THE ROLE OF CHANCE: Total dairy food intake was inversely related to sperm morphology (P-trend = 0.004). This association was mostly driven by intake of full-fat dairy foods. The adjusted difference (95% confidence interval) in normal sperm morphology percent was -3.2% (-4.5 to -1.8) between men in the upper half and those in the lower half of full-fat dairy intake (P < 0.0001), while the equivalent contrast for low-fat dairy intake was less pronounced [-1.3% (-2.7 to -0.07; P= 0.06)]. Full-fat dairy intake was also associated with significantly lower percent progressively motile sperm (P= 0.05). LIMITATIONS, REASONS FOR CAUTION: As it was a cross-sectional study, causal inference is limited. WIDER IMPLICATIONS OF THE FINDINGS: Further research is needed to prove a causal link between a high consumption of full-fat dairy foods and detrimental effects on semen quality. If verified our findings would mean that intake of full-fat dairy foods should be considered in attempts to explain secular trends in semen quality and that men trying to have children should restrict their intake. STUDY FUNDING/COMPETING INTEREST(S): European Union Seventh Framework Program (Environment), 'Developmental Effects of Environment on Reproductive Health' (DEER) grant 212844. Grant P30 DK046200 and Ruth L. Kirschstein National Research Service Award T32 DK007703-16 from the National Institutes of Health. None of the authors has any conflicts of interest to declare.

Proposal of guidelines for the appraisal of SEMen QUAlity studies (SEMQUA).

STUDY QUESTION: Is there a need for a specific guide addressing studies of seminal quality? SUMMARY ANSWER: The proposed guidelines for the appraisal of SEMinal QUAlity studies (SEMQUA) reflect the need for improvement in methodology and research on semen quality. WHAT IS KNOWN ALREADY: From an examination of other instruments used to assess the quality of diagnostic studies, there was no guideline on studies of seminal quality. STUDY DESIGN, SIZE AND DURATION: Through systematic bibliographic search, potential items were identified and grouped into four blocks: participants, analytical methods, statistical methods and results. PARTICIPANTS/MATERIALS, SETTING AND METHODS: Our findings were presented to a panel of experts who were asked to identify opportunities for improvement. Then, a checklist was designed containing the questions generated by the items that summarize the essential points that need to be considered for the successful outcome of a SEMQUA. MAIN RESULTS AND THE ROLE OF CHANCE: Eighteen items were identified, from which 19 questions, grouped into four blocks, were generated to constitute the final checklist. An explanation for the inclusion of each item was provided and some examples found in the bibliographic search were cited. LIMITATIONS AND REASONS FOR CAUTION: We consider that not all items are equally applicable to all study designs, and so the hypothetical results are not comparable. For that reason, a score would not be fair to critically appraise a study. This checklist is presented as an instrument for appraising SEMQUAs and therefore remains open to constructive criticism. It will be further developed in the future, in parallel with the continuing evolution of SEMQUAs. WIDER IMPLICATIONS OF THE FINDINGS: The final configuration of the SEMQUA is in the form of a checklist, and includes the items generally considered to be essential for the proper development of a SEMQUA. The final checklist produced has various areas of application; for example, it would be useful for designing and constructing a SEMQUA, for reviewing a paper on the question, for educational purposes or as an instrument for appraising the quality of research articles in this field. STUDY FUNDING/COMPETING INTEREST(S): None.

PACS monitors: an evolution of radiologist's viewing techniques.

When initially evaluating picture archiving communication systems (PACS) many radiologists try to duplicate the film environment and believe that multiple monitors are required to maintain the productivity of the radiologist. The authors were under the same impression initially but found that they underwent a paradigm shift over a period of time. This report documents the evolution that the radiologists underwent. The author's department consists of 28 diagnostic radiologists and 21 residents who actively read cases on a PACS. The department has been filmless for 6 months, although they have been reading soft copy films for 2 years. All modalities except mammography are included. The authors conducted interviews with both attending radiologists and residents to evaluate the change in methodology from the preconceptions to initial use to current use. The number and kind of monitors preferred for plain films, ultrasound scan, computed tomography (CT), and magnetic resonance imaging (MRI) were recorded. Additionally, viewing methods of different modalities were discussed. The authors found that there was a decrease in the number of monitors from preconceptions to actual use. Furthermore, to a lesser degree, there is a reduction of monitors used initially to that which is currently being used. The style of viewing cross-sectional images has changed. There has been a decrease in the number of images displayed on each monitor. The use of the roller ball on the mouse has affected this viewing style. Changing from a film-based reading environment to PACS environment not only brings about change in the overall technology in image delivery but also in the viewing techniques by radiologists. At our institution we have evolved from initially expecting to use 4 monitors all the time to actually preferring 2 monitors and occasionally 1 monitor to view images. Presentation software and viewing aids such as the roller ball on a mouse for viewing CTs in stack mode are key contributions to this paradigm shift. The decrease in monitors makes PACS more affordable and will allow further penetration of filmless radiology. The authors have found that after using PACS, radiologists prefer using 2 monitors. The style of reading films has changed with experience. Hospitals that plan to purchase PACS should consider this and ensure that the vendor has presentation software that optimizes the 2 monitor system.

Immunoglobulin heavy-chain gene rearrangement studies by Southern blot using DNA extracted from formalin-fixed, paraffin-embedded tissue.

BACKGROUND: In most clinical molecular diagnostics laboratories, Southern blots for gene rearrangement studies are not routinely performed on formalin-fixed, paraffin-embedded (FFPE) tissue samples. In this study, immunoglobulin heavy-chain gene rearrangements by Southern blot using DNA extracted from FFPE tissue samples were studied. METHODS AND RESULTS: Eleven paired freshly frozen and FFPE tissue samples were evaluated for immunoglobulin gene rearrangements by PCR and Southern blot analyses. An additional 14 selected samples sent to our laboratory to rule out lymphoma, for which only FFPE tissue (no frozen tissue) was available and for which PCR was interpreted as negative, were evaluated by the same techniques. Southern blots generated from DNA extracted from FFPE tissues were qualitatively identical to those generated from DNA extracted from fresh or freshly frozen tissue and correlated well with the final diagnoses. Ten interpretable Southern blots were generated in the 14 cases in which no frozen tissue was available. Four of these ten blots were interpreted as positive for an immunoglobulin gene rearrangement. Although the number of samples analyzed is small, success with Southern blotting correlated with increased sample size and sample width (1.17 vs 0.49 cm(2); P <.024; 0.71 vs 0.43 cm; P <. 049, respectively). CONCLUSION: DNA extracted from FFPE tissue samples using the simple, efficient, and nontoxic techniques described in this report can be used in many cases for Southern blotting for the detection of clonality by gene rearrangement studies.

Evidence for ecto-protein kinase activity on the surface of human neutrophils.

Recent studies have suggested a possible role for extracellular ATP in neutrophil function. This report provides evidence for the existence of an ecto-protein kinase activity on the surface of human neutrophils capable of phosphorylating intrinsic cell membrane proteins as well as exogenous proteins. Addition of extracellular [gamma-32P]ATP to neutrophils resulted in rapid incorporation of 32P into cellular proteins that were sensitive to trypsin. The ability of adherent cells to phosphorylate the exogenous substrate casein, while no protein kinase activity was released into the supernate, provided further evidence for a cell surface associated protein kinase activity.