Regression to the mean

The notion of “regression to the mean” is widely misunderstood. This paper explains the concept in simple terms and shows how it arises in studies of mental and physical development.     

Spontaneous communication in autism spectrum disorder: A review of topographies and interventions

Lack of spontaneous communicative initiations appears to be a consistent problem in individuals with a diagnosis of autism spectrum disorder (ASD; Fujiki & Brinton, 2009). Spontaneous communication is emitted at a much lower frequency compared to individuals with language impairment and typically developing persons. Deficits of spontaneity in social interaction have been identified explicitly in the diagnostic criteria for autism, regardless of communication level or ability (American Psychiatric Association, 1994). In addition, without intervention 21–66% of children with ASD do not develop communicative speech (Lord & McGee, 2001). Individuals with autism rarely initiate appropriate speech and often fail to engage in typical social interactions such as asking questions, requesting information, expressing affection or requesting interactions (Carr & Kologinsky, 1983). This paper provides a review of the communicative topographies used to ameliorate spontaneous communication functions in individuals with autism and addresses the behavioral interventions that are used to induce such spontaneity.     

Ovaries in sexual precocity

BACKGROUND AND OBJECTIVE Ovarian Uh8SOnOgra-phy may be helpful in distinguishing the various types of precocious puberty, and the ovarian appearances Increasingly influence choice of therapy In these girls. We examined retrospectively the ovarian volume and prevalence of polycystic ovarian appearance at ultrasound in girls with sexual precocity. DESIGN Ultrasound examinations were obtained from girls who presented with sexual precocity. If there were several scans from the same Individual, the latest was analysed. PATIENTS The girls were divided Into groups: untreated central precoclous puberty (n= 25), central precocious puberty treated with GnRH analogue (n= 18) or with GnRH analogue and recombinant human OH (n= 11), girls who had stopped treatment with GnRH analogue and GH (n= 12), premature thelarche and thelarche variant (n= 15) and premature adrenarche (n= 14). MEASUREMENTS Ovarian volume was calculated and the ovaries were assessed for polycystic appearance using standard criteria. Ovarian volume standard deviation (SD) scores were calculated using means and standard deviations derived from a control population and compared using analysis of variance. Differences from control data were assessed using Student's t-test. RESULTS Ovarian volume SD scores for all the groups studied were greater than those for control subjects. Girls who had stopped treatment with GnRH analogue and GH had mean ovarian volume of 6.98 mi and ovarian volume SD score (+1·72) greater than that of girls having treatment with GnRH analogue alone (+1·24). Polycystic appearance ovaries were found in 83% of scans in girls who had stopped treatment with GnRH analogue and GH. The ovarian volume SD score of girls with premature adrenarche was less than that of girls with untreated central precoclous puberty. CONCLUSIONS Girls with central precocious puberty had large ovaries which did not return to a volume appropriate for age. Girls treated with GnRH analogue and GH developed very large ovaries when they stopped treatment, and had an Increased prevalence of ovaries with a polycystic appearance. Central precocious puberty, or some aspect of Its treatment, results In an Increased prevalence of polycystic ovarian appearance.     

Kidney aminopeptidase A and hypertension, part I: spontaneously hypertensive rats

Tissue and plasma levels of aminopeptidase A (APA), the principal enzyme that hydrolyzes angiotensin II (Ang II) to angiotensin III, were measured in spontaneously hypertensive rats (SHR) and their normotensive control strain at 3 different ages corresponding to prehypertensive (4 weeks), developing (8 weeks), and established (16 weeks) phases of hypertension. Plasma APA activity was significantly but modestly elevated in SHR at all 3 ages compared with normotensive Wistar-Kyoto rats. Likewise, levels of APA in brain, heart, and adrenal gland were generally, but again only moderately, elevated in SHR at all ages. However, a large increase in APA activity was seen within the kidney in which APA levels were elevated 41%, 51%, and 68% in SHR at 4, 8, and 16 weeks of age, respectively. Kidney APA levels were also significantly increased in immunoblots from 8- and 16-week-old SHR. Glomeruli isolated from 16-week-old SHR had 57% higher APA activity and increased immunoreactivity compared with Wistar-Kyoto rats. To determine whether the increase in kidney APA activity in SHR was related to Ang II levels, SHR were treated for 2 weeks with the angiotensin-converting enzyme inhibitor captopril. Captopril treatment reduced blood pressure to normotensive values and resulted in a 25% reduction in kidney APA activity. These results suggest that APA expression in the kidney may be regulated by activity of the renin-angiotensin system. If so, this would further suggest that upregulation of APA during conditions in which Ang II levels were elevated would have a protective effect against Ang II-mediated cardiovascular diseases, whereas a decrease in APA expression or a failure to upregulate would exacerbate such conditions.     

Toward the development of a test for growth hormone (GH) abuse: a study of extreme physiological ranges of GH-dependent markers in 813 elite athletes in the postcompetition setting

There is a need to develop a test to detect GH abuse by elite athletes. Measured levels of GH in blood or urine, however, provide little information on the GH-IGF-I axis. Previous studies have identified a series of indirect markers of GH action that are markedly altered by the administration of GH, but to a lesser degree by acute exercise. This study was undertaken to determine the physiological range of these GH-dependent variables in elite athletes after a competitive event to determine whether such values differ from resting values in normal and athletic subjects and to establish whether any adjustments to this range are required on the basis of age, gender, demographic characteristics, or the nature of the exercise performed. Serum samples were collected from 813 elite athletes (537 males and 276 females; age range, 17-64 yr) from 15 sporting disciplines within 2 h of completion of a major competitive event. IGF-I, IGF-binding protein 2 (IGFBP-2), IGFBP-3, acid-labile subunit, and the bone and soft tissue markers, osteocalcin, carboxyl-terminal propeptide of type I procollagen, carboxyl-terminal cross-linked telopeptide of type I collagen, and procollagen type III were measured. Sporting category, gender, age, height, weight, body mass index (BMI), and racial group of the athlete were documented, and results were compared both to normative data and to values obtained from elite athletes under resting conditions. Forty-one percent of IGF-I values in male athletes and 41% of values in female athletes were above the upper limits of 99% reference ranges derived from resting values in a normal population. Postcompetition levels of all variables except carboxyl-terminal propeptide of type I procollagen and carboxyl-terminal cross-linked telopeptide of type I collagen differed from resting values. There was a consistent age-dependent fall in measured levels of all variables (P < 0.0001) with the exception of IGFBP-2, which increased with age (P < 0.0001). BMI, but not height, exerted a small, but significant, influence on several variables. After adjustment for age, there were no significant differences in the levels of any of the measured variables between sporting categories. IGFBP-2 and IGFBP-3 were lower in 35 black athletes compared with those in 35 white athletes matched for age, gender, height, BMI, and sporting category. We have demonstrated that there are predictable age-dependent levels of GH-dependent markers in elite athletes that are consistent even at the extremes of physical exertion and that these are independent of sporting category. Normative data applicable to white athletes are provided. This provides important groundwork for the development of a test for GH abuse, although these values may be specific for the reagents and assays used.     

Autochthonous dermal leishmaniasis in Texas.

Over a 2-year period two cases of dermal leishmaniasis of special interest were recognized in Texas. The first occurred in 1972 in a 74-year-old woman who had residences in Dilworth and Gahzales, Gonzales County, and the other was in a 56-year-old man from Kenedy, Karnes County, in 1974. Both cases were biopsy- and culture-positive, and the second patient exhibited anti-Leishmania antibodies by indirect immunofluorescent antibody and direct agglutination tests. Epidemiologic investigation revealed no association between the two cases and suggested that both patients had acquired their infections locally in southern Texas. Moreover, serologic evidence of Leishmania infection was uncovered in a neighbor of the second case and in 3 dogs living nearby. Potential sylvatic reservoirs and arthropod vectors of the disease are resident in the area. Epidemiologic data suggest that dermal leishmaniasis is endemic in south-central Texas.     

Circulating immunoreactive oxytocin during the human menstrual cycle comes from the pituitary and is estradiol dependent

The aims of this study were to 1) evaluate the relative contributions of hypothalamic and ovarian oxytocin (OT) to peripheral serum concentrations and 2) determine the relationship between serum OT and ovarian steroid concentrations. Four groups of women were studied: 1) women with spontaneous cycles (n = 4) and normal serum estradiol (E2), progesterone, LH, and FSH levels; 2) in vitro fertilization (IVF) patients (n = 8) undergoing ovarian hyperstimulation; 3) agonadal oocyte-recipient patients (n = 6) receiving replacement E2 and P therapy; and 4) postmenopausal women (n = 21). Peripheral serum samples were collected daily during a menstrual cycle from the normal and agonadal women and for 6 days before ovulation in the IVF group. Serum immunoreactive OT was measured by specific RIA after Sep-Pak extraction; the assay sensitivity was 0.6 pmol/L. Serum OT in the women with normal cycles increased during the follicular phase, reaching a peak 1 day after the LH surge, and decreased in the luteal phase [days 7, 16, and 21, 10.7 +/- 3.5 (mean +/- SE), 25.7 +/- 5.7, and 13.2 +/- 2.5 pmol/L, respectively; P less than 0.05]. Serum OT levels were higher in IVF patients before ovulation than in women with spontaneous cycles, but lower than those in the agonadal women, who had a peak value (49.1 +/- 9.6 pmol/L; P less than 0.05) on day 13 of E2/progesterone replacement therapy. Serum OT was positively correlated (r = 0.68, normal women; r = 0.91, oocyte recipients) with serum E2 values during the first part of the cycle (P less than 0.01). A similar positive correlation between serum OT and E2 was found in the postmenopausal women (r = 0.83). We conclude that serum OT before and around the time of ovulation comes mainly from the pituitary, and not from the ovary, and is E2 dependent.