Low language capacity in childhood: A systematic review of prevalence estimates.

BACKGROUND AND AIMS: Epidemiological studies have provided invaluable insight into the origin and impact of low language skills in childhood and adolescence. However, changing terminology and diagnostic guidelines have contributed to variable estimations of the prevalence of developmental language difficulties. The aim of this review was to profile the extent and variability of low language prevalence estimates through a systematic review of epidemiological literature. METHODS: A systematic review of the empirical research (August 2022) was undertaken to identify studies that aimed to estimate the prevalence of low language skills in children (<18 years). A total of 19 studies published between 1980-2022 met inclusion criteria for review. RESULTS: Studies reported prevalence estimates of low language skills in children between 1 and 16 years. Estimated rates varied from 0.4% to 25.2%. More stable estimations were observed in studies of children aged 5 years and older and those that applied updated diagnostic criteria to performance on standardised assessments of receptive and expressive language. CONCLUSIONS AND IMPLICATIONS: The estimated prevalence of low language skills in childhood varies considerably in the literature. Application of updated diagnostic criteria, including the assessment of functional impact, is critical to inform advocacy efforts and govern social, health and educational policies. WHAT THIS PAPER ADDS: What is already known on the subject Epidemiological research has informed our understanding of the origin and impact of low language capacity in childhood. Childhood language disorder is met with a rich history of evolving terminology and diagnostic guidelines to identify children with low language skills. Inconsistent definitions of and methods to identify low language in children have resulted in variable prevalence estimates in population-based studies. Variability in prevalence estimates impacts advocacy efforts to inform social, health and educational policy for child language disorder. What this study adds A total of 19 studies published at the time of this review aimed to provide estimates of the proportion of children who experience low language skills. Prevalence estimates varied between 0.4% and 25.2%, with more stable estimates reported in studies of older school-age children and those which utilised standardised assessments of both expressive and receptive language. Few studies utilised assessments of functional impact of language difficulties, which is misaligned with updated diagnostic criteria for child language disorder. What are the clinical implications of this work? This review reports substantial variability in estimates of the proportion of children and adolescents who live with low language skills. This variability underscores the importance of applying updated diagnostic criteria to identify the prevalence low language in childhood. Efforts to estimate the prevalence of low language must include measures of functional impact of low language skills. This aligns with clinical recommendations, which call for routine assessment of functional outcomes. To this end, we require a unified understanding of the term 'functional impact' in the context of low language, including the development and evaluation of measures that assess impact across emotional, social and academic domains.

Growing Old in the Bible Belt: Resources for Aging LGBT Adults Living in the South.

There has been an increase in the literature about LGBT older adults in recent years; however, there is a need for further sociological quantitative research examining the impact of geographic region on LGBT aging. Utilizing data from a nationwide survey, this study focuses on the availability of LGBT-specific resources for LGBT aging adults living in the South. We examine the effects of community type and sociodemographics on the availability of LGBT-specific resources as well as the type of resources available. Findings reveal that in the South, community type, having a partner, household income, and education affect the LGBT-specific resources available. Of particular interest, LGBT-affirming faith organizations are identified as the resource most frequently available for LGBT aging adults in this region often referred to as the Bible Belt. Overall, this study sheds light on the LGBT-specific resources that are available to provide social support and help meet the unique needs of LGBT adults aging in the South.

Characterization of a human lymphocyte surface sialoglycoprotein that is defective in Wiskott-Aldrich syndrome.

gpL115 is a lymphocyte surface component that is deficient in patients with the X-chromosome-linked immune deficiency Wiskott-Aldrich syndrome (6). The glycoprotein nature of gpL115 is demonstrated through labeling in carbohydrate moieties by [3H]NaBH4 and its synthesis by lymphocytes through labeling with [35S]methionine. Native gpL115 adheres to wheat germ lectin-Sepharose and sialidase-treated gpL115 does not adhere, indicating that native gpL115 adheres via clusters of sialic acid residues. When tested on peanut lectin, which shows specificity for the disaccharide Gal beta 1-3GalNAc, gpL115 is nonadherent and sialidase-treated gpL115 is adherent, indicating the presence of the sequence sialic acid-Gal beta 1-3GalNAc, which is characteristic for O-linked (mucin-type, acidic-type) carbohydrates. A surface glycoprotein with all the above characteristics was found on the lymphoblastoid cell line CEM. CEM cells were used as immunogen to generate the monoclonal antibody L10, an IgG1, which binds native and sialidase-treated gpL115 . Sialidase-treatment of gpL115 significantly alters its physical properties, reducing its electrophoretic mobility and changing its behavior on isoelectrofocusing. Cumulatively, these findings indicate that gpL115 , like glycophorin of erythrocytes and GPIb of platelets, is a sialoglyco protein with significant quantities of O-linked carbohydrate. On treatment with limiting sialidase concentrations, gpL115 of normal lymphocytes is transformed into a series of partially desialylated species of decreasing electrophoretic mobility. This finding resembles the situation with lymphocytes of some Wiskott-Aldrich syndrome patients. Lymphocytes of eight Wiskott-Aldrich syndrome patients were found to be deficient in 125I-labeled gpL115 . Lymphocytes from three of these patients displayed an abnormal 125I-component of apparent mol wt 135,000.

Central object of the 30 doradus nebula, a supermassive star.

R136 (HD 38268) is the central object of the 30 Doradus Nebula, a giant region of ionized hydrogen in the Large Magellanic Cloud. Observations of R136 at low and high spectral resolution with the International Ultraviolet Explorer reveal a peculiar hot object with a massive stellar wind. An outflow speed of 3500 kilometers per second and a temperature of approximately 60,000 K are indicated by the spectra. The bulk of the observed ultraviolet radiation must come from R136a, the brightest and bluest component of R136. Its absolute visual magnitude and observed temperature imply a luminosity about 10(8) times that of the sun. Most of the ionizations produced in 30 Doradus are provided by this peculiar object. If RI36a is a dense cluster of very hot stars, about 30 stars of classes O3 and WN3 exist in a region estimated to have a diameter of less than 0.1 parsec. This is inconsistent with the ultraviolet line spectrum and the evidence for optical variability. An alternative interpretation of the observations is that the radiation from R136a is dominated by a single superluminous object with the following approximate properties: luminosity and temperature as given above, a radius 100 times that of the sun, a mass 2500 times that of the sun, and a loss rate of 10(-3.5) solar masses per year. Model interior calculations for hydrogen-burning stars are consistent with these parameters. Such stars, however, are expected to be unstable, and this may account for the massive stellar wind.

A trial of recombinant alpha 2 interferon in the myelodysplastic syndrome: II. Characterization and response of granulocyte and platelet dysfunction.

Because qualitative neutrophil and platelet dysfunction is an important concomitant of the myelodysplastic syndrome, functional studies were performed prospectively of cells from eight patients with myelodysplastic syndrome undergoing treatment with recombinant alpha 2 interferon. Neutrophil studies performed included myeloperoxidase release and superoxide anion generation, measured spectrophotometrically, in response to stimulation by phorbol-12-myristate-13-acetate, opsonized zymosan, and the chemotactic peptide formyl-methionyl-leucyl-phenylalanine (fMLP), respectively. The most consistently abnormal of these tests was the fMLP-stimulated superoxide anion generation, which was low in six of seven patients tested. Mean results with this test were significantly lower than controls (mean +/- SD = 5.11 +/- 2.41 nmol/10(6) patient cells vs. 10.14 +/- 3.02 with normal cells, p less than 0.001). No significant change was noted following 2 or 8 weeks of interferon therapy. Because of the severe thrombocytopenia prevalent in myelodysplastic syndrome, fewer platelet studies were feasible. One patient, however, exhibited normal platelet numbers but markedly decreased aggregation in response to arachidonic acid, epinephrine, and collagen. After 4 weeks of treatment, this patient's platelet aggregation was noted to be normal. Platelets from two patients were purified by gel filtration, and the ATP/ADP ratios were determined by HPLC. Pretreatment ATP/ADP ratio of one patient was 4.85 (normal = 1.85 +/- 0.28) which declined to 3.27 on treatment and then returned to 4.80 following a 14-day period off treatment. Another patient, also with elevated ATP/ADP, exhibited a smaller decline during a treatment cycle. From these studies it was concluded that fMLP-stimulated superoxide generation may be a sensitive marker for neutrophil dysfunction in the myelodysplastic syndrome. No evidence was found for improvement of neutrophil dysfunction following alpha 2 interferon treatment. alpha 2 interferon, however, may sometimes have beneficial effects upon platelet dysfunction.

Urinary lactic acid dehydrogenase activity and the site of urinary tract infections.

A report that elevated urinary lactic acid dehydrogenase (LDH) isoenzyme 5 activity is a reliable tool for separating patients with upper from those with lower urinary tract infections (UTIs) led us to study urinary LDH enzyme activity in girls having bladder washout studies to localize the site of infection. Urinary LDH isoenzyme 5 activity in 64 instances of lower UTI was 16.1 +/- 3.3%, a value not significantly different than that of 18.2 +/- 12.6% found in 26 instances of upper tract infection (t = 0.8726, P = 0.1928). The data show that LDH isoenzyme 5 activity is of no value for localization of the site of a UTI. The data of these studies also showed that urinary LDH enzyme activity clearly separates girls with UTIs from those without infections, but it is unlikely that this finding will be of value in diagnosis or management.

Idiopathic non-syphilitic paroxysmal cold haemoglobinuria in children.

Three examples of non-syphilitic paroxysmal cold haemoglobinuria (PCH) in children are described which occurred, within a period of 16 days, in association with a febrile illness. No definite viral aetiology or obvious epidemiological association could be established. A Donath-Landsteiner antibody of anti-P specificity was demonstrated in all three patients. The serological aspects of PCH are critically discussed.

Platelet adenine nucleotide levels in patients with Dacron vascular prostheses.

Platelets adenine nucleotide levels were determined in 11 patients with Dacron bifemoral aortic prostheses using high performance liquid chromatography. Total platelet and dense granule adenine nucleotide levels were measured in neutralized perchloric acid extracts prepared from gel-filtered platelet suspensions and from platelet supernatants following thrombin-induced release of granule constituents respectively. Dense granule adenine nucleotide levels were significantly decreased in the patient group compared with age and sex-matched controls (p less than 0.01), whereas no differences in cytoplasmic adenine nucleotide levels were observed (p greater than 0.2). Platelet survival measurements were made on 3 patients; when grouped with control subjects, a positive correlation was observed between platelet survival and platelet dense granule ADP (r = 0.96; p less than 0.01). These results suggest that platelet dense granule adenine nucleotide content may be a clinically significant indicator of vascular graft thrombogenesis.

Blood sampling techniques in reptiles.

Disposition of the superficial blood vessels was studied in 38 species of reptiles with a view to examining their suitability for taking blood samples. It was concluded that the coccygeal veins were probably the most suitable for this purpose and the precise techniques for sampling from the different orders are described.

Platelet adenine nucleotide levels during room-temperature storage of platelet concentrates.

Platelet adenine nucleotide levels were measured in freshly prepared platelet concentrates and daily during storage at room temperature. Marked depletions in platelet adenosine triphosphate (ATP) and adenosine diphosphate (ADP) levels were associated with decrease in both plasma glucose levels and poststorage pH. In those concentrates with only moderate glucose consumption, platelet ATP and ADP levels were well preserved and the plasma pH remained above 6.0. The rate of glucose utilization and poststorage pH were greatly influenced by the concentration of contaminating leukocytes. These studies indicate that the rate of exogenous glucose consumption is an important factor affecting platelet adenine nucleotide levels during room temperature storage of platelet concentrates.

Rabbit erythrocyte purine nucleoside phosphorylase. Initial-velocity studies.

1. Concave-downward double-reciprocal plots were obtained for rabbit erythrocyte purine nucleoside phosphorylase when the concentration of Pi was varied over a wide range at a fixed saturating concentration of either inosine or deoxyinosine. Similar behaviour was also displayed by the calf spleen enzyme. 2. The degree of curvature of double-reciprocal plots was greatly modified by the presence of SO42-, introduced into the assay mixture with the linking enzyme xanthine oxidase; competitive inhibition by SO42- was observed over a narrow range of high Pi concentrations. 3. Partial inactivation with 5,5'-dithiobis-(2-nitrobenzoic acid) resulted in a marked alteration in the kinetic properties of the enzyme when Pi was the variable substrate. 4. Initial-velocity data are expressed in the form of Hill plots, and the significance of such plots is discussed.

Rabbit erythrocyte purine nucleoside phosphorylase. Differential-inactivation studies.

1. Qualitative studies on the stability of rabbit erythrocyte purine nucleoside phosphorylase showed a marked decrease in the susceptibility of the enzyme to thermal inactivation and digestion by proteinases of different specificities in response to certain of its substrates. 2. The extent to which inosine stabilizes the enzyme against thermal and proteolytic inactivation is related in a quantitative manner to the concentration of this substrate; it is proposed that differences in the rates of inactivation of the enzyme may reflect substrate-induced conformational changes in the enzyme structure that could alter the binding properties of the enzyme in a kinetically significant way. 3. A synergistic effect in the stabilization of the enzyme is observed in response to both substrates, inosine and phosphate, when the enzyme is inactivated with Pronase. 4. In the presence of substrate an increased rate of inactivation after reaction with 5,5'-dithiobis-(2-nitrobenzoic acid) is reported. 5. Differential-inactivation studies were also carried out with calf spleen purine nucleoside phosphorylase, and the results are discussed in relation to the kinetic properties displayed by this enzyme.