Thromboxane A2 and Prostacyclin Release in Bleeding Time Blood during Primary Haemostasis in Healthy Individuals

ABSTRACT It is generally believed that prostacyclin (PGI₂) generation is greatly stimulated when blood vessels are injured, even by minor trauma, such as venepuncture. The Simplate technique for measuring skin bleeding time was adapted to quantify by radioimmunoassay PGI₂ and thromboxane A₂ (TXA₂) in the emerging blood, as the stable degradation products 6-keto-prostaglandin F_1α (6-keto-PGF_1α) and thromboxane B₂ (TXB₂), both of which were measured in venous plasma as well as in serum (clotted at 37°C for 1 h). During bleeding, when platelets aggregate to occlude the injured vessels, the median TXB₂ level in the emerging bleeding time blood was 1.7 ng/ml. The median TXB₂ level in plasma was < 1 ng/ml and in serum 275 ng/ml. The levels of immunoreactive 6-keto-PGF_1α were always below determination limit in bleeding time blood (0.2 ng/ml) and in plasma (0.1 ng/ml), whereas in serum the levels ranged between 0.26 and 0.47 ng/ml. The fact that enhanced PGI₂ production in primary haemostasis in skin incisions could not be demonstrated calls for further investigations of possible PGI₂ production with more sensitive assays or in injured large vessels.     

Intensity of Jogging

The relationship between intensity of jogging and various menstrual/reproductive factors in women were investigated. Data were collected by questionnaire from 319 women who participated in a running event that included both a 6.2-mile (10 K) run and a 26.2-mile marathon in northeastern Ohio. Findings reaffirmed the notion that scant menstrual flow, skipped menses, and menstrual irregularity are significantly related to the intensity of jogging; age at menarche, infertility, and uterine prolapse were not. Thirty-two percent of the women felt that jogging decreased their menstrual discomfort, and 44% reported better jogging performance right after or between menstrual periods.     

Influence of Lead on Mineralization during Bone Growth

Lead will inhibit skeletal development and localize in areasof bone formation and resorption, but the mechanisms of leadtoxicity in bone are largely unknown. This study used an ectopicbone (plaque) induction method to investigate the effect oflead on mineralization of cartilage in growing bone. Demineralizedbone matrix was subcutaneously implanted in male Long-Evansrats to induce plaque formation. Of 64 rats which were provideddeionized water, 32 were implanted with control matrix (controlgroup). The remaining 32 rats were implanted with matrix containinga target concentration of 200 µg lead/g of plaque tissueas ectopic bone (lead-added group). Another group of 32 ratswas continuously exposed to 1000 ppm lead in drinking waterand subcutaneously implanted with control matrix (drinking water-leadgroup). Plaques were taken for analysis on Days 8 and 12 postimplantation.Alkaline phosphatase activity and cartilage mineralization wereobliterated in lead-added plaques. However, calcium depositionwas markedly enhanced in the lead-added plaques. Decreased alkalinephosphatase in Day 8 drinking water-lead plaques followed increasedDay 12 drinking water lead plaque calcification. Enhanced cartilagecalcification and reduced alkaline phosphatase activity in thedrinking water-lead plaques was consistent with effects observedin the metaphyseal regions of bone in lead-exposed rats andpigs. The results of this study suggest that lead adverselyinfluences bone development through disruption of mineralizationduring growth.     

Development of the PAAI as a Measure of Attitudes of Parents with Preschool Children Toward Substance Use and Abuse

Because parents have a major impact on their preschool children's development, the study of parental attitudes is crucial to understanding substance abuse behavior. This study examined the reliability of an instrument to measure attitudes of parents with preschool children regarding substance use and abuse. The sample consisted of a lower to middle socioeconomic, racially diverse population of 101 parents of preschool children. The Parent Attitude Assessment Instrument (PAAI) measured parents' attitudes toward substance use and abuse, parental role modeling, and substance abuse prevention with preschool children.     

Actinomyces viscosus and Actinomyces naeslundii agglutinins in human saliva

Abstract – The objectives were to determine the degree of Actinomyces agglutinating activity in human saliva and to begin characterizing the agglutination mechanism. Agglutination titres of whole saliva collected from adults and 6-yr-old children were compared. Titres for A. naeslundii were always higher than for A. viscosus. The mean A. naeslundii titre for the adults’ and children's samples were equivalent. The children had a slightly lower mean titre than the adults for A. viscosus. No correlation was found between IgA concentration and agglutination titre. Agglutinating activity was partially impaired by incubation with anti-IgA serum. Activity in submandibular/sublingual saliva was resistant to heat at 56°C but sensitive to boiling. Boiling the bacteria had no effect. In sugar inhibition tests, only galactosides (β-Gal) and glucosamine (for A. viscosus) affected Actinomyces agglutination but impairment was only temporary. Agglutinating activity was diminished by incubating saliva with hydroxyapatite. Thus, Actinomyces agglutinins 1) are probably distinct from IgA but may complex with it; 2) may include both β-Gal and higher affinity sites; and 3) may contribute to salivary pellicle.     

Remission Maintenance Therapy for Meningeal Leukemia: Intrathecal Methotrexate vs. Intravenous bis-Nitrosourea

Central nervous system infiltrates havebecome a major cause of morbidityamong leukemic children and may constitute a site from which a remissionmarrow is again infiltrated. Conventionalintrathecal methotrexate (IT MTX) therapy produces excellent palliation andcomplete reversal of abnormal cerebrospinal fluid findings for periods rangingfrom 6 to 414 days (median 87 days).The CNS remission maintenance potential of (1) IT MTX, 12 mg/sq m, every6-8 wk, and (2) bis-nitrosourea (BCNU),100 mg/sq m intravenously, every 6-8wk were compared with "no therapy"maintenance. Only those children inCNS remission 6-8 wk following induction therapy were eligible for randomization to the maintenance study. Theduration of CNS remission for BCNU-maintained and "no therapy" patients wassimilar, with a median length of remission of 96 days and 112 days, respectively. The median duration of remissionfor the MTX maintenance group was 472days. The differences in length of CNSremission between the MTX group andthe other two groups were statisticallyhighly significant (p < 0.01 for bothcomparisons). Headache, fever, and/orvomiting occurred in 38% of the childrenafter one or more of the intrathecal maintenance treatments and, in general,symptoms tended to worsen as maintenance continued.

Submitted on May 4, 1971 Revised on June 24, 1971 Accepted on June 29, 1971     

Baculovirus Expression of the Respiratory Syncytial Virus Fusion Protein using Trichoplusia ni Insect Cells

Respiratory syncytial virus (RSV) is a major viral pathogen responsible for severe respiratory tract infections in infants, young children, and the elderly. The RSV fusion (F) protein is highly conserved among RSV subgroups A and B and is the major protective immunogen. A genetically-engineered version of the RSV F protein was produced in insect cells using the baculovirus expression system. To express a secreted form of this protein, the transmembrane domain was eliminated by removing the region of the gene encoding 48 amino acids at the C-terminus. Production of the truncated RSV F protein (RSV-Fs) was compared in two different insect cell lines, Spodoptera frugiperda (Sf9) and Trichoplusia ni (High Five). The yield of RSV-Fs secreted from High Five insect cells was over 7-fold higher than that from Sf9 insect cells. Processing of the RSV-Fs protein was also different in the two insect cell lines. N-terminal sequencing demonstrated that while most of the RSV-Fs protein secreted by High Five cells was correctly processed at the F<$>_2<$>–F<$>_1<$> proteolytic cleavage site, most of the RSV-Fs protein secreted by Sf9 cells was unprocessed or incorrectly processed. Antigenicity of the major RSV F neutralization epitopes was maintained in the RSV-Fs protein secreted from High Five cells. The RSV-specific neutralizing antibody titres in the sera of cotton rats immunized with the RSV-Fs protein were equivalent to those in the sera of animals intranasally inoculated with live RSV. Animals immunized with either live RSV or the immunoaffinity purified RSV-Fs protein from High Five cells were completely protected against live virus challenge.     

Regional perinatal mortality and regional hospitalization at delivery in The Netherlands

Summary. In The Netherlands 34–35 % of all deliveries still take place at home, but with considerable regional differences. A study was made of the relation between the perinatal mortality rate and the percentage of hospital deliveries in the 11 provinces of The Netherlands, in municipalities divided into groups according to the number of inhabitants, and in the 17 cities with more than 100 000 inhabitants. No relation could be demonstrated between the regional percentage of hospital deliveries and the regional perinatal mortality rate. The proportion of hospital delivery appears not to be a major factor determining the regional perinatal mortality rate in the current system of obstetric care in The Netherlands.