Induction of apoptosis--new targets for cancer chemotherapy

Many anticancer agents induce an active cell death process, apoptosis, in sensitive tumour cells. Elucidation of molecular mechanisms underlying apoptosis may shed light on why some tumour cells survive chemotherapy, and may identify new targets for anticancer agents whose effects are not tightly linked to proliferative status. The signal transduction events which initiate apoptosis are unclear. A change in cytosolic calcium is generally assumed to be a key signal for apoptosis although the evidence for this is not conclusive. Other putative signal transducers which may modulate apoptosis are protein kinase C and cAMP. Genes which induce apoptosis in response to such signals are largely unidentified, but certain oncogenes, notably bcl-2, act to delay or suppress apoptosis in several cell types.

Growth and development in orthodontics

The recent literature on growth and development of the face and dentition includes important articles about assessment of growth, maturation, growth in the vertical dimension, treatment effects, experimental growth, and craniofacial anomalies. An underlying theme can be detected in these reports--the individuality of the child and his or her response to treatment. Central trends can be determined from growth data, but these generalizations should be applied with caution. When formulating treatment goals and planning mechanics, great variability can exist among growing children.

Cellular signalling events stimulated by myeloid haemopoietic growth factors

In haemopoietic cells, proliferation, commitment to development, lineage restriction and survival via suppression of apoptosis can all be controlled by haemopoietic growth factors. The mechanisms underlying the regulation of these events can now be studied since recombinant forms of most of these haemopoietic growth factors are now available. Recent advances in cell purification techniques and the development of multipotent cell lines (see Spangrude et al, 1988; Whetton, 1990; Heyworth et al, 1988, 1990a; Jones et al, 1990) have provided suitable cell populations on which to study the cellular signalling events associated with differentiation and lineage restriction. This process has started with the elucidation of the structure and expression of many of the myeloid growth factor receptors, which should now facilitate progress in the study of the signal transduction mechanisms these growth factors employ. Another important facet of these studies will be to determine whether a single growth factor with multiple target cell types, ranging from multipotent cells to postmitotic cells (e.g. neutrophils), employs distinct signalling mechanisms depending on the target cell in question. The cellular signalling events elicited by each of these growth factors and the ways in which they can regulate the transcriptional activation of genes associated with specific developmental events are going to be key areas of haemopoietic research in the next few years.

Sibling response to childhood cancer: a new approach

It is well recognized that serious illness in children can have important consequences for siblings who may manifest their concerns as behavioural difficulty. The aim of the present study was to explore sibling psychological response to childhood cancer and to observe the effects that sibling knowledge had on their response. Siblings and parents of patients at the Children's Hospital, Birmingham, were interviewed using the Achenbach Child Behavior Checklist and semi-structured 'Illness Knowledge' questionnaires designed by the first author. Siblings were not experiencing significant behaviour problems. The level of sibling knowledge about cancer was related to the level of sibling social competence but not to the prevalence of behaviour problems. One-third of the siblings were talking to no one at all about their feelings, and sibling feedback yielded some important sibling needs. It was concluded that sibling response to childhood cancer may not necessarily be pathological and may also be mediated by the level of sibling social competence as well as sibling knowledge.

Public health week: marketing the concept of public health

The Public Health Programs and Services (PHP&S) Branch of the Los Angeles County Department of Health Services began a strategic planning effort in January 1986 to meet new disease trends, curb rising health care costs, consolidate limited resources, and handle shifting demographics. A strategic plan was designed to assess the opportunities and challenges facing the agency over a 5-year horizon. Priority areas were recognized, and seven strategic directives were formulated to guide PHP&S in expanding public health services to a changing community. Health promotion was acknowledged as a critical target of the strategic planning process. Among the most significant results of the health promotion directive was the establishment of an annual Public Health Week in Los Angeles County. Beginning in 1988, 1 week per year was selected to enhance the community's awareness of public health programs and the leadership role PHP&S plays in providing these programs to nearly 9 million residents of Los Angeles County. Events in Public Health Week include a professional lecture series and the honoring of an outstanding public health activist and a media personality who has fostered health promotion. Other free community activities such as mobile clinics, screenings, and health fairs are held throughout the county. With intensive media coverage of Public Health Week, PHP&S has been aggressive in promoting its own services and accomplishments while also educating the community on vital wellness issues. The strategic methodology employed by PHP&S, with its emphasis on long-range proactive planning, is receiving national recognition and could be adopted by similar agencies wishing to enhance their image and develop unique health promotion projects in their communities.

Psychosocial adjustment in children with hemifacial microsomia and other craniofacial deformities

Psychosocial adjustment was evaluated in different groups of children with craniofacial deformities in order to examine the relationships between symmetry, functional impairments, and social adaptation. Thirty patients, ages 6 through 16 years, were assessed using a battery of standard psychologic measures including Human Figure Drawing, Tasks of Emotional Adjustment, and Children's Depression Inventory. Parents and teachers also provided ratings of the children's functioning using the Child Behavior Checklist (parent and teacher forms). Scores on the outcome measures were summarized with descriptive statistics and then multivariate analyses of variance were conducted to determine the differences in psychosocial development between children with symmetric versus asymmetric craniofacial deformities and between the presence or absence of a functional impairment in children with craniofacial deformities. The results indicate that children with symmetric craniofacial deformities score poorer on measures of psychosocial adjustment than children with asymmetric deformities (F = 3.20, p less than 0.015); however, differences among the groups with or without functional impairments were not significant.

Gonadotropin, steroid, and inhibin levels in women with incipient ovarian failure during anovulatory and ovulatory rebound cycles

We have identified a group of women with infertility and regular menses who have persistently raised FSH levels and probable incipient ovarian failure (IOF). Thirteen such women (19 cycles) had serum samples taken for RIA of LH, FSH, estradiol, and progesterone (P) 3 times a week over 1 menstrual cycle. Sixty infertile women with normal ovulatory cycles (as determined by hormones and ultrasound scan) served as controls. Overall, the FSH was higher (P less than 0.01) on all days of the cycle in the IOF group, serum LH was raised on days-14 to-5 before and days 5-11 after the LH surge. There was no difference between estradiol and P levels in the two groups. Ultrasound scanning showed failure of normal ovulation in the IOF group. Inhibin, measured by RIA in 9 cycles in the IOF group was lower (P less than 0.01) during the follicular phase than in 43 normal cycles. The highest inhibin level was seen in the luteal phase, as in normal cycles, but levels were still lower (P less than 0.01) in the IOF group. Inhibin was inversely correlated with FSH (P less than 0.05) during the follicular and luteal phases and was correlated with P during the luteal phase (P less than 0.05) in the IOF group. After 3 weeks of suppression (39 cycles) with an estrogen-progestogen preparation in the IOF group, LH and FSH fell to normal values. Ovulation occurred in 22 cycles on withdrawal of suppression in the presence of high FSH levels and low inhibin levels. No pregnancies occurred. These findings are consistent with the suggestion that diminished ovarian inhibin secretion may contribute to the elevated FSH levels of IOF and indicate that ovulation in the rebound cycle after suppression occurs in the presence of high FSH and low inhibin levels. Such cycles, however, still appear to be subfertile.

Characterization of rat liver beta-adrenoceptors during perinatal development as determined by [125I]-iodopindolol radioligand binding assays

1. The subtype specificity of beta-adrenoceptors in foetal (20 days post coitum) rat liver membrane preparations has been determined by use of [125I]-iodopindolol binding assays and the characteristics of radioligand binding have been resolved. 2. The kinetics of radioligand association and dissociation (in the presence of 5 x 10(-4) M isoprenaline) showed an association rate constant of 1.5 x 10(7) M-1 S-1 and dissociation rate constant of 9.1 x 10(-4) S-1, corresponding to a dissociation constant for [125I]-iodopindolol of 60.7 pM. A similar dissociation constant (75 pM) was determined by saturation binding assays. 3. The rank order of potency for displacement of [125I]-iodopindolol binding was consistent with binding to a predominantly beta 2-adrenoceptor population (i.e. ICI 118551 greater than isoprenaline greater than adrenaline greater than noradrenaline greater than atenolol). Computer analysis of displacement curves in the presence of a beta 1-subtype selective agent (atenolol) or a beta 2-subtype selective agent (ICI 118551) revealed the presence of beta 2- and beta 1-adrenoceptor subtypes in a ratio of about 80:20%. 4. Saturation binding assays by use of [125I]-iodopindolol were carried out at different perinatal ages to determine total beta-adrenoceptor concentrations and beta 2-subtype (in the presence of 5 x 10(-7) M atenolol) adrenoceptor concentrations. Competition binding assays with atenolol confirmed that at all ages apparent beta 2-adrenoceptor binding accounted for 84-95% of the total beta-adrenoceptor binding. The total beta- and beta 2-adrenoceptor binding capacity increased by 2.3 fold from 20 days post coitum to birth, and then decreased postnatally at 1 and 2 days post partum. The dissociation constant for [125I]-iodopindolol binding did not show any change with age. 5. The change in beta 2-adrenoceptor concentration with age is discussed in relation to the changing beta-adrenoceptor-mediated responsiveness of glucose production by rat liver during perinatal development.

Simultaneous pressure and 19F NMR pH measurements of smooth muscle cells of intact hog carotid arteries at rest and during contractions with norepinephrine

Using 19F NMR we have measured the intracellular pH of the vascular smooth muscle cells of hog carotid arteries at rest and during contractions induced with norepinephrine. Experiments were performed on single, intact arteries closed at both ends, superfused from the lumen and loaded with the 19F NMR pH indicator alpha-difluoromethylalanine. At rest, luminal pressure was maintained at 100 +/- 2 mm Hg and intracellular pH was 7.12 +/- 0.04. Contractions elicited with 10(-5) M norepinephrine were associated with a pressure increase of 18 +/- 6 mm Hg and a decrease in pH of 0.04 +/- 0.02 units.

Facial skeletal changes following hypertelorbitism correction

This is a retrospective study of skeletal changes in 19 patients with corrected hypertelorism. A favorable outcome, defined as relapse less than 5 mm, occurred in patients with an average interorbital distance of 32 mm, whereas patients with an average interorbital distance of 40 mm tended to relapse over 5 mm. Neither age, interorbital configuration, nor diagnosis affected the stability of orbital translocation. At last evaluation (mean 6.7 years postoperatively), the mean interorbital distance was 22.4 mm in the favorable outcome group and 28.3 mm in the unfavorable category. This study suggested that the standard hypertelorism operation may interfere with anterior facial growth. Unless psychosocial factors predominate in a child with mild deformity, repair should be postponed until late adolescence. In a young child with gross telorbitism, nasoethmoidal resection and transmaxillary osteotomies or facial bipartition is justified. Another long-term skeletal problem was resorption of the reconstructed nasal complex. Technical and biological explanations for this are given. The correction of hypertelorism is surgery of the nose and of the midface.

RED: a red-cell antibody identification expert module

We describe a software module in an expert system RED, which interprets data related to red cell antibody identification. There are three portions to this module: the problem-solving component, which incorporates the knowledge required for antibody identification as a hierarchy of programs. The programs in the hierarchy organize within themselves small pieces of knowledge represented in the form of production rules, which are capable of making judgments concerning a specific hypothesis; an intelligent data base for storage of patient data, red cell attributes, and test results; the "overview critic" portion, which combines the atomic hypotheses judged favorably by the antibody programs into a unified judgment concerning the case. Overview makes the decision to terminate processing with a conclusion about which antibodies are actually present and what specific further tests need to be performed to resolve any remaining ambiguities.

CSF-brain permeability in the immature sheep fetus: a CSF-brain barrier

The permeability of the neuroependyma between CSF and brain extracellular space has been studied in fetal sheep of 60 and 125 days gestation. Both radioactive ([3H]inulin, [14C]sucrose, [125I]albumin) and visible (horseradish peroxidase) markers have been perfused through the ventricular system for periods of up to 5 h in anaesthetized exteriorized fetal sheep whose physiological condition was monitored continuously. A previously undescribed barrier between CSF and brain extracellular fluid has been discovered in the immature (60-day) fetal sheep. Horseradish peroxidase penetration was confined to a limited depth of the neuroependyma and was mainly into the cells lining the cerebral ventricles; in older fetuses there was extracellular penetration to a distance of several millimetres from the ventricular surface, as previously described in adult animals. The volumes of distribution of sucrose and insulin were less in the immature brain than in the more mature brain, which may be a reflection of restricted diffusion across the neuroependyma in the younger brains. The morphological nature of the barrier in fetuses of 60 days and younger appears to be a membrane specialization between the cells of the neuroependyma. It is of a type not previously described; it seems to have the effect of narrowing rather than obliterating the extracellular pathway between CSF and brain. The possible functional significance of this observation is discussed.

The bacterial flora of the forehead and back of Alaskan native villagers in summer and in winter

The bacterial flora of the forehead and back of Eskimo and Indian villagers in arctic Alaska was determined in midsummer and in winter (temperature -29 degrees to -46 degrees C). Specimens collected by the wet swab method were transported overnight, chilled, to Seattle in buffered diluent with Triton X-100. Control tests showed good survival of principal skin organisms with moderate or large initial populations and a disproportionately greater loss with an initial sparse population. Results of these studies are compared with earlier studies of the forehead flora of a Seattle urban population. On most Alaskan subjects Propionibacterium acnes was more abundant than staphylococci on both sites and both organisms had greater population densities on the forehead than on the back. Population densities for P. acnes varied from none detected to more than 10(6) per cm2 on the forehead and 10(5) per cm2 on the back. For coagulase-negative staphylococci the range was from none detected to more than 10(5) per cm2 on the forehead and the back. The proportion of subjects with relatively abundant or relatively sparse populations of P. acnes and of staphylococci did not change seasonally. Of 51 staphylococcal isolates, 65% were S. epidermidis, 22% S. capitis, and 10% S. hominis. P. saccharolyticus was found on a minority of subjects on both sites. The kinds of organisms found on the forehead and their variable individual population densities were essentially the same on the Alaskan villagers and the Seattle subjects.

Comparison of proteins in CSF of lateral and IVth ventricles during early development of fetal sheep

This study examines the relationship between plasma proteins in blood and in CSF in the developing brain of sheep fetuses between 30 and 60 days gestation. Five proteins account for the very high concentration of protein in fetal CSF (over 1000 mg/100 mg/100 ml at 30 days): alpha-feto-protein, fetuin, albumin, alpha 1-antitrypsin and transferrin; the concentration of each protein is similar in lateral and IVth ventricular CSF at 30 days. By 40 days there is considerable decrease in protein concentration in lateral ventricular CSF. At this age in the IVth ventricle the overall total was unchanged, although there were changes in concentration of individual proteins. At 60 days the concentration of each protein in both compartments had fallen below that at 40 days; the marked concentration difference between lateral and IVth ventricular CSF was still present. Experiments using i.v. [125I]- or [3H] labeled plasma proteins in 30-40-day fetuses showed that very little protein penetrated into lateral ventricular CSF by 3-5 h after injection; in the same experiments [125I]albumin reached a CSF/plasma ratio of about 15% in the IVth ventricle (compared with 55% for the natural steady state). Autoradiographic studies carried out on material from the same animals did not give evidence for transfer of labeled protein across the choroid plexuses although any such penetration may have been below the threshold of the method. Other explanations for the high concentration of protein in CSF that were considered include penetration via cerebral vessels and synthesis of plasma proteins by choroid plexus epithelial cells or neurons within the brain.

Mechanical measurement of red cell membrane thickness

The thickness of intact human red cell membrane is measured by a light-microscope technique in which membrane material with a known surface area is extracted into a long, thin cylindrical strand. The radius of the strand is calculated from its known length and surface area. The minimum radius, obtained at high extraction velocities or large membrane tensions, is 55 angstroms. A collapsed membrane cylinder with a mean-mass radius of 55 angstroms would have a membrane thickness of 78 angstroms.

The effects of indomethacin on uterine activity and prostaglandin (PG) concentrations during labor induced by administering ACTH to fetal sheep

To assess the importance of endogenous prostaglandins in parturition, we have examined the effects of indomethacin on maternal steroid concentrations and on the frequency and maximum amplitude of uterine contractions during delivery induced by administering adrenocorticotrophic hormone (ACTH) to fetal sheep. Uterine contractions were evaluated by measuring amniotic fluid pressure in chronically catheterized sheep, 130-days pregnant treated for 70 h with continuous infusions of intrafetal ACTH1–24, and with indomethacin or vehicle into the maternal femoral vein. Maternal plasma progesterone and estrone concentrations and fetal plasma Cortisol concentrations were estimated by radioimmunoassays (RIAs). Concentrations of prostaglandin E (PGE), PGF, and 6-oxoPGF1α (the hydrolysis product of PGI2) were measured by RIAs in myometrium, endometrium, cotyledons, amnion, and chorioallantois at different locations of the uterus. Labor was initiated after 70 h intrafetal ACTH treatment as indicated by a significant fall in maternal progesterone (P4) and rises in maternal plasma estrone (E1) and fetal plasma Cortisol concentrations, and by increased frequency and maximum amplitude of uterine contractions. indomethacin treatment had no significant effect on maternal plasma P4 or E1. Prostaglandin (PG) concentrations within uterine tissues varied with different uterine areas. However, overall, indomethacin significantly decreased concentrations of all PGs in all tissues examined, except for PGE in myometrium and endometrium. Indomethacin administration reduced the degree of cervical softening. After ACTH infusion alone there was an increase in the frequency and maximum amplitude of uterine contractions. In animals receiving concomitant indomethacin the frequency, but not the maximum amplitude of contractions, was significantly decreased. These results suggest that PGs play a role in the regulation of myometrial activity during ovine parturition, and that their action may be directed towards the modulation of the frequency of uterine contractions.

Eight year persistence of individual differences in the bacterial flora of the forehead

Eight subjects having a rich (greater than or equal to 100,000 per cm2) population of Propionibacterium acnes on the forehead and 7 with a sparse population (great than or equal to 15,000 per cm2) in earlier tests were reexamined after median interval of 8 yr. All of those with an initial rich population had greater than or equal to 100,000 per cm2 on retest. Of the 7 with an initial sparse population, 4 again had fewer than 15,000, one had more than 100,000 per cm2 and 2 were intermediate. Three subjects harbored Peptococcus saccharolyticus in the initial test (26,000 to 75,000 per cm2) and all 3 carried this organism on the later test (5,000 to 49,000 per cm2). Of the 12 without P. saccharolyticus initially, 11 were again negative and one had a small number (200 per cm 2). We conclude that the presence or absence of P. saccharolyticus and the relative population density of P. acnes were individual characteristics that persisted in most subjects for at least 8 yr.