New products related to kinamycin from Streptomyces murayamaensis. I. Taxonomy, production, isolation and biological properties

Six new products of Streptomyces murayamaensis sp. nov. Hata et Ohtani, the producer of the kinamycins, were isolated by silica gel column chromatography. The antibacterial activities of the new products, as well as that of dehydrorabelomycin and murayaquinone, previously isolated products of the same organism, were compared to the kinamycins. Three of the products had antibacterial activities similar to the kinamycins, while two others had activity only against Gram-positive bacteria. Dehydrorabelomycin and one other metabolite had no detectable antibacterial activity. The organism was found to be capable of aerial mycelium formation, with sporophores branched at regular intervals bearing square-ended spores with smooth surfaces. The culture contains L,L-diaminopimelic acid in the cell wall (Type I), is highly resistant to lysozyme, and lecithinase- and melanin-positive, suggesting a relationship with the genus Streptoverticillium and the lavendulae group of the genus Streptomyces.

New products related to kinamycin from Streptomyces murayamaensis. II. Structures of pre-kinamycin, keto-anhydrokinamycin, and kinamycins E and F

Four new colored components of Streptomyces murayamaensis sp. nov. Hata et Ohtani, the producer of the kinamycins, have been isolated and their structures determined by a combination of mass spectral, high field NMR and biosynthetic techniques. The first compound with the benz[b]carbazole skeleton in the biosynthetic pathway of kinamycin D has been named "pre-kinamycin" (7). A keto-epoxide kinamycin intermediate has been labeled "keto-anhydrokinamycin" (9), and the 1'-monoacetate of kinamycin has been called kinamycin E (12). Natural production of deacetylkinamycin (13, now labeled kinamycin F) by S. murayamaensis has been confirmed by an isotope trapping experiment. The role of these new intermediates in kinamycin biosynthesis is discussed.

The use of health care services: is illness the only motivator?

Increasingly, consumer researchers and marketers have turned their attention to the marketing of health care services. In that vein, this paper addresses the question of what determines a consumer's use of these services. Through a review of relevant studies, an examination is made of such factors as illness, social and behavioral variables, and changing attitudes toward health, which have been prompted by various social movements. It is concluded that while illness is a critical factor in the use of health care services, other factors are playing an increasingly important role. Strategic marketing implications are offered as to how health care marketers should address the illness factor in the promotion and delivery of care services. Finally, future research directions are suggested which would help to define and gauge the role of illness in the consumption and strategic marketing of health care services.

Firefly luciferase as a tool in molecular and cell biology

The unique properties of firefly luciferase and the cloning of the gene for this enzyme have spawned a number of novel applications of this protein. We summarize a few of these applications including its use as a reporter gene, as a model for the study of protein import into peroxisomes, and as a component of a heterologous gene expression system.

An immunocytochemical study of the germinal layer vasculature in the developing fetal brain using Ulex europaeus 1 lectin

The characteristics of the germinal matrix vasculature were studied in the developing fetal brain using immunocytochemical methods. A preliminary comparative immunocytochemical study was made on six fetal brains to compare endothelial staining by Ulex europaeus I lectin with that of antibody to Factor VIII related antigen. Ulex was found to stain germinal layer vessels better than Factor VIII related antigen. Subsequently, the germinal layers of a further 15 fetal and preterm infant brains ranging from 13 to 35 weeks' gestation were stained with Ulex europaeus I to demonstrate the vasculature. With increasing gestation, there was a gradual increase in vessel density, particularly of capillaries. This was not a uniform process. A plexus of capillaries was prominent immediately beneath the ependyma while the more central parts of the germinal matrix contained fewer, but often larger diameter, vessels. The variation in vessel density which was a feature of the later gestation brains may have implications for local blood flow and may be a factor in haemorrhage at this site.

Identification of peroxisomal targeting signals located at the carboxy terminus of four peroxisomal proteins

As part of an effort to understand how proteins are imported into the peroxisome, we have sought to identify the peroxisomal targeting signals in four unrelated peroxisomal proteins: human catalase, rat hydratase:dehydrogenase, pig D-amino acid oxidase, and rat acyl-CoA oxidase. Using gene fusion experiments, we have identified a region of each protein that can direct heterologous proteins to peroxisomes. In each case, the peroxisomal targeting signal is contained at or near the carboxy terminus of the protein. For catalase, the peroxisomal targeting signal is located within the COOH-terminal 27 amino acids of the protein. For hydratase:dehydrogenase, D-amino acid oxidase, and acyl-CoA oxidase, the targeting signals are located within the carboxy-terminal 15, 14, and 15 amino acids, respectively. A tripeptide of the sequence Ser-Lys/His-Leu is present in each of these targeting signals as well as in the peroxisomal targeting signal identified in firefly luciferase (Gould, S.J., G.-A. Keller, and S. Subramani. 1987. J. Cell Biol. 105:2923-2931). When the peroxisomal targeting signal of the hydratase:dehydrogenase is mutated so that the Ser-Lys-Leu tripeptide is converted to Ser-Asn-Leu, it can no longer direct proteins to peroxisomes. We suggest that this tripeptide is an essential element of at least one class of peroxisomal targeting signals.

Precision of ultrasound diagnosis of pathologically verified lesions in the brains of very preterm infants

Abnormalities detected by a mechanical sector scanner were compared 'blind' with autopsy findings in the brains of 56 infants born at less than 33 weeks gestation. Intraventricular haemorrhage was found in 53 of 112 hemispheres and had been accurately diagnosed by ultrasound (sensitivity 91 per cent; specificity 81 per cent). Isolated germinal layer haemorrhage was less successfully identified (sensitivity 61 per cent; specificity 78 per cent); false-positive diagnoses were partly due to difficulty in distinguishing haemorrhage from the normal choroid plexus in extremely preterm infants. Haemorrhagic parenchymal lesions were correctly identified in nine infants (sensitivity 82 per cent; specificity 97 per cent). Only 11 of 39 hemispheres with histological evidence of hypoxic-ischaemic injury, without marked bleeding, were correctly identified by ultrasound (sensitivity 28 per cent), mainly because of failure to detect small areas of periventricular leucomalacia and diffuse gliosis. 10 hemispheres with periventricular echodensities thought to represent leucomalacia showed no histological evidence of hypoxic-ischaemic injury (specificity 86 per cent). Ventricular dilatation in seven infants was always associated with evidence of hypoxic-ischaemic injury at autopsy.

Physician professional opinion leadership and physician advertising: a consumer view

The author reports a study of consumers' attitudes toward information provided by personal physicians versus information provided by physicians' advertising and introduces the concept fo professional opinion leadership. The results provide evidence that the credibility of physicians is related to several attitude measures and that there are important differences in how individuals rate that credibility. Evidence also suggests that advertising by doctors is perceived as less credible than personally communicated information; nonetheless, some of the other findings indicate positive consumer response to such advertising. Comparisons are made with information provided by scientists and chiropractors.

Glial differentiation in the germinal layer of fetal and preterm infant brain: an immunocytochemical study

The germinal layer in preterm infants is a common site of intracerebral hemorrhage that is associated with increased mortality and morbidity in survivors. This matrix is composed of a mass of immature cells containing many thin-walled blood vessels. A major factor in the occurrence of hemorrhage at this site is the absence of a network of fibers to support these vessels. This immunocytochemical study has examined glial differentiation within the germinal layer of brains from fetuses and preterm infants of gestational ages 18 to 35 weeks. Progressive glial differentiation with gestation is described. This process is not uniform and the more posterior germinal layer, lying over the body of the caudate nucleus, demonstrates more rapid maturation than that lying anteriorly near the head of the caudate nucleus. Anteriorly, even at 35 weeks of gestation, a central core of germinal layer cells remains immature with little evidence of glial differentiation. These changes may be related to the occurrence and distribution of germinal layer hemorrhages in preterm infants of varying gestations.

An immunohistochemical study of the germinal layer in the late gestation human fetal brain

In the cerebral lateral ventricle of the human fetus, the embryonic ventricular and subventricular zones (VZ and SVZ) persist into the latter half of gestation, particularly in the lateral wall. The SVZ is usually referred to as the germinal layer at this stage. The VZ is gradually replaced by ependyma, a single epithelial layer composed of tanycytes and ciliated columnar cells. In the prematurely born infant, the germinal layer is frequently the site of haemorrhage, the incidence of which diminishes with increasing maturity. There are many contributory pathogenetic factors but the structure of the germinal layer itself is considered important. It contains numerous, thin walled vessels in a cellular matrix which demonstrates little fibrillary background. Immunohistochemical evidence of glial differentiation in the germinal layer was sought in 21 preterm brains, using antibody to glial fibrillary acidic protein (GFAP). Early immunoreactivity was due to GFAP positive tanycyte fibres. Subsequently, associated with astrocyte differentiation, there was progressive development of a glial fibre network. It is suggested that the increase in glial fibres may be a significant factor in capillary stabilization, and in the inverse relationship between gestation of the infant and the risk of intracerebral haemorrhage. The possible structural significance of the tanycyte is also highlighted.

Asymmetry of Lineages and the Direction of Evolutionary Time

Evolutionary time has a characteristic direction as demonstrated by the asymmetry of clade diversity diagrams in large statistical samples. Evolutionary groups generally concentrate diversity during their early histories, producing a preponderance of bottom-heavy clades among those that arise early in the history of a larger group. This pattern holds across taxonomic levels and across differences in anatomy and ecology (marine invertebrates, terrestrial mammals). The quantitative study of directionality in life's history (replacing vague, untestable, and culturally laden notions of "progress") should receive more attention from paleobiologists.

Misdiagnosis of omphalocele associated with Edwards syndrome and congenital heart disease

We present a case in which an apparent omphalocele, diagnosed at 30 weeks gestation by ultrasound, led to identification of fetal trisomy 18 and congenital heart disease. At delivery, the fetus had the features of trisomy 18 and congenital heart disease but the omphalocele was absent. We suggest that the appearances seen are easily confused with a small omphalocele and could potentially result in unnecessary further investigations being performed.

Periventricular intraparenchymal cerebral haemorrhage in preterm infants: the role of venous infarction

Haemorrhage into cerebral parenchymal tissue supero-lateral to the angles of the lateral ventricles is a major cause of death and disability in preterm infants. It is frequently associated with germinal layer and intraventricular haemorrhage but the mechanism by which parenchymal haemorrhage occurs is uncertain. Recent studies have suggested that it is due to bleeding into tissue previously damaged by ischaemia following cerebral hypoperfusion. We have studied 68 preterm infant brains, of which four contained early intraparenchymal haemorrhage supero-lateral to the angles of the lateral ventricles which were associated with large germinal layer and intraventricular haemorrhages. The anatomical distribution and histological features of these haemorrhages suggested that they resulted from venous infarction and that the venous drainage of the periventricular tissues had been obstructed by the germinal layer haemorrhages. In these four infants, bleeding into parenchymal tissues could be regarded as a complication of germinal layer and intraventricular haemorrhage rather than of cerebral hypoperfusion.

Early phosphorylation events following the treatment of Swiss 3T3 cells with bombesin and the mammalian bombesin-related peptide, gastrin-releasing peptide

Bombesin and the related mammalian peptides, such as gastrin-releasing peptide (GRP), are potent mitogens for some fibroblast cell lines. Here we have examined the bombesin- and GRP-mediated changes in the phosphorylation of proteins in Swiss 3T3 cells and compared these to the events observed after platelet-derived growth factor (PDGF), epidermal growth factor (EGF) and tumor promoter treatment. In agreement with previous reports, bombesin, GRP and PDGF, but not EGF, increased the activity of protein kinase C. This was assayed by an inhibition of [125I]EGF binding, stimulation in phosphorylation of pp60c-src on serine 12 and stimulation in phosphorylation of a group of 80 kd proteins. The different phosphorylated forms of the 80 kd proteins were examined by tryptic peptide mapping and shown to contain multiple phosphorylation sites. An investigation of the tyrosine phosphorylation events following mitogen treatment revealed a significant difference between PDGF and the bombesin peptides. PDGF treatment caused a marked increase in total cellular phosphotyrosine levels, and tyrosine phosphorylation both of known substrates and its own receptor. In contrast, bombesin and GRP treatments resulted in only a weak or undetectable increase in tyrosine phosphorylation of total cellular protein or known substrates. In this respect bombesin and GRP were more similar to EGF. The fact that the bombesin peptides do not induce a phosphorylation response identical with either PDGF or EGF suggests that there is not a single common signal pathway which is activated by all these mitogens.

Subglottic stenosis: a clinicopathological study

Subglottic stenosis is the most common serious long-term complication of endotracheal intubation in neonates and its pathogenesis is poorly understood. We describe the experience of one unit with 15 cases of subglottic stenosis requiring operative intervention seen over a 3-year period and review the pathology and pathogenesis of the condition. In 1 instance operative intervention was successful in treatment and avoided the need for long-term tracheostomy. A possible aetiological factor in at least 2 of the cases of subglottic stenosis was insertion of the wide shoulder of the endotracheal tube through the vocal cords. It is suggested that subglottic stenosis is due to reparative fibrosis following particularly severe acute intubation injury. Another factor may be delayed healing of the subglottic mucosa possibly exacerbated by full thickness cricoid cartilage necrosis. Although severe subglottic injury may occur at any time that the endotracheal tube is in situ, the most critical period is the first week of intubation.

The histopathology of the larynx in the neonate following endotracheal intubation

Subglottic stenosis is the most common serious complication of endotracheal intubation in the neonate with an incidence of between 1-8 per cent. While considered a complication of traumatic injury to the larynx and possibly associated with prolonged intubation, the pathogenesis is poorly understood and the pathology has not been described in detail. The nature of intubation induced injury has been investigated by examining step-sections of 43 larynges removed from neonates post-mortem who had been intubated for periods ranging from 10 min to 12 weeks. Focal ulceration was identified in the supraglottis and the anterior glottis. Similar injury was seen in the posterior glottis and subglottis but with more prolonged intubation there was full thickness mucosal necrosis, perichondritis and partial destruction of the arytenoid and cricoid cartilages. Although the severity of the injury progressed with time and many of the most severe injuries occurred early, in the second and third weeks of intubation, the larynx usually healed despite the continued presence of the endotracheal tube. Prolonged intubation on its own does not appear to be an important factor in the production of severe laryngeal injury nor, therefore, the subsequent complications such as subglottic stenosis.

The microslicing method in the study of temporal bone changes in the perinatal period: an interim report

The microslicing method was used to study the temporal bones of 49 perinatal deaths in the gross. X ray of the temporal bones was an important part of the investigation. The principle pathological changes were clearly observed. They were: acute otitis media in two cases; an anterior crural deformity of the stapes in four infants and haemorrhage of the apex of the fundus of the internal auditory meatus in 12. Primitive mesenchymal tissue was frequently seen in the infants of younger gestational age, but had largely disappeared by term.

Spinal cord transection, cerebral ischaemic and brain-stem injury in a baby following a Kielland's forceps rotation

A full-term infant suffered a high cervical cord transection after a Kielland 's forceps rotation and extraction. Quadriplegia developed immediately and initial cerebral swelling was followed by atrophy with ventricular dilatation on CT examination. Death occurred at 60 days. At post-mortem complete necrosis of the cervical cord at C2-C3 with old haemorrhage in the meninges was found, with damage to the inferior corpora quadrigemina , the thalamus, striatum, cerebellar and cerebral cortex. The mechanism is discussed briefly.

Darwinism and the expansion of evolutionary theory

The essence of Darwinism lies in the claim that natural selection is a creative force, and in the reductionist assertion that selection upon individual organisms is the locus of evolutionary change. Critiques of adaptationism and gradualism call into doubt the traditional consequences of the argument for creativity, while a concept of hierarchy, with selection acting upon such higher-level "individuals" as demes and species, challenges the reductionist claim. An expanded hierarchical theory would not be Darwinism, has strictly defined, but it would capture, in abstract form, the fundamental feature of Darwin's vision--direction of evolution by selection at each level.

The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme

An adaptationist programme has dominated evolutionary thought in England and the United States during the past 40 years. It is based on faith in the power of natural selection as an optimizing agent. It proceeds by breaking an oragnism into unitary 'traits' and proposing an adaptive story for each considered separately. Trade-offs among competing selective demands exert the only brake upon perfection; non-optimality is thereby rendered as a result of adaptation as well. We criticize this approach and attempt to reassert a competing notion (long popular in continental Europe) that organisms must be analysed as integrated wholes, with Baupläne so constrained by phyletic heritage, pathways of development and general architecture that the constraints themselves become more interesting and more important in delimiting pathways of change than the selective force that may mediate change when it occurs. We fault the adaptationist programme for its failure to distinguish current utility from reasons for origin (male tyrannosaurs may have used their diminutive front legs to titillate female partners, but this will not explain why they got so small); for its unwillingness to consider alternatives to adaptive stories; for its reliance upon plausibility alone as a criterion for accepting speculative tales; and for its failure to consider adequately such competing themes as random fixation of alleles, production of non-adaptive structures by developmental correlation with selected features (allometry, pleiotropy, material compensation, mechanically forced correlation), the separability of adaptation and selection, multiple adaptive peaks, and current utility as an epiphenomenon of non-adaptive structures. We support Darwin's own pluralistic approach to identifying the agents of evolutionary change.

Morton's ranking of races by cranial capacity. Unconscious manipulation of data may be a scientific norm

Samuel George Morton, self-styled objective empiricist, amassed the world's largest pre-Darwinian collection of human skulls. He measured their capacity and produced the results anticipated in an age when few Caucasians doubted their innate superiority: whites above Indians, blacks at the bottom. Morton published all his raw data, and it is shown here that his summary tables are based on a patchwork of apparently unconscious finagling. When his data are properly reinterpreted, all races have approximately equal capacities. Unconscious or dimly perceived finagling is probably endemic in science, since scientists are human beings rooted in cultural contexts, not automatons directed toward external truth.

The general practice and social work. Report on a trial

This report describes the experience of a social work student placement of 10 weeks' duration in a two-man general practice in Perth, Western Australia. The student was completing the final year of the degree of Master of Social Work at the University of Western Australia, and this was the student's third and final practical assignment. In particular, the report describes the means of referral, the nature and size of the social work service on the doctor-patient relationship.

Size and scaling in human evolution

Our general conclusion is simply stated: many lineages display phyletic size increase; allometric changes almost always accompany increase in body size. We cannot judge adaptation until we separate such changes into those required by increasing size and those serving as special adaptations to changing environments. In our view, the three australopithecines are, in a number of features, scaled variants of the "same" animal. In these characters, A. africanus is no more "advanced" than the larger, more robust forms. The one early hominid to show a significant departure from this adaptive pattern toward later hominids-cranially, dentally, and postcranially-is H. habilis from East Africa. The australopithecines, one of which was probably a precursor of the Homolineage, were apparently a successful group of basically vegetarian hominids, more advanced behaviorally than apes (87), but not hunter-gatherers. The fossil hominids of Africa fall into two major groupings. One probable lineage, the australopithecines, apparently became extinct without issue; the other evolved to modern man. Both groups displayed steady increase in body size. We consider quantitatively two key characters of the hominid skull: cranial capacity and cheek tooth size. The variables are allometrically related to body size in both lineages. In australopithecines, the manner of relative growth neatly meets the predictions for functional equivalence over a wide range of sizes (negative allometry of cranial capacity with a slope against body weight of 0.2 to 0.4 and positive allometry of postcanine area with a slope near 0.75). In the A. africanus to H. sapiens lineage, cranial capacity increases with positive allometry (slope 1.73) while cheek teeth decrease absolutely (slope - 0.725). Clearly, these are special adaptations unrelated to the physical requirements of increasing body size. We examined qualitatively other features, which also seem to vary allometrically. Of course, many characters should be studied quantitatively, but we think that the scheme outlined here should be treated as the null hypothesis to be disproved.