Ocular Damage in the Battered-baby Syndrome

Twelve out of 19 battered babies seen with ocular damage have permanent impairment of vision affecting one or both eyes. Ocular disease, especially retinal haemorrhage, is common in the battered-baby syndrome, and infants with this condition should always have a complete ophthalmic examination.     

Ophthalmic Manifestations of the Battered-baby Syndrome

Eleven battered babies who had ocular manifestations of their abuse are presented. Eight of these suffered a permanent impairment of visual function. Ten had extensive intraocular haemorrhage, and the importance of this physical sign in the diagnosis of the syndrome and in the development of a consequent visual handicap is emphasized.     

Brain death in Britain as reflected in renal donors.

The diagnostic mix of 1228 brain-dead renal donors in Britain was similar to that of 479 cases of brain death recently reported from three neurosurgical units. About half the donors came from non-teaching hospitals without a neurosurgical unit, many of them small and distant from the centre. The different circumstances that preceded brain deaths were examined--namely, diagnosis and whether the fatal ictus of brain damage occurred when the patient was already in hospital--to explain why donors spend varying times on the ventilator. Head injuries accounted for half the donors, and intracranial haemorrhage for almost a third. While many potential donors are not made available, the size of the pool has been overestimated, particularly in regard to head injury. Reduction in organ donation since "Panorama" has been very uneven, with some places increasing their yield; this suggests reluctance of doctors to initiate donation rather than relatives withholding permission.     

Recurrent Haemorrhage after Acute Gastrointestinal Bleeding

A retrospective survey of 472 consecutive hospital admissions for acute upper gastrointestinal bleeding showed that patients with a large initial bleed are more likely to bleed again than those with a small initial bleed. The incidence of recurrent haemorrhage is also related to the interval since the last bleeding episode, so that patients showing no clinical evidence of haemorrhage for 48 hours are unlikely to bleed again in the near future. Patients admitted after a haematemesis have a higher incidence of recurrent haemorrhage than those admitted after melaena only. Aetiology has been confirmed as an additional important factor, the incidence being highest in those with oesophageal varices or a chronic gastric ulcer. Contrary to widespread belief, age does not appear to affect the incidence of recurrent haemorrhage, nor do other constitutional factors such as sex or the ABO blood group.     

Trial of the RBC aggregometer head for estimating blood flow in veins in vivo

The whole blood RBC aggregometer head reported previously for measuring the degree of RBC aggregation in whole blood was tested for its usefulness as a flowmeter of blood vessels in situ. Modifications to its construction were made so that it became readily attachable and detachable without damage to the vessels. In ex vivo experiments employing a transparent vinyl tube and freshly drawn heparinized human whole blood, the RBC aggregometer head was applicable for evaluating semiquantitative flow changes within a limited flow range based on the degree of RBC aggregation. A linear relationship was observed between the logarithm of blood flow in a low shear range (below approximately 180/s) and changes in the light transmission of the flowing blood. The RBC aggregometer head with or without an electromagnetic flowmeter (EMF) was applied to the jugular vein and femoral vein in cats. A stop-flow change of whole blood in the jugular vein was detected by the RBC aggregometer head as a dramatic change in light transmission (LT). The aggregometer head recorded a similar LT change consistently, whereas the EMF was found to be rather discrepant, indicating the occurrence of anomalous flow. It is concluded that the RBC aggregometer head can be used as an semiquantitative flowmeter for relative changes in blood flow in veins in situ.     

Innervation of the basicranial muscle of Latimeria chalumnae

Synopsis New observations based on a serial reconstruction of histological sections of a prenatal coelacanth demonstrate that, in contrast to previous reports, the basicranial muscle is innervated by the abducent nerve rather than the vagal nerve. A detailed account of the course of the abducent nerve and its terminal arborizations in the basicranial muscle and lateral rectus muscle is provided. This finding bears on the phylogenetic derivation of the basicranial muscle in sarcopterygians, its possible homologues in other vertebrates., and patterns of head segmentation in craniates.     

Post-strike orientation of the prairie rattlesnake facilitates location of envenomated prey

Prairie rattlesnakes (Crotalus viridis) typically release adult rodent prey after envenomation. The post-strike head orientation of the snake may facilitate location of the trail left by the rodent. To examine this possibility, mice were presented using a pair of tongs so that no chemical cues were deposited on any surfaces. Snakes exhibited a change in head orientation after predatory strikes, bringing them closer to the departure bearing of the prey. In addition, when trail searching began snakes contacted the departure bearing of the prey first rather than the entry bearing. When rodent trails are available, we expect this initial contact to bias the snake towards selecting the post-envenomation trail.     

Hedgehog signaling in the Drosophila eye and head: an analysis of the effects of different patched trans-heterozygotes

Characterization of different alleles of the Hedgehog receptor patched (ptc) indicates that they can be grouped into several classes. Most mutations result in complete loss of Ptc function. However, missense mutations located within the putative sterol-sensing domain (SSD) or C terminus of ptc encode antimorphic proteins that are unable to repress Smo activity and inhibit wild-type Ptc from doing so, but retain the ability to bind and sequester Hh. Analysis of the eye and head phenotypes of Drosophila melanogaster in various ptc/ptc(tuf1) heteroallelic combinations shows that these two classes of ptc allele can be easily distinguished by their eye phenotype, but not by their head phenotype. Adult eye size is inversely correlated with head vertex size, suggesting an alteration of cell fate within the eye-antennal disc. A balance between excess cell division and cell death in the mutant eye discs may also contribute to final eye size. In addition, contrary to results reported recently, the role of Hh signaling in the Drosophila head vertex appears to be primarily in patterning rather than in proliferation, with Ptc and Smo having opposing effects on formation of medial structures.     

The problem of "benign macrocephaly"

24 families of probands with a high head circumference/height ratio greater than the 97th percentile were investigated for head circumference and height. It is concluded that "benign macrocephaly" represents rather the upper extreme of the normal distribution of head circumference than--as has been suggested by some authors--a discrete and autosomal dominant entity.     

Plurisegmental neurones of the cricket Gryllus campestris L. that discharge in the rhythm of its own song

Male crickets (Gryllus campestris L.) mounted so that their wings and abdomen could move freely were induced to stridulate by brain lesion. During the song the activity of single neurones was recorded extracellularly in a cervical connective. Nine distinct spike patterns were observed. Patterns I and II tend to copy the chirp as a whole rather than the onset of the syllables (the recorded potentials of the wing-opener muscle M99 marked the syllable onset). The other patterns reflect the syllabic structure. Each, in its own way, marks the various syllables with different numbers of spikes. The delay of the spike response is different for each pattern. Some patterns, but not others, also reflect the beginning or end of the song, or the abdominal expiratory activity. One neurone also responds in correlation with muscle discharges typical of the courtship song. In some of the patterns it is evident that there is a stronger correlation with the closer muscle (M90) discharge than with the opener muscle discharge. Activation by auditory self-stimulation by way of the tympanal organs can be ruled out for all patterns. It is possible that patterns I–V are induced by afferent activity coupled to the wing movement. Patterns VI–VIII are probably copies of motor signals ascending from the thoracic song-pattern generators to the head ganglia. It is evident that the head ganglia have detailed information as to the motor output for stridulation and abdominal expiration.     

The N terminus of the head protein of T4 bacteriophage directs proteins to the GroEL chaperonin

The head protein of T4 bacteriophage requires the GroEL chaperonin for its insertion into a growing T4 head. Hundreds of thousands of copies of this protein must pass through the chaperonin in a limited time later in infection, indicating that the protein must use GroEL very efficiently and may contain sequences that bind tightly to GroEL. We show that green fluorescent protein (GFP) fused to the N terminus of the head protein can fold at temperatures higher than those at which the GFP protein can fold well by itself. We present evidence that this folding is promoted by the strong binding of N-terminal head protein sequences to GroEL. This binding is so strong that some fusion proteins can apparently deplete the cell of the GroEL needed for other cellular functions, altering the cellular membranes and slowing growth.     

A model for the packing of lipids in bilayer membranes.

A number of known structural properties of mixed lipid bilayer membranes and monolayers are accounted for by a model in which lipids pack into bilayers and monolayers like building blocks, each characterized by a surface head group area and characteristic solid angle. In phospholipids above the melting transition the head group area (at a given temperature and degree of hydration) is fairly invariant while the hydrocarbon region may be liquid-like so long as the molecule is not compressed beyond its characteristic solid angle. Phosphatidylcholine and phosphatidylserine are tapered lipids, i.e. their surface head group areas are greater than their non-polar end areas; cholesterol is frayed, i.e. its polar end area is less than its non-polar end area; while phosphatidylethanolamine is almost cylindrical. The "condensing" effect of cholesterol in mixed phospholipid-cholesterol films is seen as a taper-fray accommodation. The lipid distribution in erythrocyte membrane is shown to be conducive to a stable strain-free membrane.     

Protective effect of vitamin E (DL-alpha-tocopherol) against intraventricular haemorrhage in premature babies.

Forty four babies, of less than 32 weeks'' gestation, were either randomly given 25 mg/kg vitamin E (DL-alpha-tocopherol acetate) intramuscularly after birth (day 0) and on days 1, 2, and 3 or served as controls. Frequent real time ultrasound examinations of the brain were made in each baby during the first week and less frequently thereafter. In babies under 32 weeks'' gestation the incidence of intraventricular haemorrhage was lower in supplemented babies (18.8%) compared with the controls (56.3%). On days 0, 1, 2, and 3 median plasma vitamin E concentrations in babies without haemorrhage and in those with subependymal haemorrhage only were similar. Babies with intraventricular haemorrhage had lower median concentrations on day 1 (p less than 0.002) and day 2 (p less than 0.05) compared with those with subependymal haemorrhage and lower concentrations on day 0 (p less than 0.02) and day 1 (p less than 0.05) compared with those without haemorrhage. These findings suggest that in premature babies vitamin E, an antioxidant, protects endothelial cell membranes from oxidative damage and disruption and limits the magnitude of haemorrhage and its spread from the subependyma into the ventricles.     

A model for the packing of lipids in bilayer membranes

A number of known structural properties of mixed lipid bilayer membranes and monolayers are accounted for by a model in which lipids pack into bilayers and monolayers like building blocks, each characterized by a surface head group area and characteristic solid angle. In phospholipids above the melting transition the head group area (at a given temperature and degree of hydration) is fairly invariant while the hydrocarbon region may be liquid-like so long as the molecule is not compressed beyond its characteristic solid angle.Phosphotidylcholine and phosphotidylserine are tapered lipids, i.e. their surface head group areas are greater than their non-polar end areas; cholesterol is frayed, i.e. its polar end area is less than its non-polar end area; while phosphotidylethanolamine is almost cylindrical. The “condensing” effect of cholesterol in mixed phospholipid-cholesterol films is seen as a taper-fray accomodation. The lipid distribution in erythrocyte membranes is shown to be conductive to a stable strain-free membrane.     

Resolving head rotation for human bipedalism

Alignment of the body to the gravitational vertical is considered to be the key to human bipedalism. However, changes to the semicircular canals during human evolution suggest that the sense of head rotation that they provide is important for modern human bipedal locomotion. When walking, the canals signal a mix of head rotations associated with path turns, balance perturbations, and other body movements. It is uncertain how the brain uses this information. Here, we show dual roles for the semicircular canals in balance control and navigation control. We electrically evoke a head-fixed virtual rotation signal from semicircular canal nerves as subjects walk in the dark with their head held in different orientations. Depending on head orientation, we can either steer walking by "remote control" or produce balance disturbances. This shows that the brain resolves the canal signal according to head posture into Earth-referenced orthogonal components and uses rotations in vertical planes to control balance and rotations in the horizontal plane to navigate. Because the semicircular canals are concerned with movement rather than detecting vertical alignment, this result shows the importance of movement control and agility rather than precise vertical alignment of the body for human bipedalism.     

Abnormalities of cells and extracellular matrix of T/T embryos

Abstract. The dominant mutation T , (Brachyury), of the T/t -complex in the mouse causes severe disorganization in neural tube, notochord, and somites in homozygotes. The use of scanning electron microscopy to investigate the relationships of cells to one another and to the extracellular matrix in the three axial organs and in the head mesenchyme reveals that cells in all areas examined are abnormal in size, shape, and arrangement in T/T embryos. Cells of T/T head mesenchyme and somites are arrayed in flat sheets of broadened cells with fewer cytoplasmic processes than those of normal littermates. The notochord is discontinuous and its surface is exposed rather than covered by a dense matrix as in the normal. Likewise the sheath of the T/T neural tube is less dense than normal. Cell size and shape are very irregular whereas normal neural tube cells are all about the same size. Extracellular matrix in T/T embryos is greatly decreased in all areas.     

Mutations in the Putative Dimer-Dimer Interfaces of the Measles Virus Hemagglutinin Head Domain Affect Membrane Fusion Triggering

Measles virus (MV), an enveloped RNA virus belonging to the Paramyxoviridae family, enters the cell through membrane fusion mediated by two viral envelope proteins, an attachment protein hemagglutinin (H) and a fusion (F) protein. The crystal structure of the receptor-binding head domain of MV-H bound to its cellular receptor revealed that the MV-H head domain forms a tetrameric assembly (dimer of dimers), which occurs in two forms (forms I and II). In this study, we show that mutations in the putative dimer-dimer interface of the head domain in either form inhibit the ability of MV-H to support membrane fusion, without greatly affecting its cell surface expression, receptor binding, and interaction with the F protein. Notably, some anti-MV-H neutralizing monoclonal antibodies are directed to the region around the dimer-dimer interface in form I rather than receptor-binding sites. These observations suggest that the dimer-dimer interactions of the MV-H head domain, especially that in form I, contribute to triggering membrane fusion, and that conformational shift of head domain tetramers plays a role in the process. Furthermore, our results indicate that although the stalk and transmembrane regions may be mainly responsible for the tetramer formation of MV-H, the head domain alone can form tetramers, albeit at a low efficiency.     

小孤山发现的骨鱼镖——兼论与新石器时代骨鱼镖的关系

本文结合一些民族学资料,对小孤山出土骨鱼镖的用途、使用方法等有所探讨,并讨论它与新石器时代骨鱼镖的关系。     

Further Haemorrhage after Admission to Hospital for Gastrointestinal Haemorrhage

During 1967 and 1968 817 episodes of acute alimentary tract haemorrhage were treated in Aberdeen hospitals. In 229 cases further haemorrhage occurred in hospital, with a mortality of 28·8%; the mortality among patients who did not have this complication was 7·8%. This was true of any kind of further haemorrhage. As judged by transfusion requirements and mortality the severity of the further haemorrhage was unaffected by its occurrence as haematemesis and melaena or as melaena only or by whether it took place before or after 48 hours from the time of admission. The occurrence of further haemorrhage did not appear to be affected by the sex or blood group of patients, by aspirin ingestion, or by a history of a previous haemorrhage.The effects of the occurrence of further haemorrhage, of the age being over 60 years, or of coincidental disease being present were of descending importance in regard to mortality.Among 151 patients with peptic ulcer and further haemorrhage half required urgent surgery and 20% died. Further haemorrhage is a dangerous condition and its occurrence should immediately signal the need for vigilance and for urgent consultation between physician and surgeon. Any delay in treatment entails increased mortality.     

Structure of yeast hexokinase-B: I. Preliminary X-ray studies and subunit structure

Initial X-ray diffraction studies of large single crystals of yeast hexokinase-B provide information on its subunit structure and show the crystals to be suitable for a high resolution structure determination. Patterson maps of the native protein crystals suggest that the two 50,000 molecular weight subunits are identical, or very nearly so, and that they are related by an approximate rather than a true diad axis; that is, one subunit is translated relative to the other by 3.6 Å along the molecular symmetry axis. This results in heterologous subunit interactions rather than the isologous interactions expected.