An immunohistological study of macrophages in the human fetal brain

Brains from human fetuses of 13 to 27 weeks gestation have been examined immunohistologically for the presence of macrophages using the marker alpha-1-anti-chymotrypsin. A preliminary study demonstrated this to be a satisfactory marker of brain macrophages, although macrophages were also weakly positive for the more specific marker MAC-387. Macrophages were widely present within the cerebral hemispheres following their rapid accumulation between 14 and 16 weeks of gestation. They were identified in characteristic locations which, in the earliest gestation brains examined at 13 weeks, included the mid-line of the corpus callosum, around the optic tract and at the junction of the external and internal capsules near the apex of the putamen. Subsequently, macrophages were identified in abundance in the internal and external capsules and, by 22 weeks gestation, in the periventricular tissues. Their consistent presence and distribution indicate that at least the majority of these macrophages are a normal feature of the developing brain possibly related to remodelling processes.

Synthesis and antineoplastic properties of ether-linked thioglycolipids

Ether-linked glycero-alpha- and beta-D-glucopyranosides and glycero-1-thio-alpha- and beta-D-glucopyranosides have been synthesized by modifications of the Königs-Knorr procedure, and their antitumor activities have been evaluated. The bioactivities of these compounds have been evaluated in five different cell lines (WEHI 3B, C653, X63/OMIL3, R6X-B15, and HL-60) and compared with the activities of 1-O-hexadecyl-2-O-methyl-sn-3-glycerophosphocholine (GPC) and its enantiomer, 3-O-hexadecyl-2-O-methyl-sn-1-GPC. The results indicate that a alpha-D-thioglucopyranoside [1-O-hexadecyl-2-O-methyl-3-S-(alpha-D-1'- thioglucopyranosyl-sn-glycerol)] is selective with respect to its action on target cells, with high activity for killing of WEHI 3B and C653 cells as determined by inhibition of [3H]thymidine incorporation into DNA and HL-60 cell cytotoxicity, but unable to induce aggregation of rabbit platelets at 10(-5) M. The corresponding beta-linked thioglycolipid was ineffective with respect to cytotoxicity against each cell line tested, indicating the importance of configuration at the anomeric position; the beta-thioglycoside was also ineffective with respect to inducing platelet aggregation. 1-O-Hexadecyl-2-O-methyl-sn-3-GPC and 3-O-hexadecyl-2-O-methyl-sn-1-GPC were potent inhibitors of growth of each cell line tested but also caused rabbit platelet aggregation at concentrations greater than or equal to 10(-7) M. Thus, 3-S-(alpha-thioglycopyranosyl)-sn- glycerols bearing a long-chain O-alkyl group at the sn-1 position and a methoxy group at the sn-2 position of glycerol appear to be a promising class of antineoplastic agents with lower risk of inducing thrombosis than the widely studied platelet activating factor analogue, 1-O-octadecyl-2-O-methyl-rac-3-GPC.

The development of ependyma in the human fetal brain: an immunohistological and electron microscopic study

The stratified inner layer of the embryonic fetal brain, the ventricular zone (VZ), contains glial fibrillary acidic protein (GFAP)-positive cell bodies of radial glia. The adult cerebral ventricle is lined by a single layer of cuboidal, ciliated common ependymal cells which are, immunohistologically, GFAP negative. In late gestation, the ventricular lining is formed by tanycytes, ependymal cells with short, intensely GFAP-positive basal fibres. The development of ependyma was examined, morphologically and immunohistologically, in human fetal brain from between 11 weeks gestation to 6 months post-term to determine the relationship between the radial glia cell, tanycyte and common ependymal cell. This study was not able to show whether tanycytes were formed from radial glia or were formed from a previously uncommitted population of VZ cells. The study did show, however, that tanycytes probably mature into common ependymal cells following acquisition of cilia and loss of basal fibres. Electron microscopic data indicate that tanycytes have features suggestive of a secretory and/or transport function.

Relative survival rates after alternative therapies for uveal melanoma

Survival in a group of 556 patients with uveal melanoma treated by proton beam irradiation with a median follow-up of 5.3 years was compared with that of 238 patients enucleated during the same 10-year period as irradiated patients (July 1975 to December 1984) with a median follow-up of 8.8 years, and 257 patients enucleated during the preceding 10 years (January 1965 to June 1975) with a median follow-up of 17.0 years. Adjustments were made for known prognostic factors including age, tumor location, tumor height, and clinical estimate of tumor diameter (for enucleated patients this was estimated in a regression equation relating histologic to clinical measurement). The overall rate ratio for all cause mortality was 1.2 (95% confidence interval, 0.9-1.6) for the concurrent enucleation series versus proton beam, and 1.6 (95% confidence interval, 1.2-2.1) for the earlier enucleation series versus proton beam. Relative rates of metastatic death, cancer death, and all cause mortality comparing alternative treatments were found to vary with time after treatment. Interval-specific rate ratios were evaluated using proportional hazards models fitted to separate time intervals after treatment. For all three outcomes, rate ratios were over two and statistically significant for the first 2 years after treatment and closer to one and nonsignificant after year 6 comparing the two enucleation groups with proton beam. Results suggest that treatment choice has little overall influence on survival in patients with uveal melanoma.

Translocation-independent activation of protein kinase C by platelet-activating factor, thrombin and prostacyclin. Lack of correlation with polyphosphoinositide hydrolysis in rabbit platelets

The relationship between polyphosphoinositide hydrolysis and protein kinase C (PKC) activation was explored in rabbit platelets treated with the agonists platelet-activating factor (PAF), thrombin and 12-O-tetradecanoylphorbol 13-acetate (TPA), and with the anti-aggregant prostacyclin (PGI2). Measurement of the hydrolysis of radiolabelled inositol-containing phospholipids relied upon the separation of the products [3H]inositol mono-, bis- and tris-phosphates by Dowex-1 chromatography. PKC activity, measured in platelet cytosolic and Nonidet-P40-solubilized particulate extracts that were fractionated by MonoQ chromatography, was based upon the ability of the enzyme to phosphorylate either histone H1 in the presence of the activators Ca2+, diacylglycerol and phosphatidylserine, or protamine in the absence of Ca2+ and lipid. Treatment of platelets for 1 min with PAF (2 nM) or thrombin (2 units/ml) led to the rapid hydrolysis of inositol-containing phospholipids, a 2-3-fold stimulation of both cytosolic and particulate-derived PKC activity, and platelet aggregation. Exposure to TPA (200 nM) for 5 min did not stimulate formation of phosphoinositides, but translocated more than 95% of cytosolic PKC into the particulate fraction, and induced a slower rate of aggregation. PGI2 (1 microgram/ml) did not enhance phosphoinositide production, and at higher concentrations (50 micrograms/ml) it antagonized the ability of PAF, but not that of thrombin, to induce inositol phospholipid turnover, even though platelet aggregation in response to both agonists was blocked by PGI2. On the other hand, PGI2 alone also appeared to activate (by 3-5-fold) cytosolic and particulate PKC by a translocation-independent mechanism. The activation of PKC by PGI2 was probably mediated via cyclic AMP (cAMP), as this effect was mimicked by the cAMP analogue 8-chlorophenylthio-cAMP. It is concluded that this novel mechanism of PKC regulation by platelet agonists may operate independently of polyphosphoinositide turnover, and that activation of cAMP-dependent protein kinase represents another route leading to PKC activation.

Reactions of 1-bromo-2-[14C]pinacolone with acetylcholinesterase from Torpedo nobiliana. Effects of 5-trimethylammonio-2-pentanone and diisopropyl fluorophosphate

1-Bromo-2-[14C]pinacolone, (CH3)3C14COCH2Br [( 14C]BrPin), was prepared from [1-14C]acetyl chloride and tert-butylmagnesium chloride with cuprous chloride catalyst, followed by bromination. It was examined as an active-site directed label for acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7) (AcChE). AcChE, isolated from Torpedo nobiliana, has k(cat) = (4.00 +/- 0.04).10(3) s-1, Km = 0.055 +/- 0.008 mM in hydrolysis of acetylthiocholine, and k(cat) = (5.6 +/- 0.2).10(3) s-1, Km = 0.051 +/- 0.003 mM in hydrolysis of acetylcholine. BrPin, binding in the trimethyl cavity, acts initially as a reversible competitive inhibitor, Ki = 0.20 +/- 0.09 mM, and, with time, as an irreversible covalently bound inactivator. Introduction of 14C from [14C]BrPin into Torpedo AcChE at pH 7.0 was followed by SDS-PAGE, autoradiography and scintillation counting, in the absence and presence of 5-trimethylammonio-2-pentanone (TAP), a competitive inhibitor (Ki = 0.075 +/- 0.001 mM) isosteric with acetylcholine; 1.8-1.9 14C was incorporated per inactivated enzyme unit at 50% inactivation. TAP retarded inactivation by [14C]BrPin, and prevented introduction of 0.9-1.1 14C per unit of enzyme protected. Prior inactivation of AcChE by BrPin prevents reaction with [3H]diisopropyl fluorophosphate [( 3H]DFP). Prior inactivation by DFP or [3H]DFP does not prevent reaction with [14C]BrPin, and this subsequent reaction with BrPin does not displace the [3H] moiety. [14C]BrPin alkylates a nucleophile in the active site, and this reaction does not alkylate or utilize the serine-hydroxyl.

Tissue-specific expression, developmental regulation, and genetic mapping of the gene encoding CCAAT/enhancer binding protein

This paper presents the results of experiments that determine the chromosomal location of the mouse gene encoding CCAAT/enhancer binding protein (C/EBP) and measure its expression as a function of tissue type and temporal period of development in mice and rats. Three alleles of the C/EBP gene were identified according to restriction fragment length polymorphisms. The strain distribution pattern of the three alleles was determined in recombinant inbred mouse strains and compared to that of other mouse genes. These results mapped the gene to a position within 2.5 centimorgans (cM) of the structural gene encoding glucose phosphate isomerase on chromosome 7 of the mouse. The expression pattern of the C/EBP gene was studied by a combination of nucleic acid hybridization and antibody staining assays. High levels of C/EBP mRNA were observed in tissues known to metabolize lipid and cholesterol-related compounds at uncommonly high rates. These included liver, fat, intestine, lung, adrenal gland, and placenta. More detailed analysis of two of these tissues, liver and fat, showed that C/EBP expression was limited to fully differentiated cells. Moreover, analysis of the temporal pattern of expression of C/EBP mRNA in two tissues, liver and intestine, revealed a coordinated induction just prior to birth. These observations raise the possibility that the synthesis of C/EBP may be responsive to humoral factors and that modulation in C/EBP expression might mediate coordinated changes in gene expression that facilitate adaptive challenges met during development or during the fluctuating physiological states of adult life.

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.

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.

Dissolution rate studies from a stationary disk/rotating fluid system

The dissolution rates for hydrocortisone alcohol and acetate were determined using a stationary disk/rotating fluid system. The hydrocortisone was compressed in a tablet die, and the die placed in a vessel above a rotating magnetic bar. Dissolution rates were evaluated in aqueous media under conditions involving the following independent variables: solubility (Cs), diffusion coefficient (D), viscosity (v), rotational speed (omega), and tablet radius (r). A design equation which relates dissolution rate (R) to these variables was formulated for the system R alpha Cs D2/3 (v) -1/6(omega)1/2(r)3/2 This design equation adequately represents the system, which is related to fluid mechanics and convective diffusion models. The fluid mechanics model assumes that the fluid ideally rotates as solid-body rotation and the momentum layer is initiated at the outside radius of the tablet die. The convective diffusion model is based on the formation of a diffusion layer at the outside radius of the dissolving surface and a predictable relationship between the momentum and the mass transport quantities of bulk viscosity and diffusion coefficient. This configuration, like the rotating disk in a stationary fluid, offers the attractive attribute of being useful to study drug release mechanisms for systems of pharmaceutical interest.

A randomized study of oral metoclopramide in small bowel biopsy of infants and children

As an intravenous injection is not used in our premedication of infants and children for small bowel biopsy, we investigated what effects oral metoclopramide might have on small bowel biopsy procedure time and fluoroscopy time. Eighteen infants and children were randomized to receive 0.2 mg/kg metoclopramide or placebo orally, 40-45 min before starting the procedure, and the procedure was monitored for the time required for the biopsy capsule to reach the pylorus, to cross into the proximal duodenum, and to reach the biopsy site. Corresponding fluoroscopy times were recorded as well. Mean total procedure time was less for those treated with metoclopramide, 43.7 +/- 11 min, than for controls, 86.5 +/- 15.5 min (p less than 0.005). Mean total fluoroscopy time was also less in treated patients (40.9 +/- 11.5 s versus control 84.4 +/- 17 s) (p less than 0.005). The effect of metoclopramide occurred in the interval for the biopsy capsule to cross the pylorus (15.1 +/- 2.7 min versus control 60.8 +/- 16.6 min) (p less than 0.005) and in fluoroscopy time required (15.1 +/- 1.9 s versus control 46 +/- 17 s) (p less than 0.005). Oral metoclopramide is effective in reducing procedure time for small bowel biopsy, and its predictable action facilitates reduction in fluoroscopy exposure.

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.

Age-dependent antibody response in mice and humans following oral influenza immunization

In order to compare the antibody response in serum and secretions from healthy young subjects and the elderly (greater than 60 years), volunteers were immunized with the commercial inactivated influenza virus vaccine, by the usual (parenteral) route or orally. Also, young and old mice (mean age, 20 months) were orally immunized with live influenza virus. The older mice responded with a very slight rise in their serum and respiratory tract antibody levels compared with the young mice but showed no diminution in protection against lethal viral challenge. Elderly volunteers showed only slight serum antibody responses after parenteral immunization compared with the young. Neither group demonstrated a rise in serum antibody following oral immunization. With respect to the secretory IgA (SIgA) antibody response, certain differences were noted between the young and the elderly: the preimmunization levels of antibody to influenza virus were significantly greater in nasal secretions and saliva in the elderly as compared to the young volunteers, and the salivary antibody response was diminished in the elderly. This lack of a salivary antibody response in the elderly was explicable by the inverse relationship between the preimmunization SIgA antibody titers and the response to immunization. Oral immunization led to no more side effects than observed in the placebo control group.

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.

Secretory antibody following oral influenza immunization

Secretory IgA antibody may be important in protection against respiratory viral infections, and the concept of a common mucosal immune system offers the theoretical basis for the convenient stimulation of this antibody. Therefore, the oral route was compared with intramuscular injection in a double-blind, placebo-controlled study in young healthy volunteers. A killed influenza vaccine, given in enteric-coated capsules (total of 98 ug hemagglutinin of A/Bangkok) led to significant salivary and nasal IgA antibody rises in a 4-week period. The preimmunization titers in secretions were inversely correlated with the antibody rise after immunization. The orally administered vaccine was associated with no more side effects than placebo, in contradistinction to reactions following the intramuscular route. The latter route also was without significant effect in regard to a stimulation of secretory antibodies. The observed simultaneous induction of antibodies in saliva and nasal secretions following oral administration of killed vaccine gives further evidence of a common mucosal immune system and its possible clinical use.

Determination of the chromosomal locations of four Bacillus subtilis genes which code for a family of small, acid-soluble spore proteins

The chromosomal locations of four genes which code for small, acid-soluble spore proteins (SASP) in Bacillus subtilis have been determined. Although these four genes code for extremely homologous small, acid-soluble spore proteins (greater than 65% sequence identity), the genes are not clustered but are located at 70 degrees (adjacent to glyB [sspB gene]), 115 degrees (between metC and pyr cluster [sspD gene]), 180 degrees (between metB and kauA [sspC gene]), and 260 degrees (between ilvC and aroG [sspA gene]) on the B. subtilis genetic map.

Evaluation of a tube method for determining diffusion coefficients for sparingly soluble drugs

Evaluation of a non-steady state method using glass tubes for the determination of diffusion coefficients is the purpose of this study. Unlike capillaries, glass tubes accommodate a larger volume of solution, facilitating assay procedures. Tubes are more susceptible to convection than are capillaries, but this effect is anticipated and accounted for in experimental design and data treatment. Glass tubes, 66 or 90 mm in length and 2 mm outer diameter, were siliconized and then filled with aqueous drug solution and placed in a jacketed flask containing gently stirred solvent at 25 degrees C. Diffusion experiments were run from 140 to 168 hours. At the end of this time period, the tubes were removed from the flask, placed in an ultrasonic vibrator for one minute, and their contents assayed spectrophotometrically. Data collected using potassium chloride as the diffusant showed little tube-to-tube variability, demonstrating the precision of the tube method, while diffusion coefficients determined for benzoic acid and p-aminobenzoic acid using the tube method tested the accuracy of the method by comparing reasonably well with values obtained using standard methods such as the rotating disk, free boundary, and membrane cell. Experiments done with either hydrocortisone or sulfisoxazole as the diffusant demonstrated the appropriateness of the tube method for the study of the diffusion of sparingly soluble pharmaceutical solutes.

Burns: causes and risk factors

In a retrospective study of 277 adult patients consecutively hospitalized for burns over a five-year period (1975-1979) patients' characteristics, circumstances of burn injury and prevalence of established predisposing factors were determined. The average age was 44.5 years, 78% were black and 62% were men. Average extent of burn was 19.7% body surface area. Major causes included flames in 44.8%, scalds in 28.5%, and chemicals in 9.7%. Seventy-four percent of all burns occurred at home. Burns resulting from assault accounted for 20.9%. Fifty-six percent of the patients had one or more of the established predisposing factors. Judged to be predisposed to burn injury were all of those who attempted suicide, all who were using self-treatment for some preexisting conditions, 85% of the elderly, 83% of those who died, 81% of those burned in the bathtub and 80% of those assaulted. Other described groups were also at high risk. Living alone increased risk of injury in persons prone to burn. The most common predisposing factors were alcohol and drug abuse, physical and mental illness and advanced age. Mortality rate was 12.6%. This study emphasizes the urgent need for effective burn prevention programs in which all health professionals should play an important role.

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 effect of amniocentesis and drainage of amniotic fluid on lung development in Macaca fascicularis

Amniocentesis and withdrawal of amniotic fluid was performed on pregnant monkeys (Macaca fascicularis) at two stages in development, either between 47 and 64, or between 85 and 95 days gestation. After birth the lungs of each infant monkey were studied using precise morphometric techniques, and compared with those in a control group of animals. The lungs after amniocentesis had alveoli of normal maturity but reduced in number and increased in size, features which both reduce the relative area for gas exchange. There was also a reduction in the number of respiratory airways. These changes occurred regardless of the time of amniocentesis, the amount of fluid removed and even if the membranes were simply punctured with no fluid removal. There is some evidence to suggest that similar sublethal effects may be present in human infants after maternal amniocentesis.

Immunization against influenza in humans using an oral enteric-coated killed virus vaccine

By ingestion of subunit-killed influenza virus vaccine in the form of enteric-coated capsules, local synthesis of secretory IgA (sIgA) antibody was stimulated in human nasal secretions. A fairly equal antibody response initiated by oral and intramuscular administration was demonstrated in the nasal secretions, although a systemic immune response was not elicited from ingestion of the vaccine. If the secretory antibody response resulted from absorption of antigen and transport to the respiratory mucosa, systemic (serum) antibody would be expected. Therefore these findings support the hypothesis that specialized collections of lymphoid cells in the small intestines have IgA precursor cells which circulate and populate distant mucosal sites. A number of studies have suggested that protection against mucosal infection by a variety of respiratory viruses correlates better with the presence and level of sIgA antibody than with serum antibody. The orally administered vaccine was associated with no more side effects than placebo, in contradistinction to the intramuscular route. Thus, the oral method of influenza vaccination could prove to be superior in providing for immunological protection due to equal secretory antibody stimulation, improved convenience and less toxicity.

Morphometric studies on the structural development of the lung in Macaca fascicularis during fetal and postnatal life

The structural development of the normal monkey lung (Macaca fascicularis) from 61 days of gestation to 14 days postnatal age has been described using quantitative morphometric techniques. The lung of the adult monkey has also been studied. The airway and arterial branching pattern has been traced using serial sections. The alveolar number and size have been estimated and the structure of the arteries after postmortem arterial injection has been assessed. Comparison of lung morphology in monkey and man shows that there are similarities in segmental arrangement, structure and branching pattern of airways, in arterial structure and in changes in the arteries after birth. Although there are differences in the number of lobes, the number of generations of different types of airways and the number and size of alveoli, the overall structure in the monkey is more similar to that in man than is the structure of the lung in species such as sheep, pig or rat. During fetal life the monkey lung passes through the same stages of development as the human fetus but at birth the monkey has a full complement of airways and mature alveoli. Postnatal growth of airways and alveoli is due to increase in size rather than to multiplication. In man there is an increase in the number of alveoli and alveolar ducts after birth as well as an increase in size. Despite the differences between the species it seems appropriate to use the monkey in experimental studies on the lung.

The influence of in situ repair systems on survival of several irradiated parenchymal cell types

Radiation survival curves are presented for several normal parenchymal cell types irradiated in situ or in vitro. The data presented indicate that the in situ survival parameters for a specific cell type cannot be simply extrapolated from the results of either in vitro assays or rapid in vivo clonal transplantation assays. The data suggest that the D0 and terminal slope of in vitro survival curves can reflect those parameters for cells left in situ, but the shoulder width and the n value cannot. This appears to be due to the inability of the in vitro environment to support two major forms of repair that occur in situ, i.e. the "contact effect" and in situ repair (ISR). ISR is a form of potentially lethal damage repair (PLDR) that occurs when certain cells are allowed to remain in situ following irradiation. ISR is characterized by an increased shoulder in the survival curve without a change in slope and it has been observed in rat mammary, thyroid and liver epithelia.

Oral route as method for immunizing against mucosal pathogens

In the past three decades significant strides have been made in attempts at nonparenteral immunization. Appreciation of the importance of secretory immunity led to attempts to stimulate antibody production locally. The vaccines developed against respiratory pathogens as a result of this new knowledge have many practical limitations, such as the need for highly trained personnel, expensive equipment, very cooperative recipients for intranasal or aerosol administration, and a vaccine that is both adequately attenuated, immunogenic, and stable during storage. With recognition of the presence of a common mucosal defense system, new approaches to vaccine development have become possible. Oral immunization, by stimulating GALT, presents a promising approach for protecting many secretory surfaces against a variety of infectious agents. Recently, emphasis has been placed on developing an oral vaccine against S. mutans. McGhee et al. have demonstrated antibody to S. mutans in saliva and tears following oral ingestion of that antigen, without a rise in serum antibody, in both humans and rats. The rats were afforded protection from caries after rechallenge with both the original and cross-reacting serotypes of S. mutans. Similar results have recently been seen with viral antigens. Mice have been shown to have significant protection against influenza infection following oral immunization. And in a pilot study with human volunteers, the secretory antibody response in nasal washes was similar following either oral or parenteral vaccination. Oral immunization may prove to be far superior to parenteral vaccination against a variety of pathogens, because of fewer side effects and greater ease in vaccine preparation and administration.

Model systems for dissolution of finely divided (multisized) drug powders

Several reports have dealt with model systems for the dissolution of log-normally distributed powders. A numerical solution is presented for the previously published Higuchi-Hiestand equations for a log-normal particle-size distribution. This solution was realized via an application of the System 360 Continuous System Modeling Program (CSMP). The resulting computer-aided calculations were utilized in the comparisons between the Higuchi-Hiestand model and other existing models. These comparisons provided a basis for the development of an adaptation of the Nielsen moving sphere model for log-normally distributed powders. The adaptation of the Nielsen equation for multisized particle systems is suggested as being potentially useful for treating experimental data where hydrodynamic effects must be considered.

Oedipus of Thebes: the myth and its other meanings

Sigmund Freud used the Oedipus myth to represent a crucial part of sexual development. Careful attention to the details of the myth as related by Sophokles points the way to entirely different and fruitful understandings. Myth is seen as an external representation of man's inner life; omens and the gods are viewed in this context. We can then see Oedipus' suffering as inseparable from loss and growth. In his struggle and ambivalence, Oedipus represents that suffering and transcendence for all of us. The myth tells us of the responsibilty, the pain, and the courage which are necessary ingredients in all human growth.

The Vietnam warrior: his experience, and implications for psychotherapy

The psychodynamic experience of the Vietnam trooper is described and emotionally evoked by the author, who is both a psychiatrist and a combat veteran of that war. It is shown how that experience continues to affect the lives of these men. The special implications of that experience for psychotherapy are then discussed.

Use of carboxyhaemoglobin levels to predict the development of diseases associated with cigarette smoking

Carboxyhaemoglobin (COHb) levels in tobacco smokers vary throughout the day since they are affected by the pattern of tobacco consumption and the rate at which COHb is eliminated. A method is described whereby a single COHb measurement together with a recent smoking history may be used to estimate the average COHb "boost" produced by each cigarette, the total daily carbon monoxide (CO) uptake from smoking, and the mean COHb level throughout the day. These three indices of tobacco smoke absorption were estimated in nine healthy cigarette smokers on different days, each set of three estimations being derived from separate COHb determinations. The indices were reasonably reproducible within the same person, and the differences between people were statistically highly significant (P less than 0-001). For example, the estimates of mean daily COHb level resulting from smoking ranged from 0-7% to 9-3% in smokers who smoked 15 to 40 cigarettes a day. These differences are sufficiently large to distinguish possible differences in the risk of developing diseases such as ischaemic heart disease which may result from the inhalation and absorption of tobacco smoke. The suggested indices also depend less on the time of the blood test and on the daily pattern of smoking than a COHb level alone. The ratio of the COHb boost to the CO yield of a cigarrette may reflect depth of inhalation more accurately than a smoker's self-assessment. Moreover there was little correlation between these two measures of inhalation in the nine subjects studied.

Panel on race and poverty as considerations in the management of motor disability

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Association between atherosclerotic diseases and carboxyhaemoglobin levels in tobacco smokers

In a cross-sectional study carboxyhaemoglobin (COHb) levels in tobacco smokers were found to provide a better indication of a person's risk of having developed certain atherosclerotic diseases, including ischaemic heart disease, than the smoking history. In the age group 30-69 years a person with a COHb level of 5% or more was found to be 21 times (lower 95% confidence limit 3.3 times) as likely to be affected by these diseases as another person of the same age and sex with similar smoking history and current smoking habits but with a COHb level of less than 3%.