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The human myeloid nuclear differentiation antigen (MNDA) is expressed specifically in maturing cells of the myelomonocytic lineage and in monocytes and granulocytes. Epitope enhancement was used to confirm the strict lineage- and stage-specific expression of MNDA in bone marrow as well as in other paraffin-embedded fixed tissues. A 1-kb region of the gene that includes 5' flanking sequence was reported earlier to contain functional promoter activity and was specifically demethylated in expressing cells in contrast to null cells. Further analysis has revealed that this 1-kb fragment promotes higher reporter gene activity in MNDA-expressing cells than non-expressing cells, indicating cell-specific differences in transactivation. This sequence contains consensus elements consistent with myeloid-specific gene expression, including a PU.1 consensus site near the major transcription start site and a cluster of c-Myb sites located several hundred bases upstream of this region. However, analysis of deletion mutants localized nearly all of the promoter activity to a short region (-73 to -16) that did not include the cluster of c-Myb sites. A 4-bp mutation of the core Sp1 consensus element (GC box) (-20) reduced overall promoter activity of the 1-kb fragment. Mutation of the PU.1 site did not significantly affect promoter activity. Only a small region (-35 to +22) including the Sp1 element and transcription start site, but not the PU.1 site was footprinted. The 4-bp mutation of the core Sp1 consensus element abolished footprinting at the site and an antibody super-shift reaction showed that Sp1 is one of the factors binding the consensus site. The Sp1 site also co-localizes with a DNase I hypersensitive site. The results indicate that DNA methylation, chromatin structure, and transactivation at an Sp1 site contribute to the highly restricted expression of this myelomonocytic lineage specific gene.

Fabrication of group-Ill nitride electronic and photonic devices relies heavily on the ability to pattern features with anisotropie profiles, smooth surface morphologies, etch rates often exceeding 0.5 μm/min, and a low degree of plasma-induced damage. Patterning these materials has been especially difficult due to their high bond energies and their relatively inert chemical nature as compared to other compound semiconductors. However, high-density plasma etching has been an effective patterning technique due to ion fluxes which are 2 to 4 orders of magnitude higher than conventional RIE systems. GaN etch rates as high as -1.3 μm/min have been reported in ECR generated ICI plasmas at -150 V dc-bias. In this study, we report high-density GaN etch results for ECR- and ICP-generated plasmas as a function of Cl2- and BCl3-based plasma chemistries.

To follow incidence of Pasteurella haemolytica (PH) in the upper respiratory tract of healthy calves at the farm and through the marketing process, and to determine the effect of vaccination on PH colonization of the upper respiratory tract and on the incidence of respiratory tract disease (RTD).2- to 5-month-old calves (n = 104) from 4 farms.Calves were vaccinated with a killed PH serotype-1 product. Nasal secretion and tonsil wash specimens were cultured for PH, and serum antibody was measured by indirect hemagglutination. Calves with RTD were treated with tilmicosin phosphate.At the feedyard, 73 calves had RTD. The incidence of RTD was significantly related to the farm of origin, and was inversely related to the PH serum titer at the farm, but was not influenced by vaccination. Isolations of PH serotype 1, however, were reduced by vaccination. The major serotypes of PH encountered were 1 and 6.Vaccination can reduce the frequency of colonization of the upper respiratory tract by PH.

An international external quality assessment scheme for trace elements in biological fluids is described. Programmes for aluminium, copper, zinc, selenium, gold, lead, cadmium and mercury in serum, blood, urine, dialysis fluids and water are included with others under development. Preparation of reports is described and assessments of performance based on proximity to assigned values, differences in results between duplicate measurements and recovery of added analyte are given. Performance standards have been introduced to stimulate improvements in the quality of results.

Otitis externa is a common condition presenting in both general and hospital practice. Diagnosis and treatment are usually straightforward; however appropriate management requires recognition of predisposing and precipitating factors, effective cleaning of the external auditory canal and administration of suitable topical or systemic medication or both. The aim of this article is to provide an overview of the clinical features and management of otitis externa with a discussion of the differential diagnosis.

A rifampicin-resistant Pasteurella haemolytica serotype 1 with 2 added plasmids was used as a colonization-challenge strain in calves to test the resistance to colonization elicited by vaccination. Nine calves were vaccinated with a tissue culture-derived P haemolytica serotype-1 vaccine which, in a prior study, had elicited a serotype-specific inhibition of nasal and tonsillar colonization by the homologous serotype under field conditions. The vaccinates and 9 nonvaccinated control calves were exposed by tonsillar instillation with the challenge strain. The P haemolytica were enumerated in nasal secretion and tonsil wash specimens collected biweekly for 3 weeks. Rifampicin-supplemented agar medium inhibited growth of other bacterial species in the specimens and, thus, increased the sensitivity of detection of the challenge P haemolytica by 100-fold. The challenge strain retained its plasmids during the period of colonization. Inhibition of colonization was evidenced by lower frequency of isolations and fewer isolations of the challenge strain from nasal secretion and tonsil wash specimens of the vaccinates than from those of the nonvaccinates.

The analytical performance of laboratories participating in the dialysis fluids and water aluminum program of the Guildford External Quality Assessment Scheme over the period 1986-1993 has been reviewed. For aluminum concentrations > 3.33 mumol/L in dialysis fluids, the between-laboratory CV has fallen from approximately 36% to 23%, whereas for specimens of water the reduction was from 36% to approximately 18%. Improvements at lower concentrations were less impressive. Performance of individual participants varied; only a few consistently provided accurate results. Many of the participants are able to measure serum aluminum well, so lack of expertise is not responsible for poor results. We suggest that matrix effects associated with different specimen types have a significant influence on performance and that due account is not always taken of these factors. Resolution of these problems would be aided by appropriate reference materials.

Vaccination of cattle with a tissue culture-derived Pasteurella haemolytica serotype 1 vaccine elicited a serotype-specific inhibition of nasal and tonsillar colonization by the homologous serotype under field conditions. Calves (n = 101) originated from a single farm, where half the calves were vaccinated. The calves were delivered to an order-buyer barn 105 days later, and given a second dose of vaccine. At the order-buyer barn, calves were mixed with 27 calves, some of which had clinical signs consistent with respiratory tract disease. Also 12 of the original calves were infected with P haemolytica serotype 1 by tonsillar instillation. After 6 days at the order-buyer barn, calves were shipped 1,600 km by truck to a feedyard, and arrived the next day. Tonsillar wash and nasal secretion aspiration specimens were collected for culture of P haemolytica on days 1, 8, and 29 at the feedyard. Inhibition of colonization was evidenced by lower frequency of isolations from the vaccinates than from the nonvaccinates after transport to the feedyard. Selectively lowering the frequency of colonization by P haemolytica serotype 1 could reduce losses attributable to pneumonic pasteurellosis.

The focus of this article is the diagnosis and surgical correction of conductive hearing loss in children without aural atresia, cholesteatoma, or otitis media with effusion. An overview of the incidence of congenital conductive hearing loss and the types of middle ear anomalies are provided. Techniques of surgical correction are described with respect to the types of ossicular and middle ear abnormalities encountered for both congenital and acquired conductive hearing loss, including otosclerosis.

The introduction of various pieces of legislation concerned with health and safety at work, along with increasing public concern about possible adverse health effects caused by human exposure to low levels of toxic chemicals, has increased the need to carry out workplace monitoring. Knowledge of the risk to human health of handling toxic chemicals clearly needs measurement of the exact levels that humans are exposed to. The vast number of chemicals now encountered in the workplace means that no single sampling strategy and no single analytical technique is applicable to all situations. Although the development of direct reading instruments for on-site monitoring, giving fairly instant results, is progressing the majority of measurements of trace organic compounds in workplace samples require collecting samples in the workplace and sending to an analytical laboratory for instrumental analysis.

There is a paucity of data on which to base estimates of the energy requirements of the elderly. In general, ageing appears to be associated with a reduction in energy requirement arising from a reduction in physical activity and loss of fat-free mass. The aim of the present study was to measure the total energy expenditure (TEE), basal metabolic rate (BMR), and energy expended on physical activity (calculated as TEE–BMR) in a group of healthy elderly women living in the community in Southampton. Mean rates of TEE (9.21 (SD 1.48) MJd) and energy expended on physical activity (4.12 (SD 1.19) MJ/d) were higher than those observed in some studies of younger adults in the UK, and higher than the factors used to estimate the average energy requirement for the elderly. The results suggest that an age-related reduction in energy requirement is not inevitable and support the hypothesis that the effects of ageing on physical activity, body composition, and hence energy requirements, are variable.

Down's syndrome is the most common autosomal chromosomal abnormality in humans and is associated with a number of well known clinical findings. Atlantoaxial instability is a less recognized, yet potentially significant, manifestation of Down's that has gained importance because of the widespread participation of Down's syndrome individuals in athletic events. Early recognition and appropriate management of patients with atlantoaxial instability can significantly reduce the morbidity and mortality associated with this condition and guide patients and their parents toward continued safe participation in athletics.

The competitive N-methyl-D-aspartate (NMDA) receptor antagonist [3H]3-((+-)-2-carboxypiperazin-4-yl)propyl-1-phosphonic acid ([3H]CPP) interacts with two discrete binding sites, one of high- and the other of low-affinity, on rat forebrain synaptic plasma membranes. The high affinity site exhibited a Kd of 101.5 nM and a Bmax of 2.01 pmol/mg, while for the low affinity site the Kd was 4.11 microM with a Bmax of 19.7 pmol/mg. The glycine site antagonists 3-amino-1-hydroxy-2-pyrrolidone (HA-966), 1-aminocyclobutanecarboxylic acid (ACBC), the glycine site agonist 1-aminocyclopropanecarboxylic acid (ACC) and glycine itself (as well as the polyamines spermine and spermidine), enhanced [3H]CPP binding. When subjected to saturation analysis, this enhancement was found primarily to involve an increase in the affinity of the high affinity component of [3H]CPP binding. Neither of the parameters of the low affinity component of binding were affected. Although a similar enhancement was observed with the polyamines, the effects of these two classes of ligands were additive, consistent with their having actions at different recognition sites on the NMDA receptor complex.

Tonsils of 10 calves were inoculated with Pasteurella haemolytica (PH) and the degree of colonization was followed by collecting sequential tonsil. wash specimens. Tonsils were colonized for at least 3 weeks after instillation of PH into the tonsillar sinus. Calves with colonized tonsils responded with serum and nasal secretion antibody responses to PH and to leukotoxin. Pasteurella haemolytica was detected in nasal mucus specimens of 2 calves during the week after inoculation of the tonsils, but all other specimens were culture-negative. Infectious bovine rhinotracheitis virus-induced respiratory tract disease 25 days later did not elicit a population increase of PH in the tonsils, and did not elicit shedding of PH in nasal mucus.

The binding of [3H]3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid ([3H]CPP) was studied in rat and human brain synaptic membranes. Specific binding was saturable, reversible and inhibited by a range of compounds active at N-methyl-D-aspartate (NMDA) receptors such as 2-amino-5-phosphonopentanoate (AP5), 2-amino-7-phosphonoheptanoate (AP7), NMDA and cis-2,4-methanoglutamate. Binding was heterogeneous as evidenced by non-linear Scatchard plots and Hill coefficients for binding inhibitors significantly different from unity. LIGAND analysis of the binding data indicated the likely presence of two distinct binding components for CPP, one of high (Kd values approx. = 70 nM) and the other of low (Kd values approx. 5 microM) affinity. Possible alterations in the binding of [3H]CPP to either site were investigated in medial frontal and medial temporal cortex from Alzheimer's disease brains and compared with control tissues, carefully matched for age and postmortem delay. While there were considerable inter-individual variations in binding, no significant differences were detected either between brain regions in either Alzheimer or control subjects, or between Alzheimer's disease and control brains. These data suggest the presence of at least two components of [3H]CPP binding in both rat and human brain tissue. The integrity of neither of these components is altered in Alzheimer's disease, consistent with a lack of gross alterations of NMDA receptors in this disorder.

The effects of external pH, temperature, and Ca2+ and Mn2+ concentrations on the compartmentation and NMR visibility of inorganic phosphate (Pi) were studied in isolated rat liver mitochondria respiring on succinate and glutamate. Mitochondrial matrix Pi is totally visible by NMR at 8 degrees C and at low external concentrations of Pi. However, when the external Pi concentration is increased above 7 mM, the pH gradient decreases, the amount of matrix Pi increases, and the fraction not observed by NMR increases. Raising the temperature to 25 degrees C also decreases the pH gradient and the Pi fraction observed by NMR. At physiologically relevant concentrations, Ca2+ and Mn2+ do not seem to play a major role in matrix Pi NMR invisibility. For Ca2+ concentrations above 30 nmol/mg of protein, formation of insoluble complexes will cause loss of Pi signal intensity. For Mn2+ concentrations above 2 nmol/mg of protein, the Pi peak can be broadened sufficiently to preclude detection of a high-resolution signal. The results indicate that mitochondrial matrix Pi should be mostly observable up to 25 degrees C by high-resolution NMR. While the exact nature of the NMR-invisible phosphate in perfused or in vivo liver is yet to be determined, better success at detecting and resolving both Pi pools by NMR is indicated at high field, low temperature, and optimized pulsing conditions.

Human promyelocytic leukemia cells, HL-60, were treated with cisplatin [cis-diamminedichloroplatinum (II)] (2 mM, 1 h). DNA-cisplatin-protein complexes were isolated and exposed to thiourea (1 M), NaCN (100 mM), diethyldithio-carbamate (500 mM), or N-methyl-D-glucamine dithiocarbamate (500 mM) for 12 h. The release of platinum was measured by atomic absorption spectroscopy. Sodium cyanide was the most effective agent, releasing about 90% of the DNA-bound platinum. Thiourea was the least effective agent, while dithiocarbamates exhibited an intermediate. The ability of the same group of agents to split the proteins off from the protein-cisplatin-DNA complex was also evaluated and similarly dithiocarbamate were also the most effective.

12-Hydroxyeicosatetraenoic acid (HETE) is associated with a variety of inflammatory conditions. For studies on pathophysiological function of 12-HETE, metabolically more stable analogs of 12-HETE would be useful. We biologically synthesized 20,20,20-trifluoro-12-HETE (20-F3-12-HETE) by incubating enantioselectively synthesized 20,20,20-trifluoro-arachidonic acid with human platelets. The product was identified by UV absorption spectrophotometry and gas chromatography-mass spectrometry. When 1 microgram 20-F3-12-HETE was incubated with 5 X 10(6) human neutrophils for 45 min, only 5% of the analog was metabolized while 66% of 12-HETE was metabolized in the same incubation condition. With 2 X 10(7) neutrophils, 37% of the analog was metabolized at the same incubation condition while 87% of 12-HETE was metabolized. Thus, by blocking omega-oxidation of 12-HETE with fluorine atoms, the stability of 12-HETE was greatly increased. This result indicates that the omega-oxidation is a major pathway for 12-HETE metabolism. The analog demonstrated as much chemotactic activity on human neutrophils as 12-HETE, and binding affinity of the analog for 12-HETE receptor in human epidermal cell was equal to that of 12-HETE. An analog of 12-HETE, which has extended metabolic stability without alteration of neutrophil chemotactic activity and binding affinity, would be a useful tool for studies on pathophysiological role of 12-HETE in inflammatory conditions.

Despite the complex nature of the project, the clients brief of a 14 month design and installation period was achieved within the approved budget of 2.5 million pounds. Early performance figures indicate that the scheme is on target to achieve the original payback of under four years. Queen Elizabeth Hospital: installation of integrated combined heat and power plant. Client: Central Birmingham Health Authority. Consulting Engineers/Project Managers: Yates, Edge and Partners. Architects: Temple Cox and Nichols. Structural Engineers: Peel and Fowler. Quantity Surveyor: West Midlands Regional Health Authority.

Absenteeism of 130 direct-care staff was reduced by 27% through a mixed consequence procedure consisting of positive reinforcement for reliable attendance and punishment (progressive discipline) for attendance abuse. Reduced rates of absenteeism were maintained over a 12-month period. A 17% reduction in overtime and an increase in annual staff turnover from 34% to 45% also occurred. Results extend the findings of mixed consequence procedures to residential facilities for persons with developmental disabilities. Development of a more powerful positive reinforcement component was discussed.

Children born with prominent bowing of the tibia are an obvious concern to parents and physicians. Managing these congenital angulations requires early and accurate diagnosis. Classification is based on the direction of the angulation and its associated pathology. The three basic classes of tibial angulations commonly accepted are based on the work of Heyman and Herndon. The success of treating these children depends on the type and severity of the angulation. This article presents three cases of tibial bowing and describes the treatment and prognosis of each.

Inbred lines of corn (Zea mays L.) have been characterized, which exhibit differential sensitivity to the sulfonylurea herbicide primisulfuron (2-[3-(4,6-bis(di-fluoromethoxy) pyrimidin-2-yl)-ureidosulfonyl]-benzoic acid methylester). When treated postemergence with 160 g a.i. per hectare, inbred 4CO exhibited complete tolerance while inbred 4N5 was killed. The F1 hybrid 4C0 x 4N5 was uniformly tolerant indicating dominance of the tolerance trait. The field observations correlated with laboratory tests in which seedling root growth was measured. Based on IC50, inbred 4CO was more than ten times more tolerant than inbred 4N5. In the F2 and F3 generations, a 3∶1 segregation of tolerant and sensitive individuals was observed, consistent with tolerance being inherited as a single dominant trait. Backcrosses of heterozygous F1 plants with the sensitive parent (4N5) yielded progeny that segreated at the expected 1∶1 ratio. Backcrosses with 4C0 yielded tolerant offspring only. Inhibition characteristics of acetohydroxyacid synthase (AHAS; E.C. 4.1.3.18) were determined. The enzymes from both inbreds and their F1 hybrid were equally sensitive and strongly inhibited by primisulfuron (IC50: 7 nM). The fate of (14)C-labeled primisulfuron in seedling tissues of inbred 4C0 and the hybrid, 4C0 x 4N5, indicated rapid metabolism with a half-life (t 1/2) of approximately 3 h. On the other hand, the herbicide-sensitive inbred 4N5 was considerably slower to metabolize primisulfuron (t 1/224 h). These data indicate that differential metabolism is the mechanism of tolerance to the sulfonylurea herbicide primisulfuron in tolerant corn.

Protein-DNA interactions of the human myeloid cell nuclear differentiation antigen (MNDA) were examined in vivo in proliferating HL-60 promyelocytic leukemia cells and following induction of differentiation by 1,25-dehydroxyvitamin D3. Intact cells were treated with the reversible cross-linking agent cis-diamminedichloroplatinum(II) and the MNDA levels in the isolated protein-DNA complexes were determined. Less than 1% of the total intracellular level of MNDA was cross-linked to DNA in the noninduced proliferating HL-60 cells. Once the cells were induced to differentiate into monocytes, the amount of antigen cross-linked to the DNA increased to over 5% of the total intracellular level. The increased efficiency of cross-linking the MNDA to DNA was specific for monocyte-induced HL-60 differentiation, achieved with three inducers, and was not observed in association with granulocyte-induced differentiation. On a molar basis the phorbol ester (12-O-tetradecanoylphorbol-13-acetate) was the most effective inducer of monocyte differentiation, followed by 1,25-dihydroxy-16-ene-23-ynecholecalciferol which was more effective than 1,25-dihydroxycholecalciferol. A cesium chloride gradient analysis of the nucleic acid-protein fraction isolation from cis-diamminedichloroplatinum(II)-treated, monocyte-induced HL-60 cells documented the authenticity of the association between the MNDA and DNA. The results indicate that a significant level of chromatin reorganization may accompany monocyte-induced differentiation that leads to much higher levels of MNDA-DNA cross-linking to DNA. The expression of the MNDA is restricted to human myeloid cells and the present results indicate that a fraction of this low abundance nuclear protein is specifically located near the DNA [within cis-diamminedichloroplatinum(II) cross-linking distance] and that this association may be modulated specifically during monocyte differentiation.

Dinitrophenyl (DNP) derivatives of various molecular weights were tested for their ability to elicit ocular anaphylaxis after topical application to the eye of immunized animals. Adult male Sprague-Dawley rats were immunized by intraperitoneal injection of DNP-Ascaris suum extracts and alum and were then skin-tested with DNP-bovine serum albumin on day 13 post-immunization to assess their sensitivity to the DNP hapten. On day 14, animals were challenged topically with DNP derivatives in one eye; PBS was applied to the contralateral, control eye. Animals were evaluated clinically, and ocular tissues were processed for histologic evaluation. The compounds used for topical ocular challenge included the DNP derivative of egg albumin (MW 43,500 D), soybean trypsin inhibitor (MW 20,080 D), insulin (MW 5733 D), B-chain insulin (MW 3496 D), and lysine (MW 478 D). Only di-DNP-lysine elicited clinical signs of redness, edema, and tearing and histologic evidence of mast cell degranulation. None of the other compounds, tested in solutions of either equal numbers of milligram per milliliter or equimolar concentrations, elicited ocular anaphylaxis after topical application. A compound of low molecular weight, less than 3496, is needed to elicit ocular anaphylaxis when applied topically.

A review of 286 children who presented with transient synovitis of the hip over a 6-year period shows that the condition remains a benign disease of the paediatric hip which settles quickly with simple symptomatic treatment. We have not found any obvious causal agent for the condition despite intensive laboratory investigation. There was only one subsequent case of Perthes' disease in association with transient synovitis, causing doubt on any relationship between the two conditions. The need for extensive investigation and long-term follow-up seems to be unnecessary in transient synovitis of the hip.

Children presenting with an intoeing gait are the most common pediatric problem seen by orthopedists. Most parents are concerned that this rotational problem may result in a permanent disability or impediment of their child's physical performance. The etiologies of these conditions are still debated, although the structural conditions giving rise to intoeing can be correlated with the age of onset. The extent of the rotational problem is determined through physical examination and the measurement of indicative angles. A rotational profile is compiled from the values obtained, allowing the child's progress to be followed. Many children spontaneously resolve the structural problems responsible for their intoeing gait. The success one attributed to the traditional methods for treating intoeing is now believed to be the result of this natural resolution.

A model of topically induced ocular anaphylaxis in guinea pigs was developed. A guinea pig anti-dinitrophenyl (DNP) bovine gamma-globulin antiserum rich in IgG1 antibodies was injected subconjunctivally; various serum dilutions and latent periods were tested. The anaphylactic response was elicited with di-DNP-lysine applied topically. The response was characterized by rating 11 ocular signs. Although the 4-hour latent period is considered optimal for passive cutaneous anaphylaxis, a 14-hour latent period yielded the strongest ocular reaction and appeared to the most appropriate time for clinical assessment. Both an early-phase reaction (peaking in the 21st hour) and a late-phase reaction (peaking at 6-10 h) were observed. The two signs of the early-phase reaction that recurred in the late-phase reaction were periorbital swelling and lid redness. The anaphylactic reaction displayed different patterns in different animals: protracted, biphasic and multiphasic.

A 300 ft (91.4 m) cable stayed bridge near Skagway, Alaska carries in addition to normal traffic 160,000 lb (71.576 kg) ore trucks. It has a laminated timber deck supported by transverse floor beams spanning two stiffened ASTM A588 steel box girders. Two inclined cables stay the girders near midlength to a single tower. The abutments and tower were rock anchored to the canyon walls.

Rationale The delayed introduction of solids, particularly of allergenic foods, into an infants diet is advocated by the American Academy of Pediatrics as an allergy prevention measure. Such advice is also incorporated into many allergy prevention studies. Methods We compared retrospectively sensitization rates of control groups of two intervention allergy prevention studies. Recruitment to the studies ran consecutively, with the same criteria and procedures being applied to each. Mothers from the first intervention study (S1) received no weaning advice, whereas mothers from the later study (S2) were advised to delay the introduction of solids until 4 months of age and not to introduce allergenic foods until after 6 months of age. Skin prick test results and presence of eczema were compared at 1 year (n=185) and 3 years of age (n=79). Results At one year, sensitization rates in S2 mothers was 21% to food allergens and 36% to food and aeroallergens combined. In S1 mothers these values were 8% and 20% respectively. These differences are significant (p=0.023 and p=0.015). At three years of age there was no difference in sensitization rates (p=1.0 and p=0.79). There was no significant difference in eczema rates at either time point (p=0.3 and p=0.3). Conclusions Delayed weaning strategies may not be as an effective allergy prevention measure as is currently thought and should be further investigated.

MgO or Sc 2 O 3 passivated AlGaN/GaN high electron mobility transistors (HEMTs) were irradiated with 40 MeV protons at a dose equivalent to ∼10 years in low-earth orbit. Very little change in drain-source current, transconductance, or diode ideality factor was observed under these conditions, but the reverse breakdown increased due to a decrease in channel electron density. In addition, no significant change was observed in the drain-source current under pulsed conditions, indicating that the proton irradiation did not alter the effectiveness of the MgO and Sc 2 O 3 in passivating surface states.

The authors describe an (InGaAl)As/InGaAs vertical-cavity optical transmission modulator operating at 1.32 /spl mu/m, and having a single pass contrast /spl Delta/T/T of 24% at

The effects of a single 384 mg oral dose of chlormethiazole were compared with those of 20 mg of temazepam and placebo in healthy old and young women (mean ages 72.9 and 24.7 years respectively). Both drugs were effective hypnotics and had no detectable pharmacological action the next morning. Even four hours after administration performance of a simple psychomotor test was not impaired and sway (measured by an ataxiameter) was not increased in either age group. Pharmacokinetic studies showed that chlormethiazole was rapidly absorbed, distributed, and eliminated by both groups, so that minimal plasma concentrations existed 11 hours after administration. Temazepam, however, was less quickly absorbed and distributed, especially in the young group, and substantial amounts remained in the plasma 11 hours after administration. No unwanted effects occurred after temazepam, but 17 of the 20 subjects suffered from nasal irritation after taking chlormethiazole. Thus hangover effects may be avoided in elderly subjects after they have taken hypnotic drugs, and temazepam and chlormethiazole allow sleep to be interrupted safely.

Although normal pressure hydrocephalus is one of the few remediable causes of dementia, the diagnosis is often not considered in the elderly. Three patients are described who presented to an acute geriatric unit within a six-month period during which normal pressure hydrocephalus was actively sought and treated. Although two made striking initial improvement, the long-term prognosis was poor: complications were frequent, and all three died within two years of operation. This pilot study indicates that normal pressure hydrocephalus may account for a proportion of cases of 'senile' dementia, but that formal controlled studies are required to establish the best means of diagnosis and treatment.

Head orientation during auditory discriminations was studies in squirrel monkeys using a two-lever trial-by-trial procedure. Animals were studied using auditory discriminations based on the position of the sound and on the spectral content differences between a pure tone and a noise. After the percentage of correct responses reached asymptote, head orientation was measured using videotape recordings. Orientation occurred on virtually every trial and was under the control of the position of the sound under all conditions. Lever responding was controlled by the same parameters of the sound under some conditions, and by different parameters in others. Orientation and lever responding were correlated (a level response could be predicted from the direction of orientation) when both responses were under the control of the same parameters of the sound. The two responses were uncorrelated when they were controlled by different parameters of the sound. Orientation and lever responding were not functionally related.

Rats were treated continuously for 12 months with therapeutically equivalent doses of either haloperidol (1.4-1.6 mg/kg/day), sulpiride (102-109 mg/kg/day), or clozapine (24-27 mg/kg/day). After treatment for 3 and 12 months with haloperidol or clozapine but not sulpiride, striatal acetylcholine levels were increased. Striatal choline acetyltransferase activity was not altered by any drug treatment. Vmax for striatal acetylcholinesterase activity during the course of 12 months' treatment with haloperidol or clozapine, but not with sulpiride, tended to increase; Km was not altered by any drug treatment. Bmax for specific striatal [3H]quinuclidinyl benzilate binding was not altered by haloperidol or sulpiride treatment but was transiently elevated after 6 months of clozapine treatment, thereafter returning to control levels. Kd was not altered by any drug treatment. These findings indicate that alterations in striatal acetylcholine content caused by chronic treatment with some but not all neuroleptics are due to changes in cholinergic neuronal activity rather than neurotransmitter synthesis or destruction. The effects of haloperidol but not those of clozapine may be related to the emergence of functional striatal dopamine receptor supersensitivity. Since haloperidol (which is associated with a high prevalence of tardive dyskinesias) but not clozapine (which is not) had similar effects on striatal cholinergic function, the latter may not be related to the emergence of tardive dyskinesias during chronic therapy.

Few investigations into the general biology of associated copepods have been made, although studies dealing with their taxonomy and structure are well documented, for example the many papers of Gotto, Bocquet, Humes and Stock. This work is an attempt to fill certain gaps in our biological information by considering the copepod Paranthessius anemoniae Claus, a cyclopoid associate of the snakelocks anemone Anemonia sulcata (Pennant). First described by Claus (1889) and later by Bocquet & Stock (1959) from Mediterranean waters, Paranthessius has only recently been reported from Irish and British waters (Gotto & Briggs, 1972; Briggs & Gotto, 1973).

We have used phosphorus-31 nuclear magnetic resonance to study the secretion of adenosine 5'-triphosphate (ATP) from the medulla of perfused pig adrenal glands. The resonances of the nucleotide pools in the chromaffin granules and cytoplasm are clearly resolved and therefore the intragranular and cytoplasmic processes involving ATP can be monitored simultaneously in the gland during secretion. Secretion of nucleotide during a 3 h continuous stimulation by infusion of acetylcholine chloride was monitored by the decrease in intensity of the intragranular ATP resonances. Up to 40% of the total intragranular nucleotide was released under these conditions. The rate of secretion decreased with duration of stimulation. No significant changes in the steady-state levels of cytoplasmic ATP or in oxygen consumption were observed. The intragranular pH in ischaemic glands was 5.52 + 0.15, while in glands which had been perfused until their cytoplasmic nucleotide levels had recovered, the intragranular pH was 5.76 ± 0.16. These results provide the first estimate of the internal pH of the chromaffin granules in intact perfused adrenal glands and show that no net acidification occurs in the presence of cytoplasmic ATP. However, the isolated chromaffin granule possesses a proton-pumping adenosine 5'-triphosphatase which, in the presence of a permeant counter-ion, such as chloride, acidifies the granule interior. It is, therefore, suggested that in the intact cell, the cytoplasmic concentration of permeant counter-ions is too low to allow electrically neutral proton accumulation in the granules.

SUMMARYLaboratory studies showed that few rabbit fleas (Spilopsyllus cuniculi (Dale)) transmitted myxomatosis after removal from wild rabbits (Oryctolagus cuniculus (L)) that had been infected for fewer than 10–12 days, irrespective of the virulence of the myxoma virus strain involved. Rabbits infected with fully virulent (Grade I) strains died within 10–15 days and few fleas from these hosts became infective; averaging all the samples taken, 12% of the fleas were infective. Also, few fleas acquired infectivity on individual rabbits which recovered from infection with attenuated strains; the mean was 8% infective. Rabbits which died between 17 and 44 days after infection had higher proportions of infective fleas at all sampling times; the mean was 42% infective. Male and female fleas transmitted virus with equal efficiency.For rabbits infected with any of the attenuated virus strains the mean percentage of infective fleas was inversely related to the survival time of the host. Rabbits infected with moderately attenuated strains (Grades IIIA and IIIB) had, on average, the highest proportion of infective fleas; hence such strains have a selective advantage and have become predominant under natural conditions in Britain. The changes that might occur if there is an increase in host resistance to myxomatosis are discussed.

Samples of rabbits were obtained throughout each month over the 4-year period 1967–70. All fleas were removed, sexed and counted and the reproductive condition of the rabbits recorded. Rabbit fleasSpilopsyllus cuniculi(Dale) were present on both sexes of rabbit at all times of the year. In each year significantly high numbers of fleas were found on the rabbits in January, February, March and April and significantly low numbers in August, September and October. Mean flea counts were significantly higher on female rabbits than on males during April, May and June. During the rest of the year counts from each sex of host did not differ significantly. There were significant differences in flea numbers between years. More female than male fleas were found on both sexes of host throughout the year. The rabbit population sampled is shown to be typical of post-myxomatosis populations with regard to breeding performance and juvenile mortality. The relationship of the observed patterns of change in flea numbers to host and flea breeding and to host behaviour, population size and structure is discussed.

The first-order Raman spectrum of $\ensuremath{\alpha}$-quartz, consisting of four totally symmetric ${A}_{1}$ lines, four $E$ lines with "unresolved" LO-TO components, and four LO-TO split $E$ doublets, have been investigated under uniaxial stress. A compressive force $\stackrel{\ensuremath{\rightarrow}}{\mathrm{F}}$ was applied along the trigonal axis $\stackrel{^}{z}$, along the binary axis $\stackrel{^}{x}$, or along ${\stackrel{^}{z}}^{\ensuremath{'}}=(\frac{1}{\ensuremath{\surd}2})(\ensuremath{-}\stackrel{^}{y}+\stackrel{^}{z})$. All splittings and/or shifts were found to be linear in stress and hence describable in terms of a linear-deformation-potential theory. From measurements using these three force directions the two deformation-potential constants characterizing each ${A}_{1}$ and the four constants characterizing each $E$ line have been deduced. The extreme sharpness of the 128-${\mathrm{cm}}^{\ensuremath{-}1}$ $E$ line at liquid-helium temperature allowed a Fabry-Perot interferometer to be used in the study of its behavior. The LO-TO splittings of the $E$ lines at 263, 695, and 1160 ${\mathrm{cm}}^{\ensuremath{-}1}$ were measured to be 1.25 \ifmmode\pm\else\textpm\fi{} 0.09, 2.39 \ifmmode\pm\else\textpm\fi{} 0.10, and -3.02 \ifmmode\pm\else\textpm\fi{} 0.45 ${\mathrm{cm}}^{\ensuremath{-}1}$, respectively, for the phonon wave vector, $\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}$ along $\stackrel{^}{y}$; the LO-TO splittings are comparable to the observed linewidths at liquid-helium temperature and were deduced from the zero-stress intercepts of the least-squares fits characterizing the stress dependence of the components. The LO-TO splittings of the 695- and 1160-${\mathrm{cm}}^{\ensuremath{-}1}$ lines were just resolved at liquid-helium temperature for $\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}\ensuremath{\parallel}\stackrel{^}{y}$. The LO-TO splittings calculated from the reststrahlen spectra for all eight $E$ lines are in satisfactory agreement with those measured in the present Raman study, even as to the unusual negative sign for the splitting of the 1160-${\mathrm{cm}}^{\ensuremath{-}1}$ line.