Brain function in spider phobia

Measurements of regional cerebral blood flow (rCBF) were performed in 16 women suffering from spider phobia. The non-invasive 133Xe inhalation method, giving information about the blood flow of superficial areas, was used. The subjects were studied under three conditions: during resting, when exposed to a videotape showing nature scenery, and finally when watching a video with living spiders. During the rCBF measurements the subjects' behaviour was registered systematically and respiration, blood pressure, Pco2, and heart rate were monitored. Eight subjects who showed and reported severe panic during the spider exposure had marked rCBF decreases in frontal areas, especially in the right hemisphere. The remaining eight subjects displayed a more efficient control of their emotions and became frightened, but not panic-stricken, during the spider exposure. These showed a consistent rCBF increase in the right frontal area compared to neutral stimulation. Thus, results revealed significant functional changes in the frontal cortex in subjects with spider phobia during phobogenic exposure. It seems likely that these frontal changes are related to the experience and control of phobic anxiety.

Effect of a clinical case manager/clinical nurse specialist on patients hospitalized with congestive heart failure

The purpose of this study was to evaluate the effect of case management by a Clinical Case Manager/Clinical Nurse Specialist (CCM/CNS) on hospitalized length of stay and hospital charge throughout a 12-month period for patients with congestive heart failure. A total of 491 patients were discharged during 1997 with a diagnosis-related group code of 127. Of this number, 88 were case managed by a CCM/CNS. The remaining 403 received the usual management of their care. The group who were case managed by the CCM/CNS demonstrated significantly shorter length of stay (t = 5.40, P < 0.00) and lower hospital charges (t = 4.26, P < 0.00) than the patients with congestive heart failure who were not case managed. Secondary analysis indicated a significant interaction between case management and involvement of a cardiologist in the care of the patient. Patients whose care involved a cardiologist without case management by a CCM/CNS demonstrated significantly greater (alpha = 0.01) length of stay and hospital charges than patients who were case managed by a CCM/CNS or patients whose care did not involve a cardiologist.

Inverse relationship of urinary cyclic GMP to blood pressure reactivity in the CARDIA study: vasodilatory regulation of sympathetic vasoconstriction. Coronary Artery Risk Development in Young Adults

OBJECTIVE

To determine whether urinary cyclic GMP (cGMP), which mediates the actions of the vasodilators nitric oxide and atrial natriuretic factor, is inversely related to blood pressure (BP) reactivity. In previous work, we found that urinary cGMP was inversely related to diastolic BP, but cGMP levels were higher among individuals presumed to have increased adrenergic activity, increased reactivity, and increased risk of hypertension (blacks, individuals with a family history of hypertension).

METHOD

We measured 24-hour urinary cGMP levels in a substudy of 529 individuals in the Coronary Artery Risk Development in Young Adults (CARDIA) study; the sample was 23 to 35 years of age and approximately balanced for race (black/white) and gender. BP reactivity to stressors (video game, star-tracing, cold pressor) was tested 3 years earlier. Baseline BP was included as a covariate in all analyses.

RESULTS

Diastolic BP reactivity to cold pressor was inversely related to cGMP excretion (p < .05); the relationship was strongest among black women with a family history of hypertension (partial r = -.33, p < .01). Systolic BP reactivity to star-tracing was also inversely related to cGMP (p < .01); the relationship for both star-tracing and video game stressors was strongest among black men (partial r values = -.25 and -.24, respectively; p values < .01).

CONCLUSIONS

The results indicate that vasodilatory activity may impact the BP response to stress through modulation of adrenergic activation, particularly among blacks.

Sydenham's chorea

Sydenham's chorea (SC) is a disorder of the central nervous system (CNS) characterized by sudden, involuntary, arrhythmic, clonic, and purposeless movements. SC appears to provide a model for understanding various neuropsychiatric dysfunctions. Its relationship with attentional deficits, obsessive-compulsive symptoms (OCS) as well as movement disorders provides support for the hypothesis of the involvement of the corticostriatal loops in the pathophysiology of the disorder.

Associative learning by locusts: pairing of visual cues with consumption of protein and carbohydrate

We investigated whether fifth instar African migratory locusts, Locusta migratoria could learn to associate visual cues with the macronutrient content of synthetic foods. During a 48-h training period, the insects had ad libitum access to two synthetic foods which were identical in all respects except that one lacked protein and the other lacked digestible carbohydrate. One food was placed at the end of a transparent Perspex cylinder which had been tinted green, and the other at the end of a yellow-tinted cylinder which was similar in all other respects. To obtain a balanced diet, the insects were thus forced to ingest the two macronutrients in visually different environments. Following this training period, they were then made selectively deficient in either protein or carbohydrate, before being tested for their tendency to enter, and the depth of entry into, yellow- or green-tinted cylinders that did not contain food. Locusts entered significantly more frequently the colour of cylinder that had previously been paired with the deficient nutrient (henceforth termed the 'training colour'). This was true irrespective of whether the nutrient was protein or carbohydrate, and whether the training colour was green or yellow. There was no effect of training on the average depth of entry into the cylinders. However, protein-deprived locusts penetrated significantly more deeply than carbohydrate-deprived locusts into both green and yellow cylinders, irrespective of the training colour. A separate experiment demonstrated that naive locusts entered more frequently into the yellow than the green side-arm, but there was no influence of colour on the depth of entry by naive locusts.Copyright 1997 The Association for the Study of Animal BehaviourCopyright 1997The Association for the Study of Animal Behaviour.

Aural rehabilitation and graduate audiology programs

The quantity and quality of aural rehabilitation training that audiology graduate students receive versus the current services available to those students regarding work with the hearing impaired, cochlear implant recipients, patients with vestibular disorders, patients with central auditory processing disorders, and patients suffering from tinnitus were examined. Forty ASHA-accredited colleges and universities were contacted by telephone and audiology faculty members were surveyed. The results of the survey may provide valuable information for identifying and addressing shortfalls in aural rehabilitation programs.

Relationship of diastolic blood pressure with cyclic GMP excretion among young adults (the CARDIA Study): influence of a family history of hypertension. Coronary Artery Risk Development in Young Adults

BACKGROUND

Guanosine 3':5'-cyclic monophosphate (cGMP) is the second messenger of nitric oxide and atrial natriuretic factor, and mediates local vasodilatation. These vasodilatory factors are important in blood pressure regulation and possibly in the etiology of hypertension. Urinary cGMP levels among normotensive young adults have not previously been studied.

SUBJECTS

A subset of normotensive participants from the CARDIA study (n = 563), aged 23-35 years, was studied. The sample was approximately balanced for sex and race (black/white).

METHODS

Twenty-four-hour urinary cGMP levels were measured using an enzyme immunoassay; levels were adjusted for creatinine excretion. The blood pressure, smoking status, and risk factors for hypertension [including a family history of hypertension (FHH), the body mass index, education, alcohol intake, and sodium excretion] were also measured.

RESULTS

Women excreted more cGMP than did men, and blacks excreted more cGMP than did whites (both P < 0.0001). Excretion of cGMP was also greater among smokers (P < 0.001) and those with an FHH (P = 0.05), and was related directly and independently to sodium excretion (P < 0.02). The diastolic blood pressure (DBP) was related inversely to the excretion of cGMP among individuals without an FHH (r = -0.36, P < 0.001), but not among individuals with an FHH. In multiple regression analysis, the excretion of cGMP remained related significantly to the DBP and accounted for more variance in DBP than did any other variable among those without an FHH (delta R2 = 0.08, P < 0.001).

CONCLUSIONS

Urinary cGMP excretion is related inversely and independently to the DBP among those without an FHH but not among those with an FHH, suggesting that cGMP-related vasodilatation is impaired in those with an FHH. Sex differences in urinary excretion of cGMP are consistent with results from studies showing that estrogen increases the endothelial production of nitric oxide.

Indicators of delayed maturation of rat heart treated prenatally with dexamethasone

We investigated the effects of prenatal dexamethasone treatment on indicators of cardiac maturation: heart weight/body weight ratios, myosin heavy chain (MHC) expression, cell proliferation, and extracellular matrix. We administered dexamethasone, a synthetic glucocorticoid (approximately 48 microg/d, 3-wk slow release pellets), to pregnant rats (n = 8) beginning at 17 d postconception. Control dams were unmanipulated (n = 8). After approximately 4-5 d of dexamethasone exposure, hearts were collected from neonatal rats (12-24 h after birth). The prenatal dexamethasone treatment produced smaller pups with larger heart/body weight ratios, accompanied by a higher proliferative index and a reduction in extracellular matrix in the ventricles (with lowest values in the septal region) compared with control pups. We also report that, although there were no sex differences in body mass or heart and heart/body weight ratios, females had a greater proportion of cells synthesizing DNA in the heart. In addition, ventricles of male pups treated with dexamethasone contained lower levels of alpha-MHC mRNA, as reflected in a sex by treatment interaction. The changes in each parameter are consistent with delayed maturation. Our findings suggest that exposure to excess glucocorticoids in utero can affect cardiac development in potentially detrimental ways and that assessment of cardiac function should be closely monitored when such circumstances arise.

Morphological and morphometric characterisation of Onuf's nucleus in the spinal cord in man

In the absence of a systematic morphometric study of Onuf's nucleus in man, this investigation defines the limits of variation of segmental position and the range of length and volume of Onuf's nucleus in 6 normal humans displaying no neurological disease (2 males, 4 females). Serial section reconstruction methods in conjunction with the disector method provided information on the numbers, sizes and shapes of the constituent motor neurons of Onuf's nucleus. In contrast to previous descriptions, the cranial origin of Onuf's nucleus occurred in rostral S1 in 50% of subjects, and midcaudal S1 in the remaining subjects. Onuf's nucleus varied in length between 4 and 7 mm, and was 0.2-0.37 mm3 in volume. Differences in length or volume between males or females, or between the left and right side of the cord were not statistically significant. Neurons in Onuf's nucleus varied in diameter between 10 microns and 60 microns (mean 26 microns) and their mean number was 625 +/- 137. A higher density of neurons occurred at the cranial and caudal ends of the nucleus relative to the middle. While 37% of neurons were approximately spherical (shape index approximately 1), 44% were ellipsoid and 19% fusiform (shape indices varying between 0.26 and 0.8). These findings are compared with previous studies of Onuf's nucleus in man and animals. The results form a basis for further studies on Onuf's nucleus in normality and neurodegenerative diseases.

Genetic transformation, recovery, and characterization of fertile soybean transgenic for a synthetic Bacillus thuringiensis cryIAc gene

Somatic embryos of jack, a Glycine max (L.) Merrill cultivar, were transformed using microprojectile bombardment with a synthetic Bacillus thuringiensis insecticidal crystal protein gene (Bt cryIAc) driven by the 35S promoter and linked to the HPH gene. Approximately 10 g of tissue was bombarded, and three transgenic lines were selected on hygromycin-containing media and converted into plants. The recovered lines contained the HPH gene, but the Bt gene was lost in one line. The plasmid was rearranged in the second line, and the third line had two copies, one of which was rear-ranged. The CryIAc protein accumulated up to 46 ng mg-1 extractable protein. In detached-leaf bioassays, plants with an intact copy of the Bt gene, and to a lesser extent those with the rearranged copy, were protected from damage from corn earworm (Helicoverpa zea), soybean looper (Pseudoplusia includens), tobacco budworm (Heliothis virescens), and velvetbean caterpillar (Anticarsia gemmatalis). Corn earworm produced less than 3% defoliation on transgenic plants, compared with 20% on the lepidopteran-resistant breeding line GatIR81-296, and more than 40% on susceptible cultivars. Unlike previous reports of soybean transformation using this technique, all plants were fertile. To our knowledge, this is the first report of a soybean transgenic for a highly expressed insecticidal gene.

Morphologic changes following in vitro CO2 laser treatment of calculus-ladened root surfaces

BACKGROUND AND OBJECTIVE

The purpose of this study was to compare morphologic changes following C02 laser or manual curette treatment of calculus-ladened tooth root surfaces.

STUDY DESIGN/MATERIALS AND METHODS

Laser treatment consisted of repeated single passes with a 6 Watt focused beam at 20 pulses per second, a pulse length of 0.01 second, and a manufacturer's laser efficiency rating of 86% (i.e., the amount of total power delivered through the aperture). The rate of beam passage over the target surface was controlled at 4 mm/second using an 0.8 mm diameter tip. The calculated energy density was 240 J/cm2 for each pass of the beam. Scaled and root planed surfaces were treated with a standardized force of 600 grams using new curettes. Specimens were evaluated by scanning electron microscopy.

RESULTS

Laser-induced surface changes included charring, meltdown and resolidification of calculus mineral, and ablation of microbial plaque. Laser-treated specimens also exhibited residual calculus and microbial plaque deposits in areas directly adjacent to the beam path. Scaled and root planed surfaces featured smooth and/or scale like smear layers and islands of residual calculus and microbial plaque.

CONCLUSIONS

The rough surface topography resulting from laser treatment and residual calculus and microbial plaque deposits indicates that C02 laser treatment of exposed root surfaces is, at best, an adjunct to traditional methods of therapy.

Transcription of interferon-alpha 2 alleles from virus-induced human leucocytes and lymphoblastoid cells of African origin

It has been previously shown that the genomic DNA of both the lymphoblastoid cell line (Namalwa) and certain human donors (of African origin) contain sequences corresponding to two allelic variants, b and c, of the interferon-alpha 2 gene (IFNA2). Little is known however about the relative expression of these two alleles in heterozygous cells. We have therefore examined the transcription of allelic variants of the human IFNA2 locus by both normal human leucocytes (from a heterozygous donor) and Namalwa cells. Analysis of cDNA clones identified sequences of both allelic variants, IFNA2b and c, indicating active transcription by both cell types. Analysis of tryptic and peptic peptides derived from purified IFN-alpha 2 also demonstrated both IFN-alpha 2b and IFN-alpha 2c proteins. Populations of virus induced heterozygous cells can therefore effectively transcribe and secrete both forms of IFN-alpha 2 simultaneously, with no apparent restrictions on expression of either allele.

Immigrant families coping with schizophrenia. Behavioral family intervention v. case management with a low-income Spanish-speaking population

BACKGROUND

This investigation compared the effectiveness and cross-cultural applicability of behavioural family management (BFM) and standard case management in preventing exacerbation of symptoms and relapse in schizophrenia.

METHOD

Forty low-income Spanish-speaking people with a diagnosis of schizophrenia were randomly assigned to receive standard case management or behavioural family management after stabilisation with neuroleptic medication.

RESULTS

Survival analyses indicated that among the less acculturated patients BFM was significantly related to greater risk of exacerbation of symptoms. Among the more acculturated patients, risk of exacerbation could be predicted by medication compliance but not by type of intervention. In analyses of symptom severity and functional status at 1-year follow-up, the level of patient acculturation was found to be significantly related to various measures of treatment outcome.

CONCLUSION

Sociocultural factors affect responses to different types of intervention. The results did not support earlier findings of a beneficial effect of BFM when applied to a socioculturally diverse population.

Detection of rare allelic variants of the interferon-alpha 2 gene in human genomic DNA

We have analyzed human donor DNA for the presence of sequences corresponding to allelic variants of the IFN-alpha 2 locus. Using both restriction enzyme digestion of PCR-amplified fragments and sequence analysis of these fragments, we have identified the three reported allelic variants, IFN-alpha 2a, IFN-alpha 2b, and IFN-alpha 2c, in genomic DNA derived from donors of African or Afro-Caribbean origin. This is the first report of the IFN-alpha 2a and IFN-alpha 2c alleles occurring in human donor DNA and supports the view that these are variants of the predominant IFN-alpha 2b allele rather than arising from mutations occurring in cultured cells.

Inhibition of pancreatic proglucagon gene expression in mice bearing subcutaneous endocrine tumors

The proglucagon-derived peptides (PGDPs) play key roles in the regulation of carbohydrate metabolism and insulin secretion, yet the factors important for the regulation of proglucagon gene expression remain poorly understood. Recent experiments demonstrated that nude mice carrying subcutaneous proglucagon-SV40 T antigen tumors contained markedly reduced levels of the pancreatic PGDPs. To determine if elevated circulating levels of the PGDPs are consistently associated with inhibition of endogenous pancreatic proglucagon gene expression, we have now studied islet hormone gene expression in mice bearing three different endocrine tumors (InR1-G9, RIN1056A, and STC-1) that express the proglucagon gene. All tumors synthesized large amounts of the PGDPs. Plasma levels of the PGDPs were elevated in all tumor-bearing mice (8- to 22-fold greater than controls, P < 0.001), and this was associated with marked inhibition of mouse pancreatic proglucagon gene expression. The levels of pancreatic PGDPs were also significantly lower in tumor-bearing mice compared with controls (71 +/- 4, 38 +/- 6, and 18 +/- 2% of controls for InR1-G9-, RIN1056A-, and STC-1-bearing mice, respectively, P < 0.05-0.001). This inhibition of proglucagon gene expression was highly specific, in that no consistent change in pancreatic insulin or somatostatin gene expression was detected. Examination of proglucagon posttranslational processing in the tumors demonstrated that proglucagon was processed differently in each tumor to yield a unique profile of PGDPs. These observations demonstrate that elevated circulating levels of the PGDPs are associated with reduction in islet size and inhibition of proglucagon gene expression and PGDP synthesis in the pancreatic A cell.

Results of intensive therapy in childhood acute myeloid leukemia, incorporating high-dose melphalan and autologous bone marrow transplantation in first complete remission

Childhood acute myeloid leukemia (AML) has a poor prognosis with standard chemotherapy. Allogeneic bone marrow transplantation (BMT) in remission improves the outlook only for the one third of patients with sibling donors. Autologous BMT with a lower morbidity and mortality is available to all. In this study, maximum cytoreduction was achieved by intensive early chemotherapy. Final intensification, with autologous BMT was offered to all those remaining in first complete remission (CR). Patients received two induction and two consolidation courses of intensively scheduled chemotherapy. Cytoreduction was assessed on day 14 and remission was assessed after courses 2 and 4. Bone marrow was harvested after recovery from the second consolidation course or after the first maintenance course and separated on a discontinuous percoll gradient before cryopreservation. Twenty-eight of 31 consecutively enrolled patients achieved CR. Three relapsed early and, of the 25 eligible, 24 underwent autologous BMT. Twenty-three patients received high-dose melphalan and 1 received busulphan and cyclophosphamide before autologous BMT at a median of 113 days (range, 86 to 301) after initial CR. Trilineage engraftment occurred in all. Neutrophil recovery to greater than 0.5 x 10(9)/L occurred at a median of 46 days (range, 13 to 92) after autologous BMT. Platelet recovery was delayed, with a median time to achieve greater than 20 x 10(9)/L of 42 days (range, 18 to 215). With a minimum follow up of 25 months following autologous BMT only 3 children have relapsed. The 5-year event-free survival rate (EFS) from diagnosis is 68% (95% confidence interval, 46% to 90%). Five-year EFS following autologous BMT is 87% (95% confidence interval, 67% to 100%). Autologous BMT with high-dose melphalan administration after intensive chemotherapy has produced EFS equivalent to allogeneic BMT and is associated with a strikingly low relapse rate. High-dose melphalan appears to be a valuable agent for conditioning therapy in AML.

Characterization of stroma-adherent colony-forming cells: a clonogenic assay for early hemopoietic cells?

Hemopoietic cells that adhered to preformed selected marrow stromal cell layers were characterized on the basis of progenitor cell production capacity, colony-formation kinetics and forward light scatter (FLS) properties. It was shown that early hemopoietic cells attached to the stromal layers within 2 hours of incubation, and were responsible for the initial production of the more differentiated granulocyte-macrophage colony-forming cells (day 14 GM-CFC) in long-term cultures (LTC). In a clonogenic assay system, hemopoietic cells that adhere to stromal layers can be detected by the formation of small colonies of blast-like cells and are designated as stroma-adherent CFC. Cell fractionation on the basis of FLS and counting colonies on days 5, 14 and 21 revealed that there was a succession of colony formation, indicating that the stroma-adherent CFC consisted of subpopulations with different lag-phases before initiation of proliferation. Day 5, day 14 and day 21 stroma-adherent CFC were shown to have a high, intermediate and low FLS, respectively. The cells that produced GM-CFC by day 21 showed FLS properties similar to those of day 21 stroma-adherent CFC, suggesting a correlation between day 21 stroma-adherent CFC and CFC-producing cells in LTC. The CFC present on day 21 required the synergistic action of GM-CSF+IL-3 + stem cell factor (SCF) for optimal proliferation. The prolonged lag-phase, the low FLS and the multifactor-responsive progeny are properties similar to those reported for other early cells, and it is proposed that day 21 stroma-adherent CFC represent an early hemopoietic cell type whereas day 5 stroma-adherent CFC represent a more mature stage of differentiation.

Enhancement of chest images by automatic adaptive spatial filtering

Postprocessing of the image data is an exciting capability of digital radiography that may improve diagnostic performance. We present a new algorithm that selectively enhances edges and contrast in both lungs and mediastinum while minimally amplifying noise in chest images. Using different size kernels, two smoothed images are generated from the original chest image. The two regions of interest (lungs and mediastinum) are identified based on the distribution of pixel values in the image. A modified nonlinear unsharp mask subtraction technique is then applied. The resulting image has enhanced high- and middle-frequency information in the mediastinum without distorting lung parenchyma or significantly enhancing noise. We consider that the technique employed in this study could be suitable for routine use although its true effectiveness in improving diagnostic accuracy awaits observer-performance evaluation that is currently under way.

Developing a plan to evaluate the use of nursing conceptual frameworks

Five hospitals in the Metropolitan Toronto area have introduced a nursing conceptual framework as the basis of practice in their agencies. A research team representing the hospitals and the University of Toronto has developed a comprehensive plan to evaluate the impact of using a nursing framework on nursing practice. This paper describes the selection of variables to be studied and the ways selected to measure them. A series of papers will follow describing the establishment of psychometric properties of the instruments and the results of the pre-test phase. Although this paper describes a process that began some time in the past, the authors have kept current the literature on the subject and the most current references are included in this paper.

Implementation of nursing conceptual models: observations of a multi-site research team

The general acceptance by nursing of the nursing process as the methodology of practice enabled nurses to have a common grounding for practice, research and theory development in the 1970s. It has become clear, however, that the nursing process is just that--a process. What is sorely needed is the nursing content for that process and consequently in the past 10 years nursing theorists have further developed their particular conceptual models (CM). Three major teaching hospitals in Toronto have instituted a conceptual model (CM) of nursing as a basis of nursing practice. Mount Sinai Hospital has adopted Roy's adaptation model; Sunnybrook Medical Centre, Kings's goal attainment model; and Toronto General Hospital, Orem's self-care deficit theory model. All of these hospitals are affiliated through a series of cross appointments with the Faculty of Nursing at the University of Toronto. Two community hospitals, Mississauga and Scarborough General, have also adopted Orem's model and are related to the University through educational, community and interest groups. A group of researchers from these hospitals and the University of Toronto have proposed a collaborative project to determine what impact using a conceptual model will make on nursing practice. Discussions among the participants of this research group indicate that there are observations associated with instituting conceptual models that can be identified early in the process of implementation. These observations may be of assistance to others contemplating the implementation of conceptually based practice in their institution.

The latent factor structure of the WAIS-R: a factor analysis of individual item responses

Factor analytic examination of a 166 x 166 intercorrelational matrix that represents individual item scores from the 11 subtests of the WAIS-R provided evidence of five interpretable factors (N = 409). Two of these were identified as the Verbal and Performance factors previously encountered in traditional WAIS-R subtest-based factor analyses. The other three factors were characterized readily as involving (1) Advanced Vocabulary skills; (2) Basic Responsivity and (3) Advanced Computational ability. All three of these "new" factors accounted for at least 10% of the total variance, and comments are made with regard to the possible significance of their discovery to such topics as subtest variation and profile psychodiagnostics, theories that pertain to the nature and structure of human intellectual functioning, and subtest-based personality measurement theories.

1,3-Dinitrobenzene-induced encephalopathy in rats

Exposure to 1,3-dinitrobenzene (1,3-DNB) in humans induces methaemoglobinaemia, nausea and nervous symptoms. When given to conventional rats, twice-daily oral doses of 10 mg kg-1 1,3-DNB produce methaemoglobinaemia and frequently ataxia after four or five doses. In germ free rats given only a single oral dose of 20 mg kg-1, similar symptoms occur but are of more rapid onset. Light and electron microscope examinations reveal an acute thiamine deficiency-like lesion in the brain stems of both ataxic and apparently normal rats. Bilaterally symmetrical vacuolated lesions involve cerebellar roof, vestibular and superior olivary nuclei and the inferior colliculi. Frequent petechial haemorrhages are associated with these lesions, the erythrocytes usually being limited to enlarged Virchow-Robin spaces but sometimes spreading more widely. The primary cellular targets appear to be astrocytes, oligodendrocytes and vascular elements with secondary neuronal involvement. It is suggested that 1,3-DNB interferes with intracellular redox mechanisms resulting in impaired glucose oxidation.

Responsiveness of the olfactory receptor cells in dog to some odors

A preparation has been developed in the dog which allows recording the electrical activity from an olfactory nerve twig containing the axons of a small group of olfactory receptor cells. The dog's response to n-pentyl acetate is vigorous and stable, like that of other air-breathing animals. The dog's response magnitude dependence on the nasal flow rate was noticeable for n-pentyl acetates, but not so great as for n-butyric acid. The response to n-butyric acid strongly depends on the nasal flow. The start of the nasal air flow caused an increase of neural activity, which is called flow response. The results show that the nasal flow rate is a very important factor which determines the response to odors. Methyl p-hydroxybenzoate is known as a dog's pheromone, however, this odor caused the feeble response in the electrical activity of the dog's olfactory receptor cells. The differences may be dependent on several factors.

CT diagnosis of emphysematous pyelonephritis

Emphysematous pyelonephritis is a rare but frequently fatal complication of renal infection in the diabetic patient. The diagnosis is usually only made roentgenographically. We present a patient in whom the initial plain abdominal film was normal and renal sonogram was nondiagnostic. The correct diagnosis was made only on the subsequent CT scan.

Hypopyon following laser iridotomy

Two patients who had laser iridotomy performed for pupillary block glaucoma developed hypopyon following surgery. One case had iris bombé with rubeosis iridis, and the other had chronic angle closure glaucoma. Factors contributing to inflammation and possible hypopyon following laser iridotomy are discussed.

Lack of Z-DNA conformation in mitomycin-modified polynucleotides having inverted circular dichroism

Poly(dG-dC) . poly(dG-dC) and Micrococcus lysodeikticus DNA were modified by exposure to reductively activated mitomycin C, an antitumor antibiotic. The resulting covalent drug-polynucleotide complexes displayed varying degrees of CD inversions, which are strikingly similar to the inverted spectrum observed with Z-DNA. The following criteria have been used to establish, however, that the inverted CD pattern seen in mitomycin C-polynucleotide complexes does not reflect a Z-DNA conformation. (i) The ethanol-induced transition of poly(dG-dC) . poly(dG-dC) from B to Z conformation is not facilitated but rather is inhibited by mitomycin C modification. This may be due to the presence of crosslinks, (ii) Radioimmunoassay indicated no competition for Z-DNA-specific antibody by any of the mitomycin C-modified polynucleotides, (iii) 31P NMR of the complexes yielded a single relatively narrow resonance, which is inconsistent with the dinucleotide repeat characteristic of Z-DNA. Alternative explanations for the inverted CD pattern include a drug-induced left-handed but non-Z conformational change or the superposition of an induced CD onto the CD of B-DNA due to drug-base electronic interactions. These results illustrate the need for caution in interpreting CD changes alone as an indication of Z-DNA conformation.

Does intermittent mandatory ventilation accelerate weaning?

Intermittent mandatory ventilation (IMV) was introduced to facilitate the weaning of patients from mechanical ventilation. The outcome of ventilator management in 116 patients who were treated in the first three months of 1975 was compared retrospectively with that of 135 patients who were treated in the first three months of 1976. All patients who were treated in 1975 received conventional (assisted or controlled) mechanical ventilation. In 1976, seventy-seven patients (57%) were treated with the use of IMV, and 58 (43%) were treated with the use of conventional mechanical ventilation. Sixty-five patients who were treated in 1976 with the use of IMV were matched with patients who were treated in 1975 with the use of conventional ventilation, on the basis of age, sex, race, history of pulmonary disease, smoking history, diagnosis, service, and location of therapy. The average time spent on a ventilator by the IMV patients was 145 hours, whereas the matched control patients spent 142 hours. The length of hospitalization was 36 days for the IMV patients and 30 days for the control patients. These time periods were not significantly different and indicate that IMV did not reduce the length of ventilator management.

A practical approach to management of lithium concurrent with hyponatremia, diuretic therapy and/or chronic renal failure

Lithium therapy concurrent with hyponatremia, thiazides and possibly other diuretics and/or chronic renal failure has generally been avoided. However, despite greater risk for lithium toxicity, such combinations are feasible with appropriate precautions, especially lower lithium dosage and closer follow-up. Under the right circumstances hyponatremia, diuretics, and/or chronic renal failure are only relative lithium contraindications.

Rapid Isolation and Purification of Antibodies to Coagulation Factors by Protein A

A simple and reproducible method has been developed for rapidly isolating and purifying antibodies to Factor VIII from the plasma of both haemophilic and non-haemophilic patients. The one-step separation of these immunoglobulins makes use of the high affinity binding of staphylococcal cell wall protein A with the Fc region of the human γG1, 2 and 4 subclasses but not with the γG3 subclass. Plasma, as little as 0.5 ml, can be chromatographed on protein A Sepharose CL-4B gel columns. The majority of the plasma proteins, including IgG3, are not bound to the protein A, and are eluted as the first peak at neutral pH. Bound proteins are eluted as a second peak at pH 2.4. Plasmas from ten haemophilic and ten non-haemophilic patients with antibody to Factor VIII have been fractionated by this method. Without exception, the anti-factor VIII activity was bound to the protein A gel and thus eluted in the second peak. The yield of antibody was 70-80%. It is concluded that the great majority, if not all, of the antibodies to factor VIII belong to one or more of the IgG subclasses 1, 2 and 4 and can therefore be efficiently isolated by protein A chromatography. The plasma of a patient with antibody to factor V was also fractionated by protein A gel with similar results.

Biochemical investigations in cultured skin fibroblasts from patients with Duchenne muscular dystrophy

Cultured skin fibroblasts from patients with Duchenne muscular dystrophy were studied with a double-labeling procedure. Preliminary evaluation of the growth characteristics and average viability of dystrophic cells did not show any major abnormalities. Analysis of doubly labeled fibroblast mixture did not disclose any consistent anomaly in the distribution of subcellular fractions or in the major protein components of dystrophic fibroblasts.

Specific anosmia in the laboratory mouse

As an approach to a general theory of olfaction, different specific anosmia phenotypes characterized by different profiles of odorant sensitivities have been proposed for humans. In the present experiments, male inbred mice were tested for relative odorant sensitivity using a conditioned aversion technique and odors classified as primary or complex for humans. C57BL/6J and C57BL/10J mice appeared to be less sensitive to the primary odorant isovaleric acid than were males of seven other inbred strains (A/J, AKR/J, BALB/cJ,C3HeB/FeJ, DBA/2J, SJL/J, and SWR/J). In comparisons of C57BL/6J and AKR/J strains, the relative insensitivity of C57 to isovaleric acid did not generalize to the musklike primary odor of pentadecalactone or to the complex odor of amyl acetate. The C57BL/6J genotype may provide an animal model of a specific anosmia as characterized among humans.

The underwater electro-olfactogram: a tool for the study of the sense of smell of marine fishes

Recording the olfactory receptor activity of marine fishes presents problems due to the shunting of the electrical signals by the highly conductive sea water, which results in significant signal loss. By recording the large signal-to-noise ratio D. C. potentials using the underwater electro-olfactogram (EOG), we were able to study olfactory receptor properties of freshwater and marine fishes in a comparable manner.