Aquatic plants of acid lakes in Kejimkujik National Park, Nova Scotia; floristic composition and relation to water chemistry

To document the aquatic flora of acid lakes in Kejimkujik National Park, N.S., the presence and abundance of aquatic macrophytes growing in water deeper than 3 dm were recorded in 20 lakes. Of the 45 species found, the most important were Sphagnum macrophyllum, Eriocaulon septangulare, Utricularia purpurea, Scirpus subterminalis, Pontederia cordata, Nuphar variegatum, Nymphaea odorata, Eleocharis acicularis, Sparganium angustifolium, Potamogeton confervoides, Lobelia dortmanna, Potamogeton epihydrus, and Utricularia vulgaris. To explore the relationship between floristic composition and water chemistry, information on 12 chemical variables and colour was related to species presence–absence using a nonparametric test based on relative neighbourhood graphs. Analyses of variance (ANOVAs) using chemical data and six groups suggested by a conditional clustering of the species presence–absence data demonstrated significant heterogeneity in Ca, pH, and HCO3. Furthermore, these three proved to be highly correlated. A canonical variate analysis of the six groups revealed one significant axis and separated the lakes into two major groups, characterized by relative acidity. An ANOVA of these two groups established that colour was also significant. There were fewer species in the more acidic (range 8–20, average 15) than in the less acidic lakes (range 15–32, average 22).

Insulin pump treatment in insulin-dependent diabetes mellitus. Children, adolescents, and young adults

Twenty-four children, teenagers, and young adults (8 to 26 years old) with insulin-dependent diabetes mellitus were treated with continuous subcutaneous insulin infusion (CSII). Criteria for using CSII included persistent high glycohemoglobin (GHb) values and/or wide swings in blood glucose values despite arduous efforts to improve glycemia. Thirty percent discontinued CSII. Improvement was significant by three months for GHb and blood glucose values, but plateaued thereafter. Only three patients attained a normal GHb value. No predictors for degree of control were identified. Diabetic ketoacidosis did not occur more frequently with CSII. Electromechanical problems with the devices, patient errors, or local skin problems occurred in 50% of patients, although none produced ketoacidosis or severe hypoglycemia. Dietary noncompliance and decreased intensive home monitoring were contributory factors. Better ways to predict success or failure are needed if normalization or even near-normalization is a goal of CSII in younger patients with insulin-dependent diabetes mellitus followed up in a nonresearch setting.

The prevalence of retained testes in Dunedin

A cohort of approximately 500 boys was screened for retained testes at ages five and seven years and when the boys were aged three, five, seven and nine years, their parents were questioned about hospitalisation for surgery. Orchidopexy for retained testes had been performed on 15 of the 536 boys (2.8%) while one other had orchidopexy for high retractile testes (0.2%). Eighty-one percent of this surgery was performed between the seventh and ninth years of age.

Discrepancy in ER levels of breast carcinoma in biopsy vs mastectomy specimens

The presence of estrogen receptors (ER) in breast tumors has been used by many as the major indicator for hormonal treatment of breast cancer. However, multiple factors have been shown to be involved in determining the hormone dependence of breast cancer. This paper reports another factor that influences the accuracy of ER determination. From January 1977 through December 1983 fifty-eight (58) of these patients had ER determination of both biopsy and mastectomy specimens. Of the 31 patients that remained ER positive in mastectomy specimen, 13 had significantly lower ER levels (by at least 50%) from the mastectomy specimens. These findings indicate that ER status is greatly influenced by the source of the specimen.

Spectral and other physicochemical properties of submicron powders of hematite (alpha-Fe2O3), maghemite (gamma-Fe2O3), magnetite (Fe3O4), goethite (alpha-FeOOH), and lepidocrocite (gamma-FeOOH)

Spectral and other physicochemical properties were determined for a suite of submicron powders of hematite (alpha-Fe2O3), maghemite (gamma-Fe2O3), magnetite (Fe3O4), goethite (alpha-FeOOH), and lepidocrocite (gamma-FeOOH). The spectral reflectivity measurements were made between 0.35 and 2.20 micrograms over the temperature interval between about -110 degrees and 20 degrees C. Other physicochemical properties determined were mean particle diameter, particle shape, chemical composition, crystallographic phase, magnetic properties, and Mossbauer properties. Only the magnetite powders have significant departures from the stoichiometric phase; they are actually cation-deficient magnetites having down to about 18.0 wt % FeO as compared with 31.0 wt % FeO for stoichiometric magnetite. A structured absorption edge due to crystal field transitions and extending from weak absorption in the near-IR to intense absorption in the near-UV is characteristic of the ferric oxides and oxyhydroxides and is responsible for their intense color. Particularly for hematite, the number and position of the spectral features are consistent with significant splitting of the degenerate cubic levels by noncubic components of the crystal field. The position of the crystal-field band at lowest energy, assigned to the envelope of the components of the split cubic 4T1 level, is near 0.86, 0.91, 0.92, and 0.98 microgram at room temperature for hematite, goethite, maghemite, and lepidocrocite, respectively. Comparison with Mossbauer data suggests covalent character increases sequentially through the aforementioned series. The positions of the spectra features are relatively independent of temperature down to about -110 degrees C. The maximum shifts observed were on the order of about 0.02 microgram shortward for the ferric oxyhydroxides. Variations in the magnitude of the reflectivity of the hematite powders as a function of mean particle diameter are consistent with scattering theory. The absorption strength of the crystal-field bands increases with increasing mean particle diameter over the range 0.1-0.8 micrometer; visually this corresponds to a change in color from orange to deep purple. The position of the split cubic 4T1 band shifts longward by about 0.02 micrometer with decreasing mean particle diameter over the same range; this trend is consistent with wavelength-dependent scattering. The cation-deficient magnetite powders are very strong absorbers throughout the near-UV, visible and near-IR; their spectral properties are independent of temperature between about -110 and 20 degrees C.

Frostbite

Frostbite can cause loss of life and limbs. Proper treatment and follow-up care are essential in reducing morbidity and mortality. Management of the frostbite patient consists of three stages. Initial care includes protection of the extremity from trauma or partial thawing. The second stage consists of rapid rewarming in a whirlpool bath containing hot water, with continued protection of the tissues. The third stage is long-term care of the affected body parts.

Administration of activated charcoal for the treatment of lantana poisoning of sheep and cattle

The use of activated charcoal for treating lantana poisoning was investigated. When 500 g of activated charcoal was given orally with toxic Lantana camara, it protected sheep against intoxication. Administration to sheep of 500 g of activated charcoal in 4 1 of electrolyte solution orally 6 days after the onset of lantana poisoning and then 4 1 of electrolyte solution the next day, was followed by recovery from the intoxication. Mortality was significantly higher in intoxicated sheep given only the electrolyte solution and in untreated sheep. Six cows with naturally occurring lantana poisoning were treated with 2-2.5 kg of charcoal in 20-30 1 of electrolyte solution given by stomach tube and all the animals recovered. It is recommended that sheep with lantana poisoning be treated orally with 500 g of activated charcoal in 4 1 of electrolyte solution, and that cattle be given 2 kg of charcoal in 20 1 of electrolyte solution. Supportive treatment for photosensitization and dehydration may also be required.

Platelet and fibroblast monoamine oxidase in alcoholism

Monoamine oxidase (MAO) activity has been reported to be low in platelets (MAO B) and brain (MAO A and B) of some patients with alcoholism compared to control subjects. Whether the decreased platelet MAO activity found in alcoholism is secondary to the effect of alcohol or exists before alcohol abuse is not clear. The hypothesis that altered MAO A activity is determined by an abnormality in the genetic regulation of the enzyme can be tested by measuring MAO A activity in human fibroblasts cultured under controlled conditions. We first studied the kinetic parameters of platelet MAO B activity in patients hospitalized for treatment of alcoholism. Vmax was 38% lower in the patients (n = 14) than in normal controls (n = 22), but the enzyme affinity (Km) for the substrate tyramine was unchanged. Patients with the five lowest levels of platelet MAO activity had MAO activity measured from fibroblasts cultured from skin punch biopsies. Their fibroblast MAO activity was within the normal range, showing a dissociation between platelet MAO B and fibroblast MAO A activities and suggesting that MAO A activity is not low for genetic reasons in alcoholic subjects who do have low platelet MAO B activity.

Murine gamma interferon activates the release of a macrophage-derived Ia-inducing factor that transfers Ia inductive capacity

In this report we demonstrate that when the murine macrophage tumor cell line P- 388D1 is incubated for 48-72 h with either concanavalin A-stimulated rat spleen cell supernatant or cloned murine immune interferon (IFN-gamma), the cultured cells release a cell-free factor activity that in turn induces the cell surface expression of Ia antigen on the murine monocyte cell line WEHI-3. This IFN-gamma-stimulated, Ia-inducing activity cannot be blocked with an anti-IFN-gamma heteroantiserum that does block the induction of Ia expression on WEHI-3 by both cloned murine IFN-gamma and rat Con A supernatant. The Ia-inducing factor ( IaIF ) generated from P- 388D1 after stimulation by IFN-gamma does not demonstrate any antiviral activity. The P- 388D1 -derived IaIF is not shed plasma membrane Ia glycoprotein molecules, as demonstrated by the inability of the active component to bind specifically to an anti-I-Ad affinity column or to a protein A column after the active supernatant is first treated with an excess of anti-I-E/Cd,k monoclonal antibody.

The effect of asymmetrically focused attention upon subsequent ear differences in dichotic listening

In a series of four experiments, normal right-handed adults engaged in dichotic listening with free-report instructions after having completed a selective listening task. The usual right-ear advantage (REA) for dichotic digit names was altered according to the ear previously monitored. Most notably, the REA was absent among subjects who had monitored the left ear. Additional experiments showed that the "priming bias" is material-specific; it did not occur if consonant-vowel nonsense syllables (CV's) were substituted for digit names in either the selective listening task or the subsequent free-report test. The findings help clarify the nature of one of the attentional mechanisms that influence auditory laterality.

X chromosome-linked transmission and expression of retroviral genomes microinjected into mouse zygotes

A genomic clone consisting of the Moloney leukemia proviral genome with moderately repetitive mouse sequences was microinjected into the pronucleus of a mouse zygote. An animal was derived that carried multiple copies of proviral DNA in a tandem array. No evidence for homologous recombination was obtained. The viral genome was expressed in this animal and was transmitted as a single unit to its offspring. Subsequent breeding studies revealed that the proviral DNA had integrated on an X chromosome.

Septo-optic dysplasia and median cleft face syndrome in a patient with isolated growth hormone deficiency and hyperprolactinemia

A pituitary evaluation was carried out in a 12-year-old girl who had early puberty, short stature, optic nerve hypoplasia, and agenesis of the corpus callosum. Her growth hormone (GH) response to insulin-induced hypoglycemia and arginine infusion was blunted. Basal and stimulated levels of prolactin were elevated. The association of GH deficiency and hyperprolactinemia suggests a disruption of the dopaminergic modulation of these hormones. The facial features seen in our patient, such as hypertelorism, V-shaped frontal hairline, and cleft nose and upper lip, are enough to justify the diagnosis of median cleft face (MCF) syndrome. However, the optic nerve hypoplasia and the GH deficiency are characteristics of septo-optic dysplasia, and, to our knowledge, they have never been described in patients with MCF syndrome. Our case fulfills the diagnostic criteria of both, representing a link between both ends of this spectrum.

Effect of oral zinc supplements on growth, hormonal levels, and zinc in healthy short children

13 short children aged 7-13 years who had a retarded bone age and low hair zinc concentration (under 140 micrograms/g) were treated with oral zinc supplements for a year. There was a significant increase in the growth rate in the children whose hair zinc concentration increased. Growth hormone, testosterone and somatomedin C also increased after oral zinc supplementation. Data from 755 short healthy children who have attended our Growth Clinic are presented which describe their hair and serum zinc concentration at different ages. The data indicate a decline in hair zinc concentration after birth with a gradual increase at age 4-6 years, finally reaching adult normal levels after adolescence.

Growth hormone receptors in lymphocytes of growth hormone-deficient children

Human growth hormone was injected intravenously into 18 growth hormone-deficient children and growth hormone binding sites in lymphocytes were investigated. Fresh circulating lymphocytes had a low initial value for the binding of growth hormone to solubilized receptors (3.45 +/- 1.46%) but after growth hormone injection, the binding rapidly increased to 14.8 +/- 4.2% at 2 1/2 h and 8.7 +/- 1.8% at 5 h. The sharp increase in binding is due to increase in the number of binding sites. Two control children who received chorionic gonadotropin had no change in lymphocyte growth hormone receptors. The methodological differences between the present study and previous attempts to identify human growth receptors in lymphocytes were (1) lymphocytes were separated and disrupted with Triton X-100 as quickly as possible (to avoid error from receptor leaking out of the cell) and (2) the receptors were assayed at 2 1/2 h after growth hormone administration (previous studies were 12-24 h later). One possible explanation for the data is that growth hormone receptor from liver is taken up by lymphocytes and rapidly released again, thus, contributing to the hormonal receptor economy in humans.

DNA methylation, retroviruses, and embryogenesis

By exposing preimplantation embryos to Moloney leukemia virus (M-MuLV), we have previously derived substrains of mice designated as Mov-1-Mov-13 which genetically transmit the virus from one generation to the next. In some of the substrains the inserted viral genome becomes activated at specific stages of embryogenesis and the available evidence suggests that these viral genomes are developmentally regulated. To investigate the effect of cellular differentiation on virus expression, M-MuLV was introduced either into preimplantation or post-implantation mouse embryos or into embryonal carcinoma (EC) cells. Whereas preimplantation embryos or EC cells are not permissive for virus expression, efficient replication occurred in postimplantation embryos or in differentiated cell lines. The viral genomes introduced into early embryonal cells were highly methylated and noninfectious when analyzed in the adult. In contrast, viral genomes introduced into postimplantation embryos or into differentiated cells remained unmethylated and were infectious in a transfection assay. These results demonstrate an efficient de novo methylation activity which appears to be involved in repression of genes introduced into pluripotent embryonal cells and which is not observed in cells of the postimplantation embryo or in differentiated cells in tissue culture.

Occupational cancer: experience in Ontario

This paper reviews the experience of the Workmen's Compensation Board of Ontario in identifying cases of cancer that could be attributed to occupational hazards. Worker's claims for compensation are allowed if there is reasonable medical evidence that their cancer was caused by exposure to risk factors associated with their occupation. Details of the types of cancer associated with specific carcinogens or fields of employment are discussed. About 50% of the cases were related to exposure in particular industrial operations that functioned for relatively brief periods. The number of deaths from cancer identified as being caused by occupational factors is compared with the total for cancer from all causes in Ontario during the period 1971 through 1975. Although all workers eligible for compensation may not have been identified, the data suggest that less than 1% of cancer is presently caused by occupational factors.

Transient adrenogenital syndrome due to exposure to danazol in utero

We describe a premature female infant exposed in utero to danazol during the first trimester of pregnancy. She was first observed in the newborn period with marked degree virilization and clinical findings suggestive of salt-losing congenital adrenal hyperplasia. This was supported by the high plasma levels of 17 alpha-hydroxyprogesterone and adrenocorticotropic hormone and low plasma cortisol level. Levels of testosterone, androstenedione, 11-deoxycortisol, and renin were also elevated. An excessive increase in the levels of 17 alpha-hydroxyprogesterone and 11-deoxycortisol to corticotropin administration associated with impaired increase in plasma cortisol level strongly suggests a partial block in the 21-hydroxylation of 17 alpha-hydroxyprogesterone. However, the high levels of 11-deoxycortisol also suggest a block of the steroid 11 beta-monooxygenase. A year later she was found to have normal basal levels of the adrenal steroids and normal response to corticotropin administration, pointing out the transitory nature of these abnormalities. It may be hypothesized that danazol produced a transitory block of the steroid 21- and 11 beta-monooxygenases in this child.

Loss of organized fibronectin matrix from the surface of aging diploid fibroblasts (IMR-90)

Indirect immunofluorescence was used to investigate the production of a fibrillar fibronectin matrix by human diploid fibroblasts (IMR-90) as cells progress through their in vitro lifespan. Early and mid-passage cultures displayed a prominent fibrillar reticulum over the cell layer which formed within 24 hours of seeding. Even sparsely seeded early-passage cells exhibited fibrils of fibronectin on external surfaces. In contrast, fibrillar fibronectin was reduced or absent on surfaces of late-passage cells. However, the larger, non-proliferating, late-passage cells were producing fibronectin, 1h determined by radioimmunoassay of the medium.

Principles of patient education for the patient with an altered neurological status

Teaching patients with an altered neurological status is a difficult task but a task which is a priority to consider when planning patient care. The task can be accomplished as principles are considered, barriers are removed, and the process is adapted to meet the individual's needs.

Aggregation between teratocarcinoma cells and preimplantation mouse embryos

The ability of two embryonal carcinoma (EC) cell lines, F9 and PC13, to aggregate with preimplantation 8-cell mouse embryos is described. Both adhere to the embryonic cells and subsequently compact with the embryos. The aggregates form blastocysts in culture. The blastocysts sometimes contain the EC cells, located almost always in their inner cell mass. Differentiated derivatives of EC cells, namely PYS-1 and PYS-2, as well as STO fibroblasts do not aggregate with embryos.