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Biomedical subjects

J Janus

Publications and source records attributed to J Janus.

32 records · Page 2Linked to original sources
PubMed1990

The vasopressin and oxytocin content in the neurohypophysis under conditions of increased beta-adrenergic transmission in euhydrated and dehydrated rats.

In rats euhydrated or dehydrated for two or four days the neurohypophysial vasopressin and oxytocin content was estimated. Rats were given intracerebroventricularly (i.c.v.) isoprenaline in a daily dose of 10 micrograms dissolved in 10 microliters of 0.9% sodium chloride. The neurohypophysial vasopressor and oxytocic activity diminished progressively during deprivation of water. A single dose of isoprenaline diminished the neurohypophysial content of vasopressin in euhydrated rats. In animals dehydrated for two or four days the depletion of neurohypophysial vasopressin storage (as brought about by osmoreceptor stimulation) was distinctly less marked under treatment with isoprenaline. The neurohypophysial oxytocin storage was diminished by a single dose of isoprenaline; on the contrary, during dehydration isoprenaline distinctly intensified the oxytocin depletion in the neurohypophysis.

Adrenergic Fibers↗
PubMed1990

Human immune responses to dengue viruses.

Dengue fever (DF) and dengue hemorrhagic fever (DHF)/dengue shock syndrome (DSS) are major public health problems in many areas of the world. We are analyzing the human immune responses to dengue viruses, in order to understand the mechanism of recovery from dengue virus infections and the pathogenesis of DHF/DSS. Human natural killer (NK) cells lyse dengue virus-infected cells to a greater degree than uninfected cells. Antibodies to dengue viruses augment the lysis of dengue virus-infected cells by NK cells. Dengue virus-infected monocytes produce high levels of interferon alpha (IFN alpha). DR+ lymphocytes also produce high levels of IFN alpha after contact with dengue virus-infected monocytes. The IFN alpha produced protects uninfected monocytes from dengue virus infection. These results suggest that NK cells and IFN alpha may play an important role in controlling primary dengue virus infection. Dengue virus-specific CD4+CD8(-)T lymphocytes and CD4(-)CD8+T lymphocytes are present in the peripheral blood mononuclear cell population from donors who were infected with dengue virus. Most of CD4+T lymphocytes are dengue serotype-crossreactive. They lyse dengue virus-infected autologous cells in an HLA class II-restricted fashion, and produce interferon gamma (IFN gamma). IFN gamma augments dengue virus infection of monocytic cells in the presence of antidengue virus antibodies by increasing the number of Fc gamma receptors. Dengue virus-specific CD8+T lymphocytes lyse dengue virus-infected autologous cells in an HLA class I-restricted fashion. These CD8+T lymphocytes are also dengue serotype-crossreactive.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Differentiation, T-Lymphocyte↗
PubMed1989

Improving the utilization of screening mammography in primary care practices.

Screening mammography is underutilized in many primary care practices. We designed a prospective, controlled trial to evaluate two strategies for improving the utilization of mammography in an academic general medicine clinic. We assigned teams of house officers to (1) physician audit with periodic feedback, (2) a visit-based strategy directed at both patient and physician, or (3) a no intervention concurrent control arm. After 6 months, the percentage of 50- to 74-year-old women meeting the standard of an annual mammogram was 36% for patients in the control arm, 62% for patients of feedback residents, and 54% for patients of the arm receiving the visit-based strategy. Patients of female providers were slightly more likely to meet the standard, but no effects were detected for patient race, new as opposed to follow-up patient, or higher frequency of clinic visits. We conclude that audit with feedback and a new visit-based strategy of a patient cue associated with a simplification of the ordering process each greatly improved the rate of utilization of screening mammography. Practitioners could reasonably choose the strategy most suited to their own situation.

Aged↗
PubMed1988

Vasopressin and oxytocin neurohypophysial content under conditions of beta-adrenergic blockade in euhydrated and dehydrated rats: further studies.

Rats euhydrated and dehydrated for two days were given intracerebroventricularly (i.c.v.) propranolol hydrochloride in a daily dose of 10 micrograms. In euhydrated rats the single dose of propranolol diminished significantly the vasopressin and oxytocin content in the neurohypophysis. On the contrary, in animals dehydrated for two days the depletion of the vasopressin and oxytocin neurohypophysial storage was distinctly less marked during i.c.v. treatment with propranolol.

Animals↗
PubMed1987

Use of special mammographic views to maximize radiographic information.

Additional x-ray views can offer helpful information in both symptomatic patients (better evaluating the area of clinical abnormality) and screening patients (often preventing unnecessary biopsies). A wide variety of views have been devised to help solve specific problems raised by either suspected clinical or mammographic abnormalities. We have found those views described above to be most useful.

Breast Neoplasms↗
PubMed1986

Breast MR imaging with loop-gap resonators.

Breast images obtained at 1.5 T using a loop-gap resonator pair as both the excitation and detection device are presented. The efficiency of this approach is high, as judged by the low level of radio frequency (RF) power required to obtain a 90 degree pulse and the uniformity of the RF field within the resonator pair. A modification of the pair geometry provides for reasonable observation of the tissues through the chest wall and laterally to the axillae.

Breast Diseases↗
PubMed1982

Screening for breast cancer in a high-risk series.

A unique cohort of women at increased risk of breast cancer because of prior X-ray treatment of acute mastitis and their selected high-risk siblings were offered periodic breast cancer screening including physical examination of the breasts, mammography, and thermography. Twelve breast cancers were detected when fewer than four would have been expected based on age-specific breast cancer detection rates from the National Cancer Institute/American Cancer Society Breast Cancer Demonstration Detection Projects. Mammography was positive in all cases but physical examination was positive in only three cases. Thermography was an unreliable indicator of disease. Given the concern over radiation-induced risk, use of low-dose technique and of criteria for participation that select women at high risk of breast cancer will maximize the benefit/risk ratio for mammography screening.

Adult↗
PubMed1980

The hypothalamic and neurohypophysial vasopressor and oxytocic activities as influenced by beta-adrenergic blockade during long-term dehydration in the white male rat.

Rats dehydrated up to 12 days were given intraperitoneally propranolol hydrochloride in daily dose of 1.0 mg/100 g of initial body weight. In not dehydrated animals the only dose of propranolol increased significantly the vasopressin and oxytocin release from the neurohypophysis. In dehydrated animals propranolol restrained somewhat the decrease of vasopressin in the neurohypophysis, but intensified the vasopressin depletion in the hypothalamus. The oxytocic potency of both the neurohypophysis and hypothalamus decreased progressively in animals deprived of water. Propranolol potentiated this effect of osmoreceptor stimulation.

Animals↗
PubMedDate not supplied

The vasopressin content in the neurohypophysis under conditions of intracerebroventricular beta-adrenergic blockade in euhydrated and dehydrated rats.

Rats dehydrated for up to 8 days were given propranolol hydrochloride into the left brain ventricle in a daily dose of 10 micrograms. In euhydrated rats the single dose of propranolol diminished significantly the vasopressin content in neurohypophysis. In animals dehydrated for two days, the depletion of the neurohypophysial vasopressin storage was less marked under conditions of treatment with propranolol. At the fourth and eighth day of deprivation of water, propranolol did not modify the decrease of neurohypophysial vasopressin due to stimulation of osmodetectors.

Animals↗
PubMedDate not supplied

The release of neurohypophysial hormones as influenced by stimulation of alpha-adrenergic transmission in long-term dehydrated male white rats. Information 1: hypothalamic and neurohypophysial vasopressor activity.

Rats dehydrated up to 12 days were given intraperitoneally methoxamine hydrochloride in a daily dose of 1.0 mg/100 g of the initial body weight. The single dose of methoxamine administered to normally hydrated animals was followed by a significant increase of the vasopressin content of the neurohypophysis and hypothalamus (both in NSO and NPV regions). Under conditions of severe dehydration a more marked depletion of hypothalamic and neurohypophysial vasopressin stores was noted in methoxamine-treated animals.

Animals↗
PubMedDate not supplied

The release of neurohypophysial hormones as influenced by stimulation of alpha-adrenergic transmission in long-term dehydrated male white rats. Information 2: hypothalamic and neurohypophysial oxytocic activity.

Rats dehydrated up to 12 days were given intraperitoneally methoxamine hydrochloride in a daily dose of 1.0 mg/100 g of initial body weight. The only dose of methoxamine injected into normally hydrated animals did not influence significantly the oxytocic activity neither in the hypothalamus nor in the neural lobe. Following four days of dehydration a distinctly more marked depletion of the hypothalamic (both in the NSO and NPV region) and neurohypophysial oxytocin content was found in animals treated with methoxamine. For the neurohypophysis, a similar effect has been noted under severe dehydration (8th and 12th day) as well.

Animals↗
PubMedDate not supplied

The vasopressor and oxytocic activities of the hypothalamus and neurohypophysis are influenced by inhibited alpha-adrenergic transmission during dehydration and subsequent rehydration in the white rat.

During equilibrated water metabolism a single dose of dihydroergotamine (DHE) increased vasopressin release from the neurohypophysis; it had no effect on oxytocin content in the hypothalamus and neurohypophysis. After two days of dehydration DHE somewhat restrained the decrease of oxytocin in the hypothalamus; the release of vasopressin from the neurohypophysis was then increased. Under severe dehydration, i.e. under conditions of potent osmoreceptor stimulation, DHE influenced the vasopressin content neither in the hypothalamus nor in the neurohypophysis, but in some way it intensified oxytocin depletion in the neurohypophysis. Following two days of rehydration DHE somewhat restrained the renewal of vasopressin in the hypothalamus. No changes of oxytocin in the hypothalamus could be demonstrated at that time; in the neurohypophysis DHE intensified vasopressin repletion, but inhibited oxytocin repletion. Following four and eight days of rehydration DHE had no influence on vasopressin repletion rate in the hypothalamus and neurohypophysis. At that time oxytocin repletion in the neurohypophysis was increased; in the hypothalamus it was not affected by DHE. It is concluded that the response of the hypothalamo-neurohypophyseal system to alpha-adrenergic blockade-as brought about by dihydroergotamine treatment-seems to be dependent on the actual state of water metabolism. Impulses from the osmoreceptors may be therefore of some important in modifying the change in vasopressin and oxytocin release resulting from inhibition of alpha-adrenergic transmission through neural chains including units susceptible to dihydroergotamine.

Animals↗