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J Fang

Publications and source records attributed to J Fang.

At least 289 records · Page 16Linked to original sources
PubMed1995

Cytokines in sleep regulation.

The central thesis of this essay is that the cytokine network in brain is a key element in the humoral regulation of sleep responses to infection and in the physiological regulation of sleep. We hypothesize that many cytokines, their cellular receptors, soluble receptors, and endogenous antagonists are involved in physiological sleep regulation. The expressions of some cytokines are greatly amplified by microbial challenge. This excess cytokine production during infection induces sleep responses. The excessive sleep and wakefulness that occur at different times during the course of the infectious process results from dynamic changes in various cytokines that occur during the host's response to infectious challenge. Removal of any one somnogenic cytokine inhibits normal sleep, alters the cytokine network by changing the cytokine mix, but does not completely disrupt sleep due to the redundant nature of the cytokine network. The cytokine network operates in a paracrine/autocrine fashion and is responsive to neuronal use. Finally, cytokines elicit their somnogenic actions via endocrine and neurotransmitter systems as well as having direct effects neurons and glia. Evidence in support of these postulates is reviewed in this essay.

Acute-Phase Reaction↗
PubMed1995

Neurochemical, neuroprotective and neurorescue effects of aliphatic N-methylpropargylamines; new MAO-B inhibitors without amphetamine-like properties.

A series of aliphatic N-methylpropargylamine MAO-B inhibitors have been synthesized and their structural and functional relationships have been investigated. 2-Hexyl-N-methylpropargylamine (2-HxMP), for example, has been found to be a highly potent, irreversible, selective, MAO-B inhibitor both in vitro and in vivo. The R-(-)-enantiomers are much more active than the S-(+)-enantiomers at inhibiting MAO-B activity. Some of these compounds protect mouse nigrostriatal dopamine neurons against the neurotoxin MPTP and the mouse hippocampal noradrenergic system against the neurotoxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4). They rescue hippocampal neurons after damage induced by ischemia and kainic acid treatment, as well as motoneurons in young mice following facial nerve axotomy. Such rescue effects are, interestingly, unrelated to inhibition of MAO-B activity. Some of the aliphatic propargylamines enhance the survival of neuroblastoma cells co-cultured with astrocytes following serum depletion. They stimulate the expression of AADC mRNA and inhibit GFAP mRNA expression. They do not possess amphetamine-like properties and exhibit no effect on noradrenaline or dopamine uptake nor do they increase hypertensive effects in the tyramine pressor test. Unlike R(-)-deprenyl, 2-HxMP does not potentiate dopamine toxicity in vitro. These new MAO-B inhibitors may possess significant chemotherapeutic implications for certain psychiatric and neurodegenerative disorders.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1995

Growth-hormone-releasing hormone mediates the sleep-promoting activity of interleukin-1 in rats.

The involvement of endogenous growth-hormone-releasing hormone (GHRH) in the sleep-promoting activity of interleukin-1 (IL1) was studied. The effects on sleep of intracerebroventricular injection of IL1 were tested in rats pretreated with intracerebroventricular antibodies to GHRH (GHRH-ab). One group of rats received two treatments each consisting of two injections, control IgG + physiological saline (IgG + Sal) and on another day GHRH-ab + Sal, whereas another group of rats received IgG + Sal, IgG + IL1 and GHRH-ab + IL1 on separate days with one day off between the various treatments. IgG or GHRH-ab was injected 6 h prior to dark onset; Sal or IL1 was administered at dark onset. Recording of sleep-wake activity and cortical brain temperature (Tcrt) was started with the injection of IgG or GHRH-ab and continued for 18 h. GHRH-ab (GHRH-ab + Sal) suppressed rapid eye movement sleep (REMS), non-REMS (NREMS) and EEG slow-wave activity (SWA) during NREMS throughout the recording period. IL1 treatment (IgG + IL1) enhanced NREMS and SWA, and induced fever for 6 h. Pretreatment with GHRH-ab (GHRH-ab + IL1) abolished the IL1-induced increases in NREMS, attenuated the enhancements in SWA, and suppressed fever for 6 hours after IL1. The results indicate that the sleep-promoting activity of IL1 is mediated at least in part via GHRH. The suppression of the IL1-induced fever by GHRH-ab might be attributed to an inhibition of hypothalamic somatostatin.

Animals↗
PubMed1995

Isolated diastolic hypertension. A favorable finding among young and middle-aged hypertensive subjects.

To identify pretreatment characteristics associated with subsequent myocardial infarction in young and middle-aged previously untreated hypertensive individuals, we examined the experience of 1560 participants in a work-site hypertension control program who were younger than 60 years. Subjects were categorized by initial blood pressure as having isolated diastolic hypertension (< 160/> or = 90 mm Hg, n = 965) or combined systolic and diastolic hypertension (> or = 160/> or = 90 mm Hg, n = 595). During 4.5 years of follow-up, there were 24 myocardial infarctions, yielding an overall incidence of 3.89 per 1000 person-years. Subjects with systolic/diastolic hypertension were older, had higher cholesterol and blood sugar levels, and included more smokers and people with left ventricular hypertrophy on electrocardiogram than those with isolated diastolic hypertension. Age-adjusted incidence rates for myocardial infarction were 5.20 and 2.21 per 1000 person-years in systolic/diastolic hypertension and isolated diastolic hypertension, respectively, and the relative risk of systolic/diastolic hypertension was 2.31 (95% confidence interval, 1.29-4.15). Among subjects with isolated diastolic hypertension, no myocardial infarction occurred in those with systolic pressure less than 140 mm Hg. Cox regression analysis including other known risk factors showed that pulse pressure, as a continuous variable (hazards ratio, 1.54; 95% confidence interval, 1.08-2.20), and type of hypertension, ie, systolic/diastolic hypertension versus isolated diastolic hypertension (hazards ratio, 2.11; 95% confidence interval, 1.08-4.13), were independently associated with myocardial infarction. These results suggest that young and middle-aged treated hypertensive individuals with normal pretreatment systolic pressure enjoy a more favorable prognosis than do those with systolic elevation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Influenza viral infections enhance sleep in mice.

Sleepiness is a common perception during viral infection. Nevertheless, very little is known about the effects of viral infection on sleep. The aim of the present study was to test whether sleep was altered by influenza viral infection in mice. After 2-3 days of baseline sleep recordings, Swiss-Webster mice were infected intranasally with a lethal (H1N1) or a nonlethal (H3N2) strain of influenza virus. Sleep was recorded again for an additional 3 days. Non-rapid eye movement sleep (NREMS) was dramatically increased after inoculation of the H1N1 virus with a latency about 16 hr. Rapid eye movement sleep (REMS) was significantly suppressed after a long latency. Both changes lasted until the end of the recording and occurred in both young (35-day-old) and adult (90- to 100-day-old) animals. Control animals did not show changes in sleep after sham infection with allantoic fluid. The H1N1 virus also caused dramatic decreases in body temperature and locomotor activities with a latency about 4-5 hr after viral inoculation. The H3N2 virus induced very similar changes in sleep, although the effects were much smaller in magnitude than those induced by the H1N1 virus, even though a much higher dose (10-fold) of the H3N2 virus was used. The present study shows that influenza viral infection induces profound and long-lasting increase of NREMS and suppression of REMS. These viral-induced changes in sleep likely represent a host-defense response.

Animals↗
PubMed1995

Differential mortality in New York City (1988-1992). Part One: excess mortality among non-Hispanic blacks.

To determine the distribution of mortality for non-Hispanic blacks and non-Hispanic whites in New York City, death certificates issued in New York City during 1988 through 1992, and the relevant 1990 US census data for New York City, have been examined. Age-adjusted death rates for blacks and whites by gender and cause of death were computed based on the US population in 1940. Also, standard mortality ratios and excess mortality were calculated using the New York City mortality rate as reference. The results showed that New York City blacks had higher age-adjusted death rates than whites regardless of cause, including stroke, AIDS, homicide, and diabetes. The rate for New York City blacks was also higher than the US total for both genders. Using New York City mortality rates as a reference, more than 80% of excess deaths in blacks occurred before age 65. Injury/poisoning was the leading cause of excess death (20.1%) in black males, while in black females, cardiovascular disease was the largest single cause of excess deaths (24.8%). The higher death rates, especially premature death, of blacks in New York City are related to conditions such as violence, substance abuse, and AIDS, for which prevention rather than medical care is the more likely solution, as well as to cardiovascular diseases, where both prevention through behavioral change, and health and medical care, can influence outcome.

Black or African American↗
PubMed1995

Differential mortality in New York City (1988-1992). Part Two: excess mortality in the south Bronx.

To display the extent of variations in mortality according to geographic regions in New York City, we have compared mortality in New York City as a whole with that of the South Bronx. Mortality records for 1988 to 1992 and 1990 US census data for New York City were linked. The 471,000 residents of the South Bronx were younger, less educated, and more likely to lack health insurance than other New Yorkers. Using age- and gender-stratified populations and mortality in New York City as standards, age-adjusted death rates and excess mortality in the South Bronx were determined. All-cause mortality in the South Bronx was 26% higher than the city as a whole. Mortality for AIDS, injury and poisoning, drug and alcohol abuse, and cardiovascular diseases were 50% to 100% higher in the South Bronx than in New York City; years of potential life lost before age 65 in the South Bronx were 41.6% and 44.2% higher for men and women, respectively, than in New York City; AIDS accounted for the largest single share of excess premature deaths (21.8%). In summary, inequalities in health status, reflected by higher mortality rates in the South Bronx, are consistent with, and perhaps caused by, lower socioeconomic status and deficient medical care among residents of this inner-city community.

Cause of Death↗
PubMed1995

Effects of Phytolacca acinosa polysaccharides I combined with interleukin-2 on the cytotoxicity of murine splenocytes against tumor cells.

Phytolacca acinosa polysaccharides I (PAP-I), a kind of purified polysaccharides, isolated from Phytolacca acinosa Roxb was found to significantly augment the cytotoxicity of murine splenocytes and interleukin-2 (IL-2) activated splenocytes against P815 tumor cells in vitro. The optimal concentration of PAP-I was 1 microgram.ml-1 and the peak level of the cytotoxicity against P815 tumor cells was reached on d 3-5. The supernatants collected from splenocytes cultured with PAP-I alone or in combination with IL-2 showed no effect on the cytotoxicity against P815 tumor cells. Splenocytes from mice injected ip with PAP-I, 5, 10 and 50 mg.kg-1, thrice a week produced more cytotoxicity against P815 and L929 tumor cells compared with the control group. PAP-I ip was shown to significantly increase IL-2 activated killer cell activity (LAK) against P815 tumor cells. The higher the dosage of PAP-I, the more potent the LAK activity was observed. These results confirmed that PAP-I can augment the cytotoxicity of murine splenocyte against tumor cells and LAK activity and warranted further evaluation of its clinical usefulness.

Animals↗
PubMed1995

Differential expression of neural cell adhesion molecule (NCAM) during osteogenesis and secondary chondrogenesis in the embryonic chick.

Progenitor cells in the periosteum-perichondrium of the posterior hook of the quadratojugal (QJ, a membrane bone) in the embryonic chick are bipotential for osteogenesis and chondrogenesis. These cells switch from osteogenesis to chondrogenesis between 10 to 11 days in normal (mobile) embryos but not in paralyzed (immobile) embryos. Expression of neural cell adhesion molecule (NCAM) was studied using a monoclonal antibody in QJ hooks from normal and paralyzed chick embryos between 10 and 21 days of incubation. NCAM is expressed in osteoprogenitor cells and osteoblasts but not in chondroprogenitor cells, chondroblasts, or chondrocytes. The switch of progenitor cell differentiation from an osteogenic to a chondrogenic pathway between 10 and 11 days of incubation coincides with down-regulation of NCAM expression. Both initiation of secondary chondrogenesis and down-regulation of NCAM depend on biomechanical stimulation. In embryos paralyzed at 9 days, secondary cartilage fails to form and progenitor cells remain positive for NCAM. Furthermore, paralysis influences NCAM expression in progenitor cells before secondary chondrogenesis morphologically begins, indicating that NCAM may play a role in the initiation of secondary chondrogenesis. In 15-day normal embryos, NCAM-positive cells accumulate between the perichondrium and secondary cartilage in a position that prevents further cartilage formation in the hook. In 19-day embryos, these cells lose their NCAM expression and restart chondrogenesis in a second phase of differentiation, forming an articular cartilage. Loss of NCAM expression in this cell layer and re-commencement of chondrogenesis do not occur in embryos paralyzed at 13 days, and therefore also require biomechanical stimulation. Hence, down-regulation of NCAM expression correlates with two phases of secondary chondrogenesis in embryonic life, both of which are dependent upon embryonic movement.

Animals↗
PubMed1995

[Effect of xiaopiling granules on muscular histochemistry of gastric precancerous changes in rats].

The effect of Xiaopiling Granules on muscular histochemistry of gastric precancerous changes in rats was observed quantitatively. The activity of SDH and M-ATPase as well as the content of muscular glycogen in model groups were found significantly lower than those of the normal groups (p < 0.01), and in this decrease Xiaopiling Granules had markedly played a preventive and therapeutic role.

Animals↗
PubMed1995

Measures of blood pressure and myocardial infarction in treated hypertensive patients.

OBJECTIVE: To identify entry characteristics associated with subsequent myocardial infarction in treated hypertensive patients. DESIGN: Nested case-control study and cohort study. SETTING AND PATIENTS: The 5730 participants (mean age 53 years; 61% male and 45% Caucasian) were selected from a worksite-based, union-sponsored, systematic hypertension control program from 1973 to 1992. METHODS: In the case-control study myocardial infarction cases were matched by age, sex, year of entry to the program, years of follow-up and previous treatment status (treated or untreated) with non-event subjects. Baseline clinical and biochemical characteristics were analyzed with regard to the outcome of myocardial infarction, using univariate and multivariate analyses, respectively, in case-control and cohort studies. RESULTS: During 5.43 years of follow-up the incidence of myocardial infarction was 6.75/1000 person-years. Univariate analysis indicated that myocardial infarction cases had higher cholesterol level and were more likely to have a previous history of diabetes than controls. The initial systolic blood pressure and pulse pressure of cases were significantly higher than in controls. Logistic regression models indicated that initial pulse pressure, either as a continuous or as a categorical variable, was the only measure of blood pressure independently associated with myocardial infarction after adjustment for other risk factors. Analysis of the experience of the total 5730 as well as 2445 previously untreated patients with a cohort study generated identical results. CONCLUSION: A large pulse pressure difference appears to be the most powerful measure available of initial blood pressure to identify, in advance, those hypertensive patients at greatest risk for a subsequent myocardial infarction.

Blood Glucose↗
PubMed1995

[Effects of 3 kinds of decoction on serum gastrin, gastrin cell density and the content of PGE2 of gastric antral mucosa in experimental chronic gastritis in rats].

Experimental chronic gastritis (ECG) models were established in rats by inserting a spring into pyloric canal as well as feeding sodium deoxycholate. An experiment was undertaken to observe the therapeutic effects of three formulas of traditional Chinese medicine "Shipitong" (SPT), "Ganpingyangwei" (GPYW) and "Weile" (WL). The experimental results show that all of the three decoctions can make serum gastrin, gastrin cell density and amount of antral mucosal PGE2 of the ECG rats return to normal levels.

Animals↗
PubMed1995

[Antitumor activities of 8-chloroadenosine in vivo and in vitro].

8-chloroadenosine showed marked activity against mice solid tumor hepatoma 22 (H22) and ascitic leukemia L-1210. At 100mg. Kg-1. /d x 7, the inhibition rate of H22 was 71.7 +/- 13.3% (P < 0.01) and 66.1 +/- 4.46% (P < 0.01), i.p. and i.v., respectively; at the same dose, the life-prolonging rate of mice bearing L-1210 was 124.0 +/- 22.1% (P < 0.01) and 104.2 +/- 20.1% (P < 0.01), i.p. and i.v., respectively. 8-chloroadenosine also showed activity against 3 human cancer cell lines in vitro. The IC50 values were determined by measuring cell growth using trypan blue dye exclusion. The results showed that HL-60 and K562, and human gastric cancer cell line MGc80-3 and IC50 values of 1. 8 mumol/L, 4.2 mumol/L and 1.56 mumol/L, respectively. The toxicity of 8-chloroadenosine was low, with LD50 of 1025.0 +/- 52.4 mg/kg for mice and 793.4 +/- 70.1 mg/kg for rats by single i.p. injection.

2-Chloroadenosine↗
PubMed1995

Crossed inhibition in the human motor system.

We used transcranial magnetic stimulation in humans to investigate the effect of focal unilateral stimulation of the motor cortex on the function of the contralateral motor cortex. Surface-recorded, rectified, averaged electromyography (EMG) showed relative silent periods in small hand muscles at 35-64 and 123-158 ms following ipsilateral cortical stimulation over the hand area. The first inhibitory phase started 11 ms after the minimum corticospinal conduction time from the contralateral cortex, appropriate for transcallosal conduction. Foot muscles (with focal stimulation over the ipsilateral hand area) also showed silent periods at 61-104 ms, indicating a marked spread of the inhibitory effect throughout the opposite motor cortex. H-reflex studies in the upper limb showed that this inhibitory effect was not mediated at the level of the alpha motoneuron. Single motor unit peristimulus time histogram studies in upper limb muscles showed inhibition similar to that seen in the surface recordings and no evidence of excitation following ipsilateral motor cortex stimulation. Transcranial magnetic stimulation performed with large circular coils centered at the vertex activates both excitatory and inhibitory processes bilaterally so that focal unilateral stimulation is preferable in detailed studies of motor system physiology.

Adult↗
PubMed1995

Prolactin and rapid eye movement sleep regulation.

During the past few years data have accumulated suggesting the involvement of prolactin (PRL) in rapid eye movement sleep (REMS) regulation. Pituitary PRL secretion seems to be, at least in part, sleep-dependent. PRL is also found in the central nervous system. PRL-containing neurons in the hypothalamus project to various structures in the brain. Systemic injection of PRL promotes REMS in rats, cats and rabbits. Intracerebroventricular injection of PRL enhances REMS in rats. Stimulation of endogenous PRL secretion by vasoactive intestinal peptide (VIP) also promotes REMS. Immunoneutralization of blood-borne PRL slightly reduces REMS. Various observations (hypoprolactinemic and hyperprolactinemic rats) indicate that PRL may act on REMS via modulating the diurnal rhythms of REMS. It is likely that hypothalamic PRL is more important for sleep regulation than circulating PRL. Hypothalamic PRL is likely involved in the mediation of the REMS-promoting activity of VIP. We conclude that PRL has a role in REMS regulation.

Animals↗
PubMed1995

[Effects of three kinds of decoction on histopathology of gastric mucosa, gastric pH and the content of bile acid in experimental chronic gastritis in rats].

Experimental chronic gastritis (ECG) models were established in rats by inserting a spring into pyloric canal as well as feeding sodium deoxycholate. An experiment was undertaken to observe the therapeutic effects of three formulas of traditional Chinese medicine "Shipitong", "Ganpingyangwei" and "Weile". The experimental results show that all of the three decoctions can reduce gastric pH and bile acid of the ECG rats and make gastric mucosal histomorphology of these rats change markedly.

Animals↗
PubMed1995

[Experimental studies on the pharmacokinetics of cefoperazone (CPZ) injection under burn eschar].

UNLABELLED: In this study, the rabbits were categorized into three groups. The scald (III degrees TBS 10%-15%) was caused by exposing these area to hot water at 90 degrees C for 40 seconds. Every rabbit was injected CPZ (25 mg/kg) three times. The changes in the concentration of CPZ were measured by employing MBPD and HPLC methods and experimental data were analyzed by using pharmacokinetic computer program. RESULTS: 1) The T1/2e of CPZ injection in subeschar region was longer and the Cmax was higher than that of intravenous route. 2) The concentration in blood was shown two times higher than after subeschar injection. 3) The levels of concentration were higher than MIC'S in an area of 6.5 cm diameter 24-36 hours after injection. CONCLUSION: CPZ injection in subeschar region was the best route of treatment and prevention of subeschar infection.

Animals↗