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Biomedical subjects

F Mori

Publications and source records attributed to F Mori.

At least 73 records · Page 4Linked to original sources
PubMed2000

Instigation and control of treadmill locomotion in high decerebrate cats by stimulation of the hook bundle of Russell in the cerebellum.

In high decerebrate cats, pulse train microstimulation of a restricted region of the midline cerebellar white matter produced a generalized increase in postural muscle tone in the neck, trunk, and limb extensor muscles, and air-stepping of all four legs on a stationary surface. On the moving belt of a treadmill, such stimulation produced well coordinated, fore- and hindlimb locomotion as evoked by stimulating the mesencephalic locomotor region (MLR). Microinjection of a neural tracer into the cerebellar locomotion-inducing site resulted in a bilateral retrograde labeling of cells limited to the fastigial nuclei simultaneously with anterograde labeling of fibers projecting bilaterally to the medial pontomedullary reticular formation (mPMRF) the vestibular complex and upper cervical segments. These results have led to our proposition that the effective cerebellar locomotor region (CLR) corresponds to the midline region of the hook bundle of Russell. Passing through this structure are crossed fastigioreticular and fastigiovestibular fibers, together with fastigiospinal fibers. Subsequently, we showed that CLR stimulation resulted in simultaneous short-latency synaptic activation of long-descending reticulospinal and vestibulospinal cells with high synaptic security. Clearly, the fastigial nucleus possesses potential capability to recruit and regulate posture- and locomotor-related subprograms which are distributed within the brainstem and spinal cord by the in-parallel activation of fastigiospinal, fastigioreticular, and fastigiovestibular pathways.

Animals↗
PubMed1999

Morphology of single pontine reticulospinal axons in the lumbar enlargement of the cat: a study using the anterograde tracer PHA-L.

The fine morphology of single pontine reticulospinal axons in the lumbar enlargement was investigated by using an anterograde Phaseolus vulgaris-leucoagglutinin (PHA-L) tracing technique. Localized injections of PHA-L were made into the nuclei reticularis pontis oralis and caudalis in four cats. Following survival periods of 8-9 weeks, PHA-L-labeled axons were found throughout the lumbar enlargement from segments L4 to S2, in which the diameter of labeled axons was 0.6-2.5 microns. From serial transverse sections (50 microns), trajectories of 21 single pontine reticulospinal axons were traced in continuity over distances of 18.9-36.3 mm, corresponding to three to six segments, respectively. All the identified axons gave off multiple (two to nine) axon collaterals along their courses, with mean intercollateral distances of approximately 5-6 mm. Detailed reconstruction of the collateral arborization in the lumbar enlargement showed a high degree of similarity to that of single axons in the cervical enlargement previously reported (Matsuyama et al. [1997] J. Comp. Neurol. 377:234-250). First, axon collaterals arising from a majority (n = 18) of identified axons innervated the gray matter unilaterally, ipsilateral to the parent axons, whereas those from the remaining three axons innervated the gray matter bilaterally. Second, collateral projections terminated mainly in laminae VIII and VII, with the arborization field confined to a narrow rostrocaudal extent (< 1 mm). Third, the termination fields of axon collaterals arising from a given reticulospinal axon were similar at each segmental level and differed from one stem axon to another. These results suggest that the long descending pontine reticulospinal pathway is composed of different types of axons that may innervate the cervical and lumbar enlargements in continuity in a similar manner.

Animals↗
PubMed1999

[Cardiac events in vasospastic angina: site and morphology of coronary artery spasm is related to the long-term prognosis of vasospastic angina].

To determine whether the site and morphology of coronary artery spasm provoked with acetylcholine can predict the long-term prognosis of vasospastic angina, coronary artery spasm (more than 90% narrowing) provoked with acetylcholine was studied in 66 consecutive patients (56 males, 10 females, mean age 56 +/- 9 years) with vasospastic angina. All patients were followed for 6.7 +/- 0.9 years and the incidence of cardiac events such as sudden death, myocardial infarction or worsened unstable angina was compared with the site and morphology of provoked spasm. The site of spasm was regarded as proximal when spasm occurred in the proximal site of 3 major coronary arteries which was designated as segment 1, 6 or 11, according to the classification of the American Heart Association, and distal in other segments. The morphology of spasm was classified into 3 types, focal (12 cases, localized more than 90% narrowing with adjoining parts constricting less than 25%), diffuse (17 cases, diffuse more than 90% narrowing), and intermediate (37 cases, localized more than 90% narrowing with adjoining parts constricting 25-90%). The site of spasm was classified into 2 types, the proximal group (24 cases) and the distal group (42 cases). Cardiac events occurred in 7 patients during the follow-up period: sudden death in 2, myocardial infarction in 2, and worsened unstable angina in 3. As to the site of spasm, the incidence of cardiac events was 21% (5/24 patients) in the proximal group, significantly higher than 5% (2/42) in the distal group (p < 0.05). As to the site of spasm, the incidence of cardiac events was 41% (5/12) in the focal group, significantly higher than 3% (1/37) in the intermediate group and 6% (1/17) in the diffuse group (p < 0.001). The presence of proximal and focal coronary artery spasm was associated with a significantly higher incidence of cardiac events. The site and morphology of coronary artery spasm provoked with acetylcholine is related to the long-term prognosis of vasospastic angina.

Acetylcholine↗
PubMed1999

[Should the patient with an interatrial defect recognized in adulthood always be operated on?].

BACKGROUND: Atrial septal defect (ASD) can be recognized in adult age, mostly in asymptomatic or scarcely symptomatic patients. These patients differ from patients in "historical" clinical series, in whom diagnosis was done on the basis of clinical evidence, and their natural history is probably different. AIM OF THE STUDY: Our aim was to verify retrospectively results of surgery versus medical follow-up in an adult population with ASD with age at first diagnosis > or = 30 years. PATIENTS AND METHODS: Seventy-two patients with ASD, 52 females (72%), observed at our Institution since 1978, were considered. Mean age at diagnosis was 48 +/- 12 years (range 30-79); 36 patients (50%, group A) are still on medical therapy, 36 patients (group B) were operated. As groups A and B did not differ significantly in any demographic, clinical or echocardiographic parameter, they were compared for the incidence of complications. RESULTS: During follow-up (100 +/- 70 months, range 12-240), the incidence of major clinical events showed no significant differences in the two groups, as cardiac death or cardiovascular complications (cerebral ischemic events, severe mitral insufficiency, reoperation) occurred in 4 patients in group A (11%) and in 4 patients in group B (11%). Worsening of NYHA class was observed in 3 patients from group A (8%) and 2 patients from group B (5.5%; p = ns). New onset of supraventricular arrhythmias occurred more frequently in group B (14 patients, 39%) than in group A (5 patients, 14%) (p = 0.01; OR = 3.9; CI 95%: 1.2-12.6). CONCLUSIONS: In an adult population affected with asymptomatic or mildly symptomatic ASD and age at first diagnosis > or = 30 years, surgical closure of the defect did not modify morbidity and mortality at a mid-term follow-up. We suggest that, mostly in older asymptomatic patients, surgery should not be a routine choice and clinical decision-making should be individualized in each case.

Adult↗
PubMed1998

Diurnal variation of corneal autofluorescence in normal and diabetic eyes.

PURPOSE: To examine the diurnal variations in corneal autofluorescence in normal and diabetic patients. METHODS: We measured corneal autofluorescence using a fluorophotometer fitted with an anterior segment adapter. Corneal autofluorescence was measured 10 times at 3 min intervals to evaluate the reproducibility of this instrument in 4 eyes of 4 normal subjects. The diurnal variation in corneal autofluorescence was determined by measuring the fluctuations in 10 eyes in 10 normal subjects and one unoperated eye each of 10 patients with proliferative diabetic retinopathy (PDR). We performed five consecutive measurements at 1000, 1130, 1400, 1630 and 1900 hours. The mean value of five measurements, the variation range and the coefficient of variation were analysed. RESULTS: The mean coefficient of variation in the measurement using this instrument was 8.6 +/- 1.0%. In the patients with PDR, the mean corneal autofluorescence value was significantly higher (p < 0.001), the variation range was significantly wider (p < 0.001) and the coefficient of variation was significantly greater (p < 0.01) than in the normal subjects. CONCLUSIONS: The results of this study suggest that corneal autofluorescence changes over the course of a day in patients with diabetes. This may be caused by the breakdown of the blood-aqueous barrier that we reported previously.

Adult↗
PubMed1998

[Bactericidal and anti-toxin activities of catechin on enterohemorrhagic Escherichia coli].

We examined the bactericidal activity of catechin, an astringent ingredient of tea, on enterohemorrhagic Escherichia coli (EHEC) O157:H7 and the anti-toxin activity of catechin on vero toxin (VT), the main pathogenic factor of EHEC O157:H7. To examine bactericidal activity, we added 1 X 10(4) CFU/ml bacteria to 1.25 to 20 W/V% of green tea extract or the PBS solution containing 25 to 400 micrograms/ml of (-) epigallocatechin gallate (EGCg), which is the main catechin ingredient of green tea leaf, and counted the number of live bacteria at various intervals. After 3 to 5 hours, no live bacteria were seen in 1.25 to 2.5 (regular drinking concentration) % green tea extract. In the high concentrations of 100 to 400 micrograms/ml EGCg the number of live bacteria decreased with time and after 24 hours no survivors were seen. In the low concentrations of 25 to 50 micrograms/ml EGCg, however, no change was observed in the number of live bacteria during 5 hours. After 24 hours the bacteria in 50 micrograms/ml were killed and the number of bacteria in 25 micrograms/ml decreased to one tenth of that at the start. To examine the anti-toxin activity, we mixed equal volumes of 2 ng/0.1 ml VT2 and 0.5 to 2 mg/0.1 ml catechin in vitro and incubated them at 37 degrees C for various times. Then we inoculated 0.2 ml of the mixture intraperitonealy to BALB/c mice. One mg of catechin inhibited by 100% the lethal toxicity of 2 ng of VT2 (LD 100) to mice. The inhibition of lethal toxicity of VT2 by catechin depended on the incubation time. The rate of inhibition was 0, 40 and 100% for 9, 12 and 18-24 hours incubation, respectively. These results suggest that catechin has not only bactericidal activity on EHEC O157:H7 but also anti-toxin activity on vero toxin.

Animals↗
PubMed1998

Corneal and lens autofluorescence in young insulin-dependent diabetic patients.

To study the early ocular abnormalities in young diabetic patients, corneal and lens autofluorescence was measured by fluorophotometry in 30 eyes of 30 insulin-dependent diabetic patients without retinopathy. The lens [f(l)] and the corneal [f(c)] autofluorescence values in diabetic patients were significantly higher than in controls. In diabetic patients, f(l) was significantly correlated with the duration of diabetes, the f(c) was significantly correlated with the duration of diabetes and the indices of metabolic control, i.e. HbA1c and fructosamine. Our study demonstrated that young diabetic patients clearly had corneal and lens abnormalities before the appearance of overt diabetic retinopathy. The f(c) value might be a good indicator of metabolic control in diabetic patients.

Adolescent↗
PubMed1997

Fetal transplants alter the development of function after spinal cord transection in newborn rats.

Pieces of fetal spinal tissue were transplanted into the site of complete midthoracic spinal transections in neonatal rat pups (transplant rats). The development of locomotion in these animals was compared with that of unoperated control rats and rats that received spinal transections alone (spinal rats). Reflex, treadmill and overground locomotion, staircase descent, and horizontal ladder crossing for a water reward were tested in control, spinal, and transplant rats from 3 weeks to adulthood. All tests were readily performed by control animals. Most spinal rats were unable to make many linked weight-supported steps on these tasks. Transplant rats were variable in their locomotor capabilities, but a subset of rats were able to demonstrate coordinated and adaptable locomotion on these tasks. Some transplant rats performed better on more challenging tasks, suggesting that motor strategies for these tasks used different information, perhaps from descending systems. Transplanted tissue survived, and in most cases there was immunocytochemical staining of serotonergic fibers passing into and caudal to the transplant, supporting the conclusion that descending systems grew through the transplanted tissue. Integration with the host tissue was often poor, suggesting that nonspecific or trophic effects of the transplant might also contribute to the development of locomotor function. Therefore several mechanisms may contribute to the repair of injured spinal cord provided by transplants that permit the development of useful locomotion.

Aging↗
PubMed1997

Fetal spinal cord transplants rescue some axotomized rubrospinal neurons from retrograde cell death in adult rats.

Intraspinal transplants of fetal spinal cord may contribute to recovery after spinal cord injury by keeping axotomized neurons alive. In this study we examined whether transplants rescued axotomized red nucleus (RN) neurons from retrograde cell death in adult rats. RN neurons were labeled by retrograde transport of Fluorogold (FG); 1 week later right-sided RN neurons were axotomized by left-sided hemisection at C3-4 vertebral level, and Embryonic Day 14 spinal cord or gelfoam was introduced into the cavity. Additional rats received hemisection and a transplant of fetal spinal cord or gelfoam without FG injection. At 2 and 4 months, the number of neurons in the magnocellular portion of the RN contralateral to the hemisection decreased 35-40% in rats that received gelfoam; mean soma area of surviving neurons decreased 40%. RN cell loss was reduced to 20% in rats that received fetal spinal cord transplants, but the decrease in mean soma area was unchanged. Transplants therefore rescued about half of the axotomized RN neurons that otherwise would have died but did not prevent perikaryal atrophy. Anterograde transport of WGA-HRP injected into RN 2 months after transplantation showed that rubrospinal axons reached the site of injury but rarely entered transplants; FG injections caudal to transplants showed that axons of transplant neurons extended at least two segments into host spinal cord. Fetal spinal cord transplants may therefore contribute to locomotor recovery in adults with spinal cord injuries both by preventing retrograde cell death and by establishing novel circuits across the site of injury.

Animals↗
PubMed1997

Vascular endothelial growth factor and severity of nonproliferative diabetic retinopathy mediate retinal hemodynamics in vivo: a potential role for vascular endothelial growth factor in the progression of nonproliferative diabetic retinopathy.

PURPOSE: To determine the effect of vascular endothelial growth factor and retinopathy level on retinal hemodynamics in nondiabetic and diabetic rats and to evaluate retinal hemodynamics in nondiabetic and diabetic patients. METHODS: Forty-eight diabetic and 22 nondiabetic patients had their diabetic retinopathy levels determined from fundus photographs according to Early Treatment Diabetic Retinopathy Study (ETDRS). Fluorescein angiograms were recorded from the left eye by video fluorescein angiography. Retinal blood flow was calculated from the digitized angiograms. Human recombinant vascular endothelial growth factor or vehicle alone was injected intravitreally into 13 nondiabetic and 11 diabetic rats. RESULTS: Retinal blood flow decreased 33% in patients with ETDRS retinopathy level 10 compared with control patients (P = .001) and increased sequentially in more advanced stages of retinopathy, with a strong correlation between retinal blood flow and retinopathy level (r2 = 0.434, P = .001). In the diabetic rats, retinal blood flow was decreased 35.6% (P = .01). Vascular endothelial growth factor maximally increased retinal blood flow by 36.1% in nondiabetic rats after 25 minutes (P = .001) and by 73.7% in diabetic rats after only 5 minutes (P = .01) and caused a greater response in diabetic than in nondiabetic rats. CONCLUSIONS: Retinal blood flow increases with advancing nonproliferative diabetic retinopathy in humans, and diabetes accentuates the vascular endothelial growth factor-induced increase in retinal blood flow and venous dilation in rats. Vascular endothelial growth factor may contribute to the changes in retinal hemodynamics and morphology observed in early diabetic retinopathy.

Adult↗
PubMed1997

Changes in corneal and lens autofluorescence and blood glucose levels in diabetics: parameters of blood glucose control.

PURPOSE: We investigated corneal and lens autofluorescence in patients with proliferative diabetic retinopathy (PDR) to determine a correlation between the two parameters and blood glucose levels and HbA1c. METHODS: Corneal and lens autofluorescence levels in 17 PDR patients and 8 healthy controls were measured with a fluorophotometer fitted with an anterior segment adapter. We measured the lower blood glucose level (BS1), corneal autofluorescence (CA1), and lens autofluorescence (LA1) simultaneously and the higher blood glucose level (BS2), CA2, and LA2 simultaneously on the same day. We defined parameter changes as: delta BS = BS2 - BS1, delta CA = CA2 - CA1, and delta LA = LA2 - LA1. RESULTS: Corneal and lens autofluorescence significantly increased in the patients, compared with the controls (p < 0.001). Lens autofluorescence had a significant positive correlation with HbA1c (r = 0.656, p < 0.01) in the patients. delta CA (ngEq/ml) correlated significantly with delta BS (mg/dl) (r = 0.631, P < 0.01). CONCLUSIONS: Results suggest that lens autofluorescence might represent the long-term control of diabetes, and corneal autofluorescence levels may represent short-term changes in the blood glucose level, because hyperglycemia accelerates with increasing corneal autofluorescence in PDR patients. Corneal and lens autofluorescence may be related to the breakdown of the blood-aqueous barrier.

Adult↗
PubMed1997

Effect of timolol and UF-021 (a prostaglandin-related compound) on pulsatile ocular blood flow in normal volunteers.

The effects of topically applied timolol (a nonselective beta-blocker) and UF-021 (a prostaglandin-related compound) on pulsatile ocular blood flow (POBF) were investigated in 9 healthy volunteers. One drop of either UF-021 or timolol was instilled in one randomly selected eye and the fellow eye received physiologic saline. Before and 90 min after drop instillation, we measured intraocular pressure (IOP), POBF, heart rate (HR) and blood pressure (BP). After a washout interval of at least 1 week, the other drug was instilled in the previously treated eye. IOP, POBF, HR, and PB were measured following the same protocol. After timolol administration, IOP and POBF decreased significantly in the treated eye (26%, p = 0.01, and 13%, p = 0.02, respectively) and in the fellow eye (11%, p = 0.01, and 11%, p = 0.03, respectively). HR also decreased (10%, p = 0.03), but BP did not change significantly. After UF-021 administration, no significant changes were found in IOP, POBF, HR, or BP. Our results suggest that in normal subjects timolol decreases POBF in both the treated and the untreated eyes, whereas UF-021 has no action on either IOP or POBF.

Administration, Topical↗
PubMed1997

Vascular endothelial growth factor-induced retinal permeability is mediated by protein kinase C in vivo and suppressed by an orally effective beta-isoform-selective inhibitor.

Increased vascular permeability and excessive neovascularization are the hallmarks of endothelial dysfunction, which can lead to diabetic macular edema and proliferative diabetic retinopathy in the eye. Vascular endothelial growth factor (VEGF) is an important mediator of ocular neovascularization and a known vasopermeability factor in nonocular tissues. In these studies, we demonstrate that intravitreal injection of VEGF rapidly activates protein kinase C (PKC) in the retina at concentrations observed clinically, inducing membrane translocation of PKC isoforms alpha, betaII, and delta and >threefold increases in retinal vasopermeability in vivo. The effect of VEGF on retinal vascular permeability appears to be mediated predominantly by the beta-isoform of PKC with >95% inhibition of VEGF-induced permeability by intravitreal or oral administration of a PKC beta-isoform-selective inhibitor that did not inhibit histamine-mediated effects. These studies represent the first direct demonstration that VEGF can increase intraocular vascular permeability through activation of PKC in vivo and suggest that oral pharmacological therapies involving PKC beta-isoform-selective inhibitors may prove efficacious for the treatment of VEGF-associated ocular disorders such as diabetic retinopathy.

Animals↗
PubMed1997

[A case report of Listeria monocytogenes infection in a patient with AIDS. Efficacy of treatment with cotrimoxazole associated with rHuG-CSF (filgrastim)].

Listeriosis is an emerging opportunistic infection in the immunocompromised host. A case of sepsis due to Listeria monocytogenes in a patient with advanced HIV infection and severe neutropenia, treated for an underlying non-Hodgkin's lymphoma, is described. Therapy with cotrimoxazole associated with rHuG-CSF (filgrastim) led to a rapidly favourable clinical and microbiological outcome, and to the correction of concurrent neutropenia. The case report is discussed according to a literature review of all cases of listeriosis reported until now in the setting of HIV infection and AIDS. In particular, the role of both cotrimoxazole and rHuG-CSF adjunct in the treatment of listeriosis in the immunocompromised patient is focused.

English Abstract↗
PubMed1997

Embryonic spinal cord transplants enhance locomotor performance in spinalized newborn rats.

The results of the present experiments demonstrate that fetal spinal cord transplants placed into the site of a complete transection in newborn rats permit the development of complex patterns of locomotion. These patterns differ in some respects from normal, but include weight support, appropriate postural adjustment, and coordination between forelimbs and hindlimbs. 5-HT agonists administered to transplanted rats can further modify these motor patterns in ways that may prove able to enhance locomotion. When placed into lesion cavities in adult spinal cord, cells genetically modified to express neurotrophins can survive, differentiate, and mimic at least one consequence of fetal transplants, rescue of axotomized neurons from retrograde cell death.

Animals↗