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PubMed1982

The rim nephrogram in renovascular compromise.

The nephrogram is a sensitive indicator of renovascular compromise. An infrequently reported but characteristic nephrographic abnormality is the cortical rim nephrogram. This "rim sign" refers to a thin nephrographic rim outlining a kidney with an otherwise faint nephrogram. We report 2 patients with this nephrographic appearance due to acute renal artery insult. The rim nephrogram is a reliable sign of underperfusion of the kidney. It is dependent on collateral capsular vessels supplying the outer renal cortex. Underperfusion can be due to a primary renal artery problem or secondary to compromise of renal artery perfusion because of elevated interstitial or tubular pressure in the kidney. The sign has not been described with systemic circulatory problems.

Adult↗

PubMed1994

gamma-Aminobutyric acid (GABA): a fast excitatory transmitter which may regulate the development of hippocampal neurones in early postnatal life.

The properties of neonatal GABAergic synapses were investigated in neurones of the hippocampal CA3 region. GABA, acting on GABAA receptors, provides most of the excitatory drive on immature CA3 pyramidal neurones at an early stage of development, whereas glutamatergic synapses (in particular, those mediated by AMPA receptors) are mostly quiescent. Thus, during the first postnatal week of life, bicuculline fully blocked spontaneous and evoked depolarising potentials, and GABAA receptor agonists depolarised CA3 pyramidal neurones. GABAA mediated currents also had a reduced sensitivity to benzodiazepines. In the presence of bicuculline, between P0 and P4, increasing the stimulus strength reveals an excitatory postsynaptic potential which is mostly mediated by NMDA receptors. During the same developmental period, pre- (but not post) synaptic GABAB inhibition is present. Intracellular injections of biocytin showed that the axonal network of the GABAergic interneurones is well developed at birth, whereas the pyramidal recurrent collaterals are only beginning to develop. Finally, chronic bicuculline treatment of hippocampal neurones in culture reduced the extent of neuritic arborisation, suggesting that GABA acts as a trophic factor in that period. In conclusion, it is suggested that during the first postnatal week of life, when excitatory inputs are still poorly developed, GABAA receptors provide the excitatory drive necessary for pyramidal cell outgrowth. Starting from the end of the first postnatal week of life, when excitatory inputs are well developed, GABA (acting on both GABAA and GABAB receptors) will hyperpolarise the CA3 pyramidal neurones and, as in the adult, will prevent excessive neuronal discharges. Our electrophysiological and morphological studies have shown that hippocampal GABAergic interneurones are in a unique position to modulate the development of CA3 pyramidal neurones. Developing neurones require a certain degree of membrane depolarisation, and a consequent rise in intracellular calcium, for stimulating neurite outgrowth; the GABAergic network, which develops prior to the glutamatergic one, appears to provide this depolarisation. Starting from the end of the first postnatal week of life, at a time when excitatory pathways are developing, GABA (acting on both GABAA and GABAB receptors) would reverse its action, and start to play its well-known role as an inhibitory neurotransmitter.

Animals↗

PubMed2003

Vanilloid receptor VR1-positive afferents are distributed differently at different levels of the rat lumbar spinal cord.

The vanilloid receptor VR1 renders a group of primary afferents that express it sensitive to noxious heat and capsaicin, and is thus an important marker for nociceptors. We use double immunofluorescence and confocal microscopy to show that the density of VR1-positive fibers and boutons in the dorsal horn increases progressively from spinal segments L4 to L6 and that the colocalization of VR1 with the neuropeptide substance P (SP) in lamina I and along the lateral collateral path, where the majority of visceral afferents terminate, is negligible at L4, but substantial at L6. We conclude that VR1 is expressed by visceral afferents to the lower lumbar spinal cord in the rat, which also express SP.

Animals↗

PubMed2003

Immunological indicators of morbidity in human schistosomiasis mansoni: role of vascular endothelial growth factor and anti-soluble egg antigen IgG4 in disease progression.

Based sonographic examinations of 90 schistosomiasis mansoni, they were divided into five groups: lightly infected, heavily infected, intestinal, early hepatosplenic and periportal fibrosis. Using ELISA, the levels of circulating vascular endothelial growth factor (VEGF) and anti-soluble egg antigen (SEA) IgG4 were measured in their sera. Compared to normal controls, VEGF levels were significantly raised in all schistosomiasis patients groups except lightly infected and intestinal patients were insignificantly elevated. The level of VEGF correlated with disease progression from lightly infected to periportal fibrosis patients. It also correlated with sonographic indicators of portal hypertension; presence of portosystemic collaterals, portal vein dilatation and splenomegaly. Serum IgG4 was significantly raised in only periportal fibrosis and portal hypertension patients. The results provided evidence that circulating levels of VEGF can serve as a new indicator of progression of schistosomiasis mansoni reflecting angiogenesis that regulates the granuloma and fibrosis development in liver while IgG4 seemed to be an indicator of only fibrosis development. Both are potential sensitive markers for effectiveness of treatment in periportal fibrosis patients. The understanding of the key role of VEGF in schistosomiasis mansoni pathogenesis may provide a new pharmacological target.

Adolescent↗

PubMed2004

Distinguishing between anterior cerebral artery and middle cerebral artery perfusion by color-coded perfusion direction mapping with arterial spin labeling.

The purpose of this study was to evaluate collateral circulation by describing anterior cerebral artery and middle cerebral artery perfusion areas. Pairs of image sets spin labeled on the medial and lateral side were used. A pixel-by-pixel t test was performed, with blue gradation used to display lateral perfusion (ie, middle cerebral artery) and orange gradation for anterior cerebral artery perfusion. Extensions of anterior cerebral artery perfusion areas in cases of middle cerebral artery stenosis were described. This method may aid in estimation of collateral circulation for stroke treatment.

Cerebral Angiography↗

PubMed1986

Tectal neurons of the frog: intracellular recording and labeling with cobalt electrodes.

With the aid of cobalt-filled intracellular electrodes, responses evoked by electrical and visual stimulation were recorded from tectal neurons. Diffuse light and "edge" and "spot" stimuli were used for visual stimulation; electrical stimuli were delivered by means of bipolar electrodes to the optic tract. The cells were subsequently filled with cobalt for a correlative histological study. The following types of neurons were distinguished: (1) Pear-shaped neurons with restricted and broad dendritic fields occurring in tectal layers 8, 6, 4, and 2. In one group, the dendrites bore beads and small protrusions and the short axon arborized within, or close to, the dendritic arbor. They responded mostly with inhibitory postsynaptic potentials to the various stimulations. This type of neuron was interpreted to be a tectal interneuron. In the second group the dendrites were smooth, the dendritic arbor was large, and the axon could be followed to layer 7 in a few cases. Excitatory activities with frequent spike discharges prevailed in their responses. They were regarded as efferent neurons of the tectum. (2) Large ganglionic neurons showed a greater variation in form than has been described in previous Golgi studies. Their responses to the different stimulations were also very variable. The axons of five neurons could be followed to the dorsal part of the thalamus, to the postoptic commissural system, and to the direct and crossed tectobulbar tract. These axons emitted several collaterals to tectal, pretectal, and tegmental structures. (3) A single stellate neuron was impaled in layer 9. It responded only to electrical stimulation with excitation. (4) Deep bipolar neurons were not mentioned in earlier works. Their somata were found in layer 6; the vertically oriented dendrites arborized in plexiform layers 7, 5, and 3, over a distance of more than 1 mm. These cells were sensitive only to electrical stimulation.

Animals↗

PubMed1991

Cross-resistance patterns related to glutathione metabolism in primary human renal cell carcinoma.

In 59 cases of primary human renal cell carcinoma (RCC), cross-resistance and collateral susceptibility patterns were determined in an MTT microculture assay. Concomitantly, the glutathione (GSH) content and the enzymatic activity of gamma-glutamyl transpeptidase (GGT) were measured as distinct resistance characteristics. Resistance or chemoresponse towards Vinca alkaloids and anthracyclines were found to be highly coincident, suggesting that the classical multidrug resistance mechanism is active in human RCC. Strong resistance to platinum complexes combined with relative sensitivity to bleomycin was significantly associated with elevated glutathione levels, providing evidence for another pathway instigating chemoresistance. In contrast, despite substantial enzymatic activity, GGT effects revealed no correlation to the chemoresistance pattern. This result implies that it is the GSH-linked binding and reduction potential rather than the GGT-associated transportation capacity that has an impact on the expression of chemoresistance in human RCC.

Antineoplastic Agents↗

PubMed2000

The effect of the point of application of anterior tibial loads on human knee kinematics.

Coupled axial tibial rotation in response to an anterior tibial load has been used as a common diagnostic measurement and as a means to load the ligamentous structures during laboratory tests. However, the exact location of the point of application of these loads as well as the corresponding sensitivity of the coupled tibial rotation to this point can have an effect on the function of the soft tissues at the joint. Therefore, the purpose of this study was to determine the effects of four different points of application of the anterior tibial load on the anterior tibial translation and coupled axial tibial rotation. The four points include: (1) geometric point - midway between the collateral ligament insertion sites on the tibia, (2) clinical point - a position that attempts to simulate clinical diagnostic tests, (3) medial point - a position medial to the geometric point and (4) lateral point - a position lateral to the clinical point. A robotic/universal force-moment sensor testing system was used to apply the anterior tibial load at the four points of application and to record the resulting joint motion. Anterior tibial translation in response to an anterior tibial load of 100N was found not to vary between the four points of application of the anterior tibial load at all flexion angles examined. However, internal tibial rotation was found for the lateral point (13+/-10 degrees at 30 degrees of knee flexion) in all specimens and clinical point (8+/-10 degrees at 30 degrees of knee flexion) while external rotation resulted when the load was applied at the medial point (-8+/-7 degrees at 30 degrees of knee flexion). Both internal and external tibial rotations occurred throughout the range of flexion when the tibial load was applied at the geometric point. The results suggest that the clinical point should be used as the point of application of the anterior tibial load whenever clinical examinations are simulated and multi-degree-of-freedom joint and soft tissue function are examined.

Aged↗

PubMed2004

Spiral CT arthrography of multiplanar reconstruction and virtual arthroscopy technique in diagnosis of knee with internal derangements.

OBJECTIVE: To evaluate the values of spiral CT arthrography with multiplanar reconstruction and virtual arthroscopy technique in diagnosis of internal derangements of the knee. METHODS: Ten bovine knees were used for experiment. The menisci, anterior and posterior cruciate ligaments and cartilage of these 10 bovine knees were injured with a hook. Each of the joints was injected with 100 ml air, then soon scanned with a PQ6000 spiral computed tomography scanner. The data obtained was input into the work station, and multiplanar reconstruction technique was used to illustrate lesions in the knees. The results of CT diagnosis were compared to those found by gross inspection of the specimens. Clinically, 10 knees of 9 patients diagnosed as internal derangement were evaluated with the same method after 50-70 ml air was injected into each of the joints. Nine months later, the data of 2 patients were used for CT endoscopy reconstruction. The results were compared with intraoperative findings. RESULTS: Experimentally, the sensitivity and specificity were 88.9% and 93.9% by detection of meniscal abnormalities, 85.7% and 100% by detection of cruciate ligament lesions, and 72.7% and 100% by detection of cartilage damage, respectively. Clinically, the sensitivity and specificity were 90.0% and 95.0% by detection of meniscal lesion. As to ligament, the figures were 85.7% and 100% respectively. Images of virtual arthroscopy simulated the images of real arthroscopy. CONCLUSIONS: Spiral CT arthrography of multiplanar reconstruction technique offers fine images of internal structures of the knee, with clear border and internal structure. It is an accurate method for detecting meniscal, cruciate and collateral ligament and cartilaginous lesions that cause internal derangement of the knee. Virtual arthroscopy technique is a hopeful method for detecting reasons of derangement of the knee.

Animals↗

PubMed1982

[Phlebography in venous thrombosis of the lower limbs (author's transl)].

Phlebography is the best diagnostic technique for deep venous thromboses of the lower limbs. The authors use the "free flow" technique which they have modified by visualisation of the I. V. C. and I. V. A lacunar appearance or cupola-shaped interruption are indicative of a recent thrombosis, whilst the absence of a main venous trunk and a collateral circulation are more common in the presence of an old thrombosis. They emphasise the possible sources of error in interpretation and the difficulty in determining how long the thrombosis has been present. Despite its disadvantages, phlebography remains the essential examination in order to select treatment in patients in whom there is a suspicion of venous thrombosis or pulmonary embolism. Venous Doppler and rheoplethysmography, less sensitive and less specific, have a place in routine detection and the surveillance of treatment.

Diagnosis, Differential↗

PubMedDate not supplied

[Extrapyramidal type collateral effects of the administration of metoclopramide to children].

Metoclopramide (M.) is a neurolectic drug used with good results in digestive tracts disorders. Even in minimum doses Metoclopramide may cause side effects to children. The most frequent are: localized hypertonia, oculogyric fits, trismus, cervical, oral and lingual dyskinesias, tremors and agitations. Symptoms seem to be serious but it is sufficient to stop the cure that all signs fade away. Manufactures show three personal side-effects' remarks by M. and advise to administer the drug to children with more caution since they are very sensitive to the substance.

Adolescent↗

PubMed2005

Sulfhydryl oxidation reduces hippocampal susceptibility to hypoxia-induced spreading depression by activating BK channels.

The cytosolic redox status modulates ion channels and receptors by oxidizing/reducing their sulfhydryl (SH) groups. We therefore analyzed to what degree SH modulation affects hippocampal susceptibility to hypoxia. In rat hippocampal slices, severe hypoxia caused a massive depolarization of CA1 neurons and a negative shift of the extracellular DC potential, the characteristic sign of hypoxia-induced spreading depression (HSD). Oxidizing SH groups by 5,5'-dithiobis 2-nitrobenzoic acid (DTNB, 2 mM) postponed HSD by 30%, whereas their reduction by 1,4-dithio-dl-threitol (DTT, 2 mM) or alkylation by N-ethylmaleimide (500 microM) hastened HSD onset. The DTNB-induced postponement of HSD was not affected by tolbutamide (200 microM), dl-2-amino-5-phosphonovaleric acid (150 microM), or 6-cyano-7-nitroquinoxaline-2,3-dione (25 microM). It was abolished, however, by Ni2+ (2 mM), withdrawal of extracellular Ca2+, charybdotoxin (25 nM), and iberiotoxin (50 nM). In CA1 neurons DTNB induced a moderate hyperpolarization, blocked spontaneous spike discharges and postponed the massive hypoxic depolarization. DTT induced burst firing, depolarized glial cells, and hastened the onset of the massive hypoxic depolarization. Schaffer-collateral/CA1 synapses were blocked by DTT but not by DTNB; axonal conduction remained intact. Mitochondria did not markedly respond to DTNB or DTT. While the targets of DTT are less clear, the postponement of HSD by DTNB indicates that sulfhydryl oxidation increases the tolerance of hippocampal tissue slices against hypoxia. We identified as the underlying mechanism the activation of BK channels in a Ca(2+)-sensitive manner. Accordingly, ionic disregulation and the loss of membrane potential occur later or might even be prevented during short-term insults. Therefore well-directed oxidation of SH groups could mediate neuroprotection.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

PubMed1999

Modifications of the elbow induced by the practice of handball on radiography, US and MRI.

The objective of this study was to evaluate plain radiographs, US and MRI in detection of occult lesions of the elbow in asymptomatic handball players. Comparative plain films of both elbows were obtained in an anteroposterior and lateral projection. A bilateral comparative ultrasound examination was performed with measurement of the thickness of the flexor and extensor tendons, the triceps tendon, the lateral collateral ligament and the anterior bundle of the medial collateral ligament (MCL). Echogenicity of these structures was evaluated. Articular recesses were scanned for fluid and loose bodies. Axial and coronal MRI of the dominant elbow was performed using a T1W sequence after intravenous injection of gadolinium 30 minutes before the examination and by a FISP 3D T2W echo gradient sequence in coronal plane and reconstruction in a sagittal plane. Twenty-eight male asymptomatic members of the national handball team with 7 to 25 years of experience and undergoing 3 to 4 training sessions per week were studied. Paraphysiological modifications such as hypertrophy of bone and muscles were evidenced. Flexion deformity of the elbow was present even in the youngest players, but valgus deformity occurred preferentially in the more experienced players. US was more efficient in detection of small loose bodies and gave more precise information on the structure of the MCL and the tendons compared with MRI. Plain film and US were sufficient for the detection of chronic lesions of the elbow. MRI did not add significant findings.

Adolescent↗

PubMed1988

Computed electroencephalographic topographic brain mapping. A new and accurate monitor of cerebral circulation and function for patients having carotid endarterectomy.

To determine the usefulness of computed electroencephalographic (EEG) topographic (CET) brain mapping to monitor neurologic function during carotid endarterectomy (CEA), 46 consecutive patients having CEA were monitored preoperatively, intraoperatively, and immediately postoperatively by CET brain mapping and simultaneous 16-lead EEG. Preoperative studies revealed that 7 of 16 asymptomatic patients, 5 of 11 patients with amaurosis fugax, and 8 of 12 patients with transient ischemic attacks (TIAs) had abnormal CET brain mapping suggestive of previous subclinical stroke. EEG was abnormal in only 8 of the 20 patients with abnormal CET brain mapping. Intraoperatively during carotid cross-clamping, ischemic changes were seen on CET brain mapping in 23 patients whereas EEG detected these changes in only 13 patients. Ischemic changes detected by intraoperative CET brain mapping were more likely to occur in patients with previous stroke (six of seven) than in patients without previous stroke (17 of 39), p less than 0.05. Patients with changes detected by intraoperative CET brain mapping had an average carotid back-pressure of 38 mm Hg, in contrast to 57 mm Hg for patients without CET brain mapping changes, p less than 0.05. After endarterectomy, CET brain mapping revealed new ischemic changes in one patient who awoke with a mild stroke and in one patient who had TIAs and amaurosis fugax within 6 hours of surgery. We conclude that CET brain mapping is a sensitive, accurate, and useful noninvasive monitor of cerebral circulation and function for patients having CEA.(ABSTRACT TRUNCATED AT 250 WORDS)

Blindness↗

PubMed1992

Improvement of ultrasonographic and serologic changes in Schistosoma japonicum-infected patients after treatment with praziquantel.

We previously reported ultrasonographic and serologic abnormalities in 102 patients infected with Schistosoma japonicum in Leyte, The Philippines. These patients were subsequently treated with praziquantel (3 x 20 mg/kg), and changes in ultrasonographic images and the serum levels of liver function markers in 52 patients were followed up every three months for a period of 17 months. Improvement in the thickening of the portal vein wall and the intensity of echogenic bands was detected six months after treatment with praziquantel. The level of splenomegaly was also reduced in 42 patients who originally did not show the production of collateral vessels. A significant decrease in the serum total bile acid (TBA) level was detected in all patients six months after treatment with praziquantel. However, significant ultrasonographic changes could not be detected in the patients classified as type 3, with severe hepatic fibrosis caused by the long-term infection. These results clearly show that ultrasonographic examination, along with data on the serum TBA level, provides a sensitive tool to monitor the severity of hepatic fibrosis and portal hypertension caused by S. japonicum infection, as well as the improvement resulting from praziquantel treatment.

Adolescent↗

PubMed2000

Role of nitric oxide in the control of cerebral microcirculation under physiological and pathological conditions.

Effect of nitric oxide (NO) on vasomotor tone of cerebral parenchymal arterioles was studied in rats. Then, the role of NO was clinically investigated in the pathogenesis of progressive cerebral vascular occlusive disease, moyamoya disease. In rat, the cerebral arterioles, about 30-60 microm in diameter, were dilated by L-arginine, a precursor of NO, at concentrations as low as 0.1 micromol with maximal dilation of 14% at 100 micromol. The arterioles were constricted by N(G)-monomethyl-L-arginine (L-NMMA), a NO synthesis inhibitor. Superoxide dismutase, which seems to protect NO from inactivation, increased sensitivity of L-arginine. Compared with control specimens of cerebral spinal fluid (CSF) obtained from 16 patients, concentrations NO metabolites in the CSF of 23 patients with moyamoya disease were significantly higher. NO metabolites concentrations obtained during initial surgery decreased during a second, contralateral procedure. NO plays an important role in the regulation of basal tone of cerebral parenchymal arterioles and contributes to the increase in collateral circulation in cerebral occlusive disease like moyamoya disease. Vascular bypass surgery can reduce NO metabolites together with abnormal collateral circulation.

Animals↗

PubMedDate not supplied

Prospective anatomic study of the inferior vena cava and renal veins: comparison of selective renal venography with cavography and relevance in filter placement.

PURPOSE: To compare the sensitivity of selective renal venography with that of cavography in the detection of variant anatomic structures of the renal vein that may affect the placement of inferior vena caval (IVC) filters and to define IVC dimensions. PATIENTS AND METHODS: Flush cavography, selective bilateral renal venography, and bilateral iliac venography were performed in 108 patients referred for IVC filter placement or vena cavography. Infrarenal IVC length and width were determined with a sizing catheter during cavography. Anomalies were considered significant if they altered placement or selection of the vena cava filter or if they represented a potential collateral pathway for clot to bypass a filter. RESULTS: Variant anatomic structures in the renal vein were found in 11% of patients with cavography and in 37% of patients with selective renal vein injection. Detected anomalies included circumaortic veins (n = 11), multiple veins (n = 25), retroaortic veins (n = 2), and a partially duplicated IVC (n = 1). Selective venography depicted anomalies not suspected at standard cavography in 28 cases (26%); in 20 cases (18% of population) they were significant. The average infrarenal width was 20 mm on the anteroposterior view and was 17 mm on the lateral projection. CONCLUSION: IVC anomalies are common, and selective renal venography can depict significant anomalies in renal vein anatomic structures not shown at standard cavography.

Adult↗

PubMed1996

The use of invertebrate peptide toxins to establish Ca2+ channel identity of CA3-CA1 neurotransmission in rat hippocampal slices.

The relative contribution(s) of different Ca2+ channel subtypes to synaptic transmission between Schaffer collaterals of hippocampal CA3 pyramidal cells and CA1 pyramidal cell dendrites has been assessed using the synthetic invertebrate peptide toxins omega-conotoxin GVIA to block N-type Ca2+ channels, omega-agatoxin-IVA to block P-type Ca2+ channels and omega-conotoxin MVIIC to block N-, P- and Q-type Ca2+ channels. Omega-Agatoxin-IVA, omega-conotoxin GVIA and omega-conotoxin MVIIC all produced dose-dependent inhibitions of the excitatory post-synaptic field potential (fEPSP) recorded from the CA1 region of transverse hippocampal slices. Application of 300 nM omega-conotoxin GVIA generally produced no further inhibition to that observed with 100 nM, resulting in a maximal 50% inhibition of the fEPSP. By contrast, 30 nM omega-agatoxin-IVA reduced the fEPSP slope by only 4.6 +/- 11.1% (mean +/- S.D., n = 3), suggesting the lack of involvement of classical P-type Ca2+ channels, whereas 300 nM omega-agatoxin-IVA reduced the fEPSP slope by 85.7 +/- 15.3% (n = 3) at the end of 44 min application. Similar applications of 100 and 300 nM sigma-conotoxin MVIIC reduced the fEPSP slope by 30.9 +/- 6.6% and 79.7 +/- 5.7% respectively. Application of 30 nM omega-agatoxin-IVA together with omega-conotoxin GVIA (300 nM) produced no greater inhibition of the fEPSP than that observed with omega-conotoxin GVIA alone, suggesting that the omega-agatoxin-IVA-sensitive and omega-conotoxin MVIIC-sensitive component presents a pharmacology similar to the reported Q-type Ca2+ channel. The inhibition produced by omega-conotoxin GVIA and omega-conotoxin MVIIC showed no recovery with prolonged washing (1-2 h) whereas that produced by omega-agatoxin-IVA was slowly reversible. The observation that omega-agatoxin-IVA, which does not effect N-type Ca2+ channels (Mintz et al. (1992a) Neuron 9, 85), is capable of completely suppressing the fEPSP suggests that, whilst N-type Ca2+ channels may contribute to normal synaptic transmission at Schaffer collateral-CA1 synapses, they are not capable of supporting transmission when Q-type channels are blocked.

Action Potentials↗