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The in vivo and in vitro effects of 4-amino-3-(D-glucopentitol-1-yl)-5-mercapto-1,2,4-triazole and its 3-methyl analogue on alpha- and beta-glucosidases, beta-glucuronidase as well as alpha-amylase have been investigated. alpha-Glucosidase is the enzyme that is markedly affected in vivo and in vitro in a dose-dependent manner. The compounds showed a reversible inhibition of a competitive type for alpha-glucosidase. Moreover, they exert a relatively potent inhibition on alpha-glucosidase with a Ki magnitude of 3.6 x 10(-4), 9.5 x 10(-5) M.

We have analysed the result of 17,173 pap smears screened in the national research center in reproductive health of Ariana from 1 may 1993 to 30 april 1997. Among these pap smears, 613 colposcopy and 380 biopsy have been performed. The results show that: 1.9% of pap smears present cytological anomalies with 0.79% of low Squamous Intraepithelial lesions and 0.66% high Squamous Intraepithelial lesions. The incidence of CIN III is 1.8% and 0.9% for invasive cancer. The age interval 35-44 years is at high risk of CIN III and invasive cancer of the cervix. evaluation of our diagnostic approach shows that: positive predictive value of pap smears with low SLI is 43.2% positive predictive value of pap smears with high SLI is 37.3%.

Background & Aims: Immune responses during the first few months of acute hepatitis C virus (HCV) infection seem crucial for viral control, but the relationship of these responses to natural history is poorly characterized., Methods: This prospective study investigated the HCV-specific CD4(+) and cytokine responses in patients with acute HCV hepatitis with or without Schistosoma mansoni coinfection, a parasitic infection with T helper (Th) 2 immune bias. HCV-specific CD4(+) proliferative responses and cytokine production in peripheral blood mononuclear cells were correlated with liver biopsy results at 6 months and at the end of follow-up., Results: Whereas 5 of 15 patients with HCV alone recovered from acute HCV, all (17 of 17) patients with S. mansoni coinfection progressed to histologically proven chronic hepatitis. Coinfected patients had either absent or transient weak HCV-specific CD4(+) responses with Th0/Th2 cytokine production. The magnitude of the HCV-specific CD4(+) response at week 12 was inversely correlated with the fibrosis progression rate in chronically infected patients., Conclusions: Patients with acute hepatitis C and schistosomiasis coinfection cannot clear viremia and show rapid progression once chronic infection is established. This rapid progression is associated with a strong Th2 response in peripheral immune responses, suggesting that early development of vigorous Th1 responses not only facilitates clearance but delays disease progression.

Introduction: Death due to acquired torsades de pointes usually is caused by ventricular fibrillation (VF), but the contributing factors to VF triggered by pause-dependent torsades de pointes are not understood., Methods and Results: We evaluated 91 patients who fulfilled four criteria: (1) pause-dependent torsades de pointes; (2) prolonged QT interval and/or corrected QT (QTc) (>0.44 sec); (3) long-short initiation sequence; and (4) conditions known to induce pause-dependent torsades de pointes. There were 38 patients with a documented VF (group I) and 53 without VF (group II). Absolute and relative dispersions of QT and QTc were calculated based on the 12-lead standard ECG. Group I differed from group II with regard to myocardial infarction history (32% vs 13%; P = 0.035), left ventricular ejection fraction (44% +/- 14% vs 65% +/- 9%; P < 0.0001), presence of structural heart disease (100% vs 20.8%; P < 0.0001), QT mean (591 +/- 73 msec vs 514 +/- 78 msec; P < 0.0001), QTc mean (563 +/- 76 msec vs 508 +/- 90 msec; P = 0.002), absolute QT dispersion (166 +/- 56 msec vs 84 +/- 49 msec; P < 0.0001), relative QT dispersion (9.9% +/- 3.5% vs 6.3% +/- 3.2%; P < 0.0001), absolute QTc dispersion (158 +/- 57 msec vs 81 +/- 44 msec; P < 0.0001), and relative QTc dispersion (9.9% +/- 3.6% vs 6.2% +/- 3%; P < 0.0001). Multiple regression analysis showed that ejection fraction (P = 0.0001), presence of structural heart disease (P < 0.0001), and relative QTc dispersion (P = 0.038) were the only independent predictors of VF., Conclusion: Left ventricular function, presence of structural heart disease, and QTc relative dispersion should be evaluated carefully in patients with conditions susceptible to inducing torsades de pointes.

Introduction: Junctional rhythm usually is considered a sensitive but nonspecific marker of successful ablation of the slow pathway in AV nodal reentrant tachycardia. Nevertheless, this junctional rhythm has been little studied, and its relations to recognized predictors of successful radiofrequency (RF) application were never established in any study., Methods and Results: Thirty-nine patients underwent RF ablation of the slow pathway for AV nodal reentrant tachycardia. Ninety RF applications were delivered, and each ablation site was determined using three different fluoroscopic projections. Six anatomic zones were defined from low posterior septum to the site of distal His-bundle recording (P1, P2, M1, M2, A1, and A2). Characteristics of junctional rhythm during RF applications were analyzed. Atrial electrogram characteristics at the ablation sites also were studied. All patients had successful slow pathway ablation, without any complication. The ablation sites were located as follows: 41 at P1, 26 at P2, 20 at M1, and 3 in M2. Forty RF applications were successful: 14 of 41 attempts at P1, 7 of 26 at P2, 16 of 20 at M1, and 3 of 3 at M2. Mid-septal ablation site (M1 and M2) was associated with higher occurrence of junctional rhythm (P < 0.0001), earlier first junctional beat (P = 0.008), and earlier occurrence of the longest junctional burst (P = 0.03) compared with posterior ablation site (P1 and P2). The combination of a mid-septal ablation site and a first junctional beat occurring < or = 3 seconds after onset of RF application identified successful RF application with 100% accuracy. Using multivariate analysis, the ablation site, duration of atrial electrogram (including slow pathway potential when present), and occurrence of junctional rhythm were independent predictors of success., Conclusion: Successful slow pathway ablation depends on many factors. Junctional rhythm characteristics are related to the site of RF delivery and can be helpful in assessing successful slow pathway ablation.

Our objective was to evaluate life-cycle performance of flocks of two Egyptian breeds, Rahmani (R) and Ossimi (O), and their crosses with Finnish Landrace (F) in two management systems. Management systems were one mating season per year (1M) and three mating seasons per 2 yr (3M). Breeds and crosses studied included purebred R and O, F1 crosses 1/2F-1/2R (FR) and 1/2F-1/2O (FO), and inter se matings of 1/4 F-3/4 R (RFR) and 1/4 F-3/4 O (OFO). A dynamic computer model was used to simulate animal performance and enterprise efficiency and profit. Two measures of lifecycle feed conversion (biological efficiency) were computed: kilograms of TDN input per kilograms of empty body weight output (TDN/EBW) and kilograms of TDN input per kilogram of carcass lean output (TDN/CLN). Profit was measured as gross margin (income minus variable costs per ewe per year, GM/EWE). Input parameters for the model were obtained from published results and analyses of data collected from experimental flocks of the same genetic stocks in Egypt. Profit for FR and RFR was 42 and 6% higher in 1M than in 3M. However, profit for all other genetic types was 4 to 8% greater in 3M than in 1M. Breed rankings changed depending on the measure of evaluation (i.e., biological efficiency or profit). Maximization of system output did not necessarily improve efficiency. Under accelerated lambing systems, greater overhead costs associated with labor and feed offset gains in ewe productivity. Genetic stocks should be matched to resources and management systems.

Objectives for this study were to estimate relative economic weights for performance traits for two native and two composite sheep breeds under two management systems in Egypt. Breeds studied were Rahmani (R), Ossimi (O), 3/4R-1/4Finnish Landrace (RFR), and 3/4O-1/4Finn (OFO); OFO and RFR were composite breeds. Management systems were one mating season per year (1M) and three mating seasons per 2 yr (3M). A dynamic computer model was used to simulate animal performance and enterprise efficiency and profit. Input parameters for the model were obtained from published results and analyses of data collected from experimental flocks of the same genetic stocks in Egypt. Responses for two measures of life-cycle feed conversion and one measure of enterprise profit were evaluated. Life-cycle feed conversion was calculated as kilograms of TDN input per kilogram of empty body weight output (TDN/EBW) and kilograms of TDN input per kilogram of carcass lean output (TDN/CLN). Profit was measured as annual gross margin/ewe (GM/EWE). Traits evaluated were conception rate (CR), lambing rate (LR), mortality rate (MR), mature weight (MW), and milk production (MK). Based on responses to percentage changes in trait means, CR was most important for TDN/EBW, followed by LR and MR. For TDN/CLN, LR, MR, and CR were most important. For GM/EWE, CR was most important, followed by LR, MW, and MR. In the systems studied, there was little response to changes in MK. Based on changes in GM/EWE per genetic standard deviation change, LR was most important, followed by CR, MR, MW, and MK in all systems. Relative economic weights for O and OFO were similar, as were weights for R and RFR. Differences in economic weights between management systems for the same breed were not large enough to justify separate selection lines within breeds.

Biventricular pacing has recently been proposed for treating patients with drug refractory heart failure and intraventricular conduction delay. The purpose is to restore ventricular relaxation and contraction sequences as homogeneously as possible. The aim of this study was to determine if some factors could predict the long-term clinical effectiveness of that new treatment. This study included 26 patients, aged 66 +/- 7 years, with drug refractory heart failure and wide QRS. Patients were implanted with a biventricular pacemaker. The left ventricle was paced through a coronary sinus tributary. New York Heart Association functional class, exercise tolerance, and left ventricular (LV) ejection fraction were collected at baseline and after pacemaker implantation. Patients were divided into 2 groups: group I = responders; group II = nonresponders. QRS duration and axis at baseline and during biventricular pacing, interventricular conduction time, and LV and right ventricular lead positions were compared between the 2 groups. Group I patients (n = 19) had a mean reduction of 1.3 in functional class and an increase in peak oxygen consumption rate by a mean of 50%. The only parameter that differed between the 2 groups was the QRS duration during biventricular pacing, with a significantly shorter value in group I than in group II (154 +/- 17 vs 177 +/- 26 ms; p = 0.016). Thus, a positive response to biventricular pacing is correlated with the quality of electrical resynchronization. The optimal positions of the right and LV leads would be those that could induce the greatest shortening of QRS duration.

This is a two-dimensional and Doppler echocardiographic study of the hemodynamic changes in patients with heatstroke and heat exhaustion. It demonstrates that the hemodynamic changes in severe heat exposure reflect a hyperdynamic circulation with tachycardia and high cardiac output states. Relative hypovolemia was more pronounced in patients with heatstroke compared to patients with heat exhaustion. Signs of peripheral vasoconstriction were more often present in patients with heatstroke, while patients with heat exhaustion more often demonstrated peripheral vasodilatation.

Objectives: We report our experience in Tunisia with contraception by subdermal levonogestrel implants., Methods: From January 1, 1990 through June 30, 1994 we inserted 1021 implants at our family planning center in Ariana., Results: Our experience with this pure progesterone implant showed that this method provides effective long-duration contraception. There was only one case of ectopic pregnancy among our 1021 patients. The most frequent undesirable effect and the first cause of discontinuing treatment was disturbed menstrual cycle with irregular discharge., Conclusion: Our results underline the importance of counselling before implant insertion. A 10-day estrogen regimen may provide a solution for menstrual disorders.

The Hemophilus influenzae blood culture and nasopharyngeal isolates, collected during a limited Surveillance of Antimicrobial Resistance in 1991-1993 from 1,635 Egyptian children under 5 years of age, presenting with pneumonia to Embaba and Abbassia Fever Hospitals, were serotyped. The 8 blood culture isolates confirmed H. influenzae to be responsible for 0.5% of the cases of pneumonia, versus 50 Streptococcus pneumoniae blood culture isolates from the same population that confirmed it responsible for 3.1% of the cases. The invasive Hemophilus strains were exclusively isolated from infants below 1 year, from one hospital (Embaba), on one winter season (January to March, 1992). On serotyping, 50% of the blood culture isolates were found to be non-b by latex agglutination. Some 297 nasopharyngeal isolates from cases of pneumonia were also serotyped and 45% were found to be non-b, thus confirming the invasive strains findings. Furthermore, the typing results from ARI-free controls nasopharyngeal isolates--though limited--were consistent with the findings and showed a 43% proportion of non-b. These findings put a question mark on the benefit of a large scale use of the available H. influenzae type b polysaccharide and conjugated vaccines in Egypt. But before interpreting out data in terms of vaccine needs, more specifically designed epidemiological studies need to be conducted to assess the role of H. influenzae as a pathogen in Egypt.

Rats exposed to normobaric oxygen received a single i.p. injection of 2.5 mg/kg of poly I: poly C at various times (-120 to +36 h) before and after the beginning of oxygen exposure. Hyperoxic lung damage and modifications in cytochrome P-450 system components were evaluated. Our results confirmed the protective effect of poly I: poly C on rats exposed to oxygen, reducing the lung edema and the mortality. This effect was only observed when poly I: poly C was injected 48 or 36 h before the beginning of oxygen exposure. Although oxygen exposure per se decreased the total level of lung cytochrome P-450, poly I: poly C per se induced a deeper decrease to levels similar in air- or oxygen-exposed rats. Poly I: poly C did not modify the NADPH-cytochrome c reductase level nor the cytochrome P-450 peroxidase activity in air-exposed rats. The oxygen exposure induced a decrease of these two enzymes, either in the absence or in the presence of poly I: poly C, except when poly I: poly C was injected 48 or 36 h before the beginning of oxygen exposure, times at which poly I: poly C restored the enzymatic values measured in rats exposed to air. Because the times of injection of poly I: poly C were those at which the protective effect was observed, it suggested that the protective effect of poly I: poly C against oxygen toxicity was associated with a lack of oxygen-induced decrease of both the lung NADPH-cytochrome c reductase level and the lung cytochrome P-450 peroxidase activity.

Fragments of dorsal root ganglia (DRG) were grafted into rat brain and examined one month later. The autografts were similar to their normal counterparts when stained with toluidine blue or by indirect immunofluorescence with laminin and neurofilament antibodies. However, a major difference was observed with antibodies to the glial fibrillary acidic protein (GFAP). Normal DRG were GFAP-negative while the autografts were intensely and diffusely stained. The GFAP antibodies used in this study did not decorate Schwann cells or satellite cells in peripheral nerve and DRG, and thus appeared to recognize the "central" form of GFAP (17). Thus reactive astrocytes appear to be capable of migration into grafted nervous tissues without producing apparent neuronal damage.

Two distinct types of reactive astrocytes were studied in rat CNS. Reactive astrocytes secondary to penetrating trauma (anisomorphic gliosis) were induced by stab wounds to the brain. Reactive astrocytes secondary to Wallerian degeneration (isomorphic gliosis) were induced in spinal cord dorsal columns by dorsal rhizotomy proximal to dorsal root ganglia. Anisomorphic glial scars did not stain with antibodies to the glial hyaluronate-binding protein (GHAP), a structural glycoprotein of white matter extracellular matrix. Conversely, isomorphic glial scars were still GHAP-positive 3 months after dorsal root transection. Only after 5 months did GHAP immunoreactivity start to disappear from the isomorphic glial scar. Extensive dorsal rhizotomy was performed at the lumbar level to produce Wallerian degeneration of spinal cord dorsal columns. One month later, the rats were reoperated and two thoracic dorsal roots were implanted in the degenerated dorsal columns. The rats were examined 1 month after grafting. As expected, there was a dense anisomorphic glial scar at the site of surgery, while the dorsal columns above the graft showed isomorphic gliosis. Extensive axonal growth was observed in the dense glial scar surrounding the graft. Conversely, no axonal growth was observed in the degenerated dorsal columns undergoing isomorphic gliosis above the implant. The findings suggested that GHAP-negative astrocytes responding to traumatic injury are permissive for axonal growth and that GHAP-positive astrocytes responding to Wallerian degeneration are not permissive.

The time course of the respiratory consequences of alpha-naphthyl thiourea (ANTU)-induced lung oedema was studied in adult albino rats, up to 6 h after the injection of 5 mg/kg ANTU. Control rats were injected with olive oil (ANTU solvent). After 6 h, pulmonary extravascular water increased by 50% in ANTU-treated rats and the volume of the pleural effusion reached 3.4 +/- 0.1 ml (mean +/- s.e. mean). The most striking point is the absence of hypoxaemia in the ANTU-treated rats: PaO2 = 103 +/- 1.5 Torr vs 100 +/- 1 Torr in the control rats. The non-decreased PaO2 can be related to the patency of the alveolar airspaces. The predominant location of the oedema in the lung interstitium is caused by a specific lymphatic drainage pathway towards the pleura in the rat which prevents alveolar flooding. Histological findings support this hypothesis. PaCO2 is unaltered: 32 +/- 1 Torr in ANTU rats vs 33.5 +/- 1 Torr in control rats. A slight downward shift of arterial pH is found in ANTU rats: (7.440 +/- 0.010 vs 7.475 +/- 0.010, P less than 0.01). Concomittently (HCO3-)a decreases in ANTU-treated rats (22.2 +/- 1.2 mmol l-1 vs 24.8 +/- 0.6 mmol l-1, P less than 0.01). The absence of hypoxaemia is common with normobaric oxygen (02) and ANTU-induced lung oedema in the rat. A comparison is made between 02 and ANTU toxicity, as for respiratory events and histological features.

Serotonergic neurons have their perikaraya concentrated in the raphe nuclei. In the present experiment, pieces of raphe nuclei containing serotonergic neuroblasts were dissected from 14 days rat embryos, mechanically dissociated, and 1 microliter of a cell suspension containing 30,000 cells was injected slowly under stereotaxic control in the olfactory bulb of adult rats. Three weeks after transplantation, the brain of the rats were processed for immunocytochemical detection of 5-HT. In all of the grafted animals, 5-HT neurons were found in the olfactory bulb. They exhibited the morphology of adult neurons, with well developed axon and dendrites, extending far from the injection site. Ultrastructural immunocytochemistry disclosed afferent and efferent synapses to the grafted neurons. Three preliminary results indicates that the transplanted neurons have been integrated in the host's neuronal circuitry. Ongoing electrophysiological studies are now directed at investigating the functional status of these grafted neurons.

Prolonged exposure of C57B16 mice to pure O2 at 1 ATA induced pulmonary edema associated with involution of lymphoid system and depressed immunity. The consequences of these toxic events were evaluated by 1) mortality rate, 2) determination of pulmonary water, 3) thymic and splenic cellularity, and 4) humoral (primary antibodies) and cellular (mitogenic) immune responses. Pretreatment of mice with 125 mg kg-1 of diethyldithiocarbamate (DDC) several days before exposure to O2 resulted in 1) an increase in animal survival (92-100% vs. 59% O2 controls), 2) a reduction in pulmonary edema, 3) partial stabilization of thymus and spleen lymphocyte populations, and 4) restoration of the humoral response (specific antibodies appeared earlier than in O2 control animals) and improvement of the mitogenic proliferative response of the spleen cells after hyperoxia. None of these effects were observed when DDC treatment coincided with the beginning of exposure. Our results indicated that DDC protects mice from both pulmonary and lymphoid hyperoxic injury, but only in a partial manner. It is suggested that the mechanism of this antioxidative property is indirect.

The effects of cytochrome P-450 inducers on O2 toxicity were studied in mice. We first examined three cytochrome P-450 inducers, which differ by their specific tissue affinity: phenobarbital sodium (PB), essentially active in the liver, and 3-methylcholanthrene (3-MC) and beta-naphthoflavone (BNF), which are also active in the lung. Both BNF and 3-MC increased the survival rate and significantly decreased pulmonary edema (pulmonary water and wet-to-dry weight ratio) in C57BL/6J mice exposed to hyperoxia (O2 greater than or equal to 95%), whereas PB had no protective effect. In the second part of this study, we compared the action of BNF in two strains of mice. In one (C57BL/6J), cytochrome P-450 can be induced by aromatic hydrocarbons, whereas in the other (DBA/2J) cytochrome P-450 is not inducible by these compounds. Protection against O2 toxicity was assessed in terms of lethality and pulmonary edema and of lung lipid peroxidation (assessed by measuring malondialdehyde). BNF only protected against O2 toxicity in the inducible strain. This protective effect of BNF on O2 toxicity in C57BL/6J mice was associated mainly with a large increase in the components of the cytochrome P-450 system (cytochrome P-450 and cytochrome b5) in the lung. The activity of pulmonary superoxide dismutase was also slightly increased, but the enhancement was not statistically significant. In contrast, in DBA/2J mice neither the components of the cytochrome P-450 system nor the activity of superoxide dismutase showed any increase.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of the cytochrome P450 inducer beta-naphthoflavone (BNF) on NO2 toxicity were studied in two strains of mice. In one strain (C57B1/6J), cytochrome P450 could be induced by the aromatic hydrocarbon, while in the other strain (DBA/2J) cytochrome P450 was not inducible by this compound. Mice were treated with BNF before and during 4 days of exposure to 20 ppm NO2. The body growth of NO2-exposed mice improved only in BNF-treated C57B1/6J mice. In this strain, BNF reduced both pulmonary edema (as measured by wet and dry lung weights or as assessed by histological studies) and lung peroxidation (as measured by malondialdehyde). This protective effect of BNF on NO2 toxicity in C57B1/6J mice was associated with an increase in the components of the cytochrome P450 system (cytochrome P450 and cytochrome b5), whereas the activities of pulmonary antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and glutathione reductase) were not significantly increased. These data suggest that the induction of the cytochrome P450 system may be important in promoting NO2 tolerance in those strains of mice in which the cytochrome P450 system is genetically inducible.

Twenty adult rats underwent a complete section of the spinal cord at the lower thoracic level. One week later, 15 of them received a cell suspension obtained from raphe nuclei of 14-day-old foetuses into the distal fragment of the spinal cord. They were sacrificed after survival periods of 10-60 days, and vibratome sections of the spinal cord were processed for immunocytochemical detection of serotonin (5-HT). The control, non-transplanted animals showed a total absence of 5-HT immunoreactivity below the section, whereas the transplanted rats showed many immunoreactive 5-HT perikarya in the graft region, some at a distance of up to 10 mm, and a progressive innervation of the whole grey matter extending at least over 20 mm from the graft site.

A patient rarely has a single, isolated disease. The situation is usually much more complex since the different parts of the human organism and its metabolism interact with each other on multiple levels and follow several feedback patterns. These interactions and feedback patterns become even more complex when the effects of the external environment are considered. When several diseases are present, the first steps in medical diagnosis are to determine whether one of the diseases interacts with ("Censors") or changes the significant symptoms, signs, or results of the laboratory tests of the other diseases. We will try, within this paper, to go beyond the scope of the first generation of Artificial Intelligence systems in medicine to determine the effects of two diseases on each other. One important part of the effect of two diseases on each other is the effect of Censors. In addition, causal reasoning, reasoning by analogy, and learning from precedents are important and necessary for a human-like expert in medicine. Their application to thyroid diseases, with an implemented system, are considered in this paper.

The thoracic discal hernia is a rare affection whose prognosis has been transformed by the present diagnostic means and the technical progress of surgery. A case history has been reported of a thoracic discal hernia, T9-T10, with Brown-Sequard Syndrome and vertebral CT Scanning showed a left lateral localization. A posterior access remains indicated in lateral localization of those hernias, and it confirms clinical and neuroradiological findings showing a direct compression of the Adamkiewicz artery in the intervertebral foramen.

Analysis of variance and principal components methods have been suggested for estimating repeatability. In this study, six estimation procedures are compared: ANOVA, principal components based on the sample covariance matrix and also on the sample correlation matrix, a related multivariate method (structural analysis) based on the sample covariance matrix and also on the sample correlation matrix, and maximum likelihood estimation. A simulation study indicates that when the standard linear model assumptions are met, the estimators are quite similar except when the repeatability is small. Overall, maximum likelihood appears the preferred method. If the assumption of equal variance is relaxed, the methods based on the sample correlation matrix perform better although others are surprisingly robust. The structural analysis method (with sample correlation matrix) appears to be best.

Cerebral ultrasound imaging by a transfontanelle approach is now a common investigation during the first year of life. This exploratory procedure is non-invasive, non-irradiating, requires no sedation and can be carried out at the infant's bedside. In addition, the classical apparatus can be completed by deep Doppler allowing deep cerebral vessels to be studied. Three cases are reported of aneurysm of Galen's ampulla detected by ultrasound imaging during the neonatal period. Images demonstrated the presence of an abnormal fluid mass in the region of Galen's ampulla, confirmed as of vascular origin by Doppler, and allowed assessment of degree of subjacent ventricular dilatation and possible secondary ischemic lesions. In massive neonatal forms this exploration may be sufficient since prognosis is poor, but in lesions of moderate size CT scan and angiographic examinations and perhaps MR imaging are required. This technique allows detection of this malformation in the fetus and could therefore influence therapy.

It is known that catecholaminergic drugs can induce both locomotion and a late flexion reflex in spinalized animals. We studied spinal reflexes and locomotor activity in five adult spinal rats which had received a suspension of fetal noradrenergic (NA) neurons below the transection and in three control spinal rats. A rhythmical activity similar to the one of locomotion was regularly observed in three of the grafted rats held above a moving belt. In two of them, the step frequency was increased when the velocity of the moving belt was increased. This was not observed in control rats. A late flexion reflex was obtained in grafted rats that displayed locomotor activity, as well as in two controls. In the two rats which exhibited locomotor activity, analysis showed numerous immunoreactivite (against NA) cells and processes with terminals concentrated around the perikarya of motoneurones.

Inducers of cytochrome P450-linked mono-oxygenases increase the normobaric oxygen tolerance of the adult rat. Pulmonary inducers, as 3-methylcholanthrene and beta-naphthoflavone permit the rat survival and simultaneously a decrease of pulmonary edema. Phenobarbital, an hepatic inducer had lesser effects both on survival rate and on pulmonary and lymphoïd oxygen toxicity.

Radical surgery of pain is destined for chronic and intolerable pain, resistant to causal treatment, and rebellious to the various medicinal therapeutics. Conventional neuro surgery by selective section of nociceptive fibers is very valuable for cancerous subjects with a limited life span. On the other hand, there has been skepticism concerning the real efficiency of neuro stimulation. The advance made in the knowledge of neurophysiologic and neurochemical mechanism of pain will allow a radical transformation as substitute for this invasive type surgery.

Already advocated by Cushing to complement surgery of pituitary adenomas, radiotherapy remains useful in these benign tumours despite controversies concerning long-term results, pituitary cell resistance and potential harmful effects on the optic nerve, glands and skin. Radiotherapy was applied to 36.6 p. 100 of 150 patients with pituitary tumours operated upon by the same surgical team. Some very good results were obtained, notably in invasive and recurrent tumours. In a case of chromophobe adenoma operated twice at 1 year interval, radiotherapy (4,500 rads) after the second operation resulted in complete cure confirmed by computerized tomography 15 years later. Similarly, in an 8-year old girl reoperated upon for severe recurrent suprasellar craniopharyngioma 3 years after the initial excision, post-operative radiotherapy (5,000 rads) produced excellent remission which persists after 19 years. Thus, even with the modern diagnostic and microneurosurgical procedures, radiotherapy remains, for many authors, a useful and safe method to improve the prognosis of pituitary tumours.

The physician or scientist must contend with multiple interactions in medicine. Differential diagnosis, or the determination of which of two or more diseases a patient is suffering from, arises from the complexity of these interactions. Some of these interactions can mask or inhibit the true diagnosis. These inhibiting factors are called censors. Because of censors, switching points are required in non-monotonic reasoning associated with a differential diagnosis. In order to render these censors--and non-monotonic reasoning--susceptible of computation, they must first be circumscribed. This paper examines circumscription as a form of non-monotonic reasoning augmenting first-order logic through censorship in the diagnosis of thyroid patients. This approach to circumscription is inspired by the influential work of John McCarthy at Stanford University.

The evoked compound action potential of lumbar nerve roots after posterior tibial nerve stimulation at the ankle during operation were studied in 10 patients with lumbar disc herniation. The recording needle electrode was inserted into compressed the nerve root before and after excision of disc herniation. The evoked nerve root action potentials consisted of a positive-negative complex. Before excision, this predominant positive complex was recorded in every patient with a mean peak latency of P1 at 16.64 +/- 1.69 msec, and a mean peak to peak amplitude of P1-N1 of 1.94 +/- 0.52 microv. In three cases with migratory disc herniation, the P1-N1 complex was followed by smaller negative component. After excision of disc herniation, the amplitude of the P1-N1 complex decreased significantly with no significant latency modification. The second negative component was not recorded in the three cases with migratory disc herniation. The recording of nerve root evoked potential during operation is of interest for diagnostic purposes. In addition, it allows electrophysiological monitoring of nerve root traumatism during operation procedures.

Adult male Sprague-Dawley rats were made paraplegic by a complete transection of the spinal cord at lower thoracic level. One week later they were transplanted, below the level of the section, with a cell suspension prepared from the raphe region of 14-day embryos. After survival periods of 10 days to 1 year, the animals were sacrificed and the spinal cord processed for the immunocytochemical detection of 5-HT. Axons from grafted cells grew extensively into the grey matter of the host, and established axosomatic and axodendritic synapses in the anterior horn and intermediolateral column, similar to those of the intact animal. In addition, a group of transplanted animals was tested for sexual reflexes which are under the control of serotonin. It was found that ejaculation reflexes, which are absent in paraplegic rats, are restored in transplanted animals.

Rat spinal cord was stained by indirect immunofluorescence with 11 neurofilament monoclonal antibodies that recognize phosphorylated epitopes. All monoclonals were axon-specific in this location. The large motoneurons containing bundles of neurofilaments did not stain and the pattern remained unchanged after transection of the sciatic nerve in the thigh. With nine monoclonals, stained motoneurons were observed in the ventral horns 3 days, 5 days, 1 week, and 2 weeks after transection of the ventral roots close to the spinal cord. The abnormal motoneurons were typically scattered among normal (i.e., nonstained) cells. Even in animals showing the most severe reaction, the whole motoneuron population at the site of rhizotomy was not affected, stained and nonstained perikarya often coexisting side by side. Stained motoneurons were no longer observed 3 weeks after ventral root transection. Changes in neuronal immunoreactivity were also observed after dorsal root transection. However, a different population was affected, i.e., middle-sized neurons in dorsal horns and at the base of ventral horns. With two monoclonals (A9 and D21), cell bodies remained negative following all operations. It is concluded that axotomy in proximity of the cell body may induce certain neurofilament phosphorylation events in motor neuron perikarya, whereas other phosphorylation events remain confined to the axons under these experimental conditions. The absence of changes after transection of the sciatic nerve in the thigh suggests that neurofilament phosphorylation is a reaction to cell injury rather than a cellular event related to nerve regeneration.

The transection of spinal cord can be seen as an interruption of the continuity in between the control command and the peripheral reception. The consequence is an anarchic reorganization of the distal spinal cord often responsible of spasticity and painful rigidity. We have, in a first step, sectioned the spinal cord at lower thoracic level in adult rats. Knowing the modulatory role of aminergic neurotransmitters, we have then one week later transplanted foetal 5-HT neurons into the distal segment of the cord, in half of the transsected animals. Functional results suggest the constitution of sphincteral autonomy in the grafted animals whereas the controls showed either an acute urine retention leading to death within two to three weeks after the section, or an absence of sphincteral control. Immunocytochemical study with specific 5-HT antibodies showed adult-looking neurons extending processes towards the intermediolateral nucleus and the anterior horn. Ultrastructural immunocytochemistry disclosed afferent and efferent synapses to the grafted neurons.

In 135 operated pituitary adenomas of different histological nature, seen over 20 years, the initial treatment was surgical, by trans-sphenoidal or transcranial approach depending on the tumour extent, followed by radiotherapy if necessary. In spite of modern investigation methods, diagnosis is still often made late, so that 118 of our cases already had visual symptoms. After surgery alone (87 cases) made by the same team recurrences occurred in 16%. Reoperations (14 cases) were generally more difficult and could also be followed by new recurrences needing finally radiotherapy with still positive results. Two cases had initial radiotherapy, the other 46 cases were treated by surgery and radiotherapy with a recurrence level of 8.3%. These results indicate the need to use immediate postoperative radiotherapy in every pituitary adenoma showing even the slightest invasive potential because radical surgery is hypothetical and recurrences possible. The recurrence of pituitary adenomas remains a difficult problem of anticipation and of curative management. Our position in terms of these benign tumours is to adopt readily this therapeutic course: surgery followed by radiotherapy, which provides the best prognosis without major risks.

Wallerian degeneration of spinal cord dorsal columns was produced in three dogs by unilateral extradural dorsal rhizotomy at the lower thoracic level. The spinal cord was studied 1 month, 2 months, and 3 months after surgery. Transverse cryostat sections at the site rhizotomy and at the mid-thoracic level were stained by indirect immunofluorescence with antibodies to the glial fibrillary acidic protein (GFAP) and to the glial hyaluronate-binding protein (GHAP). GHAP immunoreactivity was almost unchanged in the degenerated dorsal column 1 month after rhizotomy. After 2 and 3 months, staining with GHAP antibodies was markedly decreased in the gliosed dorsal column at the site of rhizotomy, but it still persisted at the mid-thoracic level. It is concluded that GHAP persists for long periods of time in dorsal columns undergoing Wallerian degeneration, a finding consistent with its putative role as a nonpermissive substrate preventing nerve regeneration in CNS white matter.

Rats were pretreated with various inducers of cytochrome P-450 before being exposed to pure normobaric oxygen (O2) in order to determine whether the inducers interfere with toxicity. The pulmonary and liver inducers beta-naphthoflavone (beta NF) and 3-methylcholanthrene (3MC) increased the survival rate and decreased the amount of pleural and lung fluid accumulation in adult rats exposed to oxygen. Phenobarbital (PB), which is essentially active in the hepatic microsomal cytochrome P-450, was less effective in counteracting oxygen toxicity. After 7 days of exposure to oxygen, none of the untreated rats survived, whereas 40, 73, and 90% survival was observed in rats treated with PB, 3MC, and beta NF, respectively. After 60 h of O2 exposure, significantly less pleural and lung fluid accumulation was observed in beta NF- and 3MC-treated rats than in untreated or PB-treated rats (p less than 0.001). Both beta NF and 3MC prevented the increase of lung peroxidation (assessed by measuring of malondialdehyde) and that of hydrogen peroxide production by lung microsomes induced by O2 exposure. These protective effects are associated with a large increase in the components of the pulmonary cytochrome P-450 system and its peroxidase activity and with an increased response to hyperoxia by lung antioxidant enzyme activities. In contrast, in control rats, the activities of the antioxidant enzymes were not increased, and both the quantity and the peroxidase activity of cytochrome P-450 were significantly decreased by O2 exposure. We conclude that in the rat, pretreatment by inducers of pulmonary cytochrome P-450 results in marked protection against O2 toxicity and an increase of antioxidant enzyme response to hyperoxia.(ABSTRACT TRUNCATED AT 250 WORDS)