Synthesis, herbicidal activity, and mode of action of IR 5790.

IR 5790, an arylthiadiazolone herbicide structurally related to oxadiargyl and oxadiazon, was synthesized. The herbicidal activity and mode of action of IR 5790 were investigated. This herbicide has broad-spectrum pre-emergence activity against both dicotyledonous and monocotyledonous weeds. The phenotypic responses of susceptible plants, such as interruption of growth and light-dependent development of necrotic areas on the foliage, are consistent with those observed with protoporphyrinogen oxidase-inhibiting herbicides. Tissues exposed to IR 5790 in darkness accumulated protoporphyrin IX, which led to a photodynamic loss of membrane integrity upon exposure to light. Consistent with these physiological symptoms, IR 5790 strongly inhibited protoporphyrinogen oxidase, with an I(50) value of 3 nM. The presence of a sulfur atom did not significantly alter the molecular properties of the thiadiazolone ring, relative to the oxadiazolone ring of oxadiargyl, which explains why IR 5790 has the same mode of action as this herbicide.

Central nervous system involvement in a child with hemolytic uremic syndrome.

We report a 20-month-old girl with postdiarrheal (Shiga toxin) hemolytic uremic syndrome and severe encephalopathy. Magnetic resonance (MR) images were obtained in the acute phase of the disease and after 10 months. The first MR images showed widespread high signal intensity on T2-weighted and low signal intensity on T1-weighted images, in deep and subcortical white matter; the splenium of the corpus callosum was also involved, as well as cerebellar hemispheres. Neurological symptoms and signs gradually disappeared within 35 days. Follow-up MR imaging showed almost complete resolution of the previous findings, and the patient recovered without central nervous system impairment. The neurological lesions were probably due to hypoxia, although several other mechanisms could be involved, such as metabolic derangements and the action of Shiga toxin. In spite of the dramatic clinical manifestations, we observed a good outcome, indicating that patients with similar lesions do not necessarily have a poor prognosis.

Renovascular disease and hypertension in children with neurofibromatosis.

Neurofibromatosis type 1 (NF1) is associated with vascular lesions, such as renal artery stenosis, and secondary hypertension. The real prevalence is largely unknown, particularly in children. We observed 27 patients with NF1, mean age 12.8 years (range 4.2-24 years), for 2-10 years to assess the association of NF1 with vascular abnormalities and secondary hypertension. Patients were studied with angiography, 24-h blood pressure monitoring, a captopril test, and Doppler ultrasonography of aorta and renal arteries. The prevalence of hypertension was 18.5%; 61.5% of patients studied with angiography had vascular lesions, half of whom were apparently normotensive. However, they had abnormal 24-h blood pressure monitoring, which was a first sign of poor blood pressure control. Those patients with severe hypertension (11.1%) were successfully treated with percutaneous transluminal angioplasty (PTA); stenosis recurred in 2 of 3 patients after a 2-year follow-up period, and was responsive to drugs. We conclude that hypertension is a frequent complication of NF1 in pediatric patients, it is usually secondary to typical vascular lesions, and requires careful follow-up. Ambulatory blood pressure monitoring (24-h) is a sensitive method for detecting initial alterations of the blood pressure pattern. PTA may be an effective treatment in this condition.

Longitudinal changes of bone density and bone resorption in hyperthyroid girls during treatment.

Low bone mineral density (BMD) and increased bone turnover are common features of untreated hyperthyroidism in adult patients. The effect of treatment on BMD is still controversial. BMD and bone metabolism in hyperthyroid children have not been thoroughly investigated. In the present study, we measured spinal and whole body BMD by dual-energy X-ray absorptiometry in a group of 13 girls (aged 5.0-14.9 years) at diagnosis of hyperthyroidism. The bone resorption rate was assessed by urine measurement of N-terminal telopeptide of type I collagen (NTX). Hyperthyroid patients have been studied longitudinally during treatment. BMD values and NTX urine concentrations have been also determined in 155 healthy Caucasian girls (aged 2.4-24.2 years). Spinal and whole body bone density measurements were significantly lower compared with healthy controls in untreated hyperthyroid girls, after correction for differences in age and anthropometric measurements (p

Unusual clinical features and early brain MRI lesions in a family with cerebral autosomal dominant arteriopathy.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a recently described inherited disorder. The pathologic gene maps on chromosome 19. The clinical spectrum of the disease consists of recurrent strokes, migraine, transient ischemic attacks, mood changes, and dementia. We report a genetically assessed CADASIL family with atypical clinical presentations of epileptic seizures. In two asymptomatic family members there were early brain abnormalities on MRI. Our report expands the clinical spectrum of CADASIL and suggests that it is possibly an undiagnosed disorder.

Bronchioloalveolar lung carcinomas: K-ras mutations are constant events in the mucinous subtype.

Bronchioloalveolar carcinoma (BAC) is a form of peripheral lung adenocarcinoma growing as a single layer of malignant cells along the walls of terminal airways. The existence of BAC as a separate clinico-pathological entity has been a matter of controversy, mainly because its histogenesis is uncertain and it is not easily distinguishable from conventional lung adenocarcinoma (CLA). Three subtypes of BAC have been described using histological and cytological criteria: mucinous, non-mucinous, and sclerosing. The clinical behaviour of BAC appears to be dependent on the histological subtype. The different morphological patterns and clinical outcome of the subtypes of BAC suggest that their biological behaviour may be different from one another and from CLA. This study has investigated 58 BACs (10 mucinous, 40 non-mucinous, and 8 sclerosing) and 50 control CLAs for mutations at codon 12 of the K-ras oncogene. Twenty-one (36 per cent) BACs and 13 (26 per cent) CLAs showed K-ras mutations. A clear association (P < 0.0001) between K-ras mutations and the mucinous type of BAC was observed: all 10 mucinous tumours examined were scored positive for mutations in the K-ras gene, while only 9 (23 per cent) of the 40 non-mucinous and 2 (25 per cent) of the 8 sclerosing BACs were found to be positive. The frequency of ras mutations in non-mucinous BAC, sclerosing BAC, and CLA was not statistically different. Our data indicate that BACs are a heterogeneous group of lung tumours and that the mucinous form might represent a biological entity separate from both the other two BAC types and CLA.

Cerebrotendinous xanthomatosis (van Bogaert-Scherer-Epstein disease): CT and MR findings.

PURPOSE: To describe the CT and MR findings in the brain and spinal cord of patients with cerebrotendinous xanthomatosis and to seek possible correlations between clinical, biochemical (cholestanol levels), and neuroimaging findings. METHODS: Ten patients with well-defined clinical and biochemical diagnoses of cerebrotendinous xanthomatosis were examined. Brain CT was performed in eight cases. In all patients MR was obtained using spin-echo and gradient-echo sequences. In eight patients spine MR was also performed. RESULTS: Neuroradiologic findings included diffuse cerebral and cerebellar atrophy. In half the cases, atrophy of the brain stem and corpus callosum was also found. In the majority of patients cerebellar bilateral focal lesions and mild white matter signal alterations were present. Spinal cord MR did not show signal abnormalities or atrophy. CONCLUSIONS: We found cranial alterations in patients with severe neurologic impairment, but there was no correlation with cholestanol plasma levels. No spinal cord abnormalities were present.

Epilepsy with bilateral occipital calcifications: Sturge-Weber variant or a different encephalopathy?

A series of cases of epilepsy with associated bilateral occipital calcifications (EBOC) without signs of phakomatosis and without any disorders known to produce cerebral calcifications have been reported. It is unclear whether EBOC is an incomplete variant of Sturge-Weber disease (SWD) or if it is a different, as yet undefined encephalopathy. We describe four new cases of EBOC that are different clinically by age of onset, type, course, severity of epilepsy, and associated cognitive deficits but that are linked by similar neuroradiologic findings. Similar to cases described in the literature, there is convincing evidence in favor of the hypothesis that these cases belong to an encephalopathy different from SWD and frequently associated with celiac disease.

Magnetic resonance imaging findings in Leber's hereditary optic neuropathy.

The authors describe magnetic resonance imaging (MRI) findings in 15 subjects with different clinical stages of Leber's disease. A few and no characteristic abnormalities of the optic nerve signal were found. Nevertheless, MRI can be considered as a useful tool to differentiate optic neuritis together with visual and brainstem auditory evoked potentials.

Prognostic value of the dense middle cerebral artery sign in patients with acute ischemic stroke.

The presence of a dense appearance of the horizontal part of the middle cerebral artery (the "dense middle cerebral artery sign") was looked for on CT scans taken on admission in 90 consecutive patients with ischemic stroke in the carotid artery distribution. The outcome of the 14 patients with the sign was poorer than that of 76 patients without the sign (Odds ratio 4.3). We suggest that this sign could be a useful prognostic variable in the acute phase of an ischemic stroke.

[Memory changes in herpes virus encephalitis: report of a case]. / Alterazione della memoria nell'encefalite da herpes virus: a proposito di un caso.

A case of Herpes Simplex Encephalitis with a benign course was present in a 66-year-old patient. A year after the acute phase of the illness, the patient continued to suffer from inability to fix verbal material in memory. During the acute phase, cerebral NMR revealed a large evolving lesion in the right temporal region, and an old lesion located in the same region of the opposite hemisphere. From the medical history, we learned that the patient, 35 years earlier, suffered a similar episode, including a short-term memory deficit. In the following study, we will discuss this case report in relation to data found in the literature dealing with memory deficit, caused by mono and bilateral, temporal lesions.

Is multi-infarct dementia representative of vascular dementias? A retrospective study.

Multi-infarct dementia (MID) indicates a dementia disorder primarily caused by multiple cerebral infarcts. Since other pathogenetic mechanisms cause vascular dementia we evaluated clinical, CT scan and CSF neurochemical parameters of 134 MID and 67 PVD (probable vascular dementia) patients. We found no differences with regard to the presence of major risk factors. Only TIA/stroke episodes and focal neurological signs were significantly more frequent in MID than in PVD cases, an anticipable result on the basis of MID definition. CT scan findings showed a prevalence of subcortical with respect to cortical lesions in both groups, with a higher frequency in MID patients. Subjects with deep infarcts more frequently showed TIA/stroke episodes and diabetes mellitus. No differences were detectable in CSF monoamine metabolite levels. We conclude that in the majority of vascular dementias subcortical damage seems to have a major pathogenetic role.

CT-ventriculography in a cystic lesion of the third ventricle.

One case of cystic lesion of the third ventricle is reported. The authors stress the importance of CT combined with ventriculography for the diagnosis of the intraventricular cystic lesions.

Value of CT scanning in outpatients: preliminary report on a controlled study.

A series of 100 consecutive new outpatients attending the neuroradiology service for a cranial CT scan between 1 October and 24 December 1984 were analyzed. On the day of the investigation each patient was examined by a neurologist, who gave his opinion on the value of a CT scan. The neurologist's ratings were then compared with the CT reports. More than 2/3 of the requests for CT were useless and could have been avoided by thorough clinical evaluation of the patients and full awareness of what CT scanning can contribute to diagnosis and treatment.

Memory impairment in the elderly: a three-year follow-up.

A 3-yr follow-up study on the trend of memory performance in 9 elderly subjects with selective memory defects, which was carried out in an attempt to clarify the evolution of the disorder, revealed marked worsening of sensory visual memory, retention capacity and recent memory. No other mental function was compromised. The results of this study suggest that the onset of a selective memory defect in the elderly is not necessarily the expression of a demential amnestic syndrome, but rather the manifestation of a senile brain deterioration limited to the anatomo-functional memory system.

Third ventricle gliomas. Report of 7 cases with benign clinical behaviour.

Neoplasms of the third ventricle are lesions arising within the ventricular cavity, often free but more often pedunculated. True third ventricle tumours are surgically removable. In a consecutive surgical series of 580 intracranial tumours the authors operated on 27 lesions of the third ventricle, 7 of which were benign gliomas. The histological diagnosis was polar spongioblastoma in 5 cases and fibrillar subependymal astrocytoma in 2 cases. The dominant clinical features were a slowly progressive or intermittently increased intracranial pressure syndrome, and mental and visual disturbances. CT and CSF contrastographic studies provided the essential diagnostic data for the therapeutic plan. CT scans at follow-up studies confirmed the successful removal of the lesions. A right trans-ventricular approach was employed in all cases. Depending on the size and position of the lesion, removal was performed through the foramen of Monro or through a sub-choroidal approach. In two patients a ventriculo-atrial shunt was necessary in spite of tumour removal. No surgical mortality occurred and patients are well at a follow-up time of from 2 to 6 years.