A new route to platencin via decarboxylative radical cyclization.

A new approach to platencin, a potent antibiotic isolated from Streptomyces platensis, has been established. The highly congested tricyclic core of the natural product was successfully constructed by decarboxylative radical cyclization of an alkynyl silyl ester with Pb(OAc)4 in the presence of pyridine in refluxing 1,4-dioxane. The key decarboxylation, which likely takes place via lead(IV) esterification followed by carbon-centered radical generation and subsequent capture of the radical with a triple bond, allows the rapid construction of the twisted polycyclic system.

Synthesis and structure of dinuclear hafnium(IV) and zirconium(IV) complexes sandwiched between 2 mono-lacunary alpha-Keggin polyoxometalates.

The synthesis and characterization of two dinuclear HfIV and ZrIV complexes sandwiched between 2 mono-lacunary alpha-Keggin polyoxometalates (POMs), i.e., (Et2NH2)8[{alpha-PW11O39Hf(micro-OH)(H2O)}2].

Sandwich-type Hf(IV) and Zr(IV)complexes composed of tri-lacunary Keggin polyoxometalates: structure of [M(3)(mu-OH)(3)(A-alpha-PW(9)O(34))(2)](9-) (M = Hf and Zr).

The syntheses and structures of hafnium(iv) and zirconium(iv) complexes with Keggin tri-lacunary polyoxometalates (POM) [A-alpha-PW(9)O(34)](9-), i.e., (Et(2)NH(2))(7)H(2)[Hf(3)(micro-OH)(3)(A-alpha-PW(9)O(34))(2)].

Crossed cerebellar hypoperfusion in hyperacute ischemic stroke.

Objective: In chronic stage of cerebral hemispheric infarction, contralateral cerebellar blood flow and metabolism are depressed, which is known as crossed cerebellar diaschisis (CCD). The present study was performed to elucidate (1) whether the diaschisis occurs in hyperacute stage of ischemic stroke when computed tomography (CT) scans is not able to identify infarction, and (2) which site of lesion in the cerebrum is responsible for the depression in contralateral cerebellar blood flow.

Methods: Single photon emission computed tomography was performed in 21 patients with middle cerebral artery (MCA) embolic infarction within 6 h of the onset (3.

[Late onset of spinal epidural abscess after spinal epidural catheterization].

A 76-year-old diabetic woman received epidural catheterization for sigmoid colectomy. Four months later she started to complain of fever and severe lumbago, and finally fell into coma and tetraplegia. She had severe neck stiffness, and lumbar puncture yielded yellowish pus.

[A case of hypoxic brain damage induced by severe asthma successfully treated by hypothermia therapy].

We experienced a case of hypoxic brain damage induced by severe asthma who was successfully treated by hypothermia. A 20-year-old woman with a history of bronchial asthma suffered from severe respiratory distress and she stopped breathing for about 20 minutes. She was admitted to our hospital with respiratory arrest, deep coma, mydriasis and weak motor response to pain.

Reappraisal of early CT signs to predict the arterial occlusion site in acute embolic stroke.

Objective: To elucidate the value of early computed tomographic (CT) signs of stroke in predicting the occlusion site in the cerebral arteries.

Patients: 105 consecutive patients with acute embolic stroke affecting the anterior circulation.

Methods: Four early signs were evaluated on cranial CT within six hours of stroke onset: loss of the insular ribbon (LIR); attenuation of the lentiform nucleus (ALN); hemispherical sulcus effacement (HSE); and the hyperdense middle cerebral artery sign (HMCAS).

MRI findings of hemolytic uremic syndrome with encephalopathy: widespread symmetrical distribution.

The authors report the magnetic resonance imaging (MRI) findings in a 22-year-old woman with hemolytic uremic syndrome and encephalopathy secondary to verotoxin-producing Escherichia coli. Multiple lesions in the midbrain, cerebellum, occipital lobe, and basal ganglia showed high signal intensity on T2-weighted images with widespread symmetrical distribution. Most of these findings showed remarkable reduction on MRI images obtained 70 days after the onset.

Solitary pontine tuberculoma.

A 66-year-old man, with a history of pulmonary tuberculosis 40 years before admission, complained of headache and dysarthria that lasted for 2 weeks and was followed by diplopia. MRI revealed an isolated nodular lesion in the pons with a marked enhancement mimicking brain tumor and other diseases. Antituberculous drugs were started under the presumptive diagnosis of tuberculoma.

Depression among caregivers of elderly patients on chronic hemodialysis.

The present study was conducted to investigate depression in caregivers of elderly hemodialysis patients. Caregivers answered a self-administered questionnaire about various factors that may affect their depression, and also completed a Center for Epidemiologic Studies Depression Scale evaluation (CESD). The frail elderly who received regular nurse visits were used as controls.

Progressive motor deficits in lacunar infarction.

Objective: To study the clinical characteristics of the progression of motor deficits in lacunar stroke patients.

Background: Some patients with lacunar infarction have progression of their neurologic deficits, but it is not known which patients will progress or why they progress.

Methods: The authors evaluated 92 consecutive patients (47 men, 45 women; age, 69.

Blood pressure control and recurrence of hypertensive brain hemorrhage.

Background And Purpose: Recent studies have demonstrated that recurrence of hypertensive brain hemorrhage (HBH) is not uncommon. However, risk factors for the recurrence of HBH have not been evaluated systematically.

Methods: We analyzed 74 patients with HBH who were admitted to our clinic and followed up as outpatients for a mean of 2.

Sonographic detection of haemodynamic changes in a case of vertebrobasilar insufficiency.

We present a diagnostically challenging case of vertebrobasilar insufficiency caused by head rotation. The patient was a 58-year-old man complaining of dizziness and faintness with head rotation to the left. Vertebral arteriography with the head turned to the left revealed mechanical compression of the right vertebral artery at the occipitoatlantal joints and an occluded left vertebral artery.

Simultaneous multiple brain hemorrhage associated with migraine--a case report.

A fifty-five-year-old woman with a history of migraine suddenly developed an occipital headache and visual disturbance after a typical migrainous attack. On admission, she had a left homonymous hemianopsia, and computed tomography of the brain demonstrated intracranial hematomas in the occipital subcortices bilaterally. Cerebral arteriography revealed diffuse vasospasm of the intracranial arteries attributed to the migraine.

Medial medullary infarction: analyses of eleven patients.

Of 2,130 consecutive patients admitted to two hospitals with acute brain infarction, we examined 11 patients (0.52%) with medial medullary infarction. The infarcts documented by MRI were unilateral in 9 patients and bilateral in 2 patients, and located in the anteromedial arterial territory of the upper or middle part of the medulla.

Serial changes in blood pressure and neurohormone levels after the onset of lacunar stroke.

To assess serial changes in blood pressure and its circadian variation following a lacunar stroke, the authors studied 7 patients who developed a single lacunar infarction in either the internal capsule or the corona radiata. Blood pressure and pulse rate were monitored noninvasively for twenty-four hours by an ambulatory blood pressure monitoring device in the acute, subacute, and chronic phases of the strokes. In the acute and chronic phases, the authors also measured urinary excretion of catecholamines every 6 hr, and serum cortisol concentration at 9:00, 17:00, and 21:00 hr.

Circadian blood pressure in patients in a persistent vegetative state.

We examined circadian variations in blood pressure, pulse rate, and other physiological variables, including hormone levels, in 16 patients in a persistent vegetative state (mean age -/+ SE; 66.1 -+/ 3.9 yr).

Pontine infarction extending to the basal surface.

Background And Purpose: Etiology and symptomatology in pontine infarction extending to the basal surface are supposed to be different from those in deep pontine infarction of the lacunar type. The aim of this study was to compare the infarct size and location, vascular lesions, risk factors, and neurological deficits in three different types of acute pontine infarction.

Methods: We studied isolated pontine infarction extending to the basal surface on brain imaging (group 1, n = 30), deep pontine infarction without extension to the basal surface (group 2, n = 23), and pontine infarction with simultaneous extrapontine infarct in the posterior circulatory system (group 3, n = 20).

Purulent meningitis after endoscopic injection sclerotherapy for esophageal varices.

A 57-year-old man with liver cirrhosis developed alpha-hemolytic streptococcal meningitis following endoscopic injection sclerotherapy for esophageal varices. Central nervous system infection is uncommon as a complication of sclerotherapy, however, when such an infection does develop, it is usually intractable. We therefore emphasize the importance of immediate antibiotic therapy right after the onset of inflammatory symptoms in order to prevent the development of undesired infectious complications following sclerotherapy.

Multiple brain infarction and hemorrhage by nonbacterial thrombotic endocarditis in occult lung cancer--a case report.

A fifty-four-year-old woman died from multiple brain infarction and hemorrhage in the bilateral cerebrum, cerebellum, and brainstem, with renal infarction. She developed hematuria and transient blindness sixteen days before admission. Low-grade fever, heart murmur, and aortic valve vegetation on ultrasonic cardiography suggested infectious endocarditis.