Usefulness of MRA-DWI mismatch in neuroendovascular therapy for acute cerebral infarction.

BACKGROUND: This study evaluated the usefulness of MR angiography (MRA)-diffusion-weighted imaging (DWI) mismatch in neuroendovascular therapy over 3 h after onset of acute cerebral infarction. METHODS: The subjects were 14 cases (age, 73 ± 8.4 years) who had an anterior circulation deficit on DWI/MRA on arrival and underwent neuroendovascular therapy over 3 h after onset. MRA-DWI mismatch (MDM) (+) was defined as 'major artery lesion (+) and diffusion-weighted image-Alberta Stroke Program Early CT Score (DWI-ASPECTS) ≥6'; MDM (-) was defined as 'major artery lesion (+) and DWI-ASPECTS <6'. RESULTS: Reperfusion was achieved in nine of 14 patients (64%) undergoing neuroendovascular therapy. Within the reperfusion group, in the five MDM (+) patients and the four MDM (-) patients, the outcome was a favorable clinical response in the MDM (+) group. The modified Rankin Scale (mRS) scores after 90 days were 0-2 in 3 (60%) and 3-6 in 2 (40%) of the MDM (+) group patients and 0-2 in 0 (0%) and 3-6 in 4 (100%) of the MDM (-) group patients. In the MDM (+) group, a good outcome was achieved. However, the number of cases was small, so this was not a significant difference. Within the non-reperfusion group, in the three MDM (+) patients and the two MDM (-) patients, the mRS scores after 90 days were 0-2 in 1 (33%) and 3-6 in 2 (67%) of the MDM (+) group patients and 0-2 in 0 (0%) and 3-6 in 2 (100%) of the MDM (-) group patients. In both groups, the outcome was poor. CONCLUSIONS: With neuroendovascular therapy, a good outcome with reperfusion was achieved in the MDM (+) group compared to the MDM (-) group. This suggests that the presence or absence of MDM may be useful in determining prognosis after reperfusion.

Classic polyarteritis nodosa presenting with rapidly progressive renal insufficiency.

Rapidly progressive renal insufficiency is rare in patients with classic polyarteritis nodosa (cPAN). We describe two cases of cPAN who presented with rapid and progressive deterioration of renal function. Renal biopsies showed severe necrotizing vasculitis in medium-sized arteries but no changes in glomeruli. Combination therapy of corticosteroid and cyclophosphamide resulted in marked improvement of clinical symptoms, amelioration of renal function and lack of subsequent relapse of vasculitis. These findings suggest good prognosis of patients with cPAN who show rapid and progressive deterioration of renal function who respond to immunosuppressive therapy.

Conserved base-pairings between C266-A268 and U307-G309 in the P7 of the Tetrahymena ribozyme is nonessential for the in vitro self-splicing reaction.

P7 is highly conserved in Group I self-splicing intron ribozymes. This region is known to coordinate metal ions and bind a cofactor guanosine required for the self-splicing. To further investigate the fundamental role of the corresponding region in the Tetrahymena ribozyme, we attempted to identify minimal requirements for the base-paired region excluding the guanosine binding site. We discovered that a variety of sequences are eligible and its derivatives possessing extra nucleotide(s) can still conduct the first step of splicing, indicating that no particular base-pairing is essential in this region for conducting the reaction in vitro. The results provide two hypotheses for the fundamental role of this region: (i) if the region contains element(s) that are strictly required in the catalysis, they are not necessarily tightly fixed in the ribozyme and (ii) if not, its fundamental role may simply be to coordinate neighboring regions that are directly involved in the catalysis.

Analysis of the P7 region within the catalytic core of the Tetrahymena ribozyme by employing in vitro selection.

The highly conserved P7 region is generally believed to act as a major portion of the catalytic site in the Group I intron ribozyme. However, its functions have not been elucidated except for the fact that it specifically binds a cofactor guanosine required for self-splicing reaction. We attempted an in vitro selection experiment to determine the sequence requirements of this region in the mechanism of catalysis by using the Tetrahymena ribozyme. We found that the selected active clones have the secondary structure similar to that of the wild type with few exceptions. However, their primary sequences were not conserved except G264 and C311 that are the major elements of the binding site for the guanosine. Our results suggest that the unique secondary structure of the P7 region is a primary requisite for the catalytic function of this class of ribozymes.

[Hypercapnea during thoracoscopic surgery under regional anesthesia].

A 23-year-old woman was supposed to undergo thoracoscopic surgery for the 10th pneumothorax that accompanied histiocytosis X. The past history included Lylle's disease, asthma, myocarditis, drug-induced leucocytopenia and bronchitis obliterans. The preoperative arterial blood gas analysis under receiving O2 at rate of 2 l.min-1 via a nasal cannula revealed normal values. General anesthesia and intubation with a double-lumen endotracheal tube would have been preferable, but regional anesthesia was chosen because of her medical history and positive results of the skin tests for vecuronium, pancronium, diazepam and midazolam. During the first 10 min of thoracoscopic procedure, her respiration became rapid and shallow and she was restless and comatose. The operation was cancelled. Arterial blood gas analysis under receiving O2 at rate of 4 l.min-1 via a face mask revealed: pH 7.025, PaO2 113.8 mmHg, PaO2 244.8 mmHg, HCO3- 29.7 mEq.l-1, BE-5.6, and O2 saturation 99.1%. Manual artificial ventilation with a mask and bag was initiated. Her spontaneous respiration and consciousness recovered in next 30 min. The postoperative course was uneventful. Tachypnea, caused from anxiety, dyspnea and stimulation of irritant receptors in the airway, were considered to be responsible for the event. The duration of inspiration became shorter as tachypnea developed, that made the tidal volume to decrease and hypercapnea ensued.

Selective medium containing fosfomycin, nalidixic acid, and culture supernatant of Rhodococcus equi for isolation of Corynebacterium pseudotuberculosis.

FNR medium containing fosfomycin, nalidixic acid, bovine blood and culture supernatant of Rhodococcus equi was prepared by the present authors, and the medium did not inhibit growth of Corynebacterium pseudotuberculosis but completely hampered the growth of Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. The culture supernatant of R. equi facilitated detection of suspected colonies of C. pseudotuberculosis due to synergistic hemolysis. Rate of isolation of the organisms (from the trachea, larynx and nasal cavity of 16 slaughtered sheep with caseous abscess in the lung) was higher with FNR, the selective medium, than with nonselective medium. The selective medium was thus found to be useful for isolation of C. pseudotuberculosis from sheep.