Revascularization of the Posterior Circulation

The primary objective of revascularization procedures in the posterior circulation is the prevention of vertebrobasilar ischemic stroke. Specific anatomical and neurophysiologic characteristics such as posterior communicating artery size affect the susceptibility to ischemia. Current indications for revascularization include symptomatic vertebrobasilar ischemia refractory to medical therapy and ischemia caused by parent vessel occlusion as treatment for complex aneurysms. Treatment options include endovascular angioplasty and stenting, surgical endarterectomy, arterial reimplantation, extracranial-to-intracranial anastomosis, and indirect bypasses. Pretreatment studies including cerebral blood flow measurements with assessment of hemodynamic reserve can affect treatment decisions. Careful blood pressure regulation, neurophysiologic monitoring, and neuroprotective measures such as mild brain hypothermia can help minimize the risks of intervention. Microscope, microinstruments and intraoperative Doppler are routinely used. The superficial temporal artery, occipital artery, and external carotid artery can be used to augment blood flow to the superior cerebellar artery, posterior cerebral artery, posterior inferior cerebellar artery, or anterior inferior cerebellar artery. Interposition venous or arterial grafts can be used to increase length. Several published series report improvement or relief of symptoms in 60 to 100% of patients with a reduction of risk of future stroke and low complication rates.     

THE IMPACT OF PRE-CLERKING CLINICS ON SURGICAL OPERATION CANCELLATIONS: A PROSPECTIVE AUDIT

Pre-clerking of all patients undergoing elective general surgical operations was introduced at our hospital in an attempt to reduce an unacceptably high operation cancellation rate. A prospective audit has been performed on the effect of this policy on the cancellation rate. Before the introduction of pre-clerking there was a marked seasonal variation in the number of patients who failed to attend for surgery, which could be explained by absence on holiday. This seasonal variation disappeared after the start of pre-clerking clinics, but there has been no reduction in the number of cancellations for medical reasons.     

Adjuvant therapy for pituitary adenomas: the possible role of photodynamic therapy.

Although benign, pituitary adenomas may not always be curable by surgery alone. This is usually owing to dural infiltration and the technical problems of removal of involved dura in the sellar region. In such circumstances, some form of adjuvant therapy may be needed to address residual tumour and forestall recurrence. Radiotherapy and drugs, such as bromocriptine or octreotide, although effective are far from ideal adjuvant therapies and this has led to the study of the effects of photodynamic therapy on pituitary adenomas. It has been shown that photodynamic therapy using the photosensitising drugs haematoporphyrin derivative and aluminium phthalocyanine is active experimentally against these tumours. This could provide another useful weapon to use against these challenging lesions.     

Impact of clinical history on fracture detection with radiography

The effect of knowledge of localizing symptoms and signs in the detection of fractures was studied. Forty radiographs of the extremities were examined twice by seven radiologists; the sessions were separated by 4 months. In 26 cases, a subtle fracture was present; 14 cases were normal. In half of the cases at each session, the precise location of pain, tenderness, or swelling was provided. The observer was asked to determine if the case was normal or abnormal (provide the exact location of the fracture) and to indicate the degree of confidence in the diagnosis. Responses were converted to a numeric scale for analysis. Analysis of receiver operator characteristic parameters indicates that clues regarding location of trauma facilitate detection of fractures. The improvement is based largely on an increased true-positive rate without an increased false-positive rate, regardless of the decision criteria of the radiologist (overall willingness to "overread" or "underread"). This has direct clinical applicability and reinforces the plea of radiologists for precise clinical information.     

Phase I trial and clinical pharmacological evaluation of 10-ethyl-10-deazaaminopterin in adult patients with advanced cancer

10-Ethyl-10-deazaaminopterin (10-EDAM) is an analogue of methotrexate with improved preclinical anticancer activity, more selective entry, and greater conversion to polyglutamate forms in neoplastic cells. In this Phase I trial, we have treated 62 adults with advanced solid tumors, giving 10-EDAM i.v. on either a weekly x 3 schedule (35 patients) or a weekly schedule (27 patients). The dosage levels ranged from 5 to 120 mg/m2. The toxicity observed with 10-EDAM was qualitatively similar to that of methotrexate. Oral mucositis was the dose-limiting toxicity; diarrhea, skin rash, leukopenia, thrombocytopenia, and mild elevations of serum glutamic-oxaloacetic transaminase, prothrombin, and partial thromboplastin times were also observed, but were not dose limiting. A weekly dosage of 80 mg/m2 with escalation or attenuation in accordance with patient tolerance, or 100 mg/m2 weekly for 3 weeks, followed by a 2-week "rest period" are recommended for Phase II assessment. 10-EDAM produced partial remissions in three patients with non-small cell lung cancer and one patient with breast cancer lasting 6, 40+, 26+, and 15 months, respectively. Pharmacokinetic studies carried out at the 5, 30, and 100 mg/m2 dosage levels demonstrated the drug to have a triphasic disappearance from plasma. Elimination was independent of dose over the range tested, with mean plasma half-lives of: alpha = 12.9 min, beta = 1.5 h, and gamma = 11.9 h. Cumulative urinary excretion of the drug ranged from 13 to 55% of the administered dose (mean = 33%); 88% of the urinary drug appeared within the first 4 h following drug administration. The pharmacokinetic behavior of the first and second weekly dosages were consistent within a given patient. The metabolites 7-hydroxy-10-EDAM, and 10-ethyl-10-deaza-2,4-diamino-pteroic acid were demonstrated in the plasma and urine of treated patients. In studies of tissue homogenates from two patients with skin metastases, more extensive retention of the drug and of its polyglutamates was observed in the breast cancer metastases than in the metastases from a kidney cancer or in normal skin.     

The relationship of antipsychotic drug use, behavior, and diagnoses among nursing home residents

Nursing homes have been criticized for frequent use and possible misuse of psychoactive agents. These issues are of clinical concern and policy relevance, especially since the passage of the Omnibus Budget Reconciliation Act (OBRA) of 1987. Using a sample of 419 residents, the authors examined the relationships among antipsychotic drug (AP) use, behavior, and mental health diagnoses. Only 23.2% of the residents were administered APs on a routine and/or "as-needed" basis. Based on the Multidimensional Observation Scale for Elderly Subjects (MOSES) ratings, AP users were more irritable, disoriented, and withdrawn than were nonusers. Also, AP users demonstrated agitated behaviors more frequently. Notably, AP users and nonusers differed significantly in terms of documented mental health diagnoses. Among AP users, 70.1% had documented dementia, 8.3% were psychotic or had other psychiatric disorders, and 21.6% had no mental health diagnoses. In contrast, the majority of nonusers had no mental health disorders. Logistic regression revealed that diagnostic factors, frequency of agitation, level of withdrawal, and marital status were significant predictors of AP use.     

Divided attention performance in cannabis users and non-users following alcohol and cannabis separately and in combination

The effect of 9-tetrahydrocannabinol ( 9-THC) and alcohol, singly and in combination, on divided attention performance was investigated in cannabis users and non-users who were matched for alcohol use. Both cannabis and alcohol produced decrements in central and peripheral signal detections. Drug and alcohol effects were greater for signal presentations in the periphery. Cannabis users were less impaired in peripheral signal detection than non-users while intoxicated by cannabis and/or alcohol. These findings suggest the development of tolerance and cross-tolerance in regular cannabis users and/or the ability to compensate for intoxication effects.     

雷丸多糖的抗炎及免疫刺激作用

Lei Wan, Poliporus mylittae Cook et Mass(Omphalia lapidescena Scbraet) is a kind of fungus used in traditional Chinese medicine, as an antheiminthie From Lei Wan, an "active component designated as. S-4001 had been isolated.Preliminary results indicate that S-4001 belongs to D, β, 1-3 glucan with some 1-6 linkages.After administration of S-4001, significant antiinflammatory activity was found in various experimental animal models, including croton oil induced ear edema in mice and agar or yeast induced ankle swelling in rats. An inhibitory action on leucocyte migration inducced by intraperitoneal injection of CMC in rats was also observed. The plasma content of corticosterone was significantly increased, but the content of ascorbic acid in the adrenals did not change in rats given S-4001. Apart from these actions, S-4001 showed a number of immunostimulating actions such as increasing the clearance of Congo red from mice blood and potentiating the immunohemolysis reaction in 615 mice.