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1.
A sensitive protein-fold recognition procedure was developed on the basis of iterative database search using the PSI-BLAST program. A collection of 1193 position-dependent weight matrices that can be used as fold identifiers was produced. In the completely sequenced genomes, folds could be automatically identified for 20%-30% of the proteins, with 3%-6% more detectable by additional analysis of conserved motifs. The distribution of the most common folds is very similar in bacteria and archaea but distinct in eukaryotes. Within the bacteria, this distribution differs between parasitic and free-living species. In all analyzed genomes, the P-loop NTPases are the most abundant fold. In bacteria and archaea, the next most common folds are ferredoxin-like domains, TIM-barrels, and methyltransferases, whereas in eukaryotes, the second to fourth places belong to protein kinases, beta-propellers and TIM-barrels. The observed diversity of protein folds in different proteomes is approximately twice as high as it would be expected from a simple stochastic model describing a proteome as a finite sample from an infinite pool of proteins with an exponential distribution of the fold fractions. Distribution of the number of domains with different folds in one protein fits the geometric model, which is compatible with the evolution of multidomain proteins by random combination of domains. [Fold predictions for proteins from 14 proteomes are available on the World Wide Web at. The FIDs are available by anonymous ftp at the same location.]  相似文献   

2.
Seventeen patients with cortical dysplasia who had surgical resection for medically intractable partial epilepsy were studied. Compared with two groups of surgically treated patients with intractable epilepsy due to tumour (n = 20) and mesial temporal sclerosis (n = 40), patients with cortical dysplasia showed significantly more frequent extratemporal lesions, more frequent non-epileptiform EEG abnormalities and less favourable surgical outcome for seizure control. Patients with cortical dysplasia were younger at onset of seizures and had a lower detection rate of CT abnormalities compared with the tumour group, and lower IQ compared with the mesial temporal sclerosis group. MRI was abnormal in five of seven patients. Six patients became seizure-free or almost seizure-free but eight did not experience relief of seizures. Surgical outcome related to the extent of pathology but not to the histological abnormality. Lesions outside the temporal and frontal lobes were correlated with poor surgical outcome, as were generalised interictal EEG abnormalities, which may reflect extensive or multiple lesions. Ictal intracranial recordings were not useful for presurgical evaluation of cortical dysplasia.  相似文献   

3.
Spoiled fast three-dimensional gradient-echo magnetic resonance imaging of the aorta and iliac arteries was performed in 13 patients after administration of a single bolus of gadopentetate dimeglumine. The imaging table was moved manually 40-45 cm between two acquisitions. Arterial signal-to-noise ratio did not vary significantly between the thoracic (aortic) and pelvic stations, but venous signal-to-noise ratios increased and arterial contrast-to-noise ratios decreased on the pelvic studies. This method was feasible and increased anatomic coverage.  相似文献   

4.
OBJECTIVE: The purpose of this study was to describe the radiologic and pathologic features of pulmonary carcinosarcoma in three patients. CONCLUSION: The tumors measured 9-14 cm in diameter, had inhomogeneous contrast enhancement, and in two cases had invaded the mediastinum or chest wall extensively. Carcinosarcomas are rare tumors that tend to be large, necrotic, enhancing, and locally invasive.  相似文献   

5.
OBJECTIVE: The purpose of this study was to review the radiologic manifestations of the hepatopulmonary syndrome. MATERIALS AND METHODS: We retrospectively reviewed clinical records, chest radiographs, 99m Tc-macroaggregated albumin (MAA) perfusion lung scans, chest CT scans, and pulmonary angiograms of 10 patients with proven hepatopulmonary syndrome. RESULTS: Chest radiographs showed basilar, medium-sized (1.5-3.0 mm) nodular or reticulonodular opacities in all cases. CT was done in eight cases and showed basilar dilatation of lung vessels with a larger than normal number of visible branches. The vascular basis for these opacities was best appreciated on conventional CT scans of 10-mm sections. No individual arteriovenous malformations were seen on CT scans. High-resolution CT scans showed no evidence of interstitial fibrosis. 99mTc-MAA perfusion lung imaging, done in seven patients, showed pulmonary arteriovenous shunting in five. Contrast echocardiography confirmed intrapulmonary shunting in these five patients. Pulmonary angiography, done in four cases, showed subtle distal vascular dilatation in two and moderate dilatation with early venous filling in two but did not reveal any individual arteriovenous malformations. CONCLUSION: Chest radiographs in hepatopulmonary syndrome usually show bibasilar nodular or reticulonodular opacities. Conventional CT shows that these opacities represent dilated lung vessels. High-resolution CT is useful in excluding pulmonary fibrosis or emphysema as the cause of these opacities. 99mTc-MMA perfusion imaging or contrast echocardiography can be used to confirm intrapulmonary arteriovenous shunting.  相似文献   

6.
BACKGROUND: The Schatzki ring is a well-known clinical and radiologic entity in adults, but is thought to be rare in childhood. Objective. To review the clinical presentations and radiologic findings of children and young adults with Schatzki rings. MATERIALS AND METHODS: A retrospective review of all barium swallow examinations done between 1990 and 1996 revealed 20 patients with Schatzki rings. RESULTS: The most frequent presenting symptoms of these patients were progressive dysphagia with solid food and acute food impaction. Radiographic findings of Schatzki rings were typical in all cases. Twelve patients had endoscopy and all had evidence of esophagitis. CONCLUSION: Schatzki rings are not rare in childhood. The patients are symptomatic, presenting with either progressive dysphagia with solids or acute food impaction. A thorough evaluation of the distal esophagus should be performed in patients with a suggestive clinical history.  相似文献   

7.
BACKGROUND: Seizures in patients with tuberous sclerosis complex (TSC) are often intractable to antiepileptic medications and searching investigation may provide evidence that surgical treatment can be considered. OBJECTIVE: To review the results of investigation and surgical therapy, a treatment modality not generally considered in patients with medically refractory seizures and TSC. METHODS: We report 18 patients (9 male) with TSC who underwent surgical treatment of medically refractory epilepsy. Twelve patients had a well-localized epileptogenic lesion and were treated by lesionectomy or focal resection. Resections were: 7 frontal, 4 temporal, 1 frontotemporal, 1 occipital, and 1 frontoparietal. Four patients underwent more than one operation. Six patients had corpus callosotomy (CC). RESULTS: Follow-up ranged from 1 month to 47 years. Outcome of the patients treated by resection was excellent in 7 (5 were seizure-free and 2 had auras only), good in 1, fair in 3, and 1 was lost to follow-up. Best outcome was obtained in patients who had focal seizures and good imaging and EEG correlation, although they might have multiple seizure types, other imaging abnormalities, and multifocal or generalized EEG findings. When there was no such correlation, CC was found to be an option as five patients had at least some improvement and only one showed no change. CONCLUSION: Surgical treatment of patients with TSC and intractable epilepsy is most effective when a single tuber or epileptogenic area can be identified as the source of seizures and resected. This may be possible even when other tubers or diffuse EEG abnormalities are present. In patients with unlocalizable epileptic abnormalities, palliation may be obtained by CC.  相似文献   

8.
Jejunogastric intussusception is a rare complication after gastric surgery and when its diagnosis is delayed a high mortality rate can be expected. This paper reports on the characteristic findings of this entity at ultrasound and CT examination. Both diagnostic procedures have a high sensitivity. Sonography is the method of first choice because the diagnosis can be made with a high grade of certainty. CT allows the differentiation of the distinct stages of the disease and the views given by CT are often more easily accepted by the surgeons.  相似文献   

9.
Hemifacial spasm: clinical findings and treatment   总被引:1,自引:0,他引:1  
Hemifacial spasm (HFS) is a peripherally induced movement disorder characterized by involuntary, unilateral, intermittent, irregular, tonic or clonic contractions of muscles innervated by the ipsilateral facial nerve. We reviewed the clinical features and response to different treatments in 158 patients (61% women) with HFS evaluated at our Movement Disorders Clinic. The mean age at onset was 48.5+/-14.1 years (range: 15-87) and the mean duration of symptoms was 11.4+/-8.5 (range: 0.5-53) years. The left side was affected in 56% instances; 5 patients had bilateral HFS. The lower lid was the most common site of the initial involvement followed by cheek and perioral region. Involuntary eye closure which interfered with vision and social embarrassment were the most common complaints. HFS was associated with trigeminal neuralgia in 5.1% of the cases and 5.7% had prior history of Bell's palsy. Although vascular abnormalities, facial nerve injury, and intracranial tumor were responsible for symptoms in some patients, most patients had no apparent etiology. Botulinum toxin type A (BTX-A) injections, used in 110 patients, provided marked to moderate improvement in 95% of patients. Seven of the 25 (28%) patients who had microvascular decompression reported permanent complications and the HFS recurred in 5 (20%). Although occasionally troublesome, HFS is generally a benign disorder that can be treated effectively with either BTX-A or microvascular decompression.  相似文献   

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11.
There is an increasing trend toward the use of indwelling central venous catheters (CVC) for maintenance hemodialysis. Although such devices are necessary in some problematic cases, the general use of CVC is worrisome. Not only may CVC prejudice the ultimate success of future permanent vascular access, but CVC also may be associated with reduced dialysis delivery and with several important complications. This review summarizes recent developments in catheter design, placement techniques, maintenance of the indwelling catheter, and complications of CVC use. Based on cumulated experience, a judicious position is taken that recognizes the place of CVC among the various access options but that favors permanent vascular access whenever feasible.  相似文献   

12.
13.
The characteristics of patients suffering from drug resistant epilepsy, including the results of the preoperative evaluation and epilepsy surgery were retrospectively analyzed in a Swedish multicenter 10-year cohort of children and adults. Altogether 152 patients (65 children and 87 adults) treated during the period 1980-1990 in three epilepsy centers were included and followed-up 2 years after surgery. Median age at onset of seizures was 4 years for the children and 12 years for the adults. A localization related epilepsy was present in 85% of the children and in 95% of the adults. The mean number of seizure types in the children was 1.7 (range 1-4) and in the adults 1.8 (range 1-4). The median monthly seizure frequency was 52 and 15 for children and adults respectively. Resective surgery was performed in 143 cases (94 temporal, 31 extratemporal, 9 multilobar and 9 major resection procedures) and palliative procedures in 16 cases (13 callosotomies and 3 stereotactic amygdalotomies). Postoperative neurological deficits were detected in 9% of the patients after temporal lobe resections and in 15% of the patients after extratemporal and multilobar resection procedures. Two years after resective surgery 53% of the children and 49% of the adults were seizure free. Another 25% of the patients had a more than 50% reduction of seizure frequency. In the postoperative non seizure free group of patients there was a negative correlation between decrease in weighted seizure severity and decrease in seizure frequency. This finding stresses the need for including other parameters than seizure frequency when evaluating the outcome of epilepsy surgery.  相似文献   

14.
This paper presents a data-driven method for the reconstruction and visualisation of curvilinear slices from three-dimensional (3D) magnetic resonance (MR) scans of the head. Visualisation of curvilinear slices, rather than standard planar slices, produces symmetrical views of the cortex and allows small abnormalities to be detected by comparing the two hemispheres of the brain. In our method, the surface defined by the upper half of the brain is used as a reference shape for curvilinear reconstructions. The brain is first segmented from the 3D scan using a 3D region growing method associated to an unsupervised threshold selection technique. The upper half of the segmented brain is then extracted and fitted by a deformable surface model. This surface is finally interactively moved by the operator in the 3D scan, to visualise the desired curvilinear slice, which is projected on the screen as a two-dimensional image. We show an application of this visualisation technique to the localisation of cerebral epileptogenic lesions. The procedure has proven efficient and handy in clinical use.  相似文献   

15.
Long-standing intractable seizures are common manifestation of cerebral gangliogliomas. There is much controversy regarding the most appropriate surgical treatment (lesionectomy vs resection of the epileptogenic cortex with the lesion) for patients with intractable epilepsy associated with gangliogliomas. We reported 2 cases, in which the favorable seizure outcome was obtained following lesionectomy alone. (Case 1) Nine-year-old female developed attack of abnormal sensation in her left upper limb followed by motor seizure in her left limbs since 5 years old. MRI revealed hyperintense tumor in the right medial frontal lobe. Chronic invasive subdural recording showed that ictal onset zone was located in the hand motor area. Following lesionectomy alone, she became free from seizures. (Case 2) Eight-year-old girl had intractable generalized seizure since 6 years old. MRI revealed a cystic tumor in the right parietal lobe. She had multiple spike foci on electroencephalography and magnetoencephalography, and intraoperative electrocorticography failed to reveal the paroxysm. Following lesionectomy, she had good relief with less than one minor seizure per 1-3 months. Thus, lesionectomy, even without resection of the epileptogenic cortex, may improve seizure outcome in patients with ganglioglioma-associated epilepsy.  相似文献   

16.
STUDY OBJECTIVE: To determine the influence of temperature and duration of cardiopulmonary bypass (CPB) on blood loss and transfusion requirements. DESIGN: Retrospective chart review. SETTING: Tertiary care, academic medical institution. MEASUREMENTS AND MAIN RESULTS: The charts of 378 patients who had undergone primary elective coronary artery bypass graft surgery were studied. Systemic perfusion of CPB had been conducted between 20 degrees C and 37 degrees C in all patients. Patient demographic, temperature during CPB, duration of CPB, blood loss, and transfusion requirements were all recorded. Hypothermic CPB patients had minor increases in requirements for transfusion of red blood cells (RBC; p = 0.01), fresh frozen plasma (FFP; p = 0.01), platelets (PLT; p = 0.003), and total (allogeneic and autologous) blood products (p < 0.001). Multivariate analysis revealed that decreased temperature after adjusting for duration was predictive of allogeneic (RBC, FFP, PLT, and cryoprecipitate) and total (allogeneic and autologous) transfusion requirements. The duration of CPB correlated with decreased temperature (r = -0.455; p < 0.0001). After adjusting for temperature, duration was only predictive of total (allogeneic and autologous) transfusion requirements. CONCLUSIONS: The institution of warm CPB has many ramifications for clinical practice. The hypothermic induced platelet dysfunction and increased duration associated with cold CPB may contribute to the minor increases in transfusion requirements. However, temperature appears to be a weak factor, neither supporting nor refuting the use of warm or cold CPB.  相似文献   

17.
We describe the radiologic findings of autoimmune pancreatitis, a rare variant of pancreatitis. The radiologic findings of autoimmune pancreatitis are pathognomonic and very different from those of ordinary types of acute or chronic pancreatitis. This condition is a new clinical entity that is effectively treated with steroid therapy. It is important to recognize the radiologic characteristics of autoimmune pancreatitis to avoid surgical resection and start steroid therapy.  相似文献   

18.
BACKGROUND: To analyse extracranial complications and basic variables in head-injury patients, such as Glasgow coma score (GCS), intracranial pressure (ICP) and cranial computerized tomography (CT), in relation to the outcome of these patients. PATIENTS AND METHODS: 64 consecutive patients (47 males and 17 females) with head injury, admitted from January 1992 to May 1994, were studied in this prospective study. Mean age was 37 +/- 18 years. Overall mortality was 23% (15/64). Student-t and Chi-square tests were used for statistical analysis, and p < 0.05 was considered statistical significant. RESULTS: Overall GCS was 7 +/- 3, survivors presenting GCS of 7.7 +/- 2.9 and non-survivors 4.7 +/- 1.5 (p = 0.04). CT were classified as follows: diffuse injury, 4 patients (7%); focal injury, 32 (53%), and mixed injury 24 (40%). Depending on the presence or absence of mesencephalic cisterns in the CT, GSC was 7.6 +/- 2.8 and 4.3 +/- 1.4, respectively (p = 0.04). Subarachnoid hemorrhage (SAH) was associated to a GCS of 6.3 +/- 2.5 and its absence to 8 +/- 3.3 (p = 0.03). The absence of mesencephalic cisterns and SAH were more frequent in the non-survivors, 72% and 32% (p = 0.01 and 0.04), respectively. ICP was recorded in 42 patients. Regarding to ICP, mortality was: 6.7% with ICP < or = 20 mmHg, 37% with ICP 21-30, 44% with ICP 31-40 and 67% with ICP > 50 mmHg (p = 0.03). Diabetes insipidus, cardiorespiratory arrest, shock, prolonged mechanical ventilation, SDRA and sepsis were the most frequent extracranial complications in non-survivors. CONCLUSIONS: There is an association between the outcome of head-injury patients with the GCS and ICP values. Absence of mesencephalic cisterns and SAH were radiologic signs of poor prognosis. Patients who died had more extracranial complications.  相似文献   

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20.
We conducted a retrospective longitudinal self-controlled study of 64 patients aged 4-19 years treated with resective surgery for partial epilepsy from 1952 to 1988. Approximately 60% of patients experienced > 95% reduction in seizure frequency, and 70% had worthwhile improvement of at least 75% reduction. Seizure relief was more frequent among patients who underwent operation after 1978, and significant differences by time period of operation were noted for those with temporal lobe excisions and patients with normal tissue histology. The region of resection and the age at treatment did not provide significant information with respect to seizure outcome. Postresection electrocorticography (ECoG) and EEG of the first postoperative year predicted later seizure outcome. Small neurologic deficits were more common among patients resected in the temporal lobe than in patients resected in the frontal lobe. Half of the patients with preoperative unilateral focal activity and a third of those with bilateral focal activity had normal EEG postoperatively. One fourth had discontinued antiepileptic drug (AED) therapy. As expected, long-term mortality was significantly higher than the mortality of the general population. Seven patients died during follow-up. Two male patients committed suicide.  相似文献   

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