Molecular epidemiological study on tetracycline resistance R plasmids in enterohaemorrhagic Escherichia coli O157:H7

Restriction patterns obtained with EcoRI and Southern hybridization were used for the differentiation of tetracycline-resistant (Tet(r)) R plasmids in enterobaemorrhagic Escherichia coli (EHEC) O157:H7 isolates from a mass outbreak at a kindergarten in Obihiro-City, Hokkaido, Japan, 1996. Two kinds of Tet(r) R plasmids of 50 and 95 kb were detected. The 50-kb plasmids were identical to each other, while the 93-kb plasmids were of three types that were very similar to each other. The tet genes of both 50- and 95-kb R plasmids were 100% identical to the tet gene of pSC101 and all plasmids hybridized to a probe for tet. Because food-origin O157 strains were sensitive to tetracycline, we concluded that such Tet(r) R-plasmids might transfer to drug-sensitive O157 strains in the infected individuals.

Postencephalitic focal retrograde amnesia after bilateral anterior temporal lobe damage

BACKGROUND

Marked retrograde amnesia with no or almost no anterograde amnesia is rare. Recently, a combination of ventrolateral prefrontal and temporopolar cortical lesions has been suggested as the cause of such isolated or focal retrograde amnesia. It is also assumed that when the right-sided cortical structures are damaged, autobiographical episodic memories are affected.

OBJECTIVE

To search for new anatomic substrates for focal retrograde amnesia.

METHODS

We performed extensive neuropsychological tests and obtained detailed neuroimages on a 43-year-old woman who showed a severe, persistent retrograde amnesia but only a limited anterograde amnesia after probable herpes simplex encephalitis.

RESULTS

Tests of autobiographical memory revealed that she had a memory loss extending back to her childhood for both semantics and incidents; however, the ability to recall specific episodes appeared much more severely impaired than the ability to recall factual information about her past. The patient also showed profound impairments in recalling public memories; however, her scores improved nearly to a control level on forced-choice recognition memory tasks, although the recall of memories for a decade just before her illness remained mildly impaired. MRI revealed focal pathologies in the temporal poles and the anterior parts of the inferotemporal lobes on both sides, predominantly on the left, with some extension to the anterior parts of the medial temporal lobes. There was additional damage to the left insular cortex and its surrounding structures but no evidence of frontal lobe damage on MRIs or cognitive tests.

CONCLUSIONS

A profound retrograde amnesia may be produced by damage to the bilateral temporal poles and anterior inferotemporal lobes in the absence of frontal lobe pathologies, and a dense and persistent episodic old memory loss can arise even with a relatively small lesion in the right anterior temporal lobe if it is combined with extensive damage to the left.

[Non-culture based laboratory diagnosis of sepsis]

Blood culture is clearly the most important diagnostic procedure for sepsis. In the majority of cases, however, it yields negative results when bacterial or fungal sepsis is strongly suspected in view of an excellent response to antibacterial or antifungal medication. This is likely because infecting microbes have already been too seriously damaged in the blood stream to grow in culture media. Therefore, various tests have been devised to detect cellular components of pathogens including endotoxin for gram-negative bacteria, (1-->3)-beta-D-glucan for fungi, a non-mannan heat-labile candida antigen, glucronoxylomannan for Cryptococcus neoformans, and galactomannan for Aspergillus. The first two tests are particularly suitable for screening purposes, because, in addition to their high sensitivity and specificity, they cover a wide range of species in each category, though not as widely as blood culture. The candida antigen detectable by Candi-Tec is probably a complex of immune-related proteins, and appears to be a poor indicator in immunocompromised hosts. Glucronoxylomannan has been established as a useful marker of cryptococcosis, whereas galactomannan, though highly specific for aspergillosis, needs a more sensitive detection system to be useful for diagnostic purposes.

[Mapping-guided focal cryoablation and endoaneurysmorrhaphy for a case of ischemic ventricular tachycardia with left ventricular aneurysm]

A 74-year-old woman admitted with exertional dyspnea. Echocardiography revealed the giant left ventricular aneurysm. In the hospital course, she fell into sustained monomorphic ventricular tachycardia. Coronary angiogram showed complete obstruction of the LAD. Left ventricular ejection fraction was 20%. The origin of tachycardia seems to be at infero-apicallateral area of LV by electrophysiology study. Because of the failure of RF energy ablation, we planned mapping-guided cryoablation, CABG and endoaneurysmorrhaphy. To prevent air embolism and myocardial ischemic damage for long aortic cross clamp, intraoperative endocardial mapping was carried out on beating heart due to continuous normothermic coronary blood perfusion (300 ml/min) from the aortic root cannula under aortic clamping. Cold crystalloid cardioplegia changed into the root cannula after EPS, focal cryoablation (-100 degrees C) was performed 3 times on cardiac arrest. Sustained VT was not inducible in the following study. CABG and endoaneurysmorrhaphy was performed on repeated cardiac arrest during single aortic clamp. Postoperative course was uneventful, and she discharged 8 weeks after the operation.

Current trends in the detection of antigenaemia, metabolites and cell wall markers for the diagnosis and therapeutic monitoring of fungal infections

There have been several recent developments in the diagnosis of fungal infections, including the production of novel antigen detection tests, the G-test, and assays for the detection of fungal metabolites. In this article we present an overview of these developments and examine the value of including these tests in clinical trials.

[Aortic regurgitation with stenosis due to congenitally bicuspid valve with fibrous band: a surgical case report]

A 62-year-old man with aortic regurgitation and stenosis underwent aortic valve replacement. Intraoperative findings showed fibrous band between the edge of the raphe and the ascending aorta. Such fibrous bands are usually observed in juvenile pure aortic valve regurgitation due to congenitally bicuspid valve with degenerative change and are related to cause aortic insufficiency. The present patient was comparatively old, and the aortic regurgitation was combined with stenosis, which revealed sclerotic change on histological examination.

Primary antiphospholipid syndrome with acute myocardial infarction recanalised by PTCA

A 20 year old man with severe chest pain was hospitalised for acute myocardial infarction. Coronary angiography revealed total obstruction of his right coronary artery, which was successfully recanalised by direct percutaneous transluminal coronary angioplasty (PTCA). There was also diffuse thrombi in the left coronary artery that was not recanalised by perfusion with 3000 U pro-urokinase. Anticoagulant therapy was performed after PTCA. Creatine kinase peaked one day after hospitalisation (4805 U/l). The activated partial thromboplastin time was 62.6 seconds (45%). Plasma anticardiolipin IgG antibodies were high (3.8 and 2.7) in repeated examinations. The PTCA site was patent after three months. Primary antiphospholipid syndrome should be considered as a cause of acute myocardial infarction in young adults, and PTCA with anticoagulant treatment is effective for initial treatment of the syndrome.

Detection of plasma (1 --> 3)-beta-D-glucan in patients with Fusarium, Trichosporon, Saccharomyces and Acremonium fungaemias

(1 --> 3)-beta-D-glucan, a characteristic fungal molecule, is known to increase in blood in invasive candidiasis, aspergillosis and cryptococcosis. This report shows that the plasma glucan concentration was also elevated in four patients infected with Fusarium, Trichosporon beigelii, Saccharomyces cerevisiae and Acremonium. In three of the patients, the elevation preceded positive blood cultures by 5-17 days, and in one of them it even preceded the onset of fever by 6 days. In a fourth patient, the glucan level decreased with clinical improvement. Plasma (1 --> 3)-beta-D-glucan determination appears to be useful also for diagnosis and follow-up of these unusual deep mycoses.

[Usefulness of transcranial magnetic stimulation in the objective assessment of therapy for adrenoleukodystrophy]

Adrenoleukodystrophy (ALD) is a hitherto untreatable, X-linked recessive disorder of the central nervous system characterized by the systemic accumulation of very-long-chain fatty acids. Although various treatments have been proposed, objective evidence of their efficacy is insufficient. This is partly due to the absence of an appropriate method for evaluating the functions of the central nervous system (CNS). In this study, we took up the central motor conduction time (CMCT) as an index of the CNS functions, and measured it in two patients with ALD under steroid pulse therapy to know if this parameter is useful in assessing the effects of therapy. The right and the left motor cortex was stimulated separately with a MAGSTIM 200 magnetic stimulator, using a round coil of 9cm mean diameter to stimulate the hand area or a double cone coil to stimulate the leg area. CMCT, the time an impulse takes to travel from the motor cortex to the anterior horn cells in the corresponding region, was measured by a combination of transcranial magnetic stimulation (TMS) and F wave technique. Before treatment, CMCT to the cervical cord was prolonged slightly in both patients; CMCT to the lumbar cord was prolonged slightly in one and moderately in the other. After repeated steroid pulse therapy, a definite improvement, although partial and transient, was observed in either case. TMS thus seems to be useful not only for detecting functional derangement of the pyramidal tract but for evaluating the efficacy of therapy for this disease.

[Acute retrograde dissection of the aorta is a formidable complication in retrograde perfusion through the femoral artery]

To avoid this complication, we applied a Nelaton catheter (Imamura, Tokyo, Japan: standard type) as a guide to insert an arterial perfusion cannula (Bardic) into the femoral artery. Initially, the Nelaton catheter is accurately placed into the femoral artery through a purse string suture without applying vascular clamps on the artery or its branches. Then the perfusion cannula is advanced using the Nelaton catheter as a guide. We believe this procedure will avoid acute retrograde dissection of the aorta since it protects the femoral artery from injuries caused by the vascular clamps or the tip of the perfusion cannula.

Differentiation of renal cell carcinomas from angiomyolipomas by ultrasonic frequency dependent attenuation

PURPOSE

We determined the usefulness of ultrasonic frequency dependent attenuation in differentiating hyperechoic renal cell carcinoma from angiomyolipoma.

MATERIALS AND METHODS

Frequency dependent attenuation values were determined in 29 renal cell carcinomas and 13 angiomyolipomas.

RESULTS

Frequency dependent attenuation values were significantly lower in renal cell carcinomas than in angiomyolipomas (0.42 versus 0.76 dB./cm./MHz.). Two of the renal cell carcinomas were as hyperechoic as the angiomyolipomas but they were clearly differentiated by the low frequency dependent attenuation. Two other renal cell carcinomas exhibited high values because of the abundance of fibrous tissue. However, they were readily diagnosed by the typical low echoic B-mode images. Frequency dependent attenuation did not differ between histological types of renal cell carcinoma. One angiomyolipoma that was poor in fat and rich in muscle components had an exceptionally low frequency dependent attenuation. Therefore, frequency dependent attenuation values can be regarded as an inversion of computerized tomography numbers.

CONCLUSIONS

Frequency dependent attenuation measurement is a promising diagnostic aid in differentiating hyperechoic renal cell carcinomas from angiomyolipomas.

[A case report of type A dissection of the aorta presenting as a superior vena cava syndrome 10 years after aortic valve replacement]

Aortic dissection usually result in chest pain and back pain. This patient is a 58 year-old man who received aortic valve replacement for aortic regurgitation 10 years ago. In this case, the patient had superior vena cava syndrome as a result of a painless aortic dissection. The superior vena cava was compressed by the ascending aorta itself, which had become very large but had not ruptured into the mediastinum. He underwent modified Carbrol's operation under hypothermic cardiopulmonary bypass and circulation arrest on May 8, 1995. Dissecting aneurysm in the late term after aortic valve replacement is rare, and for it to result in superior vena cava syndrome is especially rare.

[Hemorheological effects of autologous blood storage before surgery for cardiac valvular diseases]

The hemorheological effects of autologous blood storage with or without the use of erythropoietin were examined before surgery for valvular disease. There was no rheological difference between patients with aortic (16 cases) or mitral (10 cases) valve disease. Before storage, the levels of hematocrit, whole blood viscosity, and especially coefficient of rheology, were lower (p < 0.05) in the blood stored with erythropoietin, but this difference disappeared after storage. The plasma viscosity of both groups did not change before and after storage. The viscosity of blood was equalized after the storage of blood, irrespective of the use of erythropoietin.

[Surgical treatment of malignant hemangioendothelioma originated from the right atrium: a case report]

A 32-year-old man was admitted to our hospital because a cardiac tumor had been pointed out by a physician. CT scans showed a mass lesion with irregular patterns in the right atrium. The patient had the diagnosis of a malignant cardiac or pericardial tumor and an operation was performed. The mass originated from the right atrium included massive coagulated blood, and was resected with the pericardium and the right pleura. The histological diagnosis was malignant hemangioendothelioma. We present this case because only 35 patients with cardiac malignant hemangioendothelioma were reported in Japan.

Comparative ultrasonographic and angiographic study of carotid arterial lesions in Takayasu's arteritis

The purpose of this study was to compare the usefulness of ultrasonography to that of angiography for studying arterial lesions in Takayasu's arteritis. Ultrasonographic and angiographic findings from 44 carotid arteries of 22 patients with Takayasu's arteritis (2 men and 20 women; mean age, 41.2 years) were compared. Angiography was used to classify the patency of the carotid arteries into three groups: nonstenotic, stenotic, and occlusive. Ultrasonography was also used to classify the same arteries into four groups: nonstenotic, mildly stenotic, moderately stenotic, and occlusive. Thickness of the wall (intima-media complex) of the carotid artery was measured with high-frequency transducers. Angiography showed 23 carotid arteries to be nonstenotic; 12, stenotic; and 9, occlusive; whereas ultrasonography showed 16 to be nonstenotic; 18, mildly stenotic; 7, moderately stenotic; and 3, occlusive. Results of the two diagnostic modalities correlated closely (P < 0.0001). Ultrasonography, aided by color flow imaging, detected six instances of a marginal but definite blood flow that angiography had failed to reveal. Arterial wall thickness correlated closely with the severity of ultrasonographic stenosis (P < 0.005). This thickness was 1.3 +/- 0.4 mm in the nonstenotic group, 1.6 +/- 0.5 mm in the mildly stenotic group, 2.2 +/- 0.8 mm in the moderately stenotic group, and 1.9 +/- 0.2 mm in the occlusive group. Even the walls of the nonstenotic arteries were significantly thicker than those of the normal carotid arteries (0.7 +/- 0.1 mm, P < 0.01). Ultrasonography appeared to be more useful than angiography in estimating stenotic severity of the carotid artery in Takayasu's arteritis. Characteristic ultrasonic findings included luminal stenosis or occlusion on two-dimensional ultrasonograms, decrease in or lack of flow shown by color Doppler flow imaging, and concentric thickening of the carotid arterial walls. Ultrasonographic mural thickness was the most sensitive indicator of early, latent inflammation.

Plasma (1-->3)-beta-D-glucan assay and immunohistochemical staining of (1-->3)-beta-D-glucan in the fungal cell walls using a novel horseshoe crab protein (T-GBP) that specifically binds to (1-->3)-beta-D-glucan

A highly sensitive enzyme-linked immunosorbent assay specific to (1-->3)-beta-D-glucans (GBP-ELISA) has been developed using a novel (1-->3)-beta-D-glucan-binding protein (T-GBP), which was purified from the amebocyte lysate of the Japanese horseshoe crab, Tachypleus tridentatus. This method allowed quantitation of the glucans in a concentration range of 0.1-1,000 ng/ml, regardless of linear and branched structures, and was applied to determine the amounts of (1-->3)-beta-D-glucan in human and animal plasmas for diagnosis of fungemia. High levels of plasma glucan contents in clinical samples were found to be correlated closely with the severity of fungal infection. T-GBP was successfully utilized for indirect immunofluorescence staining of (1-->3)-beta-D-glucan in Candida albicans cell walls.

Does appropriate endurance exercise training improve cardiac function in patients with prior myocardial infarction?

OBJECTIVE

The objective of the present study was to determine whether appropriate endurance exercise training improves cardiac function in patients with prior myocardial infarction.

METHODS

Twenty-nine patients with prior myocardial infarction were divided into three groups (Group 1: control, Group 2: low-intensity training, Group 3: high-intensity training). Low and high training intensities were determined according to the gas exchange threshold of each patient. The patients in Groups 2 and 3 performed 15 min of home-based physical training safely, twice a day, 5 days a week for 2 months. Prior to and following this training, each patient performed two constant work rate tests (moderate and heavy intensity) and a symptom-limited incremental exercise test.

RESULTS

Heart rates at rest and during exercise were decreased significantly after 2 months in all three groups. Stroke volume at rest increased significantly after 2 months only in Group 3. Stroke volume after 6 min of heavy-intensity exercise increased significantly in Groups 2 and 3. However, the ejection fraction at 6 min of heavy-intensity exercise increased significantly only in Group 3. The maximal work rate attained during incremental exercise testing increased significantly in Groups 2 and 3. This parameter did not significantly change in the control group.

CONCLUSIONS

Effects of physical training on maximal exercise capacity were noted in both exercise training groups. However, improvement in cardiac function (such as stroke volume), both at rest and during exercise, was noted only in the high-intensity training group. Our results suggest that relatively high-intensity training may improve exercise capacity and cardiac function of patients with prior myocardial infarction.

[Plasma (1-->3)-beta-D-glucan determination for screening deep mycosis]

Plasma (1-->3)-beta-D-glucan determination has been developed for the diagnosis of fungemia and deep mycosis to make up for the low yield of blood culture. This method uses Factor G, a coagulation enzyme of the horseshoe crab that is highly sensitive to this glucan. Since (1 -->3)-beta-D-glucan is a characteristic fungal cell-wall constituent which is common to virtually all fungi, the method aims to screen fungal infections as a whole. This is advantageous today when new fungi are appearing one after another as a causative agent of opportunistic deep fungal infections. Plasma (1-->3)-beta-D-glucan concentrations in 60 normal individuals were less than 10pg/ml. With a cutoff value at 20pg/ml, the sensitivity of the test was 90%, and the specificity was 100%. No cases of fungal colonization showed values above the cutoff level. In addition to invasive candidiasis, aspergillosis, and cryptococcosis, trichosporonosis was also found positive with the test. Glucanemia was not associated with primary cryptococcosis, probably because the growth of the organism is checked by the competent immunity in these afebrile patients. Levels of plasma (1-->3)-beta-D-glucan were variable in aspergilloma, indicating that the disease is essentially a colonization, but that (1-->3)-beta-D-glucan may appear in the blood when cavitary walls are invaded, depending on the integrity of local or systemic immunity. In addition to being useful for diagnosis, the test is also helpful in initiating early treatment of deep mycosis with improved survival.

Diagonistic dyspraxia. Clinical characteristics, responsible lesion and possible underlying mechanism

We present three patients who showed, in addition to signs of callosal interruption, a variety of abnormal motor behaviour of the left hand dissociated from conscious volition, in the absence of pathological grasping phenomena. The abnormal movements of the left hand consisted of (i) antagonistic movements to the right; (ii) non-antagonistic, irrelevant movements to the right; (iii) symmetric movements to the right in which the left hand sometimes preceded the right, and (iv) occasional inability to move at will during a bimanual task. From these observations and a review of previous publications, we propose that, in most right-handed subjects; diagonistic dyspraxia could be defined as abnormal motor behaviour of the left hand activated by voluntary movements of the right hand. Motor phenomena similar to diagonistic dyspraxia but attributable to impulsive groping movements induced by medial frontal lobe pathology should be excluded from diagonistic dyspraxia. Comparison of MRIs of the three patients with those of five patients who developed no diagonistic dyspraxia following an infarction of the corpus callosum, with or without medial hemispheric involvement, revealed that damage to the ventral part of the posterior end of the body of the corpus callosum was crucial for the development of diagonistic dyspraxia. Since the commissural fibres between the superior parietal lobules pass through the caudal part of the body of the corpus callosum, and also since there is accumulating evidence that the human superior parietal lobule is concerned with selection of movement based on the integration of visual and/or somatosensory information, we infer that diagonistic dyspraxia is produced by a disconnection of the right superior parietal lobule from the left which is dominant for volitional control of movement in most right-handed subjects.

[Aortic regurgitation due to ruptured fibrous band in the noncoronary cusp: a case report]

A 67-year-old man with aortic regurgitation underwent aortic valve replacement with a 25 mm St. Jude Medical artificial valve. Intraoperative observation found several ruptured fibrous bands between the noncoronary cusp and sino-tubular ridge over the left noncoronary commissure. The same structure was observed at the left cusp, which were not ruptured. The ascending aorta was dilated to about 4 cm in diameter, so was wrapped with an artificial graft to prevent aneurysmal change. Pathological examination revealed chronic valvulitis and degenerative change at the aortic valve, and idiopathic medial degeneration at the aortic wall.

Mitochondrial encephalomyopathy with A to G transition of mitochondrial transfer RNA(Leu(UUR)) 3,243 presenting hypertrophic cardiomyopathy

In a 24-year-old woman with mitochondrial encephalomyopathy presenting hypertrophic cardiomyopathy, microscopical examination of myocardial biopsy specimen disclosed severe vacuolar degeneration of myocardium and aggregates of enlarged mitochondria with proliferated cristae. Limb muscle biopsy specimen showed "ragged-red fibers" light microscopically and enlarged abnormal mitochondria with markedly increased cristae ultrastructurally. Mitochondrial DNA analysis by polymerase chain reaction (PCR) revealed an A-to-G transition in the mitochondrial transfer RNA(Leu)(UUR) gene at nucleotide position 3,243 which is reported to be associated with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). However, the clinical features of this case, presenting mainly cardiac abnormalities, were not consistent with the typical MELAS.

Plasma (1-->3)-beta-D-glucan measurement in diagnosis of invasive deep mycosis and fungal febrile episodes

(1-->3)-beta-D-glucan is a characteristic fungal cell-wall constituent. To assess the clinical usefulness of this glucan in screening for invasive fungal infection or fungal febrile episodes, we measured the plasma concentration at the time of routine blood culture in 202 febrile episodes by means of factor G, a horseshoe-crab coagulation enzyme that is extremely sensitive to this polysaccharide. With a plasma cut-off value of 20 pg/mL, 37 of 41 episodes of definite fungal infections (confirmed at necropsy or by microbiology) had positive results (sensitivity 90%). All of 59 episodes of non-fungal infections, tumour fever, or collagen diseases had concentrations below the cut-off value (specificity 100%). Of 102 episodes of fever of unknown origin, 26 had plasma glucan concentrations of more than 20 pg/mL. With those 102 cases taken as non-fungal infections, the positive predictive value of the test was estimated as 59% (37/63), the negative predictive value as 97% (135/139), and the efficiency as 85% (172/202). The positive predictive value should improve if there were a sensitive gold standard that could discriminate fungal from non-fungal infections. Causative fungi included candida, aspergillus, cryptococcus, and trichosporon. Determination of plasma (1-->3)-beta-D-glucan with factor G is a highly sensitive and specific test for invasive deep mycosis and fungal febrile episodes, and will substantially benefit immunocompromised patients.