The utility of balloon enteroscopy in the diagnosis of histiocytic sarcoma of the small intestine: a case report

The diagnosis of the rare neoplasm histiocytic sarcoma (HS) relies on morphology and the presence of immunophenotypic features of histiocytic lineage. More than 57 cases, including 16 cases involving the gastrointestinal (GI) tract, have been described since the World Health Organization issued its classification system for tumors of hematopoietic and lymphoid tissue in 2001. HS is often diagnosed in its late stages, at which point the prognosis is poor. Only a small proportion of these patients can undergo surgical resection with curative intent. The present report describes how HS can be diagnosed at a stage of favorable prognosis using balloon enteroscopy (BE), thereby enabling surgical resection before the development of metastases. This strategy is reviewed in the setting of a patient with jejunal HS, followed by a discussion of data from 16 other reported cases of GI HS.

Molecular evolution of GB virus B hepatitis virus during acute resolving and persistent infections in experimentally infected tamarins

GB virus B (GBV-B) causes acute hepatitis in experimentally infected tamarins. We compared evolutionary features in acute resolving and persistent GBV-B infection. We detected no evidence of evolution in four animals with clearance during weeks 9-12, whereas three animals with clearance during weeks 13-26 had several substitutions in their polyprotein sequence. A single tamarin had long-term GBV-B viraemia; analysis of virus recovered at weeks 2, 5, 12, 20, 26, 52 and 104 demonstrated that mutations accumulated over time. Overall, the amino acid substitution rate was 3.5x10(-3) and 1.1x10(-3) substitutions per site year(-1) during weeks 1-52 and 53-104, respectively. Thus, there was a significant decrease in evolution over time, as found for hepatitis C virus. The rate of non-synonymous substitution per non-synonymous site compared with that of synonymous substitution per synonymous site decreased over time, suggesting reduction of positive selective pressure. These data demonstrate that prolonged GBV-B infection is associated with viral evolution.

Mutational analysis of the hepatitis C virus E1 glycoprotein in retroviral pseudoparticles and cell-culture-derived H77/JFH1 chimeric infectious virus particles

Cell entry by enveloped viruses is mediated by viral glycoproteins, and generally involves a short hydrophobic peptide (fusion peptide) that inserts into the cellular membrane. An internal hydrophobic domain within E1 (aa262-290) of hepatitis C virus (HCV) may function as a fusion peptide. Retrovirus-based HCV-pseudotyped viruses (HCVpp; genotype 1a) containing Ala or Pro substitutions at conserved amino acid positions within this putative fusion peptide were generated. Mutation of conserved residues significantly reduced efficiency of HCVpp entry into Huh-7 cells. The majority of amino acid substitutions appeared to disrupt necessary interactions between E1 and E2. For some mutants, reductions in HCVpp-associated E1 were associated with the incorporation of a high molecular weight, hyperglycosylated E2 that displayed decreased CD81-binding. Other entry-deficient mutants displayed normal E1E2 incorporation into pseudoparticles and normal CD81-binding, and therefore might affect viral fusion. One mutant (S283P) consistently displayed two- to threefold higher infectivity than did wild-type. Three mutations that decreased HCVpp infectivity also reduced levels of HCVcc infectious virus production. However, the S283P mutation had a different effect in the two systems as it did not increase production of infectious HCVcc. This comprehensive mutational analysis of the putative HCV fusion peptide provides insight into the role of E1 in its interaction with E2 and in HCV entry.

Psychosocial factors are independent risk factors for the development of Type 2 diabetes in Japanese workers with impaired fasting glucose and/or impaired glucose tolerance

AIMS

We prospectively studied Japanese workers with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) and analysed possible risk factors for diabetes, including psychosocial factors such as stress.

METHODS

The participants were 128 male Japanese company employees (mean age, 49.3 +/- 5.9 years) with IFG and/or IGT diagnosed by oral glucose tolerance test (OGTT). Participants were prospectively studied for 5 years with annual OGTTs. The Kaplan-Meier method and Cox's proportional hazard model were used to analyse the incidence of diabetes and the factors affecting glucose tolerance, including anthropometric, biochemical and social-psychological factors.

RESULTS

Of 128 participants, 36 (28.1%) developed diabetes and 39 (30.5%) returned to normal glucose tolerance (NGT) during a mean follow-up of 3.2 years. Independent risk factors for diabetes were night duty [hazard ratio (HR) = 5.48, P = 0.002], higher fasting plasma glucose (FPG) levels within 6.1-6.9 mmol/l (HR = 1.05, P = 0.031), stress (HR = 3.81, P = 0.037) and administrative position (HR = 12.70, P = 0.045), while independent factors associated with recovery were lower FPG levels (HR = 0.94, P = 0.017), being a white-collar worker (HR = 0.34, P = 0.033), non-smoking (HR = 0.31, P = 0.040) and lower serum alanine aminotransferase (ALT) levels (HR = 0.97, P = 0.042).

CONCLUSIONS

In addition to FPG levels at baseline, psychosocial factors (night duty, stress and administrative position) are risk factors for Type 2 diabetes, while being a white-collar worker, a non-smoker and lower serum ALT levels are factors associated with return to NGT in Japanese workers with IFG and/or IGT.

In vivo study of the HC-TN strain of hepatitis C virus recovered from a patient with fulminant hepatitis: RNA transcripts of a molecular clone (pHC-TN) are infectious in chimpanzees but not in Huh7.5 cells

Both viral and host factors are thought to influence the pathogenesis of hepatitis C virus (HCV) infection. We studied strain HC-TN (genotype 1a), which caused fulminant hepatic failure in a patient and, subsequently, severe hepatitis in a chimpanzee (CH1422), to analyze the relationship between disease severity, host immune response, viral evolution, and outcome. A second chimpanzee (CH1581) was infected from CH1422 plasma, and a third chimpanzee (CH1579) was infected from RNA transcripts of a consensus cDNA of HC-TN (pHC-TN). RNA transcripts of pHC-TN did not replicate in Huh7.5 cells, which were recently found to be susceptible to infection with another fulminant HCV strain (JFH1). The courses of viremia were similar in the three animals. However, CH1581 and CH1579 developed a less severe acute hepatitis than CH1422. CH1579 and CH1422 resolved the infection, whereas CH1581 became persistently infected. CH1579 and CH1581, despite their differing outcomes, both developed significant intrahepatic cellular immune responses, but not antibodies to the envelope glycoproteins or neutralizing antibodies, during the acute infection. We analyzed the polyprotein sequences of virus recovered at five and nine time points from CH1579 and CH1581, respectively, during the first year of follow-up. High mutation rates and high proportions of nonsynonymous mutations suggested immune pressure and positive selection in both animals. Changes were not selected until after the initial decrease in virus titers and after the development of immune responses and hepatitis. Subsequently, however, mutations emerged repeatedly in both animals. Overall, our results indicate that disease severity and outcome of acute HCV infection depend primarily on the host response.

Functional analyses of GB virus B p13 protein: development of a recombinant GB virus B hepatitis virus with a p7 protein

GB virus B (GBV-B), which infects tamarins, is the virus most closely related to hepatitis C virus (HCV). HCV has a protein (p7) that is believed to form an ion channel. It is critical for viability. In vitro studies suggest that GBV-B has an analogous but larger protein (p13). We found that substitutions of the -1 and/or -3 residues of the putative cleavage sites (amino acid 613/614 and 732/733) abolished processing in vitro and rendered an infectious GBV-B clone nonviable in tamarins. Internal cleavage was predicted at two sites (amino acid 669/670 and 681/682), and in vitro analysis indicated processing at both sites, suggesting that p13 is processed into two components (p6 and p7). Mutants with substitution at amino acid 669 or 681 were viable in vivo, but the recovered viruses had changes at amino acid 669 and 681, respectively, which restored cleavage. A mutant lacking amino acid 614-681 (p6 plus part of p7) was nonviable. However, a mutant lacking amino acid 614-669 (p6) produced high titer viremia and acute resolving hepatitis; viruses recovered from both animals lacked the deleted sequence and had no other mutations. Thus, p6 was dispensable but p7 was essential for infectivity. The availability of a recombinant GBV-B virus containing a p7 protein with similarities to the HCV p7 will enhance the relevance of this model and will be of importance for identifying compounds that inhibit p7 function as additional therapeutic agents.

Intraoperative measurement of arterial blood flow using a transit time flowmeter: monitoring of hemodynamic changes during cerebrovascular surgery

BACKGROUND

The purpose of this study was to examine the utility and reliability of arterial flow measurements made with a transit time ultrasonic flowmeter for monitoring blood flow changes during intracranial and carotid surgery.

METHOD

A total of 25 patients underwent intra-operative arterial blood flow measurements. The pulsatile flow curve and mean flow values were obtained using 1- to 6-mm transit time probes with a dual channel flowmeter. Four cases underwent aneurysm clipping, 11 cases superficial temporal artery (STA)--middle cerebral artery (MCA) bypass, 2 cases external carotid artery (ECA)--radial artery--MCA bypass for aneurysm trapping, and 8 cases carotid endarterectomy. In aneurysm clipping, blood flow in the branches distal to the aneurysm was measured before and after clipping. Blood flow in the STA was measured before and after STA-MCA anastomosis, and blood flow in the internal carotid artery (ICA) cervical portion was measured during carotid endarterectomy. Blood flow in the MCA and STA was monitored during radial artery grafting.

FINDINGS

Blood flow in the STA was elevated after STA-MCA anastomosis. However, post-operative hyperperfusion syndrome was found in some cases whose flow elevation was over 50 ml/min. Also in one case of carotid stenosis, of which blood flow of ICA was elevated to 400 ml/min after carotid endarterectomy, hyperperfusion syndrome was found after surgery. In the cases of MCA aneurysm clipping, decreasing of M2 flow was detected when clipping caused bifurcation stenosis.

INTERPRETATION

We found transit time flow measurement useful for management of cerebrovascular surgery: the technique was simple to use and provided stable, reliable results. The method was able to reveal distal branch flow diminution in aneurysm clipping, or residual flow during temporary clipping in aneurysm surgery, and has the potential to predict post-operative complications such as hyperperfusion by signalling over-elevation of donor artery flow in bypass surgery or ICA flow in carotid surgery.

[The present studies of the development of HCV vaccine]

After isolation of a hepatitis C virus genome in 1989, all donated blood samples have been analyzed by a sensitive screening system, which brought us 'safety transfusion' (free from HCV). However it is likely that about 170 million people around the world, more than 2 million people in Japan have already infected with HCV. Despite the numerous efforts, the lack of efficient cell culture system makes it difficult to develop HCV vaccine. Some novel strategies are engineered day by day that might be useful tools. Hereafter we must clarify the mechanisms of replication and infection in depth, to develop a vaccine that clear HCV from carrier.

Low-intensity pulsed ultrasound initiates bone healing in rat nonunion fracture model

Low-intensity pulsed ultrasound exposure has been shown clinically to shorten the fracture repair process and to induce healing of nonunions in humans, but its mechanism of action remains unclear. In this study we investigated the effect and mechanism of low-intensity pulsed ultrasound on nonunion fracture healing in rat tibias. A consistently reproducible nonunion was produced in rat tibias by muscle interposition without osteotomy. This model was produced by creating a closed tibial fracture with only the distal end of the tibialis anterior muscle interposed into the fracture site. One limb was noninvasively exposed to low-intensity pulsed ultrasound (a 200-millisecond burst of sine waves of 1.5 MHz, repeating at 1.0 kHz) for 20 minutes daily. The incident intensity was approximately 30 mW/cm2. Rats were killed at intervals between 2 and 6 weeks. The events were assessed by radiographs, microfocus X-ray computed tomograms, and histologic examination. After 6 weeks of exposure, 7 of 14 nonunion fractures showed healing on radiologic assessment. The results of three-dimensional microfocus X-ray computed tomographic reconstruction and histologic examination also supported this finding. On the other hand, all control tibias remained in a state of nonunion during the same period. These results indicate that low-intensity pulsed ultrasound promotes healing in the rat nonunion fracture model.

Cell fusion activity of hepatitis C virus envelope proteins

To examine the cell fusion activity of hepatitis C virus (HCV) envelope proteins (E1 and E2), we have established a sensitive cell fusion assay based on the activation of a reporter gene as described previously (O. Nussbaum, C. C. Broder, and E. A. Berger, J. Virol. 68:5411-5422, 1994). The chimeric HCV E1 and E2 proteins, each consisting of the ectodomain of the E1 and E2 envelope protein and the transmembrane and cytoplasmic domains of the vesicular stomatitis virus G glycoprotein, were expressed on the cell surface. Cells expressing the chimeric envelope proteins and T7 RNA polymerase were cocultured with the various target cell lines transfected with a reporter plasmid encoding the luciferase gene under the control of the T7 promoter. After cocultivation, the cell fusion activity was determined by the expression of luciferase in the cocultured cells. The induction of cell fusion requires both the chimeric E1 and E2 proteins and occurs in a low-pH-dependent manner. Although it has been shown that HCV E2 protein binds human CD81 (P. Pileri, Y. Uematsu, S. Campagnoli, G. Galli, F. Falugi, R. Petracca, A. J. Weiner, M. Houghton, D. Rosa, G. Grandi, and S. Abrignani, Science 282:938-941, 1998), the expression of human CD81 alone is not sufficient to confer susceptibility to cell fusion in the mouse cell line. Treatment of the target cells with pronase, heparinase, or heparitinase reduced the cell fusion activity induced by the chimeric envelope proteins. These results suggest (i) that both HCV E1 and E2 proteins are responsible for fusion with the endosomal membrane after endocytosis and (ii) that certain protein molecules other than human CD81 and some glycosaminoglycans on the cell surface are also involved in the cell fusion induced by HCV.

Intra-operative premature rupture of the cerebral aneurysms. Analysis of the causes and management

The causes and management of intra-operative premature rupture are analysed and discussed. During the past 6 years, the authors, performed 398 consecutive direct surgical interventions for ruptured cerebral aneurysms. Intra-operative premature rupture is defined as a rupture which occurs before the securing of the parent arteries or the neck of the aneurysm and is out of control, at least temporarily. The causes and management were retrospectively analyzed by reviewing video tape recordings. Intra-operative premature ruptures which met the above definition occurred in 24 cases (6.0%). The causes were as follows: 1.) dural opening and arachnoid opening (8.3%), 2.) haematoma removal (12.5%), 3.) brain retraction (16.7%), 4.) aneurysm dissection (62.5%). A double suction technique was used to control bleeding and haemostasis with a small piece of cotton or a temporary clip, performed in 20 cases (83.3%). However, in cases with premature rupture immediately after the dural or arachnoid opening, the extension of the haematoma into the subarachnoid space resulted in severe brain swelling and partial resection of the brain had to be done to secure temporary clipping. The double suction technique and primary haemostasis using a small piece of cotton or temporary clip resulted in good outcome even in cases with premature rupture. However, very early premature rupture also occurred although its incidence was extremely rare. The removal of part of the brain can secure the working space but the outcome was poor.

[Digital recording in neurosurgery]

The purpose of this study is to examine the image quality of multi-media for digital recording of surgical procedure using an operating microscope in neurosurgery. For video recording, high vision recording, digital video recording and analogue VHS recording were used. For still pictures, an analogue camera with 35 mm silver halide film and a micro-digital camera were used. The quality of photographs taken with a microdigital camera was superior to the quality of those taken with the conventional 35 mm film camera. The micro-digital camera system is superior to the conventional 35 mm camera in neurosurgery in its quality and success rate. In video recording, high vision analogue recording was superior to any other media as far as its image quality is concerned although its practical convenience is limited and cost performance is not always good. On the other hand, digital video can record high quality images, including still pictures, with satisfactory quality to the neurosurgeon. These digital recording media are also space saving for storing the huge amount of data obtained during surgery and the cost-performance is superior to that of the conventional method. In the near future, most of surgical procedures are supposed to be expected using digital media.

[Validation and optimization of the use of standardized arterial input function in N-isopropyl-p[123I]iodoamphetamine cerebral blood flow SPECT]

Use of a standardized arterial input function and calibrating it by a single blood sample has been proposed to assess quantitatively cerebral blood flow using N-isopropyl-p[123I]iodoamphetamine (IMP) and single-photon emission computed tomography. This study was intended to validate this approach using a larger number of measured arterial radioactivity curves in the clinical setting.

METHOD

Arterial input function was measured for 50 patients at rest following the i.v. IMP, and its inter-subject variation was assessed. Difference between smokers and non-smokers in addition to effects of acetazolamide administration were particularly investigated. We also evaluated the accuracy of the calibration procedures by means of either a single blood sample or a continuous arterial blood withdrawal sampling for an early period.

RESULTS

Inter-subject variation of the observed arterial input function appeared not to show large variations among the 50 patients, thus suggesting the validity of using the standardized arterial input function for the IMP SPECT study. There was a significant difference in the shape of the arterial input function between the smokers and non-smokers, but the calibration at an optimized sampling time provided the area-under-the curve (AUC) that was not significantly different between the two groups. The arterial input function after the acetazolamide showed no significant difference as compared with the shape at rest. The calibration of the standardized input function by means of the early integration of individual curve did not show better accuracy except for a short period of AUC (i.e., < 20 min) for longer integration period > 10 min.

CONCLUSION

Thus, use of the standardized arterial input function has been validated for the IMP SPECT study. The single blood sampling procedure for calibrating the standardized input function has also been validated, and has been shown to provide better accuracy compared with the continuous withdrawal procedure.

Quantitative brain FDG/PET studies using dynamic aortic imaging

Positron emission tomography (PET) measurements of cerebral glucose utilization using 18F-fluorodeoxyglucose (FDG) are a useful tool in the investigation of localized brain function in normal and disease states. A major impediment to the application of FDG/PET in clinical investigation has been the need for arterial blood sampling to quantify cerebral glucose metabolism (CMRGlc). Qualitative studies, though informative in a variety of clinical settings, are of limited value for research applications and do not utilize the inherent quantitative nature of PET. We present a novel PET technique employing a whole-body PET tomograph with abdominal aortic imaging from 0 to 30 min as an alternative to arterial blood sampling to obtain the input function for cerebral metabolic rate calculations. Two or three arterial samples taken during the 10-45 min period were used to scale and extend the blood curve and the brain was imaged from 35-55 min post-injection. We performed 12 studies in which both arterial blood sampling and aortic scans were obtained. We found the correlation of global metabolic rates (GMR) when comparing the two techniques to be extremely high (R2 = 0.99). This suggests that the use of dynamic aortic imaging is less invasive and a viable alternative to arterial blood sampling in quantitative FDG/PET imaging.

Bladder wall radiation dose in humans from fluorine-18-FDOPA

PET, in conjunction with 18F-fluorodopa (FDOPA), has become the standard technique to assess basal ganglia degeneration in patients with movement disorders. Based on published dosimetry data, the injected dose of FDOPA is limited to 111 Mbq (3 mCi) because of exposure to the bladder wall, which is the critical organ for such studies. These dosimetry studies are based on mathematical models for the bladder radioactivity accumulation and clearance when the subjects were asked to void approximately 2 hr after the intravenous injection of FDOPA. In this study, we improved the radiation dose estimate to the bladder wall using dynamic PET to image the bladder during the uptake phase as well as before and after voiding.

METHODS

The subjects were tested on a new protocol. They were hydrated preinjection and given a first bladder void break at 40 min postinjection and a second void at the end of study at 120 min.

RESULTS

The MIRD model, applied to the data collected from 10 adults of both sexes, yielded an average absorbed dose of 0.15 +/- 0.08 mGy/MBq (0.57 +/- 0.28 rad/mCi).

CONCLUSION

This absorbed dose is significantly lower than previous estimates and allows for FDOPA injections up to 333 Mbq (9 mCi).

Discovery of a new tetrahydrobiopterin-synthesizing enzyme in the lemon mutant of the silkworm Bombyx mori

A new tetrahydrobiopterin-synthesizing enzyme, which is different from sepiapterin reductase (EC 1.1.1.153), was discovered in the integument of the lemon mutant of the silkworm Bombyx mori. This enzyme converted 6-pyruvoyltetrahydropterin to tetrahydrobiopterin, an essential cofactor in the hydroxylation of aromatic amino acids, in the presence of NADPH. The reaction proceeded via 6-lactoyltetrahydropterin and 1'-hydroxy-2'-oxopropyltetrahydropterin as intermediates. The molecular mass of this enzyme was estimated to be 40 kDa. N-Acetylserotonin, a potent inhibitor of sepiapterin reductase, slightly inhibited the enzymatic reaction. In the presence of 0.5 mM N-acetylserotonin, the formation of tetrahydrobiopterin by sepiapterin reductase purified from the normal strain silkworm was completely inhibited. However, the formation of tetrahydrobiopterin by the enzyme purified from the lemon mutant was inhibited by only about 50%. These results suggest an alternative biosynthetic pathway to tetrahydrobiopterin.

Cerebral metabolic topography in unilateral temporal lobe epilepsy

OBJECTIVE

Fluorodeoxyglucose positron emission tomography (FDG-PET) studies of temporal lobe epilepsy (TLE) generally report interictal hypometabolism in the vicinity of the seizure focus. Yet, other evidence suggests that interictal metabolic abnormalities might extend to remote brain areas. We used FDG-PET to evaluate metabolism in selected regions distant from the focus in TLE.

SUBJECTS

Twenty adult patients with medically intractable TLE were selected by criteria favoring a unilateral mesiobasal temporal focus. Structural imaging in this sample were normal except for medial temporal sclerosis in 13 patients. Twenty normal volunteers were controls.

DESIGN

PET imaging was performed interictally. Regional glucose metabolism normalized by global metabolism was analyzed using t tests and correlation analysis.

RESULTS

Ipsilateral to the seizure focus, metabolism was depressed compared with normal in the temporal pole (p = 0.001), but relatively elevated in the mesiobasal region (p = 0.005). Contralateral to the focus, metabolism was elevated in lateral temporal cortex (p = 0.0003) and mesiobasal regions (p = 0.0001). Metabolic correlation between ipsilateral and contralateral mesiobasal regions was similar in normal subjects (r = 0.74) and patients (r = 0.68). In contrast, correlations were abnormal between temporal poles and other temporal lobe subregions, both ipsilateral and contralateral to the seizure focus.

CONCLUSIONS

Relative to normal values, both elevations and depressions of metabolism exist interictally in TLE. Such abnormalities, and accompanying changes in interregional correlations, may have wide spatial distribution. These findings are atypical among PET studies but are consistent with other physiologic, anatomic, and neuropsychological investigations of TLE.

[Pharmacokinetics of transbronchially injected flconazole in pulmonary aspergillosis]

A 68-year-old woman had a pulmonary aspergilloma in the left upper lobe, with old cavitary pulmonary tuberculosis. Surgery was not possible because of marginal ventilation, and the patient was treated by transbronchial injection of Fulconazole. After five injections of 50 mg of Fulconazole, the fungus ball had decreased in size. To study the pharmacokinetics of Fulconazole after transbronchial injection, its concentration in serum was measured. The values of serum Fulconazole concentration were 0.7 microgram/ml at 1 h, 0.8 microgram/ml at 4 h, 0.8 microgram/ml at 8 h, 0.7 microgram/ml at 12 h, 0.7 microgram/ml at 24 h, and 0 microgram/ml at 48 h after transbronchial injection. These results indicate that Fulconazole was absorbed well. Furthermore, these values are equal to those obtained after intravenous administration of 50 mg and are higher than those obtained after intravenous administration of 25 mg. Fulconazole may have been absorbed via the bronchial epithelium, because of destruction of alveoli, connective tissue proliferation in the cavitary wall and secondary bronchiectasis.

Anatomic and physiological considerations in pallidotomy for Parkinson's disease

Our ongoing study of ventral pallidotomy for the control of Parkinson's disease in selected patients has provided the opportunity to explore the topographical and somatotopic organization of the human globus pallidus. Utilizing microelectrode techniques we have obtained recordings which were correlated with data from MPTP-parkinsonian primates. In addition, we performed pre- and post-operative FDG/PET scans in these patients. Our studies reveal similarities between the MPTP-parkinsonian primate model and human Parkinson's disease in terms of physiologic recordings and responses. However, we have encountered significant differences between dominant and non-dominant hemisphere representations, particularly for the hand, in the human. In addition, our PET studies confirmed, as in previous parkinsonian primate models, glucose hypermetabolism in the lenticular area of Parkinson's disease patients. This hypermetabolism is dramatically altered by creation of a lesion in the globus pallidus medialis. This is demonstrated by follow-up PET scans which reveal not only a decrease in metabolism of the operated lenticular region, but also in the frontal cortical projections. These combined observations of the cellular activity in the globus pallidus and the observed changes in PET metabolism support the selection of the pallidum for lesioning and control of Parkinson's disease, and offer insight into the underlying physiology of this disorder. The above physiological and PET data will be clinically correlated with our ongoing series of 35+ patients.

Metabolic topography of the hemiparkinsonism-hemiatrophy syndrome

We estimated regional and global metabolic rates for glucose using 18F-fluorodeoxyglucose (FDG) and PET in six patients with hemiparkinsonism-hemiatrophy syndrome (HPHA; mean age, 41.0 +/- 12.4 years). We used 18F-fluorodopa (FDOPA) and PET in two patients to quantify presynaptic nigrostriatal dopaminergic function. We compared measures of brain glucose metabolism and striatal FDOPA uptake with those calculated for 10 age-matched normal volunteers (mean age, 35.1 +/- 8.0 years) and 10 patients with typical unilateral Parkinson's disease (unilat-PD; mean age, 58.2 +/- 13.8 years). All six HPHA patients demonstrated significant metabolic reductions (> 3 SD) in the contralateral basal ganglia or frontal cortex as compared with normal control values. Mean normalized glucose metabolism was reduced in the contralateral caudate and lentiform nuclei (p < 0.005) as compared with that in unilat-PD and normal controls. In both patients studied with FDOPA, contralateral striatal uptake was significantly reduced (> 3 SD) as compared with normal control values. These results suggest that the clinical manifestations of HPHA arise through a combination of pre- and postsynaptic nigrostriatal dopaminergic dysfunction. FDG and PET may be useful in differentiating this disorder from typical unilat-PD.

The metabolic topography of parkinsonism

We used [18F]fluorodeoxyglucose/positron emission tomography (18F-FDG/PET) and a statistical model of regional covariation to study brain topographic organization in parkinsonism. We studied 22 patients with Parkinson's disease (PD), 20 age-matched normal volunteers, and 10 age- and severity-matched patients with presumed striatonigral degeneration (SND). We used FDG/PET to calculate global, regional, and normalized metabolic rates for glucose (GMR, rCMRglc, rCMRglc/GMR). Metabolic parameters in the three groups were compared using an analysis of variance, with a correction for multiple comparisons, and discriminant analysis. The scaled subprofile model (SSM) was applied to the combined rCMRglc dataset to identify topographic covariance profiles that distinguish PD patients from SND patients and normals. GMR, rCMRglc, and rCMRglc/GMR were normal in PD; caudate and lentiform rCMRglc/GMR was reduced in the SND group (p < 0.01). SSM analysis of the combined group of patients and normals revealed a significant topographic profile characterized by increased metabolic activity in the lentiform nucleus and thalamus associated with decreased activity in the lateral frontal, paracentral, inferior parietal, and parietooccipital areas. Individual subject scores for this profile were significantly elevated in PD patients compared with normals and SND patients (p < 0.001) and discriminated the three groups. In the PD group, subject scores for this factor correlated with individual subject Hoehn and Yahr (H & Y) scores (p < 0.02), and with quantitative rigidity (p < 0.01) and bradykinesia (p < 0.03) ratings, but not with tremor ratings. SSM analysis of right-left metabolic asymmetries yielded a topographic contrast profile that accurately discriminated mildly affected PD patients (H & Y Stage I) from normals. Our findings demonstrate that abnormal topographic covariance profiles exist in parkinsonism. These profiles have potential clinical application as neuroimaging markers in parkinsonism.

Input functions for 6-[fluorine-18]fluorodopa quantitation in parkinsonism: comparative studies and clinical correlations

PET has been used to quantify striatal 6-[18F]fluoro-L-dopa (FDOPA) uptake as a measure of presynaptic dopaminergic function. Striatal FDOPA uptake rate constants (Ki) can be calculated using dynamic PET imaging with measurements of the plasma FDOPA input function determined either directly or by several estimation procedures.

METHODS

We assessed the comparative clinical utility of these methods by calculating the striato-occipital ratio (SOR) and striatal Ki values in 12 patients with mild to moderate PD and 12 age-matched normal volunteers. The plasma FDOPA time-activity curve (KiFD); the plasma 18F time-activity curve (KiP); the occipital time-activity curve (KiOCC); and a simplified population-derived FDOPA input function (KiEFD) were used to calculate striatal Ki.

RESULTS

Mean values for all striatal Ki estimates and SOR were significantly lower in the PD group. Although all measured parameters discriminated PD patients from normals, KiFD and KiEFD provided the best between-group separation. KiFD, KiEFD and KiOCC measures correlated significantly with quantitative disease severity ratings, although KiFD predicted quantitative clinical disability most accurately.

CONCLUSION

These results suggest that KiFD may be an optimal marker of the parkinsonian disease process. KiEFD may be a useful alternative to KiFD for most clinical research applications.

Impaired biliary excretion of copper and lysosomal enzymes in Long-Evans cinnamon

Although impaired biliary excretion of copper through hepatocyte lysosomes has been postulated as a pathogenesis of Wilson's disease, direct evidence has been lacking. Our aim was to investigate the dynamics of biliary excretion of copper and lysosomal enzymes in the Long-Evans Cinnamon (LEC) rat, a recently established rodent model of Wilson's disease. Liver homogenate and bile were obtained from 12 week-old LEC rats (n = 7), Long-Evans Agouti rats (n = 3) and Sprague-Dawley rats (n = 8) and analyzed for copper and lysosomal enzymes. Structural integrity of hepatic lysosomes was assessed by the latency of N-acetyl-beta-glucosaminidase. Compared with the controls, LEC rats exhibited a 43-fold increase in hepatic copper concentration (p < 0.001), a significant increase in hepatic activities of lysosomal enzymes (p < 0.001) and reduction of lysosomal latency (p < 0.05). In contrast, biliary excretion of copper and lysosomal enzymes were significantly impaired in LEC rats (p < 0.05). These results suggest a coupled alteration between copper and lysosomal enzymes in both the liver and bile of LEC rats (i.e., increase in liver and decrease in bile). Defective biliary excretion of copper via hepatocyte lysosomes may play a role in part in spontaneous copper accumulation in LEC rats.

Anatomic and physiological considerations in pallidotomy for Parkinson's disease

Our ongoing study of central pallidotomy for the control of Parkison's disease in selected patients has provided the opportunity to explore the topographical and somatotopic organization of the human globus pallidus. Utilizing microelectrode techniques we have obtained recordings which were correlated with data from MPTP-parkinsonian primates. In addition, we performed pre- and postoperative FDG/PET scans in these patients. Our studies reveal similarities between the MPTP-parkisonian primate model and human Parkinson's disease in terms of physiological recordings and responses. However, we have encountered significant differences between dominant and nondominant hemisphere representations, particularly for the hand, in the human. In addition, our PET studies confirmed, as in previous parkinsonian primate models, glucose hypermetabolism in the lenticular area of Parkinson's disease patients. This hypermetabolism is dramatically altered by creation of a lesion in the globus pallidus medialis. This is demonstrated by follow-up PET scans which reveal not only a decrease in metabolism of the operated lenticular region, but also in the frontal cortical projections. These combined observations of the cellular activity in globus pallidus and the observed changes in PET metabolism support the selection of the pallidum for lesioning and control of Parkinson's disease, and offer insight into the underlying physiology of this disorder. The above physiological and PET data will be clinically correlated with our ongoing series of 35+ patients.

Striatal 18F-dopa uptake: absence of an aging effect

L-[18F]6-Fluoro-DOPA (L-[18F]6-fluoro-3,4-dihydroxyphenylalanine; FDOPA) has been used with quantitative positron emission tomography (PET) to assess presynaptic nigrostriatal dopaminergic function in life. The relationship of estimated kinetic rate constants for striatal FDOPA uptake [Ki(FDOPA)] to the normal aging process has been the subject of conflicting reports. Resolution of this issue has been hampered by methodological differences in previous FDOPA/PET investigations. We studied 19 healthy normal subjects (aged 27-77 years) and measured striatal Ki-(FDOPA) according to each of the earlier methods. While significant correlations (p < 0.005) existed between Ki(FDOPA) values estimated by the various techniques, none correlated with normal aging. We conclude that normal striatal Ki(FDOPA) values estimated using quantitative FDOPA/PET are uncorrelated with the aging process.

Positron emission tomographic findings in Filipino X-linked dystonia-parkinsonism

Regional and global metabolic rates for glucose (rCMRGlc and GMR) were estimated using [18F]fluorodeoxyglucose and positron emission tomography in 3 patients with Filipino X-linked dystonia-parkinsonism (lubag). In all 3 patients a selective reduction in normalized striatal glucose metabolism (rCMRGlc/GMR) was observed compared with 15 normal volunteer subjects. Presynaptic nigrostriatal function was assessed in these patients using [18F]fluorodopa and positron emission tomography. Striatal rate constants for [18F]flurodopa uptake were found to be in the normal range in all 3 patients with lubag. These findings suggest that the extrapyramidal manifestations of lubag are metabolically localized to the striatum and that clinical parkinsonism in these patients may be secondary to extranigral factors.

Noninvasive quantitative fluorodeoxyglucose PET studies with an estimated input function derived from a population-based arterial blood curve

The authors have developed a technique to estimate input functions from a population-based arterial blood curve in positron emission tomography (PET) studies with fluorine-18 fluorodeoxyglucose (FDG). A standardized pump injection was used in 34 subjects. A population-based blood curve was generated based on the first 10 subjects. In the remaining 24 subjects, an estimated input function (EIFa) was obtained by scaling the population-based curve with two arterial blood samples, one obtained at 10 minutes and the other at 45. Time integrals for EIFa and the real arterial input function (RIF) were in excellent agreement (r = .998, P < .0001). Cerebral metabolic rates for glucose calculated with EIFa and RIF and the autoradiographic method also correlated excellently (r = .992, P < .0001). Analogous correlations were achieved with arterialized venous samples as scaling factors. These results suggest that individually scaled, population-derived input functions may serve as an adequate alternative to continuous arterial blood sampling in quantitative FDG-PET imaging.

Striatal hypometabolism distinguishes striatonigral degeneration from Parkinson's disease

Regional and global metabolic rates for glucose were estimated using 18F-fluorodeoxyglucose and positron emission tomography in 10 patients with a clinical likelihood of striatonigral degeneration (2 men and 8 women; mean age, 61.8 +/- 6.9 years; mean disease duration, 4.7 +/- 2.2 years; mean Hoehn and Yahr score, 3.5 +/- 0.8). Measures of brain glucose metabolism in these patients were compared with those for 10 age-matched normal volunteers, 10 disease severity-matched patients with Parkinson's disease (PD), and 10 disease duration-matched patients with PD. Normalized glucose metabolism was significantly reduced in the caudate (p < 0.03) and putamen (p < 0.003) as compared with that in normal and PD control subjects, and discriminated patients with striatonigral degeneration from control subjects (p < 0.002). Putamenal hypometabolism in patients with striatonigral degeneration correlated significantly with quantitative ratings of motor disability (p < 0.02). These results suggest that quantitative 18F-fluorodeoxyglucose positron emission tomography techniques may be useful in supporting a diagnosis of striatonigral degeneration in life, and in objectively assessing disease severity and potential therapeutic interventions.

Pteridines in the yellow-colored chromatophores of the isopod, Armadillidium vulgare

Biochemical analyses of the dorsal integument of the isopod, Armadillidium vulgare, revealed that sepiapterin, biopterin, pterin, isoxanthopterin and uric acid accumulated in the yellow-colored chromatophores which are distinguishable from ommochrome chromatophores. The pattern of the yellow-colored chromatophores in the female is externally observable at the dorsal surface of the integument as yellow markings. In contrast, the yellow-colored chromatophores are not externally observable in the male, since they are covered by an ommochrome chromatophore layer. The content of both sepiapterin and biopterin in the male chromatophores was about two times greater than that in the female. The yellow-colored chromatophores were observable by light microscopy as pigmented granules. Electron microscopy showed that morphological properties of the granules were similar to those of pteridine granules which contain uric acid occurring in the silkworm integument. These facts indicate that both pteridines and uric acid in the integument of A. vulgare are localized in the pigmented granules of the yellow-colored chromatophores.

Proximal clipping and bypass between bilateral vertebral arteries using a radial arterial graft for the treatment of a dissecting aneurysm of the vertebral artery

Proximal clipping has been performed recently as the main surgical treatment for a dissecting aneurysm of the vertebral artery. When there is a contralateral vertebral artery of a smaller size with arteriosclerotic changes, some form of bypass to prevent cerebellar and brain stem infarction is needed in addition to proximal clipping. We treated a 50-year-old man with a ruptured dissecting aneurysm of the left vertebral artery and stenosis at the V3 segment of the right vertebral artery. The caliber of the right vertebral artery was smaller than the left. After an anastomosis between bilateral vertebral arteries using a radial arterial graft, dissecting aneurysm was clipped at the proximal portion of the aneurysm.

[Neurological deterioration due to cerebral hyperperfusion following carotid endarterectomy. Case report]

Recently attention has been drawn to postoperative cerebral hyperperfusion after carotid endarterectomy (CEA) associated with a preoperative state of impaired cerebral hemodynamics. Rarely postoperative neurological deficits are caused by cerebral edema due to hyperperfusion. The patient was a 65-year-old male with dysarthria and right hemiparesis. Because of the presence of severe stenosis of the left carotid artery, CEA was performed. On the 6th postoperative day, he developed severe right hemiparesis and aphasia due to cerebral edema in the subcortical region of the left cerebral hemisphere. Left carotid angiography showed normal circulation without evidence of the carotid stenosis. Later the cerebral edema and the neurological deficits gradually disappeared.

[Usefulness of MRI in the diagnosis of spontaneous hematomyelia; a case of intramedullary cavernous hemangioma]

Recent improvement of MRI has enabled us to clearly visualize intramedullary spinal lesions which previously could not be recognized by CT scan or myelography. We reported a case of hematomyelia caused by intramedullary cavernous hemangioma. In this case, MRI was very useful in efforts to recognize the lesions. With the use of MRI, we will be able to accurately ascertain the location and characteristics of intramedullary spinal lesions. The number of surgically treated cases of idiopathic hematomyelia will increase in the future.

[Vertebral dissecting aneurysm treated with trapping and bilateral posterior inferior cerebellar artery side-to side anastomosis; case report]

A case is reported of ruptured dissecting aneurysm of the intracranial vertebral artery (VA) operated on with VA trapping and bilateral posterior inferior cerebellar artery (PICA) side-to-side anastomosis. A 42-year-old male suddenly developed severe headache and vomiting. On admission, 3 hours later, he was in a state of moderate confusion (Japan Coma Scale 3) and had neck stiffness. Computed tomography (CT) revealed diffuse subarachnoid hemorrhage, especially thick in the posterior fossa with right side dominance. Right vertebral angiography disclosed a fusiform dilatation with proximal narrowing of the right VA which originated just proximal to the VA-PICA junction. Lateral suboccipital craniectomy was undertaken with the patient in a left park bench position. Right VA was dilated and discolored black, and right PICA arose from the proximal portion of this aneurysmal dilatation. Since it was impossible to clip the VA distal to the PICA for the proximal clip-occlusion, the VA including the VA-PICA junction was trapped. Considering the risk of developing infarction at the PICA territory, bilateral PICA was anastomosed at their posterior medullary segment in a side-to-side fashion because the occipital artery (OA) had been cut at the skin incision and could not be used for the OA-PICA anastomosis. The postoperative course was benign, but a mild lateral medullary syndrome developed. CT revealed no abnormal low density area and left vertebral angiography demonstrated the patency of the bypass. Thereafter, the deficit subsided gradually and the patient was discharged. He is presently working without neurological deficit.(ABSTRACT TRUNCATED AT 250 WORDS)

[A case report: intraspinal canal osteochondroma at the cervicothoracic junction causing spinal cord compression]

Osteochondromas are one of the most common benign tumors. They typically develop on long, tubular bones, only rarely compressing the spinal cord. We report the case of a 9-year-old boy who suffered paraparesis secondary to a cervical osteochondroma based at the vertebral body. The tumor was removed using laminectomy. CT scanning, plain X-ray films, and MR imaging were used in the preoperative assessment of the lesion and the operative method.

[Complete occlusion of right middle cerebral artery by radiation therapy after removal of pituitary adenoma: case report]

Radiation angiopathy is a well-known complication accompanying irradiation. But the majority of effected vessels are small vessels. Cases of intracranial major arteries being effected are not so numerous. We report the case of a 47-year-old female patient. The removal of pituitary adenoma was carried out on her in 1982. After that, 4500rad irradiation was performed. It was about six years after irradiation that the first angiography was made. Right MCA occlusion, multiple stenosis of both ACAs and Moya-Moya like vessels were discovered. On admission light paresis on her left lower extremity was recognized and hyperlipidemia was noted. It was interesting that the multiple stenosis was found in an area outside the irradiation field. MCA-STA anastomosis was performed and the prognosis was good. The authors described this case and reviewed the pertinent literature.

Hemodynamic evaluation of vascular reconstructive surgery for childhood moyamoya disease using single photon emission computed tomography

To evaluate the efficacy of vascular reconstructive surgery for childhood moyamoya disease, the cerebral blood flow (CBF) in 31 hemispheres of 16 patients was examined by single photon emission computed tomography (SPECT) using the 133Xe inhalation method. Results were divided into two groups; 17 hemispheres with superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis [A(+) group] and 14 hemispheres without anastomosis [A(-) group]. The mean hemispheric CBF (mCBF) and regional CBF (rCBF) in the frontal, temporal, occipital, and basal ganglia regions were calculated. Pre- and postoperative SPECT on the 10 hemispheres of the A(+) group showed an increase in mCBF in 6 hemispheres, the disappearance of the low perfusion area (LPA) in all 5 hemispheres where LPA was present before surgery, and an improvement in rCBF distribution (an increase in rCBF in the frontal and temporal lobes and a decrease in the basal ganglia). This suggests that vascular reconstruction is greatly effective in treating this disease. A comparison between the A(+) group and the A(-) group by postoperative SPECT, as well as the clinical outcomes and the postoperative findings of electroencephalography and angiography, revealed that the A(+) group was superior to the A(-) group in the frequency of LPA (12% and 43%, respectively) and rCBF in the frontal region where STA-MCA anastomosis was usually performed. These results indicate that STA-MCA anastomosis with indirect synangiosis is the most effective treatment of childhood moyamoya disease.

Biosynthesis of tetrahydrobiopterin. Purification and characterization of 6-pyruvoyl-tetrahydropterin synthase from human liver

6-Pyruvoyl-tetrahydropterin synthase, which catalyzes the first step in the conversion of 7,8-dihydroneopterin triphosphate to tetrahydrobiopterin, was purified approximately 140,000-fold to apparent homogeneity from human liver. The molecular mass of the enzyme is estimated to be 83 kDa. 7,8-Dihydroneopterin triphosphate was a substrate of the enzyme in the presence of Mg2+, and the pH optimum of the reaction was 7.5 in Tris HCl buffer. The Km value for 7,8-dihydroneopterin triphosphate was 10 microM. The product of this enzymatic reaction was the presumed intermediate 6-pyruvoyl-tetrahydropterin. This latter compound was converted to tetrahydrobiopterin in the presence of NADPH and partially purified sepiapterin reductase from human liver. The conditions and the effect of N-acetylserotonin on this reaction, and on the formation of the intermediates 6-(1'-hydroxy-2'-oxopropyl)-tetrahydropterin and 6-(1' oxo-2'-hydroxypropyl)-tetrahydropterin have been studied.

Purification of 6-pyruvoyl-tetrahydropterin synthase from human liver

The enzyme which catalyzes the first step in the conversion of dihydroneopterin triphosphate to tetrahydrobiopterin has been purified approx. 40,000-fold from human liver to apparent homogeneity. The enzyme has a native molecular weight of approximately 83,000 and consists of four identical subunits, each of which has a molecular weight of approximately 19,000. It contains carbohydrates and is remarkably stable to heat treatment. In the presence of purified sepiapterin reductase, Mg2+, and NADPH, this enzyme catalyzes efficiently the formation of tetrahydrobiopterin from dihydroneopterin triphosphate. This indicates that these two proteins are sufficient for the overall conversion.

Pterin deaminase from Bacillus megaterium. Purification and properties

A pterin deaminase catalyzing the hydrolytic deamination of various pteridines was found in the bacterium, Bacillus megaterium, and partially purified from bacterial extract. The specific activity was raised 90-fold over that of the crude extract. The pH optimum is around 7.3, and the Km value for 6-carboxypterin is 1.3 mM. The molecular weight of the enzyme was estimated by gel filtration to be about 110,000. The enzyme deaminated pterin, 6-carboxypterin, biopterin, 6-methylpterin, 7-methylpterin, xanthopterin, 6-hydroxymethylpterin, sepiapterin, isosepiapterin, folic acid, and 6,7-dimethylpterin to their corresponding lumazines, whereas guanine, 7-carboxypterin, leucopterin, isoxanthopterin, and 6-methylisoxanthopterin did not serve as substrates. The enzyme was inhibited by PCMB and 8-azaguanine.