In vivo imaging in humanized mice

The radiological modalities that are currently utilized as critical components in clinical medicine have also been adapted to small-animal imaging, among which are ultrasound imaging, X-ray computerized tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and single-photon emission computed tomography (SPECT). Optical imaging techniques such as bioluminescence imaging (BLI) and fluorescence imaging (FLI) are approaches that are commonly used in small animals. Longitudinal surveys of living (i.e., nonsacrificed) animal models with these modalities provide some clues for the development of clinical applications. The techniques are absolutely essential for translational research. However, there are currently few tools available with sufficient spatial or temporal resolution ideal for all experimental studies. In this chapter, we provide a rationale and techniques for visualizing target cells in living small animals and an overview of the advantages and limitations of current imaging technology. Finally, we introduce a humanized mouse and a novel in vivo imaging system that we have developed. We also discuss real-time observations of reconstructs and clinical manifestations.

Serum keratan sulfate is a promising marker of early articular cartilage breakdown

OBJECTIVES

To find serum markers that may serve as indices for an early diagnosis of degeneration or damage of the articular cartilage.

METHODS

Twenty-four healthy volunteers, 19 individuals with knee trauma (KT) and 31 with knee osteoarthritis (OA) were evaluated. KT patients were divided into a group (n = 5) with an injury <2 months old (recent KT) and a group (n = 14) with that >2 months old (old KT). Articular cartilage damage was assessed using either arthroscopy or direct observation. Serum concentrations of hyaluronic acid (HA), cartilage proteoglycan aggrecan turnover epitope (CS846) and cartilage oligomeric protein (COMP) were measured using enzyme-linked immunosorbent assay kits and those of keratan sulfate (KS) and chondroitin-6-sulfate (C6S) using high-performance liquid chromatography.

RESULTS

Serum KS in the recent KT group (2095 +/- 594 ng/ml) was significantly higher than that in the old KT group (1373 +/- 418 ng/ml; P = 0.021), and serum COMP in the recent KT group (1572 +/- 182 ng/ml) showed a tendency that was higher than that in the old KT group (1350 +/- 250 ng/ml; P = 0.079). Serum KS in OA patients with Kellgren and Lawrence (KL) grades 0 and I (1456 +/- 334 ng/ml) showed a tendency that was higher than that in OA patients with KL grades II, III and IV (1248 +/- 220 ng/ml; P = 0.084).

CONCLUSIONS

The serum concentration of KS correlated with the damage of the articular cartilage and it was significantly increased even at an early stage after the injury.

INFLUENCE OF DRINKING ALCOHOL ON ATHEROSCLEROTIC RISK IN ALCOHOL FLUSHERS AND NON-FLUSHERS OF ORIENTAL PATIENTS WITH TYPE 2 DIABETES MELLITUS

AIMS

Facial flushing caused by alcohol drinking is a typical symptom of high sensitivity to alcohol in orientals. We investigated whether drinking alcohol influences atherosclerotic risk factors in alcohol flushers and non-flushers in patients with diabetes mellitus.

METHODS

A cross-sectional study was performed using 225 subjects with type 2 diabetes. Sensitivity to alcohol was surveyed by a questionnaire on facial flushing. Subjects were divided into three groups by average amount of alcohol drinking (non-drinkers; light drinkers: <140 g/week; heavy drinkers: 140 g/week or more).

RESULTS

Systolic blood pressure and blood HDL cholesterol were significantly higher in heavy drinkers than in non-drinkers. There were no significant differences in body mass index, blood pressure, blood total cholesterol, HDL cholesterol, uric acid, fibrinogen and sialic acid levels in flushers and non-flushers. In alcohol flushers, diastolic blood pressure and HDL cholesterol in heavy drinkers were significantly higher than those in non-drinkers, and systolic blood pressure was significantly higher in heavy drinkers than in non-drinkers and light drinkers. On the other hand, blood pressure and HDL cholesterol in non-flushers were not significantly different among non-, light and heavy drinkers. Serum total cholesterol was not significantly different among the three drinking groups both in flushers and non-flushers.

CONCLUSIONS

Blood pressure and HDL cholesterol are more prone to be affected by drinking in flushers than in non-flushers, suggesting that alcohol sensitivity evaluated by flushing response due to drinking alcohol should be taken into account when the effects of alcohol drinking on atherosclerotic risk factors are considered in oriental patients with type 2 diabetes mellitus.

Age-dependent relation of serum sialic acid concentration to aortic pulse wave velocity in type 2 diabetes

OBJECTIVE

The purpose of this study was to determine whether age affects the significance of serum sialic acid concentration as a marker of atherosclerosis in patients with diabetes.

METHODS

In this cross-sectional study, we investigated the relationship of serum sialic acid concentration to aortic pulse wave velocity (a-PWV) and the effects of age on this relationship in patients with type 2 diabetes.

RESULTS

In the elderly (70 years or over) diabetic patients, a-PWV showed a significant positive correlation with serum sialic acid. This relationship was also significant after adjustment for age, duration of diabetes, body mass index, systolic blood pressure, LDL cholesterol, HDL cholesterol and fibrinogen levels. In elderly diabetic patients, a-PWV also showed a significant positive correlation with age and duration of diabetes and a significant negative correlation with serum HDL cholesterol level. On the other hand, in the younger (31-60 years) diabetic patients, there was no significant correlation between serum sialic acid level and a-PWV, while a-PWV showed significant positive correlations with age, duration of diabetes and plasma fibrinogen level.

CONCLUSIONS

Serum sialic acid level reflects atherosclerosis in elderly diabetic patients but not in younger diabetic patients. This may explain recent controversial findings regarding the relationship between serum sialic acid level and incidence of coronary heart disease in diabetes.

Characteristics and trends of clarithromycin-resistant Helicobacter pylori isolates in Japan over a decade

Clarithromycin has been administered to patients in Japan since 1991. Clarithromycin-resistant Helicobacter pylori strains have been on the rise in Japan. We obtained H. pylori isolates between 1989 and 2000 and examined mutations of the 23S rRNA gene, which are closely associated with clarithromycin resistance. Isolates were obtained from 356 patients with H. pylori infection treated at the Hiroshima University. Sixty-one of the patients received clarithromycin-based H. pylori eradication therapy. Mutations of the 23S rRNA gene were examined by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) followed by sequencing analysis. Mutant strains were found in 42 of the 356 patients (11.8%). The prevalence of mutant strains increased from 0 to 20.4% during the 12-year study period. The prevalence increased to more than 10% by 1995 and then to more 20% after 1999. The H. pylori eradication rate was significantly higher in patients with wild-type strains than in patients with mutant strains (72.0 vs. 36.4%, p = 0.024). Our data indicate that clarithromycin-resistant H. pylori strains have increased rapidly since 1995 and that the effectiveness of clarithromycin-based H. pylori eradication therapies may soon be compromised. Other new therapies may be necessary as first-line treatments in Japan.

The role of lipoxygenase products on the endocytosis of yolk proteins in insects: participation of cAMP

The participation of eicosanoids and second messengers in the regulation of endocytosis by the ovaries was investigated using the uptake of Rhodnius heme binding protein (RHBP) as an experimental model. The rate of RHBP uptake decreased up to 40% in the presence of BWA4C and NDGA, 5 and 12-lipoxygenase inhibitors, respectively, suggesting the involvement of lipoxygenase products in endocytosis regulation. Addition of Leukotriene B4 (LTB(4); one product of the 5 lipoxygenase pathway) increased in vitro the uptake of RHBP by 30%. The content of cAMP in the Rhodnius' ovaries were monitored after treatment with different eicosanoids and inhibitors of eicosanoids synthesis. The amount of cAMP decreased in the presence of indomethacin (by 50%), while treatment with PGE(2) induced an increase of 85% of this messenger in the ovaries. The presence of LTB(4) in the medium inhibited in 60% the content of cAMP in the ovaries, while BWA4C induced a 100% increase of this messenger in the ovaries. Addition of 1 microM DBcAMP in the medium resulted in a 30% decrease in the rate of RHBP uptake. Taken together, these data show that cyclooxygenase and lipoxygenase products participate in the control of protein internalization by modulation of cAMP levels.

Magnetoencephalographic representation of the sensorimotor hand area in cases of intracerebral tumour

OBJECTIVE

To assess the clinical value of magnetoencephalography (MEG) in localising the primary hand motor area and evaluating cortical distortion of the sensorimotor cortices in patients with intracerebral tumour.

METHODS

10 normal volunteers (controls) and 14 patients with an intracerebral tumour located around the central region were studied. Somatosensory evoked magnetic fields (SEFs) following median nerve stimulation, and movement related cerebral magnetic fields (MRCFs) following index finger extension, were measured in all subjects and analysed by the equivalent current dipole (ECD) method to ascertain the neuronal sources of the primary sensory and motor components (N20m and MF, respectively). These ECD locations were defined as the primary hand sensory and motor areas and the positional relations between these two functional areas in controls and patients were investigated.

RESULTS

The standard range of ECD locations of MF to N20m was determined in controls. In 11 of the 14 patients, MRCFs could identify the primary motor hand area. ECD locations of MF were significantly closer to the N20m in the medial-lateral direction in patients than in controls. In patients with a tumour located below the sensorimotor hand area, relative ECD locations of MF to N20m moved anteriorly over the standard range determined in the control subjects. These MEG findings correlated well with radiological tumour locations. The mean estimated ECD strength of MF was significantly lower in patients than in controls.

CONCLUSIONS

MRCF was useful in localising the primary motor hand area in patients with intracerebral tumour. The relative ECD locations of MF to N20m describe the anatomical distortion of the sensorimotor cortex.

Necessity of multiple gastric biopsies from different sites for detection of clarithromycin-resistant Helicobacter pylori strains

BACKGROUND

It has been reported that approximately 10% of patients infected with Helicobacter pylori have both clarithromycin-susceptible and clathromycin-resistant strains. However, there have been no reports indicating whether only one gastric biopsy is sufficient to detect clarithromycin-resistant strains.

METHODS

Sixty-five H. pylori-infected patients were selected for this study, and 40 of them were given clarithromycin-based eradication therapy. Four gastric biopsies, 2 from the antrum and 2 from the corpus, were obtained from each of the 65 patients. Susceptibility of H. pylori strains to clarithromycin was examined by detecting mutations of the 23S ribosomal RNA (rRNA) gene of H. pylori.

RESULTS

The clarithromycin-resistant strains were detected in 16 of the 65 (25%) patients. Only 5 of the 16 (31%) patients had the resistant strains in both the antrum and corpus. When only 1 or the other biopsy from the antrum was used, the resistant strains were detected in 8 (50%) or 9 (56%) of the 16 patients.

CONCLUSIONS

These data indicate that multiple gastric biopsies from both the antrum and the corpus should be used to detect clarithromycin-resistant H. pylori strains.

Spontaneous regeneration of the seriously injured sympathetic pathway projecting to the prostate over a long period in the dog

OBJECTIVES

To explore the spontaneous regeneration, over a long period, of the seriously injured sympathetic pathway controlling the prostate.

MATERIALS AND METHODS

The hypogastric nerve (HGN), which is part of the sympathetic pathway from the spinal cord to the prostate, was partly removed over half of its length on both sides in six dogs. Four years after surgery the responses of the prostate to electrical stimulation of the lumbar splanchnic nerve (LSN) or the HGN proximal to the site removed, were assessed.

RESULTS

In six dogs, 10 of the 17 LSNs (second to fourth) and four of the 10 HGNs stimulated elicited prostatic contraction. The pathways via the ipsilateral HGN and/or the contralateral HGN from the LSNs to the prostate were identified as having regenerated in four of six dogs.

CONCLUSION

These results indicate that the sympathetic pathways via the HGN to the canine prostate can regenerate spontaneously over a long period after serious injury, and that their cross-innervation system can also be repaired.

Ictal magnetoencephalographic discharges from elementary visual hallucinations of status epilepticus

PURPOSE

To report the rare opportunity to study ictal magnetoencephalography (MEG) in a 26 year old man with simple partial status epilepticus that presented as elementary visual hallucinations (EVHs) in the right upper visual field.

METHODS

The patient described his EVHs as "snowing on TV," "flickering lights," and "rotating coloured balls" that continued for several days. MEG and simultaneous EEG were recorded twice: during an episode of EVHs (ictal recordings) and after EVHs were controlled by medications (interictal recordings).

RESULTS

During EVHs, MEG showed continuous periodic epileptiform discharges over the left posterior superior temporal region, while simultaneous EEG showed rhythmic theta waves and sporadic spikes over the left temporal region. The MEG discharge consisted of a three phase spike complex. Equivalent current dipoles (ECDs), modelled from spike complexes, localised in the left superior temporal area. After drug treatment controlled the EVHs, interictal MEG and EEG showed rare spikes over the same left temporal region. The average ictal ECD moment (mean (SD)) (128.7 (32.8 nAm)) was significantly weaker than the average interictal ECD moment (233.0 (63.9) nAm) (p<0.05).

CONCLUSIONS

The continuous, periodic, and clustered discharges seen on ictal MEG were the sources of EVH. The weaker ictal ECD sources were frequently not detected by scalp EEG, while the stronger interictal sources, presumably originating from an extensive interictal zone, were sufficiently large to be seen as EEG spikes.

Myocardial hypertrophy of the recipient twins in twin-to-twin transfusion syndrome and cerebral palsy

OBJECTIVES

This study was performed to determine risk factors for cerebral palsy (CP) in monochorionic twins, especially with twin-to-twin transfusion syndrome (TTTS).

METHODS

In 33 pathologically confirmed monochorionic pregnancies, we analyzed the incidence of cardiovascular and neurological complications.

RESULTS

Seventeen cases were diagnosed as TTTS. Myocardial hypertrophy was detected in seven recipient twins of TTTS, but not found in the donor twins of TTTS or in non-TTTS. CP developed in six out of 29 in TTTS and one out of 32 in non-TTTS. In TTTS, all the cases with CP were seen in the recipient twins. The development of CP was significantly associated with cardiovascular complications such as myocardial hypertrophy and hydropic changes.

CONCLUSIONS

Myocardial hypertrophy found in the recipient twins in TTTS seems to be a risk for developing CP later on, which may have implications in understanding the pathogenesis of CP.