Theoretical Design and Synthesis of Caged Compounds Using X-Ray-Triggered Azo Bond Cleavage

Caged compounds are frequently used in life science research. However, the light used to activate them is commonly absorbed and scattered by biological materials, limiting their use to basic research in cells or small animals. In contrast, hard X-rays exhibit high bio-permeability due to the difficulty of interacting with biological molecules. With the main goal of developing X-ray activatable caged compounds, azo compounds are designed and synthesized with a positive charge and long π-conjugated system to increase the reaction efficiency with hydrated electrons. The azo bonds in the designed compounds are selectively cleaved by X-ray, and the fluorescent substance Diethyl Rhodamine is released. Based on the results of experiments and quantum chemical calculations, azo bond cleavage is assumed to occur via a two-step process: a two-electron reduction of the azo bond followed by N─N bond cleavage. Cellular experiments also demonstrate that the azo bonds can be cleaved intracellularly. Thus, caged compounds that can be activated by an azo bond cleavage reaction promoted by X-ray are successfully generated.

MicroRNA-125b regulates proliferation and radioresistance of oral squamous cell carcinoma

BACKGROUND

MicroRNAs (miRNAs) are involved in essential biological activities, and have been reported to exhibit differential expression profiles in various cancers. Our previous study demonstrated that intercellular adhesion molecule-2 (ICAM2) inhibition induces radiosensitisation in oral squamous cell carcinoma (OSCC) cells. Thus, we hypothesised that certain miRNAs play crucial roles in radioresistance in OSCC by regulating ICAM2 expression.

METHODS

Because predicted target gene analyses revealed that microRNA-125b (miR-125b) potentially regulates ICAM2 mRNA expression, we examined the association between miR-125b and radioresistance. The expression of miR-125b was investigated by real-time quantitative reverse transcriptase-PCR. For a functional analysis, miR-125b was transfected to OSCC-derived cells.

RESULTS

A downregulated expression of miR-125b was found in OSCC-derived cell lines and OSCC samples. The miR-125b-transfected cells showed a decreased proliferation rate, enhanced radiosensitivity to X-ray irradiation and diminished ICAM2 mRNA expression. Moreover, miR-125b expression correlated with OSCC tumour staging and survival.

CONCLUSION

These findings suggested that the downregulated miR-125b expression was associated with proliferation and radioresistance mechanisms, probably through ICAM2 signalling. Thus, controlling the expression or activity of miR-125b might contribute to suppressing proliferation and overcoming radioresistance in OSCC.

Network-based analysis of calcium-binding protein genes identifies Grp94 as a target in human oral carcinogenesis

To characterise Ca(2+) -binding protein gene expression changes in oral squamous cell carcinomas (OSCCs), we compared the gene expression profiles in OSCC-derived cell lines with normal oral tissues. One hundred Ca(2+) -binding protein genes differentially expressed in OSCCs were identified, and genetic pathways associated with expression changes were generated. Among genes mapped to the network with the highest significance, glucose-regulated protein 94 kDa (Grp94) was evaluated further for mRNA and protein expression in the OSCC cell lines, primary OSCCs, and oral premalignant lesions (OPLs). A significant (P<0.001) overexpression of Grp94 protein was observed in all cell lines compared to normal oral epithelium. Immunohistochemical analysis showed highly expressed Grp94 in primary OSCCs and OPLs, whereas most of the corresponding normal tissues had no protein immunoreaction. Real-time quantitative reverse transcriptase-PCR data agreed with the protein expression status. Moreover, overexpression of Grp94 in primary tumours was significantly (P<0.001) correlated with poor disease-free survival. The results suggested that Grp94 may have potential clinical application as a novel diagnosis and prognostic biomarker for human OSCCs.

Monophasic epithelial synovial sarcoma arising in the temporomandibular joint

Synovial sarcoma is a mesenchymal spindle-cell tumour that occurs infrequently in the head and neck. It originates from unknown stem cells differentiating into mesenchymal and/or epithelial structures. Most synovial sarcomas are biphasic in character, consisting of epithelial and spindle-cell elements. Here is reported a case of monophasic epithelial synovial sarcoma arising in the temporomandibular joint. The tumour was of a predominantly epithelial pattern, although a minute area of sarcomatous cells was found. The primary mode of treatment was wide en-bloc excision. Two years after surgery, the patient died of hepatocellular carcinoma, but there was no evidence of synovial sarcoma recurrence.

Abnormal muscle responses in hemifacial spasm: F waves or trigeminal reflexes?

OBJECTIVE

In patients with hemifacial spasm (HFS), abnormal muscle responses (AMR) are frequently present. The objective of this study was to investigate whether the afferent input of AMR is mediated by antidromic facial nerve stimulation or orthodromic trigeminal nerve stimulation.

METHODS

AMR in the orbicularis oris muscle were recorded in 28 patients with HFS. When AMR were present, they were recorded after subthreshold stimulation of the facial nerve and weak stimulation delivered to the skin.

RESULTS

AMR were recordable in 24 (86%) of the patients, and usually consisted of the early constant component (mean onset latency, 10.0 ms) and late variable component (35.3 ms), similar to R1 and R2 of the blink reflex. The early or late components of AMR, or both, were frequently elicited after subthreshold stimulation of the facial nerve (43%) and skin stimulation (88%).

CONCLUSIONS

AMR are likely to be mediated by trigeminal afferent inputs, rather than antidromic activation of the facial nerve, and are a type of trigeminal reflex.

Monitoring of circulating tumour-associated DNA as a prognostic tool for oral squamous cell carcinoma

Frequent allelic imbalances (AIs) including loss of heterozygosity and microsatellite instability on a specific chromosomal region have been identified in a variety of human malignancies. The objective of our study was to assess the possibility of prognostication and monitoring of oral squamous cell carcinoma (SCC) by microsatellite blood assay. DNA from normal and tumorous tissues and serum DNA obtained at three time points (preoperatively, postoperatively, and 4 weeks postoperatively) from 64 patients with oral SCC was examined at nine microsatellite loci. In all, 38 (59%) DNA samples from tumorous tissues and 52% from serum showed AIs in at least one locus. Patterns of AIs in the serum DNA were matched to those detected in tumour DNA. Of them, AIs were frequently detected preoperatively (44%, 28 of 64), and postoperatively (20%, 13 of 64). Moreover, among 12 cases with AIs during the postoperative period, six had no evidence of an AI 4 weeks postoperatively, and they had no recurrence and were disease free. In contrast, six patients with AI-positive DNA 4 weeks postoperatively have died with distant metastasis within 44 weeks. Thus, our results suggest that the assessment of microsatellite status in the serum DNA could be a useful predictive tool to monitor disease prognosis.

Recovery patterns and long term prognosis for axonal Guillain-Barré syndrome

BACKGROUND

Little is known about the long term prognosis for patients the severe acute motor axonal neuropathy (AMAN) form of Guillain-Barré syndrome (GBS), unlike those with acute inflammatory demyelinating neuropathy (AIDP).

OBJECTIVE

To clarify the long term prognosis for patients with AMAN.

METHODS

Clinical recovery and outcome in 97 consecutive GBS patients were reviewed.

RESULTS

Electrodiagnostic criteria showed that 44 patients (45%) had AMAN, 33 (34%) had AIDP, and 20 (21%) were unclassified. Most of the severely affected patients had received plasmapheresis or immunoglobulin therapy. Slow recovery (inability to walk independently at six months after onset) was found in six of the AMAN patients (14%) and in two of the AIDP patients (6%). Of the six AMAN patients, four could walk independently one year after the onset, and the other two could walk independently at 28 and 57 months after onset. Of the two AIDP patients, one could walk at nine months after the onset while the other died of pneumonia seven months after onset.

CONCLUSIONS

AMAN electrodiagnosis is not always a marker of poor recovery. Almost all the severe AMAN patients who had slow recoveries over the first six months could eventually walk independently, although some required several years.

Patterns and serial changes in electrodiagnostic abnormalities of axonal Guillain–Barré syndrome

BACKGROUND

In Guillain-Barré syndrome (GBS), anti-ganglioside antibodies are strongly associated with the acute motor axonal neuropathy (AMAN) form, but there are also cases of the demyelinating form of GBS (acute inflammatory demyelinating polyneuropathy [AIDP]) with anti-ganglioside antibodies.

OBJECTIVE

To elucidate the patterns and sequential changes in electrodiagnostic abnormalities of anti-ganglioside-positive GBS.

METHODS

Detailed serial electrodiagnostic findings were reviewed for 51 patients with GBS. Anti-ganglioside antibodies were measured by ELISA.

RESULTS

Antibodies to GM1, GM1b, GD1a, or GalNAc-GD1a were present in 25 patients. Of these, 12 (48%) showed the AMAN pattern, 5 (20%) the AIDP pattern, and 3 (12%) isolated F-wave absence in the first examination. All five patients with the AIDP pattern showed prolonged distal latencies, but three eventually showed the AMAN pattern or rapid normalization. The remaining two still had similarly prolonged distal latencies in weeks 4 to 6, but the serial changes were distinct from those in the anti-ganglioside-negative AIDP patients who showed progressive increases in distal latencies over 2 months after onset.

CONCLUSIONS

Besides the simple axonal degeneration pattern, patients with anti-ganglioside-positive Guillain-Barre syndrome can show transient conduction slowing/block in the distal or proximal nerve segments, mimicking demyelination, but anti-ganglioside antibodies do not appear to be associated with acute inflammatory demyelinating polyneuropathy.

Enhancement of topical delivery of drugs via direct penetration by reducing blood flow rate in skin

The purpose of this work was to investigate the effect of blood flow in the skin on the direct penetration of topically applied drugs into the muscular layer, and to show that the skin blood flow could also be one of the important factors determining the direct penetration of drugs to the muscular layer. In vivo percutaneous absorption study was performed for antipyrine, salicylic acid or diclofenac by using rats with tape-stripped skin. Phenylephrine, which is well known to reduce the local blood flow by vasoconstrictor action, was topically applied to decrease the local blood flow in the skin. The concentrations of drugs in viable skin and muscle, and the local blood flow in the skin under the applied and the contralateral sites were determined to evaluate the effect of the local blood flow on the delivery of topically applied drugs into the muscular layer. Dose dependency for the effect of phenylephrine was, first of all, investigated for antipyrine in the range from 0.4 to 10 micromol. The distribution of antipyrine into the viable skin and muscular layer 2 h after topical application significantly increased, but the effect of phenylephrine was saturated around 2 micromol and the dose-dependent profiles for both tissues were almost superimposed. On the other hand, the fraction dose absorbed, plasma concentration and concentrations in viable skin and muscular layer under the contralateral site showed the decreasing tendency and the saturation of the effect around 2 micromol. To confirm the effect of phenylephrine on the local blood flow in the skin, the skin blood flow was measured 2 h after topical application of 2 micromol phenylephrine, and the significant decrease in the blood flow was recognized. In vivo percutaneous absorption studies were performed for salicylic acid and diclofenac, too. Extensive enhancement of penetration into the viable skin and muscular layer was observed for both drugs, although total absorption from the donor cell showed the decreasing tendency. In conclusion, direct penetration of drugs applied topically is enhanced by reducing the local blood flow in the skin, which would be a possible approach to improve the local delivery of drugs applied topically.

Does Campylobacter jejuni infection elicit "demyelinating" Guillain-Barre syndrome?

BACKGROUND

Campylobacter jejuni enteritis is the most common antecedent infection in Guillain-Barré syndrome (GBS). C. jejuni-related GBS is usually acute motor axonal neuropathy (AMAN), but previous reports described many cases of the demyelinating subtype of GBS (acute inflammatory demyelinating polyneuropathy [AIDP]) after C. jejuni infection.

OBJECTIVE

To investigate whether C. jejuni infection elicits AIDP.

METHODS

In 159 consecutive patients with GBS, antibodies against C. jejuni were measured using ELISA. Antecedent C. jejuni infection was determined by the strict criteria of positive C. jejuni serology and a history of a diarrheal illness within the previous 3 weeks. Electrodiagnostic studies were performed weekly for the first 4 weeks, and sequential findings were analyzed.

RESULTS

There was evidence of recent C. jejuni infection in 22 (14%) patients. By electrodiagnostic criteria, these patients were classified with AMAN (n = 16; 73%) or AIDP (n = 5; 23%) or as unclassified (n = 1) in the first studies. The five C. jejuni-positive patients with the AIDP pattern showed prolonged motor distal latencies in two or more nerves and had their rapid normalization within 2 weeks, eventually all showing the AMAN pattern. In contrast, patients with cytomegalovirus- or Epstein-Barr virus-related AIDP (n = 13) showed progressive increases in distal latencies in the 8 weeks after onset.

CONCLUSION

Patients with C. jejuni-related Guillain-Barré syndrome can show transient slowing of nerve conduction, mimicking demyelination, but C. jejuni infection does not appear to elicit acute inflammatory demyelinating polyneuropathy.

Trigeminal afferent input alters the excitability of facial motoneurons in hemifacial spasm

OBJECTIVE

To investigate whether skin or muscle afferent input via the trigeminal nerve alters the excitability of facial motoneurons in hemifacial spasm (HFS).

METHODS

Botulinum toxin type A (BTX) was injected only to the orbicularis oculi (O. oculi) muscle of 21 patients with idiopathic HFS, and the excitability of the orbicularis oris (O. oris) motoneurons was monitored. The synkinetic response (SR) of the blink reflex and abnormal muscle response (AMR) were recorded from the O. oris before and after treatment.

RESULTS

BTX injections produced marked to moderate improvement in the O. oculi of all 21 patients and in the O. oris of 17 (81%). The rectified areas of SR1 and SR2 were smaller after treatment. In particular, the AMR area showed a reduction (p = 0.02).

CONCLUSIONS

The significant lessening of spasms in the O. oris after BTX injection to the O. oculi and the concomitant reduction in excitability of O. oris neurons are consistent with the hypothesis that in HFS, skin or muscle afferent volleys via the trigeminal nerve enhance the excitability of facial nerve motoneurons.

Differences in patterns of progression in demyelinating and axonal Guillain-Barré syndromes

BACKGROUND

Immune treatments are recommended for patients with Guillain-Barré syndrome (GBS) who cannot walk independently, but a considerable number of GBS patients are in the progressive phase at the first examination.

OBJECTIVE

To investigate whether progression patterns differ in demyelinating and axonal subtypes of GBS.

METHODS

Clinical, laboratory, and electrophysiologic data on 131 consecutive patients with GBS were reviewed. Patients were classified as having acute inflammatory demyelinating polyneuropathy (AIDP) or acute motor axonal neuropathy (AMAN) based on electrodiagnostic criteria.

RESULTS

Forty-one patients had AIDP, 62 AMAN, and 28 were unclassified. Age, sex, and Hughes Functional Grading Scale score at the first medical examination did not differ for the AIDP and AMAN patients. Mean periods between neurologic onset and first examination (5.3 vs 4.2 days; p = 0.01) and neurologic onset and nadir (18.0 vs 11.5 days; p = 0.001) were longer for the AIDP group. In the subgroup of those with mild disability (able to walk independently at the first neurologic examination), 88% of the AMAN patients had reached the nadir, whereas 65% of the AIDP patients had reached it. The remaining 35% progressed to it over the next 1 to 2 weeks and were unable to walk at nadir.

CONCLUSIONS

The patterns and speeds of progression differ in AMAN and AIDP, AMAN having a rapid progression and an early nadir. AIDP patients frequently have a significantly long progression after the first examination; therefore, they need to be carefully monitored.

Properties of human skin mechanoreceptors in peripheral neuropathy

OBJECTIVES

To investigate the properties of mechanoreceptors in patients with peripheral neuropathy. The skin mechanoreceptor is a terminal organ of the primary sensory neuron, which is likely to be affected earlier and more severely than is the nerve trunk by peripheral neuropathies.

METHODS

Single sensory unit responses to air-puff and electric stimulation were recorded using the microneurographic technique in the glabrous skin of the hand. Receptor transduction time was estimated by a latency difference between electric- and air-puff-induced responses.

RESULTS

A total of 38 mechanoreceptive units were obtained from 14 normal subjects. All the units responded to air-puff stimuli irrespective of the receptor type, and receptor transduction time was approximately 2 ms. A total of 32 units were recorded from 11 patients with neuropathy of variable causes. Seven (22%) of the 32 neuropathic units did not respond to air-puffs despite their ability to respond to electric stimulation. Compared to normal ones, units from patients with peripheral neuropathy had significantly higher mechanical thresholds, but receptor transduction times did not differ significantly.

CONCLUSIONS

Changes in receptor properties in human neuropathy are characterized by increased mechanical threshold without prolongation of receptor transduction time, possibly due to a high threshold for generating receptor potentials.

Distribution patterns of demyelination correlate with clinical profiles in chronic inflammatory demyelinating polyneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a heterogeneous disorder having a wide clinical range, and is characterised by multifocal demyelination that can involve the distal nerve terminals, intermediate nerve segments, and nerve roots.

OBJECTIVE

To investigate whether the distribution patterns of demyelination along the course of the nerve correlate with clinical profiles in patients with CIDP.

METHODS

Motor nerve conduction studies were carried out on 42 consecutive patients. According to the physiological criteria for demyelination, the presence of a demyelinative lesion was determined in the distal nerve segments (distal pattern) or intermediate nerve segments (intermediate pattern), or in both (diffuse pattern). The serum concentration of tumour necrosis factor (TNF)-alpha was measured by immunoassay.

RESULTS

Patients were classified as having a distal (n=10), intermediate (n=13), or diffuse (n=15) pattern, or were unclassified (n=4). Patients with the distal or diffuse pattern had common clinical features such as subacute onset, symmetric symptoms, and weakness involving proximal as well as distal muscles. Patients with the distal pattern had a good response to treatment and a monophasic remitting course, but the diffuse pattern was associated with a treatment dependent relapsing course, reflecting longer disease activity. The serum TNF-alpha concentrations increased only in the "diffuse" subgroup of patients, and this might be associated with breakdown of the blood-nerve barrier and therefore, involvement of the intermediate segments. The intermediate pattern was characterised by a chronic course, asymmetric symptoms, less severe disability, and refractoriness to treatments.

CONCLUSIONS

CIDP consists of subtypes with varying predilections for lesions along the course of the nerve. The distribution patterns of conduction abnormalities may be useful in the prediction of outcome of patients with CIDP.

Surface hydrophobicity of particles is not necessarily the most important determinant in their in vivo disposition after intravenous administration in rats

The in vivo disposition of polystyrene microsphere (MS) with the particle size of 50 nm (MS-50) and lecithin-coated MS-50 (LMS-50) after intravenous administration to rats was characterized. While a rapid elimination from the systemic circulation was observed for MS-50, much more prolonged circulating property was observed for LMS-50. In addition, this in vivo disposition property of LMS-50 was suggested to be ascribed to its lower affinity to the liver, which is the determining organ of the in vivo disposition of MS-50. The evaluation of surface hydrophobicity of MS-50 and LMS-50 in buffer solution revealed that the surface of MS-50 is more hydrophobic than that of LMS-50. However, LMS-50 was oppositely found to be more hydrophobic than that of MS-50 in rat serum. The profiles of serum proteins associated with MS-50 and LMS-50 were also examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that the amounts of some adsorbed proteins are greatly different between MS-50 and LMS-50. From these findings, it was suggested that the substantial difference in the in vivo disposition between MS-50 and LMS-50 would not be attributed to the difference in their surface hydrophobicity in the blood, but the difference in the type of serum proteins associated with them.

Amino acids protect epithelial cells from local toxicity by absorption enhancer, sodium laurate

To develop the safe absorption-enhancing formulation attenuating the local toxicity caused by an absorption enhancer, sodium laurate (C12), the effects of amino acids on the local toxicity by C12 were examined in rats. The absorption of phenol red, an unabsorbable marker drug, was significantly enhanced by 10 mM C12 in an in situ colon loop study and the addition of L-glutamine (L-Gln), L-arginine, or L-methionine at 10 mM did not change the promoting effect of C12. However, C12 significantly increased the elution of phospholipids, total protein, and lactate dehydrogenase, which are markers for local toxicity, from colon, but these amino acids attenuated the local toxicity caused by C12 significantly. Transport study using an Ussing-type chamber showed that the permeability of colonic membrane to phenol red was significantly enhanced by C12 and that L-Gln did not decrease the permeability enhanced by C12. Transmucosal electrical resistance was extensively decreased by C12, indicating that C12 could enhance the drug absorption at least partly by expanding the paracellular route. L-Gln significantly, but not completely, recovered resistance lowered by C12. Electrical potential difference was markedly reduced by C12, suggesting that C12 lowered the viability of mucosal cells, but 10 mM L-Gln significantly recovered potential difference almost to the control level. These results suggested the possibility that absorption-enhancing formulation with low local toxicity, which is low enough to be used practically, could be developed by using an amino acid like L-Gln as an ingredient attenuating the local toxicity caused by C12.

Biliary excretion of polystyrene microspheres depends on the type of receptor-mediated uptake in rat liver

Hepatic uptake and biliary excretion of fluorescein isothiocyanate-labeled polystyrene microspheres with a particle size of 50 nm (MS-50) were studied in rats. Liver perfusion studies revealed that not only apo-E-mediated but also asialoglycoprotein receptor-mediated uptake is involved in the mechanism of the serum protein-dependent uptake of MS-50 in the liver. The uptake of MS-50 mediated by apo-E contributes more to the total uptake of MS-50 by the hepatocytes than that via asialoglycoprotein receptor in the presence of serum in the perfusate. Furthermore, it was found that MS-50 is substantially excreted into the bile by transcytosis. The extent of exocytosis of MS-50 taken up by the hepatocytes was much higher after MS-50 was endocytosed via asialoglycoprotein receptor than after taken up via the process mediated by apo-E. On the basis of these results, a possible regulation of the intracellular sorting of ligands, depending on the receptor-mediated uptake mechanism, was inferred.

Indicators of rapid clinical recovery in Guillain-Barré syndrome

To elucidate the features of patients with Guillain-Barré syndrome who show markedly rapid clinical recovery, clinical, serological, and electrophysiological data of 80 consecutive patients were reviewed. Antigangliosides, and Campylobacter jejuni and Haemophilus influenzae antibodies were measured by enzyme linked immunosorbent assays. Nine (11%) patients showed rapid recovery (improvement by two or more Hughes grades within 2 weeks). They often had electrodiagnosis of acute motor axonal neuropathy (AMAN; 67%), preserved tendon reflexes (44%), anti-GM1 antibodies (89%), preceding H influenzae infection (44%), and received immunoglobulin treatment (44%). On the other hand six patients with poor prognosis often had AMAN (100%) and anti-GM1 antibody (83%), but a higher incidence of preceding C jejuni infection (83%). It is concluded that patients with Guillain-Barré syndrome with AMAN and anti-GM1 antibodies have either faster or slower recoveries. Among the axonal subgroup of patients with Guillain-Barré syndrome, preserved tendon reflexes, H influenzae infection, and the patient having received immunoglobulin treatment may be indicators of rapid recovery.

Estimation of absorption enhancement by medium-chain fatty acids in rat large intestine

The absorption enhancement by the sodium salts of several fatty acids was investigated in rat large intestine for model compounds having a wide range of molecular weight. Sodium caprylate (C8), sodium caprate (C10), sodium laurate (C12), which are categorized in medium-chain fatty acid, and sodium oleate (C18:1), long-chain unsaturated fatty acid, were employed as lipoidal adjuvants. Phenol red (MW=354.4), glycyrrhizin (822.9), fluorescein isothiocyanate-dextran-4 (FD-4, 4400), FD-10 (9400) and FD-40 (38900) were selected as model compounds for the assessment of the enhancing effect of the lipoidal adjuvants. The absorption of phenol red was promoted at the highest level, about 20 times higher by C12 and C18:1 than the control. The absorption rate - time profiles calculated by deconvolution method showed that C12 takes effect most rapidly and efficiently. In the case of glycyrrhizin, four adjuvants including C12 showed almost the same improvement of the absorption, about 30-40 times larger than the control. C8 and sodium citrate did not significantly enhance the absorption of those model compounds. For FD-4, FD-10 and FD-40, C10, C12 and C18:1 revealed almost the same enhancing effect and the absorption of FD-4, FD-10 and FD-40 was enhanced about 80 times, 1000-1800 times and about 200 times, respectively, larger than the control. The enhancement ratio, the ratio of AUC with adjuvant to AUC of control, suggests that these lipoidal adjuvants would improve most efficiently the absorption of the compound having the molecular weight of around 10000. Furthermore, C12 was suggested to be an effective adjuvant for the compounds with the wide range of molecular weight.

Mechanisms of early and late recovery in acute motor axonal neuropathy

Motor unit number estimate (MUNE) of the abductor pollicis brevis (APB) was sequentially performed in seven patients with acute motor axonal neuropathy (AMAN). The MUNE markedly decreased (mean, 11) at the peak of the illness. Clinical recovery of APB strength began during week 4, with an increase in amplitude of distal compound muscle action potentials. The MUNE did not change significantly in this early recovery phase and increased slowly with time. The main mechanism for early recovery in AMAN may be collateral reinnervation, with nerve regeneration developing later.

Intravenous immunoglobulin therapy for Guillain-Barré syndrome with IgG anti-GM1 antibody

To compare the effects of intravenous immunoglobulin (IVIg) therapy and plasmapheresis for the IgG anti-GM1-positive subtype of Guillain-Barré syndrome (GBS), clinical and electrophysiological recoveries were analyzed in 24 patients treated with IVIg (n = 10) or plasmapheresis (n = 14). At entry, there were no significant differences between the two patient groups in age, sex, clinical severity (Hughes grade), sum scores of distally evoked amplitudes of compound muscle action potentials (CMAPs), and frequency of Campylobacter jejuni infection. The patients treated with IVIg had significantly lower Hughes grade scores 1, 3, and 6 months after onset (P = 0.03), and a higher probability to regain independent locomotion at 6 months [P(logrank) = 0.044]. In the IVIg group, markedly rapid recovery (improvement by two or more Hughes grade scores within 4 weeks) was more frequent (6 of 10 vs. 3 of 14, P = 0. 03), and delayed recovery (unable to walk independently at 6 months) was less frequent (0 of 10 vs. 4 of 14, P = 0.06). CMAP sum score at 6 months tended to be greater for the IVIg group (P = 0.07). For the IgG anti-GM1-positive subgroup of GBS patients, IVIg therapy may be a more efficacious treatment than plasmapheresis.

Axonal Guillain-Barré syndrome: relation to anti-ganglioside antibodies and Campylobacter jejuni infection in Japan

To clarify the relations of the axonal form of Guillain-Barré syndrome (GBS) to anti-ganglioside antibodies and Campylobacter jejuni infection, 86 consecutive Japanese GBS patients were studied. Electrodiagnostic criteria showed acute inflammatory demyelinating polyneuropathy in 36% of the patients and acute motor axonal neuropathy (AMAN) in 38%. Frequent anti-ganglioside antibodies were of the IgG class and against GM1 (40%), GD1a (30%), GalNAc-GD1a (17%), and GD1b (21%). Identified infections were C. jejuni (23%), cytomegalovirus (10%), Mycoplasma pneumoniae (6%), and Epstein-Barr virus (3%). There was a strong association between AMAN and IgG antibodies against GM1, GD1a, GalNAc-GD1a, or GD1b. Almost all the patients with at least one of these antibodies had the AMAN pattern or rapid resolution of conduction slowing/block possibly because of early-reversible changes on the axolemma. C. jejuni infection was frequently associated with AMAN or anti-ganglioside antibodies, but more than half of the patients with AMAN or anti-ganglioside antibodies were C. jejuni-negative. These findings suggest that the three phenomena "axonal dysfunctions (AMAN or early-reversible conduction failure)," "IgG antibodies against GM1, GD1a, GalNAc-GD1a, or GD1b," and "C. jejuni infection" are closely associated but that microorganisms other than C. jejuni frequently trigger an anti-ganglioside response and elicit axonal GBS.

Haemophilus influenzae infection and Guillain-Barré syndrome

It has been reported recently that Haemophilus influenzae can elicit an axonal form of Guillain-Barré syndrome. To investigate the incidence and features of H. influenzae-related Guillain-Barré syndrome, anti-H. influenzae antibody titres were measured by enzyme-linked immunosorbent assay (ELISA) in 46 consecutive Japanese patients with Guillain-Barré syndrome, 49 normal controls, 24 patients with multiple sclerosis and 27 patients with amyotrophic lateral sclerosis (ALS). Whole bacteria of non-encapsulated (non-typable) H. influenzae isolated from one of the Guillain-Barré syndrome patients was the antigen used. Elevated anti-H. influenzae antibodies for two or three classes of IgG, IgM and IgA were found in six (13%) Guillain-Barré syndrome patients, but not in the normal controls and patients with multiple sclerosis or ALS. The incidence was significantly higher in patients with Guillain-Barré syndrome than in the normal controls (P = 0.01) and patients with multiple sclerosis or ALS (P = 0.009). Western blot analysis confirmed that the H. influenzae-positive patients' IgG recognized the lipopolysaccharides of H. influenzae. Guillain-Barré syndrome patients with anti-H. influenzae antibodies showed relatively uniform clinical and laboratory features: prodromal respiratory infection, less frequent cranial and sensory nerve involvement, pure motor axonal degeneration on electrophysiology, and positivity for IgG anti-GM1 antibodies. Although the features were similar to those in Guillain-Barré syndrome patients infected by Campylobacter jejuni, the recoveries seemed to be better in patients with H. influenzae-related Guillain-Barré syndrome. It is concluded that a form of Guillain-Barré syndrome occurs after respiratory infection by H. influenzae in the Japanese population. A particular strain of non-typable H. influenzae has a ganglioside GM1-like structure and elicits axonal Guillain-Barré syndrome similar to C. jejuni-related Guillain-Barré syndrome.

Single unit responses of human cutaneous mechanoreceptors to air-puff stimulation

OBJECTIVE

To investigate responsiveness of human cutaneous mechanoreceptor to selective tactile stimuli produced by brief air-puff stimulation.

METHODS

Using percutaneous microneurography, activities of single sensory units innervating glabrous skin of the hand were recorded, and air-puff stimuli with a short rise time (0.5 ms), generated by a high-speed air control system, were applied to the receptive field. Receptor activation time was estimated as the latency difference between electrically and air-puff evoked responses.

RESULTS

Thirty units were analyzed: all 4 kinds of mechanoreceptors of human glabrous skin (fast adapting type 1 [FA I, n=7], fast adapting type 2 [FA II, n=4], slowly adapting 1 [SA I, n=5] and slowly adapting 2 [SA II, n=14]) were activated by air-puff stimulation. Estimated receptor activation times were 0.6-6.2 ms (mean 2.2 ms). FA II units occasionally responded twice or more to a single air-puff stimulus.

CONCLUSIONS

Brief air-puffs can activate all 4 human cutaneous mechanoreceptors, and the receptor transduction time is estimated as approximately 2.0 ms. Properties of human mechanoreceptors can be studied using air-puff stimulation and microneurography.

Uptake by hepatocytes and biliary excretion of intravenously administered polystyrene microspheres in rats

The in vivo uptake by hepatocytes and biliary excretion of fluorescein isothiocyanate-labeled polystyrene microsphere with a particle size of 50 nm (MS-50) after intravenous administration was studied in rats. It was confirmed by using confocal laser scanning microscopy that MS-50 was partially phagocytosed by the hepatocytes and that MS-50 taken up by the hepatocytes existed exclusively inside the cells 1 h after intravenous administration. Studies on the mechanism of the uptake of MS-50 by the hepatocytes using the liver perfusion technique revealed that a process mediated by apo-E was involved. After intravenous administration of MS-50, about 4% of dose was excreted into bile in 24 h. Pharmacokinetic evaluation of the excretion rate of MS-50 into bile showed that the process followed first-order kinetics. Qualitative evaluation of the fluorescence detected in the bile after intravenous administration of MS-50 revealed that the particles were certainly excreted into bile in an intact form. From these results, it was suggested that intravenously administered MS-50 would be partially phagocytosed by hepatocytes through a process mediated by apo-E and that MS-50 ingested by hepatocytes would be partially excreted into the bile.

"Tactile" sensory nerve potentials elicited by air-puff stimulation: a microneurographic study

To investigate the sensory nerve responses to selective touch stimulation, sensory nerve action potentials after brief air-puffs were recorded with a microelectrode. In patients with peripheral neuropathy, those with impairment of tactile sensations had significantly smaller responses than did those without tactile impairment, suggesting receptor activation failure as well as nerve conduction failure. Brief air-puff stimulation, when combined with microneurography, could be used for evaluating the tactile receptor properties in humans.

Isolated absence of F waves and proximal axonal dysfunction in Guillain-Barré syndrome with antiganglioside antibodies

OBJECTIVES

To investigate the pathophysiology of selective absence of F waves and its relation with antiganglioside antibodies in Guillain-Barré syndrome (GBS). Some patients with GBS show the absence of F waves as an isolated conduction abnormality, which has been interpreted as demyelination in the proximal nerve segments.

METHODS

In 62 consecutive patients with GBS, sequential nerve conduction and F wave studies were reviewed, and antibodies against ganglioside GM1, GM1b, GD1a, GalNAc-GD1a, GD1b, and GQ1b were measured by an enzyme linked immunosorbent assay.

RESULTS

In the first electrophysiological studies, isolated absence of F waves was found in 12 (19%) patients. Sequential studies in 10 of these patients showed two electrophysiological sequel patterns; rapid restoration of F waves (six patients), and persistent absence of F waves with distal motor nerve degeneration (acute motor axonal neuropathy, four patients). None of the 10 patients showed evidence of demyelination in the proximal, intermediate, or distal nerve segments throughout the course. Of the 62 patients, IgG antibodies against GM1, GM1b, GalNAc-GD1a, or GD1b were significantly associated with the electrodiagnosis of acute motor axonal neuropathy, and patients with these antibodies more often had isolated absence of F waves than patients without them (11 of 36 (31%) v one of 26 (4%); p<0.01). Eleven of the 12 patients with isolated absence of F waves had positive serology for one or more antiganglioside antibodies.

CONCLUSIONS

In GBS with antiganglioside antibodies, isolated absence of F waves is a frequent conduction abnormality especially in the early phase of the disease, and may be caused by axonal dysfunction, such as physiological conduction block or axonal degeneration at the nerve roots.

IgG anti-GQ1b positive acute ataxia without ophthalmoplegia

IgG anti-GQ1b antibody was present in a patient with acute ataxia and areflexia without ophthalmoplegia or elementary sensory loss. Sensory nerve conduction studies and somatosensory evoked potentials were normal, but postural body sway analysis showed dysfunction of the proprioceptive afferent system. The clinical presentation and laboratory results for this patient resemble those of Miller Fisher syndrome, except for the lack of ophthalmoplegia. This case may represent part of an IgG anti-GQ1b syndrome.

Interaction of polystyrene microspheres with liver cells: roles of membrane receptors and serum proteins

Our previous studies have demonstrated that serum would play an important role in the hepatic disposition of polystyrene microspheres (MS) and that complement C3 should be involved as the serum opsonin. In this study, we tried to identify the entity of other serum opsonins and dysopsonin for the hepatic uptake of MSs with particle sizes of 50 nm (MS-50) and 500 nm (MS-500) by isolated liver perfusion studies using a recirculation procedure in rats. Pretreatment of the liver by trypsin significantly suppressed the serum-dependent hepatic uptake of both MSs, suggesting that some protein components on the cell surface should be necessary for the serum-dependent phagocytosis of MSs. Pretreatment of the serum by the anti-fibronectin antibody resulted in a significant reduction in the hepatic disposition of MS-500 (49% of control), suggesting that fibronectin should also work as the opsonin for the hepatic uptake of MS-500. The hepatic disposition of both MSs in the presence of serum was inhibited by the addition of N-acetylgalactosamine into the perfusate, suggesting the possible involvement of lectin in the serum-dependent hepatic uptake of MSs. Furthermore, a more intensive hepatic disposition of MSs was observed in the presence of plasma compared with that in the presence of serum in the perfusate, suggesting the possible involvement of blood coagulation factors, such as fibrinogen, as the opsonin in the hepatic disposition of MSs.

Mechanisms of hepatic disposition of polystyrene microspheres in rats: effects of serum depend on the sizes of microspheres

To study the mechanisms of the hepatic disposition of polystyrene microspheres (MS), effects of serum on their hepatic disposition characteristics were investigated for MSs with particle sizes of 50 nm (MS-50) and 500 nm (MS-500) by isolated liver perfusion experiments. It was revealed that serum in the perfusate inhibited and promoted the hepatic disposition of MS-50 and MS-500 at 37 degrees C, respectively. However, pre-heating at 56 degrees C or pre-treatment with anti-C3 antibody of serum reduced the promotive effect of serum on the hepatic uptake of MS-500, suggesting that the complement system should be involved as opsonins for the hepatic uptake of MS-500. Hepatic disposition of both MSs at 4 degrees C was reduced by the addition of serum into the perfusate, which could be ascribed to the reduction of the surface hydrophobicity of MSs due to the adsorption of serum proteins onto the surface of MSs and to resultant decrease in non-specific disposition to the liver. From these results, serum was found to function both as the opsonin to enhance the hepatic uptake of MSs and as the inhibitor by reducing non-specific interaction between MSs and the plasma membrane. Whether serum promotes or inhibits the hepatic disposition of MSs would be dependent on the particle sizes of MSs.

Carrier-mediated transport systems for glucose in mucosal cells of the human oral cavity

The in vitro uptake study was performed using the isolated cells of human oral mucosa, buccal and the dorsum of the tongue, to investigate the mechanisms of glucose uptake. The uptake of D-glucose was much larger in cells of the dorsum of the tongue than in buccal cells and was inhibited more extensively by 2-deoxy-D-glucose, a substrate of facilitative glucose transporters, than by alpha-methyl-D-glucoside, a specific substrate of SGLT1, suggesting the larger contribution of a facilitative transporter than Na(+)/glucose cotransporter. Furthermore, from the results of inhibition studies by several sugar analogues including maltose and D-mannose, GLUT1 and/or GLUT3 were suggested to take part in the glucose uptake by oral mucosa. Therefore, we have attempted to confirm the expression of glucose transporters on the oral mucosa by employing Western blotting. As a result, it was suggested that SGLT1, GLUT1, GLUT2, and GLUT3 are expressed in the epithelial cells of human oral mucosa.

Hyperreflexia in Guillain-Barré syndrome: relation with acute motor axonal neuropathy and anti-GM1 antibody

OBJECTIVES

To investigate the incidence of hyperreflexia in patients with Guillain-Barré syndrome (GBS), and its relation with electrodiagnosis of acute motor axonal neuropathy (AMAN), antiganglioside GM1 antibody, and Campylobacter jejuni infection. It was reported that patients with AMAN in northern China often had hyperreflexia in the recovery phase.

METHODS

In 54 consecutive Japanese patients with GBS, sequential findings of tendon reflexes were reviewed. By electrodiagnostic criteria, patients were classified as having AMAN or acute inflammatory demyelinating polyneuropathy (AIDP). Anti-GM1 and anti-C jejuni antibodies were measured by enzyme linked immunosorbent assays.

RESULTS

Seven (13%) patients developed hyperreflexia with the spread of the myotatic reflex to other segments in the early recovery phase, one of whom already had hyperreflexia in the acute progressive phase. Of the seven patients, six had AMAN and all seven had anti-GM1 antibodies, whereas only two had anti-C jejuni antibodies. Hyperreflexia was more often found in patients with AMAN than AIDP (6/23 v 1/18, p=0. 002), and in patients with anti-GM1 antibodies than without them (7/26 v 0/28, p=0.01). Hyperreflexic patients had milder peak disabilities than patients without hyperreflexia (p=0.03). Increased motor neuron excitability in the hyperreflexic patients was supported by increased soleus H-reflex amplitudes and the appearance of H-reflexes in the small hand or foot muscles.

CONCLUSIONS

Hyperreflexia often occurs in patients with GBS especially with AMAN, anti-GM1 antibodies, and milder disease. Increased motor neuron excitability further characterises the subgroup of patients with GBS with AMAN and anti-GM1 antibodies.

Activity-dependent excitability changes in chronic inflammatory demyelinating polyneuropathy: A microneurographic study

The purpose of this study was to investigate activity-dependent excitability changes in polyneuropathy and their correlation with symptomatology. First, we recorded sensory nerve action potentials (SNAPs) with an intraneural microelectrode during impulse trains in 11 patients with chronic inflammatory demyelinating polyneuropathy. When the stimulus frequency was increased to >/=20 Hz, all patients showed marked decreases in the amplitudes of averaged SNAPs (128 responses) associated with latency increases. The amplitude decreases were much greater than those in patients with axonal neuropathies. In single-unit recordings, responses showed latency increases, which were small but sufficient to cause decreases in the averaged responses. Clinical sensory impairment was correlated with the degree of preexisting conduction block or axonal loss, but not with the degree of rate-dependent amplitude decreases. Activity-dependent changes occur preferentially in demyelinating neuropathy and are a sensitive measure of demyelination. The mechanism responsible for the amplitude decreases could be conduction slowing or block caused by activity-dependent hyperpolarization.

Dissociated small hand muscle involvement in amyotrophic lateral sclerosis detected by motor unit number estimates

In some patients with amyotrophic lateral sclerosis (ALS), the thenar hand is more severely affected than the hypothenar hand. To quantify the dissociated involvement, we examined the motor unit number estimate (MUNE) of both the abductor pollicis brevis (APB) and abductor digiti minimi (ADM) muscles in 23 patients with ALS. Whereas ALS patients had significantly smaller MUNEs than normal subjects in both muscles, the extent of motor unit loss was significantly greater in the APB than ADM. Moreover, a simple comparison of the amplitude of compound muscle action potentials (CMAPs) showed that ALS patients had significantly smaller APB/ADM ratios than normal subjects and patients with cervical spondylotic amyotrophy, bulbospinal muscular atrophy, or peripheral neuropathy. The more severe involvement of the APB probably reflects the specific pathophysiology in ALS, and possible mechanisms for the dissociated involvement are discussed.

Axonal involvement at the common entrapment sites in Guillain-Barré syndrome with IgG anti-GM1 antibody

If anti-GM1 antibody plays a role in the axonal damage in Guillain-Barré syndrome, the common entrapment sites may be preferentially involved with evidence of axonal dysfunction. To assess this hypothesis, we studied nerve conduction across the cubital tunnel in 44 patients. Abnormal amplitude reduction of compound muscle action potentials (CMAPs) was found in 45% of 20 immunoglobulin G (IgG) anti-GM1-positive and in 29% of 24 anti-GM1-negative patients. The time course and sequel were distinct between the two groups. In the former group, the amplitude reduction was prominent in weeks 1 to 2 and was followed by a decrease in distal CMAPs (axonal degeneration) or an increase in proximal CMAPs (resolution of conduction block). In contrast, anti-GM1-negative patients showed slower resolution with temporal dispersion. In anti-GM1-positive cases, amplitude reduction at the common entrapment site is frequent and may reflect wallerian degeneration or physiological conduction block at the nodes of Ranvier, both suggesting axonal involvement.

Pharmacokinetic evaluation of mannosylated bovine serum albumin as a liver cell-specific carrier: quantitative comparison with other hepatotropic ligands

To assess the feasibility of mannosylated macromolecules as a liver-specific carrier system, hepatic uptake characteristics of mannosylated bovine serum albumin (Man-BSA) were pharmacokinetically investigated. After intravenous injection, 111In-Man18-BSA accumulated in the liver up to 70% of dose at 2h; the endothelial cells and Kupffer cells contributed about 66% and 21% of the uptake, respectively. In single-pass perfusion experiments using rat liver at varying inflow concentrations (0.1-2.0 microg/ml), 111In-Man18-BSA and 111In-Man33-BSA were continuously extracted by the liver and their extraction ratios decreased with the increasing inflow concentrations. The outflow curves of each 111In-Man-BSA at three concentrations were simultaneously fitted to a pharmacokinetic model including a binding to the cell surface and an internalization, by using a nonlinear regression program MULTI(RUNGE). The binding constant augmented with the increase in the number of mannose per BSA, whereas the internalization rate constant was quite comparable for both derivatives. The pharmacokinetic analysis has demonstrated that the uptake process of 111In-Man-BSA is characterized to possess fewer binding sites and a greater internalization rate in comparison with other liver-specific carriers such as galactosylated, succinylated and cationized BSAs. These results will provide useful information in designing drug targeting systems to the liver nonparenchymal cells via mannose receptors.

Hepatic uptake of polystyrene microspheres in rats: effect of particle size on intrahepatic distribution

The in vivo disposition of polystyrene microsphere (MS) with the particle size of 50 nm (MS-50) or 500 nm (MS-500) was characterized after intravenous administration to rats. A rapid elimination from systemic circulation was observed for both MSs. Tissue distribution of MS-50 and MS-500 at 1 h after intravenous injection indicated that both MSs were exclusively distributed to liver and that small but significant amounts of MS-50 and MS-500 were also distributed to lung and spleen, respectively. To investigate the intrahepatic distribution of MS, liver was separated into liver parenchymal cells (PC) and non-parenchymal cells (NPC) at 1 or 6 h after intravenous administration. The contribution of each cell fraction was dependent on both the size of MS and the time after administration. Furthermore, by separating the NPC into endothelial cells and Kupffer cells using a centrifugal elutriation method, their contribution was also evaluated. For both MSs, Kupffer cells were recognized to be mostly responsible for the hepatic uptake, although a significant amount of MS-50 (about 28% of total uptake) was taken up by PC. On the other hand, there was little contribution of PC (about 5%) to the hepatic uptake of MS-500. The endothelial cells were contributed larger to the uptake of MS-500 (about 24%) than that of MS-50 (13%).

Pure topographical disorientation due to right posterior cingulate lesion

We report an 82-year-old woman who developed pure topographical disorientation after a cerebral infarction involving the isthmus of the right posterior cingulate gyrus. She lost her way in new environments such as the hospital, but not in old ones such as her own house. She correctly identified familiar or unfamiliar landscapes and buildings by photographs. Her failure to memorize a new route likely resulted from a loss of directional memory over a wide area. We suggest that the right posterior cingulate gyrus contributes to memorizing a new route.

Estimation of intradermal disposition kinetics of drugs: I. Analysis by compartment model with contralateral tissues

PURPOSE

The objectives of dermal application of drugs are not only systemic therapeutic, but also local ones. We would expect its intradermal kinetics to be dependent on its therapeutic purpose. To develop more efficient drugs for local or systemic therapeutics, it will be important to estimate quantitatively the intradermal disposition of drugs applied topically. We tried, therefore, to develop the compartment model to describe the intradermal disposition kinetics after topical application of drugs.

METHODS

In vivo percutaneous absorption study for antipyrine, a model compound, was performed using rats with tape-stripped skin, using the assumption that the stratum corneum permeability to drugs would be improved enough not to be a rate-limiting process.

RESULTS

To analyze the results obtained, a 4-compartment model, composed of donor cell, viable skin, muscle, and plasma compartments, was applied. Although the fitting lines obtained could describe the concentration-time profiles of antipyrine in each compartment very well, the concentration profiles in the contralateral tissues were extensively overestimated. Therefore, we developed a 6-compartment model which included the viable skin and muscle in the contralateral site, and analysed the concentration-time curve of each compartment. The fitting curves were in good agreement with the experimental data for all the compartments including the contralateral viable skin and muscle, and thus, this model was recognized to be adequate for the estimation of intradermal kinetics after topical application. Judging from the obtained values of clearance from viable skin to plasma and from viable skin to muscle, about 80% of antipyrine penetrated into viable skin, which suggested it was absorbed into circulating blood and 20% was transported to muscle under viable skin.

CONCLUSIONS

Pharmacokinetic analysis using the 6-compartment model would be very useful for the estimation of local and systemic availability after topical application of drugs.

Absorption behavior of orally administered drugs in rats treated with propantheline

The effect of gastrointestinal (GI) transit rate on the absorption behavior of orally administered drugs was investigated using rats pretreated with propantheline. The propantheline-treatment reduced the transit rate in all segments to approximately 50%. The absorption behavior was examined for three model drugs with different absorption characteristics: theophylline as a highly absorbable drug without the first-pass elimination, ampicillin as a poorly absorbable one, and cephalexin as a highly absorbable one via carrier-mediated transport system. In the GI transit-retarded state, the Tmax of the plasma concentration-time curve was delayed in all the three drugs. However, the extent of bioavailability was not changed in theophylline and cephalexin. On the other hand, the extent of bioavailability of ampicillin was increased in rats pretreated with propantheline. This might be caused by the increased residence time in the absorption site, i.e., small intestine. These results were generally predicted by use of the convolution method based on the GI-Transit-Absorption Model, which was developed in our previous study, using the GI transit rate parameters in rats pretreated with propantheline. The analysis using this model could clarify that the substantial absorption site of cephalexin moved to the upper region of the small intestine by the reduction of the GI transit rate.

Absorption behavior of orally administered drugs in rats treated with propantheline

The effect of gastrointestinal (GI) transit rate on the absorption behavior of orally administered drugs was investigated using rats pretreated with propantheline. The propantheline-treatment reduced the transit rate in all segments to approximately 50%. The absorption behavior was examined for three model drugs with different absorption characteristics: theophylline as a highly absorbable drug without the first-pass elimination, ampicillin as a poorly absorbable one, and cephalexin as a highly absorbable one via carrier-mediated transport system. In the GI transit-retarded state, the Tmax of the plasma concentration-time curve was delayed in all the three drugs. However, the extent of bioavailability was not changed in theophylline and cephalexin. On the other hand, the extent of bioavailability of ampicillin was increased in rats pretreated with propantheline. This might be caused by the increased residence time in the absorption site, i.e., small intestine. These results were generally predicted by use of the convolution method based on the GI-Transit-Absorption Model, which was developed in our previous study, using the GI transit rate parameters in rats pretreated with propantheline. The analysis using this model could clarify that the substantial absorption site of cephalexin moved to the upper region of the small intestine by the reduction of the GI transit rate.

Allelic loss of chromosome 13q14.3 in human oral cancer: correlation with lymph node metastasis

To evaluate the role of chromosome 13 deletions in oral squamous cell carcinoma (SCC) progression and to define the precise localization of putative tumor suppressor genes, we studied tumors from 34 unrelated patients with oral SCC by the polymerase chain reaction (PCR)-loss of heterozygosity (LOH) assay, using 18 different polymorphic loci. Chromosome 13q allelic losses (LOH) were observed in 67.6% at 1 or more loci. These results enabled the identification of a putative minimal region of deletion mapped at 13q14.3. The commonly deleted region is located close, but telomeric to the RB1 locus. We also examined the same samples for inactivation of the RB1 gene by immunohistochemical analysis of paraffin-embedded samples, but no significant variation in RB protein expression was detected. In addition, we also performed PCR-single-strand conformational polymorphism (SSCP) analysis to detect any mutation of the RB1 gene using 52 primer pairs, which covers all exons of this gene. We found no mutations of the RB1 gene in our samples. Interestingly, we found significant correlation between LOH of 13q14.3 and lymph node metastasis. Our results indicate that LOH of 13q is a common event in oncogenesis and/or progression of oral SCC, and also suggest the existence of a new suppressor gene near D13S273-D13S176 loci which may play a role in these events.

Allelic loss of chromosome 13q14.3 in human oral cancer: correlation with lymph node metastasis

To evaluate the role of chromosome 13 deletions in oral squamous cell carcinoma (SCC) progression and to define the precise localization of putative tumor suppressor genes, we studied tumors from 34 unrelated patients with oral SCC by the polymerase chain reaction (PCR)-loss of heterozygosity (LOH) assay, using 18 different polymorphic loci. Chromosome 13q allelic losses (LOH) were observed in 67.6% at 1 or more loci. These results enabled the identification of a putative minimal region of deletion mapped at 13q14.3. The commonly deleted region is located close, but telomeric to the RB1 locus. We also examined the same samples for inactivation of the RB1 gene by immunohistochemical analysis of paraffin-embedded samples, but no significant variation in RB protein expression was detected. In addition, we also performed PCR-single-strand conformational polymorphism (SSCP) analysis to detect any mutation of the RB1 gene using 52 primer pairs, which covers all exons of this gene. We found no mutations of the RB1 gene in our samples. Interestingly, we found significant correlation between LOH of 13q14.3 and lymph node metastasis. Our results indicate that LOH of 13q is a common event in oncogenesis and/or progression of oral SCC, and also suggest the existence of a new suppressor gene near D13S273-D13S176 loci which may play a role in these events.

Role of P-glycoprotein as a secretory mechanism in quinidine absorption from rat small intestine

The intestinal transport of quinidine was characterized in rat small intestine, using the Ussing-type chamber under short-circuited conditions. In the short-circuited condition, quinidine transport was predominantly secretory and the transport rate in jejunum was 3.5 times larger in the secretory direction than that in the absorptive direction. The secretion of quinidine was found to be dependent upon its concentration and to be via a carrier-mediated system in both jejunum and ileum. Although the kinetic characteristic of the carrier-mediated secretion of quinidine was very similar in jejunum and ileum, its contribution was much greater in jejunum because of a higher passive diffusion component in ileum. The secretion of quinidine, well-known as an inhibitor of P-glycoprotein, was inhibited significantly and its absorption was enhanced significantly by several substrates of P-glycoprotein including verapamil, diltiazem, and digitoxin in jejunum. These phenomena were also observed by the addition of 2,4-dinitrophenol. Furthermore, the voltage-clamp studies indicated that the inhibition of quinidine secretion occurred in the transcellular pathway. On the other hand, neither tetraethylammonium nor p-aminohippuric acid affected the transport of quinidine. Quinidine was also recognized to inhibit the secretion and to promote the absorption of substrates of P-glycoprotein, chlorpromazine, and verapamil. These results strongly suggest that quinidine is not only an inhibitor but also a substrate of P-glycoprotein and that the P-glycoprotein-mediated secretory flux acts as a barrier to quinidine absorption in the small intestine, especially jejunum.

Pharmacokinetic analysis of hepatic uptake of galactosylated bovine serum albumin in a perfused rat liver

Hepatic uptake of 111In-labelled galactosylated bovine serum albumin (Gal-BSA) with different number of galactose residues per BSA were studied in rat liver perfusion experiments. During a single-pass constant infusion mode, [111In]Gal-BSAs (0.1-2.0 micrograms/ml) were continuously extracted by the liver and its extraction ratio at steady-state (Ess) was lowered as the inflow concentration increased. Hepatic clearance of [111In]Gal-BSAs increased significantly according to the increase in the number of galactose residues per BSA at an inflow concentration of 0.7 micrograms/ml. The outflow patterns of [111In]Gal-BSAs at various inflow concentrations were simultaneously fitted to a one-organ pharmacokinetic model, by which we can characterize their binding to the cell surface and internalization processes separately. The parameters obtained were varied significantly among [111In]Gal-BSAs depending on the number of galactose residues and indicate that not only the binding to the receptors but also the internalization after the binding are regulated by the number of galactose residues per BSA during hepatic uptake.

[Efficacy of TRH-T for spinocerebellar degeneration--the relation between clinical features and effect of TRH therapy]

Thyrotropin releasing hormone (TRH) therapy has been frequently attempted for the treatment of spinocerebellar degeneration (SCD) and its efficacy has been confirmed. However, effectiveness is considered to differ depending on disease type, severity and the method of evaluating clinical improvement. We investigated the efficacy of thyrotropin releasing hormone-tartrate (TRH-T) in 23 patients with SCD consisting of cerebellar form (cortical cerebellar atrophy (CCA) and hereditary cortical cerebellar atrophy (H-CCA)), and multiple system form (multiple system atrophy (MSA) and hereditary olivopontocerebellar atrophy (H-OPCA)). TRH-T, 2 mg per day, was given intravenously for 20 days. The effect of TRH therapy was evaluated by assessing changes in balance function while lying, sitting, standing and walking, that may reflect the movement functions in active daily life (ADL) for the patients with SCD. The speech function was also evaluated qualitatively using acoustic analysis. The amine metabolites (HVA and 5-HIAA) in cerebrospinal fluid possibly reflecting the noradrenaline and serotonin metabolism in the central nervous system were measured before and after treatment. Although mild or moderate improvement of the balance function during the course of TRH therapy was seen in 16 of the 23 patients, patients with cerebellar forms (CCA and H-CCA) improved significantly as compared to patients with MSA. The effect persisted for a long time (mean; 3.8 months) after TRH therapy in nine of the 16 patients, and eight (88.9%) of the nine had the cerebellar form of SCD. The levels of HVA and 5-HIAA in CSF also increased in patients with CCA as compared to patients with MSA and H-OPCA. The disease severity before the treatment in 14 (87.5%) of 16 patients who showed improvement of balance functions by TRH therapy was mild or moderate; possible of walking without support, or occasionally with support. Considering these results together, TRH therapy may be effective in patients with the cerebellar form of SCD, whose illness severity is mild, and may be recommended for support of ADL in patients with the cerebellar form of SCD.