A cross-sectional study of vitamin C and cognitive function in older adults: the differential effects of gender

Previous studies have suggested that vitamin C status may be associated with cognitive function in community-dwelling populations. However, this has not been consistent across all studies due to methodological differences. This cross-sectional study assessed the association between vitamin C and cognitive function in 544 community-dwelling older adults aged 65 or older who participated in both the Cardiovascular Health Study (CHS) and the CLUE II study in 1989. Three percent of the subjects had low plasma vitamin C concentrations (< 40 mg/dL) and 15% had low total vitamin C intake (< 60 mg/day). Most participants (96.7 percent) had normal cognitive function. In the unadjusted analyses, the highest fifth of plasma vitamin C concentration was associated with better Digit Symbol Substitution Test (DSST) scores and marginally associated with Mini-Mental State Examination (MMSE) compared to the lowest fifth. Total vitamin C intake, measured by Block's food frequency questionnaire, was generally associated with higher MMSE scores, though it was not significant. Adjusting for numerous factors did not substantially change results. In a stratified analysis by gender, higher plasma concentrations or intake were associated with higher MMSE scores for men but not for women. These mixed results do not provide strong evidence of an association between vitamin C concentrations or intake and cognitive function.

Practice patterns of Japanese physicians in urologic surveillance and management of spinal cord injury patients

STUDY DESIGN

Analysis of answers to a new questionnaire.

OBJECTIVE

To examine current practice patterns of physicians in the urological surveillance and management of spinal cord injury (SCI) patients in Japan.

SETTING

Nationwide questionnaire survey to physicians in Japan.

METHODS

A Japanese version of the 14-item questionnaire survey carried out in US was mailed to 770 members of the Japanese Neurogenic Bladder Society (JNBS).

RESULTS

We received answers to our questionnaire from 333 (43.2%) members of JNBS. The responders were all urologists. For surveillance of the upper urinary tract (UUT), 239 (71.8%) respondents preferred abdominal ultrasound. Cystometry was performed routinely by 174 (52.3%) respondents for the evaluation of vesicourethral function. Cystoscopy was carried out in cases of hematuria (88.0%) and bladder stone (55.3%). Surveillance of the urinary tract was performed every year in 154 (46.2%). For detection of bladder cancer, which 119 (37.9%) respondents have experienced, 94.9% physicians perform cystoscopy, 76.3% urinary cytology, and 60.4% ultrasound. For initial treatment of detrusor-sphincter dyssynergia (DSD), 225 (69.2%) respondents chose alpha-blocker, and 94 (28.9%) chose clean intermittent catheterization (CIC) with/without anticholinergic agent(s). For initial treatment of overactive bladder, 245 (74.7%) chose anticholinergic agent(s) only and 63 (19.2%) chose anticholinergic agent(s) with CIC. For initial treatment of areflexic bladder, 233 (73.7%) chose CIC and 63 (19.9%) chose Credé maneuver or tapping.

CONCLUSIONS

This survey shows that there are some differences in urological surveillance and management of SCI patients between Japan and the US. Reasons for the discrepancy should be examined.

Cervical angina: a seemingly still neglected symptom of cervical spine disorder?

STUDY DESIGN

Retrospective, case series.

DESIGN

A review of 10 surgical cases with symptoms of cervical angina.

OBJECTIVE

To stress the importance of symptoms of cervical angina in patients with cervical spine disorders.

SETTING

Fukui University Hospital, Japan.

RESULTS

A total of 10 patients complaining of symptoms of cervical angina were admitted with a tentative diagnosis of coronary artery disease. Pain relief was achieved by anterior surgical decompression in all patients.

CONCLUSION

We stress that physicians should be aware of the symptoms of cervical angina and that surgical intervention often leads to complete relief of symptoms.

Cruciate paralysis and hemiplegia cruciata: report of three cases

STUDY DESIGN

Report of three cases of cruciate paralysis and hemiplegia cruciata.

OBJECTIVE

To stress the importance of upper cervical spine lesions causing neurological symptoms and signs.

SETTING

Neuro-orthopedic service, Fukui University Hospital, Japan.

RESULTS

Three patients (all females; one with congenital anomaly at the occiput-atlas level, one with assimilation of the atlas, and one with rheumatoid arthritis-related proliferative synovium) had clinical features of cruciate paralysis and hemiplegia cruciata. All three cases underwent decompressive surgeries.

CONCLUSION

Neurological symptoms and signs of cruciate paralysis and hemiplegia cruciata should be carefully assessed, and surgical therapy should be based on the pathological condition.

Retroperitoneal lymphocele associated with lumbar spine fracture: report of an unusual case

DESIGN

To describe a case of retroperitoneal lymphocele as an extremely rare complication after lumbar spine fracture.

OBJECTIVE

To discuss the possible mechanism of development of retroperitoneal lymphocele following blunt trauma to the ureter and lumbar spine.

SETTING

Fukui University Hospital, Fukui, Japan.

RESULTS

A 71-year-old man presented with severe intractable low back pain caused by a huge retroperitoneal lymphocele, which was considered to be related to an occult L4 vertebral fracture and a blunt ureteral injury. The retroperitoneal lymphocele also caused significant instability at L3-4 level, thus requiring surgical resection followed by interbody fusion.

CONCLUSION

Physicians should be aware that such unusual retroperitoneal lymphocele might develop even after a blunt ureteral injury or a minor lumbar spine fracture.

Primary osteosarcoma of the thoracic spine: report of an unusual elderly patient with autopsy findings

STUDY DESIGN

A case report of primary osteosarcoma of the spine in an elderly patient.

OBJECTIVE

The histopathological features of osteosarcoma vary widely, often leading to diagnostic difficulties particularly when there is little evidence of osteoid formation. The report describes the difficulty in the diagnosis of osteosarcoma of the thoracic vertebra.

SETTING

Department of Orthopaedics and Rehabilitation Medicine, Fukui University Faculty of Medicine, Fukui, Japan.

METHOD

A 78-year-old man presented with paraparesis and underwent urgent anterior excision of a primary spinal tumor emanating from the T10 vertebra followed by artificial vertebral replacement. The patient eventually died of disseminated disease of vertebral osteosarcoma.

RESULTS

Samples from the T10 vertebral tumor showed neoplastic growth of atypical spindle-shaped cells, with foci of storiform-like proliferation. The tissue also demonstrated positive immunohistochemical staining for vimentin and alpha-smooth muscle actin and a tentative diagnosis of leiomyosarcoma was made. However, a metastatic nodule of the chest wall at autopsy showed focal osteoid formation, a finding not seen in the primary tumor.

CONCLUSION

Early detection and accurate diagnosis is important for improving not only patient prognosis but also the quality of life. We should always consider this rare entity, particularly in elderly patients who present with back pain and vertebral collapse.

Lymph node pathway in the spread of endometrial carcinoma

OBJECTIVE

To elucidate the sentinel nodes of endometrial carcinoma, the spread pathway was clarified. The correlation between lymph node spread and other clinicopathological variables was also analyzed.

METHODS

Dissected lymph node samples in 342 patients who underwent pelvic and selective paraaortic lymphadenectomy were reviewed. Pelvic and paraaortic node (PLN and PAN) status was compared with clinicopathological parameters.

RESULTS

Lymph node metastasis was demonstrated in 52 patients, including 46 cases with PLN metastasis and six patients with independent PAN metastasis. The metastatic sites were most frequent in the obturator and internal iliac nodes. Eleven of 49 patients who underwent PAN dissection were positive for metastasis. Sixteen of 23 cases with parametrial metastasis also metastasized in the retroperitoneal lymph node.

CONCLUSION

The lymph node spread pathway in endometrial carcinoma consists of a major route via the obturator node or internal iliac node with or without parametrial involvement, and rarely a direct PAN pathway.

Prevention of critical telomere shortening by oestradiol in human normal hepatic cultured cells and carbon tetrachloride induced rat liver fibrosis

BACKGROUND AND AIM

Significant telomere shortening of hepatocytes is associated with replicative senescence and a non-dividing state in chronic liver disease, resulting in end stage liver failure and/or development of hepatocellular carcinoma. To prevent critical telomere shortening in hepatocytes, we have focused on oestrogen dependent transactivation of the human telomerase reverse transcriptase (hTERT) gene as a form of telomerase therapy in chronic liver disease.

METHODS

We examined expression of hTERT mRNA and its protein, and telomerase activity (TA) in three human normal hepatic cell lines (Hc-cells, h-Nheps, and WRL-68) before and after treatment with 17beta-oestradiol. The effects of exogenous oestradiol administration were examined in a carbon tetrachloride (CCl(4)) induced model of liver fibrosis in rats.

RESULTS

Expression of hTERT mRNA and its protein was upregulated by oestradiol treatment. Telomere length decreased in Hc-cells and h-Nheps with accumulated passages whereas with long term oestradiol exposure it was greater than without oestradiol. The incidence of beta-galactosidase positive cells, indicating a state of senescence, decreased significantly in oestradiol treated cells in comparison with non-treated cells (p<0.05). TA in both male and female rats with CCl(4) induced liver fibrosis was significantly higher with oestradiol administration than without (p<0.05). Long term oestradiol administration markedly rescued the hepatic telomere from extensive shortening in both male and female rats.

CONCLUSION

These results suggest that oestradiol acts as a positive modulator of the hTERT gene in the liver. Oestrogen dependent transactivation of the hTERT gene is a new strategy for slowing the progression of chronic liver disease.

Common virus infections in cats, before and after being placed in shelters, with emphasis on feline enteric coronavirus

The purpose of this study was to determine the origin and subsequent spread of feline calicivirus (FCV), feline herpesvirus (FHV), and feline enteric coronavirus (FECV) in cats relinquished to shelters. FCV was isolated from the oral fauces of 11% of healthy cats upon entry, and isolation rates were highest for kittens (33%). FHV shedding was very low (4%) at the time of entry and occurred mainly in juveniles. FECV shedding was also common among newly relinquished cats (33%), especially older kittens and juveniles (90%). The subsequent spread of all three viruses was rapid and efficient in the shelter environment. Fifteen percent of cats were shedding FCV, 52% FHV, and 60% FECV after 1 week. More detailed studies were done with FECV shedding, which could be accurately quantitated. The amounts of FECV shed by infected cats ranged from 10²to 10¹⁶particles/swab of feces. FECV shedding was several logs higher in young kittens with primary infection than adult cats with primary infections. The mean levels of FECV shedding among adults were the same for primary and chronic infections. Although shelters were not the primary source of these viruses for many relinquished cats, factors intrinsic to the shelter environment were critical in amplifying shedding and spread to susceptible individuals. Extrinsic factors were especially important for the spread of FHV and FECV. FHV shedding rates increased from 4% to 50% in 1 week's time. The speed and magnitude of the increase in FHV shedding suggested that there was reactivation of latent infections as well as acquisition of new infections. FECV shedding increased 10 to 1,000,000 fold in 1 week among cats that were already infected at entry, and more than one-half of initially negative cats were shedding FECV a week later. Feline calicivirus infection was the least likely to spread in the shelter. The infection rate only increased from 11 to 15% in 1 week.

Saline-assisted endoscopic resection of rectal carcinoids: cap aspiration method versus simple snare resection

BACKGROUND AND STUDY AIMS

Complete resection of small carcinoid tumors of the rectum is difficult during endoscopic polypectomy, because these tumors are often located in the submucosal layer of the rectal wall. To completely remove these tumors, we have used aspiration lumpectomy. In this study, we evaluated its clinical usefulness in comparison with strip biopsy.

PATIENTS AND METHODS

We performed strip biopsy (December 1996 through March 2000) or aspiration lumpectomy (April 2000 through February 2003) in a consecutive series of patients with rectal carcinoid tumor. Eight carcinoid tumors in eight patients were resected by strip biopsy, and eight tumors in eight patients were resected by aspiration lumpectomy.

RESULTS

The rate of complete removal of carcinoid tumors with aspiration lumpectomy (100 %) was significantly higher (P < 0.05) than that with strip biopsy (37.5 %).

CONCLUSIONS

Endoscopic resection with aspiration lumpectomy is a useful and safe method for resection of small carcinoid tumors of the rectum.

CTLA-4 blockade inhibits induction of Helicobacter pylori-associated gastritis in mice

The balance between Th1 and Th2 response determines the outcome of Helicobacter pylori infection. Interferon (IFN)-gamma plays an inductive role in gastric inflammation, whereas interleukin (IL)-4 counterbalances Th1 response and suppresses the development of gastritis. Th cell response is regulated by co-stimulatory factors. A co-stimulatory molecule, cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), plays an inhibitory role in IL-2-dependent cell growth and mediates an optimal inhibitory signal to Th1 and Th2 cells. We administered anti-CTLA-4 monoclonal antibody (MoAb), which blocks CTLA-4 signalling, to examine the relative role for this signalling during maturation of Th1 and Th2 cells in H. pylori infection in mice. Mice treated by anti-CTLA-4 MoAb within the first week of infection showed an inhibition of gastric inflammation, accompanied by an increasing ratio of H. pylori-specific IgG1/IgG2a in serum following infection. Furthermore, the treatment resulted in the higher ratio of IL-4/IFN-gamma by splenocytes in response to H. pylori antigen at 6 weeks after infection, compared with untreated mice. These results suggest that the predominance of Th2 response by CTLA-4 blockade leads to an inhibition of the development of gastric inflammation. CTLA-4 signalling could contribute to the regulation of Th subsets and the development of gastric inflammation in H. pylori infection.

Clinical evaluation of combined endoscopic variceal ligation and sclerotherapy of gastric varices in liver cirrhosis

BACKGROUND AND STUDY AIMS

Endoscopic injection sclerotherapy (EIS) using cyanoacrylate and balloon-occluded retrograde transvenous obliteration (B-RTO) are the main procedures used to treat gastric varices. However, neither technique is free of problems. EIS for gastric varices may cause embolism in other organs; B-RTO requires a gastrorenal shunt and may aggravate esophageal varices. We have developed a combined form of endoscopic therapy involving band ligation and sclerotherapy which is an effective and safe procedure for treating gastric varices.

PATIENTS AND METHODS

Fifty-six patients with gastric varices and liver cirrhosis were treated at Almeida Memorial Hospital from June 1997 to May 2002 using the combined procedure. Each gastric varix was tightly ligated with O-rings, and 1 % polidocanol was injected into the submucosa around the ligated varix. If necessary, additional sclerotherapy was carried out after the initial treatment.

RESULTS

The rate of hemostasis for variceal bleeding was 100 %, and no critical complications were noted. Complete disappearance of the gastric varices was observed endoscopically in all cases. Computed tomography showed that collateral vessels outside the gastric wall were not occluded by the treatment. Endoscopic follow-up examinations were carried out, and gastric varices recurred in seven patients (12.5 %). Only two of the patients (3.6 %) had a small amount of oozing bleeding. Additional endoscopic variceal ligation (EVL) and/or EIS were performed in these seven cases, and none of the patients died as a result of a bleeding gastric varix.

CONCLUSIONS

The combined procedure was easily performed immediately after endoscopic examination, and required no special apparatus. It was found to be a safe and effective method of treating gastric varices.

Parametrial spread is a prognostic factor in endometrial carcinoma

OBJECTIVE

Parametrial spread of endometrial carcinoma, including the histopathological pattern of the spread and its significance as a prognostic factor, as well as its correlation with other prognostic factors are not well understood.

METHODS

We reviewed histopathologically the resected parametria from 269 patients with endometrial carcinoma who underwent radical or modified radical hysterectomy with pelvic lymphadenectomy. The relationship between parametrial spread and other histopathological features, including histological type, tumor grade, depth of myometrial invasion, lymph vascular space invasion (LVSI) of the myometrium, cervical invasion, adnexal metastasis, lymph node metastasis and peritoneal cytology was studied. Clinical outcomes of the patients with parametrial spread were also evaluated.

RESULTS

Parametrial spread was demonstrated in 16 patients (5.9%). Direct invasion of cancer cells to connective tissue, LVSI and lymph-node metastasis in the parametrium were seen in 13, seven and three cases, respectively. Three patients had all three spread patterns. According to the FIGO surgical stage, parametrial spread was found in none of the 164 patients in Stage I, two (6.3%) of 32 in Stage II, 12 (16.9%) of 71 in Stage III, and two (100%) of two in Stage IV. The presence of parametrial involvement was significantly correlated with depth of myometrial invasion, cervical involvement, lymph-node metastasis, adnexal metastasis. LVSI in the myometrium and peritoneal cytology (each, p < 0.01). With a median follow-up of 68.3 months, six (37.5%) of 16 patients with parametrial involvement developed recurrence and died.

CONCLUSION

Direct parametrial extension or lymphatic involvement within the parametrium can occur in endometrial carcinoma. Patients with parametrial spread have a poor prognosis.

Effects of rebamipide, a gastro-protective drug on the Helicobacter pylori status and inflammation in the gastric mucosa of patients with gastric ulcer: a randomized double-blind placebo-controlled multicentre trial

AIMS

To investigate the effects of rebamipide on the Helicobacter pylori eradication rate with amoxicillin and omeprazole. The trial also examined its histological effects on gastro-mucosal inflammation after eradication.

METHODS

Two hundred and six H. pylori-positive patients with active gastric ulcer underwent 8-week based therapy (OA) consisting of 2-week amoxicillin with omeprazole and subsequent 6-week omeprazole. They randomly received either rebamipide (OA-R) or placebo (OA-P) for 16 weeks: combined with the OA based therapy, and subsequently for another 8 weeks. Besides eradication rate, inflammatory findings of gastric mucosa after eradication were evaluated histologically.

RESULTS

Per Protocol Set analysis showed no significant difference in eradication rate between OA-R (64.6%; 95% confidence interval, 54.3-75.0%) and OA-P (67.9%; 95% CI, 57.6-78.3%). Histological findings in the gastric mucosa of the ulcer region, however, indicated a significant improvement (P = 0.017) in inflammation scores in OA-R (1.84 +/- 0.41) compared with that in OA-P (2.02 +/- 0.39) after 16-weeks of treatment. This suppressive effect on inflammation was observed even in the OA-R patients unsuccessfully eradicated.

CONCLUSION

Rebamipide demonstrated a suppressive effect on the persistent and possibly chronic inflammation in the gastric mucosa of the ulcer region after eradication, but the drug did not improve the eradication rate.

Efficacy of triple therapy comprising rabeprazole, amoxicillin and metronidazole for second-line Helicobacter pylori eradication in Japan, and the influence of metronidazole resistance

BACKGROUND

The widespread use of eradication therapy for Helicobacter pylori in Japan has led to an increase in antibiotic-resistant strains and the problem of re-treatment in cases of eradication failure.

AIM

To perform drug sensitivity testing for metronidazole in 92 H. pylori-positive patients who had failed eradication treatment with first-line triple therapy, consisting of a proton pump inhibitor, amoxicillin and clarithromycin, and were administered metronidazole-containing second-line therapy.

METHODS

Second-line eradication therapy, consisting of rabeprazole (20 mg b.d.), amoxicillin (750 mg b.d.) and metronidazole (250 mg b.d.), was administered for 1 week and the eradication rates and influence of metronidazole resistance were determined.

RESULTS

The eradication rates for rabeprazole-amoxicillin-metronidazole were 88% (81/92) using intention-to-treat analysis and 91% (81/89) using per protocol analysis. The eradication rates were 97% (61/63) for metronidazole-sensitive strains and 82% (18/22) for metronidazole-resistant strains.

CONCLUSIONS

As second-line H. pylori eradication treatment in Japan, rabeprazole-amoxicillin-metronidazole triple therapy is effective, even with metronidazole-resistant strains.

Association of polymorphisms of the renin-angiotensin system and bradykinin B2 receptor with ACE-inhibitor-related cough

The use of angiotensin-converting enzyme (ACE) inhibitors to treat hypertension has recently increased. However, their use is associated with a persistent dry cough in a significant percentage of such patients. The present study was designed to assess the contribution of polymorphisms as a genetic marker of ACE-inhibitor-related cough in a Japanese hypertensive population. Genotyping was carried out in 190 patients, 70 with cough and 120 without cough, who had been treated with ACE inhibitors. Polymorphisms of ACE insertion/deletion (I/D), angiotensin II type 1 receptor (1166A/C), type 2 receptor (3123C/A), and bradykinin B2 receptor (-58T/C, exon 1, I/D), were analyzed in these subjects. The TT genotype and T allele of bradykinin B2 receptor (-58T/C) were identified at a significantly higher frequency in the cough (+) patients than in the cough (-) patients. This difference was even more pronounced in women. However, there was no significant relationship between polymorphisms of ACE, angiotensin II receptors, or bradykinin B2 receptor exon 1, and occurrence of ACE-inhibitor-related cough. The transcriptional activity of the bradykinin B2 receptor promoter is involved in the occurrence of cough, and this new marker may provide a valuable tool to detect patients at risk of developing this side effect of ACE inhibitors. In conclusion, Susceptibility to develop cough is associated with a genetic variant of the bradykinin B2 receptor promoter; thus, it may be possible to identify those patients who will develop this adverse reaction to ACE inhibitors in advance.

Eradication rates of clarithromycin-resistant Helicobacter pylori using either rabeprazole or lansoprazole plus amoxicillin and clarithromycin

BACKGROUND

The resistance of Helicobacter pylori to clarithromycin has become one of the primary reasons for eradication failure.

AIM

To compare the eradication rates of triple therapy using amoxicillin (A), clarithromycin (C) and rabeprazole (R) or lansoprazole (L) against clarithromycin-sensitive and clarithromycin-resistant strains.

METHODS

Two hundred and ninety-five patients were randomly divided into four groups and treated for 1 week: 147 cases were treated with RAC, i.e. 49 cases with R20C400 (10 mg R + 750 mg A + 200 mg C, twice daily), 48 cases with R40C400 (20 mg R + 750 mg A + 200 mg C, twice daily) and 50 cases with R40C800 (20 mg R + 750 mg A + 400 mg C, twice daily); 148 cases with treated with LAC (30 mg L + 750 mg A + 200 mg C, twice daily).

RESULTS

According to intention-to-treat and per protocol analyses, the eradication rates were 88% and 91% with RAC and 78% and 81% with LAC; the eradication rates with R20C400, R40C400 and R40C800 were 94%, 81% and 86%, respectively, in the intention-to-treat analysis. In addition, the eradication rates for clarithromycin-sensitive strains with RAC and LAC were 98% and 89%, respectively, and for clarithromycin-resistant strains with RAC and LAC were 8.1% and 0%, respectively.

CONCLUSIONS

The eradication rate was significantly higher with RAC than LAC. The eradication rate for clarithromycin-resistant strains was low in both groups, and an improved eradication rate could not be achieved by changing the dose of clarithromycin or proton pump inhibitor.

Development of high-performance and rapid immunoassay for model food allergen lysozyme using antibody-conjugated bacterial magnetic particles and fully automated system

A high-performance and rapid chemiluminescence immunoassay for model food allergen lysozyme, one of the major allergenic components in egg white, using antibody-conjugated bacterial magnetic particles and a fully automated system was developed. This system contains a reaction station, tip rack, and an eight-tip pipettor that is able to attach and detach a strong magnet to the tip surface. The immunoreaction time was shortened to 5 min, and the assay was completed within 20 min. The lower detection limit for lysozyme was 10 ng/mL. This system can be used to perform 24 samples in 60 min within 10% coefficient of variation.

Sensitivity of biopsy site in evaluating regression of gastric atrophy after Helicobacter pylori eradication treatment

BACKGROUND

Helicobacter pylori infection is a major cause of the progress of gastric glandular atrophy, a high-risk background factor in the development of gastric cancer. Regression of gastric atrophy is critical to prevention of cancer by H. pylori eradication treatment. However, it is controversial whether gastric atrophy regresses after H. pylori eradication.

AIM

To determine the most sensitive and appropriate biopsy site for evaluation of regression of atrophy after treatment.

SUBJECTS AND METHODS

Thirty-eight patients who showed regression of gastric atrophy in histology after treatment were investigated. Four biopsy specimens from the lesser and greater curvatures in the antrum and corpus were evaluated before and after treatment according to the Updated Sydney System.

RESULTS

Regression of atrophy after treatment was seen in 30 of 38 biopsy specimens from the lesser curvature of the corpus (79%), and this site was most sensitive. Odds ratio of this site to the others was 8.28. Regression of atrophy in this site was observed at 12.2 months in the younger patients and 15.9 months in the elder patients.

CONCLUSION

Biopsy sampling from the lesser curvature of the corpus is the most sensitive and appropriate for evaluation of regression of gastric atrophy after H. pylori eradication treatment.

Distribution pattern of versican, link protein and hyaluronic acid in the rat periodontal ligament during experimental tooth movement

The ability of the periodontal ligament (PDL) to rapidly remodel is the basis of orthodontic tooth movement. During the tooth movement, matrix proteoglycans (PGs) may play important roles in spatial, mechanical and biological aspects for the maintenance and repair of the PDL. The aim of this study was to characterize the distribution of a large hyaluronic acid (HA)-binding proteoglycan, versican, link protein (LP) and HA in the rat molar PDL during experimental tooth movement by histochemical and immunohistochemical methods. Experimental tooth movement was performed according to Waldo's method. Histologically, regressive changes, such as decrease of fibroblasts and collagen fibers and exudative change of edema were observed in the compressive side and progressive changes, such as proliferation of fibroblasts and collagen fibers, in the strain side one day after treatment. By 3 days after tooth movement, regressive or progressive changes were not observed in either side. Using monoclonal antibodies specific to versican core protein or LP, the positive immunoreactivity for both molecules was constantly observed throughout the PDL. After the experimental force was applied to the tooth, however, the immunostainings of versican and LP became significantly intense only in the compressive side but decreased in the strain side. The intensity in the compressive side was strongest one day after the force was applied and gradually diminished thereafter. HA of both sides did not change during experimental tooth movement. Since HA is present in the PDL, large amounts of versican and LP expressed in the compressive side may create large hydrated aggregates via their association with HA that dissipates the compressive force applied to this tissue.