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Biomedical subjects

K Haraguchi

Publications and source records attributed to K Haraguchi.

At least 19 recordsLinked to original sources
PubMed2006

Bioaccumulation of naturally occurring mixed halogenated dimethylbipyrroles in whale and dolphin products on the Japanese market.

Mixed halogenated dimethyl bipyrroles (HDBPs), which are thought to be produced naturally, were quantified in whale and dolphin products marketed for human consumption in Japan. The major component of HDBPs was 3,3',4,4'-tetrabromo-5,5'-dichloro-1,1'-dimethyl -2,2'-bipyrrole (Br(4)Cl(2)-DBP), accounting for 85% of the total of five HDBPs detected, followed by Br(3)Cl(2)-DBP. Mean concentrations of HDBPs ranged from 0.27 microg/g lipid (n = 31) in minke whale (Balaenoptera acutorostrata) from the northwest Pacific Ocean to 11.8 microg/g lipid (n = 33) in bottlenose dolphin (Tursiops trucatus) from the southwest Japanese coastal water. At higher levels, HDBPs made up 37% of the total organohalogen body burden in Dall's porpoise (Phocoenoides dalli), whereas the contribution was less than 8.9% in minke whales. In two data subsets from Baird's beaked whale (Berardius bairdii), the products from the Pacific Ocean contained significantly higher concentrations of HDBPs than those from the Sea of Japan. Furthermore, the geographical distribution of HDBPs did not resemble those of ubiquitous anthropogenic organochlorines, such as polychlorinated biphenyl (PCBs). Higher concentration ratios of SigmaHDBP/SigmaPCB and different patterns of HDBP congeners were observed in whale products from the Asia-Pacific as compared to non-Pacific Ocean mammals reported previously. These results support the hypothesis that HDBPs and anthropogenic organochlorines have different sources and that the consumption of HDBPs by Japanese individuals could be an exposure/health risk.

Animals↗
PubMed2005

Distribution and toxicity of mercury in rats after oral administration of mercury-contaminated whale red meat marketed for human consumption.

Toothed-whales and dolphins have been hunted for human consumption in Japan, and their muscles (red meats) are highly contaminated with mercury (Hg). We investigated the distribution and toxicity of Hg in rats after oral administration of Hg-contaminated whale red meat marketed for human consumption in Japan. Rats were orally administered the red meat homogenate for seven consecutive days (0.5 g red meat/kg-bw/day). The red meat administered to rats contained 81microg/g of total mercury (T-Hg) and 13.4 microg/g of methyl mercury (M-Hg). This dose corresponds to the human consumption of 210 g red meat/60 kg-bw/week, exceeding by about 29 times the provisional tolerable weekly intake of M-Hg at 1.6 microg/kg-bw/week set by JECFA [JECFA, 2003. Joint FAO/WHO expert committee on food additives. 61st meeting, Rome]. Twenty-four hours after the last administration, the distribution of T-Hg in rat organs and biochemical parameters in serum were analyzed. The administration of red meat significantly elevated T-Hg concentrations in the liver, kidney, erythrocytes, cerebral cortex and medulla oblongata from the control levels but did not elevate the T-Hg concentration in serum, showing the typical distribution pattern of M-Hg, not of inorganic Hg. The administration slightly but significantly increased GTP activity and P concentration and decreased BUN concentration in serum, although no abnormalities were observed in rat body weight gain and movement during the 7 days. The occasional consumption of red meat from small cetaceans, therefore, could pose a health problem for not only pregnant women but also for the general population.

Administration, Oral↗
PubMed2005

Species differences in the tissue distribution of catechol and methylsulphonyl metabolites of 2,4,5,2',5'-penta- and 2,3,4,2',3',6'-hexachlorobiphenyls in rats, mice, hamsters and guinea pigs.

Polychlorinated biphenyls (PCBs) are metabolized to phenolic or methylsulphonyl PCBs (MeSO(2)-CBs) in animal species. The study determined the species differences in the tissue distribution of persistent PCB metabolites in rats, mice, hamsters and guinea pigs 4 days after exposure to 2,4,5,2('),5(')-pentachlorobiphenyl (CB101) or 2,3,4,2('),3('),6(')-hexachlorobiphenyl (CB132). For CB101 metabolism, the hydroxylation in rats, mice and hamsters occurred primarily at the 3(')-position in the 2('),5(')-dichlorinated phenyl ring, whereas the hydroxylation in guinea pigs occurred preferentially at the 3-position. Metabolite profiles in tissues of hamsters were dominated by 3('),4(')-catechol-CB101, whereas metabolite profiles in rats and mice were dominated by 3(')- or 4(')-MeSO(2)-CBs. For CB132 metabolism, rats and mice produced 4(')- and 5(')-MeSO(2)-CBs at similar concentration ratios, whereas guinea pigs produced MeSO(2)-CBs at higher levels and selectively retained 5(')-MeSO(2)-CB in liver. In contrast, hamsters preferentially produced 4('),5(')-catechol-CB132 that was retained in serum. Consequently, hamsters produced catechols, whereas guinea pigs produced meta-substituted MeSO(2)-CBs, preferentially from CB132. These findings indicate that PCBs with 2,3,6-chlorine substitution are preferred substrates for the formation of catechols or MeSO(2)-CBs and the differences in metabolite profiles are related to species-dependent metabolic capacities.

Animals↗
PubMed2005

In vitro metabolism of 2,2',3,4',5,5',6-heptachlorobiphenyl (CB187) by liver microsomes from rats, hamsters and guinea pigs.

The metabolism of 2,2',3,4',5,5',6-heptachlorobiphenyl (heptaCB) (CB187) was studied using liver microsomes of rats, hamsters and guinea pigs, and the effect of cytochrome P450 (CYP) inducers, phenobarbital (PB) and 3-methylcholanthrene (MC), was also investigated. In untreated animals, guinea pig liver microsomes formed three metabolites which were deduced to be 4'-hydroxy-2,2',3,5,5',6-hexachlorobiphenyl (M-1), 4'-hydroxy-2,2',3,3',5,5',6-heptaCB (M-2) and 4-OH-CB187 (M-3) from the comparison of GC/MS data with some synthetic authentic samples. The formation rate of M-1, M-2 and M-3 was 18.1, 36.6, 14.7 pmol h-1 mg protein-1, respectively. Liver microsomes of untreated rats and hamsters did not form CB187 metabolites. In guinea pigs, PB-treatment increased M-1 and M-2 significantly to 1.9- and 3.4-fold of untreated animals but did not affect the formation of M-3. In rats, PB-treatment resulted in the appearance of M-2 and M-3 with formation rates of 87.1 and 13.7 pmol h-1 mg protein-1, respectively, but M-1 was not observed. In hamsters, PB-treatment formed only M-2 at a rate of 29.4 pmol h-1 mg protein-1. On the other hand, MC-treatment of guinea pigs decreased the formation of M-1 and M-2 to less than 50% of untreated animals. MC-microsomes of rats and hamsters produced no metabolites. Preincubation of antiserum (300 microl) against guinea pig CYP2B18 with liver microsomes of PB-treated guinea pigs produced 80% inhibition of M-1 and the complete inhibition of M-2 and M-3. These results suggest that PB-inducible CYP forms, especially guinea pig CYP2B18, rat CYP2B1 and hamster CYP2B, are important in CB187 metabolism and that CB187 metabolism in guinea pigs may proceed via the formation of 3,4- or 3',4'-oxide and subsequent NIH-shift or dechlorination.

Animals↗
PubMed2004

Contamination by mercury and cadmium in the cetacean products from Japanese market.

Cetaceans hunted coastally in Japan include several species of odontocete (dolphins, porpoises and beaked whales), and fresh and frozen red meat and blubber, as well as boiled internal organs, such as liver, lung, kidney and small intestine, are still sold for human consumption. Furthermore, red meat and blubber products originating from mysticete minke whales caught in the Antarctic and Northern Pacific are also sold for human consumption. We surveyed mercury and cadmium contamination levels in boiled liver, lung, kidney and red meat products being marketed in Japanese retail outlets. We also analyzed the DNA of these products to obtain information concerning gender and species. Total mercury (T-Hg) and methyl mercury (M-Hg) contamination levels in all the cetacean products were markedly higher in odontocete species than in mysticete species, and slightly higher in females than in males. T-Hg contamination in the organs was seen in the following order: boiled liver>boiled kidney=boiled lung>red meat. In particular, T-Hg concentrations in the boiled liver were high enough to cause acute intoxication even from a single ingestion: the mean +/-SD (range) of T-Hg was 388+/-543 (0.12-1980) microg/wetg. In contrast, although M-Hg contamination in the liver was not markedly higher than that in other organs, M-Hg contamination was in the following order: boiled liver>odontocete red meat>boiled kidney>boiled lung. The contamination levels of T-Hg and M-Hg in odontocete red meat, the most popular whale product, were 8.94+/-13.3 and 5.44+/-5.72 microg/wetg, respectively. These averages exceeded the provisional permitted levels of T-Hg (0.4 microg/wetg) and M-Hg (0.3 microg/wetg) in marine foods set by the Japanese Ministry of Health, Labor and Welfare by 22 and 18 times, respectively, suggesting the possibility of chronic intoxication by T-Hg and M-Hg with frequent consumption of odontocete red meat. Cadmium contamination levels in boiled liver, kidney and lung were 8.59+/-12.0, 10.4+/-8.6 and 1.66+/-1.27 (microg/wetg), respectively.

Animals↗
PubMed2004

Recovery of Valpha24+ NKT cells after hematopoietic stem cell transplantation.

Human Valpha24+ natural killer T (NKT) cells have an invariant T-cell receptor-alpha chain and are activated in a CD1d-restricted manner. Valpha24+ NKT cells are thought to regulate immune responses and to play important roles in the induction of allograft tolerance. In this report, we analyzed the recovery of Valpha24+ NKT cells after hematopoietic stem cell transplantation and its correlation with graft-versus-host disease (GVHD). Patients who received a dose-reduced conditioning regimen, antithymocyte globulin- or CAMPATH-1H-containing conditioning regimen were excluded. NKT cells were reconstituted within 1 month after transplantation in peripheral blood stem cell transplantation recipients, while their numbers remained low for more than 1 year in bone marrow transplantation (BMT) recipients. The number of Valpha24+ NKT cells in BMT recipients with acute GVHD was lower than that in patients without acute GVHD, and both the CD4+ and CD4- Valpha24+ NKT subsets were significantly reduced. With regard to chronic GVHD, BMT recipients with extensive GVHD had significantly fewer Valpha24+ NKT cells than other patients. Furthermore, the number of CD4+ Valpha24+ NKT cells was also significantly reduced in patients with chronic extensive GVHD. Our results raise the possibility that the number of Valpha24+ NKT cells could be related to the development of GVHD.

Adolescent↗
PubMed2003

Mercury contamination in the red meat of whales and dolphins marketed for human consumption in Japan.

Cetacean products sold for human consumption in Japan originate from a wide range of whale, dolphin, and porpoise species caught off several areas of the Japan coast, Antarctic and North Pacific Oceans. We surveyed the total mercury (T-Hg) levels in red meat, the most popular cetacean products in Japan. We also analyzed the DNA of these to obtain information regarding species. According to the genetic analysis, the red meats originating from nine species of odontocete and six species of mystecete were sold in Japanese markets. T-Hg concentrations in all odontocete red meats (0.52-81.0 microg/wet g, n = 137) exceeded the provisional permitted level of T-Hg in marine foods set by the Japanese government (0.4 microg/wet g). The highest and second highest levels of T-Hg in the red meats were found in the false killer whale (81.0 microg/wet g) and striped dolphin (63.4 microg/wet g), respectively. These concentrations of T-Hg exceeded the permitted level of T-Hg by about 200 and 160 times, respectively, suggesting the possibility of chronic intoxication by methyl mercury due to frequent consumption of odontocete red meats. The T-Hg concentration levels were higher in odontocete species such as Baird's beaked whales and pilot whales caught off southern areas than those caught off northern areas, probably reflecting a higher Hg concentration in the seawater and/or their diet (squid and fish) in the southern area. On the other hand, T-Hg concentrations in all mystecete red meat samples except for one (0.01-0.54 microg/ wet g, n = 62) were below the permitted level of T-Hg, probably reflecting their lower trophic levels.

Animals↗
PubMed2002

Human health significance of organochlorine and mercury contaminants in Japanese whale meat.

The concentrations of total mercury, polychlorinated biphenyls (PCBs), and organochlorine pesticides (SigmaDDT, dieldrin, hexachlorobenzene [HCB], and SigmaHCH) were determined in 61 whale meat products (bacon, blubber, red meat, liver, intestine, and tongue) purchased from retail outlets across Japan. Mean (range) concentrations of contaminants in all samples were: total mercury 4.17 (0.01-204); SigmaPCB 1.14 (0-8.94); SigmaDDT 0.98 (0-7.46); dieldrin 0.07 (0-0.35); HCB 0.06 (0-0.22); and SigmaHCH 0.07 (0-0.19) micro g/g (wet weight). The data were used to calculate estimated daily intakes (EDIs) of contaminants at two hypothetical levels of whale meat consumption. These EDIs were compared with FAO/WHO "tolerable daily intake" (TDI) values for each chemical. EDIs calculated for higher levels of whale meat consumption were in some cases exceptionally high and for many products exceeded FAO/ WHO-TDIs for total mercury, PCBs, and dieldrin, with exceedance factor values (EDI/TDI) for total mercury, PCBs, and dieldrin reaching maxima of 175, 5.36, and 2.1, respectively. For sensitive consumers and those with high-level consumption (e.g., whaling communities), exposure to mercury and to a lesser extent PCBs from certain whale blubber and bacon and striped dolphin liver products could lead to chronic health effects. The Japanese community should therefore exercise a precautionary approach to the consumption of such foods in excess, particularly by high-risk members of the population.

Animals↗
PubMed2002

MR detection of iliac bone marrow involvement by malignant lymphoma with various MR sequences including diffusion-weighted echo-planar imaging.

OBJECTIVE: To assess the diagnostic accuracy of MR imaging for detecting bone marrow infiltration by malignant lymphoma. PATIENTS AND DESIGN: Fifty-three patients with malignant lymphoma underwent MR imaging and bone marrow biopsy. In 80 iliac crests of the 53 patients (13 positive specimens in 9 patients and 67 negative specimens in 44 patients), biopsy results and the signal intensity characteristics were compared. MR sequences included T1-weighted SE, T2-weighted FSE with fat suppression, FSE STIR, and diffusion-weighted EPI with fat suppression at 1.5 T. RESULTS AND CONCLUSIONS: To detect lymphoma infiltration, T1-weighted SE had the highest sensitivity (92%) and diffusion-weighted EPI with fat suppression and FSE STIR had the highest specificity (92.5% and 92%, respectively). A combination of T1-weighted SE and FSE STIR yielded the highest sensitivity and specificity (85% and 97%, respectively). A combination of T1-weighted SE and FSE STIR sequences seems to be the current choice of imaging protocol for detecting bone marrow infiltration by malignant lymphoma.

Biopsy↗
PubMed2002

Metabolite of 2,2',4',5-tetrabromobiphenyl, 3-methylsulphonyl-2,2',4',5-tetrabromobiphenyl, a potent inducer of CYP2B1/2 in rat.

1. 3-Methylsulphonyl- and 4-methylsulphonyl-2,2',4',5-tetrabromobiphenyls (3-MeSO(2)- and 4-MeSO(2)-TetraBrBs) were detected in the liver, lung, kidney, adipose tissue and faeces of the 2,2',4',5-tetrabromobiphenyl (TetraBrB)-dosed rat. 2. The administration of 0.05-2.0 micromol kg(-1) doses of 3-MeSO(2)-TetraBrB produced corrresponding increases in the hepatic concentration of the methyl sulphone metabolite, corresponding increases in the content of total cytochrome P450, and corresponding increases in the activities of 7-benzyloxy-, 7-ethoxy- and 7-pentoxyresorufin O-dealkylases. The inducing effects of the 3-MeSO(2)-TetraBrB (0.2 micromol kg(-1)), both on the content of total P450 and on the activities of the three alkoxyresorufin O-dealkylases, were higher than that of the parent TetraBrB (342 micromol kg(-1)). 3. The major phenobarbital (PB)-inducible forms of P450, CYP2B1, CYP2B2, CYP3A2 and CYP2C6, were substantially induced by 3-MeSO(2)-TetraBrB, but CYP1A1 and CYP1A2 were not. On the other hand, the activities of drug-metabolizing enzymes and the four PB-inducible forms of P450 were unchanged by 4-MeSO(2)-TetraBrB treatment. 4. The induction profiles of these enzymes and P450 forms in rat treated with 3-MeSO(2)-TetraBrB were similar to those treated with PB. 5. The inducing ability of 3-MeSO(2)-TetraBrB (0.5 micromol kg(-1)) both on the activities of the three alkoxyresorufin O-dealkylases and on the contents of four PB-inducible forms of P450 was roughly equal to that of PB (431 micromol kg(-1) twice at a 24-h interval) or 3-MeSO(2)-2,2',4',5-tetrachlorobiphenyl (1 micromol kg(-1)). It is noteworthy that the effects of 3-MeSO(2)-TetraBrB on the drug-metabolizing enzymes CYP2B1 and CYP2B2 were several thousand-fold higher than those of parent TetraBrB, while the effect of its isomeric 4-MeSO(2)-TetraBrB were not. 6. The extent of hepatic accumulation of the 3-MeSO(2) metabolite after the administration of TetraBrB (342 micromol kg(-1)) was almost the same as that after the administration of 3-MeSO(2)-TetraBrB (0.1-0.2 micromol kg(-1)). The relationship between the hepatic concentration of the 3-MeSO(2) metabolite and the extent of enzyme induction after the administration of TetraBrB or 3-MeSO(2)-TetraBrB suggests that 3-MeSO(2)-TetraBrB plays an important role in the induction of microsomal drug-metabolizing enzymes by TetraBrB.

Animals↗
PubMed2001

Transcriptional activation of the thyroglobulin promoter directing suicide gene expression by thyroid transcription factor-1 in thyroid cancer cells.

Gene therapy with thyroglobulin (TG) promoter and a prodrug/suicide gene combination may prove useful as a treatment for thyroid carcinoma. However, most poorly differentiated and anaplastic thyroid carcinomas have lost the ability to express the TG gene expression accompanied by loss of transcription factors [thyroid transcription factor-1 (TTF-1), TTF-2, or Pax-8] interacting with the TG promoter. In anticipation of developing transcriptionally targeted gene therapy of TG-nonproducing thyroid carcinomas, we investigated the effect of TTF-1 gene transfer on TG promoter activity and the cytotoxic effect obtained by the TG promoter-driven HSV-TK gene along with ganciclovir in thyroid carcinoma and nonthyroidal cells. Using a chimeric construct containing the 5'-flanking region of the rat TG gene between -826 and +39 bp and the luciferase gene, TG promoter activity was detected in a normal rat thyroid cell line (FRTL-5), but not in a dedifferentiated line of thyroid cells (FRT) expressing Pax-8 but not TTF-1, TTF-2, or TG [TTF-1(-)/TTF-2(-)/Pax-8(+)/TG(-)], or in a human papillary thyroid carcinoma cell line [BHP15-3; TTF-1(-)/TTF-2(-)/Pax-8(-)/TG(-)], a human pulmonary cell line [H441; TTF-1(+)/TTF-2(-)/Pax-8(-)/TG(-)], or a dog kidney epithelial cell line [MDCK; TTF-1(-)/TTF-2(-)/Pax-8(+)/TG(-)]. Cotransfection of the TTF-1 expression vector stimulated TG promoter activity in FRT and BHP15-3 dedifferentiated thyroid cells, but not in H441 pulmonary cells. Only weak activation was observed in MDCK kidney cells. We then constructed recombinant adenovirus vectors, AdTTF-1 and ADTGTK: AdTTF-1 contained cytomegalovirus promoter and rat TTF-1 cDNA; AdTGTK carried the TG promoter-driven HSV-TK gene. Infection with AdTGTK and combined with GCV treatment induced a cytotoxic effect in FRTL-5 cells but not in dedifferentiated thyroid or nonthyroid cells. Cotransduction of AdTTF-1 and AdTGTK permitted 90% cytotoxicity for BHP15-3 and >95% cytotoxicity for FRT, as well as for BHP7-13 and BHP18-21v thyroid cancer cell lines [both/TTF1(-)/TTF-2(-)/Pax-8(+)/TG(-)]. In contrast, little cytotoxicity was seen for H441 and MDCK cell lines even with 300 microg/ml of ganciclovir. These results suggest that cotransduction of a TG promoter-controlled suicide gene and the TTF-1 gene by adenoviral vectors confers transcriptionally targeted gene-mediated cytotoxicity in poorly differentiated thyroid carcinoma cells unable to express the TG gene.

Adenoviridae↗
PubMed2001

Bioaccumulation of polychlorinated biphenyls (PCBs) and dichlorodiphenylethane (DDE) methyl sulfones in tissues of seal and dolphin morbillivirus epizootic victims.

Polychlorinated biphenyl (PCB) and dichlorodiphenylethane (DDE) methyl sulfone (MSF) metabolites possess high affinities for binding two homologous 16,000 Da homodimeric receptor proteins in the lung (Clara cell secretory protein, CCSP) and the uterus (uteroglobin, UG), leading to selective bioaccumulation of MSFs in these tissues. As marine mammals are highly exposed to organochlorines, concentrations of PCBs, PCB MSFs, DDT, and DDE MSF were analyzed in blubber, lung, and uterus samples from harbor seal (Phoca vitulina) and striped dolphin (Stenella coeruleoalba) morbillivirus epizootic victims to investigate uterine and lung MSF accumulation. Mean uterus concentrations of PCB MSFs and DDE MSF in harbor seals were 0.61 and 0.04 microg/g lipid weight and in striped dolphins 0.05 and 0.01 microg/g lipid weight. Mean lung concentrations of PCB MSFs and DDE MSF in harbor seals were 0.96 and 0.02 microg/g lipid weight and in striped dolphins 0.16 and 0.01 microg/g lipid weight. To ascertain whether uterine and lung bioaccumulation of MSFs is possible due to the presence of CCSP and UG in seals, CCSP and UG proteins in uterine flushings and in uterine and lung and epithelial tissue from Baltic gray and ringed seals were characterized using gel electrophoresis and Western blotting techniques. UG- and CCSP-like proteins with molecular weights of 16,000 Da were resolved in all samples. This is the first demonstration of this protein in any marine mammalian species. The toxicological implications of MSF binding with UG and CCSP in marine mammals are discussed.

Adipose Tissue↗
PubMed2001

Comparison of fit and fill between anatomic stem and straight tapered stem using virtual implantation on the ORTHODOC workstation.

The objective of this article was to determine the influence of stem design on fit and fill using the preoperative planning workstation of the ROBODOC system. Anatomic ABG and straight Osteolock femoral components were virtually implanted into 50 femora (25 from patients with developmental dysplasia of the hip (DDH), 25 morphologically normal) on the workstation display. Fit and fill, and length of the proximal posterolateral femoral cortex removed by milling (LPFCR), were measured on the cross-sectional images. Lateral curvature (alpha angle) and anteversion of the femur were evaluated. The ABG components showed significantly better fit than the Osteolock components at the levels proximal to the lesser trochanter. The Osteolock components showed significantly greater LPFCR than the ABG components, especially in the patients with DDH. The patients with DDH showed significantly greater alpha angle and femoral anteversion than those with morphologically normal femora. With the Osteolock components, the alpha angle correlated significantly with femoral anteversion and LPFCR. Use of an anatomic proximal body of the stem helped to improve the proximal canal fit. Greater LPFCR was required when a straight stem was implanted in patients with a relatively high alpha angle.

Adult↗
PubMed2001

Relationship between bone marrow cellularity and apparent diffusion coefficient.

This study was performed to determine if there is a relationship between apparent diffusion coefficient (ADC) and cellularity of bone marrow of the posterior ilium. Four groups of various marrow cellularity underwent diffusion-weighted echo-planar imaging: 1) adults with normal hypocellularity (21 patients); 2) adults with normal normocellularity (13 patients); 3) young children with normal hypercellularity (5 patients); and 4) adults with lymphoma-related hypercellularity (3 patients). In all adults, marrow cellularity was confirmed by uni-or bilateral bone marrow biopsies. In children, the iliac marrow was presumed hypercellular because of their ages. A total of 66 ADC values of bone marrow calculated from diffusion-weighted images with b-values of 30 and 300 seconds/mm(2) was evaluated. Hypercellular marrow (normal and lymphoma-related) showed the highest mean ADC, and hypocellular the lowest ADC. Statistically significant differences were found between three groups of normal marrow: hypocellular, normocellular, and hypercellular. There is a positive correlation between ADC and cellularity of bone marrow. J. Magn. Reson. Imaging 2001;13:757-760.

Adult↗
PubMed2001

Full weight-bearing after cementless total hip arthroplasty.

In a prospective study of cementless total hip arthroplasty, 19 hips in 17 patients (Group A) were allowed full weight-bearing immediately after the operation while 18 hips in 16 patients (Group B) were first allowed weight-bearing after 6 weeks. Patients were matched for sex, age at surgery, height, weight, and follow-up period and there were no significant differences in hip scores between the two groups. Rehabilitation to gain walking ability with a cane lasted 5.8 days for Group A and 44.8 days for Group B (P = 0.0001). The hospital stay after surgery was 30.1 days for Group A and 46.7 days for Group B (P = 0.006). All patients showed bone ingrowth radiographically. There were no complications in either group.

Activities of Daily Living↗
PubMed2001

Influence of polyethylene and femoral head surface quality on wear: a retrieval study.

Thirty-two polyethylene sockets and 22 femoral heads were retrieved because of aseptic loosening more than 9 years after total hip arthroplasty. The volumetric wear rates of the retrieved polyethylene sockets were significantly greater in those coupled with an alumina head (P < 0.05). The retrieved alumina heads showed significantly better surface roughness and roundness than heads of Co-Cr and of stainless steel (P < 0.05). However, no significant difference was found in polyethylene quality demonstrated as fusion defects among the three different groups. The present study suggests that maintaining better surface roughness and roundness of the femoral heads does not always result in an in vivo reduction of polyethylene wear.

Adult↗