Biomedical subjects

K Sasaki

Publications and source records attributed to K Sasaki.

At least 109 records · Page 6Linked to original sources

PubMed2001

Preferential loss of 5q14-21 in intestinal-type gastric cancer with DNA aneuploidy.

BACKGROUND: Little is known about the genetic changes associated with DNA ploidy in gastric cancer (GC). The aim of this study was to identify recurrent or specific chromosomal regions of DNA sequence copy number aberrations (DSCNAs) that might harbor genes associated with DNA aneuploidy in GC. METHODS: We analyzed DSCNAs with comparative genomic hybridization and DNA ploidy by laser scanning cytometry in 16 primary intestinal-type GCs. RESULTS: All GCs examined showed at least one DSCNA (loss or gain); eight were DNA diploid (DD) tumors and eight were DNA aneuploid (DA) tumors. The frequent (>30%) DSCNAs were loss of 5q14-21 and gains of 7p11-14, 8q, 20q, and Xq25-26. Recurrent amplifications (>10%) were detected at chromosomal regions 6p, 7p, and 13q. The overall number of DSCNAs was significantly greater in DA than in DD tumors (P = 0.006). Furthermore, the number of aberrations was clearly greater with 5q loss than without 5q loss (P = 0.002). Losses of 5q14-21, 9p21-pter, 16q, and 18q21-qter were preferentially detected in DA tumors. CONCLUSION: The present observations indicate that there is a close relationship between DSCNA and DNA ploidy in intestinal-type GC and that gene(s) at 5q14-21, 9p21-pter, 16q, and/or 18q21-qter may play important roles in acquisition of DNA aneuploidy.

Adult↗

PubMed2001

Augmentation of postnatal neovascularization with autologous bone marrow transplantation.

BACKGROUND: Endothelial progenitor cells (EPCs) have been identified in adult human peripheral blood. Because circulating EPCs should originate from bone marrow (BM), we examined whether BM mononuclear cells (BM-MNCs) can give rise to functional EPCs and whether transplantation of autologous BM-MNCs might augment angiogenesis and collateral vessel formation in a rabbit model of hindlimb ischemia. METHODS AND RESULTS: Rabbit BM-MNCs were isolated by centrifugation through a Histopaque density gradient and cultured on fibronectin. EPCs developed from BM-MNCs in vitro, as assessed by acetylated LDL incorporation, nitric oxide (NO) release, and expression of von Willebrand factor and lectin binding. Unilateral hindlimb ischemia was surgically induced in rabbits (n=8), and fluorescence-labeled autologous BM-MNCs were transplanted into the ischemic tissues. Two weeks after transplantation, fluorescence microscopy revealed that transplanted cells were incorporated into the capillary network among preserved skeletal myocytes. In contrast, transplanted autologous BM-fibroblasts did not participate in EC capillary network formation (n=5). Then, in an additional 27 rabbits, saline (control; n=8), autologous BM-MNCs (n=13; 6.9+/-2.2x10(6) cells/animal), or BM-fibroblasts (n=6; 6.5+/-1.5x10(6) cells/animal) were injected into the ischemic tissues at postoperative day 7. Four weeks after transplantation, the BM-MNC-transplanted group had more angiographically detectable collateral vessels (angiographic score: 1.5+/-0.34 versus 0.94+/-0.26 and 1.1+/-0.14; P:<0.05), a higher capillary density (23+/-5.8 versus 10+/-1.9 and 11+/-0.8 per field; P:<0.001), and a greater laser Doppler blood perfusion index (505+/-155 versus 361+/-35 and 358+/-22 U; P:<0.05) than the control and BM-fibroblast-transplanted groups. CONCLUSIONS: Direct local transplantation of autologous BM-MNCs seems to be a useful strategy for therapeutic neovascularization in ischemic tissues in adults, consistent with "therapeutic vasculogenesis."

Angiography↗

PubMed2001

Comparative genomic hybridization analysis of genetic aberrations associated with development and progression of biliary tract carcinomas.

BACKGROUND: Little is known about genetic aberrations associated with development and progression of biliary tract carcinomas. METHODS: To study chromosomal aberrations associated with development and progression of biliary tract carcinomas, the authors used comparative genomic hybridization to examine 50 such carcinomas. RESULTS: Gains in part or in whole of chromosomes 1q, 8q, and 20q and losses of 5q, 8p, 9p, and 18q were detected frequently in early stage (T1/T2 classification) biliary tract carcinomas (> or = 40% of 19 early stage tumors), and they also were found in advanced stage (T3/T4 classification) tumors. In particular, loss of 9p was the most frequently observed aberration in both early stage (15 of 19; 78%) and advanced stage tumors (21 of 31; 68%). The frequencies of gains of 7p12-p14 (P < 0.003), 7p21-pter (P < 0.007), and 7q31 (P < 0.01) differed significantly between biliary tract carcinoma with and without distant metastasis. Also, gains of 5p and 19q13 and loss of 6q14-q16 were more frequent in tumors with lymph node metastasis than in those without it (P < 0.02). CONCLUSIONS: It is likely that loss of 9p is one of the genetic aberrations critical for the development of biliary tract carcinoma, whereas gains of 5p, 7p, 7q, and 19q and loss of 6q are considered later events associated with tumor progression and are thought to confer metastatic potential to biliary tract carcinomas.

Adult↗

PubMed2001

Recognition of cell surface GD3 by monoclonal antibody anti-6C2 in rheumatoid arthritis synovial fluid: expression on human T cells with transendothelial migratory activity.

OBJECTIVE: We have previously reported that the anti-6C2 monoclonal antibody (mAb) defines a subset of human CD4+ memory T cells. The present study sought to determine the nature of the 6C2 molecule and the function associated with 6C2+ T cells, and to examine whether this T cell subset is involved in the pathophysiology of rheumatoid arthritis (RA). METHODS: Cytofluorographic analysis was performed for identification of T cell surface molecules displaying a distribution similar to that of the 6C2 molecule. T cells in the synovial fluid of RA patients were examined for expression of the 6C2 molecule. Transendothelial migratory activity was assessed by assay using monolayers of human endothelial cells. Specific reactivity of the anti-6C2 mAb was determined by immunoblotting on gangliosides separated by thin-layer chromatography, and flow cytometric analysis of the cells transfected with complementary DNA (cDNA) was performed for determination of the glycosyltransferases involved in biosynthesis of the gangliosides. RESULTS: On human peripheral T cells, the 6C2 molecule was distributed, by and large, in a pattern similar to that of CDw60, or O-acetyl-GD3. The majority (>70%) of synovial fluid T cells from patients with RA were found to be 6C2 positive, and those 6C2+ T cells exhibited a transendothelial migratory capacity that was inhibited by pretreatment of T cells with anti-6C2 mAb. Moreover, treatment of T cells with neuraminidase resulted in a loss of 6C2 expression as well as a reduction in the transendothelial migratory activity. Anti-6C2 mAb reacted specifically with GD3, but not with O-acetyl-GD3. The reactivity of anti-6C2 mAb was induced on the cell surface only by transfection with cDNA for GD3 synthase. CONCLUSION: The 6C2 molecule is a disialoganglioside, GD3, and is present on a subset of T cells with transendothelial migratory capacity. The 6C2/GD3 molecules, as well as 6C2/GD3+ T cells, appear to play a role in T cell migration and in the inflammation of RA.

Antibodies, Monoclonal↗

PubMed2001

Treatment of murine collagen-induced arthritis by ex vivo extracellular superoxide dismutase gene transfer.

UNLABELLED: OBJECTIVE; Superoxide dismutase (SOD) is a potent antiinflammatory enzyme that has received growing attention for its therapeutic potential. This study was undertaken to examine the efficacy of extracellular SOD (EC-SOD) gene therapy in murine collagen-induced arthritis. METHODS: Embryonic DBA/1 mouse fibroblasts were infected with a recombinant retrovirus expressing human EC-SOD. DBA/1 mice that had been treated with type II collagen were administered subcutaneous injections of 2 x 10(7) EC-SOD-expressing fibroblasts on day 29, when symptoms of arthritis were already present. The severity of arthritis in individual mice was evaluated in a double-blind manner; each paw was assigned a separate clinical score, and hind paw thickness was measured with a caliper. Mice were killed on day 50 for histologic examination of the joints. RESULTS: High serum concentrations of EC-SOD were maintained for at least 7 days. Mice treated with the transgene exhibited significant suppression of clinical symptoms such as disabling joint swelling, deformity, and hind paw thickness, compared with the untreated group (mean +/- SD maximum clinical score in the untreated and the transgene-treated groups 2.71 +/- 1.08 and 1.35 +/- 1.22, respectively; P < 0.01, and hind paw thickness 3.04 +/- 0.18 mm and 2.56 +/- 0.12 mm, respectively; P < 0.05). Histologic abnormalities, including destruction of cartilage and bone, infiltration of mononuclear cells, and proliferation of synovial cells, were also markedly improved in the EC-SOD-treated mice compared with the control group (histopathologic score 7.50 +/- 1.13 and 4.13 +/- 1.88 in the untreated and transgene-treated groups, respectively; P < 0.05). CONCLUSION: These results indicate that EC-SOD gene transfer may be an effective form of therapy for rheumatoid arthritis.

Animals↗

PubMed2001

Identification of recurrent chromosomal rearrangements and the unique relationship between low-level amplification and translocation in glioblastoma.

To elucidate the structural abnormalities and the relationship between chromosome structural disorders and DNA copy number aberrations in tumor cells, we applied the techniques of spectral karyotyping (SKY), comparative genomic hybridization (CGH), and fluorescence in situ hybridization (FISH), using yeast artificial chromosome (YAC) probes for nine human glioblastoma cell lines. One striking finding was that independently derived cell lines had the same recurrent marker chromosomes. Seven recurrent chromosomes were detected by these cytogenetic methods. In particular, cell lines U251, SNB-19, and U373-MG showed very similar karyotypes. It is also interesting that regions of DNA amplification were found translocated and/or inserted at a high rate (91.7%). In all, there were 12 amplified loci in five of the nine cell lines. These amplified chromosomal bands were scattered on the chromosomes, including the normal chromosome, with one exception (7q32-qter in U373-MG). FISH with YAC clones mapping to these chromosomal regions as DNA probes often showed DNA probe signals not only at original chromosomal sites but also in translocated or inserted segments. This form of DNA amplification was characterized by low-level increases (four- to 10-fold) and by translocation or insertion of the relevant chromosomal locus. These studies shed light on typical derivative chromosomes and the relationship between DNA amplification and chromosomal translocation in glioblastoma.

Chromosome Aberrations↗

PubMed2001

Quantitative analysis of mRNA expression of TIMPs in the periprosthetic interface tissue of loose hips by real-time PCR system.

Matrix metalloproteinases (MMPs) and their endogenous inhibitors, tissue inhibitors of metalloproteinases (TIMPs), have been reported to play a critical role in extracellular degradation around artificial hip joints. Although messenger ribonucleic acid (mRNA) expression patterns of several MMPs and TIMPs were reported, there is no report of quantitative mRNA analysis of TIMPs in periprosthetic tissues. In this study, mRNA expression of four different types of TIMPs in periprosthetic interface tissue of loose hips was analyzed by a quantitative polymerase chain reaction system. The mRNA expression level of TIMP-1, -2, and -3 in periprosthetic interface tissue was significantly higher than that in control. In contrast, the mRNA expression level of TIMP-4 in the periprosthetic interface tissue was lower. This study suggested that increased levels of TIMP-1, -2, and -3, and decreased levels of TIMP-4 may contribute to pathologic extracellular matrix degradation in combination with MMPs, thus leading to prosthetic loosening and osteolysis around artificial total hip joints.

Aged↗

PubMed2001

Three-dimensional morphological analysis of antigen-antibody reaction in hepatic sinusoids preserved in hypothermic UW solution.

ICAM-1 antigen-antibody reaction was visualized by three-dimensional immunoscanning electron microscopy of hepatic sinusoids in rat liver treated with hypothermic University of Wisconsin (UW) organ preservation solution. The results were compared with similar antigen-antibody reactions carried out with immunoliposomes injected in vivo. Morphologically, the hepatic sinusoids were preserved well during the hypothermic procedure. Endothelial cells had a large number of fenestrations, which partly aggregated and formed sieve plates. ICAM-1 expression was induced by injection of LPS and detected by monoclonal antibody in the UW solution followed by gold-labeled secondary antibody. ICAM-1 was restricted mostly to the unique areas of sieve plates with immature, small fenestrations. A similar distribution of ICAM-1 was present when detected by in vivo injection of immunoliposomes containing the monoclonal ICAM-1 antibody. The results showed that antigen-antibody reactions can take place in livers preserved in hypothermic UW solution. Further, the reaction is similar to that which could occur in vivo during transplantation. This suggests that it may be possible to block potentially harmful antigen-antibody reactions by addition of appropriate antibodies to hypothermic UW solution prior to transplantation.

Adenosine↗

PubMed2001

Engraftment of genetically engineered amniotic epithelial cells corrects lysosomal storage in multiple areas of the brain in mucopolysaccharidosis type VII mice.

Cell-mediated gene therapy for visceral lesions of lysosomal storage diseases is promising; however, the treatment of central nervous system (CNS) lesions remains a challenge. In this study, we generated rat amniotic epithelial cells (AEC) that overexpress and secrete human beta-glucuronidase (GUSB) following transduction with an adenoviral vector encoding human GUSB. The AEC were used as donor cells for cell-mediated gene therapy of CNS lesions in mice with mucopolysaccharidosis type VII (MPSVII), a lysosomal storage disorder caused by an inherited deficiency of GUSB activity. After confirmation that the secreted GUSB was taken up mainly via mannose 6-phosphate receptors in primary cultured neurons, the AEC were transplanted into the brains of adult MPSVII mice. Histochemical analysis showed extensive GUSB activity throughout the ipsilateral hemisphere of the recipient brains, and pathological improvement of the lysosomal storage was observed even in regions far from the site of injection. These results suggest that intracerebral transplantation of genetically engineered AEC has therapeutic potential for the treatment of CNS lesions in lysosomal storage disorders.

Adenoviridae↗

PubMed2001

Adenovirus-mediated gene therapy for corneal clouding in mice with mucopolysaccharidosis type VII.

Recent advances in systemic treatments for mucopolysaccharidosis have led to therapies that improve the multiple somatic features of this disease, but the therapeutic effect on ocular manifestations such as corneal clouding is not satisfactory. Here, we administered an adenovirus expressing human beta-glucuronidase (AxCAhGUS) into the anterior chamber or intrastromal region of the cornea in mice with mucopolysaccharidosis type VII (B6/MPSVII), and successfully treated corneal clouding of MPSVII. When we injected AxCAhGUS into the anterior chamber of the eyes, cells expressing beta-glucuronidase (GUSB) were located mainly in the trabecular meshwork as well as in all corneal regions, and subsequent pathological corrections in the cornea were achieved. Widespread transgene expression was also observed when we administered AxCAhGUS inside the cornea after lamellar keratotomy, and rapid elimination of the lysosomal storage in the corneal keratocytes occurred. Furthermore, intrastromal vector administration did not generate significant levels of anti-adenovirus neutralizing antibodies, and secondary vector administration was effective. Based on these observations, we conclude that it is worth developing a treatment strategy for corneal clouding in mucopolysaccharidosis based on direct intraocular administration of adenoviral vectors.

Adenoviridae↗

PubMed2001

Involvement of thromboxane A2 and peptide leukotrienes in early and late phase nasal blockage in a guinea pig model of allergic rhinitis.

OBJECTIVE AND DESIGN: We investigated the effects of the thromboxane (TX) A2 antagonist seratrodast, the peptide leukotriene (p-LT) antagonist pranlukast, the antihistaminic drug terfenadine and the glucocorticoid dexamethasone on antigen-induced sneezing, biphasic nasal blockage and nasal hyperresponsiveness to histamine using a guinea pig model of allergic rhinitis. SUBJECTS: Male Hartley guinea pigs were used. TREATMENT: Intranasally sensitized guinea pigs were challenged once every week for 13 weeks by inhalation of Japanese cedar pollen as the antigen. Dexamethasone and other agents were administered orally 3 and 1 h, respectively, before the 4th, 6th and 13th challenge. METHODS: Sneezing frequency and the change in specific airway resistance (sRaw) were measured at these challenges. Two days after the 13th challenge, nasal responsiveness to histamine was evaluated by measuring sRaw after intranasal instillation of increasing doses of histamine. Moreover, the levels of TXB2, p-LTs and histamine were estimated in nasal cavity lavage fluid (NCLF) collected at the 13th challenge. RESULTS: Only terfenadine (10 mg/kg) significantly inhibited sneezing at any challenge time. Seratrodast (3 and 10 mg/ kg), pranlukast (30 mg/kg) and dexamethasone (10 mg/kg), but not terfenadine, suppressed both the early and late phase elevation of sRaw (biphasic nasal blockage), although the degree of inhibition on the early phase response varied with the challenge time. In contrast, the development of nasal hyperresponsiveness to histamine was inhibited by only dexamethasone. Furthermore, biphasic increases in TXB2, p-LTs and histamine in NCLF were observed after the challenge in sensitized animals. CONCLUSIONS: These results suggest that TXA2 and p-LTs, but not histamine, play important roles in both the early and the late phase nasal blockage in this model of allergic rhinitis.

Animals↗

PubMed2001

Pharmacological characterization of the leukocyte kinetics after intranasal antigen challenge in a guinea pig model of allergic rhinitis.

OBJECTIVE AND DESIGN: We characterized the leukocyte kinetics after antigen challenge, and investigated the effects of the thromboxane (TX) A2 antagonist seratrodast, the peptide leukotriene (p-LT) antagonist pranlukast, the antihistaminic drug terfenadine and the glucocorticoid dexamethasone on this leukocyte response in a guinea pig model of allergic rhinitis. SUBJECTS: Male Hartley guinea pigs were used. TREATMENT: Intranasally sensitized guinea pigs were challenged once every week for 15 weeks by inhalation of Japanese cedar pollen as the antigen. Dexamethasone and other agents were administered orally 3 and 1 h, respectively, before the 15th challenge. METHODS: The time-related changes in the numbers of differential leukocytes in nasal cavity lavage fluid (NCLF) and in peripheral blood after pollen inhalation challenge were investigated. The effects of the drugs on the antigen-induced changes in the leukocyte counts were evaluated. In addition, histopathological examination of the nasal mucosa was also performed 5 h after the challenge. RESULTS: There was a marked increase in the number of leukocytes in NCLF, especially of eosinophils, which peaked at 5 h, after antigen challenge in this model. This response was also accompanied by the peripheral blood eosinophilia and neutrophilia. Seratrodast (30 mg/kg), pranlukast (30 mg/kg) and dexamethasone (10 mg/kg) inhibited the eosinophilia in all of the blood, the nasal mucosa and NCLF seen 5 h after the antigen challenge. Terfenadine (10 mg/kg) had no apparent effect on the blood and the mucosal eosinophilia, although it tended to suppress the eosinophil accumulation in NCLF. CONCLUSIONS: These results suggest that the present model is useful for analyzing the mechanisms of antigen-induced eosinophilic inflammation in allergic rhinitis and that both TXA2 and p-LTs, but not histamine, contribute to the antigen-induced eosinophilia in this model of allergic rhinitis.

Administration, Intranasal↗

PubMed2001

Endoscope-assisted facial fracture repair.

We describe the use of an endoscope-assisted technique for nasal osteotomy and mandibular fracture repair. The endoscopic visual enhancement has been especially helpful in making osteotomy safe and accurate as compared to the drawbacks associated with conventional blind osteotomy. The technique of endoscopically assisted fracture repair of the mandible facilitates anatomic restoration and fixation of the displaced condyle with limited-access incision. Under optical endoscopic magnification, the disadvantages associated with open surgical repair including the risk of facial nerve injury and external facial scarring are minimized. No postoperative complications have been attributable to the endoscopic approach.

Adolescent↗

PubMed2001

Silent mixed corticotroph and somatotroph macroadenomas presenting with pituitary apoplexy.

We discuss three unique cases of pituitary macroadenoma presenting with pituitary hemorrhage but without typical endocrine symptomatology. Immunohistochemical analysis indicated positive reactivity for adrenocorticotropic hormone (ACTH) and growth hormone (GH), and in situ hybridization indicated the expression of proopiomelanocortin (POMC) and GH mRNA. We designated these cases silent mixed corticotroph and somatotroph adenoma. Patient 1 was a 30-year-old man, patient 2 was a 29-year-old woman, and patient 3 was a 59-year-old woman. All patients presented with a headache of sudden onset and visual disturbance. The patients did not exhibit typical Cushing's or acromegalic features. Serum ACTH level was remarkably elevated in patient 1, and slightly elevated in patients 2 and 3. In all patients, serum GH levels were within normal range and magnetic resonance imaging revealed an intra- and suprasellar mass with pituitary hemorrhage. Transnasal pituitary surgery in the three patients disclosed a pituitary adenoma producing ACTH and GH. In patient 2, the residual adenoma reappeared along with an intratumoral hemorrhage, and was resected by secondary transnasal surgery. Silent mixed corticotroph and somatotroph adenomas are characterized by the following: no endocrine symptoms; presentation dominated by mass effect symptoms; macroadenoma presenting with acute pituitary hemorrhage; and production of both ACTH and GH.

Adenoma↗

PubMed2001

Influence of fatty alcohol and other fatty acid derivatives on fatty acid uptake into rat intestinal epithelial cells.

We investigated the influence of various substrates on the uptake of long-chain fatty acid into IEC-6, rat intestinal epithelial cell line. The uptake of [3H]oleic acid into IEC-6 cells was a saturable function of the oleic acid concentration. Long-chain fatty acids significantly inhibited the oleic acid uptake into IEC-6 cells and shorter-chain fatty acids had little or no effect. Various fatty acid esters suppressed the oleic acid uptake into IEC-6. Fatty alcohols also inhibited oleic acid uptake into IEC-6 and the length of the carbon chain played an important role. These results suggest that long-chain fatty acid uptake was inhibited by the substrates which had a structure similar to long-chain fatty acids, especially those with a long carbon chain. At least two molecules, fatty acid translocase and fatty acid transport protein type 4, which are considered to be involved in the long-chain fatty acid transport into the cell, were expressed on IEC-6 cells, supporting the existence of the carrier-mediated system of long-chain fatty acid transport on IEC-6 cells.

Animals↗

PubMed2001

A case of 46,X,der(X)(pter-->q21::p21-->pter) with gonadal dysgenesis, tall stature, and endometriosis.

OBJECTIVE: To report a case of 46,X,der(X)(pter-->q21::p21-->pter) with gonadal dysgenesis, tall stature, and endometriosis. DESIGN: Case report. SETTING: A university hospital. PATIENT(S): A 20-year-old primary amenorrheal woman receiving estrogen-progestogen substitution. INTERVENTION(S): G-banding, comparative genomic hybridization, fluorescence in situ hybridization (FISH), and laparoscopy. MAIN OUTCOME MEASURE(S): A recombinant X chromosome, 46,X,der(X)(pter-->q21::p21-->pter), and pelvic endometriosis. RESULT(S): The patient's chromosomal abnormality was misjudged by the use of G-banding as a distal part deletion of the long arm in one X chromosome. Comparative genomic hybridization and fluorescence in situ hybridization analyses with locus-specific probes revealed 46,X,der(X)(pter-->q21::p21-->pter). The laparoscopic examination showed bilateral streak gonads and blue berry spots at the pelvic peritoneum, which were confirmed by evaluation of biopsy specimens. CONCLUSION(S): Recent advances of genetic strategies make it easy to determine karyotype and phenotype abnormalities. We have to keep our mind on the potential of endometriosis with patients who are receiving estrogen-progestogen substitution.

Adult↗

PubMed2001

Intracameral and Lenticular Penetration of Locally Applied Deuterium-Labeled Vitamin E in Rats.

Purpose: To confirm the intraocular dynamics of 1% deuterium (D) labeled alpha-tocopheral acetate (VEA) solution.Methods: The concentrations of D(3)-VEA and D(3)-alpha-tocopherol (VE) derived from D(3)-VEA in the aqueous humor and lens were measured after instilling 1% D(3)-VEA continuously into the cul-de-sac of rat eyes for one and three weeks. D(3)-VEA and D(3)-VE concentrations were determined by gas chromatograph/mass spectrometry.Results: D(3)-VEA and D(3)-VE concentrations in the aqueous humor after one and three weeks of continuous administration were 93.1 and 498.9, and 9.4 and 21.5 ng/mL, respectively. The concentrations in the lens were 15.0 and 6.1, and 9.8 and 4.8 ng/g, respectively.Conclusion: The penetration of VEA into the aqueous humor and lens by eyedrop application was confirmed.

Journal Article↗

PubMed2001

Physiology of diapause and cold hardiness in the overwintering pupae of the fall webworm Hyphantria cunea (Lepidoptera: Arctiidae) in Japan.

The fall webworm Hyphantria cunea Drury, which was accidentally introduced to Japan in 1945, overwinters on the ground in pupal diapause. Diapause termination, as indicated by the respiration rate and the period required for adult emergence, began in March and ended in April. Cold hardiness (the ability to survive exposure to -15 degrees C) decreased linearly with diapause development from November to the following April under field conditions. Cold hardiness of diapause pupae (DP) decreased as the acclimation temperature decreased from 15 to -10 degrees C, whereas cold hardiness of non-diapause pupae (NDP) remained high as the acclimation temperature decreased from 5 to -5 degrees C. However, H. cunea in Japan can survive exposure to -5 degrees C for two weeks, whether it is in a diapause or non-diapause state. Trehalose was the main sugar detected in the body, but its level was less than 0.8%. Trehalose levels increased in field-collected pupae from January to March. DP accumulated less trehalose than NDP, as the acclimation temperature was decreased from 5 to -5 degrees C. The alanine content in field-collected pupae increased from November to February. Both diapause and low temperature caused an accumulation of alanine. These results suggest that under field conditions, overwintering pupae of H. cunea in Japan do not accumulate high levels of sugars and polyols and do not develop a high level of cold hardiness. Furthermore, DP do not accumulate high levels of sugars and polyols and their ability to survive exposure to -15 degrees C is not greater than that of NDP. The physiological and biochemical bases of diapause in H. cunea from Japan are discussed.

Journal Article↗