Expression of Bombyx mori cytoplasmic polyhedrosis virus polyhedrin in insect cells by using a baculovirus expression vector, and its assembly into polyhedra

A cDNA encoding the cytoplasmic polyhedrin of Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) strain H was introduced into an improved baculovirus expression vector which can be utilized to express foreign genes in the Spodoptera frugiperda cell line IPLB-SF-21AE (Sf21 cells) and the B. mori cell line BmN. A recombinant virus produced large, cubic inclusion body-like structures in infected Sf21 and BmN cells. Western blot analysis showed that these structures were BmCPV polyhedra. This result suggested that the supramolecular assembly of BmCPV polyhedrin is responsible for its properties.

Angina pectoris caused by dynamic exercise in hypertrophic cardiomyopathy with normal coronary arteries

To evaluate the relationship between angina pectoris caused by dynamic exercise and the time course of heart rate (HR) and hemodynamics during dynamic exercise in 15 patients with hypertrophic cardiomyopathy (HCM) with normal epicardial coronary arteries, the supine ergometer exercise test was performed during cardiac catheterization. The HCM patients were divided into a chest pain group (n = 6) and a no chest pain group (n = 9) based upon the results of the ergometer exercise test. There was no significant difference in the level of ST-segment depression after exercise in both the chest pain and no chest pain groups (-2.1 +/- 0.6 mm vs -2.6 +/- 1.1 mm, NS). Increase in heart rate (HR) and left ventricular end-diastolic pressure (LVEDP) in the early phase of the exercise test was significantly greater in the chest pain group compared with the no chest pain group. These observations suggest that in HCM patients, the occurrence of exertional chest pain has a close relationship with the rapid increase in HR and LVEDP in the early phase of dynamic exercise, but does not have a relationship with the gradual increase in these parameters.

Effects of X-irradiation on N-methyl-N-nitrosourea-induced multi-organ carcinogenesis in rats

The effects of X-irradiation on N-methyl-N-nitrosourea (MNU)-induced multi-organ carcinogenesis were examined in both sexes of ACI/N rats. At 6 weeks of age, rats in groups 1 (25 males, 25 females) and 3 (24 males, 23 females) received a single i.p. injection of MNU (25 mg/kg body weight), while those in groups 2 (25 males, 26 females) and 4 (25 males, 25 females) were administered the carcinogen at a dose of 50 mg/kg body weight. At 10 weeks of age, groups 3 and 4 were X-irradiated at a dose of 3 Gy. Group 5 (24 males, 24 females) received X-irradiation alone. Group 6 (21 males, 21 females) served as an untreated control. As a result, neoplasms developed mainly in the digestive tract, kidney, uterus, and hematopoietic organ in groups 1-5. The incidences of adenocarcinoma in small and large intestines of male rats of group 4 (50 mg/kg MNU and X-irradiation) (small intestine: 48%, large intestine: 32%) were significantly higher than those of group 2 (50 mg/kg MNU) (small intestine: 17%, P < 0.05; large intestine: 8%, P < 0.05), and also the frequency of adenocarcinoma in the large intestine of males of group 3 (25 mg/kg MNU and X-irradiation) (22%) was significantly greater than that of group 1 (25 mg/kg MNU) (0%, P < 0.05). These results indicated that X-irradiation enhanced the development of intestinal neoplasms induced by MNU in male ACI/N rats.

Evaluation of myocardial damage in Duchenne's muscular dystrophy with thallium-201 myocardial SPECT

Myocardial damage and cardiopulmonary functions in patients with Duchenne's muscular dystrophy (DMD) were assessed using thallium-201 myocardial single-photon emission computed tomography (SPECT) and technetium-99m multigated radionuclide angiography. Twenty-five patients with DMD were divided into 4 groups according to percent of perfusion defect (%PD) calculated by the bull's-eye method and age. PD was detected in 24 (96.0%) of 25 patients with DMD, and it spread from the left ventricular lateral wall to the anterior wall and/or interventricular septum. PD was detected even in a 6-year-old DMD boy. Patients in Group I (%PD > or = 10 and age < 15 years old) were shown to have a higher risk of left-sided heart failure without respiratory failure. Patients in Group II (%PD > or = 10 and age > or = 15) showed decreased pulmonary function and worsened arterial blood gas values as compared with Group IV (%PD < 10 and age > or = 15). There was no significant difference in cardiac function among the 4 groups. It is postulated that myocardial damage in Group II patients is dependent primarily on a deficiency of dystrophin and on chronic respiratory failure, and that some of them are at risk of cardiopulmonary failure. It is concluded that myocardial SPECT is useful for the early diagnosis of myocardial damage and evaluation of cardiopulmonary function in DMD patients.

[Non-radioisotopic reverse transcriptase assay using biotin-11-deoxyuridine-triphosphate and a primer-immobilized microtiter plate: application for detection and identification of isolated retroviruses from HIV-1-seropositive hemophiliac patients]

Non-radioisotopic reverse transcriptase assay (Non-RTA) was successfully applied for detection and identification of the retroviruses isolated from peripheral mononuclear cells from eight HIV-1-seropositive hemophiliac patients. Of 40 samples, 36 (90%) were consistent in detection between Non-RI and RI RTA. Four samples which showed RT activities slightly above the cutoff level of RI RTA were not detected by Non-RI RTA. Non-specific RT-inhibitors in the culture supernatant decreased the sensitivity of Non-RI RTA more significantly than that of RI RTA. It was demonstrated that higher concentrations (> 20%) of fetal calf serum in RPMI-1640 culture medium inhibited the hybridization of poly rA template with immobilized primer, resulting in reducing the sensitivity of Non-RI RTA. Then we identified the isolated retroviruses using specific RT-inhibiting (RTI) antibodies against HIV-1 and HIV-2. HIV-1 RTI antibody specifically inhibited RTs of isolated retroviruses and HIV-1 strain, LAV-1, but not HIV-2 and Rous-associated virus 2 (RVA-2) RT. Conversely, HIV-2 RTI antibody specifically inhibited HIV-2 RT, but not HIV-1 and RAV-2 RT. These findings agreed with previously reported results showing the type-specificity of HIV-1 and -2 RTI antibodies, and suggest the possibility that isolated retroviruses could be identified by these antibodies.

Monoclonal antibody to beta peptide, recognizing amyloid deposits, neuronal cells and lipofuscin pigments in systemic organs

A monoclonal antibody (AmT-1) produced against synthetic amyloid beta peptide (1-28 residues) was revealed to be reactive with amyloid beta peptide blotted on nitrocellulose membrane, but not with that dissolved in sodium dodecyl sulfate and electrophoresed. AmT-1 immunostained senile plaques of typical, primitive and diffuse type, as well as amyloid deposits in cerebral vessels. It also reacted with neuronal and glial cells of normal and Alzheimer's disease (AD) brains. In addition, AmT-1 was also reactive strongly with lipofuscin pigments of adrenal reticular cells, and weakly with those of eccrine glands and liver cells. A rat neural cell line (PC12h) was reactive with AmT-1. By immunoelectron microscopy, a positive reaction was seen in ribosomes along the rough endoplasmic reticulum of nerve cells and PC12h cells. By immunoprecipitation, AmT1 reacted with a band at 36 kDa in the brain homogenates from Ad patients as well as from normal aged subjects. By immunoblotting analysis, AmT1 reacted with a band at 36 kDa in the cytosolic fraction of PC12 cells, and three bands (12-17 kDa) in the lipopigment fraction of the adrenal gland. These findings suggest that the cerebral amyloid deposits contain substance(s) having an epitope common to neuronal cells and lipofuscin pigments. The possible relationship between cerebral amyloid deposits and lipofuscin pigments in systemic organs is discussed.

[The effectiveness of radiotherapy for Merkel cell carcinoma]

Merkel cell carcinoma is a high-grade malignant tumor of the skin that tends to extend locally and metastasize to regional lymph nodes. Surgical resection is the treatment of choice, and the effectiveness of radiotherapy for this disease has not yet been established. We report two cases of biopsy-proven Merkel cell carcinoma effectively treated with radiotherapy. Histopathological examination of the resected specimens after radiotherapy of 50 Gy and 38 Gy, respectively, using 6 approximately 15 MeV electrons showed no malignant cells in either case. No evidence of recurrence or metastasis has been noted in 11 to 21 months after radiotherapy. To our knowledge, no case of Merkel cell carcinoma in which complete cure was obtained by radiotherapy alone has been reported previously. It is considered that preoperative radiotherapy would contribute to the management of this locally invasive but radiosensitive tumor.

Extra-adrenal pheochromocytoma-ganglioneuroma. A case report

A case of rare extra-adrenal tumor composed of pheochromocytoma-ganglioneuroma which developed in a 48-year-old Japanese male is reported. Histologically, the tumor contained equal proportion of two distinct patterns, pheochromocytoma and ganglioneuroma. Immunohistochemical examination revealed that pheochromocytoma cells were positive for Leu-7 and ganglion cells in ganglioneuroma were positive for vasoactive intestinal peptide (VIP), respectively. Neuron specific enolase (NSE) was positive in the neoplastic cells of both components, and S-100 protein was also positive in fibers around ganglion cells. Ultrastructural examination revealed that neurosecretory granules were present in the neoplastic cells.

Adenomyomatosis of the gallbladder with subserosal fatty proliferation: CT findings in two cases

Adenomyomatosis of the gallbladder is frequently seen in ordinary operative specimens. Subserosal fat may proliferate in the presence of adenomyomatosis, but the amount of subserosal fat may be quite variable. Typical and atypical computed tomographic (CT) findings in two cases of adenomyomatosis with subserosal fatty proliferation of the gallbladder are presented. The thick fatty layer surrounding the thickened gallbladder wall with intramural diverticula and stones, typical of CT findings, was seen in one case, and fat interspersed in the periphery of the thickened gallbladder wall without intramural stones, atypical of CT findings, was seen in a second case.

[The first cholera case diagnosed early in the clinical laboratory by DNA probe method]

An alkaline-phosphatase-labelled synthetic oligonucleotide probe was applied to detect the structural gene of cholera enterotoxin (ctx). This DNA probe has a complementary base sequence to 30 base of the CT-A subunit. This method was, for the first time, applied to diagnosis of a diarrheal patient. The probe detected ctx rapidly and simply as compared with reversed passive latex agglutination (RPLA) and Beads-ELISA. The cfu minimal dose for detection with the probe was about 10(6-7)/ml. This method can be easily performed in any clinical laboratory because the procedure is safe, simple and rapid (it can be completed within about 3 hours).

[Effect of suplatast tosilate (IPD-1151T) on types I-IV allergic reactions]

We examined the effect of suplatast tosilate (IPD-1151T), which exhibits a class-specific suppression of IgE antibody production, on types I-IV allergic reactions. 1) Type I reaction: IPD-1151T dose-dependently inhibited 48-hr homologous passive cutaneous anaphylaxis (PCA) when the agent was given p.o. 30 min prior to the antigen challenge. To observe the time course of the inhibitory activity, IPD-1151T in a dose of 50 mg/kg was given orally at various times prior to the antigen challenge. IPD-1151T showed inhibitory activity when it was given at 0.5 to 2 hr prior to the antigen challenge, and the maximum inhibition was found when the IPD-1151T pretreatment was 2-hr before the challenge. IPD-1151T also suppressed the antigen-induced degranulation of mesenteric mast cells and histamine release from peritoneal exudate cells of rats. 2) Type II reaction: Only a high dose of IPD-1151T given orally inhibited reversed cutaneous anaphylaxis in rats, whereas the agent did not affect Forssman shock in guinea pigs. 3) Types III and IV reactions: IPD-1151T neither affected the Arthus reaction in rabbits nor the picryl chloride-induced contact dermatitis and sheep erythrocytes-induced footpad reaction in mice. The results obtained here indicate that IPD-1151T shows a relatively specific suppression of the type I allergic reaction with the inhibition of degranulation and histamine release from mast cells.

New nonradioactive microspheres and more sensitive X-ray fluorescence to measure regional blood flow

We developed new nonradioactive microspheres and used more sensitive X-ray fluorescence spectrometers than used previously to measure regional blood flow in the heart and other organs. We demonstrated the chemical stability of eight kinds of heavy element-loaded microspheres and validated their use for regional blood flow measurement by comparing duplicate flows measured with radioactive and/or nonradioactive microspheres in both acute and chronic dog experiments. The wavelength-dispersive spectrometer (Philips PW 1480) has a higher sensitivity than the previously described X-ray fluorescent system and reduced the number of microspheres required for accurate measurement. The fine energy resolution of this system makes it possible to increase the numbers of different kinds of microspheres to be quantitated, but at present only eight kinds are available. We also used a synchrotron radiation-excited energy dispersive spectrometer. The monochromatic synchrotron radiation allowed us to obtain much higher signal-to-background ratios of X-ray fluorescence spectra than with the wavelength-dispersive system (50 dB more for Zr-loaded microspheres) and will enable analysis of fluorescent activity in smaller regions (< 20 mg) than the radioactive method does.

Performance of an Enzyme-Linked Immunosorbent Assay System for Antibodies to Hepatitis C Virus with Two New Antigens (c11/c7)

We developed an enzyme-linked immunosorbent assay (ELISA) system for antibodies to the hepatitis C virus (HCV), using two new recombinant antigens (c11 and c7) derived from the HCV genome. The performance of this ELISA system (Imucheck HCV Ab) was examined. The CV values for both intra-assay precision and reproducibility of identifying HCV antibody in the panel sera ranged from 3.5% to 6.4%. The blood elements in serum and anticoagulants did not interfere in this ELISA system. The specificity of Imucheck HCV Ab to samples from patients with non-A, non-B (NANB)-type chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma was 93.7%, 93.5%, and 81.4%, respectively. These results are more sensitive than those obtained by the first-generation anti-HCV ELISA system. In the samples from patients with NANB-type acute hepatitis, Imucheck HCV Ab enabled detection of HCV antibodies at an early stage. This system increased the sensitivity for blood donor screening and for monitoring patients with acute hepatitis.

Performance of an enzyme-linked immunosorbent assay system for antibodies to hepatitis C virus with two new antigens (c11/c7)

We developed an enzyme-linked immunosorbent assay (ELISA) system for antibodies to the hepatitis C virus (HCV), using two new recombinant antigens (c11 and c7) derived from the HCV genome. The performance of this ELISA system (Imucheck HCV Ab) was examined. The CV values for both intra-assay precision and reproducibility of identifying HCV antibody in the panel sera ranged from 3.5% to 6.4%. The blood elements in serum and anticoagulants did not interfere in this ELISA system. The specificity of Imucheck HCV Ab to samples from patients with non-A, non-B (NANB)-type chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma was 93.7%, 93.5%, and 81.4%, respectively. These results are more sensitive than those obtained by the first-generation anti-HCV ELISA system. In the samples from patients with NANB-type acute hepatitis, Imucheck HCV Ab enabled detection of HCV antibodies at an early stage. This system increased the sensitivity for blood donor screening and for monitoring patients with acute hepatitis.

[Effects of suplatast tosilate (IPD-1151T) on antibody formations in mice]

We examined the effects of suplatast tosilate (IPD-1151T) on antibody formation in mice, and the following results were obtained: 1) IPD-1151T clearly increased the productions of IgM and IgG-hemolytic plaque forming cells (PFC) in mice immunized with sheep red blood cells (SRBC) when the agent was given p.o. for 5 days from the day of immunization. 2) IgM and IgG-PFC productions in old mice, 60 weeks of age, were clearly lower than those in adult mice, 10 weeks of age; and an oral administration of IPD-1151T significantly recovered the decayed PFC-production in the old mice. 3) IPD-1151T clearly suppressed the production of anti-dinitrophenyl (DNP)-IgE antibody in mice when the agent was given p.o. for 5 days from the day of immunization, whereas the agent did not affect anti-DNP-IgM and IgG antibody productions. 4) IPD-1151T did not affect the induction phase of the cellular immune reaction of picryl chloride-induced contact dermatitis and the SRBC-induced footpad reaction. Our present results suggest that IPD-1151T has a class-specific suppressive effect on the production of IgE antibody, but does not suppress the other immune responses.

Cell kinetic analysis of the mucosal epithelium and assay of ornithine decarboxylase activity during the process of 1-hydroxyanthraquinone-induced large bowel carcinogenesis in rats

Cell kinetics and activity of ornithine decarboxylase (ODC) were studied during the process of 1-hydroxyanthraquinone (1-HA)-induced intestinal carcinogenesis in rats. Starting at 6 weeks of age, a total of 37 male ACI/N rats were divided into two groups and treated as follows: group I (18 rats) received diet containing 1% 1-HA for 12 months; group II (19 rats) was given the basal diet alone. Sub-groups of 5-7 rats were sequentially killed at 4, 8 and 12 months for evaluation of the length, cell numbers and 5-bromo-2'-deoxyuridine (BrDU) labeling indices of large bowel crypts together with ODC activity. All kinetic and ODC data indicated increased DNA synthesis and proliferation at all time points. Morphological observation of the intestines also revealed melanosis, crypt abscesses and erosion, becoming more pronounced with length of exposure to the anthraquinone. The data thus suggest that cell proliferation in the crypts of the cecum or colon is important for 1-HA-induced intestinal carcinogenesis.

Risk factors for coronary heart disease: synthesis of a new hypothesis through adaptation

A risk factor is a characteristic which is associated with a greater than average probability of developing coronary disease. Raised serum cholesterol and hypertension are two such factors. Intervention studies conducted to confirm the risk factor hypothesis have shown that reduction of serum cholesterol and essential hypertension may be associated with a small decreased CHD incidence, however there were almost as many deaths due to coronary disease in the intervention groups as in the control groups. These findings suggest that our approach to risk factor intervention may be a misguided attempt which needs modification. It is possible that the major risk factors develop in an attempt of our body to adapt to environmental factors such as increased intake of salt, saturated fat and cholesterol, physical inactivity, increased intake of calories and obesity and stress. Smoking may be the result of social changes. Since the body has to modify its metabolic mechanism depending upon the factor to which it adapts, development of hyperlipidemia and hypertension may be protective mechanisms of the body which it has developed while fighting against environmental factors. Reduction of major risk factors by drug therapy may mean that we are trying to prevent the body, fighting environmental factors. Thus our approach to control of the major risk factors should be to treat the causative environmental factors or alter the lifestyle.(ABSTRACT TRUNCATED AT 250 WORDS)

Modifying effects of fungal and herb metabolites on azoxymethane-induced intestinal carcinogenesis in rats

Modifying effects of a fungal product, flavoglaucin, and four plant-derived chemicals, shikonin, gingerol, oleanolic acid and paeoniflorin, on intestinal carcinogenesis were examined in a rat model using azoxymethane (AOM). A total of 280 male F344 rats, 6 weeks old, were divided into 12 groups. Group 1 (30 rats) was given two subcutaneous injections of 15 mg/kg of AOM at the start of the experiment. Groups 2 (30 rats), 3 (20 rats), 4 (20 rats), 5 (30 rats) and 6 (30 rats) received a test chemical (flavoglaucin, shikonin, gingerol, oleanolic acid or paeoniflorin, respectively) in the diet at a concentration of 0.02% for 3 weeks, during which time AOM was applied, and then kept on basal diet until the end of experiment (one year). Groups 7-11 (each 20 rats) were given a test chemical corresponding to Groups 2-6, respectively. Group 12 (20 rats) served as a control. The incidence and average number of intestinal tumors in Group 2 (47%, 0.57 +/- 0.68) were significantly less than in Group 1 (74%, 1.07 +/- 0.87) (P < 0.05, respectively). Multiplicity of intestinal neoplasms of Group 3 (0.55 +/- 0.60) or 4 (0.47 +/- 0.51) was also significantly smaller than that of Group 1 (P < 0.05 and P < 0.01, respectively). These results suggest that flavoglaucin, shikonin and gingerol might be promising chemopreventive agents for intestinal neoplasia.

Neoadjuvant intraarterial infusion chemotherapy with a combination of mitomycin-C, vincristine, and cisplatin for locally advanced cervical cancer: a preliminary report

Combination chemotherapy including cisplatin was administered intraarterially from the internal iliac artery as neoadjuvant chemotherapy to six patients with locally advanced uterine cervical cancer (stage higher than IIIB of FIGO). The drugs and doses were mitomycin-C 10 mg/m2, vincristine 1 mg/m2, and cisplatin 50 mg/m2. Two or three courses were repeated at intervals of 3 weeks. In three patients, dose reductions were undertaken for decreased renal function and thrombocytopenia. Partial response was, however, observed in all patients (response rate 100%), and five of six patients were able to undergo a radical hysterectomy. The major toxic effects were leukocytopenia, nausea, and vomiting. Our preliminary experience suggests that pelvic intraarterial infusion of combination chemotherapy is effective against primary and advanced uterine cervical cancer, and this preoperative treatment can lead to easier radical hysterectomy. However, further studies are warranted.

[Unsuspected painless subacute thyroiditis detected by radiogallium scintigraphy]

Two cases of painless subacute thyroiditis were presented in whom fever, fatigue and arthralgia except for thyroidal pain and swelling were complained. Until a intense uptake of the thyroid was found on radiogallium scintigraphy, the examinations of the thyroid had not been done. Laboratory data showed increased erythrocyte sedimentation rate, C-reactive protein and serum alkaline phosphatase, and mild leukocytosis. Skeletal, hepatic and biliary diseases were denied. In patients who have fever, increased erythrocyte sedimentation rate and serum alkaline phosphatase elevation without apparent sources, thyroid function should be evaluated because subacute thyroiditis can be associated with elevation of the serum alkaline phosphatase.

Extensive arterial calcification of unknown etiology in a 29-year-old male

A 29-year-old male with generalized arterial calcification is presented. The roentgenogram showed extensive calcification bilaterally in the facial, brachial, renal, external iliac, femoral, and popliteal arteries. There was also calcification around the joints of the fingers, toes, elbows, and shoulders. The uniformity of arterial calcification in the radiograph differentiated this lesion from Mönckeberg's arteriosclerosis. The serum concentration levels of calcium, phosphorus, alkaline phosphatase, and calcium regulatory hormones were normal. The patient did not have diabetes mellitus, renal disease, or connective tissue disease, thus the etiology of the calcification was not identified. However, a bone scintigram showed that the uptake of 99 mTc-methylene diphosphate was significantly increased in the calcified arteries. Therefore, increased metabolic activity was associated with the derangement leading to arterial calcification.

Cloning and expression of the epsilon 4 subunit of the NMDA receptor channel

The primary structure of a novel subunit of the mouse NMDA (N-methyl-D-aspartate) receptor channel, designated epsilon 4, has been revealed by cloning and sequencing the cDNA. The epsilon 4 subunit shares high amino acid sequence identity with the epsilon 1, epsilon 2 and epsilon 3 subunits of the mouse NMDA receptor channel, thus constituting the epsilon subfamily of the glutamate receptor channel. Expression from cloned cDNAs of the epsilon 4 subunit together with the zeta 1 subunit in Xenopus oocytes yields functional NMDA receptor channels. The epsilon 4/zeta 1 heteromeric channel exhibits high apparent affinities for agonists and low sensitivities to competitive antagonists. The epsilon 4 subunit is thus distinct in functional properties from the epsilon 1, epsilon 2 and epsilon 3 subunits, and contributes further diversity of the NMDA receptor channel.

Purification, cDNA cloning and Northern-blot analysis of mitochondrial chaperonin 60 from pumpkin cotyledons

Two different cDNA clones, pMCPN60-1 and pMCPN60-2, encoding the mitochondrial homologues of chaperonin 60 (Cpn60) were isolated from a cDNA library of germinating pumpkin cotyledons by use of mixtures of synthetic oligonucleotides based on the N-terminal amino acid sequence of the protein. Determination of the complete nucleotide sequences of the two cDNA revealed that pMCPN60-1 and pMCPN60-2 each contain one open reading frame that encodes a protein of 575 amino acids with molecular masses of 61052 Da and 61127 Da, respectively. The deduced amino acid sequences of the two polypeptides include a 32-residue N-terminal putative mitochondrial presequence attached to the mature polypeptides, and they are 95.3% identical. From a comparison of deduced amino acid sequences with other Cpn60, it appears that the mature polypeptides of pumpkin mitochondrial Cpn60 are 44-59% identical to the other Cpn60, namely, GroEL of Escherichia coli, the 60-kDa heat-shock protein (Hsp60) of mitochondria in the yeast Saccharomyces cerevisiae, P1 protein of mammalian mitochondria and the Ribulose-1,5-bisphosphate carboxylase/oxygenase subunit-binding proteins alpha and beta of plastids in higher plants. Genomic Southern-blot analysis identified at least two copies of the gene for mitochondrial Cpn60 in the pumpkin genome. The levels of mRNA for mitochondrial Cpn60 in cotyledons, hooks and hypocotyls of pumpkin seedlings increased in response to heat stress, as deduced from Northern-blot analysis, indicating that pumpkin mitochondrial Cpn60 is a heat-induced stress protein.

Regulation of intestinal apo A-IV mRNA abundance in rat pups during fasting and refeeding

The amount of intestinal apolipoprotein (apo) A-IV mRNA was examined in rat pups during fasting and refeeding. When 14-day old pups were fasted for 15 h, apo A-IV mRNA levels in the whole intestine decreased to 20% of the prefasting level. Refeeding casein and lactose, and the artificial milk composed of Intralipid, casein and lactose, caused an elevation of the apo A-IV mRNA after 3 h, without accompanying an elevation of serum triacylglycerols and apo A-IV (fat-independent elevation of apo A-IV mRNA). Refeeding Intralipid alone simultaneously elevated the apo A-IV mRNA, and serum triacylglycerols and apo A-IV after 3 h (fat-dependent elevation of apo A-IV mRNA). Administration of physiological saline during fasting partly suppressed the reduction of the apo A-IV mRNA (40% of the prefasting level), and the dietary fat-independent elevation of the message disappeared. Refeeding dam's milk to the pups, fasted without water administration, increased the apo A-IV mRNA after 3 and 15 h, although the elevation of serum triacylglycerols and apo A-IV occurred only after 15 h. Refeeding the milk increased the apo A-IV mRNA after 3 h and 15 h. Refeeding dam's milk to the pups fasted with saline administration accelerated the fat-dependent elevation of the apo A-IV mRNA. Simultaneously refeeding Intralipid and Pluronic L-81, an inhibitor of lymphatic fat transport, delayed the elevation of the apo A-IV mRNA and serum triacylglycerols and apo A-IV. Transcription rates of the apo A-IV mRNA, determined by nuclear run/on assay, were similar before and after fasting and refeeding Intralipid. During fasting, administration of puromycin, as compared with actinomycin D, enhanced the disappearance rate of the apo A-IV message. Intestinal mRNA for apo B, but not for apo A-I and beta-actin, similarly changed to the apo A-IV message. Thus, it can be concluded that: (1) dietary fat-dependent and -independent factors are involved in the elevation of the intestinal apo A-IV message; (2) the elevation of the message is not mediated by lipid uptake in the enterocytes but rather stimulated by the events leading to secretion of chylomicrons; and, (3) dietary fat-dependent elevation of the message appears to be due to the stabilization of the message.