Clinicopathological study of expression of lymphatic vessels in renal allograft biopsy after treatment for acute rejection

BACKGROUND

Lymph vessel expression is related to inflammatory cell infiltration, around renal tubules in acute rejection episodes (ARE) of transplanted kidneys. However, there is little information on the lymph vessels after treatment of an ARE, particularly in relation to renal function and histological findings.

PATIENTS AND METHODS

We investigated 13 cases of ARE diagnosed by kidney transplant biopsy performed from 1997 to 2005 within 3 years of transplantation. Treatment of the ARE lead to an improved serum creatinine level in all cases. There was neither an ABO-incompatible nor an acute humoral rejection case. Lymphatic vessels in re-biopsies were examined using immunohistochemical staining with D2-40 antibody that detected lymphatic endothelium. Re-biopsy cases in which the baseline creatinine had increased by more than 20% despite treatment were considered the severe group; the others, as the stable group. The relation between lymphatic vessel density (LVD) and renal function was examined using Banff scores.

RESULTS

LVD was significantly higher in the severe than the stable group. The expression of lymph vessels versus the Banff score showed a direct relation: greater Banff scores showed higher expressions of lymph vessels.

CONCLUSIONS

The expression of lymph vessels in renal allograft specimens after treatment of an ARE was related to deterioration of renal function and inflammatory cell invasion. We plan a further examination of the relationship between the expression of lymph vessels and long-term prognosis.

Hepatocyte growth factor and interleukin-6 in combination with prostate volume are possible prostate cancer tumor markers in patients with gray-zone PSA levels

The aim was to assess whether hepatocyte growth factor (HGF) and interleukin (IL)-6 in combination with prostate volume are able to accurately detect prostate cancer in patients with gray-zone prostate-specific antigen (PSA) levels. A total of 159 patients with PSA levels of <10 ng ml(-1) were enrolled. Forty-two (35.3%) were diagnosed with prostate cancer, whereas 117 (64.7%) had no cancer and were used as benign group. HGF and IL-6 density (HGFD and IL-6D, respectively) values were calculated by dividing serum HGF and IL-6 levels with prostate volume. Median IL-6 (2.3 pg ml(-1)) levels for the prostate cancer group were significantly higher than those for the benign group before adjustment for age (1.7 pg ml(-1)) (P=0.0098). After age adjustments, median IL-6 (2.17 pg ml(-1)), HGFD (0.00972 ng ml(-1) cm(-3)), and IL-6D (0.0848 pg ml(-1) cm(-3)) values for the prostate cancer group were significantly higher than those for the benign group (IL-6, 1.78 pg ml(-1); HGFD, 0.00732 ng/ml/cc; and IL-6D, 0.049 pg/ml/cc; P=0.0416, 0.007 and 0.0005, respectively). In receiver operating characteristic analyses, the areas under the curves for HGFD (0.64) and IL-6D (0.68) were significantly greater than those for HGF (0.52) and IL-6 (0.61) (P=0.0006 and 0.019, respectively). With an HGFD cutoff value of 0.00392 ng ml(-1) cm(-3) (sensitivity=100%, specificity=11%), 11.1% of the benign group were able to avoid unnecessary biopsies without missing prostate cancer. HGF and IL-6 levels in combination with prostate volume were shown to be useful parameters for prostate cancer screening in patients with gray-zone PSA levels.

Development of an immunochromatographic test kit for rapid detection of bovine viral diarrhea virus antigen

An immunochromatographic test was developed for rapid diagnosis of bovine viral diarrhea virus (BVDV) infections using monoclonal antibodies against the nonstructural protein, NS3, of the virus. The kit detected specifically the NS3 of various BVDV strains. Using the kit, leukocyte extracts of cattle infected persistently with BVDV were found positive while those of healthy cattle were negative. The sensitivity and specificity of this kit in compared with virus isolation were 100% and 97.2%, respectively. Furthermore, the test also gave positive results for calves infected acutely with BVDV in experimental infection. The BVDV antigen was detected in 1 ml of blood using a relatively simple procedure. This test kit should be useful for rapid diagnosis of BVD.

Increased Expression of Renin in Chronic Allograft Nephropathy

BACKGROUND

Chronic allograft nephropathy (CAN) is the main cause of renal transplant failure in the first decade posttransplant. The precise pathogenetic mechanism for CAN is not completely understood. A possible role of renin-angiotensin system for CAN has been suggested through clinical observations that angiotensin-converting enzyme inhibition and angiotensin II receptor blockers prevent CAN.

METHODS

Distribution of renin-positive cells in allograft biopsy specimens was examined immunohistochemically in 23 renal transplant recipients diagnosed with CAN Biopsy specimens obtained from seven recipients with stable renal function were examined as controls. Histologic evaluation was performed based on the Banff 97 classification.

RESULTS

Renin-positive cells were found in the juxtaglomerular apparatus (JGA) adjoining the afferent arterioles in both groups. When the number of renin-positive cells in JGA was defined as a renin index, it was significantly higher in the CAN than the control group (P = .007). There was no significant difference in age, interval between transplantation and biopsy, and blood pressure between groups. Only a significantly higher serum creatinine was found in the CAN group.

CONCLUSIONS

The increased renin-positive cells in JGA suggest a significant role of the intrarenal renin-angiotensin system activation in the development of CAN.

Effects of single and long-term administration of wheat albumin on blood glucose control: randomized controlled clinical trials

OBJECTIVE

To examine the effects of single and long-term administration of wheat albumin (WA) on blood glucose levels and blood glucose control, respectively.

DESIGN

Randomly arranged crossover trial for single administration in healthy subjects and double-blinded randomized controlled trial for long-term administration (3 months) in diabetic patients. In vitro alpha-amylase inhibitory activity of WA was also determined.

SETTING

Central Research Laboratories of Nisshin Flour Milling Co. Ltd. (Saitama, Japan) for single administration and Aiwa Clinic (Saitama, Japan) for long-term administration.

SUBJECTS

A total of 12 healthy adult male volunteers for the single administration and 24 type II outpatient diabetics with mild hyperglycemia for the long-term administration.

INTERVENTIONS

Subjects took soups containing 0, 0.25, 0.5, and 1.0 g WA before test meals for single administration, and patients took soups with or without 0.5 g WA before every meal for the long-term (3 months) administration.

RESULTS

In vitro alpha-amylase inhibitory activity of WA was 150 times that of wheat flour. In the single administration experiment, WA suppressed peak postprandial blood glucose levels in a dose-dependent manner: 31, 47, and 50% reduction after 0.25, 0.5, and 1.0 g administrations, respectively. In the long-term administration, 0.5 g of WA did not affect fasting blood glucose levels, whereas it reduced hemoglobin A1c levels. No significant adverse effects such as hypoglycemia or gastrointestinal disturbances were observed in the two experiments.

CONCLUSION

In the treatment of type II diabetic patients, WA might be a useful functional food, which, with diet and exercise, could help to improve blood glucose control without any critical adverse effects.

Comparison of histopathological characteristics of allograft biopsy between responder and non-responder to antiproteinuric effect of angiotensin-converting enzyme inhibitor (ACEI)

Angiotensin-converting enzyme inhibitor (ACEI) has become recognized as agents that have renoprotective effects in the treatment of progressive renal diseases including post-transplant kidneys. Previously we demonstrated the safety and effectiveness of ACEI treatment on the hypertensive proteinuric post-transplant patients (N = 10) who had been followed up for 12 months. However, not all patients show good response in urinary protein reduction. We aimed to analyse the histopathological factor(s) affecting the responsiveness of proteinuria to ACEI treatment. Fourteen post-transplant patients with proteinuria who were treated with ACEI and underwent allograft biopsy were analysed. Eight patients showed 50% or more reduction in proteinuria (responder). The other 6 patients showed less (< 50%) reduction in proteinuria (non-responder). There was no difference in clinical characteristics (BP, renal function, donor age, recipient body mass index), dietary sodium or protein intake, and diuretic use between the two groups. As a histopathological characteristic, glomerular size in responder group was significantly larger than that in non-responder group. This suggests that the large glomerular size at least partly contributes to the responsiveness in urinary protein reduction to ACEI treatment in kidney allograft recipients with proteinuria.

Risk factors for graft loss in patients with recurrent IGA nephropathy after renal transplantation

BACKGROUND

The recurrence rate of IgA nephropathy (IgAN) in transplanted kidneys has been reported to be >50%. Although recurrent IgAN has a benign clinical course, recent data suggest that it leads to graft loss in a substantial number of patients.

METHODS

We performed a retrospective single-center analysis of 34 renal transplant recipients, with biopsy-proven IgAN as the cause of end-stage renal failure.

RESULTS

Renal allograft biopsies were performed in 30 patients, of whom 24 did and 6 did not have biopsy-confirmed recurrent transplant IgAN. Recurrent transplant IgAN was more often detected in men and at later timepoints after post-transplantation. Four patients with recurrent transplant IgAN progressed to graft failure. Progression to graft failure was associated with worsened renal function, higher systolic blood pressure, and the lack of presenation of angiotensin-converting enzyme inhibitors (ACEs) at the time of allograft biopsy. Immunologic factors such as frequency of acute rejection, HLA typing, and immunosuppression did not show a relation to recurrence or graft loss.

CONCLUSIONS

Recurrent transplant IgAN increased with long-term graft survival and risk factors for graft loss due to recurrent IgAN were similar to those among IgAN in native kidneys.

Investigation of the pharmacokinetics of cyclosporine in patients following long-term administration after a kidney transplant: comparison of neoral and sandimmune

A crossover administration of Neoral and Sandimmune was performed in 43 renal allograft recipients who had been on cyclosporine maintenance therapy for 2 to 19 years posttransplant to investigate the pharmacokinetics of cyclosporine. Although there was no difference in C0 values (trough values) when Neoral and Sandimmune were administered at the same doses, AUC(0-4) and AUC(0-12) values of Neoral were 1.57- and 1.36-fold greater than those of Sandimmune, respectively. For both Neoral and Sandimmune, there was a high correlation between the C2 value and AUC(0-4). The Pearson's product-moment coefficient for the correlation between the C2 value and AUC(0-4) was R=0.91642. On the other hand, the correlation with the C0 value (trough value) was low (R=0.53181). During the period of the study, there was no acute rejection episode, onset of adverse drug reaction symptoms, or marked change in laboratory test values.

Ventromedial hypothalamus lesions induce jejunal epithelial cell hyperplasia through an increase in gene expression of cyclooxygenase

BACKGROUND

We demonstrated that ventromedial hypothalamus (VMH) lesions facilitate DNA synthesis, which reflects cell proliferation in abdominal organs, including the liver, pancreas, stomach, small intestine and large intestine, all of which are amply innervated by the vagal nerve.

OBJECTIVE

To investigate which area DNA synthesis facilitates and what factors contribute to cell proliferation in the small intestine in VMH-lesioned rats.

DESIGN

At 7 days after VMH lesions or sham operations, a segment of rat jejunum was taken for histological examination. A part of the jejunum was also removed from VMH-lesioned and sham-operated rats after 3 days and examined for 5-bromo-2'-deoxyuridine (BrdU) incorporation. At 6, 12 and 24 h after VMH lesions, the proximal intestine was removed from individual rats, from the pylorus to the mid-jejunum. Total RNA was extracted from these tissues of each rat, and the levels of epidermal growth factor (EGF) and transforming growth factor (TGF)-alpha mRNA were determined using reverse-transcription polymerase chain reaction. Cyclooxygenase (COX)-1 and -2 mRNA levels were determined using Northern blotting.

RESULTS

: Jejunal villi in VMH-lesioned rats were markedly enlarged compared to those of sham-operated rats and jejunal crypts in VMH-lesioned rats more markedly incorporated BrdU. Northern blot analysis revealed an increase in COX-1 mRNA after 6, 12 and 24 h in the jejunum of VMH-lesioned rats. COX-2 mRNA was decreased 6 and 12 h after VMH lesioning; however, it was significantly increased 24 h after VMH lesions in comparison to sham-operated rats. The levels of EGF and TGF-alpha mRNA were unchanged in VMH lesioned rats.

CONCLUSION

VMH lesions induced enlargement of jejunal villi and increased the gene expression of COX-1 in the small intestine. Prostaglandins, probably E(2), induced by COX-1 may be one candidate factor responsible for the cell proliferation of the small intestinal epithelium in these rats.

[Aging society and an adult guardianship system]

Prior to recent revisions, civil law had established a system of interdict and quasi-incompetency. This system was begun in 1898 and, up until the revisions of April 2000, it had spanned more than one hundred years without undergoing any major changes. Statistically, there was a steady increase in the number of pronouncements and retractions of incompetency in recent years. A 1980 survey showed that people in their 40s were the most common, and that the proportions of psychiatric disorder, mental retardation, and dementia were of nearly the same level. A 1996 survey, in contrast, showed a greater proportion of elderly, with about half of cases being dementia or a vegetative state. The new adult guardianship system currently in place, as well as a voluntary guardianship system (enduring power of attorney), was established together with the change from the interdict/quasi-incompetency system to a system of assistance, curatorship, and guardianship. The care insurance system that was put in effect at the same time shifted from an enforcement system to a contract system, so the judgment ability of the person at the time of the decision to enter the contract has become an issue. Finally, in dealing with people with dementia, especially mild dementia, problems arise as to the best method of informed consent, including notifying people of their specific disease, and who should decide the treatment for incompetent people with dementia.

[A case of gliomatosis cerebri in an elderly woman]

Gliomatosis cerebri is a rare form of glioma, which diffusely extends to both cerebral hemispheres. Because it sometimes fails to show severe neurological symptoms in spite of diffuse invasion, the antemortem diagnosis is difficult. We report a case of a 77-year-old woman, who was admitted with progressive left hemiparesis and dysarthralgia. Plain CT scan of the brain showed almost no abnormal findings. MRI T2-weighted image revealed widespread and nearly symmetrical extension of a high intensity area from the corpus callosum to the deep white matter of both cerebral hemispheres. Open biopsy of the brain showed glioblastoma multiforme, which finally confirmed the clinical diagnosis of gliomatosis cerebri. We also review the classic and recent literatures.

Photodynamic therapy targeted to tumor-induced angiogenic vessels

Cancer photodynamic therapy (PDT) with benzoporphyrin derivative monoacid ring A (BPD-MA, verteporfin) may be effective not only by being directly cytotoxic to tumor cells, but also by being cytotoxic to the endothelium of tumor neovasculature. In the present study, we investigated the effect of PDT with an experimental liposomal formulation of BPD-MA on tumor-induced angiogenic vessels using a murine dorsal air sac model. First, hemostasis of neovasculature was examined by varying the regimen of PDT. Laser irradiation at 15 min after injection of 2 mg/kg liposomal BPD-MA (15 min PDT) caused complete blocking of blood flow in neovasculature. In contrast, PDT did not inhibit blood flow when the irradiation occurred 3 h after the injection of liposomal BPD-MA (3 h PDT). Next, the antitumor effect of PDT on Meth A sarcoma-bearing mice was investigated by using the hemostasis-inducing regimen. Tumor growth was strongly inhibited after the 15 min PDT with BPD-MA at a dose of 0.5-2 mg/kg. In contrast, 3 h PDT with BPD-MA at a dose of 2 mg/kg suppressed tumor growth only partially. The current study indicates that 15 min PDT causes strong suppression of tumor growth, perhaps through damaging endothelial cells in the tumor neovasculature rather than through a direct cytotoxic effect on tumor cells.

The treatment of port wine stains with a dye laser: a study of 644 patients

Between June 1989 and December 1996, the flashlamp pumped pulsed dye laser was used to treat port wine stains (PWS) in 644 patients, age range 3 months-93 years (mean 21). The efficacy of the treatment was assessed after more than one year of follow-up. Each factor that might affect the efficacy was then evaluated statistically. Broad lesions required more laser treatments than narrow lesions and clearing tended to start from the periphery of the lesion, indicating the three-dimensional depth of the broader PWS. Patients who had been given previous treatments such as argon laser required about two more laser treatments than those who had not, but there were no clear differences in the efficacy of dye laser treatment between the two groups.

Different origin of hypertriglyceridemia induced by a high-fat and a high-sucrose diet in ventromedial hypothalamic-lesioned obese and normal rats

OBJECTIVE

To clarify the mechanism by which plasma triacylglycerol is affected by a high fat or a sucrose diet.

DESIGN

Two sets of six groups each having six rats were prepared-(1) ventromedial hypothalamic (VMH)-lesioned rats fed a standard diet; (2) sham VMH-lesioned rats fed a standard diet; (3) VMH-lesioned rats fed a high-fat diet; (4) sham VMH-lesioned rats fed a high-fat diet; (5) VMH-lesioned rats fed a high-sucrose diet; and (6) sham VMH-lesioned rats fed a high-sucrose diet. After VMH lesions and sham operations, the rats were provided standard, high-fat and high sucrose diets for 2 weeks. Two weeks later, blood samples were collected after overnight fast to determine plasma triacylglycerol (TAG), hepatic triacylglycerol secretion rate (TGSR), fractional catabolic rate (FCR) of triacylglycerol and postheparin plasma lipoprotein lipase (LPL), plasma glucose, insulin and leptin.

RESULTS

Values of TAG, TGSR, FCR and LPL in VMH-lesioned obese rats were all greater than those in sham-operated rats, regardless of the diet fed. In sham-operated rats, high-fat diet fed rats showed higher TAG with similar TGSR, higher LPL and lower FCR than those of standard diet fed rats. High-sucrose diet fed rats showed significantly higher TAG with higher TGSR, higher LPL and lower FCR than those of standard diet fed rats. Moreover, high-sucrose diet fed rats showed higher TAG with higher TGSR, lower LPL and higher FCR than those of high-fat diet fed rats. In VMH-lesioned rats, high-fat diet fed rats showed higher TAG with similar TGSR, higher LPL and lower FCR than those of standard diet fed rats. High-sucrose diet fed rats showed markedly higher TAG with notably higher TGSR, higher LPL and lower FCR than those of standard diet fed rats. High-sucrose diet fed rats showed still higher TAG with markedly higher TGSR, similar LPL and higher FCR than those of high-fat diet fed rats.

CONCLUSIONS

The mechanism by which TAG metabolism is affected by a high-fat or a high-sucrose diet differed; a high-fat diet increased plasma TAG level by lowering removal of TAG without increase in hepatic TAG secretion in sham-operated (normal) rats. A high-sucrose diet, in contrast, induced much higher plasma TAG levels by both increased hepatic TAG secretion and decreased removal of TAG. The effects of a high-fat or a high-sucrose diet were similar but exaggerated in VMH lesioned animals.

A study of reproductive performance in pregnant, IL-2 receptor beta-chain overexpressed transgenic mice

Relationships between female reproductive performance and uterine natural killer (uNK) cells were investigated in pregnant IL-2 receptor beta-chain overexpressed transgenic (Tg2Rbeta) mice. At 8 days of pregnancy, all fetuses were alive, suggesting that implantation normally occurred in these mice. However, 47% of fetuses were dead at 10 days of pregnancy and at 12 days all fetuses were resorbing, indicating that fetal loss progressed with the advance of pregnancy. The placenta of Tg2Rbeta mice gradually decreased in weight with the advance of pregnancy. At 10 days the placental labyrinth, decidua basalis, and metrial gland in Tg2Rbeta mice were poorly developed, and more uNK cells were found in Tg2Rbeta mice than in the control mice. We propose that Tg2RPbeta mice are the first and interesting model that uNK cells can cause abortion, to clarify the involvement of uNK cell function in female reproductive performance.

Liposomes modified with a synthetic Arg-Gly-Asp mimetic inhibit lung metastasis of B16BL6 melanoma cells

Administration of large amounts of synthetic peptides based on the Arg-Gly-Asp (RGD) sequence has been shown to suppress tumor metastasis. To overcome the rapid degradation of peptides in the circulation, an RGD mimetic, L-arginyl-6-aminohexanoic acid (NOK), was synthesized and conjugated with phosphatidylethanolamine (PE) (NOK-PE) for liposomalization. Cell adhesion assays revealed that B16BL6 murine melanoma cells adhered to immobilized NOK-PE. This adhesion was inhibited by addition of either soluble RGDS or NOK at similar concentration in a dose-dependent manner. Administration of NOK-PE liposomes (equivalent to ca. 500 microg RGD peptides) via the tail vein completely inhibited lung colonization of B 16BL6 cells. The same dose of soluble NOK was not effective in inhibition of the tumor metastasis. In addition, injection of NOK-PE liposomes via the tail vein inhibited spontaneous lung metastasis of B16BL6 cells from the primary tumor site in the hind footpad. These results suggest that NOK, a structural mimetic of RGD, is capable of suppressing metastasis by blockade of the binding of the integrins present on tumor cells to the RGD-containing extracellular matrix.

Disulfide bonds in rat cutaneous fatty acid-binding protein

Unlike other fatty acid-binding proteins, cutaneous (epidermal) fatty acid-binding proteins contain a large number of cysteine residues. The status of the five cysteine residues in rat cutaneous fatty acid-binding protein was examined by chemical and mass-spectrometric analyses. Two disulfide bonds were identified, between Cys-67 and Cys-87, and between Cys-120 and Cys-127, though extent of formation of the first disulfide bond was rather low in another preparation. Cys-43 was free cysteine. Homology modeling study of the protein indicated the close proximity of the sulfur atoms of these cysteine pairs, supporting the presence of the disulfide bonds. These disulfide bonds appear not to be directly involved in fatty acid-binding activity, because a recombinant rat protein expressed in Escherichia coli in which all five cysteines are fully reduced showed fatty acid-binding activity as examined by displacement of a fluorescent fatty acid analog by long-chain fatty acids. However, the fact that the evolutionarily distant shark liver fatty acid-binding protein also has a disulfide bond corresponding to the one between Cys-120 and Cys-127, and that fatty acid-binding proteins play multiple roles suggests that some functions of cutaneous fatty acid-binding protein might be regulated by the cellular redox state through formation and reduction of disulfide bonds. Although we cannot completely exclude the possibility of oxidation during preparation and analysis, it is remarkable that a protein in cytosol under normally reducing conditions appears to contain disulfide bonds.

Sucrose-diet feeding induces gene expression of heat shock protein in rat brain under stress

Stress-induced hyperphagia is enhanced in the presence of sweets, particularly sucrose, which may act to attenuate stress. Recently, it was also reported that heat shock protein (HSP) may be involved in the defense against stress. To explore whether sucrose alters gene expression of HSP under stress, we determined the HSP mRNA levels in the hypothalamus, cerebellum, and cerebral cortex after restraint stress in sucrose-diet-fed rats. Competitive RT-PCR revealed that gene expressions of HSP27 in the cerebral cortex and cerebellum and of HSP70 in the cerebral cortex, hypothalamus, and cerebellum were induced by restraint stress under a sucrose-diet-fed condition. However, restraint stress by itself or sucrose diet alone did not induce expression of HSP27 or HSP70 mRNA in any of the three anatomical parts. It is suggested that sucrose facilitates the gene expression of HSP27 and HSP70 in brain after restraint stress, which may attenuate stress.

Lack of integrative control of body temperature after capsaicin administration

BACKGROUND

Body temperature is usually regulated by opposing controls of heat production and heat loss. However, systemic administration of capsaicin, the pungent ingredient of hot peppers, facilitated heat production and heat loss simultaneously in rats. We recently found that the capsaicin-induced heat loss and heat production occur simultaneously and that the biphasic change in body temperature is a sum of transient heat loss and long-lasting heat production. Moreover, suppression of the heat loss response did not affect capsaicin-induced heat production and suppression of heat production did not affect capsaicin-induced heat loss. These observations suggest the independent peripheral mechanisms of capsaicin-induced thermal responses. Thus, the capsaicin-induced thermal responses apparently lack an integrated control.

METHODS

Male Wistar rats were maintained at an ambient temperature of 24 +/- 1 degrees C on a 12 h on-off lighting schedule at least for two weeks before the experiments. They were anesthetized with urethane (1.5 g/kg, i.p.) and placed on a heating pad, which was kept between 29 and 30 degrees C. Skin temperature(Ts) was measured with a small thermistor, which was taped to the dorsal surface of the rat's tail, to assess vasoactive changes indirectly. Colonic temperature(Tc) was measured with another thermistor inserted about 60 mm into the anus. O2 consumption was measured by the open-circuit method, and values were corrected for metabolic body size (kg0.75). Capsaicin (Sigma) was dissolved in a solution comprising 80% saline, 10% Tween 80, and 10% ethanol, and injected subcutaneously at a dose of 5 mg/kg. Each rat received a single injection of capsaicin because repeated administration of capsaicin renders an animal insensitive to the subsequent administration of capsaicin. Laminectomy was performed at the level of the first and second cervical vertebrae to expose the cervical spinal cord for sectioning. The brain was transected at 4-mm rostral from the interaural line with an L-shaped knife.

RESULTS

After administration of capsaicin, O2 consumption increased from 13.5 +/- 0.4 mL/min/kg0.75 at 0 min to a peak of 15.9 +/- 0.4 mL/min/kg0.75 at 71 min and gradually declined but remained higher than the basal value until the end of the 4-h observation period. Ts also immediately increased from 27.7 +/- 0.2 degrees C to 31.9 +/- 0.3 degrees C at 39 min, and it returned to the baseline level within 90 min after the capsaicin administration. Tc initially decreased from 37.1 +/- 0.1 degrees C to 36.8 +/- 0.2 degrees C at 43 min and then gradually increased over the baseline level and remained at 37.6 +/- 0.2 degrees C until the end of the experiment. In spinalized rats, the capsaicin-induced increases in O2 consumption was largely attenuated, while the basal O2 consumption was similar to that of control rats. The basal Ts of spinalized rats was 32.4 +/- 0.3 degrees C, which was higher than that of control rats. Capsaicin increased Ts by less than 1 degree C, and Tc did not change after the capsaicin administration. O2 consumption of decerebrated rats was statistically higher than that of control rats after the injection of capsaicin. However, capsaicin did not increase Ts, showing a lack of a vasodilatory response. Decerebration between the hypothalamus and midbrain prevented the capsaicin-induced heat loss but not the heat production response.

CONCLUSION

These results show that the capsaicin-induced heat production and heat loss are controlled separately by the brainstem and by the forebrain, respectively, and suggest that the body temperature regulation is performed without an integrative center.

Lack of integrative control of heat production and heat loss after capsaicin administration

Body temperature is usually regulated by opposing controls of heat production and heat loss. However, systemic administration of capsaicin activates heat loss and heat production simultaneously. Because capsaicin receptors are located mainly on primary sensory neurons and body temperature is regulated by the central nervous system, we investigated the brain mechanisms involved in these capsaicin-induced thermal responses. For this purpose, we examined the effects of spinalization and decerebration on these responses in artificially ventilated, urethane-anesthetized rats. Cervical spinal transection largely attenuated both responses, showing the critical involvement of the brain. Colonic temperature (Tc) did not change after the capsaicin administration to the spinalized rats. Decerebration between the hypothalamus and midbrain prevented the capsaicin-induced heat loss and enhanced the capsaicin-induced heat production. Consequently, Tc increased without a hypothermic period. The results show that capsaicin activates brainstem-controlled heat production and forebrain-controlled heat loss separately.

Modeling and measurements of atomic surface roughness

We present a geometrical model of atomic topography with which to obtain a quantitative assessment of surface roughness. A series of two- and three-dimensional atomic surface roughness equations with sufficiently realistic parameters is developed to permit quantitative comparison with scanning-tunneling microscope and atomic-force microscope (AFM) experimental results. The model is sufficiently simple that one can easily use it to interpret experimental data. Tables are provided with estimated values for two- and three-dimensional rms atomic surface roughness in pure metal crystals and ionic crystals based on the atomic surface roughness equations. We use these roughness equations to determine the roughness of cleaved muscovite mica [essentially, KAl(2)(OH)(2)Si(3)AlO(10)]; the calculated values for both two- and three-dimensional roughness are consistent with those obtained in our AFM measurements. In addition, we demonstrate both theoretically and experimentally that atomic surface roughness is never zero.

Effects of fructose and glucose on plasma leptin, insulin, and insulin resistance in lean and VMH-lesioned obese rats

To determine the influence of dietary fructose and glucose on circulating leptin levels in lean and obese rats, plasma leptin concentrations were measured in ventromedial hypothalamic (VMH)-lesioned obese and sham-operated lean rats fed either normal chow or fructose- or glucose-enriched diets (60% by calories) for 2 wk. Insulin resistance was evaluated by the steady-state plasma glucose method and intravenous glucose tolerance test. In lean rats, glucose-enriched diet significantly increased plasma leptin with enlarged parametrial fat pad, whereas neither leptin nor fat-pad weight was altered by fructose. Two weeks after the lesions, the rats fed normal chow had marked greater body weight gain, enlarged fat pads, and higher insulin and leptin compared with sham-operated rats. Despite a marked adiposity and hyperinsulinemia, insulin resistance was not increased in VMH-lesioned rats. Fructose brought about substantial insulin resistance and hyperinsulinemia in both lean and obese rats, whereas glucose led to rather enhanced insulin sensitivity. Leptin, body weight, and fat pad were not significantly altered by either fructose or glucose in the obese rats. These results suggest that dietary glucose stimulates leptin production by increasing adipose tissue or stimulating glucose metabolism in lean rats. Hyperleptinemia in VMH-lesioned rats is associated with both increased adiposity and hyperinsulinemia but not with insulin resistance. Dietary fructose does not alter leptin levels, although this sugar brings about hyperinsulinemia and insulin resistance, suggesting that hyperinsulinemia compensated for insulin resistance does not stimulate leptin production.