Modulation by dietary restriction in gene expression related to insulin-like growth factor-1 in rat muscle.

Physiological adaptations induced by dietary restriction might include the modulation of the insulin-like growth factor 1 (IGF-1) axis. We investigated the effects of dietary restriction on aging-dependent changes in plasma level of IGF-1 and gene expression levels of type-1 IGF receptor (IGFR), insulin receptor substrate-1 (IRS-1), and IGF-1 in the diaphragm and quadriceps femoris muscle (QFM) of male F344 rats. The animals were fed ad libitum throughout life (AL), or provided with 70% of diet of AL rats from 6 weeks of age (DR). The plasma IGF-1 and steady-state levels of the genes were quantified by radioimmunoassay and the reverse transcription-polymerase chain reaction method, respectively. Immunohistochemical analysis in tissue sections was also performed for IGFR. Our results showed that dietary restriction: 1) decreased the plasma level of IGF-1; 2) increased the steady-state level of IGFR-mRNA at 6 and 16 months of age. and the peptide level at 6 months; 3) maintained IGF-1- and IRS-1-mRNA at a level similar to that in AL rats; and 4) delayed or inhibited an aging-dependent increase in IGFR-mRNA in the muscles. The present results suggest that dietary restriction could modulate IGF-1 signaling by augmenting local tissue response to IGF-1 and by maintaining the local production of the peptide, even though plasma IGF-1 is reduced.

A case of bilateral middle-ear squamous cell carcinoma.

Only eight cases of bilateral middle-ear squamous cell carcinoma (SCC) have been reported to date. We present the case of a 75-year-old male with bilateral middle-ear SCC and review the previously reported cases. The patient was diagnosed as having moderately-differentiated SCC in the left middle ear in February 1995 and well-differentiated SCC in the right middle ear in September 1997. He initially received radiation therapy with (60)Co pendulum (64 Gy) in the left ear and was subsequently treated by Liniac irradiation (50 Gy) in the right ear. He has now been followed up at our ENT clinic for 29 months without vertigo or facial nerve palsy since the second radiation therapy. Although he has a residual tumour in the right middle ear invading the middle cranial fossa dura, no sign of recurrence has been detected in the left ear.

Leptin signaling and aging: insight from caloric restriction.

Organisms have evolved neuroendocrine and metabolic response systems to enhance survival during periods of food shortage, which occur frequently in nature. The anti-aging effect of caloric restriction (CR) might derive from these adaptive responses to maximize organism survival. The present article discusses the potential role for leptin, a hormone secreted from adipocytes, as a key signal that induces the adaptive responses relevant to CR. Evidence indicates that a CR-induced reduction of the plasma leptin concentration suppresses the gonadal, somatotropic, and thyroidal axes, and activates the adrenal axis. Metabolic adaptation, a shift in fuel utilization mainly conducted in the liver, seems to require leptin signaling. Although alternative signaling pathways might also mediate the anti-aging effects of CR, leptin signaling could be a substantial pathway involved in these effects. Molecular dissection of the mechanisms underlying the effects of CR will contribute to a better understanding of the aging process, leading to the extension of a healthy lifespan in humans.

Leptin and anti-aging action of caloric restriction.

Evolutional theories of aging and caloric restriction (CR) in animals predict the presence of neuroendocrine signals to divert the limited energy resources from energy-costly physiologic processes such as reproduction to those essential for survival in response to food shortage. The diversion of energy and subsequent molecular mechanisms might extend the lifespan. A growing body of evidence indicates that leptin, a peptide hormone secreted from adipocytes, has a key role in neuroendocrine adaptation against life-threatening stress such as fasting. The present review discusses the potential role of leptin in the anti-aging action of CR. Although several alternative signaling pathways might also mediate the anti-aging action of CR, leptin signaling could be a substantial pathway in the CR action. Research on neuroendocrine mechanisms of CR is warranted, because such efforts might provide clues to the regulation of the aging process in humans.

Primary low-grade MALT lymphoma of the gallbladder.

We report a case of primary low-grade B-cell lymphoma of the mucosa-associated lymphoid tissue (low-grade MALT lymphoma) in the gallbladder. A 58-year-old woman suspected of gallbladder carcinoma underwent laparoscopic cholecystectomy. Microscopic examination of the gallbladder demonstrated lymphoid cell infiltration forming lymphoid follicles with hyperplastic secondary follicles. The surrounding monocytoid B cells and centrocyte-like cells selectively infiltrated the crypt epithelium forming lympho-epithelial lesions. Plasma cells were also noted beneath the mucosal epithelium. Bile culture revealed the Gram-negative bacilli Enterococcus faecalis and Morganella morganii. Immunoglobulin heavy chain gene rearrangement was confirmed using polymerase chain reaction (PCR) and oligoclonal lymphoid proliferations was detected. Because autoimmune diseases, or chronic inflammatory disorders, seem to correlate with the occurrence of MALT lymphoma, Gram-negative bacterial infection could also be considered as a prodrome of MALT lymphoma of the gallbladder.

Intravenous injection of cycloheximide induces apoptosis and up-regulates p53 and Fas receptor expression in the rat liver in vivo.

A single administration of protein synthesis inhibitor, cycloheximide (CHX) induces apoptosis of hepatocytes in vivo. We investigated the underlying mechanisms of this phenomenon and the role of p53 and Fas receptor using terminal dUTP nick end labeling (TUNEL), quantitative reverse transcription polymerase chain reaction and immunohistochemistry. Rat liver tissue specimens were obtained at different time intervals after injection of CHX. The proportion of TUNEL-positive apoptotic hepatocytes increased with time and reached a plateau at 2.5h after the injection. The p53 and Fas receptor mRNAs and the proportion of immunoreactive p53-positive and Fas receptor-positive hepatocytes increased markedly with time from 1h after the administration. Since the time course of increased proportion of apoptotic hepatocytes does not parallel that of p53- or Fas receptor-positive hepatocytes and apoptotic hepatocytes appeared prior to up-regulation of p53 and Fas receptor expression, it is likely that the enhanced expression of p53 and Fas receptor is not involved directly in CHX-induced apoptosis of hepatocytes in vivo. Rats injected with a single intravenous dose of CHX, however, provide a simple and useful model for investigating the apoptotic machinery and the molecular mechanism of transcriptional up-regulation of p53 and Fas receptor in hepatocytes.

Apoptosis in the aging process.

Although many hypotheses have been proposed to explain the aging process, the exact mechanisms are not well defined. Recent accumulating evidence indicates that dysregulation of the apoptotic process may be involved in some aging processes; however, it is still debatable how exactly apoptosis is expressed during aging in vivo. In this review, we discuss recent findings related to apoptosis of individual organs during aging and their significance. We demonstrate that aging enhances apoptosis and susceptibility to apoptosis in several types of intact cells. In contrast, in certain genetically damaged, initiated, and preneoplastic cells, aging suppresses these age-associated apoptotic changes. In various cells, apoptosis enhances the elimination of damaged and dysfunctional cells presumably caused by oxidative stress, glycation, and DNA damage. In these cases, the incidence of apoptosis correlates with the level of accumulated injury. It is concluded that apoptosis plays an important role in the aging process and tumorigenesis in vivo probably as an inherent protective mechanism against age-associated tumorigenesis.

Effects of aging and dietary restriction on mRNA levels of receptors for growth hormone-releasing hormone and somatostatin in the rat pituitary.

Aging impairs and dietary restriction may modulate pituitary response to growth hormone (GH)-releasing hormone (GHRH) and somatostatin (SRIH) for GH secretion. Using the semiquantitative reverse-transcription polymerase chain reaction method, we analyzed the mRNA levels of the GHRH receptor (grfr) and SRIH receptor subtype 2 (sstr2) and subtype 5 (sstr5) in anterior pituitaries of male rats fed ad libitum or 30% dietary restricted. Aging reduced the mRNA levels of these receptors in a slightly different manner. The levels of grfr progressively decreased between 6 and 24 months, whereas those of sstr2 and sstr5 declined after 16 months. Dietary restriction did not diminish the aging-dependent changes, although it slightly augmented the levels of grfr, but not sstr2 and sstr5. The present results suggest that the aging-dependent impairment in pituitary response for GH secretion could result mostly from a decline in grfr rather than relative increase of sstrs. Although DR could slightly enhance the pituitary sensitivity to GHRH, the antiaging action may be minor at the level of gene expression.

Dietary restriction reduces hepatocyte proliferation and enhances p53 expression but does not increase apoptosis in normal rats during development.

Dietary restriction (DR) retards physical growth, resulting in small body size, reduced liver weight and reduced number of hepatocytes in rats. We examined the effects of DR on proliferation and apoptosis of hepatocytes during development and explained these changes subcellularly using immunohistochemistry for bromodeoxyuridine (BrdU) incorporation, proliferating cell nuclear antigen (PCNA) and p53, terminal dUTP nick end labeling (TUNEL) and quantitative reverse transcription-polymerase chain reaction (RT-PCR) for TGFalpha, TGFbeta1, p53, Fas and TNF receptor (TNFr). Tissue samples included the livers of 3-month-old male Fischer 344 rats fed ad libitum (AL) or on 70% DR. DR significantly reduced the proportions of BrdU-positive and PCNA-strongly-positive hepatocytes compared with AL rats but not the proportions of PCNA-positive hepatocytes and TUNEL-positive hepatocytes. On the other hand, DR enhanced the expression of p53 and Fas mRNAs but failed to influence the expression of TGFalpha, TGFbeta1 and TNFr mRNAs. Moreover, DR significantly increased the proportion of p53-positive hepatocytes. Our findings suggest that DR suppresses the proliferation of hepatocytes, resulting in a reduced number of hepatocytes during development. This process may be mediated by overexpression of p53 suppressor gene. While DR accelerates the expression of Fas antigen, this result does not influence the rate of apoptosis of hepatocytes under physiological conditions.

Granulomatous lobular mastitis: difficulty of diagnosis.

We report a case of a rare inflammatory disease, granulomatous lobular mastitis. Two weeks prior to admission the patient, a 43 year-old woman, (gravida 1, para 1) had noticed a left breast mass associated with tenderness. Palpation, gross inspection, and clinical examination, as well as the rapid growth of the mass lesion led us to believe that it was highly suspicious of malignant neoplasm. Mammography, ultrasonography, and computed tomography did not differentiate it from a malignant neoplasm. Aspiration cytology revealed an inflammatory lesion with a few clusters of epithelial cells it was diagnosed as borderline malignancy(class III) by a prudent pathologist, and thus mastectomy was performed. However, the final histologi-cal diagnosis was granulomatous lobular mastitis with no evidence of malignancy. As the clinical manifestations of granulomatous mastitis are similar to those of mammary carcinoma and, as it is an inflammatory lesion of uncertain etiology and pathogenesis, it has often been mistaken clinically for carcinoma and treated as such. Our review of the literature indicated that granulomatous mastitis most often occurs in young patients with a history of childbirth or oral contraceptive usage. Recurrence was documented in 38% of patients, and, accordingly long-term follow-up by aspiration cytology, complete resection, and adequate drug treatment with corticosteroids are recommended.

Malignant mesothelioma of the tunica vaginalis testis: report of a case.

We describe herein the case of a 68-year-old man with malignant mesothelioma of the tunica vaginalis testis. The pathological diagnosis was based upon the clinical findings, gross and microscopic morphology, and special stains. Malignant mesothelioma is a rare tumor associated with asbestos exposure that can be effectively treated with orchidectomy via an inguinal approach.

Life-long dietary restriction modulates the expression of collagens and collagen-binding heat shock protein 47 in aged Fischer 344 rat kidney.

It has been shown that the expression of HSP47 and collagens is substantially increased in the sclerotic/fibrotic process in various organs, including kidney. However, the factors regulating the increased expression of HSP47 are not yet clear. In this study, we examined the effect of dietary restriction for the expression of collagens and collagen-binding HSP47 in the kidneys of 6- and 24-month-old male Fischer 344 (F 344) rats fed ad libitum or 30% diet-restricted. No significant histological alteration was found in the kidneys of 6-month-old fed or diet-restricted rats. Kidneys obtained from 24-month-old freely fed rats showed glomerulosclerosis with marked tubulointerstitial damage including interstitial fibrosis, while in the kidneys of 24-month-old diet-restricted rats, renal damage was remarkably less than those noted in 24-month-old freely fed rat kidneys. Immunohistochemical analysis showed an increased accumulation of type I, type III and type IV collagens in areas of glomerulosclerosis and interstitial fibrosis in old rat kidneys. Dietary restriction significantly reduces renal accumulation of collagens in old age. Aging enhanced expression of HSP47 in 24-month-old freely fed rat kidneys whereas dietary restriction suppressed its expression in 24-month-old diet-restricted rat kidneys. Also, phenotypic alterations of mesangial cells and interstitial cells (immunopositive for alpha-smooth muscle actin), glomerular epithelial cells (immunopositive for desmin) and tubular epithelial cells (immunopositive for vimentin) were seen in 24-month-old freely fed rat kidneys and found to express HSP47. Dietary restriction significantly diminished phenotypically altered renal cells in 24-month-old rat kidneys. Our results suggest that increased expression of HSP47 is associated with age-related renal damage and that diet-restricted alteration of its expression is associated with the modulation of age-associated renal sclerosis/fibrosis.

Clinical experiences of microsurgical side-to-end epididymovasostomy for epididymal obstruction.

BACKGROUND: Some surgical treatments are performed for obstructive azoospermia in urology and good results have been reported. Of 61 azoospermic patients who visited our department of urology, nine were diagnosed as having epididymal obstruction of unknown etiology. METHODS: We describe nine consecutive side-to-end epididymovasostomy procedures performed on these patients. These procedures are microsurgical two-layer anastomosis. RESULTS: Of the nine men, five (55.6%) had sperm in the ejaculate postoperatively and, up until publication, the pregnancy rate was 33.3% (three of nine). CONCLUSIONS: These results suggest that reconstruction of the seminal tract should be considered first for obstructive azoospermia.

Life-long caloric restriction suppresses age-associated Fas expression in the Fischer 344 rat kidney.

It has been shown that the expression of Fas is substantially increased in the aging process in various organs, but its role in the aging kidney is not yet clear. In this study, the expression of Fas in the kidneys of 6- and 24-month-old male Fischer 344 rats fed ad libitum was studied by using quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. In addition, possible effects of life-long caloric restriction (30% as those of ad libitum fed group) in the expression of Fas were also studied in 6- and 24-month-old rat kidneys. Kidneys obtained from 24-month-old ad libitum fed rats showed glomerulosclerosis with marked tubulointerstitial damage including interstitial fibrosis, while in the kidneys of 24-month-old calorie-restricted rats, renal damage was remarkedly less than that noted in 24-month-old ad libitum fed rats kidneys. RT-PCR and immunohistochemical analysis showed an increased expression of Fas in both mRNA and protein level in 24-month-old rat kidneys; life-long caloric restriction significantly reduces renal expression of Fas. Our results suggest that increased expression of Fas is associated with age-related renal damage and that life-long diet-restricted alteration of its expression is associated with the modulation of age-associated renal structural damage.

Dietary restriction reduces the prevalence of osteonecrosis of the caput femoris in spontaneously hypertensive rats.

We investigated the effects of dietary restriction (DR), an experimental intervention known to suppress several strain-specific diseases, on the prevalence of osteonecrosis of the caput femoris in spontaneously hypertensive rats (SHR). At 6 weeks of age, the food intake of DR rats was restricted to 65% of the mean intake of control rats fed ad libitum (AL). Acute osteonecrosis of the caput femoris without reparative tissue response (RTR) was observed at 10 and 15 weeks in both DR and AL groups; no such acute lesion was seen at 20 and 30 weeks. The prevalence of osteonecrosis, osteonecrosis with/without reparative tissue response was significantly reduced in DR rats at 15 and 20 weeks, but not at 10 weeks. DR reduced the body weight by 30% and the length of the femur by 10%. Ossification of the caput femoris, known to be delayed in AL rats compared with Wistar Kyoto rats, was also restored by DR. Our results showed that dietary restriction reduced the prevalence of osteonecrosis and modulated the mechanical factors involved in the lesion. They also indicate that utilization of dietary restriction is a useful research tool for investigating the underlying mechanisms of osteonecrosis of the caput femoris in SHR.

A role for leptin in the antiaging action of dietary restriction: a hypothesis.

A neuroendocrine signal may play an important role in the antiaging action of dietary restriction (DR). Recent studies have suggested that falling leptin levels by starvation activate the hypothalamic-pituitary-adrenal axis, and suppress gonadal, somatotropic, and thyroid axes as a response for adaptation. Accumulated evidence indicates that similar hormonal changes also occur in DR rodents. In this article, we advance that a reduction in plasma leptin levels in DR rodents might be a critical neuroendocrine modulator in the antiaging action of dietary restriction.

Age-related nephropathy in the Fischer 344 rat is associated with overexpression of collagens and collagen-binding heat shock protein 47.

To explore the possible role of heat shock protein (HSP) 47 in the age-related renal changes in Fischer 344 (F 344) rats, the expression of collagen-binding HSP47 with various proteins implicated in phenotypic modulation (alpha-smooth muscle actin, desmin, and vimentin) and fibrosis (type I, type III, and type IV collagens) was examined in young and old F 344 rat kidneys. Male F 344 rats often develop spontaneous nephropathy in old age. Kidneys obtained from 24-month-old F 344 rats showed glomerulosclerosis with marked tubulointerstitial damage including interstitial fibrosis, while no significant histological alteration was found in the kidneys of 6-month-old rats. Immunohistochemical analysis showed an increased accumulation of type I, type III, and type IV collagens in areas of glomerulosclerosis and interstitial fibrosis in old rat kidneys. In kidneys of young rats, collagen-binding HSP47 expression was weak in the glomeruli and occasionally seen in the interstitial cells. In contrast, strong immunostaining for HSP47 was noted in the glomeruli, tubular epithelial cells, and interstitial cells in kidneys of old rats. In addition, phenotypic alterations of mesangial cells and interstitial cells (immunopositive for alpha-smooth muscle actin), glomerular epithelial cells (immunopositive for desmin), and tubular epithelial cells (immunopositive for vimentin) were found in the kidneys of old F 344 rats. Double immunostaining showed that all these phenotypically altered renal cells express HSP47 and that increased expression of HSP47 was always associated with increased expression of collagens in the old rat kidneys. From the above observations, it is concluded that overexpression of HSP47 by phenotypically altered renal cells might play an important role in the excessive assembly of collagens and could thereby contribute to the glomerulosclerosis and interstitial fibrosis found in kidneys of aged F 344 rats.

Malignant peripheral nerve sheath tumors developing multifocally in the central nervous system in a patient with neurofibromatosis type 2.

We describe autopsy findings of multifocal malignant peripheral nerve sheath tumors (MPNSTs) appearing in the central nervous system in a 45-year-old Japanese female with neurofibromatosis type 2. Multiple MPNSTs were detected in both III and VIII, left IV, and V cranial nerves, and a number of nerve roots of the spinal cord. Neurofibromata were on the other hand evident on some nerve roots of the spinal cord and femoral and sciatic nerves. Our results suggest that a mutation of p53 gene may have played a role in the malignant transformation of nerve tumors in this patient since p53 protein was immunohistochemically detected in MPNST cells but not in tumor cells of the neurofibromata.

Advanced glycosylation end products in adrenal lipofuscin.

The present study examined the presence of advanced glycosylation end products (AGEs) in lipofuscin present in the brain and adrenal gland of aging rats by immunohistochemistry using antibodies raised against AGEs. Lipofuscin identified as yellow to brown granules emitting bright yellow to orange autofluorescence with ultraviolet light were detected in cortical neurons, cerebellar Purkinje cells, and adrenal cells in the inner part of the zona reticularis. However, none of the antibodies visualized lipofuscin in these areas. The outer part of the zona reticularis contained yellow granules emitting a faint orange autofluorescence. These granules were immunostained by an antibody that reacted with AGEs structures unrelated to the carboxymethyllysine moiety. Newly formed adrenal cortical cells are thought to migrate from the outer layer to the inner layer of the zona reticularis. Therefore, our results suggest that glycosylation-related processes are involved in lipofuscinogenesis, at least in its early stage, in the adrenal zona reticularis.

Allergic granulomatous angitis (Churg-Strauss syndrome) with multiple intestinal fistulas.

A 40-yr-old man who had a known diagnosis of allergic granulomatous angitis (Churg-Strauss syndrome) and had been on steroids was found to have a stone in the common bile duct. At surgery, multiple internal fistulas were found in the small bowel. Cholecystectomy, removal of the stone in the common bile duct, and resection of the small bowel because of fistulas were performed. To our knowledge, the formation of an intestinal fistula has not been reported as a clinical manifestation of allergic granulomatous angitis. This rare condition occurs in the terminal stage of this disease.