Neuropathology of fragile X-associated tremor/ataxia syndrome (FXTAS).

Fragile X-associated tremor/ataxia syndrome (FXTAS) is an adult-onset neurodegenerative disorder that affects carriers, principally males, of premutation alleles (55-200 CGG repeats) of the fragile X mental retardation 1 (FMR1) gene. Clinical features of FXTAS include progressive intention tremor and gait ataxia, accompanied by characteristic white matter abnormalities on MRI. The neuropathological hallmark of FXTAS is an intranuclear inclusion, present in both neurons and astrocytes throughout the CNS. Prior to the current work, the nature of the associations between inclusion loads and molecular measures (e.g. CGG repeat) was not defined. Post-mortem brain and spinal cord tissue has been examined for gross and microscopic pathology in a series of 11 FXTAS cases (males, age 67-87 years at the time of death). Quantitative counts of inclusion numbers were performed in various brain regions in both neurons and astrocytes. Inclusion counts were compared with specific molecular (CGG repeat, FMR1 mRNA level) and clinical (age of onset, age of death) parameters. In the current series, the three most prominent neuropathological characteristics are (i) significant cerebral and cerebellar white matter disease, (ii) associated astrocytic pathology with dramatically enlarged inclusion-bearing astrocytes prominent in cerebral white matter and (iii) the presence of intranuclear inclusions in both brain and spinal cord. The pattern of white matter pathology is distinct from that associated with hypertensive vascular disease and other diseases of white matter. Spongiosis was present in the middle cerebellar peduncles in seven of the eight cases in which those tissues were available for study. There is inclusion formation in cranial nerve nucleus XII and in autonomic neurons of the spinal cord. The most striking finding is the highly significant association between the number of CGG repeats and the numbers of intranuclear inclusions in both neurons and astrocytes, indicating that the CGG repeat is a powerful predictor of neurological involvement in males, both clinically (age of death) and neuropathologically (number of inclusions).

Protein composition of the intranuclear inclusions of FXTAS.

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder caused by premutation expansions (55-200 CGG repeats) in the fragile X mental retardation 1 (FMR1) gene. The pathologic hallmark of FXTAS is the ubiquitin-positive intranuclear inclusion found in neurons and astrocytes in broad distribution throughout the brain. The pathogenesis of FXTAS is likely to involve an RNA toxic gain-of-function mechanism, and the FMR1 mRNA has recently been identified within the inclusions. However, little is known about the proteins that mediate the abnormal cellular response to the expanded CGG repeat allele. As one approach to identify the protein mediators, we have endeavoured to define the protein complement of the inclusion itself. Fluorescence-activated flow-based methods have been developed for the efficient purification of inclusions from the post-mortem brain tissue of FXTAS patients. Mass spectrometric analysis of the entire protein complement of the isolated inclusions, combined with immunohistochemical analysis of both isolated nuclei and tissue sections, has been used to identify inclusion-associated proteins. More than 20 inclusion-associated proteins have been identified on the basis of combined immunohistochemical and mass spectrometric analysis, including a number of neurofilaments and lamin A/C. There is no dominant protein species in the inclusions, and ubiquitinated proteins represent only a minor component; thus, inclusion formation is not likely to reflect a breakdown in proteasomal degradation of nuclear proteins. The list of proteins includes at least two RNA binding proteins, heterogeneous nuclear ribonucleoprotein A2 and muscle blind-like protein 1, which are possible mediators of the RNA gain-of-function in FXTAS.

Retroperitoneal fibrosis and immune-complex glomerulonephritis.

A 63-year-old man with rapidly progressive glomerulonephritis of the immune-complex type showed typical findings of idiopathic retroperitoneal fibrosis involving the left ureter resulting in hydronephrosis. Treatment with steroid improved both conditions. Our case and previously reported cases showing the same association of conditions support the hypothesis that the association is not fortuitous but reflects a common immunological mechanism.

Whole almonds and almond fractions reduce aberrant crypt foci in a rat model of colon carcinogenesis.

Almonds and other nuts appear to confer health benefits despite their high fat content. To assess the effect of almonds on colon cancer, whole almond-, almond meal- or almond oil-containing diet effects on aberrant crypt foci (ACF) in azoxymethane-treated F344 male rats were investigated. Six-week-old male F344 rats were fed the various almond and control diets and given subcutaneous injections of azoxymethane (15 mg/kg body weight) twice 1 week apart. After 26 weeks animals were injected with bromodeoxyuridine 1 h prior to sacrifice, after which colons were evaluated for ACF and cell turnover (labeling index, LI). Whole almond ACF and LI were both significantly lower than wheat bran and cellulose diet groups (-30 and -40%, respectively), while almond meal and almond oil ACF and almond meal LI declines were only significant vs. cellulose (P<0.05). These results suggest that almond consumption may reduce colon cancer risk and does so via at least one almond lipid-associated component.

Redox regulation of wound healing? NF-kappaB activation in cultured human keratinocytes upon wounding and the effect of low energy HeNe irradiation.

The complex process of wound healing as well as the signaling systems orchestrating this intricate process remain incompletely defined. Using human keratinocytes in primary culture, we sought to characterize their NF-kappaB responses to wounding alone or in combination with other treatments. We initially characterized these cultured human keratinocytes responses to known NF-kappaB activators (PMA, TNF-alpha and IL-1) using two different assays, immunohistochemistry and electrophoretic mobility shift (EMSA). After eliciting the expected NF-kappaB responses, we applied these same assays to assess responses to either wounding or HeNe irradiation alone. The results obtained indicated that only a modest/sporadic activation of NF-kappaB was elicited by these which was only detectable using immunohistochemistry. When the combination of wounding and HeNe irradiation on NF-kappaB status was assessed, a marked, localized activation of NF-kappaB in keratinocytes along the wound edge was found. Treatment induced NF-kappaB activation (e.g., wounding, HeNe irradiation and combined wounding and HeNe irradiation) was abrogated by pyrrolidine dithiocarbamate (PDTC) which inhibits NF-kappaB activation through an as yet incompletely understood (antioxidant?) mechanism. These data therefore suggest that NF-kappaB and oxidation mediated changes in its activation state likely play important roles in normal cutaneous wound healing.

[A case of malignant rheumatoid arthritis complicated by secondary amyloidosis and membranous nephropathy].

A 30-year-old man had been treated for malignant rheumatoid arthritis from 1989 with a non-steroidal anti-inflammatory drug, then bucillamine for six months and prednisolone. Mild proteinuria appeared in May 1994, 4 years after bucillamine therapy was conducted. The patient was admitted to our hospital for a renal biopsy in July 1994. The specimen revealed secondary amyloidosis and membranous nephropathy (MGN). These findings suggest that MGN unrelated to bucillamine therapy might have occurred with secondary amyloidosis in rheumatoid arthritis.

[Anterior ischemic optic neuropathy in a case of polyarteritis nodosa].

A 68-year-old male admitted to our hospital because of fever, body weight loss and multiple mononeuropathy. He developed visual loss in his right eye due to anterior ischemic optic neuropathy (AION). Surgical treatment of jejunal perforation was performed and histological examination of jejunal ulcer confirmed the diagnosis of polyarteritis nodosa (PN). Combination therapy of steroid (prednisolone 50 mg/day) and cyclophosphamide (50 mg/day) was started, which saved him from any other ischemic change including that of his left eye. As long as we know, AION occurring in PN is very rare, that is, only 4 cases have been reported in Japan.

Apolipoprotein E in the subretinal fluid of rhegmatogenous and exudative retinal detachments.

BACKGROUND: Apolipoprotein E plays a key role in lipoprotein metabolism and is believed to be an important protein in other biologic functions such as wound healing processes of nerve tissue. Because the neurosensory retina is rich in lipids, we analyzed the subretinal fluid from patients with acute and chronic retinal detachments to determine whether apolipoprotein was present and whether it was involved in lipid metabolism during wound repair of the detached retina. METHODS: The subretinal fluid collected from eyes with rhegmatogenous and exudative retinal detachments first was analyzed by agarose and sodium dodecyl sulfate gel electrophoresis to identify the lipoprotein profiles. Western blot analysis confirmed the presence of apolipoprotein E, and semiquantitation was performed by densitometry of the corresponding immunodot-blot. RESULTS: Apolipoprotein E was present in the subretinal fluid of eyes with rhegmatogenous and exudative retinal detachments. Its concentration increased in eyes with chronic retinal detachments. CONCLUSIONS: We implicate apolipoprotein E found in the subretinal fluid in the wound-healing process of the detached retina.

Stimulation of epithelial cell growth by the neuropeptide substance P.

The neuropeptide substance P (SP) was found to stimulate DNA synthesis and cell growth for epithelial cells (cornea and lens) in a serum-free environment. The length of treatment time was shown to be important since longer times shifted the dose-response curve to the left. In short-term DNA synthesis studies (40 h) the stimulation with SP (or synergism with insulin) was not apparent until close to 10 microM, however, when DNA synthesis assays were carried out over a long period of time (5 days) stimulation with SP was seen at 1 pM. The stimulation of DNA synthesis by SP was synergistic with insulin for lens epithelial cells, but little synergism was seen with corneal epithelial cells. It cell growth studies on lens epithelial cells SP also showed growth stimulation by itself and synergism with insulin at concentrations of 1-2 pM. The neuropeptide calcitonin gene related peptide (CGRP) showed no DNA synthesis stimulating ability on epithelial cells by itself at concentrations as high as 2.5 microM; however, it was synergistic with SP at a concentration of 0.025 microM. SP pretreatment of epithelial cells for 2 h causes an increase in cellular sensitivity to subsequent addition of either SP or insulin. This increase is consistent with the hypothesis that either the signal from SP persists after its removal from the cell or the dissociation time for SP from its receptor is longer than the wash time.

[Clinico-pathological study of focal glomerular sclerotic lesions in idiopathic membranous nephropathy].

Sixty-one patients with idiopathic membranous nephropathy (MN) were studied clinicopathologically to determine the significance of focal glomerular sclerotic lesions (FGSL). Renal biopsy specimens were examined by light and immunofluorescence microscopy. The light microscopic specimens were cut into 20 serial sections and odd-numbered ones were stained with Masson trichrome staining. The histopathological findings were scored and statistically analyzed. The patients were divided into two groups: Group I consisted of 15 MN patients with FGSL; the other 46 MN patients without FGSL composed Group II. Group I showed higher systolic blood pressure (p less than 0.01), longer duration of proteinuria (0.05), and higher levels of serum creatinine (p less than 0.001) than Group II. In Group I, the stage of membranous lesions was more advanced (p less than 0.01), and tubular atrophy, interstitial fibrosis and arteriolosclerosis were more severe than in Group II (p less than 0.05). The above results suggest that FGSL in MN may be related to the impairment of the renal function, but an only explanation for the cause of FGSL by the glomerular hyperfiltration theory is unlikely. Further investigations are required to clarify the full pathogenesis of FGSL.

[Acute myelomonocytic leukemia with Inv(16) (p13 q22) relapsed in transverse myelopathy].

We report a case of AML (M 4) with eosinophilia who developed meningeal relapse and transverse myelopathy. A 37-year-old woman was admitted to our hospital because of lymphadenopathy and ecchymosis. One week prior to admission, she noticed swelling of the cervical lymph nodes and bleeding tendency. On admission, low-grade fever, gingival swelling, generalized lymphadenopathy, and ecchymosis on the lower legs were found. A white blood cell count was 93,900/microliters with 82% blast cells, and a platelet count was 24,000/microliters. A bone marrow was composed of 45.3% myeloblasts, 27% monocytes and 7.1% eosinophils. Chromosome analysis revealed inv(16). The diagnosis of M4Eo was made. About one year after she gained complete remission, she was readmitted because of disturbance of urination. There was a sign of transverse myelopathy at the seventh vertebral level, and blast cells were detected in the cerebrospinal fluid. Despite of radiation and chemotherapy, paresis of lower extremities and sensory disturbance were persistent, and the patient died on 52th hospital day.

[Acute myelofibrosis terminating in acute myelomegakaryoblastic leukemia].

We report a case of acute myelofibrosis (AMF) developing into acute myelomegakaryoblastic leukemia. A 33-year-old woman was admitted to our hospital because of fever and chest pain. On physical examination, hepatosplenomegaly was not noticed. Pancytopenia and a small number of blast cells were observed in the peripheral blood. Poikilocytosis was not detected. Bone marrow examination revealed dry tap on aspiration, and moderate increase in reticulin fiber on biopsy. The diagnosis of AMF was made. Eight months later, blast cells markedly increased. Surface marker was investigated and MCS-2 (CD13), C17 (CDw41) and P2 (CDw41) were found to be positive. Electron microscopic examination revealed that blast cells were composed of PPO-positive cells and MPO-positive cells. Based on these findings, it was considered that the patient developed acute myelomegakaryoblastic leukemia. Recently AMF is thought to be a state to have the ability to develop into various types of acute leukemia. Adequate therapy may be required before the development of leukemia.

Increased Na+-taurine symporter in rat renal brush border membranes: preformed or newly synthesized?

The renal adaptive response to a varied intake of sulfur amino acids is demonstrated by an increase in the initial rate of Na+-taurine symport (cotransport) by rat renal brush border membrane vesicles (BBMVs) after 8-14 days of a low methionine diet. A high (3%) taurine diet reduces Na+-taurine symport. Fasting for 3 days, which depletes renal tubule cell taurine content, also enhances Na+-taurine symport both initially (15 s) and throughout the overshoot. In this study we examine the possibility that a rapid-onset adaptive response is expressed in BBMV, with the increased Na+-taurine symport reflecting the incorporation of preformed symporter into membranes rather than new synthesis. Rats fed the low methionine diet for 14 days were placed on the high taurine diet for 12-18 h; Na+-taurine symport activity fell by 40%. Fasting for 4 h restored low methionine diet levels of Na+-taurine symport activity (92 pmol.mg protein-1.15 s-1), defining a rapidly induced rise in uptake. Colchicine (0.6 mg) was injected prior to fasting in a group of rats because it blocks the incorporation (import) of preformed symporter into the membrane. Animals injected with colchicine had a pattern of BBMV uptake similar to that found in animals switched to the high taurine diet for 18 h. This agent blocked the rapidly induced rise in uptake. Feeding with the high taurine diet for 4 h caused a fall in uptake of 16.5%; colchicine blocked this reduction in uptake. These results indicate that the nephron can respond rapidly to changes in the intake of amino acids, conserving taurine in periods of nutrient lack and excreting excess taurine within 4 h in periods of surfeit. This rapid response is expressed at the brush border surface. The use of cholchicine indicates that the increase or reduction in Na+-taurine symport activity is due to incorporation (import) of transporter into the BBMV rather than to de novo synthesis.

Identification of serotonin from rabbit upper stomach as a stimulant of in vitro gallbladder contraction.

Using an in vitro rabbit gallbladder bioassay, the distribution and identification of bioactive substances in rabbit gastrointestinal tract were investigated. Comparison of the bioactivities of tissue extracts before and after cholecystokinin was removed by affinity chromatography demonstrated that the distributions of cholecystokinin and non-cholecystokinin substances were different. While cholecystokinin bioactivity per g of tissue was highest in the duodenum, non-cholecystokinin bioactivity was greatest in the upper stomach. The biochemical properties of the non-cholecystokinin substance in the upper stomach could not be distinguished from those of serotonin. These included molecular weights of 176, identical ultraviolet spectra, similar nuclear magnetic resonance spectra, and co-chromatography in HPLC. By weight, serotonin had 1/6th of the bioactivity of cholecystokinin octapeptide. We conclude that the principal gallbladder-contracting substance in rabbit upper stomach is serotonin.