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Notes: Abstract: The β-amyloid peptide (Aβ), a main constituent in both senile and diffuse plaques in Alzheimer's disease brains, was previously shown to be neurotoxic and to be able to interact with several macromolecular components of brain tissue. Previous investigations carried out in our laboratory demonstrated free radical species formation in aqueous solutions of Aβ(1–40) and its C-end fragment, Aβ(25–35). Toxic forms of Aβ rapidly inactivate the oxidation-sensitive cytosolic enzyme glutamine synthetase (GS). In this regard, we suggested and subsequently demonstrated that Aβ radicals can cause an oxidative damage of cell proteins and lipids resulting in disruption of membrane functions, enzyme inactivation, and cell death. Because GS can be a substrate for Aβ-derived oxidizing species, the present study was conducted to determine if GS could protect against Aβ neurotoxicity. In contrast to this initial hypothesis, we here report that GS significantly enhances the neurotoxic effects of Aβ(1–40). The Aβ-mediated inactivation of GS was found to be accompanied by the loss of immunoreactive GS and the significant increase of Aβ(1–40) neurotoxicity.

Notes: Phosphorus is one of several dopants that electronically compensate the native deep donor responsible for the yellow coloration observed in bismuth silicon oxide (BSO). Low-temperature optical absorption measurements of a series of Czochralski-grown P-doped BSO crystals show that ∼0.1–0.15 at. % P is needed in the sample to fully remove the yellow coloration. The absorption cutoff in the fully compensated P-doped sample was at 3.2 eV while compensated Al- and Ga-doped samples cutoff at 3.35 eV. Excitation at 10–15 K with near band-edge light produces photochromic absorption bands. In the lightly-doped (partially bleached) samples these bands were identical to those observed in undoped BSO. In the fully bleached sample a new spectrum was observed. Its major contribution was a band centered near 1.8 eV with a weaker absorption in the blue-green. By comparison with the spectra observed in undoped and in Al-doped material before and after photoexcitation it is believed that the 1.8 eV band is due to the [PO4]− center and that the broad 2.45 eV band observed in Al- and Ga-doped BSO is due to the [BiO4]0 center. © 1995 American Institute of Physics.

Notes: During the last 40 years, nitrate (NO3−) has become one of the most common ground water contaminants. Stream riparian zones are considered important ecological ecotones that decrease the NO3− load of ground water discharging into streams. This study uses NO3−/Cl− ratios, natural abundances of15N and18O in NO3−, and an in situ15NO3− tracer experiment to evaluate NO3− reducing processes occurring in ground water within a narrow grassed buffer strip bordering a stream in an agricultural watershed. The NO3−/Cl− ratios (1.9-0.0 [M/M]) indicate that both NO3− consuming processes and mixing of two ground water flow regimes with different NO3− loads contribute to the drop observed in ground water NO3− concentrations within the riparian zone. δ15N and δ18O of the ground water NO3− within the riparian zone (δ15N = 5.1 to 48.8 %c; δ18O = 1.1 to 17.8 %c) were enriched compared to the ground water below the adjacent cultivated field (δ15N = 3.8 to 10.1 %0; δ18O = 0.5 to 6.2 %c). A significant linear relationship (r2=0.97) between ground water δ15N and δ18O in NO3− was found, which is consistent with NO3− consumption by microbial denitrification. The estimated enrichment factors for15N are a factor of 1.5 higher than for18O. The in situ15NO3− tracer experiment conclusively confirmed that denitrification is occurring within the ground water of the riparian zone and demonstrates that denitrification rates can be directly measured in situ.

Notes: Abstract We discuss methods using stimuli to manipulate behavior of a pest for the purpose of protecting a valued resource. The methods are divided into two categories: those that manipulate behavior over a long distance, e.g. volatile chemicals, visual, and auditory stimuli, and those that manipulate behavior at a short distance (〉1 cm), e.g. involatile chemicals. Particular emphasis is placed on methods that have been developed through studies of pest behavior and on combining stimuli to increase efficacy. Future prospects for behavioral manipulation methods in pest management are discussed.

Notes: We describe the clinicopathological features of gastrointestinal autonomic nerve tumours in nine patients where the diagnosis was confirmed by electronmicroscopy. Most patients presented with abdominal pain. At laparotomy, large intra-abdominal tumour masses were found which tended to be cystic and haemorrhagic. The predominant histological patterns were nests, sheets and fascicles of spindle and epithelioid cells. Immunohistochemistry showed positive staining for neuron specific enolase (9/9), PGP 9.5 (9/9), NKI/C3 (7/9), vimentin (7/9), α-smooth muscle actin (5/9), vasoactive intestinal peptide (3/9) and CD34/QBend10 (2/9). Grimelius staining was positive in two of nine cases. All tumours were negative for CAM 5.2, chromogranin, synaptophysin, Leu 7, neurofilament protein, muscle-specific actin (HHF-35) and desmin (D33). Ultrastructural examination showed cellular processes and dense-core granules in all cases. Three tumours had microtubules and/or intermediate filaments, particularly in cell processes. Skeinoid fibres were seen in three cases. No convincing synapses or small (synaptic-type) vesicles were identified. There was no evidence of epithelial, smooth muscle or nerve sheath differentiation. Two patients died due to tumour, two died of unknown causes and the remainder are alive 2–44 months after presentation. Four of the five survivors have recurrent/residual intra-abdominal tumour. So-called gastrointestinal autonomic nerve tumours are apparently slow-growing malignant tumours showing neuronal differentiation. Four cases arose in the mesentery/retroperitoneum or omentum rather than bowel wall and therefore a more appropriate nomenclature might be intra-abdominal stromal tumour with neuronal differentiation.

Notes: Oral submucous fibrosis (OSF) is a chronic disease of the oral cavity characterized by inflammation and progressive mucosal fibrosis. These reactions may be the result of either direct stimulation from exogenous antigens like areca alkaloids or by changes in tissue antigenicity that may lead to an autoimmune response. This study investigated the presence and distribution of inflammatory cells and MHC class II antigen expression by epithelial and immunocompetent cells using a three-stage immunoperoxidase method on frozen sections. Thirty OSF tissue specimens and ten normal buccal mucosae were studied and compared. All tissues were investigated using antibodies to T cells (CD3), T helper/inducer cells (CD4), T suppressor/cytotoxic cells (CD8), B cells (CD20), naive T cells and monocytes (CD45RA), macrophages. Langerhans' cells (CD68) and HLA-DR-positive cells (HLA-DR alpha). The predominant cell populations detected in normal tissues were CD3, CD4 and HLA-DR-positive cells. The distribution of CD4-positive cells was similar to that of CD3-positive cells, which were scattered, often uniformly distributed, both in the epithelium and connective tissue. CD8-positive cells were occasionally seen in the normal epithelium and lamina propria. Few scattered B cells (CD20) and macrophages (CD681) were observed in normal mucosa. Naive T cells (CD45RA) were seen in all normal tissues focally concentrated around the connective tissue papillae with a similar distribution to that of CD3-positive cells. All normal sections showed HLA-DR-positive cells scattered both in the epithelium and in the lamina propria. Epithelial cells did not show any positive reaction to this antibody and many intraepithelial positive cells showed a dendritic morphology. The cell populations detected in OSF showed higher numbers of CD3 and HLA-DR-positive cells compared with those of the normal tissues. The pattern of staining for CD4-positive cells in OSF tissues was similar to that of CD3-positive cells both in the epithelium and connective tissue and was higher than that in normal tissues. A few scattered CD8-positive cells and only occasional CD20- and CD68-positive cells were seen in OSF sections. Few CD45RA-positive cells were found in the epithelium and lamina propria of OSF sections. However, OSF specimens showed high numbers of HLA-DR-positive cells in the basal layer of the epithelium, juxtaepithelium and in the lamina propria in a similar distribution to that of CD3 cells compared with the normal tissues. Most HLA-DR-positive cells in the epithelium showed dendrites directed vertically towards the surface. The increased evidence of CD4 and HLA-DR-positive cells in OSF tissues suggests that most lymphocytes were activated and shows an increased presence of Langerhans' cells. The presence of these immunocompetent cells and high ratio of CD4 to CD8 in OSF tissues suggest an ongoing cellular immune response leading to a possible imbalance of immunoregulation and alteration in local tissue architecture.

Notes: Aims: To describe the clinicopathological and immunophenotypic features of 25 cases of Kikuchi–Fujimoto disease (K–F), which remains a poorly recognized entity and is still frequently confused with malignant lymphoma, and to discuss the main diagnostic problems experienced by the referring pathologist.〈section xml:id="abs1-1"〉〈title type="main"〉Methods and resultsHaematoxylin and eosin sections of 27 lymph node biopsies were re-examined. Immunostains for B-lymphocytes, T-lymphocytes and macrophages were performed. Clinical and follow-up data were obtained through a questionnaire to the referring pathologist or from the patients' notes where available. The suggested initial diagnoses are discussed. The lymph nodes showed a necrotizing process characterized by patchy or confluent areas of necrosis associated with karyorrhexis and absence or paucity of granulocytes. This was associated with a proliferation of large blastic cells consisting of a mixture of T-lymphocytes and histiocytes. Fragmentation of the biopsy was a frequent feature. The diagnosis of K–F was suggested by the referring pathologist in three cases only. The most common suggested diagnosis was that of a non-Hodgkin's lymphoma.〈section xml:id="abs1-2"〉〈title type="main"〉ConclusionThis series documents continuing difficulties in the diagnosis of Kikuchi–Fujimoto disease in the UK and emphasizes that cases are still being mistakenly diagnosed as malignant lymphomas. The diagnosis of Kikuchi–Fujimoto disease merits active consideration in any nodal biopsy showing fragmentation, necrosis and karyorrhexis, especially in young women presenting with cervical lymphadenopathy.

Notes: Aims: Two cases of angiotropic high-grade B-cell lymphoma are described in which involvement of endocrine glands was a prominent feature. Methods and results: One patient had marked unilateral adrenomegaly due to lymphoma within adrenal blood vessels. He is alive 5 years after presentation following combination chemotherapy. The diagnosis was made at autopsy in the second patient who presented with pyrexia of unknown origin and had hypothyroidism and a thyroid nodule. The thyroid gland and pituitary showed striking involvement by angiotropic lymphoma and the thyroid nodule was a cavernous haemangioma heavily colonized by lymphoma cells. Conclusions: Our cases illustrate endocrine organ manifestations of this rare disease. The condition may respond to combination chemotherapy.

Notes: To study the clinical and histopathological features of sclerosing epithelioid fibrosarcoma, and to define diagnostic criteria for this uncommon soft-tissue tumour.〈section xml:id="abs1-2"〉〈title type="main"〉Methods and resultsStandard histological, immunohistochemical and ultrastructural techniques were applied to five tumours from head and neck, chest wall and groin. Tumours consisted of groups of monomorphic rounded/epithelioid cells surrounded by a prominent collagenous stroma. Tumour cells showed positive vimentin staining but were negative for other markers. They contained prominent rough endoplasmic reticulum and a large Golgi apparatus which in one case was producing collagen secretion granules, an ultrastructural marker for collagen production. Three patients had medium to long-term survival (3–7 years). Of these, one was disease-free for 3 years, and two experienced multiple recurrences: one of the latter died of metastatic disease.〈section xml:id="abs1-3"〉〈title type="main"〉ConclusionCriteria for diagnosing this uncommon tumour include: small to medium cell size, clear or pale cytoplasm, cellular arrangement in cords and strands, dense collagenous stroma; vimentin staining; rough endoplasmic reticulum and a Golgi apparatus producing, in well preserved examples, collagen secretion granules. The paper emphasizes the value of electron microscopy, supporting an appropriate histological picture and immunophenotype, in identifying these relatively low-grade sarcomas.

Notes: To study the clinical and pathological features of primary malignant peripheral primitive neuroectodermal tumours (PNETs) of the skin and subcutaneous tissue, to discuss the differential diagnosis, and to review the existing literature on these tumours.〈section xml:id="abs1-2"〉〈title type="main"〉Methods and results:Eight cases of PNETs presenting in the skin and subcutaneous tissue were identified from the pathology records of the Christie Hospital, Manchester. Detailed immunohistochemical studies were performed on all cases and seven tumours were subjected to electron microscopic examination. Detailed clinical and follow-up information was obtained on seven cases. Six tumours occurred in children and adolescents and two were seen in young adults (age range, 8–36 years). No sex or site predilection was observed. Five tumours occupied the dermis and subcutis and three were entirely located in the subcutaneous tissue. Microscopically, they were composed of small round cells and seven tumours contained glycogen. Only one tumour focally exhibited Homer–Wright rosettes and neuropil. Two tumours contained rhabdoid or plasmacytoid cells in places and all cases showed microcystic and pseudovascular spaces. Immunostains revealed MIC2 (8/8), NSE (7/8), PGP9.5 (7/8), β2 microglobulin (7/8), neurofilament protein (6/8), S100 protein (3/8), synaptophysin (2/8) and Leu-7 (1/8) positivity. Anomalous cytokeratin (4/8), desmin (2/8), myoglobin (2/8), NKIC3 (4/8) and GFAP (1/8) staining was also noted. Ultrastructurally, neuroendocrine granules were detected in five cases and one case exhibited microtubules in processes. Adequate follow-up information was available in four cases. One patient died of metastatic disease. One child developed axillary lymph node metastasis but is alive with no evidence of disease 96 months after treatment. Two other patients are alive with no residual or recurrent disease 44 and 52 months after excision and radio/chemotherapy.〈section xml:id="abs1-3"〉〈title type="main"〉Conclusion:PNETs are rare malignant small round cell tumours of the skin and subcutaneous tissue which are probably underdiagnosed. A correct diagnosis can be made on light microscopic features, demonstration of neuroendocrine granules on electron microscopy and a combination of MIC2, β2 microglobulin, and more than one neural marker positivity. These neoplasms should be differentiated from other cutaneous neoplasms composed of small round cells. The number of cases of cutaneous PNETs studied so far is rather small, and no firm conclusion can be drawn about their behaviour but long-term survival is possible in some cases.