Serosal reaction in chronic gastric ulcers: an immunohistochemical and ultrastructural study.

AIM: To study the serosal reaction in gastrectomy specimens with benign chronic peptic ulcers. METHODS: Gastrectomy specimens were fixed in neutral buffered formalin and paraffin wax, and examined using immunohistochemical and ultrastructural techniques. RESULTS: Nine of the 22 (41%) cases examined showed reactive hyperplasia of the serosal cells. The cells were predominantly spindle-shaped and were positive on staining with Cam 5.2, AE1/3 and for vimentin. Eight of nine were also positive for smooth muscle actin and five for desmin. Ultrastructural analysis of these cells suggests that they may be myofibroblastic in nature. CONCLUSIONS: These results support the concept of "multipotential" subserosal cells which may differentiate into surface serosa or, in the reactive state, modulate the thin cytoskeletal filaments and become more myofibroblastic. Particular care should be taken not to confuse these reactive serosal cells with carcinoma or smooth muscle tumours in endoscopic biopsy specimens.

Multinucleated stromal giant cells of the colonic lamina propria in ulcerative colitis.

Multinucleated stromal giant cells were seen in the colonic mucosa in biopsy specimens from two patients with long-standing quiescent ulcerative colitis. Similar cells have been described at other sites associated with chronic inflammation, including the lower female genital tract, bladder and anus. The immunophenotype of the cells in the colonic mucosa suggested that they had originated from fibroblasts rather than histiocytes, in common with cells seen at other sites of inflammation. These examples lend support to the concept of there being a reactive morphological change possibly related to interaction with mast cells. These multinucleated giant cells are distinct from histiocytic giant cells and should not be confused with them.

Pseudoangiosarcomatous carcinoma of the genitourinary tract.

Two cases of pseudoangiosarcomatous carcinoma of the genitourinary tract, arising in the vulva in one and the bladder in the other, are presented. In case 1, an 84 year old woman, the vulvectomy specimen contained an irregular ulcerated tumour, infiltrating the left labia and extending into the clitoris. In case 2, a 59 year old woman, the excised bladder showed diffuse thickening of its wall by infiltrating haemorrhagic tumour. Both tumours showed focal keratinisation. This, in association with the presence of atypical squamous epithelium, immunohistochemistry and ultrastructural analysis, led to a diagnosis of pseudosarcomatous carcinoma in both cases. Pseudoangiosarcomatous carcinoma should be considered in the differential diagnosis of malignant angiomatoid tumours, particularly those that arise at sites, like the genitourinary tract, where angiosarcoma is rare.

Perception of pitch and timbre by musically trained and untrained listeners.

In 2 experiments the author investigated how musicians and nonmusicians differentially perceive the dimensions of pitch and timbre. A categorization task was used in Experiment 1 to assess Ss' ability to identify how 2 consecutively presented tones changed along these dimensions. A speeded classification task was used in Experiment 2 to measure Ss' ability to ignore or take advantage of information in 1 dimension while attending to the other. The 2 groups differed in the degree to which variation along the dimensions influenced responses. Timbre variation affected nonmusicians' judgments of pitch more than the reverse. Musicians showed no such asymmetry.

The use of rhythm in attending to speech.

Three experiments examined attentional allocation during speech processing to determine whether listeners capitalize on the rhythmic nature of speech and attend more closely to stressed than to unstressed syllables. Ss performed a phoneme monitoring task in which the target phoneme occurred on a syllable that was either predicted to be stressed or unstressed by the context preceding the target word. Stimuli were digitally edited to eliminate the local acoustic correlates of stress. A sentential context and a context composed of word lists, in which all the words had the same stress pattern, were used. In both cases, the results suggest that attention may be preferentially allocated to stressed syllables during speech processing. However, a normal sentence context may not provide strong predictive cues to lexical stress, limiting the use of the attentional focus.

The role of spectral and dynamic cues in imagery for musical timbre.

The musical quality of timbre is based on both spectral and dynamic acoustic cues. Four 2-part experiments examined whether these properties are represented in the mental image of a musical timbre. Experiment 1 established that imagery occurs for timbre variations within a single musical instrument, using plucked and bowed tones from a cello. Experiments 2 and 3 used synthetic stimuli that varied in either spectral or dynamic properties only, to investigate imagery with strict acoustic control over the stimuli. Experiment 4 explored whether the dimension of loudness is stored in an auditory image. Spectral properties appear to play a much larger role than dynamic properties in imagery for musical timbre.

An empirical and meta-analytic evaluation of the phoneme identification task.

Recent studies that used Ganong's (1980) identification task have produced discrepant results. The present study sought to resolve these discrepancies by examining the influence of methodological factors on phoneme identification and differences in data analysis techniques. Three factors were examined across 2 experiments: position of target phoneme, phonetic contrast, and 2 task conditions in which stimulus quality (S/N ratio) or cognitive load varied. A meta-analysis was then performed on the results from all identification studies, including the present one, in an effort to obtain additional insight on factors that influence the task. The experiments and meta-analysis identified the importance of several methodological factors in affecting identification, most notably position of the target phoneme.

Syllabic effects in word processing: evidence from the structural induction paradigm.

Spoken words have a rich structural organization in memory, consisting of syllabic and subsyllabic representations. A phoneme monitoring paradigm, in which the target phoneme occurs more frequently in one syllabic position than another (e.g., onset of the 2nd syllable vs. the coda of the 1st syllable: neu-tral vs. nut-meg; C. Pallier, N. Sebastian-Galles, T. Felguera, A. Christophe, & J. Mehler, 1993) was used to explore the formation of syllabic structure during word processing. Experiment 2 investigated how a recognition system that uses syllabic structure processes words with unclear syllable boundaries (e.g., pa-lace or pal-ace?). Two methodological issues were explored: The importance of a baseline condition for measuring effects of induction (Experiment 1) and the form of the representation used in the induction paradigm (Experiment 3). Findings suggest that syllabic structure begins to form early in word processing, and they demonstrate the adequacy of the induction procedure for measuring such processes.

Leishmaniasis of the tongue treated with liposomal amphotericin B.

A 66-year-old man, immunosuppressed because of a lymphoma and with severe ischaemic heart disease and proteinuria, presented with a swelling on the tongue due to leishmaniasis. His travel history suggested that he had acquired the infection in the Mediterranean area some years earlier. He was treated with liposomal amphotericin B for 21 days and made a good recovery despite a temporary deterioration in renal function. Oral lesions are a rare manifestation of Old World leishmaniasis. Liposomal amphotericin B is a novel treatment that may be well tolerated when there is concern about the toxicity of more established drugs.

The locus of the lexical shift in phoneme identification.

The lexical identification shift is used as a measure of speech processing in the phoneme identification task (W. F. Ganong, 1980). Interactive (bottom-up and top-down) models of word recognition account for the shift by claiming that lexical knowledge feeds back to a prelexical level and aids speech processing. Autonomous models (bottom-up only) maintain that the shift arises by other means and at later stages of processing. The locus of the lexical shift was investigated by using detection theory analysis procedures to measure perceptual changes in phoneme processing. Lexical status (word-nonword) of the utterance was varied in Experiments 1 and 3 and was found to influence phoneme processing. In Experiment 2 the effects of a postperceptual manipulation, monetary payoff, did not show up in the detection theory analysis. Implications of the results for both classes of models are discussed.

Data fitting and detection theory: reply to Massaro and Oden (1995).

D. W. Massaro and G. C. Oden (1995) claimed that M. A. Pitt's (1995) data provide strong evidence in favor of independence, not interactivity, as argued by Pitt. Massaro and Oden's arguments rested on an evaluation of the fit of the fuzzy logical model of perception (FLMP) to the identification data and on criticisms of the detection theory analyses. In this reply, Pitt shows that the latter criticisms were unfounded and that the data-fitting demonstrations raised questions about FLMP's ability to capture the phenomenon of interest (i.e., lexical context effects).

Phonological processes and the perception of phonotactically illegal consonant clusters.

The perception of consonant clusters that are phonotactically illegal word initially in English (e.g., /tl/,/sr/) was investigated to determine whether listeners' phonological knowledge of the language influences speech processing. Experiment 1 examined whether the phonotactic context effect (Massaro & Cohen, 1983), a bias toward hearing illegal sequences (e.g.,/tl/) as legal (e.g., /tr/), is more likely due to knowledge of the legal phoneme combinations in English or to a frequency effect. In Experiment 2, Experiment 1 was repeated with the clusters occurring word medially to assess whether phonotactic rules of syllabification modulate the phonotactic effect. Experiment 3 examined whether vowel epenthesis, another phonological process, might also affect listeners' perception of illegal sequences as legal by biasing them to hear a vowel between the consonants of the cluster (e.g., /talae/). Results suggest that knowledge of the phonotactically permissible sequences in English can affect phoneme processing in multiple ways.

Evidence for a central representation of instrument timbre.

An information processing account of perception seeks to delineate the stages of processing through which a stimulus passes and determine the properties of the representation at each stage. Research in phonetic perception has identified two stages, the second of which is thought to encode abstract acoustic attributes of sounds. The present study provided a further test of this proposal by assessing whether nonphonetic stimuli could yield results similar to those obtained with phonetic stimuli. Five selective adaptation experiments were carried out with a trumpet-piano timbre continuum. Two manipulations were used to measure abstract encoding: cross-ear presentation of adaptor and test series, and the use of adaptors that were acoustically different from the continuum end-points. The results provide evidence for an abstract representation of timbre. The similarity of the findings to those in the phonetic adaptation literature is discussed.

Molybdenum toxicity: interactions between copper, molybdenum and sulphate.

Molybdenum toxicity and the interactions between copper, molybdenum and sulphate are reviewed. The main signs of molybdenum poisoning are poor growth and anaemia (rat, chick, rabbit, cattle and sheep), anorexia (rat), diarrhoea and achromotrichia (cattle and sheep), joint and bone deformities (rat, rabbit, cattle), central nervous system degeneration and loss of crimp in wool (sheep). The following topics are discussed: (1) The effect of sulphate and sulphur compounds on molybdenum toxicity. (2) The effect of molybdenum on tissue copper levels. (3) The effect of molybdenum on the distribution of copper in plasma. (4) The effect of molybdenum on uptake and excretion of copper. (5) The possible existence of copper(II) molybdate in vivo. (6) The influence of molybdenum on sulphide production by ruminal micro-organisms. (7) Competition between molybdenum and sulphate in intestinal transport. (8) Interaction of sulphur with copper in vivo. (9) The possible involvement of molybdenum in gout and multiple sclerosis in humans.

Interaction of molybdate with copper(II)-histidine.

Molybdate and copper(II)-histidine form an insoluble complex of empirical formula Cu2(His)3(MoO4)2(H2O)2ESR-spectroscopy indicated that the complex had tetragonal symmetry. IR-spectroscopy showed the presence of a carboxylate anion and suggested that the molybdate ion formed an ammonium-type salt with the nitrogens of the imidazole. The complex did not form following dissociation of the protonated imidazole (above a pH of approximately 6).

Interference effects in short-term memory for timbre.

Four experiments investigated memory for timbre using the interpolated-tone paradigm [Deutsch, Science 168, 1604-1605 (1970)], in which participants discriminate pairs of tones (standard and comparison) separated by intervening (interpolated) tones. Interpolated tones varied from the standard tone in spectral similarity (within-dimensional variation), fundamental frequency (cross-dimensional variation), and repetition frequency. While the latter two variables had negligible effects on timbre memory, interference with timbre memory increased with the spectral similarity of the interpolated tones to the standard tone. The findings closely parallel those found for pitch memory, and suggest that memory interference depends on perceptual similarity in both cases.

Lexical and sublexical feedback in auditory word recognition.

Currently, there are two qualitatively different model classes in the field of spoken language understanding. Autonomous models allow only bottom-up information flow, whereas interactive models allow higher level representations (e.g., lexical) to affect processing at lower levels (e.g., phonemic). Part 1 of the present study included a test of a prediction that differentiates the two model classes: Is phoneme monitoring faster for targets in real words than in pseudowords, even before the word could in principle be recognized? The results indicate that this lexical advantage does occur, in accord with the predictions of interactive models. In Part 2, speech compression and expansion were used to assess the sufficiency or necessity of bottom-up evidence and of processing time in accomplishing lexical access. The results of Parts 1 and 2 suggested that in addition to the lexical effects posited by current models, sublexical activation may also play an important role. Data are presented in Part 3 that support this interpretation. Collectively, the results in the current study support interactive models of lexical processing, but require additional sublexical processes as well.

The distribution of type IV collagen in invasive carcinoma of the uterine cervix.

The presence of type IV collagen at the tumour/stromal interface of invasive carcinoma of the cervix was evaluated in 60 cases. It was assessed semi-quantitatively according to its staining characteristics, and expressed as: thick, with or without minimal discontinuity; thin, with or without moderate discontinuity; fragmentary or absent. In each case the tumour type was identified, the differentiation, growth pattern and peritumoural inflammatory infiltrate was graded and lymph node status established. There was, overall, a significant correlation between a paucity of type IV collagen and a poorer prognosis and an infiltrating growth pattern. There was a highly significant correlation for adenocarcinomas in relation to poor outcome, infiltrating growth pattern and lymph node metastases. By contrast, no statistically significant correlation was found between paucity of type IV collagen and the other parameters for either squamous or adenosquamous carcinomas. The presence of absence of type IV collagen may be a useful prognostic marker, particularly for adenocarcinomas, and may play a part in the invasive and metastatic process.

A biochemical investigation of amyloidosis in the duck.

A field case of amyloidosis in a laying flock of white Pekin ducks was investigated biochemically. The following biochemical parameters were found to differ from those of a healthy flock matched for genetic background and age: whole blood glucose, serum uric acid, calcium, magnesium, sodium, GOT and AP.

Lack of association between helicobacter pylori and gastric atrophy or intestinal metaplasia in elderly patients.

Helicobacter pylori (Hp) is associated with gastritis and peptic ulcers. It may also induce gastric atrophy (GA) and intestinal metaplasia (IM), and these changes may be the precursors of gastric carcinoma. The aim of this study was to determine if GA or IM is associated with Hp infection in elderly patients. Consecutive patients admitted for gastroscopy were recruited. Multiple biopsies were taken for histology and rapid urease (CLO) tests along with IgG enzyme-linked immunosorbent assay antibodies and (13)C-urea breath tests. Statistical analysis was by chi(2) tests. 114 patients were recruited, the average age was 78.9 + or - 5.4 years. Histology was available on 105 patients, 80 (76.2%) had gastritis, and 61/80 (76.25%) had evidence of definite current Hp infection. Seven patients had reflux gastritis, and these were excluded from the analysis described below. 20 patients had GA and 24 IM. The relationship between Hp and GA or IM was investigated by dividing patients into four groups: Group 1 patients (n = 57) were taken to be definitely currently infected (GA 7 patients, IM 11, both 1). Group 2 patients (n = 18) had old infection (GA 2, IM 4, both 3). Group 3 patients (n = 16) have never been infected previously (GA 1, IM 1, both 3). Group 4 patients (n = 4) had a poor immunological response to Hp (GA 1, IM 1, both 0). There were no significant differences in the numbers of patients with GA or IM in any group as compared with any other, with the exception of less patients with histological evidence of combined GA and IM among patients with definite current infection as compared with those with either previous infection (p = 0.04) or 'never' infection (p = 0.03). We conclude that the mucosal changes of GA or IM are not consistently associated with Hp infection in the elderly.