PubMed Health⌕ Search

Biomedical subjects

A Protopapas

Publications and source records attributed to A Protopapas.

At least 19 recordsLinked to original sources
PubMed2004

The prognostic significance of the immunohistochemical expression of p53, bcl-2, c-erb B-2 and cathepsin-D in ovarian cancer patients receiving platinum with cyclophosphamide or paclitaxel chemotherapy.

PURPOSE: To evaluate the prognostic significance of the immunohistochemical expression of p53, bcl-2, c-erbB-2 and cathepsin-D in epithelial ovarian cancer (EOC). METHODS: We analyzed 100 patients with ovarian carcinoma, FIGO Stage IC-IV who underwent primary cytoreductive surgery and received adjuvant chemotherapy with cyclophosphamide and a platinum analogue (CP) (n = 46) or paclitaxel and a platinum analogue (TP) (n = 54). Immunohistochemical expression was studied on paraffin-embedded tissue from the primary tumor. RESULTS: After a median follow-up of 55 months median progression-free survival (PFS) and overall survival (OS) were 16 and 41 months, respectively. Positive bcl-2 staining and absence of cathepsin-D expression were associated with an increased complete response rate in the CP group (p = 0.011 and p = 0.003) but not in the TP group. PFS and OS were not associated with the expression of any of the markers studied. FIGO stage (p = 0.006) and histology (p = 0.047) were the only independent prognostic factors for survival. CONCLUSION: Bcl-2 and cathepsin D expression are associated with response to CP but not TP chemotherapy. P53, bcl-2, c-erb B-2 and cathepsin D expression was not correlated with PFS and OS in our study.

Adenocarcinoma, Clear Cell↗
PubMed2002

Septic lithiasis of the pelvis.

Laparoscopic cholecystectomy has become a standard technique for the treatment of symptomatic cholelithiasis. Despite a significant reduction in the complication rate with increasing experience, bile duct injury and gallstone spillage still occur more frequently with this approach than with the open procedure. Unretrieved gallstones, in particular, have been associated with late infection and the formation of abscesses in virtually every area of the abdominal cavity. We present a rare case of an isolated pelvic abscess that developed in a postmenopausal woman 5 months after laparoscopic cholecystectomy for recurrent cholecystitis. The preoperative differential diagnosis of this case is also discussed.

Abdominal Pain↗
PubMed2001

Speech comprehension is correlated with temporal response patterns recorded from auditory cortex.

Speech comprehension depends on the integrity of both the spectral content and temporal envelope of the speech signal. Although neural processing underlying spectral analysis has been intensively studied, less is known about the processing of temporal information. Most of speech information conveyed by the temporal envelope is confined to frequencies below 16 Hz, frequencies that roughly match spontaneous and evoked modulation rates of primary auditory cortex neurons. To test the importance of cortical modulation rates for speech processing, we manipulated the frequency of the temporal envelope of speech sentences and tested the effect on both speech comprehension and cortical activity. Magnetoencephalographic signals from the auditory cortices of human subjects were recorded while they were performing a speech comprehension task. The test sentences used in this task were compressed in time. Speech comprehension was degraded when sentence stimuli were presented in more rapid (more compressed) forms. We found that the average comprehension level, at each compression, correlated with (i) the similarity between the frequencies of the temporal envelopes of the stimulus and the subject's cortical activity ("stimulus-cortex frequency-matching") and (ii) the phase-locking (PL) between the two temporal envelopes ("stimulus-cortex PL"). Of these two correlates, PL was significantly more indicative for single-trial success. Our results suggest that the match between the speech rate and the a priori modulation capacities of the auditory cortex is a prerequisite for comprehension. However, this is not sufficient: stimulus-cortex PL should be achieved during actual sentence presentation.

Auditory Cortex↗
PubMed2001

Relations between the neural bases of dynamic auditory processing and phonological processing: evidence from fMRI.

Functional magnetic resonance imaging (fMRI) was used to examine how the brain responds to temporal compression of speech and to determine whether the same regions are also involved in phonological processes associated with reading. Recorded speech was temporally compressed to varying degrees and presented in a sentence verification task. Regions involved in phonological processing were identified in a separate scan using a rhyming judgment task with pseudowords compared to a lettercase judgment task. The left inferior frontal and left superior temporal regions (Broca's and Wernicke's areas), along with the right inferior frontal cortex, demonstrated a convex response to speech compression; their activity increased as compression increased, but then decreased when speech became incomprehensible. Other regions exhibited linear increases in activity as compression increased, including the middle frontal gyri bilaterally. The auditory cortices exhibited compression-related decreases bilaterally, primarily reflecting a decrease in activity when speech became incomprehensible. Rhyme judgments engaged two left inferior frontal gyrus regions (pars triangularis and pars opercularis), of which only the pars triangularis region exhibited significant compression-related activity. These results directly demonstrate that a subset of the left inferior frontal regions involved in phonological processing is also sensitive to transient acoustic features within the range of comprehensible speech.

Adult↗
PubMed2001

Diagnostic and therapeutic advantages of hysteroscopic surgery in management of intrauterine lesions in postmenopausal women.

STUDY OBJECTIVE: To determine the value of hysteroscopic surgery in the management of intrauterine lesions in postmenopausal women. DESIGN: Descriptive study (Canadian Task Force classification II-2). SETTING: Tertiary care university hospital. Patients. Fifty postmenopausal women, most with vaginal bleeding, all with intrauterine lesions (leiomyomas, polyps, adhesions) on hysteroscopy or ultrasound. INTERVENTION: Hysteroscopic operations consisting of myomectomy, polypectomy, and adhesiolysis. MEASUREMENTS AND MAIN RESULTS: Forty-seven procedures were completed successfully by hysteroscopy; partial myomectomies were performed in three women for large or deeply embedded leiomyomas. The only complication was one case of fluid overload. Median operating time was 20.0 minutes (range 5.0-60.0 min) and median postoperative hospital stay was zero days (range 0-2 days). Eight patients (16%) subsequently underwent hysterectomy, mostly for uterine malignancy or premalignancy. In two cases, the operative specimen included malignant elements that were not evident on preoperative endometrial biopsy. During mean follow-up of 33.1 months (range 6-72 mo), 95.2% of women without hysterectomy were free of symptoms. CONCLUSION: Hysteroscopic surgery is an effective and safe option for postmenopausal women with intrauterine lesions. It allows the correct diagnosis to be made, reduces the need for major and unnecessary surgery, and is therapeutic in most patients. (J Am Assoc Gynecol Laparosc 8(1):87-91, 2001)

Female↗
PubMed2001

Postoperative ascites developing after laparoscopic surgery can become a difficult diagnostic dilemma.

Postoperative ascites is a rare complication of laparoscopic surgery. Life-threatening and serious etiologies such as unrecognized bowel or urinary tract injury should be excluded promptly to avoid prolonged morbidity and even mortality. Occasionally, no definitive cause can be identified after an extensive diagnostic work-up. In such cases, idiopathic allergic or inflammatory peritoneal reaction may be the final diagnosis.

Adult↗
PubMed2001

Laparoscopic 'oophorectomy-in-a bag'--an alternative to laparotomy for the evaluation of suspicious ovarian masses.

A prospective observational study was performed to assess the feasibility of the technique of laparoscopic 'oophorectomy-ina bag' for the safe removal of ovarian masses that do not meet the standard guidelines for laparoscopic management of adnexal pathology. Ovarian lesions were selected preoperatively by: age of the patient, ultrasound appearance, bilaterality and size. None of the women had ascites or matted bowel on ultrasound, and all had normal serum tumour markers. There were no stigmata of malignant disease in any of the cases at the time of surgery. Twenty women were recruited. Eighteen procedures (90.0%) were completed successfully laparoscopically. In two cases the bag could not be removed laparoscopically and minilaparotomy was performed. Nineteen of the tumours (95.0%) were removed without intra-abdominal spillage; the bag ruptured in one case. There were no major complications. One case of borderline ovarian tumour (stage Ia) was discovered. We conclude that laparoscopic 'oophorectomy-in-a bag' allows for the safe removal of suspicious ovarian tumours. The advantages of this approach are that women can be treated locally, a laparotomy is avoided, and the subgroup with ovarian malignancy can be identified to be referred to an oncological centre.

Journal Article↗
PubMed2000

Disruption of the neural response to rapid acoustic stimuli in dyslexia: evidence from functional MRI.

The biological basis for developmental dyslexia remains unknown. Research has suggested that a fundamental deficit in dyslexia is the inability to process sensory input that enters the nervous system rapidly and that deficits in processing rapid acoustic information are associated with impaired reading. Functional magnetic resonance imaging (fMRI) was used to identify the brain basis of rapid acoustic processing in normal readers and to discover the status of that response in dyslexic readers. Normal readers showed left prefrontal activity in response to rapidly changing, relative to slowly changing, nonlinguistic acoustic stimuli. Dyslexic readers showed no differential left frontal response. Two dyslexic readers participated in a remediation program and showed increased activity in left prefrontal cortex after training. These fMRI results identify left prefrontal regions as normally being sensitive to rapid relative to slow acoustic stimulation, insensitive to the difference between such stimuli in dyslexic readers, and plastic enough in adulthood to develop such differential sensitivity after intensive training.

Acoustic Stimulation↗
PubMed2000

Auditory processing parallels reading abilities in adults.

A broad battery of psychoacoustic measures and standard measures of reading and spelling were applied to 102 adults. The test group included individuals with a childhood history of reading difficulties and controls with no reported reading difficulties. Reading scores were variable in both groups. Poor auditory processing abilities were recorded in poor readers; particular difficulties were posed by tasks requiring spectral distinctions, the simplest of which was pure tone frequency discrimination. In absolute terms, the greatest deficits were recorded in tasks in which stimuli were presented in brief forms and in rapid succession. Auditory processing abilities accounted for more than 50% of the reading score variance in the control group, but their correlation with reading scores was lower in the group with childhood histories of reading difficulties. The additional variability in the latter group resulted largely from the prevalence of reading-compensated poor psychoacoustic performers, whose short-term word memory was also typically poor. Taken together, these findings support a link between impaired auditory resolution and poor reading. Psychoacoustic difficulties are largely retained through adulthood and may be the source of the retained reading difficulties.

Adolescent↗
PubMed2000

Intramural leiomyoma of the bladder.

Mesodermal tumors of the urinary bladder are rare and the majority of them are malignant. We report a case of an intramural leiomyoma of the bladder presenting with symptoms of a mild lower urinary tract infection. The patient was managed with partial cystectomy and the outcome was excellent.

Adult↗
PubMed1999

Connectionist modeling of speech perception.

Connectionist models of perception and cognition, including the process of deducing meaningful messages from patterns of acoustic waves emitted by vocal tracts, are developed and refined as human understanding of brain function, psychological processes, and the properties of massively parallel architectures advances. The present article presents several important contributions from diverse points of view in the area of connectionist modeling of speech perception and discusses their relative merits with respect to specific theoretical issues and empirical findings. TRACE, the Elman/Norris net, and Adaptive Resonance Theory constitute pivotal points exemplifying overall modeling success, progress in temporal representation, and plausible modeling of learning, respectively. Other modeling efforts are presented for the specific insights they offer, and the article concludes with a discussion of computational versus dynamic modeling of phonological processes.

Brain↗
PubMed1999

How to avoid suboptimal management of cervical carcinoma by simple hysterectomy.

OBJECTIVE: To determine the reasons leading to an inappropriate simple hysterectomy in the presence of carcinoma of the cervix and to evaluate factors related to survival. METHODS: All preoperative information was abstracted from 63 cervical cancer patients cleared by simple hysterectomy from 1980-1993. Cervical cancer screening history as well as the indication for hysterectomy were analyzed. The 5-year survival was calculated and correlated with the tumour histological subtype and presumed stage of disease. RESULTS: The most common preoperative symptom was abnormal uterine bleeding (73%). The absence of preoperative cytology, an inadequately evaluated abnormal Pap smear and the failure to differentiate from endometrial carcinoma were the main causes leading to an inappropriate simple hysterectomy. The cumulative 5-year survival was 63.5% and was correlated with the presumed stage of disease and the histological subtype. CONCLUSION: Only with close adherence to the cervical cancer screening guidelines and appropriate evaluation of presenting symptoms can we avoid inappropriate management of cervical carcinoma with simple hysterectomy.

Adult↗
PubMed1998

Myometrial scoring: a new technique for the management of severe Asherman's syndrome.

OBJECTIVE: To describe a new hysteroscopic technique for the management of severe Asherman's syndrome. DESIGN: Prospective observational study. SETTING: Volunteers in an academic research environment. PATIENT(S): Seven patients with secondary infertility associated with amenorrhea or oligomenorrhea secondary to severe Asherman's syndrome. INTERVENTION(S): Six to eight longitudinal incisions were made into the myometrium extending from the uterine fundus to the isthmus with a resectoscope fitted with a Collins knife electrode. MAIN OUTCOME MEASURE(S): Restoration of menses, symptomatic relief, and postoperative reproductive performance. RESULT(S): The amount of menstrual bleeding increased in all cases, including two women who were amenorrheic before their surgery. Pelvic pain decreased in two of the four symptomatic cases. Three to four months after surgery, hysteroscopy showed a normal sized uterine cavity in five cases. After a median follow-up of 12 months, three women conceived four pregnancies, including a missed abortion, a tubal abortion, an ongoing pregnancy currently at 7 weeks' gestation, and one child delivered at 36 weeks gestation after premature rupture of the membranes. CONCLUSION(S): Hysteroscopic myometrial scoring enlarges uterine cavity size in cases of severe Asherman's syndrome and improves menstrual function. Reproductive performance seems to be improved also, but longer follow-up is required.

Adult↗
PubMed1998

Selective speech motor, syntax and cognitive deficits associated with bilateral damage to the putamen and the head of the caudate nucleus: a case study.

Deficits in speech production, sentence comprehension and abstract reasoning occurred in a subject having profound bilateral damage to the putamen and the caudate nucleus. Acoustic analyses indicated that the subject's speech was degraded due to inappropriate sequencing of articulatory gestures that involve different articulatory structures. Transitions between sounds were slow and often did not achieve target configurations. The subject had a 14% error rate comprehending distinctions in meaning conveyed by syntax in English sentences; normal controls make virtually no errors in this test. Cognitive deficits involving impaired sequencing occurred: the subject had a 70% error rate on the Odd Man Out test when making decisions within a single category. Cognitive perseveration occurred when the subject was asked to shift categories. In contrast, performance was within normal ranges in tests of lexical access and memory. The pattern of deficits provides evidence for basal ganglia involvement in the regulation of sequencing across modalities.

Adult↗
PubMed1997

Fundamental frequency of phonation and perceived emotional stress.

Nonlinguistic information about the speaker's emotional state is conveyed in spoken utterances by means of several acoustic characteristics and listeners can often reliably identify such information. In this study we investigated the effect of short- and long-term F0 measures on perceived emotional stress using stimuli synthesized with the LPC coefficients of a steady vowel and varying F0 tracks. The original F0 tracks were taken from naturally occurring speech in highly stressful (contingent on terror) and nonstressful conditions. Stimuli with more jitter were rated as sounding more hoarse but not more stressed, i.e., a demonstrably perceptible amount of jitter did not seem to play a role in perceived emotional stress. Reversing the temporal pattern of F0 did not affect the stress ratings, suggesting that the directionality of variations in F0 does not convey emotional stress information. Mean and maximum F0 within an utterance correlated highly with stress ratings, but the range of F0 did not correlate significantly with the stress ratings, especially after the effect of maximum F0 was removed in stepwise regression. It is concluded that the range of F0 per se does not contribute to the perception of emotional stress, whereas maximum F0 constitutes the primary indicator. The observed effects held across several voices that were found to sound natural (three male voices and one of two female ones). An effect of the formant frequencies was also observed in the stimuli with the lowest F0; it is hypothesized that formant frequency structure dominated the F0 effect in the one voice that gave discrepant results.

Affect↗
PubMed1997

Perceptual differences in infant cries revealed by modifications of acoustic features.

Previous studies of infant cry acoustics and their perceptual significance have remained inconclusive as to the graded nature of cry production and perception and to the exact role and importance of particular acoustic features. In this study, a set of infant cries were digitally analyzed and resynthesized to form natural-sounding cries with varying fundamental frequency (F0), degrees of jitter (period to period variations in F0), and rise time (time for F0 to reach its maximum value). In a perceptual rating task, higher-F0 cries as well as cries with larger amounts of jitter tended to be given more negative ratings than were lower-F0 cries and cries with less jitter, respectively. The perceptual ratings of the rise time manipulations were inconclusive. This study demonstrated a perceptual effect of F0 and jitter independently of other parameters, consistent with current notions of infant cry gradedness. It was also shown that digital signal processing techniques can be fruitfully applied to infant cry research.

Acoustics↗