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Biomedical subjects

C Singer

Publications and source records attributed to C Singer.

At least 37 records · Page 2Linked to original sources
PubMed2001

Papillary lesions of the breast: evaluation with stereotactic directional vacuum-assisted biopsy.

PURPOSE: To evaluate the use of stereotactic directional vacuum-assisted biopsy (SDVAB) in diagnosing and managing papillary lesions of the breast. MATERIALS AND METHODS: The authors retrospectively reviewed the mammographic and histopathologic findings of 26 cases in which papillary lesions were diagnosed at SDVAB. In all cases, subsequent surgical excision (n = 20) or long-term imaging follow-up (n = 6) was performed and correlated with findings at SDVAB. RESULTS: SDVAB of 26 lesions yielded tissue that was classified as benign in 12, atypical in six, and malignant in eight. Of the 12 lesions that were diagnosed as histologically benign at SDVAB, six were surgically excised. Of these six lesions, five yielded benign correlative results. The sixth lesion was thought to be discordant with the imaging findings, and was surgically excised and determined to be malignant. Of the six benign lesions that were not surgically sampled for biopsy, five decreased in size and one was not seen at radiographic follow-up. Of the six lesions diagnosed as atypical at SDVAB that were surgically excised, one was benign and five were atypical. None proved to be malignant. Of the eight lesions diagnosed as malignant at SDVAB, surgical excision demonstrated ductal carcinoma in situ in all eight; two also had foci of invasive carcinoma. CONCLUSION: Benign and malignant papillary lesions of the breast can be reliably diagnosed at SDVAB when the SDVAB results correlate with the imaging findings. However, the extent of malignant papillary disease may be underestimated at SDVAB; in our study, invasive carcinoma was later discovered in 25% of patients with this diagnosis.

Adult↗
PubMed2001

Mammographic appearance of axillary lymph node calcification in patients with metastatic ovarian carcinoma.

OBJECTIVE: We describe the mammographic appearance of axillary lymph node calcification in three patients with metastatic ovarian carcinoma. CONCLUSION: Axillary lymph node calcification may be identified mammographically in patients with metastatic ovarian carcinoma and may be evidence of unsuspected metastatic disease. The pattern of calcification differs from that seen with metastatic breast carcinoma.

Aged↗
PubMed2000

The incidence of positive margins with breast conserving therapy following mammotome biopsy for microcalcification.

BACKGROUND AND OBJECTIVES: The ability to achieve clean margins with breast conserving therapy varies greatly even when the diagnosis of carcinoma is known beforehand. Although several reports reveal that the incidence of positive margins decreases after stereotaxic core biopsy of nonpalpable lesions and fine-needle aspiration biopsy of palpable lesions, the data on the results following mammotome biopsy (mmbx) is scanty. METHODS: Two hundred and ninety-eight biopsy specimens for mammographically indeterminate microcalcification from 1/97 through 3/30/98 were reviewed. Biopsies were performed using the biopsys method utilizing an 11-gauge multidirectional, vacuum-directed device. RESULTS: Ten percent (n = 31) of the mammotome biopsies were atypical and 9% (n = 27) were malignant. These 58 cases (19%) were recommended for surgical excision. The incidence of positive margins in this subset was determined. Of patients who underwent lumpectomy as their initial surgical procedure 69% had negative surgical margins. Seventy-seven percent of patients with carcinoma diagnosed by mammotome biopsy had definitive initial surgery with a single surgical procedure. CONCLUSIONS: Mmbx facilitates fewer surgical procedures to achieve negative margins, and thus provides a better cosmetic result.

Adult↗
PubMed2000

Electromyography during stereotactic pallidotomy for Parkinson's disease.

In stereotactic pallidotomy for Parkinson's disease, care must be taken to avoid internal capsule injury while maximizing improvement of rigidity and tremor. In 21 patients, intraoperative electromyography (EMG) was used to assess stimulation thresholds required for capsular responses and to monitor muscle tone and tremor. Surface EMG electrodes were placed on the face and multiple muscle groups of the extremities. The stimulation and lesion electrode was introduced via MRI-guided stereotaxis toward a point 2-3 mm anterior to the midcommissural point, 5-6 mm inferior to the AC-PC plane, and 21-22 mm lateral to the midline. Exact targets were modified according to MRI-visualized anatomy. With stimulation at 5 and 50 Hz, thresholds for detection of EMG responses were usually seen at 4-5 mA. EMG responses were consistently seen prior to visual observation of muscle activity. Timing of EMG response relative to stimulus aided in differentiating stimulus-related movement from spontaneous tremor. Resting spontaneous EMG activity was seen to decrease as rigidity was improved by incremental lesion production. EMG activity related to tremor was recorded; tremor decrease by lesion production was documented by EMG recording. Patient cooperation with physiologic testing during stimulation and lesion production may become limited. Intraoperative EMG monitoring provides an adjunct to improve reliability of assessment of capsular stimulation and rigidity while providing documentation of lesion impact on rigidity and tremor.

Aged↗
PubMed1999

Safety and efficacy of NeuroBloc (botulinum toxin type B) in type A-responsive cervical dystonia.

OBJECTIVE: To determine the safety and efficacy of botulinum toxin type B (BoNT/B) in patients with cervical dystonia (CD). BACKGROUND: BoNT/B is a form of chemodenervation therapy for the treatment of patients with CD. METHODS: The authors performed a 16-week, randomized, multicenter, double-blind, placebo-controlled trial of BoNT/B in patients with CD who continue to respond to botulinum toxin type A. Placebo, or 5,000 U or 10,000 U of BoNT/B was administered in two to four muscles involved clinically in CD. The Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS)-Total score at week 4 was the primary efficacy measure. Clinical assessments and adverse events were recorded for treatment day 1 and at weeks 2, 4, 8, 12, and 16. RESULTS: A total of 109 patients were enrolled randomly across all three treatment groups. The mean improvement in the TWSTRS-Total scores in each group at week 4 was 4.3 (placebo), 9.3 (5,000 U), and 11.7 (10,000 U). For the prospectively defined primary contrast (10,000 U versus placebo), highly significant differences were noted for the primary (TWSTRS-Total, baseline to week 4, p = 0.0004) and supportive secondary (Patient Global Assessment, baseline to week 4, p = 0.0001) outcome measures. Improvement in pain, disability, and severity of CD occurred for patients who were treated with BoNT/B when compared with placebo-treated patients. Overall, improvements associated with BoNT/B treatment were greatest for patients who received the 10,000-U dose. The duration of treatment effect for BoNT/B was 12 to 16 weeks for both doses. CONCLUSION: Botulinum toxin type B (NeuroBloc) is safe and efficacious at 5,000 U and 10,000 U for the management of patients with cervical dystonia.

Adult↗
PubMed1999

A head-to-head comparison between technetium-99m-tetrofosmin and technetium-99m-MIBI scintigraphy to evaluate suspicious breast lesions.

The aim of this study was to assess the diagnostic value of technetium-99m-tetrofosmin and technetium-99m-MIBI in a head-to-head comparison. Both radiopharmaceuticals are routinely used for detecting breast cancer. In a prospective, open, diagnostic trial, the two radiopharmaceuticals were administered randomly on different days to the same 101 women suffering from 103 breast tumours. Planar images and single photon emission computer tomography (SPET) were performed. After histological examination of the tumours, sensitivity, specificity and positive and negative predictive value were compared. 99mTc-tetrofosmin and 99mTc-MIBI showed low sensitivity in planar images (44% vs 46%, respectively). SPET improved sensitivity (70% vs 69%, respectively). Specificity in planar images was 83% and 87%, and it was even lower using SPET (70% vs 78%, respectively). Positive predictive value in planar images was 76% vs 81%, and it was not changed by SPET. Negative predictive value was low in planar images (54% vs 57%, respectively), but it was improved by using SPET (65% vs 67%, respectively). In conclusion, 99mTc-tetrofosmin and 99mTc-MIBI scintigraphy show similar diagnostic value in assessing suspicious breast lesions.

Adult↗
PubMed1998

Evidence against a significant younger dryas cooling event in new zealand

Pollen records of deglacial sequences from northwest Nelson, New Zealand, demonstrate that there was no significant temperature decline associated with the Younger Dryas in New Zealand. Records of glacial advances at this time were either the product of increased snow accumulation under enhanced precipitation regimes or random variation rather than the result of a regional thermal decline. This finding supports those models of Younger Dryas initiation that require neither enhanced westerly circulation nor significant thermal decline in the Southern Hemisphere.

Journal Article↗
PubMed1998

Randomized, placebo-controlled study of tolcapone in patients with fluctuating Parkinson disease treated with levodopa-carbidopa. Tolcapone Fluctuator Study Group III.

OBJECTIVE: To assess the efficacy and tolerability of the catechol-O-methyltransferase inhibitor tolcapone in reducing "off/on" fluctuations in levodopa-treated parkinsonian patients. DESIGN: A randomized, double-blind, placebo-controlled, parallel-group study. SETTING: Fifteen Parkinson disease clinics. PATIENTS: Two hundred fifteen referred outpatients with Parkinson disease who showed predictable end-of-dose motor fluctuations that were not controlled by a stable levodopa-carbidopa (Sinemet) regimen of at least 4 weeks' duration. INTERVENTIONS: In addition to their usual levodopa-carbidopa regimen, patients received placebo or tolcapone, 100 or 200 mg, 3 times daily orally for 6 weeks. PRIMARY OUTCOME MEASURE: Change in daily off/on time. RESULTS: Tolcapone, 100 and 200 mg 3 times daily, reduced off time by 2.0 and 2.5 hours per day, respectively, and increased on time by 2.1 and 2.3 hours per day, respectively (P<.001 vs placebo). Investigators' global measures of disease severity indicated that significantly more tolcapone-treated patients had reduced wearing off and symptom severity (P<.001 vs placebo). No significant change in quality-of-life measures occurred. Clinical improvements occurred despite a reduction in total daily levodopa dose of 185.5 mg (23%) in the tolcapone, 100 mg 3 times daily, group and 251.5 mg (29%) in the 200 mg 3 times daily group. Principal adverse events (mainly dyskinesia and nausea) were levodopa related, were not treatment limiting, and were seldom reported as reasons for withdrawal. The frequency of withdrawals because of adverse events was similar in all groups (3% to 7%). CONCLUSIONS: Tolcapone was well tolerated and substantially increased on time and reduced off time in patients with fluctuating Parkinson disease. Additionally, levodopa requirements were significantly decreased.

Aged↗
PubMed1998

Asymmetric predominantly ipsilateral blepharospasm and contralateral parkinsonism in an elderly patient with a right mesencephalic cyst.

A 66-year-old woman presented with a 3-year history of predominantly right-sided blepharospasm and a 1-year history of progressive predominantly left-sided hemiparkinsonism manifested by a left upper extremity resting tremor and left-sided bradykinesia. Magnetic resonance imaging of the brain revealed a large right mesencephalic cyst with mass effect. Positron emission tomography revealed bilateral striatal hypometabolism consistent with nigrostriatal dopaminergic dysfunction. The association of predominantly ipsilateral blepharospasm and predominantly contralateral hemiparkinsonism is very rare, and its association with a posterior fossa space-occupying lesion has been reported only once. This is the second report of such an association and the first description of adult-onset symptomatology.

Aged↗
PubMed1998

Acute skin GVHD following syngeneic BMT for CLL.

A 41-year-old woman received a syngeneic BMT for CLL and subsequently developed acute skin GVHD. Transfusion-related allogeneic GVHD was excluded on the basis of an unchanged HLA type in circulating lymphocytes. Short tandem repeat PCR was used to confirm syngeneicity between donor and recipient. The patient had a personal and family history of autoimmune disease which may have made her particularly susceptible to development of syngeneic GVHD. The distinction between allogeneic and syngeneic or autologous GVHD is important because of therapeutic implications.

Acute Disease↗
PubMed1998

Inflammatory pseudotumor of the liver--a rare entity and a diagnostic challenge.

Inflammatory pseudotumors are rare benign lesions that occur throughout the body. Hepatic pseudotumors are uncommon lesions, accompanied by fever, malaise, abdominal pain, and mass effect, and therefore are commonly misdiagnosed as malignant tumors or liver abscesses. Because even routine imaging procedures usually fail to differentiate hepatic pseudotumors from liver neoplasms, a diagnostic histology procedure is usually needed. We present a case of hepatic pseudotumor that resolved spontaneously and review the literature, including 40 previously reported cases and the differential diagnosis.

Adult↗
PubMed1998

Urinary dysfunction in Parkinson's disease.

Urinary symptoms are very common in Parkinson's disease (PD). They are primarily irritative (frequency, urgency, urge incontinence) and correlate with the urodynamic finding of involuntary detrusor contractions at early stages of bladder filling (detrusor hyperreflexia). Obstructive symptoms (hesitancy, weak urinary stream) may be seen in a smaller number of patients by themselves or combined with irritative symptoms. They may be secondary to anticholinergics, obstructive uropathy, or point to the presence of multiple system atrophy. Dysfunction of the striated urethral sphincter and pelvic musculature can be seen in variable numbers in PD, with the main abnormality that of delayed relaxation at the time of initiation of voluntary voiding.

Constriction, Pathologic↗
PubMed1997

Efficacy of Lactobacillus GG as a Diarrheal Preventive in Travelers.

Traveler's diarrhea can be a debilitating problem for individuals on international trips. Retrospective and prospective studies have shown the incidence of traveler's diarrhea to range from 15-56%. 1,2A placebo-controlled, double-blinded study in Finnish travelers found that the probiotic Lactobacillus GG decreases the incidence of traveler's diarrhea.3 Lactobacillus GG, initially isolated from healthy humans, is remarkable in its ability to resist acid and bile degradation and to adhere to the intestinal mucosa.4 To assess the efficacy of Lactobacillus GG in preventing diarrhea in American tourists, a study was conducted at the Travel and Immunization Center of the Long Island Jewish Medical Center (LIJMC).

Journal Article↗
PubMed1997

Adult-onset subacute sclerosing panencephalitis: case reports and review of the literature.

Subacute sclerosing panencephalitis (SSPE) is mainly thought of as a disorder of childhood and adolescence and may not be readily recognized when presenting later in life. Prior reports have suggested that adult-onset SSPE may have atypical features. We have added two cases to the existing literature on adult-onset SSPE, compared them with a more classic juvenile presentation, and extensively reviewed those reports that were published after the etiological link with the measles virus had been established. Adult-onset SSPE patients present at a mean age of 25.4 years (range 20-35 years). They have a higher proportion of either negative history of measles exposure or undocumented history by the reporting authors. Those with available history of measles exposure tend to have it either earlier (younger than 3 years old) or later (after 9 years) than the usual childhood measles infection. Where the primary infection is known, unusually long measles-to-SSPE intervals have been documented, ranging from 14 to 22 years. None of the cases followed measles vaccination. Visual symptomatology was very frequent, with 8 of the 13 cases reviewed having a purely ophthalmological presentation; only 2 patients presented with behavioral changes. Although the course of the disease was progressive and fatal in the majority, there appeared to be a higher rate of spontaneous remission as compared with childhood-onset SSPE. Myoclonus, spastic hemiparesis, bradykinesia, and rigidity were the predominant motor manifestations. Neuropathology revealed cortical and subcortical gray matter involvement preferentially of the occipital lobes, thalamus, and putamen. The importance of recognizing the spectrum of potential presentations of SSPE and providing an early diagnosis will increase as more effective treatments become available.

Adolescent↗
PubMed1997

Tourette syndrome. Coprolalia and other coprophenomena.

Coprolalia has been a recognized symptom of Tourette syndrome from the first description of the syndrome. Copropraxia is seen less frequently and almost always occurs in association with coprolalia. Prevalence of coprolalia varies from 8% in primary pediatric practices to over 60% in tertiary referral centers. Coprolalia tends to peak in severity during adolescence and to wane during adulthood. The pathogenesis may be related to dysfunction of basal ganglionic and limbic mini-circuits. Coprolalia has also been seen in a variety of other neurologic disorders. Treatment is primarily pharmacologic with dopamine-blocking agents.

Brain↗