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Biomedical subjects

G Rosen

Publications and source records attributed to G Rosen.

At least 19 recordsLinked to original sources
PubMed2005

Transthoracic needle biopsy of lung masses: a survey of techniques.

AIM: In order to assess the range and everyday use of the various techniques for percutaneous transthoracic needle biopsy of lung masses in the USA and Canada, we surveyed thoracic radiologists in academic and community practice on their standard approach to the procedure. MATERIALS AND METHODS: The 300 questionnaires that were mailed to members of the Society of Thoracic Radiology throughout the USA and Canada contained specific questions on their approach to a transthoracic needle biopsy of a routine case of a 3cm lung mass located in the right lower lobe 1cm from the pleural surface. RESULTS: A total of 140 (47%) members responded. Of the 139 responders who performed lung biopsies, 103 (74%) were located at a teaching centre affiliated to a university or medical school, and 36 (26%) were community-based radiologists. In total 97 (70%) replied that they would perform the procedure under CT guidance, 31 (22%) under either CT or fluoroscopy guidance, and 11 (8%) only under fluoroscopy. Fine-needle aspiration was the procedure of choice for the given case by 101 (73%) responders, whereas 20 (14%) preferred doing core biopsy, and 18 (13%) chose both techniques. On-site cytology confirmation for obtaining diagnostic material was available to 101 (73%) responders. Before performing the procedure, 107 (77%) verified coagulation tests whereas 32 (23%) did not. Follow-up imaging for pneumothorax assessment was not routinely performed by 15 (11%) responders. CONCLUSION: The majority of radiologists performed percutaneous transthoracic needle biopsy of a lung mass under CT guidance, by fine-needle aspiration, using repeated pleural puncture technique, and with a cytologist on site. A significant minority did not obtain coagulation screening before the procedure, and a small minority did not routinely assess for pneumothorax by late chest radiography.

Biopsy, Fine-Needle↗
PubMed2005

Hemolysis during percutaneous mechanical thrombectomy can mimic a hemolytic transfusion reaction.

BACKGROUND: Interventional radiologists have developed percutaneous mechanical thrombectomy (PMT) devices to remove intravascular thrombi. Hemolysis, secondary to thrombus destruction from these devices, has been described in radiology journals, but similar reports appear to be lacking in the transfusion medicine literature. Two cases of hemolysis after PMT are described that involved the transfusion service, one of which was reported as a hemolytic transfusion reaction. CASE REPORTS: The first patient received 4 units of red cells (RBCs) during a thrombectomy and subsequent placement of a transjugular intrahepatic portosystemic shunt. The patient developed hemoglobinuria, and it was reported to the blood bank as a possible hemolytic transfusion reaction. After RBC mismatch and bacterial contamination were excluded, the hemolysis was attributed to thrombectomy-related mechanical hemolysis. In the second case, a hemolyzed sample was sent to the blood bank for a type and cross-match. Upon requesting that the sample be redrawn, it was learned that the sample was obtained after PMT. CONCLUSION: Patients who have undergone PMT can have clinical and laboratory findings suggestive of hemolytic transfusion reactions. Although interventional radiologists are familiar with these side effects, the blood bank profession needs to be aware that these procedures cause nonimmune hemolysis and must consider this possibility when evaluating transfusion reactions in these patients.

Aged↗
PubMed2004

Identification of a Fusobacterium nucleatum 65 kDa serine protease.

A 65 kDa protease was partially purified from extracellular vesicles of Fusobacterium nucleatum cultures by preparative SDS-PAGE followed by electroelution. The pH optimum of the protease is 7.5-8.0 and its activity could be inhibited by serine protease inhibitors. The protease was found to degrade the extracellular matrix proteins fibrinogen and fibronectin as well as collagen I and collagen IV which were degraded at 37 degrees C but not at 28 degrees C, indicating the presence of a gelatinase activity in these bacteria. The 65 kDa protease was also able to digest the alpha-chains of immunoglobulin A but not immunoglobulin G. The 65 kDa F. nucleatum protease, capable of degrading native proteins, may play an important role in both the nutrition and pathogenicity of these periodontal microorganisms. The degradation of extracellular matrix proteins by bacterial enzymes may contribute to the damage of periodontal tissues, and degradation of IgA may help the evasion of the immune system of the host by the bacteria.

Collagen Type I↗
PubMed2002

Distribution of androgen receptor mRNA expression and immunoreactivity in the brain of the green anole lizard.

Male courtship and copulation are androgen dependent in the green anole lizard, and female receptivity can be facilitated by testosterone. However, only a few, and relatively large, regions in the brain have been implicated in the control of these behaviours. In situ hybridization and immunohistochemistry were therefore used to determine in detail where androgens are likely to act in the brains of breeding males and females. A 697-bp fragment of the anole androgen receptor (AR) was cloned from total RNA isolated from the kidney, which contains the highly androgen-sensitive renal sex segment. The cloned fragment spanned part of the C, the entire D, and part of the E domains, and shared a high degree of similarity with the AR of various species. 35S-labelled antisense and sense probes were generated from the 697-bp fragment for use in in situ hybridization, and the AR antibody PG-21 was used for immunohistochemistry. Both sexes consistently had AR mRNA expression and immunoreactivity in areas associated with vertebrate reproductive behaviours and in motor areas of the brainstem. Interestingly, the PG-21 antibody produced labelling in both the nucleus and cytoplasm, including neuronal processes. The distribution of mRNA and immunoreactivity were comparable in males and females, and the amount of labelling was generally similar, although slightly greater in females. The expression pattern of AR in this species supports the idea that distribution is highly conserved among vertebrates, but that it probably does not dictate behavioural differences between the sexes in anoles.

Amino Acid Sequence↗
PubMed2001

Treatment-induced pathologic necrosis: a predictor of local recurrence and survival in patients receiving neoadjuvant therapy for high-grade extremity soft tissue sarcomas.

PURPOSE: To determine whether treatment-induced pathologic necrosis correlates with local recurrence and overall survival in patients who receive neoadjuvant therapy for high-grade extremity soft tissue sarcomas. PATIENTS AND METHODS: Four hundred ninety-six patients with intermediate- to high-grade extremity soft tissue sarcomas received protocol neoadjuvant therapy. All patients underwent surgical resection after neoadjuvant therapy and had pathologic assessment of tumor necrosis in the resected specimens. RESULTS: The 5- and 10-year local recurrence rates for patients with > or = 95% pathologic necrosis were significantly lower (6% and 11%, respectively) than the local recurrence rates for patients with less than 95% pathologic necrosis (17% and 23%, respectively). The 5- and 10-year survival rates for the patients with > or = 95% pathologic necrosis were significantly higher (80% and 71%, respectively) than the survival rates for the patients with less than 95% pathologic necrosis (62% and 55%, respectively). Patients with less than 95% pathologic necrosis were 2.51 times more likely to develop a local recurrence and 1.86 times more likely to die of their disease as compared with patients with > or = 95% pathologic necrosis. The percentage of patients who achieved > or /= 95% pathologic necrosis increased to 48% with the addition of ifosfamide as compared with 13% of the patients in all the other protocols combined. CONCLUSION: Treatment-induced pathologic necrosis is an independent predictor of both local recurrence and overall survival in patients who receive neoadjuvant therapy for high-grade extremity soft tissue sarcomas. A complete pathologic response (> or = 95% pathologic necrosis) correlated with a significantly lower rate of local recurrence and improved overall survival.

Adolescent↗
PubMed2001

Methadone is safe for treating hospitalized patients with severe pain.

PURPOSE: Methadone is still regarded as a second line opioid for patients suffering from severe pain, and is rarely used in hospitalized patients. The infrequent use of methadone is probably due to its long plasma half-life that could lead to accumulation and toxicity. In the present study we report that clinically effective analgesic doses of methadone, given either epidurally or orally, can be used safely for prolonged treatment in hospitalized patients. CLINICAL FEATURES: Over a five-year period we administered methadone at Hadassah Hospital in Jerusalem to 3,954 in-patients with severe pain, 12% of whom were younger than 17 yr. Satisfactory pain relief was recorded in more than 85% of the patients. None of the patients treated with oral methadone developed serious side effects. Three patients, treated with epidural methadone (0.09%), developed a clinically significant respiratory depression. In all three cases, epidural pump failure or pump misprogramming resulted in methadone overdose. None of the children or adults treated with methadone developed addiction during hospitalization. CONCLUSION: Based on its analgesic properties and marked safety profile, we suggest that methadone could be added to the analgesic armamentarium of in-hospital health-care providers. Moreover, methadone could serve as the opioid of first choice in some in-patient populations.

Administration, Oral↗
PubMed2001

Acute mastoiditis--the antibiotic era: a multicenter study.

OBJECTIVES: To evaluate the clinical course and identify the causative organisms of acute mastoiditis in a community where most of the patients who develop acute otitis media are treated with antibiotics. METHODS: A multicenter retrospective review of a series of 223 consecutive cases of acute mastoiditis. SETTING: Nine secondary or tertiary academic or non-academic referral centers. RESULTS: Prior to the diagnosis of acute mastoiditis, 121 of the patients (54.3%) had been receiving oral antibiotic treatment for acute otitis media for periods ranging from 1 to 21 days (mean 5.3 days). Samples for bacterial culture were obtained from 152 patients. Cultures were negative in 60 patients. The organisms isolated in the 92 positive cultures were: Streptococcus pneumoniae (15 patients), Streptococcus pyogenes (14 patients), Staphylococcus aureus (13 patients), Staphylococcus coagulase negative (three patients), Pseudomonas aeruginosa (eight patients), Haemophilus influenzae (four patients), Proteus mirabilis (two patients), Escherichia coli (two patients), Klebsiella pneumoniae (one patient), Enterobacter (one patient), Acinetobacter (one patient), anaerobic gram-negative bacilli (one patient), and fungi (two patients). Ten patients had mixed flora. Sixteen patients presented with complications (cerebellar abscess, perisinus empyema, subdural abscess or empyema, extradural abscess, cavernous sinus thrombosis, lateral sinus thrombosis, bacterial meningitis, labyrinthitis, petrositis, or facial nerve palsy). CONCLUSIONS: Antibiotic treatment cannot be considered an absolute safeguard against the development of acute mastoiditis. Early myringotomy for acute otitis media seems to decrease the incidence of complications. The distribution of causative organisms in acute mastoiditis differs from that in acute otitis media. Intracranial complications in acute mastoiditis are not rare. Because of the diversity of causative organisms in acute mastoiditis and the growing resistance of bacteria to the various antibiotics, all means to obtain a sample for culture prior to antibiotic treatment, including general anesthesia.

Acute Disease↗
PubMed2001

The purification and characterization of an 88-kDa Porphyromonas endodontalis 35406 protease.

A Porphyromonas endodontalis ATCC 35406 protease was purified from Triton X-114 cell extracts by preparative SDS-PAGE followed by electroelution. The purified enzyme exhibits a molecular size of 88 kDa and was dissociated into two polypeptides of 43 and 41 kDa upon heating in the presence of sodium dodecyl sulfate with or without a reducing agent. The protease (pH optimum 7.5-8.0) degraded the extracellular matrix proteins fibrinogen and fibronectin. Collagen IV was also degraded at 37 degrees C but not at 28 degrees C. The protease also cleaved the bioactive peptide angiotensin at amino acid residue phenylalanine-8 and tyrosine-4 but failed to hydrolyze bradykinin, vasopressin and synthetic chromogenic substrates with phenylalanine or tyrosine at the P1 position. In addition, two peptidases were detected in P. endodontalis cells: a proline aminopeptidase that remained associated with the cell pellet after detergent extraction and peptidase/s that partitioned into the Triton X-114 phase after phase separation and degraded the bioactive peptides bradykinin and vasopressin. These P. endodontalis peptidases and proteases may play an important role in both the nutrition and pathogenicity of these assacharolytic microorganisms. The inactivation of bioactive peptides and degradation of extracellular matrix proteins by bacterial enzymes may contribute to the damage of host tissues accompanied with endodontic infections.

Aminopeptidases↗
PubMed2001

Circadian rhythms and circadian rhythm disorders in children and adolescents.

A clinically applicable review of circadian rhythm physiology is presented, including a detailed examination of the interaction of circadian and homeostatic systems and the maturation of the circadian system from preconception through adolescence. Emphasis is placed on the clinical evaluation gathering information through the history, sleep log, and if necessary, actigraphy and polysomnography. Circadian disorders, including advanced sleep phase syndrome, circadian disorders seen in blind children, delayed sleep phase syndrome, and non-24-hour sleep phase are described. Case descriptions of each are provided. Treatment and interventions for these disorders are described, including the importance of education, light therapy, sleep-wake schedule adjustments, and the occasional use of medications, such as sedative hypnotics and melatonin.

Adolescent↗
PubMed2001

Role of repeated F-18 fluorodeoxyglucose imaging in management of patients with bone and soft tissue sarcoma.

AIM OF THE STUDY: To assess the impact of repeated F-18 FDG studies on the management of patients with bone and soft tissue (B&S) sarcomas. MATERIAL AND METHODS: Twenty patients with B&S tissue tumors (11 M and 9 F age 17-72 years) had 52 F-18 FDG Dual Head Coincidence Imaging (DHCI) studies. 7 patients were followed for 6 months to 2 years clinically after removal of the primary tumor. Thirteen patients were evaluated for suspected recurrences. Patient's preparation, F-18 FDG injection and imaging procedure were done according to department protocol. Attenuation corrected images were interpreted visually by 3 trained physicians. Tumor to background ratios were calculated for all lesions. RESULTS: In 13 patients having both studies, baseline FDG and CT/MRI were concordant in 8 patients, FDG detected more lesions in 3 patients but it did not detect 4 metastatic pulmonary nodules in 2 patients. Follow up studies showed stable disease in 10 patients while 6 patients who showed worsening disease needed to change their chemotherapy. Surgery was avoided in 2 patients and 2 patients showed improved response. CONCLUSION: Repeated F-18 FDG DHCI examinations proved to have an impact on the clinical management of patients with malignant bone and soft tissue sarcoma. It helps to differentiate postoperative changes from local recurrence.

Adolescent↗
PubMed2000

Comparison of the incidence of cholesteatoma surgery before and after using ventilation tubes for secretory otitis media.

Inserting ventilation tubes has become, probably, the most common surgical operation performed on children in the free world. In our study, we attempted to examine whether the widely used procedure of inserting ventilation tubes in children with secretory otitis media is indeed justified in the long term. For this purpose, we have studied the influence of the procedure on the formation of cholesteatoma by comparing the incidence of cholesteatoma surgery before and after using ventilation tubes in our department. The data were divided into two periods. The first period included the number of operations in the 10 years (1961-1970) before ventilation tubes were used as a routine treatment for secretory otitis media in our department. The second period included the number of operations in the last 10 years (1989-1998) following the usage of ventilation tubes over 30 years. We found that the number of cholesteatoma operations has decreased, from 413 operations in the 10 years before ventilation tubes were used to 228 operations over the last 10 years. The number of operations per 10000 of the entire population has decreased from 20 operations to 6.6 operations after using ventilation tubes (P=0.0000001). We have shown that the incidence of surgery for cholesteatoma has been declining. Having analyzed the options that might cause this decline, we believe that using ventilation tubes in secretory otitis media might help to reduce the incidence of cholesteatoma surgery in the long term.

Adolescent↗
PubMed2000

Recurrent gastrointestinal stromal sarcomas.

Gastrointestinal stromal sarcomas, formerly categorized as leiomyosarcomas of gastrointestinal origin, have a common pattern of intraperitoneal dissemination. Despite surgical resection with or without adjuvant systemic chemotherapy the vast majority of these patients succumb to intraperitoneal sarcomatosis and/or hepatic metastases. In an attempt to improve upon the morbidity and mortality associated with this disease we and several other centers have begun treating these patients with intraperitoneal chemotherapy. We have found that aggressive surgical resection with postoperative intraperitoneal chemotherapy has significantly lowered the peritoneal recurrence rate in patients with recurrent gastrointestinal stromal sarcomas as compared to those who have undergone surgical resection alone. However, this treatment approach has proven to be ineffective in preventing hepatic metastases, and thus has had little effect upon overall survival. With the treatment of primary rather than recurrent disease we hope to interrupt the disease process at an earlier stage further decreasing peritoneal recurrences and potentially improving survival.

Antineoplastic Agents↗
PubMed2000

Attenuation-Correction Induced Artifact in F-18 FDG PET Imaging Following Total Knee Replacement.

Purpose: The clinical use of PET FDG in the work-up of patients with bone and soft tissue malignant tumors is rapidly increasing. The recognition of any source of artifact, therefore, is important to avoid interpretation pitfalls.Procedures: Two patients with complete knee joint replacement by metallic prosthesis in the course of their treatment for malignant bone and soft tissue sarcoma were evaluated by PET F-18 FDG imaging using a dual head coincidence gamma camera.Results: Both studies demonstrated in the attenuation-corrected images intense increase activity at the joint space between the metallic prosthetic surfaces at the level of the knee joint. No uptake, however, was noted in the same location on the non-attenuation-corrected images. Subsequent bone and thallium-201 scans confirmed the absence of tumor recurrence in the first patient. The second patient had multiple follow up F-18 FDG scans over a period of 16 months that show no changes from the baseline study.Conclusion: In the F-18 FDG PET images of patients with total knee metallic prosthesis, an intense activity tends to be seen in the joint space, only in the attenuation-corrected images. Such pattern of uptake is considered artifactual and should always be verified in the non-attenuated images.

Journal Article↗
PubMed2000

Duration of antibacterial effectiveness of gentamicin ear drops in external otitis.

The recommendation of Anderson and Steele, for the use of ear drops four times a day, has not been changed since 1948. In order to re-evaluate the frequency of using ear drops, we examined the duration of the effectiveness of the antibacterial activity of gentamicin ear drops in external otitis. Seventeen patients (25 ears) with external otitis were studied. We took 18 samples from each ear at 0, 1, 2, 3, 6, 8, 10, 12 and 14 hours and measured the concentration of gentamicin on the wick and in the ear canal. We found that the concentration of gentamicin began to decrease only after 12 hours and a more significant decrease was detected after 14 hours of treatment. We have shown that the antibiotic used on the wick is effective for 12 hours. In conclusion, we recommend using ear drops twice a day on a wick as routine therapy for external otitis.

Anti-Bacterial Agents↗
PubMed2000

Isolated extramedullary plasmacytoma of the true vocal fold.

We report a rare case of isolated extramedullary plasmacytoma (EMP) of the right true vocal fold in a 38-year-old male with a one-year history of hoarseness. Immunohistochemical staining of plasma cells in the tumour, showed over 90 per cent of them to be positive for kappa light chains. After two attempts at local surgical excision and recurrence within 10 months, the tumour was irradiated. Only seven reported cases of isolated EMP of the true vocal fold are reported in the literature. The therapeutic options are discussed.

Adult↗
PubMed2000

Contaminant dispersion in the vicinity of a worker in a uniform velocity field.

The transportation of gaseous contaminant from a low and moderate low impulse (momentum<1 m s(-1)) source to the breathing zone was studied in a uniform air stream flow. Results of the effects of the direction and the velocity of principal air flow, convection due to a human body, arm movement of a human being and the type of source on the concentration profiles are presented. Three important results were obtained. Firstly, for a given low and moderate impulse low impulse contaminant source in the near field of a worker, his/her orientation relative to the principal air flow direction is the most important factor in reducing occupational exposure, with an air velocity of about 0.3 m s(-1). Secondly, the effect of convection resulting from body heat on air flow was lower than expected. Thirdly, arm movements influence contaminant dispersion, and should be included when models assessing exposure are developed. The present data can also be used to validate existing computational fluid dynamic (CFD) models.

Air Movements↗