Search PubMed⌕ Search

Biomedical subjects

R Greenberg

Publications and source records attributed to R Greenberg.

At least 37 records · Page 2Linked to original sources
PubMed2000

Therapeutic drug monitoring of once daily gentamicin in serum and saliva of children.

UNLABELLED: Gentamicin is widely used in paediatric medicine and therapeutic monitoring is mandatory due to the narrow margin of safety. Saliva sampling may be of potential interest, especially in children in whom blood sampling is often difficult. Experience with once daily intravenous administration of aminoglycosides has grown in recent years. Gentamicin levels were measured in serum and saliva of 55 children treated with the drug (5 mg/kg per day), administered intravenously in three different regimens: thrice (n = 19), twice (n = 18), and once daily (n = 18). No correlation was found between serum gentamicin concentrations and saliva levels when the drug was administered twice or thrice daily, however, there was good correlation when the drug was administered once daily (r2 = 0.96, P < 0.0001). CONCLUSION: In children with uncomplicated infections treated with once daily gentamicin, trough concentrations of the drug can be monitored in saliva.

Child↗
PubMed2000

Endovascular repair of descending thoracic aortic aneurysms: an early experience with intermediate-term follow-up.

PURPOSE: The purpose of this study was to report an initial experience with the endovascular repair of descending thoracic aortic aneurysm. Complications and intermediate-term morphologic changes were identified with the intent of altering patient selection and device design. METHODS: Endografts were placed into 25 patients at high-risk for conventional surgical repair over a 3(1/2)-year period. Devices were customized on the basis of preoperative imaging information. Follow-up computed tomography scans were obtained at 1, 3, 6, and 12 months and yearly thereafter. Additional interventions occurred in the setting of endoleaks, migration, and aneurysm growth. RESULTS: The overall 30-day mortality rate was 20% (12.5% for elective cases; 33% for emergent cases). There were 3 conversions to open repair. Neurologic deficits developed in 3 patients; 1 insult resulted in permanent paraplegia. Neurologic deficits were associated with longer endografts (P =.019). Three endoleaks required treatment, and 1 fatal rupture of the thoracic aneurysm treated occurred 6 months after the initial repair. Migrations were detected in 4 patients. The maximal aneurysm size decreased yearly by 9.15% (P =.01) or by 13.5% (P =.0005) if patients with endoleaks (n = 3 patients) were excluded. Both the proximal and distal neck dilated slightly over the course of follow-up (P =.019 and P =.001, respectively). The length of the proximal neck was a significant predictor of the risk for endoleakage (P =.02). CONCLUSION: The treatment of descending thoracic aortic aneurysms with an endovascular approach is feasible and may, in some patients, offer the best means of therapy. Early complications were primarily related to device design and patient selection. All aneurysms without endoleaks decreased in size after treatment. Late complications were associated with changing aneurysm morphologic features and device migration. The morphologic changes remain somewhat unpredictable; however, alterations in device design may result in improved fixation and more durable aneurysm exclusion.

Aged↗
PubMed2000

Endovascular grafting in patients with short proximal necks: an analysis of short-term results.

OBJECTIVES: To evaluate the safety of endovascular graft placement in patients with short proximal aneurysm necks, and assess factors contributing to endoleak formation. METHODS: 55 patients were enrolled over a two year period from five centers following the placement of a Talent endograft with a suprarenal stent. Preoperative and 30-day post-implant CT scans were retrospectively analyzed in a blinded fashion by two physicians. Aortic measurements were obtained, the amount of thrombus was subjectively graded, and any extravasation of contrast into the aneurysm sac defined an endoleak. The data were analyzed using a t-test. Analyses compared patients with proximal necks<10mm (SN), n=13) to those with longer necks (LN, n=42), and then contrasted patients with endoleaks (n=12), to those without (n=43). RESULTS: Endoleak rates were identical in the SN and LN groups (21 and 23%). Maximal aneurysm size was larger in the SN group (63 vs 56 mm, P<0.05). Endoleaks were more frequently noted in larger aneurysms (P<0.05), but not related to SN (P=0.6). There was no correlation between endoleaks and the amount of thrombus, aneurysm length, proximal neck diameter or other morphologic characteristics. One of 12 endoleaks resulted from a problem with proximal fixation, nine were due to perfusing vessels, and two were undefined. The proximal neck diameter increased (0.9 mm) over the 30 days (P<0.005). CONCLUSIONS: Short-term proximal fixation can be achieved in proximal necks measuring less than 10mm. The narrow margin of acceptable seal mandates careful follow-up. Larger aneurysms were associated with an increased incidence of endoleaks. SNs were associated with larger aneurysms, but not with an increased incidence of endoleaks. Proximal neck dilation was noted, but likely relates to the placement of an oversized endograft during this brief period of observation.

Aortic Aneurysm, Abdominal↗
PubMed2000

First trimester exposure to cefuroxime: a prospective cohort study.

AIMS: There are no published studies on the safety of cefuroxime use during pregnancy. We therefore investigated prospectively the possible teratogenic effect of intrauterine exposure to cefuroxime. METHODS: One hundred and six women who received cefuroxime during the first trimester of pregnancy were recruited from three teratogen information centres in Israel. Exposed women were paired for age, smoking habits and alcohol consumption with references being exposed to nonteratogenic antibiotics administered for the same indications. RESULTS: Maternal history, birthweight, gestational age at delivery, rates of live births, spontaneous abortions and fetal distress were comparable among the two groups. Rates of major malformations in the cefuroxime group (3.2%) did not differ from references (2%) (P = 0. 61, relative risk = 1.56, 95% confidence interval 0.27-9.15). There was a significantly higher rate of induced abortions among the cefuroxime exposed women as compared to the references (P = 0.04, relative risk = 3.33, 95% confidence interval 0.94-11.77). CONCLUSIONS: Our data may suggest that exposure to cefuroxime during the first trimester is probably not associated with an increased risk for malformations or spontaneous abortions; however, in light of the small sample size and the broad confidence limits, larger studies are needed to confirm these findings.

Abnormalities, Drug-Induced↗
PubMed2000

The effects of somatostatin and octreotide on experimental and human acute pancreatitis.

The role of somatostatin and octreotide for AP has been studied for two decades, yet the data still remain inconclusive. The inconsistencies of the results of experimental studies and clinical trials may stem from the fact that the optimal therapeutic modality has not been determined. Furthermore, although they are similar in structure and physiologic activities, the mechanisms of action and effects of somatostatin and octreotide in AP may be different. Because the data are sparse, most reports, primarily those in the English literature, on the efficacy of somatostatin and octreotide in the management of AP were reviewed. Included are both nonrandomized and prospective, double-blind, clinical trials and studies on the effects of these agents on various experimental models of the disease. The results of the studies on somatostatin and octreotide are presented and discussed separately, with specific reference to the experimental and treatment details. The main focus of the review is the effect of subcutaneous and intravenous administration of octreotide. Analysis of the data suggests that somatostatin could not be recommended for AP and that the efficacy of subcutaneous administration of octreotide is also questionable. Theoretically, intravenous octreotide may be more appropriate for this condition, but recent results with this therapeutic method are limited and contradictory. Studies that would delineate the optimal therapeutical modality and the patient population most likely to respond to the treatment are prerequisite for large-scale clinical trials on the effects of octreotide on human pancreatitis.

Acute Disease↗
PubMed2000

Eversion endarterectomy of the carotid artery: technical considerations and recurrent stenoses.

PURPOSE: The purpose of this study was to examine the characteristics of residual and recurrent lesions after eversion endarterectomy of the carotid artery (E-CE) and compare these results with those following endarterectomy and patch closure (CE-P). METHODS: We reviewed 274 patients who underwent carotid endarterectomy in 1998 with electroencephalographic monitoring, general anesthesia, completion duplex scan, and 1-year follow-up. CE-P was preferred for patients who required temporary shunting. In the E-CE group an additional proximal 2-cm arteriotomy was made in the common carotid artery (CCA) in 79 patients, a longer arteriotomy was made for extensive involvement of the CCA in 14 patients, and the internal carotid artery was advanced proximally as a patch for the CCA arteriotomy closure in 14 patients. Stenoses of > 50% that were present at 1 month were considered residual, and those of > 50% that were present at 1 year but not at 1 month were considered recurrent. RESULTS: There were five (1.8%) postoperative strokes (four after CE-P and one after E-CE, P = not significant). At 30 days there were 28 patients (10.2%) with residual stenoses > 50% (11 patients [10.2%] in the E-CE group and 17 patients [10.1%] in the CE-P group; P = not significant). The incidence of recurrent lesions of more than 50% was similar (4.6% for E-CE vs 4.7% for CE-P). CONCLUSION: The pattern of residual lesions and recurrent stenoses differs with each technique of endarterectomy. Proximal stenoses are more common after E-CE, and distal stenoses are more common after CE-P at both 1 month and 1 year. The frequency of proximal lesions is reduced in E-CE when either the internal carotid artery is advanced proximally onto the CCA or a long CCA arteriotomy is made. Distal recurrences do not seem to be a problem after eversion endarterectomy.

Angiography↗
PubMed2000

Abdominal recovery after laparotomy and omental transposition into a grossly contaminated median sternotomy wound.

Grossly contaminated median sternotomy wounds are frequently treated with transposed omental flaps. A laparotomy adjacent to such an infected wound carries the risk of peritonitis. It has been suggested that this risk may increase when the omentum, which has anti-infective properties, is removed from the abdominal cavity and is transposed to the chest. The authors evaluated abdominal recovery after laparotomy and omental transposition into an adjacent, grossly contaminated median sternotomy wound. The study group included 15 patients who had sternal wound reconstruction with an omental flap between 1990 and 1998. All patients underwent median sternotomy reconstruction according to a "two-compartment" operative sequence protocol, which included division of the surgical field into an upper (thoracic) contaminated zone and a lower (abdominal) clean zone. The control group was comprised of 15 patients who underwent elective laparotomy for splenectomy during the same time period. The effect of the surgical procedure on the abdomen was compared between the two groups. The timing of the reappearance of peristalsis and regular bowel function, and the incidence of bowel obstruction and postoperative peritonitis were similar in the two groups. The findings indicate that laparotomy and omental transposition in the presence of a grossly contaminated median sternotomy wound is a safe procedure, and is associated with a low rate of abdominal complications.

Aged↗
PubMed2000

False-high blood salicylate levels in neonates with hyperbilirubinemia.

Drug assays may yield false-positive results caused by cross-reacting compounds. After finding a serum salicylate concentration of 81 microg/mL by using Trinder's colorimetric method, in a comatose child admitted to the authors' pediatric intensive care unit, in the absence of reported salicylate intake, the authors aimed to compare this situation with the phenomenon involving endogenous digoxin-like substances, which cross-react with the routine assay of digoxin. None of the participants in the study had been exposed to salicylate. Salicylate concentration was measured in all patients using Trinder's colorimetric method and in the second stage of the study also by AxSYM salicylate assay. Salicylate concentration using Trinder's method was 18 +/- 25 (4-81) microg/mL among nine seriously ill children in the pediatric intensive care unit, of whom two children with extensive burns had salicylate levels of 30 and 81 microg/mL, respectively. Salicylate concentrations were 107 +/- 24 (45-143) microg/mL and 60 +/- 25 (28-92) microg/mL, among 18 premature newborns and 18 term newborns, with hyperbilirubinemia, respectively. In the second stage, which involved 22 jaundiced term newborns and cord blood from 21 pregnant women, Trinder's method yielded elevated salicylate blood levels among the hyperbilirubinemic infants: 82 +/- 5 (73-89) microg/mL; however, the AxSYM assay yielded significantly lower blood levels: 2.5 +/- 3.4 (0-10.9) microg/mL (P < 0.0001). Among the pregnant women, salicylate cord blood levels were found to be low-within the limit error of the assay with both assay methods. In conclusion, when salicylate intoxication is suspected, particularly during the neonatal period, it is advisable to measure salicylate levels by immunoassay technology.

Adult↗
PubMed2000

Return visits to the emergency room after minor trauma from motor vehicle accidents.

Most patients with minor trauma following motor vehicle accidents (MVAs) are discharged from the emergency room (ER) of a trauma centre after evaluation and observation. Some return with similar or additional symptoms. This study aimed to determine which patients returned, if any injuries had been missed, and what should be the policy of medical management. We reviewed the records of 8836 patients with minor trauma following MVAs who were examined in an inner city trauma centre during 1997. When the group of patients who returned to the emergency room (n = 160) was compared with the whole post-MVA minor trauma group, the former was found to have more males (75.6% vs. 55.9%), younger age (36.31 years vs. 39.72 years), more motorcyclists than drivers, passengers and pedestrians ( p < 0.002, for the three variables), and had more multi-site injures. During the return visits the patients stayed longer in the emergency room, were examined by more consultants and had repeated radiological evaluations and tests, compared with the initial visit. However, in none of the patients was the initial diagnosis revised nor were additional injuries found and consequently the initial management was not changed in any of them. It is concluded that the initial thorough evaluation by the primary traumatologist is adequate for MVA patients with minor trauma. These patients do not require any follow up in specialized clinics, and are best managed in the community by their general practitioners.

Accidents, Traffic↗
PubMed2000

Avoiding common pitfalls in qualitative data collection and transcription.

The subjective nature of qualitative research necessitates scrupulous scientific methods to ensure valid results. Although qualitative methods such as grounded theory, phenomenology, and ethnography yield rich data, consumers of research need to be able to trust the findings reported in such studies. Researchers are responsible for establishing the trustworthiness of qualitative research through a variety of ways. Specific challenges faced in the field can seriously threaten the dependability of the data. However, by minimizing potential errors that can occur when doing fieldwork, researchers can increase the trustworthiness of the study. The purpose of this article is to present three of the pitfalls that can occur in qualitative research during data collection and transcription: equipment failure, environmental hazards, and transcription errors. Specific strategies to minimize the risk for avoidable errors will be discussed.

Data Collection↗
PubMed2000

Talismans and amulets in the Pediatric Intensive Care Unit: legendary powers in contemporary medicine.

BACKGROUND: For centuries talismans and amulets have been used in many cultures for their legendary healing powers. METHODS: We asked the parents of every child (Jews and Arabs) admitted to the Pediatric Intensive Care Unit over a 2 month period to complete a questionnaire, which included demographic data on the patient and the family, the use of talismans or other folk medicine practices, and the perception of the effects of these practices on the patient's well-being. A different questionnaire was completed by the ICU staff members on their attitude toward the use of amulets. RESULTS: Thirty percent of the families used amulets and talismans in the ICU, irrespective of the socioeconomic status of the family or the severity of the patient's illness. Amulets and talismans were used significantly more by religious Jews, by families with a higher parental educational level, and where the hospitalized child was very young. The estimated frequency of amulet use by the children's families, as perceived by the staff, was significantly higher than actual use reported by the parents. In Jewish families the actual use of amulets was found to be 30% compared to the 60% rate estimated by the medical staff; while in Moslem families the actual use was zero compared to the staff's estimation of about 36%. Of the 19 staff members, 14 reported that the use of amulets seemed to reduce the parents' anxiety, while 2 claimed that amulet use sometimes interfered with the staff's ability to carry out medical treatment. CONCLUSIONS: The use of talismans in a technologically advanced western society is more frequent than may have been thought. Medical and paramedical personnel dealing with very ill patients should be aware of the emotional and psychological implications of such beliefs and practices on patients and their families.

Adolescent↗
PubMed2000

Photodynamic therapy of murine colon cancer and melanoma using systemic aminolevulinic acid as a photosensitizer.

BACKGROUND: Side effects of conventional photosensitizers, such as hematoporphyrins, are a limiting factor in the use of photodynamic therapy (PDT). We evaluated the effect of PDT on mice colon carcinoma and melanoma using systemic 5-aminolevulinic acid (ALA). METHODS IN VITRO STUDIES: CT26 colon carcinoma and B16 melanoma cells were incubated with ALA for 48 h. Subsequently, cells were subjected to photoradiation at 40, 60 and 100 J/cm2 and viability was assessed. In vivo studies: Balb/C mice were injected subcutaneously with 2x10(5) CT26 colon cancer cells and C57/Bl mice were injected subcutaneously with 2x10(5) melanoma cells. ALA 60 mg/kg was injected intra-peritoneally when tumors were visible. After 24 h mice were subjected to photoradiation (100 J/cm2). RESULTS IN VITRO STUDIES: There was a significant decrease in the viability of treated cells as compared with non-treated tumor cells and with treated splenocytes (p<0.001). In vivo studies: PDT induced necrosis of both tumors. PDT also significantly prolonged the survival of the treated mice (p<0.05). CONCLUSIONS: Photodynamic therapy using systemic ALA as a photosensitizer was effective in treating mice colon cancer and melanoma in both in-vitro and in-vivo studies. Further pre-clinical and clinical studies are being conducted now.

Aminolevulinic Acid↗
PubMed1999

Formation of cycloidal features on Europa.

Cycloidal patterns are widely distributed on the surface of Jupiter's moon Europa. Tensile cracks may have developed such a pattern in response to diurnal variations in tidal stress in Europa's outer ice shell. When the tensile strength of the ice is reached, a crack may occur. Propagating cracks would move across an ever-changing stress field, following a curving path to a place and time where the tensile stress was insufficient to continue the propagation. A few hours later, when the stress at the end of the crack again exceeded the strength, propagation would continue in a new direction. Thus, one arcuate segment of the cycloidal chain would be produced during each day on Europa. For this model to work, the tensile strength of Europa's ice crust must be less than 40 kilopascals, and there must be a thick fluid layer below the ice to allow sufficient tidal amplitude.

Extraterrestrial Environment↗
PubMed1999

Characterization of replication-competent adenovirus isolates from large-scale production of a recombinant adenoviral vector.

Replication-deficient adenoviral vectors have been developed for the delivery of DNA sequences encoding a variety of proteins intended for the management of disease through gene therapy. One concern is the occurrence of replication-competent adenovirus (RCA) in the population of replication-deficient adenoviral vectors as a result of recombination or contamination. To address this concern, it is necessary to determine the frequency of occurrence and to fully characterize the molecular structure and biological infectivity of RCA. rAd/p53 is a pIX-deleted p53 gene therapy vector that is designed to lower the RCA occurrence and to deliver the tumor suppressor gene p53 for treatment of various cancers. Multiple preparations of the replication-deficient adenoviral vector rAd/p53 were tested for the presence of RCA, employing a sensitive biological assay. Single plaques from RCA-positive preparations of rAd/p53 were isolated for molecular characterization. All of the RCA isolates displayed a single unique structure that contains the complete E1 sequence of adenovirus type 5 but lacks the p53 sequence. The detailed sequence analysis of the RCA suggests that it is most likely generated as a result of recombination events between the rAd/p53 DNA and the 293 host adenoviral sequence. Results from viral infectivity analysis by flow cytometry demonstrate no substantial difference in infectivity of RCA, rAd/p53, and wild-type adenovirus type 5 in 293 cells.

Adenovirus E1A Proteins↗
PubMed1999

Awareness of folic acid for neural tube defect prevention among Israeli women.

The failure of neural tube closure during early embryogenesis results in a range of neural tube defects (NTD), the most common of which is spina bifida. The role of folic acid in reducing the rate of NTD has been well-established. Three recent cases of infants with NTD inspired this investigative study into the level of awareness and knowledge of folic acid and its function in the prevention of NTD among Israeli women. Of 920 women interviewed, only 51 (5.5%) had heard of folic acid, and 27 (2.8%) were reported to have taken it. The source of information and the motivation for self-medication were also explored with regard to socioeconomic and health profile. Awareness of folic acid was significant among women aged 17-29 years (P = 0.005) and those aged 30-39 years (P = 0.009), and among semireligious and nonreligious women (P = 0.008 and 0.01, respectively). Among women who were aware of folic acid, only nonreligious women tended to take it. No correlation was found between folic acid intake and age, religiosity, nationality, number of pregnancies, and health status among women who were aware of folic acid intake. The poor level of awareness, evident in our study, demands that the medical community broadcast the benefit of folic acid. Furthermore, government health initiatives, such as the addition of folic acid to flour preparations, may effectively ensure its appropriate daily intake. These improved education and prevention programs may forcibly reduce the rate of NTD-affected pregnancies.

Adolescent↗