Biomedical subjects

Rachel Simmons

Publications and source records attributed to Rachel Simmons.

8 recordsLinked to original sources

PubMed2006

Are one or two dangerous? Phenothiazine exposure in toddlers.

Traditionally, pediatric phenothiazine exposures are considered dangerous even at low doses. The actual risk of exposure to 1-2 tablets is unclear. In an attempt to determine this risk, the authors performed a literature search, review of the American Association of Poison Control Center data, and evaluation of related resources (e.g., textbooks, bibliographies of relevant papers). This review reveals only sparse data from case reports regarding morbidity and mortality in the pediatric population despite years of clinical experience. Serious toxicity from exposure to low doses is rare and nearly always the result of chlorpromazine ingestion. Although the risk to the toddler ingesting 1-2 tablets seems to be extremely low, several factors should be considered when determining the need for triage to a health care facility.

Administration, Oral↗

PubMed2005

Conservative and surgical approaches to the treatment of overactive bladder.

Overactive bladder is a prevalent and often distressing condition that has a significant negative effect on the quality of life of those affected. It contributes to the huge burden of incontinence on NHS resources. Effective treatment is available; however, most patients will never admit their problems, seek advice or be identified.

Adult↗

PubMed2004

Renal vein or inferior vena caval extension in patients with renal cortical tumors: impact of tumor histology.

PURPOSE: We determined the prognostic significance of renal vein or inferior vena caval (IVC) extension in patients with nonmetastatic renal cell carcinoma (RCC) or oncocytoma undergoing surgery. MATERIALS AND METHODS: The charts of patients undergoing radical or partial nephrectomy from 1989 to 2001 for nonmetastatic RCC or oncocytoma were retrospectively reviewed. A total of 1082 patients (1120 renal units) underwent radical (850 renal units) or partial (270 renal units) nephrectomy. RESULTS: Renal vein extension was present in 60 patients (65.9%) and IVC extension was present in 31 (34.1%). The histological type associated with an increased risk of renal vein/IVC extension was conventional (80 of 702 cases, p <0.0001) and histological types with a decreased risk were oncocytoma (0 of 117, p = 0.00052) and papillary histology (0 of 146, p <0.0001). The 5-year actuarial recurrence-free probability was 59%, 65% and 91% in patients with IVC extension, renal vein extension and no renal vein or IVC extension, respectively. Larger tumor size, nodal metastases and conventional histology were associated with an increased risk of recurrence (RR = 3.38, 95% CI 2.53 to 4.51 for a doubling in size, RR = 9.97, 95% CI 5.51 to 18.1 and RR 3.78, 95% CI 2.15 to 6.65) as well as death (RR = 1.44, 95% CI 1.20 to 1.74 for a doubling in size, RR = 5.39, 95% CI 2.86 to 10.2 and RR = 1.56, 95% CI 1.09 to 2.24, respectively). CONCLUSIONS: Conventional RCC is associated with an increased risk, and oncocytoma and papillary histology are associated with a decreased risk of renal vein or IVC extension. Renal vein or IVC extension alone does not impart a worse prognosis independent of tumor size, nodal status and histology.

Adenoma, Oxyphilic↗

PubMed2004

Can antiretroviral therapy ever be stopped? An update.

Eradication of virus is not a reasonable goal of anti-HIV therapy because of the latent reservoir of HIV-1 in resting memory CD4+ T cells, which guarantees lifetime persistence of virus. Any drug-resistant viruses that arise and circulate for significant periods can be stored in the reservoir, limiting future treatment options, and mistakes in treatment can be "remembered" by the virus. Wild-type virus is also preserved in the reservoir and can reemerge if therapy is stopped. Since wild-type virus can be more virulent, suppression of this virus is one benefit of continuing therapy in patients who are experiencing treatment failure. If therapy is stopped, the reemergence of wild-type virus does not mean that drug-resistant virus is gone; it is still preserved in the latent reservoir. In patients who have viral suppression to below 50 copies/mL, there is still a low level of virus in the plasma, but it does not appear to be evolving. Thus, in principle, lifelong control of viral replication is possible if suppression of viremia to below 50 copies/mL is maintained.

Anti-Retroviral Agents↗

PubMed2003

Long-term follow-up of bilateral sporadic renal tumors.

OBJECTIVES: To assess the clinical characteristics, pathology, and long-term follow-up of patients with bilateral nonfamilial renal tumors (BNFRTs). METHODS: Patients with BNFRTs and unilateral tumors were identified from a prospective surgery database. The Mann-Whitney U test, Cox proportional hazards regression analysis, and the log-rank test were used to compare groups. RESULTS: From a database of 1082 patients with nonmetastatic renal tumors, 46 were identified with BNFRTs (4.25%). Thirty-three had synchronous tumors and 13 had asynchronous tumors. The median patient age of BNFRT patients was 61 years. Of the 92 renal tumors in these 46 patients, 42% were managed with radical nephrectomy (RN) and 58% with partial nephrectomy (PN); 7 underwent bilateral PN. The tumors were conventional clear cell carcinoma in 66% (n = 61), papillary carcinoma in 14% (n = 13), and the remaining 20% were of varied histologic origin. A 76.2% concordance was noted between the histologic subtypes of the two renal tumors in each patient. Median follow-up was 74 months. Thirty-three patients (72%) were disease-free and 7 patients had recurrence (2 local, 5 metastatic). Compared with patients having unilateral disease, BNFRT patients had an equivalent disease-free survival (DFS) (bilateral: 3-year DFS 90%, 5-year DFS 83%; unilateral: 3-year DFS 92%, 5-year DFS 82% [P = 0.449]). No difference in DFS was observed between synchronous and asynchronous tumors. CONCLUSIONS: BNFRTs were present in 4.25% of patients with sporadic renal tumors. Conventional clear cell histology was the most common histologic subtype; concordance among tumors was found to be 76%. DFS rates comparable to those of unilateral tumors can be obtained by using combinations of PN and RN.

Brain Neoplasms↗

PubMed2002

Partial nephrectomy: the rationale for expanding the indications.

BACKGROUND: We report preliminary results of partial nephrectomy for renal tumors of > or =4 cm in 39 patients with the intent of extending the indications for kidney-sparing surgery. METHODS: From July 1989 to October 2001, 39 patients underwent a partial nephrectomy for renal cortical tumors >4 cm in maximum diameter. Fourteen (36%) had the procedure performed for essential reasons, and 25 (64%) had an elective kidney-sparing operation. We evaluated tumor location and histology, perioperative renal function, and postoperative complications. RESULTS: There were 20 conventional clear-cell (51%), 13 papillary (33%), 4 chromophobe (10%), and 3 oncocytomas (8%) with a median tumor size of 5 cm. After a median follow-up of 13 months, 36 patients had no evidence of disease, 1 patient had died as a result of other causes, and 2 patients who had essential operations were alive with disease. Twenty-three patients (70%) maintained normal postoperative renal function. Of six patients with moderate preoperative renal dysfunction, five (83%) had no change in postoperative renal function and only one patient required short-term dialysis. CONCLUSIONS: With careful patient selection, partial nephrectomy can be effectively used to treat patients with renal cortical tumors >4 cm in diameter. The benefits of this approach include the effective local tumor control while at the same time preserving maximum renal function.

Adult↗

PubMed2002

Natural history of chronic renal insufficiency after partial and radical nephrectomy.

OBJECTIVES: To compare the incidence of newly developed chronic renal insufficiency after partial nephrectomy (PN) and radical nephrectomy (RN). Elective PN for renal tumors is intended to preserve renal function; however, studies of transplant donors suggest normal renal function is also maintained after unilateral nephrectomy. METHODS: We retrospectively compared all patients undergoing PN or RN for renal tumors 4 cm or less in the presence of a normal contralateral kidney from 1989 to 2000. Creatinine failure was defined as a serum creatinine value greater than 2.0 mg/dL. Risk factors for renal insufficiency, including diabetes, hypertension, American Society of Anesthesiologists score, age, preoperative creatinine, and history of smoking tobacco, were compared between the two groups. We compared the two groups using the chi-square and Mann-Whitney U tests and the creatinine failure rates using the Kaplan-Meier method. RESULTS: One hundred seventy-three patients met the criteria for analysis after RN and 117 did so after PN (median follow-up 25 months). The 5-year freedom from recurrence rate was 96.4% and 98.6% for PN and RN, respectively (P >0.05). The mean preoperative serum creatinine was 1.0 mg/dL (range 0.4 to 1.4) and 0.98 (range 0.6 to 1.5) for RN and PN, respectively (P = 0.4, not significant). The incidence of risk factors for renal insufficiency did not differ between the two groups. The mean postoperative serum creatinine in the RN and PN groups was 1.5 mg/dL (range 0.8 to 3.8) and 1.0 mg/dL (range 0.5 to 1.9), respectively (P <0.001). The chance of creatinine failure over time was significantly greater in the RN group (P = 0.008). CONCLUSIONS: When controlled for preoperative risk factors for renal insufficiency, patients undergoing RN are at a greater risk of chronic renal insufficiency than a similar cohort of patients undergoing PN.

Adult↗

PubMed2002

Partial nephrectomy for renal cortical tumors: pathologic findings and impact on outcome.

OBJECTIVES: To review the experience with partial nephrectomy for the diagnosis and treatment of renal cortical tumors at the Memorial Sloan-Kettering Cancer Center with a particular focus on the histologic findings at the time of surgery. METHODS: The results of 292 consecutive partial nephrectomies were reviewed. Demographic data, perioperative complications, and disease status were recorded. The specimens were reviewed for histologic subtyping in accordance with the Heidelberg classification for renal cortical tumors. The probabilities of recurrence and disease-specific death were assessed with the cumulative incidence estimate. RESULTS: The median follow-up was 25.3 months (range 1 to 155). A total of 246 patients (87%) were diagnosed with a renal cortical tumor, 1 patient (less than 1%) was diagnosed with another cancer, and 34 (12%) were diagnosed with benign lesions. The most frequent histologic finding among the renal cortical tumor subgroup was conventional clear cell carcinoma in 148 cases (51%), followed by papillary carcinoma in 54 (18%), oncocytoma in 32 (11%), and chromophobe carcinoma in 21 (7%). Bilateral disease and multifocality were most prevalent in the conventional and papillary subtypes, respectively. The 5-year probability of recurrence and disease-specific death was 12% and 8%, respectively, for the conventional clear cell type. No local or distant disease recurrence was observed in any other renal cortical tumor subtypes. CONCLUSIONS: Partial nephrectomy should be considered a diagnostic and therapeutic surgical approach for renal cortical masses. Conventional clear cell carcinoma is the most frequent histologic subtype and is associated with a less favorable outcome compared with papillary carcinoma and chromophobe carcinoma. Radical nephrectomy for renal lesions that could be removed by partial nephrectomy will risk renal impairment in a substantial proportion of patients with benign disease.

Adult↗