Biomedical subjects

G J Bowers

Publications and source records attributed to G J Bowers.

13 recordsLinked to original sources

PubMed1998

Trends in surgical treatment of breast cancer at an urban teaching hospital: a six-year review.

The treatment of breast cancer at an urban teaching hospital from 1990 to 1995 was analyzed according to age, stage, race, and funding status. Two hundred thirty-eight patients (mean age, 55 years) with newly diagnosed breast cancers were retrospectively identified and reviewed. A larger proportion of all funded patients (F; n = 131) presented with early-stage cancers (ductal carcinoma in situ, stage I) compared to nonfunded (NF, n = 107) (41 vs 25%; P = 0.03). Additionally, there was an increasing rate of early cancers occurring in F over the study interval (40% in 1990 to 69% in 1995), but there was no such increase in NF. There was an increasing trend in the overall use of breast conservation therapy (BCT) over this interval (11.6% of all cancers in 1990, 50.8% in 1994 and 1995). Although F were overall more likely to undergo BCT than NF (40% vs 29%, P = 0.04), there was no statistical difference in the use of BCT for nonadvanced (ductal carcinoma in situ, stage I and II) cancers (44% of F, 46% of NF). Age did not affect the overall use of BCT (36% of patients 55 or older, 35% younger than 55). Mean age was significantly greater in F than in NF (60 vs 49, P < 0.000001), but racial composition did not differ between these two groups. In conclusion, funded status of our patients corresponded with earlier diagnosis, perhaps due to better access to screening. Additionally, neither funding status nor age affected the use of BCT in our patients with nonadvanced cancers. Our rate of BCT far exceeds that seen nationally, perhaps reflecting a trend at academic institutions.

Black or African American↗

PubMed1994

Surgical limb perfusion for extremity melanoma.

For over 35 years, various centres throughout the world have surgically perfused extremities afflicted with various stages of melanoma. Throughout these years the true effectiveness of this invasive technique has remained controversial. Herein, an attempt has been made to critically survey this literature, with emphasis on reports from the past few years, to ascertain what role limb perfusion may play in the 1990s.

Antineoplastic Agents↗

PubMed1993

Nonpalpable breast lesions: association of mammographic abnormalities with diagnosis after needle-directed biopsy.

We reviewed the experience with needle-directed breast biopsies (NDBB) in a military medical center. In 195 patients, 207 NDBBs were done; 49 of these biopsies (24%) rendered a diagnosis of malignancy. The majority of patients (78%) had invasive cancer; 44% of them were found to have associated malignant axillary adenopathy. Mammographic indications were examined; 65% of the biopsies were done for microcalcifications with or without an associated mass/density. Approximately one third of these lesions harbored malignancy or high-risk hyperplasia. Discrete nodular densities had a low rate of malignancy (7%), while spiculated/stellate masses proved almost uniformly to be invasive cancer. NDBB should be considered in all women with mammographic abnormalities. The associated risk of malignancy may vary depending on the specific mammographic appearance of the lesion. Unfortunately, a significant number of women may have relatively advanced malignancy when first seen, despite having nonpalpable disease.

Aged↗

PubMed1991

Staging laparotomy in Hodgkin's lymphoma: 1979 to 1988.

A retrospective review of patients with Hodgkin's lymphoma undergoing staging laparotomy was done. Ninety-four patients were identified for analysis. Preoperative lymphangiography was performed in 86 patients, and computed tomography of the abdomen was performed in 53. Both proved to have an accuracy rate of 76%. Mortality and 30-day morbidity rates were 0% and 17%, respectively, when both major (8%) and minor (10%) complications were considered. Late complications (greater than 30 days) were noted in 5%. The results of the laparotomy required a change in staging in 28% of patients, with alterations in subsequent clinical management occurring in 18%. In selected patients, staging laparotomy is safe and remains a reliable means of determining the intra-abdominal extent of Hodgkin's lymphoma.

Adult↗

PubMed1990

Major hepatic resection in a residency training program.

Records of 30 major hepatic resections performed at David Grant USAF Medical Center and Wilford Hall USAF Medical Center were analyzed to assess the feasibility, safety, and resources required for such procedures in a general surgery residency training program. The mean intraoperative blood loss during surgery was 2022 mL and the mean intraoperative transfusion volume was 4.2 units of packed red blood cells. Patients spent an average of 2.7 days in the intensive care unit, with a mean overall postoperative stay of 15 days. One death occurred within 30 days of operation due to a postoperative myocardial infarction, and another death during the hospital stay was due to hepatic insufficiency and Candida endocarditis. Overall, five major postoperative complications occurred (17%), one requiring reoperation. All but one procedure was done by a closely supervised surgical resident. This experience compares favorably with others in the literature and supports the practice of hepatic resection as part of surgical training.

Adult↗

PubMed1990

Breast cancer: the military's experience at Wilford Hall USAF Medical Center.

We reviewed the experience with breast cancer at Wilford Hall USAF Medical Center for the years 1978 through 1988. A total of 868 cases were identified in the Wilford Hall Tumor Registry; overall 5-year and 10-year survivals were 63% and 39%, respectively. Infiltrating ductal carcinoma represented the principal histologic category. The other predominant variants included invasive lobular carcinoma, lobular carcinoma in situ, and ductal carcinoma in situ. Until recently, most of these patients (90%) had modified radical mastectomy as their definitive surgical therapy, with chemotherapy reserved primarily for patients with advanced disease.

Actuarial Analysis↗

PubMed1989

Glucan enhances survival in an intraabdominal infection model.

The immunomodulator glucan exists in two forms, particulate (glucan-P) and soluble (glucan-F). Both preparations of glucan, either alone or in combination with antibiotic therapy, were evaluated for their ability to augment survival in rats following cecal ligation and puncture (CL/P). Adult male rats were infused once daily for 5 consecutive days with either glucan-P (10 mg/kg), glucan-F (10 mg/kg), or 5% (w/v) dextrose in water. Three days later all rats underwent CL/P. Postoperatively, the rats received (a) no therapy, (b) saline (1 ml subcutaneously every 12 hr) or (c) ampicillin (33 mg/kg subcutaneously every 12 hr) for 7 days. Without any associated pre-or postoperative treatment, CL/P was associated with an 85% 7-day mortality. Neither glucan preparation alone significantly altered this mortality. Administering ampicillin postoperatively decreased the mortality to 53% (P less than 0.001 vs untreated controls). When postoperative ampicillin therapy was combined with preoperative glucan treatment, the mortality was reduced even further (26% for glucan-P, 21% for glucan-F; P less than 0.02 vs ampicillin-treated controls). We conclude from these results that (i) neither glucan preparation alone effectively enhances survival following CL/P when using the doses and administration schedule employed herein, (ii) both glucan-P and glucan-F do act synergistically with antibiotics to enhance survival in this rat model of polymicrobial sepsis, and (iii) in this particular model, nontoxic glucan-F is as efficacious as glucan-P.

Abdomen↗

PubMed1989

Response to Simko.

Explore the source record for details and available documents.

Esophageal Neoplasms↗

PubMed1988

Prograde versus retrograde endoscopic laser therapy for the treatment of malignant esophageal obstruction: a comparison of techniques.

The prograde and retrograde approaches to the treatment of malignant esophageal obstruction with the Nd:YAG, or neodymium: yttrium, aluminum, garnet, laser are compared. With the prograde technique, tumor destruction proceeds from the proximal to the distal tumor margin. In retrograde treatment, the endoscope is passed to the distal tumor margin so that the treatment can proceed in the reverse direction, thereby completing therapy in a single treatment session. This is usually accomplished by passage of a guide wire down the biopsy channel of the endoscope, tumor dilatation, and then passage of the endoscope over the guide wire to the distal tumor margin, where laser destruction is begun. Twenty nonrandomly selected patients with malignant esophageal obstruction were studied. The first ten patients were treated with the prograde technique, the next ten with the retrograde technique. The two groups were similar with respect to age, sex, and tumor histologies. Patients treated retrogradely had narrower pretreatment lumens (average 2.3 vs. 4.1 mm) as well as longer tumor lengths (average 8.9 vs. 4.8 cm). The posttreatment luminal diameters were similar for each group: 18.0 mm for prograde; 16.3 for retrograde. In the retrograde group, therapy was completed in fewer treatments (1.6 vs. 2.9) and over a shorter period of time (3.6 vs. 7.8 days), despite the longer tumor lengths. All patients in both groups were able to tolerate a regular diet at the completion of therapy. The complication rate was low in both groups. It is felt that the retrograde technique (single session therapy) is the preferred method because it allows more-rapid treatment without increased complications and thereby shortens hospital stay and reduces hospital costs.

Adenocarcinoma↗

PubMed1988

Palliative laser therapy of advanced esophageal carcinoma: an alternative perspective.

Endoscopic Nd:YAG laser therapy was used on 91 occasions in 26 consecutive unselected patients with advanced malignant obstruction of the esophagus. Patients were treated predominantly by the retrograde method after initial esophageal dilatation. Laser therapy was effective in restoring esophageal luminal patency. However, luminal patency did not guarantee restoration of adequate oral nutritional intake. Twenty-seven percent of patients required additional nutritional support. Twenty-six percent of procedures were complicated by significant events, predominantly cardiorespiratory. Six deaths occurred within 30 days of laser therapy. Mean survival from time of first laser therapy was 16 wk. We conclude that laser therapy of malignant esophageal obstruction provides effective palliation of dysphasia; however, in older patients with advanced disease, this therapy often results in complications, as do other methods of treatment for this condition.

Adenocarcinoma↗

PubMed1986

A comparative evaluation of particulate and soluble glucan in an endotoxin model.

Particulate glucan (P) but not soluble glucan (F) has been shown to sensitize rats to endotoxins. This phenomenon is believed to be mediated by the reticuloendothelial system (RES). The effect of glucan-P and -F on the RES, and the response of glucan-treated rats to nonlethal doses of endotoxin were investigated. Rats were injected for 5 days with 10 mg/kg of glucan-P, -F or saline. Three days later rats were either (1) injected with colloidal carbon for clearance studies, (2) sacrificed for organ histology and determination of serum glucose, plasma thromboxane (Tx) B2, and plasma 6-keto-prostaglandin (PG) F1 alpha concentrations, or (3) challenged with a nonlethal dose of endotoxin. The latter were further subdivided into groups for either 30-day survival or for sacrifice at 30 min or 4 h post-endotoxin infusion to obtain blood samples for glucose, TxB2, and 6-keto-PGE1 alpha determinations. Glucan-P induced hepatosplenomegaly and granulomatous changes within the liver and spleen. The carbon clearance halftime was markedly decreased in these animals. In glucan-P-treated rats challenged with endotoxin, elevated concentrations of both plasma prostanoids were observed as well as alterations in serum glucose levels. These changes were less pronounced in glucan-F- or saline- treated rats. Following endotoxin challenge, only 40% of glucan-P-treated rats survived 30 days whereas 100% of both the glucan-F and saline-treated rats survived. We conclude that glucan-P, in contrast to glucan-F, significantly heightens RES function and that this effect likely accounts for the endotoxin sensitivity.

Animals↗

PubMed1985

Prostanoid production by lipopolysaccharide-stimulated Kupffer cells.

Although some data suggest that macrophages in the reticuloendothelial system (RES) are important sources of thromboxane A2 (TxA2) and prostacyclin (PGI2) during endotoxic shock, we are unaware of data documenting the ability of hepatic macrophages (Kupffer cells) to release either TxA2 or PGI2 when exposed to lipopolysaccharide (endotoxin, LPS). In this study, Kupffer cells were examined for their ability to release prostaglandin E2 (PGE2), TxA2, and PGI2 following stimulation with 0, 1.0, 50.0, and 100.0 micrograms/ml of Escherichia coli LPS. Kupffer cells were obtained from rat livers by enzymatic digestion with 0.05% collagenase followed by enrichment of the macrophage population on the basis of differences in density and adherence among the various cell populations isolated. Based on several criteria (phagocytosis of opsonized sheep erythrocytes, positive staining for esterase and peroxidase, failure to replicate), 95% of adherent cells were Kupffer cells. After 4 days of incubation, cells were stimulated with various doses of LPS for 4 and 8 hr. Prostanoid concentrations in culture supernatants were determined by radioimmunoassay. Increasing doses of LPS significantly (P less than 0.001) increased the concentration of immunoreactive PGE2 (iPGE2) and iTxB2 (the stable metabolite of TxA2). The concentration of i6-keto-PFG1 alpha (stable metabolite of PGI2) increased following stimulation with 1.0 microgram/ml of LPS, but declined as the dose of LPS was increased. The results provide evidence that endotoxin-activated Kupffer cells, like other macrophage populations, release several metabolites of arachidonic acid. Kupffer cell-derived prostanoids, particularly TxA2, may be important mediators of some of the pathophysiologic manifestations of acute endotoxemia.

6-Ketoprostaglandin F1 alpha↗

PubMedDate not supplied

Irradiated trauma victims: the impact of ionizing radiation on surgical considerations following a nuclear mishap.

The combination of conventional traumatic injuries and radiation exposure has synergistic consequences, the full extent of which may take days to weeks to become apparent. Our understanding of such is derived from a variety of laboratory and clinical scenarios involving both therapeutic and accidental exposures. When presented with such an individual one must discern whether the victim has been bodily contaminated versus exposed to a source or both. The former will necessitate decontamination procedures which may be as simple as declothing and showering the individual. Simply removing the victim from the source will suffice to halt further radiation induced injury. In the vast majority of cases basic life support and other emergency medical procedures should be expeditiously instituted as warranted and without fear of personal hazard for health care teams. Following stabilization, further medical/surgical support must be predicated upon the extent of the radiation injury with the circulating absolute lymphocyte count serving as both a reliable and readily accessible indicator of the degree of underlying radiation injury. As radiation has profound consequences on immune and wound healing systems, therapies must be tempered by an understanding of the impact of radiation upon these systems. Overall, the consequences of irradiation injury will be the potential for an exacerbation of the effects of conventional traumatic injuries with a higher than expected morbidity and mortality.

Accidents↗