Current controversies in sentinel lymph node biopsy for breast cancer.

Despite the widespread use of sentinel lymph node biopsy (SLNBx) in the surgical management of breast cancer patients, several areas remain controversial. The following controversies are reviewed: Learning curves and validation studies. There clearly is a learning curve, and a completion ALND should be done until adequate proficiency is exhibited, both in terms of identification and false-negative rates. Location of injection. Intradermal injection offers superior identification rates compared with peritumoral injection, with comparable false-negative rates. Subareolar injection is as accurate as peritumoral injection. The value of scintigraphy. Routine scintigraphy does not enhance identification or false-negative rates. Mapping agents. Blue dye and radioactive tracer combined to provide a higher identification rate than either used alone.SLNBx in DCIS. In patients with a high risk of microinvasion, such as large tumors, a mass or high-grade DCIS-SLNBx is justified.SLNBx following neoadjuvant chemotherapy. Although there is evidence that SLNBx after neoadjuvant chemotherapy may be accurate, these data should be applied cautiously. Implications of non axillary SLN, especially internal mammary nodes. Data do not support routine resection of internal mammary sentinel lymph nodes outside a clinical trial. Implications of micrometastases in the sentinel lymph node seen only on immunohistochemistry. Since the significance of such metastases is unclear, decisions regarding treatment of these patients should be individualized. The value of completion axillary lymph node dissection. Is being addressed in clinical trials. Until those studies mature, completion ALND should be performed for patients with SLN metastases, but may be abandoned for patients with a negative SLN.

Bacterial wall lipopolysaccharide as a cause of intussusception in mice.

BACKGROUND: There is evidence that intussusception is associated with bacterial infection. It was hypothesized that a component of the bacterial wall may induce the intussusception. This study was intended to determine whether lipopolysaccharide from Escherichia coli or Salmonella can initiate intussusception in mice. METHODS: Lipopolysaccharide was injected intraperitoneally in mice, and the animals were examined for the presence of intussusception from 2 to 192 hours after injection. Gastrointestinal transit was assessed by measuring the passage of charcoal in the small intestine. Transit index was defined as the ratio between the distance traveled by charcoal and the total length of the small intestine. RESULTS: Intussusceptions were found in as much as 25.9% of lipopolysaccharide-injected animals, whereas in control animals, the incidence was zero. The threshold for the lipopolysaccharide effect was at 4 mg/kg and incidence reached a plateau at 8 mg/kg to 16 mg/kg. The incidence of intussusception peaked 6 hours after injection of lipopolysaccharide and declined to zero after 15 hours. To test the possibility that lipopolysaccharide induces intussusception by altering motility, its effect on transit index was measured. A dose of 12 mg/kg lipopolysaccharide reduced the transit index from 56.2+/-1.4% to 37.7+/-2.1% (p < 0.05). No microscopic histologic changes were found in the bowels with intussusception. CONCLUSIONS: Intraperitoneal bacterial wall lipopolysaccharide causes intussusception in mice by disturbing gastrointestinal motility.

Generation of polyclonal rabbit antisera to mouse melanoma associated antigens using gene gun immunization.

Lymphocytes from patients with melanoma have been used to clone melanoma associated antigens which are, for the most part, nonmutated melanocyte tissue differentiation antigens. To establish a mouse model for the use of these 'self' antigens as targets for anti-tumor immune responses, we have employed the mouse homologues of the human melanoma antigens Tyrosinase, Tyrosinase Related Protein-1 (TRP-1), gp100, and MART-1. We sought to generate antisera against these proteins for use in the construction of experimental recombinant and synthetic anti-cancer vaccines, and for use in biologic studies. Using genes cloned from the B16 mouse melanoma or from murine melanocytes, we immunized rabbits with plasmid DNAs coated onto microscopic gold beads that were then delivered using a hand-held, helium-driven 'gene gun'. This strategy enabled us to generate polyclonal rabbit sera containing antibodies that specifically recognized each antigen, as measured by immunostaining of vaccinia virus infected cells. The sera that we generated specifically for TRP-1, gp100, and MART-1 recognized extracts of the spontaneous murine melanoma, B16. The identities of the recognized proteins was confirmed by Western blot analysis. The titers and specificities of these antisera were determined using ELISA. Interestingly, serum samples generated against murine MART-1 and gp100 developed antibodies that were cross-reactive with the corresponding human homologues. Recognition of human gp100 and murine Tyrosinase appeared to be dependent upon conformational epitopes since specificity was lost upon denaturation of the antigens. These antisera may be useful in the detection, purification and characterization of the mouse homologues of recently cloned human tumor associated antigens and may enable the establishment of an animal model of the immune consequences of vaccination against 'self antigens.

Malnutrition-associated reactive hypoglycemia induced by TPN.

The availability and widespread use of TPN enables physicians to help patients in a way that had not been possible in the past. However, in order to best utilize this modality, we must be aware of potential hazards and metabolic complications. Many patients receiving TPN, particularly those receiving perioperative TPN, are malnourished to various extents, and careful monitoring of glucose metabolism is warranted to avoid malnutrition-associated reactive hypoglycemia.

[Nissen fundoplication by laparoscopy].

Short term results following laparoscopic Nissen fundoplication were evaluated in 31 patients with symptomatic gastroesophageal reflux. 6 were females and 26 males, and they ranged in age from 5 months to 64 years (mean: 4.9 years in 19 younger than 18 years, and 39.3 years in 12 adults). Most of the adults who complained of pain and heartburn underwent pH monitoring, endoscopy, and manometry as needed. Milk scan was the most useful diagnostic tool for the evaluation of the children, who suffered mainly from gastroesophageal-related pulmonary disease. Indications for laparoscopic operation were identical with those for conventional open Nissen fundoplication. 1 case of dysautonomia died postoperatively; the rate of complications, mostly minor, was 22.5%. 3 patients required conversion to open Nissen fundoplication due to cardiorespiratory instability secondary to pneumothorax in 2, and to esophageal perforation in the third. 5 adults developed temporary dysphagia. 3 children had only partial improvement in their pulmonary disease following the operation, while the other 15 had complete relief. The total time for the laparoscopic operation averaged 245 minutes in adults, and 228 in children. Discharge was usually on the fourth postoperative day in adults (mean: 6.0 days). Regurgitation and heartburn were cured in 10 out of 11 adults (91%). All parents of children were satisfied. Symptomatic outcomes following laparoscopic Nissen fundoplication compare favorably with those of open surgery with respect to mortality, complications, and outcome.

Water-soluble contrast material has no therapeutic effect on postoperative small-bowel obstruction: results of a prospective, randomized clinical trial.

BACKGROUND: Hyperosmotic water-soluble contrast materials have been fo und to be helpful diagnostic tools in postoperative small-bowel obstruction (POSBO); however, their therapeutic value remains controversial. PATIENTS AND METHODS: A prospective, randomized clinical study was conducted to examine the use of meglumine ioxitalamate as a supplement to the standard conservative treatment of POSBO. Patients with POSBO (n = 50) suitable for a conservative approach were randomized to receive standard conservative treatment with (n = 25) or without (n = 25) the addition of 100 mL of meglumine ioxitalamate via the nasogastric tube (patients with diffuse carcinomatosis and early POSBO were excluded). Both groups were compared for resolution of obstruction, need for surgical relief of obstruction, and complications. RESULTS: Seven (14%) patients required surgery: 3 in the contrast material group and 4 in the control group (P = not significant [NA]. Resolution of symptoms was achieved in nonsurgical patients within an average of 25.7 hours in the contrast material group and 28.7 hours in the control group (P = NS). There was no mortality in this study. In 2 (4%) patients (1 in each group), strangulated bowel was found during surgery, but only the 1 (2%) patient in the contrast material group required bowel resection. No difference was found in the length of hospital stay or rate of complications. There were no complications that could be attributed to the use of the contrast material itself. CONCLUSIONS: Although water-soluble contrast material is a safe and useful diagnostic tool, it offers no advantage as a supplement to the usual conservative treatment of POSBO.

How conservatively can postoperative small bowel obstruction be treated?

Although postoperative adhesion ileus is the most common cause of small bowel obstruction in adults, its management remains controversial. We retrospectively studied 297 admissions of 227 patients over a period of 14 years to evaluate our conservative approach in managing adhesion ileus. We found that nonoperative therapy of up to 5 days' duration can be used safely for the majority of patients who present with postoperative intestinal obstruction, including those with complete obstruction. In those patients, who responded to conservative treatment, the obstruction resolved within a mean of 22 hours and a maximum of 5 days. A trial of more than 5 days' duration proved ineffective. The conservative approach resulted in a 73% resolution of obstruction with no significant increase in mortality or in the rate of strangulated bowel.

Erythrocyte hexose monophosphate shunt is intact in healthy aged humans.

The integrity of the erythrocyte (RBC) hexose monophosphate shunt was investigated in a group of 33 healthy elderly individuals by determining their RBC glutathione content, glucose-6-phosphate dehydrogenase activity and glutathione regeneration. When these parameters were compared with those of the controls, 44 young healthy adults, no significant differences were found. This study indicates that the RBC hexose monophosphate shunt in healthy elderly individuals is intact. Factors other than senescence per se should be sought in elderly individuals who exhibit dysfunction of this shunt.