Spontaneous migration of biliary calculi

Summary A case illustrating the phenomenon of spontaneous migration of biliary calculi through the ductal system is presented. Several radiographically authenticated cases previously presented in the literature are reviewed. Spontaneous migration of biliary calculi can occur without abnormalities in any of the standard laboratory tests and in the absence of any symptoms or physical findings. An awareness of the phenomenon, leading to radiographic studies prior to surgery, may occasionally prevent an unnecessary operative procedure.Fellow in the Harrison Department of Surgical Research.     

Bowel obstruction in cancer patients: Performance status as a predictor of survival

Ninety-five patients with known cancer who developed bowel obstruction were reviewed in an effort to evaluate the reliability of preadmission performance status as a predictor of outcome of therapy. Based on the review, a number of conclusions can be reached. Performance status, which is more easily measured than stage of disease at admission, is correlated with successful resolution of obstruction and survival. Many patients with known cancer who develop bowel obstruction have a non-malignant cause of obstruction. Prolonged nonoperative treatment of cancer patients with bowel obstruction is unlikely to be successful and is fraught with complications.     

Integration of full-dose adjuvant chemotherapy with definitive radiotherapy for primary breast cancer: four-year update

Controversy exists over the effect of definitive radiotherapy on the ability to administer full doses of adjuvant chemotherapy in primary breast cancer. Ninety-six consecutive women with clinical stage I and II breast cancer were treated with radiotherapy plus chemotherapy. Three combinations of drugs were used: cyclophosphamide and 5-fluorouracil (CF); cyclophosphamide, methotrexate, and 5-fluorouracil (CMF); or cyclophosphamide, methotrexate, 5-fluorouracil, and prednisone (CMFP). Chemotherapy consisted of two cycles of CF (cyclophosphamide at a dosage of 100 mg/m2 orally on days 1-14+5-fluorouracil at 600 mg/m2 iv on days 1 and 8) during concurrent radiotherapy, followed by six cycles of CMFP (same CF dosages+methotrexate at 40 mg/m2 iv on days 1 and 8+prednisone at 40 mg/m2 orally on days 1-14). The study included 63 premenopausal and 33 postmenopausal patients; 72 had 1-3 positive nodes, had greater than or equal to 4 positive nodes, and 9 had negative nodes and negative estrogen receptors. The mean CF doses delivered during concurrent radiotherapy were 95% of the optimal doses, and the mean CMF doses administered during the six cycles after radiotherapy were 89%. The CMF was delivered at level I (greater than or equal to 85% of optimal doses) to 73% of the patients. With a median follow-up of 36 months, 16 relapses have been observed. Two of these patients had treatment failure only in the breast or axilla and are disease free after mastectomy. Of the 72 patients with 1-3 positive nodes, 10 relapsed in distant sites, while 4 of 15 patients with greater than or equal to 4 positive nodes have had distant failure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fate of mutation rate depends on agr locus expression during oxacillin-mediated heterogeneous-homogeneous selection in methicillin-resistant Staphylococcus aureus clinical strains

Methicillin-resistant Staphylococcus aureus (MRSA) strains are characterized by a heterogeneous expression of resistance. We have previously shown in clinical oxacillin-susceptible, mecA-positive MRSA strains that selection from a very heterogeneous (HeR) to highly homogeneous (HoR) resistant phenotype was mediated by acquisition of mutations through an oxacillin-induced SOS response. In the present study, we used a spotted DNA microarray to evaluate differential gene expression during HeR-HoR selection and found increased expression of the agr two-component regulatory system. We hypothesized that increased expression of agr represents a mechanistically relevant component of this process. We demonstrated that inactivation of agr during the HeR-HoR selection process results in a significant increase in mutation rate; these effects were reversed by complementing the agr mutant. Furthermore, we found that extemporal ectopic expression of agr and, more specifically, RNAII in agr-null mutant HeR cells suppressed mutation frequency and the capacity of these cells to undergo the HeR-HoR selection. These findings sustain the concept that increased expression of agr during HeR-HoR selection plays a critical role in regulating the β-lactam-induced increased mutation rate in very heterogeneous MRSA strains. Moreover, they indicate that a temporally controlled increase in agr expression is required to tightly modulate SOS-mediated mutation rates, which then allows for full expression of oxacillin homogeneous resistance in very heterogeneous clinical MRSA strains.     

The slipping rib syndrome

The slipping rib syndrome is a cause of upper abdominal pain that is not widely known, possibly because of failure of recognition rather than infrequent occurrence. The syndrome should be suspected when pain can be reproduced by a rib-hooking maneuver. However, a thorough evaluation including intercostal nerve blocks is necessary both to eliminate coexistent gastrointestinal and psychiatric disorders as a cause of pain and to assure adequate treatment and a good prognosis. Patients with obvious slipping ribs appear to benefit from surgical excision.