Pre-B acute lymphoblastic leukemia cells may induce T-cell anergy to alloantigen

Even if neoplastic cells express tumor associated antigens they still may fail to function as antigen presenting cells (APC) if they lack expression of one or more molecules critical for the induction of productive immunity. These cellular defects can be repaired by physiologic activation, transfection, or fusion of tumor cells with professional APC. Although such defects can be repaired, antitumor specific T cells may still fail to respond in vivo if they may have been tolerized. Here, human pre-B cell acute lymphoblastic leukemia (pre-B ALL) was used as a model to determine if primary human tumor cells can function as alloantigen presenting cells (alloAPC) or alternatively whether they induce anergy. In the present report, we show that pre-B cell ALL express alloantigen and adhesion molecules but uniformly lack B7-1 (CD80) and only a subset express B7-2 (CD86). Pre-B ALL cells are inefficient or ineffective alloAPC and those cases that lack expression of B7-1 and B7-2 also induce alloantigen specific T- cell unresponsiveness. Under these circumstances, T-cell unresponsiveness could be prevented by physiologic activation of tumor cells via CD40, cross-linking CD28, or signaling through the common gamma chain of the interleukin-2 receptor on T cells. Taken together, these results suggest that pre-B ALL may be incapable of inducing clinically significant T-cell-mediated antileukemia responses. This defect may be not only due to their inability to function as APC, but also due to their potential to induce tolerance. Attempts to induce clinically significant antitumor immune responses may then require not only mechanisms to repair the antigen presenting capacity of the tumor cells, but also reversal of tolerance.     

Natural history of supravalvular aortic stenosis and pulmonary artery stenosis

Data from 35 patients with supravalvular aortic stenosis or pulmonary artery stenosis, or both, undergoing cardiac catheterization between 1973 and 1989 were analyzed retrospectively. Twenty-seven patients had supravalvular aortic stenosis: 11 required surgery after the first investigation and 8 (80%) of 10 others undergoing serial investigation showed an increase in the left ventricle to aorta pressure gradient. Angiographic measurements showed that the increase in the aortic pressure gradient was related to failure of normal growth of the ascending aorta lumen. Nineteen patients had pulmonary artery stenosis, with a right ventricular pressure greater than 33 mm Hg. At restudy, right ventricular pressure had decreased in 9 (82%) of 11 patients. This decrease in right ventricular pressure was associated with an increase in the systolic distensibility of the proximal pulmonary arteries, although there was no increase in the diastolic diameters. One patient had a rapid early increase in right ventricular pressure and no pulmonary artery growth. In two patients, multiple peripheral pulmonary artery stenoses became evident with time and produced persistent right ventricular hypertension. Supravalvular aortic stenosis is usually a progressive lesion, with an increase in left ventricular outflow tract pressure gradient related to poor growth of the ascending aorta. Pulmonary artery stenosis usually improves and only rarely limits prognosis.     

IgG Against Dengue Virus in Healthy Blood Donors,Zanzibar, Tanzania

We conducted a seroprevalence survey among 500 healthy adult donors at Zanzibar National Blood Transfusion Services. Dengue virus IgG seroprevalence was 50.6% and independently associated with age and urban residence. These data will aid in building a surveillance, preparedness, and response plan for dengue virus infections in the Zanzibar Archipelago.Key words: dengue, seroprevalence, Zanzibar, viruses, vector-borne infections     

Identification of Possible Virulence Marker from Campylobacter jejuni Isolates

A novel protein translocation system, the type-6 secretion system (T6SS), may play a role in virulence of Campylobacter jejuni. We investigated 181 C. jejuni isolates from humans, chickens, and environmental sources in Vietnam, Thailand, Pakistan, and the United Kingdom for T6SS. The marker was most prevalent in human and chicken isolates from Vietnam.     

Mental stress experienced by first-year residents and expert surgeons with robotic and laparoscopic surgery interfaces

Prior research has indicated that novices experienced a beneficial stress profile in the robotic surgery (da Vinci) training environment when compared to the laparoscopic surgery training environment. The objective of this study was to assess whether this finding generalizes to expert surgeons. Towards that end, first-year residents’ and attending surgeons’ performances and subjective stress experiences were assessed in a surgical training task that was performed with the da Vinci and laparoscopic surgery interfaces. This study indicated that both groups exhibited superior performance and lower stress with the da Vinci surgical system than the laparoscopic system. The results provide further support for the sensitivity of the Dundee Stress State Questionnaire in identifying different stress responses experienced by trainees and experts in the minimally invasive surgery environment.     

Cardiac rhythm in atrial isomerism

Standard electrocardiograms from 126 consecutive patients with atrial isomerism were reviewed. Of 67 patients with left isomerism, 49 had sinus rhythm, 8 nodal rhythm and 10 atrioventricular (AV) block. Fifty-eight of 59 patients with right isomerism had sinus rhythm. Complete AV block was significantly more frequent in association with AV septal defect in left isomerism (5 of 45 patients) than in right isomerism (0 of 47 patients, p = 0.049). The P-wave axis was superior in 49% of patients with left isomerism but did not correlate with abnormalities of systemic or pulmonary venous connection. A significant shift of P-wave axis (more than 90 degrees) was seen on a subsequent electrocardiogram in 14 of 44 patients (32%) with left isomerism and 2 of 16 (13%) with right isomerism. Ambulatory electrocardiographic monitoring in 17 patients (14 with left isomerism) showed that only 4 had sinus rhythm throughout 24 hours. Only 1 patient with complete AV block received a permanent pacemaker. Despite the high incidence of electrocardiographic abnormalities, significant arrhythmias appear to be rare. The arrhythmias apparently do not influence the natural history of this condition or affect the outcome of palliative or corrective surgery. The prognosis is determined mainly or solely by the associated anatomic abnormalities.     

Does an infected peripancreatic fluid collection or abscess mandate operation?

OBJECTIVE: To assess the treatment of peripancreatic fluid collections or abscess with percutaneous catheter drainage (PCD). SUMMARY BACKGROUND DATA: Surgical intervention has been the mainstay of treatment for infected peripancreatic fluid collections and abscesses. Increasingly, PCD has been used, with mixed results reported in the literature. METHODS: A retrospective chart review of 1993 to 1997 was performed on 82 patients at a tertiary care public teaching hospital who had computed tomography-guided aspiration for suspected infected pancreatic fluid collection or abscess. Culture results, need for subsequent surgical intervention, length of stay, and death rate were assessed. RESULTS: One hundred thirty-five aspirations were performed in 82 patients (57 male patients, 25 female patients) with a mean age of 40 years (range 17-68). The etiologies were alcohol (41), gallstones (32), and other (9). The mean number of Ranson's criteria was four (range 0-9). All patients received antibiotics. Forty-eight patients had evidence of pancreatic necrosis on computed tomography scan. Cultures were negative in 40 patients and positive in 42. Twenty-five of the 42 culture-positive patients had PCD as primary therapy, and 6 required subsequent surgery. Eleven patients had primary surgical therapy, and five required subsequent surgery. Six patients were treated with only antibiotics. The death rates were 12% for culture-positive patients and 8% for the entire 82 patients. CONCLUSIONS: Historically, patients with positive peripancreatic aspirate culture have required operation. This series reports an evolving strategy of reliance on catheter drainage. PCD should be considered as the initial therapy for culture-positive patients, with surgical intervention reserved for patients in whom treatment fails.     

The Role of Smoking in Breast Cancer Development: An Analysis of a Mayo Clinic Cohort

Abstract:  The purpose of this study was to assess the predictive value of smoking history on breast cancer diagnosis in a referral clinic population. We conducted a case–control study using clinical data collected on 8,097 female patients (1,225 breast cancer cases and 6,872 controls) seen in the Mayo Clinic Breast Clinic between August 1, 1993 and November 31, 2003. Breast cancer patients and noncancer patients significantly differed with respect to age at time of the index visit (p < 0.001), number of pregnancies (p = 0.006), number of live births (p = 0.002), vital status at last known follow-up (p < 0.001), current menstruation (p < 0.001), age at menopause (p < 0.001), history of hysterectomy (p < 0.001), use of oral contraception (p = 0.05), duration of oral contraception use (p = 0.001), use of other exogenous hormones (p < 0.001), duration of exogenous hormone use (p = 0.05), breast pain at time of index visit (p = 0.002), smoking status (p < 0.001), and use of five or more alcoholic beverages per week (p = 0.002). After adjustment for these baseline characteristics, having a personal history of smoking was found to be predictive of breast cancer diagnosis (odds ratios [OR] = 1.25, p = 0.004). Other positive predictors for breast cancer diagnosis were: age (OR = 1.02, p < 0.001), history of hysterectomy (OR = 0.66, p < 0.001), prior use of oral contraception for more than 11 years (OR = 2.10, p < 0.001), and prior use of other exogenous hormones/estrogen (OR = 1.81, p < 0.001). In this referral practice having a personal history of smoking is predictive of breast cancer diagnosis. Further studies are needed to further explore this relationship.     

Pulp revascularization for immature replanted teeth: a case report

Immature avulsed teeth are not usually treated with pulp revascularization because of the possibility of complications. However, this therapy has shown success in the treatment of immature teeth with periapical lesions. This report describes the case of an immature replanted tooth that was successfully treated by pulp revascularization. An 8‐year‐old boy suffered avulsion on his maxillary left lateral incisor. The tooth showed incomplete root development and was replanted after 30 minutes. After diagnosis, revascularization therapy was performed by irrigating the root canal and applying a calcium hydroxide paste and 2% chlorhexidine gel for 21 days. In the second session, the intracanal dressing was removed and a blood clot was stimulated up to the cervical third of the root canal. Mineral trioxide aggregate was placed as a cervical barrier at the entrance of the root canal and the crown was restored. During the follow‐up period, periapical repair, apical closure and calcification in the apical 4 mm of the root canal was observed. An avulsed immature tooth replanted after a brief extra‐alveolar period and maintained in a viable storage medium may be treated with revascularization.