A Possible Correlation Between Growth-Factor Sensitivity and Response to Mitoxantrone Treatment in a Murine Myeloid Leukaemia (SA7HD) Cell Line

SA7 murine myeloid leukaemia cells usually respond to stimulation in vitro by WEHI-conditioned medium by displaying increased dose-dependent proliferation. However, at recurrence following in vivo treatment of the leukaemia with mitoxantrone, the leukaemia cells developed significant insensitivity (p - 0.04) to stimulation by WEHI-conditioned medium. This altered growth-factor sensitivity was detected when two different assays were used. The recurrent leukaemic cells were morphologically indistinguishable from untreated leukaemic cells, but in normal mice they regained sensitivity to growth factors after a single transplant. The recurrent leukaemic cells were significantly resistant to some concentrations of mitoxantrone in vitro (p = 0.012). The magnitude of this resistance was mainly a function of the dose of mitoxantrone used in the initial treatment of the leukaemia. These data suggest an association between growth-factor sensitivity and response to mitoxantrone treatment including the development of resistance in the SA7HD murine myeloid leukaemia cell line.     

Lymphatic drainage from the skin of the back to retroperitoneal and paravertebral lymph nodes in melanoma patients

Background: Preoperative lymphoscintigraphy (LS) with^99mTc antimony sulphide colloid is now part of the routine management of patients with intermediate thickness melanoma at the Sydney Melanoma Unit. Over a 13-year period, 1375 patients have been examined using LS, and we have observed many unusual lymphatic drainage pathways, including direct drainage through the body wall to retroperitoneal and paravertebral lymph nodes from the skin of the back. The aim of this study was to determine the incidence of such drainage in the 542 patients who had primary melanoma sites on the posterior trunk. Methods: The lymphoscintigrams performed on these patients were examined for the presence of direct lymphatic drainage through the posterior body wall to sentinel nodes in the retroperitoneal and paravertebral regions. Results: Lymphatic drainage directly through the body wall to such lymph nodes occurred in 14 of these 542 patients. Conclusions: Preoperative knowledge of the presence of this lymph drainage pattern may influence surgical management, and follow-up investigations in these patients can be tailored to ensure that the relevant areas are examined with anatomic imaging or F18-FDG PET scans.     

Molecular epidemiology of the RNA satellite of <Emphasis Type="Italic">Rice yellow mottle virus</Emphasis> in Africa

Summary. Satellite RNA was sought in 51 isolates of Rice yellow mottle virus (RYMV) representative of the geographical, molecular and pathogenic variability of the virus in Africa. Three-quarters of the isolates from cultivated rice and wild gramineaceous hosts supported a satellite RNA. The prevalence of RYMV isolates that were associated with a satellite differed among regions, being c. 100% in West and Central Africa and c. 36% in East Africa. The RYMV satellite showed a low diversity as only seven of the 220 sequenced positions were variable. One insertion also occurred after serial host passages of the satellite. Two forms of the satellite differed by six substitutions forming three base pairs in one branch of the predicted RNA secondary structure. There was no evidence of intermediates between these two forms, but double-infection occurred. Each form had a specific geographical distribution: one occurred in Central Africa, the other elsewhere in Africa. There was no relation between the occurrence or the forms of the satellite and the phylogeny of the helper virus. The satellite was not involved in symptom modulation or ability to break host-plant resistances to the disease.Received January 29, 2003; accepted April 12, 2003 Published online June 24, 2003     

Metastatic embryonal rhabdomyosarcoma of the breast: A case report and literature review

Rhabdomyosarcoma (RMS) is a common malignancy in children, but embryonal rhabdomyosarcoma (ERMS) deposits rarely occur in the breast in adults. Therefore, little is known about magnetic resonance imaging (MRI) features of breast metastases from RMS, especially the embryonal type. We reported a case of a 22-year-old woman who was diagnosed with ERMS at left foot 2 years ago and accepted operation and chemotherapy. She was confirmed to have breast metastases from the left foot. Successive imaging examinations were performed 3 months apart. Breast ultrasound indicated a benign lesion, and further examination did not reveal any bone metastases. However, predominant restricted diffusion and rim contrast enhancement on MRI combined with the patient's medical history suggested a malignancy of BI-RADS 5. After 3 months, breast ultrasound revealed masses detected last time became larger and lobulated. In addition, internal heterogeneous intensity and rim contrast enhancement with restricted diffusion were revealed on MRI. We speculated that typical MRI findings of breast metastases from RMS may include iso- to hypointensity on T1WI, heterogeneous hyperintensity on T2WI, and circular enhancement with restricted diffusion. Moreover, mild peritumoral edema, rapid expansion of necrosis, and ascending time-intensity curve detected on MRI may be features of the ERMS type.     

Is the IV obstructed or infiltrated? A simple clinical test

Objective. The objective of our study was to determine if clinical observation of pressure-flow relationships (PFR) can differentiate between partial external obstruction (obstruction) and infiltration as a cause of poor performance of gravity-fed infusions.Methods. A total of 24 patients with functional intravenous cannulae in situ had obstruction simulated by the application of a tourniquet proximal to the cannula. The change in flow (F) for a discrete change in pressure (P) was determined in each case by counting drop rates at two different elevations of the fluid reservoir level, 10 cm apart. The same process was repeated in 15 patients in whom the cannula was in an extra vascular location (infiltration). Three sizes of cannula—16-gauge, 18-gauge, and 20-gauge—were examined, with equal distribution of sizes in each group. The effect on flow rates of inflating a blood pressure (BP) cuff proximally on the cannulated limb was assessed. The ratio P/F is the total resistance of the infusion system, and by subtracting known values for resistance of infusion tubing and cannula, the venous or tissue resistance was calculated.Results. There was a statistically significant difference between the change in flow for obstructed compared with infiltrated cannulae for the same change in pressure for each cannula size. The mean venous resistance was 23 mm Hg/L/hr, while that of tissue was 280 mm Hg/L/hr, with no overlap between groups. There was no effect on flow rate with blood pressure cuff inflation in the infiltrated group whereas flow progressively fell in the obstructed group.Conclusions. Clinical observation of PFRs in poorly functioning gravity-fed IV infusions can assist in detecting infiltration as a cause. Inflation of a blood pressure cuff will further impair flow where the cannula is intravascular, but will have no effect in an extravascular location.     

Success in Surgical Intervention for Morbid Obesity: Is Weight Loss Enough?

Varieties of gastric surgery have increasingly been used in the management of morbid obesity. Generally, however, research and commentary in this area have related to surgical technique, with weight loss or morbidity being regarded as the most important dependent measures. In the context of the publication of several papers relating to the effects of surgery in the long-term, we believe that it is timely for surgeons to examine their criteria for success. In this paper, we argue that weight loss is inadequate as a primary criterion for success in this context, and that the value of the intervention should be measured against a multidimensional concept of success.     

Treatment of Cervical Incompetence by Transabdominal Cervicoisthmic Cerclage

Summary: Cervical incompetence is a condition traditionally treated by cervical cerclage which in most cases is inserted via the transvaginal route. However the insertion of a transabdominal cervicoisthmic suture is indicated in those patients with recurrent mid-trimester losses due to an incompetent cervix where it is not technically possible to insert a transvaginal suture. Between 1987 and 1996, 12 women at the Royal Women's Hospital, Melbourne were treated with transabdominal cervicoisthmic cerclage (TCC). Eight patients had cerclage in the nonpregnant state, and 4 were pregnant at the time. The completed pregnancies thus far have resulted in 10 surviving infants, a successful pregnancy rate of 69.2%. This compares favourably with a corrected preTCC successful pregnancy rate of only 13%. There were minimal intraoperative complications in our series. Bleeding, chorioamnionitis and premature rupture of the membranes have been reported elsewhere and occurred in 2 of our patients. Our results and a review of the literature confirms that TCC has an important role in carefully-selected patients.     

Frontal sinus surgery 2004: update of clinical anatomy and surgical techniques

Endoscopic frontal sinus surgery is still considered difficult, risky to perform, and likely to result in a high failure rate. We have previously reported on our technique of endoscopic frontal sinus surgery, stressing the importance of identification and preservation of natural outflow tract. Our study of frontal sinus anatomy shows that the mean frontal ostium anterior—posterior and transverse dimensions are 7.22 ± 2.78 mm and 8.92 ± 2.95 mm, respectively; therefore, dissection of obstructive structures in frontal recess leads to a wide opening of frontal sinus outflow. A key surgical landmark in our technique is the superior attachment of the uncinate process. This article provides an update of the surgical anatomy of the frontal recess region and our surgical technique, as well as a discussion of our approach to frontal sinus revision surgery.