To thin or not to thin: the use of the anterolateral thigh flap in the reconstruction of intraoral defects.

The anterolateral thigh (ALT) flap has achieved popularity recently for free-flap reconstruction of intraoral defects following excision of squamous cell carcinoma. We have assessed the feasibility of the ALT flap as a free flap for oral lining and the potential use of the thinned ALT flap in a one-stage reconstruction. We used the ALT flap to reconstruct the oral cavity in 18 consecutive patients between December 2000 and December 2001 following intraoral resection of squamous cell carcinoma. Twelve patients underwent reconstruction using a standard ALT flap, four patients received a thinned ALT flap in a one-stage procedure, one patient received a standard ALT flap in combination with a fibula flap and one patient received a combination of a standard ALT flap and vascularised iliac bone. There were no complications in any of the 14 cases in which a standard ALT flap was used. Two of these flaps were thinned subsequently as secondary procedures. Of the four thinned ALT flaps, one flap failed completely and two flaps experienced partial necrosis. In all but one case the donor site was closed directly with minimal donor-site morbidity. The ALT flap is a versatile flap that can be used in combination with other flaps for more complex defects with minimal donor-site morbidity and is a useful alternative in the armamentarium of the head and neck surgeon. Thinning of the flap is best performed as a secondary procedure, should it be required.     

Tissue lipid levels of the clam,Villorita cyprenoides var. cochinensis,following exposure to endosulfan,malathion, and methyl parathion

Sublethal stress of toxicants on organisms is generally measured through metabolic changes. The effects of three pesticides (endosulfan, malathion, and methyl parathion) on tissue lipid levels in the estuarine bivalve, Villorita cyprenoids var. cochinensis, have been measured. The reduction in lipid content was expressed as a function of the pesticide concentrations and the duration of the exposure periods (24, 48, 72, and 96 h). The results point to the existence of a direct relationship between the applied stress and the fall in the lipid content. The order of toxicity was endosulfan > malathion > methyl parathion. The depletion in lipid content observed may reflect an adaptive response of the organism to pesticide stress. Thus lipids in bivalves have been shown to be an important reserve material that may be utilized under stressed conditions as an energy source. © by John Wiley & Sons, Inc.     

Developmental patterns of intermediate filament gene expression in the normal hamster brain

We have examined the patterns of expression of the major intermediate filament (IF) protein mRNAs during development of the hamster brain. Quantitative northern blotting was used to examine changes in the levels of mRNAs for the low, middle and high molecular weight neurofilament proteins (NF-L, NF-M, NF-H) as well as peripherin, vimentin and glial fibrillary acidic protein (GFAP). Total RNA was isolated from hamster brains at embryonic (E) days 12 and 14 and postnatal (P) days 1, 3, 5, 7, 9, 11, 13, 15, 20, 28 and 60-90 (adult), and probed with specific IF cDNAs. Northern blotting revealed that NF-L and NF-M mRNAs were present at very low levels in embryonic brain and that significant expression of these genes only occurred postnatally when the levels increased dramatically until P28 and then declined again in the adult. Increases in NF-H mRNA levels were somewhat delayed relative to those of NF-L and NF-M. NF-H mRNA was not seen at embryonic stages and was expressed at very low levels prior to P9; after that time the levels increased rapidly until P28 and then declined in the adult. Two of the type III IF genes, peripherin and vimentin, followed a pattern of expression opposite that of the NF genes. Both peripherin and vimentin mRNAs were present in embryonic brain and were expressed at higher levels during early postnatal stages than at later times. The magnitude and rate of reduction in vimentin gene expression in the postnatal interval was much greater than that of peripherin. GFAP mRNA levels were extremely low prior to P9 after which a robust increase occurred, followed by a decline in the adult. We discuss the implication of the dramatic changes in IF isotype expression in brain to the pathways of both neuronal and glial development in vivo.     

Effect of the development of portosystemic shunts in the maintenance of portal hypertension in rats

We studied the role of portosystemic shunt development in the maintenance of portal hypertension in a prehepatic portal hypertension rat model. A first group was studied two days after partial portal vein ligation. When portosystemic shunts were negligible; the second group was studied 3 weeks after the partial portal vein ligation, when large portosystemic shunts were present. Portal pressure was significantly higher in the first group than in the second group (19.9 +/- 0.8 mmHg (mean +/- 1 SD) and 12.8 +/- 2.3 mmHg, respectively; p less than 0.001). When compared with sham operated rats: a) portal tributary blood flow (measured with the radioactive microspheres method) was decreased in the first group (- 34 p. 100; p less than 0.01) and increased in the second group (+ 32 p. 100; p less than 0.02); b) portal system vascular resistance was markedly increased in the first group (+ 269 p. 100; p less than 0.001) and did not significantly change in the second group (+ 30 p. 100). These results suggest that portosystemic shunt development decreases portal pressure but not to normal value because portal tributary blood flow is increased. Moreover the increase in portal system vascular resistance and in portal tributary blood flow play different roles in the maintenance of portal hypertension depending on the stage of evolution of portal hypertension.     

Supracerebellar arachnoid cyst - A rare cause of acquired Chiari I malformation.

Chiari I malformation (CM) associated with a cervico-thoracic syrinx due to supracerebellar arachnoid cyst has not been reported in the literature. We report such a case, managed by fenestration of the arachnoid cyst and foramen magnum decompression (FMD), aiming to reduce the inferiorly directed pressure on the cerebellum and eliminate the craniospinal pressure dissociation respectively. Imaging done post-operatively showed upward displacement of the cerebellar tonsils with a decompressed craniovertebral junction and disappearance of the syrinx.     

Comparison of the Amplicor HIV-1 monitor test and the nucleic acid sequence-based amplification assay for quantitation of human immunodeficiency virus RNA in plasma, serum, and plasma subjected to freeze-thaw cycles.

The Amplicor HIV-1 Monitor test was compared to the nucleic acid sequence-based amplification (Nasba) assay system for the quantitation of human immunodeficiency virus (HIV) RNA in three different types of clinical samples: plasma, serum, and plasma subjected to freeze-and-thaw cycles. Each assay detected HIV RNA in the same 73 (90%) of 81 samples tested, and the quantitative results obtained with the two assays were significantly correlated. Both assays detected higher RNA levels in patients with CD4+ cell counts lower than 200 cells/mm3 than in patients with CD4+ cell counts higher than 200 cells/mm3. In addition, RNA levels in plasma higher than 5 logs predicted higher numbers of clinical events than did RNA levels in plasma lower than 5 logs. Quantitation of HIV RNA in paired plasma and serum samples showed lower HIV RNA content in serum than in the paired plasma sample, with mean differences between HIV RNA contents of plasma and serum of 0.54 and 0.28 log RNA copy/ml by the Nasba assay and the Amplicor HIV-1 Monitor assay, respectively. No significant loss of HIV RNA was detected with either assay in plasma samples subjected to multiple freeze-and-thaw cycles. These studies demonstrate that the Nasba and Amplicor assays perform similarly with plasma and serum samples. Further, the results indicate that freeze-and-thaw cycles do not result in significant loss of detectable HIV RNA.     

Isolated splenic hemangioma presenting with bleeding into serous body cavities

We present two children with massive bleeding into the serous body cavities accompanied by intractable consumption coagulopathy. One had a large spleen palpable at admission, the other developed progressive splenomegaly while in hospital. Neither child had any external evidence of angiomatous lesions. A splenic hemangioma was suspected clinically and on abdominal ultrasound; the diagnosis was confirmed at laparotomy. Splenectomy resulted in a prompt cure in both cases.