Recent synchronous radiation of a living fossil.

Modern survivors of previously more diverse lineages are regarded as living fossils, particularly when characterized by morphological stasis. Cycads are often cited as a classic example, reaching their greatest diversity during the Jurassic-Cretaceous (199.6 to 65.5 million years ago) then dwindling to their present diversity of ~300 species as flowering plants rose to dominance. Using fossil-calibrated molecular phylogenies, we show that cycads underwent a near synchronous global rediversification beginning in the late Miocene, followed by a slowdown toward the Recent. Although the cycad lineage is ancient, our timetrees indicate that living cycad species are not much older than ~12 million years. These data reject the hypothesized role of dinosaurs in generating extant diversity and the designation of today's cycad species as living fossils.

Decolorization of triphenylmethane dye-bath effluent in an integrated two-stage anaerobic reactor.

In the present study, decolorization of a simulated dye waste containing three different triphenylmethane (TPM) dyes--Magenta, Malachite Green and Crystal Violet, was investigated in a laboratory scale, two-stage anaerobic high-rate reactor. The effect of various parameters (influent dye concentration, hydraulic and co-substrate loading rates) on color and COD removal efficiency of the reactor has been studied. It has been shown that the influent dye concentration had little effect on overall COD and color removal efficiency. More than 99% color removal and 96% COD removal efficiency were maintained even at a dye concentration of 500 mg/l and a dye loading rate of 1000 mg/l day. However, a minimum level of glucose as supplementary carbon source is required to maintain the maximum color removal efficiency and it drops appreciably when no glucose is added to the influent. The study also showed that the acidogenic phase of the reaction plays an important role in decolorization of the TPM dyes. In addition, the two-stage anaerobic reactor was observed to have distinct advantages over the single-stage system, as the drop in color and COD removal efficiency of stage 1 are adequately compensated by stage 2 of the reactor especially under high dye loading rates accompanied by low co-substrate loading and under reduced HRTs.

Balloon dilatation in achalasia cardia.

Treatment of achalasia cardia by pneumatic dilatation is an established method. However, data on results of pneumatic dilatation in Indian patients with achalasia cardia are scarce. We report our experience with treatment of achalasia cardia by pneumatic dilatation in 38 patients. The diagnosis of achalasia cardia was based on clinical examination, barium swallow and upper gastrointestinal (GI) endoscopy. Twenty nine (76.3%) patients improved with first dilatation, 8 (21%) patients had to undergo second dilatation and 1 (2.6%) required a third. Most of the patients remained asymptomatic during a follow-up of 6 months to 6 years. Immediate and late complications occurred in 5 (13%) and 2 (5.2%) patients, respectively. Thus, pneumatic dilatation is a simple, safe and effective method for treating Indian patients with achalasia cardia.

Postcholecystectomy problems and the role of endoscopic retrograde cholangiopancreatography.

Many patients continue to have symptoms even after cholecystectomy. We studied 4 patients with postcholecystectomy problems over a period of seven years; 208 were females, males and their mean age was 41.8 years (range 14-70). Presenting symptoms were abdominal pain (217), jaundice (74), cholangitis (38) and external biliary fistula (eight). Fifteen patients also had a t-tube in situ. Endoscopic retrograde cholangiopancreatography was successfully performed in 239 patients and revealed abnormal findings in 179. These included: stones (89), strictures (53), choledochoduodenal fistula (10), choledochal cyst (three), biloma (three), ligation of bile duct (five), ascaris in bile duct (three), pancreatitis (nine), long cystic duct stump (11), and various other findings. Endoscopic sphincterotomy was carried out in 59 patients with stones. Seven patients with strictures were managed with stents. Ascaris in the bile duct of three patients was removed with the help of a Dormia basket. To conclude, stones and strictures are common postcholecystectomy problems and endoscopic retrograde cholangiopancreatography is very helpful in the diagnosis and management of postcholecystectomy patients.

Endoscopic sphincterotomy for common bile duct stones with and without gall bladder/'T' tube 'in situ'.

Eighty-seven patients underwent endoscopic sphincterotomy (ES) for common bile duct (CBD) stones. Out of these, 66 patients had post-cholecystectomy CBD stones and 21 had CBD stones with gall bladder 'in situ'. In post-cholecystectomy group, 15 patients had 'T' Tube 'in situ'. The presenting symptoms in the post-cholecystectomy group were: pain abdomen, jaundice and cholangitis in 51, 20 and 11 patients respectively. The fifteen patients with 'T' tube used to experience pain after clamping of 'T' tube. Those with gall bladder 'in situ' had cholangitis in 12 and jaundice only in 9 patients. CBD clearance was achieved in 80 patients (91.95%). The sphincterotomy cut had to be extended in 19 patients. There was no mortality following sphincterotomy. Nine patients (10.3%) had minor complications such as bleeding (4), cholangitis (3), pancreatitis and impaction of Dormia basket in one patient each. Thus ES is a safe and effective treatment for CBD stones with or without gall bladder/'T' tube 'in situ'.

Ultrasound guided percutaneous renal biopsy.

Percutaneous renal biopsy is a useful tool in the diagnosis and prognostication of the medical renal diseases. The ultrasonography helps in accurately localising the site of renal biopsy as well as in detecting contra-indications like polycystic disease, solitary kidney and hydronephrosis, etc. In this series of 100 consecutive cases of ultrasound guided renal biopsy, the success rate was 99% and reasonably good length of renal tissues were obtained in 97% cases.