Soil bacterial community dynamics in plots managed with cover crops and no-till farming in the Lower Mississippi Alluvial Valley, USA.

AIMS: Assess bacterial community changes over time in soybean (Glycine max) crop fields following cover crop (CC) and no-till (NT) implementation under natural abiotic stressors. METHOD AND RESULTS: Soil bacterial community composition was obtained by amplifying, sequencing, and analysing the V4 region of the 16S rRNA gene. Generalized linear mixed models were used to assess the effects of tillage, CC, and time on bacterial community response. The most abundant phyla present were Acidobacteria, Actinobacteria, Bacteroidetes, and Verrucomicrobia. Bacterial diversity increased in periods with abundant water. Reduced tillage (RT) increased overall bacterial diversity, but NT with a CC was not significantly different than RT treatments under drought conditions. CCs shifted abundances of Firmicutes and Bacteroidetes depending on abiotic conditions. CONCLUSIONS: In the Lower Mississippi Alluvial Valley (LMAV), USA, NT practices lower diversity and influence long-term community changes while cover crops enact a seasonal response to environmental conditions. NT and RT management affect soil bacterial communities differently than found in other regions of the country.

Biliary clonorchiasis.

Parasitic infection of the biliary tree may be seen more frequently because of changing patterns in travel, and may come to the attention of the surgeon when obstruction or secondary bacterial infection occurs. In this case, intraoperative cholangiography indicated common duct abnormalities, and choledochotomy led to the diagnosis of Clonorchis sinensis. A recommendation is made to follow up patients with bilary parasite infections to determine the long-term sequelae.

The endoscopic diagnosis of an aortoduodenal fistula.

An aortoduodenal fistula is a serious complication of aortic reconstructive surgery. This artile describes a case in which the diagnosis of an aortoduodenal fistula was made by upper gastrointestinal endoscopy. The endoscopic finding of a vascular prosthesis within the duodenum allowed immediate surgical intervention and control of the gastrointestinal hemorrhage.

Sump tube drainage as a source of bacterial contamination.

There is well documented evidence indicating in-appropriately high basal gastrins in patients with duodenal ulcer disease. After stimulation by protein meals, calcium infusion, and insulin-induced hypoglycemia there appears to be an exaggerated release of gastrin in patients with duodenal ulcers compared to control subjects. Vagotomy in general tends to increase serum gastrin by decreasing acid secretion and allowing less inhibition for antral gastrin release. This increase appears less with selective vagotomy and parietal cell vagotomy compared to truncal vagotomy, suggesting vagal inhibition of gastrin release outside the antrum. Antrectomy may decrease serum gastrins by removing a major source of the hormone. However, extra antral gastrin sources, if stimulated properly, may result in little postoperative change.

Management of noncalcified aneurysms of the abdominal aorta.

Occasionally a previously undiagnosed aneurysm of the abdominal aorta will be found during the course of surgical procedure. When circumstances prevent extending the procedure to include resection and grafting of the aneurysm, the proper placement of silver clips as radiopaque markers may be of substantial benefit in managing this patient until definitive therapy can be instituted.

Atherosclerosis obliterans in healthy young adults.

A healthy young man developed unilateral claudication due to an isolated lesion of his external iliac artery, At operation, this was found to be obliterated by atherosclerotic change of long standing. No evidence of systemic disease was noted. A vascular reconstruction has allowed the patient to return to an active life style.

Indications for exploring the retroperitoneal space.

The retroperitoneal space is an area that deserves consideration in patients with serious bleeding problems. This area should be explored in all patients with a history of previous reconstructive vascular surgery of the abdominal aorta and iliac vessels and who subsequently present with gastrointestinal hemorrhage. It should also be considered for exploration in patients presenting with serious bleeding problems when the bleeding site cannot be identified and the area in which blood is accumulating cannot be detected. We present three cases in which early adequate exploration of the retroperitoneal space would have been beneficial to the patients.

Staging carcinoma of the penis.

Presently there are six clinical staging systems in use for carcinoma of the penis. We propose a method which compares these systems by means of a check list type of format. With the aid of this device, any penile carcinoma can readily be staged in terms of all six systems. Advantages of multiple system staging include comparing series of patients which have been discussed only in terms of a single staging system and selecting the appropriate therapeutic modality in terms of the stage of disease.

Squamous cell carcinoma arising in benign adenolymphoma (Warthin's tumor) of the parotid gland.

Adenolymphoma of the parotid gland is a benign tumor occurring primarily in middle-aged males. Major texts of surgery and pathology state that this tumor is not malignant nor does it undergo malignant degeneration. This report demonstrates squamous cell carcinoma arising in a parotid adenolymphoma in a patient with no other malignancy or previous irradiation to the head and neck.

Filtration surgery in black patients: early results in a West Indian population.

We reviewed the early results of 80 filtration procedures when used as the initial surgical treatment in a Saint Lucian West Indian black population with primary open angle glaucoma. Two techniques were used: trabeculectomy under a scleral flap with fornix-based conjunctival flap (Group 1) and full thickness posterior lip sclerectomy with limbal-based conjunctival flap (Group 2). Postoperatively, with an average follow-up of six months, Group 2 had significantly lower intraocular pressures, reduced glaucoma medication requirements, and increased cystic bleb formation. Vision did not differ significantly between the two groups postoperatively, although two Group 1 patients developed progressive glaucomatous visual loss. Complications were slightly more frequent in Group 2. The results of this study suggest that a full thickness sclerectomy technique merits consideration as the initial filtration procedure of choice in West Indian blacks with advanced open angle glaucoma.

Carcinoma of the penis.

This study updates the experience at our hospital with cancer of the penis, which now includes 122 consecutive cases seen between 1940 and 1974 with 100 per cent followup. Historical, clinical, pathological, therapeutic and followup data were extracted for all cases in a digital code for transfer to computer storage. Life tables giving cumulative survival rates through 10 years with standard deviations and age corrections were calculated for each variable. The data were tabulated for publication to emphasize the prognostic significance of individual variables for the purpose of prospective research planning. The data were then evaluated regarding indications for prophylactic inguinal lymph node dissections, if any.