PubMed Health⌕ Search

Biomedical subjects

R Pennell

Publications and source records attributed to R Pennell.

8 recordsLinked to original sources
PubMed1998

Cell walls: structures and signals.

Cell walls harbor proteins and polysaccharides able to condition the development of a plant. In the past year, genes and enzymes modulating the composition and physical properties of walls have been characterized, and wall composition has been linked to the way a cell interacts with another cell, and to the way in which it differentiates. The sum of the signaling and physical activities of a cell wall may explain much about the control of development.

Arabidopsis↗
PubMed1997

Use of ultrasound to determine need for laparotomy in trauma patients.

STUDY OBJECTIVE: To determine whether abdominal ultrasound can be used routinely as the primary screening test to identify the need for laparotomy in trauma patients. METHODS: Ultrasound was used at a Level II trauma center as a primary screening test for evaluation of intraabdominal injury. We reviewed the charts of all patients from trauma codes presenting between January 1, 1991, and December 31, 1993, to determine the results of abdominal ultrasound evaluation and to learn whether laparotomy was required. RESULTS: A total of 2,013 trauma patients presented during the study interval. Ultrasound was performed in 1,631 patients as the primary screening test for abdominal injury (mean time after arrival, 22.9 minutes), abdominal computed tomography (CT) was performed as the primary screen on 8 (mean time, 68.6 minutes), and 93 patients underwent both ultrasound and CT of the abdomen. Of 86 patients requiring laparotomy who were screened by ultrasound, 80 had positive diagnostic findings, for a sensitivity of 93.0%. Of the 1,545 ultrasound-screened patients who did not require laparotomy, 1,390 had negative findings, for a specificity of 90.0%. None of the patients with negative ultrasound results died or sustained identifiable mortality as a consequence of their negative scans. CONCLUSION: Ultrasound is a sensitive and specific test with which to evaluate trauma patients for abdominal injury requiring surgery. Routine abdominal ultrasound can be performed at the bedside in the emergency department as a timely, noninvasive diagnostic test. This use of a screening abdominal ultrasound examination can improve clinical decision-making for the use of emergency laparotomy. Ultrasound may be a better alternative to CT or diagnostic peritoneal lavage for the initial screening evaluation of abdominal trauma.

Abdominal Injuries↗
PubMed1989

Hand-held and automated sonomammography. Clinical role relative to X-ray mammography.

A retrospective analysis of 73 patients who had undergone X-ray mammography (XRM), automated sonomammography (ASM), and hand-held sonomammography (HSM) was performed to evaluate the clinical role of both types of sonomammography (SM) relative to XRM. The results were classified on the basis of mammographic and sonographic findings. Clinical and/or surgical proof was obtained in all 73 patients. The SM was complementary to XRM, depending on the radiographic breast density. When comparison was made between ASM (4.5 MHz) and the HSM (7.5 MHz), the pathologic condition was better identified by HSM in 86% of the cases. Moreover, in no cases was ASM better than HSM.

Adult↗
PubMed1988

Ultrasound for guidance of breast mass removal.

Hand-held sonomammography was used intraoperatively to localize 52 masses in 45 women in an out patient operating suite. All but five women had a positive X-ray mammogram. The ultrasound mammogram was able to identify all lesions. In 42 women studied by a preoperative ultrasound examination before the operating room procedure, all the masses were successfully identified. Precise localization was successfully performed in the operating room before sterile preparation in less than 10 minutes. Relocalization after incision in the sterile operating field was necessary in two cases. This technique requires no ionizing radiation and expedites outpatient surgical removal of the lesion. Of the 52 masses, there were 32 fibroadenomas, three carcinomas, three cysts, six cases of focal fibrous mastitis, and eight patients with focal fibrocystic disease. In patients with positive sonograms for nonpalpable masses, ultrasound localization is a fast, accurate alternative to X-ray needle placement.

Adenofibroma↗
PubMed1984

A comparison of ductal management techniques in an in situ canine pancreas model.

Twenty-five dogs underwent right pancreatectomy leaving the tall of the pancreas in situ. Five equal groups underwent either intraperitoneal drainage (open-duct group), duct ligation, acrylate glue occlusion, neoprene glue occlusion, or Roux-en-Y pancreaticojejunostomy. On day 21 the tall of the pancreas was removed and on day 28 the dogs were killed. Daily serum glucose and amylase and biweekly insulin determinations were performed, and intravenous glucose tolerance tests ( IVGTTs ), with simultaneous insulin assays, were carried out before and after distal pancreatectomy. The mean daily blood glucose level prior to distal pancreatectomy was 95.6 +/- 3.2 mg/dL in the open-duct group, 91.6 +/- 3.0 mg/dL in the ligation group, 94.0 +/- 4.0 mg/dL in the acrylate group, 226.3 +/- 56.6 mg/dL in the neoprene group, and 94.1 +/- 2.6 mg/dL in the Roux-en-Y group. Mean K values (rate constant of glucose clearance) were as follows: open-duct group, -0.907+ +/- 0.240% per minute; ligation group, -1.024% +/- 0.253% per minute; acrylate group, -0.820% +/- 0.087% per minute; neoprene group, -0.526% +/- 0.186% per minute; and Roux-en-Y group, -1.399% +/- 0.566% per minute (normal, -2.201% +/- 0.388% per minute). Insulin release during IVGTT (basal to peak insulin difference) was greatest in the open-duct and Roux-en-Y groups. Although glucose clearance and insulin release were optimal with pancreaticojejunostomy, peripancreatic complications developed in two of the five dogs. In conclusion, the open-duct technique and Roux-en-Y pancreaticojejunostomy result in optimal endocrine function in this in situ model. Due to its simplicity, the open-duct technique is most suitable for further laboratory investigations of segmental pancreatic transplantation.

Acrylic Resins↗