Biomechanical performance of cutting edge surgical needles

The purpose of this study was to compare the biomechanical performance of cutting edge needles made of S45500 stainless steel alloy to Surgalloy stainless steel. The new high-nickel stainless steel alloy, Surgalloy, has superior performance characteristics over that of the other high-nickel stainless steel alloy, S45500. The Surgalloy needle is produced from a stronger stainless steel alloy than the S45500 needle. The Surgalloy needle has considerably greater resistance to bending than the needle produced from S45500 alloy. In addition, Surgalloy stainless steel has almost a twofold greater resistance to fracture than the S45500 stainless steel alloy.     

D-xylose test of resorption as a method to determine radiation side effects in the small intestine

Microscopic papillary carcinoma of the thyroid gland (MPC) measuring < or = 1.0 cm in diameter has a generally benign outcome, but is often overtreated with additional surgery. Ninety cases of MPC and 77 cases of nonmicroscopic papillary carcinoma of the thyroid gland (non-MPC) from 1970 to 1980 were retrieved from the Endocrine Registry of the Armed Forces Institute of Pathology (AFIP), Washington, D.C. Histologic features and patient follow-up were analyzed. Twenty-one patients with MPC had multifocal disease within the affected thyroid lobe, while a further 15 had either bilateral or intraglandular spread. Four of 10 patients who had additional surgery were found to have additional foci of tumor. Fourteen patients with lymph node metastases at initial surgery had no subsequent nodal metastases. All patients were either alive without disease or had died of unrelated causes after an average follow-up period of 17.3 years. Of the 77 non-MPC patients, 13 developed lymph node metastases or local recurrences, and one died of metastatic disease. Sixty-four of these patients were alive without evidence of disease after an average follow-up of 22 years. Present findings show that while MPC may present with perithyroidal lymph node metastases (15.56%), patients do not develop clinical tumors in the remaining thyroid tissue. Our experience indicates that close clinical follow-up without additional surgery is the preferable management for patients with MPC.     

Somatostatin in neuroblastoma and ganglioneuroma

Neuroblastoma, a childhood tumour of the sympathetic nervous system, may in some cases differentiate to a benign ganglioneuroma or regress due to apoptosis. Somatostatin may inhibit neuroblastoma growth and induce apoptosis in vitro and was therefore investigated. Using a radioimmunoassay, we found that all ganglioneuromas contained high somatostatin concentrations (> 16 pmol/g), significantly higher than neuroblastomas (n = 117, median 2.8 pmol/g), healthy adrenals, Wilms' tumours, phaeochromocytomas and other neuroendocrine tumours (P < 0.001). Neuroblastomas contained more somatostatin than control tumours (P < 0.001-0.05). Neuroblastomas amplified for the MYCN oncogene contained less somatostatin than non-amplified tumours (1.2 pmol/g versus 4.0 pmol/g, respectively; P = 0.026). In a clinically unfavourable neuroblastoma subset (age > 12 months, stage 3 or 4) 16 children with high concentrations of somatostatin in primary tumours had a better prognosis than 23 with low somatostatin (46.7% versus 0% survival at 5 years, P < 0.005). Scintigraphy using 111In-pentetreotide identified tumours expressing high-affinity somatostatin receptors in vivo. However, no significant correlation was found between somatostatin receptor expression and peptide content in 15 tumours. Similarly, human SH-SY5Y neuroblastoma xenografts grown in nude rats showed low somatostatin concentrations, but were positive for somatostatin receptor scintigraphy. Treatment of these rats with the somatostatin analogue octreotide seemed to upregulate in vivo receptor expression of somatostatin and vasoactive intestinal peptide more effectively than 13-cis retinoic acid. In conclusion, somatostatin in neuroblastoma is associated with differentiation to benign ganglioneuromas in vivo and favourable outcome in advanced tumours. Furthermore, somatostatin receptor scintigraphy may identify tumours with high-affinity receptors in children that might benefit from targeted therapy using synthetic somatostatin analogues.     

Left ventricular shape analysis from three-dimensional echocardiograms

Cystic fibrosis patients require pancreatic enzyme supplements to aid food digestion. It is suspected that incorrect delivery of this enzyme may result in both significant malabsorption and the development of strictures in the proximal colon caused by the high-dose supplement reaching this region before the food. Investigations into the drug's delivery were performed using dual-isotope imaging; a method was developed to directly label the enteric-coated enzyme pellets with 111In, re-applying the enteric coating afterwards, and this was then ingested with a pancake meal labelled with 99Tcm-tin colloid. Consecutive image data, acquired over a period of > or = 4 h using a dual-headed gamma camera, were analysed to assess intestinal transit. In-vitro stability checks on these labelling techniques were encouraging, showing < 2% 99Tcm and < 7% 111In elution over 90 min in hydrochloric acid. In 5 of the 12 patients studied to date, the pellets were seen to pass through significantly faster than the food, with a mean difference in 50% gastric emptying time of greater than 93 min. The mean absolute difference in emptying time for all 12 patients was > 67 min. Thus, a technique has been developed to effectively radiolabel pancreatic enzyme pellets, and analysis of dual-isotope images using this preparation, together with radiolabelled solid food, has demonstrated significant differences in the transit of these two substances through the gastrointestinal tract of some cystic fibrosis patients.     

FGF-2 is sufficient to isolate progenitors found in the adult mammalian spinal cord

The adult rat brain contains progenitor cells that can be induced to proliferate in vitro in response to FGF-2. In the present study we explored whether similar progenitor cells can be cultured from different levels (cervical, thoracic, lumbar, and sacral) of adult rat spinal cord and whether they give rise to neurons and glia as well as spinal cord-specific neurons (e.g., motoneurons). Cervical, thoracic, lumbar, and sacral areas of adult rat spinal cord (>3 months old) were microdissected and neural progenitors were isolated and cultured in serum-free medium containing FGF-2 (20 ng/ml) through multiple passages. Although all areas generated rapidly proliferating cells, the cultures were heterogeneous in nature and cell morphology varied within a given area as well as between areas. A percentage of cells from all areas of the spinal cord differentiate into cells displaying antigenic properties of neuronal, astroglial, and oligodendroglial lineages; however, the majority of cells from all regions expressed the immature proliferating progenitor marker vimentin. In established multipassage cultures, a few large, neuron-like cells expressed immunoreactivity for p75NGFr and did not express GFAP. These cells may be motoneurons. These results demonstrate that FGF-2 is mitogenic for progenitor cells from adult rat spinal cord that have the potential to give rise to glia and neurons including motoneurons.     

Limb swelling in patients who have fibrodysplasia ossificans progressiva

Fibrodysplasia ossificans progressiva is a rare heritable disorder of connective tissue characterized by progressive heterotopic ossification of soft tissues and by congenital malformation of the great toes. Limb swelling has also been noted, yet little is known about this complication of fibrodysplasia ossificans progressiva. To determine the prevalence of limb swelling in this condition, the authors reviewed detailed medical records on 74 patients (25 males, 49 females; age range, 1-49 years) who had a documented history of fibrodysplasia ossificans progressiva. The study population included more than 90% of all patients known to have fibrodysplasia ossificans progressiva in the United States. Acute swelling of the limbs occurred in association with flareups of the condition in nearly all cases. Acute swelling in the upper limbs was focal and nodular in contrast to acute swelling in the lower limbs, which was more diffuse. Acute swelling in the upper limbs occurred in all 74 patients whereas acute swelling in the lower limbs occurred in 47 of the 74 patients (64%). Two of the 74 patients who had acute swelling in the lower limbs (4%) had a documented episode of deep vein thrombophlebitis. Chronic swelling in the upper limbs occurred in 9 of the 74 patients (12%) and was not seen before the age of 12 years. Chronic swelling in the lower limbs occurred in 36 of the 74 patients (49%) and was not seen before the age of 9 years. The intense angiogenesis and edema seen on histopathologic evaluation of preosseous fibrodysplasia ossificans progressiva lesions may play a role in the pathogenesis of the limb swelling. The data show an age related prevalence of limb swelling in fibrodysplasia ossificans progressiva and suggest a model for understanding the complex pathways leading to limb swelling in this disorder.     

Failure of ketoprofen and interferon combination therapy to improve interferon-resistant chronic hepatitis C

Previous studies have documented the effectiveness of magnetic resonance imaging for evaluating and following up the development of avascular necrosis of the femoral head. One of the limitations of this technique, however, is the distortion that is encountered with ferromagnetic screws. A traumatic fracture to the femoral head is a risk factor for avascular necrosis. The addition of internal fixation, which is often required in Pipkin-type fractures of the femoral head, creates significant image distortion on magnetic resonance scans used for postoperative follow-up. The artifact and field distortion present in magnetic resonance imaging when ferromagnetic screw fixation is used has been avoided at our institution by the use of titanium hardware. The authors, therefore, recommend the use of titanium screws in the fixation of Pipkin-type fractures in the hip joint.     

Prevalence and clinical significance of combined K-ras mutation and p53 aberration in pancreatic adenocarcinoma

CONCLUSION: This study could not attribute survival differences to the coincident acquisition of two common genetic alterations, K-ras mutation and p53 overexpression in pancreatic adenocarcinoma patients. Additionally, our data indicate the converse to be true: Those patients lacking both K-ras mutation and aberrant p53 expression showed the shortest survival when compared with cases showing either alteration or both. This study also showed the negative effect of K-ras mutation and p53 expression on pancreas cancer patients' survival after treatment with either radiation therapy or chemotherapy. BACKGROUND: Mutations of the oncogene K-ras at codon 12 are reported to be the most common genetic alteration in pancreatic carcinoma, whereas either overexpression or mutation of the tumor suppressor p53 gene is considered the most common genetic alteration in neoplasia of all types. p53 overexpression has been attributed to survival differences in pancreatic carcinoma, but such association is still controversial. No studies have fully documented the combined incidence of K-ras and p53 alterations in pancreatic adenocarcinoma, or their combined effect on patient survival in a large case series. The influence of radiation or chemotherapy in groups showing both, either, or neither mutation is also undocumented. METHODS: Paraffin-embedded tissue sections from 76 cases of pancreatic adenocarcinoma were cut for DNA extraction for K-ras analysis and immunohistochemical staining for aberrant p53 expression. K-ras mutation was determined by single-strand conformation polymorphism (SSCP) and slot-blot allele-specific oligonucleotide (ASO) hybridization of PCR-amplified DNA product p53 expression was scored on the basis of percent nuclear staining with the MAb DO7. RESULTS: Sixty-four of 76 cases (84%) showed K-ras mutation, p53 expression, or both, K-ras was mutated in 55 of 76 cases (72%). p53 was expressed in 33 of 76 cases (43%). Twenty-four of 76 cases (31%) showed both K-ras mutation and p53 expression. The presence of both alterations was not related to significant differences in tumor grade, stage, or survival compared to either alteration alone. A sizable subset (16% of cases) lacked either alteration, and surprisingly, this group showed the shortest median survival compared to those with K-ras mutation, p53 expression, or both (p = 0.024). Patients whose tumors were K-ras-negative showed the greatest difference in median survival with radiation therapy (median survival 30.8 mo vs 7.8 mo with no radiation, p = 0.005).     

Scintigraphic detection of infection and inflammation: new developments with special emphasis on receptor interaction

Various conventional radiopharmaceuticals are currently available for scintigraphic imaging of infection and inflammation. Although a wide variety of infectious and inflammatory foci can be detected with these agents, several disadvantages limit their application. These limitations have stimulated the search for new radiopharmaceuticals. In the past decade a new class of radiopharmaceuticals has emerged: radiolabelled receptor-specific small proteins and peptides. These proteins and peptides are naturally occurring inflammatory mediators which specifically bind to receptors abundantly present in the area of inflammation. In addition, owing to their small size, they rapidly clear from all non-target tissues. This paper provides an overview of these newly developed agents, focussing on imaging characteristics and in vivo uptake mechanisms.