The structural basis of cooking loss in beef: Variations with temperature and ageing.

Meat loses fluid during cooking, resulting in textural changes and loss in cook yield. To understand the structural basis of cooking losses, this work used 10 bovine semitendinosus muscles and two ageing periods (1 vs 14days) to examine micro- and macro-level dimensional changes in muscle during heating. Muscle blocks, muscle fibre fragments and myofibrils all showed similar maximum shrinkage in cross sectional area (20-24%) but maximum length shrinkage was less in myofibrils (15%) than muscle blocks and fibre fragments (25%). Dimensional changes were dominated by shrinkage in individual muscle fibres and myofibrils, indicating that connective tissue does not play a major role. Transverse shrinkage predominantly occurred over 50-65°C whereas the longitudinal shrinkage predominantly occurred over 70-75°C; we attribute these two separate shrinkage events to denaturation of myosin and actin respectively. Higher cook losses in samples aged for 14days versus 1day suggests that desmin, nebulin and titin denaturation are not major drivers of fluid expulsion as these proteins are degraded during ageing. We postulate that proteolysis during ageing produces protein fragments which are more easily lost from the structure during cooking, along with water.

A structural approach to understanding the interactions between colour, water-holding capacity and tenderness.

The colour, water-holding capacity (WHC) and tenderness of meat are primary determinants of visual and sensory appeal. Although there are many factors which influence these quality traits, the end-results of their influence is often through key changes to the structure of muscle proteins and their spatial arrangement. Water acts as a plasticiser of muscle proteins and water is lost from the myofibrillar lattice structure as a result of protein denaturation and consequent reductions in the muscle fibre volume with increasing cooking temperature. Changes in the myofilament lattice arrangement also impact the light scattering properties and the perceived paleness of the meat. Causes of variation in the quality traits of raw meat do not generally correspond to variations in cooked meat and the differences observed between the raw muscle and cooked or further processed meat are discussed. The review will also identify the gaps in our knowledge and where further investigation would beneficial.

Vitamin B12 deficiency and gastric histopathology in older patients.

AIM: To compare upper gastric endoscopic and histopathologic findings in older adults in the presence and absence of B12 deficiency. METHODS: A prospective analysis of upper gastric endoscopic and gastric histopathologic findings from 30 newly identified B12-deficient patients (11 males, 19 females) and 16 controls with normal B12 status (6 males, 10 females) was performed. For all subjects, the indication for upper endoscopy and gastric biopsy were unrelated to B12 status. A single pathologist, blinded to B12 status, processed and interpreted the biopsy samples. Endoscopic and histopathologic findings were correlated with age, gender, hematocrit (Hct), MCV and B12 status. RESULTS: The B12-deficient group had significantly lower mean serum B12 levels compared to the controls (P<0.00005) while their mean Hct, MCV and serum albumin levels were similar. Iron deficiency (ferritin-based) was present in 21% of B12-deficient patients and intrinsic factor antibodies were present in 29% (5/17) of B12-deficient patients. The endoscopic findings revealed significantly different rates of gastritis and atrophy between the B12-deficient and control groups (P=0.017). B12-deficient patients had significantly less superficial gastritis (62% vs 94%) and significantly more atrophic gastritis (28% vs 0%) as compared to the controls (P=0.039). Intestinal metaplasia was similar in both groups. Helicobacter pylori infection rates were similar in the B12-deficient patients and controls (40% vs 31%). CONCLUSION: Significantly different endoscopic findings and types of gastritis could often be observed in the presence and absence of B12 deficiency. Atrophy, based on endoscopy, and atrophic gastritis, based on histopathology, suggest the presence of B12 deficiency. Gastric histopathology is not influenced by the age, gender, Hct or MCV of the patients.

Gastric ganglioneuroblastoma: a rare finding in an infant with multifocal ganglioneuroblastoma.

PURPOSE: This report describes a female infant with stage 4 multifocal ganglioneuroblastoma with gastric involvement. PATIENT: The patient had a right cervical tumor, a left posterior mediastinal tumor, bilateral adrenal tumors, and bony and bone marrow metastases. The tumor cells were diploid and lacked N-myc gene amplification. The gastric involvement, which did not produce clinical symptoms, was only detected by meticulous exploration during laparotomy. RESULTS: Our patient achieved only a partial response to alternating cycles of cyclophosphamide, vincristine, and adriamycin; and etoposide and cisplatin. She currently has stable, unresectable disease with elevated catecholamines. CONCLUSIONS: Multifocal ganglioneuroblastomas may arise from either neuroblastic rests or aberrant deposits of neuroblasts. The latter mechanism may have accounted for our patient's gastric tumor. Patients with multifocal ganglioneuroblastomas warrant meticulous radiographic and surgical evaluation to completely document the full extent of disease, and to ensure appropriate staging and therapy.

Pleural liposarcoma presenting with respiratory distress and suspected diaphragmatic hernia.

A young woman with a history of diaphragmatic hernia presented to the hospital in respiratory distress and in premature labor. Her admission chest roentgenogram showed opacification of the left hemithorax, and her arterial blood gas analysis revealed hypoxemia. Emergency cesarean section and exploratory left thoracotomy were carried out; a large tumor occupied the left side of the chest, and pneumonectomy was performed. No diaphragmatic hernia was present. A pathologic diagnosis of primary liposarcoma was made.