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H C Bertram

Publications and source records attributed to H C Bertram.

4 recordsLinked to original sources
PubMed2001

Post mortem energy metabolism and pH development in porcine M. longissimus dorsi as affected by two different cooling regimes. A (31)P-NMR spectroscopic study.

(31)P-NMR spectroscopy was carried out on M. longissimus dorsi samples chilled by two different cooling profiles corresponding to commercial batch and tunnel chilling. The half-life of post mortem phosphocreatine (PCr) degradation was found to be significantly less in muscle samples exposed to tunnel chilling (rapid) compared with muscle samples exposed to batch chilling (soft) conditions, while no difference in the post mortem ATP degradation was found. Moreover, the post mortem pH development in the muscle samples differed considerably between the two cooling regimes. A maximum difference of approx. 0.25 pH units between the two cooling profiles was observed around 150 min post mortem. Theoretical calculations of the registered pH difference between rapid and soft chilling of muscle samples revealed that the temperature effect on the buffer capacity of muscle is the major determining factor in the detected difference in intracellular pH between the two cooling profiles, while any contribution from a temperature-induced delayed progress in the lactate formation post mortem seems negligible. Moreover, calculations on the effect of the registered pH difference between rapid and soft chilling of muscle samples resemble a 2.5 times greater denaturation of myosin in samples which were chilled softly compared with samples chilled more rapidly. Finally, the relationship to the functionality of meats from soft and rapid chilled pork carcasses is discussed.

Analysis of Variance↗
PubMed2001

Origin of multiexponential T(2) relaxation in muscle myowater.

To obtain a further understanding of the nature of the multiexponential T(2) relaxation seen in muscle tissue water (myowater), relaxation measurements were carried out on whole, minced, and homogenized pork of three different qualities with regard to water-holding capacity (normal, red soft exudative, and dark firm dry). Whole, minced, and homogenized pork all resulted in multiexponential T(2) relaxation (three components) independently of the quality, even though microscopic studies on homogenized meat revealed considerable disruption of the macroscopic structure. This states that the relaxation behavior in meat cannot be explained by intra-/extracellular compartmentalization of the water as suggested in earlier studies. Subsequent studies of T(2) relaxation in either whole meat, where the structure integrity was changed by the introduction of dimethyl sulfoxide (membrane disruption) or urea (protein denaturation), or minced meat with added NaCl (inter-/intraprotein interactions) lead to the suggestion that in whole meat (i) the fastest relaxation component reflects water tightly associated with macromolecules, (ii) the intermediate relaxation component reflects water located within highly organized protein structures, for example, water in tertiary and/or quaternary protein structures and spatials with high myofibrillar protein densities including actin and myosin filament structures, and (iii) the slowest relaxation component reflects the extra-myofibrillar water containing the sarcoplasmatic protein fraction. Finally, relaxation patterns in heat-set gels of superprecipitated actomyosin and bovine serum albumin similar to that identified in whole meat support the proposed nature of T(2) relaxation in muscle myowater.

Animals↗
PubMed2001

Immunophenotyping large B-cell lymphomas. Flow cytometric pitfalls and pathologic correlation.

Large cell lymphomas often challenge the diagnostic flow cytometrist. The purposes of this study were to improve our protocols for diagnosing large cell lymphomas and to correlate flow cytometric (FC) data with demographic and histologic features. We identified 63 cases of large B-cell lymphoma between January 1, 1995, and July 30, 1999, and reviewed the diagnostic slides and FC light scatter and staining patterns. The 51 lymphomas with adequate material for systemic review fell into 2 light scatter patterns: "clear cut," with large abnormal cells (high forward scatter relative to normal lymphocytes), 17 cases (33%); and "complex," 34 cases (67%). Clear-cut cases were more mitotically active (average of 42 vs 25 per 10 high-power fields), with higher cellularity. Apoptosis, geographic necrosis, and sclerosis were present histologically in many cases, regardless of FC findings. We conclude that morphologic features of large cell lymphomas do not predict which cases will be difficult to diagnose by FC. Gating strategies can be critical to improve the diagnostic yield.

Adult↗