Post-operative analgesia following thoracotomy in the dog: an evaluation of the effects of bupivacaine intercostal nerve block and nalbuphine on respiratory function.

Pain following thoracotomy reduces pulmonary ventilation in man and a similar effect is believed to occur in animals. The effects of two analgesic regimens on arterial blood gas parameters were studied in dogs following thoracotomy. Post-Operative analgesia was provided with intermittent nalbuphine, either alone or in combination with an intercostal nerve block using bupivacaine. Arterial blood gas analysis was carried out at 4, 8 and 16 h post-operatively, both before the administration of nalbuphine and again 30 min later. Animals which received nalbuphine alone had a significant rise in arterial oxygenation following administration of this analgesic. This effect was not observed at 4 and 8 h post-operatively in dogs which had an intercostal block with bupivacaine, but was seen at 16 h post-operatively when it could be anticipated that the effects of bupivacaine would have waned. These results suggest that intercostal block with bupivacaine can provide analgesia for over 8 h, and that the duration of action of nalbuphine in controlling post-operative pain in the dog is probably less than 4 h.     

Hematology, serum chemistry values, and rectal temperatures of adult greater galagos (Galago garnetti and G. crassicaudatus)

Hematological and serum chemistry values, as well as rectal temperatures, were obtained from greater galagos (Galago garnettii and G. crassicaudatus), in order to establish normative values. No species or sex differences were found for four hematological parameters and 15 serum chemistry parameters. Species differences were seen in phosphate, magnesium, cholesterol, alkaline phosphate, G-glutamyl transferase, mean corpuscular volume and leucocyte, neutrophil, and lymphocyte number. Significant sex differences were observed in glucose, hemoglobin, and hematocrit values. Species and sex differences were seen in chloride and erythrocyte number.     

Prediction of femoral impact forces in falls on the hip.

A major determinant of the risk of hip fracture in a fall from standing height is the force applied to the femur at impact. This force is determined by the impact velocity of the hip and the effective mass, stiffness, and damping of the body at the moment of contact. We have developed a simple experiment (the pelvis release experiment) to measure the effective stiffness and damping of the body when a step change in force is applied to the lateral aspect of the hip. Results from pelvis release experiments with 14 human subjects suggest that both increased soft tissue thickness over the hip and impacting the ground in a relaxed state can decrease the effective stiffness of the body, and subsequently reduce peak impact forces. Comparison between our fall impact force predictions and in-vitro measures of femoral fracture strength suggest that any fall from standing height producing direct, lateral impact on the greater trochanter can fracture the elderly hip.     

Isolation, identification and synthesis of locustamyoinhibiting peptide (LOM-MIP), a novel biologically active neuropeptide from Locusta migratoria.

A novel peptide termed locustamyoinhibiting peptide (LOM-MIP) was isolated from brain-corpora cardiaca-corpora allata-suboesophageal ganglion extracts of the locust, Locusta migratoria. The primary structure of this nonapeptide has been determined Ala-Trp-Gln-Asp-Leu-Asn-Ala-Gly-Trp-NH2. LOM-MIP suppresses the spontaneous contractions of the hindgut and oviduct of Locusta migratoria and of the hindgut of Leucophaea maderae. This novel peptide is, however, structurally different from leucomyosuppressin, a hindgut suppressing peptide isolated from Leucophaea maderae heads. LOM-MIP has a Gly-TrpNH2 carboxy-terminal in common with APGWamide, a penis retractor muscle inhibiting peptide isolated from the snail, Lymnea stagnalis. In addition, it shows carboxy-terminal sequence similarities with locust AKH II which ends in AGWamide. No sequence similarities were found with other vertebrate or invertebrate peptides. Synthetic LOM-MIP showed biological as well as chemical characteristics indistinguishable from those of native LOM-MIP.     

The relative importance of local phase and local amplitude in patchwise image reconstruction

Natural images were subjected to patchwise Fourier analysis, and the local amplitude and phase spectra were swapped between different images. When the patches were large relative to the image size, the appearance of the reconstructed image was similar to that of the image from which the phase information had been derived, in agreement with previous reports of phase-dominance in the global Fourier Transform. However, when the patch size was made sufficiently small, the appearance of reconstructed images was dominated by amplitude rather than phase. This was not simply due to the DC component of the amplitude spectrum. Prior low-pass filtering of the images enhanced the dominance of amplitude information in the patchwise transform. We conclude that patchwise-reconstructed images contain two quite distinct kinds of information for the human observer. The first is the positional information (local sign) of the patches themselves; the second is the textural information within patches, which is dominated by amplitude rather than phase. The reason why the global Fourier Transform is dominated by phase is that in the absence of any other information about local sign, phase is necessary to reconstruct localised features such as edges.     

(Thr-59)-insulin-like growth factor I stimulates 2-deoxyglucose transport in BC3H1 myocytes through the insulin-like growth factor receptor, not the insulin receptor

The murine non-fusing muscle cell line contains distinct receptors for insulin and insulin-like growth factors. Pretreatment of myocytes with insulin for 20 h at 37 degrees C inhibits the binding of [125I]iodoinsulin by 60% without affecting the binding of [125I]iodoinsulin-like growth factor I. The ED50 values for down-regulation of the insulin and insulin-like growth factor receptor by their respective ligands are 1 nM and 3 nM, respectively. Insulin, (Thr-59)-insulin-like growth factor I and multiplication-stimulating activity stimulate 2-[3H]deoxyglucose transport in myocytes with ED50 values of 5 nM, 5.6 nM and 33 nM, respectively. In order to determine whether (Thr-59)-insulin-like growth factor I stimulates 2-[3H]deoxyglucose transport in myocytes via its own receptor or the insulin receptor, we determined the activity of these peptides after down-regulation of the insulin receptor. The rate of 2-[3H]deoxyglucose transport in myocytes pretreated with insulin (5 nM) is elevated but returns to control levels by 1 h after the washout of insulin. The dose-response curve for insulin-stimulated 2-[3H]deoxyglucose transport is shifted to the right (ED50 greater than 100 nM) immediately after insulin washout but is normal by 1 h after insulin washout. In contrast, the dose-response curve for (Thr-59)-insulin-like growth factor I is unchanged in insulin-pretreated cells immediately after insulin washout. These data show that (Thr-59)-insulin-like growth factor I stimulates 2-[3H]deoxyglucose transport in myocytes by acting through an insulin-like growth factor receptor and not through the insulin receptor. Since multiplication-stimulating activity is 6-fold less active than (Thr-59)-insulin-like growth factor, they both may be acting through a type 1 insulin-like growth factor receptor.     

In vitro induction of suppressor cells by plasma of rats with Trypanosoma brucei rhodesiense infection

Mitogenic responses of B and T lymphocytes from spleens of rats infected with Trypanosoma brucei rhodesiense were suppressed. Plasma from infected rats suppressed the mitogenic responses of B and T lymphocytes from spleens of normal uninfected rats. Removal of immune complexes from plasma of infected rats significantly reduced the suppressive effect of the plasma on splenic lymphocytes of normal uninfected rats. Normal thymus cells treated with plasma from infected rats and added to cultures of normal spleen lymphocytes inhibited the mitogenic responses of B and T lymphocytes. We suggest that the interaction of immune complexes and Fc or C3b receptors of T lymphocytes resulted in the in vitro induction or activation of T suppressor lymphocytes.     

The use of 36Cl- to measure cell plasma membrane potential in isolated hepatocytes--effects of cyclic AMP and bicarbonate ions

The plasma membrane potential of hepatocytes was calculated from the distribution of 36Cl-. The potential observed under several conditions was equivalent to that previously measured using microelectrodes in perfused liver. Dibutyryl cAMP increased the membrane potential. Replacement of bicarbonate ions by morpholinosulphonate decreased the potential and reduced the effect of cAMP. The effect of both bicarbonate and cAMP was abolished by ouabain. Both bicarbonate and cAMP stimulated the activity of the (Na+ + K+)-ATPase as measured by ouabain-inhibitable 86Rb+ uptake. It is suggested that the stimulation of alanine transport by these effectors is mediated by an increase in cell membrane potential via stimulation of the (Na+ + K+)-ATPase.