Differences in body temperature regulation during heat stress and seasonal depression in milk yield between Holstein, Brown Swiss, and crossbred cows.

It is not clear whether cattle that are genetically superior in regulation of body temperature during heat stress are also better able to sustain milk production during hot conditions. Objectives were to evaluate differences in body temperature regulation during heat stress between Holstein, Brown Swiss, and crossbred cows under semi-tropical conditions and test whether the seasonal depression in milk yield was greater for genetic groups less able to regulate body temperature. For the first objective, conducted during heat stress, vaginal temperature was measured at 15-min intervals for 5 d in 133 pregnant lactating cows. Vaginal temperatures were affected by time and interaction between genetic group and time. Vaginal temperatures were higher for Holsteins for most times of the day. Moreover, the maximum daily vaginal temperature was higher for Holstein (39.8 ± 0.1°C) than for Brown Swiss (39.3 ± 0.2°C) or crossbreds (39.2 ± 0.1°C). For the second objective, 6,179 lactation records from 2,976 cows were analyzed to determine effects of genetic group and season of calving (cool season = Oct to March; warm season = April to Sept) on 305-d milk yield. Milk yield was affected by genetic group and season but not by the interaction of genetic group and season. The difference in average 305-d milk yield between cows calving in cool versus hot weather was 310 kg (4% decrease) for Holstein, 480 kg (7% decrease) for Brown Swiss, and 420 kg (6% decrease) for crossbreds. In conclusion, Brown Swiss and crossbreds regulated body temperature during heat stress better than Holsteins but these breeds were not more resistant to heat stress with respect to milk yield. Thus, genetic differences in thermotolerance are likely to exist that are independent of regulation of body temperature.

Effectiveness of the Australian breeding value for heat tolerance at discriminating responses of lactating Holstein cows to heat stress.

Heat stress has negative consequences for milk production and reproduction of dairy cattle. These adverse effects are likely to increase because of climate change and anticipated increases in milk yield. Some of the variation among cows in ability to resist effects of heat stress is genetic. The current objective of this observational study was to assess the effectiveness of the Australian breeding value for heat tolerance (ABVHT) based on the decline in milk yield with heat stress for predicting cow differences in effects of heat stress on regulation of body temperature, milk production, and reproductive function. Genomic breeding values for heat tolerance were calculated for 12,487 cows from a single California dairy farm. Rectal temperature in the afternoon (1100-2045 h) was measured on a subset of 626 lactating cows with ABVHT ≥102 (heat tolerant) or <102 (heat sensitive). Rectal temperature was 0.12°C lower for heat-tolerant cows than heat-sensitive cows. Vaginal temperatures were measured every 15 min for 5 d in 118 cows with ABVHT ≥108 (extreme heat tolerant) or <97 (extreme heat sensitive). Vaginal temperature was 0.07°C lower for extreme heat-tolerant cows than extreme heat-sensitive cows. Lactation records for 4,703 cows with ABVHT were used to evaluate seasonal variation in first 90-d milk yield, fat percent, and protein percent for each ABVHT quartile. Overall, cows with higher ABVHT had lower milk yield, fat percentage, and protein percentage and higher first service pregnancy rate. There was no summer depression in production or reproduction or interactions between season and ABVHT quartile. We observed that ABVHT can successfully identify heat-tolerant cows that maintain lower body temperatures during heat stress. The lack of a pronounced seasonality in milk production or reproduction precluded evaluation of whether ABVHT is related to the magnitude of effect of heat stress on those traits.

Description and evaluation of a net energy intake model as a function of dietary chewing index.

Previously, a linear relationship has been found between net energy intake (NEI) and dietary chewing index (CI) of the diet for different types of cattle. Therefore, we propose to generalize and calibrate this relationship into a new model for direct prediction of NEI by dairy cows from CI values (CINE; min/MJ of NE). Furthermore, we studied the forage-to-concentrate substitution rate in this new NEI model. To calibrate the model on a diverse set of situations, we built a database of mean intake from 14 production experiments with a total of 986 primi- and multiparous lactating dairy cows of different breeds fed 136 different diets ad libitum. The NEI were estimated by the Nordic feed evaluation system. The CINE value of diets was estimated from the intake of concentrate, intake of forage neutral detergent fiber (NDFf), particle length of forage, indigestible NDFf/NDFf, body weight, NDFf/body weight, and the content of NE in DM. We show that the slope values in this regression are proportional to the squared intercepts, giving the nonlinear equation NEI=NEI0-k×NEI0a×CINE, where the parameter k represents the decline in NEI with the increasing CINE of the diet and a was estimated to have a value of 2, implying a constant maximum daily chewing time. The intercept NEI0 in the regression of NEI on CINE may be interpreted as metabolic net energy intake capacity of the cows fed without physical constraints on intake. Based on experimental data, the maximum chewing time was estimated as 1/(4 × k). The NEI0 values were parameterized as a linear function of metabolic body size, energy-corrected milk yield (kg/d), days in milk, and days in milk squared. Prediction accuracy was evaluated by mean square prediction error (MSPE) and its decomposition into central tendency, regression, and disturbance, across and within experiments on independent data from 19 experiments including 812 primi- and multiparous lactating dairy cows of different breeds fed 80 different diets ad libitum. The NEI model predicted NEI with an MSPE of 8% of observed, and across the 19 experiments the error central tendency, error regression, and error disturbance were 4.2, 40.6, and 84.9% of MSPE, respectively. The described intake model implies a variable forage-to-concentrate substitution rate as a nonlinear function of NEI0, CINE of forage, and supplementation of concentrate.

Moment-angle relationship at lower limb joints during human walking at different velocities.

The coupling between joint kinematics and kinetics during level walking was analysed by plotting joint angles vs. joint moments about the hip, knee and ankle in nine normal male subjects walking at three different velocities. The curves obtained were reproducible, and variability among subjects was relatively low. Counterclockwise loops corresponded to energy produced, and clockwise loops to energy absorbed at the joint; both loops are described in different phases of the stride cycle. At increasing walking velocity some of the loops narrowed, thus revealing the possibility of energy recovery. Analysis of individual diagrams revealed that consistent portions of the moment-angle loops can be described as a sequence of quasi-constant slope phases, separated by transition periods where quasi-isometric changes in joint moment occur. This figure, which was particularly evident of the hip and ankle joints, is reminiscent of a mechanical system with elastic components, which, in different phases of the rhythmic locomotion activity, moves along discrete status levels characterized by specific length-tension relationships. Implications of the above results in terms of the neurol control of joint properties during active movement are discussed.

[Analysis of fetal ECG during delivery]. / Føtal ekg-analyse under fødsel.

In order to render monitoring of delivery optimal, several new technological methods have found favour during the years. The few randomized investigations of foetal monitoring available do not show any effect on morbidity and mortality. Changes in the foetal ECG have been the object of intense research in the hope of obtaining a better indicator of foetal asphyxia. Experimental and also clinical investigations suggest that detailed analysis of the foetal ECG supplements cardiotocography and improves its diagnostic specificity. Many investigations have demonstrated that changes in the ST-segment, particularly increase in the T-wave are related to foetal hypoxia. The ratio between the height of the T-wave and the QRS complex (T/QRS-ratio) quantities this change in the ST-segment. Registration and quantitating of this change in the ST-segment require a microprocessor monitor to automize ECG analysis. Investigations to date suggest that this monitor can diagnose foetal asphyxia but more extensive investigations are necessary in order to establish the validity of an ECG analysis of this type during delivery.

[T/QRS-ratio and cardiotocographic changes in the second stage of labor--related to fetal condition at delivery]. / T/QRS-ratio og kardiotokografiforandringer i andet stadium af fødslen--relateret til fostrets tilstand ved fødslen.

The T/QRS ratio of the foetal electrocardiogram (ECG) was recorded from 92 women in labour. Recordings to within 30 min of delivery from 55 women were available for analysis. There was a weak but statistically significant correlation between increasing mean T/QRS ratio and increasing pH/standard base excess (SBE) in the umbilical artery of the 55 foetuses (Spearman, respectively r = 0.28, p = 0.04 and r = 0.29, p = 0.04); the corresponding numbers for the subgroup of 22 where the cardiotocogram was classified as normal being respectively r = 0.51, p = 0.02 and r = 0.61, p = 0.003. The mean T/QRS ratio of foetuses born with an umbilical artery pH of > 7.15 was 0.12 (range -0.05-0.32). There was no significant difference in mean T/QRS ratio between foetuses born with an umbilical artery pH < 7.16 (n = 10) and those born with a pH > 7.15. No trend in T/QRS ratio was found as labour progressed. There were only three cases of metabolic acidose (SBE = -10.3 to -10.6 mmol/l and pH = 7.09-7.14. In two of the cases the CTG was abnormal and in one case intermediate; mean T/QRS ratio was normal in all three cases with metabolic acidosis. Abnormal CTG was able to predict an umbilical artery pH < 7.15 with a sensitivity of 67% and a positive predictive value of 27%. T/QRS ratio (T/QRS = -0.05-0.25: "normal") was not able to predict a low pH. The chance of finding significant changes in T/QRS ratio was limited by the small number of foetuses with clinically significant acidosis.(ABSTRACT TRUNCATED AT 250 WORDS)

[Technology use in connection with delivery in Danish maternity departments]. / Fødselsrelaterede teknologier på fødeafdelinger i Danmark.

With the object of obtaining information about the technology use employed in Danish maternity departments, a questionnaire was sent to the 58 maternity departments which existed in Denmark in May 1989. These maternity departments covered 99% of the 55,660 births in Denmark (in 1987). Deliveries at home (a total of 511) and delivers in departments with less than four deliveries annually (a total nine) were responsible for the remaining 1%. 100% of the departments returned a completed questionnaire. The following percentages are based on the deliveries included in this investigation. The review revealed that 93.5% of Danish women are delivered in departments with access to carditocographic equipment (CTG), 34% in departments where this is offered routinely to all parturient women. Sixteen departments which did not possess CTG equipment all had fewer than 400 deliveries per annum and 12 of these stated that they wished they had had CTG. Only four of the 58 maternity departments (managing 3.4% of the deliveries in 1987) never employ human placental lactogen (HPL) or oestriol (O3) analyses. The most commonly employed hormone parameter is HPL which is undertaken on appropriate indications in 51 of 54 departments and routinely in the remaining three. Scalp-pH is carried out in 13 of the Danish maternity departments. Thus 41.7% of all the parturient women have access to this analysis. However, only 20% are delivered in maternity departments where this test is employed frequently. Cord-blood-pH is employed routinely in 31.7% of the neonates. Measurement of intrauterine pressure is employed in six out of the 58 maternity departments which are responsible for 25% of Danish deliveries. It is concluded that the slightly increased employment of technology use during delivery in 1989 as compared with practice in 1984 may primarily be due to the closing of several small maternity units during the past five years. In general, the use of technologies are less intensive than in England, Germany, France and the USA.

[Postoperative morbidity after hysterectomy is related to alcohol consumption]. / Postoperativ morbiditet efter hysterektomi er relateret til alkoholforbruget.

Postoperative morbidity after hysterectomy was studied prospectively in 229 consecutive patients in our departments. The incidence of alcohol abuse (> or = 60 gm of alcohol daily) and moderate drinking (between 25 and 60 gm of alcohol daily) was 6.5% for each. When compared with the moderate drinkers and the control group, the alcohol abusers developed significantly more complications (80% versus 27% and 80% versus 13% respectively). Preoperative history of alcohol consumption may define a group of patients at particular risk for increased postoperative morbidity.

Strongly interacting Fermi gases with density imbalance.

We consider density-imbalanced Fermi gases of atoms in the strongly interacting, i.e., unitarity, regime. The Bogoliubov-de Gennes equations for a trapped superfluid are solved. They take into account the finite size of the system, as well as give rise to both phase separation and Fulde-Ferrel-Larkin-Ovchinnikov-type oscillations in the order parameter. We show how radio-frequency spectroscopy reflects the phase separation, and can provide direct evidence of the FFLO-type oscillations via observing the nodes of the order parameter.

Phenotypic differentiation of aphidicolin-selected human neuroblastoma cultures after long-term exposure to nerve growth factor.

Human neuroblastoma SH-SY5Y (SY5Y) cultures, exposed to murine 7 S nerve growth factor (NGF) for 5 weeks and selected with aphidicolin (Aph) for 1 week, acquire several properties indicative of mature peripheral nerve cells. The mitotic activity of treated cultures decreases prior to Aph selection and ultimately reaches a level approximately 3% that of untreated cultures by Week 4 of treatment. The measured plasma membrane resting potential of the cells increases from -5 mV for untreated cells to -(45-56) mV for NGF/Aph-treated cells. Intracellular stores of monoamines are increased as determined by histochemical staining, and levels of neuron-specific enolase antigen increase as a result of NGF/Aph treatment. The resulting outgrowth of neurites is extensive and large bundles of processes commonly exceed 300 micron in length. NGF/Aph-treated cells acquire a dependence upon NGF for survival; however, with continued administration of NGF, the cultures appear to be capable of surviving indefinitely. Retinoic acid will also promote certain aspects of a differentiated phenotype under similar culture conditions. As judged by these criteria, cells of the SY5Y human neuroblastoma cell line have the potential for phenotypic and irreversible differentiation in vitro and can survive for prolonged periods under these culture conditions.

Abiotic formation of particles from extracellular organic carbon released by phytoplankton.

(14)C-labeled extracellular organic carbon (EOC) released by the phytoplankton in a Danish Estuary was shown immediately to form particles (>0.2µm) when the products were added to a natural water sample. About 14%-20% of the added activity could be recovered as particles. Any bacterial assimilation of the extracellular products was thus masked. The abiotic origin of the particulate EOC was verified, and it was shown that the particle formation was due to some factors present in the estuarine water with a nominal diameter >0.2µm. Precaution must be taken to avoid misinterpretations in studies concerning carbon flow from algae to bacteria.

Technology use, cesarean section rates, and perinatal mortality at Danish maternity wards.

Fifty-eight Danish maternity units, managing 99% of Danish deliveries, participated in a cross sectional study to assess the relationship between use of birth-related technologies, cesarean section rates and perinatal mortality for births after 35 completed weeks of gestation. A regional technology index (0-10) was calculated for each maternity unit according to its use of ante and intra partum fetal heart rate monitoring (FHM), hormone analysis (human placental lactogen (HPL) and/or estriol (O3)), fetal blood samples (scalp-pH), intrauterine catheter and umbilical cord-pH. Maternity units using FHM had a 15% higher cesarean section rate (not planned) than units not using FHM (p < 0.05). The referral of potentially complicated deliveries to central units, which at the same time relatively often use FHM, is probably responsible for this association. Trying to encounter this selection bias a technology index was calculated for eight regions in Denmark, weighting the index of each unit in a region according to its number of deliveries. There was no association between the technology index in these eight regions in Denmark and their cesarean section rates. Use of FHM, technology index, and unplanned cesarean section rates in the eight regions were all without significant association to the perinatal mortality in the same regions. For births after the 35th completed week of gestation, this study could not confirm a relationship between different degrees of use of birth-related technologies and perinatal mortality.

Influence of alcohol intake on postoperative morbidity after hysterectomy.

Postoperative morbidity after hysterectomy was prospectively studied in 229 consecutive patients in our departments. The incidence of alcohol abuse (greater than 60 gm of alcohol daily) and social drinking (between 25 and 60 gm of alcohol daily) was 6.5% for each. When compared with the social drinkers and the control group, the alcohol abuse group had significantly more complications (80% vs 27% and 80% vs 13%, respectively).

Steady-state polypeptide modulations associated with nerve growth factor (NGF)-induced terminal differentiation and NGF deprivation-induced apoptosis in human neuroblastoma cells.

Human neuroblastoma SH-SY5Y cells differentiate terminally in culture upon exposure to nerve growth factor (NGF) for 4-5 weeks. The neuronal phenotypic properties acquired in response to prolonged NGF treatment include morphological differentiation, cessation of mitotic activity, neuronal marker expression, increased membrane electrical potentials, and a survival dependence upon NGF for trophic support (Jensen, L.M. (1987) Dev. Biol. 120, 56-64). Thus, differentiated cultures survive indefinitely in the continued presence of NGF, however, withdrawal of NGF from differentiated cultures effects the loss of cellular viability within 3-6 days. Here, we show that death of differentiated SH-SY5Y cells caused by NGF deprivation is characteristic of apoptosis. To compare the differentiation promoting and the neurotrophic properties of NGF, whole SH-SY5Y cell extracts were analyzed by two-dimensional polyacrylamide gel electrophoresis using isoelectric focusing and nonequilibrium pH gradient electrophoresis gels in the first dimension. Steady-state levels of polypeptides extracted from whole-cell lysates of naive (untreated) cells, terminally differentiated cells, and NGF-deprived differentiated cells were compared. Over 1,000 spots from each were analyzed using computer-aided spot matching and densitometry. We noted 25 polypeptides that decreased during differentiation, including 15 that decreased by a factor of 10 or more. The levels of five polypeptides were induced from very low or undetectable levels in naive cells. Withdrawal of NGF from terminally differentiated cells produced alterations in steady-state protein patterns substantially distinct from those occurring during differentiation. While levels of most proteins do not appear affected early after NGF withdrawal, others rapidly return to levels comparable with those of the naive state and some changes occurring with differentiation are enhanced further upon NGF withdrawal. Three polypeptides were regulated uniquely by NGF withdrawal, including two that were induced, on average, 20- and 28-fold and another that was depressed more than 7-fold after NGF deprivation, before cell death. These data indicate that NGF elicits both constitutive and nonconstitutive changes in gene expression and suggest that the differentiation promoting and the neurotrophic properties of NGF correlate with the regulation of different gene products.

Malignant fibrous histiocytoma of the kidney.

Malignant fibrous histiocytoma is a primitive mesenchymal tumor which seldom occurs in the genitourinary organs. Despite radical operation, prognosis is generally poor and seems not to be improved by chemotherapy or radiotherapy. We present a case of a malignant fibrous histiocytoma of the renal capsule. The tumor could be removed totally and no signs of metastases were found. Eight months later the patient was readmitted with recurrence of tumor and widespread metastases.

The effect of posture on late postoperative oxygenation.

Twelve patients had their arterial oxygen saturation measured pre-operatively and on days 1, 4 and 7 after laparotomy. Measurements were performed in the supine, sitting and standing positions on each day. Arterial oxygen saturation was significantly higher during sitting and standing on days 1 and 4 after operation compared with the supine position (p < 0.05). These results give further evidence for the benefits of patient mobilisation after major surgery.