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Biomedical subjects

H Gustafsson

Publications and source records attributed to H Gustafsson.

At least 19 recordsLinked to original sources

15-Ketodihydro-PGF(2 alpha), progesterone and uterine involution in primiparous cows with induced retained placenta and post-partal endometritis treated with oxytetracycline and flunixin.

Retention of the foetal membranes (RFM) and post-partal endometritis are common problems in dairy cows. Among other things, the disease is characterized by a bacterial endometritis with aerobic as well as anaerobic bacteria. From an endocrine perspective, cows with RFM have high levels of 15-ketodihydro-PGF(2 alpha) (PG-metabolite) immediately after parturition but these levels fall rapidly within 2 weeks post-partum (early PG-metabolite elevation). After this decline, the PG-metabolite levels increase again and the levels (at this time of a lower magnitude) remain elevated during the period of uterine infection (late PG-metabolite elevation). The aim of this study was to investigate the PG-metabolite profiles in cows with retained placenta and post-partal endometritis treated with the prostaglandin synthesis inhibitor flunixin (F), either alone or in combination with oxytetracycline (T). The study was accomplished over 2 years with 12 primiparous cows in each experiment. As a model for RFM, preterm parturition was induced in late-pregnant heifers by injecting PGF(2 alpha) (25 mg i.m) twice with a 24 h interval. In each experiment, the cows were divided into four groups and treated with either T (10 mg/kg b.w. i.m. once daily), F (2.2 mg/kg b.w. p.o. twice per day), a combination of T and F (dosage, as above), or conservatively (0). The treatment periods lasted from day 11 to day 14 post-partum (pp) in experiment 1 (after placental shedding, groups T1, F1, TF1 and 0) and from day 3 to day 6 pp in experiment 2 (before placental shedding, groups T2, F2, TF2 and 0). Jugular vein blood samples were collected for analyses of PG-metabolite and flunixin. Uterine biopsies were collected twice weekly for investigation of endometrial microbiology. Rectal palpation and ultrasonographic examinations were performed three times per week for investigations of uterine and cervical involution and ovarian activity. No attempts were made to remove the placentas manually. The experiment lasted until day 56 pp. The induction of parturition was successful in all heifers and 22 of 24 animals had RFM. All RFM cows had bacterial endometritis, based on bacteriological examinations. Flunixin treatment (F1, TF1, F2 and TF2) suppressed PG-metabolite levels significantly (p=0.006) during the period of treatment in both experiments. However, the early flunixin treatment only suppressed PG synthesis partially. Late oxytetracycline treatment (T1) did not influence the PG-metabolite levels but oxytetracycline treatment (T2 and TF2) before placental shedding significantly altered the kinetics of the early PG-metabolite elevation compared with other treatments. Late PG-metabolite elevation was significantly correlated to duration of uterine infection and cervical involution. In conclusion, flunixin treatment of cows with retained placenta either before or after placental shedding suppresses prostaglandin synthesis. However, early treatment, when the release of prostaglandins is high, might need more intensive treatment in order to prevent the PG synthesis effectively. Oxytetracycline treatment during the period immediately after parturition before placental shedding might influence the PG-metabolite profile and suggests a bacteriological contribution to the high levels of PG-metabolite seen during the first 2 weeks pp in cows with retained placenta. In this study, a correlation between prostaglandin release, the final cervical involution and the end of infection was found. This suggests a link between uterine endocrinology, bacteriology and involution in cows with retained placenta.

Animals↗

Insulin-like growth factor type 1 upregulates uncoupling protein 3.

In this study the expression of uncoupling protein 3 (UCP3) and its regulation by insulin-like growth factor 1 (IGF-I) and insulin in human neuroblastoma SH-SY5Y cells were characterized. Reverse transcriptase-PCR, Western blot, and immunofluorescence analysis showed that SH-SY5Y cells express UCP3 natively. IGF-I induced a time- and concentration-dependent induction of UCP3 protein reaching a twofold expression after 72 h with 10 nM IGF-I. Extremely high insulin concentrations (860 nM) and 10 nM trIGF-I, a truncated form of IGF-I with the same affinity for the IGF-I receptor as the full-length IGF-I, but with lower activity on the insulin receptor, also upregulated UCP3. We conclude that SH-SY5Y cells express UCP3 natively and that the expression is regulated by IGF-I via the IGF-I receptor.

Carrier Proteins↗

Changes in spinal cholecystokinin release after peripheral axotomy.

The gene expression of cholecystokinin (CCK), a neuropeptide with anti-opioid properties, has been reported to be upregulated in some primary sensory neurons after a peripheral nerve lesion. We have recently demonstrated that the upregulation of CCK mRNA is not accompanied by an increased potassium-evoked release CCK-like immunoreactivity (CCK-LI) 2-4 weeks after a complete transection of the sciatic nerve. The potassium-evoked release of CCK-LI at earlier and later time points has, however, not been studied. The aim of the present in vivo microdialysis study was to monitor how the basal and stimulated extracellular level of CCK in the dorsal horn of the spinal cord is affected at various time points after a complete transection of the sciatic nerve (axotomy). During the first week after transection of the sciatic nerve a tendency towards an elevation of the potassium-induced (100 mM in the perfusion fluid) release of spinal CCK-LI was observed. In contrast, no potassium-induced release of CCK-LI could be detected 2-3 weeks and 2 months after axotomy. No significant effect was observed on the basal extracellular levels of CCK-LI in the dorsal horn. The present study provides further support for the notion that the adaptive changes in the dorsal horn 2 weeks and later after a deafferentiation injury do not include an increased release of CCK.

Animals↗

Involvement of spinal N-methyl-D-aspartate receptors in capsaicin-induced in vivo release of substance P in the rat dorsal horn.

The aim of the present in vivo microdialysis study was to determine the possible contribution of N-methyl-D-aspartate (NMDA) or alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)/kainate (KA) receptors to capsaicin-induced release of substance P-like immunoreactivity (SP-LI) in the dorsal horn of the rat. Perfusion of a microdialysis probe with capsaicin (50 or 100 microM) induced a significant eight-fold increase of the extracellular SP-LI level. The capsaicin (50 microM)-evoked release of SP-LI was blocked by spinal administration of the NMDA antagonist 2-amino-5-phosphonopentanoic acid (D-APV; 5 mM), but not by the AMPA/KA antagonist 6-nitro-7-sulphamoylbenzo[f]quinoxaline-2,3-dione disodium (NBQX; 0.5 mM). In contrast, the SP-LI release induced by 100 microM capsaicin could not be prevented by D-APV (10 mM) or NBQX (0.5 mM). The data suggest that the spinal SP-LI release induced by a moderate concentration of capsaicin is in part dependent on the release of glutamate acting on NMDA receptors.

2-Amino-5-phosphonovalerate↗

Clinical and bacteriological aspects on the use of oxytetracycline and flunixin in primiparous cows with induced retained placenta and post-partal endometritis.

Retention of the fetal membranes and post-partal endometritis (RFM) are common problems in dairy cows. Treatment often includes manual removal of the placenta in combination with antibiotic treatment. Earlier studies have shown that cows with endometritis post-partum have a strong tendency to recover spontaneously. The present study focused on treatments of post-partal endometritis with the prostaglandin synthesis inhibitor, flunixin (F) either alone or combined with oxytetracycline (T). The study was conducted in two experiments, using 12 primiparous cows in each. As a model for RFM, premature parturition was induced in late pregnant heifers by injecting PGF2alpha (25 mg i.m.) twice with a 24 h interval. In each experiment the cows were set into four groups and treated with either T (10 mg/kg BW i.m. once daily), F (2.2 mg/kg BW p.o. twice daily), a combination of T and F (dosage, as above) or conservatively (group 0, no drugs). The treatment periods lasted from days 11-14 post-partum in experiment I (groups T1, F1, TF1 and 0) and from days 3-6 post-partum in experiment 2 (groups T2, F2, TF2 and 0). Jugular vein blood samples were collected for analyses of flunixin and total white blood cells. Uterine biopsies were collected twice weekly for investigation of endometrial microbiology. Rectal palpation and ultrasonographic examinations were performed three times weekly for investigations of uterine involution and ovarian activity. No attempts were made to remove the placentas manually. The experiment lasted until day 56 post-partum. The induction of parturition was successful in all heifers and 22 of 24 animals had RFM. All RFM cows had bacterial endometritis. The predominant bacteria were Escherichia coli alpha-haemolytic streptococci, Fusobacterium necrophorum, Arcanobacterium (Actinomyces) pyogenes, Bacteroides spp., Pasteurella spp. and Proteus spp. Fusobacterium necrophorum and A. pyogenes could be isolated for 3-5 weeks post-partum and E. coli Pasteurella and Proteus could be isolated for 2-3 weeks post-partum. Animals treated with tetracycline after placental shedding (T1 and TF1) had a more rapid recovery from infections with A. pyogenes and F. necrophorum than animals that were not treated with tetracycline. No other genera were affected. Antibiotic treatment before placental shedding (T2 and TF2) did not shorten the uterine infection but altered the bacterial flora, seen as an overgrowth of Proteus spp. (p < 0.05) and increased frequency of Pasteurella (p < 0.05). The alpha-haemolytic streptococci were less common in T2 and TF2 than in other groups (NS). Antibiotic treatment of cows before placental shedding (T2 or TF2, n = 6) postponed detachment of placenta compared to cows were no antibiotics were administered before placental shedding (T1, TF1, F1, F2 and 0, n = 16. 9.8 days pp (median) versus p = 0.004). Neither treatment shortened uterine involution. Flunixin treatments did not seem to influence recovery from infection or uterine involution. It was concluded that early oxytetracycline treatment of retained fetal membranes in the cow did not shorten the uterine involution or uterine infection but it did slow down the detachment process of the retained placenta. Oxytetracycline treatment after placental shedding might shorten the uterine infection but otherwise did not affect the clinical results. Flunixin treatment had no influence on the clinical outcome of the disease.

Administration, Oral↗

Morphine-induced in vivo release of spinal cholecystokinin is mediated by delta-opioid receptors--effect of peripheral axotomy.

Morphine and other opioid agonists induce spinal in vivo release of cholecystokinin (CCK), a neuropeptide with anti-opioid properties. However, so far the opioid receptor subtype responsible for this effect has not been determined. In the present in vivo microdialysis study, the morphine-induced release of cholecystokinin-like immunoreactivity (CCK-LI) in the dorsal horn was completely blocked by the delta-opioid antagonist naltrindole (10 microM in the perfusion fluid). Neither the mu-opioid receptor antagonist D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr amide (CTOP; 10 microM in the perfusion fluid), nor the kappa-opioid receptor antagonist nor-binaltorphimine (nor-BNI); 10 microM in the perfusion fluid) had any significant effect in this respect. In addition, systemic administration of the delta-opioid receptor agonist BW373U86 (1 mg/kg, s.c.) and spinal administration of the delta(2)-opioid receptor agonist, Tyr-D-Ala-Phe-Glu-Val-Val-Gly amide ([D-Ala(2)] deltorphin II) (1 microM in the perfusion fluid) induced a significant increase of the CCK-LI level. The effect of BW373U86 on spinal CCK-LI release was completely blocked by spinal administration of naltrindole. The mu-opioid receptor agonist [D-ala(2)-N-Me-Phe(4)-Gly(5)-ol]-enkephalin (DAMGO) (1 microM in the perfusion fluid or 1 mg/kg, s.c.) failed to alter the CCK-LI level. Peripheral nerve lesions have previously been shown to down-regulate mu- and delta-opioid receptors in the dorsal horn, to increase the gene-expression of CCK and CCK-receptor mRNA in dorsal root ganglion neurons and to alter the potassium-induced spinal CCK-LI release. After complete sciatic nerve transection, administration of the two selective delta-opioid receptor agonists induced a significant release of CCK-LI, which was comparable to controls. In contrast, neither systemic nor spinal administration of morphine and DAMGO altered the spinal CCK-LI release in axotomized animals. The present data indicate that the delta-opioid receptor mediates morphine-induced CCK-LI release in the spinal cord.

Analgesics, Opioid↗

15-ketodihydro-PGF2 alpha, progesterone and cortisol profiles in heifers after induction of parturition by injection of dexamethasone.

In order to study rapid changes in 15-ketodihydro-PGF2 alpha, cortisol and progesterone in the period preceding parturition in cattle, pre-term parturition was induced in 4 late pregnant heifers. Parturitions were induced by 2 intramuscular injections of 20 mg dexamethasone with a 24-h interval. The first injection was made on days 254, 258, 264 and 265 in gestation, respectively. Twenty-four h before the first injection an intravenous polyurethane cannula was inserted. Blood samples were collected at least every hour until 12 h after parturition and during the second stage of labour at least 6 times per hour. Plasma was analysed for 15-ketodihydro-PGF2 alpha and progesterone by radioimmunoassays, and for cortisol by an ELISA. The average time from injection to parturition was 7.7 (6.6-8.9) days (mean (range)). Two of the heifers had retained foetal membranes (RFM). At the start of the experiment the levels of PGF2 alpha metabolite were low (< 300 pmol/L) and increased slowly to levels between 1000 and 2000 pmol/L at one day before parturition. During the last day, however, the levels increased rapidly and the highest levels (> 10,000 pmol/L) were reached at the time of delivery. No pulsatile release was seen. Immediately after foetal expulsion the PG-metabolite levels decreased rapidly in all animals. In the 2 animals with RFM, however, this decline ceased within a few h. The PG-metabolite levels in these animals then started to increase and reached levels as high as during parturition. Luteolysis occurred between 1.6 and 0.4 days before parturition in all animals. The cortisol profile showed a distinct peak at the time of parturition in the RFM heifers. This peak was absent in the non-RFM heifers. This study shows that the PGF2 alpha release at prepartal luteolysis and parturition is not pulsatile in cattle and that cortisol profiles in heifers with retained foetal membranes might differ from the profiles in non-RFM heifers at the time of parturition.

Animals↗

Effect of tetracosactid on post partum cyclicity in cows after induction of parturition with PGF2 alpha.

Parturition and retention of fetal membranes were induced with PGF2 alpha in 3 primiparous dairy cows. Starting on day 12 post partum (PP) the cows were treated with 500 micrograms i.m. of ACTH-analogue (tetracosactid) every 6 h for 6 times. Changes in plasma concentrations of cortisol, progesterone and 15-ketodihydro-PGF2 alpha were evaluated immediately after treatment. The effects on the resumption of ovarian activity were evaluated by clinical and ultrasound examinations and by progesterone and 15-ketodihydro-PGF2 alpha analyses for 56 days after parturition. Treatment was able to induce a statistically significant (p < 0.01) similar increase in cortisol and progesterone after both the 1st and the 6th injections, in all cows. No changes in 15-ketodihydro-PGF2 alpha concentrations were seen after any of the injections of ACTH-analogue. The first corpus luteum (CL) was seen on day 18 PP (cow A), and 28 (cow B) and in both cases it was followed by a normal ovarian cyclicity. No CL was observed during the whole period of study in cow C. Progesterone profiles confirmed these clinical and ultrasonographic findings. The steroid output, especially progesterone, induced by the ACTH-analogue might be a stimulus for the onset of ovarian cyclicity, since 2 of the 3 animals ovulated earlier than expected. These findings point to the fact that interference with the stress system might have a positive effect on ovarian cyclicity. The different pattern of response does however demand further studies.

Animals↗

Vascular function and blood pressure in GH transgenic mice.

Acromegaly is associated with cardiovascular disease. We studied vascular function and mean arterial blood pressure in transgenic mice overexpressing bovine GH. Mean arterial blood pressure was measured in conscious, unrestrained male and female bovine GH and littermate control mice during normal as well as high salt intake using telemetric devices. Structure in artificially perfused maximally dilated hindquarter vascular beds and vascular reactivity and endothelial function in small mesenteric vessels were studied in female bovine GH and control mice. Mean arterial blood pressure was increased in female bovine GH transgenic (126 +/- 3 mm Hg) and male bovine GH transgenic (129 +/- 4 mm Hg) compared with female (109 +/- 3 mm Hg, P < 0.05) and male (111 +/- 3 mm Hg, P < 0.05) controls respectively. Increased salt intake had no effect on mean arterial blood pressure. Perfusion studies showed a significant decrease in the average diameter of the female bovine GH transgenic hindquarter vascular bed (P < 0.05). The responses of isolated resistance arteries to nor-epinephrine, potassium-induced depolarization, acetylcholine, or sodium-nitroprusside did not significantly differ between bovine GH transgenic and control mice. We conclude that the phenotype of the bovine GH transgenic mice includes a salt-resistant form of hypertension. Furthermore, the increase in mean arterial blood pressure is accompanied by a significant structural narrowing of the resistance vasculature without changes in vascular reactivity or endothelial function. The results imply that hypertension in bovine GH transgenic mice is maintained mainly by a structurally based increase in peripheral vascular resistance.

Animals↗

Peripheral axotomy increases cholecystokinin release in the rat anterior cingulate cortex.

The anterior cingulate cortex (ACC) is a limbic region with a high density of cholecystokinin (CCK) immunoreactivity, that has been suggested to be of importance for the affective and emotional component of pain. In the present microdialysis study, performed in the awake rat, we demonstrate a bilateral 4- to 6-fold increase of the potassium-induced release of CCK-like immunoreactivity (CCK-LI) in the ACC 2-3 weeks after a unilateral transection of the sciatic nerve (axotomy), an animal model of phantom limb or deafferentiation pain. Considering the implication of CCK in pain modulation and anxiety, we suggest that an altered activity of CCK containing neurons in the ACC may be of importance for the affective component of certain pain conditions.

Animals↗

Effect of ACTH-challenge on progesterone and cortisol levels in ovariectomised repeat breeder heifers.

In order to investigate the potential influence of stress as a component of the repeat breeding syndrome, the adrenocortical capacity for steroid production was evaluated in ovariectomised dairy heifers. In repeat breeder heifers (RBH), marginally elevated plasma progesterone levels during oestrus, so-called suprabasal progesterone levels, have earlier been measured and are believed to impair fertility. The aim was to distinguish if this progesterone could be of extra-gonadal or in this case, adrenal origin. Baseline levels of plasma cortisol and progesterone were determined as well as the corresponding response after induced acute stress in the form of an adrenocorticotropin (ACTH)-challenge. Comparisons were made between strictly selected RBH, n=5 and virgin heifers (VH), n=5 of the Swedish Red and White breed. The heifers were used as their own pre-challenge controls in a 2-day trial. On the control day, saline was injected i.v. and on the treatment day, a synthetic analogue of ACTH (60 microg Synachten(R)). Via a jugular vein catheter, blood samples were collected every 30 min for 6 h each day of the experiment. Analyses for plasma progesterone and cortisol were made. RBH had a significantly higher (P<0.01) pretreatment baseline cortisol level (10.1+/-2.3 nmol l(-1)) than VH (2.6+/-0.2 nmol l(-1)). Moreover, the cortisol response after stimuli was stronger in RBH than VH, especially concerning total hormone production (P<0. 001), but there was also a tendency towards higher peak values (P=0. 06) and longer duration of significantly increased hormone concentrations (P=0.08). Progesterone concentrations, however, did not differ between the groups. Both baseline levels (P=0.25) and posttreatment production (P=0.45) were of the same magnitude in RBH and VH. In conclusion, the study could not confirm that suprabasal progesterone concentrations during oestrus in RBH derive from the adrenal glands. Still, apparent differences were found in adrenocortical activity when ovariectomised heifers, VH and RBH, were subjected to an ACTH-challenge. It is suggested that a sustained adrenal stimulation associated with environmental or social stress could be one factor in the repeat breeding syndrome.

Adrenal Cortex↗

Preface

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Journal Article↗

Induction of parturition with prostaglandin f2 alpha as a possible model to study impaired reproductive performance in the dairy cow.

Parturitions were induced in five cows, 2 weeks before term using prostaglandin (PG) F(2alpha). Two i.m. injections were performed with an interval of 24 h. All cows calved within 5 days (average 2.7 days) after the first injection of PGF(2alpha). Out of five cows, four had retained fetal membranes (RFM). Each animal was sampled for bacteriological examination using uterine biopsies twice a week during 42 days postpartum (PP). Jugular vein blood samples were withdrawn for PGF(2alpha)-metabolite and progesterone analyses five times per day during the first week PP and eight times per 24 h during the 2nd and 3rd weeks PP. From the 4th week, the sampling interval was reduced back to five times per day. From the 5th week PP, the sampling was reduced to two times per day and sampling was terminated after day 46 PP. Only morning samples were used for progesterone analyses. From day 10 PP, ultrasonography (US) was performed every 3rd day until day 39 PP for detection of ovarian activity and follicular dynamics. The highest incidence of bacteriological species was found during the first 3 weeks PP. After the 5th week of collection, all animals were free from bacteria. The species of bacteria found were Arcanobacterium (Actinomyces) pyogenes, Escherichia coli, alpha-hemolytic streptococcae and Pasteurella multocida. Immediately after parturition, very high levels of the PG-metabolite were seen in all animals, with a sharp decrease to line of significance around days 9-12 PP. Small increases above the line of significance were detected up to day 27 PP in cows with RFM, and after that time the levels were considered to be at baseline. Low levels of progesterone were seen in four animals during the whole experimental time. In one animal, an increase was seen on day 43 PP, which was maintained until the end of the experimental period on day 46 PP. Based on US, follicular waves were detected in all animals during the experimental period. In three animals, three non-ovulatory follicular waves were detected and in two animals, four non-ovulatory follicular waves were detected during 39 days of ultrasound sessions. Based on progesterone levels, only one animal was considered to have ovulated around day 40 PP. Results from the present study indicate that reproductive performance of cows after PG-induced parturitions differs from those of spontaneous cases of RFM. Differences regarding the resumption of ovarian activity were also observed between previous studies of dexamethasone-induced parturitions and the present study.

Actinomyces↗

Elevated substance-P-like immunoreactivity levels in spinal dialysates during the formalin test in normal and diabetic rats.

Pharmacologic studies implicate the involvement of substance P in spinal nociceptive processing during the formalin test. However, no direct measurement of the temporal changes in substance P levels within the spinal cord of conscious animals has been reported. Further, dissociation between substance P levels and formalin-evoked nocifensive behavior may exist in diabetic rats, as exaggerated hyperalgesic behavior coexists with reduced peripheral nerve substance P levels. The present study was performed to directly measure the appearance of substance-P-like immunoreactivity (SP-LI) in spinal CSF of conscious, unrestrained rats using microdialysis techniques following injection of formalin into the hindpaw. The effect of diabetes upon formalin-evoked SP-LI levels in spinal CSF dialysates was also determined. In control rats, SP-LI increased in spinal dialysates following formalin injection and levels were maximal 20-30 min after injection, rising to 325% of basal values (p<0.02). Diabetic rats exhibited reduced (p<0.05) SP-LI in their spinal roots, while basal levels in spinal CSF were not different from controls. Formalin-evoked nocifensive behavior was increased in diabetic rats but SP-LI levels in spinal CSF dialysates after paw formalin injection were significantly (p<0.05) attenuated, reaching a maximum of only 161% of basal levels. This was accompanied by attenuated swelling at the formalin injection site and increased thermal response latencies. While increased SP-LI in spinal CSF coincides with phase 2 behavior in the formalin test and may contribute to spinal nociceptive processing during this period, exaggerated spinal substance P release is unlikely to underlie the increased nocifensive behavior seen in diabetic rats.

Animals↗

Clinical signs and hormonal changes in dairy heifers after induction of parturition with prostaglandin F2 alpha.

Parturition was induced in 12 dairy heifers with prostaglandin (PG) F2 alpha about 2 weeks before the expected time of calving. Eight animals gave birth after two injections (group 1), three animals needed more than two injections (group 2) and one animal (cow no. 740) required one injection. All animals in groups 1 and 2 had retained foetal membranes and the time needed to induce parturition was 59 +/- 7 and 149 +/- 10 h, respectively. As cow no. 740 did not have retained foetal membranes and calved 24 h after one PGF2 alpha injection, it was excluded from the results. Udder distension and relaxation of the pelvic ligaments could predict the calving to within 12 h. Furthermore, the pre-calving drop of body temperature could predict the time of parturition to within 16 h. The total white blood cells and polymorphonuclear cells were at their highest values on the day preceding parturition whereas mononuclear cells had a tendency to increase 3 days after calving. Increased levels of haemoglobin were found at the time of parturition, whereas, plasma-calcium levels significantly decreased after parturition (P < 0.001). Progesterone levels markedly decreased after the first PGF2 alpha injection and reached 2 nmol/l at the time of parturition. Plasma levels of oestradiol-17 beta reached the peak at the time of parturition, whereas, the highest levels of the PGF2 alpha metabolite and cortisol were recorded 16 h after calving.

Animals↗

Expression and mutation patterns of p53 in benign and malignant salivary gland tumors.

The expression and mutation patterns of p53 were studied in a series of 68 benign pleomorphic adenomas and 237 malignant salivary gland tumors. p53 overexpression (nuclear staining exceeding 10%) was detected in 20% of the malignant salivary gland tumors, with the highest prevalence observed in polymorphous low grade adenocarcinoma, squamous cell carcinoma, and carcinoma ex pleomorphic adenoma and the lowest in adenoid cystic carcinoma and acinic cell carcinoma. In contrast, none of the 68 benign pleomorphic adenomas had nuclear staining exceeding 10%. SSCP and nucleotide sequence analysis of exons 4 to 9 of p53 in 19 malignant tumors revealed 9 mutations in 7 tumors. Our findings indicate that p53 may be a useful marker to help discriminate between benign and malignant salivary gland tumors.

Blotting, Western↗

Measurement of cholecystokinin release in vivo in the rat spinal dorsal horn.

The microdialysis technique, used to monitor extracellular levels of transmitter substances in the central nervous system of laboratory animals as a reflection of transmitter release, is based on the ability of neurotransmitters to diffuse in the extracellular fluid from the site of release and to cross a semipermeable dialysis membrane. Even though the surgical procedure is not very complicated, the detection of released substances in the recovered dialysate may be difficult. Especially, the measurement of neuropeptide release is limited by the low extracellular concentration and of low recovery as compared to, for example, monoamines. Thus, for example, cholecystokinin (CCK), which is the most abundant neuropeptide in the central nervous system, is found at concentrations that are several orders of magnitude lower than those of classical transmitters. Therefore a highly sensitive detection method is of utmost importance. In the dorsal horn of the spinal cord CCK is found mainly in interneurons and in terminals of descending fibers. CCK seems to be involved in nociceptive transmission and CCK attenuates morphine-induced antinociception. We here describe in vivo microdialysis in the lumbar dorsal horn of the rat with subsequent quantification of the level of CCK-like immunoreactivity (-LI) by a highly sensitive radioimmunoassay.

Afferent Pathways↗