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Biomedical subjects

H Gustafsson

Publications and source records attributed to H Gustafsson.

At least 73 records · Page 4Linked to original sources

Ultrastructure of bovine ovarian follicles induced to extended growth by perioestrous suprabasal progesterone levels.

The present study was undertaken to determine if a short-term prolonged growth of the ovulatory follicle (12 to 18 h after expected time of ovulation), induced by progesterone implants, would cause ultrastructural changes in the follicular wall. Oestrous behaviour, follicular growth, follicular and blood plasma levels of oestradiol-17 beta, progesterone and plasma luteinizing hormone (LH) were monitored in heifers oophorectomized at 9 to 12 h (controls) or 36 h after the onset of oestrus, in order to sample the pre-ovulatory follicle present. The suprabasal plasma progesterone concentrations (approximately 1.2 nmol L-1) allowed expression of oestrus at the expected time, but ovulation was delayed owing to the absence of a LH-surge. The resulting prolongation of follicle growth was associated with mild degenerative changes in the follicle wall, i.e. both granulosa and thecal cells presented increased electron density, higher amounts of secondary lysosomes and lipid droplets, increased intercellular spaces with presence of debris. No signs of luteinization were seen.

Animals↗

Time- and dose-related changes in the expression of substance P in salivary glands in response to fractionated irradiation.

PURPOSE: The expression of different neuropeptides in the innervation of submandibular and parotid glands of the rats was examined 2 and 5 days after initiation of radiation treatment as well as 10 and 180 days following the termination of irradiation. METHODS AND MATERIALS: The irradiation was given on 2 or 5 consecutive days with daily doses of 4-8 Gy up to a total dose of 20-40 Gy. Immunohistochemical methods were used for the demonstration of substance P (SP), calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY) and, the rate-limiting enzyme in the catecholamine synthetic pathway, tyrosine hydroxylase (TH). The content of SP was also analyzed by the use of radioimmunoassay (RIA). RESULTS: In the parenchyma of both the submandibular and the parotid glands of control animals as well as after 2 days of irradiation treatment, a few nerve fibers showing SP-like immunoreactivity (LI) were observed. A marked increase in the expression of SP in the innervation of the parenchyma in both glands was observed 10 days after cessation of radiation treatment. The number of stained nerve fibers and the intensity of fluorescence in the fibers seemed to be dose dependent because the group subjected to a total dose of 40 Gy displayed a more pronounced staining intensity than that treated with 30 Gy. These results were supported by the RIA analysis. One hundred eighty days after treatment no obvious differences in SP-expression were seen between control and irradiated animals. No acute and long-term alterations were seen with regard to the other peptides and TH. CONCLUSIONS: These results suggest that specific dose- and time-dependent changes in the expression of SP in the parenchyma of both submandibular and parotid glands occur in response to fractionated irradiation. The observations add further aspects to the tissue differences in physiological response and sensitivity to irradiation.

Animals↗

p53 expression and cell proliferation in squamous cell carcinomas of the head and neck.

BACKGROUND: In squamous cell carcinoma of the head and neck (SCCHN), overexpression of the p53 protein has been found in 34-80% of the tumors studied. No data are available regarding p53 expression versus tumor cell proliferation and prognosis for this tumor type. METHODS: p53 protein levels were studied by immunohistochemical staining of 33 primary SCCHN using 3 antibodies (DO7, PAb 1801, and CM1) that react with different epitopes of the p53 protein. The cellular expression of p53 was compared with in vivo incorporation of the thymidine analog iododeoxyuridine (IdUrd) and expression of proliferating cell nuclear antigen (PCNA). RESULTS: Twenty-one tumors (64%) had a positive nuclear staining for p53 with the monoclonal antibody DO7, which reacts with a denaturation-resistant epitope in wild-type and mutant p53. PAb 1801 and CM1 reacted with 19 and 20 tumors, respectively, all of which were DO7-positive. No correlation was found between incorporation of IdUrd and p53 expression or between PCNA and p53 expression. The data indicate that intracellular accumulation of the p53 protein was related to tumor stage and localization of the tumor. No indication of a clinical or prognostic significance of p53 expression in SCCHN was found. CONCLUSIONS: No association between p53 deregulation and tumor cell proliferation was found.

Carcinoma, Squamous Cell↗

Irradiation influences the expression of substance P and enkephalin in the rat larynx.

The effects of radiotherapy on neuropeptide expression in the rat larynx were studied. Irradiation was given for five days, 6 or 8 Gray daily. Ten days after the end of irradiation, the larynx, the laryngeal nerves and different ganglia related to the larynx were dissected out from irradiated and control animals and processed for neuropeptide immunohistochemistry. There was an increased immunolabelling for two of the neuropeptides tested, substance P and enkephalin, in the innervation of the subglottic glands and in the acetylcholinesterase-positive ganglionic cells of the local ganglia. These cells were interpreted as representing postganglionic parasympathetic ganglionic cells. The changes seen in the subglottic glands were interpreted as most likely being related to the changing pattern of staining seen in the local ganglia. No changes in substance P- and enkephalin expression were observed in other laryngeal structures, the nodose ganglia, superior cervical ganglia or laryngeal nerve paraganglia. Thus, in certain respects neuropeptide expression in the larynx is modulated by radiotherapy. Since neuropeptides have both neurotransmitter and/or neuromodulator effects in airway tissue and since they show effects as growth factors, the occurrence of this plasticity in neuropeptide expression should be taken into consideration in future studies examining the effects of irradiation on normal/diseased airway tissues.

Animals↗

Malignant oral tumours in Sweden 1960-1989--an epidemiological study.

Epidemiological data from the Swedish Cancer Registry of new cases of malignant oral tumours in Sweden 1960-1989 are presented, including the total number and the age-standardised incidence rate per 1 million population, by site and sex, (I(s)). An analysis of the various histopathological types of malignant oral tumours in the different sublocations is also given. A comparison is made between the three 10-year periods 1960-1969, 1970-1979 and 1980-1989 regarding total number and I(s). The total number of cases, 17,158, represented 1.8% of all newly diagnosed cancers in Sweden. The following relative frequencies were noted for the respective sites: intra-oral region 0.7%, lip 0.6% and pharynx 0.5%. The results indicated an increase in total number and a statistically significant increase of I(s) for malignant lip tumours in females over the whole period. A corresponding increase in total number during the periods 1960-1969 and 1980-1989 and a decrease in I(s) during the periods 1970-1979 and 1980-1989 in lip tumours for males was observed. For males there was an increase in total number and a statistically significant increase in I(s) for malignant tongue tumours, while the corresponding figures for females remained constant. For malignant floor of the mouth tumours there was an increase in total number and a statistically significant increase in I(s) for both men and women. In the intra-oral region, including the sublocations oral cavity-other sites, tongue and floor of the mouth, the male:female ratio was 1.8:1 and I(s) changed from 22.8 (1960-1969) to 29.6 (1980-1989).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Superovulatory response in lactating cows with different follicular dynamics.

To determine the influence of a dominant follicle on the superovulatory response in midlate lactating cows, the dynamics of follicular growth and the development of corpora lutea and embryos were studied. Real-time B-mode ultrasonography with a 7.5 MHz rectal linear-array transducer was used to scan the ovaries daily, from 8-12 days before superovulation until day 7 post-estrus, when embryos were recovered. On the first day of superovulation cows were classified as belonging to either a 'dominant' group (n = 12) having a 'dominant follicle', i.e. > 9 mm in diameter in growing phase or stable for < 4 days, or a 'non-dominant' group (n = 11) those carrying a 'non-dominant follicle', i.e. a follicle in a regressing phase or with the same diameter for > 4 days. Cows in the 'dominant' group had significantly higher numbers of 4-6 and 7-10 mm follicles than cows in the 'non-dominant' group on the third and the fifth day of superovulation. The total number of follicles (> 4 mm) preovulation and the number of CL day 7 postovulation was higher in the 'dominant' group than in the 'non-dominant' group. There were no differences between groups regarding the total number of embryos or transferable embryos recovered. The results indicate that superovulation in mid-late lactation is not negatively affected by the presence of a 'dominant follicle'. The criteria to define 'dominant' and 'non-dominant' follicles might be redefined when applied to lactating cows, whose response to superovulation seems to be under the influence of many other factors.

Animals↗

Regeneration of parotid acinar cells after high radiation doses. A morphological study in rat.

The acute and late effects of fractionated irradiation on rat parotid gland acinar cells were studied by light and electron microscopy. At 10 days after the last irradiation session (6 Gy or 9 Gy daily during five consecutive days) no effects were seen. At 180 days, minor loss of acini was detectable after a total dose of 30 Gy. After 45 Gy a massive acinar loss was seen at that time; the number of acini had diminished and minor duct-like structures and scattered amounts of fibrous stroma dominated the slides. The remaining acini were disorganized and usually larger compared with the control side and to non-irradiated animals. The acinar cells appeared larger than in the controls. The ducts were better preserved but the intercalated ducts often seemed to be larger than normal. We suggest that this phenomenon indicates a remaining capacity of the parotid gland to regenerate acinar cells even after high radiation doses.

Animals↗

Non-random chromosome rearrangements in adenoid cystic carcinoma of the salivary glands.

The chromosomal findings in 10 adenoid cystic carcinomas (ACC) of the salivary glands are described. Clonal numerical deviations as the sole anomaly were detected in four cases and structurally rearranged stemlines and sidelines in four cases. An apparently identical t(6;9)(q23;p21) was found in two tumors; in one case the translocation was part of the abnormal stemline and in the other case it was the sole anomaly in a single variant cell. A similar or identical t(6;9)(q21-24;p13-23) has recently been reported in three of 15 previously published cases of ACC. The three remaining tumors with abnormal stemlines all had rearrangements of chromosome 9, including t(1;9)(q21;p21-22), der(9)i(9)(q10)inv(9)(q12q13), and der(X)t(X;9)(p21;p22-23), respectively. The latter case also had a t(17;18)(p12;q11.2) that was common to both abnormal clones present in this tumor. In addition to other abnormalities, the clone with der(X)t(X;9) also showed a del(6)(q13q21). In two cases fluorescence in situ hybridization (FISH) was used for further characterization of the marker chromosomes. A survey of the present findings together with previous results from 15 ACC clearly demonstrates that rearrangements of 6q21-24 (deletions or translocations in 11 cases), 9p13-23 (translocations in seven cases), and 17p12-13 (translocations in three cases) are recurrent, and often primary, in ACC, and that the t(6;9)(q21-24;p13-23), found in five tumors, is a non-random, primary aberration.

Adult↗

Effects of irradiation on neuropeptide expression in rat salivary gland and spinal cord.

It is well-known that a large number of factors can influence the expression of neuropeptides in the nervous system. In the present study, the effects of unilateral and bilateral irradiation to the rat head and neck on the expression of neuropeptides in the innervation of the submandibular gland and in the ganglionic cells of the submandibular ganglion was examined ten days and six months after treatment. Antisera directed against enkephalin and bombesin and immunohistochemical methods were used. The effects of bilateral irradiation on the staining pattern of various neuropeptides in the cervical spinal cord were also studied. In the submandibular gland and in the submandibular ganglionic cells, there was a markedly increased neuropeptide expression ten days after bilateral treatment, as seen after staining with both antisera used, while no changes occurred after unilateral treatment. Six months after treatment, the pattern of neuropeptide expression in the submandibular gland/ganglion corresponded to that seen in controls. Irradiation did not lead to any changes in the staining pattern of neuropeptides in the spinal cord. The observations show that there is a great complexity in the susceptibility of nervous tissues to radiotherapy with respect to influences on the expression of neuropeptides.

Animals↗

Effect of induced suprabasal progesterone levels around estrus on plasma concentrations of progesterone, estradiol-17beta and LH in heifers.

A controlled study was carried out to investigate the effects of suprabasal plasma progesterone concentrations on blood plasma patterns of progesterone, LH and estradiol-17beta around estrus. Heifers were assigned to receive subcutaneous silicone implants containing 2.5 g (n=4), 5 g (n=4), 6 g (n=3), 7.5 g (n=3) or 10 g (n=4) of progesterone, or implants without hormone (controls, n=5). The implants were inserted on Day 8 of the cycle (Day 0=ovulation) and left in place for 17 d. The time of ovulation was determined by ultrasound scanning. Blood was collected daily from Days 0 to 14 and at 2 to 4-h intervals from Days 15 to 27. Control heifers had the lowest progesterone concentrations on Days 20.5 to 21 (0.5 +/- 0.1 nmol L(-1)); a similar pattern was observed in heifers treated with 2.5 and 5 g of progesterone. In the same period, mean progesterone concentrations in the heifers treated with 6, 7.5 and 10 g were larger (P < 0.05) than in the controls, remaining between 1 and 2.4 nmol L(-1) until implant removal. A preovulatory estradiol increase started on Days 16.4 to 18.4 in all the animals. In the controls and in heifers treated with 2.5 and 5 g of progesterone, estradiol peaked and was followed by the onset of an LH surge. In the remaining treatments, estradiol release was prolonged and increased (P < 0.05), while the LH peak was delayed (P < 0.05) until the end of the increase in estradiol concentration. The estrous cycle was consequently extended (P < 0.05). In all heifers, onset of the LH surge occurred when progesterone reached 0.4 to 1.2 nmol L(-1). The induction of suprabasal levels of progesterone after spontaneous luteolysis caused endocrine asynchronies similar to those observed in cases of repeat breeding. It is suggested that suprabasal concentrations of progesterone around estrus may be a cause of disturbances oestrus/ovulation.

Journal Article↗

Recurrent rearrangements of 11q14-22 in mucoepidermoid carcinoma.

We describe the cytogenetic findings in five mucoepidermoid carcinomas (MEC) of the major and minor salivary glands. Three of the five tumors analyzed showed an apparently identical t(11;19)(q14-21;p12). In one case, the t(11;19) was the only common clonal abnormality, while in the other two cases the translocation was found together with +16, +20, and inv(1)(p32-33q42), t(6;15)(p12;q25), respectively. The latter case also showed an interstitial short arm deletion of the der(11) chromosome. Of the two remaining cases, one had a del(3)(p13p23) as the sole karyotypic abnormality, while the other had a hyperdiploid stemline characterized by the following numerical deviations: +2, +5, +6, +7, +8, +17, +18, and +19. These findings, together with previously published data from seven from seven MEC, indicate that at least two different, partially overlapping cytogenetic subgroups exist: 1) cases with structural rearrangements of 11q14-22; the finding of three tumors with an apparently identical t(11;19)(q14-21;p12) demonstrates that this is a non-random, and possibly primary abnormality in MEC, and 2) single or multiple trisomies, either observed as the sole anomalies or in combination with structural rearrangements.

Adult↗

A serum-free, cell-free culture system for development of bovine one-cell embryos up to blastocyst stage with improved viability.

With the aim of developing a serum-free, cell-free culture system for embryo development, in vitro-matured (IVM) and -fertilized (IVF) bovine oocytes were cultured in TCM 199 with the following supplements: 1) BSA alone (10 mg/ml); 2) BSA with ITS (5 mug/ml insulin, 5 mug/ml transferrin and 5 ng/ml selenium; BSAITS medium); 3) estrous cow serum alone (ECS; 10%); or 4) ECS with BOEC (bovine oviduct epithelial cells) (Experiment 1). In Experiment 2, embryos were cultured in BSAITS medium with or without feeding with fresh medium on Day 4 (day of insemination = Day 0). Embryos were evaluated on Day 2 for first cleavage, on Day 7 for morulae and blastocysts, and on Day 8 for blastocysts. Blastocysts from Experiment 1 were frozen in 10% glycerol in PBS, thawed and further cultured in ECS medium with BOEC for 48 h, and evaluated for formation of a distinct blastocoel, or expansion and hatching of blastocysts. In vivo-developed, Grade-1 and Grade-2, 7-d-old embryos served as control for the freezing, thawing and subsequent culture procedures. The percentage of first cleavage did not differ between the treatments (74 to 79% in Experiment 1 and 80 to 83% in Experiment 2). The percentage of blastocysts developed in BSAITS medium did not differ from that in ECS medium whether BOEC were present or not. However, medium with BSA alone had fewer blastocysts than any other culture system (P<0.05). Feeding embryos with fresh BSAITS medium on Day 4 did not lead to any further increase in the proportion of blastocysts. The culture systems had a significant effect on the post-thaw viability of blastocysts developed in them (P<0.001). Blastocysts developed in BSAITS medium had better (P<0.05) viability (14/38) than those from medium with ECS alone (1/27) or with ECS and BOEC (3/37). The post-thaw survival of control embryos was 80% (n=30). One of the three transfers of BSAITS-treated, frozen-thawed blastocysts resulted in a pregnancy. The results indicate that a serum-free, cell-free culture system can support the development of IVM-IVF bovine oocytes up to the blastocyst stage with better viability than a complex co-culture system.

Journal Article↗

Increase in mast cells and hyaluronic acid correlates to radiation-induced damage and loss of serous acinar cells in salivary glands: the parotid and submandibular glands differ in radiation sensitivity.

The detailed mechanisms which can explain the inherent radiosensitivity of salivary glands remain to be elucidated. Although DNA is the most plausible critical target for the lethal effects of irradiation, interactions with other constituents, such as cell membrane and neuropeptides, have been suggested to cause important physiological changes. Moreover, mast cells seem to be closely linked to radiation-induced pneumonitis. Therefore, in the present study the effects of fractionated irradiation on salivary glands have been assessed with special regard to the appearance of mast cells and its correlation with damage to gland parenchyma. Sprague-Dawley strain rats were unilaterally irradiated to the head and neck with the salivary glands within the radiation field. The irradiation was delivered once daily for 5 days to a total dose of 20, 35 and 45 Gy. The contralateral parotid and submandibular glands served as intra-animal controls and parallel analysis of glands was performed 2, 4, 10 or 180 days following the last radiation treatment. Morphological analysis revealed no obvious changes up to 10 days after the irradiation. At 180 days a radiation dose-dependent loss of gland parenchyma was seen, especially with regard to serious acinar cells in parotid gland and acinar cells and serous CGT (convoluted granular tubule) cells in the submandibular gland. These changes displayed a close correlation with a concomitant dose-dependent enhanced density of mast cells and staining for hyaluronic acid. This cell population seems to conform with the features of the connective tissue mast cell type. The parotid seems to be more sensitive to irradiation than the submandibular gland. Thus, the present results further strengthen the role of and the potential interaction of mast cells with radiation-induced tissue injury and alterations in normal tissue integrity.

Animals↗

Renin-angiotensin system in neonatal rats: induction of a renal abnormality in response to ACE inhibition or angiotensin II antagonism.

In experiments designed to analyze cardiovascular structure in response to antihypertensive therapy with an ACE inhibitor, we decided to start very early in life with the aim to prevent blood pressure increases and the development of vascular structural changes. In these treated groups of rats we unexpectedly observed that after they were weaned, their water consumption and urine volume, respectively, increased substantially. The present study was designed to determine if inhibition of the renin-angiotensin system produced similar effects in different strains of rats, and focused on characterizing the abnormal fluid balance occurring as a consequence to neonatal treatment with ACE inhibitors or angiotensin II blockers. Three-day-old Wistar Kyoto (WKY), Wistar (WR) and spontaneously hypertensive rats (SHR) were given either saline, enalapril, captopril, losartan and the AT2 blocker, PD123319, in the same amount of volume for 20 days. Treatment was stopped and rats were examined with regard to renal morphology at 4, 14 and 30 weeks of age. In addition, water consumption, urine volume, urine electrolytes and osmolality were analyzed at 14 weeks of age, that is, 10 weeks off treatment. Early treatment with the ACE inhibitors, enalapril and captopril, and the AT1 blocker, losartan, but not the AT2 blocker, PD 123319, in the SHR and in the normotensive strains WKY and WR produced persistent, irreversible histopathological renal abnormalities in adult life, long after the rats had been taken off treatment. These abnormalities consisted of mainly cortical tubulointerstitial inflammation, various degrees of papillary atrophy and pelvic dilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin I↗

Application of dual parameter analysis in flow cytometric DNA measurements of paraffin-embedded samples.

In a comparison of flow cytometric DNA measurements on fresh and paraffin-embedded material from primary squamous cell carcinomas of the head and neck region, we discovered that previously undetected aneuploid clones could be detected by dual parameter analysis of cytokeratin and DNA applied to disintegrated cells from paraffin sections. Using this new approach the correlation coefficient between DNA-indices from fresh and paraffin-embedded material increased from 0.423 to 0.904.

Aneuploidy↗

Rhythmic contractions in isolated small arteries of rat: role of K+ channels and the Na+,K(+)-pump.

Small mesenteric arteries from Wistar rats display rhythmic tension oscillations, associated with oscillations in membrane potential, when stimulated with noradrenaline. The purpose of this study was to investigate the role of potassium conductance and Na+, K(+)-pump activity in the generation of these oscillations. The effect on the rhythmic contractions of several agents, interacting with K+ channels, was studied. Application of apamin, pinacidil or glibenclamide did not affect the rhythmic activity. Tetraethylammonium (TEA) increased the frequency of the rhythmic contractions, while application of 4-aminopyridine (4-AP) increased the amplitude by approximately 50%, with no changes in frequency. Ba2+, on the other hand, impaired the rhythmic contractions or converted them to irregular oscillations in the presence of functional endothelium, but did not affect oscillations in endothelium-denuded vessels. Ouabain or exposure to K(+)-free solution, procedures known to inhibit the Na+,K(+)-pump, abolished the rhythmic contractions. This effect was immediate, suggesting that it was due to elimination of the electrogenic action of the Na+,K(+)-ATPase, rather than to a change in intracellular ion concentrations. Exposure to an extracellular potassium concentration of more than 20 mM also inhibited the oscillation activity. The results suggest that the oscillations are not caused by, but may be modulated by, variations in potassium conductance. The Na+,K(+)-pump seems to play an important role in the generation of rhythmic contractions in these vessels.

4-Aminopyridine↗

Rhythmic contractions of isolated, pressurized small arteries from rat.

The present study was undertaken to examine the influence of transmural pressure on vasomotion and to determine if any such influence was endothelium-dependent. Responses to changes in intravascular pressure of cannulated mesenteric small arteries were investigated under no-flow conditions. Both intact and endothelium-denuded arteries dilated passively when intravascular pressure was increased stepwise from 20 to 140 mmHg. When tone was induced by noradrenaline, pressure increase resulted only in dilatation, independent of endothelium. The sensitivity to noradrenaline was significantly increased in vessels without endothelium, indicating a relaxing influence of the endothelium. Rhythmic contractions in response to noradrenaline occurred in all intact arteries, but were absent when the endothelium was removed. The amplitude of the rhythmic contractions decreased significantly when transmural pressure was elevated. The frequency increased when pressure was elevated from 20 to 80 mmHg and then remained rather constant during further pressure increases. As shown previously in non-pressurized arteries, exogenous cyclic GMP induced oscillations in endothelium-denuded arteries. Pressure-related effects on vasomotion were not dependent on an intact endothelium. Ryanodine, ouabain or verapamil inhibited the rhythmic activity, confirming previous results in non-pressurized arteries. Thus, changes in transmural pressure can modulate vasomotion, but this effect does not appear to be mediated by the endothelium. Generation of vasomotion may depend on release of Ca2+ from intracellular stores, the activity of the Na+, K(+)-pump and transmembrane Ca2+ inflow in a pressurized artery as shown previously in these arteries under isometric conditions.

Animals↗