Mechanism of liver-selective thyromimetic activity of SK&F L-94901: evidence for the presence of a cell-type-specific nuclear iodothyronine transport process

The thyromimetic compound SK&F L-94901 shows more potent thyromimetic activity in the liver than in the pituitary gland or heart when administered to rats. The mechanisms of liver-selectivity of SK&F L-94901 were examined using cultured rat hepatoma cells (dRLH-84) and rat pituitary tumor cells (GH3), both of which showed saturable cellular uptake of tri-iodothyronine (T(3)). When isolated nuclei with partial disruption of the outer nuclear membrane were used, SK&F L-94901 competed for [(125)I]T(3) binding to nuclear receptors almost equally in dRLH-84 and GH3 cells. SK&F L-94901 also did not discriminate thyroid hormone receptors (TR) alpha1 and beta1 in terms of binding affinity and activation of the thyroid hormone responsive element. In intact cells, however, SK&F L-94901 was a more potent inhibitor of nuclear [(125)I]T(3) binding in dRLH-84 cells than in GH3 cells at an early phase of the nuclear uptake process and after binding equilibrium. These data suggest that SK&F L-94901 is more effectively transported to nuclear TRs in hepatic cells than in pituitary cells and therefore shows liver-selective thyromimetic activity. In conclusion, SK&F L-94901 discriminates hepatic cells and pituitary cells at the nuclear transport process. The cellular transporters responsible for this discrimination were not evident.

Chromogranin A expression in hepatocellular carcinoma in a patient with germline MEN1 gene mutation

Hepatocellular carcinoma (HCC) was found in a patient with multiple endocrine neoplasia type 1 (MEN 1). The intriguing finding was that the HCC in the patient was positively stained for chromogranin A (CgA), a cellular marker for endocrine and neuroendocrine tumors. The patient had a pancreas endocrine tumor and type C hepatitis, that made pathological diagnosis of the origin of the tumor complicated.

Alkalinizing local anesthetic does not decrease pain during injection for dorsal penile nerve block

STUDY OBJECTIVE

To evaluate whether alkalizing local anesthetic with sodium bicarbonate reduces pain related to infiltration of local anesthetic during dorsal penile nerve block for circumcision.

DESIGN

Prospective, randomized, double-blind, controlled study.

SETTING

E. Wolfson Medical Center, Holon, Israel.

PATIENTS

144 patients aged 15 to 54 years (mean +/- SD = 22.7 +/- 8.8 years), randomized before the block into four groups of 36 patients each.

INTERVENTIONS

Group A (control) received a standard solution of 1 mg/kg lidocaine 2% mixed with 0.5 mg/kg bupivacaine 0.5% without epinephrine (pH = 6.3). Patients in Group B, Group C, and Group D received this mixture added with 8.4% sodium bicarbonate for a mean final pH of 6.90, 7.16, and 7.43, respectively. Penile block was performed using a 23-gauge needle by an anesthetist who was blinded to the pH of the solution.

MEASUREMENTS AND MAIN RESULTS

Patients were questioned regarding pain suffered during injection of the anesthetic solutions by another physicians who also was blinded to the drug used. Pain was rated by a previously reported subjective pain scale. Mean pain scales were 2.0 +/- 0.17, 2.3 +/- 0.15, 2.2 +/- 0.16, and 1.94 +/- 0.15 for Groups A to D, respectively. The differences between these results were not statistically significant.

CONCLUSION

Alkalinizing the acidic local anesthetic solution by sodium bicarbonate does not decrease pain related to infiltration during penile nerve block for circumcision.

Atypical Wegener's granulomatosis with positive cytoplasmic antineutrophil cytoplasmic antibodies, ophthalmologic manifestations, and slowly progressive renal failure without respiratory tract involvement

A 68-year-old woman had microscopic hematuria and proteinuria since the age of 50. She also had hearing impairment, arthralgia, retinal embolism, peripheral arterial occlusion of the right foot and chronic renal failure during the course. At the age of 68, she had progressive renal failure and nephrotic syndrome with high titers of serum cytoplasmic antineutrophil cytoplasmic antibodies (c-ANCA). No evidence of respiratory tract involvement was found. Methylprednisolone pulse therapy and low dose cyclophosphamide therapy ameliorated the renal failure and reduced the serum c-ANCA level. She, however, died on July 19, 1998 due to pulmonary fungal and pneumocystis carinii infection.

Characterization of two novel retinoic acid-resistant cell lines derived from HL-60 cells following long-term culture with all-trans-retinoic acid

Either all-trans-retinoic acid (RA) or vitamin D3 (VD) induces differentiation of the myeloid leukemia cell line HL-60. RA is available for the treatment of acute promyeloleukemia, although the development of resistance to the agent is a serious problem for differentiation-inducing therapy. To approach the mechanisms of resistance to RA, we developed two novel cell lines, HL-60-R2 and R9, which were subcloned after exposure to increasing concentrations of RA. The growth rate of HL-60-R2 cells was significantly increased by RA treatment, whereas the growth rate of HL-60-R9 was not affected. RA induces apoptosis in the parental HL-60 cells. The number of apoptotic cells, however, was not increased and nitroblue tetrazolium (NBT) reduction was not altered by 1 microM RA in either of the cloned cell lines. Treatment with VD induced monocytic differentiation and increased the expression of CD11b in HL-60 and HL-60-R9 cells, but not in HL-60-R2 cells. Flow cytometric and G-banding analysis demonstrated that R2 cells were near-triploid. The sequencing analysis revealed a deletion of three nucleotides in the sequence of the RAR alpha gene in HL-60-R9 cells, resulting in deletion of codon 286. No mutation was found in HL-60-R2 cells. Taken together, these data indicate that the resistance to RA is caused by the mutation in RAR alpha of HL-60-R9, but by other factor(s), which also affect the VD-response pathways, in HL-60-R2. The abnormal response to VD may be associated with the abnormal ploidy of the R2 cells.

Multiple endocrine neoplasia type 1 concomitant with Prader-Willi syndrome: case report and genetic diagnosis

A case of multiple endocrine neoplasia type 1 (MEN 1) accompanied with Prader-Willi syndrome (PWS) was reported. Diagnosis of both diseases have been genetically confirmed. Delay in the diagnosis and management for PWS made surgery for endocrine tumors difficult. This is the first report on the concomitance of MEN 1 with PWS.

1,25-Dihydroxyvitamin D3 suppresses the expression of the VCAM-1 receptor, VLA-4 in human leukemic HL-60 cells

Very late antigen-4 (VLA-4) is the complex with alpha4 and beta1 integrins, which is the receptors to fibronectin and VCAM-1. We evaluate the effect of 1,25(OH)2D3 on the expression of VLA-4 in human leukemic HL-60, U937 cells and human melanoma A375 cells. Flow cytometric analysis demonstrate that the expression of alpha4 integrin is negatively regulated in the cell lines we studied. The expression of beta1 integrin is also decreased in HL-60 and U937 cells. The mRNA expression of alpha4 integrin is significantly decreased by the treatment with 1,25(OH)2D3, whereas 1,25(OH)2D3 does not alter the expression of beta1 mRNA. The adhesion assay demonstrate that the number of adherent cells treated with 1, 25(OH)2D3 is significantly lower than that untreated on VCAM-1-coated wells. Because VCAM-1 is highly expressed in the endothelial cells, it is possible that 1,25(OH)2D3 prevents the attachment of the cells from the endothelial cells in vivo.

Effect of zinc sulfate on sensorineural olfactory disorder

We administered zinc sulfate to patients with sensorineural (post-viral, post-traumatic, or unknown aetiology) olfactory disorder and examined its effects. The patients were divided into three groups by method of treatment: zinc sulfate only, combination of zinc sulfate and the usual therapy, or the usual therapy. For disorders of post-viral and unknown aetiologies, there were no significant differences in improvement among the three groups. However, for post-traumatic olfactory disorder, the zinc sulfate groups had significantly higher improvement rates than did the group that received the usual therapy. The difference between post-traumatic and post-viral olfactory disorders in the effect of zinc sulfate therapy appeared to depend on the pathology of the associated lesions. In cases of post-traumatic olfactory disorder, regenerative capacity is retained in the olfactory epithelium because the blast cells of olfactory receptor cells remain intact. However, for post-viral olfactory disorder, the lack of olfactory receptor cells and blast cells due to viral infection results in loss of regenerative capacity. We also determined pre-treatment serum zinc concentrations in those patients who planned to be treated with zinc sulfate. Pre-treatment serum zinc concentration was not significantly related to improvement rates.

An epidemiological study of postviral olfactory disorder

Postviral olfactory disorder develops after infection with the common cold, and is a relatively severe and prolonged disorder without rhino-sinusitis. This epidemiological study aimed to characterize its clinical pathology and determine the causative virus. Postviral olfactory disorder occurs most commonly in middle-aged women and is most prevalent in spring and summer. A comparison of the monthly frequency of the disorder with the incidence of isolation of various viruses suggest that the influenza virus, respiratory syncytial virus, and herpes virus are not causative viruses, while parainfluenza virus type 3 is most likely to be a causative virus. This conclusion is supported by immunological study and analysis of symptoms of the cold. All patients with postviral olfactory disorder had increased serum antibody titre for parainfluenza virus type 3. No prominent or specific symptoms of common cold were identified as a potential trigger of this syndrome in patient questionnaires.

Clinical study of olfactory disturbance

The clinical records of 889 patients with olfactory disturbance who had been examined at the Olfaction Clinic, Osaka City University Hospital, Japan from January 1982 to December 1996 were studied in order to investigate the relationship between the patients' characteristics and their prognoses. Aetiologically the characteristic variables of "head trauma" and "congenital" had the greatest influence on prognosis, representing poor recovery. The patients with "rhinitis" and "head trauma" showed faster improvement of olfactory disturbance in "females", "those with short duration of olfactory disorder" and "those with high olfactory acuity before treatment". None of the characteristic variables influenced prognosis in the patients with "viral infection". Age did not significantly influence prognosis. Improvement was recognized in most patients within 6 months. Hence, we should treat patients with olfactory disturbance for at least this length of time.

Slow injection of local anaesthetic will decrease pain during dorsal penile nerve block

PURPOSE

To evaluate whether a very slow injection of local anaesthetics during dorsal penile nerve block for circumcision causes less pain than a more rapid injection.

METHODS

In a prospective, double-blind, randomized study, 75 patients aged 15 to 53 yr (mean +/- SD = 22 +/- 8.4 yr) were randomized into two groups. A solution of 2% lidocaine, 1 mg.kg-1, and 0.5% bupivacaine, 0.5 mg.kg-1 without epinephrine to a maximum dose of 10 ml was injected using either a very slow rate (injection time 100 to 150 s, Group A) or a faster rate (injection time 40 to 80 s, Group B). Patients were questioned regarding pain by a physician who was blinded to the mode of therapy. Pain was rated as 1) mild (negligible), 2) moderate (non-negligible, but easily endurable), 3) intense (but endurable) and 4) total refusal to continue.

RESULTS

A significant pain score difference was found between Groups A and B (median = 1 vs. 2, P = 0.0006) as well as a significant correlation between pain score and the rate of infiltration (rs = -0.394, P < 0.0001).

CONCLUSIONS

Slow injection is an important factor in reducing pain during penile block.

Induction of fertile estrus in bitches using a sustained-release formulation of a GnRH agonist (leuprolide acetate)

A single subcutaneous injection of a sustained-release formulation of a potent GnRH agonist, leuprolide acetate (LA; [D-Leu6, Pro9NEt]-GnRH), was evaluated as a method of inducing fertile estrus in 12 mature anestrous and 6 prepubertal beagle bitches. The bitches were treated with microencapsulated LA (100 micrograms/kg, s.c.) at 120 or 150 d post partum, or at 1 yr of age, followed by a GnRH-analogue (fertirelin; [Pro9NEt]-GnRH, 3 micrograms/kg, i.m.) on the first day of induced estrus. Signs of estrus were seen within 10.3 +/- 0.9 d after LA administration in all bitches. The interestrous interval in 120- and 150-d post-partum bitches was shortened (P < 0.05) to 191 +/- 3 and 222 +/- 3 d, respectively, compared with 264 +/- 11 d in control bitches. All LA treated dogs demonstrated behavioral estrus and mated. Three of 6 (50%) at 120 d post partum, 6 of 6 (100%) at 150 d post partum and 5 of 6 (83%) of prepubertal (1-yr old) bitches then became pregnant and produced a mean litter size of 4.1 +/- 0.8 pups. A normal circulating estrogen and progesterone response pattern was observed in mature anestrous bitches. A prepubertal bitch that failed to become pregnant had a similar estrogen response pattern but an insufficient progesterone profile. The results suggest that microencapsulated LA can be useful in inducing fertile estrus in the domestic dogs.

Expression and purification of biologically active porcine follicle-stimulating hormone in insect cells bearing a baculovirus vector

Biologically active recombinant porcine FSH (rec-pFSH) free from the cognate pituitary glycoprotein hormone LH was produced. It was synthesized by a baculovirus vector-insect cell system using two cDNAs encoding the glycoprotein alpha and FSH beta subunits. Its antigenicity was the same as that of pFSH prepared from the pituitary. Glycosylation of rec-pFSH was shown by tunicamycin treatment but the molecular mass of each subunit was lower than that of pituitary-derived FSH, because of the absence of trimming of terminal sugars in insect cells. Rec-pFSH was secreted into the culture medium at about 1 mg/l and purified in six fractions, because of the heterogeneity of the sugar group, by S-Sepharose and concanavalin A-Sepharose column chromatography. The biological activity of rec-pFSH was examined by measuring its effect on progesterone secretion from porcine granulosa cells and germinal vesicle breakdown (GVBD) of porcine oocytes. It showed adequate activity with respect to progesterone secretion, although some fractions rich in the sugar group showed lower activity than that of pituitary-derived FSH. It exhibited higher GVBD activity than that of pituitary-derived FSH at concentrations as low as 1 ng/ml. These results demonstrate that the baculovirus vector-insect cell system can provide biologically active rec-pFSH.

Efficacy of EMLA cream prior to dorsal penile nerve block for circumcision in children

BACKGROUND

While circumcision may be performed solely with dorsal penile nerve block (DPNB), some painful steps in its use are skin needle penetration and infiltration of the anesthetic product. The objective of this study was to evaluate the efficacy of EMLA cream, prior to DPNB for circumcision in children.

METHODS

We conducted a prospective, randomized, double-blinded, placebo-controlled study with 42 children undergoing circumcision with DPNB alone, as an ambulatory procedure. Overall efficacy of EMLA cream (Group A) during needle penetration and infiltration was assessed using a visual analog scale, compared with a placebo cream (Group B). Patients were asked to orally report any pain during skin needle penetration and infiltration of anesthetic, and were graded from 1 to 4 according to intensity of pain, as 1) none, 2) slight, 3) moderate, or 4) severe. The child graded the global discomfort of the entire procedure using the visual analog scale.

RESULTS

When assessing needle penetration, none from Group A suffered any pain, whereas all from Group B suffered at least mild pain. Considering infiltration of the anesthetic, all children suffered at least slight-to-moderate pain. Based on the children's visual analog scale scores, EMLA cream has no beneficial effect for penile block.

CONCLUSION

Since the dorsal penile nerves are located under the Buck's fascia, topical anesthesia may not reach them and other techniques may be necessary to anesthetize them. We found that although EMLA cream is efficient as a topical anesthesia during needle penetration for DPNB, it has no beneficial effect during infiltration.

Recombinant porcine follicle stimulating hormone produced in baculovirus-insect cells induces rat ovulation in vivo and gene expression of tissue plasminogen activator in vitro

Superovulatory responses in cattle are known to be highly variable. In the present study, a recombinant porcine follicle stimulating hormone (rpFSH) produced in baculovirus-insect cells was utilised to evaluate the role of this recombinant FSH in control of the ovulatory process. Immature hypophysectomised rats were implanted with oestrogen pellet (10 mg diethylstilbestrol) and then primed with pregnant mare serum gonadotropin (PMSG, 17.5 IU, sc). Fifty-two hours later, 100 microg rpFSH or saline was injected (sc) to induce ovulation. All rats that received rpFSH ovulated with about eight ova rat(-1), whereas none of the control animals did. Ovulation induced by rpFSH was associated with an increase in the ovarian activity and message levels of tissue-type plasminogen activator (tPA), a protease important in the preovulatory degradation of the follicle wall. Furthermore, addition of rpFSH to the cultured rat granulosa cells resulted in a significant increase in tPA enzyme activity. These results demonstrate that rpFSH produced in baculovirus-insect cells has biological potency in ovulation as well as gene expression of tPA, providing a large advantage of this massive expression system in the reproduction of domestic animals.

Induction of luteinizing hormone surge by pulsatile administration of gonadotropin-releasing hormone analogue in cows with follicular cysts

LH release in response to pulsatile administration of small amounts of GnRH analogue in cows with follicular cysts was examined. The pulsatile administration of GnRH analogue induced a LH-surge like peak over 10 hr in both normal cows and cows with follicular cysts. The mean peak value of LH in follicular cystic cows did not differ significantly from that of normal cows. All the cows with cysts resumed normal estrous cycles with ovulations within 3 weeks of this treatment. These results suggest that the function of the anterior pituitary for LH release in response to GnRH analogue is not abnormal in cows with follicular cysts, and that cystic cows recover to normal conditions after the pulsatile administration of GnRH analogue.

Elevation of serum creatine kinase during treatment with antithyroid drugs in patients with hyperthyroidism due to Graves disease. A novel side effect of antithyroid drugs

We describe 4 patients with Graves disease who had abnormal increases of serum creatine kinase (CK) concentrations during treatment with antithyroid medications. Three of the patients experienced myalgia and muscle cramps. All of the patients manifested an increase in serum CK levels 1 to 3 months after the administration of antithyroid drugs. Thyrotropin concentrations and cardiac systolic time indexes during the elevation of serum CK concentrations were not consistent with hypothyroidism. The mechanisms are not obvious, but it is likely that the rapid decrease of thyroid hormones in tissues may temporarily cause hypothyroid states, resulting in alterations in CK concentrations. It is suggested that hasty correction of thyrotoxicosis should be avoided in susceptible patients, unless the thyrotoxic conditions are critical.

Physiological role of 20alpha-dihydroprogesterone during the estrous cycle in goats

The relationships between the effects of single or repeated subcutaneous injections of 25 mg progesterone on luteal function during the estrous cycle in goats as well as the secretion of 20alpha-dihydroprogesterone or 15-keto-13, 14-dihydro-prostaglandin F(2alpha) (PGFM), the major metabolite of PGF(2alpha), were investigated. A single dose of progesterone given on Day 4, 10, or 18 of the estrous cycle increased the concentration of 20alpha-dihydroprogesterone and did not affect the length of the cycle. Each dose of progesterone on Days 2 to 5 increased the concentration of 20alpha-dihydroprogesterone (with a later decrease each day to a nadir which then increased daily) and shortened the cycle. The 20alpha-dihydroprogesterone concentration remained high; when it decreased, the concentration of the luteolytic agent PGFM began to increase. Daily doses of 25 mg 20alpha-dihydroprogesterone given on Days 2 to 5 had no effect on the length of the cycle. These results indicate that during the estrous cycle in goats, progesterone is catabolized to the biologically inactive steroid 20alpha-dihydroprogesterone, but much of the progesterone that is given early in the luteal phase of the estrous cycle causes premature luteolysis by stimulating an increase in the release of PGF(2alpha) . The secretion of 20alpha-dihydroprogesterone may help to regulate progesterone production during the estrous cycle in goats.

3,5,3'-Triiodo-L-thyronine potentiates all-trans-retinoic acid-induced apoptosis during differentiation of the promyeloleukemic cell HL-60

Although the programmed cell death mediated by thyroid hormone is not well evaluated in mammalian cells, thyroid hormone plays a crucial role in differentiation of the cells during the metamorphosis of Xenopus, suggesting that thyroid hormone has the potential ability to induce the apoptosis. To investigate the thyroid hormone-inducible apoptosis, we cultured HL-60 cells with various amounts of all-transretinoic acid (RA) and L-T3. T3 alone did not induce the apoptosis of the cells. T3, however, suppressed the proliferation of cells in the presence of RA. DNA ladder and microscopical examination showed that the reduction of cell number was due to the apoptosis induced by RA. These findings suggested that T3 affects the apoptotic process during the differentiation of HL-60 cells by RA. T3-inducible apoptosis may require the factors augmented by RA in HL-60 cells.

Baculovirus-insect cell production of bioactive porcine FSH

The in vitro and in vivo bioactivity of recombinant porcine FSH (rpFSH) produced from insect cells through use of a baculovirus expression system were studied and compared with those of natural FSH preparations. Determination of in vitro bioactivity, using the rat Sertoli cell aromatase bioassay, indicated that rpFSH is as active as purified pituitary FSH. Determination of in vivo bioactivity, using the mouse uterine weight bioassay, indicated that rpFSH is as active as purified pituitary FSH. Using the mouse Leydig cell testosterone bioassay, it was demonstrated that the intrinsic LH bioactivity of rpFSH is negligible. The increases in ovarian and uterine weight, and the stimulation in follicular growth in immature hypophysectomized rats induced by rpFSH supplemented with hCG were comparable to those induced by natural FSH preparations. Furthermore, rpFSH alone in hypophysectomized mice stimulated preantral follicular growth to preovulatory stages, and the subsequent injection of hCG caused ovulation. These results demonstrate that in vitro and in vivo biological characteristics of rpFSH produced from baculovirus-insect cells are indistinguishable from those of FSH isolated from natural sources.

Dorsal penile nerve block in children undergoing circumcision in a day-care surgery

PURPOSE

Circumcision is performed under general anaesthesia (GA) with dorsal penile nerve block (DPNB) as an analgesic technique for postoperative pain. The purpose of this study was to compare DPNB as the sole anaesthetic procedure vs GA and DPNB for circumcision in children as an outpatient procedure.

METHODS

In a six-month prospective study, 250 boys aged 6 to 17 yr (mean age 11.5 +/- 3.5 yr) were randomized into two groups. Group A (n = 122) received DPNB only prior to circumcision, and Group B (n = 128) received GA + DPNB. The groups were compared for complications of the block, effectiveness of anaesthesia, operating room time, postoperative time and ease of recovery.

RESULTS

There were no major operative complications in the two groups. Minor block complications, including oedema and haematoma, occurred in 16 (13.1%) boys in Group A and 27 (21.10%) boys in Group B (NS). At surgery, 3 (2.6%) from Group A received additional GA and 1 (0.8%) received additional local anaesthesia. They represent a DPNB failure rate of 3.3%. Mean operating room time was 11 +/- 2.5 min in Group A and 19 +/- 3.5 min in Group B, and post-anaesthesia care unit (PACU) time was 51 +/- 10 min in Group A and 101 +/- 14.5 min in Group B (P < 0.001). Nausea and vomiting in the PACU were noted in one patient in Group A and in 15 in Group B (P < 0.05). Only patients in Group B required additional analgesia and tranquilizers in the PACU (0 versus 20; P < 0.05).

CONCLUSIONS

These data confirm that DPNB has advantages over GA + DPNB for paediatric circumcision in day-care surgery.

Reversible suppression of pituitary-testicular function by a sustained-release formulation of a gnrh agonist (Leuprolide acetate) in dogs

Pituitary-testicular function was studied in 15 dogs following treatment with a sustained-release formulation of a GnRH agonist, leuprolide acetate (LA). Adult male dogs were treated with a single subcutaneous injection of microencapsulated LA (0.1 or 1 mg/kg). Treatment with LA at a dose of 1 mg/kg resulted in decreased (P<0.001) ejaculatory volume and disappearance of morphologically normal spermatozoa within 8 wk and the effect persisted for 6 wk, while the 0.1 mg/kg dose was not adequate to effect suppression of spermatogenesis. The larger dose treatment (1 mg/kg) caused a transient rise in plasma levels of LH and testosterone followed by a marked decline to below the normal level by 2 wk, the low levels being maintained for at least 5 wk, indicating a prolonged effect of LA treatment on pituitary-gonadal axis. Twenty weeks after treatment with LA, a complete return to normal spermatogenesis was observed. The full reversibility of spermatogenesis in the dog after LA treatment suggests that this peptide could be used as a reversible method of male contraception.

Effect of benzodiazepine on antigen-induced eosinophil infiltration into guinea pig conjunctiva

The effect of benzodiazepine (BZP) on experimental allergic conjunctivitis was studied. Male Hartley guinea pigs were sensitized with ovalbumin (OVA) and then homologous anti-OVA serum was injected intravenously into guinea pigs for passive sensitization. BZP was administered at a dose of 5 mg/kg by intraperitoneal injection (i.p.) according to the following schedule respectively; a single, repeated twice a day for 3 days, repeated twice a day for 3 days plus a single and repeated twice a day for 7 days. OVA challenge was performed to the conjunctiva, 20 minutes later, conjunctival edema during the early phase response (EPR) was observed and again at 6 hours later, both eosinophil infiltration into the conjunctiva and the platelet activating factor (PAF) serum level during the late phase response (LPR) were examined. BZP did not inhibit the development of conjunctival edema during the EPR. A single dose of BZP did not inhibit, but repeated doses of BZP for 3 or 7 days significantly suppressed eosinophil infiltration during the LPR. And after repeated doses of BZP for 7 days, all PAF serum levels during the LPR were under the lower detection limit of the assay. These results suggest that BZP has an inhibitory effect on antigen-induced eosinophil infiltration into the conjunctiva during the LPR.

Increasing gonadotropin-releasing hormone release by perifused hypothalamus from early to late anestrus in the beagle bitch

An in vitro perifusion system was used to investigate pulsatile gonadotropin-releasing hormone (GnRH) release from hypothalamic fragments derived from beagle bitches at different stages of the estrous cycle. The spontaneous GnRH release from the excised tissue fragments that include the "mediobasal hypothalamic-preoptic area-suprachiasmatic nucleus units' was episodic throughout all stages of the estrous cycle with a significantly high release rate during late anestrus and late proestrus. The GnRH release rate and plasma levels of luteinizing hormone were positively correlated (r = 0.94, P < 0.01). These results suggest that during the course of anestrus in the bitch the GnRH release rate increases while the pituitary responds accordingly.