Acute left atrial thrombus causing cardiogenic shock following mitral valve replacement: report of a case

We report herein the rare case of a 53-year-old woman who developed cardiogenic shock due to an acute left atrial thrombus following replacement of the mitral valve. A definitive diagnosis was not able to be made using precordial echocardiography because of the broad, flat shape of the thrombus; however, transesophageal echocardiography imaged the thrombus in detail. The patient was initially stabilized by percutaneous cardiopulmonary support after which a thrombectomy was successfully performed.

Role of endothelin-1 in beagles with dehydromonocrotaline-induced pulmonary hypertension

BACKGROUND

Although plasma levels of endothelin-1 (ET-1) increase in patients with pulmonary hypertension (PH), its role in PH is unknown. We investigated the contribution of endogenous ET-1 to cardiopulmonary changes in beagles with dehydromonocrotaline (DMCT)-induced PH.

METHODS AND RESULTS

Eight 3-month-old beagles were given a single injection of 3 mg/kg DMCT via the right atrium. During the 8 weeks after injection, the mean pulmonary arterial pressure (PAP) and plasma ET-1 level increased significantly from 11.6 +/- 2.3 to 35.9 +/- 7.1 mm Hg and from 1.24 +/- 0.25 to 3.25 +/- 0.94 pg/mL, respectively. In controls, ET-1 infusion elevated the systemic arterial pressure (SAP) but did not alter PAP. In PH beagles, ET-1 infusion increased SAP, which was attenuated by FR139317 (an endothelin type [ET] A receptor antagonist), and produced a dose-dependent decrease in PAP, which was attenuated by RES-701-1 (an ETB receptor antagonist). In PH beagles, FR139317 infusion decreased PAP, and RES-701-1 infusion increased PAP. Sarafotoxin S6c (an ETB agonist) infusion decreased PAP in PH beagles.

CONCLUSIONS

These results suggest that endogenous ET-1 is elevated in PH disease and may mitigate PH by acting on ETB receptors.

Streptokinase gene variable region classification in streptococci: lack of correlation with post-streptococcal glomerulonephritis

To investigate a possible causal role of streptokinase (SKase) in acute post-streptococcal glomerulonephritis (APSGN), the major variable region of SKase genes of Streptococcus pyogenes strains isolated from patients with and without APSGN were analyzed using the polymerase chain reaction, restriction enzyme analysis and the direct sequencing of SKase genes. In the APSGN-associated strains, six of nine revealed mutant classes corresponding to the nephritogenic classes I and II proposed by Johnston et al. [1992], the remaining three belonged to non-nephritogenic classes. In twenty strains not associated with APSGN, seventeen belonged to classes I and II, while three were from other classes. The major variable region of the SKase gene shows no apparent relation with induction of APSGN in humans, suggesting that unique classes of streptococcal SKase do not play a role in the pathogenesis of APSGN.

Prognostic significance of microvessel count in low stage renal cell carcinoma

BACKGROUND

It has been postulated that tumors beyond a certain size are dependent on angiogenesis, which might also be related to distant metastasis. We therefore assessed the prognostic significance of tumor microvasculature in renal cell carcinoma.

METHODS

Tumor specimens from 84 patients with primary renal cell carcinoma were examined by immunohistochemical staining for factor VIII. Individual microvessels were counted in a 200 x field overlying the area of highest neovacularization.

RESULTS

The mean number of microvessels in patients with metastases was significantly higher than that in patients who were disease-free for more than three years (P = 0.004). The survival of patients with less than 30 microvessels per 200 x field was significantly higher than that of patients with more than 30 microvessels per 200 x field (P = 0.007). Multivariate analyses revealed that these microvessel counts were the only significant predictor of prognosis in 45 patients with T1-2 and M0 tumors (P = 0.028).

CONCLUSIONS

Assessment of tumor microvasculature is therefore probably one of the most important prognostic predictors in renal cell carcinoma.

Intraocular pressure response to intravitreal injection of endothelin-1 and the mediatory role of ETA receptor, ETB receptor, and cyclooxygenase products in rabbits

Endothelin-1 (ET-1) affects intraocular pressure (IOP) in rabbits. First, we studied IOP responses to the intravitreal injection of various doses of ET-1 ranging from 5 ng to 5 micrograms in unanesthetized rabbits, and observed a transient rise in IOP, from 0.5 to 2 h in duration, invariably followed by a prolonged IOP reduction, lasting for more than 72 h in rabbits treated with 0.5 microgram and 5 micrograms of ET-1. ET-1 (0.05 microgram and 0.15 microgram) resulted in a prolonged IOP reduction without an early IOP rise. Both IOP rise and reduction were significantly related to the dose of ET-1. A masked, randomized, study revealed that the intraperitoneal administration of indomethacin (50 mg/kg) prior to ET-1 injection significantly reduced the ocular hypertensive response, but not th ocular hypotensive response, to ET-1. The ETA receptor selective antagonist, 97-139 (155 micrograms) had no effect on IOP when used alone. However, when used in combination with 0.5 microgram of ET-1, 97-139 significantly inhibited both the IOP rise (0.5-2 h) and reduction (8-96 h) caused by ET-1. The ETB receptor selective agonist, sarafotoxin S6c (0.5 microgram), caused a sustained IOP reduction of 2 to 96 h in duration without the initial IOP rise. We also determined the concentration of prostaglandin (PG) E2 in the aqueous humor using radioimmunoassay techniques on samples obtained at 1 and 24 h after ET-1 injection, and examined the effects of pretreatment with indomethacin or 97-139 on PGE2 concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

[Value of serum PSA and PAP measurement with newly developed latex turbidimetric immunoassay]

Serum prostate specific antigen (PSA) and prostatic acid-phosphatase (PAP) levels in normal controls, and patients with prostate cancer, benign prostate hypertrophy (BPH) and other urological diseases were examined with a newly developed latex turbidimetric immunoassay (LPIA ACE PSA, LPIA ACE PAP, IATRON LABORATORIES, INC., Tokyo, Japan). The advantageous characteristics of this method are small amount (10 microliters) of serum required and short time (about 20 min.) for performing this assay. There was a high linear correlation between LPIA ACE PSA and MARKIT-F PA (r2 = 0.953), between LPIA ACE PSA and TANDEM-E PSA (r2 = 0.881) and between LPIA ACE PAP and ABBOTT-PAP EIA (r2 = 0.946). When the BPH patients (n = 110) were used as negative controls, the cut-off value of PSA was determined to be 4.3 ng/ml. Using this level as the cut-off value, the sensitivity was 78% (42 positive/54 untreated prostate cancer patients), specificity (negative rate in BPH patients) was 95% and efficiency was 89%. In a follow-up study of prostate cancer, the PSA value was elevated above the cut-off value in 68% at the time of clinical progression. These findings suggest that LPIA ACE PSA is a useful tool for serum PSA measurement. The cut-off value of PAP measured with LPIA ACE PAP was 9.0 ng/ml, which was determined by the same method as PSA. The sensitivity, specificity and efficiency ware 39%, 96% and 77%, respectively. These findings indicate that PAP is less useful than PSA in the diagnosis of prostate cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Caloric intake stimulates growth hormone secretion in food-deprived rats with anterolateral deafferentation of the medial basal hypothalamus or administered antiserum to somatostatin

In rats, food deprivation inhibits episodic growth hormone (GH) secretion. On the basis of previous studies, we hypothesized that during a recovery from prolonged fasting, caloric intake stimulates the release of GH-releasing factor (GRF) and this process does not depend on the specific macronutrients in the meal, while protein in the meal acts to restore characteristic ultradian rhythmicity of GH secretion. To test this hypothesis, the effect of caloric intake on GH secretion was examined in fasted adult male Wistar rats devoid of somatostatin (SS) influence on GH secretion either by anterolateral deafferentation (ALC) of the medial basal hypothalamus (MBH) or administration of anti-SS goat serum (ASS). Rats were provided with an indwelling right atrial cannula and were deprived of food for 72 h. ALC was performed 2 weeks prior to the study. ASS was given i.v. 8 h and 7 h prior to refeeding, respectively. Serial blood specimens were collected every 10 min. In rats with ALC (ALC rats) or rats given ASS (ASS rats), the blood GH level revealed irregularly occurring small fluctuations, instead of the usual high bursts and low trough level. The baseline GH level and the mean GH level of fasted ALC rats or fasted ASS rats were significantly lower than those of fed ALC rats or fed ASS rats. Feeding the isocaloric mixed meal, the protein meal or the protein-deficient meal increased the GH pulse frequency, the pulse amplitude, the baseline GH level and the mean GH level in 72-h fasted ALC rats. These changes in GH secretory pattern persisted during the period of observation and were independent of the type of meal ingested. Following feeding the mixed meal, similar changes in the GH secretory pattern demonstrated in 72-h fasted ALC rats were also observed in 72-h fasted ASS rats, suggesting that the stimulation of GH secretion following caloric intake is not limited to ALC rats. Since the influence of SS on GH secretion has been largely eliminated in ALC or ASS rats, it is highly unlikely that the augmentation of GH secretion following feeding after prolonged food deprivation was the consequence of inhibition of SS secretion. Although GRF measurement was not performed, it is conceivable that the signal of caloric intake is conveyed to the MBH and acts to stimulate GRF release.

[Surgical treatment and long-term results of cardiac myxoma in 38 patients]

Long-term results of thirty-eight patients with cardiac myxoma, who underwent resection at National Cardiovascular Center between May, 1978 and December, 1993, were reviewed focussing on embolism, cerebral complication, tumor recurrence and metastasis. The mean age was 49.6 years (range 0 to 74) in 20 female and 18 male. Overall follow-up were known for 35 of 38 patients (92.1%), and an average of follow-up period was 6.7 years (range 0.5 to 15.9 years). 15 of 38 patients (34.2%) had embolism (brain 10, peripheral artery 4, coronary 1) preoperatively. All patients survived operation and the hospital mortality rate was 0%. Long-term results were almost satisfactory (myxoma related-death in one patients). However, distant metastasis occurred in two patients, and tumor recurrence in one patient irrespective of a presence of preoperative embolism. Cerebral embolism occurred in one patient and cerebral arterial lesins were noticed in five patients postoperatively. Cardiac myxoma has a malignant potentiality and a close follow-up is necessary about recurrence, metastasis and cerebral artery disease.

Methylprednisolone inhibits increase of interleukin 8 and 6 during open heart surgery

It has been reported that interleukin 8 (IL-8) and interleukin 6 (IL-6) are two of the chemical mediators causing myocardial injury. It is not clear whether treatment with corticosteroids in vitro in these patients can prevent the production of interleukin 8 and 6. This prospective study was conducted to investigate whether methylprednisolone (MP) pretreatment (30 mg.kg-1 before CPB and before declamping of aorta) influenced the production of IL-8 and 6 in the peripheral circulation in 27 patients undergoing elective coronary artery bypass surgery. The IL-8 and IL-6 concentrations were measured by ELISA kit. We also studied the effect of MP pretreatment on postoperative cardiac function. Serum concentration of IL-8 in non-MP-treated patients (37 +/- 44 pg.ml-1 preoperatively) increased to 169 +/- 86 pg.ml-1 60 min after declamping of the aorta (P < 0.001). The increase was greater than the increase from 22 +/- 8.9 pg.ml-1 to 52 +/- 35 pg.ml-1 in the MP-treated patients (P < 0.01). Serum IL-6 concentration in non-MP-treated patients increased from the preoperative value of 59 +/- 30 pg.ml-1 to 436 +/- 143 pg.ml-1 60 min after declamping of the aorta (P < 0.001). The increase was greater than the increase from 36 +/- 15 pg.ml-1 to 135 +/- 85 pg.ml-1 in the MP-treated patients (P < 0.01). Furthermore, postoperative cardiac index in MP-treated patients (3.6 +/- 1.1 L.min-1.m-2) was higher than 2.3 +/- 0.8 L.min-1.m-2 of non MP-treated patients (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of target organs for the latency of murine cytomegalovirus DNA using specific pathogen free and germfree mice

Cytomegalovirus (CMV) establishes a latent infection in its host; however, the organ sites of viral latency and its mechanism still remain to be fully clarified. To elucidate this issue, a latent infection with murine (M) CMV was attempted to induce in mice and the organ sites of the latent viral genome were examined for more than one year by a polymerase chain reaction (PCR). As a result, latent MCMV DNA was detectable in both the lung and the spleen as late as 59 weeks after infection. The heart was also observed to be a target organ of latent MCMV DNA, though the amount of viral DNA was much less than that seen in the lung and spleen. In germfree (GF) mice, on the other hand, no such latent viral DNA was observed in the spleens, while it was seen, but to a significantly smaller degree, in the lungs and the hearts than in the same organs of specific pathogen-free (SPF) mice. The amount of infectious virions generated in the host appeared to be almost equal between the GF and SPF mice. The above findings therefore suggest that the spleen, lung and heart are target organs for MCMV latency and the indigenous bacterial flora, which are not colonizing in GF mice, play an important role in the establishment of such viral latency in SPF mice.

[Clinical evaluation of 99mTc-MAG3 as a radiotracer to assess the function of transplanted kidney: comparison with 123I-OIH]

99mTc-MAG3 (mercaptacetyl glycilglycilglycine) is a newly developed radiopharmaceutical for the functional imaging of kidneys. We evaluated the clinical usefulness of 99mTc-MAG3 in 12 cases (7 men and 5 women, aged from 18 to 57 years old) with transplanted kidney, and compared it with 123I-OIH (o-iodohippurate). Immediately after bolus injection of 300 MBq of 99mTc-MAG3, first pass images (1 frame/3 sec for 1 min) and dynamic renal images (1 frame/60 sec for 30 min) were recorded. In 10 of 12 cases, the same examination was carried out using 37 MBq of 123I-OIH within 2 weeks. Because of its larger dose and suitable gamma-ray energy, 99mTc-MAG3 provided much better images than 123I-OIH, particulary among first pass images. Effective renal plasma flow (ERPF) calculated from the clearance of 99mTc-MAG3 was less (about 70%) than that of 123I-OIH, however, a strong correlation (r = 0.98, p < 0.001) was observed between the ERPF values of the two radiotracers. No adverse effects were caused by 99mTc-MAG3. Our data suggested that 99mTc-MAG3 was a promising radiopharmaceutical with which to evaluate regional dynamic renal function.

Two isotypes of murine nm23/nucleoside diphosphate kinase, nm23-M1 and nm23-M2, are involved in metastatic suppression of a murine melanoma line

A series of sublines of a murine melanoma B16 of C57BL/6 origin were established and examined regarding their metastatic capacity and expression of nm23. The number of pulmonary metastases developed by these sublines was inversely correlated with the expression of two isotypes of nm23, nm23-M1 and nm23-M2. The cDNAs of nm23-M1, nm23-M2, and a combination of both were transfected into the highly metastatic melanoma subline FE7, with low nm23 expression. FE7 transfectants of any of these cDNAs expressed transfected genes, and their metastatic capacity was suppressed when compared with parental FE7 or FE7 transfected with a control neo gene. These cell lines, however, did not change in terms of in vitro growth in the presence of 3 or 10% fetal bovine serum and in vivo growth when injected s.c. into C57BL/6-nu/nu mice. Similar experiments were also performed using FE7 transfectants of human nm23 genes. Transfectants of nm23-H1, nm23-H2, and their combination did not present altered metastatic potential. These findings indicated that two murine isotypes of nm23 but not those of humans are intimately related with the suppression of metastasis in the murine body.

Hyper-dopaminemia may produce an increased outlet resistance of the prostatic urethra: a case report of malignant pheochromocytoma

We report on a 43-year-old man with difficult urination attributed to malignant pheochromocytoma with hyper-dopaminemia. A decrease and increase in the plasma dopamine values during the clinical course clearly coincided with improvement and deterioration, respectively, in urination difficulty. The prostatic peak pressure decreased by 37% when the plasma dopamine value was minimal. Detrusor function was normal throughout. Endocrinological and urodynamic studies suggested that hyper-dopaminemia produced an increased outlet resistance of the prostatic urethra without altering detrusor function. Thus, peripheral dopaminergic systems may influence voiding mechanisms, especially those involving the proximal urethra.

Choroid plexus papilloma containing melanin pigment

The authors report a case of a choroid plexus papilloma in the fourth ventricle containing melanin pigment. The pigmented granules in this tumor were positive for Fontana-Masson, periodic acid-Schiff, acid fast and Sudan staining, suggesting that the pigment contained lipofuscin as well as melanin. The possibility that the melanin derived from lipofuscin by "melanization" through pseudoperoxydation is discussed.

Identification of a new bovine MHC class II DRB allele by nucleotide sequencing and an analysis of phylogenetic relationships

Three overlapping cDNA clones coding for the bovine major histocompatibility complex (MHC) class II DR beta chain were isolated. A clone NR1 encoded a primary translated product of 266 amino acids, 29 of which were deduced to form a signal peptide and 237 to form the mature polypeptide. The protein predicted from this cDNA appeared to have all the features expected of an expressed MHC class II molecule. Comparison of the sequences and construction of a phylogenetic tree revealed that NR1 represents a BoLA-DRB3 gene and not a BoLA-DRB1 or BoLA-DRB2 pseudogene. NR1 and ovine sequences exhibited the greatest overall similarity among sequences from various mammalian species, followed by the equivalent human sequences. Indeed, the bovine allele was more closely related to certain ovine alleles than to other bovine alleles. A large number of replacement substitutions were identified when beta 1 domains encoded by NR1 and each of the 36 distinct BoLA-DRB3 alleles were compared, and most of the allelic variations were found in regions that are commonly polymorphic in DRB sequences from different species and correspond to the predicted antigen-recognition site. Thus, the predicted structure of the unique NR1 allele for BoLA-DRB3 further confirms the overall conservation of the product of this locus, as previously established from studies in rodent and man.

Effect of cyclic AMP on urokinase-type plasminogen activator receptor and fibrinolytic factors in a human osteoblast-like cell line

We investigated the effect of cyclic AMP (cAMP) on the pericellular fibrinolytic system in NY cells. Dibutyryl cAMP (dbcAMP) or forskolin increased the level of urokinase-type plasminogen activator (u-PA) mRNA and enhanced the secretion of u-PA antigen into the conditioned medium. These agents also increased u-PA antigen on the cell surface. PA inhibitor-1 (PAI-1) antigen was inhibited by dbcAMP or forskolin. Butyrate had no effect on the production and secretion of u-PA and PAI-1. A binding assay of 125I-DFP-u-PA to NY cells revealed a single class of binding sites with a Kd of 3.85 nM and Bmax of 0.89.10(5) binding sites/cell. The Bmax was increased by dbcAMP (1 mM or 10 mM), forskolin (2 microM or 20 microM) of 1.0-, 1.4-, 1.2- and 1.8-fold, respectively. However, the Kd value was not changed. Furthermore, the level of mRNA for the u-PA receptor (u-PAR) was increased by these agents 1.2-, 1.7-, 1.8- and 2.5-fold, respectively. However, butyrate did not alter either the Bmax or the u-PAR mRNA level. These results indicated that the pericellular fibrinolytic activity induced by u-PA/u-PAR is modulated by cAMP in osteoblast-like cells.

Endothelin receptor antagonists in a beagle model of pulmonary hypertension: contribution to possible potential therapy?

OBJECTIVES

This study investigated the pharmacologic effect of endothelin receptor antagonists on cardiopulmonary hemodynamic variables in a beagle model of pulmonary hypertension.

BACKGROUND

We recently developed a beagle model of pulmonary hypertension that allows accurate determination of cardiopulmonary hemodynamic variables and is associated with elevated plasma endothelin-1 concentrations similar to those in pulmonary hypertension in humans.

METHODS

Twelve beagles (pulmonary hypertension, n = 6; control group, n = 6) were studied during baseline conditions and during right atrial infusion of FR139317 (an ETA receptor antagonist), RES-701-1 (an ETB receptor antagonist), nitroglycerin and prostaglandin E1. Pulmonary hypertension was induced in experimental beagles 8 weeks after injection with 3 mg/kg body weight of dehydromonocrotaline.

RESULTS

FR139317 lowered pulmonary artery and systemic arterial pressures in both pulmonary hypertensive and control beagles, with a significantly greater effect on pulmonary artery pressure in pulmonary hypertensive dogs. RES-701-1 tended to increase pulmonary artery pressure only in pulmonary hypertensive beagles. Nitroglycerin depressed pulmonary artery and systemic arterial tone equally well in control and pulmonary hypertensive animals. Prostaglandin E1 produced a greater decrease in systemic arterial pressure in pulmonary hypertensive than in normal beagles despite having the same effect on pulmonary artery pressure in both.

CONCLUSIONS

ETA receptor antagonists decrease pulmonary artery pressure in a beagle model and may therefore be clinically useful for treatment of pulmonary hypertension.

Neutrophil elastase inhibitor reduces asthmatic responses in allergic sheep

To determine the role of neutrophil elastase in asthmatic responses, we studied the effect of ONO-5046, a specific neutrophil elastase inhibitor, on antigen-induced asthmatic responses in allergic sheep. Pulmonary resistance (RL) was measured for 8 h after antigen challenge. Measurements of airway responsiveness to methacholine and bronchoalveolar lavage fluid (BALF) were obtained 8 h after challenge. Antigen challenge caused early and late increases in RL, airway hyperresponsiveness (AHR), and recruitment of neutrophils and eosinophils along with increases in TXB2 and LTB4 in BALF. ONO-5046 treatment significantly reduced both early and late bronchoconstriction, neutrophil recruitment, increases in LTB4 in BALF, and AHR. ONO-5046 post-treatment significantly reduced the increase in RL 8 h after antigen challenge. Another neutrophil elastase inhibitor, FR 134043, significantly reduced both early and late bronchoconstriction. ONO-5046 had little effect on calcium ionophore-induced LTB4 release from isolated neutrophils and whole blood obtained from drug-treated sheep. These findings suggest that neutrophil elastase is involved in antigen-induced bronchoconstriction and AHR mediated by neutrophil accumulation and 5-lipoxygenase products in allergic sheep.

[Morphological changes in major pelvic ganglion neurons and histological structure of bladder using rat model of partial urethral ligation]

Ninety six rats were divided into 4 groups (normal control group (N = 4), ligation group (N = 20), ligation-removed group (N = 36), and sham surgery group (N = 36)). The neuronal size of the 4-week ligated rats returned to normal 6 weeks after removal of the ligation. Rats ligated for 7, 11 and 20 weeks also exhibited a significant increase in the mean area but they could not make a complete recovery after removal of ligation for 6 weeks. Only the rats in the 1- and 4-week ligation groups could recover their neuronal size. Area densities of smooth muscle: connective tissue (ADsc ratio) was calculated using Elastica van Gieson staining sections of bladder strips. When ligation was removed, the ratio dropped and became nearly equal to the value of the sham surgery group. Only the 7-week group showed a lower ADsc ratio than the sham surgery group after the ligation was removed. These findings suggest that the reversibility of neuronal hypertrophy might become irreversible when the period of partial urethral ligation persisted beyond 7 weeks. Irreversible hypertrophy of major pelvic ganglion (MPG) neurons might be greatly related with the irreversibly enlarged fibrous bladder which could not show the same ADsc ratio as was seen in the sham surgery groups.

[Experimental studies on evaluation of rat testicular function by 31P magnetic resonance spectroscopy]

To evaluate the efficacy of 31P magnetic resonance spectroscopy (31P MRS) as a diagnostic method for abnormal testicular function, we examined three conditions using rat testes, ischemia, irradiation, and hormone manipulation. 1) Ischemia: Immediately after clamping of the feeding vessels, ATP signals began to fall and disappeared within 60 minutes. With the release of blood supply after 3 hours of ischemia, ATP appeared within 2 hours. However, after more than 4 hours of ischemia, ATP did not recover within 2 hours and the testis became necrotic after 1 week. 2) Irradiation: 31P MRS of the testis 2 weeks after irradiation with 10 Gy., 9 MeV showed a significant decrease (P < 0.05) in the PME/beta-ATP ratio from 1.30 +/- 0.11 (control level) to 1.11 +/- 0.12 and a decrease in PME/PDE ratio from 1.43 +/- 0.17 to 1.13 +/- 0.20. However 3 weeks later, the PME/beta-ATP ratio recovered to a control level. 3) Hormone manipulation: In the testes 5 weeks after weekly intramuscular injections of estradiol benzoate and testosterone enanthate, PDE/beta-ATP ratio significantly increased (P < 0.01) from 0.83 +/- 0.09 (control level) to 1.03 +/- 0.19. 31P MRS is a non-invasive method for evaluation of various testicular abnormalities, and ATP signals may be useful to evaluate an acute ischemic change for example testicular torstion and the changes of PME, PDE signals may be useful parameters in the assessment of the status of spermatogenesis.

Suppression of lymphocyte blastogenesis in cows with puerperal metritis and mastitis

Mitogenic responses of peripheral blood lymphocytes in naturally occurring clinical puerperal metritis and mastitis were investigated. Glucose consumption index (GCI) values for phytohaemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) in the puerperal metritic cows and mastitic cows were significantly lower than those in the healthy cows. Suppression of lymphocyte blastogenesis was correlated to an increased concentration of serum ammonia in the puerperal metritic cows, and of alpha 1-acid glycoprotein (alpha 1AG) in the mastitic cows. Lymphocyte blastogenesis in the mastitic cows was also correlated to the serum concentration of vitamin E. These findings indicate that the puerperal metritic and mastitic cows are associated with impaired lymphocyte blastogenesis.

The ocular hypotensive effect of the ETB receptor selective agonist, sarafotoxin S6c, in rabbits

PURPOSE

Endothelin-1 (ET-1) is known to affect intraocular pressure (IOP) in rabbits, and the IOP response is likely to be mediated by the receptors ETA, ETB, or both. Sarafotoxin S6c (STX-S6c) is a selective agonist to ETB receptors. The authors attempted to clarify the role of ETB receptors in changes in IOP induced by ET-1 in rabbits using STX-S6c and to determine the relationship between the IOP response and various doses of STX-S6c.

METHODS

Each concentration (10(-4) to 10(-7) M) of STX-S6c was injected intravitreally (20 microliters/eye) into one eye. The contralateral eye of each was used as a control. The IOP was measured periodically using a calibrated pneumatonometer. Indomethacin (50 mg kg-1) or vehicle (10 ml kg-1; 0.05 M phosphate buffer) was administered intraperitoneally twice, before and after intravitreal injection of STX-S6c (10(-5) M), and IOP was measured in the same protocol for 24 hours.

RESULTS

In the STX-S6c (10(-4) and 10(-5) M) group, the IOP reduction was significant compared with the baseline (P < 0.05 to P < 0.01), starting from 6 and 4 hours and continuing until 192 and 72 hours after injection, respectively. A solution of 10(-6) M STX-S6c also resulted in significant reduction of IOP observed from 24 to 72 hours after injection (P < 0.05). The 10(-7) M solution of STX-S6c failed to affect IOP. The area under the curve of IOP response exhibited a significant correlation with the doses of STX-S6c (r = -0.856; P = 0.0001) in the treated eyes. Treatment with indomethacin failed to affect the IOP reduction caused by STX-S6c (10(-5) M). Ciliary injection and some dilatation of the iridial vessels were observed in eyes that received higher doses of STX-S6c.

CONCLUSION

STX-S6c reduces the IOP in rabbits in a dose-dependent fashion, presumably mediated through the ETB receptors.

Recurrent pneumococcal meningitis in a patient with transient IgG subclass deficiency

We report the case of a 3 year old boy who exhibited recurrent serious infections with a transient imbalance of IgG subclass in the second year of life. He suffered from pneumococcal meningitis at 3 months, hepatitis at 9 months, and purulent arthritis at 11 months of age. The second episode of pneumococcal meningitis occurred at 14 months. Serum IgG level was normal for age. Low level of IgG2, undetectable level of IgG4 and negligible level of pneumococcus-specific IgG1-G2 antibodies were found. No other primary immunodeficiency was apparent. Serum IgG2-G4 levels but not pneumococcus-specific IgG1-G2 titers increased by the age of 30 months. At that time, he was inoculated with a polyvalent pneumococcal vaccine along with acellular diphtheria-pertussis-tetanus vaccine. He acquired the immunity against these agents, and had no episodic infections in the following 2 years. This observation stresses the existence of transient IgG subclass deficiency associated with delayed development of the anti-polysaccharide antibody response.