Response of mouse lens to central needle injury

We examined the difference in response to different degrees of injury in the mouse lens. The anterior side of the lens was pricked through the cornea by a microsyringe with a 31-gauge needle or an ordinary needle. The location of the needle tip was mostly marked with Evans' blue (EB) stain. At least three types of responses were recognizable. The first was a recovery type in which the wound was healed by an epithelial reaction. EB was localized at the superficial zone of the anterior cortex. The second was a type in which the change within the lens was stationary after forming a spherical body with a slightly smaller diameter than that of the entire lens. EB was observed in the intermediate zone of the anterior cortex. The third was a rapid progressive type of cataract which caused lens opacity within 3 days. The trace of the needle tip was observed around the perinuclear zone. These results suggest that the cortex of the mouse lens consists of three zones which may be functionally different around the lens nucleus: superficial, intermediate and perinuclear zones.

The presence of two sites of action of endothelins in the isolated rabbit iris sphincter and dilator muscles

The contractile activity of endothelins (ETs) and their effect on twitch contraction evoked by electrical field stimulation were studied in the isolated rabbit iris sphincter and dilator muscles using the isometric tension recording method. ET-1, ET-2 and ET-3 caused slow contractile response of the sphincter as well as the dilator muscles, with sphincter muscle EC50 values of 37.3, 58.0 and 84.3 nM, and dilator muscle values of 31.7, 69.0 and 224.4 nM, respectively. These contractile responses were not affected by atropine (1 microM), prazosin (1 microM) or indomethacin (1 microM). ET-1 and ET-3 slightly but significantly inhibited the fast cholinergic component of twitch contraction of the sphincter muscle evoked by field stimulation, without affecting the response to carbachol. However, ET-1 did not affect the slow substance P-ergic component of twitch contraction of this preparation. In the dilator muscle, ET-1 and ET-3 had little effect on the contraction induced by phenylephrine but reduced the amplitude of the twitch contraction evoked by the field stimulation. The inhibitory effect of ETs on the dilator muscle was antagonized by pretreatment with BQ-123 (100 nM), which is a selective ETA receptor antagonist. Pretreatment with indomethacin (1 microM) also attenuated the inhibitory effect of ETs on the twitch contraction. These results suggest that ETs may have two sites of action, pre- and post-synaptic effects, on the rabbit iris sphincter muscle as well as the dilator muscle. All three ET isopeptides may have direct contractile activity on the smooth muscles of the sphincter as well as the dilator without mediation by prostaglandins or neuronal mechanisms.(ABSTRACT TRUNCATED AT 250 WORDS)

Morphological study of the cataractous lens of the senescence accelerated mouse

A murine model of accelerated aging, the senescence accelerated mouse (SAM), has been developed. There are three accelerated senescence-resistant (SAM-R) strains and eight senescence-prone (SAM-P) strains. The SAM-P strains have an earlier onset and more rapid advancement of senescence resulting from a significantly shorter lifespan compared with the SAM-R strains. Spontaneous cataracts have been found in some individuals of the SAM-P/9 strain. The SAM-P/1 strain, which was used in the present study, has such systemic senescent characteristics as senile amyloidosis and alopecia, but it was previously thought that cataract does not occur in this strain. However, we found cataractous changes in the lens of these animals at early stages of their life. The earliest change was the appearance of a ripple-mark body at about 3 months of age. The number of rippled rings increased with age. These changes later induced refractive distortion of retinal vessels. Whole-mount flat preparations of the epithelium showed that the number of cells was markedly decreased at the advanced stages of cataract. At the late stages of life the lens cortex became liquefied and developed into a mature cataract. Cataract formation in this strain may be related to reduced viability of the lens epithelium.

Changes in pH affect Cl- removal and AVP action in collecting tubules

We examined what mechanisms are involved in the alteration by chloride (Cl-) removal of arginine vasopressin (AVP)-induced cellular cAMP production, and cellular free calcium ([Ca2+]i) mobilization in rat renal papillary collecting tubule cells in culture, using two buffer systems: bicarbonate and non-bicarbonate buffers. The first study was performed in the bicarbonate-supplemented buffer. Removal of Cl-, which was replaced by methylsulfonate or gluconate, increased cellular pH (pHi) from 7.19 to 7.26. AVP increased cellular cAMP production in a dose-dependent manner; 1 x 10(-9) and 1 x 10(-7) M AVP-induced increases in cellular cAMP production were significantly enhanced by the Cl- removal. Also, 1 x 10(-7) M AVP-mobilized [Ca2+]i was augmented by the Cl- removal (181.3 vs. 224.5 nM, P < 0.05). The second study was carried out with the Krebs-Ringer buffered saline (KRB). Removal of Cl- lowered pHi from 7.20 to 7.09. AVP-induced increases in cellular cAMP production were significantly reduced in the Cl(-)-free KRB compared to those in the KRB. The reduction was obtained with KRB containing less than 25 mM Cl-. Similar results were obtained with 2 x 10(-8) M forskolin, a diterpene activator of adenylate cyclase. 1 x 10(-7) M AVP-mobilized [Ca2+]i was also diminished by the Cl(-)-free KRB. These results indicate that Cl- depletion affects the cellular response to AVP mediated via the changes in pHi in renal papillary collecting tubule cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Histopathological study of hereditary cataractous lenses in SCR strain rat

A new cataractous rat strain, Shumiya Cataract Rat (SCR), which was derived from the cross-breeder formed between the spontaneous hypertensive rat and the Zucker fatty rat, was studied by light and electron microscopy. The earliest change was the occurrence of some displaced nuclei in the posterior cortical fibres at birth. By 2 weeks of age, mild dysplasia of the anterior suture, aggregated epithelial cells overlying the sutural area, and poorly differentiated epithelial cells at the bow area were observable. At 3 weeks, unusually dense lens fibres near dense epithelial cells were found at the equator, and some epithelial cells showed accellularity after 4 weeks. Swelling and liquefaction of the lens fibres appeared in the anterior cortex by this stage. By 6 weeks, these changes extended toward the equatorial region. At 7 weeks, a sutural gap occurred at the anterior polar area, and this gap reached a maximum at 8 weeks. At this time, swelling of the posterior extremities of the lens fibres appeared, showing a small placoid opacity of the posterior subcapsular region under a dissecting microscope. At 10 weeks, small amounts of liquefaction were observed in this region. Between 10.5 and 11 weeks, as the posterior suture of liquefaction were observed in this region. Between 10.5 and 11 weeks, as the posterior suture separated, opacification appeared around the separated sutural area and rapidly developed into a mature cataract. The mechanism of cataract formation in the SCR rat lens may be associated with the continuous occurrence of a small proportion of poorly-differentiated epithelial cells at the bow area and sutural dysplasia of the anterior lens fibres.

[Effect of extended thymectomy in myasthenia gravis of pure ocular type]

The effect of extended thymectomy in myasthenia gravis of pure ocular type was investigated in 13 patients, who were divided into the surgical group of nine and the conservative group of four. In the surgical group, the onset was at 47 +/- 20 years old. The preoperative duration of symptoms was 4 +/- 6 years. The age at the time of operation was 51 +/- 16 years old. Three patients had thymomas, including one malignant thymoma. Acetylcholine receptor antibody titer was over normal range with 34.0 +/- 49.7 nmol/l. No postoperative crisis occurred. The palliation rate of the surgical group was more higher through the whole period than that of the conservative group, and increased with progress of the course. The remission occurred in the surgical group, but did not in the conservative group. It took 7 months to improve the symptom in the surgical group, while 18 months in the conservative group. We conclude extended thymectomy is reasonable for patients with myasthenia gravis of pure ocular type.

Dietary soybean protein compared with casein retards senescence in the senescence accelerated mouse

The effects of replacing dietary casein with soybean protein on mean life span, mean life span of the last one-tenth of a group, grading scores of senescence and deposition of senile amyloid were investigated in senescence accelerated mice (SAM-P/1) compared with a control strain (SAM-R/1). SAM-R/1 mice fed the soybean protein-containing diet had mean life spans of 618 +/- 42 d (males) and 578 +/- 62 d (females), 58% (males) and 44% (females) longer than those of corresponding casein fed mice (P < 0.01). Similarly, in SAM-P/1 mean life-spans were 265 +/- 16 d (males) and 307 +/- 23 d (females) in the soybean diet group, 27% (males) and 30% (females) longer than in the casein diet groups (P < 0.01). The mean life span of the last one-tenth of each group fed soybean protein was significantly longer than the corresponding group fed casein. In SAM-R/1 mice, pathological studies revealed that severe secondary amyloid deposition (amyloid A protein) in the kidneys, spleen, stomach and liver was significantly suppressed, in males only, by replacing casein with soybean protein (P < 0.01). The occurrence of contracted kidneys caused by the infiltration of amyloid A protein was suppressed in SAM-R/1 mice fed the soybean protein-containing diet (P < 0.05). The deposition of senile amyloid in SAM-P/1 mice with aging was retarded by replacing casein with soybean protein (P < 0.01). These results indicate that dietary protein source is important in modulating the advance of senescence in SAM mice.

Calcitonin induces a decreased Na+ conductance in identified neurons of Aplysia

The ionic mechanism of the effect of extracellularly ejected calcitonin (CT) on the membrane of identified neurons R9 and R10 of Aplysia was investigated with voltage-clamp, micropressure ejection, and ion substitution techniques. Micropressure-ejected CT caused a marked hyperpolarization in the unclamped neuron. Heat-inactivated CT was without effect. Clamping the same neuron at its resting potential level (-60 mV) and re-ejecting CT with the same dose produced a slow outward current (Io(CT), 30-40 sec in duration, 4-6 nA in amplitude) associated with a decrease in input membrane conductance. Io(CT) was decreased by depolarization and increased by hyperpolarization. The extrapolated reversal potential of Io(CT) was approximately +10 mV. Io(CT) was sensitive to changes in the external Na+ concentration but not to changes in K+, Ca2+, and Cl- concentrations. Micropressure-ejected forskolin produced a slow outward current, which, like the current to CT, was associated with a decrease in input membrane conductance, and was sensitive to changes in the external Na+ concentration. Io(CT) was prolonged by bath-applied isobutylmethylxanthine (IBMX) but was not affected by 1-oleoyl-2-acetylglycerol (OAG) and calphostin C. Neither superfusion of the neuron with nordihydroguaiaretic acid (NDGA) nor superfusion with indomethacin caused any changes in Io(CT). These results suggest that extracellular CT can induce a slow outward current associated with a decrease in Na+ conductance, mediated by a receptor-controlled increase in intracellular cyclic adenosine 3',5'-monophosphate.

[Recent progress in the diagnosis and treatment of diabetes insipidus]

Recent progress in the diagnosis and treatment of diabetes insipidus (DI) is reviewed. Response of plasma vasopressin (AVP) to 5% hypertonic saline can be a new indicator of the capacity of AVP response to osmotic stimuli. Marked progress in the imaging analysis by computed tomography and magnetic resonance imaging (MRI) has made it possible to evaluate hypothalamic-pituitary lesions in detail. Especially, signal intensity on T1-weighted MR image of neurohypophysis is suggested to reflect its function. Sequencing analysis of genes encoding AVP-neurophysin precursor or AVP receptor is expected to be a most useful method for the diagnosis of inherited DI. Intranasal administration of DDAVP (1-deamino-8-D-AVP) is recommended as a standard therapy for DI.

Enhancement of vascular action of arginine vasopressin by diminished extracellular sodium concentration

The present study was undertaken to examine the effects of diminished extracellular sodium concentration on the vascular action of arginine vasopressin (AVP) in cultured rat vascular smooth muscle cells (VSMC). The preincubation of cells with the 110 mM extracellular Na+ ([Na+]e) solution supplemented with 30 mM choline chloride for 60 minutes enhanced the effect of AVP- (1 x 10(-8) M) induced VSMC contraction. The treatment of 110 mM [Na+]e solution also enhanced the cellular contractile response to the protein kinase C (PKC) activators, phorbol 12-myristate 13-acetate and 1-oleoyl-2-acetyl-glycerol. Furthermore, preincubation with the 110 mM [Na+]e solution also potentiated the effect of 1 x 10(-8) M AVP, but not 1 x 10(-6) M, to increase the cytosolic-free Ca2+ ([Ca2+]i) concentration. The 110 mM [Na+]e media decreased the basal intracellular Na+ concentration and increased intracellular 45Ca2+ accumulation, basal [Ca2+]i and AVP-produced 45Ca2+ efflux. These effects of 110 mM [Na+]e solution to enhance the vascular action of AVP were abolished by using Ca(2+)-free 110 mM [Na+]e solution during the preincubation period. The preincubation with the 110 mM [Na+]e solution did not change either the Kd and Bmax of AVP V1 receptor of VSMC or the AVP-induced production of inositol 1,4,5-trisphosphate. The present in vitro results therefore indicate that the diminished extracellular fluid sodium concentration within a range observed in clinical hyponatremic states enhances the vascular action of AVP.(ABSTRACT TRUNCATED AT 250 WORDS)

Accommodative adaptation and age of onset of myopia

Tonic accommodation in an empty field and accommodative adaptation, defined as accommodation shift after 2 min viewing of a 4 D near task, were measured using an infrared optometer. Subjects were classified into three types: emmetropes (n = 18), early onset myopes (n = 18) and late onset myopes (n = 15). The relationship between accommodative adaptation and the onset age of myopia were compared. There was no statistical difference in the pre-task tonic accommodation among the three subject groups. However, the accommodative adaptation differed in the three groups during the 5 min post-task period. The average accommodative adaptation of emmetropia, early onset myopia and late onset myopia were 0.66, 0.27 and 1.19 D, respectively. Accommodative adaptation in the late onset myopia group was significantly higher than in the emmetropia group. Furthermore, the accommodative adaptation in the early onset myopia group was significantly lower than in the emmetropia group. Two possible aetiologies of myopia are discussed: one for the group which shows low accommodative adaptation that has no relationship with the age of onset and another for the group which shows high accommodative adaptation that has a relationship to an onset age of 15 years or later. The aetiology is also considered with regard to a potentiating chemical effect on the synapses of the ciliary muscle.

Regulation of Na,K-adenosine triphosphatase gene expression by sodium ions in cultured neonatal rat cardiocytes

Na,K-ATPase (Na,K-pump) plays an important role in the regulation of intracellular ion composition. The purpose of this study is to determine whether Na+ regulates the levels of mRNA coding for Na,K-ATPase alpha and beta subunits in cultured neonatal rat cardiocytes. We measured intracellular Na+ levels ([Na+]i) in cardiocytes using a Na(+)-sensitive fluorescence dye (SBFI). 1 mM ouabain caused a significant increase in [Na+]i in cardiocytes; from 12.8 +/- 0.3 to 28.8 +/- 1.8 mM. Exposure of cardiocytes to 1 mM ouabain resulted in a three- to fourfold increase in alpha 1, alpha 2, and alpha 3 mRNA accumulation, and an approximate two-fold increase in beta 1 mRNA accumulation. A maximum elevation was reached at 60 min in both cases. The ouabain-induced alpha 1 mRNA accumulation was still observed in the Ca(2+)-free culture medium. Exposure of cardiocytes to 10 microM monensin in the absence of extracellular Ca2+ also resulted in a threefold increase in alpha 1 mRNA accumulation. The increased alpha 1 mRNA expression by 1 mM ouabain was associated with a fourfold increase in alpha 1 subunit protein accumulation. Transfection experiments with chimeric plasmids containing 5'-flanking sequences of alpha 1, alpha 2, and alpha 3 isoform genes and a luciferase reporter gene revealed that 1 mM ouabain caused a twofold increase in luciferase activity in each alpha system. These results suggest that Na+ directly regulates Na,K-ATPase gene expression in cardiocytes. The transfection study further supports the premise that Na(+)-responsive elements are located within the 5'-flanking sequences of each alpha isoform gene.

Spontaneous perforation of pyometra presenting as generalized peritonitis in a patient with cervical cancer

Pyometra is a relatively common event. However, it is extremely rare for this condition to perforate spontaneously into the peritoneum, and to date only 14 cases have been reported in English literature. We recently experienced such a case in a patient with cervical cancer. The clinical features, pathologic findings, diagnosis, therapy, and outcome of these 15 cases were reviewed. Only 5 cases were associated with malignant diseases, consisting of 2 cervical cancers, 2 colon cancers, and 1 endometrial cancer. All of the patients developed generalized peritonitis, and 4 patients died of this. Correct preoperative diagnosis was difficult. Therefore, immediate and appropriate therapy is important.

Enhancement of intracellular sodium by vasopressin in spontaneously hypertensive rats

The arginine vasopressin-induced increase in intracellular sodium concentration was augmented in cultured rat vascular smooth muscle cells derived from 12-week-old spontaneously hypertensive rats (SHR) compared with those from 12-week-old normotensive Wistar-Kyoto (WKY) rats. This difference was enhanced by treatment with a Na+,K(+)-ATPase inhibitor, ouabain. The calcium-free state did not affect the basal intracellular sodium concentration but completely blocked the arginine vasopressin-induced increase in intracellular sodium concentration in both cell groups. The arginine vasopressin-mobilized cytosolic free calcium was enhanced in SHR compared with WKY rats. This enhancement was diminished but not completely inhibited in the calcium-free state. Also, arginine vasopressin-produced intracellular alkalinization was augmented in SHR. Pretreatment of both cell groups with a calmodulin antagonist, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide, completely blocked arginine vasopressin-induced intracellular alkalinization and increased intracellular sodium concentration. Scatchard analysis showed that the V1 receptor number of either quiescent or proliferative cells of SHR was five to seven times greater than that of WKY rats, without any change in receptor affinity. These findings therefore indicate that the arginine vasopressin-induced increase in intracellular sodium concentration is augmented in vascular smooth muscle cells of SHR mediated through the enhancement of the mobilization of cytosolic free calcium and the activity of sodium-hydrogen exchange, which depends on an increase in V1 receptor number.

[Surgical treatment of elderly patients with primary lung cancer]

Fourteen patients with lung cancer over the age of 70 years had the standard operation with mediastinal lymph node dissection. Their postoperative complications and prognoses were compared with those of 47 patients under the age of 70 years with the same operation. The propriety of the standard operation with mediastinal lymph node dissection for lung cancer in elderly patients was studied. A program of respiratory training was arranged preoperatively for the patients. Preoperative complications was more common in elderly than in younger patients, but postoperative complications were less frequent. The prognosis in elderly patients was also satisfactory. We conclude that the standard operation with mediastinal lymph node dissection for lung cancer can be performed as well in elderly as in younger patients.

Thapsigargin increases cellular free calcium and intracellular sodium concentrations in cultured rat glomerular mesangial cells

We examined whether thapsigargin increases cellular free calcium ([Ca2+]i) and intracellular sodium concentration ([Na+]i) in cultured rat glomerular mesangial cells. 1 x 10(-6) M Thapsigargin increased [Ca2+]i to 244.4 from 86.6 nM, an increase sustained at least during the 15 min observation period. Such an increase in [Ca2+]i was transient in Ca(2+)-free medium containing 1 x 10(-4) M EGTA. An increase in [Ca2+]i by thapsigargin was not altered by 1 x 10(-6) M nicardipine, a L-type Ca2+ channel blocker. Thapsigargin also produced a sustained rise in [Na+]i in a dose-dependent manner. However, preincubation of cells with Ca(2+)-free medium completely blocked the increase in [Na+]i by thapsigargin. These results indicate that thapsigargin increases [Ca2+]i by blocking endoplasmic Ca(2+)-ATPase and enhancing Ca2+ entry, and that the increased Ca2+ influx is triggering an increase in [Na+]i stimulated by thapsigargin per se in glomerular mesangial cells.

[Double blind controlled study of ubenimex (Bestatin) against squamous cell lung cancer--a multicenter cooperative study]

To investigate effects of the combination of ubenimex, chemotherapy, and radiotherapy against unresectable advanced squamous cell carcinoma of the lung, a placebo controlled double-blind study was performed. Of 365 registered cases, there were 258 cases in the complete radiation group in which the treatment as specified in the protocol (irradiation of 40 Gy or more to the thorax subsequent to chemotherapy) was conducted; the 50% survival time was 449 days and 363 days in the ubenimex group and the placebo group, respectively. A significant (p = 0.0473) prolongation of the survival time was noted in the ubenimex group, and the response rate was 60.9% and 50.0% (p = 0.087). From these results it was confirmed that ubenimex, when used in combination with chemotherapy and radiotherapy, not only enhances the tumor-reducing effect but also prolongs the survival time.

[Cor triatriatum with situs inversus totalis: a case report of an infant]

Cor triatriatum associated with situs inversus is rare. A 6-month-old male who had cor triatriatum with atrial septal defect (ASD) and situs inversus totalis was successfully operated. Urgent surgical intervention was performed because of congestive cardiac failure despite drug therapy. The abnormal septum in the left atrium was resected and ASD was closed. His postoperative course has been uneventful.

Therapeutic efficacy of non-peptide ADH antagonist OPC-31260 in SIADH rats

The present study was undertaken to determine whether the non-peptide V2 antidiuretic hormone (ADH) antagonist 5-dimethylamino-1[4-(2- methylbenzoylamino)benzoyl]-2,3,4,5-tetrahydro-1H-benzazepine (OPC-31260) normalized hyponatremia in rats with an experimental syndrome of inappropriate secretion of ADH (SIADH). Rats were administered V2 agonist 1-deamino-8-D-arginine vasopressin (dDAVP) subcutaneously at a rate of 5 ng/hr using an osmotic minipump and a 40 ml/day liquid diet. Serum sodium levels (SNa) and serum osmolality (SOsm) markedly decreased to 119 mEq/liter and 249 mOsm/kg H2O, respectively, 48 hours after the start of dDAVP administration. Hyponatremia persisted in a similar magnitude during the observation period of 14 days. On days 7 to 13 OPC-31260, administered 5 mg/kg per day orally, promptly raised SNa and SOsm to 134 mEq/liter and 282 mOsm/kg H2O in half a day, respectively, followed by the normalization of SNa and SOsm during the rest of the observation period. The cease of administration of OPC-31260 again decreased SNa and SOsm in rats receiving dDAVP. In contrast, SNa and SOsm were within the normal values in rats receiving 0.15 M NaCl, a vehicle for dDAVP, in the presence or absence of OPC-31260. The administration of OPC-31260 promptly caused marked water diuresis on day 7 in the hyponatremic rats receiving dDAVP, namely 5 mg/kg OPC-31260 markedly increased urinary volume and decreased UOsm. These results indicate that there is dilutional hyponatremia in rats receiving dDAVP and 40 ml/day liquid diets, and that OPC-31260 is an effective therapeutic for hyponatremia associated with dDAVP-induced SIADH.