A novel human glassy-cell carcinoma cell line producing IL-6 and IL-8 from uterine cervix

A novel human cell line, TOM-2, was established from a rare uterine cervical cancer, glassy cell carcinoma (GCC). TOM-2 is the second established GCC cell line so far reported. The cells were intermediately or poorly differentiated with dysplastic nuclei and polygonal shape and secreted two tumor markers and cytokines, i.e., CA-125 and SCC, interleukin (1L)-1alpha, -6, and -8, and TNF-alpha. Growth of TOM-2 was so strongly dependent on population density that it was not possible to determine the plating efficiency. In mass culture, the following characteristics were observed: doubling time, 83 h; mode of chromosome number, 79; human papillomavirus type 18 DNA, detectable; tumorigenicity, easily transplantable into subcutis of nude mice; chemosensitivity in vitro, considerably sensitive to Cisplatin and 5-FU but not to 9 other antineoplastic agents. This novel cell line will be useful for developing new therapeutic strategies for the rare cancer, GCC.

MRI evaluation of the inferior glenohumeral ligament. Comparison with arthroscopic findings in 81 shoulders

Arthroscopic Bankart repair, using staples, requires a thick and wide anterior band of the inferior glenohumeral ligament. We compared MRI and arthroscopic findings of the ligament in 81 shoulders with traumatic anterior glenohumeral instability. When fluid was present in the shoulder, sensitivity and specificity of the MRI evaluation for the presence of a thick and wide ligament were 82% and 100%, respectively. In shoulders without joint fluid, the condition of the ligament was evaluated according to the presence of a low- or moderate-signal triangle structure on the anterior margin of the glenoid cavity in the 3 MR images obtained from the inferior 2 cm of the glenoid. Sensitivity and specificity of the MRI evaluation in cases without fluid were 84% and 93%, respectively. The MR technique needs to be further improved to achieve better sensitivity for preoperative selection of shoulders suitable for Bankart repair with staples.

Neuron-glia interaction in the suprachiasmatic nucleus: a double labeling light and electron microscopic immunocytochemical study in the rat

The morphological interactions between astroglial and neuronal elements were elucidated in the rat suprachiasmatic nucleus (SCN) by light and electron microscopic immunocytochemistry using antibodies against glial fibrillary acidic protein (GFAP), vasoactive intestinal peptide (VIP) and arginine-vasopressin (AVP). Throughout the SCN, particularly in its ventral portion, GFAP-like-immunoreactive (GFAP-LI) astroglial elements were found. These astrocytes displaying GFAP-like immunoreactivity occasionally contained fairly well-developed organelles. Some of these astrocytes were found as satellite cells in close contact with non-immunoreactive neuronal perikarya and processes. Around the neurons, GFAP-LI astroglial processes were also observed to cover some portions of presynaptic and postsynaptic elements. In addition, these astroglial elements were seen between two neuronal somata and pericytes of blood capillaries as glial endfeet. By double labeling immunoelectron microscopy using antibodies against GFAP/VIP and GFAP/AVP, some portions of VIP-like-immunoreactive or AVP-like-immunoreactive neuronal somata and processes were found to be engulfed by GFAP-LI astroglial processes. The possible functional roles of the morphological interactions between astroglial and neuronal elements are discussed.

Altered cholinergic mechanisms and blood pressure regulation in the rostral ventrolateral medulla of DOCA-salt hypertensive rats

We examined whether cholinergic transmission in the rostral ventrolateral medulla (RVLM) of deoxycorticosterone acetate-salt hypertensive rats (DHR) is enhanced and the enhancement is involved in the maintenance of hypertension in DHR, and whether cholineacetyltransferase (ChAT) activities and ChAT mRNA expression are enhanced in neurons intrinsic to the RVLM of DHR. Rats were anesthetized, paralyzed, and artificially ventilated. Unilateral microinjection of cholinergic agents into the RVLM produced a pressor response. The pressor response to physostigmine was greater in DHR than in control rats, whereas the response to carbachol was the same in both sets of rats. Bilateral microinjection of scopolamine into the RVLM produced a decrease in blood pressure. The depressor response was greater in DHR than in control rats. The number of ChAT-activity-detected neurons in the RVLM was greater in DHR than in control rats. The number of ChAT mRNA-expressing neurons in the RVLM was also clearly greater in DHR than in control rats. These results demonstrate that cholinergic transmission in the RVLM is enhanced in DHR, and this enhancement may play a role in the maintenance of hypertension in DHR. It is probable that enhanced activity of cholinergic neurons intrinsic to the RVLM is at least in part, responsible for the enhanced cholinergic transmission in the RVLM of DHR.

Effect of growth hormone therapy in children with achondroplasia: growth pattern, hypothalamic-pituitary function, and genotype

OBJECTIVE

Although there are a few reports on GH therapy in achondroplasia, these were based on a small sample and/or short-term observation. To clarify the effectiveness of GH treatment on short stature in achondroplasia and hypochondroplasia, a long-term treatment study in a larger number of patients was performed.

METHOD

Forty-two children (16 males and 26 females, age 3-14 years) with achondroplasia were examined in this study. Initially, we evaluated hypothalamic-pituitary function and point mutation analysis as previously reported. After the evaluation, the children were treated with GH for more than 2 years; then post-treatment growth velocity and body proportion parameters were determined.

RESULTS

The 35 typical variants of our achondroplasia patients showed previously reported point mutation in the fibroblast growth factor receptor 3 gene. The annual height gain during GH therapy was significantly greater than that before therapy (3.9 +/- 1.0 cm/year before treatment vs 6.5 +/- 1.8 cm/year for the first year and 4.6 +/- 1.6 cm/year for the second year of treatment). The body disproportion had not been aggravated during the treatment period.

CONCLUSION

We conclude that GH might be beneficial in the treatment of short stature in children with achondroplasia in the first 2 years of treatment.

[Flow cytometric DNA analysis and MR imaging of salivary gland tumors]

We correlated the histopathology of 32 cases of salivary gland tumors with MR imaging and flow cytometric DNA analysis. All malignant tumors were invasive and/or had an ill-defined margin. Fifty-seven percent of the pleomorphic adenomas were shown as a high signal intensity area on T2 weighted images. Fifty-six percent of Warthin tumors were shown as a low or iso signal intensity area on T2 weighted images associated with the cystic portion. Sixty-seven percent of malignant tumors were characterized by DNA aneuploidy and/or a total percentage of the S-phase fraction plus the G2 + M fraction higher than 10%. It was less than 10% and the Ki-67 positive fraction was higher than 20% in all pleomorphic adenomas. The Ki-67 positive fraction was less than 20% in 78% of Warthin tumors. The histopathology of all malignant tumors, 86% of the pleomorphic adenomas, and 89% of Warthin tumors was correctly predicted by the combination of MR images and flow cytometry. We suggest that the MR images combined with flow cytometric analysis of fine needle aspiration-derived materials is useful in the pre-operative histopathologic diagnosis of salivary gland tumors.

Brainstem auditory evoked potentials during brainstem ischemia and reperfusion in gerbils

To evaluate the reversibility of neural function in the brainstem following ischemia, we investigated the effect of transient brainstem ischemia on the brainstem auditory evoked potential in gerbils. Brainstem ischemia was produced by bilateral extracranial occlusion of vertebral arteries. Local cerebral blood flow was measured by quantitative autoradiography after 5 min of ischemia and was reduced to less than 3 ml/100 g per min in the pons and lower midbrain, indicating severe and reproducible brainstem ischemia. During brainstem ischemia, brainstem auditory evoked potential waveforms disappeared completely. After a brief ischemic insult (5 min), all four brainstem auditory evoked potential components recovered to normal. After longer ischemic insults (10-30 min), brainstem auditory evoked potential components never recovered to normal. Microtubule-associated protein 2 immunoreactivity revealed differential vulnerability of the acoustic relay nuclei in the brainstem. Neurons in the lateral lemniscus were most vulnerable, followed in order by neurons in the trapezoid body, the superior olive and the cochlear nucleus. We also demonstrated a close relationship between the reversibility of ischemia-induced changes on brainstem auditory evoked potential and ischemic lesions of these relay nuclei. These data may be useful for evaluating the therapeutic window of thrombolytic therapy during acute vertebrobasilar occlusion.

Activin-induced inhibin alpha-subunit production by rat granulosa cells requires endogenous insulin-like growth factor-I

Inhibin-alpha subunit (Inh-alpha) gene expression is important for granulosa cell (GC) differentiation and prevention of ovarian tumorigenesis. Studies on Inh-alpha regulation have implicated activin and insulin-like growth factor-I (IGF-I) in the mechanisms of expression. Here we present evidence that endogenously produced IGF-I plays an obligatory role in activin-induced Inh-alpha production. Primary cultures of rat GC were incubated with increasing concentrations of various regulatory molecules, and the levels of Inh-alpha protein and its mRNA were measured in conditioned medium and cells, respectively. Recombinant activin A stimulated Inh-alpha expression, and the effects were dose- and time-dependent. The receptor tyrosine kinase inhibitor tyrphostin A23 caused a dose-dependent inhibition of activin-dependent Inh-alpha expression, whereas the inactive isomer, A63, had no effect. The stimulatory effect of activin was also blocked in a dose-dependent manner by added IGF binding protein-4 or -5, and the effects were reversed by IGF-I. Moreover, increasing concentrations of an anti-IGF-I antibody had a similar inhibitory effect on activin-stimulated Inh-alpha expression. Collectively, these results suggest, for the first time, that endogenously produced IGF-I is required for activin stimulation of Inh-alpha expression in cultured rat GC.

L-type calcium channels in vascular smooth muscle cells from spontaneously hypertensive rats: effects of calcium agonist and antagonist

Studies using the whole-cell voltage-clamp technique have demonstrated that L-type Ca2+ channel activity is increased in vascular smooth muscle cells from spontaneously hypertensive rats (SHR). We recorded L-type Ca2+ channel currents in cultured mesenteric artery smooth muscle cells from SHR and Wistar Kyoto (WKY) rats by using the cell-attached patch-clamp technique. Depolarizing voltage steps from a holding potential of -40 mV elicited voltage-dependent inward Ba2+ currents. There was no difference in the L-type Ca2+ channel I-V curve or in the open probability between SHR and WKY. The inward currents were inhibited by the Ca2+ antagonists nifedipine and verapamil, but were enhanced by the Ca2+ agonist Bay K 8644 in a concentration-dependent manner. The Bay K 8644-induced increase and the nifedipine-induced inhibition of the inward currents were enhanced in SHR, whereas there was no difference in the verapamil-induced inhibition of the currents between the two strains of rats. These results suggest that the enhanced L-type Ca2+ channel activity observed in vascular smooth muscle cells from SHR is not due to altered function of a single L-type Ca2+ channel. It appears that the sensitivity of dihydropyridine receptors in the channels is enhanced in SHR.

Vitamin A deficiency reduces the responsiveness of pineal gland to light in Japanese quail (Coturnix japonica)

Synthesis of melatonin in pineal gland is under the control of light environment. The recent finding of the presence of rhodopsin-like photopigment (pinopsin) and retinal in the avian pinealocytes has led to a hypothesis that vitamin A is involved in photoresponses of the pineal gland. We have thus analyzed the effect of vitamin A deficiency on the regulatory system of melatonin synthesis in the pineal gland of Japanese quail. Depletion of vitamin A from Japanese quails was attained by feeding them with a vitamin A-free diet supplemented with retinoic acid. In the vitamin A-deficient birds, diurnal rhythm in melatonin production persisted such that the phase of the wave was similar to that seen in the control birds. However, the amplitude of the nighttime surge of pineal melatonin was damped by vitamin A deficiency. When the control birds were briefly exposed to light at night, pineal melatonin dropped to the daytime level. In contrast, only slight decrease was observed in the vitamin A-deficient quails. The light responsiveness was restored after feeding the vitamin A-deficient quails with the control diet for 1 week. These results indicate that vitamin A plays essential roles in maintaining sufficient responsiveness of the avian pineal gland to photic input.

Baroreceptor activation causes release of acetylcholine in the rostral ventrolateral medulla of the rat

We examined whether baroreceptor activation causes a release of acetylcholine (ACh) in the rostral ventrolateral medulla (RVLM) of the rat, in order to investigate a possible connection between RVLM cholinergic systems and cardiovascular baroreflexes. Male Wistar rats were anesthetized, paralyzed and artificially ventilated. Either electrical stimulation of aortic nerve or baroreceptor activation by intravenous phenylephrine produced an increase of the release of ACh in the RVLM, whereas baroreceptor denervation and tetrodotoxin (TTX) microinfusion in the RVLM inhibited the increase in ACh release induced by phenylephrine. TTX injected in the caudal ventrolateral medulla (CVLM) inhibited the phenylephrine-induced increase of ACh release. The excitatory amino acid L-glutamate microinfused in the CVLM produced an release in ACh release in the RVLM. These results suggest that there is a connection between RVLM cholinergic systems and cardiovascular baroreflexes. It is probable that neurons in the CVLM are involved in mediating the release of ACh in the RVLM.

Preferential expression of the gene for a putative inositol 1,4,5-trisphosphate receptor homologue in the mushroom bodies of the brain of the worker honeybee Apis mellifera L

A gene expressed preferentially in the mushroom bodies of the brain of the worker honeybee Apis mellifera L. was identified by the differential display method and its cDNA was isolated. The cDNA fragment of 534 bp (clone A1) contained an open reading frame encoding 177 amino acid residues having 78, 72, 70, 59 and 55% sequence identities with the inositol 1,4,5-trisphosphate (IP3) receptors of Drosophila melanogaster, Xenopus laevis and humans (types 1, 2 and 3), respectively, suggesting that it encodes a putative IP3 receptor homologue of the honeybee. In situ hybridization revealed that the gene encoding clone A1 was expressed preferentially in the mushroom bodies and not in the optic lobes, antennal lobes and central bodies; in the mushroom body, it was expressed strongly in the large type Kenyon cells and weakly in the small type Kenyon cells. Reverse transcription polymerase chain reaction analysis showed that the gene was expressed strongly in the head and weakly in the antennae, legs, thorax, and abdomen. These results suggest that the A1 gene product plays a crucial role in neural transmission in the mushroom bodies of the worker bee brain.

Differences in the repair process of longitudinal and transverse injuries of cartilage in the rat knee

OBJECTIVE

To clarify the relationship between type or direction of cartilage injury and its repair process, we investigated defects produced in rat knees histologically, immunohistochemically, and histomorphometrically.

METHODS

A full-thickness cartilage injury (1 mm wide and 5 mm long) was produced on the patellar groove of one knee (L-injury) and transversely on the other knee (T-injury) in 42 male Wistar rats. Six rats each were sacrificed at 1, 2, 3, 4, 6 and 8 weeks after surgery, and cartilage tissues were obtained, prepared into 4 microns-thick histologic specimens, and stained with hematoxylin and eosin. Cartilage thickness, cartilage area, and surface roughness were measured using a computer system. Localization of S-100 proteins was evaluated with immunohistochemistry.

RESULTS

Grossly, there were no difference in repair process between L- and T-injuries. However, histological and histomorphometric differences became apparent after the third week: cartilage thickness, repair area, and surface roughness showed better recovery in L-injury than in T-injury. Appearance of S-100-positive protein preceded the appearance of chondrocytes, and L-injury presented S-100 in the entire defect while S-100 in T-injury appeared mainly on the margins of the defect.

CONCLUSIONS

Repair mechanisms of cartilage injury differs according to injury direction. Better repair can be obtained in the injury which is parallel to the direction of joint motion.

Patterns of change in growth function of distortion product otoacoustic emissions in Menière's disease

The patterns of change in the growth function of distortion product otoacoustic emissions (DPOAEs) associated with hearing improvement in six patients with Menière's disease were investigated. The growth functions of 2F1-F2 DPOAEs at F2 frequencies of 1001, 2002 and 4004 Hz (DP-1, DP-2 and DP-4, respectively) were measured with F2 intensities ranging from 70 to 37 dBSPL in 3-dB steps. The F1 intensity was maintained 10 dB higher than the F2 intensity. The growth function was paired with the hearing threshold at the corresponding F2 frequency, and the relationships between changes in DP-1, DP-2 and DP-4 and those in hearing thresholds at 1, 2 and 4 kHz, respectively, were also investigated. The patterns of change in the growth function associated with hearing improvement could be classified into five types. In the first type, the DPOAE growth function became detectable, while the remaining four types were distinguished by combinations of changes in DPOAE amplitudes for lower and higher primary intensities. Multiple parameters, such as maximum amplitude and detection threshold of the growth function, appeared to be required for simple detection and discrimination of these patterns of change. It was also found that the DPOAE growth functions clearly changed in some cases even though the hearing thresholds did not change significantly at the corresponding F2 frequencies. This finding suggests that DPOAE growth function measurement can detect small changes in cochlear function which do not lead to changes in hearing threshold, and has higher sensitivity than pure tone audiometry in monitoring of cochlear function. In conclusion, our findings suggest that measurement of the DPOAE growth function is useful for monitoring cochlear function, and that information on its patterns of change is clinically important and useful.

A case of pulmonary embolism caused by paroxysmal nocturnal hemoglobinuria

A patient with pulmonary embolism caused by paroxysmal nocturnal hemoglobinuria (PNH) is described. PNH sometimes causes venous thrombosis in the extremities, hepatic vein, or cerebral vein, but pulmonary embolism rarely occurs.

[Identification of vestibular compensation-associated molecules by means of differential display]

The differential display method was used to identify gene expression which is altered in the cerebellar flocculus after unilateral labyrinthectomy (UL). Total RNA from flocculi of sham-operated and labyrinthectomized rats was isolated, amplified by PCR using arbitrary primer sets and separated by electrophoresis on a polyacrylamide gel. PCR products, whose amounts were significantly different in samples from labyrinthectomized animals and those from controls, were cut out of the gel and sequenced. One of the up-regulated products was the rat protein phosphatase 2A beta catalytic subunit mRNA and one of the down-regulated products was the rat glutamate receptor delta-2 subunit mRNA. Histochemical examination of in situ hybridization showed that those molecules were intensively localized in the Purkinje cell layer. In labyrinthectomized rats, UL-induced nystagmus gradually disappeared within 3 days after UL. These findings suggest that changes in expression of those molecules in the floccular Purkinje cells after UL is involved in vestibular compensation. So far various kinds of neural plasticity-associated molecules have been investigated, mainly by slice-in vitro studies. This study indicates that differential display is a feasible molecular biological in vivo method for investigation of the mechanism of neural plasticity.

[Radiation therapy for non-small cell lung cancer with postoperative intrathoracic recurrence]

We reviewed patients with intrathoracic recurrence of non-small cell lung cancer after surgery, with reference to the feasibility of radiotherapy. The series consisted of 46 patients (39 males and 7 females) treated by radiotherapy from 1982 to 1995. Histology included squamous cell carcinoma (28 patients), adenocarcinoma (17), and large cell carcinoma (1). Clinical stage by UICC classification (1987) was as follows: stage I(2 patients), stage II(1), stage IIIa(13), stage IIIb(23), and stage IV(7). Recurrences were noted in bronchial stump (18 patients) and surgical scar (4). Metastases occurred in hilar-mediastinal lymphnodes (15), lung fields (7), and pleuropericardium (2). The mean interval from surgery to recurrence was 27 months. Delivered dose ranged from 45 to 80 Gy, and 19 patients received combined chemotherapy. Therapeutic results were as follows: complete response in 16 patients, partial response in 27, no response in 12 and progressive disease in 1, Overall 2- and 5-year survival rates were 17% and 11%, respectively, and 10 months in MST. On univariate analysis, significant prognostic factors were sex, stage at recurrence, recurrence pattern, performance status and initial response to radiotherapy, while multivariate analysis showed sex and initial response. From these data, we are encouraged by effective radiotherapy for postoperative intrathoracic recurrence of non-small cell lung cancer, especially in patients with stump or lymphnode recurrence.

Effect of pituitary adenylate cyclase-activating polypeptide (PACAP) on progestin biosynthesis in cultured granulosa cells from rat ovary and expression of mRNA encoding PACAP type IA receptor

The purpose of this study was to detect the presence of mRNA encoding pituitary adenylate cyclase-activating polypeptide (PACAP) type I receptor in granulosa cells from rat ovary and to examine the effect of PACAP on progestin biosynthesis. mRNA was isolated from granulosa cells from the ovaries of immature rats treated with pregnant mares' serum gonadotrophin. The technique of reverse transcription and polymerase chain reaction with primers specific to PACAP type I receptor were used to demonstrate the expression of mRNA encoding PACAP type IA receptor in these cells. Granulosa cells were also cultured in the absence or presence of 100 ng LH ml-1 with various doses of PACAP-38 (10, 100 and 1000 ng ml-1). At the end of the incubation period, the incubation media were collected and concentrations of progesterone, 20 alpha-hydroxypregn-4-en-3-one (20 alpha-OH-P) and cAMP were measured. Increasing concentrations of PACAP-38 significantly stimulated the production of progestins (progesterone and 20 alpha-OH-P) and cAMP accumulation in a dose-dependent manner (P < 0.01; ANOVA). This effect was observed in media cultured for 24 and 48 h in both basal and LH-stimulated states. PACAP-38 did not significantly affect the ratio of progesterone: 20 alpha-OH-P produced by granulosa cells cultured for 24 h in the LH-stimulated state. However, at 1000 ng ml-1, PACAP-38 significantly decreased the ratio of progesterone to 20 alpha-OH-P production in granulosa cells cultured for 48 h (P < 0.01). These results suggest that granulosa cells from rat ovary express mRNA encoding PACAP type IA receptor and that PACAP may regulate granulosa cell differentiation and play an important role in the reproductive process.

Image analysis of the human inner ear

The KS 300 is a multifunctional software image analysis system using an object-oriented programming environment. The possibility of its application for the inner ear was studied by using specimens from humans and squirrel monkeys, immunostained for the brain-derived calcium-binding protein, S-100 protein. Grey images were used for measurements. The cell borders were outlined by hand, using a digitizer. The absolute grey values of the pixels changed when the brightness of the images or other conditions changed. By contrast, the relative grey values, i.e. the absolute grey values correlated to the mean grey values of the histoimage, remained constant. By utilizing these relative grey values, it was possible to compare cells both between different specimens and between different areas within the same specimen. The different grey values of spiral ganglion cells stained for S-100 protein are objective quantitative measurements and are believed to reflect differences in their function. In some regions of both human and squirrel monkey specimens, relatively intensely stained cells predominated, whereas in other regions, relatively weakly stained cells were mainly observed. Thus, our image analysis system using the relative grey values has proved suitable for quantitative analysis of immunostained specimens in order to compare them and to assess cell function.

Long-term effects of hyaluronan on experimental osteoarthritis in the rabbit knee

OBJECTIVE

Long-term assessment of the effect of hyaluronan (HA) on the articular cartilage and synovium in an animal knee joint during the development of osteoarthritis (OA).

DESIGN

Sixty mature New Zealand white rabbits underwent unilateral anterior cruciate ligament transection (ACLT) and were divided into two groups. Group 1 (SA) received intra-articular injections of 0.3 ml hyaluronan (HA) (i.e., ARTZ, MW: 8 x 10(5)) beginning 4 weeks after ACLT, once a week for 5 weeks. Group 2 (SV) received injections of the vehicle (phosphate buffered saline) in the same fashion as with the SA group. The contralateral nonoperated knee served as control. All animals were killed 21 weeks after surgery and their knee joints evaluated by gross morphologic, histologic, histomorphometric and biochemical analyses.

RESULTS

Gross morphological inspection indicated that the femoral condyles from the knees injected with vehicle suffered more severe cartilage damage than cartilage from the knees injected with HA. Furthermore, two out of three histomorphometric parameters measured in the HA-treated cartilage (i.e., cartilage thickness and cartilage area which were not statistically different than control) provided evidence showing a protective effect of HA on the femoral condyles following ACLT. Biochemical analysis showed articular cartilage remaining on the femoral condyles following ACLT to have similar characteristics to contralateral controls. However, DNA concentration in the synovium from the ACLT knees of the vehicle-treated animals was greater than contralateral control, while this parameter was not statistically different than contralateral control in the HA treated animals.

CONCLUSIONS

These results demonstrate a protective effect of HA on preservation of the articulating surface of the femoral condyle following ACLT up to 21 weeks post-surgery.

Staphylococcus aureus exotoxin has limited and transient effects on cochlear electrophysiology

Seven ears of Sprague-Dawley rats were exposed to 20 microliters Staphylococcus aureus exotoxin suspension by injection via the tympanic membrane into the round window niche. Another 6 ears were exposed to 20 microliters broth as controls. ABR was performed in the interval 2-31.5 kHz immediately before and 1, 2, 5, 7 and 10 days after the exposure. Although threshold changes could be found in the toxin-exposed group but not the control group in the frequency range 10-20 kHz, there were only statistically significant threshold changes--at 31.5 kHz--on the 1st, 2nd, 5th, and 7th days after the exotoxin injection. S. aureus exotoxin has minor transient but reversible effects on the inner ear, causing chiefly high-frequency threshold and latency changes.

Endogenous insulin-like growth factor-I is obligatory for stimulation of rat inhibin alpha-subunit expression by follicle-stimulating hormone

Insulin-like growth factor-I (IGF-I) is essential for FSH-dependent steroidogenesis by rat granulosa cells (GC), but whether IGF-I is required for other FSH-dependent functions is unknown. To investigate the role of IGF-I in the mechanisms of FSH-stimulated inhibin alpha-subunit (Inh-alpha) production, rat GC were cultured with FSH, IGF-I, insulin-like growth factor-binding protein (IGFBP)-4, IGFBP-5, and/or anti-IGF-I antibody. Inh-alpha protein and mRNA levels were measured in conditioned medium and cells by Western immunoblotting and Northern analysis, respectively. Inh-alpha expression was increased by FSH (3.5-fold) and IGF-I (2.5-fold), and the effects were dose and time dependent. FSH stimulation of Inh-alpha was attenuated by IGFBP-4 or -5 in a dose-dependent fashion, and the effects were reversed by IGF-I. Anti-IGF-I antibody mimicked the inhibitory effects of IGFBP-4 and -5. Forskolin, cholera toxin, and 8-bromo-cAMP increased Inh-alpha production approximately 3.5-fold, and the effects were blocked by IGFBP-4 or -5. Increases in Inh-alpha by FSH, IGF-I, forskolin, cholera toxin, and 8-bromo-cAMP were totally blocked by the protein tyrosine kinase inhibitor, tyrphostin A23. In summary, these results suggest that the stimulation of Inh-alpha expression by FSH requires activation of protein tyrosine kinases by endogenously produced IGF-I. We propose that the IGF-I signaling is obligatory for FSH stimulation of Inh-alpha expression in rat GC.

Localization of heat shock protein in osteoarthritic cartilage

In osteoarthritic (OA) chondrocytes, expression of 70 kD heat shock protein (HSP70) is enhanced under stress. The HSP70 level is also related to OA severity in humans. In the present study, specimens of OA cartilage were obtained from 14 surgically treated female patients. Their disease severity was evaluated according to Mankin's histological/histochemical grading scores. The ratio of HSP70-positive cells was examined by using immunohistochemistry. As OA became more severe, the ratio of HSP70-positive cells increased in deeper areas from the surface, and there was a positive correlation between the grade and the ratio. Distribution of cells expressing HSP70 mRNA detected by in situ hybridization was similar to the distribution of positive cells in the immunohistochemistry. It was presumed that HSP70 plays a role in cell protection from stress, and that mechanical and biological factors which are related to the enhancement of HSP70 expression, have a considerable influence on OA progressions.

Ribozyme-based gene cleavage approach to chronic arthritis associated with human T cell leukemia virus type I: induction of apoptosis in synoviocytes by ablation of HTLV-I tax protein

OBJECTIVE

To develop gene therapy for patients with human T cell leukemia virus type I (HTLV-I)-associated arthropathy (HAAP), we investigated the effects of ribozyme-mediated cleavage of HTLV-I tax/rex messenger RNA (mRNA) on synovial overgrowth.

METHODS

We introduced 2 hammerhead ribozymes targeted against HTLV-I tax/rex mRNA into synovial cells obtained from patients with HAAP and from patients with HTLV-I-negative rheumatoid arthritis (RA) and examined the ribozyme-mediated ablation of Tax expression. Using standard methods, we also determined the cells' ability to stop proliferating and to undergo apoptosis.

RESULTS

The ribozymes successfully cleaved tax/rex mRNA in HAAP patient synoviocytes. Both tax mRNA expression and Tax protein synthesis were inhibited significantly, resulting in inhibition of synovial cell growth and induction of apoptosis. In contrast, synovial cells from RA patients were not affected.

CONCLUSION

In vitro results suggest that ribozyme-mediated gene therapy can inhibit the growth of HTLV-I-infected synovial cells, which is maintained by Tax protein, in HTLV-I-related diseases including HAAP.