The role of androgen in the sexual dimorphism in hypothalamic growth hormone (GH)-releasing hormone (GHRH) and somatostatin (SS) gene expression was examined in rats. In the first study, the SS and GHRH mRNA levels were measured in both male and female rats at 4, 6, 8, and 10 weeks of age. A significant sex-related difference in the SS and GHRH mRNA levels was observed after 8 weeks of age, when sexual maturation is fully attained. Male rats had higher SS and GHRH mRNA levels than the female rats. In the second study, adult ovariectomized rats received daily injection of dihydrotestosterone (DHT), nonaromatizable testosterone, at a dose of 2 mg/rat for 21 days. The DHT treatment masculinized the GH secretory pattern, which was indistinguishable from that of intact male rats, and simultaneously augmented the SS and GHRH mRNA levels. The DHT treatment of ovariectomized rats after hypophysectomy significantly raised the level of SS mRNA, but not that of GHRH mRNA compared to the control animals. These findings suggest that the activation of the SS gene expression through androgen receptor plays an important role in the maintenance of sexual dimorphism in GH secretion in rats.

Animals↗

PubMedDate not supplied

Effects of radiation on chondrocytes in culture.

Using an in vitro model, we studied the direct effects of radiation on both DNA and glycosaminoglycan (GAG) synthesis of chondrocytes. Chondrocytes from articular cartilage of 21-day-old rabbits were cultured in monolayer or in pellets with matrix as a three-dimensional tube culture. These cells were exposed to a single dose of X-rays at either 2 or 10 Gy. Following irradiation at 2 Gy, DNA synthesis in the chondrocytes was temporarily suppressed but rapidly returned to the control level, while at 10 Gy, DNA synthesis was markedly suppressed and there was no increase in cell number. On the other hand, GAG synthesis was not affected by a single dose of X-rays at either 2 or 10 Gy, nor did GAG content decrease in the three-dimensional tube cultures. These results show that radiation affects the proliferation and differentiation of chondrocytes differently, and that the synthesis of the components of cartilaginous matrix such as GAG is relatively radioresistant in contrast to DNA synthesis.

Animals↗

PubMedDate not supplied

Combined effect of extracellular matrices and growth factors on bovine corneal endothelial cells in culture.

PURPOSE: First, to confirm that corneal endothelial cells in the confluent state have the capability to form cellular covering. Second, to establish a method to study the combined effect of extracellular matrices (ECMs) and growth factors on the biological response in corneal endothelial cells in culture. METHODS: Bovine corneal endothelial cells were cultured inside a cylinder set on a plastic dish. They formed a confluent cell nest on the dish coated with type I or type IV collagen, laminin, or fibronectin. After the removal of the cylinder, hepatocyte growth factor (HGF), epidermal growth factor, transforming growth factor-alpha or transforming growth factor-beta(1) was added to the cultures. Each confluent cell nest enlarged outward, and its increased area size was measured. Cellular response in the nest, including cellular proliferation, was analyzed. RESULTS: The size of the increased area of the culture on type IV collagen plus HGF was the largest of all the combinations of ECMs and growth factors. The responses of component cells in the increased area consisted of cellular hypertrophy, proliferation, migration and giant cell formation. The treatment with type IV collagen plus HGF clearly promoted all the above responses. CONCLUSIONS: The biological response of corneal endothelial cells was regulated by ECMs and growth factors.

Animals↗

PubMedDate not supplied

Estimation of coronary flow reserve with the use of dynamic planar and SPECT images of Tc-99m tetrofosmin.

BACKGROUND: We developed a noninvasive method to examine coronary flow reserve with technetium 99m tetrofosmin based on the microsphere model. According to the microsphere model, myocardial blood flow (MBF) can be calculated by MBF = q / integral C(t)dt, where q is myocardial activity and C(t) is tracer concentration in blood. Because the ratio of integral C(t)dt at stress to rest is equal to the ratio of the first transit count in the pulmonary artery (PA) and attenuation factors were canceled out, we calculated the increase ratio of MBF (MBF(IR)). METHODS AND RESULTS: After injection of dipyridamole, tetrofosmin was injected as a bolus and serial dynamic planar images were obtained to measure the first transit count in PA (PAC). Myocardial single photon emission computed tomography was performed to measure the regional myocardial count (RMC). MBF(IR) was calculated as [(RMCs x PACr)/(RMCr x PACs) - 1] x 100, where r and s denote resting and stress conditions, respectively. In contrast, the increase in the myocardial uptake ratio (MUR(IR)) was defined as (RMCs x SCr/RMCr x SCs - 1) x 100, where SC is syringe count of tracer. The results were as follows: (1) The mean MBF of healthy subjects was 46.9% +/- 22.8%. (2) MBF(IR) of the infarcted region and ischemic region was significantly decreased (8.3% +/- 12.2% and 11.2% +/- 11.9%, respectively; P <.001). (3) MUR(IR) was significantly lower than MBF(IR) (14.1% +/- 21.2%; P <.001). (4) MBF(IR) decreased according to the heart rate at rest (r = 0.47; P <.05). CONCLUSIONS: MBF(IR) is a potential parameter with which to evaluate coronary flow reserve when the changes of arterial input function during stress are considered.

Coronary Circulation↗

PubMedDate not supplied

Imprint cytology of Gaucher's disease presenting as a splenic mass. A case report with molecular approaches.

BACKGROUND: Gaucher's disease is an autosomally transmitted lysosomal storage disease caused by a defect in the lysosomal enzyme, beta-glucosidase. CASE: A 43-year-old male presented with splenomegaly and anemia. Magnetic resonance imaging examination of the abdomen revealed huge, round masses in the spleen. Intraoperative cytology of the spleen showed Gaucher cells that resembled macrophages, with eccentric, small, oval nuclei, but distinguished by their abundant cytoplasm with the characteristic "wrinkled tissue paper" appearance. The cytologic features of the smears correlated well with the histologic sections from the splenectomized specimen. The DNA from this patient was examined for seven glucocerebrosidase mutations that are known to cause Gaucher's disease. The patient was heterozygous for the 754 mutation. Diagnosis was confirmed by a deficiency of beta-glucosidase. The residual activity was 15% of control values. CONCLUSION: Diagnosis of Gaucher's disease was made cytologically and subsequently confirmed by the polymerase chain reaction. Imprint cytology is a sensitive diagnostic test, and the combined use of histology and molecular techniques offers the highest probability of identifying this common lysosomal storage disorder.

Adult↗

PubMedDate not supplied

Cytologic features of granulomatous mastitis. Report of a case with fine needle aspiration cytology and immunocytochemical findings.

BACKGROUND: Granulomatous mastitis, a rare condition of unknown etiology, affects women of childbearing age and clinically simulates breast carcinoma. CASE: Granulomatous mastitis of the breast in a 32-year-old female was studied by fine needle aspiration cytology. Aspirated material was quite cellular and consisted of epithelioid histiocytes, lymphocytes, plasma cells, neutrophils and multinucleated Langhans-type giant cells. However, no cheesy, necrotic material in the background was noted. CONCLUSION: Granulomatous mastitis, although infrequently reported, appears to have rather characteristic cellular features that may allow its recognition.

Adult↗

PubMedDate not supplied

Nerve contact with muscle component in neuromuscular hamartoma.

Neuromuscular hamartoma is a very rare soft tissue tumor, of which only 20 cases have been reported previously. None of these reports has described the relation between hamartomatous skeletal muscle and nerve fibers in the tumor. We experienced a patient with neuromuscular hamartoma arising at the brachial plexus. In this tumor, the localization of synaptophysin (SYP), S-100 protein (SP), neuron-specific enolase (NSE) neurofilament protein (NFP) and myoglobin (MG) was immunohistochemically detected. The results showed that SYP and MG were diffusely localized in the hamartomatous muscle fibers, SP in the schwann cells, and NSE and NFP in the axons of the hamartomatous nerve. Therefore, it is suggested that in the neuromuscular hamartoma, the structure of the neuromuscular junction may be similar to that in the motor end-plate of the normal muscle, but it may not be functional, because the hamartomatous muscles could not contract by nerve stimulation.

Hamartoma↗