Detection and characterization of simian retroviruses homologous to human T-cell leukemia virus type I

Lymphoid cell lines were established from five different species of monkeys which were positive in antibodies cross-reactive with human T-cell leukemia virus type I (HTLV-I) and were shown to contain provirus sequences homologous to HTLV-I. Gene-specific probes of HTLV-I, gag, pol, env, pX, and LTR, hybridized efficiently with monkey DNAs from these cell lines under stringent conditions, indicating that the proviruses are very similar to HTLV-I along with whole viral genomes. However, the preliminary restriction mapping turned out the difference between simian retroviruses and HTLV-I and also among simian retroviruses. These findings suggest a common ancestor of simian and human retroviruses, but exclude the recent interspecies transmission between monkeys and humans.     

Photoreceptor differentiation of retinoblastoma: An electron microscopic study of 29 retinoblastomas

Retinoblastomas exhibit a unique form of differentiation to produce cell elements similar to those seen in a photoreceptor cell. An ultrastructural study was performed on 29 cases of retinoblastoma to further clarify the cytologic characteristics of the tumor cells. The age of the retinoblastomas averaged 17.1 months and the tumor cells showing photo-receptor differentiation were demonstrated in 10 cases (35%). The findings were especially notable in retinoblastomas with Flexner-Wintersteiner rosette formation (seven cases, 28%). Similar photoreceptor differentiation was also evident in solid cell clusters without rosette formation (four cases, 14%). The presence of photoreceptor elements was assumed to be significantly frequent both in Flexner-Wintersteiner rosettes and in the solid cell clusters. The cell cytoplasm also showed proliferation of long mitochondria and microtubules, reflecting photoreceptor differentiation. The hereditary-type retinoblastoma showed more advanced cell differentiation than the non-hereditary type. Photoreceptor differentiated retinoblastoma showed rather indolent growth compared with the undifferentiated type, and the former can expect a curative treatment by operation. These observations provide additional findings of the biological nature of retinoblastomas.     

Infiltration and tissue concentration of intravesically instilled (2"R)-4'-O-tetrahydropyranyladriamycin or adriamycin in rat bladder tumor induced by BBN

Rats with bladder tumor induced by BBN were treated by intravesical instillation of 0.8 mg of (2"R)-4'-O-tetrahydropyranyladriamycin (THP) (9 rats) or adriamycin (ADM) (8 rats) dissolved in 0.2 ml of distilled water. Thirty minutes later, the bladder was removed surgically. Rats without the tumor received the same treatment of THP (8 rats) or ADM (9 rats). THP and ADM infiltrations to the normal bladder tissue and the tumor were estimated by the use of the photonic microscope system, since both drugs were known to emit characteristic fluorescence. It was found that infiltration of THP to the tumor tissue was more prominent in amounts and deeper than that of ADM, while smaller amounts of THP infiltrated into the normal mucosa compared to ADM. The fact might explain the clinical finding that THP instilled intravesically in half a concentration of ADM showed the same effect on the tumor as ADM. Subsequently, tissue concentrations of THP and ADM were estimated by high performance liquid chromatography. Either THP or ADM was instilled intravesically for 30 minutes to 6 rats with bladder tumor. Similarly, either THP or ADM was instilled in 5 rats without the tumors. Contrary to the result of the photonic microscope system, the tissue concentration of THP was not different from that of ADM not only in the tumor tissues but also in the normal bladder ones. Furthermore, the tissue concentration of both drugs in the normal bladder was higher than that in the bladder tumor.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cohort study of the total leukocyte count and periodontal disease among company employees

There have been few epidemiological studies of the relationship between the leukocyte count and dental disease. In the present study, therefore, we investigated the relationship between oral health indicated by the Community Periodontal Index of Treatment Needs (CPITN) and the total leukocyte count in the cohort study. The 1,035 subjects were male factory workers employed at a chemical factory in Osaka, Japan. Their oral conditions were recorded as the CPITN score. The relationship between the total leukocyte count and the oral condition of the subjects classified according to their smoking habits was investigated over a 5-year period. Among the current smokers, the total leukocyte count was highest each year for the group with CPITN level 4, followed by those with CPITN levels 3 and 2 in descending order, showing that the total leukocyte count was reduced as the periodontal diseases ameliorated. Among the nonsmokers, the total leukocyte count was high every year in the group with CPITN levels 4 or 3 compared to that of the group with CPITN level 2. The fluctuations of the total leukocyte count in current smokers and nonsmokers whose CPITN score increase or decreased in five years was investigated. There were no significant differences among the all groups.     

Pseudolesions of the liver possibly caused by focal rib compression: analysis based on hemodynamic change

OBJECTIVE: The purpose of this study is to show and analyze the CT appearance of pseudolesions of the liver caused by rib compression and to discuss the possible mechanism on the basis of findings of incremental dynamic CT, CT during arterial portography, and CT hepatic arteriography. CONCLUSION: Focal compression of the liver caused by curved ribs can cause transient focal diminishment of portal venous perfusion without significantly altering hepatic arterial perfusion. Such diminishment may be observed as low-density areas on the early phase of incremental dynamic CT.     

Hepatic angiomyolipoma: report of changing size and internal composition on follow-up examination in two cases

We present two cases of hepatic angiomyolipoma in which the size and internal composition of the tumor changed during the course of follow-up study. The tissue elements composing the tumor are thought to grow or regress independently during the disease's clinical course. Radiologists should be aware that hepatic angiomyolipoma can change in size and internal composition during its natural course.     

MR detection of cytoplasmic fat in clear cell renal cell carcinoma utilizing chemical shift gradient-echo imaging

We attempted to determine whether cytoplasmic fat in clear cell renal cell carcinoma (RCC) can be identified by chemical shift gradient-echo magnetic resonance imaging (CSI). CSI was performed for 22 clear cell RCCs and 30 other renal tumors (including 16 non-clear cell RCCs), all of which were surgically proven. Signal reduction in out-of-phase images of these tumors was retrospectively evaluated and compared. The signal loss ratio (SLR) was defined and calculated. Fat staining of specimens from 16 tumors was performed and correlated with SLR. SLR was significantly higher in clear cell RCCs than in non-clear cell RCCs (P < 0.001). There was a significant correlation between degree of fat staining positivity of the specimens and SLR (P < 0.01). When signal reduction in out-of-phase images suggested the diagnosis of clear cell RCC, correct diagnosis of this entity was made in resected renal tumors with sensitivity, specificity, and accuracy of 82%, 90%, and 87%, respectively. CSI can demonstrate cytoplasmic fat in clear cell RCCs, which helps to differentiate this entity from other RCCs.     

Sellar chondroma--case report

A 12-year-old boy presented with right visual disturbance. Skull radiography and computed tomography (CT) showed an irregular deformity of the sella turcica, hypertrophic change of the dorsum sellae, and an inhomogeneously calcified mass in the sella turcica. Magnetic resonance (MR) imaging demonstrated the mass lesion filled the hypophyseal fossa, and extended to the dorsum sellae, right cavernous sinus, and right suprasellar region. The Dolenc pterional combined epidural and subdural approach was carried out. The histological diagnosis was chondroma. Sellar chondroma requires relief of the compression to the chiasm or optic nerve as soon as possible, so partial resection can still be beneficial. However, follow-up MR imaging or CT, visual examination, and control of pituitary dysfunction are required after the operation.