[The anchoring of newly synthesized adenovirus DNA to the nuclear matrix]

After adenovirus infected HeLa cells were pulse labeled and pulse-chase labeled with 3H-thymidine, the nuclear matrix and DNA remaining tightly bound to the matrix were obtained by sequential cell fractionation. Measuring the radioactivity of labeled DNA indicated that newly synthesized viral DNA specifically attach to the nuclear matrix and the amount of binding DNA is in direct proportion to the viral DNA replication activity: then the DNA gradually detach from the matrix and are involved in viral assembly. Electron microscopic autoradiography of the extracted cells showed the virion and viral DNA associated with the nuclear matrix, and thus further confirmed the anchoring of newly synthesized viral DNA to the nuclear matrix.

Receptor binding of epidermal growth factor in cultured human choriocarcinoma cell lines: effects of actinomycin-D and methotrexate

Binding of epidermal growth factor (EGF) to its receptor was evaluated in the four cultured choriocarcinoma cell lines BeWo, NaUCC-1, NaUCC-2, and NaUCC-3. Also, the effect of the anti-tumor drugs actinomycin-D (Act-D) and methotrexate (MTX) on the EGF receptor binding was investigated in these cell lines. Incubation of these cells with [125I]EGF at 37 degrees C resulted in a higher binding than that at 22 degrees C or at 4 degrees C. These bindings were saturable during 30- to 60-min incubation, and were specific and reversible. Scatchard analysis showed that the maximal number of receptor binding sites was 2.89 X 10(3)/cell in BeWo cells, 2.04 X 10(3)/cell in NaUCC-1 cells, 1.84 X 10(3)/cell in NaUCC-2 cells, and 1.01 X 10(3)/cell in NaUCC-3 cells. Preincubation with Act-D or MTX for 24 hr decreased the number of receptor binding sites (26%-53%) and slightly increased the receptor binding affinities. Combination of the two drugs resulted in a further diminution of EGF receptor binding sites in BeWo, NaUCC-1, and NaUCC-3 cells, respectively, but reversed the Act-D effect in NaUCC-2 cells. These results indicated that choriocarcinoma tissue is rich in EGF receptors, that the anti-tumor drugs Act-D and MTX diminish the receptor binding sites in the tissue, and suggest that MTX might induce a drug resistance to Act-D in some choriocarcinoma tissue.

[Rupture of splanchnic artery aneurysms (a report of 19 cases)]

During the past 30 years, 19 patients were admitted in our hospital with acute rupture of splanchnic artery aneurysms. There were 12 hepatic artery, 5 gastroduodenal-pancreaticoduodenal and 2 superior mesenteric artery aneurysms. The aneurysms ruptured into the biliary tract in 13 patients, and 3 into the abdominal cavity, and 3 into the upper gastrointestinal tract. Twelve aneurysms resulted from choledochitis or pancreatitis, 5 from atherosclerosis and 2 from trauma. It is difficult to make a correct diagnosis preoperatively. The most valuable examination is selective angiography of the celiac and superior mesenteric arteries. Nine of our patients were correctly diagnosed preoperatively by arteriography. Thirteen patients were treated by surgery and 7 died. Prognosis depended on anatomic relations of the aneurysms and the primary underlying disease.

Möbius and Möbius-like syndromes (TTV-OFM, OMLH)

There exists a spectrum of syndromes characterized by cranial nerve palsies, limb anomalies, and craniofacial malformations. Criteria based on type and severity of limb anomaly or presence or absence of cranial nerve palsy may alter the syndrome nomenclature due to a selection bias but do not appear to benefit syndrome delineation to any extent. Patients with seventh nerve palsy and abduction weakness are usually diagnosed as having Möbius syndrome by ophthalmologists. The observed ocular motility findings range from primarily abduction deficiencies to patients who have a Duane or gaze palsy pattern of horizontal movements. Some cases previously described as "sixth nerve and partial third" may better fall into one of the latter groups, since an isolated adduction deficit as a manifestation of third nerve involvement is rare. The presence of clinical appearance of Duane syndrome in these Möbius-type patients raises the possibility of abnormal innervation of the lateral rectus as an explanation of some patterns of motility observed.

Association of adenovirus DNA transcribed activity with nuclear matrix of host cells

With gentle cell extraction techniques, various DNA components in the HeLa cells after 6 h of adenovirus infection have been obtained. Adenovirus, early transcribed regions (E2a, E1b) and a late transcribed region (L2) were used as probes in Southern hybridization, respectively. The experiment showed that only actively transcribed adenovirus DNA fragments would tightly bind to the nuclear matrix of host cells. We inferred that the nuclear matrix of host cells plays an important role in viral DNA transcription.

The effect of thiamine deficiency on the structure and physiology of the rat forebrain

Dietary thiamine deficiency, enhanced by pyrithiamine administration in adult rats, produces overt lesions in the brain that are especially prominent in the thalamus. The present study was undertaken to determine whether the thalamic lesions could be correlated with alterations in the physiological properties of neurons in the thalamus and somatosensory cortex. The regimen for experimentally inducing thiamine deficiency produced large lesions in the thalamus of every case; the lesions included most, if not all, of the neurons in the intralaminar thalamic nuclei. The extent of the lesion in the intralaminar thalamus was highly correlated with the loss of bilaterally synchronous spontaneous activity in the cerebral cortex. This correlation was seen in animals analyzed as early as 1-18 hr after the appearance of opisthotonus, the crisis state of thiamine deficiency, and as late as 2-9 weeks of recovery following thiamine replacement therapy. The loss of bilateral synchronous bursting neuronal activity following intralaminar thalamic lesions is consistent with the proposed role of the intralaminar thalamus as a pacemaker for rhythmic cortical activity (Armstrong-James et al., Exp. Brain Res., 1985; Fox and Armstrong-James, Exp. Brain Res. 63: 505-518, 1986). The location and size of the central lesions within the thalamus suggest that the observed neuronal loss could result from a nonhemorrhagic infarction in the ventromedial branches of the superior cerebellar arteries. Experimental thiamine deficiency also produced alterations in the receptive field properties of the somatosensory cortex neurons in all animals examined. Changes in cortical receptive field properties were correlated with the destruction of sensory relay neurons in the thalamic ventrobasal complex. The loss of the central lateral thalamic input to the cortex and the loss of somatosensory relay neurons in the ventrobasal thalamus in experimental thiamine deficiency produce alterations in cortical function which may contribute to deficits in memory and cognition analogous to those which characterize Korsakoff's psychosis in humans.

Dissociation of hCG-receptor complex and detection of hCG receptors in human chorionic tissues

We developed a radioreceptor assay (RRA) system for investigating occupied hCG receptors by using a rat testis membrane fraction. Treatment with dithiothreitol, neuraminidase, and low pH (3.3) buffer partially dissociated hCG from its receptor with dissociation rates of 42.8%, 35.2%, and 68.7%, respectively. Specific receptor rebinding was unaffected and showed competitive inhibition of [125I]hCG rebinding by unlabeled hCG. Scatchard plot analysis yielded a rebinding Km of 1.798-3.496/pM. High concentrations of NaCl and MgCl2 had no obvious effect on the [125I]hCG-receptor complex. Triton X-100 and high concentration MnCl2 treatments resulted in the loss of the receptor rebinding activity. We also investigated human chorionic tissue (at 8 weeks, 11 weeks, 16 weeks, 24 weeks, and term) for hCG receptors using the above method. Treatments with different agents increased [125I]hCG binding in this tissue preparation 139-226%, but Scatchard analysis failed to demonstrate any specificity. [125I]hCG uptake by the choriocarcinoma BeWo cell-line increased 151-193% after similar treatments, but this increase could not be competitively inhibited by unlabeled hCG. Treatment with dithiothreitol, neuraminidase, and low pH (3.3) buffer seems feasible for detecting hCG-occupied receptors. Our results suggest that there are no hCG receptors distributed on the surface of the syncytiotrophoblast of human placenta.

Inherited snowflake cataracts

The authors report two unusual pedigrees of flake-like cataracts inherited as an isolated mendelian trait, presumably autosomal dominant. The most striking biomicroscopic feature is an accumulation of large white irregular flakes ('type B opacities') scattered throughout the equatorial cortex, with apparently less involvement of the nucleus. Some of these opacities are globular, but most are flattened and have feathery edges. These type B opacities are clinically and microscopically identical in the two families. Type B lesions are characterized histologically by irregular pale-staining areas. Ultrastructurally, these areas show large collections of microglobular degeneration immediately adjacent to normal-appearing lens fibers. Electron probe studies demonstrate normal calcium levels. 'Type A' opacities are biomicroscopically smaller, punctate, and clinically non-specific. Ultrastructurally, type A opacities include clusters of medium sized lenticular globules, each of which is larger than the individual microglobular abnormalities of type B lesions, although the aggregated type B lesion is considerably larger than an individual type A lesion. The microscopic appearance of this inherited cataract appears to be unique.

The RBE of the leakage radiation from the Hiletron neutron therapy unit

The RBE of the leakage radiation from the Hiletron 14.7 MeV neutron therapy unit has been measured using three sensitive biological systems in mice, which differ markedly in their radiobiological characteristics. These systems comprise type A spermatogonia and bone marrow stem cells, which are affected insignificantly by dose rate, and pigment abnormalities in hair follicles which are affected markedly by dose rate. For mice irradiated at 10 cm depth in a water phantom, the leakage radiation up to 40 cm from the beam axis was virtually as effective as the primary beam for the latter two biological systems, and for spermatogonia in mice when irradiated in air. At this distance, the total dose rate was about 0.2 cGy (rad) per minute (3% of that in the primary beam), and the gamma-ray component was about 70%. This equal effectiveness of the total dose for all three systems was considered fortuitous, and it implied high RBE values for equal effect with the small neutron component at far distances. Considering published data on RBE versus neutron energy, the evidence suggested either a positive interaction of neutron and gamma-ray components in killing bone marrow stem cells when the neutron component was less than 40% of the total dose, or an increased efficiency of neutrons when delivered at very low dose rates. However the components were additive in killing spermatogonia.

Measurement of velocity of propagation from ultrasonic pulse-echo data

A method is proposed for determining velocity of propagation of ultrasound in tissue by processing the pulse-echo data obtained from a compound scan. Individual sectors from different transducer positions are reconstructed and a suitable area common to the two sectors is selected. Cross-correlation of the region of interest is used to detect an apparent shift in the image due to refractive effects. The refractive effects are analysed by a ray-tracing procedure to determine an effective velocity within the tissue. The system has been tested using the U.I. Octoson as input device and both model targets with known velocity of propagation and in vivo liver tissue. The accuracy in the model experiment was +/- 5 ms-1 while the repeatability of measurements in tissue was +/- 15 ms-1. techniques for extending the method to multiple region systems are suggested.

Traumatically acquired color vision defect

A 24-year-old man acquired a color vision defect shortly after an accident in which he struck the back of his head. Results of the Farnsworth-Munsell 100-hue test showed that the patient had poor color discrimination in both eyes. His color matches on the Nagel anomaloscope suggested a red/green disturbance. Results from increment threshold testing demonstrated on absence of the blue mechanism. Results of field sensitivity measurements confirmed that foveal vision was mediated by the red or green mechanism. This case showed both similarities and differences to previously reported cases of acquired color vision defects secondary to cortical trauma.

Previous strabismus surgery and eye position under anesthesia

We studied eye position under general anesthesia in 51 patients with concomitant esotropia or exotropia, divided into two groups. One group consisted of strabismus patients who had had no previous surgery. The second group consisted of strabismus patients who had undergone previous surgery on one (asymmetric) or both (symmetric) eyes. We found that both groups showed either no change or more divergence under general anesthesia in comparison to their preoperative state. Those patients who had had no previous surgery revealed an equal divergence in both eyes. This relationship also held true for those patients who had undergone symmetrical surgery in both eyes. However, those patients who had had surgery in one eye only showed more divergence in the operated eye than in the unoperated one. These findings reflect the mechanical--anatomical factors created by the surgery itself.

The formation of photoreceptor synapses in the retina of larval Xenopus

The first appearance and early development of synapses between photoreceptors, bipolar cells and horizontal cells were studied in the retina of larval Xenopus, between stages 37/8 and 46. Synapse morphology was reconstructed from examination of serial sections. Additional data were obtained from E-PTA stained tissue, Photoreceptors initially contacted horizontal cell dendrites via ribbon synapses at the photoreceptor basal surface (stages 37/8--39). Later, horizontal cell dendrites penetrated the receptor as digitiform processes (stages 39--40) which subsequently expanded extensively within the invagination (stages 40--44). At stages 41--46, a photoreceptor ribbon generally was associated with two horizontal processes in a synaptic dyad complex; each ribbon participated in 1 or 2 such complexes. Bipolar cell dendrites made contact with receptors via superficial or invaginating basal-type junctions. Such junctions were observed first at stage 39, but increased greatly in number beginning at stage 42. Basal junctions were characterized by marked staining of the paramembranous receptor cell cytoplasm and a 9--13 nm wide cleft containing an electron-dense material. No association of bipolar cell dendrites with photoreceptor ribbons was noted. Junctional complexes presumed to be gap junctions first were observed at stage 39 between photoreceptor bases and basal processes emitted by neighbouring photoreceptors.

Cholesterol oxidase: thermochemical studies and the influence of hydroorganic solvents on enzyme activity

Thermal and binary cosolvent studies of the cholesterol oxidase (cholesterol: oxygen oxidoreductase, EC 1.1.3.6) reaction have been carried out using batch microcalorimetry and ultraviolet spectrophotometry respectively. Heat conduction measurements are shown to provide the basis for a serum cholesterol assay yielding results comparable to conventional automated clinical assay. The enthalpy of the reaction for cholesterol oxidation, measured with different sources of the enzyme in the presence and absence of catalase is -113 +/- 7.2 mJ/mumol. The value is agreement with calculated estimates based on bond energies, enthalpies of formation and trigonal additivity contribution calculations. From this heat of reaction the deltaHf0 of cholestenone (c) is calculated to be -490 kJ . mol-1. No evidence for the reverse reaction could be adduced. Enzyme activation with detergent (Surfal) is attributed to the formation of mixed micelles of cholesterol with detergent molecules. The detergent concentration at which the enzyme is half activated corresponds to the critical micelle concentration of Surfal. The enhanced enzyme activity found when ethanol, acetonitrile and dioxane were examined as binary cosolvents with water is ascribed to a conformational change in the enzyme mediated through the altered structuredness of water. This cosolvent effect is abolished in the presence of 0.18% Surfal due to the formation of inverted mixed micelles of detergent with cholesterol.