[The interaction between neural activity and intracellular pH]

The regulation of intracellular pH (pH(i)) in the nervous system has been vigorously studied using a variety of animal cells in the last decade, through advances in techniques for measuring pH(i) accurately in living cells. These studies have elucidated the mechanisms of pH(i) regulation, such as intracellular buffering and acid transport across the cell membrane, in neurons and glial cells. Following an outline of pH(i) regulation, the interaction between neural activity and acid-base balance is discussed. The dynamic change of pH(i), produced by neural activity, and the effect of pH(i) on the electrical properties of neurons and other excitable cells is emphasized.

[Gross anatomical study of veins in the orbit]

The aim of this study is to clarify the major route of venous return in the orbit. Minute dissections were performed in 10 adult cadavers (5 males and 5 females) after being fixed in a 10% formalin solution. The superior ophthalmic vein (SOV) and its ascending anastomotic branch were consistently well-developed (the average maximum diameter: 6.2mm and 3.2mm, respectively) and these two veins formed the main venous channel from the orbital contents. The ascending anastomotic branch ran between the optic nerve and the medial rectus just behind the eyeball and joined the SOV. A large number of veins, including the inferior ophthalmic vein, which originated from the inferior contents of the orbit, drained into the ascending anastomotic branch. Arteries and/or nerves did not accompany their respective veins in the orbit, except for the lacrimal and ethmoidal veins. The posterior end of the SOV was severely narrowed lateral to the aponeurosis of the lateral rectus, while being conspicuously dilated just behind the eyeball. The above findings suggested that the dilated portion of SOV may act as a reservoir of the venous return of the orbit.

[Radiation therapy for unresected gastric lymphoma]

Six consecutive patients with unresected gastric lymphoma which were treated by radiation therapy between November, 1976 and March 1989 were reviewed. Radiation therapy was performed using involved fields, total radiation dosages of which ranged from 25.2 to 36 Gy (mean, 29.3 Gy). Five out of the 6 patients were treated with chemotherapy combined with radiation. Regimen of the chemotherapy was CHOP (cyclophosphamide, adriamycin, vincristine and prednisone) in most cases. Three out of the 6 underwent probe laparotomy, but the tumors were diagnosed as unresectable due to locally invading the adjacent structures. They were treated by chemo-radiotherapy and 2 of them are surviving as of the present study (40 and 116 months). The other 3 patients were diagnosed as with clinical stage IV disease and 2 of them were successfully treated with chemo-radiotherapy (21 and 66 months, surviving). These data suggest that unresected gastric lymphomas, which are locally advanced or stage IV disease, are treated by chemoradiotherapy with high curability without any serious complications.

[The role of gallium-67 citrate scintigraphy in gastro-intestinal malignant lymphoma]

To evaluate the clinical usefulness of gallium-67 scintigraphy in the detection of the gastrointestinal (GI) non-Hodgkin's lymphoma (NHL) and in the assessment of the therapeutic effects, gallium-67 scintigraphy was reviewed on 24 cases (25 lesions; stomach in 20, ileum in 2, and terminal ileum and/or cecum in 3). Twenty-three out of the 25 lesions (92.0%) were detected by gallium-67 scintigraphy, while barium study could detect all of the 25 lesions. The sizes of the gallium-67 negative 2 lesions were the smallest of all (2.5 and 3.0 cm). The tumor size was considered to the most important factor in the detection by gallium-67 scintigraphy, while the histological classification and the location of the tumor were not related to its detectability. Findings in follow-up gallium-67 scintigraphy after therapy on 10 cases were correlated well with the therapeutic effects. These data suggest that gallium-67 scintigraphy is useful for the detection of GI involvement of NHL and for the assessment of therapeutic effects.

Mutational and gene dosage analysis of calcium-activated potassium channels in Drosophila: correlation of micro- and macroscopic currents

In Drosophila, two Ca2(+)-activated K+ currents, ICF and ICS, have previously been distinguished in conventional voltage clamp experiments. The slowpoke (slo) mutation eliminates ICF specifically. We report that in patch clamp recordings a single-channel Ca2(+)-activated K+ current is readily distinguished from other channel activities in normal larval muscle membrane, whereas no such current is observed in slo muscles. This single-channel current thus correlates with the macroscopic ICF. No obvious differences in amplitude or properties were detected between normal (+/+) and heterozygous (slo/+) ICF channels in whole-cell voltage clamp recordings or single-channel patch clamp recordings. These results are consistent with the hypothesis that slo is a structural gene for the ICF channels only under certain conditions. The selective effect of the slo mutation may reflect a defect in a regulatory mechanism that is specific for the functioning of the ICF channel protein.

The role of gallium 67 imaging in non-Hodgkin's lymphoma of the gastrointestinal tract

To evaluate the clinical usefulness of gallium 67 imaging in the detection of gastrointestinal (GI) non-Hodgkin's lymphoma (NHL) and in the assessment of the therapeutic effects, images were reviewed in 24 cases (25 lesions: stomach, 20; ileum, 2; and terminal ileum and or cecum, 3) and were compared using barium studies and, in 16 cases, computerized tomography (CT). In all, 23 (92.0%) of the 25 lesions were detected by 67Ga citrate imaging, the barium studies detected all 25, and CT detected 15 of 16 lesions (93.8%). The two lesions not identified by imaging and the one not found by CT were the smallest of all. In 2 (8.7%) of the 23 lesions positively identified by 67Ga-citrate imaging, both CT and imaging revealed the extent of the tumor more accurately than did the barium studies. In all but one of the patients, a close correlation existed between the imaging results and the therapeutic effects. These data suggest that 67Ga imaging is useful in conjunction with CT and barium studies for the detection of GI NHL and for the assessment of both the spatial extent of disease and the therapeutic effects, although a lack of 67Ga uptake after therapy does not always indicate a good therapeutic effect.

Age-related changes in cerebral white matter measured by computed cranial tomography

Changes in the cerebral white matter in relation to aging were studied quantitatively by computed cranial tomography (CT) in 70 healthy subjects aged 30 to 94 years. There were no age-related changes in the CT number of the white matter (WMCT) in 41 younger subjects aged 30 to 65 years. But, there was a significant negative correlation between age and the WMCT in 29 elderly subjects aged 66 to 94 years. Brain atrophy was significantly correlated with the WMCT. The WMCT decreased with aging even in neurologically healthy elderly persons.

Central respiratory oscillator: phase-response analysis

To investigate properties of the central respiratory oscillator, phrenic nerve activity, perturbed by electrical stimulation of the middle external intercostal nerve, was analyzed in rabbit by using a phase-response curve (PRC). During inspiration, the stimuli (4-8 pulses) caused all-or-none responses, i.e. a phase advance or no phase shift, and strong stimuli (10 pulses) induced only phase advances. During expiration only graded phase delays were observed. The overall slope of PRC was 0 for 2 pulses and 1 for 10 pulses. At the transition from expiration (E) to inspiration (I), the PRC was discontinuous. This discontinuity corresponds to a phase singularity. In contrast, at the transition from I to E, the PRC was continuous. Therefore, our findings indicate that E-I switching may differ from I-E switching in nature. The respiratory rhythm could not be stopped by perturbation at the phase singularity as predicted from the PRCs. Similarities between the reported PRCs, obtained by inhibitory stimulation of an endogenous bursting neuron and the PRCs in the present study, suggest a possibility that endogenous bursting neurons take part in the function of a mammalian central respiratory oscillator.

Application of a drug delivery system to a steroidal ophthalmic preparation with lipid microspheres

The applicability of a drug delivery system to an ophthalmic preparation was examined using lipid microspheres containing hydrocortisone 17-butyrate 21-propionate (HBP). A 3H-labelled HBP ophthalmic suspension and 3H-labelled HBP lipid microspheres were applied to rabbit eyes, which were then enucleated at fixed intervals to determine the level of 3H-labelled HBP in ocular tissues. The lipid microspheres were shown to deliver the drug to the anterior ocular tissues more effectively than the ophthalmic suspension. It is suggested that a lipid microsphere ophthalmic preparation of various lipophilic drugs including steroids may be useful as a drug delivery system for ophthalmic therapy.

Normal pressure hydrocephalus. Neuropathological study

The pathological changes in the brains of seven patients who had been clinically diagnosed as normal pressure hydrocephalus (NPH) are described and the possible etiological mechanisms are discussed. The pathological findings in all cases consisted of demyelination akin to Binswanger's type of encephalopathy, especially in the frontal lobes. Arteriosclerosis accompanied by occasional organized thrombi and scattered microinfarcts in the periventricular white matter were seen. Focal leptomeningeal fibrosis, diminution of arachnoidal granulations, and non-specific aging processes were noted. Among the above of particular interest, was the degeneration of both periventricular and deep white matters with microinfarcts, and moderate to severe arteriosclerosis. On the basis of these observations, we assume that the degeneration in the white matter is not merely a secondary change due to the result of enlargement of ventricle, but plays an important role in the development of NPH. The development of NPH requires not only the disturbance of cerebrospinal fluid, but also the pre- or coexisting vulnerability in the white matter caused by variables such as ischemia, hypoxia, and trauma.

Amplification of N-myc in a rhabdomyosarcoma

N-myc is a member of the myc oncogene family and has been thought to be specific to neurogenic cells, since it is amplified in some neuroblastomas, retinoblastomas and small-cell lung carcinomas with endocrine properties. Hybridization analyses of DNAs isolated from surgically removed tumors revealed that N-myc was amplified about 6-fold in one of the three embryonic rhabdomyosarcomas examined. The rhabdomyosarcoma containing the amplified N-myc had metastasized into bone marrow, which is preferentially involved in the metastasis of neuroblastomas but is usually not involved in the case of rhabdomyosarcomas. Since rhabdomyoblasts are derived from mesenchyme, this indicates that N-myc gene amplification is not restricted to neurogenic tumors.

Synaptic input driving respiratory motoneurons in dragonfly larvae

Intracellular recordings were made from respiratory motoneurons in dragonfly larvae. Current injection into a motoneuron did not affect other respiratory motoneuron activity. Long-lasting hyperpolarizing current injection revealed that both inspiratory and expiratory motoneurons receive excitatory and inhibitory synaptic input with a reverse phase.