Neonatal effects of the delivery interval during cesarean section under spinal anesthesia

The relationships between I-DI (induction to delivery interval) or U-DI (uterine incision to delivery interval) and fetal acid-base status or neonatal clinical condition were studied in 60 healthy parturients undergoing elective cesarean section under spinal anesthesia. The patients were divided into groups, i.e. group A (U-DI less than 90 sec, I-DI greater than 14 min, 18 cases), group B (U-DI less than 90 sec, I-DI greater than 14 min, 12 cases), group C (U-DI greater than 90 sec, I-DI less than 14 min, 15 cases) and group D (U-DI greater than 90 sec, I-DI greater than 14 min, 15 cases). Acid-base values for maternal arterial (MA), umbilical venous (UV) and umbilical arterial blood (UA), and acid-base gradients for (MA-UV) and (UV-UA) in each group were all in the normal range and revealed no significant differences among 4 groups, though U-DI was correlated with UVPCO2, UAPCO2, and (UV-UA) base deficit (r = 0.322, 0.266, -0.256: p less than 0.05). Acid-base states in cases of long and excessively long U-DI (greater than 90 sec and greater than 150 sec, respectively) were more acidotic than those of short U-DI groups (less than 90 sec). Both 1 and 5 minute Apgar scores were 8 or more in all neonates. There was no correlation between I-DI and fetal acid-base values or neonatal clinical conditions. It is conceivable that gentle and careful manipulations of the uterus and fetus rather than shortening of U-DI might be important in preventing against fetal or neonatal depression during cesarean section under spinal block.     

Malignant recurrence of childhood cerebellar astrocytoma: case report

A 15-year-old boy developed a glioblastoma in a cerebellar hemisphere 7 years after surgical excision and local irradiation of a pilocytic astrocytoma in the cerebellar vermis. Clinical and histopathological details are presented, and the literature on late malignant recurrence of childhood cerebellar astrocytoma is reviewed.     

Timolol induces HSV-1 ocular shedding in the latently infected rabbit

Timolol iontophoresis into the eye can induce herpes simplex virus type 1 (HSV-1) shedding in rabbits latently infected with HSV-1 strain McKrae. Anodal iontophoresis of 0.01% timolol was done at 0.8 mAmp for 8 min once a day for 3 consecutive days. Viral shedding was determined by the presence of HSV-1 in the preocular tear film obtained by eye swabs. In two experiments, iontophoresis of 0.01% timolol resulted in all eyes (18/18) shedding HSV-1 for an average duration of 4.3 days. When 5.0% timolol was applied topically to rabbit eyes supersensitized by iontophoresis of 6-hydroxydopamine (6-HD), all eyes (10/10) shed virus for an average duration of 2.9 days. All eyes (12/12) receiving iontophoresis of 6-HD, pre- and posttreatment with topical application of 5.0% timolol, and posttreatment with topical application of 1.0% epinephrine shed virus for an average duration of 3.6 days. Eyes treated with topical application of 5.0% timolol alone showed no difference in HSV-1 ocular shedding, compared with untreated eyes. We concluded that both iontophoresis of 0.01% timolol and topical application of 5.0% timolol to adrenergically supersensitized eyes induced HSV-1 shedding reliably and with a high frequency, and that topically applied timolol does not block the HSV-1 ocular shedding induced by epinephrine in adrenergically supersensitized eyes.     

Pathology of brain parenchyna in meningeal carcinomatosis; Immunohistochemical study with astroprotein (GFAP) and tubulin

Effects of leptomeningeal tumor on the brain parenchyma was studied by the immunohistochemical method with astroprotein (GFAP) and tubulin in a rat model of meningeal carcinomatosis. Thickening of subpial glial lining (external glial layer) and hypertrophy of subpial astrocytes, detected by the antiserum to GFAP, was the early sign of parenchymal involvement. The glial lining was continuous as far as the tumor cells were confined to the subarachnoid space, however, penetration of tumor cells into subpial brain was associated with disruption of the glial lining. Speculative role of this lining in preventing the tumor cell to infiltrate into brain tissue was discussed. In contrast to the prominent immunohistochemical changes in astrocytes, neuronal tubulin immunoreactivity was not altered even in the late stage of the disease. The present study demonstrated that the leptomeningeal dissemination of tumor cells did cause pathologic change in brain parenchyma as was evidenced by the reactive change of astrocytes. However, the preserved immunoreaction for tubulin suggested that the nerve cell damage was not severe even at the advanced stage of the disease. address for offprints     

Experimental study on transferability to cerebrospinal fluid of cefodizime in combination with ampicillin

A study was done on cefodizime (THR-221, CDZM) in combination with ampicillin (ABPC) for its transferability to cerebrospinal fluid (CSF) of rabbits with experimental meningitis caused by Staphylococcus aureus. Blood and CSF were collected at 15, 30, 45, 60, 90, 120 and 180 minutes after intravenous administration of CDZM at 100 mg/kg to 6 rabbits, ABPC at 100 mg/kg to 4 rabbits and simultaneous administration of both drugs at 100 mg/kg each to 5 rabbits. Drug concentrations were assayed with an high performance liquid chromatography method, and pharmacokinetic parameters were calculated. The comparison revealed no significant difference in concentrations achieved among different groups. Therefore, the mutual transferability of these drugs to CSF was not considered to interact adversely due to the simultaneous administration of both drugs. Accordingly, CDZM may be a candidate of chemotherapeutics in the therapy of purulent meningitis, and it is worthy of further investigations.     

Capillary permeability factor produced by C 6 glioma cells: role in peritumoral brain edema and possible mechanism of glucocorticoid action

We studied whether C6 glioma cells produce a diffusible factor that increases capillary permeability of rat brains. Culture supernatant after 4 hours' incubation of C6 glioma cells in serum-free medium was obtained (SUP-N). SUP-N was concentrated 80-fold by dialysis-concentration (MW cut off was 10 kd) (SUP-C). These two supernatant fractions were tested for capillary permeability activity by their infusion into normal rat brains (right caudate-putamen). Control materials (MEM or concentrated MEM) were also infused into the left caudate-putamen as well as supernatants. Capillary permeability was measured by a quantitative autoradiographic method with 14C-aminoisobutyric acid (AIB) and expressed as an unidirectional blood-to-brain transfer constant (K). Effects of infusates were quantitatively estimated by two parameters, i.e., the highest K value (Kmax) (microliter/g/min) and the spatial extent (D1/2) (mm). The protein concentration of SUP-N and SUP-C was 15 and 950 micrograms/ml, respectively. SUP-N showed a slight increase of capillary permeability, particularly, around the needle track (infusion site) in the brain, but it was not significantly different from the control on the value of Kmax. On the other hand, SUP-C markedly increased capillary permeability (Kmax; SUP-C: 10.83 +/- 0.99, control: 2.53 +/- 0.22, p less than .001) and the effect was much more extensive than that of SUP-N (D1/2; SUP-C: 2.23 +/- 0.26, SUP-N: 0.83 +/- 0.07). A factor in SUP-C increased capillary permeability after a lag phase of 1.5 hours reaching the maximum after 6 hours of infusion, and 24 hours later the effect declined to 30% of Kmax at 6 hours.(ABSTRACT TRUNCATED AT 250 WORDS)     

Modification of anoxic neuronal injury by human recombinant epidermal growth factor and its possible mechanism

A primary culture of cortical neurons was established from a 17-day rat embryo. Twenty-four hours after plating, the culture medium was changed to a chemically defined one, and human recombinant EGF (rEGF) was added to the medium at concentrations of 1, 10, and 100 ng/ml. Anoxic stress was exerted on the cultured neurons for 4 hr. Without anoxia, rEGF at a concentration of 10 ng/ml supported neuronal survival. When rEGF was not present in the culture medium, anoxic stress reduced neuronal density to one-tenth that of the nonanoxic group. The rEGF improved neuronal recovery from anoxia significantly, with survival dependent on rEGF dosage. Monoclonal antibody for EGF receptors canceled the effect of rEGF on survival of neurons in a dose-dependent manner. Therefore, rEGF functioned to support neuronal survival from anoxia through EGF receptors. Ontogeny of the EGF receptors was detected immunocytochemically with anti-EGF receptor antibody. About 70% of the cultured neurons were stained by the anti-EGF receptor antibody 3 days after change of medium, and immunoreactivity for EGF receptors was found to be located on the soma of neurons. Binding activity of EGF receptors was detected 5 days after change of medium with receptor binding assay and Scatchard analysis. High-affinity binding sites were detected only in neurons cocultured with rEGF (10 ng/ml) for 5 days. The data indicate that rEGF in sufficient concentration induces high-affinity sites of the EGF receptor and that EGF may have an antianoxic effect through the EGF receptors.     

Growth activity of tumors at different intracranial structures: immunohistochemical study with bromodeoxyuridine

Summary To elucidate the environmental influence on the growth of a tumor, bromodeoxyuridine (BrdU) uptake in multiple tumor foci within the intracranial cavity was studied immunohistochemically with a monoclonal antibody. Walker 256 tumor implanted intracerebrally produced multifocal tumors presented as (1) intraparenchymal solid tumor, (2) tumor in the choroid plexus, and (3) leptomeningeal dissemination. The BrdU-labeling indices, or the S-phase fractions (% of nuclei labeled by BrdU divided by the number of tumor cell nuclei scored; LI), of those tumors were 48.4±1.1, 59.1±1.3, and 27.9±5.9, respectively (means ± SEM). These differences in LI, or the tumor growth activity, are discussed in relation to the different environmental conditions in different host structures. These host structure-related modification of tumor growth would be important in evaluating the proliferative activity of tumors growing at various intracranial structures.Supported in part by the Grant-in-Aid for Cancer Research (59-22) from Ministry of Welfare     

Computer assisted neurosurgery: development of a frameless and armless navigation system (CNS navigator)

We have developed a computer assisted neurosurgical navigation system, which displays the point of ongoing surgical manipulation on the CT or MR images. The system utilizes magnetic field modulation technology for the detection of the 3 dimensional position and orientation angles of the probe, a resin pointer or suction tube with a small magnetic field sensor. Four fiducial markers on the scalp were used to translate the spatial data of the probe onto the CT/MRI images. This frameless and armless navigator with a spatial accuracy of 4mm, introduces CT/MRI-stereotaxy to conventional open neurosurgery without limiting the operative field or interfering with surgical procedures.