Anterior screw fixation combined with posterior interlaminar fusion for fracture of axis: report of two cases

Two cases of axis fracture are reported. Traffic accidents were the cause of injury in both cases. The odontoid process was dislocated anterolaterally with fracture of the lateral mass of the axis in both cases. In Case 1 good alignment of the atlas and axis could not be maintained even with a Halo-vest. The case 2 patient with spinal cord compression caused by dislocation of the axis was referred to our hospital 8 weeks after the accident. Both cases were surgically treated in a similar fashion. Because of the lateral mass fracture and lateral displacement of the atlas relative to the axis, posterior screw fixation with interlaminar fixation (Magerl) was thought to carry a risk of causing damage to the vertebral artery. Because of this, anterior screw fixation combined with posterior wiring was conducted. First, the odontoid process was fixed anteriorly by a screw because it was able to be placed back in good alignment while the patient was in the supine position. Then, the posterior C1-2 interlaminar wiring with iliac bone graft was added. Rigid fixation was obtained without any complication. Various kinds of fixation, such as posterior interlaminar wiring, odontoid screw fixation and Magerl's fixation, have been reported for the treatment of unstable axis fracture. Among them Magerl's method has been regarded as the most stable. When it is not applicable, combination of the first two methods can be an alternative way of treatment for this odontoid process fracture.     

An experimental model for side-to-side microvascular anastomosis

Side-to-side microvascular anastomosis may be required in certain clinical situations, although the technique is difficult and the incidence of usage remains low. A new experimental model using rat femoral vessels for side-to-side microvascular anastomosis is presented, in which 100 percent patency was accomplished immediately and was maintained for 7 days after anastomosis. This model can provide a training tool for acquisition of advanced microsurgical technique for side-to-side anastomosis of small vessels.     

Pharmacokinetic interactions between HIV-protease inhibitors in rats

The interactions of four HIV-protease inhibitors, ritonavir (RIT), saquinavir (SAQ), indinavir (IND) and nelfinavir (NEL), were examined by in vitro metabolic studies using rat liver microsomal fractions. The substrate concentrations employed were 0.75 approximately 12 microM, and the inhibitor concentrations were 2.5 approximately 60 microM. The metabolic clearance rates of SAQ, NEL and IND as determined by V(max)/K(m) were 170.9+/-10.9, 126.0+/-4.4 and 73.0+/-2.0 microL/min/mg protein, respectively. RIT was a potent inhibitor of the other three protease inhibitors, and the inhibition constants (K(i)) were 1.64 microM for SAQ, 0.95 microM for IND and 1. 01 microM for NEL. NEL was the second strongest inhibitor with a K(i) for NEL inhibition of IND metabolism of 2.14 microM. IND was the third strongest inhibitor with K(i)s of 2.76 microM for inhibition of NEL and 3.55 microM for inhibition of SAQ. As SAQ has the highest metabolic clearance rate, the K(i) for the SAQ inhibition of IND metabolism was high, 9.50 microM. Based on these in vitro results, drug interactions between NEL and IND or RIT were studied after oral administration to rats where the dose of each drug was 20 mg/kg. The C(max) and AUC of NEL were increased 3.6- and 8.5-fold by the co-administration with RIT. However, in contrast to co-administration of NEL and RIT, the effect of IND on the pharmacokinetics of NEL was negligible and the t(1/2) of NEL was not significantly increased by IND. Therefore, the combination of NEL and IND is recommended as a combination therapy for AIDS patients.     

Metabolism of liriodendrin and syringin by human intestinal bacteria and their relation toin vitro cytotoxicity

When liriodendrin or syringin was incubated for 24 h with human intestinal bacteria, two metabolites, (+)-syringaresinol-beta-D-glucopyranoside and (+)-syringaresinol, from liriodendrin and one metabolite, synapyl alcohol, from syringin were produced. The metabolic time course of liriodendrin was as follows: at early time, liriodendrin was converted to (+)-syringaresinol-beta-D-glucopyranoside, and then (+)-syringaresinol. The in vitro cytotoxicities of these metabolites, (+)-syringaresinol and synapyl alcohol, were superior to those of liriodendrin and syringin.     

Effect of biphenyl dimethyl dicarboxylate on the cellular and nonspecific immunosuppressions by ketoconazole in mice

The effect of biphenyl dimethyl dicarboxylate (PMC) on the cellular and nonspecific immunosuppressions by ketoconazole (KCZ) was investigated in ICR mice. PMC at a dose of 6 mg/kg was administered orally to mice daily for 14 consecutive days. KCZ was suspended in RPMI 1640 medium and orally administered at 160 mg/kg/day 2 hrs after the administration of PMC. Immune responses of the delayed-type hypersensitivity (DTH) reaction to sheep red blood cells (SRBC), phagocytic activity and natural killer (NK) cell activity were evaluated. DTH reaction to SRBC was enhanced to normal level by the combination of PMC and KCZ, compared with treatment of KCZ alone. In the combination of PMC and KCZ, as compared with the treatment of KCZ alone, there were also significant increases in activities of natural killer (NK) cells and phagocytes along with circulating leukocytes. These findings indicate that PMC shows a significant restoration from the immunotoxic status induced by KCZ.     

Cytologic correlates of chemical carcinogens in respiratory tracts of dogs.

During canine respiratory carcinogenesis studies with benzo[a]pyrene (BP) and N-methyl-N-nitrosourea (NMU), a stereotypic pattern of cytomorphology characteristic for each carcinogen was observed. In the early stage, BP induced changes primarily in the cytoplasm. These changes consisted of incresaed size, basophilia, and vacuolization. In contrast, NMU induced primarily nuclear enlargement and enhanced the prominence of the nucleolus. Subsequently, cells exposed to BP demonstrated pleomorphism of the cytoplasm and nucleus, whereas cells exposed to NMU formed bizarre spindle-shaped cells. Cells were generally more scattered from one another following BP treatment than after NMU treatment. When the mucosa was exposed to NMU after the previous use of BP, the cytologic findings promptly became those characteristic of NMU.     

Cytotoxic,mutagenic, and cell-cell communication inhibitory properties of DDT,lindane, and chlordane on Chinese hamster cellsin vitro

The cytotoxicity, mutagenicity, andin vitro inhibition of metabolic cooperation of DDT, lindane, and chlordane were studied with Chinese hamster V79 cells. The results showed differential cytotoxicity of these three pesticides (lindane < DDT < chlordane). There was no detectable mutagenic activity of any of these pesticides, using two genetic markers (6-thioguanine and diphtheria toxin resistance). DDT and lindane, however, were shown to have properties similar to 12-O-tetradecanoylphobol-13-acetate (a powerful mouse skin tumor promoter). Above what appeared to be a threshold level, there was a clear dose response of DDT and lindane in thein vitro cell-cell communication assay. Chlordane, which was the most cytotoxic pesticide tested, did not inhibit metabolic cooperation as significantly as did DDT or lindane. The role of these pesticides in carcinogenesis was speculated as being their tumor promoting properties, either at non-cytotoxic levels by mimicing TPA-like membrane alterations or at cytotoxic levels by mimicing partial hepatectomy.     

Effect of recombinant granulocyte colony-stimulating factor (rG-CSF) on chemotherapy-induced neutropenia in patients with urogenital cancer

Summary The effects of recombinant granulocyte colony-stimulating factor (rG-CSF) on the myelosuppression, especially neutropenia, induced by cancer chemotherapy in patients with urogenital cancer were investigated in a randomized, controlled clinical study. In this study, rG-CSF was given subcutaneously at a dose of 2 g/kg per day for 14 consecutive days. Changes in neutrophil counts were compared between the first (no rG-CSF) and second cycles (rG-CSF treatment period) of chemotherapy. rG-CSF administration was found to be effective in reducing the duration of neutropenia, in elevating the neutrophil nadir, and in reducing recovery time. Based on comparisons between the randomized rG-CSF treatment group (with rG-CSF) and the control group, treatment with rG-CSF resulted in the moderation or prevention of neutropenia and the acceleration of recovery. These results demonstrate that in chemotherapy of patients with urogenital cancer, in which neutropenia is a dose- or schedule-limiting factor, the concomitant use of rG-CSF may enable an increase in the dose (higher single dose or increased dose per unit of time) or shorten the chemotherapy period.     

Pterion and epipteric bones in Japanese adults and fetuses, with special reference to their formation and variations]

The formation and variations of the pterion and epipteric bones were examined in total of 614 Japanese skulls. The materials used consisted of 258 skulls of Japanese fetuses ranging from the fourth to the ninth month, 20 skulls of Japanese juveniles from the third month to 17 years of age, and 336 skulls of Japanese adults from 20 to 89 years of age. For the skulls examined the incidence of ossification in the fetal sphenoidal fontanelle was 3.6% on each side, whereas epipteric bones were observed in more than 10% of the juvenile and adult pteria. Great variation was seen in the form of the adult pterion. The most common form was a sphenoparietal contact in which the pteria were classified into usual (306 pteria), high (119), low (21), and narrow (32) types Another form of this type, a frontal process of the temporal bone without contact with frontal bone, was found in five pteria. The form of frontotemporal contact is classified into two types: One is with a frontal process of the temporal bone (17 pteria), and another is a K-shaped contact referred to as "stellate" (four). The two types were observable in adult skulls of all ages, although the fused pteria and fusing epipteric bones were most often seen in cases over 40 years of age. The results suggest that the pterion formation has two phases, the first occurring before the occlusion of sphenoidal fontanelle, and the second starting after 40 years of age.     

An extensive transbasal approach to frontal skull-base tumors. Technical note

Lesions in the base of the frontal fossa have conventionally been approached extra- and intradurally through a bilateral frontal craniotomy. However, when the lesion is large or deeply situated, wider bilateral retraction of the frontal lobes is required to obtain a sufficiently large operative field. The authors describe a new operative approach for huge tumors at the frontal skull base, employing an en bloc bilateral osteotomy of the orbital roofs and frontal sinus. This procedure, which is a modification of the transbasal approach described by Derome and Guiot, is termed the "extensive transbasal approach." The advantages of this technique over conventional operative approaches are described.