Combined effects of arbekacin with other antibiotics against methicillin-resistant Staphylococcus aureus. III. Combined effects of arbekacin with cefotiam or cefuzonam]

Antibacterial effects of combination use of arbekacin (ABK) with cefotiam (CTM) or cefuzonam (CZON) were evaluated against methicillin-resistant Staphylococcus aureus (MRSA) and the following results were obtained. 1. Antibacterial effects of combinations of ABK with CTM and with CZON were equally potent against MRSA at clinically expected 1 MIC of ABK in blood. However, at a sub MIC of ABK the different effects were observed between the 2 combinations. The antibacterial effect of the former was strong and that of the latter was a little weak. 2. In either combination the potency of the antibacterial activity was less dependent on the concentration of CTM or CZON, but was strongly dependent on ABK concentrations. These results suggest that antibacterial effects of the combinations were highly dependent on antibacterial potency and concentration of ABK as previously reported for combinations of ABK with other drugs. 3. The combination use of ABK with CTM appears to be useful in cases of infection by MRSA alone while the combination use of ABK with CZON appears to be useful in cases of double infection with MRSA and Gram-negative bacterium.     

Anterior basal encephalocele of the neonatal and infantile period

Diagnosis of occult basal encephalocele is not difficult if the peculiar clinical and radiological signs of this anomaly are borne in mind. Recent surgery for transsphenoidal encephalocele has had better results than realized. However, high surgical risks may still be encountered in transsphenoidal encephalocele of the early infantile period, because the pituitary-hypothalamic structures are usually incorporated in the herniated encephalocele of this age group. Surgical indications for and operative approaches to transsphenoidal encephalocele in the infantile period are discussed on the basis of the authors' failure in transcranial repair, which resulted in early postoperative death due to hypothalamic dysfunction. Reviewing the reported cases of anterior basal encephalocele, a high correlation between transsphenoidal encephalocele, particularly in the pediatric age group, and allied malformations of the face, eye, and brain was disclosed. This characteristic malformation complex may be explained by a common pathogenetic mechanism operating in the embryonal period at about the stage of the anterior neuropore closure and occurring in the ventral surface of the cephalic end of the neural tube. Three cases of transsphenoidal encephalocele diagnosed in the neonatal period with progressive obstruction in the nasopharyngeal airway are also reported. A characteristic malformation complex consisting of median cleft face syndrome, optic nerve dysplasia, and agenesis of the corpus callosum was associated in two cases; the other patient had an extremely rare combination of septooptic dysplasia. Two patients died pre- and postoperatively, respectively; the other patient did not undergo operation because of grave multiple anomalies.     

MR appearance of parasymphyseal insufficiency fractures of the os pubis

 Objective. To clarify the MRI features of parasymphyseal insufficiency fractures of the os pubis. Design and patients. MRI was performed in four postmenopausal women with parasymphyseal insufficiency fractures. The diagnosis was confirmed with plain films in every patient. T1-weighted and T2-weighted images were obtained in four patients using a 1.5-T unit. Postcontrast T1-weighted imaging was also done in three patients. Results and conclusions. MRI of pubic parasymphyseal insufficiency fracture characteristically demonstrates a hyperintense mass lesion with a hypointense rim on T2-weighted imaging, showing peripheral and septal enhancement after contrast administration. It is important to have this entity in mind in patients with osteoporosis, especially in patients with a history of pelvic irradiation for malignant disease, so as not to misinterpret it as a chondroid tumor or bone metastasis.     

Disappearance of Philadelphia chromosomes after remission induction in lymphoid crisis of chronic myelogenous leukemia]

The authors report a rare case of chronic myelogenous leukemia (CML) in which the Ph1 clone disappeared after remission induction of lymphoid crisis. A 58-year-old man was admitted to our hospital because of fever in July 1988. The white cell count was elevated. Bone marrow aspirate showed hypercellularity with myeloid hyperplasia. In the chromosomal analysis, Ph1 chromosomes were detected in 100% of bone marrow cells analysed. Diagnosis of CML was made and treatment was initiated with recombinant interferon-alpha 2a. Hematological remission without cytogenetic improvement was achieved. In March 1990 he developed lymphoid crisis with proliferation of CD10-positive cells. The chromosomal analysis revealed additional abnormalities including, 45, X, -Y, t(9;22) (q34;q11), +1, -8. With vincristine 0.6 mgX4, pirarubicin 15 mgX4, dexamethasone 40 mgX4 therapy complete remission was obtained. In December 1990 the Ph1 positive clone completely disappeared judging from normal karyotypes in the chromosomal analysis and the disappearance of M-bcr gene rearrangement.     

Nerve conduction and microanatomy in the rabbit sciatic nerve after gradual limb lengthening-distraction neurogenesis.

To clarify how the peripheral nerve adapts to elongation during gradual limb lengthening, electrophysiological and histomorphometric examinations were performed on the sciatic nerves in 18 rabbits. External fixators were used to lengthen the right femora by 30 mm (30%), at a daily rate of 0.5 mm (Group 1) or 2.0 mm (Group 2). Examinations were performed immediately after the limb lengthening procedure. Electrophysiologically, mild conduction slowing was observed in Group 1; a conduction block was evident in Group 2. Histologically, the mean diameter of myelinated fibers was unchanged in Group 1, but a significantly decreased diameter was observed in Group 2. Electron microscopy revealed that mild degenerative change of unmyelinated axons occurred sporadically in two cases in Group 2, but neither group showed evidence of thinning of myelin sheath of myelinated fibers. The mean internodal length (between nodes of Ranvier) of teased fibers was 1216+/-295 microm in the control contralateral side, 1484+/-347 microm in Group 1, and 1467+/-322 microm in Group 2. Thus the internodes were lengthened by 22.1% (Group 1) and 20.7% (Group 2) in comparison with those of the controls. Straightening of the geometry of paranodal myelin sheath was significantly correlated with the rate of distraction. These results indicate that myelinated nerve fibers adapt to gradual elongation by lengthening each Schwann cell body, not by proliferation of Schwann cells.     

Effect of meropenem on fecal flora in children]

Meropenem (MEPM, SM-7338), a novel parenteral carbapenem antibiotic, was examined for its effect on intestinal flora in children. Seven children with infectious diseases (3 male and 4 female children of age's ranging from 4 months to 8 years and 9 months weighing from 7.3 to 23.0 kg) were treated with MEPM at doses ranging 10.3 to 40.5 mg/kg 3 or 4 times a day for 6 to 12 days. Before, during and after the treatment, identities and numbers of various bacteria contained in 1 g of feces were determined and fecal beta-lactamase activity and Clostridium difficile D-1 antigen were also assayed. Changes in fecal flora during MEPM treatment was somewhat different depending on cases. Regarding Enterobacteriaceae among aerobes, all of 7 cases exhibited moderate or pronounced reductions in Escherichia coli. Some of the cases exhibited the tendency to increase in Klebsiella oxytoca. Enterobacter cloacae and Citrobacter freundii. E. coli which was reduced during the treatment increased rapidly after the treatment in 5 out of 7 cases, and the initial bacterial counts were restored. Diverse strains were observed within the genus Enterococcus, while the overall bacterial counts of this genus exhibited the tendency to increase during the treatment. As a result, no significant change in total aerobe count was observed in any case except 1 case where Enterococcus count was somewhat reduced. Among anaerobes, major bacteria such as Bacteroides, Bifidobacterium, Eubacterium and Peptococcaceae exhibited tendencies to decrease in some cases during the antibiotic treatment. Two infants and 1 child exhibited significant decreases in total anaerobe counts. In most of the cases, such changes in major anaerobes were transient and bacterial counts recovered to their initial values rapidly after completion of the treatment. In no cases, glucose non-fermentative Gram-negative bacilli or fungus became predominant. Although C. difficile D-1 antigen was observed in 4 cases, its changes had no relationship with characteristics of feces. C. difficile was not detected in any of the cases. MEPM was detected in feces in 4 cases being treatment, in concentrations ranging from 0.35 to 66.0 micrograms/g. Fecal MEPM levels were very low except in 1 case in which beta-lactamase was negative. From these results, effects of MEPM on intestinal flora in children were relatively minor compared to other new beta-lactam drugs. However, a care should be taken to minimize diarrhea and bacterial turnover when a prolonged use of the antibiotic, was practiced because of potential significant effects on intestinal flora.     

Urodynamic characteristics during animal hypnosis in the rabbit

In animal experiments, in assessing the vesicourethral function, it is desirable to keep the micturition reflex in a physiologic state. Most anesthetics used to immobilize the animals tend to suppress the micturition reflex. An alternative means is decerebration. However, a decerebrate animal is not easily prepared. Instead of anesthesia or decerebration, we applied animal hypnosis to rabbits for immobilization. The urodynamic characteristics during animal hypnosis were compared with those under anesthesia. Twenty male rabbits weighting 2.5 to 3.0 kg were used. Animal hypnosis was produced by placing the rabbit on its back and restraining it in a V-shape trough and maintaining it there until it relaxed. Under hypnosis, cystometry was performed by the suprapubic route. The external sphincter EMG was recorded simultaneously with bladder pressure using a needle electrode. The urethral pressure profile was also measured during hypnosis. These measurements were repeated under anesthesia induced by intravenous pentobarbital injection (30 mg/kg). Furthermore, the hypnotic degree was assessed from respiratory rate and pupil size during these urodynamic measurements. In the rabbit, hypnosis began within 1 min and lasted for 30 to 60 min. During hypnosis, insertion of a catheter, pricking with a needle electrode and suprapubic puncture did not interrupt the immobility. Urodynamic study under animal hypnosis showed that, as bladder volume increased, the sphincter EMG activity increased and that the EMG activity ceased with bladder contraction. Bladder contraction coincided with the expulsion of saline from the urethral meatus. The maximal bladder pressure during micturition was 23.5 +/- 8.0 mmHg. The maximal bladder capacity at which the micturition reflex occurred was 41.4 +/- 22.3 ml.(ABSTRACT TRUNCATED AT 250 WORDS)