A randomized prospective study of oral versus intravenous antibiotic prophylaxis against postoperative infection after sagittal split ramus osteotomy of the mandible

BACKGROUND

We investigated whether oral levofloxacin was as effective as intravenous cefazolin sodium for preventing postoperative infections in patients undergoing sagittal split ramus osteotomy of the mandible.

METHODS

Forty-four patients were randomized to treatment with levofloxacin or cefazolin sodium. Levofloxacin (100 mg t.d.s.) was administered orally, and cefazolin sodium (1 g b.i.d.) by intravenous infusion. Both drugs were given until 5 days postoperatively. The concentrations of levofloxacin in the mandibular bone marrow and serum were measured.

RESULTS

The mean levofloxacin concentration 4 h and 53.7 min after administration was 1.086 microg/ml in serum and 1.328 microg/ml in the mandibular bone marrow. The efficacy rate of levofloxacin was 95% and that of cefazolin sodium was 85.7%, with no significant difference between the two drugs (p = 0.322).

CONCLUSION

Oral administration of levofloxacin is a simple, cost-effective and safe alternative to intravenous antibiotic prophylaxis after mandibular surgery.

Asymmetry in jaw-jerk reflex latency in craniomandibular dysfunction patients with unilateral masseter pain

The purpose of the present study was to elucidate the effects of unilateral masseter muscle pain on the jaw-jerk reflex. The latency and peak-to-peak amplitude of bilateral electromyographic activity recorded at the masseter muscles during the jaw-jerk reflex were measured in 18 patients with craniomandibular dysfunction (CMD) with strictly unilateral masseter pain or tenderness and 10 control subjects using a computerized recording and analysis system. The reflex was elicited, at the mandibular rest position, by tapping the centre of the chin downwards with a reflex hammer incorporating a microswitch that triggered the sweep of the recording apparatus upon contact with the chin. In the CMD group, the jaw-jerk latency on the affected side (6.89 +/- 0.98 ms) was significantly shorter (P < 0.01) than that on the unaffected side (7.59 +/- 0.92 ms). In the control group, there was no difference between the jaw-jerk latencies on the right (7.06 +/- 0.64 ms) and the left (7.08 + 0.65 ms) sides. The range of side asymmetry for jaw-jerk latencies in the CMD group was greater than that in the control group. In six patients, the latency difference exceeded 1 ms. The asymmetry of latency of the jaw-jerk reflex was thought to be due to facilitation on the side with masseter pain or tenderness. This facilitation on the ipsilateral side might be produced by enhanced gamma drive induced by sustained nociceptive stimulation. Such effects may be related with clinically derived concepts regarding such muscle dysfunction as myospastic activity or trigger points.

Experience with freeze-dried PGLA/HA/rhBMP-2 as a bone graft substitute

We investigated bone induction by recombinant human bone morphogenetic protein-2 in rodents. The purpose of this study was to evaluate the osteoinductive potential of a resorbable bone substitute fabricated from freeze-dried poly(glycolic acid-co-lactic acid) (PGLA) mixed with hydroxyapatite particles incorporated with bone morphogenetic protein-2 in skull defects of rats (FD-PGLA/HA/rhBMP-2). The FD-PGLA/HA/rhBMP-2 composite or as a control, the FD-PGLA/HA by itself were implanted in skull defects (psi 8 mm) of rats. The samples were harvested at 2 or 4 weeks postoperatively and were studied radiographically and histologically. Four weeks after implantation, the FD-PGLA/HA/rhBMP-2 discs were completely replaced by newly-formed bone possessing bone marrow. In contrast, the defects implanted with FD-PGLA/HA were filled only with fibrous connective tissue. The results suggest that the FD-PGLA/HA/rhBMP-2 composite could be an optimum bone substitute with osteoinductive potential and could function as an alternative bone graft material for autogenous bone in humans.

Comparison of the effectiveness of arthrocentesis in acute and chronic closed lock: analysis of clinical and arthroscopic findings

The objective of this study was to investigate the effectiveness of temporomandibular joint arthrocentesis in acute and chronic closed lock patients. Eighteen patients with closed lock of the temporomandibular joint (TMJ) were treated with fine needle fiber arthroscopic observation following arthrocentesis. Maximal mouth opening (MMO) and intensity of pain (VAS) were evaluated at pretreatment and each posttreatment appointment (one week, one month, three months following treatment). The clinical and arthroscopic findings were analyzed categorizing two groups into: good (A) and poor (B) groups. At pretreatment there was no significance relative to age or the mean MMO and VAS between the groups, but the mean of duration of the symptoms in group B was significantly longer than in group A (P < 0.03). Group B showed more severe synovitis, adhesions, and chondromalacia than group A (P < 0.01). Results suggest that arthrocentesis is more effective in closed lock of short duration where there is less severe synovitis, adhesions, and chondromalacia.

Identification of a novel allele of SIR3 defective in the maintenance, but not the establishment, of silencing in Saccharomyces cerevisiae

Using a screen for genes that affect telomere function, we isolated sir3-P898R, an allele of SIR3 that reduces telomeric silencing yet does not affect mating. While sir3-P898R mutations cause no detectable mating defect in quantitative assays, they result in synergistic mating defects in combination with mutations such as sir1 that affect the establishment of silencing. In contrast, sir3-P898R in combination with a cac1 mutation, which affects the maintenance of silencing, does not result in synergistic mating defects. MATa sir3-P898R mutants form shmoo clusters in response to alpha-factor, and sir3-P898R strains are capable of establishing silencing at a previously derepressed HML locus with kinetics like that of wild-type SIR3 strains. These results imply that Sir3-P898Rp is defective in the maintenance, but not the establishment of silencing. In addition, overexpression of a C-terminal fragment of Sir3-P898R results in a dominant nonmating phenotype: HM silencing is completely lost at both HML and HMR. Furthermore, HM silencing is most vulnerable to disruption by the Sir3-P898R C terminus immediately after S-phase, the time when new silent chromatin is assembled onto newly replicated DNA.

A survey of trace elements in pteridophytes

Concentration of 11 trace elements (Ca, Sc, Cr, Fe, Co, Zn, Rb, Cs, Ba, La, and Ce) in 96 pteridophytes (fern and fern ally species) was determined by instrumental neutron activation analysis to evaluate a concentration range for each element and also to find species characteristic in the uptake of trace elements. Asplenium trichomanes was found to accumulate Sc, Cr, and Co to the highest concentrations among 96 pteridophytes. The highest concentration of Ca and Zn was observed for Asplenium obscurum. The other Pteridophytes exhibited only one element whose concentration was the highest. A positive correlation was found between the concentrations of Fe and Sc, and also between the concentrations of Cr and Co. The remarkable accumulation of lanthanides (La and Ce) was observed mainly in diversifying genera (Polystichum and Dryopteris in Dryopteridaceae, Diplazium in Woodsiaceae, and Asplenium in Aspleniaceae).

Hepatic zinc response via metallothionein induction after tumor transplantation

Based on previous findings that liver zinc and metallothionein (MT) levels increase after tumor transplantation, zinc metabolism in tumor-bearing mice was studied to clarify the role of zinc-MT in host defense systems. Zinc in the hepatic cytosolic MT fraction did not increase in tumor-bearing mice fed a zinc-deficient diet, suggesting that dietary zinc is necessary for apo-MT induction in the liver after tumor transplantation and is then incorporated into the apo-MT. When (65)ZnCl(2) was intravenously injected, liver (65)Zn levels in the tumor-bearing mice were higher than those in control mice for 72 h after the injection. Pancreatic and blood (65)Zn levels in tumor-bearing mice were lower than those in controls for 24 h (pancreas) and 6 h (blood) after the injection. These findings indicate that the hepatic zinc response via MT induction influences zinc metabolism in the body after tumor transplantation. Moreover, (65)Zn uptake in the liver of MT-deficient tumor-bearing mice was lower than that in control tumor-bearing mice 1 h after injection. (65)Zn uptake in the tumor and blood (65)Zn levels in the MT-deficient tumor-bearing mice were higher than those in the control tumor-bearing mice. Tumor weight increased more in MT-deficient mice than in control mice. The formation of zinc-MT in the liver of tumor-bearing mice might decrease blood zinc availability for tumors and other tissues, such as the pancreas.

Measure of bite force and occlusal contact area before and after bilateral sagittal split ramus osteotomy of the mandible using a new pressure-sensitive device: a preliminary report

PURPOSE

This study examined bite force and occlusal contact area in prognathic patients before and after bilateral sagittal split ramus osteotomy of the mandible using a newly developed pressure-sensitive sheet (Dental-Prescale, Fuji Photo Film Co, Tokyo, Japan).

PATIENTS AND METHODS

Twenty-five prognathic patients were examined. Bite force and occlusal contact area were measured preoperatively, at 2, 4, and 8 weeks, and at 3 and 6 months after surgery. The bite force and occlusal contact area of 20 healthy subjects were also measured.

RESULTS

Both bite force and occlusal contact area of the patients were the lowest 2 weeks after surgery and recovered to the preoperative level between 8 weeks and 3 months. Subsequently, they increased slowly and exceeded the preoperative level at 6 months after surgery. However, even at 6 months, both the bite force and the occlusal contact area of the patients were still only about half or less than that of healthy subjects.

CONCLUSION

This pressure-sensitive device can be used as a simple indicator of postoperative recovery and occlusal improvement in patients following orthognathic surgery.

Radiotherapy for primary localized (stage I and II) non-Hodgkin's lymphoma of the oral cavity

PURPOSE

To assess the role of radiation therapy in the treatment of primary localized (Stage I: 24 cases and Stage II: 13 cases) non-Hodgkin's Lymphoma (NHL) of the oral cavity.

METHODS AND MATERIALS

In total, 37 patients (27 male, 10 female) with primary localized NHL of the oral cavity have been treated with radiotherapy alone (23 cases) or radiation with chemotherapy (14 cases). The age range was 29 to 86 years (median: 65). Clinical and treatment variables with potential prognostic significance for survival were evaluated by univariate and multivariate analysis. Of the 37 patients, 31 (84%) had intermediate-grade lymphomas and six (14%) had high-grade lymphomas. Four patients showed necrotic ulcer in the central portion of the hard palate.

RESULTS

The 5-year actuarial survival rate for all cases was 73%. The 5-year survival rates for intermediate-grade and high-grade lymphoma were 85% and 14%, respectively. Significant prognostic factors identified by the multivariate analysis were histologic grade of malignancy (p = 0.02) and central necrotic ulcer in the tumor (p = 0.02). Chemotherapy did not improve survival (p = 0.41).

CONCLUSIONS

Our analysis suggests that radiotherapy alone may be approved as the treatment for localized oral NHL with no ulceration and intermediate histology. However, patients with high-grade lymphoma and/or necrotic ulcer are difficult to cure with radiation alone and aggressive treatment should be advocated to improve survival.

Congenital lipomatoid mass of the tongue

A congenital lipomatoid mass of the tongue in a 5-year-old boy is reported.

Suppression of a high-affinity transport system for manganese in cadmium-resistant metallothionein-null cells

Cadmium is a hazardous heavy metal existing ubiquitously in the environment, but the mechanism of cadmium transport into mammalian cells has been poorly understood. Recently, we have established a cadmium-resistant cell line (Cd-rB5) from immortalized metallothionein-null mouse cells, and found that Cd-rB5 cells exhibited a marked decrease in cadmium uptake. To investigate the mechanism of altered uptake of cadmium in Cd-rB5 cells, incorporation of various metals was determined simultaneously using a multitracer technique. Cd-rB5 cells exhibited a marked decrease in manganese incorporation as well as that of cadmium. However, the reduced uptake of manganese was observed only at low concentrations, suggesting that a high-affinity component of the Mn(2+) transport system was suppressed in Cd-rB5 cells. Competition experiments and kinetic analyses revealed that low concentrations of Cd(2+) and Mn(2+) share the same high-affinity pathway for their entry into cells. The mutual competition of Cd(2+) and Mn(2+) uptake was also observed in HeLa, PC12, and Caco-2 cells. The highest uptake of Cd(2+) and Mn(2+) by parental cells occurred at neutral pH, suggesting that this pathway is different from a divalent metal transporter 1 that can transport various divalent metals including Cd(2+) and Mn(2+) under acidic conditions. These results suggest that a high-affinity Mn(2+) transport system is used for mammalian cellular cadmium uptake, and that the suppression of this pathway caused a marked decrease in cadmium accumulation in cadmium-resistant metallothionein-null cells.

[Clinical study on risk management for dental implant treatment--Part 1. Clinical retrospective study on the medically compromised patients at clinic for oral implant]

A retrospective study on medically compromised patients was made using 1,000 outpatients who visited the Clinic for Oral Implant, University Hospital, Faculty of Dentistry, Tokyo Medical and Dental University between April 1995 and June 1998. The results were as follows: 1. 35.3% (353 patients: 140 males and 213 females) of the outpatients were medically compromised. 2. The greatest number of medically compromised patients was in the 50-59 age group (118 cases), followed by those in the 40-49 and 60-69 age groups. 3. The highest ratio of medically compromised patients was in the 60-69 age group (48.2%), followed by those in the 70-79 and 50-59 age groups. 4. Among the 353 patients, 96 (27.2%) underwent surgical treatment such as insertion of implant (68 cases), removal of implant, extraction of tooth, and free gingival graft. 5. Among the 68 patients who underwent insertion of implant, in a classification by type of disease, the patients with cardiovascular diseases were the most numerous (33.9%), followed by metabolic and digestive tract diseases. 6. All surgical treatments of implant insertion were performed under local anesthesia, while monitoring cardiac and respiratory function, and SpO2. Among the 68 patients, 9 underwent operation under intravenous sedation and 2 under nitrous oxide inhalation sedation. All 11 patients had hypertension. The results suggested that identification of preoperative risk factors, precise recognition of general condition, and establishment of control system are important to manage medically compromised patients for dental implant treatment.

Blockade of CTLA-4 signals inhibits Th2-mediated murine chronic graft-versus-host disease by an enhanced expansion of regulatory CD8+ T cells

CTLA-4 (CD152) is thought to be a negative regulator of T cell activation. Little is known about the function of CTLA-4 in Th2-type immune responses. We have investigated the effect of initial treatment with anti-CTLA-4 mAb on murine chronic graft-vs-host disease. Transfer of parental BALB/c splenocytes into C57BL/6 x BALB/c F1 mice induced serum IgE production, IL-4 expression by donor CD4+ T cells, and host allo-Ag-specific IgG1 production at 6-9 wk after transfer. Treatment with anti-CTLA-4 mAb for the initial 2 wk significantly reduced IgE and IgG1 production and IL-4 expression. Analysis of the splenic phenotype revealed the enhancement of donor T cell expansion, especially within the CD8 subset, and the elimination of host cells early after anti-CTLA-4 mAb treatment. This treatment did not affect early IFN-gamma expression by CD4+ and CD8+ T cells and anti-host cytolytic activity. Thus, blockade of CTLA-4 greatly enhanced CD8+ T cell expansion, and this may result in the regulation of consequent Th2-mediated humoral immune responses. These findings suggest a new approach for regulating IgE-mediated allergic immune responses by blockade of CTLA-4 during a critical period of Ag sensitization.

[Blast crisis of chronic myelocytic leukemia that was difficult to differentiate from Ph+ acute lymphoblastic leukemia]

We encountered a 44-year-old woman with suspected chronic myelocytic leukemia (CML) in the acute phase that was difficult to be differentiate from Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). At disease onset, her bone marrow showed an increase in blasts that were negative for myeloperoxydase (MPO) and Positive for CD10, 19, 34, and HLA.DR. Standard type Ph was detected by chromosome analysis, and both major and minor BCR/ABL m-RNA were detected by reverse-transcriptase polymerase chain reaction (RT-PCR) methods. Neutrophil alkaliphosphatase (NAP) score was normal, and neither eosinophilia nor basophilia was observed in peripheral blood. Under a presumptive diagnosis of Ph-positive ALL (L2), the patient was given AdVP (doxorubicin, vincristine, and prednisolone) therapy followed by a regimen of LMVP (L-asparaginase, mitoxantrone, and VP), and obtained a complete remission 2 months later. At that time, FISH analyses of her bone marrow and blood cells no longer detected bone marrow Ph or BCR/ABL fusion gene. A month later, however, the leukemia relapsed with an increase in MPO-positive blasts in bone marrow, and the patient died soon thereafter. We finally concluded that her leukemia was not Ph-positive ALL, but CML in the acute phase at disease onset.

Roles of bone morphogenetic protein type I receptors and Smad proteins in osteoblast and chondroblast differentiation

The biological effects of type I serine/threonine kinase receptors and Smad proteins were examined using an adenovirus-based vector system. Constitutively active forms of bone morphogenetic protein (BMP) type I receptors (BMPR-IA and BMPR-IB; BMPR-I group) and those of activin receptor-like kinase (ALK)-1 and ALK-2 (ALK-1 group) induced alkaline phosphatase activity in C2C12 cells. Receptor-regulated Smads (R-Smads) that act in the BMP pathways, such as Smad1 and Smad5, also induced the alkaline phosphatase activity in C2C12 cells. BMP-6 dramatically enhanced alkaline phosphatase activity induced by Smad1 or Smad5, probably because of the nuclear translocation of R-Smads triggered by the ligand. Inhibitory Smads, i.e., Smad6 and Smad7, repressed the alkaline phosphatase activity induced by BMP-6 or the type I receptors. Chondrogenic differentiation of ATDC5 cells was induced by the receptors of the BMPR-I group but not by those of the ALK-1 group. However, kinase-inactive forms of the receptors of the ALK-1 and BMPR-I groups blocked chondrogenic differentiation. Although R-Smads failed to induce cartilage nodule formation, inhibitory Smads blocked it. Osteoblast differentiation induced by BMPs is thus mediated mainly via the Smad-signaling pathway, whereas chondrogenic differentiation may be transmitted by Smad-dependent and independent pathways.

Successful treatment of two patients with primary cardiac malignant lymphoma

We describe two patients with primary cardiac malignant lymphoma involving the right atrium and superior vena cava, resulting in intractable right cardiac failure and superior vena cava syndrome. Patients were diagnosed by surgical myocardial biopsy and were treated with combination chemotherapy for non-Hodgkin's lymphoma. Each attained a marked response, and hence avoided sudden death from tricuspid atresia. Both have remained alive for more than 21 and 34 months, respectively, and continue intermittent combination chemotherapy.

[Efficacy of mupirocin in eradicating methicillin-resistant Staphylococcus aureus from nasal discharge in carrying cardiovascular surgical patients]

Methicillin-resistant Staphylococcus aureus from nasal discharge was identified in 37 (2.5%) cardiovascular patients operated between 1995 and 1997; 25 male and 12 female, ranging from 1 to 83 years (mean 63); 2 were excluded because of Arbekacin or Isodine-gel treatment. The first 17 were treated with Vancomycin inhalation (V group) and eradication was considered to have been achieved when 3 consecutive negative cultures were obtained; the subsequent 18 were treated with Mupirocin (M group) and eradication was determined by 1 negative culture. In post-eradication electively operated 13 V and 15 M, postoperative MRSA infection was observed in one M (wound infection); the interval from the first nasal culture to the operation was 68 +/- 58 in V and 32 +/- 12 days in M, respectively (p < 0.05). In the remaining 7 who had to undergo emergency surgery while waiting for eradication because of progression of symptoms (2 V) or prior to instituting treatment (2 V, and 3 M), postoperative MRSA infection was observed in 2 M (both pneumonia). No deaths from infection were observed. Though the time required for conversion of the nasal culture was longer in V (13 +/- 20) than in M (7 +/- 1 days) differences were not significant. Mupirocin is easier to use, eradication can be achieved generally within a week.

Binding properties of various metals to blood components and serum proteins: a multitracer study

The binding affinity of various trace elements to blood components and the pH-dependence of the binding affinity of the elements to serum proteins were examined using the radioactive multitracer technique. The binding affinity of 13 elements (Be, V, Mn, Zn, Se, Rb, Sr, Ce, Eu, Gd, Tm, Yb, and Lu) was simultaneously determined by gamma-ray spectrometry. The blood drawn from rats was separated into plasma, corpuscles, and erythrocyte ghosts. It was found that Be, Sr, Mn, and Zn bind highly to the plasma proteins. V and Se were highly bound to the corpuscles, and Se to the erythrocyte ghosts as well. Similar binding percentages of rare earth elements (Ce, Eu, Gd, Tm, Yb, and Lu) were found for each of the blood components, with the highest percentages being observed for plasma proteins. Albumin, beta-globulin, gamma-globulin, apotransferrin, and holotransferrin were examined in the study on the affinity of individual serum proteins. The pH dependence of the affinity of metal ions to the serum proteins in the pH range of 6.4-8.5 was examined using ultrafiltration and gamma-ray spectrometry. Each element showed a characteristic binding affinity to each serum protein, depending on pH. The results are discussed in terms of the chelating ability of metal ions and the nature of the serum proteins.

Study on the distribution of radioactive trace elements in vitamin D-overloaded rats using the multitracer technique

The uptake and distribution of radioisotopes of beryllium, calcium, scandium, vanadium, chromium, manganese, iron, cobalt, nickel, zinc, gallium, arsenic, strontium and barium in vitamin D (VD)-overloaded rats were investigated and compared with those in control rats, using the multitracer technique. Each element revealed its characteristic distribution among various organs in control and VD-overloaded rats. For some elements, such as cobalt and chromium, the distribution patterns in them were significantly different. These results are discussed in terms of the metabolism of the elements in rats.

Plastic surgical reconstruction of left main coronary artery

OBJECTIVE(S)

To report the early and mid-term results of surgical plasty of the left main coronary artery in 12 patients operated upon between 1993 and 1997.

METHODS

The anterior approach was used in all patients. Saphenous vein (n = 4) of glutaraldehyde treated autologous pericardium (n = 8) were used as patch material. Additional coronary artery bypass grafting was performed in 7 patients, the first 3 as a safety back up, and for coexisting stenosis of other coronary branches not revascularized by the plastic procedure in the remaining 4.

RESULTS

Pathologic specimens of the left main coronary artery in 5 revealed atheroma in 3 and myxomatous intimal thickening in 2. The left main coronary artery was widely patent angiographically in all patients prior to discharge. Six patients consented to angiographic restudy 5-40 months after the procedure and revealed excellent results in 5. One patient upon whom autologous pericardial patch had been used underwent percutaneous coronary angioplasty for restenosis of the left main coronary artery and a new lesion of the proximal left anterior descending branch 5 months after the operation. There were no late deaths nor other cardiac events. All patients were in CCS class 1 at their last follow-up.

CONCLUSIONS

Surgical angioplasty of the left main coronary artery could be used to revascularize the left heart safely in patients with a discrete localized lesion of the left main coronary artery and is particularly useful in the face of unavailability of other conduits.

[Clinical retrospective study on outpatients at clinic for oral implant]

A retrospective study was made on 1,000 outpatients visiting the Clinic for Oral Implant, University Hospital, Faculty of Dentistry, Tokyo Medical and Dental University between April 1995 and June 1998. The following findings were obtained according to sex, age group, reason for visit, classification of edentulous area, indication and contraindication for implant therapy, and pre-implant surgical treatment. Forty percent of the outpatients were male and 60% were female. The largest number was in the 50-59-year-old group. The reason for visit of 822 patients was request for implant therapy. 123 patients with uncomfortable implants done at other clinics, 12 patients undergoing maintenance of implants at other clinics and 43 other patients. There were 505 upper jaw cases and 529 lower jaw cases. Most anterior edentulous cases were in the upper jaw group. Most of the posterior edentulous cases were unilateral cases and many of them were free-end saddle cases. Indication patients were 447 of the 822 outpatients. The main contraindication was insufficient volume of bone. Two hundred twenty-one of the 477 indication patients did not need the pretreatment which consisted of extraction, bone graft, free gingival graft, provisional prosthetics, sinus lift, and so on.