Fitness cost associated with resistance to fluoroquinolones is diverse across clones of Klebsiella pneumoniae and may select for CTX-M-15 type extended-spectrum ß-lactamase.

Lowered fitness cost associated with resistance to fluoroquinolones was recently demonstrated to influence the clonal dynamics of methicillin-resistant Staphylococcus aureus (MRSA) in the health care setting. We investigated whether or not a similar mechanism impacts Klebsiella pneumoniae. The fitness of K. pneumoniae isolates from major international hospital clones (ST11, ST15, ST147) already showing high-level resistance to fluoroquinolones and of strains from three minor clones (ST25, ST274, ST1028) in which fluoroquinolone resistance was induced in vitro was tested in a propagation assay. Strains from major clones showed significantly less fitness cost than three of four fluoroquinolone-resistant derivatives of minor clone isolates. In addition, plasmids with CTX-M-15 type extended-spectrum ß-lactamase (ESBL) genes were all retained in both major and minor clone isolates, irrespective of the strains' level of fluoroquinolone resistance, while each plasmid harboring SHV-type ESBLs had been lost during the induction of resistance. Major clone K. pneumoniae strains harbored more amino acid substitutions in the quinolone resistance determining regions (QRDRs) of the gyrA and parC genes than minor clone isolates. The presence of an active efflux system could be demonstrated in all fluoroquinolone-resistant derivatives of originally SHV-producing minor clone isolates but not in any CTX-M-15-producing strain. Further investigations are needed to expand and confirm our findings on a larger sample. In addition, a long-term observation of our ciprofloxacin-resistant minor clone isolates is required in order to elucidate whether or not they are capable of restoring their fitness while concomitantly retaining high minimum inhibitory concentration (MIC) values.

Prevalence of proteinuria and the development of chronic kidney disease in HIV-infected patients.

AIMS: HIV-related renal diseases are increasingly prevalent and are associated with proteinuria and rapid progression to end-stage renal failure. Early treatment with highly active antiretroviral therapy (HAART) and ACE inhibition may prevent the development of chronic kidney disease (CKD), but studies evaluating the epidemiology of proteinuria and early CKD in HIV-infected patients are lacking. METHODS: All consecutive patients at Wishard Memorial Hospital (Indiana University) whose initial HIV documentation occurred from 1990 to 1998, were retrospectively studied using a computerized medical record system. Clinical data were abstracted from time of first HIV documentation through 12/31/2000. The proportions of patients who developed CKD (doubling of serum creatinine from an initial level < or = 1.5 mg/dl) and who had proteinuria (> or = 1+ protein on the first urine dipstick after HIV documentation) were calculated. Case mix and laboratory variables at the time of HIV documentation were compared between those who did and did not develop CKD and between those who had and did not have initial proteinuria. RESULTS: Of 487 subjects with initially normal renal function, 10 (2% (95% CI, 1-4%)) developed CKD. In univariable analysis, black race, a diagnosis of diabetes or hypertension and proteinuria were all significantly associated with the development of CKD; 89 (29% (95% CI, 24-35%)) of 289 evaluable subjects had > or = 1+ proteinuria on urine analysis. Multivariable regression revealed only older age (OR 1.08 per year increase; 95% CI, 1.03-1.14) to be associated with proteinuria. CONCLUSIONS: A small, but potentially clinically meaningful proportion of HIV-infected patients develop CKD, and there appears to be a high prevalence of proteinuria on the first urine analysis obtained after HIV documentation.

Traumatic cranial injury sustained from a fall on the rigid external distraction device.

Distraction osteogenesis has become a popular treatment of congenital maxillocraniofacial anomalies. Many ingenious internal and external devices have been developed and used. The rigid external distraction system based on systems previously used in correction of maxillary retrusion offers postoperative adjustment in two dimensions. Figueroa and Polley reported the use of this device with minimal morbidity in children as young as 5 years of age. They reported no problems with infection, bleeding, pain, loosening of the intraoral splint, dental injury, or wear problems in a series of 14 consecutive cleft patients. Recent modification of the system, rigid external distraction II, has allowed it to be applied to more complex craniofacial deformities that require a LeFort III osteotomy. A review of the neurosurgery and orthopedic literature revealed that halo complications relate primarily to the skull pins. In most cases, these complications can be prevented if the device is carefully applied and monitored. Early recognition and prompt treatment of complications are important. After experience with this system for advancement at the LeFort III level, six patients with various syndromes involving the craniofacial skeleton have undergone LeFort III level distraction osteogenesis with the rigid external distraction device in combination with a planned and stabilized frontosupraorbital advancement. In one of these cases, a 7-year-old child fell on the device after discharge from the hospital and sustained a compound depressed skull fracture that required debridement and repair.

One-stage correction of complex facial disproportion.

Patients with facial disharmony frequently have abnormal nasal form and disordered jaw relationships. Both orthognathic surgery and rhinoplasty are required to correct such facial disproportions. During a 10-year period 100 patients with a spectrum of indications have had concomitant orthognathic and rhinoplasty surgery by a team consisting of the same plastic surgeon, oral and maxillofacial surgeon, and orthodontist. Of this group 51 patients were operated on solely for aesthetic reasons, the majority being long face syndrome. All had a rhinoplasty usually with septal surgery. Depending on the deformity, the jaw surgery varied: 5 patients had mandibular surgery only, 12 had maxillary surgery alone, and the remaining 34 patients had both mandibular and maxillary procedures. Patients were followed for between 1 and 62 months by the plastic surgeon and for at least 2 years by the orthodontist. There was no orthognathic relapse or other major complications, but 4 patients required secondary minor nasal tip surgery under local anesthesia and 2 patients had persisting unilateral inferior alveolar nerve damage. Orthognathic surgery and rhinoplasty are not routinely performed concomitantly due to the difficulty in predicting the outcome of the soft-tissue relationships and increased morbidity. In this series, a one-stage approach was used to provide facial harmony. This reduces the overall surgical and anesthetic morbidity, inconvenience, and expense, and has resulted in good cosmetic and functional results. Therefore, it is suggested that with a competent team, orthognathic surgery and rhinoplasty can be performed concomitantly with dependable results and without significant complications.

Distraction osteogenesis for lengthening of the hard palate: Part I. A possible new treatment concept for velopharyngeal incompetence. Experimental study in dogs.

Many procedures have been described to correct velopharyngeal incompetence. Significant complications can occur, and the results may not be satisfactory. If the short soft palate has satisfactory muscle function and if it could be moved toward the posterior pharyngeal wall by distraction osteogenesis of the hard palate, an entirely new concept of treatment for velopharyngeal incompetence would be available. The object of the present study was to explore the possibility of osteogenesis occurring in the hard palate in dogs after gradual distraction (callus distraction). Six adult, mix-bred dogs were anesthetized, and the palatal mucosa was elevated. A midpalatal transverse osteotomy and two lateral osteotomies were performed. Tantalum bone markers for cephalometric analysis were placed, and an individually fabricated, orthodontic-like distraction device with an expansion screw in the sagittal direction was inserted. The device was stabilized on the premolars and fixed to the palatal bone with titanium miniscrews. Gradual distraction began after a latency period of 10 to 18 days. The rate of the distraction varied from 0.25 to 0.75 mm per day. The device was left in place for 6 to 8 weeks after expansion to allow for bony consolidation. Assessment was by direct examination, cephalograms, computed tomography, and histology with bone labeling. Impressions of the jaws were taken preoperatively and after device removal to examine plaster cast changes in the dental occlusion. Cephalometric and computed tomographic scan analysis demonstrated a distraction of up to 8 mm. All gaps were filled with de novo osteogenesis. Comparison of the plaster casts revealed no change in the occlusion. At 1 month after distraction, the computed tomographic scan showed the first signs of ossification of the experimental gap from the anterior and posterior bone ends. After 4.5 months ossification was almost complete with a small translucent zone in the middle of the experimental gap. After 7 months ossification was complete.

Assessment and treatment of facial deformity resulting from radiation to the orbital area in childhood.

Children who receive radiation for malignant tumors in the orbital area frequently develop widespread craniofacial deformities. These affect the skull, orbit, maxilla, and mandible. When these patients seek treatment at a later age, they require careful assessment using cephalometrics and three-dimensional imaging. It is recommended that the four levels of skeletal deformity be corrected in a single procedure, that is frontotemporal expansion with repositioning of the skull base area, orbital expansion and repositioning together with maxillary and mandibular surgery. Bone grafts should be inlay rather than onlay and soft tissue should be supplied by free-tissue transfer. This counteracts any residual ischemia related to the previous radiation therapy. The second surgical stage is designed to reconstruct the socket and the eyelids to allow more satisfactory rehabilitation with an ocular prosthesis. In patients who have a globe present, the usual enophthalmos can be corrected by repositioning of the eye as part of the first procedure by reducing the anteroposterior dimensions of the socket. In bilateral cases, the deformity is hourglass in nature and requires correction in the frontal and temporal area with lateral displacement of the orbits. A bimaxillary procedure is also indicated. It is emphasized that to formulate a satisfactory operative plan an in-depth three-dimensional analysis of the deformity is mandatory.

Midface advancement by gradual distraction.

Midface osteotomy was performed on 5 young adult sheep aged 10-12 months. In 4 animals midface advancement by gradual distraction was performed using an external device; one animal served as a control. The midface was advanced by 2 mm per day for 21 days. The amount of advancement was 36 mm in the nasofrontal area and 43 mm on the lateral aspect of the maxilla. After the period of active distraction the midface was maintained with external fixation for an additional 6 weeks to allow for ossification. Radiographs were obtained immediately postoperatively, after 21 days of distraction, and at the end of the 6 week fixation period. New bone formation in the distracted area was obvious radiographically, clinically and histologically. In conclusion, midface advancement by osteotomy and gradual distraction is possible in the sheep model and may offer controlled correction of deformity, obviating the need for the bone grafting.

Effect of root canal infection and treatment of traumatized primary incisors on their permanent successors.

The purpose of the present retrospective study was to evaluate the effect of trauma, root canal infection and treatment of non-vital primary incisors on their permanent successors. A total of 117 permanent central incisors were examined clinically and radiographically for the presence of discolorations, hypoplasia, or disturbances in root development. Of these, 29 were succedaneous to traumatized, endodontically involved and treated primary incisors (Group A). Another 29 had their traumatized, endodontically involved, primary predecessors extracted or left untreated (Group B). The remaining 59 incisors were intact and had no history of trauma (Group C). Severe hypoplasia could not be observed in any of the teeth, and no disturbances in root development could be disclosed radiographically. The incidence of defects in Groups B and C was similar, whereas in Group A it was 2 or 3 times higher than in each of the other two groups. Despite this fact, root canal treatment of traumatized non-vital primary incisors should be considered a treatment option, as premature extraction of a primary incisor may lead to speech problems, premature eruption and/or malalignment of the permanent successor, or affect the child's self image.

Thylakoid membrane energization and swelling in photoinhibited Chlamydomonas cells is prevented in mutants unable to perform cyclic electron flow.

Photoinhibition of Photosystem II in unicellular algae in vivo is accompanied by thylakoid membrane energization and generation of a relatively high ΔpH as demonstrated by (14)C-methylamine uptake in intact cells. Presence of ammonium ions in the medium causes extensive swelling of the thylakoid membranes in photoinhibited Chlamydomonas reinhardtii but not in Scenedesmus obliquus wild type and LF-1 mutant cells. The rise in ΔpH and the related thylakoid swelling do not occur at light intensities which do not induce photoinhibition. The rise in ΔpH and membrane energization are not induced by photoinhibitory light in C. reinhardtii mutant cells possessing an active Photosystem II but lacking cytochrome b6/f, plastocyanin or Photosystem I activity and thus being unable to perform cyclic electron flow around Photosystem I. In these mutants the light-induced turnover of the D1 protein of Reaction Center II is considerably reduced. The high light-dependent rise in ΔpH is induced in the LF-1 mutant of Scenedesmus which can not oxidize water but otherwise possesses an active Reaction Center II indicating that PS II-linear electron flow activity and reduction of plastoquinone are not required for this process. Based on these results we conclude that photoinhibition of Photosystem II activates cyclic electron flow around Photosystem I which is responsible for the high membrane energization and ΔpH rise in cells exposed to excessive light intensities.

The three-dimensional mandibular bone plate.

A new type of mandibular bone plate implant has been described that immobilizes the mandible more ridigly than do previous bone appliances. Because of this characteristic, maxillomandibular fixation may be eliminated in a large percentage of fractured mandibles, or the time for immobilization is, at least, reduced.