X-ray absorption spectra reveal the inapplicability of the single-band Hubbard model to overdoped cuprate superconductors.

X-ray absorption spectra on the overdoped high-temperature superconductors Tl2Ba2CuO(6+delta) and La(2-x)SrxCuO(4+/-delta) reveal a striking departure in the electronic structure from that of the underdoped regime. The upper Hubbard band, identified with strong correlation effects, is not observed on the oxygen K edge, while the lowest-energy prepeak gains less intensity than expected above p approximately 0.21. This suggests a breakdown of the Zhang-Rice singlet approximation and a loss of correlation effects or a significant shift in the most fundamental parameters of the system, rendering single-band Hubbard models inapplicable. Such fundamental changes suggest that the overdoped regime may offer a distinct route to understanding in the cuprates.

Observation of a 500 meV collective mode in La2-xSrxCuO4 and Nd2CuO4 using resonant inelastic X-ray scattering.

Utilizing resonant inelastic x-ray scattering, we report a previously unobserved mode in the excitation spectrum of La2-xSrxCuO4 and Nd2CuO4 at 500 meV. The mode is peaked around the (pi, 0) point in reciprocal space and is observed to soften, and broaden, away from this point. Samples with x=0, 0.01, 0.05, and 0.17 were studied. The new mode is found to be rapidly suppressed with increasing Sr content and is absent at x=0.17, where it is replaced by a continuum of excitations. This mode is only observed when the incident x-ray polarization is normal to the CuO planes.

Eradication of cryptosporidia and microsporidia following successful antiretroviral therapy.

OBJECTIVES: Incidence of opportunistic protozoal infections causing diarrheal illnesses in patients with HIV has decreased since the introduction of highly active antiretroviral therapy (HAART). The objective of this study was to determine whether the parasites, cryptosporidia, and microsporidia were effectively eradicated or only suppressed following treatment. DESIGN: Six HIV-positive patients with diarrheal symptoms caused by cryptosporidia or microsporidia were prospectively followed up with stool samples and duodenal biopsies. Samples were taken before HAART, between 1 to 3 months, and 6 months post-HAART. METHODS: Duodenal samples were analyzed using routine histology and transmission electron microscopy. Stool samples were analyzed by both light microscopy and polymerase chain reaction (PCR) techniques. RESULTS: Patients who responded successfully to HAART eradicated both cryptosporidial and microsporidial organisms. Symptoms improved within 1 month of therapy but complete eradication of the organisms was only observed after 6 months of treatment. CONCLUSIONS: AIDs-related cryptosporidiosis and microsporidiosis can be cured following successful antiretroviral therapy.

Diffuse nodular eyelid lipogranuloma following sutureless transconjunctival blepharoplasty dressed with topical ointment.

PURPOSE: Transconjunctival blepharoplasty is becoming the approach of choice for many cosmetic surgeons. The authors describe a case of a diffuse, multinodular eyelid lipogranuloma following transconjunctival blepharoplasty, after which the unsutured wound was dressed with a topical ointment. METHODS: Report of clinical course and histopathologic findings. RESULTS: A patient developed multiple firm, nontender masses of the left lower eyelid that enlarged despite topical and systemic medical therapy. Prior to referral, the progressive lesions had recurred despite three successive attempts at surgical eradication. Histopathologic examination of excised tissue demonstrated a multifocal lipogranulomatous inflammation consistent with reaction to retained ointment. CONCLUSIONS: Sclerosing lipogranulomas are a known complication of intradermal lipid injection, as well as a late complication of sinus surgery after postoperative nasal packing with ointment-saturated gauze. The application of a topical ointment should be avoided until after transconjunctival lower blepharoplasty unless wound closure is secure or until conjunctival epithelialization is complete.

Correction of lower eyelid retraction by transconjunctival retractor excision and lateral eyelid suspension.

PURPOSE: To investigate the effectiveness of a procedure that addresses both the lower eyelid retractors and the lateral canthus in the treatment of patients with lower eyelid retraction. METHODS: Through a combined lateral canthotomy and full-length transconjunctival incision, the lower eyelid retractors were disinserted across the horizontal length of the eyelid, recessed to the inferior fornix, and excised. A lateral canthopexy elevated the mobilized eyelid, and horizontal length disparity was corrected. RESULTS: Forty lower eyelid operations in 23 patients yielded good results; all patients attained significant improvement in both eyelid position and function. No reoperations were required during a mean follow-up period of 28 months. CONCLUSION: Although not ideal for severe cases requiring posterior lamellar spacers or anterior lamellar (skin) grafts, this union of techniques successfully treats many types of lower eyelid retraction.

Difficult airway management in the neonate: a simple method of intubating through a laryngeal mask airway.

Tracheal intubation through a laryngeal mask airway is one option for securing an airway in the patient with a difficult airway. A variety of techniques and equipment have been used to stabilize the position of the tracheal tube while removing the laryngeal mask airway. We have shown that if a fibreoptic bronchoscope is used to place an tracheal tube through a laryngeal mask in neonates, additional equipment is not needed to remove the laryngeal mask airway without endangering tracheal tube placement. This is possible even in small neonates.

Evaluation of the unscanned soft-tissue thermal index.

The monopole-source solution was used to calculate the three-dimensional complex acoustic pressure field for focused circular apertures in a medium having homogeneous acoustic and thermal properties. The three source diameters were 1, 2, and 4 cm and the eight transmit f-numbers (ratio of the radius of curvature/source diameter) were 0.7, 1.0, 1.3, 1.6, 2.0, 3.0, 4.0, and 5.0. For these focused field geometries, eight ultrasonic frequencies were evaluated (1, 2, 3, 4, 5, 7, 9, and 12 MHz) from which the three-dimensional temperature distribution was calculated using the bio-heat transfer equation in homogeneous, perfused media (attenuation=absorption=0.3 dB/cm-MHz; perfusion length: 1.0 cm). For each of the 192 cases, the acoustic field was normalized to the derated spatial peak, temporal average intensity (I(SPTA.3)) of 720 mW/cm(2), the maximum value allowed by the FDA 510(k) diagnostic ultrasound equipment approval process. Using the normalized acoustic field, the axial temperature increase profiles and the maximum temperature increases (DeltaT(max)) were determined for each case. Also, from the normalized acoustic field, the unscanned soft-tissue thermal index (TIS) was determined. In general, DeltaT(max), TIS, and source power increase with increasing transmit f-number, source diameter, or frequency. The TIS generally underestimates (is less than) DeltaT(max) for f-numbers /=3. These exceptions suggest a breakdown of the ODS procedures far calculating TIS.

Sino-orbital giant cell reparative granuloma.

An otherwise healthy, 9-year-old boy had gradual onset of a mass deformity in the region of the left medial canthus with resulting superior and lateral globe displacement. Radiographic evaluation demonstrated an osteolytic, expansile lesion involving the bones of the ethmoid and maxillary sinuses. Combined anterior orbitotomy and nasal endoscopic surgical resection revealed additional involvement of the nasolacrimal sac wall. Histopathology was consistent with a giant cell reparative granuloma. The authors know of 15 case reports of sino-orbital giant cell reparative granulomas with ophthalmic manifestations; only 3 of these appeared in the ophthalmology literature. This case appears unique in that extension of the abnormal tissue into the nasolacrimal sac wall was demonstrated.

[Myositis caused by Pleistophora in a patient with AIDS]. / Miositis por Pleistophora en un paciente con sida.

The third case in the literature is reported of an infection produced by Pleistophora. The clinical detail of the three cases are discussed. Two of the patients-including the reported one-were infected by HIV. All patients suffered from myositis with fever, resting and at palpation myalgia, and progressive weakness. Blood tests showed anaemia and high levels of muscle enzymes. Necrotic muscle fibrosis induced disabling contractures. Diagnosis was obtained by detecting the protozoon in a muscle biopsy. The spores may be detectable by means of different staining methods at light microscopy although electron microscopy remains the most reliable technique. Since this is such a rare condition there is no known treatment. Whether the albendazole could be as useful as occurs in patients infected by other genera of microsporidia in still uncertain.

Aspergillus endophthalmitis after sutureless cataract surgery.

PURPOSE: We studied a case of Aspergillus endophthalmitis after sutureless cataract surgery. METHODS: A patient underwent sutureless phacoemulsification complicated by a posterior capsular tear. She subsequently developed Aspergillus endophthalmitis. Amphotericin B was injected intravitreally at the time of repeat pars plana vitrectomy. RESULTS: The eye was enucleated because of pain and poor response to treatment. CONCLUSIONS: We recommend suturing the wound in any eye that has experienced a complication of surgery.

Hematologic and growth-related effects of frequent prenatal ultrasound exposure in the long-tailed macaque (Macaca fascicularis).

Prior investigations have shown that reduced birth weights and transient neutropenias result from frequent exposure of monkey fetuses to ultrasound. To further explore these findings, 26 animals were studied (16 exposed, 10 controls; "triple mode"; ATL Ultramark 9 with HDI; ISPTAd approximately 645 to 714 mW/cm2). Exposures were performed daily for 5 days each week from gestational days (GD) 21 to 35 (5 min), three times weekly from GD 36 to 60 (5 min), then weekly from GD 61 to 153 +/- 1 (10 min). Fetal blood samples (FBS) were collected for complete blood counts (CBCs), hematopoietic progenitor assay, circulating insulin-like growth factors (IGF-I, IGF-II) and binding proteins (IGFBP-3) (GD 120, 140, 153 +/- 1). Animals were delivered by Cesarean section at term (GD 153 +/- 1), and body weights, morphometrics, CBCs, and bone marrow aspirates assessed at delivery and postnatally for 3 months. Fetal neutropenias were noted in exposed animals in addition to reduced circulating progenitors (colony forming unit-granulocyte-macrophage [CFU-GM]). Growth of CFU-GM from bone marrow was exuberant at term, whereas circulating levels were diminished comparable to prenatal samples. Exposed animals were smaller at birth; marked reductions in IGFBP-3 were noted prenatally. These data suggest that frequent prenatal ultrasound exposure can transiently alter the neutrophil lineage, although these findings may be the result of enhanced margination and organ sequestration. Data also suggest that transient, altered growth patterns may be due to perturbations of the IGF axis.

Behavioral teratologic effects of prenatal exposure to continuous-wave ultrasound in unanesthetized rats.

While there are no known risks associated with diagnostic ultrasound, uncertainty about the safety of prenatal ultrasound exposure remains. The purpose of the present experiment was to evaluate the behavioral teratogenic potential of continuous-wave (cw) ultrasound in rats, in the absence of maternal anesthesia or restraint. Pregnant CD rats, trained to remain immobile in a water-filled ultrasound exposure tank, were scanned with 3 MHz cw ultrasound at levels of 0, 2, 10, 20, or 30 W/cm2 ISPTA (spatial peak, temporal average intensity) on gestational days 4-20 for approximately 10 min/day. Offspring were examined postnatally for survival, growth, physical landmarks of development, behavioral development, and the adult functions of locomotor activity, learning and memory, and startle reactivity. No effects of prenatal ultrasound were found on maternal characteristics, offspring survival or growth, physical or behavioral landmarks of development, or adult tests of passive avoidance or startle. Effects at the highest intensity were obtained on corner and side locomotor activity and in a multiple-T water maze on measures of errors of commission and time spent finding the goal. The results showed that prenatal cw ultrasound in rats can induce effects on some postnatal neurobehavioral functions at high exposure intensities (30 W/cm2), but at lower intensities (2-20 W/cm2) no consistent evidence of neurobehavioral effects was observed.

The correction of lower lid malposition following lower lid blepharoplasty.

Lower eyelid malposition is the most common complication following lower eyelid blepharoplasty. This may take the form of a mild scleral show with the round eye syndrome or may progress to frank ectropion in some patients. When this problem occurs, it is imperative to soothe an already distressed patient by correcting the malposition by the most efficient method. A horizontal tightening of the lower lid at the lateral canthus can be helpful in many patients; however, in the more severe cases or in those in which the medial component is prominent, this procedure may not give the best correction. It is preferable to avoid using autogenous grafts in these patients because in most cases they will induce another incision line with potential deformity and, more important, are perceived by these sensitive patients as being more of an involved procedure. The preserved fasciae latae sling is an alternative procedure which is effective in the more severe cases of postblepharoplasty lower eyelid malposition, particularly in those cases in which the medial component of malposition is prominent.

Electron microscopic changes in Enterocytozoon bieneusi following treatment with albendazole.

AIM: To identify and describe electron microscopic changes occurring in Enterocytozoon bieneusi in patients treated with albendazole. METHODS: Eighteen HIV seropositive patients with E bieneusi infection of the small intestine were treated with albendazole 400 mg twice a day for one month. Duodenal biopsy specimens obtained before and at the end of treatment were examined electron microscopically by a pathologist who was unaware of the clinical response. A semiquantitative assessment of the parasite load and description of the parasite morphology was made. RESULTS: A complete resolution of diarrhoea occurred in nine patients and a further three had a greater than 50% reduction in baseline stool frequency or volume. Three of the non-responders were also infected with cryptosporidium. There was a reduction in parasite load in those responding to treatment and an increase in abnormal forms in both responders and non-responders. CONCLUSION: The clinical response to albendazole treatment seen in some patients with small intestine microsporidiosis may be due to damage to the developmental stages, causing a partial inhibition of parasite reproduction.

Electron microscopy of rectal biopsies in HIV-positive individuals.

A series of 83 rectal biopsies was examined by electron microscopy (EM), 78 from HIV-seropositive patients (64 with diarrhoea, 9 with weight loss, and 5 asymptomatic) and 5 from controls without risk factors for HIV infection. Although EM identified the likely cause of the diarrhoea in only nine cases, the majority of symptomatic HIV-seropositive patients had abnormal biopsies including the presence of tubuloreticular structures, loss of microvilli, and oedema and disruption of autonomic nerves. Neuronal abnormalities were particularly common in patients with cryptosporidiosis, but no ultrastructural marker was specific to 'pathogen-negative' diarrhoea.

Toga virus-like particles in acute liver failure attributed to sporadic non-A, non-B hepatitis and recurrence after liver transplantation.

Toga virus-like particles (typically 60-70 nm: enveloped with small surface spikes) were detected in the native hepatectomy specimens in 7 of 18 patients grafted for acute liver failure attributed to sporadic non-A, non-B hepatitis and in 2 patients grafted for fulminant hepatitis attributed to anti-epileptic drug hepatotoxicity. These particles were not detected in the hepatectomies from 12 other patients grafted for other causes of acute liver failure, 12 for various chronic liver diseases, and 2 histologically normal livers. Acute hepatic failure, characterized histologically by severe haemorrhagic necrosis, developed 7 days after grafting in 5 patients, all in the non-A, non-B group with toga virus-like particles in native liver. Similar virus-like particles were detected in all grafts and were in greater abundance than in the native livers. The agent may be novel because pre- and post-grafting sera were negative for antibodies against representative panels of arboviruses and in first and second generation antibody tests for hepatitis C virus.

Temporoparietal fascial flap for orbital and eyelid reconstruction.

The temporoparietal fascial flap is a recognized technique for the transfer of vascularized tissue in the craniofacial region. The flap has a predictable axial vessel, provides thin vascularized tissue, and can be harvested with minimal donor-site morbidity. The temporoparietal fascial flap is well suited for orbital or eyelid reconstruction because of its proximity to the orbit. The flap is useful for reconstruction of anatomic barriers between the orbit, intracranial cavity, and paranasal sinus spaces. We present four patients in whom the temporoparietal fascial flap was used for orbital reconstruction following extirpative surgery for orbital neoplasm and two patients in whom the flap was used for lower eyelid and malar reconstruction.