Electronic in-plane symmetry breaking at field-tuned quantum criticality in CeRhIn5.

Electronic nematic materials are characterized by a lowered symmetry of the electronic system compared to the underlying lattice, in analogy to the directional alignment without translational order in nematic liquid crystals. Such nematic phases appear in the copper- and iron-based high-temperature superconductors, and their role in establishing superconductivity remains an open question. Nematicity may take an active part, cooperating or competing with superconductivity, or may appear accidentally in such systems. Here we present experimental evidence for a phase of fluctuating nematic character in a heavy-fermion superconductor, CeRhIn5 (ref. 5). We observe a magnetic-field-induced state in the vicinity of a field-tuned antiferromagnetic quantum critical point at Hc ≈ 50 tesla. This phase appears above an out-of-plane critical field H* ≈ 28 tesla and is characterized by a substantial in-plane resistivity anisotropy in the presence of a small in-plane field component. The in-plane symmetry breaking has little apparent connection to the underlying lattice, as evidenced by the small magnitude of the magnetostriction anomaly at H*. Furthermore, no anomalies appear in the magnetic torque, suggesting the absence of metamagnetism in this field range. The appearance of nematic behaviour in a prototypical heavy-fermion superconductor highlights the interrelation of nematicity and unconventional superconductivity, suggesting nematicity to be common among correlated materials.

Magnetic breakdown in the electron-doped cuprate superconductor Nd(2-x)Ce(x)CuO4: the reconstructed Fermi surface survives in the strongly overdoped regime.

We report on semiclassical angle-dependent magnetoresistance oscillations and the Shubnikov-de Haas effect in the electron-overdoped cuprate superconductor Nd(2-x)CexCuO4. Our data provide convincing evidence for magnetic breakdown in the system. This shows that a reconstructed multiply connected Fermi surface persists, at least at strong magnetic fields, up to the highest doping level of the superconducting regime.

Evolution of the Fermi surface of the electron-doped high-temperature superconductor Nd(2-x)Ce(x)CuO(4) revealed by Shubnikov-de Haas oscillations.

We report on the direct probing of the Fermi surface in the bulk of the electron-doped superconductor Nd(2-x)Ce(x)CuO(4) at different doping levels by means of magnetoresistance quantum oscillations. Our data reveal a sharp qualitative change in the Fermi surface topology, due to translational symmetry breaking in the electronic system which occurs at a critical doping level significantly exceeding the optimal doping. This result implies that the (pi/a, pi/a) ordering, known to exist at low doping levels, survives up to the overdoped superconducting regime.

Experience of the posterior lip augmentation device in a regional hip arthroplasty unit as a treatment for recurrent dislocation.

INTRODUCTION: Dislocation after total hip arthroplasty (THA) remains a significant complication of the procedure and is the third leading cause for revision THA. One technique for treatment of this complication is the use of the posterior lip augmentation device (PLAD). We describe our experience using the PLAD including complication rates. METHODS: A retrospective review of 55 PLADs (54 patients) was carried out following identification from electronic theatre records. Basic patient demographics, operative records and radiographs were collected and reviewed and data was analysed using Microsoft Excel. Failure of the PLAD was defined as further operative intervention after PLAD insertion and included: dislocation, implant breakage, infection and revision of the THA for loosening of either component. RESULTS: 55 PLADs were implanted in 54 patients with an average age of 77 years. There was a significant preponderance of females and a variety of surgical approaches had been used for the original hip replacement, including trochanteric osteotomy, posterior and antero-lateral. 9 (16%) patients had recurrent dislocations,1 (2%) failed secondary to screw breakage, 3 (5%) had and infection requiring intervention and 2 (4%) underwent further revision for aseptic loosening of the femoral component. The overall failure rate was 25% with 14 patients requiring intervention post PLAD. CONCLUSION: Our results are inferior to other published results and indicate that the PLAD should be used with caution for recurrent dislocations of the Charnley hip replacement.

The influence of magnetic order on the magnetoresistance anisotropy of Fe1 + δ-x Cu x Te.

We performed resistance measurements on [Formula: see text]Cu x Te with [Formula: see text] in the presence of in-plane applied magnetic fields, revealing a resistance anisotropy that can be induced at a temperature far below the structural and magnetic zero-field transition temperatures. The observed resistance anisotropy strongly depends on the field orientation with respect to the crystallographic axes, as well as on the field-cooling history. Our results imply a correlation between the observed features and the low-temperature magnetic order. Hysteresis in the angle-dependence indicates a strong pinning of the magnetic order within a temperature range that varies with the Cu content. The resistance anisotropy vanishes at different temperatures depending on whether an external magnetic field or a remnant field is present: the closing temperature is higher in the presence of an external field. For [Formula: see text] the resistance anisotropy closes above the structural transition, at the same temperature at which the zero-field short-range magnetic order disappears and the sample becomes paramagnetic. Thus we suggest that under an external magnetic field the resistance anisotropy mirrors the magnetic order parameter. We discuss similarities to nematic order observed in other iron pnictide materials.

Ehlers-Danlos syndrome type IV: a single base substitution of the last nucleotide of exon 34 in COL3A1 leads to exon skipping.

The Ehlers-Danlos syndrome has been classified into nine phenotypic presentations. Type IV is a variant of particular importance because people affected with this genodermatosis are at great risk of spontaneous hemorrhage from vascular rupture or bowel perforation. Recent molecular advances have identified mutations in the gene for type III procollagen as responsible for Ehlers-Danlos syndrome type IV. We report a case of a 14-year-old male with a typical presentation of the type IV variant who was found to have markedly dilated fibroblast cisternae and varying collagen fibril diameter on ultrastructural study. A novel genetic defect was noted by polymerase chain reaction and DNA sequencing of genetic material isolated from skin fibroblast cultures. Analysis of the gene for type III procollagen revealed a single base mutation in the last nucleotide of exon 34. The mutation led to abnormal RNA splicing and skipping of exon 34 on the mRNA level.

Rheumatoid neutrophilic dermatitis.

BACKGROUND: Rheumatoid neutrophilic dermatitis (RND) is a recently recognized, rare cutaneous manifestation of rheumatoid arthritis. It occurs in patients with severe rheumatoid arthritis and is typically asymptomatic. Rheumatoid neutrophilic dermatitis was originally described by Ackerman in 1978. Since that time, 8 patients with this disease have been described in the literature. OBSERVATIONS: We report 2 cases of RND. Findings of skin biopsy specimens from both patients revealed characteristic signs of dermal leukocytosis and leukocytoclasia without vasculitis. The pathogenesis of the neutrophilic infiltrate is unclear. Processes that may play a role in the pathogenesis of RND include immune complex activations, cell adhesion and migration, and cytokine release. CONCLUSIONS: Rheumatoid neutrophilic dermatitis falls into the spectrum of neutrophilic vascular reactions described by Jorizzo and Daniels. Although early reports suggest that prominent leukocytoclasia is not a feature of RND, our findings confirm the observations of Lowe et al that leukocytoclasia can be seen in RND and may be striking. It is important for dermatologists to be aware of this rare manifestation of rheumatoid arthritis.

Pretibial mucin. Histologic patterns and clinical correlation.

BACKGROUND AND OBJECTIVE: We identified several patients with a histologic diagnosis of pretibial myxedema in whom thyroid disease was not found. The purpose of this study was to investigate if histologic characteristics can distinguish between pretibial mucinosis secondary to Graves' disease and that unassociated with thyroid disease. METHODS: Biopsy specimens interpreted as compatible with pretibial myxedema were reviewed; these included 12 cases of pretibial mucinosis with documented Graves' disease, and six cases of pretibial mucinosis without evidence of Graves' disease. Ten specimens interpreted as compatible with stasis dermatitis were also evaluated for histologic characteristics, including the possible presence of mucin. RESULTS: Features that distinguish between pretibial mucinosis associated with Graves' disease and pretibial mucinosis without Graves' disease included preservation of a zone of normal-appearing collagen in the superficial papillary dermis (12/12 with Graves' disease, 0/6 without), mucin deposition in the reticular dermis (12/12 with Graves' disease, 0/6 without), lack of mucin deposition in the superficial papillary dermis (11/12 with Graves' disease, 1/6 without), angioplasia (2/12 with Graves' disease, 6/6 without), and the presence of hemosiderin (2/12 with Graves' disease, 6/6 without). Mucin deposition in the papillary dermis was found in six of 10 specimens interpreted as stasis dermatitis. CONCLUSIONS: There are patients with pretibial mucinosis in whom there is no thyroid disease. Specimens from patients without Graves' disease have features of stasis dermatitis in addition to mucinosis. We conclude that pretibial mucinosis may result from stasis or Graves' disease and that histologic differences allow for accurate differentiation.

Caries among Danish schoolchildren in birth-cohorts 1950-78.

Data on caries prevalence are reported from 8- and 16-yr-old children living in a Danish community which established the Public Child Dental Health Service in 1957. Every fourth birth-cohort from 1950 through 1970 was followed longitudinally. In the 8-yr-olds, caries prevalence decreased in the primary dentition from 17 to 3 dmfs and in the permanent dentition from 3.4 to 0.3 DMFS over a 28-yr period. Among the 16-yr-olds, a reduction was observed from 16.4 to 5.1 DMFS over 20 yr. Time trends in the decreasing caries prevalence are related to various organizational events and preventive measures. Moreover, the possible influence of general changes in living conditions and health behavior is pointed out.

Changes in prevalence of approximal caries in 17-year-olds and related restorative treatment strategies over a 6-year period.

Two cohorts of 17-yr-olds treated in a municipal child dental service in 1978-79 and 1984-85 had bitewing radiographs taken at the examination before the last course of treatment in the service. All radiographs were read by one examiner, who did not know to which cohort the individual belonged. The subsequent treatment was recorded from the treatment records by another examiner, who was unaware of the results of the radiographic examination. According to radiographic scores, the proportion of decayed or filled (DFS) approximal surfaces had decreased from 23.2% to 17.4% during the period (difference: 25%). The proportion of unfilled surfaces which were decayed (DS) had remained almost constant, while 9.6% of the surfaces were filled (FS) in 1978-79 compared to 3.1% in 1984-85 (difference: 68%). Thus, in spite of a 25% decrease in total caries experience (DFS), a reduction of 68% would be claimed if fillings (FS) were interpreted as expression of disease prevalence. The risk of an approximal surface being filled decreased to about one fifth from 1978-79 to 1984-85, and the risk of being filled was nearly three times as high for approximal surfaces of children who already had approximal fillings at the time of examination. Thus, both the year of examination and the subject's previously received treatment seemed to influence the treatment strategy of the dentist.

Disseminated aspergillosis presenting as a skin abscess.

An immunocompromised patient presented with chronic low back pain as the initial symptom and a subcutaneous abscess as the initial sign of disseminated aspergillosis. With the rising incidence of immunocompromised patients, cutaneous manifestation of aspergillosis may become more common.

Fixed drug eruption from pamabrom.

A young woman presented with recurrent skin lesions that were predominantly perioral. Fixed drug reaction was diagnosed based on her history of intermittent ingestion of Pamprin, a common menstrual symptom reliever, and characteristic erythematous, pigmented, edematous patches. After oral challenge with two of the three ingredients in Pamprin, a diagnosis of fixed drug reaction to pamabrom was made. Pamabrom is a mild diuretic present in several over-the-counter and prescription menstrual symptom relievers. This is the first reported case of fixed drug reaction to pamabrom.

Iatrogenic myelomonocytic leukemia following melphalan treatment of scleromyxedema.

We report the case of a patient with scleromyxedema with abnormal monoclonal gamma globulin of the kappa type who was treated with melphalan (Alkeran), an alkylating agent. After nine and one-half years of therapy, the patient showed myelomonocytic leukemia. The risk of secondary malignancies must be considered when weighting the benefits and risks of melphalan treatment.

Skin metastases in cancer patients.

Although every cancer may cause skin metastases, some do so more frequently. Proper diagnosis can lead to early detection of a previously unrecognized malignancy. Autopsy data from 7,518 patients with internal cancer were analyzed, and the findings were compared with the literature.

Air bag injury and the dermatologist.

Most new car models have driver-side air bags and many also have passenger-side and side-impact air bags. Air bags are known to be dangerous to small children and may cause death, fractures, and cerebral spinal injury. However, the cutaneous manifestations of air bag injury are less well known. Additional potential air bag injuries include retinal damage and high-frequency hearing loss. The following case report illustrates significant burns from a low-impact air bag injury and reviews the pertinent literature.

Angiotropic lymphoma: malignant angioendotheliomatosis.

Malignant angioendotheliomatosis is an angiotropic lymphoma that may present with clinical findings suggestive of thrombophlebitis or vasculitis. Examination of a biopsy specimen with special stains for leukocyte common antigen establishes the diagnosis. Although malignant angioendotheliomatosis is usually fatal, early treatment with chemotherapeutic agents is helpful. We review the characteristics and treatment of this uncommon disorder and present an illustrative case.

Symptomatic zinc deficiency in a one-year-old child precipitated by changing from formula to cow's milk.

The case of a one-year-old girl with symptomatic zinc deficiency is presented. She had been misdiagnosed as having impetigo and/or candidiasis and had been treated with topical antifungal agents and both oral and topical antibiotic agents without success during the four months before she presented. Zinc replacement led to rapid improvement. Her nutritional history suggests that weaning from formula to cow's milk precipitated her eruption. The clinical findings, differential diagnosis, and treatment of zinc deficiency are reviewed.

Lipodystrophy.

Congenital lipodystrophy is an uncommon autosomal recessive disorder that occurs mainly in females and is characterized by loss of subcutaneous fat, insulin-dependent diabetes mellitus, and masculinization due to defective metabolism of fat. Acquired lipodystrophy is now most commonly encountered in patients infected with HIV who take protease inhibitors. We present an illustrative case of lipodystrophy and review the presenting signs allowing for an accurate clinical diagnosis.

Spiny keratoderma.

Spiny keratoderma is a descriptive term used to encompass a variety of unusual, disparate keratodermas. Spiny keratoderma has been associated with lipid abnormalities and has been limited to the palms and soles in some individuals. We describe an acquired case of spiny keratoderma in which an adult woman developed filiform lesions predominating on the trunk and proximal extremities. Treatment with topical emollients and keratolytic agents was unsuccessful, but topical tazarotene led to long periods of resolution. She has had no other associated abnormalities. The clinical features and differential diagnosis of spiny keratoderma are reviewed.

Bilateral plantar amyloidosis: a unique presentation of localized cutaneous amyloidosis.

Nodular amyloidosis is uncommon and is due to a local production of amyloid by aberrant plasma cells. Localized bosselated plantar amyloidosis has been reported before but we present the first case to our knowledge of bilateral plantar amyloidosis. The clinical presentation as well as therapeutic options for this uncommon entity are reviewed.