Current prevention and management of acute mountain sickness.

Acute mountain sickness was known to the Chinese in ancient times, as they traversed mountain passes between the Great Headache and Little Headache mountains into present-day Afghanistan. The Jesuit priest, Father Joseph Acosta, lived in Peru during the sixteenth century; he described both this syndrome and deaths which occurred in the high Andes. The incidence of high-altitude illness will rise as previously remote sites become more accessible to trekkers and skiers. Prevention and treatment are important concerns for those physicians who wish to advise their more adventuresome patients properly. This article incorporates a selected review of pertinent investigations, in the English-language literature over the past five years, into material previously presented at travel symposia for clinicians managing the prophylaxis and treatment of acute mountain sickness

Septic arthritis and osteomyelitis from a cat bite.

A 39-year-old man with no prior history of underlying arthritis developed osteomyelitis and septic arthritis in his hand following a cat bite. This case illustrates the virulence of Pasteurella multocida infections associated with animal bites, particularly those of cats, whose teeth can inoculate bone directly. The onset of cellulitis caused by P. multocida infections is often rapid, and the drug of choice for such infections remains penicillin. Appropriate antibiotic therapy, however, does not always prevent complications such as those seen in this patient

Fever, frontal sinus mass, and CSF pleocytosis in a 44-year-old man.

Intracranial complications arising from frontal sinusitis occur infrequently. However, they can progress with such rapidity that the clinical situation becomes far advanced before they are recognized. Radiographic imaging techniques may not be definitive early in the course of these complications. The infectious disease service was asked to evaluate a middle-aged man with acute global headache and nasal discharge for two weeks. CSF pleocytosis (3,600 WBC/mm3) was documented on lumbar puncture, and a dense mass was noted on sinus radiographs. At surgery, a large bony lesion was found extending from the right frontal sinus into the adjacent ethmoid sinus and nasal-frontal duct. The authors discuss the bacteriology, pathogenesis, and potentially serious intracranial and extracranial complications of frontal sinusitis which were considered during their evaluation of this patient

The evaluation of contrast-enhancing brain lesions: pitfalls in current practice.

The definitive diagnosis of space-occupying brain lesions can be established more readily since the advent of computerized tomographic (CT) scanning. Some brain lesions are more clearly defined when contrast-enhancing agents are utilized; however, so-called ring-enhancing lesions are not pathognomonic for specific neurological entities. Review of the literature suggests that at least four disorders must be considered in the differential diagnosis of contrast-enhancing lesions. These include mature brain abscesses of any etiology, cerebrovascular accidents, and primary or metastatic brain tumors. Since the medical and surgical management of these conditions is quite different, it is critical to establish a diagnosis before therapy is instituted. In many instances the combination of history, physical examination, laboratory, and radiologic examination will enable physicians to correctly diagnose the etiology of such brain lesions. However, we present two cases for which the above clinical and non-invasive parameters led to incorrect working diagnoses. Brain biopsy was required before appropriate management was eventually instituted. Potentially, such delays in diagnosis and institution of therapy can result in unnecessary morbidity and mortality. Each case illustrates the need to substantiate a presumptive diagnosis based on these clinical and radiographic criteria, regardless of how "typical" lesions may appear on CT scans

Vibrio alginolyticus cellulitis following coral injury.

Infections associated with marine activities, particularly work or recreation in salt water, present unique diagnostic challenges for the infectious disease practitioner. Those caused by halophilic, non-cholera Vibrio species are increasingly being recognized in clinical practice. They typically follow saltwater injuries, especially those associated with coral. Because these infections can be both severe and life-threatening, a consideration of halophilic Vibrio species in the differential diagnosis of marine-acquired infections is important. In this case report, we discuss the diagnosis and treatment of cellulitis in a patient with a Caribbean coral injury associated with Vibrio alginolyticus cellulitis

Fever, petechiae, and pulmonary infiltrates in an immunocompromised Peruvian man.

The diagnostic considerations raised by immunocompromised patients with opportunistic infection continue to expand. When such patients harbor latent or persistent infection acquired in a tropical environment, the diagnostic challenge is even greater. The Infectious Disease Service at Yale-New Haven Hospital was asked to see a middle-aged man from Peru with known T-cell lymphoma who had recently completed a course of chemotherapy. He presented to the hospital with fever, petechial skin rash, pulmonary infiltrates, and neutropenia. Ultimately this case illustrated the necessity for careful evaluation of such patients, looking, in particular, for evidence of opportunistic parasitic infection

The ineffectiveness of tobramycin combination therapy in Streptococcus faecium endocarditis.

A patient required mitral valve replacement following ineffective antibiotic treatment of enterococcal endocarditis caused by Streptococcus faecium. Endocarditis had relapsed despite therapy with ampicillin and tobramycin for six weeks. A second relapse had occurred following treatment with penicillin and gentamicin. Initial failure of antibiotic therapy may be related to the known lack of in vitro and in vivo synergy between penicillin and tobramycin against S. faecium. Effective therapy of enterococcal endocarditis requires considerations of bacterial speciation, determination of high-level aminoglycoside resistance, and preferably adequate antibiotic synergy studies to assure effective therapy

Hospital-acquired gangrenous mucormycosis.

A post-operative diabetic patient who had been treated for Serratia marcescens bacterial sepsis developed recurrent thrombosis of the left femoral artery following intra-arterial instrumentation. Pathological examination of arterial thrombus ultimately demonstrated invasive mucormycosis of the femoral artery and cultures of this material grew Rhizopus oryzae. The occurrence of cutaneous and subcutaneous mucormycosis is reviewed, as well as recently recognized nosocomial risk factors for mucormycosis, such as elasticized bandages and wound dressings

Fever, jaundice, and histiocytic erythrophagocytosis: fulminant infection or malignancy?

Some of the problems which we see on the infectious disease consultation service can be quite frustrating. This is one such case. A middle-aged man presented to our medical service with fever and dyspnea. His fulminant downhill course was characterized by anemia, jaundice, hypercalcemia, pulmonary abnormalities, and a lack of responsiveness to conventional antimicrobial therapy. At autopsy, malignant-appearing histiocytes were present in several organs including spleen, lymph nodes, and lung. Histopathological examination of tissues obtained at autopsy confirmed the presence of phagocytized erythrocytes within such histiocytes. This case aptly illustrates the hazy dividing line which sometimes exists between infectious and/or malignant processes which are, at present, still of undetermined etiology

Mono- versus multi-phosphonic acid based PEGylated polymers for functionalization and stabilization of metal (Ce, Fe, Ti, Al)oxide nanoparticles in biological media

For applications in nanomedicine, particles need to be functionalized to prevent protein corona formation and or aggregation. Most advanced strategies take advantage of functional polymers and assembly techniques. Nowadays there is an urgent need for coatings that are tailored according to a broad range of surfaces and that can be produced on a large scale. Herein, we synthesize mono- and multi-phosphonic acid based poly(ethylene glycol) (PEG) polymers with the objective of producing efficient coats for metal oxide nanoparticles. Cerium, iron, titanium and aluminum oxide nanoparticles of different morphologies (spheres, platelets, nanoclusters) and sizes ranging from 7 to 40 nm are studied in physiological and in protein rich cell culture media. It is found that the particles coated with mono-functionalized polymers exhibit a mitigated stability over time, whereas the multi-functionalized copolymers provide resilient coatings and long-term stability (months). With the latter, PEG densities in the range 0.2 - 0.5 nm-2 and layer thickness about 10 nm provide excellent performances. The study suggests that the proposed coating allows controlling nanomaterial interfacial properties in biological environments.Comment: 8 figures, 2 tables, 17 page