Fibrinogen concentrates for bleeding trauma patients: what is the evidence?

INTRODUCTION: A balanced transfusion of red blood cells, fresh frozen plasma and platelets are recommended for massively bleeding trauma patients. Fibrinogen concentrates could potentially lessen or replace the need for fresh frozen plasma and/or platelet transfusions. OBJECTIVE: To provide a review of the literature covering the application of fibrinogen concentrates in trauma care. METHODS: PubMed and Cochrane database search, 'fibrinogen' and ('concentrate' or 'trauma'), not 'congenital', 10 years. RESULTS: Only four papers were identified. None were randomized controlled trials. The main conclusion of these papers was that administration of fibrinogen sometimes together with prothrombin complex concentrate might improve haemostasis in trauma patients resuscitated with synthetic colloids. CONCLUSION: Evidence for the use of fibrinogen concentrate to trauma patients with massive bleeding is lacking. Well-designed prospective, randomized, double-blinded studies evaluating the effect of fibrinogen concentrate, as the only intervention, are urgently needed.

Mars Extant Life: What's Next? Conference Report.

On November 5-8, 2019, the "Mars Extant Life: What's Next?" conference was convened in Carlsbad, New Mexico. The conference gathered a community of actively publishing experts in disciplines related to habitability and astrobiology. Primary conclusions are as follows: A significant subset of conference attendees concluded that there is a realistic possibility that Mars hosts indigenous microbial life. A powerful theme that permeated the conference is that the key to the search for martian extant life lies in identifying and exploring refugia ("oases"), where conditions are either permanently or episodically significantly more hospitable than average. Based on our existing knowledge of Mars, conference participants highlighted four potential martian refugium (not listed in priority order): Caves, Deep Subsurface, Ices, and Salts. The conference group did not attempt to reach a consensus prioritization of these candidate environments, but instead felt that a defensible prioritization would require a future competitive process. Within the context of these candidate environments, we identified a variety of geological search strategies that could narrow the search space. Additionally, we summarized a number of measurement techniques that could be used to detect evidence of extant life (if present). Again, it was not within the scope of the conference to prioritize these measurement techniques-that is best left for the competitive process. We specifically note that the number and sensitivity of detection methods that could be implemented if samples were returned to Earth greatly exceed the methodologies that could be used at Mars. Finally, important lessons to guide extant life search processes can be derived both from experiments carried out in terrestrial laboratories and analog field sites and from theoretical modeling.

Uptake of 18-fluoro-2-deoxy-D-glucose by thyroid cancer: implications for diagnosis and therapy.

A patient developed a pulmonary metastasis from papillary thyroid carcinoma. This tumor concentrated relatively little 131I, but sufficient 18F-fluoro-2-deoxy-D-glucose (FDG) to be quantified and imaged by positron emission tomography. The uptake of FDG was lower on positron emission tomographic images after T4 therapy and when the serum TSH concentration was reduced to the low normal range. It may be possible to use decreases in FDG uptake by thyroid cancers, which represent declines in metabolism by the tumors, to indicate the optimum doses of T4 treatment for patients with these neoplasms. In addition, the ratio of tumor to background radioactivity was higher for FDG than for the flow agent 201Tl, so that studies with FDG may be a useful scintigraphic method for locating thyroid cancers when radioiodine imaging is unsatisfactory.

In vitro transactivation of Bacillus subtilis RNase P RNA.

Deletion of the 'signature' PL5.1 stem-loop structure of a Type II RNase P RNA diminished its catalytic activity. Addition of PL5.1 in trans increased catalytic efficiency (kcat/KM) rather than kcat. Transactivation was due to the binding of a single PL5.1 species per ribozyme with an apparent Kd near 600 nM. The results are consistent with the role of PL5.1 being to position the substrate near the active site of the ribozyme, and with the hypothesis that ribozymes can evolve by accretion of preformed smaller structures.

Quantitative autoradiography with radiopharmaceuticals, Part 2: Applications in radiopharmaceutical research: concise communication.

We describe the application of macroautoradiography, a relatively simple, quantifiable method for the evaluation of positron-emitting and gamma-emitting radiopharmaceuticals. We have investigated the response properties of two types of film to positron (F-18) and negatron (C-14) emitters. Variations in the response of film to increasing film-to-source distance are described, along with the effects of different intensifying screens and mounting tape. Digitization of whole-body autoradiograms (WBARG) in small animals was performed by using a videodensitometry system (videocamera interfaced to a computer). Quantitation was derived from analysis of a series of step-wedge standards that covered the range of radioactivities in the sample. By using a close-up lens on the videocamera, a 2- by 2-cm field is digitized as a 128 X 128 array, each pixel representing 156 X 156 micron. The effect of chlorpromazine (CPZ) on glucose metabolism in mice was studied by giving C-14 2DG followed by CPZ and F-18 FDG in the same animal. Muscle activity decreased and brown-fat activity increased. The high spatial resolution of this technique enables quantification in structures as small as the basal ganglia in mice. The use of dual-nuclide ARG permits each animal to be its own control, which greatly increases the utility of this method.

Ultrasound-guided transvaginal needle aspiration of follicles for in vitro fertilization.

In search of a simpler and less traumatic method of oocyte retrieval for in vitro fertilization (IVF), 37 infertile patients underwent ultrasound-guided transvaginal needle aspiration of the follicles instead of the conventional laparoscopic aspiration. Although only intravenous analgesics and sedatives were used, patients experienced little discomfort. There were no infections or bleeding complications after the procedure. Eleven patients (30%) achieved ongoing pregnancies; this rate of success is comparable to that with our laparoscopic method. Considering this reasonable pregnancy rate, lack of substantial morbidity, and good patient acceptance, laparoscopic oocyte retrieval for IVF can be largely replaced by the ultrasound-guided transvaginal needle aspiration technique.

Streptococcal toxic shock syndrome complicating preseptal cellulitis.

PURPOSE: Although substantial morbidity is uncommon in preseptal cellulitis, the incidence of severe infection resulting from group A streptococcal infection is increasing. METHODS: A 62-year-old man was initially examined for preseptal cellulitis sustained after minor trauma to his brow. The patient rapidly experienced shock and multisystem organ failure. Intensive medical therapy prevented circulatory collapse and death. RESULTS: A diagnosis of streptococcal toxic shock syndrome secondary to group A beta hemolytic streptococcal infection was made based on culture results and clinical course. CONCLUSIONS: The ophthalmologist plays an essential role in diagnosing this condition. Aggressive and timely treatment are essential to preventing death.

Sediment oxygen profiles in a super-oxygenated antarctic lake.

Perennially ice-covered lakes are found in the McMurdo Dry Valleys of southern Victoria Land, Antarctica. In contrast to temperate lakes that have diurnal photic periods, antarctic (and arctic) lakes have a yearly photic period. An unusual feature of the antarctic lakes is the occurrence of O2 at supersaturated levels in certain portions of the water column. Here we report the first sediment O2 profiles obtained using a microelectrode from a perennially ice-covered antarctic lake. Sediment cores collected in January and October 1987 from Lake Hoare in Taylor Valley show oxygenation down to 15, and in some cases, 25 cm. The oxygenation of sediments several centimeters below the sediment-water interface is atypical for lake sediments and may be characteristic of perennially ice-covered lakes. There is a significant difference between the observed January and October sediment O2 profiles. Several explanations may account for the difference, including seasonality. A time-dependent model is presented which tests the feasibility of a seasonal cycle resulting from the long photoperiod and benthic primary production in sediments overlain by a highly oxygenated water column.

Combined phacoemulsification and trabeculectomy with mitomycin-C.

PURPOSE: To examine the safety and efficacy of primary combined phacoemulsification, posterior chamber intraocular lens (IOL) implantation, and trabeculectomy with mitomycin-C (0.4 mg/ml) in patients with open-angle glaucoma and visually significant cataract. SETTING: University-hospital-based glaucoma referral practice. METHODS: In this study, data of 43 patients of a single surgeon were retrospectively analyzed. These consecutive patients had combined phacoemulsification, posterior chamber IOL implantation, and trabeculectomy with mitomycin-C. RESULTS: Thirty-eight patients (88%) had open-angle glaucoma and 5 (12%) pseudoexfoliative glaucoma. Thirty-eight patients (88%) had 12 months of follow-up; all had at least 6 months follow-up. Mean preoperative intraocular pressure (IOP) was 21.6 mm Hg +/- 6.8 (SD) (range 12.0 to 41.0 mm Hg) with 2.5 +/- 1.0 glaucoma medications. At last follow-up, mean IOP had decreased to 14.2 +/- 6.2 mm Hg (range 3.0 to 40.0 mm Hg) with 0.5 +/- 0.5 glaucoma medications. Twenty-one patients (55%) had an IOP of 15 mm Hg or less at 12 months. Best corrected visual acuity was 20/40 or better in 31 of 43 patients (72%) at last follow-up. A filtration bleb was noted in 33 of 40 patients (83%) at their last visit. Postoperative IOP spikes occurred in 17 patients (40%), transient hyphema in 12 (28%), transient wound leaks in 11 (26%), and superficial punctate keratopathy in 11 (26%). Three cases of persistent hypotony (IOP less than 5 mm Hg) and 1 case of epithelial downgrowth were also noted. CONCLUSION: Phacoemulsification with IOL implantation and combined trabeculectomy with mitomycin-C produced good visual acuity and excellent IOP control but resulted in some complications. The use of mitomycin-C in combined procedures does not appear to confer a significant benefit.

Evaluating brain death with positron emission tomography: case report on dynamic imaging of 18F-fluorodeoxyglucose activity after intravenous bolus injection.

A dynamic positron emission tomography (PET) study of the head was performed over 1 hour after the intravenous bolus administration of 18F-fluorodeoxyglucose (18F-FDG) to a 18-year-old patient with the clinical diagnosis of brain death. This dynamic PET study was performed on the seventh day after a severe posttraumatic closed-head injury. No intracerebral uptake or retention of tracer was noted, consistent with a diffuse absence of brain metabolism. A small amount of tracer was noted to slowly rise over time within the sagittal sinus, indicating that visualization of sagittal sinuses on technetium 99m-diethylene-triaminepentaacetic acid planar images could provide a falsely negative scintigraphic evaluation for the presence of brain death. It is concluded that PET FDG imaging may be a useful technique in evaluating patients for brain death.

Transient blindness associated with reversible occipital white matter abnormalities: two patients studied by MR, CT, and 18F-FDG PET imaging.

Reversible, multifocal hyperintense T2 signal abnormalities were noted within the occipital and posterior parietal subcortical white matter in a previously healthy 59-year-old right-handed woman with acute onset of cortical blindness and seizures. Repeat brain magnetic resonance imaging and a positron emission tomographic scan of 18F-fluorodeoxyglucose brain uptake performed 2 months after the ictal event failed to reveal any abnormality. This patient is similar to a 57-year-old female who developed severe headache and magnetic resonance signal abnormalities in the subcortical white matter of both occipital lobes, which later normalized, as judged by correlative, sequential computed tomographic examinations. This study emphasizes that an increasingly more frequent phenomenon of reversible MRI signal abnormalities can occur within the occipital subcortical white matter in acutely ill individuals, and not be associated with any lasting abnormalities on clinical examination or on radiological imaging studies such as computed tomography, magnetic resonance imaging, or positron emission tomography.

Palatal myoclonus secondary to vertebral artery compression of the inferior olive.

A 47-year-old male with a 5-year history of palatal myoclonus was found on magnetic resonance imaging (MRI) examination to have an ectatic dominant left vertebral artery that compressed the left inferior olive. Microvascular decompression effectively eliminated his symptoms. This case and a similar case presented here with an ectatic vertebral-basilar system illustrate the value of standard MRI in conjunction with magnetic resonance angiography (MRA) in evaluating palatal myoclonus, and they suggest a potential role for decompressive surgery when persistent, highly symptomatic inferior olivary ischemia or compression occurs.

Temporal lobe epilepsy presenting as panic attacks: detection of interictal hypometabolism with positron emission tomography.

Cerebral glucose metabolism was studied using positron emission tomography (PET) in a 13-year-old girl with a history of panic attacks that were thought to be of psychiatric origin. Positron emission tomography imaging revealed marked right temporal lobe hypometabolism and magnetic resonance imaging (MRI) detected T2 changes consistent with right mesial temporal sclerosis. Electroencephalogram (EEG) studies 3 years later confirmed a primary diagnosis of right temporal lobe epilepsy. As shown by this case and one other, PET and MRI imaging of patients with panic disorder who are thought to have epilepsy may be helpful in leading to definitive electrographic studies that confirm temporal lobe epilepsy as the primary diagnosis.

Sequential positron emission tomographic evaluations of brain metabolism in acute herpes encephalitis.

This first known positron emission tomography report on metabolic changes in acute herpes simplex virus (HSV-1) encephalitis demonstrates focal hypermetabolism in areas of cerebral cortex adjacent to actively inflamed hippocampus acutely infected with HSV-1. When neuropsychiatric symptoms recurred in a previously healthy 61-year-old patient 1 month after recovering from acute HSV-1 encephalitis, repeat positron emission tomography with fluorodeoxyglucose was helpful in ruling out recurrent active infection by showing marked hypometabolism throughout the previously infected temporal lobe.

Bilateral peripheral ulcerative keratitis associated with pyoderma gangrenosum.

PURPOSE: A 37-year-old Hispanic man with a history of chronic myelogenous leukemia was first seen with fever and preseptal cellulitis of this right orbit after a tooth extraction. METHODS: The patient subsequently developed bilateral, severe peripheral ulcerative keratitis. He was treated with systemic antibiotics for a presumed underlying infectious cause. Several painful, necrotizing skin lesions developed over his face, trunk, and extremities. RESULTS: Repeated skin biopsies of the necrotizing lesions were consistent with pyoderma gangrenosum. Both the skin lesions and peripheral ulcerative keratitis responded dramatically to systemic prednisone. CONCLUSIONS: Pyoderma gangrenosum should be included in the differential diagnosis of peripheral ulcerative keratitis.

Positron emission tomography in diagnosis of occult adenocarcinoma of the breast.

Occult adenocarcinoma with clinically apparent axillary lymphadenopathy represents a challenging surgical problem. Mammography is frequently unable to identify a primary breast carcinoma, and extramammary sources are common and equally difficult to identify. This may leave the clinician and patient with a conundrum of whether to proceed with "blind" mastectomy. A 35-year-old white female presented with axillary adenopathy and a normal breast physical exam. Mammography was unable to demonstrate a specific tumor. Excisional biopsy of the axillary lymph node demonstrated metastatic adenocarcinoma. Positron emission tomography showed increased uptake in the breast and the axilla, consistent with breast carcinoma and axillary metastases. The patient underwent modified radical mastectomy and pathologic review of the specimen proved infiltrating ductal carcinoma in the breast with metastatic nodes. Positron emission tomography may be helpful in localizing occult carcinoma of the breast that presents with metastatic lymph nodes and in excluding other potential primaries.

Decreased multi-band posterior interhemispheric coherence with a lipoma on the corpus callosum: a case report of a possible association.

The corpus callosum plays a role in mediating interhemisphere communication. Coherence may be a quantitative EEG-based measure of this communication. The present report is of a female schizophrenic patient with a marked coherence deficit in the temporal-parietal-occipital region involving multiple frequency bands. An MRI scan of her brain revealed a lipoma involving the splenium of the corpus callosum. It is speculated that this lipoma may have caused a physical impingment on or developmental aberration of adjacent callosal fibers, resulting in the observed coherence deficit. Further studies of coherence measures in patients with collosal lipomas are proposed.

Functional mapping of the brain with a histochemical method for the localization of glucose.

A histochemical method has been developed for the localization of endogenous glucose in hyperglycemic, hypovolemic brain tissue. The hypothesis proposes that the histochemical method could be modified for reliable use in normal animals, and be used as a potentially powerful tool to map functionally active brain regions.

A consensus approach to planetary protection requirements: recommendations for Mars lander missions.

Over the last several years, the nature of the surface conditions on the planet Mars, our knowledge of the growth capabilities of Earth organisms under extreme conditions, and future opportunities for Mars exploration have been under extensive review in the United States and elsewhere. As part of these examinations, in 1992 the US Space Studies Board made a series of recommendations to NASA on the requirements that should be implemented on future missions that will explore Mars. In particular, significant changes were recommended in the requirements for Mars landers, changes that significantly alleviated the burden of planetary protection implementation for these missions. In this paper we propose a resolution implementing this new set of recommendations, for adoption by COSPAR at its 30th meeting in Hamburg. We also discuss future directions and study areas for planetary protection, in light of changing plans for Mars exploration.

School-based health centers as a locus for community health improvement.

School-based health centers are critical resources for providing and coordinating health and medical services for children and adolescents. As such, they are an increasingly important component in a strategy to meet the comprehensive health, social, and educational needs of students and families. We show how educators and health professionals, using the language, methods and principles of continuous improvement, can collaborate effectively in addressing the specific concerns of school attendance and teen smoking.