Post-Laryngectomy stricture and pharyngocutaneous fistula: Review of techniques in primary pharyngeal reconstruction in laryngectomy.

OBJECTIVE: The purpose of this study was to find a correlation between closure technique in pharyngeal closure and outcomes of both pharyngocutaneous fistula and post-laryngectomy stricture after laryngectomy. STUDY DESIGN: Retrospective Chart Review. METHODS: We retrospectively reviewed a total of 151 patients over a 20-year period from January 1994 to December of 2013 who underwent primary pharyngeal reconstruction after total laryngectomy specifically looking at the closure technique in relation to pharyngo-cutaneous fistula (PCF) and post-laryngectomy stricture postoperatively. Patients were excluded based on secondary pharyngeal closure. Using logistic regression modelling, we performed univariate and multivariate analyses of our data. RESULTS: The overall PCF and post-laryngectomy stricture rates were 19.1% and 15.8%. When salvage laryngectomy was excluded, t-type closure had a significantly lower risk of fistula rate (P=.038) compared to vertical closure. In multivariate analysis, this statistical significance was lost (P=.23); however, non-salvage t-type closure remained significantly better than both salvage laryngectomy groups (t-type, P=.033, vertical, P=.037), while non-salvage vertical closure had no significant difference from other groups. There was no difference in stricture rate between the two closure techniques (P=.63). CONCLUSION: Our study supports the role of t-type closure decreasing fistula rates in primary pharyngeal reconstruction. Orientation of the pharyngeal closure does not appear to change the risk of post-laryngectomy stricture formation after total laryngectomy. Salvage laryngectomy with primary pharyngeal reconstruction remains an independent risk factor for fistula formation.

Monoenergetic beams of relativistic electrons from intense laser-plasma interactions.

High-power lasers that fit into a university-scale laboratory can now reach focused intensities of more than 10(19) W cm(-2) at high repetition rates. Such lasers are capable of producing beams of energetic electrons, protons and gamma-rays. Relativistic electrons are generated through the breaking of large-amplitude relativistic plasma waves created in the wake of the laser pulse as it propagates through a plasma, or through a direct interaction between the laser field and the electrons in the plasma. However, the electron beams produced from previous laser-plasma experiments have a large energy spread, limiting their use for potential applications. Here we report high-resolution energy measurements of the electron beams produced from intense laser-plasma interactions, showing that--under particular plasma conditions--it is possible to generate beams of relativistic electrons with low divergence and a small energy spread (less than three per cent). The monoenergetic features were observed in the electron energy spectrum for plasma densities just above a threshold required for breaking of the plasma wave. These features were observed consistently in the electron spectrum, although the energy of the beam was observed to vary from shot to shot. If the issue of energy reproducibility can be addressed, it should be possible to generate ultrashort monoenergetic electron bunches of tunable energy, holding great promise for the future development of 'table-top' particle accelerators.

Category-1 caesarean section: a survey of anaesthetic and peri-operative management in the UK.

A national survey of anaesthetic and peri-operative management of category-1 caesarean section was sent to 245 consultant-led maternity units. There was a 70% response rate. The median (IQR [range]) general anaesthetic rate was 51% (29%-80% [6%-100%]), 12% (9%-16% [3%-93%]), 4% (2%-5% [<1%-18%]), for category-1 caesarean section, categories 1-3 (non-elective/emergency) and category-4 (elective) caesarean section, respectively. The main operating theatre for caesarean section is on the delivery suite in 151 (88%) units, and 112 (66%) units also have a second theatre in the same location. One hundred and thirty-nine (81%) use the standard urgency classification described in the NICE caesarean section guideline. However, only 72 (42%), 24 (14%), and 16 (9%) units comply with this guideline's recommended decision-delivery intervals for category-1 (< or = 30 min), category-2 (< or = 30 min) and category-3 (< or = 75 min) caesarean sections, respectively. Practice in the smaller units was similar to that in the larger units, although there was less availability of a dedicated anaesthetist, intra-uterine resuscitation guidelines and operating theatres on the delivery suite in the smaller units.

Chemical impurity produces extra compound eyes and heads in crickets.

A chemical impurity isolated from commercially purchased acridine causes cricket embryos to develop extra compound eyes, branched antennae, extra antennae, and extra heads. Purified acridine does not produce similar duplications of cricket heads or head structures nor do the substituted acridines proflavine, acriflavine, or acridine orange. A dose-response relation exists such that the number and severity of abnormalities increase with increasing concentration of the teratogen.

Benzoquinolinediones: activity as insect teratogens.

Morphological abnormalities including extra compound eyes, extra heads, and distally duplicated legs were generated in cricket embryos by treating eggs with single doses of either benz[g]isoquinoline-5,10-dione or benzo[h]quinoline-5,6-dione. Slight structural modifications of the molecules resulted in a loss of teratogenic activity, although embryotoxicity occurred. These potent insect teratogens can be used for analysis of developmental events during embryogenesis.

Ischemic preconditioning prevents endothelial injury and systemic neutrophil activation during ischemia-reperfusion in humans in vivo.

BACKGROUND: Endothelial dysfunction leading to neutrophil infiltration of tissues has been implicated in tissue injury caused by ischemia-reperfusion (IR). Tissue injury during IR can be reduced by prior ischemic preconditioning (IPC). In humans, it is unclear whether endothelial dysfunction occurs during IR or whether IPC offers protection against endothelial dysfunction and inflammatory cell activation. We studied the effects of experimental IR on endothelial and neutrophil function in the human forearm in vivo and examined the protection afforded by IPC. METHOD AND RESULTS: The forearm was made ischemic for 20 minutes by inflating a blood pressure cuff to 200 mm Hg. We assessed endothelial function of conduit (radial artery flow-mediated dilation) and resistance vessels (blood flow responses to intra-arterial infusion of the endothelium-dependent dilator acetylcholine) in healthy volunteers before and after IR. IR reduced flow-mediated dilation of the radial artery at 15 minutes of reperfusion (7.7+/-1.5% to 3.5+/-0.9%) and the dilator response of resistance vessels to acetylcholine at 15, 30, and 60 minutes of reperfusion. IR did not reduce the dilator response of the radial artery to glyceryltrinitrate and only caused a small reduction of glyceryltrinitrate-induced dilation of resistance vessels at 60 minutes of reperfusion. IR caused an increase in neutrophil CD11b expression and platelet-neutrophil complexes in the circulating blood. IPC (three 5-minute episodes of ischemia) before IR prevented endothelial dysfunction and neutrophil activation. CONCLUSIONS: A clinically relevant period of ischemia-reperfusion causes profound and sustained endothelial dysfunction and systemic neutrophil activation. IPC attenuates both of these effects in humans.

Effect of phenformin on gluconeogenesis from lactate and intracellular pH in the isolated perfused guinea pig liver.

Gluconeogenesis from lactate and hepatic cell pH (pHi) were measured in the isolated perfused livers of starved guinea pigs in the presence and absence of phenformin (phenethylbiguanide). The observed decrease in lactate consumption and glucose output in the presence of phenformin was associated with a fall in pHi. The fall in glucose output observed was considerably greater than accountable for by the decrease in lactate consumption. A possible mechanism for the pathogenesis of clinical lactic acidosis due to phenformin therapy is suggested.

Fibrinogen, red blood cells, and factor XIII in venous thrombosis.

Cardiovascular disease is the leading cause of death and disability worldwide. Among cardiovascular causes of death, venous thrombosis (VT) is ranked third most common in the world. Venous thrombi have high red blood cell and fibrin content; however, the pathophysiologic mechanisms that contribute to venous thrombus composition and stability are still poorly understood. This article reviews biological, biochemical, and biophysical contributions of fibrinogen, factor XIII, and red blood cells to VT, and new evidence suggesting interactions between these components mediate venous thrombus composition and size.

The U.S. federal framework for research on endocrine disruptors and an analysis of research programs supported during fiscal year 1996.

The potential health and ecological effects of endocrine disrupting chemicals has become a high visibility environmental issue. The 1990s have witnessed a growing concern, both on the part of the scientific community and the public, that environmental chemicals may be causing widespread effects in humans and in a variety of fish and wildlife species. This growing concern led the Committee on the Environment and Natural Resources (CENR) of the National Science and Technology Council to identify the endocrine disruptor issue as a major research initiative in early 1995 and subsequently establish an ad hoc Working Group on Endocrine Disruptors. The objectives of the working group are to 1) develop a planning framework for federal research related to human and ecological health effects of endocrine disrupting chemicals; 2) conduct an inventory of ongoing federal research programs; and 3) identify research gaps and develop a coordinated interagency plan to address priority research needs. This communication summarizes the activities of the federal government in defining a common framework for planning an endocrine disruptor research program and in assessing the status of the current effort. After developing the research framework and compiling an inventory of active research projects supported by the federal government in fiscal year 1996, the CENR working group evaluated the current federal effort by comparing the ongoing activities with the research needs identified in the framework. The analysis showed that the federal government supports considerable research on human health effects, ecological effects, and exposure assessment, with a predominance of activity occurring under human health effects. The analysis also indicates that studies on reproductive development and carcinogenesis are more prevalent than studies on neurotoxicity and immunotoxicity, that mammals (mostly laboratory animals) are the main species under study, and that chlorinated dibenzodioxins and polychlorinated biphenyls are the most commonly studied chemical classes. Comparison of the inventory with the research needs should allow identification of underrepresented research areas in need of attention.

Cowden's disease: a further indication for prophylactic mastectomy.

Cowden's disease (multiple hamartoma syndrome) is a syndrome involving abnormalities of multiple organ systems. Transmitted in an autosomal dominant pattern, it carries a high frequency of mammary carcinoma in early middle age in affected women. The hyperkeratotic cutaneous and gingival markers of the disease are its principal overt manifestations. Prophylactic bilateral total mastectomy with optional immediate reconstruction is recommended for women Cowden's disease. An illustrative family with the disease is presented in which one affected young woman was found to have invasive mammary carcinoma with regional metastasis at the time of prophylactic mastectomy.

Evaluation of chemotherapy of American leishmaniasis by the indirect fluorescent antibody test.

Evaluation of the effectiveness of treatment of American cutaneous/mucocutaneous leishmaniasis is difficult because dramatic clinical improvement and apparent complete healing can be followed by delayed recurrence of lesions. The indirect fluorescent antibody test done with amastigote antigen was used to monitor treatment of 122 cases of cutaneous lesions and one patient with mucocutaneous disease. Clinical improvement and healing of lesions in many, but not all, cases was accompanied by a diminution of antibody titer, and in 10% of cases, by reversion to negativity. In two cases persistence of antibody in spite of healing was shown to be due to residual viable parasites which caused recurrence or new lesions. Further treatment brought about healing and reversion to seronegativity. The data suggest that successful treatment can be indicated by serologic response and, even in cases in which reversion to seronegativity does not occur, the relative reduction in serum antibody provides a basis for predicting recurrence of leishmanial lesions.

Effectiveness of allopurinol against Leishmania braziliensis panamensis in Aotus trivirgatus.

Orally administered allopurinol at 50 mg/kg for 21 days showed pronounced antileishmanial activity against experimentally induced lesions of Leishmania braziliensis panamensis on the nose of Panamanian Aotus trivirgatus monkeys, with complete healing in 4 of 5, although parasitologic cure was achieved in only 2 of 5. The same total daily dose of drug, given in a divided dose twice daily, resulted in complete healing in all 5, and parasitologic cure in 4 of 5 animals. Standard treatment controls receiving 40 mg/kg of antimony stibogluconate intramuscularly for 15 days showed healing in 4 of 5 monkeys. It is not known if a similar level of effectiveness would result with this dose of allopurinol in humans, since Aotus may have a different pattern of metabolic conversion of the drug to the more active riboside.

Differences in biological characteristics of three Leishmania isolates from patients with espundia.

Two recent Leishmania isolates from nasal lesions involving the mucosa, one from an autochthonous case from Texas and one from a case from eastern Peru, were compared with a reference strain of Leishmania braziliensis from Brazil for the biological characteristics which distinguish the L. braziliensis complex from L. mexicana. The characteristics of in vitro growth, pathogenesis in the hamster, and position of the promastigotes in the gut of vector sandflies were determined and compared with the reference strain from Brazil. In spite of the nasal involvement which resembled the clinical picture considered characteristic of L. braziliensis infection, the Texas isolate was clearly L. mexicana. It is considered that the atypical clinical feature was the result of the patient's altered immune state due to neoplastic disease and subsequent radiation therapy. The Peru isolate constitutes the first example of a "fast growing" strain isolated directly from a patient with espundia, but otherwise it demonstrated the characteristics of Leishmania braziliensis.

Diffuse cutaneous leishmaniasis in Mexico.

In Mexico, 6 cases of diffuse cutaneous leishmaniasis (DCL) were found in widely separated geographic regions. Information was also available on 2 other cases. In addition to the typical clinical features, half of the patients had evidence of nasopharyngeal mucosal involvement. All isolates from the DCL patients were identified as Leishmania mexicana mexicana by isoenzyme analysis and monoclonal antibody typing. In 1 region of Tabasco state where DCL was found, uncomplicated cutaneous leishmaniasis appeared to be highly endemic, and isolates from a few such patients were identified as L. mexicana mexicana. An incidental finding was the recovery of an isolate of L. braziliensis braziliensis from a patient with chiclero ulcer in Oaxaca state. The clinical and epidemiological significance of the reported cases are discussed.

Treatment of cutaneous leishmaniasis with localized current field (radio frequency) in Tabasco, Mexico.

In Mexico cutaneous leishmaniasis (CL) occurs in 17 of 32 States, and is a serious public health problem. This is a report of treatment of CL patients in the State of Tabasco, Mexico with a localized current field-radio frequency (LCF-RF) device to generate precisely controlled heat as an alternative to prohibitively expensive drug treatment. It was not a controlled clinical trial, but rather an evaluation of the feasibility of this form of treatment for all CL patients encountered in the endemic area. A total of 201 previously diagnosed patients with CL caused by Leishmania mexicana were treated with a portable Thermosurgery LCF-RF generator powered by rechargeable batteries. The ages of the patients ranged from two to 75 years; the sex distribution was 63% males and 37% females. A single device was used in five different municipalities. Lesions were first anesthetized with 1% lidocaine HCl and moistened with normal saline solution. Treatment consisted of a single application that produced 50 degrees C for 30 sec. After four weeks, 122 patients were available for evaluation, of which 95% were totally cured; (even those involving ear cartilage, which respond poorly to antimonials). At eight weeks post-treatment, 191 patients were evaluated, with a total cure rate of 90%. This form of treatment proved to be effective and convenient for use in primary health care facilities in Mexico and has many advantages over traditional forms of therapy.

Unsuspected intraperitoneal rupture of bladder presenting with abdominal free air.

We present a case of intraperitoneal rupture of the bladder discovered during exploratory laparotomy for abdominal free air associated with an indwelling Foley catheter found in the peritoneal cavity. This report emphasizes the need for systematic and thorough evaluation of the genitourinary tract in the patient with multiple trauma.

IS WALKING COSTLY FOR ANURANS? THE ENERGETIC COST OF WALKING IN THE NORTHERN TOAD BUFO BOREAS HALOPHILUS

Locomotor mode and the maximal capacity for aerobic metabolism are thought to be co-adapted in anuran amphibians. Species that rely heavily on walking often have high capacities for aerobic metabolism relative to species that rely primarily on saltation. We tested the hypothesis of co-adaptation of gait and aerobic metabolism by investigating the locomotor energetics of Bufo boreas halophilus, a toad that walks, but does not hop. Rates of oxygen consumption during locomotion were measured in an enclosed variable-speed treadmill. The steady-state rate of oxygen consumption (V(dot)O2ss) increased linearly within a range of sustainable speeds [V(dot)O2ss (ml O2 g-1 h-1) = 0.93 x speed (km h-1) + 0.28]. The minimum cost of transport, Cmin (the slope of this relationship), varied significantly among individual toads. When expressed in units of oxygen consumed per distance travelled (ml O2 km-1), Cmin scaled isometrically with body mass: Cmin = 0.69mass1.07. Consequently, mass-specific Cmin (ml O2 g-1 km-1) was uncorrelated with body mass. Variation in Cmin was also unrelated to experimental temperature. Mass-specific Cmin estimates were similar to previous allometric predictions for terrestrial animals of similar size, which contrasts with previous findings for another toad species. Maximum rates of oxygen consumption measured in closed, rotating respirometers were significantly higher than the maximum rates achieved on the treadmill, but lower than those measured previously in other Bufo species. Our results indicate that walking is not necessarily a costly gait for toads and that high maximum rates of oxygen consumption are not associated with reliance on walking within the genus Bufo.

Is the MIC useful in deciding to treat endocarditis surgically?

The infecting pathogen and its susceptibility to antibiotics is used to suggest prognosis in endocarditis. A case study was performed in a tertiary referral cardiology centre to assess the contribution of the measurement of minimum inhibitory concentration (MIC) to the decision to treat endocarditis surgically. The records were examined of 125 patients admitted between 1981 and 1999 in whom the minimum inhibitory concentration for the pathogen had been measured. The measures of outcome were mortality at time of hospital discharge and at 6 months, surgical referral and cure by medical treatment. Endocarditis caused by Staphylococcus aureus with a raised MIC of flucloxacillin (methicillin) was associated with higher mortality even if glycopeptides were used in treatment (< or = 35 mg/l 0/7 versus MIC 1-2 mg/l 4/13, P = 0.01). Elevated MICs of flucloxacillin in S. aureus infection or of gentamicin in streptococcal disease were associated with surgical intervention. There were no significant differences between bacterial pathogens in mortality, surgical referral or cure by medical treatment. The measurement of MIC appears prognostically important in deciding the surgical management of endocarditis.

On the identity of the parasite causing diffuse cutaneous leishmaniasis in the Dominican Republic.

Three isolates from disseminated cutaneous leishmaniasis (DCL) patients from an unusual focus in the Dominican Republic were studied and typed according to their behaviour in culture and experimental animals, their malate dehydrogenase (MDH) electrophoretic variant type, and excretory factor (EF) serotype. They were compared with parasites known to cause DCL in other parts of the world. On the basis of these characteristics, this parasite appears to be different from Leishmania aethiopica which causes DCL in the Old World and from both L. mexicana pifanoi and L. m. amazonensis, which are associated with DCL in the New World. However, it appeared to have some relationship to the L. mexicana-complex.