Distrofia miotónica tipo 1: 13 años de experiencia en un hospital terciario. Estudio clínico y epidemiológico. Correlación genotipo-fenotipo / Myotonic dystrophy type 1: 13 years of experience at a tertiary hospital. Clinical and epidemiological study and genotype-phenotype correlation

Introducción: Se desconoce la incidencia de la distrofia miotónica tipo 1 (DM1), enfermedad con gran variedad fenotípica, en nuestra región. El objetivo de nuestro trabajo es estimar la incidencia de DM1 en nuestro centro (referencia en Aragón) e identificar las características propias de nuestra población (correlación genotipo-fenotipo). Métodos: Estudio descriptivo retrospectivo de 459 pacientes clasificados según número de repeticiones CTG en: normal (5-35), premutado (36-50), protomutado (51-80), pequeñas expansiones (81-150), intermedias (151-1.000) y grandes (> 1.000). Además, según el fenotipo mostrado, se categorizaron como: no afectos (5-50 CTG), forma leve o asintomática (51-150 CTG), clásica (151-1.000 CTG) y severa (> 1.000 CTG). Resultados: La incidencia de DM1 fue de 20,61 (IC 95%: 19,59-21,63) casos por millón de individuos-año. Se evidenció una correlación inversa entre el número de CTG y la edad al diagnóstico genético (ρ = −0,547; IC 95%: −0,610 a −0,375; p < 0,001). El CTG5 fue el alelo polimórfico más frecuente en sanos. Del total de afectos, el 28,3% presentaron la forma leve o asintomática, el 59,1% la forma clásica y el 12,6% la forma severa. El 35,1% presentaron herencia materna, el 59,4% herencia paterna y el 5,5% herencia incierta. En las formas leves la calvicie frontal en varones fue el rasgo fenotípico más prevalente, junto con miotonía y cataratas, mientras que en la clásica predominó la ptosis palpebral, la debilidad facial, las alteraciones en la voz y la pronunciación, la miotonía y la sensación de cansancio/somnolencia. Conclusiones: La incidencia de DM1 es relevante en Aragón. La revisión multidisciplinar del fenotipo de pacientes con DM1 es clave para un diagnóstico precoz y medicina personalizada.(AU)

Introduction: The incidence of myotonic dystrophy type 1 (DM1), a disease with great phenotypic variety, in our region is unknown. This study aims to estimate the incidence of DM1 at our hospital (a reference centre in Aragon, Spain) and to identify the characteristics of our population (genotype-phenotype correlation). Methods: Retrospective, descriptive study of 459 patients classified according to the number of CTG repeats, as follows: normal (5-35), premutation (36-50), protomutation (51-80), small expansions (81-150), intermediate expansions (151-1000), and large expansions (> 1000). Furthermore, according to clinical phenotype, patients were categorised as unaffected (5-50 CTG repeats), mild form or asymptomatic (51-150), classical form (151-1000), and severe form (> 1000). Results: The incidence of DM1 was 20.61 cases per million person-years (95% CI: 19.59-21.63). An inverse correlation was observed between the number of CTG repeats and the age at genetic diagnosis (ρ = −0.547; 95% CI: −0.610 to −0.375; P < .001). CTG5 was the most frequent polymorphic allele in healthy individuals. Of all patients with DM1, 28.3% presented the mild or asymptomatic form, 59.1% the classical form, and 12.6% the severe form. Inheritance was maternal in 35.1% of cases, paternal in 59.4%, and uncertain in 5.5%. In mild forms, frontal balding in men was the most prevalent phenotypic trait, as well as myotonia and cataracts, while in the classical form, ptosis, facial weakness, voice and pronunciation alterations, myotonia, and fatigue/sleepiness were most frequent. Conclusions: The incidence of DM1 in Aragon is significant. Multidisciplinary study of the phenotype of patients with DM1 is key to early diagnosis and personalised management.(AU)

Myotonic dystrophy type 1: 13 years of experience at a tertiary hospital. Clinical and epidemiological study and genotype-phenotype correlation.

INTRODUCTION: The incidence of myotonic dystrophy type 1 (DM1), a disease with great phenotypic variety, in our region is unknown. This study aims to estimate the incidence of DM1 at our hospital (a reference centre in Aragon, Spain) and to identify the characteristics of our population (genotype-phenotype correlation). METHODS: Retrospective, descriptive study of 459 patients classified according to the number of CTG repeats, as follows: normal (5-35), premutation (36-50), protomutation (51-80), small expansions (81-150), intermediate expansions (151-1000), and large expansions (> 1000). Furthermore, according to clinical phenotype, patients were categorised as unaffected (5-50 CTG repeats), mild form or asymptomatic (51-150), classical form (151-1000), and severe form (> 1000). RESULTS: The incidence of DM1 was 20.61 cases per million person-years (95% CI, 19.59-21.63). An inverse correlation was observed between the number of CTG repeats and the age at genetic diagnosis (ρ = -0.547; 95% CI, -0.610 to -0.375; P < .001). CTG5 was the most frequent polymorphic allele in healthy individuals. Of all patients with DM1, 28.3% presented the mild or asymptomatic form, 59.1% the classical form, and 12.6% the severe form. Inheritance was maternal in 35.1% of cases, paternal in 59.4%, and uncertain in 5.5%. In mild forms, frontal balding in men was the most prevalent phenotypic trait, as well as myotonia and cataracts, while in the classical form, ptosis, facial weakness, voice and pronunciation alterations, myotonia, and fatigue/sleepiness were most frequent. CONCLUSIONS: The incidence of DM1 in Aragon is significant. Multidisciplinary study of the phenotype of patients with DM1 is key to early diagnosis and personalised management.

The yield of malignancy for early fixation versus routine fixation of Pleural fluid samples

Background@#The etiology of pleural effusion remains unclear in nearly 20% of cases. One way to diagnose malignancy is by doing pleural fluid cytology. There are factors that influence the yield of pleural fluid cytology and one of them is appropriate and timely fixation of samples. Currently, there is no local consensus regarding the timing with which the specimen should be fixed.@*Objective@#The study aims to compare the yield of malignancy between early fixation versus usual fixation of pleural fluid samples, meaning there is no set time for fixation to be done.@*Methodology@#The study employed a prospective cross-sectional research design. All patients with pleural effusion who fulfilled the criteria set by the study were included. Two sets of pleural fluid samples were collected amounting to 20cc each. First sample was assigned as Bottle #1 and placed immediately with fixative while the second sample was assigned as Bottle #2. Bottle #2 underwent routine fixation which follows no fixed or standard time of fixation. The time difference between the fixation of two sample groups greatly varied with Bottle #1 fixed immediately right after collection while Bottle#2 depends on the time it will be processed by the laboratory personnel. Both samples were submitted for cell block and cell cytology reading.@*Results@#Characteristics of the 55 patients included in the study showed age group range from 41 to 65 years of age, with 27 male and 28 female patients. Only one third had history of smoking. There were 21.82% who had family history of cancer and with and suspicious mass on chest radiograph. Out of 55 patients, 29 patients had history of previous diagnosis of cancer, 23 had recurrent pleural effusion, and 28 had chest radiograph with suspicious nodules. Based on gross appearance, there were 20 serous and 21 sanguineous pleural fluid noted. Mean cell count was high (1,115.50 ± 741.02) with lymphocytic predominance (82.56 ± 24.46). Elevated protein concentration (5,388.25 ± 8,230.46) and LDH (484.17 ± 248.72) were noted. Glucose (8.78 ± 6.68 mmol/L) was low. There were 21 patients who had high WBC, 24 with high protein and 16 with elevated LDH. There were 3 patients who were positive for AFB and none for KOH. Comparative analysis showed that the pleural fluid samples assigned to the routinely fixed group which were handed to the nurse after thoracentesis, then forwarded to the laboratory through a ward laboratory aide or patient watcherfor fixation with with 95% alcoholby thelaboratory personnel significantly had a longer duration of 406.62 minutes as compared to immediately fixed at 12.27 minutes (P<0.01). For diagnosis of malignancy, significantly more cases were diagnosed in the immediately fixed group with 36.36% cases versus 18.18% (p=0.016).@*Conclusion@#Among patients with suspected malignant pleural effusions, early fixation of pleural fluid samples resulted in higher histopathology yields as compared to those fixed after going through the routine fixation.

Myotonic dystrophy type1: 13years of experience at a tertiary hospital. Clinical and epidemiological study and genotype-phenotype correlation. / Distrofia miotónica tipo1: 13años de experiencia en un hospital terciario. Estudio clínico y epidemiológico. Correlación genotipo-fenotipo.

INTRODUCTION: The incidence of myotonic dystrophy type1 (DM1), a disease with great phenotypic variety, in our region is unknown. This study aims to estimate the incidence of DM1 at our hospital (a reference centre in Aragon, Spain) and to identify the characteristics of our population (genotype-phenotype correlation). METHODS: Retrospective, descriptive study of 459 patients classified according to the number of CTG repeats, as follows: normal (5-35), premutation (36-50), protomutation (51-80), small expansions (81-150), intermediate expansions (151-1000), and large expansions (>1000). Furthermore, according to clinical phenotype, patients were categorised as unaffected (5-50 CTG repeats), mild form or asymptomatic (51-150), classical form (151-1000), and severe form (>1000). RESULTS: The incidence of DM1 was 20.61 cases per million person-years (95%CI: 19.59-21.63). An inverse correlation was observed between the number of CTG repeats and the age at genetic diagnosis (ρ=-0.547; 95%CI: -0.610 to -0.375; P<.001). CTG5 was the most frequent polymorphic allele in healthy individuals. Of all patients with DM1, 28.3% presented the mild or asymptomatic form, 59.1% the classical form, and 12.6% the severe form. Inheritance was maternal in 35.1% of cases, paternal in 59.4%, and uncertain in 5.5%. In mild forms, frontal balding in men was the most prevalent phenotypic trait, as well as myotonia and cataracts, while in the classical form, ptosis, facial weakness, voice and pronunciation alterations, myotonia, and fatigue/sleepiness were most frequent. CONCLUSIONS: The incidence of DM1 in Aragon is significant. Multidisciplinary study of the phenotype of patients with DM1 is key to early diagnosis and personalised management.

Ischaemic stroke in the time of coronavirus disease 2019.

BACKGROUND AND PURPOSE: Stroke assistance is facing changes and new challenges since COVID-19 became pandemic. A variation on the patient influx might be one of the greater concerns, due to fewer people coming to emergency departments or coming too late. However, no data quantifying this have been published until now. The aim was to analyse the impact of the COVID-19 epidemic outbreak on hospital stroke admissions and their characteristics in our region. METHODS: The data of every patient admitted to any hospital of our healthcare system with a diagnosis of ischaemic stroke between 30 December 2019 and 19 April 2020 were reviewed. Demographic and clinical data were recorded and compared between periods before and after the setting of the state of emergency secondary to the COVID-19 outbreak. RESULTS: In total, 354 patients with ischaemic stroke were admitted in our study period. There was a weekly average of 27.5 cases before the setting of the state of emergency against 12 afterwards (P < 0.001). This drop in stroke cases occurred progressively from week 11, persisting in time despite the decrease in confirmed cases of COVID-19. No differences in the proportion of intravenous thrombolysis (21.1% vs. 21.5%, P = 0.935) or endovascular therapy (12.4% vs. 15.2%, P = 0.510) were found, nor in other demographic or clinical characteristics except for median onset-to-door time (102 vs. 183 min, P = 0.015). CONCLUSIONS: This observational study offers the perspective of a whole region in one of the countries more heavily stricken by the SARS-CoV-2 epidemic and shows that the decrease of stroke events, since the beginning of the COVID-19 outbreak, happened globally and without any specific patient distribution.

Four-year follow-up of two patients on maintenance therapy with fondaparinux and mycophenolate mofetil for microthrombotic antiphospholipid syndrome.

OBJECTIVES: We discuss two patients with antiphospholipid syndrome (APS) who presented with critical ischemia of both lower extremities due to arterial microthrombi. They received multimodality therapy emergently: anticoagulation, immunosuppression, and therapeutic plasma exchange (TPE). Then they were maintained on anticoagulation with fondaparinux and immunosuppression with mycophenolate mofetil (MMF), and were followed for 4 years. METHODS: Two patients with APS with ischemia and necrosis of their distal lower extremities were treated emergently with anticoagulation (intravenous heparin), immunosuppression (prednisone), and TPE. They were maintained on anticoagulation with fondaparinux and immunosuppression with MMF. RESULTS: Neither patient had recurrent microthrombotic disease during a 4-year follow-up. CONCLUSIONS: As described in our small cohort, patients with APS who suffer from microthrombotic arterial disease may benefit from maintenance therapy of anticoagulation with fondaparinux and immunosuppression with MMF, an approach which may be worthy of further trial. Fondaparinux does not require attention to diet, monitoring, and cumbersome bridging that is typical of warfarin therapy. MMF provides immunosuppression while sparing the side effects of steroid treatment.

Causa de abdomen agudo no quirúrgico: infarto omental / Cause of acute non-surgical abdomen: omental infarction

No disponible

Vaccinia virus protein A3 is required for the production of normal immature virions and for the encapsidation of the nucleocapsid protein L4.

Maturation of the vaccinia virion is an intricate process that results in the organization of the viroplasm contained in immature virions into the lateral bodies, core wall and nucleocapsid observed in the mature particles. It is unclear how this organization takes place and studies with mutants are indispensable in understanding this process. By characterizing an inducible mutant in the A3L gene, we revealed that A3, an inner core wall protein, is important for formation of normal immature viruses and also for the correct localization of L4, a nucleocapsid protein. L4 did not accumulate in the viral factories in the absence of A3 and was not encapsidated in the particles that do not contain A3. These data strengthen our previously suggested hypothesis that A3 and L4 interact and that this interaction is critical for proper formation of the core wall and nucleocapsid.

Transducing properties of a pre-structured α-helical DPT-peptide containing a short canine adenovirus type 2 E4orf4 PP2A1-binding sequence.

BACKGROUND: Induction of the death pathway resulting from the specific interaction of the PP2A1 phosphatase with adenoviral E4orf4 protein is a promising approach for cancer therapy. With the aim of deregulating tumor pathways, and mimicking E4orf4 anti-cancer signal, we have previously proposed the DPT technology concept, based on design of specific PP1/PP2A interacting penetrating peptides. METHODS: Using biochemical, structural and cell survival experiments, we have characterized new DPT-peptides containing short PP2A binding sequences. RESULTS: We identified overlapping sequences, located within the N-terminal domain E4orf423-46 of canine adenoviral E4orf4 protein, that interact with the PP2A-Bα subunit of PP2A1 holoenzyme. We characterized DPT-E4orf44 and TAT-E4orf44, two bi-partite cell penetrating peptides containing the 12 PP2A1 binding residues of the canine type 2 E4orf427-38 sequence, respectively fused to the DPT-sh1 and TAT shuttle sequences. Surprisingly DPT-E4orf44, in contrast to inactive TAT-E4orf44, adopted a well defined α-helical structure and co-precipitated PP2A1 from HeLa cell extracts. DPT-E4orf44 also internalized streptavidin-HRP and inhibited survival of HeLa cells more efficiently than TAT, TAT-E4orf44 or the previously published anti-tumor TAT-derived peptide shepherdin. DPT-E4orf44 also efficiently inhibited the survival of human adherent transformed cells, including wild type and p53 mutated colonic HCT116 cells, without affecting survival of human non-transformed fibroblasts. CONCLUSIONS: We characterized the transducing properties of a new α-helical DPT-E4orf44 peptide containing a short PP2A-interacting sequence from canine Adenoviral E4orf4 protein. GENERAL SIGNIFICANCE: Our results suggest that α-helical structured DPT peptides specifically interacting with PP2A could be a valuable anti-cancer drug design scaffold.

The role of emotions on pacing strategies and performance in middle and long duration sport events.

Thepacing strategy may be defined as the process in which the total energy expenditure during exercise is regulated on a moment-to-moment basis in order to ensure that the exercise bout can be completed in a minimum time and without a catastrophic biological failure. Experienced athletes develop a stable template of the power outputs they are able to sustain for different durations of exercise, but it is not known how they originally develop this template or how that template changes with training and experience. While it is understood that the athlete's physiological state makes an important contribution to this process, there has been much less interest in the contribution that the athlete's emotional status makes. The aim of this review is to evaluate the literature of physiological, neurophysiological and perceptual responses during exercise in order to propose a complex model interpretation of this process which may be a critical factor determining success in middle- and long-duration sporting competitions. We describe unconscious/physiological and conscious/emotional mechanisms of control, the focus of which are to ensure that exercise terminates before catastrophic failure occurs in any bodily system. We suggest that training sessions teach the athlete to select optimal pacing strategies by associating a level of emotion with the ability to maintain that pace for exercise of different durations. That pacing strategy is then adopted in future events. Finally, we propose novel perspectives to maximise performance and to avoid overtraining by paying attention also to the emotional state in training process.

Using the distribution of the CCR5-Δ32 allele in third-generation Maltese citizens to disprove the Black Death hypothesis.

Malta was under Norman rule for over 400 years and has had three major documented plague outbreaks (and a number of minor ones) since the 14th century with death tolls of 5-15% of the population at the time. This makes the Maltese population ideal for testing the hypothesis that the Black Death (particularly that of 1346-52) was responsible for a genetic shift that spread the CCR5-Δ32 allele. By enrolling 300 blood donors to determine the percentage of the Maltese population resistant to HIV-1 (which uses the CCR5-receptor to infect cells), it was established that the CCR5-Δ32 allele frequency is almost zero in third-generation Maltese citizens and sequencing showed that the deletion observed in the region of interest is the 32-base deletion expected. Thus, despite the extensive Norman occupation and the repeated plague cullings, the CCR5-Δ32 allele frequency is extremely low. This provides a basis for the discussion of conflicting hypotheses regarding the possible origin, function and spread of the CCR5-Δ32 deletion.

The influence of variable resistance moment arm on knee extensor performance.

To enhance muscular strength, resistance training machines with a cam, incorporating a variable resistance moment arm, are widely used. However, little information is available about the influence of the variable resistance moment arm on torque, velocity, and power during muscle contraction. To address this, a knee extensor machine was equipped with a cam or with a semi-circular pulley that imposed a variable or a constant resistance moment arm, respectively. Fourteen physically active men performed two full knee extensions against loads of 40-80 kg in both conditions. Participants developed significantly higher torque with the pulley than with the cam (P < 0.001). The relative differences between pulley and cam conditions across all loads ranged from 8.72% to 19.87% (P < 0.001). Average knee extension velocity was significantly higher in the cam condition than in the pulley condition. No differences were observed in average and peak power, except at 50 and 55 kg. Torque-velocity and power-velocity relationships were modified when the resistance moment arm was changed. In conclusion, whatever the link, namely cam or pulley, the participants produced similar power at each load. However, the torque-velocity and power-velocity relationships were different in the cam and pulley conditions. The results further suggest that the influence of the machine's mechanism on muscular performance has to be known when prescribing resistance exercises.

Algunos aportes de la escuela francesa a la psiquiatría de niños y de adolescentes / Some Contributions of the French School to Child and Adolescent Psychiatry

Introducción: En el artículo se realiza un breve recuento histórico de la psiquiatría de niños y adolescentes en Francia, para luego profundizar en tres aspectos que se consideran clave: la importancia otorgada a la reflexión clínico-psicopatológica, el lugar preponderante de la dimensión evolutiva en psiquiatría de niños y adolescentes y la relevancia del trabajo institucional en el abordaje terapéutico. Objetivo: Esquematizar lo que en opinión de los autores son los aportes más significativos de la escuela francesa en la psiquiatría de niños y adolescentes. Método: Revisión de la literatura. Resultado y conclusiones: El conocimiento de los aportes de las distintas escuelas en materia de psiquiatría de niños y adolescentes permite aprehender la especificidad de cada una de ellas, contrastar sus diferencias y divergencias y buscar, cuando esto resulta posible, la eventual integración de sus diversas contribuciones.

Introduction: In this article a brief historical review of child and adolescent psychiatry in France is made, and subsequently three key aspects are addressed in depth: the importance given to the clinical-psychopathological reflection, the fundamental role played by the evolutionary dimension in child and adolescent psychiatry, and the relevance of institutional work in treatment options. Objective: To describe what the authors consider are the main contributions of the French school to child and adolescent psychiatry. Method: Literature revision. Results and Conclusions: Knowing the contributions of the different schools as regards child and adolescent psychiatry, makes it possible to grasp the specificity of each one, to contrast the differences and disagreements between them, and to seek (whenever possible) an eventual integration of their various contributions.

The eccentric muscle loading influences the pacing strategies during repeated downhill sprint intervals.

The purpose was to compare self-chosen pace during ten repetitions of 60 m running sprints performed on a level surface (SPL), or when running uphill (SPU) or downhill (SPD) on a 4.7% slope. When expressed as percent of maximal running speed for corresponding condition, SPD was lower than SPL (95.28 +/- 1.93 vs. 97.31 +/- 1.29%; P = 0.044), which was lower than SPU (97.31 +/- 1.29 vs. 98.09 +/- 0.74%; P = 0.026). Heart rates, blood lactate concentrations and general perceived exertion were lower during SPD (163.8 +/- 8.3 bpm, 11.66 +/- 1.24 mmol L( -1), and 4.1 +/- 1.0) than SPL (169.8 +/- 7.8 bpm, 13.69 +/- 0.33 mmol L(-1), and 5.8 +/- 0.6), which were lower than SPU (174.9 +/- 8.7 bpm, 15.27 +/- 0.02, mmol L(-1), and 6.3 +/- 0.5) (P < 0.05 for all analyzes). Results show that the level of eccentric muscle loading influences the pacing strategy.

Uso de voriconazol tópico en queratitis por alternaria / Use of topical voriconazole in alternatia keratitis

Caso clínico: Hombre de 38 años remitido de otro centro por presentar queratitis fúngica por Alternaria 25 días después de realizarle una queratoplastia penetrante postraumática en ojo derecho. Se instaura tratamiento con voriconazol tópico y oral con buena evolución posterior. Discusión: Las queratitis fúngicas por Alternaria son poco frecuentes. Su tratamiento es difícil porque la evolución clínica no se correlaciona con la susceptibilidad in vitro del hongo. Producen cuadros clínicos que requieren un rápido diagnóstico y tratamiento, para evitar la pérdida de visión. La combinación de voriconazol tópico y sistémico puede ser una buena alternativa en caso de hongos resistentes al tratamiento convencional

Clinical case: A 38-year-old man with fungal Alternaria keratitis was referred from another hospital 25 days after post-traumatic penetrating keratoplastia surgery on his right eye. We commenced treatment with topical voriconazole and the condition resolved. Discussion: Fungal Alternaria keratitis is rare, and treatment is difficult because the clinical response does not correlate well with the antibiotic in vitro sensitivity of the fungus. Clinical cases need to be diagnosed and treated quickly if visual loss is to be avoided. The combination of topical and systemic voriconazole has been shown to be an effective treatment for this condition (Arch Soc Esp Oftalmol 2008; 83: 493-496)

[Use of topical voriconazole in Alternaria keratitis]. / Uso de voriconazol tópico en queratitis por alternaria.

CLINICAL CASE: A 38-year-old man with fungal Alternaria keratitis was referred from another hospital 25 days after post-traumatic penetrating keratoplastia surgery on his right eye. We commenced treatment with topical voriconazole and the condition resolved. DISCUSSION: Fungal Alternaria keratitis is rare, and treatment is difficult because the clinical response does not correlate well with the antibiotic in vitro sensitivity of the fungus. Clinical cases need to be diagnosed and treated quickly if visual loss is to be avoided. The combination of topical and systemic voriconazole has been shown to be an effective treatment for this condition

Transfusion support for a patient with McLeod phenotype without chronic granulomatous disease and with antibodies to Kx and Km.

BACKGROUND AND OBJECTIVES: Kell antigens are encoded by the KEL gene on the long arm of chromosome 7. Kx antigen is encoded by the XK gene on the short arm of the X chromosome. Kell and Kx proteins in the red cell membrane are covalently linked by a disulphide bond. The McLeod phenotype is characterized by weakened expression of antigens in the Kell blood group system, absence of Km and Kx antigens, and acanthocytosis. It has an X-linked mode of inheritance with transmission through carrier females. Some males with the McLeod syndrome also have chronic granulomatous disease (CGD). It is generally believed that patients with non-CGD McLeod may develop anti-Km but not anti-Kx, but that those with CGD McLeod can develop both anti-Km and anti-Kx. MATERIALS AND METHODS: We present serological data, DNA genotyping and gene sequencing, monocyte monolayer assay and neutrophil oxidative burst test from a patient with the McLeod phenotype without clinical evidence of CGD. RESULTS: We report here the second example of a patient with non-CGD McLeod who developed anti-Kx in addition to anti-Km. Sequencing of our patient's XK gene confirmed the presence of a mutation resulting in a premature stop codon and lack of Kx protein in the red cell membrane, which is consistent with the diagnosis of McLeod syndrome. Neutrophil oxidative burst test was normal, indicating that our patient did not have CGD. The challenge of providing 10 compatible blood units for multiple surgeries was met. CONCLUSION: The second case of a rare entity, a patient with non-CGD McLeod who developed anti-Kx and anti-Km, was managed successfully with a combination of autologous donations and procurement of compatible units from national and international sources.

Why does exercise terminate at the maximal lactate steady state intensity?

OBJECTIVE: The purpose of this study was to measure physiological responses during exercise performed until exhaustion at the exercise intensity corresponding to the maximal lactate steady state (MLSS) in order to determine why subjects stopped. METHODS: Eleven male trained subjects performed a test at MLSS on a cycle ergometer until exhaustion. RESULTS: Time to exhaustion was 55.0 (SD 8.5) min. No variation was observed between the 10th and the last minute for arterial pyruvate, bicarbonate, and haemoglobin concentrations, redox state, arterial oxygen pressure, arterial oxygen saturation, osmolality, haematocrit, oxygen uptake, carbon dioxide output, and gas exchange ratio (p>0.05). Arterial lactate concentration and arterial carbon dioxide pressure decreased significantly whereas pH, base excess and the Ratings of Perceived Exertion (RPE) increased significantly (p<0.05). Although respiratory rate, minute ventilation and heart rate increased significantly until exhaustion (p<0.05), values at termination of the MLSS test were significantly lower than values measured during a maximal exercise test (p<0.05). Blood ammonia concentrations rose progressively during the MLSS test. However, there is no known mechanism by which this change could cause peripheral fatigue. CONCLUSIONS: Exercise termination was not associated with evidence of failure in any physiological system during prolonged exercise performed at MLSS. Thus the biological mechanisms of exercise termination at MLSS were compatible with an integrative homoeostatic control of peripheral physiological systems during exercise.