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1.
Primates ; 64(6): 581-587, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37656337

RESUMEN

The lesser spot-nosed monkey (Cercopithecus petaurista) is a widely distributed West African guenon, which is generally considered less vulnerable to local extinctions than many sympatric primate species. Guinea-Bissau harbours the westernmost populations of the species, which is thought to be very rare or even extinct on the mainland, but to have putative populations on some islands of the Bijagós Archipelago. However, due to a lack of regional studies, baseline information on these insular populations is missing. We collected baseline data on the anthropogenic activities that possibly threaten the long-term conservation of this primate by using non-systematic ethnographic methodologies. The species was reported to be decreasing in number or rare by locals on two of the islands, and we identified two main conservation threats to it: generalised habitat loss/degradation, and hunting. While subsistence hunting has been recorded before in these areas, we report, to the best of our knowledge for the first time for these islands, the presence of a semi-organised commercial wild meat trade. The carcasses of western lesser spot-nosed monkeys were observed being stored and shipped from seaports to be sold at urban hubs (Bissau and Bubaque Island). The effect of commercial trade on the species could be severe, considering the small, naturally occurring, carrying capacities typical of insular ecosystems. The results of this study highlight the importance of understanding the leading social drivers of wild meat hunting of lesser spot-nosed monkeys on the Bijagós Archipelago, and the need to conduct baseline research on these insular populations, for which qualitative and quantitative methods could be combined.


Asunto(s)
Cercopithecus , Ecosistema , Animales , Guinea Bissau , Haplorrinos , África Occidental
2.
J Am Coll Cardiol ; 36(1): 167-73, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10898429

RESUMEN

OBJECTIVES: This study was designed to evaluate the incidence and characteristics of onset of T-wave polarity alternans (TWPA) in patients with long QT syndrome. BACKGROUND: The T-wave alternans is a phenomenon that consists of beat-to-beat variability in the amplitude, morphology, and sometimes polarity of the T-wave, and it may trigger life-threatening arrhythmias. METHODS: The 24-h Holter recordings of 11 patients with congenital long QT syndrome were studied. Episodes of TWPA with 10 or more consecutive cycles were selected and analyzed as follows: 1) mean cycle length (MCL) and QTc interval duration (QTcI) of the episodes of TWPA and the 10 cycles preceding and succeeding the TWPA; 2) MCL and QTcI of the third, second, and first minute before onset (Mn_3, Mn_2, Mn_1); 3) MCL and QTcI from the tenth to the first cycle immediately preceding the onset of TWPA (R_10 to R_1); 4) MCL and QTcI from the first to the fourteenth cycle during alternans (R0 to R14); 5) MCL and QTcI from the first to the tenth cycle immediately succeeding TWPA (R+1 to R+10); 6) linear correlation (Lnc) between QT interval and cycle length (CL) (LncQT/CL) during alternans and for the 10 preceding cycles; 7) Lnc between the first three alternans cycles and episode duration (Lnc 3CL/EpD); and 8) difference between the longest and shortest QTc interval. We also selected episodes consisting of four or more consecutive cycles in order to analyze daily rhythms of the phenomenon. RESULTS: The TWPA was observed in 5 (45%) out of the 11 patients studied. The alternans process is initiated by a sudden shortening of the first alternans cycle without previous heart rate changes and ends at the moment when prolongation of the cycle tends to occur. LncQT/ CL-alternans: r = 0.38 +/- 0.2 (p = 0.20); without alternans: r = 0.81 +/- 0.06 (p = 0.01). Lnc 3CL/EpD: r = 0.002 (p = 0.992). The QTc difference during alternans: 312.0 +/- 52.1 ms; without alternans: 86.0 +/- 36.4 ms (p = 0.001). Daily rhythm: 71% of the episodes occurred between 8 AM and 8 PM, with higher incidence during the morning. CONCLUSIONS: The TWPA was dependent on the cardiac CL; there was loss of the LncQT/CL and an increase in the QT interval variability. Like other biological variables, T-wave polarity alternans has a higher density during the morning.


Asunto(s)
Electrocardiografía Ambulatoria , Frecuencia Cardíaca/fisiología , Síndrome de QT Prolongado/congénito , Síndrome de QT Prolongado/fisiopatología , Taquicardia Ventricular/etiología , Potenciales de Acción , Adolescente , Niño , Preescolar , Ritmo Circadiano/fisiología , Femenino , Humanos , Síndrome de QT Prolongado/complicaciones , Masculino , Pronóstico , Taquicardia Ventricular/fisiopatología
3.
J Am Coll Cardiol ; 26(5): 1310-4, 1995 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-7594048

RESUMEN

OBJECTIVES: We attempted to establish a relation between the atrial conduction time assessed by the signal-averaged P wave electrocardiogram and episodes of paroxysmal atrial fibrillation in patients with the Wolff-Parkinson-White syndrome. BACKGROUND: The incidence of paroxysmal atrial fibrillation is higher in patients with the Wolff-Parkinson-White syndrome than in normal persons. However, the role of intraatrial conduction delay in precipitating the disorganization of atrial rhythm is not completely understood. METHODS: The total duration of the signal-averaged P wave and the P wave in standard lead II was evaluated after successful radiofrequency catheter ablation in 28 patients with the Wolff-Parkinson-White syndrome. The data obtained from 17 patients (61%) with a documented history of prior paroxysmal atrial fibrillation (group I) were compared with those obtained from 11 patients (39%) without a history of atrial fibrillation (group 2). Both groups were further compared with a normal control population. RESULTS: The mean +/- SD signal-averaged P wave duration in group 1 was 141.94 +/- 9.47 ms (range 130.0 to 171.0). Fourteen patients (82%) in this group showed a P wave duration > 135.0 ms. In group 2, the signal-averaged P wave duration was 126.64 +/- 8.72 ms (range 111.0 to 136.0). Only one patient in this group (9%) showed a P wave duration > 135.0 ms (p < 0.000, group 1 vs. group 2). The signal-averaged P wave duration in the control group was 124.46 +/- 4.49 ms (range 115.0 to 129.5; p < 0.000, group 1 vs. the control group; p < 0.454, group 2 vs. the control group). The P wave duration in lead II was 92.06 +/- 8.85 ms in group 1 and 92.27 +/- 7.86 ms in group 2 (p < 0.949). Using a cutoff value of < 135.0 ms for a normal signal-averaged P wave duration, the method had a sensitivity and specificity and positive and negative predictive values of 82%, 91%, 93% and 77%, respectively, for identifying patients with clinical paroxysmal atrial fibrillation. CONCLUSIONS: In the current study, the signal-averaged P wave showed a prolonged intraatrial conduction time in patients with the Wolff-Parkinson-White syndrome and paroxysmal atrial fibrillation. These patients can be differentiated from those with the pre-excitation syndrome without clinical atrial fibrillation as well as from normal subjects. The prolonged intraatrial conduction time may serve as an atrial substratum for development and maintenance of the fibrillatory state.


Asunto(s)
Ablación por Catéter , Electrocardiografía , Atrios Cardíacos/fisiopatología , Síndrome de Wolff-Parkinson-White/cirugía , Adulto , Fibrilación Atrial/fisiopatología , Femenino , Estudios de Seguimiento , Sistema de Conducción Cardíaco , Humanos , Masculino , Persona de Mediana Edad , Síndrome de Wolff-Parkinson-White/fisiopatología
4.
Arq Bras Cardiol ; 62(2): 77-83, 1994 Feb.
Artículo en Portugués | MEDLINE | ID: mdl-7944993

RESUMEN

PURPOSE: To analyze the characteristics of atrial (A) and ventricular (V) electrograms, AV and VA intervals relation to determine a precise radiofrequency ablation site. METHODS: A and V electrograms (EG) recorded at successful (group 1) and unsuccessful (group 2) sites in 22 patients submitted to RF catheter ablation were identified. Specific criteria as morphology, AV and VA intervals relation and the presence of an accessory pathway were analyzed. RESULTS: The shortest AV interval with a VEG that precedes the delta wave in the onset of the QRS recorded at the EKG leads was the best outcome predictor. The AV connection potential was only recorded in five out of 22 patients and did not interfere with the result when not present. The interval measured between the onset of the V electrogram and the onset (delta wave) of the QRS complex (V-d) varied from -4.9 to -11msec (m = 7.5 + 1.6) in G1 and from -6 to 15msec (m = 9.6 +/- 3) in G2 (p = 0.03). Unsuccessful sites had the VEG preceding the delta wave but the AV interval was not short. Success in the retrograde mapping of target site seems to be the presence of an atrial potential that occurs simultaneously with the nadir (S wave) of the QRS complex. CONCLUSION: Specific criteria such as morphology of the local VEG, a short AV or VA intervals and a VEG that precede the onset (delta wave) of the QRS identified a successful site for RF ablation. When present the accessory pathway potential indicates a high chance of a successful ablation; however when not present did not decrease the chance of success.


Asunto(s)
Ablación por Catéter/métodos , Electrocardiografía/métodos , Síndromes de Preexcitación/cirugía , Adolescente , Adulto , Función Atrial , Electrofisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Síndromes de Preexcitación/diagnóstico , Función Ventricular
5.
Arq Bras Cardiol ; 61(6): 357-60, 1993 Dec.
Artículo en Portugués | MEDLINE | ID: mdl-8204071

RESUMEN

Woman, 46 years-old with incessant supraventricular tachycardia and tachycardiomyopathy. The diagnosis of a concealed retrograde long conduction time accessory pathway was obtained with the delay of the next atrial activation by delivering a ventricular premature beat during His bundle refratoriness. During electrophysiologic investigation the earliest atrial activation was found to be within the coronary sinus ostium. Two 25 watts applications of radiofrequency were followed by the interruption of the incessant supraventricular tachycardia. The patient has remained symptom free without recurrence for 60 days. Radiofrequency was effective for the treatment of this tachycardia.


Asunto(s)
Ablación por Catéter , Sistema de Conducción Cardíaco/anomalías , Taquicardia Supraventricular/cirugía , Electrofisiología , Femenino , Sistema de Conducción Cardíaco/fisiopatología , Sistema de Conducción Cardíaco/cirugía , Humanos , Persona de Mediana Edad , Taquicardia Supraventricular/fisiopatología
7.
Arq Neuropsiquiatr ; 43(1): 91-7, 1985 Mar.
Artículo en Portugués | MEDLINE | ID: mdl-4015444

RESUMEN

A case of a 10-year-old boy with a congenital arachnoid cyst in the right middle cranial fossa is reported. The symptoms were precipitated by head injury of moderate intensity, occurred some days before the beginning of the clinical picture. The computerized tomography has demonstrated the existence of a simultaneous right fronto-parietal subdural hygroma that was responsible for the intracranial hypertension syndrome. The influence of the cyst in the hygroma formation has been suggested. The mechanisms of growth, the etiology, clinical aspects, the diagnostics and the surgical treatment of the arachnoid cysts are discussed.


Asunto(s)
Aracnoides , Encefalopatías/complicaciones , Quistes/complicaciones , Linfangioma/complicaciones , Neoplasias Meníngeas/complicaciones , Meninges , Espacio Subdural , Encefalopatías/etiología , Lesiones Encefálicas/complicaciones , Niño , Quistes/etiología , Humanos , Presión Intracraneal , Masculino
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