Bandeo de cromosomas humanos con extracto crudo de frutas u hojas de papaya / Human chromosome banding with raw extract of fruits or leaves of papaya

One week old human chromosome preparations were treated with filtrate from one liquefied leaf (53 g) of papaya (Carica papaya) in 100 ml of distilled water, and stained with 1.5 Giemsa (pH 6.8). Good chromosome banding was obtained after 2 min of treatment. Solutions that have been frozen even for years are effective and the method is cheaper and easier than others.

Enfermedad de Lafora y efecto fundador en una pequeña localidad neotropical / Lafora disease and founder effect in a small neotropical locality

The Lafora disease is an uncommon genetic condition. Four cases (two families) were detected in Zarcero, a small town in Costa Rica (population under 2000). They belonged to two separate consanguineous marriages but both families had common ancestors. The diagnosis of Lafora disease was confirmed by liver and biopsy in one of the patients. The ages of onset were 13, 14, 16 and 17 years. Patients died after four, nine, six and five year of severe progressive physical and mental deterioration, respectively. The gene for Lafora disease arrive to Zarcero from one of its founders. There are no other cases reported from Costa Rica : this is an example of genetic drift, or more specifically, founder effect. Key words: Lafora disease, myoclonic epilepsy, founder effect

Citogenética y citoquímica de pacientes con leucemias en dos hospitales neotropicales / Citogenetics and citochemistry of leukemia patients in two neotropical hospitals

A cytogenetic and/or cytochemical study was performed in 166 individuals with leukemia or related disorders, in two major Costa Rican hospitals. In those patients treated at an adult`s (14 years old and over), acute leukemias represented 66 porcent of all cases. In that hospital the most frequent types of disorders were, in decreasing order: ANLL(>M1), ALL, CML (all of them showed the Ph chromosome) and MDS. In the cases fron a children`s hospital (<14 years old) acute leukemias were 98 porcent. Among them the order of frequency was: ALL (70 porcent): ALL-1(84 porcent), ALL-2(16 porcent) and ANLL (27 porcent): M5a>M3>M4>M5b. In ALL 85 porcent were type B and occurred mostly in women while 15 porcent of them were type T and more frequent in males. There was 5.6 porcent infant leukemia, which presented a similar number of acute lymphoids and myeloids. The cytogenetic pattern was similar among Costa Rica and other tropical and temperate countries. Key words: Leukemia cytogenetics, acute lymphocytic leukemia, acute nonlymphocitic leukemia, chronic granulocytic leukemia