Congenital anomalies concomitant with persistent primary congenital hypothyroidism.

The Israeli national neonatal screening program for congenital hypothyroidism (CH) was initiated in May 1978. The overall incidence of persistent primary congenital hypothyroidism (PPCH) during the first 10 years of screening was 1:2,950 live births. The purpose of this study was to ascertain the incidence of congenital extrathyroid anomalies (ETAs) among the infants with PPCH and to compare it with the Israeli Birth Defect Monitoring System data. Among 243 PPCH infants on whom adequate data were available, 38 infants (15.6%) had associated congenital anomalies. Fourteen infants had congenital cardiac anomalies (5.8%): VSD (n = 7), PDA (n = 3), PS (n = 2), one mitral insufficiency, and one congenital atrial flutter. Eight children (3.3%) had congenital dislocation of the hip; their M:F ratio was 3:5 similar to the M:F ratio in CH (unlike the ratio in the general population). Some additional anomalies were considerably more common than in the general population. It is reasonable to assume that teratogenic effects active during organogenesis may affect simultaneously many organs, including the developing thyroid, causing a relatively high percentage of CH infants with congenital ETA.

Effects of immigration on the incidence of congenital hypothyroidism.

OBJECTIVE: The incidence of congenital hypothyroidism (CH) has been shown to vary among different parts of the world. This could result from environmental or hereditary factors. Studies of other congenital diseases have shown that immigrants tend to retain the incidence of their country of origin while their children acquire the incidence of their new homeland, suggesting an environmental influence. This study aimed to assess the differences in the incidence of CH among immigrants from different parts of the world and to study the effects of immigration on its occurrence. METHODS: During the 9-year period between 1979 and 1987, 196 Jewish infants with primary CH were born in Israel; this constitutes an incidence of 1:3354 live births. We collected data from hospitals, endocrine pediatric clinics and the children's parents regarding the birth place of the parents and grandparents of those infants. These data were compared with the birth place of the parents and grandparents of all infants born in Israel during that period in order to learn about the incidence of CH among infants of different origins and to compare the incidence between children of parents born in Israel and those of immigrants of the same grandparental origin. RESULTS: CH incidence was lower among offspring of mothers and fathers of Israeli origin (1:4717 and 1:4255 live births respectively) and higher among those of African mothers (1:2950) and Asian fathers (1:2941). Parents of Asian or African origin, born in Israel have a lower incidence of CH-affected children compared with parents of the same origin born in their own continent. This trend is reversed for European and American parents, for whom being born in Israel is related to an increase in the CH incidence in their children. The difference in CH incidence between offspring of parents born in Israel and those of parents born in their original country was statistically significant (P < 0.05). In the different origin groups the gender of the parent did not influence significantly the incidence of CH. CONCLUSIONS: Environmental changes resulting from immigration can influence the incidence of congenital hypothyroidism.

A ten-year temporal analysis of primary congenital hypothyroidism in Israel.

It was previously shown that some congenital malformations present seasonal variations, suggesting a seasonal etiology such as viral infections. Some earlier studies have shown a certain degree of variation in the incidence rates of congenital hypothyroidism. As from April 1978 all infants born in Israel were screened for congenital hypothyroidism (CH) in one central laboratory at the Sheba Medical Center Tel-Hashomer. During the 10-year screening period (April 1978 to March 1988) 303 infants were found to have primary CH, which constitutes an overall incidence of 1/3192 live births. The annual and monthly birth incidence was calculated for the 120 months of the screening period. The annual CH incidence was significantly low in 1978 and 1979 and significantly high in 1985. There were wide and significant variations in the individual monthly incidences of CH. The average monthly incidence showed a low peak in August; however the autocorrelation analysis of the monthly incidences of CH showed no significant periodicity. This was supported by the Fourier analysis which showed no distinctive frequency peak. The last menstrual period was calculated for 138 of the infants' mothers and an autocorrelation analysis of these dates showed no significant periodicity. These results support a non-periodic etiology for sporadic primary CH in Israel.

Regional and temporal fluctuations in the incidence of congenital hypothyroidism in Israel.

It is well known that the incidence of congenital hypothyroidism (CH) differs significantly among different parts of the world. Northern Israel has been shown to be an iodine deficient area with a relatively high incidence of CH. This study aimed to compare the incidence of CH between different regions of Israel and to examine the temporal fluctuations of this disease in each region. All 303 primary CH infants born in Israel during the 10-year period between April 1978 and March 1988 were classified by hospital of birth and place of residence. Using these data we calculated the incidence of CH in the different subdistricts and districts of Israel. We also calculated the annual incidence of CH in each district. The incidence of CH in each hospital was compared to the filter paper T4 levels of all newborns born in that hospital during 1993. The incidence of CH decreased gradually from northern to southern Israel. This trend was also observed for thyroid agenesis, but the incidence of ectopic thyroid was highest in central Israel. Dyshormonogenesis (DHG) was on average 3.5 fold more frequent in the Arab compared to the Jewish populations, but did not show any clear geographic pattern. A significantly increased CH incidence in north-central Israel in 1985 was opposed by a low incidence in the South. A clear correlation exists between the incidence of CH in each hospital and the mean newborns' T4 level in that hospital. The incidence of primary CH in general, and of thyroid agenesis and ectopic thyroid specifically, has a clear regional-temporal pattern. Thus, some of the factors causing CH in Israel may be local factors that show local annual fluctuations.

Maternal-fetal T4 transfer does not suffice to prevent the effects of in utero hypothyroidism.

It has been suggested recently that in congenitally hypothyroid infants with organification defect there is a maternal-fetal transfer of thyroxine (T4). The present study was conducted to evaluate how effective the maternal-fetal transfer is and whether the maternal T4 can prevent intrauterine hypothyroidism. The clinical, laboratory and radiological data on 271 full-term infants with persistent primary congenital hypothyroidism, detected by the national screening program, were used to assess the degree of in utero hypothyroidism. For 6 out of 50 athyroid infants, two pretreatment blood samples spotted on filter paper were available for calculating the T4 disappearance rate. Most infants with agenesis of the thyroid had very low T4 and very high levels of thyroid-stimulating hormone compared to infants with ectopic thyroid. In the athyroid infants the initial T4 declined to low and undetectable levels. Bone maturation was significantly delayed while the clinical symptomatology was more prominent in the athyroid congenital hypothyroid infants, as compared with the ectopic thyroid infants. In conclusion, there is some maternal-fetal transfer of T4. However, this transfer is insufficient to suppress the fetal levels of thyroid-stimulating hormone and prevent intrauterine hypothyroidism.

Creatine kinase activity decrease with short-term freezing.

Freezing of serum samples at -30 degrees C without protective agents is the simplest and least expensive method of storage in serum banks. We investigated the stability of creatine kinase (CK) in human sera after freezer storage under such conditions for 24 h (n = 30) or for 2 or 4 weeks (n = 99). CK activity was measured in fresh sera and compared to matched thawed sera after freezer storage at the designated time intervals. The enzyme's median activity decreased significantly after 24 h, 2 weeks, and 4 weeks of freezer storage by 2.6, 5.9, and 8.3%, respectively (p < 0.0001, r = 0.99). Sex or high CK initial values had no significant effect on these results. We conclude that freezer storage of serum at -30 degrees C, even for short periods, causes a steady and significant decline in CK activity. These results should be taken into consideration when analyzing CK activity in frozen sera for research or clinical purposes.

Preparing hospitals for toxicological mass casualties events.

OBJECTIVE: For most hospital staffs, treatment of chemical casualties presents an obscure and even frightening situation. We report our unique experience from hospital drills in order to improve hospital preparedness for patient management under mass casualty conditions involving hazardous chemicals. SETTING: Twenty-one major hospitals in Israel. INTERVENTIONS: A unique hospital deployment plan for the management of chemical casualties was developed, and hospitals were required to have a full chemical practice drill every 3 to 5 yrs. These drills were designed as realistically as possible, and all included the use of personal protective equipment, decontamination, and treatment of simulated patients. Twenty-five percent of these patients, simulating children and adults, required intensive care and ventilation support. Hospitals were inspected and reviewed on the quality of treatment given and the overall continuity of care as well as on their administrative performance. RESULTS: Between 1986 to 1994, 30 full chemical practice drills were conducted in 21 major hospitals. Each drill included treatment of 100 to 400 simulated patients. The lessons from the hospital drills are described and were incorporated in the proposed revised hospital deployment plan. All hospitals significantly improved their ability to respond appropriately to these incidents. CONCLUSIONS: The level of preparedness for a chemical mass casualty scenario should be established according to the existing threat and the available resources. The proposed plan can serve as a basis for hospital planning and staff training worldwide, thus facilitating optimal care in the event of an incident involving toxic chemicals. A cost-effective scale for hospital preparation levels according to the existing threat is suggested.