Microfossil evidence for pre-Columbian maize dispersals in the neotropics from San Andres, Tabasco, Mexico

The history of maize (Zea mays L.) is one of the most debated topics in New World archaeology. Molecular and genetic studies indicate that maize domestication took place in tropical southwest Mexico. Although archaeological evidence for the evolution of maize from its wild ancestor teosinte has yet to be found in that poorly studied region, other research combining paleoecology and archaeology is documenting the nature and timing of maize domestication and dispersals. Here we report a phytolith analysis of sediments from San Andrés, Tabasco, that confirms the spread of maize cultivation to the tropical Mexican Gulf Coast >7,000 years ago ( approximately 7,300 calendar years before present). We review the different methods used in sampling, identifying, and dating fossil maize remains and compare their strengths and weaknesses. Finally, we examine how San Andrés amplifies the present evidence for widespread maize dispersals into Central and South America. Multiple data sets from many sites indicate that maize was brought under cultivation and domesticated and had spread rapidly out of its domestication cradle in tropical southwest Mexico by the eighth millennium before the present.     

Sex, gestational age, and weight dependancy of adult hemoglobin concentration in normal newborns

We have measured by cation exchange high pressure liquid chromatography adult hemoglobin (HbA) concentration at birth in 6,123 unselected single newborn individuals. Probably because of the high precision of the analytical method used, we could demonstrate clear a relationship between HbA concentration and, respectively, gestational age and birth weight. We also demonstrated a significant difference in the Hb switching process between male and female newborns. Reference percentile distribution curves are given that could be used to define more precisely those children having slow or fast Hb switching.     

Prediction of body composition by age, height, weight, and skinfold thickness in normal adults

In order to establish an easy and reliable method for estimating body composition, the lean body mass (LBM) and the fat mass (FM) were measured in vivo in 228 normal adults (130 women and 98 men) using dual photon (153Gd) absorptiometry. In addition, skinfold thickness was measured at two sites in each subject. Multiple regression equations of LBM and FM based on age, height, and weight were computed (r = .86 to .95, SEE = 2.1 to 2.9 kg). These correlations were only slightly improved in men, but not in women, when the results of the skinfold measurements were included in the calculations. We conclude that LBM and FM can be estimated in normal adults from age, height, and weight with a predictive error below 3 kg.     

The normal pediatric Frank orthogonal electrocardiogram: influence of weight, height and chest circumference

The influence of body weight, height and chest circumference on the pediatric Frank vectorcardiogram (VCG) was investigated in a population of 1317 normal infants, children and adolescents. Simple linear regression analysis showed that 94, 96 and 57 VCG variables were significantly correlated with weight, height and chest circumference, respectively. These numbers were reduced to 10, 18 and 6 VCG variables after a stepwise multiple correlation analysis. The relationship between the VCG and the somatic variables was also studied in ten different age/sex subgroups. Simple regression analysis showed a residual significant correlation between the VCG and all three somatic variables in each group. The multiple correlation analysis allowed us to define a minimum set of VCG variables, from one to six, which could explain all the variation produced by the somatic variables. The coefficient of multiple correlation between VCG and weight was the highest in babies 0 to 6 months old (R = 0.73). For height, the strongest correlation was found in females two to five years old (R = 0.76). In subjects older than two years of age, the correlation between chest circumference and VCG (R = 0.30 to 0.69) was weaker than between VCG and pediatric VCG after stratification for age and sex, especially in the youngest groups.     

Urinary organic acids in normal full-term newborns aged 1-7 days

urinary organic acid metabolite excretion patterns in normal newborns aged 1 to 7 days were analysed by GC and MS. Statistical analysis showed significantly different relationships between metabolite excretion, age, sex and feed. The data provide a necessary background for the diagnosis of inborn errors or organic acid metabolism.     

Urinary organic acids in normal full-term newborns aged 1–7 days

Urinary organic acid metabolite excretion patterns in normal newborns aged 1 to 7 days were analysed by GC and MS. Statistical analysis showed significantly different relationships between metabolite excretion, age, sex and feed. The data provide a necessary background for the diagnosis of inborn errors of organic acid metabolism.     

A search for anomalies in the zeta, alpha, beta, and gamma globin gene arrangements in normal black, Italian, Turkish, and Spanish newborns

Globin gene mapping analyses of DNA from numerous Black babies, and from newborns from Sardinia, Sicily, Turkey, and Spain have identified the following: A high incidence of alpha-thalassemia-2 heterozygotes among Black babies with less than 1% Hb Bart's at birth and a high incidence of alpha-thalassemia-2 among Sardinians, but not among Sicilian, Turkish, and Spanish babies. A relatively high incidence of zeta-thalassemia was present among Black babies only, while triplicated zeta was seen in four of the five populations. Two Black babies were each found to have a different theta 1 deletion; two Sardinian babies had a newly discovered approximately 2.5 kb deletion between zeta and psi zeta; four babies had the rare Bgl II polymorphism between psi zeta and psi alpha; and one Black baby lacked the Eco RI site 3' to zeta. Quantitation of the zeta chain by reversed phase high performance liquid chromatography showed that two-thirds of the babies with four alpha genes (alpha alpha/alpha alpha) had levels between 0.1 and 1.0%, while nearly 90% of the babies with -alpha/alpha alpha had similar levels (averaging 0.2% for alpha alpha/alpha alpha; 0.35% for -alpha/alpha alpha; 0.75% for -alpha/-alpha). Additional data indicated that the occurrence and level of zeta are related to the level of beta, i.e. the gestational age. The presence of a zeta triplication did not affect the level of zeta in cord blood. The extensive search for gamma-globin gene anomalies resulted in the discovery of a chromosome with five gamma genes. gamma-Thalassemia was rare in all populations, while the -G gamma-G gamma- gene arrangement was mainly observed among Black babies; this arrangement is primarily responsible for high G gamma levels in cord blood samples. The strong correlation between the presence or absence of a C----T mutation at position -158 (measured in Xmn I digests) and the level of G gamma was confirmed for adult blood samples. A search for possible anomalies in the -delta-beta- region through gene mapping with Eco RV gave negative results except for the discovery of a polymorphic site 5' to delta in one of the 371 Black babies tested.     

Weight of normal parathyroid glands in patients with parathyroid adenomas

Although the size and weight of a parathyroid gland are frequently the only intraoperative determinants of abnormality, these parameters have not been examined in living patients with primary hyperparathyroidism (PHP). The records of 240 patients who underwent parathyroidectomy according to standard surgical practice by a single surgeon were reviewed to identify those who were euparathyroid after in toto removal of a histologically confirmed normal gland and a histologically confirmed adenoma. The 25 (86%) females and 4 (14%) males who met the study criteria had a mean age of 60 yr (range, 33-82 yr). The mean PTH level was 130.1 pg/ml (range, 58-278) before parathyroidectomy and 32.4 pg/ml (range, 1-68) after parathyroidectomy. The mean calcium level was 11.1 mg/dl (range, 10-14) before and 8.7 mg/dl (range, 8-10) after parathyroidectomy. Thirty-four intact normal glands were removed and available for analysis. Their mean weight was 62.4 +/- 31.6 mg (range, 18-161 mg), and 15 (44%) weighed 60 mg or more. The mean weight of the adenomas was 553.7 +/- 520.5 mg (range, 66-2536). Adenomas were clearly distinguished from normal glands by cellularity, stromal fat, and intracellular fat in chief cells. The weight of normal parathyroid glands removed at surgery in patients with PHP may be greater than that reported in autopsy studies. Therefore, certain histological features are a better measure than weight in determining whether a gland is normal, and intraoperative identification of slightly enlarged glands should not lead to immediate subtotal parathyroidectomy.     

Craniotabes in normal newborns: the earliest sign of subclinical vitamin D deficiency

CONTEXT: Craniotabes in otherwise normal neonates has been regarded as physiological and left untreated. OBJECTIVE: Our objective was to investigate the role of vitamin D deficiency in the development of craniotabes in normal neonates. DESIGN AND SETTING: Newborn screening of craniotabes was conducted at the single largest obstetrical facility in Kyoto, Japan. Follow-up study at 1 month was conducted at Kyoto University Hospital. SUBJECTS: A total of 1120 consecutive normal Japanese neonates born in May, 2006, through April, 2007, were included in the study. MAIN OUTCOME MEASURES: The incidence of craniotabes was scored each month. Neonates with craniotabes were followed up at 1 month with measurements of serum calcium, phosphorus, alkaline phosphatase (ALP), intact PTH, 25-OH vitamin D (25-OHD), urinary calcium, phosphorus, creatinine, and hand x-rays. RESULTS: Craniotabes was present in 246 (22.0%) neonates, and the incidence had obvious seasonal variations, highest in April-May and lowest in November. At 1 month, infants with craniotabes had significantly higher serum ALP compared with normal neonates; 6.9% of them had elevated intact PTH over 60 pg/ml, and 37.3% had 25-OHD less than 10 ng/ml. When separately analyzed according to the method of feeding, 56.9% of breast-fed infants showed 25-OHD less than 10 ng/ml, whereas none of formula/mixed-fed infants did, and breast-fed infants had significantly higher serum PTH and ALP compared with formula/mixed-fed infants. SUMMARY: These results suggest that craniotabes in normal neonates is associated with vitamin D deficiency in utero, and the deficiency persists at 1 month in many of them, especially when breast-fed.     

Plasma immunoreactive thyrotropin releasing hormone (TRH) values in normal newborns.

The study reported here extends investigation on the pituitary thyroid axis in newborn infants, including the assay of plasma immunoreactive TSH levels at different intervals after delivery. Blood samples were collected at birth and after 30, 60, 120 minutes, 6, 24 and 48 hours. Plasma TRH levels were also estimated in normal adult subjects and pregnant women. No significant difference was observed with regard to sex, pregnancy or age, except for a marked increase in newborn infants after delivery. Plasma TRH values, already moderately high at birth (mean 46 pg/ml, range 34-57) reached rapidly a peak of 78 pg/ml (range 60-93) 30 minutes after delivery, decreased rapidly between 30 minutes and 2 hours post-partum, then fell gradually to normal range at 24 hours. A comparison of plasma TRH and TSH levels measured simultaneously suggests that the acute TSH surge at delivery is mediated by TRH secretion.