The [4 + 3]-cycloaddition/quasi-Favorskii process. Synthesis of the carbocyclic core of tricycloclavulone

[reaction: see text] The [4 + 3]-cycloadduct derived from the reaction of 2,5-dibromocyclopentanone with cyclopentadiene was converted via a quasi-Favorskii rearrangement and ring-opening, ring-closing metathesis sequence to the carbocyclic core of the prostanoid tricycloclavulone.

Endocrine Abnormalities in Patients with Frontoethmoidal Encephalomeningocele

BACKGROUND

Frontoethmoidal encephalomeningocele (FEEM) is a congenital neural tube defect which is more common in Southeast Asia. Its etiology is unknown. No one has ever reported endocrine abnormalities in this condition.

METHOD

We retrospectively reviewed medical records of 84 patients with FEEM, primarily focused on the clinical data suggestive of endocrine disorders including growth parameter, thyroid function test, serum electrolyte and serum osmolality.

RESULTS

Nasoethmoidal was the most common subtype found in this study. Sixty-four percent of our patients had their heights below the mean height of normal Thai children. The incidence of hypothyroidism (1:28), central DI (1:42) and GHD (1:42) were higher than that in the general population.

CONCLUSION

A significant number of patients with FEEM had clinical evidences suggestive of hypothalamopituitary insufficiency. Appropriate replacement therapy is mandatory in order to prevent untoward complications.

The Addition of sp2- and sp-Hybridized Nucleophiles to a Bridgehead Bromoketone

The reaction of various sp2- and sp-hybridized organolithium species with bromoketone 1 is presented. In most cases, control over the course of the process is possible and products from simple addition, addition followed by a quasi-Favorskii rearrangement or addition, rearrangement, and addition can be selectively prepared.

New Synthesis of Benzothiazines and Benzoisothiazoles Containing a Sulfoximine Functional Group

The reaction of S-2-bromophenyl-S-methylsulfoximine with terminal alkynes in the presence of a palladium catalyst resulted in the formation of both 1,2-benzothiazines and 1,2-benzoisothiazoles. A preference for the former was seen with alkylalkynes, while the latter were preferentially formed with alkynylarenes.

Pallister-Hall syndrome with hypoparathyroidism

We report on a 5 2/12 year-old boy who presented with convulsions, precocious puberty due to a 1.9 x 1.9 x 1.6 hypothalamic hamartoma of the tuber cinereum, and some dysmorphic features including polysyndactyly of hands and feet, suggesting the diagnosis of Pallister-Hall syndrome. Hypocalcemia due to hypoparathyroidism was demonstrated, and this combination has not been reported previously. Therefore, we can add hypoparathyroidism as another feature of Pallister-Hall syndrome.

Asymmetric organocatalysis of 4 + 3 cycloaddition reactions

Treatment of several 4-trialkylsilyloxypentadienals with a chiral secondary amine, trifluoroacetic acid, and a diene resulted in the formation of 4 + 3 cycloaddition products, which were enantiomerically enriched. This represents the first examples of the asymmetric organocatalysis of the 4 + 3 cycloaddition reaction. 2,5-Dimethylfuran reacted with 4-trimethylsilyloxy-2,4-pentadienal in the presence of catalytic amounts of chiral amine and acid to afford a cycloadduct in 64% yield as a single diastereomer with an enantiomeric excess of 89%.

Substitution of a bridgehead bromide by primary organolithium reagents

The reaction of ketone 1 with primary organolithium reagents in THF/HMPA affords not the expected carbonyl addition product but the product of bromide substitution, in reasonable yield.

Clinical and molecular characteristics of Thai patients with achondroplasia

Achondroplasia is an autosomal dominant disorder characterized by disproportionately short stature, frontal bossing, rhizomelia, and trident hands. Most patients appear sporadically resulting from a de novo mutation associated with advanced paternal age. A glycine to arginine mutation at codon 380 (G380R) of the fibroblast growth factor receptor 3 gene (FGFR3) was found to be the most common cause of achondroplasia in various populations. We identified and clinically characterized 3 Thai patients with achondroplasia. In all of them, we also successfully identified the G380R mutation supporting the observation that this is the most common mutation in achondroplasia across different ethnic groups including Thai.

Does GnRH analog improve the final height in Thai girls with idiopathic central precocious puberty?

Ten Thai girls with idiopathic central precocious puberty (ICPP) were treated with gonadotrophin releasing hormone (GnRH) analog for a mean period of 1.5+/-0.4 years. The predicted adult height at the end of treatment was significantly higher than that at the start of treatment (158.2+/-7.9 vs 153.0+/-8.7 cm, p=0.009). In addition, treatment with GnRH analog could significantly regress the breast staging from 3.4+/-0.8 to 2.6+/-1.0 (p=0.04),but not the pubic hair staging. Five of them reached a final height which was not significantly higher than the predicted adult height before treatment (153.1+/-4.8 vs 150.7+/-1.0 cm, p=0.5). In conclusion, treatment with GnRH analog in Thai girls with ICPP can improve the predicted adult height and regress the breast staging. However, the improvement of final height is not promising.

A cost-benefit of gnRH stimulation test in diagnosis of central precocious puberty (CPP)

The GnRH stimulation test is the gold standard to diagnose central precocious puberty (CPP). Conventionally, we need at least 2 hours to finish the test which seems to be costly and time consuming. In this study, we described the pattern of LH and FSH levels during the GnRH test in 27 girls who presented with various degrees of precocious puberty. We found that the blood samples at 90 and 120 min after GnRH were not necessary. To save the cost of diagnosis, the basal LH/FSH ratio > 0.2, the 30 min LH/FSH ratio after GnRH > 0.9 and the peak LH/FSH ratio > 1.0 can be used to diagnose CPP with positive predictive values (PPV) of 87.3, 89.4 and 93.8 per cent respectively.

Establishing gas chromatography-mass spectrometry to diagnose organic acidemias in Thailand

Disorders of organic acid metabolism are a group of disorders which has long been ignored by majority of Thai physicians. Part of this is due to lack of laboratories in Thailand to verify the diagnosis of the disorders. We have recently developed a technique to qualitatively analyze organic acids utilizing Gas Chromatography-Mass Spectrometry (GC-MS). Eight patients in four families were successfully identified as having organic acidemias (OA) by this method. Two families had methylmalonic acidemia, one had propionic acidemia, and the other had 3-methylcrotonyl CoA carboxylase deficiency. To our knowledge, this is the first laboratory in Thailand being able to use GC-MS to diagnose OA. Availability of a laboratory in Thailand and affordability of the test are expected to result in earlier diagnosis and identification of more cases of OA in Southeast Asian countries. Consequently, prompt and proper treatment can be anticipated which should lead to better prognosis for patients with this group of disorder.

Measurement of serum free IGF-I in diagnosis of growth hormone deficiency

Serum levels of total insulin-like growth factor-I (IGF-I) are growth hormone (GH) dependent and can be used as the screening tool for GH deficient status. However, most of them are bound to IGF-binding proteins, leaving less than 1 per cent in the free or unbound forms which represent the active biological fractions. Serum free IGF-I levels were measured by radioimmunoassay (IRMA) in 48 short children with various conditions. We found that the means +/- SEM of free IGF-I in children with panhypopituitarism (PAN) and complete growth hormone deficiencies (cGHD) were significantly lower than those in sex and age matched normal children (0.02 +/- 0.01 vs 2.01 +/- 0.7 ng/ml, p = 0.0006 and 0.42 +/- 0.18 vs 1.72 +/- 0.27 ng/ml, p = 0.0007 respectively) but not in children with partial growth hormone deficiencies (pGHD) (0.91 +/- 0.3 vs 1.97 +/- 0.4 ng/ml, p = 0.27) and idiopathic short stature (ISS) (0.94 +/- 0.3 vs 1.95 +/- 0.6 ng/ml, p = 0.13). However, when we classified the pGHD children into 2 groups according to IGFBP-3 SDS for normal Thai children, we found that the mean of free IGF-I levels in pGHD children with IGFBP-3 SDS < or = -1.3 was significantly lower than that of the controls. (0.68 +/- 0.55 vs 2.66 +/- 0.71 ng/ml, p = 0.04) In conclusion, the measurement of free IGF-I level can be used to evaluate the GH status of short children and might be used as a guide when starting treatment.

Responsiveness of IGF-I and IGFBP-3 to therapeutic intervention in children and adolescents with Crohn's disease

OBJECTIVE

Abnormal linear growth is common in childhood and adolescent Crohn's disease. We have studied the concentrations of the inflammatory marker CRP and of serum IGF-I and IGFBP-3 in patients with active Crohn's disease and have assessed the changes in these parameters during therapeutic intervention with enteral nutrition or intestinal resection.

DESIGN

Children and adolescents attending the inflammatory bowel disease clinic at our hospital underwent treatment either with enteral nutrition (Study A) or intestinal resection (Study B). These are two separate studies and the results cannot be compared. Serum concentrations of CRP, IGF-I and IGFBP-3 were determined at 0, 2, 8 and 16 weeks after start of enteral nutrition and in addition to height velocity, at 0 and 6 months after intestinal resection.

SUBJECTS

Study A: 14 patients, 9 male, 5 female, median age 12.5 years (range 7.0-17.2), puberty stage 1 (n = 13), stage 3 (n = 1). All had active Crohn's disease. Study B: 9 patients, 7 male, 2 female, median age 13.5 years (range 7.8-16.5), puberty stage 1 (n = 5), stages 2-4 (n = 4). All had Crohn's disease resistant to medical therapy.

METHODS

Crohn's disease was confirmed radiologically, endoscopically and histologically. Disease activity was scored using the Lloyd Still index (LSI). Study A: nutritional support was with a polymeric, casein-based formula feed AL 110. Study B: surgical procedures were small bowel resection (n = 2), right hemicolectomy (n = 5), subtotal colectomy (n = 2).

MEASUREMENTS

Study A: weight SDS, CRP, IGF-1 and IGFBP-3 were measured at 0, 2, 8, 16 weeks after start of enteral feeding. Study B: height velocity, CRP, IGF-I and IGFBP-3 were measured 0, 6 months after intestinal resection.

STATISTICAL ANALYSIS

Medians and ranges were used. Significance of changes was calculated using the Wilcoxon rank test for the analysis of paired data.

RESULTS

Study A: median LSI before treatment was 39 and increased after 8 weeks of enteral nutrition to 60 (P < 0.05). Weight SDS increased at 8 and 16 weeks (P < 0.05) compared to pretreatment. CRP was elevated at 0 weeks, falling during treatment. Median (range) values (normal < 5 mg/l) at 0 at 2, 8, 16 weeks were 53 mg/l (15-150), 8 mg/l (5-25), 7 mg/l (5-83) and 14 mg/l (5-39), all P < 0.001 compared with pretreatment. Median IGF-I-values increased during treatment. Median (range) values at 0, 2, 8, 16 weeks (all P < 0.005) compared to pretreatment, median (range) values at 0, 2, 8, 16 weeks were 78 micrograms/l (50-204), 131 micrograms/l (73-251), 119 micrograms/l (77-291) and 133 micrograms/l (67-497), all P < 0.005 compared to pre-treatment. IGFBP-3 levels increased during treatment. Median (range) values at 0, 2, 8, 16 weeks were 2.4 mg/l (1.4-3.1), 2.9 mg/l (1.8-4.6), 3.0 mg/l, 3.2 mg/l (1.8-4.5), all P < 0.01 compared to pretreatment. Study B: height velocity increased during 6 months after surgery. Median (range) values; 3.3 cm/year (0-8.3) before surgery, 8.4 cm/year (2-12.6) 6 months post-surgery, P < 0.01. Median (range) CRP values fell from 45 mg/l (5-150) to 8 mg/l (5-31) and IGF-I-values increased from 163 micrograms/l (64-286) to 226 micrograms/l (71-391). These changes were not statistically significant. IGFBP-3 values did not change.

CONCLUSION

The IGF system, as shown by serum IGF-I and IGFBP-3, is responsive to therapeutic intervention in active Crohn's disease. It is likely that a combination of decreased inflammatory activity and improved nutrition contributes to these changes.

Thyroid scintigraphy in children with hypothyroidism: a five-year experience

The presence or absence of thyroid glandular tissue demonstrated by thyroid scintigraphy is important for genetic and prognostic counseling and for acceleration of diagnosis in other affected siblings. Technetium-99m-pertechnetate thyroid scintigraphy was performed on 27 children with cretinism at the Division of Nuclear Medicine, Faculty of Medicine Siriraj Hospital during the 5-year period from June 1991. Based on scintigraphic findings, three main groups of thyroid localization were seen. Thirteen (48.1%) were athyrotic while 3 (11.1%) had an ectopic thyroid and 11 (40.8%) had gland in normal position. Perchlorate discharge test was performed in 8 children of the last group and the results were positive indicating an organification defect. Thyroid scintigraphy and perchlorate discharge test provided the useful information for diagnosis, follow-up, and prognosis in children with cretinism.

Serum IGF-I and IGFBP-3 levels for normal Thai children and their usefulness in clinical practice

Serum IGF-I and IGFBP-3 levels are growth hormone (GH) dependent and reflect the endogenous GH secretion. Two hundred and forty-four healthy children were evaluated for serum IGF-I and IGFBP-3 levels and then the age-defined normal values for Thai children were constructed. The results showed that the serum IGF-I and IGFBP-3 levels were age dependent, gradually increased from birth and reached the peak values around the age of 14-16 years. In addition, we studied the IGF-I and IGFBP-3 values in 28 GH deficient children and 26 normal variant short stature (NVSS) by using our normal constructed values as the reference. To minimize the influence of age, both IGF-I and IGFBP-3 values were transformed to standard deviation score (SDS). In clinical practice, we recommend using the IGF-I SDS and IGFBP-3 SDS of -1 and -1.3 respectively as a cut-off point to discriminate between GH deficiency and NVSS to avoid risky GH provocative tests and unnecessary GH replacement with the sensitivity of 71 per cent and the specificity of 92 per cent.

Normal growth hormone secretion in growth hormone insufficient children retested after completion of linear growth

OBJECTIVE

The recognition of the syndrome of adult GH deficiency suggests that young GH deficient adults, deprived of GH replacement at completion of linear growth, may suffer effects of GH deficiency. We assessed GH reserve in young adults previously diagnosed as having idiopathic GH insufficiency, who were treated with hGH replacement (14 IU/m2/week) in childhood.

DESIGN

Eight patients (7 males, 1 female) diagnosed as having GH insufficiency by insulin tolerance test (ITT) in childhood (ages 8.5-15.6 years) were retested by ITT at completion of linear growth (ages 15.1-19.6 years), 3 months after discontinuation of hGH therapy.

MEASUREMENTS

GH reserve was measured during ITT at diagnosis and at retesting. Height velocity (HV) and HV SDS were calculated before and during GH therapy.

RESULTS

At diagnosis, the mean peak GH response to ITT was 10.5 +/- 2.0 mU/l (range 7.7-13.6). At retesting, mean GH was 52.4 +/- 33.2 mU/l (range 10.4-100), 7/8 subjects having peak GH levels greater than 15 mU/l. During hGH therapy mean HV increased from 4.0 +/- 1.5 cm/year at diagnosis to 7.3 +/- 1.9 cm/year during the 1st year (P = 0.004) and 6.9 +/- 2.3 cm/year during the 2nd year (P = 0.02). Mean HVSDS increased from -1.6 +/- 2.1 at diagnosis to 3.1 +/- 2.9 during the 1st year (P = 0.004) and 2.2 +/- 4.2 during the 2nd year (P = 0.05, NS) of treatment.

CONCLUSIONS

Seven out of 8 children diagnosed as having idiopathic GH insufficiency had normal GH secretion at completion of linear growth. Children with GH insufficiency cannot be assumed to become GH deficient adults and should not continue on GH therapy into adult life without reinvestigation. All who were GH insufficient children should be retested at completion of linear growth to identify those who are truly GH insufficient adults and may benefit from replacement therapy.

Treatment of constitutional growth delay in prepubertal boys with a prolonged course of low dose oxandrolone

Forty six prepubertal boys who had constitutional growth delay were treated with oxandrolone. Mean age at the onset of treatment was 11.9 years (range 9.0-14.0) and bone age delay was 1.9 'years'. The dose of oxandrolone used was a mean of 0.05 mg/kg (range 0.03-0.18) for a mean of 0.9 years (range 0.2-3.6). Height velocity increased from a mean (SD) before treatment of 4.0 (1.0) to 7.5 (1.2) cm/year with oxandrolone. Growth rate was sustained at 7.6 (2.2) cm/year in the period after treatment. Those boys who attained a testicular volume of 4 ml or greater at the end of the treatment period had the most pronounced sustained growth acceleration. Height for bone age SD score did not alter significantly from a mean of -1.0 before treatment to -1.2 after treatment. Oxandrolone is a safe and effective treatment for prepubertal boys with constitutional growth delay.