Normocortisolemic Cushing's syndrome initially presenting with increased glucocorticoid receptor numbers.

A girl who developed Cushingoid features in peripuberty, but was eucortisolemic, was previously reported to have markedly elevated lymphocyte glucocorticoid receptor sites per cell with normal binding affinity as a potential cause of her phenotype. Her circadian rhythm of cortisol and pituitary-adrenal axis were initially intact, but later proved to be dysregulated. The patient presented at age 10.8 yr with centripetal obesity, moon facies, buffalo hump, and purple striae, but no statural stunting, which is a cardinal sign of Cushing's syndrome. At 11.5 yr she suffered a compression fracture of the L1 vertebra. That prompted treatment with the antiprogestin drug mifepristone (RU486), which was administered at high dose to achieve an antiglucocorticoid effect. From ages 13.75 yr through 15.5 yr, RU486 was administered in various intervals to suppress her Cushingoid features. Once RU486 was introduced, however, a consistent correlation over time between the Cushingoid features and glucocorticoid receptor sites per cell was no longer observed. However, the number of glucocorticoid receptor sites per cell tended to decrease in response to administering RU486. Ultimately, her Cushingoid phenotype proved to be transient.

Bone mineral density in young adult survivors of childhood cancer.

PURPOSE: Childhood cancer and its treatment can affect normal bone accretion. In this study, bone mineral density (BMD) in young adult survivors of childhood cancer is assessed to determine what cancer-related factors, patient characteristics, or treatment-related complications correlate with reductions in BMD. PATIENTS AND METHODS: The study population consisted of 40 (24 women) long-term survivors of childhood cancer treated at the Memorial Sloan-Kettering Cancer Center for a solid tumor (n = 16), lymphoma (n = 14), or acute leukemia (n = 10) at a mean age of 12.7 +/- 0.96 years and evaluated at a mean age of 25.8 +/- 0.7 years. Dual energy X-ray absorptiometry was used to determine BMD of the lumbar spine, femoral neck, and total body and single photon absorptiometry was used to determine BMD of the distal radius. RESULTS: The mean BMD standard deviation score (SDS) for the patients was significantly reduced compared to controls at the distal radius (-1.57 +/- 0.18, p = 0.0001), femoral neck (-0.68 +/- 0.20, p = 0.00014), and total body (-0.33 +/- 0.15, p = 0.03) but not at the lumbar spine (-0.22 +/- 0.22, p = 0.33). Univariate analysis revealed that gonadal dysfunction (i.e., estrogen or testosterone insufficiency) (p = 0.018) was the only variable that correlated with a reduced BMD. CONCLUSION: Young adult survivors of childhood cancer have reduced BMD. Because age at study coincides with the normal age of attainment of peak bone mass and peak bone mass is a major determinant of BMD later in life, many of these patients are at increased risk for osteoporosis and fractures.

Defects in the HSD11 gene encoding 11 beta-hydroxysteroid dehydrogenase are not found in patients with apparent mineralocorticoid excess or 11-oxoreductase deficiency.

The syndrome of apparent mineralocorticoid excess (AME) is a form of low renin hypertension that is thought to be caused by congenital deficiency of 11 beta-hydroxysteroid dehydrogenase (11HSD) activity. This enzyme converts cortisol to cortisone and apparently prevents cortisol from acting as a ligand for the mineralocorticoid (type I) receptor. It also catalyzes the reverse oxoreductase (cortisone to cortisol) reaction. Four patients with AME and the parents of the first patient described (now decreased) were analyzed for mutations in the cloned HSD11 gene encoding an 11HSD enzyme. A patient with suspected cortisone reductase deficiency was also studied. No gross deletions or rearrangements in the HSD11 gene were apparent on hybridizations of blots of genomic DNA. Direct sequencing of polymerase chain reaction-amplified fragments corresponding to the coding sequences, intronexon junctions, and proximal untranslated regions of this gene revealed no mutations. AME may involve mutations in a gene for another enzyme with 11HSD activity or perhaps another cortisol-metabolizing enzyme.

Congenital adrenal hyperplasia. Molecular insights learned from patients.

Congenital adrenal hyperplasia (CAH) results from enzymatic blocks in the synthesis of cortisol. All enzyme defects causing CAH are autosomal recessive traits. It is a relatively common disease, occurring in 1 in 5000 to 1 in 15,000 births in most populations. Since the isolation of the gene responsible for steroid 21-hydroxylase deficiency (involved in about 90% of the cases of CAH) in 1984, knowledge of the specific mutations that cause the different forms of CAH has grown rapidly. Mutations in the encoding gene have been confirmed as the basis of endocrine disease in the case of all of the adrenal steroidogenic enzymes required for synthesis of cortisol but one (cholesterol desmolase). The clinical expression of endocrine disease is not always correlated with the mutations of the primary structural gene. Clinicians cannot accurately predict the course of the disease or make therapeutic decisions based on the genotype alone. We will review the various forms of clinical presentation of CAH, their etiology, diagnosis, molecular genetics, and treatment.

Cefuroxime treatment failure of nontypable Haemophilus influenzae meningitis associated with alteration of penicillin-binding proteins.

A 10-year-old boy presented with nuchal rigidity and cerebrospinal fluid (CSF) leukocytosis initially and again on day 6 of intravenous cefuroxime therapy (200 mg/kg/day). Both CSF specimens yielded nontypable beta-lactamase-negative Haemophilus influenzae that were susceptible by disk tests but relatively resistant to cefuroxime (MIC, 8- to 16-fold greater than that of control isolates). To define the mechanism of resistance, the cefuroxime resistance marker was transformed to a susceptible H. influenzae recipient; inactivation and permeability of beta-lactam substrate were tested and the penicillin-binding protein (PBP) profiles were examined. Inactivation of beta-lactam substrate was not detected and reduced permeability was not found. However, reduced beta-lactam binding to PBPs 4 and 5 was observed; 18- to 27-fold more penicillin and 2.5-to 4-fold more cefuroxime was required to saturate or block 50% of the binding sites of these PBPs, respectively. Thus, reduced affinity of PBPs 4 and 5 for beta-lactam substrate appears to be the mechanism of cefuroxime resistance in this strain. The reduced affinity of these targets appears to have contributed to the bacteriologic and clinical failure in this patient.

Penicillin-binding proteins and ampicillin resistance in Haemophilus influenzae.

Ampicillin-resistant, non-beta-lactamase-producing isolates of Haemophilus influenzae contain a variety of penicillin-binding protein (PBP) patterns that differ from the single pattern of eight PBPs characteristic of susceptible strains. During genetic transformation of resistance, only some of the anomalies in PBP pattern were transformed, specifically those relating to the penicillin-binding capacities of PBPs 4 (Mr of 62,000) and 5 (Mr of 59,000) and, in some transformations, PBP 3 (Mr of 71,000). Comparison of the binding of penicillin by PBPs 4 and 5 of three resistant transformants (derived with DNA from different donors) revealed a decrease in the rate of PBP acylation and no appreciable change in the rate of deacylation as compared to the susceptible recipient. Thus, rapid turnover of these PBPs does not play a role. Retransformation studies confirm that altered PBPs 3, 4, and 5 are associated with resistance and suggest that these PBPs are major targets for the beta-lactam antibiotics in H. influenzae.

Genetic diversity of penicillin G-resistant Neisseria meningitidis from Spain.

Genotypic and phenotypic diversity among 16 penicillin G-resistant (Penr) isolates of Neisseria meningitidis recovered from human blood or cerebrospinal fluid in Spain was compared with that among 12 penicillin-susceptible (Pens) isolates by the use of multilocus enzyme electrophoresis, serotyping, auxotroph testing in chemically defined media, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of penicillin-binding proteins (PBPs). Thirteen distinctive multilocus enzyme genotypes (electrophoretic types [ETs] ) were identified among the 28 isolates. There was slightly less genetic diversity among the eight ETs of Penr isolates (H = 0.385) than among the eight ETs of Pens isolates (H = 0.431). Cluster analysis demonstrated two distinctive complexes of ETs and one ET that was not closely related to either complex. The possibility of a singular clonal origin of penicillin G-resistant isolates was excluded by the observations that resistance occurred in isolates of each of the two distantly related complexes of ETs, that three of the four ETs represented by multiple isolates included both susceptible and resistant strains, and that serotypes and growth requirements were not associated with the resistance phenotype. The 28 isolates showed a relatively homogeneous pattern of four PBPs, with apparently reduced penicillin G binding by PBP 3 of the Penr isolates.