Synthesis of analogs of the Gwt1 inhibitor manogepix (APX001A) and in vitro evaluation against Cryptococcus spp

Fosmanogepix (APX001) is a first-in-class prodrug molecule that is currently in Phase 2 clinical trials for invasive fungal infections. The active moiety manogepix (APX001A) inhibits the novel fungal protein Gwt1. Gwt1 catalyzes an early step in the GPI anchor biosynthesis pathway. Here we describe the synthesis and evaluation of 292 new and 24 previously described analogs that were synthesized using a series of advanced intermediates to allow for rapid analoging. Several compounds demonstrated significantly (8- to 32-fold) improved antifungal activity against both Cryptococcus neoformans and C. gattii as compared to manogepix. Further in vitro characterization identified three analogs with a similar preliminary safety and in vitro profile to manogepix and superior activity against Cryptococcus spp.

(1aR,5aR)1a,3,5,5a-Tetrahydro-1H-2,3-diaza-cyclopropa[a]pentalene-4-carboxylic acid (MK-1903): a potent GPR109a agonist that lowers free fatty acids in humans

G-protein coupled receptor (GPCR) GPR109a is a molecular target for nicotinic acid and is expressed in adipocytes, spleen, and immune cells. Nicotinic acid has long been used for the treatment of dyslipidemia due to its capacity to positively affect serum lipids to a greater extent than other currently marketed drugs. We report a series of tricyclic pyrazole carboxylic acids that are potent and selective agonists of GPR109a. Compound R,R-19a (MK-1903) was advanced through preclinical studies, was well tolerated, and presented no apparent safety concerns. Compound R,R-19a was advanced into a phase 1 clinical trial and produced a robust decrease in plasma free fatty acids. On the basis of these results, R,R-19a was evaluated in a phase 2 study in humans. Because R,R-19a produced only a weak effect on serum lipids as compared with niacin, we conclude that the beneficial effects of niacin are most likely the result of an undefined GPR109a independent pathway.

Potent tricyclic pyrazole tetrazole agonists of the nicotinic acid receptor (GPR109a)

Tricyclic pyrazole tetrazoles which are potent partial agonists of the high affinity niacin receptor, GPR109a, have been discovered and optimized. One of these compounds has proven to be effective at lowering free fatty acids in vitro and in vivo.

3-(1H-tetrazol-5-yl)-1,4,5,6-tetrahydro-cyclopentapyrazole (MK-0354): a partial agonist of the nicotinic acid receptor, G-protein coupled receptor 109a, with antilipolytic but no vasodilatory activity in mice

The discovery and profiling of 3-(1H-tetrazol-5-yl)-1,4,5,6-tetrahydro-cyclopentapyrazole (5a, MK-0354), a partial agonist of GPR109a, is described. Compound 5a retained the plasma free fatty acid lowering effects in mice associated with GPR109a agonism, but did not induce vasodilation at the maximum feasible dose. Moreover, preadministration of 5a blocked the flushing effect induced by nicotinic acid but not that induced by PGD2. This profile made 5a a suitable candidate for further study for the treatment of dyslipidemia.

3-Nitro-4-amino benzoic acids and 6-amino nicotinic acids are highly selective agonists of GPR109b

A series of 3-nitro-4-substituted-aminobenzoic acids were prepared and found to act as potent and highly selective agonists of the orphan human GPCR GPR109b, a low affinity receptor for niacin. No activity was observed at the closely homologous high affinity niacin receptor, GPR109a. A second series, comprising 6-amino-substituted nicotinic acids was, also prepared and several analogues showed comparable activity to the nitroaryl series.

Fluorinated pyrazole acids are agonists of the high affinity niacin receptor GPR109a

A series of 5-alkyl pyrazole-3-carboxylic acids were prepared and found to act as potent and selective agonists of the human GPCR, GPR109a, the high affinity nicotinic acid receptor. No activity was observed at the highly homologous low affinity niacin receptor, GPR109b. A further series of 4-fluoro-5-alkyl pyrazole-3-carboxylic acids were shown to display similar potency. One example from the series was shown to have improved properties in vivo compared to niacin.

Agonist lead identification for the high affinity niacin receptor GPR109a

A strategy for lead identification of new agonists of GPR109a, starting from known compounds shown to activate the receptor, is described. Early compound triage led to the formulation of a binding hypothesis and eventually to our focus on a series of pyrazole acid derivatives. Further elaboration of these compounds provided a series of 5,5-fused pyrazoles to be used as lead compounds for further optimization.

1-Alkyl-benzotriazole-5-carboxylic acids are highly selective agonists of the human orphan G-protein-coupled receptor GPR109b

1-Substituted benzotriazole carboxylic acids have been identified as the first reported examples of selective small-molecule agonists of the human orphan G-protein-coupled receptor GPR109b (HM74), a low-affinity receptor for the HDL-raising drug niacin. No activity was observed at the highly homologous high-affinity niacin receptor GPR109a (HM74A). The high degree of selectivity was attributed to a difference in the amino acid sequence adjacent to a key arginine-ligand interaction allowing somewhat larger ligands to be tolerated by GPR109b.

Analysis of mutations and bone marrow micronuclei in Big Blue rats fed leucomalachite green

Leucomalachite green (LMG) is the major metabolite of malachite green (MG), a triphenylmethane dye that has been used widely as an antifungal agent in the fish industry. Concern over MG and LMG is due to the potential for consumer exposure, suggestive evidence of tumor promotion in rodent liver, and suspicion of carcinogenicity based on structure-activity relationships. In order to evaluate the risks associated with exposure to LMG, female Big Blue rats were fed up to 543 ppm LMG; groups of these rats were killed after 4, 16, or 32 weeks of exposure and evaluated for genotoxicity. We previously reported that this treatment resulted in a dose-dependent induction of liver DNA adducts, and that the liver lacI mutant frequency (MF) was increased, but only in rats fed 543 ppm LMG for 16 weeks. In the present study, we report the results from lymphocyte Hprt mutant assays and bone marrow micronucleus assays performed on these same rats. In addition, we have determined the types of lacI mutations induced in the rats fed 543 ppm LMG for 16 weeks and the rats fed control diet. No significant increases in the frequency of micronuclei or Hprt mutants were observed for any of the doses or time points assayed. Molecular analysis of 80 liver lacI mutants from rats fed 543 ppm LMG for 16 weeks revealed that 21% (17/80) were clonal in origin and that most (55/63) of the independent mutations were base pair substitutions. The predominant type of mutation was G:C --> A:T transition (31/63) and the majority (68%) of these involved CpG sites. When corrected for clonality, the 16-week lacI mutation frequency (36 +/- 10) x 10(-6) in treated rats was not significantly different from the clonally corrected control frequency (17 +/- 9 x 10(-6); P = 0.06). Furthermore, the lacI mutational spectrum in treated rats was not significantly different from that found for control rats (P = 0.09). Taken together, these data indicate that the DNA adducts produced by LMG in female rats do not result in detectable levels of genotoxicity, and that the increase in lacI MF observed previously in the liver of treated rats may be due to the disproportionate expansion of spontaneous lacI mutations.

Superior mesenteric artery syndrome following surgery for scoliosis

STUDY DESIGN

A retrospective report of three cases outlining upper intestinal obstruction as a rare complication following surgery for scoliosis.

OBJECTIVE

To present the clinical features, progression, and management of duodenal obstruction due to superior mesenteric artery compression after surgical treatment of scoliosis.

SUMMARY OF BACKGROUND DATA

Superior mesenteric artery or cast syndrome has been reported historically in the literature. Many causes are described, among which is the complication of the surgical and nonoperative treatment of scoliosis.

METHODS

Three adolescent patients were investigated for nausea and vomiting following surgical correction of scoliosis.

RESULTS

Contrast radiography confirmed extrinsic obstruction of the third part of the duodenum by the superior mesenteric artery in all three patients. They were jointly managed with the gastrointestinal surgeons. Two patients recovered with conservative treatments, but the third required operative intervention with a laparotomy.

CONCLUSIONS

Vomiting following surgery for scoliosis should be investigated thoroughly, as superior mesenteric artery syndrome carries significant morbidity, protracted hospital stay, and potential mortality.

Mutagenicity and carcinogenicity in relation to DNA adduct formation in rats fed leucomalachite green

Leucomalachite green is a persistent and prevalent metabolite of malachite green, a triphenylmethane dye that has been used widely as an antifungal agent in the fish industry. Concern over the use of malachite green is due to the potential for consumer exposure, evidence suggestive of tumor promotion in rodent liver, and suspicion of carcinogenicity based on structure-activity relationships. Our previous study indicated that feeding rodents malachite or leucomalachite green resulted in a dose-related increase in liver DNA adducts, and that, in general, exposure to leucomalachite green caused an increase in the number and severity of changes greater than was observed following exposure to malachite green. To characterize better the genotoxicity of leucomalachite green, female Big Blue rats were fed leucomalachite green at doses of 0, 9, 27, 91, 272, or 543 ppm for up to 32 weeks. The livers were analyzed for lacI mutations at 4, 16, and 32 weeks and DNA adducts at 4 weeks. Using a 32P-postlabeling assay, we observed a dose-related DNA adduct in the livers of rats fed 91, 272, and 543 ppm leucomalachite green. A approximately 3-fold increase in lacI mutant frequency was found in the livers of rats fed 543 ppm leucomalachite green for 16 weeks, but significant increases in mutant frequencies were not found for any of the other doses or time points assayed. We also conducted 2-year tumorigenesis bioassays in female and male F344 rats using 0, 91, 272, and 543 ppm leucomalachite green. Preliminary results indicate an increasing dose trend in lung adenomas in male rats treated with leucomalachite green, but no increase in the incidence of liver tumors in either sex of rat. These results suggest that the DNA adduct formed in the livers of rats fed leucomalachite green has little mutagenic or carcinogenic consequence.

Iliopsoas hematoma with femoral neuropathy presenting a diagnostic dilemma after spinal decompression

STUDY DESIGN

Case report of an iliopsoas hematoma with femoral neuropathy appearing 8 weeks after a posterior spinal decompression procedure.

OBJECTIVES

To describe a potential complication and differential diagnosis for nerve root symptoms following spinal decompression.

SUMMARY OF BACKGROUND DATA

Iliopsoas hematoma is usually a complication of anticoagulation, hemophilia, or trauma. It has not been described previously as a complication of posterior spinal decompression. Femoral neuropathy results from compression within the iliopsoas compartment.

METHODS

A 53-year-old woman reported pain in the right side of her groin and an increasing fixed flexion deformity of the right hip 8 weeks after a posterior, midline, spinal decompression. A femoral neuropathy later developed. Magnetic resonance imaging and computed tomography were performed.

RESULTS

Imaging studies demonstrated a diffusely enlarged iliopsoas. Exploration revealed a large hematoma, which was evacuated. The compartment was fully decompressed with resolution of the nerve root symptoms within 48 hours.

CONCLUSIONS

Iliopsoas pathology is a rare cause of nerve root symptoms and presented diagnostic difficulties after an apparently successful spinal decompression.

The aetiology of idiopathic scoliosis: biomechanical and neuromuscular factors

The aetiology of idiopathic scoliosis: biomechanical and neuromuscular factors small curve develops due to a small defect in the neuromuscular control system and a second stage during adolescent growth in which the scoliotic curve is exacerbated by biomechanical factors.

A biomechanical analysis of the vertebral and rib deformities in structural scoliosis

Although the structural changes occurring in the scoliotic spine have been reported as early as the 19th century, the descriptions and biomechanical explanations have not always been complete and consistent. In this study, three-dimensionally rendered CT images of two human skeletons with a scoliotic deformity and two patients with serious scoliosis were used to describe the intrinsic vertebral and rib deformities. The pattern of structural deformities was found to be consistent. Apart from the wedge deformation of the apical vertebrae, a rotation deformity was found in the transversal plane between the vertebral body and the posterior complex: the vertebral body was maximally rotated towards the convexity of the scoliotic curve, whereas the tip of the spinous process was pointed to posterior. The rib deformities at the convex side of the scoliotic curve showed an increased angulation of the rib at the posterior angle, whereas the rib curve on the concave side was flattened. The observed vertebral deformities suggest that these are caused by bone remodelling processes due to forces in the anterior spinal column, which drive the apical vertebral body out of the midline, whereas forces of the musculo-ligamentous structures at the posterior side of the spinal column attempt to minimize the deviations and rotations of the vertebrae. The demonstrated rib deformities suggest an adaptation to forces imposed by the scoliotic spine.

Tissue-specific expression of messenger ribonucleic acids for insulin-like growth factors and insulin-like growth factor-binding proteins during perinatal development of the rat uterus

Insulin-like growth factor (IGF)-I and IGF-II play a number of important roles in growth and differentiation, and IGF-binding proteins (IGFBPs) modulate IGF biological activity. IGF-I has been shown previously to be essential for normal uterine development. Therefore, we used in situ hybridization assays to characterize the unique tissue- and developmental stage-specific pattern of expression for each IGF and IGFBP gene in the rat uterus during perinatal development (gestational day [GD]-20 to postnatal day [PND]-24). IGF-I and IGFBP-1 mRNAs were expressed in all uterine tissues throughout this period. IGFBP-3 mRNA was not detectable at GD-20 but became detectable beginning at PND-5, and the signal intensity appeared to increase during stromal and muscle development. IGFBP-4 mRNA was abundant throughout perinatal development in the myometrium and in the stroma, particularly near the luminal epithelium. IGFBP-5 mRNA was abundantly expressed in myometrium throughout perinatal development. IGFBP-6 mRNA was detected throughout perinatal development in both the stroma and myometrium in a diffuse expression pattern. IGF-II and IGFBP-2 mRNAs were not detected in perinatal uteri. Our results suggest that coordinated temporal and spatial expression of IGF-I and its binding proteins (IGFBP-1,-3,-4,-5, and -6) could play important roles in perinatal rodent uterine development.

Maternal diabetes induces upregulation of hepatic insulin-like growth factor binding protein-1 MRNA expression, growth retardation and developmental delay at the same stage of rat fetal development

Since maternal diabetes is associated with fetal growth abnormalities in humans and rats, effects of maternal diabetes on fetal expression of genes regulating growth are of interest. Increased expression of Insulin-Like Growth Factor Binding Protein-I (IGFBP-1) is associated with several examples of growth retardation and is upregulated in response to diabetes. As we have shown previously, IGFBP-1 expression is upregulated in gestational day (GD) 14 rat fetuses in response to maternal diabetes. Here we analyze the effect of streptozotocin-induced maternal diabetes on IGFBP-1 mRNA expression during GD12-16 of rat fetal development, using in situ hybridization. IGFBP-1 mRNA was more abundant in GD12-14 fetal livers from diabetic dams than in livers of age-matched controls. This upregulation is not due to the approximately 1-day fetal developmental delay associated with maternal diabetes, as there is no gross difference in the level of IGFBP-1 mRNA in GD13 vs GD12 or GD14 vs GD13 control fetal livers. At GD15-16, however, we detected little difference in IGFBP-1 expression between experimental and control fetuses. This transient period of maternal diabetes-stimulated IGFBP-1 mRNA expression (GD12-14) is coincident with the sensitive period for maternal diabetes-induced defects in fetal growth and development, suggesting that IGFBP-1 is involved in the regulation of fetal growth and development in response to the maternal condition.

Gorham's disease of the spine

Massive osteolysis is a rare condition and is very uncommon in the spine. The MRI appearance of Gorham's disease of the spine has not previously been reported. We present here a case of this condition with imaging details.

Spinal fusion in situ in osteogenesis imperfecta

Osteogenesis imperfecta in its most severe forms has a devastating effect on the peripheral and central skeleton, and patients are unable to walk. Spinal deformity is common and causes difficulty in sitting, pain and potentially life-threatening complications. Instrumented spinal fusion might be considered the treatment of choice, but the bone may be too weak to sustain the implants and autogenous bone graft is poor in quantity and quality. We present the preliminary results of a technique of fusion without instrumentation and using Keil bone graft in 5 patients with severe osteogenesis imperfecta. The curve was stabilised and back pain relieved.

Effects of maternal diabetes on fetal expression of insulin-like growth factor and insulin-like growth factor binding protein mRNAs in the rat

Maternal diabetes is associated in humans and rats with an increased risk for fetal growth abnormalities and malformations. Therefore, the effect of maternal diabetes on expression of genes that regulate fetal growth and differentiation is of considerable interest. Developmental growth is regulated in part by the expression and availability of insulin-like growth factors (IGFs). Postnatal expression of a subset of the IGFs and IGF binding proteins (IGFBPs) has been demonstrated to be regulated in response to diabetes and other metabolic conditions. We used in situ hybridization to analyze the effect of maternal diabetes, induced by streptozotocin (STZ) prior to mating, upon prenatal rat IGF and IGFBP mRNA expression. At gestational day (GD) 14, the most striking effect of maternal diabetes on fetal IGF/IGFBP gene expression was a marked increase in the abundance of IGFBP-1 mRNA within the liver primordia of fetuses isolated from diabetic dams compared to age-matched controls. This upregulation cannot be entirely due to the approximately one-half-day delay in fetal development (based on limb bud staging) associated with maternal diabetes, as there was no gross difference in the level of IGFBP-1 mRNA between GD13 and GD14 control fetal livers. In contrast, the fetal mRNA expression patterns of IGF-I, IGF-II and IGFBP-2, -3, -4, -5 and -6 were not grossly altered by maternal diabetes. These data are consistent with the hypothesis that IGFBP-1 produced within the fetal liver and secreted into fetal circulation may play a role in regulating rat fetal growth.

Prenatal neuroleptic exposure and growth stunting in the rat: an in vivo and in vitro examination of sensitive periods and possible mechanisms

There is increasing evidence that a number of neurotransmitters can play a trophic role in the development of the central nervous system. Dopamine is one candidate for this role. In a series of papers, Lewis, Patel, and colleagues have demonstrated that exposure to compounds which interfere with dopaminergic neurotransmission ("neuroleptics") can block cell proliferation in the brains of 11-day-old rat pups for at least 24 hr. More recently our laboratory has reported that prenatal exposure to haloperidol (HAL), a neuroleptic which binds to and blocks dopamine receptor sites in the adult brain, permanently stunts body and brain growth when that exposure extends throughout postimplantation pregnancy. Reported here are the results of two experiments conducted to further examine this phenomenon. The first experiment attempted to identify sensitive gestational periods for the HAL effect on growth in vivo. This experiment also assessed the effect of exposure to reserpine (RES), a compound which in the adult blocks dopaminergic neurotransmission by rupturing monoamine storage vesicles, an effect which is quite distinct from the HAL mechanism of action. In a second experiment, gestational day (GD) 9 embryos were exposed in vitro for 48 hr to either HAL, RES, or one of two specific blockers of dopamine receptor subtypes. Schering 23390 (SCH) was used as the D1 blocker, and sulpiride (SULP) as the D2 blocker. The in vivo experiment showed that twice-daily exposure to subcutaneous injections of HAL (5 mg/kg for each of the 2 injections) or RES (0.1 mg/kg for each injection) permanently stunted brain growth when injections were given in midpregnancy (GD 12-16), but not in late pregnancy (GD 16-20). RES was substantially more fetotoxic than HAL, especially late in pregnancy. The growth stunting produced by either compound with GD 12-16 exposure was not restricted to dopamine-rich areas of the brain, or indeed to the brain itself, in that body weight was also depressed. Pair-fed controls did not show the same magnitude or duration of stunting, indicating that this effect was not due to drug-induced maternal hypophagia. The in vitro experiment revealed that exposure to micromolar concentrations of any of the 4 neuroleptics reduced embryonic GD 11 DNA and protein content and delayed development. HAL and SCH had the most pronounced effects at concentrations close to blood levels reportedly produced by exposure to doses used in the in vivo experiments. RES was less potent, and SULP still less potent than RES.(ABSTRACT TRUNCATED AT 400 WORDS)

Delayed postoperative paraplegia with hypotension in adult revision scoliosis surgery

The clear and reversible relationship of spinal cord function to postoperative hypotension is illustrated in a case of revision scoliosis surgery in an adult patient. The correlation of spinal cord monitoring by both magnetic cortical motor evoked potentials and spinal somatosensory evoked potentials to the clinical status is shown, and the importance of close postoperative observation of the adult revision case is emphasized.

An apparently new syndrome of bowed tibiae, radial anomalies, osteopenia, multiple fractures and developmental delay

We report two siblings with bowed tibia, hypoplastic thumbs, multiple fractures, a distinctive facial phenotype and developmental delay. These children share some features with other cases reported in the literature but we consider that they represent a new syndrome.

Inadequacies of hospital medical records

We have assessed the extent to which hospital records follow the Guidelines for Medical Records and Notes published by the Royal College of Surgeons of England. Notes of 100 consecutive discharges were reviewed from two surgical units, one at a District General Hospital (DGH) and the other at a London Teaching Hospital (TH). Overall, only 65 per cent (DGH) and 67 per cent (TH) of the entries specified by College guidelines were both present and correct. Substandard categories included the regular update of notes, post-operative instructions, comments about post-operative recovery, the record of advice given to relatives and incorrect consent. The guidelines produced by the Royal College of Surgeons are being applied, but there is room for considerable improvement. Inadequate medical records limit audit and may have medico-legal consequences. We recommend regular assessment of the standard of note keeping.

Spinal cord monitoring in scoliosis surgery. Experience with 1168 cases

Since 1981, during operations for spinal deformity, we have routinely used electrophysiological monitoring of the spinal cord by the epidural measurement of somatosensory evoked potentials (SEPs) in response to stimulation of the posterior tibial nerve. We present the results in 1168 consecutive cases. Decreases in SEP amplitude of more than 50% occurred in 119 patients, of whom 32 had clinically detectable neurological changes postoperatively. In 35 cases the SEP amplitude was rapidly restored, either spontaneously or by repositioning of the recording electrode; they had no postoperative neurological changes. One patient had delayed onset of postoperative symptoms referrable to nerve root lesions without evidence of spinal cord involvement, but there were no false negative cases of intra-operative spinal cord damage. In 52 patients persistent, significant, SEP changes were noted without clinically detectable neurological sequelae. None of the many cases which showed falls in SEP amplitude of less than 50% experienced neurological problems. Neuromuscular scoliosis, the use of sublaminar wires, the magnitude of SEP decrement, and a limited or absent intra-operative recovery of SEP amplitude were identified as factors which increased the risk of postoperative neurological deficit.

Susceptibility to phenobarbital promotion of hepatotumorigenesis: correlation with differential expression and induction of hepatic drug metabolizing enzymes in heavy and light male (C3H x VY) F1 hybrid mice

Higher body and carcass (body - liver) weights in sodium phenobarbital (PB) treated mice correlate with formation of multiple hepatocellular adenomas in yellow Avy/A and agouti A/a (C3H x VY) F1 hybrid male mice. To assess differences in PB induction of hepatic drug metabolizing enzymes, yellow Avy/A (C3H x VY) F1 hybrid male mice were fed 0.05% sodium PB in NIH-31 diet for 7 months. Livers from the heaviest and lightest mice in the untreated and PB groups were assayed. Total cytochrome P450 content, cytochrome P450IA-selective 7-ethoxyresorufin-O-deethylase and P450IIIA-selective testosterone-6 beta-hydroxylase activities were preferentially induced in the light mice. In contrast, P450IIB-selective 7-pentoxyresorufin-O-dealkylase activity was increased only 3-fold by PB in the light mice but 6-fold in the heavy mice. Testosterone UDP-glucuronyltransferase and gamma-glutamyltranspeptidase activities were induced in the light mice but not in the heavy mice. Glutathione-S-transferase N1:1-dependent activity was induced preferentially in the heavy mice. Significant differences also occurred in constitutive expression of P450IIIA-selective testosterone-6 beta-hydroxylase, P450IA-selective 7-ethoxyresorufin-O-deethylase and testosterone UDP-glucuronyltransferase activities between the untreated weight groups. Thus, expression of constitutive and PB-inducible forms of hepatic drug metabolizing enzymes differs between heavy and light Avy/A (C3H x VY) F1 hybrid subpopulations. This suggests that differential susceptibility to PB promotion of hepatocellular adenomas among genetically identical mice is accompanied by differences in the regulation of gene expression.

Factors influencing the result of posterior spinal fusion in the treatment of adolescent idiopathic scoliosis

Sixty-six consecutive patients with adolescent idiopathic scoliosis treated by posterior spinal fusion using Harrington distraction compression instrumentation were followed for a minimum of 3 years. Initial surgical correction was satisfactory, but during the follow-up period, mean 4.4 years (3-5 years), there was a loss of correction. Several factors (age, sex, the number of vertebrae in the fusions, and the use of cross wires) were important influences on correction. A method of assessing the balance of a posterior spinal fusion is described that is useful when assessing radiographs.

Scoliosis in the Rett syndrome: natural history and treatment

The Rett syndrome (RS) is associated with a neurological form of scoliosis. From 1985 we have instituted a postal survey of families with Rett girls. The prevalence of scoliosis in the survey population is 64%. The age at onset of scoliosis has a normal distribution about a peak age of 8 years, with 72% of cases occurring before age 8. The scoliosis in RS is typically a long thoracolumbar curvature that progresses rapidly in girls over the age of 10 years. Operative treatment is successful in reducing the curvature, preventing curve progression and improving spinal balance for sitting and walking. The 5 girls who walked pre-operatively are still able to do so.

Effects of aging and caloric restriction on hepatic drug metabolizing enzymes in the Fischer 344 rat. II: Effects on conjugating enzymes

The effects of long-term caloric restriction on the hepatic phase II drug metabolizing enzymes were investigated in the male Fischer 344 rat. Rats that had been restricted to 60% of their pair-fed control consumption from 14 weeks post-partum exhibited altered conjugating enzyme activities at 22 months. Caloric restriction significantly reduced the age-related decrease in glutathione-S-transferase activity towards 1,2-dichloro-4-nitrobenzene, but did not significantly alter the age-related changes in UDP-glucuronyltransferase or sulfotransferase activities towards hydroxysteroids. Caloric restriction appeared to increase hepatic microsomal UDP-glucuronyltransferase activity toward bilirubin and gamma-glutamyltranspeptidase activities. These observations suggest that caloric restriction has multiple effects on the hepatic phase II drug metabolizing enzymes in the rat. Such effects may alter hepatic metabolism and activation or detoxification of drugs and carcinogens.

Effects of aging and caloric restriction on hepatic drug metabolizing enzymes in the Fischer 344 rat. I: The cytochrome P-450 dependent monooxygenase system

The effects of long-term caloric restriction on the hepatic cytochrome P-450 dependent monooxygenase system were investigated in the 22-month-old Fischer 344 rat. Caloric restriction decreased the age-related changes in hepatic testosterone metabolism, which are associated with demasculinization of the liver. Caloric restriction also increased hepatic microsomal testosterone 6 beta-hydroxylase, lauric acid 12-hydroxylase and 4-nitrophenol hydroxylase activities over corresponding values in both ad libitum fed 22-month and 60-day-old control male rats. This suggests that cytochrome P-450 isozymes, P-450 pcn1&2, P-452 and P450j may be induced by caloric restriction. Such changes in cytochrome P-450 isozyme profiles could result in altered carcinogen activation, radical formation or drug detoxication in the calorically restricted rat.

Scoliosis in neurofibromatosis. The natural history with and without operation

We reviewed 47 patients with neurofibromatosis and dystrophic spinal deformities; 32 of these patients had been untreated for an average of 3.6 years and in them the natural history was studied. The commonest pattern of deformity at the time of presentation was a short angular thoracic scoliosis, but with progression the angle of kyphosis also increased. Deterioration during childhood was usual but its rate was variable. Severe dystrophic changes in the apical vertebrae and in particular anterior scalloping have a poor prognosis for deterioration. The dystrophic spinal deformity of neurofibromatosis requires early surgical stabilisation which should be by combined anterior and posterior fusion if there is an abnormal angle of kyphosis or severely dystrophic apical vertebrae. Some carefully selected patients can be treated by posterior fusion and instrumentation alone.

Effect of prenatal reserpine exposure on development of the postnatal rat heart

Previous studies have suggested that reserpine treatment may result in altered heart development. In order to more fully investigate this possibility, reserpine was administered s.c. at 0, 0.375, or 0.75 mg/kg/day to pregnant rats on gestation days 12-15. Maternal weight gain, as well as pup weight on postnatal day (PND) 1, was significantly reduced in a dose-dependent manner. Litter size was unaffected, but reserpine-treated dams had more dead pups than did control dams. On PND 1, litters were randomly standardized at ten pups each for analysis on PNDs 5, 8, 15, and 22. Pup body weight and heart weight were reduced in a dose-related manner at all ages measured. The decreased heart weights were probably due to decreases in cell number. Beta-adrenergic receptor concentration was significantly reduced only on PND 5, at the low reserpine dose, and was not considered to be a treatment effect. Prenatal reserpine exposure had no effect on levels of basal cardiac ornithine decarboxylase (ODC), an enzyme associated with growth and development. Cardiac ODC stimulation by insulin and isoproterenol also showed no effects of maternal reserpine treatment. The results suggest that maternal reserpine treatment may lead to adverse effects in the developing offspring.

Observations on the growth of the adolescent spine

We have measured the increase in height and width of the vertebral bodies and expressed them as percentages of the total growth in children aged 10 to 17 years. The first group, 10 boys and 10 girls, each had a single thoracic adolescent idiopathic scoliosis while the second group, 10 girls, each had a single lumbar adolescent idiopathic scoliosis. No significant differences were found between the growth increments and spinal dimensions of the vertebral bodies involved in the scoliotic curve and those vertebrae outside the curve in the same patient. The vertebrae were more slender in girls than in boys.

A method of monitoring function in corticospinal pathways during scoliosis surgery with a note on motor conduction velocities

Spinal cord potentials produced by high voltage electrical stimulation of the scalp over the motor cortex were recorded intraoperatively from bipolar electrodes inserted into the epidural space of eleven patients undergoing corrective surgery for scoliosis. Responses to single stimuli could be recorded from the cord at all levels from cervical to low thoracic regions. The potentials were larger in the cervical than in the thoracic region and sometimes were followed by later waves at high stimulation intensities. Conduction velocity in large corticomotoneuron fibres was estimated to be between 50-74 ms-1 in different patients. This technique for monitoring motor tract function may be a useful adjunct to conventional monitoring of the sensory pathways during surgery.

Insulin stimulation of ornithine decarboxylase activity in developing rat heart

Ornithine decarboxylase (ODC; EC 4.1.1.17) is an important enzyme in the synthesis of polyamines and is associated with growth and differentiation. Insulin stimulation of cardiac ODC has been proposed as a marker of the functional completion of the sympathetic pathway to the rat heart. However, earlier studies, using subsaturating substrate concentrations and a single time point measurement after insulin treatment, have been inconsistent concerning the postnatal age at which significant insulin stimulation of ODC occurs. The present study, using a validated near-saturating substrate assay, examines more thoroughly early neonatal insulin induction of cardiac ODC with respect to both the magnitude and the time course of response. Insulin (20 IU/kg s.c.) significantly increased ODC activity at several time points at each postnatal age measured (days 2, 5, 8, 15 and 22), with maximum ODC activity occurring by 2.5 to 3 hr after insulin injection at all ages. Insulin-stimulated ODC activity was increased over control levels by 86, 84, 87, 150 and 127% on days 2, 5, 8, 15 and 22, respectively. These results demonstrate that age is not a variable in the time of peak insulin stimulation of ODC activity and, in contrast to earlier reports, show that significant insulin induction of cardiac ODC activity occurs reliably across ages in the early postnatal period. The inconsistency of earlier studies may be due to a number of factors, including the use of subsaturating enzyme assays only, known to be subject to several types of error.

Effect of prenatal propranolol exposure on development of the postnatal rat heart

Maternal propranolol (PRO) treatment has previously been associated with adverse effects on the fetus and neonate. In the present study, pregnant rats were treated with PRO (25 or 50 mg/kg/day s.c.) on gestation days 8-20 to assess its possible effects on the developing heart. Maternal weight gain and pup weight on postnatal day (PND) 1 were reduced in a dose-dependent manner; litter size was unaffected. Pup body weight and heart weight both showed a dose-related decrease at all ages tested (PNDs 5/6, 8/9, 15/16, and 22/23). Since heart protein, but not DNA, was similarly reduced, the decrease seen in heart weight most likely reflects a decrease in cell size instead of cell number. Basal ornithine decarboxylase (ODC), an enzyme associated with growth and development, was unaffected by maternal PRO treatment. Insulin and isoproterenol stimulation of ODC, suggested markers for testing the function of the sympathetic pathway to the heart and of the heart's ODC response system, respectively, also showed no PRO-related response. In conclusion, prenatal PRO exposure resulted in reduced body weight, heart weight, and heart protein, but had little effect on heart DNA or ODC activity. Since PRO treatment also reduced maternal weight gain, the adverse effects seen in the pups may be due to generalized PRO toxicity. The results suggest that when high PRO doses were used clinically, the careful monitoring of maternal weight gain during pregnancy might be useful in predicting adverse fetal effects.

Effect of prenatal imipramine exposure on development of the postnatal rat heart and brain

Imipramine (IMI) was administered s.c. at 0, 5, or 10 mg/kg/day to pregnant rats on gestation days 8-20 to assess possible alterations in postnatal heart and brain development. Maternal weight gain was significantly reduced in a dose-response manner, but litter size and pup weight on postnatal day (PND) 1 were unaffected. On PND 1, litters were culled to 10 pups for analysis on PNDs 4/5, 7/8, 14/15, and 21/22. Pup body weight was not affected at any age measured, but heart weight was significantly reduced at 10 mg/kg IMI on PNDs 4/5 and 7/8. Brain weight was increased in a dose-related pattern on PNDs 4/5 and 7/8 and was significantly higher at 5 mg/kg IMI on PND 14/15. No significant effect was observed in heart or brain protein and DNA content or in cardiac beta-adrenergic receptor concentration. Prenatal IMI exposure had no effect on basal cardiac ornithine decarboxylase (ODC), an enzyme associated with growth and development, but basal brain ODC was lower at 5 mg/kg IMI at all ages measured. Cardiac ODC stimulation by insulin was unaffected by prenatal exposure to IMI, but isoproterenol-stimulated ODC was increased on PND 21/22 at 5 mg/kg IMI. In conclusion, the IMI-related changes in several parameters suggest that when maternal IMI treatment is used, alterations in postnatal heart and brain development must be considered as possible outcomes.

Postnatal toxicity following prenatal reserpine exposure in rats: effects of dose and dosing schedule

Pregnant CD rats were treated subcutaneously with 0, 0.1, 0.33, or 1.0 mg reserpine/kg/day either on Days 12-15 or on Days 16-19 of gestation. Dams were allowed to deliver and litters (4 +/- 1 of each sex) were weighed weekly and held to 21 days of age. Basal ornithine decarboxylase (ODC) activity and neurochemical determinations were made on hearts and brains, respectively, from pups culled from litters on postnatal Day 1, and from two males and two females/litter at 21 days of age. Following both treatment schedules, the high dose of reserpine resulted in maternal weight loss during dosing, increased stillborn pups, reduced pup weight at birth, retarded postnatal growth, and decreased survival to 21 days of age. Basal cardiac ODC activity was reduced to 33% of control levels only on Postnatal Day 1 in both high-dose groups, while absolute heart weight decreased and relative heart weight increased in these pups. Whole-brain concentrations of two neurotransmitter metabolites, 3-4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindoleacetic acid (5-HIAA), were increased only at Postnatal Day 1 in the high dose group treated on Days 12-15 of gestation. No other changes were found in concentrations of these metabolites or in the transmitters dopamine and serotonin. The only effect found following administration of 0.33 mg/kg reserpine was a reduction in maternal weight gained during both dosing periods. No signs of toxicity were observed following low-dose exposure on either schedule. Most previously reported postnatal functional studies following reserpine exposure have used mid- to late-gestational treatment with 1.0 mg/kg, a dose shown here to result in marked overt maternal and fetal toxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Flexion contractures of the knee associated with popliteal webbing

Five children with popliteal webbing and flexion contractures of the knees are described. When their associated anatomical abnormalities are considered, classification into two distinct syndromes, multiple pterygium and popliteal pterygium, is possible and of importance in genetic counseling. Soft tissue surgical corrections of the flexion contractures were undertaken in each case. The operative technique, local abnormalities, and orthopaedic management are discussed.

Do prostacyclin and thromboxane play a role in endotoxic shock?

The role of prostacyclin and thromboxane during endotoxic shock is unknown. Using new radioimmunoassay techniques, we have studied the plasma levels of stable metabolites of prostacyclin (6-keto-PGF1 alpha) and thromboxane (TxB2) in a porcine model of endotoxic shock. TxB2 levels were markedly elevated but the production of prostacyclin appears to be impaired. Correction of this prostanoid imbalance by the infusion of prostacyclin or pre-treatment with a specific thromboxane synthetase inhibitor produces significant and beneficial effects on blood pressure and pre-kallikrein activation.

Quantitative studies of natural immunity to solid tumours in rats. The nature of the killer cell depends on the type of assay

Cell fractionation techniques were used to identify the cells in rat spleen responsible for natural killing of a syngeneic sarcoma cell in short-term (6 h and 18 h) and long-term (72 h) cytotoxicity assays. Cytotoxicity was quantified precisely using a method previously derived from consideration of natural cytotoxicity as an enzyme-substrate reaction, and by analysing results in terms of lytic units. Killing in all three assays displayed 'single-hit' kinetics implying that a single effector cell was sufficient to lyse a single target cell. The fractionation studies, using glass adherence, carbonyl iron, nylon wool, EA and EAC monolayers and congenitally athymic rats, revealed two populations of cytotoxic cells. In the 6 h assay most of the activity was due to cells with similar characteristics to the NK cells previously defined using leukaemic targets, but in the 18 h and 72 h assays macrophages played an important rôle. The activity exerted by the macrophages was cell lysis and not cytostasis. No evidence that the macrophages acted by releasing factors which stimulated NK cells could be found.