Effects of leaf extract of Stephania hernandifolia on testicular gametogenesis and androgenesis in albino rats: a dose-dependent response study

The present study was undertaken to evaluate the dose-dependent effects of a leaf extract of Stephania hernandifolia on testicular activities in albino rats. Whether this leaf extract has any toxic effect on metabolic organs or on the liver or kidney was studied. Adult male Wistar rats, maintained under standard laboratory conditions, were forcefully fed with the aqueous extract of these leaves at the dose of 2 g or 4 g of leaves/mL distilled water/100 g body weight/day for 28 days. All the animals, along with vehicle-treated controls, were killed on the Day 29 of the experiment. Treatment with this leaf extract at both doses resulted in significant reduction in relative weight in the testis, the seminal vesicles, the prostate, and the epididymis without any significant change in the liver and kidney weight in comparison to control. Activities of testicular steroidogenic key enzymes and plasma testosterone level were decreased significantly, along with a significant reduction in the number of germ cells at stage VII of the spermatogenic cycle and in the seminiferous tubular diameter in both treated groups in comparison to control. Activities of glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, acid phosphatase, and alkaline phosphatase were not altered significantly in the liver and kidney in both treated groups compared with controls. We concluded that treatment with an aqueous extract of leaves resulted in diminution in the activities of testicular androgenic key enzymes and plasma level of testosterone along with inhibition of spermatogenesis without any induction of hepatic and renal toxicity.

Effect of vaginally administered fumagillin on immunohistochemical distribution of leukemia inhibitory factor, interleukin 6, transforming growth factor beta and vascular endothelial growth factor in implantation stage endometrium of the rhesus monkey

Intravaginal administration of an anti-angiogenic agent, fumagillin, during blastocyst implantation inhibits pregnancy establishment in a dose-related manner in the rhesus monkey. In the present study, mated female rhesus monkeys were vaginally inserted with tampons containing vehicle (group 1; n = 5) and test agent (fumagillin, 4 mg/animal; group 2; n = 6) on cycle day 20, and endometrial tissue samples were collected on cycle day 24 from all monkeys and processed for histological examination and immunohistochemical localization for LIF, IL-6, TGF-beta and VEGF. Concentrations of estradiol-17 beta, progesterone and chorionic gonadotrophin in peripheral circulation were determined. From the serum profiles of the hormones, 2 monkeys in group 1, and 1 monkey in group 2 appeared pregnant. However, endometrial morphology revealed histological evidence of pregnancy in 3 out of 6 fumagillin-treated animals. Histometric analysis of immunohistochemical staining in epithelial, stromal and vascular compartments revealed that per cent areas occupied by immunoprecipitate for the cytokines studies did not change in epithelial and stromal compartments, except that for TGF-beta which was higher (P < 0.05) in epithelial compartment in group 2. No change was observed in immunoprecipitation areas for IL-6 in epithelial, stromal and vascular compartments. On the other hand, changes (P < 0.05) for LIF, TGF-beta and VEGF were evident in the vascular compartment. It is possible that disparate responses observed in glandular, stromal and vascular compartments in implantation stage endometrium following fumagillin treatment actually caused from associated decline in progesterone concentration in peripheral circulation. It is also possible that fumagillin, an angiostatic agent, affects the synthesis and secretion of cytokines primarily in the vascular compartment of implantation stage endometrium, and thereby manifests differential responses in epithelial, stromal and vascular compartments.

The multifaceted Paneth cell

Paneth cells (PCs) were described over a century ago as granulated cells located at the base of small intestinal crypts, the 'crypts of Lieberkühn.' Various histochemical staining procedures were developed that identified PCs based on their distinctive granule-staining pattern. Early on, PCs were proposed to perform a specialized function other than absorption of digested nutrients, the predominant task of the small intestinal epithelium. Since then, many constituents of the PC granules have been biochemically characterized. The presence of various granule-associated antimicrobial substances and their release upon microbial challenge suggest that PCs function as specialized defense cells in the small intestine. Altered resistance to microbial infection in animal models with disrupted or augmented PC function provides further support for the host defense role of PCs. Other PC components suggest that PCs may also participate in the regulation of lumenal ionic composition, crypt development, digestion, and intestinal inflammation.

Heuristics, Experimental Subjects, and Treatment Evaluation in Bigraph Crossing Minimization

The bigraph crossing problem, embedding the two node sets of a bipartite graph along two parallel lines so that edge crossings are minimized, has applications to circuit layout and graph drawing. Experimental results for several previously known and two new heuristics suggest continued exploration of the problem, particularly sparse instances. We emphasize careful design of experimental subject classes and present novel views of the results. All source code, data, and scripts are available on-line

Repression of Ets-2-induced transactivation of the tau interferon promoter by Oct-4

Oct-4 is a POU family transcription factor associated with potentially totipotent cells. Genes expressed in the trophectoderm but not in embryos prior to blastocyst formation may be targets for silencing by Oct-4. Here, we have tested this hypothesis with the tau interferon genes (IFNT genes), which are expressed exclusively in the trophectoderm of bovine embryos. IFNT promoters contain an Ets-2 enhancer, located at -79 to -70, and are up-regulated about 20-fold by the overexpression of Ets-2 in human JAr choriocarcinoma cells, which are permissive for IFNT expression. This enhancement was reversed in a dose-dependent manner by coexpression of Oct-4 but not either Oct-1 or Oct-2. When cells were transfected with truncated bovine IFNT promoters designed to eliminate potential octamer sites sequentially, luciferase reporter expression from each construct was still silenced by Oct-4. Full repression required both the N-terminal and POU domains of Oct-4, but neither domain used alone was an effective silencer. Oct-4 and Ets-2 formed a complex in vitro in the absence of DNA through binding of the POU domain of Oct-4 to a site located between the "pointed" and DNA binding domains of Ets-2. The two transcription factors were also coimmunoprecipitated after being expressed together in JAr cells. Oct-4, therefore, silences IFNT promoters by quenching Ets-2 transactivation. The POU domain most probably binds to Ets-2 directly, while the N-terminal domain inhibits transcription. These findings provide further evidence that the developmental switch to the trophectoderm is accompanied by the loss of Oct-4 silencing of key genes.

Purification, characterization and crystallization of human placental estrone/dehydroepiandrosterone sulfatase, a membrane-bound enzyme of the endoplasmic reticulum

Estrone (E1)/dehydroepiandrosterone (DHEA) sulfatase (ES/DHEAS) catalyzes the hydrolysis of E1 and DHEA-sulfates releasing unconjugated steroids. ES is a component of the three-enzyme system that has been implicated in intracrine biosynthesis of estradiol, hence, proliferation of hormone dependent breast tumors. ES is bound to the membrane of the endoplasmic reticulum, presumably through multiple transmembrane and other membrane anchoring segments. The highly hydrophobic nature of the enzyme has so far prevented its purification to homogeneity in quantities sufficient for crystallization. We report here the purification, biochemical characterization and crystallization of the full-length, active form of the enzyme from the membrane bound fraction of human placenta. Our results demonstrate that the key to successful purification and growth of diffraction quality crystals of this difficult membrane bound enzyme is the exploitation of optimal solubilization and detergent conditions to protect the structural and functional integrity of the molecule, thereby preventing nonspecific aggregation and other instabilities. This work paves the way for the first structural study of a membrane bound human sulfatase and subsequent rational design of inhibitors for use as anti-tumor agents.

Profiling of cancer cells using protein microarrays: discovery of novel radiation-regulated proteins

The advent of DNA microarray technology will likely have a major impact on the molecular classification and understanding of human cancer. Obtaining a global perspective of proteins expressed in cancer cells is considerably more challenging. Here we describe a microarray-based platform that can be used to measure protein levels and activities in a complex biological milieu such as a cellular lysate. Using a protein microarray made up of 1920 elements (146 distinct antibodies) we were able to monitor alterations of protein levels in LoVo colon carcinoma cells treated with ionizing radiation. The protein microarray approach revealed radiation-induced up-regulation of apoptotic regulators including p53, DNA fragmentation factor 40/caspase activated DNase, DNA fragmentation factor 45/inhibitor of caspase activated DNase, tumor necrosis factor-related apoptosis-inducing ligand, death receptor 5, decoy receptor 2, FLICE-like inhibitory protein, signal transducers and activators of transcription 1alpha, and uncoupling protein 2, among others. Consistent with this observation, an increased percentage of apoptosis was observed in irradiated LoVo cells. Interestingly, we also observed radiation-induced down-regulation of carcinoembryonic antigen, a prototypic cancer biomarker. Selected proteins assessed by microarray were validated by traditional immunoblotting. Taken together, our work suggests that protein/antibody microarrays will facilitate high-throughput proteomic studies of human cancer and carcinogenesis.

Gene for porcine pregnancy-associated glycoprotein 2 (poPAG2): its structural organization and analysis of its promoter

The pregnancy-associated glycoproteins (PAG) are abundant secretory products of the placental trophectoderm of ungulate species. They are structurally related to pepsin, having the capability to bind peptides. However, many cannot function as enzymes due to amino acid substitutions in and around the catalytic site. Here, we demonstrate that pigs, like cattle and sheep, but unlike equids, have multiple PAG genes. One of the transcribed porcine PAG (poPAG) genes, the one for poPAG2, was cloned. It had a nine-exon organization similar to that of other mammalian aspartic proteinase genes with an atypical TATA sequence. A total of 1.2 kbp upstream from exon 1 was sequenced. This region shared identity (> 65%) with the promoter regions of the bovine (bo) PAG1, boPAG2 and equine (eq) PAG genes, but not with other aspartyl proteinase genes, including that of pepsinogen A. Nor were there clear similarities to the promoters of other genes with trophoblast-specific expression. Of the different poPAG2 promoter constructs tested in transfection experiments in two human (JAr and JEG3) and one rat (Rcho) choriocarcinoma cell lines, only the shortest (-149 bp) was required to provide full expression of a luciferase reporter. Although this short promoter was not active in Cos-1 and L-929 cells, it was active in CHO cells, a transformed non-trophoblast hamster ovarian cell line. Co-transfection of Ets2 elevated the activity of this short promoter approximately six-fold in JAr cells, but, disruption of the two putative Ets sites did not alter the ability of Ets2 to transactivate the promoter. In the non-trophoblast cell lines, Ets2 failed to elicit any response. Ets2 responsiveness may be a common feature of most or all trophoblast-expressed genes, although in the case of poPAG2, the effect may be indirect.

Modulation of macrophage mannose receptor affects the uptake of virulent and avirulent Leishmania donovani promastigotes

The effect of oxidants and the anti-inflammatory steroid dexamethasone on the attachment and internalization of virulent and avirulent Leishmania donovani promastigotes by the macrophage mannosyl fucosyl receptor was examined. Oxidants and dexamethasone are known to down- and upregulate the expression of the mannose receptor. Macrophages, when treated with 500 microM H2O2 at 37 C for 30 min, stimulate about 45% inhibition in uptake of an avirulent strain (UR6), and 30 and 25% inhibition for virulent strains AG-83 and GE-I, respectively. Treatment of macrophages with dexamethasone for 20 hr resulted in a stimulation in uptake of the parasite. When UR6 was used, a 3-fold increase in uptake was observed compared with the controls. Parasite uptake was also inhibited by the H2O2-generating system, glucose/glucose oxidase; inhibition was blocked by catalase. Treatment of macrophages either with H2O2 or dexamethasone did not affect the binding of the advanced glycosylation end product-bovine serum albumin (AGE-BSA), the ligand for AGE receptor of macrophages. Similarly, indirect evidence also shows that both types 1 and 3 complement receptors (CR1, CR3) are not affected by these treatments, indicating that, besides the mannosyl fucosyl receptor, other receptors are minimally altered in the identified condition. These results suggest that the up- and downregulation of the mannose receptor of macrophages may play a role in affecting L. donovani infection.

An empirical analysis of the purchaser-provider relationship in the NHS internal market

Introduces the relationship marketing paradigm as a means of analysing the purchaser-provider relationship within the NHS internal market. This focus is justified in the context of the limitations of orthodox economic analysis. The research evidence is based upon a national survey of all NHS trust hospitals in England. The survey consisted of key questions relating to the process of relationship building strategies employed by NHS hospital trusts. In particular, emphasis was given to non-price competitive behaviour, i.e. the extent to which health care contracts were augmented or customized by providers. An empirical analysis is presented, identifying those factors driving such non-price competitive behaviour, based upon a LOGIT model. The results suggest the hypotheses tested are consistent with the evidence from our survey. Finally, the model is used to make some tentative predictions regarding the future of the purchaser-provider relationship within the reformed NHS.

Delineation of prognostic biomarkers in prostate cancer

Prostate cancer is the most frequently diagnosed cancer in American men. Screening for prostate-specific antigen (PSA) has led to earlier detection of prostate cancer, but elevated serum PSA levels may be present in non-malignant conditions such as benign prostatic hyperlasia (BPH). Characterization of gene-expression profiles that molecularly distinguish prostatic neoplasms may identify genes involved in prostate carcinogenesis, elucidate clinical biomarkers, and lead to an improved classification of prostate cancer. Using microarrays of complementary DNA, we examined gene-expression profiles of more than 50 normal and neoplastic prostate specimens and three common prostate-cancer cell lines. Signature expression profiles of normal adjacent prostate (NAP), BPH, localized prostate cancer, and metastatic, hormone-refractory prostate cancer were determined. Here we establish many associations between genes and prostate cancer. We assessed two of these genes-hepsin, a transmembrane serine protease, and pim-1, a serine/threonine kinase-at the protein level using tissue microarrays consisting of over 700 clinically stratified prostate-cancer specimens. Expression of hepsin and pim-1 proteins was significantly correlated with measures of clinical outcome. Thus, the integration of cDNA microarray, high-density tissue microarray, and linked clinical and pathology data is a powerful approach to molecular profiling of human cancer.

Structure of the insecticidal bacterial delta-endotoxin Cry3Bb1 of Bacillus thuringiensis

The coleopteran-active delta-endotoxin Cry3Bb1 from Bacillus thuringiensis (Bt) strain EG7231 is uniquely toxic to Diabrotica undecimpunctata, the Southern corn rootworm, while retaining activity against Leptinotarsa decemlineata, the Colorado potato beetle. The crystal structure of the delta-endotoxin Cry3Bb1 has been refined using data collected to 2.4 A resolution, with a residual R factor of 17.5% and an R(free) of 25.3%. The structure is made up of three domains: I, a seven-helix bundle (residues 64-294); II, a three-sheet domain (residues 295-502); and III, a beta-sandwich domain (residues 503-652). The monomers in the orthorhombic C222(1) crystal lattice form a dimeric quaternary structure across a crystallographic twofold axis, with a channel formed involving interactions between domains I and III. There are 23 hydrogen bonds between the two monomers conferring structural stability on the dimer. It has been demonstrated that Cry3Bb1 and the similar toxin Cry3A form oligomers in solution. The structural results presented here indicate that the interactions between domains I and III could be responsible for the initial higher order structure and have implications for the biological activity of these toxins. There are seven additional single amino-acid residues in the sequence of Cry3Bb1 compared with that of Cry3A; one in domain I, two in domain II and four in domain III, which also shows the largest conformational difference between the two proteins. These changes can be implicated in the selectivity differences noted for these two delta-endotoxins.

Protection of sodium arsenite-induced ovarian toxicity by coadministration of L-ascorbate (vitamin C) in mature wistar strain rat

Arsenic, a major water pollutant in India, produces toxic effects on female reproductive system in rodent models at the dose available in drinking water in arsenic-intoxicated zones. This study examines the coadministration of L-ascorbate (vitamin C) on ovarian steroidogenesis, plasma levels of gonadotrophins, brain monoamines, and ovarian as well as uterine peroxidase activities in sodium arsenite-treated rats. After sodium arsenite treatment, relative ovarian and uterine weights, ovarian Delta5-3beta-HSD and 17beta-HSD activities, plasma levels of gonadotrophins, norepinephrine levels in midbrain and diencephalon, and the activities of peroxidase in ovary and uterus were decreased significantly. On the other hand, serotonin levels in midbrain and diencephalon were increased significantly 28 days after sodium arsenite treatment at the dose of 0.4 ppm/100 g body weight/rat/day. All these parameters were protected significantly and in most cases were unchanged from control level when L-ascorbate at 25 mg/100 g body weight/rat/day was coadministered orally with sodium arsenite. This cotreatment of L-ascorbate with sodium arsenite also restored the estrous cycle in a regular manner. We concluded that L-ascorbate plays a pivotal role in maintaining normal ovarian activities and brain monoamines in arsenic-treated rats.

Isolation of measles virus from cerebrospinal fluid of children with acute encephalopathy without rash

OBJECTIVE

To determine the viral agent involved in cases of acute encephalopathy in children during an outbreak in Northern India.

DESIGN

Virological and serological studies using serum and cerebrospinal fluid specimens from patients.

METHODS

Serum and CSF specimens were tested by IgM ELISA for IgM antibodies to variety of viruses like Japanese encephalitis, West Nile, Dengue and Measles. The specimens were inoculated into Vero cell monolayer for virus isolation. The viral strains isolated were identified by indirect immunofluorescence test and qualitative in-vitro neutralization test using polyclonal and monoclonal antibodies to measles. Identity of the isolates was reconfirmed using RT-PCR method.

RESULTS

Of the 28 specimens tested, 17 had IgM antibodies to measles. Commercial IgM ELISA kits confirmed the serological findings. Vero cell cultures yielded 4 isolates from CSF and 2 from serum specimens of six different patients. Cytopathic effect was typical of measles. Indirect imunofluorescence using polyclonal and monoclonal antibodies to measles HA protein, confirmed the measles etiology. Neutralization tests reconfirmed the measles strain isolation. RT-PCR amplified product was confirmed as measles.

CONCLUSION

The isolation of measles virus from CSF and serum of children with acute encephalopathy without rash proved the etiological role of measles virus in this outbreak.

Effect of vaginally administered (Ala(8,13,18))-magainin II amide on the morphology of implantation stage endometrium in the rhesus monkey (Macaca mulatta)

Intravaginal administration of an anti-microbial agent, (Ala(8,13,18))-magainin II amide, during blastocyst implantation inhibits pregnancy establishment in a dose-related manner in the rhesus monkey (Macaca mulatta). In the present study, mated female rhesus monkeys were vaginally inserted with tampons containing vehicle (Group 1; n = 5) and test agent (magainin, 0.5 mg/animal; Group 2; n = 6) on cycle day 20. Endometrial tissue samples were collected on Cycle Day 24 from all monkeys and processed for morphometric and ultrastructural analysis. Concentrations of estradiol-17beta, progesterone, and chorionic gonadotrophin in peripheral circulation were determined, which revealed that two monkeys in Group 1 were pregnant while no animals were pregnant in Group 2. Endometrial morphology, however, revealed histologic evidence of pregnancy in three out of the six magainin-treated animals. It appears that intra-vaginal administration of magainin II amide had a marginal effect on the implantation stage endometrium and the initiation of the implantation process in the rhesus monkey.

Bilateral subdural effusion and subcutaneous swelling with normally functioning csf shunt

We report a child with hydrocephalus due to tuberculous meningitis who developed a subcutaneous fluid collection around the ventriculoperitoneal shunt tube entry point, after one month of shunting. On investigation, he had decompressed ventricles with bilateral fronto parietal subdural hygroma. Bifrontal burr hole drainage helped resolution of both subdural effusion and subcutaneous scalp swelling. This complication is unique and its pathogenesis has been postulated.

Porcine carbonyl reductase. structural basis for a functional monomer in short chain dehydrogenases/reductases

Porcine testicular carbonyl reductase (PTCR) belongs to the short chain dehydrogenases/reductases (SDR) superfamily and catalyzes the NADPH-dependent reduction of ketones on steroids and prostaglandins. The enzyme shares nearly 85% sequence identity with the NADPH-dependent human 15-hydroxyprostaglandin dehydrogenase/carbonyl reductase. The tertiary structure of the enzyme at 2.3 A reveals a fold characteristic of the SDR superfamily that uses a Tyr-Lys-Ser triad as catalytic residues, but exhibits neither the functional homotetramer nor the homodimer that distinguish all SDRs. It is the first known monomeric structure in the SDR superfamily. In PTCR, which is also active as a monomer, a 41-residue insertion immediately before the catalytic Tyr describes an all-helix subdomain that packs against interfacial helices, eliminating the four-helix bundle interface conserved in the superfamily. An additional anti-parallel strand in the PTCR structure also blocks the other strand-mediated interface. These novel structural features provide the basis for the scaffolding of one catalytic site within a single molecule of the enzyme.

Multiple conformations of catalytic serine and histidine in acetylxylan esterase at 0.90 A

Acetylxylan esterase (AXEII; 207 amino acids) from Penicillium purpurogenum has substrate specificities toward acetate esters of d-xylopyranose residues in xylan and belongs to a new class of alpha/beta hydrolases. The crystal structure of AXEII has been determined by single isomorphous replacement and anomalous scattering, and refined at 0.90- and 1.10-A resolutions with data collected at 85 K and 295 K, respectively. The tertiary structure consists of a doubly wound alpha/beta sandwich, having a central six-stranded parallel beta-sheet flanked by two parallel alpha-helices on each side. The catalytic residues Ser(90), His(187), and Asp(175) are located at the C-terminal end of the sheet, an exposed region of the molecule. The serine and histidine side chains in the 295 K structure show the frequently observed conformations in which Ser(90) is trans and the hydroxyl group is in the plane of the imidazole ring of His(187). However, the structure at 85 K displays an additional conformation in which Ser(90) side-chain hydroxyl is away from the plane of the imidazole ring of His(187). The His(187) side chain forms a hydrogen bond with a sulfate ion and adopts an altered conformation. The only other known hydrolase that has a similar tertiary structure is Fusarium solani cutinase. The exposed nature of the catalytic triad suggests that AXEII is a pure esterase, i.e. an alpha/beta hydrolase with specificity for nonlipidic polar substrates.

Immunohistochemical localization of insulin-like growth factors I and II at the primary implantation site in the Rhesus monkey

There are various cellular mediators which can affect the process of blastocyst implantation by regulating the proliferation and differentiation of conceptus and maternal endometrial cells. Insulin-like growth factors I (IGF-I) and II (IGF-II) are potent mitogenic and differentiation-promoting growth factors. However, the role of IGF peptides at implantation in primate species is not well understood. The objective of the present study was to immunohistochemically localize IGF-I and IGF-II peptides in trophoblast cells and maternal endometrial cells during lacunar and villous stages of placentation in the Rhesus monkey. Female animals (n = 10) were laparotomized on estimated days 13-16 after fertilization to collect primary implantation sites which were subjected to immunohistochemical staining for IGF-I and IGF-II peptides. Cell-type specificity for IGF-I and IGF-II was evident with a very low level of IGF-I peptide immunolocalized in trophoblast cells lining lacunae, and primary and secondary villi, while moderate to high amounts of IGF-II peptide were detected in lamellar syncytiotrophoblast cells lining lacunae, early villi and cell columns, as well as in migrating trophoblast cells in the extravillous compartment and in endovascular trophoblast cells. The observed presence of IGF-II peptide in differentiated lamellar syncytiotrophoblast cells during the very early stages of implantation and placentation in the Rhesus monkey may be important in their transition to this differentiated cell population. Maternal endometrial cells showed similar distribution profiles for IGF-I and IGF-II. In conclusion, we report differential distribution of IGF-I and IGF-II peptides in trophoblast cell populations at the feto-maternal interface during lacunar and villous stages of gestation in the Rhesus monkey.

Morphological and functional characteristics of rabbit uterine epithelial cells grown on free floating collagen gel

In the present study isolated uterine epithelial cells from normal rabbits were maintained in culture on free floating rat-tail collagen matrix, and the morphological characteristics of these cells were examined. Additionally, the pattern of protein synthesis and secretion by rabbit uterine epithelial cells grown on free floating collagen gels following estradiol and/or progesterone treatment in vitro was examined. Isolated epithelial cells cultured on collagen gels in complete medium containing serum attached to form monlayers, and eventually the gels became free floating and contracted giving rise to luminal arrangements. These cells were cytokeratin positive epithelial cells and were ultrastructurally polarized. These cells also exhibited differential upregulation and down regulation in the synthesis and secretion of proteins in response to estradiol, progesterone, and estradiol plus progesterone. Additionally, a permissive action between progesterone and estradiol in the synthesis of two species of secretory proteins was observed. It however remains to be examined whether different species of proteins produced in vitro in response to estradiol and progesterone bear any association with physiological states in reproductive cycle in this species.

Familial hypertrophic cardiomyopathy mutations in the regulatory light chains of myosin affect their structure, Ca2+ binding, and phosphorylation

The effect of the familial hypertrophic cardiomyopathy mutations, A13T, F18L, E22K, R58Q, and P95A, found in the regulatory light chains of human cardiac myosin has been investigated. The results demonstrate that E22K and R58Q, located in the immediate extension of the helices flanking the regulatory light chain Ca(2+) binding site, had dramatically altered Ca(2+) binding properties. The K(Ca) value for E22K was decreased by approximately 17-fold compared with the wild-type light chain, and the R58Q mutant did not bind Ca(2+). Interestingly, Ca(2+) binding to the R58Q mutant was restored upon phosphorylation, whereas the E22K mutant could not be phosphorylated. In addition, the alpha-helical content of phosphorylated R58Q greatly increased with Ca(2+) binding. The A13T mutation, located near the phosphorylation site (Ser-15) of the human cardiac regulatory light chain, had 3-fold lower K(Ca) than wild-type light chain, whereas phosphorylation of this mutant increased the Ca(2+) affinity 6-fold. Whereas phosphorylation of wild-type light chain decreased its Ca(2+) affinity, the opposite was true for A13T. The alpha-helical content of the A13T mutant returned to the level of wild-type light chain upon phosphorylation. The phosphorylation and Ca(2+) binding properties of the regulatory light chain of human cardiac myosin are important for physiological function, and alteration any of these could contribute to the development of hypertrophic cardiomyopathy.

Spinal dysraphism presenting as acro-osteolysis: report of four cases

The acro-osteolyses are a heterogeneous group of disorders characterized by bone resorption. The disorder may occur as familial, idiopathic, or secondary to vascular, inflammatory, or neurologic conditions. Acro-osteolysis is rare in association with spinal dysraphism. It is even rarer for it to be the presenting symptom in spinal dysraphism. We report here four patients in whom the diagnosis of spinal dysraphism was established while investigating for the various causes of acro-osteolysis. All four patients presented with trophic changes and acro-osteolysis. Hyperhidrosis in the affected limb was seen in three patients. One patient had leg pain, the others had no sensory or motor deficits. Magnetic resonance imaging showed spinal dysraphism in all four patients.

Ictal deafness--a report of three cases

Though negative phenomena like motor inhibition, blindness or aphasia are described as an ictal manifestation of seizures, ictal deafness has not been reported so far. We observed transient ictal deafness in three cases of partial seizures. One of them had seizure spread to the temporal lobe to produce a complex partial seizure. Two of them have CT-detected lesions in the left temporal/parietal area. The other one had left temporal focus on EEG with a normal imaging study. The mechanism of such ictal negative phenomena is unclear. An epileptic focus around the primary auditory cortex, dampening its receptive ability may manifest as cortical deafness.