Reversible posterior leukoencephalopathy syndrome: a report of 2 cases

Reversible posterior leukoencephalopathy syndrome (RPLE) is an increasingly recognised disorder, most commonly associated with malignant hypertension, toxaemia of pregnancy or the use of immunosuppressive agents. Two cases of RPLE syndrome occurring in the setting of accelerated hypertension and eclampsia are described. Both patients had seizures, altered sensorium and typical findings on neuroimaging. They had complete clinical and radiological recovery. The clinical course, pathophysiology and neuroimaging features of RPLE syndrome are discussed.

Interactions of beta-carotene and cigarette smoke in human bronchial epithelial cells

Results from recent intervention trials indicated that supplemental beta-carotene enhances lung cancer incidence and mortality among smokers. It was hypothesized that beta-carotene was exerting its deleterious effects through a prooxidant effect in the smoke-exposed lung. To test this hypothesis we examined the interactions of beta-carotene and cigarette smoke in transformed human bronchial epithelial cells. We studied the effects of beta-carotene supplementation on rates of gas phase smoke-induced lipid peroxidation, membrane damage and depletion of endogenous antioxidants in BEAS-2B cells. Gas phase cigarette smoke caused cellular beta-carotene levels to decrease over time. The oxidation of beta-carotene by smoke generated various oxidation products, including 4-nitro-beta-carotene, beta-apo-carotenals and beta-carotene epoxides. Peroxidation of membrane lipids by gas phase smoke progressed at a slower rate than did oxidation of beta-carotene and incorporation of beta-carotene into the cells did not enhance the overall rate of lipid peroxidation. Additionally, lactate dehydrogenase release during smoke exposure was also unaffected by the presence or absence of beta-carotene in cells. beta-Carotene incorporation in cells was not found to accelerate the rates of alpha-tocopherol and glutathione depletion by cigarette smoke. Our results indicate that beta-carotene is more sensitive than lipids to cigarette smoke oxidation, but that this preferential oxidation of beta-carotene does not lead to a prooxidant effect in human bronchial epithelial cells.

A wireless electrochemiluminescence detector applied to direct and indirect detection for electrophoresis on a microfabricated glass device

A novel electrochemiluminescence (ECL) detector is presented in this article. The detector is applied for micellar electrokinetic chromatographic separation of dichlorotris(2,2'-bipyridyl)ruthenium(II) hydrate [Ru-(bpy)] and dichlorotris(1,10-phenanthroline)ruthenium-(II) hydrate [Ru(phen)] on a microfabricated glass device. It consists of a microfabricated "U"-shape floating platinum electrode placed across the separation channel. The legs of the U function respectively as working and counter electrode. The required potential difference for the ECL reaction is generated at the Pt electrode by the electric field available in the separation channel during electrophoretic separation. Initial experiments demonstrate a micellar electrokinetic separation and direct ECL detection of 10(-16) mol of Ru(phen) (10(-6) M) and 4.5 x 10(-16) mol of Ru(bpy) (5 x 10(-6) M). Also, preliminary results show the indirect detection of three amino acids. The high voltage at the location of detection does not interfere with the electrochemistry.

Immunization with HIV-1 subtype B gp160-DNA induces specific as well as cross reactive immune responses in mice

BACKGROUND & OBJECTIVES

HIV-1 gp160 is an important structural protein for the virus cell interaction and virus entry. Therefore, it is regarded as the most important target for HIV-1 vaccine development. In this study we investigated the use of HIV-1 gp160-DNA construct in eliciting specific and cross reactive cell mediated immune response in mice.

METHODS

DNA segment encoding env, tat and rev genes of HIV-1 subtype B (strain BRU-2) was amplified and cloned into mammalian expression vector pCI to generate plasmid pCIBRU-TRE. Mice were injected intramuscularly four times at biweekly intervals with 100 micrograms/dose of pCIBRU-TRE in normal saline, and subsequently analysed for anti HIV-envelope (env) immune responses.

RESULTS

A low antibody level was detected as determined by ELISA after 4 doses. Subsequent inoculations failed to increase the antibody titres significantly. Spleen cells from the immunized mice were used for the detection of cellular immune response by lymphocyte proliferation assays (LPA), in vitro production of cytokines and cytotoxic T lymphocyte (CTL) assays. T cell response which was seen from the second week onwards, persisted even at the end of 24 wk following the last dose. Similar levels of T cell proliferation were observed on stimulation with either homologous or heterologous peptides. Cytokine studies showed a Th1 type of response. A cross clade MHC class I restricted CTL response was observed against target cells stimulated with either homologous or heterologous HIV antigens.

INTERPRETATION & CONCLUSION

This study demonstrated that DNA encoding full length HIV-1 env glycoprotein gp160 induces specific as well as cross reactive cell mediated immune responses in mice. However, the induction of antibody response was poor.

Tumourigenic studies on deltamethrin in Swiss albino mice

Deltamethrin, an alpha-cyano type II synthetic pyrethroid insecticide is used to control a wide range of insects on a variety of crops. Deltamethrin is reported to cause many adverse effects on non-target species. Deltamethrin is reported to cause DNA damage and micronuclei induction in human lymphocytes. It is highly toxic for other organisms such as aquatic invertebrates, fish and Daphnia. About the tumorigenic risk (both tumour initiating and promoting) associated with deltamethrin exposure, very few reports are available in literature. In the present set of investigations, deltamethrin has been evaluated for its tumorigenic and co-carcinogenic (tumour initiating and tumour promoting) potential following long term dermal exposure in Swiss albino mice. The results revealed that deltamethrin has only tumour initiating potential in both the sexes of Swiss albino mice, initiated with deltamethrin and promoted by standard tumour promoter, 12-O-tetra decanoyl phorbol-13-acetate (TPA). In the single dose initiated mice (deltamethrin 4 mg/kg body weight, once only), 44% males and 43% females developed benign skin tumours. A much higher incidence of tumorigenesis was recorded in multiple dose initiated animals (deltamethrin 4 mg/kg body weight, three times per week for 3 weeks), where 71% male and 75% female mice developed tumours at the site of application of deltamethrin. Deltamethrin exposure failed to show any tumour promoting and complete tumorigenic potential at all the three tested dose levels.

Transplacental carcinogenic potential of the carbamate fungicide mancozeb

We evaluated the effects of mancozeb (Dithane M4-5), a protective carbamate fungicide, on transplacental carcinogenesis in Swiss albino mice. Mancozeb, a polymeric complex of ethylene bis (dithiocarbamate) manganese with zinc salt, is reported to possess carcinogenic and cocarcinogenic activity in various tumor models. In the present study, pregnant Swiss albino mice were administered mancozeb intraperitoneally on the 14th day of gestation. The first filial generation (F1 progeny) was promoted with a well-known tumor promoter 12-o-tetradecanoyl phorbol-13-acetate (TPA). The results revealed a significantly high tumor incidence (72%) in the F1 progeny of the animals initiated with mancozeb or a well known carcinogen 7,12-dimethyl benzanthracene (DMBA) and promoted with TPA in comparison to animals that were either from mothers given only the vehicle (DMSO) and promoted with TPA in F1 progeny or not promoted with TPA in F1 progeny. No significantly higher tumor incidence was observed in any other experimental groups. These results suggest that mancozeb or its metabolites are capable of crossing the placental barrier and can exert DNA damage and tumor initiating consequences in the fetal cells that, after promotion with TPA, get converted into neoplastic cells.

Axonal Guillain-Barré syndrome: a critical review

Axonal Guillain-Barré Syndrome (GBS) was first described by Feasby et al. in 1986, challenging the existent notion of GBS being a primarily demyelinating disease. The severe course and slow recovery commonly seen in these patients was ascribed to axonal degeneration. Other authors challenged this claim on several grounds. Amidst these controversies, epidemics of a similar illness were reported from China, which were given the acronym AMAN, having exclusive motor involvement in contrast to the cases already described in which both motor and sensory involvement were present (AMSAN). Pathologically, Wallerian degeneration, minimal lymphocytic response, absent demyelination or inflammation and periaxonal macrophages are prominent features. Ultrastructural studies have revealed node of Ranvier to be the prime target of immune attack. A frequent occurrence of antecedent Campylobacter jejuni infection and a strong association between elevated titres of IgG GM1 and axonal GBS on a background of preceding C. jejunii infection has been observed and molecular mimicry between lipopolysaccharides of C. jejuni and neural epitopes has been proposed as a mechanism of injury. Clinically axonal variant is similar to AIDP, but a more severe course, with frequent respiratory involvement, ventilator dependence and significant residue may be seen. Diagnosis is essentially electrophysiological. Treatment is similar to AIDP, preferential benefit of either IVIG or plasmapheresis needs to be further evaluated. A critical review of existing literature in axonal GBS is presented.

Structure of outer membrane protein A transmembrane domain by NMR spectroscopy

We have determined the three-dimensional fold of the 19 kDa (177 residues) transmembrane domain of the outer membrane protein A of Escherichia coli in dodecylphosphocholine (DPC) micelles in solution using heteronuclear NMR. The structure consists of an eight-stranded beta-barrel connected by tight turns on the periplasmic side and larger mobile loops on the extracellular side. The solution structure of the barrel in DPC micelles is similar to that in n-octyltetraoxyethylene (C(8)E(4)) micelles determined by X-ray diffraction. Moreover, data from NMR dynamic experiments reveal a gradient of conformational flexibility in the structure that may contribute to the membrane channel function of this protein.

Management of community acquired respiratory infections

Respiratory tract infections (RTIs) are the most common diagnosis in children visiting outpatient departments in both developing and developed countries. The impact of these infections is enormous in terms of total morbidity and mortality. Management of these infections requires a meticulous evaluation and a comprehensive but rational use of supportive, symptomatic and specific therapy. Antibiotics are widely prescribed for the treatment of community acquired respiratory infections to compensate uncertainties of diagnosis and prognosis; unnecessary anti-microbial drug therapy is expensive and resistance by respiratory pathogens is increasing at an exponential rate at a time when new anti-viral as well as anti-bacterial agents are being introduced into the therapeutic armamentarium. Major dilemmas persist regarding symptomatic therapy and the indications of antimicrobial agents. A comprehensive but brief review along with latest protocols and advancements is the management of community acquired respiratory infections in children in cited.

Albendazole therapy for solitary persistent cysticercus granuloma

Use of Albendazole therapy for the treatment of patients having persisting intracranial solitary cysticercus granuloma is controversial. Most of the times these patients are treated empirically with variety of drugs for variable period. Some authors advocate biopsy before definitive treatment. 25 patients having radiologicaly persistent solitary cysticercus granuloma (>6 months) were given 15 days course of oral albendazole (15 mg/kg body wt). Cranial CT scan was repeated one month after the completion of albendazole therapy. It was evaluated for complete resolution, partial response (> 50% decrease in size of lesion) or no change as compared to previous scan. 12 patients (48%) showed complete resolution, 4 patients (16%) showed a partial response, while 9 patients (36%) did not show any change on follow up. Albendazole therapy may be useful for patients having persistent cysticercus granuloma.

Cubitus varus: problem and solution

A lateral closing wedge osteotomy was performed in 39 children with cubitus varus deformity resulting from a supracondylar fracture. All had a deformity of 15 degrees or more, with 5 having more than 30 degrees of varus. The osteotomy was fixed by three different methods. In 8 cases the osteotomy was fixed with 2 parallel Kirschner wies (group K). A modified French technique (group TBW) was used in 25 cases and held with a figure-of-8 wire loop tightened over the screw heads. In the last 6 cases the osteotomy was fixed with an external fixator (group EF). The only poor result (i.e. loss of carrying angle of more than 10 degrees and loss of flexion and extension of 20 degrees or more) was in group K due to pin tract infection and loosening of the K-wires. In the TBW group 5 patients lost some degree of correction, and none became infected. In the EF group no patient suffered pin tract infection or loss of correction. Based on our experience and results, we feel that the best age at which to correct cubitus varus deformity was 6-11 years and that the external fixator is a safe, effective and reliable method to fix the osteotomy. We propose this method of fixation as a good alternative method to the modified French technique, especially in cases of severe cubitus varus deformity, where removal of a large wedge can produce a big step at the osteotomy site, increasing the possibility of disengagement of the stainless steel wire from the screw head. In addition, minor postoperative modifications of correction, if required, can also be performed. It also avoids a second operation for implant removal.

Prediction of relapse after lymph node dissection for germ cell tumours: can salvage chemotherapy be avoided?

Salvage chemotherapy has been used by some oncology centres for patients with residual malignant or immature elements in retroperitoneal lymph node dissections removed for metastatic non-seminomatous germ cell tumours. However, surveillance of these patients shows that many are cured by surgery alone. 118 retroperitoneal lymph node dissections for metastatic non-seminomatous germ cell tumours were reviewed and the morphology seen within them was quantified. 28 of these had immature or malignant elements and had been treated by surveillance before administration of further chemotherapy. The proliferation rate in these cases was assessed by immunochemistry. The proliferation index and the amount of embryonal carcinoma (EC) were both predictors of recurrence and therefore the need for further chemotherapy. Patients with greater than 25% of EC had an 84% chance of relapse and those with a Ki-67 index of greater than 50% had a 71% chance of relapse. The two tests had a positive predictive value of 83% and 71%, respectively. Patients with such a high risk of recurrence could be considered for post-operative adjuvant therapy at this point whilst others would be suitable for a watchful waiting approach.

Isolated dislocation of the second metacarpal at both ends

A dislocation of the second metacarpal at both ends is reported herein for the first time. Six weeks after injuring her right hand in a fall while climbing stairs, a 34-year-old woman visited our clinic with pain, swelling, and deformity of her hand. The radiographs showed a volar dislocation of the head and a dorsal dislocation of the base of the second metacarpal. The probable mechanism of injury was the hyperextension at the metacarpophalangeal joint; this force dislocated the metacarpal head toward the volar plate. Force then further continued along the second metacarpal shaft in the hyperflexed wrist, thus dislocating the base dorsally. We performed an open reduction and K-wire fixation of the second metacarpophalangeal joint and an arthrodesis of the second carpometacarpal joint. At the six-month follow-up, the patient had restricted flexion (0 to 50 degrees) at the second metacarpophalangeal joint, but full range of motion at the interphalangeal joints. The grip strength on the right side was 70% of that measured in the uninvolved hand. Key Words: Dislocation, Second metacarpal.

Cure in a case of primary hepatic lymphoma

Primary hepatic lymphoma is rare malignancy. Cures in this disease are uncommon. We report a young male who was diagnosed as a case of primary lymphoma of the liver in 1992. He was treated with chemotherapy only, which included CHOP (Cyclophosphamide, Adriamycin, Vincristine and Prednisolone) - six cycles; and IMVP-16 (Ifosfamide, Methotrexate and Etoposide) -four cycles. The patient is now disease free and alive for more than five years.

Hill-Sachs type lesion of the femoral head in a case of hip instability

A Hill-Sachs lesion of the shoulder is an indicator of shoulder instability. Hip instability is also a well-recognized phenomenon. However, no operative or arthroscopic features have previously been reported that support the diagnosis of hip instability. We present a case report of a Hill-Sachs type lesion of the femoral head in a patient with acetabular dysplasia revealed by arthroscopy of the hip. We suggest that finding a Hill-Sachs type lesion of the femoral head may also be regarded as indicative of joint instability, just as it is in the shoulder.

Rapidly progressive fatal cutaneous T cell lymphoma with a trauma-related presentation

A case of rapidly progressive cutaneous T cell lymphoma with a trauma-related presentation in a 73-year-old man is reported. Clinically, the patient presented with an ulcerated cutaneous mass at the site of trauma-related hematoma of the leg. The histopathology was that of tumor phase cutaneous T cell lymphoma with involvement of the skin and subcutis. The diagnostic challenge of this clinical presentation and the rapidly progressive course are highlighted.

Reactions of Genistein with alkylperoxyl radicals

Antioxidant actions of the soy isoflavone genistein are believed to contribute to its overall chemopreventive activity. However, the mechanisms of its antioxidant reactions remain unknown. The objective of this study was to characterize the reaction products of genistein (5,7,4'-trihydroxyisoflavone) with peroxyl radicals generated by thermolysis of 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN). Genistein oxidations with AMVN-derived peroxyl radicals yielded orobol (5,7,3',4'-tetrahydroxyisoflavone), a hydroxylated derivative of genistein, and several stable adducts of 4'-oxogenistein with AMVN-derived radicals. Some of these adducts include novel structures resulting from secondary oxidations of the AMVN-derived moiety. For all the observed oxidation products, the modifications occurred on the B-ring of the molecule. Genistein oxidation product structures provide potentially useful markers of genistein antioxidant chemistry.

Refolded outer membrane protein A of Escherichia coli forms ion channels with two conductance states in planar lipid bilayers

Outer membrane protein A (OmpA), a major structural protein of the outer membrane of Escherichia coli, consists of an N-terminal 8-stranded beta-barrel transmembrane domain and a C-terminal periplasmic domain. OmpA has served as an excellent model for studying the mechanism of insertion, folding, and assembly of constitutive integral membrane proteins in vivo and in vitro. The function of OmpA is currently not well understood. Particularly, the question whether or not OmpA forms an ion channel and/or nonspecific pore for uncharged larger solutes, as some other porins do, has been controversial. We have incorporated detergent-purified OmpA into planar lipid bilayers and studied its permeability to ions by single channel conductance measurements. In 1 M KCl, OmpA formed small (50-80 pS) and large (260-320 pS) channels. These two conductance states were interconvertible, presumably corresponding to two different conformations of OmpA in the membrane. The smaller channels are associated with the N-terminal transmembrane domain, whereas both domains are required to form the larger channels. The two channel activities provide a new functional assay for the refolding in vitro of the two respective domains of OmpA. Wild-type and five single tryptophan mutants of urea-denatured OmpA are shown to refold into functional channels in lipid bilayers.

Pre-natal ventriculomegaly and hydrocephalus

Ultrasonic imaging of the human fetal brain has allowed ventriculomegaly and hydrocephalus to be categorized. In this study 40 fetuses with ventriculomegaly and 21 with an Arnold-Chiari malformation and a myelomeningocele had ventriculomegaly that resolved, stabilised or progressed in utero. Within the progressive group were those with hydrocephalus, hydrocephalus being defined as expansion of the cerebral ventricular atria together with disproportionate increase in the head circumference. The prognosis for fetuses with resolving and stable ventriculomegaly was good, reflecting the fact that the ventricular dilatation in these cases was probably caused by delayed parenchymal and cerebrospinal fluid pathway development. Whereas the prognosis for progressive ventriculomegaly was generally poor, suggesting that the causes were likely to have been chromosomal, genetic, an infective agent or a catastrophic event which had an adverse effect on parenchymal development. The causes of hydrocephalus also adversely affected brain development but additional damage was caused by raised intracranial pressure.

Modulation of liposomal membrane fluidity by flavonoids and isoflavonoids

The polyphenolic structures of flavonoids and isoflavonoids confer them with the ability to scavenge free radicals and to chelate transition metals, a basis for their potent antioxidant abilities. Another possible contributory mechanism toward their antioxidant activities is their ability to stabilize membranes by decreasing membrane fluidity. In this study, the effects of representative flavonoids, isoflavonoids, and their metabolites on membrane fluidity and their preferential localization in the membrane were investigated using large unilamellar vesicles (LUVs) as the membrane models. These results were compared with those of cholesterol and alpha-tocopherol. Changes in fluorescence anisotropy values for a series of n-(9-anthroyloxy) fatty acid probes (n = 6, 12, 16) upon addition of the test compounds were used to monitor alterations in membrane fluidity at graded depths in lipid bilayer. The results of the study suggest that the flavonoids and isoflavonoids, similar to cholesterol and alpha-tocopherol, partition into the hydrophobic core of the membrane and cause a dramatic decrease in lipid fluidity in this region of the membrane. Localization of flavonoids and isoflavonoids into the membrane interiors and their resulting restrictions on fluidity of membrane components could sterically hinder diffusion of free radicals and thereby decrease the kinetics of free radical reactions.

A Drosophila Axin homolog, Daxin, inhibits Wnt signaling

The vertebrate Axin protein, the product of the mouse fused gene, binds to beta-catenin to inhibit Wnt signaling. We have identified a homolog of Axin in Drosophila, Daxin. Using double-stranded RNA interference, we generated loss-of-function phenotypes that are similar to overexpression of the Drosophila Wnt gene wingless (wg). Overexpression of Daxin produces phenotypes similar to loss of wg. In addition, we show that Daxin overexpression can modify phenotypes elicited by wg and another Drosophila Wnt gene, DWnt-2. Using immunoprecipitation of endogenous Daxin protein from embryos we show that Daxin interacts with Armadillo and Zeste-white 3. The loss-of-function and overexpression phenotypes show that Daxin, like its mammalian counterpart, acts as a negative regulator of wg/Wnt signaling.

Microsecond motions of the lipids associated with trypsinized Na,K-ATPase membranes. Progressive saturation spin-label electron spin resonance studies

The microsecond motions of spin-labeled lipids associated with the Na(+)/K(+)-transporting ATP hydrolase (Na,K-ATPase) in native and tryptically shaved membranes from Squalus acanthias have been studied by progressive saturation electron spin resonance (ESR). This includes both the segmental mobility of the lipid chains and the exchange dynamics of the lipids interacting directly with the protein. The lipids at the protein interface display a temperature-dependent chain mobility on the submicrosecond time scale. Exchange of these lipids with those in the bulk bilayer regions of the membrane takes place on the time scale of the nitroxide spin-lattice relaxation, i.e., in the microsecond regime. The off-rates for exchange directly reflect the specificity of ionized fatty acids relative to protonated fatty acids for interaction with the Na,K-ATPase. These essential features of the lipid dynamics at the intramembranous protein surface, namely, a temperature-dependent exchange on the microsecond time scale that reflects the lipid selectivity, are preserved on removing the extramembranous parts of the Na,K-ATPase by extensive trypsinization.

Primary progressive aphasia : a case report

Primary progressive aphasia is due to focal left perisylvian degeneration and manifests with progressive decline in language function for two or more years. There is preservation of cognitive functions and activities of daily living continue to be normal. We report a case of progressive aphasia in a 65 year old lady.

Oral versus intravenous corticosteroids in children hospitalized with asthma

BACKGROUND

Previous studies have demonstrated that in the emergency treatment of an asthma exacerbation, corticosteroids used in conjunction with beta-agonists result in lower hospitalization rates for children and adults. Furthermore, orally administered corticosteroids have been found to be effective in the treatment of outpatients with asthma. However, similar data in inpatients is lacking.

OBJECTIVE

The purpose of this study was to determine the efficacy of oral prednisone versus intravenous methylprednisolone in equivalent doses for the treatment of an acute asthma exacerbation in hospitalized children.

METHODS

We conducted a randomized, double-blind, double-placebo study comparing oral prednisone at 2 mg/kg/dose (maximum 120 mg/dose) twice daily versus intravenous methylprednisolone at 1 mg/kg/dose (maximum 60 mg/dose) four times daily in a group of patients 2 through 18 years of age hospitalized for an acute asthma exacerbation. All patients were assessed by a clinical asthma score 3 times a day. The main study outcome was length of hospitalization; total length of stay and time elapsed before beta-agonists could be administered at 6-hour intervals. Duration of supplemental oxygen administration and peak flow measurements were secondary outcome measures.

RESULTS

Sixty-six patients were evaluated. Children in the prednisone group had a mean length of stay of 70 hours compared with 78 hours for the methylprednisolone group (P =.52). Children in the prednisone group were successfully weaned to beta-agonists in 6-hour intervals after 59 hours compared with 68 hours for the methylprednisolone group (P =.47). Patients receiving prednisone required supplemental oxygen for 30 hours compared with 52 hours for the methylprednisolone group (P =.04).

CONCLUSION

There was no difference in length of hospital stay between asthmatic patients receiving oral prednisone and those receiving intravenous methylprednisolone. Because hospitalization charges are approximately 10 times greater for intravenous methylprednisolone compared with oral prednisone, the use of oral prednisone to treat inpatients with acute asthma would result in substantial savings.

Probing the role of C-1 ester group in Naja naja phospholipase A2-phospholipid interactions using butanetriol-containing phosphatidylcholine analogues

To understand the role of the ester moiety of the sn-1 acyl chain in phospholipase A2-glycerophospholipid interactions, we introduced an additional methylene residue between the glycerol C1 and C2 carbon atoms of phosphatidylcholines, and then studied the kinetics of hydrolysis and the binding of such butanetriol-containing phospholipids with Naja naja phospholipase A2. Hydrolysis was monitored by using phospholipids containing a NBD-labelled sn-2 acyl chain and binding was ascertained by measuring the protein tryptophan fluorescence. The hydrolysis of butanetriol-containing phospholipids was invariably slower than that of the glycerol-containing phospholipids. In addition, the enzyme binding with the substrate was markedly decreased upon replacing the glycerol residue with the 1,3,4-butanetriol moiety in phosphatidylcholines. These results have been interpreted to suggest that the sn-1 ester group in glycerophospholipids could play an important role in phospholipase A2-phospholipid interactions.

Trivial injuries, associated congenital anomaly and medicolegal interpretation of death

Congenital hypoplasia of the odontoid process is a relatively rare phenomenon. A case is presented of a 12-year-old girl who was admitted to hospital with a history of having sustained trivial external injuries when falling after an alleged push. Later, she developed signs of compression of the spinal cord in the cervical region, resulting in quadriplegia and muscle wasting. A laminectomy was performed to relieve the symptoms but the child died 2 1/2 months later. Autopsy revealed a congenital anomaly of the atlas and axis vertebrae in the form of hypoplasia of the dens. The case being associated with a criminal assault, the post-mortem analysis and autopsy were significant in resolving medicolegal issues pertaining to the assailant, the operating surgeon and the law-enforcement agencies.

Protein-induced vertical lipid dislocation in a model membrane system: spin-label relaxation studies on avidin-biotinylphosphatidylethanolamine interactions

The change in vertical location of spin-labeled N-biotinyl phosphatidylethanolamine in fluid-phase dimyristoyl phosphatidylcholine bilayer membranes, on binding avidin to the biotinyl headgroup, has been investigated by progressive saturation electron spin resonance measurements. Spin-labeled phospholipids were present at a concentration of 1 mol%, relative to total membrane lipids. For avidin-bound N-biotinyl phosphatidylethanolamine spin-labeled on the 8 C atom of the sn-2 chain, the relaxation enhancement induced by 30 mM Ni2+ ions confined to the aqueous phase was 2.5 times that induced by saturating molecular oxygen, which is preferentially concentrated in the hydrophobic core of the membrane. For phosphatidylcholine also spin-labeled at the 8 position of the sn-2 chain, this ratio was reversed: the relaxation enhancement by Ni2+ ions was half that induced by molecular oxygen. In the absence of avidin, the enhancement by either relaxant was the same for both spin-labeled phospholipids. For a double-labeled system, in which both N-biotinyl phosphatidylethanolamine and phosphatidylcholine were spin-labeled on the 12 C atom of the sn-2 chain, the relaxation rate in the absence of avidin was greater than that predicted from linear additivity of the corresponding singly labeled systems, because of mutual spin-spin interactions between the two labeled lipid species. On binding of avidin to the N-biotinyl phosphatidylethanolamine, this relaxation enhancement by mutual spin-spin interaction was very much decreased. These results indicate that, on binding of avidin to the lipid headgroup, N-biotinyl phosphatidylethanolamine is lifted vertically within the membrane, relative to the phosphatidylcholine host lipids. The specific binding of avidin to N-biotinyl phosphatidylethanolamine parallels the liftase activity proposed for activator proteins associated with the action of certain gangliosidases.

Superior sagittal sinus and inferior vena cava thrombosis with acute Budd-Chiari syndrome

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Volar dislocation of multiple carpometacarpal joints: report of four cases

Four acute cases of volar carpometacarpal dislocations of the medial four metacarpals were treated in our hospital's emergency room. Our initial diagnosis after clinical examination was confirmed by routine x-rays of the hand. Closed reduction was followed by percutaneous fixation of the carpometacarpal joints with Kirschner wires. Satisfactory function of the hand was obtained in all cases.

Antioxidant activities of isoflavones and their biological metabolites in a liposomal system

Genistein and daidzein, the two major soy isoflavones, principally occur in nature as their glycosylated or methoxylated derivatives, which are cleaved in the large intestine to yield the free aglycones and further metabolites. The objective of this study was to compare the antioxidant activities of genistein and daidzein with their glycosylated and methoxylated derivatives and also those of their human metabolites. The abilities of these compounds to inhibit lipid peroxidation in a liposomal system were evaluated using fluorescence spectroscopy, and structural criteria that enhance antioxidant activity were established. The peroxidation initiators employed in the study were Fe(II) and Fe(III) metal ions and aqueous-phase, azo-derived peroxyl radicals. Both the parent isoflavonoids and their metabolites were more effective at suppressing metal-ion-induced peroxidations than the peroxyl-radical-induced peroxidation. Antioxidant activities for the isoflavone metabolites were comparable to or superior to those for the parent compounds. Equol and its 4-hydroxy and 5-hydroxy derivatives were the most potent antioxidants in the study, suggesting that absence of the 2, 3-double bond and the 4-oxo group on the isoflavone nucleus enhances antioxidant activity. Additionally, the number and position of hydroxyl groups were determining factors for isoflavonoid antioxidant activity, with hydroxyl substitution being of utmost importance at the C-4' position, of moderate importance at the C-5 position, and of little significance at the C-7 position.

Lipaemia retinalis

PURPOSE

To present a patient with the rare condition of lipaemia retinalis and discuss the clinical features of this condition and its association with elevated triglyceride levels.

METHODS

Clinical evaluation of the patient, including fundus photographs before and after the initiation of a low fat diet, was undertaken.

RESULTS

Lowering of serum triglyceride and cholesterol levels was associated with complete resolution of the clinical picture of lipaemia retinalis.

CONCLUSIONS

Lipaemia retinalis is a rare condition that is related to markedly elevated triglyceride levels. Lowering triglycerides levels leads to resolution of the clinical picture of this disease.

Structure-activity relationships for antioxidant activities of a series of flavonoids in a liposomal system

Structurally diverse plant phenolics were examined for their abilities to inhibit lipid peroxidation induced either by Fe(II) and Fe(III) metal ions or by azo-derived peroxyl radicals in a liposomal membrane system. The antioxidant abilities of flavonoids were compared with those of coumarin and tert-butylhydroquinone (TBHQ). The antioxidant efficacies of these compounds were evaluated on the basis of their abilities to inhibit the fluorescence intensity decay of an extrinsic probe, 3-(p-(6-phenyl)-I,3,5-hexatrienyl)phenylpropionic acid (DPH-PA), caused by the free radicals generated during lipid peroxidation. All the flavonoids tested exhibited higher antioxidant efficacies against metal-ion-induced peroxidations than peroxyl-radical-induced peroxidation, suggesting that metal chelation may play a larger role in determining the antioxidant activities of these compounds than has previously been believed. Distinct structure-activity relationships were also revealed for the antioxidant abilities of the flavonoids. Presence of hydroxyl substituents on the flavonoid nucleus enhanced activity, whereas substitution by methoxy groups diminished antioxidant activity. Substitution patterns on the B-ring especially affected antioxidant potencies of the flavonoids. In cases where the B-ring could not contribute to the antioxidant activities of flavonoids, hydroxyl substituents in an catechol structure on the A-ring were able to compensate and become a larger determinant of flavonoid antioxidant activity.

Selectivity of lipid-protein interactions with trypsinized Na, K-ATPase studied by spin-label EPR

The selectivity of the lipid-protein interactions in trypsinised Na, K-ATPase membranes from Squalus acanthias has been determined by using EPR spectroscopy with different lipid probes spin-labelled on the 14-C atom of the fatty acid chain. From measurements at low ionic strength and different pH values, the pattern of selectivity is: (stearic acid)->(phosphatidylserine)->(stearic acid)0>(phosphatidylcholine)+/-, where superscripts indicate the formal electrostatic charge on the lipid headgroup. This is in the same order as that determined with native Na,K-ATPase membranes [M. Esmann, D. Marsh, Biochemistry 24 (1985) 3572-3578]. The selectivity for phosphatidylserine is independent of pH, over the range pH 6.0-9. 0, as found also for native membranes. For membranes trypsinised in the presence of Rb+ ions, and in the presence of Na+ (which allows more extensive proteolysis), the relative association constants, Kr, of all lipids are the same as for control membranes, with the exception of ionised (stearic acid)- that shows the highest specificity. Therefore, both the stoichiometry and the principal determinants of the specificity of lipid-protein interaction are preserved on extensive trypsinisation of Na,K-ATPase membranes. This has implications for the location and arrangement of those amino acid side chains that determine the lipid selectivity of the native Na,K-ATPase.

Airway inflammation in young marijuana and tobacco smokers

Forty healthy young subjects, ages 20 to 49 yr, underwent videobronchoscopy, mucosal biopsy, and bronchial lavage to evaluate the airway inflammation produced by habitual smoking of marijuana and/or tobacco. Videotapes were graded in a blinded manner for central airway erythema, edema, and airway secretions using a modified visual bronchitis index. The bronchitis index scores were significantly higher in marijuana smokers (MS), tobacco smokers (TS), and in combined marijuana/tobacco smokers (MTS), than in nonsmokers (NS). As a pathologic correlate, mucosal biopsies were evaluated for the presence of vascular hyperplasia, submucosal edema, inflammatory cell infiltrates, and goblet cell hyperplasia. Biopsies were positive for two of these criteria in 97% of all smokers and for three criteria in 72%. By contrast, none of the biopsies from NS exhibited greater than one positive finding. Finally, as a measure of distal airway inflammation, neutrophil counts and interleukin-8 (IL-8) concentrations were determined in bronchial lavage fluid. The percentage of neutrophils correlated with IL-8 levels and exceeded 20% in 0 of 10 NS, 1 of 9 MS, 2 of 9 TS, and 5 of 10 MTS. We conclude that regular smoking of marijuana by young adults is associated with significant airway inflammation that is similar in frequency, type, and magnitude to that observed in the lungs of tobacco smokers.

Subsyndromes of chronic schizophrenia: a phenomenological study

Statistical grouping of clinical symptoms and signs is one method of classifying schizophrenia. This study attempted to find factors of symptoms generated through clinical ratings on three scales, namely the Scale for the Assessment of Positive Symptoms (SAPS), the Scale for the Assessment of Negative Symptoms (SANS) and the Comprehensive Psychopathological Rating Scale (CPRS) in a sample of 80 stable chronic schizophrenics diagnosed by DSM-III-R. It was found that the positive-negative dichotomy could not be replicated. Inappropriate affect was found to be a clear misfit in the cluster of negative symptoms. Inclusion of CPRS led to the generation of a factor loading high on depressive and asthenic items, and this could be clearly distinguished from the factor of negative symptoms. This factor had not hitherto been identified.

Coccidioidomycosis and sarcoidosis. Multiple recurrences

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Novel thermal phase transition behavior of phosphatidylcholine analogs containing 1,2,4-butanetriol as their backbone

The sn-glycerol moiety in 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) was replaced by the rac-1,2,4-butanetriol residue, and the aqueous dispersions of the resulting DPPC analogs, viz. 1,2-dihexadecanoyloxy-rac-but-4-yl-[2-(trimethyl-ammonium)ethyl]ph osphate (1,2-bPC) and 1,3-dihexadecanoyloxy-rac-but-4-yl-[2-(trimethylammonium)ethyl]pho sphate (1,3-bPC), were characterized by differential scanning calorimetry (DSC) and fluorescence polarization technique. Also, the corresponding (3R)-isomer of 1,3-bPC (1,3-(3R)bPC) was prepared and characterized by DSC. While the thermal phase transition properties of 1.2-bPC were similar to that of racemic DPPC, 1.3-bPC in identical conditions showed an abnormal property by exhibiting a metastable phase behavior at about 15 degrees C. This abnormal property was associated only with the racemic mixture and was completely absent in its 3R-isomer. 1,3-(3R)bPC, unlike DPPC, showed only two high enthalpy transitions at about 29.7 degrees C (delta H, 7.45 kcal/mol) and 35.3 degrees C (delta H, 6.93 kcal/mol). These results clearly demonstrate that an insertion of one additional methylene residue between the glycerol C1 and C2 carbons in DPPC markedly alters its thermal phase transitional properties, whereas these properties remain virtually unchanged if a similar chemical change is introduced between the glycerol C2 and C3 carbon atoms.