Tyrosinase inhibitor-loaded microsponge drug delivery system: new approach for hyperpigmentation disorders.

OBJECTIVE: The aim of the present investigation was to design and formulate appropriate form of glabridin, using microsponge drug delivery system. METHOD: Microsponges were prepared by emulsion solvent evaporation method and characterized by drug loading, infrared spectroscopy and scanning electron microscopy. In vitro diffusion studies of gel formulation were performed using ethanol: phosphate buffer (1:1) mixture as receptor medium. Animal studies were carried out using brownish guinea pigs with UV-induced pigmentation model. RESULTS: Prepared microsponges were predominantly yellowish, free-flowing and spherical in shape. The infrared spectra revealed the absence of drug polymer interaction. Scanning electron microscopy (SEM) and porosity studies confirmed spherical and porous nature. In vitro release studies data depicted highest correlation with Higuchi treatment. Animal studies also supported the better depigmenting activity as compared to plain gel. CONCLUSION: Glabridin microsponge-loaded gel could be efficacious in treating various hyperpigmentation disorders.

Clinics in diagnostic imaging (85). Mandible osteoradionecrosis complicated by infection.

Mandibular osteoradionecrosis is a rare but well-known complication that may be seen in patients with head and neck tumours following radiation therapy. A 42-year-old man presented with painful soft tissue swelling and a discharging sinus over the right mandible. Radiographs showed osteolytic destruction. Computed tomography confirmed bony destruction and fragmentation, as well as signs of soft tissue infection. The diagnosis of mandible osteoradionecrosis complicated by infection was confirmed by biopsy and surgically. The clinical and imaging features of osteoradionecrosis are highlighted.

Computed tomographic appearance of colorectal hepatic metastases.

INTRODUCTION: This article reviews the various computed tomography (CT) appearances of hepatic metastases from colorectal primaries and assesses the frequency of occurrence of the various patterns. MATERIALS AND METHODS: This is a retrospective study of the CT appearances of histologically proven colorectal hepatic metastases in a group of 52 patients who had undergone surgical hepatic resection between January 1994 and December 2001. A total of 74 hepatic metastatic lesions were reviewed. All lesions were examined in the portal venous phase. RESULTS: A discernible rim was seen in 54 lesions (73%). Thick rim was present in 36 lesions (48.6%) and thin rim in 18 lesions (24.3%). Enhancement of the rim was present in 62 cases (83.8%). Increased central attenuation was seen in 38 lesions (51.4%). Of these, the centre was heterogeneous in 76.3% and scar-like in 23.7%. A non-enhancing rim was seen in 12 lesions (16.2%) which appeared as lesions with "bevelled edge". Thick enhancing rim with non-enhancing centre was the most common combination in 15 lesions (20.3%). CONCLUSION: An enhancing rim could be seen in 83.8% of lesions. Increased central attenuation was present in 51.4% of the lesions. Familiarity with the various CT appearances may facilitate identification and diagnosis of colorectal liver metastases.

A modified rapid method of nucleic acid isolation from suspension of matured virus: applied in restriction analysis of DNA from an adenovirus prototype strain and a patient isolate.

This report describes a method for the isolation of nucleic acid from a suspension of matured virus. Nucleic acid (DNA) was isolated from a prototype strain of adenovirus type 7 and a clinical isolate of adenovirus type 7. Instead of the usual method of ultracentifugation, a filtration method was applied to concentrate the virus rapidly and nucleic acid was then isolated by a standard phenol/chloroform/isoamyl-alcohol extraction procedure. The DNA was found to be sufficiently purified to generate a reproducible restriction endonuclease digestion pattern. The clinical isolate of adenovirus type 7 revealed loss of restriction site for the endonuclease HindIII when compared with the prototype strain.

The Naval Health Research Center Respiratory Disease Laboratory.

Concern about emerging and reemerging respiratory pathogens prompted the development of a respiratory disease reference laboratory at the Naval Health Research Center. Professionals working in this laboratory have instituted population-based surveillance for pathogens that affect military trainees and responded to threats of increased respiratory disease among high-risk military groups. Capabilities of this laboratory that are unique within the Department of Defense include adenovirus testing by viral shell culture and microneutralization serotyping, influenza culture and hemagglutination inhibition serotyping, and other special testing for Streptococcus pneumoniae, Streptococcus pyogenes, Mycoplasma pneumonia, and Chlamydia pneumoniae. Projected capabilities of this laboratory include more advanced testing for these pathogens and testing for other emerging pathogens, including Bordetella pertussis, Legionella pneumoniae, and Haemophilus influenzae type B. Such capabilities make the laboratory a valuable resource for military public health.

Dietary protection by iron against clastogenic effects of short-term exposure to arsenic in mice in vivo.

Iron, as freshly prepared aqueous solution of ferrous sulfate, was administered by gavage to laboratory bred Swiss albino mice. The concentration used was 152 mg/kg body weight (1/10 of the LD(50)). While screening for protection against arsenic, in one set of experiment exposure to iron was followed after 2 hr by gavaging with 2.5 mg/kg body weight (1/10 of the LD(50)) of arsenic as sodium (III) meta arsenite in distilled water. In another set, equal amounts (1:1) of ferrous sulfate and sodium arsenite were administered simultaneously. Control sets were given sodium m-arsenite alone and distilled water (vehicle). After exposure for 24 hr in all experiments, mice were sacrificed and chromosome preparations were made from bone marrow according to a colchicine-hypotonic-fixation-air-drying-Giemsa schedule. Cytogenetic endpoints screened were chromosome aberrations and divisional frequencies. Sodium arsenite alone was highly clastogenic. Ferrous sulfate, whether given together with or before exposure to sodium arsenite, reduced the clastogenic effects of the latter to a significant extent.

Symmetric vs asymmetric PCR and molecular beacon probe in the detection of a target gene of adenovirus.

A DNA fragment (307 bp) from the conserved region of an adenovirus gene (hexon) was amplified by symmetric and by asymmetric polymerase chain reaction (PCR). Two amplifications, one in the absence other in the presence of a molecular beacon probe were conducted by both symmetric and asymmetric PCR. The probe sequence was complementary to an internal segment of the amplified fragment. The product amplified in the absence and presence of the probe was detected by agarose gel and fluorescence analysis, respectively. A symmetric PCR results in exponentially grown double stranded DNA. An asymmetric PCR generates one of the strands by linear ampIlification and a fraction of its total product as double-stranded DNA limited by the concentration ratio of the primers used. Thus asymmetric PCR provided lower intensity signal hence less sensitivity than symmetric PCR by agarose gel analysis as expected. However, signal from a beacon probe based PCR assay is generated only from the probe fraction that hybridizes successfully competing against the strand complementary to the target strand of the product generated by PCR. The symmetric PCR has so far been used for the molecular beacon based fluorescent signal detection. The present study compared the level of fluorescent signal detectable from a symmetric PCR with that from an asymmetric PCR. The fluorescent data analysis demonstrated that a significant higher level of fluorescent signal hence higher sensitivity of detection is obtainable using asymmetric PCR than symmetric PCR performed in presence of the molecular beacon probe.

Detection of adenovirus using PCR and molecular beacon.

The polymerase chain reaction (PCR) and a molecular beacon probe were used for the detection of Adenovirus. A 307 bp DNA fragment from a conserved region of the hexon gene was amplified. The specific molecular beacon was characterized with respect to its efficiency of quenching, and signal to noise ratio by spectrofluorometric analysis of its hybridization with virus specific complementary single stranded oligonucleotide target. Amplification was carried out in the presence of the molecular beacon probe, and the amplified target was detected by measurement of fluorescence signal in the post PCR sample. Separately, a 32P-labeled linear probe (having the same sequence as that of molecular beacon probe) was liquid-phase hybridized with the product of PCR performed in the absence of the molecular beacon. The virus specific target was then detected by electrophoresis of the hybridized product in a nondenaturing polyacrylamide gel and subsequent autoradiographic analysis. The detection limit of adenovirus by PCR in the presence of the molecular beacon probe was found to be similar to that obtained by labeled linear probe hybridization following PCR.

Evaluation of PCR assays in presence of antibody to thermostable DNA polymerases for detection of microbial agents: avoiding false negative results for specimen containing low-titer agent.

The serial low-titer specimens of Influenza A virus and Adeno virus type 7 were tested for the presence of virus specific genes by PCR based on Tth DNA polymerase and by that based on Taq DNA polymerase, in the absence and presence of antibody to the respective DNA polymerases. Increased product DNA synthesis and higher sensitivity of detection were observed in the presence of antibody compared to those in the absence of antibody. 10- to 100- fold lower titer specimen of Influenza A virus and 10-fold lower titer specimen of Adeno virus could be detected in the presence of antibody than those detected in the absence of antibody to the appropriate DNA polymerase, in a PCR.

Arthroplasty with a composite of an allograft and a prosthesis for knees with severe deficiency of bone.

We reviewed the clinical and radiographic results of fourteen patients who had a severe deficiency of bone and were managed with a massive allograft in conjunction with a standard total knee prosthesis between 1987 and 1990. The etiology of the bone loss included the failure of a previous total knee prosthesis, a supracondylar fracture of the femur or a fracture of the proximal part of the tibia, and débridement during the first stage of a reconstruction for the treatment of an infection. Thirteen patients had satisfactory clinical and radiographic results after the index procedure. The knee score of The Hospital for Special Surgery improved from an average of 24 points (range, 0 to 54 points) preoperatively to 82 points (range, 37 to 98 points) at the time of the most recent follow-up examination. The average duration of follow-up was forty-three months (range, twenty-nine to sixty-three months). The radiographic and functional results compare favorably with those that have been reported in most studies of otherwise comparable patients who had less deficiency of bone. While considerable risks are associated with the use of allograft bone and the true longevity of reconstructions with such bone is not yet known, the initial and short-term follow-up results support the use of allograft for the restoration of a functional knee joint in a patient who has a severe deficiency of bone.

Human MCF activates monocytes to produce IL-1 but not TNF or CSF-1.

Monocyte cytotoxicity inducing factor (MCF) is a novel cytokine which was originally characterized by its ability to induce monocyte cytotoxicity against tumor targets. The present studies were undertaken to define the mechanisms of cytotoxicity. Since the cytotoxic state may be mediated, in part, by the secretion of monokines, MCF's effect on IL-1, TNF and CSF-1 were measured. MCF caused human peripheral blood monocytes to secrete large amounts of IL-1 but not TNF. In contrast monocytes produce CSF-1 in culture and this production was not enhanced by MCF. IL-1 neither appeared to directly lyse the target K562 nor was able to activate macrophages for cytotoxicity. However, IL-1 may be necessary for lysis of K562 by activated macrophages through its cytostatic effect on K562. MCF increased monocyte surface expression of DR-beta (when studied by fluorescent microfluorometry) and messenger RNA for DR-beta after 24 h in culture. These functional studies indicate that MCF is a cytokine with a distinct spectrum of biologic activities whose functions may be mediated by synthesis and secretion of IL-1.

Acute polymyositis associated with W. bancrofti.

Two cases of acute polymyositis associated with W. bancrofti, presented with generalised painful swelling and weakness of the muscles. These patients had elevated muscle enzymes, a myopathic EMG pattern, inflammatory myopathy on biopsy and W. bancrofti in the peripheral blood smear. The clinical, improvement of the disorder and total clearance of microfilariae was obtained with the combination therapy of steroid and diethyl-carbamazine in comparison with steroid alone.

Effect of cell immobilization and organic solvents on sulfoxidation and steroid hydroxylation by Mortierella isabellina.

The effects of calcium alginate bead immobilization and the presence of organic solvents on two bioconversion reactions carried out by Mortierella isabellina ATCC 42613 have been investigated. These reactions, the 14 alpha-hydroxylation of progesterone and the sulfoxidation of thioanisole, both proceed in high yield using resting-cell bioconversions, but are not carried out by alginate bead preparations in the absence of an organic co-solvent, the best results being obtained with 5 or 10% aqueous methanol. The stereoselectivity of sulfoxidation of thioanisole was found to be dependent upon the nature and concentration of organic co-solvent.

Toxic effects of ackee oil (Blighia sapida L) following subacute administration to rats.

Subacute intraperitoneal administration of the lipid portion of the unripe ackee arillus, referred to as "ackee oil", resulted in marked neutropenia (p less than 0.001) and increase in platelets (p less than 0.01) without anaemia, in rats. Blood urea, sodium and aspartate aminotransferase levels were significantly decreased but glucose and bilirubin levels were similar to those of controls. The lungs showed areas of petechial haemorrhages and a dose-related perivascular and peribronchial mononuclear cell infiltration. The pulmonary toxicity may be interpreted as a hypersensitive reaction to ackee oil. Further research is in progress on the neutropenic effects of ackee oil.

Toxic effects of ackee oil (Blighia sapida L) following subacute administration to rats

Subacute intraperitoneal administration of the lipid portion of the unripe ackee arillus, referred to as "ackee oil", resulted in marked neutropenia (p<0.001) and increase in platelets (p<0.01) without anaemia, in rats. Blood urea, sodium amd aspartate aminotransferase levels were significantly decreased but glucose and bilirubin levels were similar to those of controls. The lungs showed areas of petechial haemorrhaghes and a dose-related perivascular and peribronchial mononuclear cell infiltration. The pulmonary toxicity may be interpreted as a hypersensitive reaction to ackee oil. Further research is in progress on the neutropenic effects of ackee oil.

Retinoic acid suppression of squamous differentiation in human head-and-neck squamous carcinoma cells.

Retinoids (vitamin A analogues) inhibit the squamous differentiation of normal and malignant epithelial cells. This study investigated the ability of the head-and-neck squamous-cell carcinoma (HNSCC) cell line 1483 to undergo squamous differentiation in the absence and presence of beta-all-trans retinoic acid (RA). The growth of these cells in culture is accompanied by an increase in keratinocyte transglutaminase, involucrin and keratin KI, 3 established markers of squamous cell differentiation. Higher levels of these differentiation markers were detected in cells cultured in delipidized serum (DLS), from which endogenous retinoids have been extracted, than in cells cultured in fetal bovine serum (FBS), which contains retinoids. Treatment with I microM RA decreased the levels of the various differentiation markers in cells cultured in either FBS or DLS as revealed by immunofluorescent labelling of permeabilized cells and by immunoblotting of cell extracts using specific monoclonal or polyclonal antibodies. The cells' ability to cross-link proteins to form envelopes under the plasma membrane was stimulated in the presence of calcium ionophore but inhibited by RA. These results indicate that the malignant 1,483 HNSCC cells recapitulate the main characteristics of normal squamous-cell differentiation in culture and that RA suppresses this differentiation as it does in normal keratinizing epithelial cells.

Morphology and histochemistry of the ferret prostate.

The gross anatomy, histology and histochemistry of the ferret prostate is described. The structure and course of the prostatic urethra and the ductus deferentes are also described. The prostate is the only accessory reproductive gland present in the ferret. The prostate consists of tubuloalveolar glands surrounded by fibromuscular connective tissue. Histochemical studies showed that the glandular parenchyma contained large amounts of sialidase-labile sialomucin as well as acid phosphatase and small quantities of alkaline phosphatase and proteins. The findings in this study are discussed in relation to similar studies in other animals and man.

Mucous cells of the tracheobronchial tree in the ferret.

Mucosubstances in the tracheobronchial tree of the ferret were studied histochemically. The submucous glands contained predominantly neutral mucins. Scattered between these were cells containing sulphated mucins and sialidase-labile and sialidase-resistant sialomucins. Most of the goblet cells in the trachea, as well as those in the bronchi and larger bronchioles, contained sulphated mucins. A smaller proportion of the goblet cells showed sialidase-labile and sialidase-resistant sialomucins. It will be interesting to see whether ferrets can be used to produce animal models for hypersecretory diseases such as cystic fibrosis and chronic bronchitis.