Pharmacophore-based 3DQSAR and molecular docking studies to identify new non-peptidic inhibitors of cathepsin S.

Cathepsin S (CatS) is one of the 11 cysteine protease cathepsins which are expressed predominantly in antigen presenting cells (APC) namely B cells, macrophages and dendritic cells. CatS has been implicated in a wide range of diseases such as rheumatoid arthritis, multiple sclerosis, neuropathic pain and allergic disorders. In the present study, pharmacophore mapping studies followed by 3D QSAR analysis was undertaken for a large set of 161 molecules reported to be non-covalent binding and non-peptidic inhibitors of CatS. The activity range (IC50) of these compounds was between 2 picomolar to 100 nanomolar. A five point pharmacophore model with three hydrogen bond acceptors (A), one hydrogen bond donor (D) and one hydrophobic (H) group as pharmacophoric features was developed. The generated model showed reasonable predictive power, with a correlation coefficient Q(2) of 0.607. The model was further confirmed by an external test-set validation that showed statistically significant parameters r(2) value of 0.840 with the R(2)p value of 0.812 and r(2)m value of 0.530. Validated model was then used to identify six diverse non-peptidic scaffolds from a commercial structure database by the analyses of parameters such as pharmacophore fitness, docking score, interacting amino acids and ADME properties to achieve prototypical lead compounds.

An integrative approach for evaluating work related musculoskeletal disorders.

OBJECTIVES: To develop a framework for evaluating the work related musculoskeletal disorders (WRMSDs). PARTICIPANTS: The proposed framework was tested on 15~jewellery manufacturing workers working at Chinchpokhli region in Mumbai, India and on 15 students studying in a management institute of Mumbai, India. METHODS: The framework has been broken into three phases. Phase 1--Ergonomic-risk evaluation; Phase 2--Musculoskeletal Disorders (MSD) evaluation and Phase 3--Clinical examination. Ergonomic-risk evaluation determines the relationship between work relatedness and musculoskeletal disorders. Musculoskeletal Disorders (MSD) evaluation tries to assess the presence of discomforts/disabilities in different body regions, through subjective evaluation tools. Ergonomic-risk evaluation involved QEC, PLIBEL and posture analysis by RULA. Musculoskeletal Disorders (MSD) evaluation involved administration of self reported questionnaires. Clinical examination involved muscle grading by a physiotherapist and back strength measurement. RESULTS: The framework suggested that ergonomic risk evaluation techniques, self reported body part questionnaires and physical measurement of physiological/biomechanical transients may have a relationship and can be used for the evaluation of work related musculoskeletal disorders. CONCLUSION: The proposed integrative approach will help in developing stage wise intervention strategies for work related musculoskeletal disorders.

Study on lumbar kinematics and the risk of low back disorder in female university students by using shoes of different heel heights.

The study was taken up to investigate the effects of heel heights on lumbar kinematics and the risk of Low Back Disorder (LBD) in females. Nineteen female university students (24.5 ± 3.36 yrs) volunteered in the study. Lumbar kinematics was measured by using Industrial Lumbar Motion Monitor (iLMM). The volunteers were asked to walk for a distance of 50 meters in 3 different given conditions i.e bare foot (Heel 0), with flat heels (Heel 1) and with high heels (Heel 2). Heights of Heel 1 and Heel 2 were 1.5 ± 0.84 cm and 5.5 ± 1.70 cm respectively. The Lumbar kinematic parameters studied were- Average Twisting Velocity (ATV), Maximum Sagital Flexion (MSF) and Maximum Lateral Velocity (MLV). It was observed that all the above mentioned Lumbar kinematics - ATV, MSF and MLV increases with increase of heel heights, which in turn increases the risk of LBD. As a result of increase in Lumbar kinematic values with increase in heel heights, LBD risk has also increased. Mean and SD of the LBD risk with Heel 0, Heel 1 and Heel 2 were 16.79 ± 6.04%, 19.00 ± 7.38% and 22.11 ± 6.98% respectively. Lower stature with high heels showed higher risk of LBD than the higher stature with high heels.

A study of subjective visual disturbances in jewellery manufacturing.

Subjective Visual Disturbances are silent adversaries that appear over a period of continued exposure and arise when the visual demands of the tasks exceed the visual abilities of the user. Jewellery manufacturing activity involves precision designs, setting the metal and stones, polishing and filing which requires higher visual demand. Therefore, it is expected that the jewellery manufacturing workers may experience subjective visual disturbances. This study was taken up with the following objectives 1) To study the presence of subjective visual disturbances among jewellery manufacturing workers and compare the same with VDT operators 2) To study the effect of work exposures on subjective visual disturbances and 3) to ascertain whether subjective visual disturbances have any permanent vision related problems. The study was carried out on jewellery manufacturing workers, VDT operators and on graduate students. The symptoms of subjective visual disturbances were identified using a questionnaire developed by Sheedy (2003). Viewing distances were measured and visual angles were calculated. The eye check--ups were also carried out. The subjective visual disturbances were higher in jewellery manufacturing workers. The findings suggest that work exposure has an impact on the causation of subjective visual disturbances. No pathological conditions of the eyes were observed.

Fatal intraoperative pulmonary fat embolism during cemented total hip arthroplasty in a dog.

A 3-year-old, German shepherd dog died suddenly during cemented total hip arthroplasty. Gross necropsy findings included severe pulmonary edema and congestion as well as congestion of the liver and kidneys. Acute pulmonary embolism was suspected as the cause of death. Microscopic examination of hematoxylin and eosin-stained, formalin-fixed, and oil red O-stained frozen tissue sections confirmed the presence of large numbers of fat globules in blood vessels in the lungs, liver, and kidneys. Fat embolism during total hip arthroplasty is a common surgical complication in humans, but it is uncommon in veterinary cases and is rarely a cause of death.

Retroviral particles in neoplasms of Burmese pythons (Python molurus bivittatus).

Neoplastic diseases associated with retroviruses were diagnosed in four Burmese pythons (Python molurus bivattatus) from a single collection. Snake No. 1 was a 7-year-old female with recurrent undifferentiated mesenchymal round cell tumor (lymphosarcoma) of the oral cavity. At necropsy, similar neoplastic masses were evident in the uterus and ovary, and there was diffuse involvement of the spleen. Snake No. 2 was a 4.5-year-old female that was euthanatized because of complications following resection of a segmental colonic adenocarcinoma. Snake No. 3 was a 5-year-old female that was euthanatized because of a large transitional cell carcinoma of the right kidney. Snake No. 4 was a 19-year-old female that was euthanatized following recurrence of an intermandibular fibrosarcoma. Ultrastructural examination revealed few to numerous extracellular and intracellular (intravacuolar) type C-like retroviral particles in all tumors. Tumors were about 90-95 nm in diameter, with an electron-dense core and bilaminar external membrane. The relationship of the intraneoplastic viral particles to the etiology of the tumors is uncertain.

The acute and subchronic toxicity of BRB-I-28, a novel class Ib antiarrhythmic agent, in CD-1 mice.

The acute and subchronic toxic effects of BRB-I-28 (7-benzyl-3-thia-7-azabicyclo[3.3.1]nonane HCl), a novel class Ib antiarrhythmic agent, were investigated in male and female mice. The estimated oral LD(50) for BRB-I-28 was 128 mg/kg (male mice) and 131 mg/kg (female mice). In subchronic oral studies, four groups of mice (15/sex/group/dose) were fed daily with diets containing BRB-I-28 for 90 consecutive days. The equivalent daily doses were approximately 0, 16, 32, 76 (male) and 0, 18, 37, 89 mg/kg (female). All mice survived. Food consumption per day was decreased, but water consumption per day was increased (in a non-dose-dependent manner). However, both mean body weight and mean body weight gain were not significantly changed as were true for hematological and clinical chemistry profiles, except for serum Na(+) concentration (male) and serum K(+) concentration in male and female mice (high dose levels). Hepatocellular necrosis occurred in male and female mice (in a dose-dependent fashion). Renal cortical vacuoles and myocardial necrosis with low numbers of lymphocytic infiltrations were present in female mice (middle and high doses). Lesions in the liver, kidney and heart were mild with (very small) changes in serum biochemical values. These data suggest that BRB-I-28 has limited toxic potential, and coupled with low proarrhythmic and other desirable cardiovascular effects, makes BRB-I-28 worthy of further development.

Primary malignant histiocytosis of the brain in a dog.

Malignant histiocytosis is a well-recognized canine tumour, occurring primarily in Bernese mountain dogs and characterized by disseminated histiocytic infiltration of multiple visceral organs. This report describes the light microscopical and ultrastructural features of a neoplasm composed of malignant histiocytes and confined to the brain. A poorly demarcated mass in the right parieto-occipital lobe of a miniature schnauzer was composed of loosely aggregated, pleomorphic cells with abundant eosinophilic cytoplasm, expanding the meninges. Many binucleated and multinucleated giant cells and mitotic figures were seen. Immunohistochemically, the tumour cells reacted intensely for lysozyme. Ultrastructurally, the neoplastic cells had features of histiocytic cells with abundant lysosomes. The findings in this case were strikingly similar to those of disseminated malignant histiocytosis described in other dog breeds.

Neurotoxicity of 1,3,5-trinitrobenzene (TNB): immunohistochemical study of cerebrovascular permeability.

1,3,5-Trinitrobenzene (TNB) is a soil and water contaminant at certain military installations. Encephalopathy in rats given 10 daily oral doses of TNB has been reported. The lesion was bilaterally symmetric vacuolation and microcavitation in the cerebellar roof nuclei, vestibular nuclei, olivary nuclei, and inferior colliculi. The contribution of the blood-brain barrier (BBB) in the genesis of these lesions remains uncertain. One of the main goals of the present work was to evaluate the functional state of the BBB. Male Fischer 344 rats (five rats/group) were euthanatized after four, five, six, seven, eight, or 10 daily doses of TNB (71 mg/kg). A different set of rats (five rats/group) was allowed to recover for 10 or 30 days after receiving 10 doses of TNB. Integrity of the BBB was assessed by immunohistochemical staining for extravasated plasma albumin on paraffin-embedded sections. Rats euthanatized after four to eight doses had no lesions, and albumin extravasation in the susceptible regions of the brain was minimal. Rats receiving 10 daily doses of TNB had bilaterally symmetric vacuolation and microcavitation in the cerebellar nuclei, vestibular nuclei, and inferior colliculi in association with multifocal, often confluent foci of extravasated albumin in susceptible nuclei. Albumin was present in vascular walls, extracellular space, and neurons. Immunoreactivity in neurons was of two types: cytoplasmic staining representing pinocytic uptake and homogeneous staining of the entire neuron (nucleus and cytoplasm) due to uncontrolled albumin leakage through the damaged cell membrane. In rats allowed to recover for 10 days, the microcavitated foci were infiltrated by glial and gitter cells. Albumin immunoreactivity was present as extracellular granular debris, and neuronal staining (for albumin) was mild. In rats allowed to recover for 30 days, immunoreactivity to albumin was not seen. This study demonstrates that TNB-mediated tissue damage is accompanied by breakdown of the BBB. The presence of vacuolation and associated extravasated serum proteins in TNB-treated rats is an indication of vasogenic brain edema, which appears to be a critical event in TNB toxicity. Additional studies are needed to determine the reason for selective regional vulnerability and brain microvascular susceptibility to TNB.

Sensory polyganglioradiculoneuritis in a dog.

Generalized reduction of nociception and conscious and unconscious proprioception were found in an approximately eight-year-old, male, Maltese mixed-breed dog presented for difficulty prehending food and experiencing ataxia of three months duration. Results of needle electromyogram, motor nerve conduction velocity, and cerebrospinal fluid analysis were normal. A diagnosis of sensory polyneuropathy was suspected. No underlying cause could be determined. Neurological signs progressed to quadriparesis over the following four months despite treatment attempts with prednisone and procarbazine. Necropsy confirmed a sensory polyganglioradiculoneuritis, but no inciting cause could be established.

Dysgerminoma in an Arabian filly.

A yearling Arabian filly was referred to the Veterinary Medical Teaching Hospital with a history of weight loss, profound anemia, and peritoneal effusion. At necropsy, a large, soft, mottled tan and red neoplastic mass was at the pelvic inlet replacing the left ovary. Additional tumor nodules of various sizes were disseminated throughout the mesentery, diaphragm, and serosal surfaces of the abdominal viscera. Histologically, the neoplasm had sheets of large round to polygonal cells separated into lobules by fibrous connective tissue with multifocal areas of necrosis. Tumor cells stained strongly for alkaline phosphatase. Immunohistochemically, tumor cells expressed vimentin and were negative for cytokeratin. Ultrastructurally, the neoplastic cells had a characteristic nucleolus with an elaborate reticular nucleolonema in an irregular configuration. This is the first in-depth detailed report of this very rare germ cell tumor of the ovary in horses.

Testicular effects of 1,3,5-trinitrobenzene (TNB). I. Dose response and reversibility studies.

Testicular effects of TNB were characterized after single and multiple oral doses of TNB at 0, 35.5, and 71 mg/kg. Male Fischer 344 (F344) rats were killed after a single dose or after 4 and 10 daily doses of TNB. Testicular effects were not evident at the light microscope level in rats killed after a single dose of TNB or after 4 daily doses at 35.5 mg/kg of TNB. Rats receiving 4 daily doses of TNB at 71 mg/kg had the earliest evidence of testicular damage, with necrosis and degeneration of pachytene spermatocytes including a significant decrease in testicular weight. Rats dosed at 35.5 mg/kg for 10 d had severe testicular lesions, in addition to the decrease in testicular weight. There was degeneration of round and elongate spermatids, and formation of multinucleate syncytial cells. The epididymis was devoid of sperm, instead containing exfoliated syncytial spermatids. Rats dosed at 71 mg/kg of TNB for 10 d had testicular atrophy and cessation of spermatogenesis. These rats also had apoptic cells in the ventral prostate. To assess the extent of reversibility in these atrophied testis, rats were allowed to recover for 10 or 30 d after 10 doses of TNB (71 mg/kg). A significant regenerative attempt with proliferating spermatocytes were present at 10 d and elongate spermatids were evident at 30 d. These reversibility studies indicate testicular effects of TNB are at least partially reversible.

Testicular effects of 1,3,5-trinitrobenzene (TNB). II. Immunolocalization of germ cells using proliferating cell nuclear antigen (PCNA) as an endogenous marker.

The applicability of PCNA as a tool for the analysis of germ cells in rats treated with 1,3,5-trinitrobenzene (TNB), a potent testicular toxicant, was evaluated. Male Fischer 344 (F344) rats were gavaged with TNB at 71 mg/kg or with corn oil (vehicle). Rats were killed after 10 daily oral doses or were allowed to recover for 10 or 30 d after the 10 doses. Testes from control rats, treated rats, and rats allowed to recover were immunohistochemically stained for PCNA. PCNA labeling in the control rats was confined to the nuclei of spermatogonia, pachytene spermatocytes, and nuclei of elongate spermatocytes. Conventional (hematoxylin and eosin) staining of testes from rats treated with TNB at 71 mg/kg for 10 d revealed loss of germ cells and cessation of spermatogenesis. Immunohistochemical staining of sections from these treated rats revealed only PCNA-positive spermatogonia. Rats allowed a 10-d recovery had both spermatogonial and spermatocytic staining, indicating partial restoration of germ-cell population. In rats allowed to recover for 30 d, the PCNA staining pattern was identical to the control rats. These results indicate that PCNA can be used to assess the proliferative status of spermatogonia (germ cells) in rodent testes exposed to testicular toxicants.

Hematological effects of 1,3,5-trinitrobenzene (TNB) in rats in vivo and in vitro.

We studied the hematological effects of single and repeated exposure to 1,3,5-trinitrobenzene (TNB) in rats. Male F-344 rats were gavaged with TNB at 35.5 and 71 mg/kg in corn oil. Blood was collected 5 h and 24 h after a single oral dose or 24 h after daily oral doses for 4 or 10 d in four different set of experiments. A dose-dependent methemoglobinemia was present only in blood collected 5 h after a single dose. A highly significant dose-dependent anemia with reduced red cells, hemoglobin, and hemotocrit was present in rats receiving TNB for 4 or 10 d. A dose-dependent decrease in serum triglycerides was present in rats receiving TNB for 10 d. There was no hemolysis when rat erythrocytes were incubated with TNB (in vitro) for 9 h. Spectral changes of hemoglobin recorded during the incubation with TNB confirm methemoglobin formation and progressive denaturation of hemoglobin-forming hemichromes. The significance of methemoglobin and hemichrome formation is discussed, and a probable hypothesis for the hemolytic anemia is suggested.

1,3,5-Trinitrobenzene-induced encephalopathy in male Fischer-344 rats.

Administration of 1,3,5-trinitrobenzene (TNB) to male Fischer-344 rats produced ataxia after 6 or 7 oral doses (71 mg/kg). Light microscopic examination after 10 days revealed petechial hemorrhages in the brain stem and cerebellum and bilaterally symmetric degeneration and necrosis (malacia) with reactive gliosis in the cerebellar peduncles. The malacia was dorsal and lateral to the fourth ventricle involving the cerebellar nuclei, medial and lateral vestibular nuclei, and inferior colliculi. Blood vessels associated with the lesion had widened Virchow-Robin spaces, occasionally with extravasated erythrocytes. Rats administered daily oral doses of 35.5 mg/kg of TNB for 10 days and 35.5 and 71 mg/kg of TNB for 1 or 4 days did not have brain lesions.

Mercury toxicosis caused by ingestion of a blistering compound in a horse.

Mercury toxicosis by ingestion was diagnosed in a 3-year-old Quarter Horse mare with a history of anorexia and signs of abdominal discomfort. Ten and 9 days prior to admission, an inorganic mercuric blistering agent has been applied for topical treatment of dorsal metacarpal disease. At referral, signs of depression, dependent edema, pollakiuria, nonproductive cough, and oral ulceration were noticed. Laboratory data were consistent with renal dysfunction. Mercury content of blood and urine was high, confirming the diagnosis. The horse responded to intensive care, consisting primarily of IV fluid treatment, and mercury-chelating agents. However, acute laminitis developed, and the owners elected to euthanatize the horse 18 days after mercury exposure. Necropsy findings included renal tubulonephrosis and ulcerative colitis and enteritis. Mercury concentration was highest in kidney and liver tissues. The potential for mercury toxicosis in horses currently exists, and although the prognosis is grave, some horses may recover with appropriate treatment and long-term supportive medical care.

Fluorosis in a wild cotton rat (Sigmodon hispidus) population inhabiting a petrochemical waste site.

We have developed an in situ mammalian model for evaluating environmental contamination using wild cotton rats. In a series of experiments, 200 male cotton rats were captured during 4 collection periods (spring 1991 = 35; fall 1991 = 60; spring 1992 = 53; fall 1992 = 52). A total of 103 of these cotton rats were captured from control sites, and the remaining 97 were captured from an abandoned oil refinery. All sites were located in the vicinity of Cyril, Oklahoma. There were alterations in the incisors of cotton rats captured from the refinery site. Normal color of cotton rat incisors is deep yellow-orange, which is imparted by a pigment normally produced by ameloblasts. Grossly, the upper incisors of 37 of 97 rats and lower incisors of 54 of 97 rats were affected. The affected incisors were white, chalky, and thin with striations and erosions of the enamel. Microscopic examination revealed that there were dysplastic and necrotic changes in the ameloblasts. The bone fluoride levels were significantly higher in rats captured from the refinery as compared to the rats captured from the control sites.