On the problem of correspondence in range data and some inelastic uses for elastic nets

In this work, the authors propose a novel method to obtain correspondence between range data across image frames using neural like mechanisms. The method is computationally efficient and tolerant of noise and missing points. Elastic nets, which evolved out of research into mechanisms to establish ordered neural projections between structures of similar geometry, are used to cast correspondence as an optimization problem. This formulation is then used to obtain approximations to the motion parameters under the assumption of rigidity (inelasticity). These parameter scan be used to recover correspondence. Experimental results are presented to establish the veracity of the scheme and the method is compared to earlier attempts in this direction.

Leiomyosarcoma of the duodenum

Leiomyosarcoma of the duodenum is a rare tumor. These tumors manifest with unexplained melena, anemia and sometimes partial duodenal obstruction. Diagnosis is difficult on account of inaccessibility for biopsy. Treatment involves excision of the duodenum with reconstruction, a difficult task with high morbidity and mortality. However, if the tumor is successfully treated, its prognosis is usually good because of its non-aggressive nature.

Emblica officinalis: a novel therapy for acute pancreatitis--an experimental study

Acute necrotising pancreatitis is associated with an unacceptably high mortality for which no satisfactory remedy exists. Emblica officinalis (E.o.) is a plant prescribed in Ayurveda, the Indian traditional system of medicine, for pancreas-related disorders. This study was carried out to evaluate the protective effect of E.o. against acute necrotising pancreatitis in dogs. Pancreatitis was induced by injecting a mixture of trypsin, bile and blood into the duodenal opening of the pancreatic duct. Twenty eight dogs were divided into 4 groups (n = 6-8 each): GpI--control, GpII--acute pancreatitis, GpIII--sham-operated, GpIV--pretreatment with 28 mg E.o./kg/day for 15 days before inducing pancreatitis. Serum amylase increased from 541.99 +/- 129.13 IU/ml to 1592.63 +/- 327.83 IU (p <0.02) 2 hrs after the induction of pancreatitis in GpII. The rise in serum amylase in both GpIII and GpIV was not significant. On light microscopic examination, acinar cell damage was less and the total inflammatory score was significantly lower in the E.o. treated group as compared to GpII. Electron microscopy confirmed this and showed an increased amount of smooth endoplasmic reticulum and small, condensed granules embedded in a vacuole. More studies are needed to explore the clinical potential of E.o. and its mechanism of action.

A 150-kDa molecule of macrophage membrane stimulates interleukin-2 and interferon-gamma production and proliferation of ovalbumin-specific CD4+ T cells

In the present study, we describe the potential co-stimulatory role of a macrophage membrane-associated protein of 150 kDa (M150). The protein was isolated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and was found to be a single molecule on two-dimensional gel electrophoresis. The molecule was re-constituted in phosphatidyl choline vesicles and tested for its ability to promote the proliferation and the secretion of lymphokines from T helper (Th) cells. The reconstituted M150 induced a significant proliferation of anti-CD3 monoclonal antibody (mAb)-stimulated ovalbumin-specific CD4+ T cells. Further, Th cells activated with this molecule in the presence of anti-CD3 mAb mainly secreted interleukin (IL)-2 and interferon-gamma but not IL-4. M150 could not promote the proliferation of Th cells, or lymphokine secretion in the absence of anti-CD3 mAb. These observations suggest that M150 acts by selectively activating a Th1-like immune response.

Human immunodeficiency viruses regulated by alternative trans-activators: genetic evidence for a novel non-transcriptional function of Tat in virion infectivity

Thirteen genetically altered HIV-1 proviruses were created. These various genomes can be segregated into three groups: (i) a set of tat(-) viruses that have a functional HTLV-I Tax inserted in nef; (ii) a set of tat(-) viruses with Gal4 binding sites inserted in U3 and a Gal4-VP16 cDNA inserted in nef; and (iii) a set of tat(+) HIV genomes that are 5' and 3' TAR(-) and are Gal4-binding-site(+) in U3 and Gal4-VP16(+) in nef. We found that viruses in groups (i) and (ii), although tat(-), were fully complemented for viral gene expression based on quantitative measurements of viral protein synthesis and on the visualization by electron microscopy of the proper assembly of morphologically correct virions. Interestingly, group (i) and (ii) virions were defective in a spreading cytopathic infection when assayed in T-lymphocytes. Group (iii) viruses, although capable of producing intact Tat protein, also could not use Tat for transcription/gene expression because of the TAR(-) genotype. However, this class of viral genomes produced viruses that were highly infectious and cytopathic in primary and in continuously propagated T-lymphocytes. These three groups of viruses are all transcriptionally Tat-TAR independent. Their distinct differences in infectivity/cytopathicity provide genetic evidence that Tat provides a transcriptionally independent function in determining infectivity and cytopathicity in the setting of a spreading viral infection. Given that all HIV virions normally contain four intact copies of TAR RNA, our findings suggest a re-examination of whether Tat could be a virion-TAR-associated protein and the possible implications of this for virus infectivity/cytopathicity.

Effect of prochlorperazine as a sensitizer of rat skin on radiation-induced AMP metabolism

The role of AMP was investigated in radiosensitization by the use of prochlorperazine in normal rat skin. AMP metabolism was evaluated by estimating the level of activities of 5' nucleotidase vis-à-vis protein, DNA and RNA contents in prochlorperazine-treated plus irradiated skin. To study radiation-induced changes in the skin, the extent of lipid peroxidation was measured in terms of enzyme lipid peroxidase. After irradiation, lipid peroxidase activity was observed to increase in prochlorperazine-treated rat skin. Subsequently the level of 5' nucleotidase was found to decrease in drug-treated plus irradiation skin. Similarly, the suppression in the levels of DNA, RNA and protein contents increased when the rat skins was irradiated in the presence of sensitizer prochlorperazine. The cytological examination, which revealed the extent of the lesions occurring in the normal rat skin, and the biochemical examination demonstrated increased cellular lethality in prochlorperazine-sensitized skin after irradiation. The results suggest that prochlorperazine probably sensitizes the normal skin tissues to radiation by inhibiting AMP metabolism via hydroxy-radical-induced decrease in DNA, RNA and protein metabolism.

Aortic cobwebs: an anatomic marker identifying the false lumen in aortic dissection--imaging and pathologic correlation

PURPOSE

To describe and estimate the frequency of fibroelastic cords or bands projecting from the false lumen wall ("aortic cobwebs") in acute and chronic dissections.

MATERIALS AND METHODS

Pathologic specimens (n = 23), routine magnetic resonance (MR) images (n = 27), and intravascular (n = 5) and transesophageal (n = 3) ultrasound (US) images from 43 patients with aortic dissection were reviewed, and the presence and configuration of cobwebs were noted.

RESULTS

Aortic cobwebs usually bridge the junction of the dissection flap with the outer wall of the false lumen (the line of dissection) but occasionally project like small tendrils from the false lumen wall remote from the line of dissection. Cobwebs were found in 17 of 23 pathologic specimens and on six of 27 MR images, two of five intravascular US scans, and one of three transesophageal US scans.

CONCLUSION

Aortic cobwebs most likely represent residual ribbons of media that have been incompletely sheared from the aortic wall during the dissection process. As such, they can serve as an anatomic marker of the false lumen. They are occasionally seen on routine aortic images and may, therefore, prove useful for orientation during percutaneous or surgical interventional procedures to relieve ischemic complications of aortic dissection.

The distribution of root caries in community-dwelling elders in New England

An in-home examination of a probability sample of elders aged 70 and older living in the six New England states was conducted to estimate the prevalence and extent of root caries. Oral examinations were conducted by the visual-tactile method using a portable lamp, explorer, and a mouth mirror. Fifty-two percent of the study participants showed root caries experience and 22 percent had untreated root caries. In contrast to previous studies, this analysis showed that buccal root surfaces were no more likely than proximal surfaces to be affected by root caries. Logistic regression analysis showed that gingival recession and number of teeth were positively associated with root caries, while better oral hygiene maintenance and regular dental visits were negatively associated with root caries lesions (all factors: P < .05). The prevalence of root caries was found to increase with higher numbers of teeth except for a minority subgroup--i.e., those who retained 25 or more teeth. This study provides much-needed data on prevalence and extent of root caries in a probability sample of the oldest old in an entire region of the United States.

Microparticulates for ophthalmic drug delivery

Microparticulates are drug-containing small polymeric particles (erodible, non-erodible or ion-exchange resins) that are suspended in a liquid carrier medium. Upon administration of particle suspension in the eye, the particles reside at the delivery site (cul-de-sac, sub conjunctiva or vitreous cavity) and the drug is released from the particles through diffusion, chemical reaction, polymer degradation, or ion-exchange mechanism. Several distinct approaches have been used to formulate drugs in microparticulate dosage form for intraocular and topical application. These include erodible microparticulates, swelling mucoadhesive particulates, pH responsive microparticulates, nanoparticles/latex systems, ion-exchange resins, etc. Injection of bioerodible microparticulates in the vitreous for treating infections of posterior segment and the release of acceptable levels of drug up to two weeks has been demonstrated. Both corneal and non-corneal routes of drug entry in the eye from topical instillations are postulated. The in vitro and in vivo studies have shown that this dosage form holds great promise for sustained drug release in the eye. However, several formulation challenges, including production of stable suspensions, uniform dose per unit volume, efficient drug entrapment, reproducible and large scale manufacturing, uniform particle size, etc., have to be addressed. Fruitful resolution of technological challenges will result in a superior dosage form for both topical and intraocular ophthalmic application. Recent developments and future challenges of microparticulate ophthalmic drug delivery system are discussed in this review.

Root caries incidence and associated risk factors in middle-aged and older adults

Data from population-based longitudinal studies required to assess the incidence of root caries and associated risk factors are sparse in the literature. To this end, a group of 130 middle-aged and older adults were examined for root caries at baseline and at a follow-up visit between nine and 24 months (median: 16 months). Dental examinations were conducted by one examiner at a Tufts dental clinic using NIDR defined diagnostic criteria. Fifty percent of subjects in this study population developed one or more new root caries lesions over the follow-up period. Also, an annualised increment of 0.60 (SD: 0.72) decayed and filled surfaces per person was observed for the 45-59 year old group while the 70+ group showed an annualised increment of 1.38 (SD: 1.97) DFS in this study. Multivariate logistic regression analysis identified past root caries experience, high plaque score, and high number of teeth (> = 22) to be positively associated with new root caries (p < 0.05).

Modulation by ascorbic acid of the cutaneous and hepatic biochemical effects induced by topically applied benzanthrone in mice

Modulation of biochemical markers by ascorbic acid was investigated in mice to which benzanthrone (BA) was applied topically (150 nmol/mouse) twice a week for 34 wk. After BA exposure without ascorbic acid, in the skin there were significant decreases in the activities of aryl hydrocarbon hydroxylase (AHH; 38% decrease relative to controls) and ethoxyresorufin-O-deethylase (EROD; 39%), and enhancement of the activities of quinone reductase (41% increase), tyrosinase (82%) and histidine decarboxylase (HDC; 190%). BA exposure also caused significant inhibition of hepatic AHH, EROD and glutathione-S-transferase activities, with concomitant increases in the activities of histidase (52%) and HDC (58%). Ascorbic acid given orally (5 mg/mouse) or topically (1 mg/mouse) twice weekly for 34 wk to BA-treated mice resulted in substantial protection against the effects of BA on these enzyme markers in both the skin and the liver. These results suggest that ascorbic acid could be useful in preventing the biochemical and toxicological manifestations caused by BA in laboratory animals.

Oral health status of the elderly in New England

The New England Elders Dental Study (NEEDS) reports the prevalence, extent and severity of oral diseases and conditions among a representative sample of community-dwelling elders age 70 and older residing throughout the six New England states. In-home, full-mouth examinations were conducted by four calibrated dentists who used National Institute of Dental Research (NIDR) standardized disease measures plus additional diagnostic codes on all tooth surfaces. Only 37.6% of elders age 70 and older were edentulous, while dentate elders had a mean number of teeth per person ranging from 21.5 to 17.9 across age and gender cohorts. The prevalence of untreated coronal decay in elders with teeth was 28% in female elders and 34% in male elders. More than 90% of all elders with teeth had coronal fillings and 22% exhibited untreated root caries. Periodontal destruction was substantial, with 66% of dentate elders exhibiting moderate periodontal pockets (4-6 mm) while 21% exhibited severe periodontal pocketing (> 6 mm). Comparisons with national surveys suggest that periodontal disease prevalence and severity appear to have been underestimated in previous national studies of the elderly. Because of aging and tooth retention trends, the periodontal disease problem of the elderly may be increasing in the face of dentists' tendency to underdiagnose the periodontal diseases, legal constraints on dental hygienists to independently treat them, and inadequate funding for conservative nonsurgical therapies.

Caries prevalence in xerostomic individuals

Saliva, via its lubricating, cleansing, remineralizing, antibacterial, and buffering actions, is an important protective factor for both dentition and soft tissue. Xerostomia is commonly found in older individuals due to the use of medications or medical conditions, such as Sjögren's, which directly affect salivary gland function. A xerostomic subgroup (n = 60), mean age = 60, 66 per cent female) of the Nutrition and Oral Health Study (n = 370) was reexamined for caries. Unstimulated and two-per-cent citric-acid stimulated parotid and submandibular/sublingual salivary flow rates were determined. This group was matched for number of teeth, age, sex, and alcohol and smoking habits with a medication-free subgroup (n = 60). Active root and coronal caries were found to be significantly higher in the xerostomic subgroup than in a matched subgroup of medication-free individuals. The mean DFS for the xerostomic subgroup was 45.4 +/- 21.7 for coronal caries and 5.3 +/- 5.8 for root caries. The mean number of teeth was 21.8. The mean DFS in the medication-free subgroup was 36.5 +/- 22.1 for coronal caries and 3.2 +/- 3.2 for root caries. The mean DFS in the xerostomic subgroup for coronal and root caries was statistically significantly higher (p < 0.05). The odds ratio was 2.89 for coronal caries and 3.27 for root caries in the xerostomic versus the medication-free subgroup. Caries varied inversely with salivary flow rate. The difference in flow rates for those in the lowest and highest quartile for coronal caries experience (DFS) in the xerostomic subgroup was found to be statistically significant (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Hydatid cyst of the tibia

A case of hydatid cyst of the tibia, which manifested as a pathologic fracture is being reported. Pain and swelling of left lower limb with inability to bear the weight were the main features. Tender swelling was also noted at the upper and middle third of tibia. Open biopsy revealed the hydatid cyst wall and scolices of Echinococcus granulosus. Albendazole treatment was followed by curettage and bone grafting.

Mastoparan blockade of currents through Ca(2+)-activated K+ channels in bovine chromaffin cells

The action of mastoparan (a wasp venom peptide) on "maxi" Ca(2+)-activated K+ channels was studied in excised inside-out patch recordings from cultured bovine chromaffin cells, under normal conditions (160 mM K+ inside, 154 mM Na+ outside). Mastoparan, when applied on the intracellular side of the membrane reduced the open channel probability in a concentration dependent manner. Changes in the channel kinetics were complex. The histograms of the open dwell times were all described by either one or two exponentials. Mastoparan shortened the mean duration of the major (long) component and to a lesser extent the minor (short) component. Closed dwell times, were described by three exponentials. While the short (major) component was prolonged by mastoparan, and the intermediate component was unaffected, the long component was shortened. Overall mean closed times were prolonged. The changes in channel kinetics could only partly be explained by a channel-blocking mechanism, even when assuming that mastoparan acts as both an intermediate and a slow channel blocker suggesting that it affects gating mechanism. The fact that mastoparan is a calmodulin inhibitor and a G-protein activator raises the possibility that in bovine chromaffin cells, either the membrane-bound calmodulin or a G-protein, plays a role in the modulation of Ca(2+)-activated K+ channels.

Multiple granular cell tumors of the gastrointestinal tract with subsequent development of esophageal squamous carcinoma

A 52-year-old woman initially presented to our medical center with synchronous, submucosal tumors of the esophagus, stomach, and transverse colon. The gastric and colonic tumors were resected, and both displayed infiltrating sheets of polygonal cells with coarsely granular cytoplasm and small vesicular nuclei. The neoplastic cells of both tumors were immunoreactive for S-100 protein. Ultrastructural studies revealed the lysosomal nature of the cytoplasmic granules. Although the esophageal mass was not resected, it was felt that this represented another focus of granular cell tumor of the gastrointestinal tract. Two years later, she presented with disseminated squamous carcinoma of the esophagus. At autopsy, a submucosal granular cell tumor was found adjacent to the squamous carcinoma of the esophagus. To our knowledge, this is the first reported case of synchronous granular cell tumors that involved multiple segments of the gastrointestinal tract, one of which was later associated with a squamous carcinoma of the esophagus.

Crossed renal ectopia with pelvic lipomatosis: a new syndrome involving chromosome 1

An 18-year-old male patient is described who possesses both kidneys on one side (crossed renal ectopia), together with pelvic lipomatosis. In general, lipomatosis is benign, but here the tissue shows the rare feature of malignancy. Chromosomally, the patient is typically characterised by somatic translocations involving chromosome 1 (37% metaphases); these almost always exhibit a whole chromosome translocation with chromosome 6 (35%), although involvement of chromosome 1 with chromosome 8 is present in 2% of metaphases. Other chromosomal features encountered in Giemsa-stained and G-banded preparations from lymphocyte cultures include the prevalence of a small Y chromosome in 25% of metaphases, the presence of marker dots in 20%, and acrocentric associations in 8%-10% of metaphases. However, more than 50% of metaphases have a normal 46XY karyotype with a normal-sized Y-chromosome. Crossed renal ectopia with pelvic lipomatosis can therefore be assigned to a new syndrome characterised by a whole-chromosome translocation involving chromosomes 1 and 6.

Improving dental epidemiologic data collection with computers

A computerized dental data recording system (DDRS) was developed for the New England Elder Dental Study to improve data quality and increase field staff efficiency. The DDRS displays video screens similar to traditional paper forms to record data on coronal and root caries, dentate and denture status, subacute bacterial endocarditis screening, gingival bleeding, calculus, and periodontal attachment level. DDRS provides facilities for date and exam-component time tracking, on-line contextual comments, random record retrieval, editing, data backup, and data output in various data formats. This study compared the DDRS with a paper-form system for data entry accuracy. Dental caries and periodontal disease measurement data from 38 subjects were recorded on paper forms and independently entered using DDRS. The DDRS identified 150 illogical data errors, 39 inconsistent data errors, 7 invalid data and 34 miscellaneous data errors. Four technicians with field experience using both paper forms and DDRS reported time savings using DDRS in the field. DDRS has the potential for additional time savings by minimizing the time for data coding, cleaning, and management. Results demonstrate that DDRS could improve the quality of oral epidemiologic data by mandating strict adherence to protocols, preventing errors, and increasing field efficiency.

Prevalence and intraoral distribution of coronal and root caries in middle-aged and older adults

This work describes the prevalence and intraoral distribution of coronal and root caries in 326 predominantly white, educated, middle-aged and older adults. Study participants were recruited from Tufts Geriatric Outreach Program, Nutritional Status Study (NSS), and the Forsyth Root Caries Study. Eighty-five percent of participants reported visiting their dentist in the last year. The median number of teeth was 21 in the 65+ age-group, and 40% of participants had coronal caries and 33% had root carious lesions. The mean coronal and root caries (DFS) was higher and the proportion of decayed surfaces to all decayed and filled surfaces (%D/DFS) was lower than in other comparable studies. A comparative analysis of intraoral distribution of coronal and root caries and their relation with age is discussed.

The dominance of cyclic sliding in producing wear in total knee replacements

From a literature survey, it was evident that a wide variety of kinematic conditions occur at the femoral-tibial bearing surfaces, including various degrees of rolling and sliding. A test machine was constructed to reproduce these conditions, applied to spherical-ended metal 'femoral' components acting on a flat polyethylene 'tibial' plateau. The load was cyclic at 2.2 kN for 10 million cycles with distilled water lubricant. For cyclic load only, a shiny depression was formed. With oscillating and sliding superimposed, there was severe surface and subsurface cracking resulting in high wear. When rolling motion was applied, a shiny wear track was formed with minimal cracking and wear. Such surface phenomena were observed in retrieved knee specimens, probably reflecting the kinematics associated with the knee. Low-conformity components inserted with high ligamentous laxity are susceptible to anteroposterior sliding and hence high wear. More-conforming components are less susceptible to wear because they limit sliding as well as reduce contact stresses.

Pollution and sanitary quality of river Narmada in relation to human use at Mandla

Study of physico-chemical characteristics and indicator bacterial population of Narmada river water at six different sites during summer, revealed extremely poor microbiological sanitary quality for human use. Free CO2 was found to be absent from all the sampling sites studied which indicates the trophogenic activity in the river water at Mandla. BOD value ranged from 1.0 to 2.5 mgl-1 and were less than the permissible limits of BOD in fresh waters i.e. 3-6 mgl-1.

Penile cancer--the sentinel lymph node controversy

The management of lymph nodes in penile cancer has always been a problem. Sentinel lymph node biopsy was supposed to solve this problem but has not been universally accepted due to conflicting results. We herein present a case of penile cancer with bilateral pathologically positive inguinal lymph nodes associated with concurrent negative sentinel lymph node biopsies. We discuss the possible reasons for this situation and suggest guidelines to study this issue.

Interaction of benzanthrone with cytochrome P450: altered patterns of hepatic xenobiotic metabolism in rats

Benzanthrone, an anthraquinone dye intermediate, is commonly used for the synthesis of a number of polycyclic vat and disperse dyes. Our prior studies have shown that benzanthrone can be metabolized by rat hepatic microsomal cytochrome P450 (P450) (Biochem. Int., 18, 1989, 1237). In this study, the interaction of benzanthrone with rat hepatic microsomal P-450 and its effect on xenobiotic metabolism have been investigated. Parenteral administration of benzanthrone (40 mg/kg body weight) for 3, 7, or 21 days caused no change in the relative body weight or organ weight of rats. The levels of P450 were found to be reduced (33%-50%) in all the benzanthrone-exposed animals at all the time periods. In vitro addition of benzanthrone caused a spectral change with oxidized P450 and concentration-dependent reduction in the carbon monoxide spectrum of dithionite-reduced P450. The addition of benzanthrone to hepatic microsomes prepared from phenobarbital-treated rats resulted in spectral changes characterized by an absorbance maximum at 397 nm indicative of type I binding. In vitro addition of benzanthrone showed a concentration-dependent inhibition of hepatic aminopyrine N-demethylase (APD) and ethoxyresorufin-O-deethylase (ERD) activities with respective I50 values of 9.5 x 10(-4) and 8.0 x 10(-5) M. However, the inhibition of aryl hydrocarbon hydroxylase (AHH) even at the highest concentration of benzanthrone (10(-2) M), was of the order of only 29%. In vivo administration of benzanthrone also led to the inhibition of APD, AHH, and ERD activities at all treatment times although the magnitude of inhibition was of a lower order.(ABSTRACT TRUNCATED AT 250 WORDS)

Cancellation in elective orthopaedic surgery

The management of operating theatre time is a crucial element in the size of surgical waiting lists, and this paper reports a survey of causes of the cancellation of operations for orthopaedic surgery. The results show that, although the majority of cancellations were due to medical causes, others were the result of extended theatre schedules. These findings suggest that closer co-operation between surgical staff, general practitioners and theatre staff could help to reduce this problem.