Statistical estimation of noise induced hearing loss among the drivers in one of the most polluted cities of India

In the present study, an attempt has been made to assess the impact of vehicular noise upon the 3-wheeler tempo drivers and to know whether there is any relationship between hearing loss and cumulative noise exposure. For this purpose, 3-wheeler tempo drivers (Exposed group) and non-commercial light motor vehicle car drivers (Unexposed group) were chosen as study subjects. Three traffic routes were selected to assess the noise level during waiting and running time in the exposed and unexposed groups. Among all three routes, the highest mean noise level (Leq) was observed on the Chowk to Dubagga route for waiting and en-route noise measurement. It was measured as 84.13 dB(A) and 86.36 dB(A) for waiting and en-route periods of 7.68 ± 3.46 and 31.05 ± 6.6 min, respectively. Cumulative noise exposure was found to be significantly different (p < 0.001) in all age groups of exposed and unexposed drivers. Audiometric tests have been performed over both exposed and unexposed groups. The regression analysis has been done keeping hearing loss among tempo drivers as the dependent variable and age (years) and Energy (Pa2 Hrs) as the independent variable using three different criteria of hearing loss definitions, i.e., World Health Organization, National Institute for Occupational Safety and Health (NIOSH), Occupational Safety and Health Administration criteria. Among these three criteria, the NIOSH criterion of hearing loss best explained the independent variables. It could explain the total variation in dependent variable by independent variable quite well, i.e., 68.1%. The finding showed a linear relationship between cumulative noise exposures (Pa2 Hrs) and the exposed group's hearing loss (dB), i.e., hearing loss increases with increasing noise dose. Based on the findings, two model equations were developed to identify the safe and unsafe noise levels with exposure time.

Validation of satisfaction questionnaire for services provided in the labour rooms of government health facilities

INTRODUCTION AND OBJECTIVES

Using the assessment of satisfaction of patients of labour room services, the caregiver or policymakers can identify the gaps in the implemented programmes and health policies. This study was aimed to design a valid and reliable satisfaction questionnaire that will help in identifying the aspects of gaps that need improvement.

METHODS

A facility and community-based observational cross-sectional study was conducted in the district of western Uttar Pradesh (India) between January 2019 and August 2020. Validation of the structured questionnaire with 34 dichotomous questions categorized under five subscales was performed by evaluating its validity and reliability. A total of 380 beneficiaries were selected from 48 government health facilities.

RESULTS

The calculated Content validity index was calculated to be 9.5 which was adequate as per the guidelines. The reliability analysis of the questionnaire showed that the internal consistency was high with an overall Cronbach's alpha of 0.710. The variation in Cronbach's alpha on the elimination of any question from the questionnaire ranged from 0.676 to 0.767. The mean patient satisfaction score in the total surveyed population was 24.39±4.684 (total score=34) and there was a greater variation in the satisfaction score of infrastructure when compared with other subscales.

CONCLUSION

The findings from this study support the reliability and validity of the patient satisfaction questionnaire as it is capable of evaluating the satisfaction in terms of delivery services provided in labour rooms as a whole.

Awareness, Practice and Level of Anxiety using Coronavirus Anxiety Scale among the Indian Population regarding COVID -19 Pandemic

Abstract: The most important aspect of Public Health Emergency Preparedness (PHEP) involves the circulation of trustworthy and accurate information in the public health interest domain. Strict stringency measures such as nationwide lockdown impacted people's mental health. Hence, this study was planned to assess the knowledge, practice, and anxiety among the Indian population about the ongoing pandemic in the initial phase. Methods: A web-based cross-sectional study was conducted between August 1, 2020, to October 5, 2020. Coronavirus Anxiety Scale was used to determine dysfunctional anxiety. Results: Among 553 participants, 73.6% had overall good knowledge of COVID-19 with mean correct score of 6.9±1.1. Majority of participants (97%) wore mask regularly, and 93% of respondents regularly washed their hands with soap and water. Only 14 participants scored ?9 on CAS, suggesting probable cases of dysfunctional anxiety associated with the COVID-19 crisis. Conclusion: The knowledge and practices of citizens in a nation reflect their preparedness and ability to deal with a pandemic of such proportion. Good knowledge translates to good practices and therefore reduces anxiety among the population. It is deemed necessary that people's knowledge and habits, including the mental impact, be accessed at periodic intervals to track their adaptation to pandemics over time.

Prevalence of needle stick injuries, its associated factors and awareness among nursing staff at tertiary care hospital of North India

Background: Needle Stick Injuries (NSIs) are defined as accidental skin penetrating injuries caused by needles. It is the single greatest occupational hazard to a medical personnel. In developing countries, needle stick injury is associated with the highest global prevalence of HIV, Hepatitis B, and Hepatitis C. Aim & Objectives: To estimate the prevalence of needle stick injuries, its associated risk factors and assess the awareness regarding needle stick injuries among nursing staff. Material & Methods: A cross-sectional study was conducted among nursing staff who were working at a tertiary care hospital in Northern India during June 2019 to November 2019. The study commenced after taking prior approval from institutional ethics committee. A census method was used to include the participants. Results: Around 66.7% of the nursing staff was exposed to NSIs during their working hours at the hospital. There was significant association of needle stick injuries with place of working and education of nursing staff in multivariate binary logistic regression. About 26% of the nurses were unaware that recapping should be done or not for used needle, and 35% of staff nurses recapped the needle after the use. Conclusion: Needle stick injuries can be prevented by continued education, effective training, providing better safety devices, a positive work environment.

Are the labour rooms of primary healthcare facilities capable of providing basic delivery and newborn services? A cross-sectional study

Objectives:

The study aimed to assess the functionality of labour rooms by evaluating the labour room infrastructure with reference to the standard guidelines, the status of the availability of human resources, the availability of essential equipment and consumables in the labour room and by documenting the knowledge of the healthcare provider in terms of labour room practices. The study also explored the facility parameters associated with its delivery load taking the facility as a unit of analysis.

Design:

A cross-sectional analytical study.

Setting:

India has realised the importance of improving the quality of care in public health facilities, and steps are being taken to make healthcare more responsive to women's needs. With an increase in the proportion of institutional deliveries in India, the outcome of the delivery process can be improved by optimising the health facility components.

Participants:

The study was conducted in 52 health facilities and healthcare providers involved in the delivery process in the selected facilities.

Results:

The infrastructure of the facilities was found to be the best for medical college followed by district hospitals, Community Health Centres (CHCs), Primary Health Centres (PHCs) and subcentres. Similar findings were observed in terms of the availability of equipment and consumables. Lack of healthcare providers was observed as only 20% of the posts for health personnel were fulfilled in CHCs followed by PHCs, subcentres and district hospitals where 43, 50 and 79% of the available vacancies were fulfilled. The level of knowledge of healthcare providers in terms of partograph, active management of the third stage of labour and post-partum haemorrhage ranged as per their designation. The specialists were the most knowledgeable while the Auxiliary Nurse Midwife (AMNs) were the least. All the components of structural capacity, i.e. infrastructure (r² = 0.377, P value < 0.001), equipment and consumable (r² = 0.606, P value < 0.001) and knowledge of healthcare providers (r² = 0.456, P value < 0.001) along with the overall facility score were positively correlated with the average delivery load of the health facility. The results from multivariate linear regression depict significant relation between the delivery load and availability of equipment and consumables (t = 4.015, P < 0.01) and with the knowledge of healthcare providers (t = 2.129, P = 0.039).

Conclusions:

The higher facilities were better equipped to provide delivery and newborn care. A higher delivery load was found at high-level facilities which can be attributed to better infrastructure, adequate supply of equipment and consumables and availability of trained human resources.

Prevalence and knowledge of hypertension among students of medical college of central Uttar Pradesh, India

Background: Hypertension is one of the biggest health challenges, which is continuously increasing among young adults, especially students. The aim of the present study was to find out the prevalence, associated factors and knowledge of hypertension among undergraduate students of a medical college of a rural area in central Uttar Pradesh, India. Methodology:  A cross-sectional study was conducted in one of the medical college of central Uttar Pradesh, India. Data were collected on socio-demographic and behavioral factors, and anthropometric assessments were carried out using standard equipment and procedures. Results: The present research involved 147 undergraduate medical students with a mean age of 21.9±2.2 years. Knowledge about hypertension was poor, average and good among19.7% (n=29), 76.8% (n=113) and 3.4% (n=5) students, respectively. Mean systolic blood pressure (mean SBP) was 127.07 ± 10.109 mm of Hg with a range 110 to 154mm of Hg, and mean diastolic blood pressure (mean DBP) was 80.5 ± 6.587 mm Hg with a range 68 to 94 mm of Hg. Conclusions: Smoking, alcoholism, non-vegetarian diet, body weight over 60 kgs and waist-hip ratio over 0.9 were recognized as risk factors of hypertension. Hence it needs a powerful surveillance program to find the exact problem.

Systemic review of CNS involvement and its manifestations in SARS-CoV2 positive patients

Coronavirus is known to cause various systemic infections both in human and animal which are mostly mild in nature. However, recent years have seen major pandemics caused by coronavirus which are very invasive and virulent in nature. The recent SARS-CoV2 is a new addition to this list of coronavirus pandemics. So the present study was done to systematically review the CNS involvement and its manifestations in SARS-CoV2 positive patients. Systemic review of article published between 1st Dec 2019 to 31st July 2020 searched through web-based database of MEDLINE (Pubmed) and Google scholar using following keywords “COVID -19” OR “CORONAVIRUS” OR “SARS-CoV2” AND “NEUROLOGICAL” OR “CNS” OR “BRAIN”. Using the steps of systemic review eight article were selected for qualitative analysis. Majority of these article were reporting neurological symptoms among patients admitted in different wards along with others general symptoms. None of the study was specifically devoted to study the neurological manifestations and complications in SARS-CoV2 positive patients. The present study concludes that there is a scarcity of good quality research which attempts to establish the role of SARS-CoV2 infection in CNS and its manifestations. However, there are evidences that CNS involvement is present in majority of the patients. Proper documentation of theses involvement and indentification of these into mild, moderate and severe infection will help in early identification and treatment of these patients.

Neurological Involvement in COVID-19 Patients: A Narrative Review

Background  Coronavirus disease 2019 (COVID-19) is a viral disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) belonging to the coronavirus family. The primary target of SARS-CoV-2 is peripheral mucosal cells of respiratory tract. Recent days have seen few cases where virus has affected extrapulmonary organ such as nervous system. Materials and Methods  The present study was a narrative review done using techniques of systemic review, that is, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic databases such as PubMed (Medline) and Google Scholar were searched systematically for published article from December 1, 2019 to June 5, 2020. A total of 189 articles were initially selected by the authors. A final list of 17 articles was prepared and following information were extracted from selected studies: study design, main result, and limitations of the study. Results  Majority of these article were descriptive studies describing spectrum of signs and symptoms among admitted patients. In majority of these studies, patients have developed symptoms suggestive of neurological involvement. Most common central nervous system symptoms reported were headache, followed by dizziness and confusion. Similarly, the most common peripheral nervous system involvement was loss of taste and smell. Conclusion  The present study concludes that there are enough evidences to prove that SARS-CoV-2 infection affects both central and peripheral nervous system. Various mechanisms are proposed to explain the pathophysiology of neurological manifestations in COVID-19-positive patients that needs to be established and verified.

Seed dispersal of wild radishes and its association with within-population spatial distribution

Background

The wild radishes, Raphanus raphanistrum and R. pugioniformis (Brassicaceae) are native to the East Mediterranean region. However, whereas R. raphanistrum is widely distributed worldwide, the endemic R. pugioniformis is limited to specific habitats. In R. raphanistrum the diaspores of the indehiscent fruits comprise glabrous, light, single-seeded segments, whereas the intact fruits of R. pugioniformis are heavy and covered with spiny backward-pointing trichomes. We aimed to investigate whether the structure of the diaspores was directly associated with long- and short-range dispersal in R. raphanistrum and R. pugioniformis, respectively. We further surveyed within-population spatial distributions, to test the hypothesis that short- and long-range dispersal contribute to a patchy vs. uniform distribution patterns of R. pugioniformis and R. raphanistrum, respectively.

Results

The results indicated that dispersal by wind and run-off water was substantially lower for diaspores of R. pugioniformis than for those of R. raphanistrum diaspores. Supporting the hypothesis that backward-pointing trichomes promote adherence to soil particles, the displacement on soil surface of R. pugioniformis fruits depended on their orientation relative to wind direction. Furthermore, trichome removal from fruits of R. pugioniformis significantly reduced wind velocity needed to remove fruits that were placed on soils typical of the species’ natural habitats. The spatial-distribution survey results indicated a patchy distribution of R. pugioniformis populations as compared with the more uniform arrangement in the studied populations of R. raphanistrum; consistent with the unidirectional vs. homogeneous wind dispersal of the respective diaspores, with respect to wind direction. In addition, R. pugioniformis population sizes changed less between years than those of R. raphanistrum.

Conclusions

Overall, our results indicate that fruit structure is strongly linked to dispersal ability and spatial distribution of the two closely related wild radish species. Whereas R. raphanistrum inhabits homogenous sandy soil habitats, the distribution range of R. pugioniformis includes heterogeneous environments in which growth niches are scarcer. We suggest that the different modes of dispersal have evolved as adaptive traits appropriate to the species’ specific habitats.

A study of Substance Abuse and Quality of Life among Street Children in District Etawah

Background: The research series on street children are carried out in major cities by neglecting the rapidly developing small cities experiencing widespread urbanization. Unfortunately, there is lack of research-based evidences in field of mental health status and quality of life of street children. Aim & Objective: The study aimed to study the pattern of substance abuse & their correlates among street children and to assess the ‘quality of life’ among street children. Material & Methods: A sample of 145 street children of 13-18 years were enrolled by purposive sampling from January 2017 - June 2018 in Market places, Railway station, Bus depot etc. Subjects were searched at known hotspots in Etawah, and further sample was covered using snowball sampling. Information was gathered using predesigned and pre-structured questionnaire, along with WHOQOLBREF and Adolescent Alcohol and Drug Involvement Scale questionnaire. Results: Average Quality of life was tested using t test and ANOVA. Most of the street children 55% were aged between 13-15 years, 65 % had attended school for at least one year. Quality of life showed higher Physical health. Street living children had less psychological health score (30.3±7.1). Prevalence of drug abuse was 54%, while tobacco, alcohol, marijuana, inhalants, were the drugs consumed. Conclusion: Psychological health was more affected. Tobacco & alcohol were the common drugs consumed.

The direct-writing of low cost paper based flexible electrodes and touch pad devices using silver nano-ink and ZnO nanoparticles

We report a novel and simple approach for the synthesis of silver nanoparticles capped with inositol (Ag NPs/Ino) by the reduction of silver salt with ascorbic acid under basic conditions. UV-vis, TEM, FTIR and TGA techniques were used to characterize the Ag NPs/Ino to determine the size, shape and surface modification of the NPs. Stable silver nano-ink was prepared in aqueous solution containing 1% PVP (stabilizer) and glycerol (cosolvent) and was used for the direct-writing of a paper electrode with a roller ball-point pen for electrochemical applications. The solvent, stabilizing agents, concentration of NPs (10%), paper substrate, sintering temperature (40 °C) and sintering time (15 min) were optimized to obtain a uniform coating of Ag NPs on the paper substrate. Further, the synthesis and fabrication of ZnO NPs on a paper substrate was put forward to design a touch pad device based on the piezoelectric effect. The preparation of paper based devices suggests a direction for the development of a simple, low cost and compatible approach for the direct-writing of paper based flexible electrodes and electronics for future applications.

Molecular dynamics of glycine ions in alanine doped TGS single crystal as probed by polarized laser Raman spectroscopy

Polarized Raman spectra of pure and alanine doped tri-glycine sulfate (TGS) single crystals at 12 K in different scattering geometries are analyzed. Sub species modes due to three crystallographically distinguishable glycine ions G (I), G (II) and G (III) are assigned. It is observed that alanine doping does not change the crystalline field and acts as local perturbation only. The major changes due to doping are observed in the relative intensities of different modes; most of the modes associated with G (I) and SO(4)(2-) ions show reversal behavior in relative intensity at high doping concentration. The observed spectral changes are analyzed in terms of reorientation of G (I) ions with sub species modes of G (II)/ G (III) following the reorientation due to complex hydrogen bonding network.

Determination of persistent organochlorine residues in a commercial fresh water catfish by GLC and study of their accumulation pattern

Concentrations of various organochlorine pesticides in a commercial fresh water catfish, Heteropneustes fossilis, were measured. This study reveals possible toxicological exposure of human beings by way of consuming such fish containing pesticide and that will amount to possible exposure. Tissue extracts obtained by Soxhlet apparatus were used for analysis and the concentrations of analytes were determined by gas chromatography with electron capture detection. The major organochlorines found in blood sample were Endosulfan, Alpha-HCH, Beta-HCH and Gamma-HCH. However, the organochlorines found in edible portion of fish (i.e.flesh) were mainly--Endosulfan, Delta-HCH, Aldrine, pp-DDE etc. The concentrations of these organochlorines were at or above the theoretical threshold limit and hence are supposed to be effectively toxic to fish eaters, due to biomagnification.

Arachidonic Acid production by fungi

After preliminary screening, Mortierella alpina and Mortierella elongata were compared with respect to arachidonic acid content. M. alpina ATCC 16266 produced 2.1 g of arachidonic acid per liter in media containing 10% glucose while the highest percentage of arachidonic acid in lipid (43.3%) was observed at a glucose concentration of 2%. Arachidonic acid content in lipids increased to 66% during storage.

An unusual photohaemolytic property of riboflavin

Riboflavin (RF) is a known photoreactive and phototoxic molecule. However, unlike other photosensitizers, it does not induce photohaemolysis of erythrocytes by itself. On the other hand, illuminated RF caused haemolysis but in the presence of serum or plasma. The kinetics of photohaemolysis in the presence of serum/plasma has been studied by monitoring the rate of haemolysis spectrophotometrically and morphological changes at erythrocytes membrane by scanning electron microscopy. We found that the extent of mammalian RBC membrane damage was dependent on the concentration of RF or hematoporphyrin (HP) (0-20 microgram/ml) and dose of sunlight (0-20 min). The RBC membrane-damaging potential of illuminated HP was not affected by the presence of plasma in the reaction system. Furthermore, RF showed a protective role against photohaemolysis caused by photoexcited HP if erythrocytes were preincubated with RF in the absence of serum/plasma. For mechanistic studies, biochemical parameters such as acetylcholinesterase activity (AChE) and formation of TBA-reactive substance (TBA-RS) were analysed in RBC and RBC+plasma under a similar set of experimental conditions. We observed about a 25% decrease in AchE activity as a synergistic action of RF or HP (20 microgram/ml) and sunlight (30 min) in both cases (RBC or RBC+plasma). Interestingly, illuminated RF caused about a 125% increase of TBA-RS in a reaction system consisting of RBC+plasma. On the other hand, an increase in the production of TBA-RS by illuminated RF was not observed in the absence of plasma/serum, in the reaction system. These results suggested that photooxidation of RBC membrane lipids by illuminated RF, under the influence of plasma/serum, may be one of the causes of membrane modification leading to RBC lysis.

Binding of 5-(2'-carboxyphenyl)azoquinolin-8-ol to bovine serum albumin: a spectroscopic study

Dye-protein interactions are of immense importance in dye-ligand chromatography of protein purification. In this type of interactions, the structure of the dye molecules has a significant role. However, studies on the structure of these ligands are scanty. Therefore, we have spectroscopically investigated interactions of three 5-(aryl)azoquinolin-8-ol derivatives, which could be used as potent chelate forming agents, with bovine serum albumin (BSA). Among these, the carboxy derivative, 5-(2'-carboxyphenyl)azoquinolin-8-ol (CPAQ) has been selected for resonance Raman study. It has been shown that BSA has six independent binding sites for CPAQ at pH 7.2, the binding constant being 6.2 x 10(3) M(-1). Assignments of Raman modes of bound CPAQ are also presented. It has also been shown that bound CPAQ exists exclusively in hydrazone form. Results further demonstrate that the azo group nitrogen adjacent to the phenyl ring probably participated in the formation of a BSA-CPAQ complex.

Biphasic biomethanation of wood-hydrolysate effluent

The dissolving pulp industry, spread throughout the world, is the principal source of wood-hydrolysate effluent rich in hemicelluloses. This effluent is the major source of pollution in the industry. COD and BOD5 values of the effluent range from 60,000 to 103,000 and 42,000 to 78,000 mg/l respectively. Biomethanation of this effluent is the best possible treatment option for reducing the COD load and recovering the bioenergy embedded in the effluent. This paper deals with the study on the biphasic biomethanation of the wood-hydrolysate in upflow acidogenic reactor coupled with anaerobic filter methanogenic reactor. The two reactors were operated at organic loading rates of 69.6 and 30.1 g COD/l/d respectively. The overall COD, hemicelluloses and lignin reductions, and methane generation were observed to be 88%, 92%, 82% and 6.5 l/l reactor volume/d respectively. The relative size of the biphasic, anaerobic filter (mono-phasic) and upflow anaerobic sludge blanket (mono-phasic) reactors is found to be 1:1.6:2.03 respectively.

Long-term delivery of testosterone by ALCAP ceramic implants in rats

The capability of ALCAP ceramic drug-delivery implantable devices to release testosterone for 12 months was investigated. A total of 120 Sprague-Dawley male albino rats were distributed equally into three groups. Two ALCAP capsules, one nonimpregnated and the other impregnated with polylactic acid (PLA) were implanted into each rat in Groups I and II. Capsules implanted into Group I rats were loaded with 40 mg testosterone (T) each. Group II rats were implanted with two empty capsules (sham group), and Group III animals served as unimplanted controls. Eight rats from each group were euthanized at the end of 1, 3, 6, 9, and 12 months following the implantation of the ceramics. No significant changes in the weights of vital organs of rats were observed between any of the three different groups. Vas deferens and epididymal fluid were devoid of normal spermatozoa within 3 months of implanting the steroid-containing ceramics. Testes and epididymis weights decreased significantly in the rats implanted with ALCAP ceramics containing steroid, and the seminiferous tubules became oligospermic after 1 month and azoospermic after 3 months. Circulating levels of both LH and FSH hormones were suppressed in experimental rats. Serum T level was lower than the control but showed no significant difference in comparison to control rats. The data collected in this study suggest that: (a) ALCAP ceramic capsules are capable of delivering T in a sustained manner for 12 months; (b) T delivered by ALCAP capsules can be used effectively to regulate spermatogenesis in rats.

A zinc based self setting ceramic bone substitute for local delivery of testosterone

Testosterone has been shown to stimulate bone healing. However, large doses of testosterone are associated with liver damage and prostate enlargement. Continuous release of testosterone at the traumatized bone site could enhance healing without inducing systemic side effects. In this investigation a self-setting zinc sulfate calcium phosphate (ZSCAP) ceramic with and without testosterone was used to fill experimentally induced bone defects in rats. Each treatment group consisted of six albino, Holtzman rats. Groups I and II consisted of non-operated and sham-operated animals. Rats in Group III, IV, V, and VI were implanted with ZSCAP particulate ceramic powders (63-75 microns) containing 0.0, 0.5, 1.0, or 1.5 mg testosterone in a 2.3 mm defect in the femur of each rat. Radiographic and morphologic examination of the implant site at four, eight, and twelve weeks post surgery showed integration of the implant in the femur of each rat. Serum testosterone of all rats was assayed at four, eight, and twelve weeks post surgery. Differences in the serum testosterone levels of rats in the six groups were not significant. Results of this study suggest that a ZSCAP-testosterone composite can be used to repair traumatized bone without increasing the levels of testosterone in the systemic circulation.

In vitro and in vivo dapsone release from hydroxyapatite reservoirs

Dapsone is a drug which is administered orally, on a daily basis, for four to five years as a cure for leprosy. The major problems associated with dapsone therapy include hemolysis, methemoglobinemia and patient non-compliance. Cimetidine reduces the side effects of dapsone and increases its levels in the blood. A ceramic drug delivery system was developed to maintain therapeutic levels of dapsone for an extended period of time and to alleviate associated side effects. In vitro release of commercial dapsone tablets (100 mg) and cimetidine pellets (400 mg) from hydroxyapatite reservoirs was studied in 100 ml absolute ethanol at 37 degrees C. Hydroxyapatite (HA) reservoirs loaded with one dapsone tablet released the drug at the rate of 8.3 mg/day for nine days, after which a much slower release occurred for another three days. With a load of two dapsone tablets, the rate of release was 6.7 mg/day for four weeks. HA reservoirs loaded with one cimetidine pellet delivered the drug at a rate of 25 mg/day for sixteen days. Combining both drugs in a single reservoir did not affect their respective release rates. When implanted subcutaneously in rats, HA reservoirs loaded with one dapsone tablet appeared to be well tolerated. After nine weeks, 77 mg of dapsone had been released. These experiments showed that HA reservoirs can be used to deliver dapsone and cimetidine in vivo.

Spectroscopic characterization of gelonin--assignments secondary structure and thermal denaturation

Gelonin, a type 1 ribosome inactivating protein (RIP), having only one polypeptide chain, and which could be used against deadly diseases like cancer and AIDS is investigated spectroscopically through infrared (IR), diffused reflectance infrared fourier transform (DRIFT) and Raman techniques and observed vibrational modes are assigned. It is found that gelonin is having mainly alpha-helix and beta-sheet structure with some turn and disordered structure, the estimated percentage structure using Raman data being approximately 32% alpha-helix, approximately 20% beta-sheet, approximately 26% turn and approximately 22% disorder type. The temperature dependent infrared study of gelonin reveals its thermal stability, the denaturation temperature being around 60 degrees C and disordered contribution increasing with heating.

In vitro delivery of dexamethasone using hydroxyapatite reservoirs

Dexamethasone has been shown to stimulate bone nodule formation in vitro. A hydroxyapatite (HA) reservoir drug release device was designed to release dexamethasone in vitro. Two HA particle sizes (< 38 microns or 63-75 microns) were used to fabricate the reservoirs. Each HA reservoir was loaded with 2 mg of dexamethasone and suspended in 100 ml of 50% aqueous ethanol at 37 degrees C for a period of 28 days. The positive controls indicated a limited solubility of dexamethasone of 1.18 mg per 100 ml of 50% aqueous ethanol. Dexamethasone was not released from any of the HA reservoirs for the first 24 hours. The largest amount of dexamethasone (0.0137 microgram/microliter) was released from the 63-75 microns particle HA reservoirs. A significantly lesser amount (0.00855 microgram/microliter) of dexamethasone was released from the < 38 microns particle HA reservoirs. The results of this study suggest that a HA ceramic reservoir loaded with dexamethasone can be used to deliver dexamethasone over long periods of time.

Hydroxyapatite-oil composites for delivering AZT in simulated body fluid

Hydroxyapatite (HA) has been used to deliver therapeutic drugs both in vitro and in vivo at a constant rate showing zero order kinetics. This study was designed specifically to analyze the effects of wheat germ (WG) incorporation with HA on the rate of delivery of AZT from an insert system over a one month period in vitro. Insert systems which were saturated with wheat germ oil delivered AZT at a slower rate over the one month period than did half-saturated or unsaturated insert systems. All systems containing 50 mg of AZT in the outer shell delivered 80% of the 100 mg AZT dosage over the first eight days. The systems which had a 100 mg AZT insert surrounded by an oily HA shell lacking AZT delivered AZT in a linear manner over the course of one month. The amounts and rates of AZT release from composites was indirectly proportional to the amount of wheat germ oil used. The results of this study show that the lipids incorporated in the ceramic composites can be tailored to deliver a 100 mg AZT dosage for a period of one month in vitro.

Parameters of protein delivery using hydroxyapatite in simulated body fluid

Various studies have been conducted using hydroxyapatite (HA) to deliver therapeutic drugs over a long period of time. However, the rate of drug release from ceramics varies tremendously. Thus a study was designed to observe the effect of particle size, pressure, drug ratio, and the addition of a zinc stearate binder on the release of BSA from ceramics. Samples were collected every two hours for a 12 hour period. Three particle sizes were used in the study (< 38, 45-63, and 63-75 microns). Variations in particle size did not influence the release of BSA. Ceramics compressed at a pressure of 150 Mpa delivered more protein than pressures of 300 MPa, 450 MPa, and 900 MPa. Drug to ceramic ratio had the most significant effect. A ratio of 1:25 BSA to HA delivered the protein quickly whereas the 1:100 BSA to HA delivered BSA to HA delivered BSA slowly and in zero order kinetics. The addition of the zinc binder improved the quality of the composite and decreased the release rate of protein delivery when present in 5% or less of the total ceramic weight. HA ceramics can be used to deliver proteins at different rates by varying compression pressure and drug to HA ratio.

Ceramic drug-delivery devices

A variety of ceramics and delivery systems have been used to deliver chemicals, biologicals, and drugs at various rates for desired periods of time from different sites of implantation. In vitro and in vivo studies have shown that ceramics can successfully be used as drug-delivery devices. Matrices, inserts, reservoirs, cements, and particles have been used to deliver a large variety of therapeutic agents such as antibiotics, anticancer drugs, anticoagulants, analgesics, growth factors, hormones, steroids, and vaccines. In this article, the advantages and disadvantages of conventional drug-delivery systems and the different approaches used to deliver chemical and biological agents by means of ceramic systems will be reviewed.

A ceramic system for delivering interleukin-2

Interleukin-2 (IL-2) is a potentially effective cytokine to be used for cancer treatment. Since keeping IL-2 doses at a low, continuous level is important to avoid side effects which accompany high IL-2 doses, a ceramic which release IL-2 could prove to be a beneficial method of drug delivery for cancer patients [1]. In vitro studies were performed to determine the optimal hydroxyapatite (HA) to IL-2 ratio for continuous release of IL-2 from HA using both a matrix and insert ceramic pellet. In the matrix pellet experiment, HA to IL-2 ratios of 25:1, 50:1 and 100:1 were tested by compressing a homogenous mixture of each variable in triplicate and placing each ceramic in 2.5 mL simulated body fluid (SBF) at 37 degrees C. The fluid was collected and replaced for each ceramic every two hours for 12 hours and at 24 hours. The collected fluid was then assayed for IL-2 content. Pellets consisting of 25:1 ceramic to drug ratio delivered almost the entire amount of IL-2 at the fastest rate. Composites of 100:1 IL-2 to HA delivered the least amount of IL-2 at the slowest rate. Release of IL-2 from the 50:1 ratio pellets was intermediate with respect to speed and amount of delivery. In the insert pellet experiment, similar laboratory procedures were used to show that 100:1 ratio insert pellets delivered IL-2 at a slower rate and in lesser amounts than 50:1 ratio insert pellets. Results of this study show that HA can deliver IL-2 at different rates by varying the ratio of HA to IL-2 in both matrix and insert ceramic pellets.

In vitro characterization of a zinc based bioceramic

Six different blends of zinc calcium phosphorous oxide ceramics (ZCAP) were prepared by mixing and calcining powders (ZnO:CaO:P2O5) of weight percent ratio: 50:30:20, 48:32:20, 44:20:26, 40:40:20, 30:40:30, and 30:30:40. ZCAP is a resorbable bioceramic and has been used to repair bone defects and deliver drugs in a continuous manner. The chemical composition, porosity, and elements released on exposure to buffered Tris HCl were measured for each blend of ZCAP. The products of mixing and thermal reaction were beta-Ca3(PO4)2, alpha-CaZn2(PO4)2, and 2CaO.P2O5. Free calcium and/or zinc oxide was present in several blends. The components of ZCAP and their volume percentages influenced the interconnected porosity of ZCAP bioceramics. The interconnected porosity for all blends of ZCAP ranged from 35 to 38%. Pore sizes from these six blends of ZCAP ranged from less 1 micron to greater than 100 microns. Results of the 12 hour dissolution study showed that more calcium was released than zinc or phosphorous from all blends of ZCAP. Zinc was released in trace amounts from all blends of ZCAP. Release of phosphorous from the different blends of ZCAP was not detected by the procedures used to detect phosphorous in this investigation. These blends of ZCAP have the potential to be used as bone substitutes and probably long term treatment of zinc deficiency in humans.

A hydroxyapatite system for the continuous release of coumadin an anticoagulant

Coumadin is an anticoagulant used in the treatment of patients with pulmonary thromboembolisms or those implanted with mechanical vascular devices. Its efficacy is complicated by side effects such as hemorrhaging. Administration of coumadin by the traditional routes of pills and injections causes wide fluctuations of the drug in plasma. Thus, experiments were conducted to develop a hydroxyapatite ceramic system for releasing coumadin in vivo continuously for 7-10 days. A series of preliminary in vivo experiments was conducted to determine an effective non-lethal therapeutic dosage of coumadin for rats. Homogenous matrices containing varying amounts of coumadin were implanted subcutaneously in rats and the blood clotting time was determined. Results of these experiments showed that one mg coumadin delivered from HA implants doubled the blood clotting time and did not induce fatal hemorrhage. Subsequent in vitro studies were conducted to determine the most efficient way to deliver coumadin at a slow and sustained rate. Results of these experiments suggested that a solid insert of one mg of compressed coumadin in a hydroxyapatite ceramic shell released the drug more slowly and efficiently than a homogenous matrix consisting of compressed coumadin and hydroxyapatite.

Possible role of mononuclear phagocytes in clearance of immune complexes in pulmonary tuberculosis

Phagocytic activity of peripheral blood mononuclear cells (PBMC) was investigated in 30 patients with pulmonary tuberculosis. The test was done using neutral red. Higher percentages of phagocytic cells were detected with PBMC of tuberculosis patients as compared with controls. An inverse relationship was observed between neutral red positive cell counts vs. relative percentages of several proteins (IgG, C3 and C4) in PEG precipitates in tuberculosis patients. It was interpreted that phagocytes might have mopped up the CICs via their surface Fc receptors.

The use of a zinc based bioceramic as an osteoconductive agent in the rat model

The many complications and risks of autograft and allograft bone have resulted in the search for an effective synthetic bone graft substitute [1,2]. The purpose of this study is to determine the effectiveness of ZCAP (zinc calcium phosphate) ceramic organic acid composite as an osteoconductive agent, including its possible benefits or risks for patients requiring bone grafting. A solid control model has been developed with an isolated mid-diaphyseal femur fracture immobilized by intramedullary threaded K-wire fixation. Two trials were performed in which two formulations of ZCAP composite ceramic were tested. The first, used in eighteen rats will be referred to as ZCAP1, the second, used in six rats will be referred to as ZCAP2. In the first trial rat femurs were augmented with 0.1 g ZCAP1 composite ceramic which varied in pore size. One pore size performed better than the others, so that pore size along with some minor changes in the composite design to increase resistance to the stresses inherent in our weight bearing model resulted in ZCAP2, which was tested in the second trial. The rats were sacrificed at ten weeks, during which time all rats remained viable. Blood work was done prior to sacrifice and radiography was done on all femurs. After sacrifice, gross morphological exam showed filling of the defect. Sections of the femurs from each group were analyzed by decalcified histological examination, electron microscopy, and tensile strength testing. The ZCAP composite ceramic had no significant effect on blood chemistry or body weight. Initial histological studies were consistent with endochondral ossification which was confirmed by electron microscopy.(ABSTRACT TRUNCATED AT 250 WORDS)

Successful antidote of multiple lethal infections using sustained delivery of difluoromethylornithine by means of ceramic drug delivery devices

The objectives of this study were (1) to cure multiple infections of trypanosomiasis in rats by the sustained release of DFMO from biodegradable tricalcium phosphate (TCP) and aluminum-calcium-phosphorous oxide (ALCAP) delivery systems, and (2) to determine if the side effects associated with oral administration of DFMO can be avoided by using TCP and ALCAP capsules. Sixty-eight SD male albino rats (235-270 g) were divided randomly into five groups. Each rat in group I (n = 16) was implanted subcutaneously (s.c.) with four TCP capsules (two large TCP (L-TCP), one PLA-impregnated large TCP (IL-TCP) and one thin TCP capsule (TN-TCP)). Rats in group II (n = 16) were implanted s.c. with four ALCAP ceramics (two large ALCAP (L-ALCAP), one PLA-impregnated large ALCAP (IL-ALCAP) and one thin ALCAP capsule (TN-ALCAP)). Rats in groups III (n = 16), IV (n = 4) and V (n = 16) were left without implants. Rats in group III (n = 16) were given 4% (w/v) DFMO (pH 7) in drinking water at the day of inoculation and continued up to 7 days postinoculation. Rats in group IV (n = 4) served as a nontreated group. Rats in group V (n = 16) served as normal controls. The results showed that all rats implanted with with TCP or ALCAP implants had no intoxications symptoms or side effects such as diarrhea during the treatment period. In contrast, rats given DFMO in drinking water exhibited foul-smelling diarrhea during the treatment period. Microscopic evaluation of blood smears collected from rats receiving DFMO chemotherapy showed an occasional or limited number of stumpy shape (SS) trypanosomes. This study suggests that (1) ceramic drug delivery systems are capable of delivering DFMO in a sustained manner for two months, and were able to cure repeated infections of trypanosomiasis; (2) the use of ceramic implants avoided widely fluctuating, irregular levels of DFMO in the body by keeping sustained levels above minimal effective concentrations; (3) ceramic drug delivery systems provide a pharmacological potentiality for drugs such as DFMO which have been withheld from the market because of severe side effects when administered using conventional methods of drug administration; and (4) DFMO-filled ceramic devices can be implanted subcutaneously in animals that face a threat of lethal protozoal infections in highly infested areas of the world.

Eicosapentaenoic acid (EPA) production from microorganisms: a review

Eicosapentaenoic acid EPA has been shown to be of major importance in the prevention and treatment of a range of human diseases and disorders. At present fish oil is the only source of EPA that is considered unattractive because it contains substantial amounts of undesirable fatty acids and cholesterol. Consequently, alternative sources of EPA are being sought, especially from algae and from fungi of the order Mucorales. This review presents information about EPA producing microorganisms, data on the production and recovery aspects along with the potential of microorganisms as commercial sources of EPA.

Light-induced biophotonic emission from plant tissues

The emission of biophotons in the visible range, following a delay time of 2-200 seconds after exposure to light, has been measured in germinating seeds, roots, flowers, leaves, and cells. It was found that the biophotonic signals are reproducible and light-induced. The observed signals from germinating seeds of Phaseolus aures and decaying leaves of Eucalyptus are presented to show that the signals have characteristic kinetics and intensity. The kinetics of the signal was found to be independent of the stage of growth or decay, though its intensity varied with biological factors. The kinetics in the first minute is characterized by a single exponential decay term while that in the region t less than or equal to 200 s is characterized by two exponentials. The variation in the intensity of the signal with mass, state of hydration, and growth, and the effect of inhibitors in various systems (e.g. leaves, lichen, Chlorella) are reported.

Arachidonic acid production by microorganisms

Arachidonic acid (AA) is a natural precursor of prostaglandins, thromboxanes, leukotrienes, prostacyclins, and a large group of C20 compounds which are of intrinsic medical interest. At present, the only source of AA is animal tissues. However, it is present in several microorganisms. This review describes the production of AA by microorganisms and its recovery and the potential of microorganisms as a source of AA.

Eicosapentaenoic acid (EPA) production by Mortierella alpina ATCC 32222

Mortierella alpina ATCC 32222 grew well at 11 degrees C, as well as at 25 degrees C in a liquid medium containing glucose or linseed oil and yeast extract. High Eicosapentaenoic acid (EPA) yield was obtained at 11 degrees C. M. alpina cells did not produce EPA at 25 degrees C in the absence of linseed oil, whereas at 11 degrees C, EPA accumulation was noted in the absence of linseed oil. When grown at 11 degrees C for 10 d in a medium containing 2% linseed oil as carbon source, the mycelium yielded 435 mg/L EPA (20 mg EPA/g dry mycelia) with 5.1% in lipid fraction. By gradually increasing the concentration of linseed oil to 4%, yield of biomass and EPA were increased to 43 g/L and 596 mg/L, respectively.

Increased production of thermostable alpha-amylase enzyme by Bacillus sp. TCRDC-25A with maltodextrins

Maltodextrins and hydrolysates of rice and corn flour of varying dextrose equivalents (DE) have been used as a carbon source for alpha-amylase enzyme production by Bacillus sp. TCRDC-25A. The rate and total enzyme production was higher in maltodextrin media than in cornstarch. The enzyme production increased with increase in DE up to 45%. The maximum enzyme production of 2390, 2450, and 2510 DUN/mL was obtained in cornstarch maltodextrins, and hydrolysates of corn and rice flours, respectively, in a bench-scale reactor in 40 h.

Ultraweak photon emission in germinating seeds: a signal of biological order

Photon emission from germinating gram seeds at various stages of growth exhibits a definite pattern. The pattern of emission changes when a seed is disrupted by physical processes, e.g. mechanical crushing, cooling or heating. The disrupted seeds do not grow. The change in the biological order responsible for seed growth and the observed changes in the pattern of photo emission suggest a link between the macroscopic spatio-temporal organization and metabolic processes.

Production of arachidonic acid byMortierella alpina ATCC 32222

When Mortierella alpina ATCC 32222 was incubated in a glucose salts medium at 25 degrees C the biomass (17.5 g/l) contained 9.62% arachidonic acid which amounted to 54% (w/w) of total biomass lipids. When the glucose concentration in the medium was varied from 0 to 150 g/l, the percentage of arachidonic acid in biomass and in lipids was highest at a glucose concentration of 30 g/l, but highest yield of arachidonic acid per litre of culture broth was observed at a glucose concentration of 100 g/l. While production of biomass reached a plateau of 17 g/l after a 3-day incubation at 25 degrees C, the percentage of arachidonic acid in lipids and biomass increased dramatically from 3 to 6 days with a concurrent arachidonic acid yield increase from 0.89 to 1.63 g/l. Optimum initial culture pH for arachidonic acid production was in the range 6.0-6.7. By increasing the concentration of the glucose salts medium three-fold, yields of biomass and arachidonic acid were increased to 35.8 g/l and 3.73 g/l, respectively.

The delivery of testosterone and dihydrotestosterone by ALCAP ceramic implants in rats

The objectives of this investigation were to evaluate the release of testosterone (T) and dihydrotestosterone (DHT) from nonimpregnated and polylactic acid (PLA) impregnated ALCAP ceramic reservoirs implanted in rats, and to study the effects of delivered androgens on the reproductive system of male rats. A total of 120 Sprague-Dawley albino male rats were distributed equally into three groups Two ALCAP capsules, one nonimpregnated and the other impregnated with PLA, were implanted into each rat in groups I and II. Capsules implanted into group I rats were loaded with a mixture of 20 mg T and 20 mg DHT. Group II rats were implanted with two empty capsules (sham group), and group III animals served as unimplanted controls. Eight rats from each group were euthanized at the end of 3, 6, 9, and 12 months following the implantation of the ceramics. No significant change in the weights of vital organs of rats was observed among any of the three different groups. Vas deferens and epididymal fluid were devoid of normal spermatozoa within 3 months of implanting the steroid-containing ceramics. Testicular weights decreased significantly in the rats implanted with ALCAP containing steroids and the seminiferous tubules became oligospermic after 1 month and azoospermic after 3 months. The data collected in this study suggest that (1) ALCAP ceramic capsules are capable of delivering T and DHT in combined form, and (2) T and DHT delivered by ALCAP capsules can be used effectively to regulate spermatogenesis in rats.

Analysis of the biocompatibility of ALCAP ceramics in rat femurs

Ceramics composed of aluminum, calcium, and phosphorus oxides (ALCAP) were tested for compatibility as bone replacement biomaterials. Implantation of ALCAP ceramics in rat femurs had no deleterious effect on body weights, organ/body weight ratios, muscle, bone, blood, and kidney function. Aluminum resorbed from ALCAP ceramic bone implants was excreted in the urine and was not deposited in adjacent muscle. Plasma levels of aluminum were not elevated in rats implanted with ALCAP ceramics. Alkaline phosphatase activity of excised implant sites indicated greater bone formation in ALCAP ceramic implants than in bone autografts. Radiographs and implant histology demonstrated excellent bone association with implants and ingrowth of new bone into ALCAP ceramic implants. ALCAP ceramics are biocompatible and suitable for reconstruction of bone.

Ceramic systems for long-term delivery of chemicals and biologicals

Evaluation of devices, drugs, and drug delivery systems have been investigated by both in vitro and in vivo procedures. Ceramic drug delivery systems can be used to evaluate chemicals and biologicals by both in vitro and in vivo procedures. The system can also reduce handling of the animals and facilitate long-term evaluations before conducting clinical trials. To date, ceramic systems have been used to deliver aldosterone, androstanedione, beta-lactoglobulin, bovine serum albumin, chymotrypsin, danazol, difluoromeythylornithine, dihydrotestosterone, estradiol, gamma globulin, gonadotrophic releasing hormone, gossypol, growth hormone, insulin, methylene blue, pepsin, progesterone, and testosterone. The data obtained suggest that ceramic delivery systems can be used in the near future to treat diseases requiring long-term chronic drug therapy as well as disorders caused by deficiency of certain hormones.

Osteoconductive composite grouts for orthopedic use

A composite of HA particulate and calcium sulfate hemihydrate has been developed. When this dry material is mixed with either sterile saline or water, the resulting mixture begins to gel. While in the gel or dough state, the composite can be manually inserted or injected under pressure into a bone defect where it sets in situ. The calcium sulfate acts as a binder to hold the HA particles in place. The subsequent resorption of the calcium sulfate leaves controlled porosity for bone ingrowth and attachment to the nonresorbable HA particulate. The combination of calcium sulfate and HA results in a composite with handling properties superior to those of HA alone. Calcium sulfate has a long history of medical use as an implant material. The biocompatibility of the material has been clearly established. The combination of HA and calcium sulfate is likewise extremely compatible as demonstrated in the present studies. Bone ingrowth concomitant with resorption occurs rapidly with efficient conduction of bone from particle to particle. Based on the experiments presented herein, the composite of HA and calcium sulfate may be a useful alternative or adjunct to autogenous bone grafting. Many questions, however, remain regarding long-term tissue response and bone remodeling as well as the efficacy of this material relative to bone grafting.

Sustained delivery of difluoromethylornithine (DFMO) by means of implantable ceramic devices

A total of 25 Sprague-Dawley albino male rats were assigned to five groups, each group consisting of five rats. Polylactic acid-impregnated ALCAP capsules filled with 40 mg DFMO were implanted subcutaneously (sc) or intraperitoneally (ip) in group I and II rats, respectively. Rats in group III were implanted with empty ALCAP capsules (ALCAP control). Group IV rats were administered orally 3% DFMO in drinking water. Rats in group V served as control. Blood samples were collected every week for six weeks via the tail artery. The concentration of DFMO was determined by a modified ninhydrin hydrindantin method. Data obtained in this investigation showed that the levels of DFMO in the serum of rats in groups I and II were 41.87 +/- 6.8 and 237.62 +/- 13.3 micrograms/mL, respectively. Body, spleen, liver, prostate, seminal vesicles, and testicular weights of the controls and DFMO treated rats were not significantly different (p less than 0.05) over the entire duration of this study. The diarrhea often noted in rats treated orally with DFMO was not observed in rats implanted with ALCAP capsules filled with DFMO. The results of this study suggest that (1) polymer-impregnated ALCAP ceramic capsules can be used to deliver DFMO in a sustained manner for long durations of time, (2) side effects associated with oral administration of DFMO can be avoided by using DFMO-filled ALCAP ceramic implants, and (3) a ceramic system can be designed to deliver DFMO and drugs such as DFMO in a sustained manner over long periods of time in humans.

Immunogenicity of glutaraldehyde-treated bovine pericardial tissue xenografts in rabbits

Xenograft valves of glutaraldehyde-treated bovine pericardial tissue have been claimed to be an excellent choice for the replacement of malfunctioning human heart valves. These valves exhibit low thrombogenicity, hemodynamic function, and transvalvular gradients superior to their mechanical and tissue counterparts. However, there are differences of opinion concerning the immunogenic properties of these valvular devices. This study was conducted to evaluate the immune reactivity of such implants. Data obtained indicated that whole xenograft sections of both untreated and treated valvular tissue remain immunogenic following initial and secondary subcutaneous implantations in rabbits. Homologous and cross-reacting antibodies were detected by means of indirect hemagglutination test 30 days after initial implantation of the grafts. Presence of cellular immune response as judged by skin reaction and leukocyte migration inhibition tests indicated that glutaraldehyde treatment of tissues does not destroy cellular immunity. Data obtained also suggest that chemical modification of such implants by glutaraldehyde probably alters, but does not abolish some antigenic determinant sites on the tissue surface. Glutaraldehyde treatment of bovine pericardial tissue does not render the tissue immunologically inert.

In vitro dissolution of Synthos ceramics in an acellular physiological environment

"Synthos" (beta-tricalcium phosphate) implants in bone are resorbed and replaced with endogenous bone. This investigation was conducted to study by continuous flow and static system techniques, whether or not resorption of synthos occurs by passive dissolution at 37 degrees C. Calcium and phosphates were released in a time dependent manner from synthos in calcium and phosphate free Tris-Hcl buffer (pH 7.4). Scanning electron micrographs (SEM) of buffer exposed ceramics indicated breakdown of grain structure. In contrast, levels of human plasma calcium and phosphate were not altered by ceramics. Significant amounts of 32p were absorbed by the ceramics in the first hour and 45Ca in the second hour of exposure to plasma containing the radioactive isotopes. Exposure of ceramics to plasma did not alter the levels of plasm isotopes significantly for the remaining duration of the experiment. However, breakdown of grain structure was evident in SEM's of ceramics exposed to plasma. It appears that in an acellular physiological environment, dissolution of synthos is diffusion dependent and is limited to a localized surface exchange phenonmenon.