Infection Prevention and Control: Baseline Knowledge and Practices of TBAs in Rural Kano, Northwestern Nigeria.

BACKGROUND: Maternal infections remain a significant contributor to maternal mortality worldwide. Majority of births in northern Nigeria occur at home and are attended by Traditional Birth Attendants (TBAs). Little has been documented about their knowledge and practice on infection prevention and control practices in Kano, northern Nigeria. OBJECTIVES: This study evaluated the level as well as factors associated with TBAs' infection prevention and control knowledge and practices. METHODS: The study is the baseline phase of a quasi-experimental study, conducted in a rural LGA in Kano State, Nigeria. Using an adapted tool, 163 eligible TBAs were surveyed. Knowledge and practice of IPC were scored, aggregated, and dichotomized into good or poor. Binary logistic regression analysis was used to predict knowledge and practice of IPC. RESULTS: Majority (79.1%) of the TBAs exhibited poor IPC knowledge but many (78.5%) reported good practice. Good knowledge of IPC was predicted by the TBAs' age: a six-fold increased likelihood (AOR=6.25, 95% CI: 1.02- 38.53) and almost five-fold increased likelihood (AOR=4.75, 95% CI: 1.39- 16.24) for those in their second and fourth decades of life. TBAs who reported poor practice of IPC were 83% less likely (AOR=0.17, 95% CI: 0.03- 0.92) to have good knowledge of IPC. TBAs' practice was only linked to previous training (AOR=0.17, 95% CI: 0.04- 0.76). CONCLUSION: TBAs knowledge of IPC was low although reported practice was good. The need for tailored training interventions to enhance knowledge and skills for safe delivery care is paramount to improve maternal and neonatal outcomes.

CONTEXTE: Les infections maternelles restent une contribution significative à la mortalité maternelle dans le monde. La majorité des accouchements dans le nord du Nigeria ont lieu à domicile et sont assistés par des TBA. Peu de choses ont été documentées sur leurs connaissances et leurs pratiques en matière de prévention et de contrôle des infections à Kano, dans le nord du Nigeria. OBJECTIFS: Cette étude a évalué le niveau de connaissances et de pratiques des TBA en matière de prévention et de contrôle des infections, ainsi que les facteurs associés. MÉTHODES: L'étude est la phase de base d'une étude quasiexpérimentale, menée dans une LGA rurale de l'État de Kano, au Nigeria. En utilisant un outil adapté, 163 TBA éligibles ont été interrogés. Les connaissances et les pratiques en matière de PCI ont été évaluées, agrégées et dichotomisées en bonnes ou mauvaises. Une analyse de régression logistique binaire a été utilisée pour prédire les connaissances et les pratiques en matière de PCI. RÉSULTATS: La majorité (79,1 %) des TBA présentaient des connaissances médiocres en PCI, mais beaucoup (78,5 %) ont déclaré avoir de bonnes pratiques. De bonnes connaissances en PCI étaient prédites par l'âge des TBA : une probabilité multipliée par six (AOR=6,25, IC à 95 % : 1,02-38,53) et presque multipliée par cinq (AOR=4,75, IC à 95 % : 1,39-16,24) pour ceux dans leur deuxième et quatrième décennies de vie. Les TBA qui ont déclaré une mauvaise pratique de la PCI étaient 83 % moins susceptibles (AOR=0,17, IC à 95 % : 0,03-0,92) d'avoir de bonnes connaissances en PCI. La pratique des TBA était uniquement liée à une formation antérieure (AOR=0,17, IC à 95 % : 0,04­0,76). CONCLUSION: Les connaissances des TBA en matière de PCI étaient faibles bien que les pratiques déclarées étaient bonnes. La nécessité d'interventions de formation sur mesure pour améliorer les connaissances et les compétences en matière de soins de l'accouchement sécurisés est primordiale pour améliorer les résultats maternels et néonatals. MOTS-CLÉS: Accoucheuses Traditionnelles, Mortalité Maternelle, Infection Maternelle, Nigeria.

Comparison of Pain Control and Analgesic Consumption With or Without Infiltration of Bupivacaine at Port Sites after Laparoscopic Cholecystectomy.

Pain management is an essential component of all surgical procedures. Analgesics are used for this purpose but there are some complications in using them. Local anesthetics like bupivacaine can be used to reduce postoperative pain as well as analgesics consumption. The objective of this study is to observe the result of infiltration of bupivacaine at port sites and to compare the postoperative pain relief with that of opioids and NSAID administration following laparoscopic cholecystectomy for chronic calculus cholecystitis. This is a cross sectional study was conducted over one year in the Department of Surgery of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from September 2018 to August 2019. Here total 40 patients were enrolled by purposive sampling. They were divided in two groups. One group received bupivacaine while other did not. A numerical pain scale was used as tool. Data will be recorded by peer reviewed interview and observation based semi structured data collection sheet. Data analysis was done by SPSS version 23.0. P-value was significant at (p<0.05) and determined by chi square test. Written informed consent was taken from the patient. The mean Numerical Rating Scale (NRS) score of pain at 6 hour was 2.55±0.6 in Group I and 6.8±1.15 in Group II. The mean NRS score of pain at 12 hour was 4.1±1.21 in Group I and 7.95±0.6 in Group II. The mean time of 1st analgesic administration was 13.85±1.57 hours in Group I and 2.75±0.72 hours in Group II. The mean repeat dose of analgesic was in 22±2.29 hours in Group I and 9.5±1.15 hours in Group II. In Group I one third patients (30.0%) single dose analgesic required in 1st 12 hours while in Group II almost 90.0% patients needed analgesics in 1st 12 hours. In Group I, total doses of analgesics required were 2 in 75.0% patients while in Group II at least 3 doses of analgesics were needed. In Group I only one patient needed analgesic in first 6 hours (5.0%) while in Group II, all the patients (100.0%) needed analgesics. The difference was statistically significant (p<0.05) between two groups. The patients receiving bupivacaine at port sites will experience less pain at postoperative period and will need less analgesic medications.

Demographic Characteristics of Patients with Breast Cancer in Bangladesh: A Single-Centre Study.

We performed this study to investigate the socio-demographic factors of breast cancer patients of Bangladesh. This cross-sectional study was conducted in the Department of General Surgery at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from July 2018 to September 2019 for a period of one (1) year. All consecutive cases of breast carcinoma admitted in hospital and attended at outpatient department during the study period were selected as study population. Total 50 patients were selected. The mean age of the study patients was 51.1. Maximum number (70.0% cases) of breast cancer was belonged in 4th to 5th decade aged group. 70.0% breast cancer patients were housewives. The most of the breast carcinoma was reported in the urban people which were 78.0% cases. The percentage of educated study population was 80.0%. On religious background, 86.0% cases of breast cancer patients were Muslim. Most of breast cancer patients were sporadic in origin 94.0% cases, had no family history of breast cancer. Breast cancer was mostly distributed in pre-menopausal aged group with 82.0% cases. Ninety percent (90.0%) of the study population was come from middle class socio-economic group. In western countries, incidence of breast cancer is more in elderly aged menopause women with high socio-economic class. In this study the breast carcinoma was most prevalent among educated urban Muslim pre-menopausal housewives of age group 4th to 5th decade and most of them belonged to middle socio-economic class. The socio-demographic factors of breast cancer patients in Bangladesh are disparate from western countries in age standard, social class group and menstrual status.

Effects of halotolerant rhizobacteria on rice seedlings under salinity stress.

Avirulent halotolerant plant growth-promoting rhizobacteria (HPGPR) located on the roots' periphery can reduce abiotic stressors (such as salinity and drought), enhance plant productivity. Salinity poses a significant challenge for growing agricultural products, like rice, in the coastal regions. It is crucial to enhance production because of limited arable land and the high growth rate of the population. This study targeted to identify HPGPR from legume root nodules and assessed their effects on rice plants experiencing salt stress in coastal regions of Bangladesh. Based on the culture morphology, biochemical, salt, pH, and temperature tolerance traits, sixteen bacteria were isolated from the root nodules of leguminous plants (Common bean, Yardlong bean, Dhaincha, and Shameplant). All the bacterial strains can tolerate 3 % salt concentration, and capable to survive at the highest 45 °C temperature and pH 11 (without isolate 1). Three preeminent bacteria, Agrobacterium tumefaciens (B1), Bacillus subtilis (B2), and Lysinibacillus fusiformis (B3) were specified through morpho-biochemical and molecular (16S rRNA gene sequence) exploration for inoculation. To assess the plant growth-promoting activities, germination tests are applied where bacterial inoculation increased germination in saline and non-saline conditions. Control group (C) showed 89.47 % and bacterial treated groups (C + B1, C + B2, and C + B3) 95 %, 90 %, and 75 % germination after 2 days of inoculation. In (1 % NaCl) saline condition control group revealed 40 % whereas three groups with bacteria showed 60 %, 40 %, and 70 % germination after 3 days, which increased 70 %, 90 %, 85 %, and 95 % respectively after 4 days of inoculation. The HPGPR significantly improved plant development metrics such as root length, shoot length, fresh and arid biomass yield, chlorophyll content, etc. Our results suggest that the salt-resistant bacteria (Halotolerant) have a great potential role in recuperating plant growth and would be cost-effective as a bio-inoculant in saline conditions to be used as a prospective bio-fertilizer for rice production. These findings indicate that the HPGPR has a substantially promising function in reviving plant development in an eco-friendly manner.

Exploring the Motivational Drivers of Young Adults with Diabetes for Participation in Kidney Research.

Understanding motivational drivers and barriers to patient participation in diabetes research are important to ensure research is relevant and valuable. Young adults with type 1 diabetes (T1D) completed a 31-question qualitative survey evaluating participant experience, understanding, and motivators and barriers to research involvement. A total of 35 participants, 19-28 years of age, 60% female, completed the survey. Motivating factors included personal benefit, relationship with the study team, curiosity, financial compensation, altruism, and nostalgia. Older participants (>22 years) reported higher levels of trust in the study team (p = 0.02) and their relationship with the study team positively influenced their decision to participate (p = 0.03). Financial compensation was a strong motivator for participants with higher education (p = 0.02). Age, sex, education level, and trust in the study team influenced participants' understanding. Barriers included logistics and lack of familial support. Important motivational drivers and barriers to participation in research by young adults with T1D must be considered to increase research engagement and facilitate the discovery of new knowledge.

A Prospective Study of Deep Vein Thrombosis after Major Abdominal Surgery in a Tertiary Level Hospital.

This prospective study was conducted to find the rate of deep and risk factors associated with vein thrombosis following major abdominal surgery in Sylhet MAG Osmani Medical College Hospital from 1st November 2017 to 30th April 2018. Total 103 patients aged above 20 years both male and female who got admitted in Department of Surgery, Sylhet MAG Osmani Medical College Hospital, Sylhet for their disease requiring routine and emergency major abdominal operation during the study period and fulfilling the inclusion and exclusion criteria were selected in this study. Informed written consent was obtained from the patients after full explanation of the purpose of the study. After full investigations and proper preparation of each patient for operative procedure major abdominal surgery were done. Peroperative findings were noted and post-operative period were followed up routinely. Duplex scanning was done on 3rd POD in all cases. The age of the patients ranged from 25 to 74 years with the mean age of 49.5±13.8 years. There were 60(58.3%) male and 43(41.7%) female. Deep vein thrombosis (DVT) developed in 5(4.9%) of cases and not developed in 98(95.1%) cases. All the five cases were confirmed by color duplex scan. DVT was detected in 2(3.3%) of the 60 males and 3(7.0%) of the 43 females undergoing major general surgical procedures. Among 63 patients in whom the duration of surgery was up to 2 hours, none developed DVT, while among the 40 patients in whom the duration of surgery lasted more than 2 hours, 5(12.5%) developed DVT. Among 23 patients in whom the surgery for malignancy was done, 4(17.4%) developed DVT, while among the 80 patients in whom surgery for non-malignancy, 1(1.2%) developed DVT. The Incidence of DVT in patients undergoing major abdominal surgery is 4.9%. Patients undergoing major abdominal surgery for malignancy and duration of operation greater than 2 hours have higher risk of developing DVT. But there is no significant increase in risk of development of DVT relation to age and sex; and also in patients on oral contraceptives, diabetes mellitus, obesity and smoking. Clinical findings alone cannot be relied upon for the diagnosis of DVT. The study has to be continued with larger sample size to get statistically significant results.

Hand Sewn versus Stapled Closure of Duodenal Stump after Gastric Resection.

This prospective comparative study was done to compare the outcome of stapled closure of the duodenal stump with hand-sewn closure during gastric resection in terms of total operating time, postoperative duodenal stump leakage, postoperative hospital stay, and surgical cost. This study was conducted from January 2013 to August 2014. Patients who were admitted to the Department of Surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh with the indication of distal or total gastrectomy were included in the study. A total of 32 patients were enrolled in this study with 16 in each group, they were divided either into Group I (Hand Sewn) or Group II (stapling). Mean±SD age of Group I was 53.38±8.69 and Group II was 50.88±9.56 (p=0.445). Male patients were predominant than the female with a male: female ratio being 3.57:1. Mean±SD total operating time was 154.38±16.32 minutes and 136.88±17.40 minutes in Group I and Group II respectively (p=0.001). In Group I, 2(12.5%) patients and in Group II, 1(6.3%) patient had duodenal stump leakage which showed no statistically significant difference (p=0.999). Postoperative hospital stay had no statistically significant difference (p=0.923). The surgical cost had a significant difference (p=0.001) which is more in Group II. This study showed there was a significant reduction in total operating time but there was no significant difference in occurring of duodenal stump leakage or postoperative hospital stay. However, use of stapler hastens the surgeon's job and it relieves extra pressure of them.

Plasmodium falciparum protein kinase as a potential therapeutic target for antimalarial drugs development.

Malaria is one of the most dangerous infectious diseases due to its high infection and mortality rates, especially in the tropical belt. Plasmodium falciparum (P. falciparum), the most virulent malaria parasite in humans, was recently reported to develop resistance against the final efficient antimalarial drug, artemisinin. Little is known about the resistance mechanisms, which further complicates the problem as a proper counteraction is unable to be taken. Hence, the understanding of drug mode of action and its molecular target is valuable knowledge that needs to be considered to develop the next generation of antimalarial drugs. P. falciparum protein kinase (Pf PK) is an attractive target for antimalarial chemotherapy due to its vital roles in all P. falciparum life stages. Moreover, overall structural differences and the presence of unique Pf PKs that are absent in human kinome, suggesting specific inhibition of Pf PK without affecting human cells is achievable. To date, at least 86 eukaryotic protein kinases have been identified in P. falciparum kinome, by which less than 40 were validated as potential targets at the erythrocytes stage. In this review, recent progress of the furthest validated Pf PKs; Pf Nek-1, Pf CDPK1, Pf CDPK4, Pf PKG, and Pf CLK-3 will be briefly discussed.

Cytologically Indeterminate Follicular Thyroid Nodule on Fine Needle Aspiration Cytology is an Indication for Total Thyroidectomy.

The magnitude of case management of indeterminate thyroid nodule is very difficult and controversial. In addition there is recent evidence that the incidence of follicular lesion may be increasing that will prove to be follicular cancer. This prospective observational study was done in the department of Surgery at Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from February 2016 to January 2017 to investigates the rate of malignancy and inability of demographical, clinical and sonographic data to predict malignancy in indeterminate nodules and the unreliability of intraoperative frozen section biopsy with the scope of determining the need for total thyroidectomy in these patients. The study population consisted of 40 cases presenting indeterminate nodules (Thy3): females (80%) and males (20%) with a mean age of 35.73±11.11 years. All patients underwent total thyroidectomy. Malignancy was diagnosed in 27 out of 40 patients (67.5%). The mean nodule size was 3.67±1.69mm in malignant lesions, 40.7% of the malignant nodules were more than 3cm in size, 51.9% of malignant cases were irregular border and 29.6% of malignant lesions were hard in consistency; these data are statistically significant (<0.05) and correlated with malignancy. The rate of malignancy in cytologically indeterminate lesions was high in the present study sample compared to other reported studies. Thus, considering the fact that demographical, clinical and sonographic features were found to be inaccurate predictors of malignancy, it is our opinion that total thyroidectomy should always be recommend in such patients.

Impact of neighbourhood-level inequity on paediatric diabetes care.

AIMS: To evaluate the association between neighbourhood-level inequity and glycaemic control in paediatric participants with Type 1 diabetes using the Neighbourhood Equity Index (NEI). METHODS: The NEI was linked to the clinical data of 519 children with diabetes followed at the Hospital for Sick Children (Toronto, Canada). The NEI is a composite measure of inequity developed using the World Health Organization's Urban Health Equity Assessment and Response Tool (HEART), which encompasses 15 weighted indicators evaluating economic, social, environmental and lifestyle factors. The geographic distribution of participants was determined using postal codes, and the relationship between HbA1c and NEI was evaluated using regression and spatial analysis techniques. RESULTS: Participants' mean HbA1c was significantly correlated with NEI (R = -0.24, P < 0.0001). Regression analysis demonstrated that NEI was a strong predictor of mean HbA1c (P < 0.0001), accounting for differences in HbA1c as large as 1.0% (11 mmol/mol) when controlled for age, sex, diabetes duration, insulin pump therapy and number of annual clinic visits. Geo-mapping using spatial scan testing revealed the presence of two clusters of low-equity neighbourhoods containing 3.22 (P = 0.001) and 2.83 (P = 0.02) times more participants with HbA1c ≥ 9.5% (80 mmol/mol) than expected. CONCLUSIONS: Our findings demonstrated that NEI was a significant predictor of HbA1c in our clinic population and a useful tool for investigating spatial trends related to inequities in health, providing evidence that a composite, area-based measure of overall inequity is well suited to the study of glycaemic control in urban paediatric Type 1 diabetes populations.

The effect of renal hyperfiltration on urinary inflammatory cytokines/chemokines in patients with uncomplicated type 1 diabetes mellitus.

AIMS/HYPOTHESIS: High intraglomerular pressure causes renal inflammation in experimental models of diabetes. Our objective was to determine whether renal hyperfiltration, a surrogate for intraglomerular hypertension, is associated with increased excretion of urinary cytokines/chemokines in patients with type 1 diabetes mellitus. METHODS: Blood pressure, renal haemodynamic function (inulin and para-aminohippurate clearances for glomerular filtration rate (GFR) and effective renal plasma flow (ERPF), respectively) and urine samples were obtained during clamped euglycaemia in individuals with type 1 diabetes with either hyperfiltration (GFR determined using inulin [GFRINULIN] ≥ 135 ml min⁻¹ 1.73 m⁻², n = 28) or normofiltration (n = 21) and healthy control individuals (n = 18). RESULTS: Baseline clinical characteristics, dietary sodium and protein intake and blood pressure levels were similar in the diabetic and healthy control groups. In addition, HbA1c levels were similar in the two diabetic groups. As expected baseline GFR was higher in hyperfilterers than either normofiltering diabetic patients or healthy control patients (165 ± 9 vs 113 ± 2 and 116 ± 4 ml min⁻¹ 1.73 m⁻², respectively, p < 0.01). ERPF and renal blood flow were also comparatively higher and renal vascular resistance was lower in hyperfiltering patients (p < 0.01). Hyperfiltering diabetic patients had higher excretion rates for eotaxin, IFNα2, macrophage-derived chemokine, platelet-derived growth factor (PDGF)-AA, PDGF-AB/BB and granulocyte-macrophage colony-stimulating factor (p ≤ 0.01). Urinary monocyte chemoattractant protein (MCP)-1 and RANTES (regulated on activation, normal T expressed and secreted) excretion was also higher in hyperfiltering vs normofiltering diabetic individuals (p < 0.01) and fibroblast growth factor-2, MCP-3 and CD40K excretion was elevated in hyperfiltering diabetic individuals vs healthy controls (p < 0.01). CONCLUSIONS/INTERPRETATION: Renal hyperfiltration is associated with increased urinary excretion of inflammatory cytokines/chemokines in patients with uncomplicated type 1 diabetes.

Urinary markers of renal inflammation in adolescents with Type 1 diabetes mellitus and normoalbuminuria.

AIMS: Patients with the highest albumin:creatinine ratio within the normal range are at an increased risk for developing microalbuminuria. The mechanistic basis for this is unknown, but may be related to renal inflammation. Our goal was to characterize the urinary excretion of cytokines/chemokines in normoalbuminuric adolescents with Type 1 diabetes to determine whether higher range normoalbuminuria is associated with evidence of renal inflammation. METHODS: Forty-two urinary cytokines/chemokines were measured in subjects who were screened for the Adolescent Type 1 Diabetes Cardio-Renal Intervention Trial. Urinary cytokines/chemokines were compared across low (n = 50), middle (n = 50) or high (n = 50) albumin:creatinine ratio tertile groups. RESULTS: At baseline, participants in the upper tertile were younger and had shorter diabetes duration compared with the other groups. Other clinical characteristics were similar. Urinary levels of interleukin 6, interleukin 8, platelet-derived growth factor-AA and RANTES differed across albumin:creatinine ratio tertiles, with higher values in patients in the middle and high tertiles compared with the lower tertile (ANCOVA P ≤ 0.01). CONCLUSIONS: Within the normal albumin:creatinine ratio range, higher urinary albumin excretion is associated with elevated urinary levels of inflammatory markers. Ultimately, this may provide mechanistic insights into disease pathophysiology and stratify the risk of nephropathy in Type 1 diabetes.

Intraoperative pacemaker dysfunction caused by the use of electrocautery during a total hip arthroplasty.

Pacemaker dysfunction encountered during orthopedic procedures is a rare but potentially life-threatening complication. With an increasing number of orthopedic procedures performed on the aging population, it is not uncommon to encounter patients with pacemakers requiring major orthopedic intervention. Most, if not all, major orthopedic procedures performed today require the use of electrocautery for hemostasis. In this article we review the literature for pacemaker complications and report a case of pacemaker failure after a single use of the unipolar electrocautery on a patient undergoing a total hip replacement.

Effects of spinal instrumentation on fusion of the lumbosacral spine.

STUDY DESIGN: This study retrospectively, reviewed the effects of pedicle screw fixation on lumbosacral fusion for degenerative conditions. The records and radiographs of a group of patients treated by wide decompression and fusion of the lumbosacral spine and by one surgeon were studied. Two treatment groups were identified by fusion technique; one group received autologous bone graft only, and second group was treated by autologous bone grafting supplemented with pedicle screw fixation. OBJECTIVES: The two study groups were compared to determine the effects of pedicle screw fixation on lumbosacral fusion for degenerative conditions after wide decompression. SUMMARY OF BACKGROUND DATA: The reported success rate of lumbar and lumbosacral fusion in the literature is variable. Although several studies have reported high fusion rates with internal fixation, few controlled studies have been published. A critical review of isolated lumbosacral fusions (for degenerative conditions) and the effects of instrumentation is necessary to determine the effectiveness and complications associated with pedicle screw systems in this setting. METHODS: This study reviewed 215 consecutive patients operated on from 1987 to 1992 for degenerative conditions of the lumbosacral spine. Group 1 included 126 patients who underwent autogenous posterolateral bone graft after decompression. Group 2 included 89 patients treated with Edwards instrumentation and autogenous bone graft. Fusion status was determined via radiographs. Clinical results were based on pain relief after a minimum 2-year follow-up period. RESULTS: In Group 1, an overall fusion rate of 65% was obtained. Clinically, 56% had good or excellent results. Complications included pseudarthroses (35%), dural tears (3.2%), and infection (2.4%). In Group 2, a fusion rate of 91% was achieved. In this group, 89% had a good or excellent clinical result. Complications included pseudarthroses (9%), dural tears (2.2%), and infection (2.2%). CONCLUSIONS: Use of pedicle screw and rod fixation with the Edwards system led to significantly improved results in lumbosacral fusions over autogenous bone graft alone, with a lower complication rate. The use of spinal is a valuable adjunct to achieve lumbosacral fusion in patients who have undergone decompressive surgery for the spine.

Reversible cystic dilatation of distal airways due to foreign body.

We describe a child with foreign body aspiration whose chest radiograph showed an unusual appearance of multiple round lucencies simulating bronchiectasis. This appearance is contrary to the usual appearance of emphysema due to the check-valve type of obstruction. This report is particularly useful for pediatricians and family physicians, who should be aware of the variable appearances of foreign body aspiration. Our case emphasizes the necessity of early bronchoscopy in pediatric patients with unresolving pneumonia.

Modulation of transmission gain by protons at the photoreceptor output synapse.

Synaptic transmission of the light response from photoreceptors to second-order cells of the retina was studied with the whole-cell patch-clamp technique in tiger salamander (Ambystoma tigrinum) retinal slices. Synaptic strength is modulated by extracellular pH in a striking manner: Light-sensitive postsynaptic currents in horizontal and bipolar cells were found to be exponential functions of pH, exhibiting an e-fold increase per 0.23 pH unit over the pH range from 7 to 8. Calcium channel currents in isolated photoreceptors were measured and also exhibited proton sensitivity. External alkalinization from pH 7 to 8 shifted the voltage dependence of channel activation negative by 12 mV. A model of the synaptic transfer function suggested that presynaptic Ca channels could be the primary sites of proton action. Increased Ca influx and transmitter release brought about by alkalinization give rise to larger postsynaptic currents. These results suggest that activity-dependent interstitial pH changes known to occur in the retina, while not alleviating signal clipping at this synapse, may provide an adaptative mechanism controlling gain at the photoreceptor output synapse.

The in vivo effects of naproxen on canine experimental osteoarthritic articular cartilage: composition, metalloproteinase activities and metabolism.

A canine experimental model of osteoarthritis (OA), generated by arthroscopic transection of the anterior cruciate ligament (ACL) of the knee, was used to investigate the in vivo effects of the NSAID naproxen on the course of cartilage degeneration. The drug was given at the time of surgery, or from before surgery, and for 16 weeks after surgery. Analysis of the articular cartilage showed the naproxen was able to significantly suppress the decrease in proteoglycan content and metalloproteinase activities. The results indicate that pharmaceutical agents have the potential to modulate the progression of degenerative joint disease.

Non-contacting electrode system for the measurement of strain generated potentials in bone.

Current methods employing contact electrodes for the measurement of the electromechanical properties of bone produce errors in the measurement due to the effects of polarization at the bone-electrode interface, and the flow of electric charges in the bone measuring circuit. In addition, signal artefacts may result from the movement of an electrode in contact with a specimen undergoing mechanical deformation. The principles for a non-contacting method, based on charge induction on a conductive plate placed in the field of a charged body (bone), and the resulting non-contacting electrode system are presented in this paper. The new electrode enabled measurement of strain generated potentials (SGP) in bone with minimal effect from the measuring circuit and provided new results previously masked by contacting measurement methods. Furthermore, the new electrode is a potential tool for further investigation of the in vitro electromechanical behaviour of bone, particularly in partially hydrated specimens and in vivo, thereby avoiding invasive methods or use of ionizing radiation.