Synthesis and biological evaluation of N4-substituted imidazo- and v-triazolo[4,5-d]pyridazine nucleosides

The chemical synthesis of certain N4-substituted imidazo[4,5-d]pyridazine and v-triazolo[4,5-d]-pyridazine nucleosides is described. In both series, the 4-chloro analogues, i.e., 4-chloro-1-(2,3,5-tri-O-acetyl-beta-D-ribofuranosyl)imidazo[4,5-d]pyr idazine (5a) and 4-chloro-1-(2,3,5-tri-O-acetyl-beta-D-ribofuranosyl)-v-triazolo[4,5- d]pyridazine (5b), were used as synthons to the target nucleosides. Nucleoside 5b was far more reactive toward nucleophilic displacements than 5a. Attempted deprotection of 5b was always accompanied with displacement of the 4-chloro substituent, whereas 5a was conveniently deacetylated without loss of the chloro group. Biological evaluation of the title nucleosides included antitumor studies and substrate/inhibition studies with certain purine-metabolizing enzymes. The corresponding adenosine analogues, i.e., 2-aza-3-deazaadenosine (6a) and 2,8-diaza-3-deazaadenosine (6b), were very slowly reacting substrates and weak inhibitors of bovine adenosine deaminase, whereas the inosine analogues were highly resistant to human purine nucleoside phosphorylase. The 4-benzylamino derivatives were weak inhibitors of adenosine transport into human erythrocytes. The inosine, adenosine, and selected N4-substituted analogues exhibited no in vitro toxicity toward murine L1210 leukemia and B16 melanoma cells.

Study of Efficacy and the Comparison Between 2.0 mm Locking Plating System and 2.0 mm Standard Plating System in Mandibular Fractures

PURPOSE

The purpose of this study was to evaluate the efficacy and comparison between 2.0 mm locking plate system and 2.0 mm Champy's titanium mini plating system in mandible fractures.

MATERIALS AND METHODS

A total of 20 patients with mandibular fractures were selected and divided into two groups A and B on randomized basis. Group A was treated with open reduction internal fixation using 2.0 mm locking plates and group B with 2.0 mm Champy's titanium miniplates. All patients were followed up for 12 weeks postoperatively.

RESULTS

Results of the study show less screw loosening, less precision in plate adaptation and less alteration of the osseous or occlusal relationship upon screw tightening in group A. Chi square test was applied to compare the results between the two groups. Statistical analysis did not show significant difference of incidence of malocclusion between the two groups (p value = 0.606). Statistical analysis using un-paired t test showed significant difference of working time between the two groups (p value = 0.00296). When comparing the overall complication rates according to plates used, the χ(2) test showed no statistically significant difference between the locking and nonlocking plates (p > 0.05).

CONCLUSION

It is observed in our study that the locking plate/screw system offers significant advantages over the conventional plating system. The precise adaptation required for using conventional plates is not needed when this locking plate/screw system is used. Locking plate/screw system provides better stability than the conventional plate/screw system.

Effect of organic farming practices on soil and performance of soybean (Glycine max) under semi-arid tropical conditions in Central India

A field experiment was conducted to evaluate the influence of organic farming practices on soil health and crop performance of Soybean (Glycine max).The crop cultivar JS-335 of soybean was grown with 30:26.2:16.6 kg ha-1 (NPK) recommended dose of fertilizers under three management practices viz., organic, chemical and integrated (50:50) in randomized block design, replicated three times. Soil organic carbon, available N, P and K, microbial enzymatic activities, total biomass, seed yield and harvest index (HI) were analysed during the study. It was observed that soil organic carbon (11.3 g kg-1), available N (125 mg kg-1), P (49.7 mg kg-1) and soil enzyme activities viz., dehydrogenase (DHA) (98.20 µ grams TPF/g soil/24 h) and alkaline phosphatase (178.2 µ grams p-nitro phenol/g soil/h) were found significantly higher in the plot managed organically while available K (320.1 mg kg-1) was not significant with respect to chemical and integrated practices. The total biomass (1927 kg ha-1) and seed yield (601 kg ha-1) of soybean was found highest in organic farming practices followed by integrated and chemical practices. Very poor microbial activities were observed in chemically managed plots. Thus, the study demonstrated that the organic farming practice improved soil health and performance of soybean crop.

Proliferating Cell Nuclear Antigen in Premalignancy and Oral Squamous Cell Carcinoma

INTRODUCTION

Cancer has multifactorial aetiology and is a multistep process involving initiation, promotion and tumour progression. Cellular proliferation is one of the important indicators for the biologic aggressiveness of a malignant lesion. The dysregulated proliferation may be a significant change to determine the potential prognosis of various malignant tumours.

AIM

The aim of this study was to evaluate the expression of proliferating cell nuclear antigen (PCNA) as an indicator for clinical aggressiveness in oral premalignancy and squamous cell carcinoma.

MATERIALS AND METHODS

A total of 50 blocks were taken from the Department of Oral Pathology which was diagnosed previously histopathologically. It comprised of normal oral mucosa (10), dysplasia (10) and grades of oral squamous cell carcinoma (30) of patients between the age group of 40-60 years. From each block, sections of 4 micro metre thicknesses were prepared and placed on poly- L lysine coated slides. These sections were immunohistochemically stained with monoclonal proliferating cell antibody (PC10). The stained slides were evaluated by a single examiner for cell count.

RESULTS

A comparison between study groups and controls showed a probability value (p-value) < 0.05. Significant increase in the proliferative index from the normal to oral squamous cell carcinoma was noticed. Poorly differentiated squamous cell carcinoma showed maximum proliferative index followed by moderately differentiated, well differentiated squamous cell carcinoma, dysplasia and normal mucosa.

CONCLUSION

Present study concluded that PCNA index can be used to assess the proliferation and aggressiveness in dysplasia and different grades oral squamous cell carcinoma.

Malakoplakia of the prostate gland--report of two cases and review of the literature

Malokoplakia of the prostate is extremely rare. We report two cases of prostatic malokoplakia in one 60-year-old and one 64-year-old Libyan man, who both were presented with enlarged prostate containing firm to hard nodules. These cases may be misdiagnosed as carcinoma clinically, but the histology points out the correct diagnosis with the presence of Michaelis-Gutmann bodies in the proliferating histiocytes.

Outcomes of Ulnar Shortening for Ulnar Impaction Syndrome Using the 2.7 mm AO Ulna Shortening Osteotomy System

Background: Ulnar shortening osteotomy is a well-established treatment for ulnar impaction syndrome. Controversy remains regarding the most effective system to achieve efficient bony union, whilst minimising incidence of complications, particularly hardware irritation. We present outcomes at 2 years using the recently released low profile AO osteotomy system.

Methods: 32 consecutive patients with significant pain from ulnar impaction syndrome (idiopathic or post-traumatic), without degenerative changes of the distal radio-ulnar joint, were included. Time to union, range of motion, grip strength, pain and complications were recorded.

Results: Median time to union was 10.14 weeks (9.27–11.01, 95%CI), with one nonunion. Visual Analogue Pain score, grip strength and range of motion improved significantly. No patient experienced hardware irritation. No plate required removal. Positive ulnar variance was reduced by 3.8 mm (mean).

Conclusions: The low profile AO system appears effective in achieving bony union whilst minimising incidence of hardware irritation, at a follow up of 2 years

Closed mitral valvotomy and elective ventilation in the postoperative period: effect of mild hypercarbia on right ventricular function

OBJECTIVES

It is customary to extubate patients immediately after closed mitral valvotomy. These patients often have deranged respiratory function caused by chronic lung congestion. The left ventricular function may also be subnormal after valvotomy in some patients. Therefore, elective ventilation for some duration in the postoperative period can be beneficial to these patients. This work is an attempt to find whether elective ventilation should be preferred over immediate extubation in these patients.

DESIGN

A prospective randomized study.

SETTING

The study was performed in a tertiary care hospital, and the patients are referred from the northern states of India.

PARTICIPANTS

One hundred patients undergoing elective closed mitral valvotomy were included in the initial part of the study. Ten more patients were studied to evaluate the effect of mild hypercarbia on right ventricular function after closed mitral valvotomy.

INTERVENTIONS

One hundred patients were divided into two groups of 50 each. Group 1 consisted of patients in whom the neuromuscular blockade was reversed at the end of surgery with neostigmine and atropine and the trachea was extubated. In group 2, the residual neuromuscular paralysis was not reversed and the patients were electively ventilated in the postoperative period for an average duration of 5 hours and 29 minutes +/- 1 hour and 58 minutes. In all the patients in both the groups, electrocardiogram, direct arterial blood pressure, and oxygen saturation were continuously monitored, and arterial blood gases were measured intermittently throughout the study period. Because the results showed that there was mild hypercarbia, 30 minutes after extubation in group 1, 10 more patients were studied to evaluate the effect of mild hypercarbia on right ventricular function after surgery. Patients were ventilated after surgery (F1O2 = 1) to maintain normocarbia (PaCO238.6 +/- 3.4 mmHg). Mild hypercarbia PaCO251.5 +/- 3.7 mmHg) followed by normocarbia (PaCO2 40 +/- 2.5 mmHg) was induced by adjusting the ventilator rate with a constant tidal volume. Standard hemodynamic measurements were performed at each stage.

MEASUREMENTS AND MAIN RESULTS

Although all the patients maintained satisfactory and stable hemodynamics in the postoperative period, the PaCO2 at the end of 30 minutes of extubation was significantly higher in group 1 (48.1 +/- 5.3 mmHg) as compared with group 2 (40.2 +/- 4.3 mmHg, p < 0.001). Mild hypercarbia significantly increased pulmonary vascular resistance (p < 0.01), mean pulmonary arterial pressure (p < 0.001), right ventricular stroke work (p < 0.01), right ventricular systolic pressure (p < 0.01), and right ventricular end-diastolic pressure (p < 0.001). The effect was not totally reversible with CO2 washout as all parameters except right ventricular end-diastolic pressure and pulmonary vascular resistance continued to remain significantly higher when normocarbia was restored. The significant changes in systemic hemodynamics produced by hypercarbia were increases in cardiac index, mean arterial pressure, and pulmonary capillary wedge pressure.

CONCLUSIONS

Avoidance of even mild hypercarbia, therefore, appears advisable in the early postoperative period because of potential impedence to right ventricular ejection. Continuous monitoring of end-tidal CO2 and frequent blood gas analyses should be practiced, and elective ventilation should be considered in patients with long-standing disease and pulmonary hypertension.

Comparative Evaluation of Dental and Skeletal Fluorosis in an Endemic Fluorosed District, Salem, Tamil Nadu

Background:

High levels of fluoride in the drinking water, especially ground water, results in skeletal fluorosis which involves the bone and major joints. This study was conducted to assess the prevalence of skeletal fluorosis to compare with dental fluorosis in an endemically fluorosed population in the District of Salem, Tamil Nadu.

Materials and Methods:

Institutional ethical clearance was obtained. A total of 206 patients who reported to the Department of Hematology for blood investigations were the participants in this study. Age, sex, place, weight, height, dental fluorosis, and skeletal complaints were noted down. Body mass index was calculated, and statistical analysis was performed.

Results:

Dental fluorosis was present in 63.1% and absent in 36.9% of the samples reported. Skeletal fluorosis was present in 24.8% and was absent in 75.2%. A large number of the patients had knee pain and difficulty in bending. Chi-square test was used for statistical analysis. Skeletal fluorosis and age were compared and P value was 0.00 and was significant. Dental fluorosis and skeletal fluorosis were compared and P value was found to be 0.000 and significant.

Discussion and Conclusion:

There is a need to take measures to prevent dental and skeletal fluorosis among the residents of Salem district. Calcium balance should be maintained, and fluoride intake should be minimized to reduce the symptoms. The government should provide water with low fluoride level for drinking and cooking. Once the symptoms develop, treatment largely remains symptomatic, using analgesics and physiotherapy.