Diagnostic significance of NM23 protein in ameloblastoma and ameloblastic carcinoma: An immunohistochemical study

BACKGROUND

Clinico-histopathologic assessment of patients with ameloblastoma and ameloblastic carcinoma remains the best diagnostic modality for the tumors. However, in cases where the criteria for arriving at a definitive diagnosis are not clearcut, the pathologist is faced with a dilemma and thus an imperative need for adjunct diagnostic methods.

OBJECTIVES

To evaluate/compare the immunohistochemical expression of NM23 in classical, borderline (atypical) ameloblastoma and ameloblastic carcinoma and to assess usefulness of NM23 in closing diagnostic gaps between ameloblastoma and ameloblastic carcinoma.

METHODS

Twenty-four (24) cases of ameloblastoma, 10 ameloblastoma with classical histopathologic features, 8 with nonclassical histopathology [atypical], and 6 cases of ameloblastic carcinoma were selected from cases seen at the Oral Pathology Laboratory of the Lagos State University College of Medicine, Nigeria. NM23 immunostaining protocol was done on the selected tissue blocks and evaluated using Sinicrope method. Analysis was done using R language.

RESULTS

Positive NM23 staining was observed in all cases of ameloblastoma and ameloblastic carcinoma, with more intense staining observed in the stellate reticulum-like areas than in the ameloblast-like areas. Ameloblastic carcinoma stained intensely with NM23 (100%) compared with atypical cases (37.5%) and ameloblastoma (20.0%; p = 0.04). The mean aggregate score was also significantly higher in AC (11 ± 2.4; p = 0.01). The mean aggregate score was also significant amongst growth pattern of ameloblastoma (p = 0 0.02).

CONCLUSIONS

The findings in this study reveal the usefulness of NM23 in differentiating ameloblastoma from ameloblastic carcinoma; a more comprehensive study with a larger sample size is recommended to corroborate or refute the findings in this study.

Ludwig's angina in Nigeria: The disease of the poor and health inequality!

AIM

highlight the health inequality and identify opportunities to improve the care delivered to the patients who suffer from Ludwig's angina which could have national and international clinical impact.

MATERIALS AND METHODS

Data was collected from three major oral and maxillofacial centers, in Nigeria including Benin, Lagos and Kano. A protocol was developed for data collection which included demographic details, socio-economic status, management of the air way, the associated morbidities and mortalities.

RESULTS

Forty-nine were managed in Benin, 57 in Lagos and 66 in Kano. Diabetes was the most prevalent underlying systematic condition, affecting 21% of the Ludwig's angina patients in Lagos. Poverty was a common denominator, 90% of the patients from Kano were unemployed compared to 23% and 8% from Lagos and Benin respectively. For most of the patients, the airway was monitored. Incision and drainage were carried out in most of the cases at Benin and Lagos, but it was only considered in 50% of the cases in Kano. Mortality ranged from 4% in Benin to 12% in Lagos and it was as high as 19% in Kano.

CONCLUSION

poor access to oral healthcare, unemployment and low socio-economic status are important predisposing factors of Ludwig's angina.

Evaluation of interaction between fluconazole and an oral contraceptive in healthy women

OBJECTIVE

To evaluate the potential pharmacokinetic interaction between 2 x 150 mg fluconazole administered once weekly and an oral contraceptive (OC) containing ethinyl estradiol and norethindrone.

METHODS

A placebo-controlled, double-masked, randomized, two-way crossover study was used to investigate the pharmacokinetic interaction between 300 mg fluconazole once weekly and the OC Ortho Novum 7/7/7 (Ortho-McNeil Pharmaceutical, Inc., Raritan, NJ) in 26 healthy women, 18-36 years old. In the first cycle (28 days), subjects received OC only. In the second cycle, subjects were assigned randomly to receive OC-fluconazole or OC-placebo. In the third cycle, subjects were crossed over to the opposite treatment.

RESULTS

Data for 21 subjects who completed the study were included in the pharmacokinetic analysis; data for all 26 subjects were included in the safety analysis (26 OC only; 24 OC-fluconazole; 23 OC-placebo). Treatment with OC-fluconazole resulted in small but statistically significant increases in 0-24 hour area under the plasma concentration-time curve (AUC(0-24)) for both ethinyl estradiol (mean 24%, 95% confidence interval [CI] 18%, 31%) and norethindrone (mean 13%, 95% CI 8%, 18%) as compared with treatment with OC-placebo. Ethinyl estradiol maximum plasma concentration (C(max)) was slightly (mean 8%, 95% CI 2%, 15%) though statistically significantly higher for OC-fluconazole treatment as compared with OC-placebo treatment. Norethindrone C(max) was not different (95% CI -6%, 11%) between the two treatment groups. No adverse events related to treatment were seen in the fluconazole treatment group.

CONCLUSION

The concomitant administration of 300 mg fluconazole once weekly, twice the recommended dose for vaginal candidiasis, to women using OCs results in a slight increase in OC concentrations. Therefore, it appears that there is no threat of contraceptive failure because of concomitant fluconazole administration.

Piperacillin/tazobactam plus tobramycin versus ceftazidime plus tobramycin for the treatment of patients with nosocomial lower respiratory tract infection. Piperacillin/tazobactam Nosocomial Pneumonia Study Group

An open-label, randomized, comparative, multi-centre study was conducted at 25 centres in the USA and Canada to compare the safety and efficacy of piperacillin/tazobactam plus tobramycin with ceftazidime plus tobramycin in patients with lower respiratory tract infections. Piperacillin/tazobactam (3 g/375 mg) every 4 h or ceftazidime (2 g) every 8 h were administered i.v. for a minimum of 5 days. Tobramycin (5 mg/kg/day) given in divided doses every 8 h was administered to all patients. Patients with Pseudomonas aeruginosa isolated from respiratory secretions at baseline were to continue tobramycin for the duration of the study. Tobramycin could be discontinued in other patients after the baseline culture results were known. A total of 300 patients was randomized, 155 into the piperacillin/tazobactam group and 145 into the ceftazidime group. Of these, 136 patients (78 in the piperacillin/tazobactam group and 58 in the ceftazidime group) were considered clinically evaluable. Both groups were comparable for age, sex, duration of treatment and other demographic features. The clinical success rate in evaluable patients was significantly greater (P = 0.006) in the piperacillin/tazobactam treatment group (58/78; 74%) than in the ceftazidime group (29/58; 50%). Eradication of the baseline pathogen was significantly greater (P = 0.003) in the piperacillin/tazobactam group (66%) than in the ceftazidime group (38%). The clinical and bacteriological responses of those patients with nosocomial pneumonia were similar to the overall results. Twelve (7.7%) piperacillin/tazobactam-treated patients and 24 (17%) ceftazidime-treated patients died during the study (P = 0.03). Seven of the 24 deaths in the ceftazidime treatment group but only one of the 12 deaths in the piperacillin/tazobactam treatment group were directly related to failure to control infection. The majority of adverse events were thought by the investigator to be attributable to the patients' underlying disease and not drug related. In this study, piperacillin/tazobactam plus tobramycin was shown to be more effective and as safe as ceftazidime plus tobramycin in the treatment of patients with nosocomial LRTI.

The helper T-cell repertoire of mice expressing class II major histocompatibility complex beta chains in the absence of alpha chains

Mutant mice generated by disrupting the H2-Aab major histocompatibility complex (Mhc) gene are demonstrated here to express Abetab chains in the absence of alpha chains. These mice possess a CD4(+) helper T cell (Th) repertoire that uses predominantly the Vbeta7 T-cell antigen receptor (Tcr) segment for recognition of any protein antigen presented by the alpha-free Abeta molecule. As an alloantigen, the Aalpha-free Abeta molecule is recognized very poorly by T cells from a series of class II disparate mouse strains, indicating that it is grossly different from normal alpha/beta heterodimers. Indeed, molecular modeling suggests a beta/beta homodimer arrangement with an altered geometry of the Tcr contact area. Interestingly, the mutant mice exhibit normal alloreactivity, without a restricted Vbeta usage, toward a series of foreign alpha/beta class II heterodimers, although their T cells developed in the absence of such heterodimers. Thus, the complementarity of Tcr to normal alpha/beta heterodimers, and thereby also alloreactivity, appears to be an ontogeny independent (i. e., germline-encoded) feature.

Safety profile of piperacillin/tazobactam in phase I and III clinical studies

The safety of piperacillin/tazobactam was investigated in Phase I and Phase III clinical studies. In 22 Phase I pharmacokinetic studies, 242 healthy subjects and 232 patients were given single and multiple doses of piperacillin/tazobactam, piperacillin alone, tazobactam alone, and/or placebo. Interaction with tobramycin and vancomycin was also studied. Of 1201 patients enrolled in Phase III trials, 944 received piperacillin 4 g plus tazobactam 500 mg every 8 h for lower respiratory tract infections, complicated urinary tract infections, skin and soft tissue infections, and intra-abdominal infections, or piperacillin 2 g plus tazobactam 500 mg 8 hourly for less severe infections; 90 patients received imipenem/cilastatin as a comparative regimen. Piperacillin 4 g and tazobactam 500 mg were also administered every 6 h with an aminoglycoside to 167 patients with pulmonary infection or neutropenia and bacterial infection. In all trials, piperacillin/tazobactam was found to be safe and well tolerated. One death was deemed possibly drug-related. Thirty-eight patients were withdrawn from the trials because of adverse experiences, most often diarrhoea and allergic skin reactions. The commonest laboratory abnormalities related to liver function. The safety of piperacillin/tazobactam appears similar to that of other beta-lactam/beta-lactamase inhibitor combinations.