Intralamellar dissection techniques in lamellar keratoplasty

PURPOSE: To evaluate and compare the efficacy of the four adjunctive agents to facilitate recipient bed intralamellar dissection in cases of lamellar keratoplasty. METHODS: Forty eyes with partial-thickness corneal opacities were recruited for this prospective, randomized clinical trial. The cases were divided into four groups per the intralamellar injection (i.e., air [group I], 2% hydroxypropyl methylcellulose [HPMC] [group II], balanced saline solution [BSS] [group III], and no adjunct [group IV] used to facilitate recipient intralamellar dissection). The intraoperative parameters evaluated were initial preparation time, dissection time, and total time. At each follow-up, visual acuity, refractive status, keratometry, and endothelial cell counts were also analyzed. RESULTS: Initial preparation time, dissection time, and total time were significantly decreased with the use of an adjunct (p < 0.05) and were found to be least with the use of BSS. No difference in these time frames was noted between group I and group II. Corneal haze and incomplete air insufflation were seen in group I, and difficulty in injection of 2% HPMC and its incomplete spread were noted in group II. The mean spherical equivalent, astigmatism, endothelial cell counts, and visual acuity did not show any significant difference between any group. CONCLUSION: Hydrodelamination with BSS is easy to perform and should be undertaken routinely to facilitate recipient intralamellar dissection.     

Basaloid squamous cell carcinoma - larynx

Basaloid squamous cell carcinoma is a rare variant of squamous cell carcinoma, Larynx has been an uncommon site of this tumour which is said to have aggressive biological behaviour with high incidence of cervical and distant metastasis along with second primary. Two cases of laryngeal basaloid squamous cell carcinoma are reported with relevant review of literature. The submucosal spread of tumour is highlighted alongwith role of preoperative radio therapy.     

Mediastinitis following deep neck infections : A therapeutic challenge

Objective

To emphasize the salient features of surgical management of Mediastinitis occurring secondary to deep neck infections.

Study design

Case series. Retrospective analysis

Setting

Institutional teaching department Patients Four consecutive cases of mediastinal abscess treated between 1990 to 1996. Selection criteria were presence of deep neck infection radiological evidence of widening of mediastinum and confirmation of mediastinal infection at surgery. Computerized tomography of neck and thorax was done in one case to document the extent of abscess.

Sargical management

All the patients underwent transcervical drainage of neck abscess and superior mediastintomy. The involved spaces in the neck and mediastinum were irrigated with betadine antimicrobial solution and negative suction drains put in the superior mediastinum ta facilitate contituous drainage of the mediastinum. One patient required intercostal chest drainage for associated empyema. Tracheotomy was done in all the patients.

Results

All the patients survived and discharged after a hospital stay of around three weeks.

Conclusions

Mediastinal complication of deep neck infections can he alarmingly rapid and can be effectively managed by early recognition and aggressive surgical drainage combined with antibiotic therapy after appropriate aerobic and anaerobic cultures.     

Novel actions of the antitumor drugs vinflunine and vinorelbine on microtubules

Vinflunine is a novel Vinca alkaloid presently in Phase I clinical trials. In preclinical studies, it exhibited superior antitumor activity to that of other Vinca alkaloids, including vinorelbine from which it was synthetically derived. Vinca alkaloids appear to inhibit cell proliferation by affecting the dynamics of spindle microtubules. Here we have analyzed the effects of vinflunine and vinorelbine on microtubule dynamic instability and treadmilling and found that these newer drugs exert effects on microtubule dynamics that differ significantly from those of the classic Vinca alkaloid, vinblastine. The major effects of vinflunine and vinorelbine on dynamic instability were a slowing of the microtubule growth rate, an increase in growth duration, and a reduction in shortening duration. In marked contrast to the action of vinblastine, they neither reduced the rate of shortening nor increased the percentage of time the microtubules spent in an attenuated state, neither growing nor shortening detectably. In addition, vinflunine and vinorelbine suppressed treadmilling, but less strongly than vinblastine. The diverse actions of these drugs on microtubules are likely to produce different effects on mitotic spindle function, leading to different effects on cell cycle progression and cell killing. Nontumor cells with normal checkpoint proteins may tolerate the relatively less powerful inhibitory effects of vinflunine and vinorelbine on microtubule dynamics better than the more powerful effects of vinblastine. Thus the unique constellation of effects of vinflunine and vinorelbine on dynamic instability and treadmilling may contribute to their superior antitumor efficacies.