Altered secretory activity in rat adrenal chromaffin cells after experimentally induced bronchial asthma and dexamethasone treatment: ultrastrucutral and biochemical study

It is generally accepted that chromaffin cells release their contents by both exocytosis and piecemeal degranulaltion [PMD]. Bronchial asthma and dexamethasone treatment might after this secretory activity. This study was designed to shed light on secretory activity in the normal adult rate chromaffin cells, in rats subjected to bronchial asthma and after treatment with dexamethasone. Rats were divided into three equal groups at random:group A[control], group B [asthmatic rats], and group C [dexamethasone-treated asthmatic rats]. In rats of group B, the chronic asthma model was established by an intraperitoneal injection and challenge with ovalbumin. In group C, the rats were pretreated with dexamethasone before each challenge. Serum epinephrine and norepinephrine levels were measured by enzyme-linked immunosorbent assay. Bronchoalveolar lavage fluid was examined for the total leukocytic count and paraffin sections from the lung were stained with H and E. Specimens of the adrenal medulla were examined by transmission electron microscope and were morphometrically analyzed. Significant decreases in serum epinephrine and norepinephrine levels were recorded in asthmatic rats and corrected after dexamethasone treatment. The total numbers of adrenaline and noradrenaline granules were significantly lower in asthmatic rats. Features of PMD manifested as tail-like projections, altered granules with eroded contents, partially empty granules, large completely empty containers, and small cytoplasmic vesicles were observed in control rats and were augmented in rats subjected to chronic asthma. Augmented features of PMD and biochemical changes in the conditions of chronic asthma could be corrected by dexamethasone treatment

Dilemma of bilateral versus unilateral neck exploration in management of primary hyperparathyroidism

There is still a considerable discussion about whether focal unilateral or bilateral neck exploration should be used in patients with primary sporadic hyperparathyroidism because of improved preoperative localization tests and intraoperative parathyroid hormone assay. Making sense of applying these new technologies is difficult and poses the question. Is limited parathyroid surgery better surgery?. Most clinicians deduce that limited surgery is better only if the success rate is equivalent to bilateral exploration. The aim of this study was to find out if there is an advantage in unilateral neck exploration over the standard bilateral neck exploration for parathyroid surgery. This is a prospective non-randomized clinical study which had been conducted in the period between October 1996 and January 2004 on 29 patients with a diagnosis of primary hyperparathyroidism divide into two groups. Group I: Fourteen patients [4M and 10F] that had bilateral neck exploration. Group II: Fifteen patients [5M and 10F] that underwent unilateral neck exploration. All patients had preoperative clinical and biochemical assessment, ultrasound, CT of the neck and sestamibi scanning [for those patients considered candidates for unilateral neck exploration]. All patients were seen on follow-up visits after 1 week, 1 month, 3 months, 6 months and then yearly. There was no statistically significant difference in preoperative serum calcium level or serum parathyroid hormone level between the two groups [p>0.5]. Median operative time was 105 minutes [range 95-180 minutes] in group I compared to 90 minutes [range 80-155 minutes] in group II [p value<0.5; significant]. Only one patient [7.2%] had postoperative hypocalcaemia in group 1. One patient [7.2%] had recurrence in group! compared with two patients [13%] in group II [p value>0.5, non-significant]. No patient had recurrent laryngeal nerve paralysis or permanent hypocalcaemia in either group. There was no statistically significant difference between group I and II patients in postoperative histopathological findings. In group II three patients [20%] required conversion to bilateral neck exploration; one patient had [7%] multiple adenomas and two patients bad hyperplasia [13%]. Bilateral neck exploration for surgery for primary hyperparathyroidism is as safe as unilateral neck exploration and has higher cure rates. It also avoids the costs of preoperative and intra-operative localization scans and techniques. In hospitals where intra-operative localization methods are not available; the conventional neck exploration for primary hyperparathyroidism should be considered the method of choice