Podisus distinctus (Hemiptera: Pentatomidae) is a zoophytophagous insect with significant potential for use as a biological control agent in agriculture and forestry because their nymphs and adults actively prey on diverse insect species. The saliva of this insect possesses active substances that cause paralysis and death of the prey. As the first step in identifying compounds of P. distinctus saliva, this study describes the ultrastructure of the salivary glands of this predator. The salivary system of P. distinctus possesses a pair of main salivary glands with a short anterior lobe, a long posterior lobe, and a pair of tubular accessory glands. The main salivary gland of P. distinctus has no associated muscles, suggesting that the saliva-release mechanism occurs with the help of certain thorax muscles. The main salivary gland epithelium has a single layer of cells (varying from cubical to columnar) with cytoplasm rich in rough endoplasmic reticulum, spherical granules of different sizes, a nucleus with a predominance of decondensed chromatin, and nucleolus. The apical cell region has a few short microvilli and the basal region has plasma membrane infoldings. The epithelium of the accessory salivary glands possesses a single-layered epithelium of cubic cells delimiting a narrow lumen. The apical cell region has a high density of microvilli and pleomorphic mitochondria, whereas the central cell region is rich in rough endoplasmic reticulum with a well-developed nucleus and decondensed chromatin. The basal cell region is characterized by the presence of several basal plasma membrane infoldings associated with mitochondria and numerous openings to the hemocoel forming large channels. The ultrastructural characteristics suggest that the main salivary glands and accessory salivary glands play a vital role in protein synthesis for saliva production and that the accessory glands are involved in transport of materials of the hemolymph.

Secretory IgA in the saliva is essential for protection from mucosally transmitted pathogens and maintaining homeostasis at mucosal surfaces of the oral cavity. Expression of submandibular gland polymeric Ig receptor (pIgR) is essential for IgA secretion. In the present study, we investigated the influence of indigestible carbohydrates on IgA production in the salivary gland and saliva. Five-week-old rats were fed a fibre-free diet (control), or a diet with 5 % (w/w) fructo-oligosaccharide (FOS) or a combination of 2·5 % (w/w) polydextrose (PDX) and 2·5 % (w/w) lactitol for 21-d. IgA concentrations in the caecal digesta, submandibular gland tissue, and saliva in the FOS and PDX+lactitol diet groups were significantly higher than those in the control group (P< 0·05). The increase in IgA in the submandibular gland tissue was confirmed using immunohistochemical analysis. However, the IgA concentrations of serum did not differ between the FOS or PDX+lactitol groups and the control group (P= 0·5). In the FOS and PDX+lactitol groups, the pIgR mRNA (pIgR/β-actin) expression level in the submandibular gland tissue was significantly higher than that in the control group (P< 0·05). The present study suggests that indigestible carbohydrates play an important role in the increase in IgA concentrations in the submandibular gland tissue, saliva, and caecal digesta.

Although there has been a great deal of research effort within the last two decades on identifying the active components of the saliva of blood-sucking ticks, mosquitoes, biting flies, fleas and bugs, essentially neglected have been the human lice. Despite initial reports in the early part of this century suggestive of vasodilatory, anticoagulant and immunosuppressive properties of the saliva, for the next 50 years there were no biochemical studies on the active principles. Very recently, anatomical and biochemical studies have begun to characterize the bioactive molecules in lice saliva. The louse stocks a salivary vasodilator in excess over what is needed for a single bite, and injects similar amounts at each successive bite. The vasodilator in lice saliva appears to have different pharmacological properties than peroxidative, oxidative and maxidilan types of vasodilators reported from other blood-sucking insects. Possible anticoagulant activities have also been characterized. This belated, but welcome, interest comes at a time of resurgence of lice-born disease in certain parts of Africa, and of resistance to chemical control in Europe and North America.

Dribbling (sialorrhoea) affects about 10 per cent of patients with chronic neurological disease. The variety of treatments currently available is unsatisfactory. This study was a clinical trial of the efficacy of ultrasound-guided, intraglandular injection of botulinum toxin A for dribbling, performed within the otorhinolaryngology department of the National University of Malaysia. Both pairs of parotid and submandibular glands received 25 U each of botulinum toxin A.

Twenty patients were enrolled in the study. The median age was 15 years. All 20 patients (or their carers) reported a distinct improvement in symptoms after injection. Using the Wilcoxon signed rank test, there were significant reductions in dribbling rating score, dribbling frequency score, dribbling severity score, dribbling visual analogue score and towel changes score, comparing pre- and post-injection states (p<0.001). There were no complications or adverse effects during or after the injection procedure.

Intraglandular, major salivary gland injection of botulinum toxin A is an effective treatment to reduce dribbling. Ultrasound guidance enhances the accuracy of this procedure and minimises the risk of complication.

BALB/c mice infested with larvae or nymphs of Ixodes ricinus develop in their lymph nodes a T cell-specific immune response triggered by salivary gland soluble antigens (SGA). SGA are apparently conserved in the 3 biological stages of I. ricinus ticks and are species specific. SGA derived from partially fed females I. ricinus stimulate lymph node T cells from mice infested with I. ricinus larvae or nymphs. In contrast, lymph node cells from mice infested with Amblyomma hebraeum nymphs do not respond. A chromatographic fraction enriched with a 65 kDa protein (IrSG65) isolated from salivary glands of I. ricinus partially fed females induces in vitro a specific T cell proliferation of lymph node cells from mice infested with I. ricinus nymphs. The depletion of CD4+ T cells drastically reduces the ability of lymphocytes from infested mice to proliferate after IrSG65 stimulation.

Ectopic cervical salivary tissue may present as a discharging sinus if a duct system and cutaneous orifice are present. Where described in previous reports these openings have been located along the anterior border of sternomastoid or in the anterior triangle, making this a differential diagnosis of a branchial sinus. We report on a patient who presented with an ectopic salivary gland in the posterior triangle of the neck.

Non-tuberculous mycobacterial (NTM) infections in children commonly present as cervicofacial masses. The importance of early diagnosis is in the exclusion of infection requiring treatment, particularly tuberculosis and the rare case of malignancy. Five children with NTM presenting with salivary gland masses illustrate the value of skin testing with new tuberculins and the place of fine-needle aspiration cytology in the investigation of these infections.

Four children who were skin tested reacted specifically to one of the new tuberculins, two indicating infection with Mycobacterium malmoense, confirmed by culture, the others responding to tuberculins from M. scrofulaceum and M. avium-intracellulare, neither having a positive culture. The one case not skin tested produced M. avium-intracellulare on culture.

All five patients were managed conservatively. The place for conservative management when the facial nerve is at risk and extensive skin excision is indicated are discussed.

A study was conducted to determine the morphology, histology and ultrastructure of the salivary apparatus of Lethocerus indicus. The apparatus was found to consist of a principal and accessory salivary gland. The former is bilobed, having a small superior lobe and a larger inferior lobe, made up of many lobules/acini. Each lobule is made up of a simple glandular layer of syncytial epithelium encompassing the lumen, which is filled with secretory granules that are elaborated from the epithelium predominantly by the apocrine mode of secretion. The accessory salivary gland is vesicular cum tubular. The vesicular part is made up of a thin layer of flat, polygonal cells, having no signs of secretory activity, while the tubular part consists of a single layer of columnar epithelial cells that show signs of secretory activity. Both the principal and accessory glands discharge their secretions through a common salivary duct which opens at the base of the hypopharynx. The ultrastructure of the lobules of the principal salivary gland reveals a thick amorphous, basement membrane (800–1000Å) which supports the glandular epithelium. The basal and apical plasma membranes of the epithelium show basal infoldings and microvilli respectively. The nucleus is highly branched and remains surrounded by a double layered nuclear envelope. The ergastoplasmic membranes show abundance of ribosomes. Many mitochondria are also visible in the cytoplasm. It is concluded that the salivary gland of L. indicus is an organ of high synthetic activity.

Autoradiographic studies using 3H uridine in the salivary glands of three bugs, Lethocerus indicus, Laccotrephes rubra and Antilochus coqueberti show that the nuclei play an important role in contributing RNA. The labelled materials are seen to move into the lumen from the epithelia. RNA shows a tendency to accumulate in the lumen with ascending incubation periods. This behaviour in conjunction with its nucleolar genesis indicates its nature as rRNA. It is also believed that RNA might conjugate with some of the protein available in the lumen to produce RNP.

A 12-year-old boy presented with a three-month history of a painful parotid swelling. Fine needle aspiration cytology indicated a pleomorphic adenoma—an uncommon lesion in a child. This diagnostic technique plays a useful role in the investigation of head and neck swellings.

Polyacrylamide gel electrophoresis of saliva infected with Trypanosoma brucei showed few, very faint protein bands as compared to 11 bands from clean saliva. If the saliva collected is 6 times the normal amount, infected saliva showed all 11 bands, plus one more. Inositol and galactosamine did not appear in infected saliva. Infected saliva contained sphingomyelin in addition to phosphatidylethano-lamine, phosphatidylinositol and phosphatidyllecithin.

Polyacrylamide gel disc electrophoresis of the salivary secretion from the tsetse, Glossina morsitans morsitans Westwood, showed 11 protein bands, four of which were characterized as glycoproteins. Sixteen amino acids and four sugars in the hydrolysates of saliva were identified. Thin layer chromatography showed five lipid classes and three phospholipids. The secretion is a clear, transparent, viscous fluid with a pH between 7.00 and 7.5. These findings are discussed in relation to the nutritional requirements of the metacyclic forms of trypanosomes that may be found in the salivary glands.