Salivary secretion and connective tissue disease in man

Inhibition of GSK-3 to induce cardiomyocyte proliferation: a recipe for in situ cardiac regeneration

With an estimated 38 million current patients, heart failure (HF) is a leading cause of morbidity and mortality worldwide. Although the aetiology differs, HF is largely a disease of cardiomyocyte (CM) death or dysfunction. Due to the famously limited amount of regenerative capacity of the myocardium, the only viable option for advanced HF patients is cardiac transplantation; however, donor's hearts are in very short supply. Thus, novel regenerative strategies are urgently needed to reconstitute the injured hearts. Emerging data from our lab and others have elucidated that CM-specific deletion of glycogen synthase kinase (GSK)-3 family of kinases induces CM proliferation, and the degree of proliferation is amplified in the setting of cardiac stress. If this proliferation is sufficiently robust, one could induce meaningful regeneration without the need for delivering exogenous cells to the injured myocardium (i.e. cardiac regeneration in situ). Herein, we will discuss the emerging role of the GSK-3s in CM proliferation and differentiation, including their potential implications in cardiac regeneration. The underlying molecular interactions and cross-talk among signalling pathways will be discussed. We will also review the specificity and limitations of the available small molecule inhibitors targeting GSK-3 and their potential applications to stimulate the endogenous cardiac regenerative responses to repair the injured heart.

Use of Human Minor Salivary Glands in Basic and Applied Secretion Research

Previous findings from studies utilizing human labial and palatine minor salivary glands are reviewed. These studies took histopathological, biochemical, and ultrastructural approaches, and focused on control and diseased glands. Disease-oriented summarizations are used, and control results are discussed in the context of disease-related findings. Findings are reviewed separately for electrolytes, macromolecules, and ultrastructure. In control subjects, minor gland salivary electrolyte concentrations are dependent on flow rate, and this dependence may be altered by diseases such as cystic fibrosis as-well as by inflammatory situations such as graft-versus-host disease. There is also evidence that salivary electrolyte secretion processes are not similar in labial and palatine minor glands. Studies of salivary macromolecular composition are reviewed for control subjects and for patients with graft-versus-host disease and Sjögren's syndrome. The findings indicate that the macromolecular contents of labial and palatine gland saliva are similar, but that both are significantly different from that for major gland saliva. Finally, studies attempting to measure disease-related changes in intracellular composition are reviewed. It is concluded that the minor salivary glands are important models for the study of exocrine gland physiology and pathophysiology in man.

Oral manifestations of rheumatoid arthritis. A cross-sectional study of 73 patients

OBJECTIVE

A study is made of the main oral manifestations of patients with rheumatoid arthritis (RA), particularly salivary flow, and of its possible association to periodontal disease.

MATERIAL AND METHODS

A prospective comparative study was made of 146 patients (73 with RA and 73 controls), recording pocket depth, clinical attachment loss, bleeding index, plaque index, and the DMFT index to assess periodontal and dental alterations. Sialometric measurements were also made to determine resting, stimulated, and parotid salivary flow.

RESULTS

The patients with RA had greater periodontal pocket depths (with moderate depths in most cases), as well as greater attachment loss and more bacterial plaque. The resting whole saliva and stimulated parotid saliva rates were also clearly decreased in the RA group compared with the controls.

CONCLUSIONS

Patients with RA are more likely to present periodontal disease, poorer oral hygiene manifesting as an increased accumulation of bacterial plaque, and decreased salivary flow rates.

CLINICAL RELEVANCE

Vulnerability to periodontitis is confirmed in one of the largest samples ever studied of patients with rheumatoid arthritis (RA). Also, there is evidence of hyposialia (decrease in salivary rate) in RA patients without Sjögren's syndrome.

Sarcoidosis and Sjögren's syndrome: clinical and salivary evaluation

BACKGROUND

Sarcoidosis and Sjögren's syndrome are two different diseases; however, when affecting the salivary glands, both diseases exhibit similar clinical signs and symptoms, which often complicates the diagnosis. The purpose of this study was to investigate the possibility of using salivary electrophoresis to differentiate between the two diseases.

METHODS

Saliva was collected from patients with sarcoidosis and patients with Sjögren's syndrome. Salivary flow rate, total protein, and electrophoretic profiles were examined.

RESULTS

Mean salivary flow rate was 0.41 ± 0.07 ml/min/gland vs. 0.43 ± 0.07 ml/min/gland; total salivary protein was 130.0 ± 29.2 mg% vs. 104.0 ± 8.8 mg% for sarcoidosis vs. Sjögren's syndrome, respectively. No differences were observed in salivary flow rate, total salivary protein, or electrophoretic profile between patients with sarcoidosis and patients with Sjögren's syndrome (P = 0.768, 0.718, and 1.000, respectively).

CONCLUSIONS

Salivary protein electrophoresis does not appear to be useful to differentiate between sarcoidosis and Sjögren's syndrome.

Sialochemistry in juvenile idiopathic arthritis

OBJECTIVES

To investigate whether there are any differences in salivary flow rates and saliva composition that may contribute to the reported increase in caries prevalence in patients with juvenile idiopathic arthritis (JIA).

DESIGN

Randomized controlled trial.

SETTING

The sialochemistry of children with JIA has rarely been investigated.

METHODS

Unstimulated and stimulated whole saliva was collected from 17 randomly selected JIA patients and 17 age and sex matched controls. Both samples were analysed for salivary flow rate, pH, calcium and phosphate.

RESULTS

Unstimulated and stimulated JIA saliva flow rates, and the flow rate change from unstimulated to stimulated in JIA saliva were all significantly lower than the controls. There were no significant differences in the pH of unstimulated and stimulated JIA saliva compared with the controls, however, the change in pH (from unstimulated to stimulated) in the study group was significantly greater. The JIA patients had non-significantly lower levels of both calcium and phosphate ions in the unstimulated and stimulated samples.

CONCLUSIONS

This data would suggest that there is both a reduced resting salivary flow and a reduced response to stimulation in JIA patients, which may contribute to a previously reported higher caries prevalence.

Therapeutic drug monitoring in saliva. An update

This article re-examines the issue of salivary therapeutic drug monitoring (STDM). The anatomy and physiology of saliva and the salivary glands, as well as the effects of disease and drugs on salivary secretion and composition, are discussed briefly. Drugs for which therapeutic drug monitoring (TDM) has been shown useful are individually considered to determine if salivary drug concentrations (Csal) are reflective of plasma free drug concentrations (C(up)). That is, is the Csal/C(up) ratio time- and concentration-independent, as supported by a review of literature data? The primary determinant which appears to govern the potential utility of STDM for many of the drugs is the pKa of the drug. Drugs which are not ionisable or are un-ionised within the salivary pH range (phenytoin, carbamazepine, theophylline) are candidates for STDM based on current literature data. Digoxin and cyclosporin are potential candidates for STDM; however, further studies are necessary to confirm these preliminary findings. On the basis of current literature data, STDM does not appear to be useful for other drugs therapeutically monitored in serum/plasma.

Sjögren's syndrome in systemic sclerosis. A clinical study of 26 patients

Features of Sjögren's syndrome were sought in 26 patients with systemic sclerosis and in age- and sex-matched control subjects. The assessments included a structured history to establish symptoms of dry eyes and dry mouth. Schirmer's I and II tear tests. Rose Bengal staining with slit lamp microscopy of the eyes, measurement of basal and stimulatory salivary secretion. We measured sweat secretion rates from the skin. Salivary scintigraphy and skin biopsies were performed on the patients. Only one patient showed the complete picture of Sjögren's syndrome with both clinical and investigational evidence of lacrimal and salivary gland involvement. A further patient had an abnormal Schirmer's II test and xerostomia with reduced salivary secretion and an abnormal scan, but no ocular symptoms and no keratoconjunctivitis sicca on ophthalmological examination. Two patients had reduced salivary flow and a dry mouth. A number of patients and control subjects showed various individual symptoms and signs of lacrimal and salivary disorders. These features alone are not sufficient for the diagnosis of Sjögren's syndrome. There is a clear need to adopt strict criteria for diagnosing the condition. The association of Sjögren's syndrome with systemic sclerosis seems doubtful and if it does occur it is very much less common than previously suggested.

Anionic salivary proteins associated with connective tissue disorders: sialated tissue kallikreins

Parotid saliva was collected from 32 patients with rheumatoid arthritis, 10 with systemic lupus erythematosus, three with mixed connective tissue disease, 12 with progressive systemic sclerosis, two with primary Sjögren's syndrome, and four with Raynaud's syndrome. Tissue kallikreins were measured by radioimmunoassay, and saliva samples were subjected to isoelectric focusing followed by immunoblotting or silver staining. The results showed that the saliva of patients with connective tissue diseases contained increased amounts of immunoreactive tissue kallikrein. In addition, there was an increase in the multiple forms of anionic tissue kallikreins, resulting mainly from a shift in their distribution towards that of higher sialic acid content and lower isoelectric point. These changes were most obvious in patients with systemic lupus erythematosus. Novel or unusual glycosylation may explain the occurrence of increased amounts of anionic salivary proteins in connective tissue diseases.

Use of human minor salivary glands in basic and applied secretion research

Previous findings from studies utilizing human labial and palatine minor salivary glands are reviewed. These studies took histopathological, biochemical, and ultrastructural approaches, and focused on control and diseased glands. Disease-oriented summarization are used, and control results are discussed in the context of disease-related findings. Findings are reviewed separately for electrolytes, macromolecules, and ultrastructure. In control subjects, minor gland salivary electrolyte concentrations are dependent on flow rate, and this dependence may be altered by diseases such as cystic fibrosis as well as by inflammatory situations such as graft-versus-host disease. There is also evidence that salivary electrolyte secretion processes are not similar in labial and palatine minor glands. Studies of salivary macromolecular composition are reviewed for control subjects and for patients with graft-versus-host disease and Sjögren's syndrome. The findings indicate that the macromolecular contents of labial and palatine gland saliva are similar, but that both are significantly different from that for major gland saliva. Finally, studies attempting to measure disease-related changes in intracellular composition are reviewed. It is concluded that the minor salivary glands are important models for the study of exocrine gland physiology and pathophysiology in man.

Sjögren's syndrome: clinical and laboratory features, immunopathogenesis, and management

Sjögren's syndrome may be accompanied by local oral problems such as dry mouth, rampant caries, candidosis, or sialadenitis, but it is a systemic autoimmune disorder with wide repercussions, including a small premalignant potential. This article reviews the clinical and immunopathogenic features, as well as the etiology, of Sjögren's syndrome and discusses the diagnosis and management of oral complications.

Sjögren's syndrome. Proposed criteria for classification

The term "Sjögren's syndrome" (SS) is frequently used to describe the occurrence of keratoconjunctivis sicca and xerostomia in association with an autoimmune disorder. However, well-defined criteria for the classification of SS have not been established, and this diagnosis is being applied to a wide spectrum of conditions, ranging from clear "autoimmune" disease in some patients, to sicca complaints without evidence of a systemic immune process in elderly patients. Here, we review the clinical and laboratory features of patients referred for evaluation of sicca symptoms. In particular, we emphasize the need for care in choosing the site for minor salivary gland biopsy, and we describe the histologic features that aid in the evaluation of these biopsy specimens. In an attempt to identify a population of patients whose conditions might have a common etiopathogenesis and, thus, a common treatment program, we propose the following criteria for a diagnosis of SS: 1) objective evidence of keratoconjunctivis sicca, as documented by rose bengal or fluorescein dye staining; 2) objective evidence of diminished salivary gland flow; 3) minor salivary gland biopsy, obtained through normal mucosa, with the specimen containing at least 4 evaluable salivary gland lobules, and having an average of at least 2 foci/4 mm2; 4) evidence of a systemic autoimmune process, as manifested by the presence of autoantibodies, such as rheumatoid factor and/or antinuclear antibody. The diagnosis of "definite SS" would be made when all 4 criteria are met; the diagnosis of "possible SS" would be made when 3 criteria are present. Specific exclusions for this diagnosis are preexisting lymphoma, graft-versus-host disease, sarcoidosis, and acquired immunodeficiency disease.(ABSTRACT TRUNCATED AT 250 WORDS)