NAIP Gene Deletion and SMN2 Copy Number as Molecular Tools in Predicting the Severity of Spinal Muscular Atrophy.

Spinal muscular atrophy (SMA) is one of the most prevalent autosomal recessive illnesses with type I being the most severe type. Genomic alterations including survival motor neuron (SMN) copy number as well as deletions in SMN and Neuronal Apoptosis Inhibitory Protein (NAIP) are greatly implicated in the emergence of SMA. However, the association of such alterations with the severity of the disease is yet to be investigated. This study was directed to elucidate the molecular assessment of NAIP and SMN genomic alterations as a useful tool in predicting the severity of SMA among patients. This study included 65 SMA pediatric patients (30 type I and 35 type II) and 65 healthy controls. RFLP-PCR was employed to determine the genetic polymorphisms of the SMN1, SMN2, and NAIP genes. In addition, qRT-PCR was used to identify the expression of the SMN1 and SMN2 genes, and serum levels of creatine kinase were measured using a colorimetric method. DNA sequencing was performed on some samples to detect any single nucleotide polymorphisms in SMN1, SMN2, and NAIP genes. All SMA patients had a homozygous deficiency of SMN1 exon 7. The homozygous deficiency of SMN1 exons 7 and 8, with the deletion of NAIP exon 5 was found among the majority of Type I patients. In contrast, patients with the less severe condition (type II) had SMN1 exons 7 and 8 deleted but did not have any deletions in NAIP, additionally; 65.7% of patients had multiple copies of SMN2. Analysis of NAIP deletion alongside assessing SMN2 copy number might enhance the effectiveness of the diagnosis that can predict severity among Spinal Muscular Atrophy patients.

Acute Kidney Injury Among COVID-19-Positive Patients Is Associated With Higher Mortality: A Single-Center Experience.

OBJECTIVES: Renal complications of COVID-19 are not yet well studied. We aimed to evaluate acute kidney injury prevalence among hospitalized patients with COVID-19 infection and explore its effect on patient outcomes. MATERIALS AND METHODS: We retrospectively evaluated 586 hospitalized patients with COVID-19. Of these patients, 267 (45.5%) developed acute kidney injury, as classified according to the Kidney Disease Improving Global Outcomes guidelines. We compared this group with 319 patients (54.5%) without acute kidney injury. RESULTS: Most patients in both study groups were men; mean age was 60.8 ± 14 versus 51.7 ± 16 years. Comorbid conditions that were substantially predominant among patients with acute kidney injury were diabetes mellitus (64% vs 42.9%), hypertension (72.6% vs 43.5%), and ischemic heart disease (25% vs 14.7%). Fever, cough, shortness of breath, and dehydration were the main presentations among patients with acute kidney injury, and patients in this group had greater prevalence of radiological findings concordant with COVID-19 (86.8% vs 59.8%). Sepsis, volume depletion, shock, arrhythmias, and acute respiratory distress syndrome were higher in patients with acute kidney injury. Anticoagulation (85% vs 59.2%), vasopressors, plasma infusions, antimicrobials, and steroids were more frequently used in patients with acute kidney injury. More patients with acute kidney injury had acute respiratory failure requiring mechanical ventilation (62.3% vs 32.9%), with higher overall mortality rate (63.2% vs 31.1%). CONCLUSIONS: We found more frequent prevalence of acute kidney injury associated with severe COVID-19 than shown in reports from Chinese, European, and North American cohorts. Patients with COVID-19 who developed acute kidney injury had risk factors such as hypertension and diabetes, greater need for mechanical ventilation, were males, and were older age. Mortality was high in this population, especially among older patients and those who developed Kidney Disease Improving Global Outcomes stage 3 disease.

Heartbeat classification based on single lead-II ECG using deep learning.

The analysis and processing of electrocardiogram (ECG) signals is a vital step in the diagnosis of cardiovascular disease. ECG offers a non-invasive and risk-free method for monitoring the electrical activity of the heart that can assist in predicting and diagnosing heart diseases. The manual interpretation of the ECG signals, however, can be challenging and time-consuming even for experts. Machine learning techniques are increasingly being utilized to support the research and development of automatic ECG classification, which has emerged as a prominent area of study. In this paper, we propose a deep neural network model with residual blocks (DNN-RB) to classify cardiac cycles into six ECG beat classes. The MIT-BIH dataset was used to validate the model resulting in a test accuracy of 99.51%, average sensitivity of 99.7%, and average specificity of 98.2%. The DNN-RB method has achieved higher accuracy than other state-of-the-art algorithms tested on the same dataset. The proposed method is effective in the automatic classification of ECG signals and can be used for both clinical and out-of-hospital monitoring and classification combined with a single-lead mobile ECG device. The method has also been integrated into a web application designed to accept digital ECG beats as input for analyses and to display diagnostic results.

Insights into Asparaginase from Endophytic Fungus Lasiodiplodia theobromae: Purification, Characterization and Antileukemic Activity.

Endobiotic fungi are considered as a reservoir of numerous active metabolites. Asparaginase is used as an antileukemic drug specially to treat acute lymphoblastic leukaemia. The presented study aims to optimize the media conditions, purify, characterize, and test the antileukemic activity of the asparaginase induced from Lasiodiplodia theobromae. The culture medium was optimized using an experiment designed by The Taguchi model with an activity ranging from 10 to 175 IU/mL. Asparaginase was induced with an activity of 315 IU/mL. Asparaginase was purified with a specific activity of 468.03 U/mg and total activity of 84.4 IU/mL. The purified asparaginase showed an approximate size of 70 kDa. The purified asparaginase showed an optimum temperature of 37 °C and an optimum pH of 6. SDS reduced the activity of asparaginase to 0.65 U/mL while the used ionic surfactants enhanced the enzyme activity up to 151.92 IU/mL. The purified asparaginase showed a Km of 9.37 µM and Vmax of 127.00 µM/mL/min. The purified asparaginase showed an IC50 of 35.2 ± 0.7 IU/mL with leukemic M-NFS-60 cell lines and CC50 of 79.4 ± 1.9 IU/mL with the normal WI-38 cell line. The presented study suggests the use of endophytic fungi as a sustainable source for metabolites such as asparaginase, provides an opportunity to develop a facile, eco-friendly, cost-effective, and rapid synthesis of antileukemic drugs, which have the potential to be used as alternative and reliable sources for potent anticancer agents.

Species-specific differences of the avian oesophagus: Histological and Ultrastructural study.

The oesophagus is a muscular tube comprised of cervical and thoracic regions. Several studies have clarified the histological structure of the oesophagus. However, its histoarchitecture in relation to variable dietary habits of each species is still unclear. In the current study, 21 pigeons, cattle egrets and ducks, n = 7, each was used. Macroscopically, the oesophagus of cattle egrets either the cervical or thoracic parts was the longest among the pigeons and ducks. Histologically, the oesophagus comprised of four distinct tunicae: mucosa, propria submucosa, musculosa and adventitia or serosa. A great structural variation in these layers among the three investigated species was recorded. In the cervical oesophagus of pigeons, the superficial squamous cells showed perinuclear halo zone, the propria submucosa was characteristically lacked any gland. Moreover, its musculosa was very thick. On the other hand, the intraepithelial glands were characteristically distributed along the whole length of the cattle egret's oesophagus. Interestingly, the cervical esophagus of the ducks showed submucosal associated lymphatic tissue; diffuse and nodular Ultrastructurally, the oesophageal glands showed secretory granules of variable electron densities, electron-lucent in the pigeons and ducks and electron-dense in the cattle egrets.

Better outcome of COVID-19 positive kidney transplant recipients during the unremitting stage with optimized anticoagulation and immunosuppression.

INTRODUCTION: COVID-19 is an ongoing pandemic with high morbidity and mortality and with a reported high risk of severe disease in kidney transplant recipients (KTR). AIM: We aimed to report the largest number of COVID-19-positive cases in KTR in a single center and to discuss their demographics, management, and evolution. METHODS: We enrolled all the two thousand KTR followed up in our center in Kuwait and collected the data of all COVID-19-positive KTR (104) from the start of the outbreak till the end of July 2020 and have reported the clinical features, management details, and both patient and graft outcomes. RESULTS: Out of the one hundred and four cases reported, most of them were males aged 49.3 ± 14.7 years. Eighty-two of them needed hospitalization, of which thirty-one were managed in the intensive care unit (ICU). Main comorbidities among these patients were hypertension in 64.4%, diabetes in 51%, and ischemic heart disease in 20.2%. Management strategies included anticoagulation in 56.7%, withdrawal of antimetabolites in 54.8%, calcineurin inhibitor (CNI) withdrawal in 33.7%, the addition of antibiotics in 57.7%, Tocilizumab in 8.7%, and antivirals in 16.3%. During a follow-up of 30 days, the reported number of acute kidney injury (AKI) was 28.7%, respiratory failure requiring oxygen therapy 46.2%, and overall mortality rate was 10.6% with hospital mortality of 13.4% including an ICU mortality rate of 35.5%. CONCLUSION: Better outcome of COVID-19-positive KTR in our cohort during this unremitting stage could be due to the younger age of patients and early optimized management of anticoagulation, modification of immunosuppression, and prompt treatment of secondary bacterial infections. Mild cases can successfully be managed at home without any change in immunosuppression.

Single-Incision Pediatric Endosurgery Cholecystectomy Performed by Residents in Children with Sickle Cell Disease.

Introduction: Few centers worldwide have advanced single-incision pediatric endosurgery (SIPES) for pediatric age group. Up to our knowledge this is the first study assessing the safety of SIPES cholecystectomy in children with sickle cell disease (SCD) done by surgical residents. Aims: To determine the feasibility, safety, and expediency of SIPES cholecystectomy in children with SCD performed by surgical residents. Materials and Methods: Retrospective study of all SIPES cholecystectomies performed in our unit from April 1, 2011 to March 31, 2018. We compared the outcome of SIPES cholecystectomy done by fellows and residents. SIPES Covidien 5-12 mm port was inserted through umbilicus. Long 50 cm laparoscope, straight regular instruments, and transabdominal gallbladder traction suture were used in all patients. The cystic duct and artery were identified and divided. The gallbladder is then dissected off the liver and extracted from the abdomen through the port. Results: Forty-three SCD patients underwent SIPES cholecystectomy for 7 years. Mean HbS was 37.56%. Mean age was 10 years. Twenty-four cases (56%) and 19 (44%) were performed by 8 fellows and 10 residents, respectively. Nine other procedures were done simultaneously with cholecystectomy and were excluded from the mean operative time (MOT). The MOT for all cases was 85 minutes, 78 minutes for fellows and 94 minutes for residents (P value is <.001). One extra port was inserted in 2 patients at the beginning of the series. Conclusion: SIPES cholecystectomy in children with SCD is safe and feasible if done by residents under supervision. Stepwise training is essential in this challenging surgery. Involving residents with other SIPES procedures and hands-on minimally invasive surgery single port workshops help them in improving their skills.

Pregnancy After Renal Transplant: Single Center Experience From the Middle East in Patients Using Different Calcineurin Inhibitors.

OBJECTIVES: Pregnancy after kidney transplant has a high risk for maternal and fetal complications; however, it can be successful if patients are properly selected. Here, we studied outcomes and complications of pregnancies in kidney transplant recipients who received calcineurin inhibitor-based immunosuppression. MATERIALS AND METHODS: In this case control study, we reviewed patients who became pregnant between 2004 and 2017. For this analysis, each pregnancy was considered an event. We divided pregnancies into 2 groups according to calcineurin inhibitor-based maintenance immunosuppression: group 1 (49 pregnancies) received cyclosporine, and group 2 (33 pregnancies) received tacrolimus. Patients also received steroids and azathioprine. Patients had regular antenatal follow-up at the Hamed Alessa Organ Transplant Center (Kuwait) and in the maternity hospital (monthly until month 7 and then weekly until delivery). RESULTS: Of 750 female kidney transplant recipients within childbearing potential, there were 82 pregnancies (10.9%) in 49 recipients (6.5%). Seventy-eight pregnancies were planned, and 4 pregnancies occurred while women were using contraception. There was 1 triple pregnancy, 5 double, and 76 single pregnancies. Two women had preeclampsia as maternal complication, 2 had uncontrolled hypertension, and 7 developed graft dysfunction. Forty-seven women (57.3%) had caesarean section, and the remaining had vaginal deliveries. Of 89 babies, 86 were viable (1 intrauterine fetal death and 2 abortions). Eight babies were delivered prematurely with low birth weight, and 2 needed incubators. Mean serum creatinine levels were 97.9 ± 24, 109 ± 38, 100 ± 39, 120 ± 46, and 115 ± 57 µmol/L at baseline, first, second, and third trimesters, and postpartum, respectively. Twelve patients showed high panel reactive antibodies but without donor-specific antibodies. CONCLUSIONS: Posttransplant pregnancy can be successful in most renal allograft recipients, but the increased risk of fetal and maternal complications, including low birth weight, spontaneous abortus, and preeclampsia, should be considered.

Extended Efficacy of Low-Dose Valganciclovir for Prevention of Cytomegalovirus Disease in Intermediate-Risk Kidney Transplant Recipients: Two-Year Follow-Up.

OBJECTIVES: In a previous study, we evaluated 1-year outcomes of using low-dose valganciclovir prophylaxis for cytomegalovirus infection in intermediate-risk kidney transplant recipients. Whether this effect persists in the long term is unknown. We aimed to evaluate the 2-year follow up of such adopted prophylaxis. MATERIALS AND METHODS: We randomized 2 matched groups of kidney transplant recipients (1:1) to receive valganciclovir as 450 mg daily (group 1) or 900 mg daily (group 2) for the first 6 months after kidney transplant. The final analysis included 196 patients as intermediate-risk patients (98 in each treatment group) after exclusion of 5 high-risk patients. Serologically, all patients were at moderate risk for cytomegalovirus infection. Long-term outcomes including cytomegalovirus disease, acute rejection, new-onset diabetes after transplant, graft loss, and patient survival were assessed. RESULTS: Through year 2 of follow-up, cytomegalovirus infection was reported in only 1 patient in group 1 (at month 13) and 1 patient in group 2 (at month 19) (not significant). Biopsy-proven acute rejection episodes were not statistically different between the groups (2 episodes in group 1 and 6 in group 2; P = .431). New-onset diabetes posttransplant was reported in 8.1% in group 1 and 13.2% in group 2 (P = .535). Graft failure was equal in both groups (1 in each group) at 2 years of follow up (not significant). Patient survival was comparable in both groups (100% in group 1 versus 97.9% in group 2; P = .661). The total number of cytomegalovirus infections at 2 years was numerically less in group 1 (P = .128). CONCLUSIONS: Low-dose valganciclovir prophylaxis for 6 months was associated with sustained reduction of cytomegalovirus infection up to 2 years after kidney transplant without significant impact on the acute rejection, new-onset diabetes posttransplant, or patient and graft outcomes.

Is It Safe for Trainees to Perform Single-Incision Pediatric Endosurgery Splenectomy?

INTRODUCTION: Few centers worldwide have advanced single-incision pediatric endosurgery (SIPES) splenectomy. The safety and feasibility of SIPES performed by trainees were not assessed before. SIPES splenectomy is a demanding technique that needs high level of skills. This is the largest series of 39 SIPES splenectomies performed by 14 trainees in one single center. AIMS: To assess the safety, feasibility, and technical challenges of SIPES splenectomy performed by trainees and to compare it with other published series. MATERIALS AND METHODS: Retrospective study of all patients operated with SIPES splenectomy for 7 years. SIPES port was inserted through 1.5 cm umbilical incision. One type of port and straight regular instruments were used in all cases. RESULTS: Forty-nine patients underwent SIPES splenectomy. Eighty percent was done by our trainees. Six cholecystectomies were done simultaneously. Forty-five patients with sickle cell disease, two with thalassemia, one spherocytosis, and one Fanconi's anemia. Mean operative time (MOT) for splenectomy was 182 minutes (130-190) and 251 minutes for splenectomy with cholecystectomy (230-270) depending on severity of adhesions and size of the spleen; P value <.001. Two conversions have to be opened due to bleeding. There is neither wound infection nor incisional hernia up to date. CONCLUSION: SIPES splenectomy is safe and feasible when performed by surgical trainees without adding any morbidity to the patient. Learning curve can quickly improve with more exposure of trainee to different SIPES procedures and hands-on workshops. More than one procedure could be done at the same time. It has excellent cosmesis and almost invisible scar.

Polyunsaturated fatty acids influence offspring sex ratio in cows.

Dietary polyunsaturated fatty acids (PUFAs) can influence fertility in farm animals. Some evidence in mice and sheep have suggested that PUFAs may influence offspring sex ratio, which may have significant value for cattle production. To test this hypothesis, three groups of Holstein cows were supplemented with either 0%, 3% or 5% protected fat (PF) in the form of calcium salt of fatty acids (rich in omega-6) from 14-21 days pre-partum until conception. Proven-fertile frozen semen from the same ejaculate was used for insemination. Calf sex recorded at birth was 8/19 (42.1%) male offspring in the control group, increasing to 14/20 (70%, P > 0.05) and 17/20 (85%, P < 0.05) in 3% and 5% PF, respectively. To test if this effect was caused by a direct influence on the oocyte, we supplemented bovine cumulus oocyte complexes during in vitro maturation with either omega-3 alpha-linolenic acid (ALA), omega-6 linoleic acid (LA) or trans-10, cis-12 conjugated linoleic acid (CLA). Sex ratio of the produced transferable embryos was determined using PCR of SRY gene. Similar to the in vivo results, sex ratio was skewed to the male side in the embryos derived from LA- and CLA-treated oocytes (79% and 71%) compared to control and ALA-treated oocytes (44% and 54%, respectively). These results indicate that both dietary and in vitro supplementation of omega-6 PUFAs can skew the sex ratio towards the male side in cattle. Further experiments are required to confirm this effect on a larger scale and to study the mechanisms of action that might be involved.

Resveratrol Supplementation in Patients with Non-Alcoholic Fatty Liver Disease: Systematic Review and Meta-analysis.

BACKGROUND: Resveratrol is a potential treatment option for management of non-alcoholic fatty liver disease (NAFLD) due to its anti-inflammatory, antioxidant properties, and calorie restriction-like effects. We aimed to synthesise evidence from published randomized clinical trials (RCTs) about the efficacy of resveratrol in the management of NAFLD. METHODS: A computer literature search of PubMed, Scopus, Web of Science, and Cochrane Central was conducted using relevant keywords. Records were screened for eligible studies and data were extracted and synthesized using Review Manager Version 5.3 for windows. Subgroup analysis and sensitivity analysis were conducted. RESULTS: Four RCTs (n=158 patients) were included in the final analysis. The overall effect estimates did not favor resveratrol group in terms of: serum ALT (MD -2.89, 95%CI [-15.66, 9.88], p=0.66), serum AST (MD -3.59, 95%CI [-13.82, 6.63], p=0.49), weight (MD -0.18, 95%CI [-0.92, 0.55], p=0.63), BMI (MD -0.10, 95 %CI [-0.43, 0.24], p=0.57), blood glucose level (MD -0.27, 95%CI [-0.55, 0.01], p=0.05), insulin level (MD -0.12, 95%CI [-0.69, 0.46], p=0.69), triglyceride level (MD 0.04, 95%CI [-0.45, 0.53], p=0.87), and LDL level (MD 0.21, 95%CI [-0.41, 0.83], p=0.51). Pooled studies were heterogeneous. CONCLUSION: Current evidence is insufficient to support the efficacy of resveratrol in the management of NAFLD. Resveratrol does not attenuate the degree of liver fibrosis or show a significant decrease in any of its parameters.

Recurrent Focal Segmental Glomerulosclerosis and Abatacept: Case Report.

Focal segmental glomerulosclerosis is a common cause of end-stage renal disease in children. Focal segmental glomerulosclerosis recurrence in renal transplants is a challenging disease, and can cause graft dysfunction and loss. Different therapies exist with varying responses, from complete remission to resistance to all modes of treatment. Abatacept was recently introduced as a treatment for primary focal segmental glomerulosclerosis in native kidneys and in recurrent disease after transplant. We present a pediatric case with immunosuppression-resistant primary NPHS2-negative focal segmental glomerulosclerosis recur-rence after renal transplant. The standard therapy for recurrent focal segmental glomerulosclerosis (rituximab, plasmapheresis, high-dose cyclosporine, and corticosteroids) was tried but failed to induce remission. Abatacept (10 mg/kg) was given at 0, 2, and 4 weeks (total, 3 doses) with no good response. We conclude that abatacept may work in patients with B7-1-positive focal segmental glomerulosclerosis recurrence and its efficacy is uncertain in disease with B7-1-negative or unknown staining status.

Predicting activity approach based on new atoms similarity kernel function.

Drug design is a high cost and long term process. To reduce time and costs for drugs discoveries, new techniques are needed. Chemoinformatics field implements the informational techniques and computer science like machine learning and graph theory to discover the chemical compounds properties, such as toxicity or biological activity. This is done through analyzing their molecular structure (molecular graph). To overcome this problem there is an increasing need for algorithms to analyze and classify graph data to predict the activity of molecules. Kernels methods provide a powerful framework which combines machine learning with graph theory techniques. These kernels methods have led to impressive performance results in many several chemoinformatics problems like biological activity prediction. This paper presents a new approach based on kernel functions to solve activity prediction problem for chemical compounds. First we encode all atoms depending on their neighbors then we use these codes to find a relationship between those atoms each other. Then we use relation between different atoms to find similarity between chemical compounds. The proposed approach was compared with many other classification methods and the results show competitive accuracy with these methods.

Fractional CO(2) laser treatment vs autologous fat transfer in the treatment of acne scars: a comparative study.

BACKGROUND: Acne scars present a highly challenging and frustrating clinical problem. Fractional CO2 laser treatment has led to marked improvement in scars, and fat transfer, or fat grafting, has also recently proven very useful in regenerative medicine. OBJECTIVE: To compare fractional CO2 laser treatment and fat grafting in the treatment of acne scars. MATERIALS AND METHODS: Twenty patients were included in this study, 10 received 3 sessions of fractional CO2 laser therapy, and 10 received fat grafting. All patients were then followed up for 3 months, and results were assessed with digital photographs taken by a committee of 3 physicians, by a single-blinded physician, and by reports of patient satisfaction. RESULTS: In the fractional CO2 laser treatment group, under 20% of patients were graded as having excellent scar improvement, 0 as having marked scar improvement, under 10% as having mild scar improvement, and almost 70% as having moderate scar improvement. In the fat-grafting group, the scar and overall improvement were graded as 30% excellent, 30% marked, 20% moderate, and 20% mild. CONCLUSION: Fat grafting proved to be more effective in the treatment of acne scars than ablative fractional CO2 laser treatment. There were many points in its favor, the most significant being the clinical improvement in scars and texture. This supports the stem cell theory of adipose tissue in regenerative medicine.

Impact of accidental discovery of renal cell carcinoma at time of renal transplantation on patient or graft survival.

BACKGROUND: Renal tumors are common in the pretransplant end-stage renal disease population. Their impact on transplant outcome has not been well addressed. METHODS: This study is a retrospective follow-up observational study conducted in 258 renal transplant recipients. All patients had an ipsilateral native nephrectomy at the time of transplantation. We reviewed the histopathology of all native nephrectomies to gauge the prevalence of renal cell carcinoma (RCC) and to investigate the impact of accidental discovery of RCC on graft and patient outcome. RESULTS: RCC was found in 12 patients (4.7%): clear type in 9 patients, and chromophobe and combined clear and papillary type in 1 and 2 patients, respectively. There was no significant difference in human leukocyte antigen mismatch, primary immunosuppression, occurrence of rejection, graft function, and patient and graft survival between patients with or without RCC. RCC presented in the other native kidney in three patients (25%) posttransplantation and one of them developed metastasis 4 years after renal transplantation in the RCC group in comparison with eight patients in the control group (3.3%; P<0.001). The median follow-up period was 56 months for the RCC group and 65 months for the control group. CONCLUSIONS: We found that renal transplant outcome and patient survival were not adversely affected by the presence of accidently discovered RCC at the time of transplantation. These patients seem to be at significantly higher risk of the occurrence of RCC in the remaining native kidney. Further studies are warranted to confirm our results.

Structural characteristics of goat (Capra hircus) parotid salivary glands.

The structural characteristics of the parotid glands in small ruminants (goat, sheep) were observed and compared to those of a major laboratory animal, the mouse. Their parotid glands consist of the purely serous type. Ultrastructurally, the serous acini of goats and sheep were characterized by the presence of well-developed basolateral expansions of folds, which are characteristics of electrolyte- and water-transporting epithelium. Moreover in ruminants, unlike the mouse, the presence of numerous intercellular canaliculi as well as microvilli projecting into both the intercellular canaliculi and the lumina of the serous acini provided a large surface area for osmotic equilibrium and isotonic saliva secretion. Most of the secretory granules in goats and sheep contained peripherally located inclusions that showed dense reaction products for acid phosphatase. This indicates that most of the secretory granules undergo lysosomal degradation rather than secretion. An apocrine mode of secretion of some secretory granules was occasionally observed in some acini of goats and sheep but only exocytotic features were observed in mice. In the goat, the serous acini showed three morphologically different types, which might be an indication of different activity phases. Furthermore, alpha-smooth muscle actin-, and vimentin-positive myoepithelial cells were observed only around the serous acini and the intercalated ducts. From these findings, we consider that the structural characteristics of ruminant parotid glands might reflect their physiological role in the copious isotonic saliva secretion with a low protein concentration.

Cytoarchitectural differences of myoepithelial cells among goat major salivary glands.

Previously, the distribution of myoepithelial cells (mecs) in the salivary glands was studied by both immunohistochemistry, and transmission electron microscopy; however, little was elucidated concerning their morphological features, especially in goats. This study was performed to investigate the correlation between the cytoarchitecture of the mecs in goat major salivary glands (parotid, mandibular, and sublingual glands) and the nature of the saliva secretion. The cytoarchitectural features of the mecs were examined by scanning and transmission electron microscopy as well as immunohistochemically. The secretory endpieces in the parotid gland are of the pure serous type, but in both the mandibular and sublingual glands they are of the mixed type. In all studied glands, the intercalated ducts were covered by mecs which, unlike the large stellate cells that surrounded the secretory endpieces, were spindle-shaped with few cytoplasmic processes. Interestingly, the mecs were found to bulge on the basal surfaces of the serous acini and intercalated ducts in all glands and to be in close contact to the seromucous tubules surface in the mandibular and sublingual glands forming a continuous network around it. In conclusion, the differences in the degree of development of the mecs as well as the number of their cytoplasmic processes may be correlated with the nature of the secretion and the number of the secretory granules. Thus these observations may have some relevance in the diagnosis of atrophy and pathogenic conditions of these glands.