Transcriptomic and Single-Cell Analysis of the Murine Parotid Gland.

The salivary complex of mammals consists of 3 major pairs of glands: the parotid, submandibular, and sublingual glands. While the 3 glands share similar functional properties, such as saliva secretion, their differences are largely based on the types of secretions they produce. While recent studies have begun to shed light on the underlying molecular differences among the glands, few have examined the global transcriptional repertoire over various stages of gland maturation. To better elucidate the molecular nature of the parotid gland, we have performed RNA sequencing to generate comprehensive and global gene expression profiles of this gland at different stages of maturation. Our transcriptomic characterization and hierarchical clustering analysis with adult organ RNA sequencing data sets has identified a number of molecular players and pathways that are relevant for parotid gland biology. Moreover, our detailed analysis has revealed a unique parotid gland-specific gene signature that may represent important players that could impart parotid gland-specific biological properties. To complement our transcriptomic studies, we have performed single-cell RNA sequencing to map the transcriptomes of parotid epithelial cells. Interrogation of the single-cell transcriptomes revealed the degree of molecular and cellular heterogeneity of the various epithelial cell types within the parotid gland. Moreover, we uncovered a mixed-lineage population of cells that may reflect molecular priming of differentiation potentials. Overall our comprehensive studies provide a powerful tool for the discovery of novel molecular players important in parotid gland biology.

Long-term antihypertensive effects and safety of nitrendipine in patients with mild, moderate, and severe hypertension.

A study of 31 patients with mild or moderate hypertension and 17 patients with severe hypertension was conducted to evaluate the long-term safety and efficacy of nitrendipine, a new calcium channel blocker with a long duration of action. Nitrendipine (5-40 mg bid) was given as monotherapy or in combination with hydrochlorothiazide and/or propranolol. Seventeen patients (54%) with mild to moderate hypertension were controlled with nitrendipine alone, but all except one patient with severe hypertension required combination therapy. In patients with mild or moderate hypertension, nitrendipine reduced supine blood pressure from a baseline mean 154/100 mm Hg to 136/87 mm Hg after 1 year of treatment (P less than .05). In patients with severe hypertension, supine blood pressure was reduced from 186/124 mm Hg to 148/91 mm Hg by the end of the planned treatment period (P less than .05; mean duration, 10 weeks). During extended observation, antihypertensive effect was sustained for up to 2.5 years and 1.6 years in patients with mild or moderate and severe hypertension, respectively. Nitrendipine was well tolerated; and only one patient, a moderate hypertensive, discontinued treatment because of pedal edema. The results of this long-term study show that nitrendipine alone or in combination with a diuretic and/or a beta blocker is a safe and effective agent for the treatment of patients with all degrees of hypertension.

Availability of iron from four prenatal multivitamin/multimineral products.

Iron absorption from four prenatal multivitamin/multimineral preparations was compared in 36 healthy pregnant women in their second or third trimester of pregnancy. The products studied were the currently marketed formulations of Stuartnatal 1 + 1, Stuart Prenatal, Materna, and Natalins Rx. Each fasted subject received each of the four preparations, according to a randomized sequence, at intervals of three to seven days between drug administrations. Stuartnatal 1 + 1 demonstrated the best iron absorption. Total iron absorbed from Stuartnatal 1 + 1 and Stuart Prenatal was well above the additional daily 3.5 mg recommended during pregnancy. Following administration of Materna the amount of iron was only slightly above that recommended, and following Natalins Rx it was well below. All formulations were generally well tolerated by the subjects.

Choline magnesium trisalicylate: comparative pharmacokinetic study of once-daily and twice-daily dosages.

This randomized crossover study compared the pharmacokinetics of choline magnesium trisalicylate tablets administered once daily (3000 mg of salicylate) or twice daily (1500 mg of salicylate) for six d. Serum salicylate levels were measured by HPLC. Mean "trough" concentrations fell within the therapeutic range (5-30 mg/dL) with either regimen and were relatively constant, indicating that the steady state had been reached. The 24-h area under the salicylate curve (AUC0-24 h) after the final 3000-mg salicylate dose averaged about twice the mean 12-h AUC after the last 1500-mg dose, indicating that the two dosing regimens were equally bioavailable. Clinical observations and results of laboratory safety studies indicate that both dosage schedules of the drug are well tolerated. The present findings support the once-daily therapeutic use of choline magnesium trisalicylate.

Ofloxacin in human serum, urine, and tear film after topical application.

We evaluated the systemic absorption of ofloxacin eyedrops in humans and their availability in the tear film. Serum, urine, and tear film concentrations of ofloxacin were measured in 30 healthy women topically treated with 0.3% ofloxacin, in both eyes, four times daily for 10 1/2 days. Serum was collected before the first daily dose on days 1 and 11 and at 18 time points before the second dose. Maximum serum ofloxacin concentrations (1.89 +/- 1.13 ng/ml) after 10 1/2 days of topical dosing were more than 1,000 times lower than those reported after standard oral doses of 300 mg ofloxacin. Urine was collected for the 24-h period after the first daily dose on days 1 and 10. Topical ofloxacin was excreted in the urine primarily in unmodified form and recovery rates were significantly higher on day 10 (76.1 +/- 41.5%) than on day 1 (56.6 +/- 31.6%) (p less than 0.05). Both serum and urine data give evidence to accumulations of ofloxacin over a 10 1/2-day period. The low serum concentration at steady state suggests an extremely low potential for producing systemic effects. No systemic side effects attributable to topical ofloxacin were observed. Mild ocular irritation was reported by two patients while under treatment. Tears were collected 4 h after the first treatment on day 11 and at 5, 10, 20, 30, and 40 min after the second treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Three-year caries increments after fluoride rinses or topical applications with a fluoride varnish.

251 9-12-yr-old children completed a 3-yr, double-blind, clinical trial of two caries preventive fluoride programs. Caries increments and progression patterns were compared in two groups of children who rinsed every fortnight with a 0.2% NaF solution or received biannual topical applications with a fluoride varnish (Fluor-Protector). Clinically recorded mean DFS increments were 3.3 +/- 0.2 (SE) in the rinse group and 3.5 +/- 0.2 in the varnish group. In both groups nearly half of these increments were recorded in the occlusal surfaces of second molars. The mean incremental DFS recorded radiographically on approximal surfaces of posterior teeth were 1.1 +/- 0.2 and 1.5 +/- 0.2 in the rinse and varnish group, respectively. None of the inter-group differences were statistically significant (P greater than 0.05). Detailed analyses of the radiographic scores revealed a similar and extremely slow caries progression in the two study groups and they strengthened the conclusion of equal clinical efficacy of the two treatments. None of the fluoride programs had been able to change preestablished patterns of caries development among the children.

Biomechanical evaluation of two different screw positions for fusion of the calcaneocuboid joint.

In triple arthrodesis performed for severe deformity and neuroarthropathy in poorly compliant patients with osteoporotic bone, fixation of the arthrodesis is critical. We biomechanically tested an alternative means of stabilization for calcaneocuboid fusions. In seven matched pairs of fresh-frozen cadaver feet, we removed the soft tissue from around the calcaneocuboid joint, except for the capsule, and we did not resect the articular cartilage. One joint of each pair was fixed with an oblique standard screw, and the contralateral joint was stabilized with an axial screw placed perpendicularly to the joint surface. Testing on an MTS Mini Bionix Test Frame (MTS Systems Corp., Eden Prairie, MN) demonstrated that the axial screw provided significantly higher initial stiffness and maximum load to failure. We concluded that an axial screw provided better fixation of the calcaneocuboid joint.

Numerical simulations of scattering in a two-photon optical data storage system.

Scattering effects in a two-photon optical data storage system are numerically studied. Surface scattering analysis with a scalar, beam propagation model is performed. We analyze the problem by modeling scattering from randomly varying surfaces and also by Fourier surface decomposition. Scattering induced by propagation through multiple pages of randomly recorded data marks is also studied with a hybrid finite-difference-time-domain/angular-spectrum model. Both surface and bulk scattering are shown to influence the spatial properties of the optical beam. Results and some possible implications are presented.

Occurrence of volatile N-nitrosamines in animal diets.

46 samples of commercially available diets for experimental animals have been analysed for their content of volatile N-nitrosamines by use of a nitrosamine-specific detection method (TEA-detector). 80% of all analysed samples were positive for N-nitrosodimethylamine with a maximum content of 79 ppb (microgram/kg) found in one sample. 59% of the samples were positive for N-nitrosopyrrolidine with 26 ppb as highest content. In 3 samples trace quantities (less than 1 ppb) of N-nitrosodiethylamine were found, one sample contained N-nitrosopiperidine (4 ppb).

Studies on the excretion of endogenously formed N-nitrosoproline. I. Percutaneous excretion of N-nitrosoproline in humans.

N-Nitrosoproline (NPRO) formed intragastrically after ingestion of 8 mg/kg body weight sodium nitrate and the same amount of proline was determined in the sweat of six volunteers during intensive sweating in a Finnish sauna (60-80 degrees C). The amounts of sweat and NPRO and the concentrations of this compound varied between individual volunteers and in the same subjects in consecutive experiments. Females excreted higher concentrations of NPRO in smaller amounts of sweat. During the second hour after the start of intragastric nitrosation of proline, the concentrations and amounts of NPRO in sweat decreased rapidly.

Carcinogenic N-nitrosodimethylamine as a contamination in drugs containing 4-dimethylamino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one (amidopyrine, aminophenazone).

A total of 68 commercially available drugs containing amidopyrine were investigated for contamination with the strong carcinogen N-nitrosodimethylamine (NDMA). All samples contained varying amounts of NDMA. About half of the drugs contained 1--10 micrograms/kg, 40% contained 11--50 micrograms/kg, 7% contained 51--10 micrograms/kg and one sample had 370 micrograms/kg. NDMA-contents in batches of pure amidopyrine that had been utilized for preparation of drugs were higher than those in the respective drugs: about one-third was in the range of 20--50 micrograms/kg, one-third had 51--100 micrograms/kg, and one-third was above 100 micrograms/kg. There was, however, no correlation between NDMA-contents of batches of the pure substance and NDMA-contents of the drugs prepared from these batched. NDMA concentrations in the samples were inhomogenously distributed. It could be demonstrated that amidopyrine in substance reacts extremely rapidly with nitrogen oxides from the air to form NDMA. Ascorbic acid, which prevents nitrosamine formation in aqueous-acidic solution, under these conditions had no protective effect.

Ankle arthrodesis with an anterior tension plate.

The incidence of complications associated with arthrodesis of the ankle has remained high, especially in wound complications and infections. A new method to achieve arthrodesis of the ankle that utilizes an anterior surgical approach and an anterior tension plate was assessed in 17 patients. This method transforms the potentially deforming force of the tendoachilles into a compressive and corrective force and facilitates realignment of the ankle in all planes. Also, dissection and subperiosteal elevation is minimized while soft tissue coverage of the hardware is maximized. Whereas the predominant preoperative diagnosis was posttraumatic degenerative joint disease, others included failed ankle arthroplasty, failed arthrodesis, and a fixed equinus deformity. A solid arthrodesis was achieved in 82% of the patients. Although complications occurred and two patients required reoperations, there were no problems with respect to wound healing or infection, which is a marked contrast to other series. This technique is recommended as a simple, safe, and effective method to achieve an arthrodesis of the ankle joint.

Food effects on the nighttime pharmacokinetics of Theo-Dur tablets.

A randomized crossover study demonstrated major food effects on the pharmacokinetics of Theo-Dur, two 200-mg theophylline anhydrous sustained-release tablets, as an evening dose. These effects included a higher maximum serum theophylline level and relatively prolonged delay in drug absorption, both significant. The findings, which showed marked individual variation, could be clinically important for patients receiving evening medication.

Research on environmental N-nitroso compounds in the USSR.

Food samples from various parts of the USSR have been analysed for volatile N-nitrosamines (NA). The results are comparable to data published elsewhere. Kilning of malt with direct combustion gases accounts for the presence of NA in beer. NA have been found in city air, diesel exhausts and in a rubber factory. Vulcanized rubber contains NDMA and NMOR. Nitrosoproline has been determined in a variety of foodstuffs. Variations of nitrate contents in vegetables due to mineral fertilizers and some herbicides are reported. A steady increase of average nitrate concentrations in vegetables has been observed in Estonia over a period of 12 years. Precursors of NA have been found in water (Moldavia), and soil (Moscow district and Tshuvash republic). Nitramines can be formed in vivo from NA, and vice versa. Formation of NDMA from aminopyrine has been inhibited under gastric conditions by properly composed meals. Numerous food components have been studied as nitrite scavengers. Modifications of analytical methods for NA have been proposed. Four laboratories in the USSR are equipped with the Thermal Energy Analyzer.

Volatile and non-volatile N-nitroso compounds in foods and other environmental media.

A further series of cured meat products (meat loaf, liver loaf, bologna) has been investigated for their nitrosamine contents before and after frying. Contents in general were in the low microgram/kg range. An extensive study of nitrosamine contents of various types of cheese has been terminated. Although 45% of all samples showed indications of nitrosamine content, only 12% had concentrations of greater than 1 microgram/kg (1-6 microgram/kg); NDMA was more often found in hard and in soft cheese, than in other types. Analytical grade dichloromethane and chloroform have been found to contain N-nitrosomorpholine in concentrations of 2-376 microgram/kg (27-40% of the samples). The origin of the contamination is not known at present. A survey of the nitrosamine content of animal diets showed that 80% of all samples had contents of greater than 1 microgram/kg. NDMA (up to 79 microgram/kg) and NPYR (up to 26 microgram/kg) were most often found. There are indications that fish meal is the main source of contamination. Drugs containing amidopyrine (AP) have invariably been found to contain NDMA. Concentrations varied within wide limits (less than 10 microgram/kg - 371 microgram/kg). No correlation has been found between samples of pure AP and NDMA contents of drugs in which pure AP had been incorporated. Also, strong variations in NDMA contents have been found within individual batches, probably caused by the high reactivity of AP towards nitrogen oxides. The determination of N-nitroso-3-hydroxypyrrolidine has been further improved and a further series of food analyses for contents of this nitrosamine has been carried out. About 30% of the samples were positive with contents below or near 10 microgram/kg. An analytical method for determination of N-nitrosamino acids has been worked out. The method consists of a series of extraction, liquid/liquid distribution and chromatography steps; N-nitrosoamino acids are finally determined, after trimethylsilylation, with a TEA detector. First results on the occurrence of these compounds in various cured meat products are reported.

Bioequivalence and metabolism of nitrendipine administered orally to healthy volunteers.

Relative bioavailability of 5-, 10-, and 20-mg nitrendipine tablets was determined in a four-way crossover bioequivalence study involving 22 normal male volunteers. Liquid suspension of nitrendipine was used as a reference. Plasma and urine samples collected during each study period were assayed by high performance liquid chromatographic and capillary gas chromatographic (GC) procedures for nitrendipine and the nitrendipine pyridine metabolite. Four other more polar urinary nitrendipine metabolites were also analyzed in urine by the GC procedure, which involved diazomethane esterification. Although relative bioavailability of the tablets ranged from 58.0 to 69.9%, there was no statistically significant difference in the area under the curve among the doses. Since 35 to 43% of both the liquid and tablet doses was recovered in the urine of volunteers, excretion of urinary metabolites appears to be independent of the dosage form. However, a rank-order correlation between the relative tablet bioavailability and cumulative amounts of excreted metabolites was observed. Nitrendipine, its pyridine metabolite, and the glucuronide conjugates were also detected in the urine, but the amount of nitrendipine and its pyridine metabolite did not exceed 0.1% of dose, whereas the glucuronides accounted for about 8% of the dose.

Effects of antacids and food on absorption of famotidine.

The effect of a high potency antacid and food on the bioavailability of famotidine was studied in 17 healthy volunteers in an open randomized three-way cross-over trial. After an overnight fast, famotidine was administered to each subject as follows: 40 mg famotidine orally alone; 40 mg orally with antacid; and 40 mg orally with a standard breakfast. Coadministration of the antacid caused a small but significant reduction in the maximum plasma concentration (Cmax) of famotidine from 81.1 +/- 54.2 to 60.8 +/- 21.6 ng ml-1 (P less than 0.05) and a small decrease in the area under plasma concentration-time curve [AUC] from 443.3 +/- 249.2 to 355.0 +/- 125.1 ng ml-1 h (P greater than 0.05). However, there was only a minimal effect of food on these parameters; the Cmax and [AUC] were 81.6 +/- 29.6 ng ml-1 and 434.8 +/- 145.9 ng ml-1 h, respectively.