Comparison of a lifestyle modification program with propranolol use in the management of diastolic hypertension.

OBJECTIVE: To compare the management of mild diastolic hypertension (90 to 104 mm Hg) using a nonpharmacologic intervention with that using propranolol or placebo. DESIGN: Randomized, placebo-controlled trial with a 2 x 2 factorial design. SETTING: University-based ambulatory care center. PARTICIPANTS: Two hundred seven men and 105 women, 22 to 59 years of age, 73% white, who had mild diastolic hypertension untreated for at least eight weeks. INTERVENTIONS: 1) a multicomponent lifestyle modification intervention (lifestyle focus group, or LFG) administered in eight weekly meetings + placebo, 2) LFG + propranolol, 3) propranolol alone, and 4) placebo alone, followed for 12 months. MEASUREMENTS: Systolic blood pressure (SBP), diastolic blood pressure (DBP), and self-reported adverse effects at each of nine follow-up visits; fasting total cholesterol, triglycerides, and glucose at baseline and 12 months; 24-hour urine sodium (Na+) and potassium (K+), three-day food records and physical activity questionnaire at three and 12 months; and a quality of life questionnaire at 12 months. MAIN RESULTS: The mean decreases in DBP at 12 months were: 8.5 mm Hg in the LFG + propranolol group; 7.7 mm Hg in the propranolol-only group; 5.9 mm Hg in the placebo-only group; and 5.4 mm Hg in the LFG + placebo group. Repeated-measures analysis of covariance showed that level of baseline DBP (p < 0.0001), time of follow-up (p < 0.0001), and propranolol use (p < 0.0001) were significantly associated with a decrease in DBP at 12 months. Despite reductions in urinary Na+ (-35 mEq; 95% CI = -50, -19), dietary Na+ (-521 mg; 95% CI = -710, -332), total calories ingested (-238; 95% CI = -335, -140), and weight (-1.4 lb; 95% CI = -3.7, +0.8), and significant increases in dietary K+ (+294 mg; 95% CI = +107, +480) and in mets-minutes of exercise (+43; 95% CI = +20, +67) at three months, assignment to the LFG intervention had no effect on DBP at three or 12 months. The subjects assigned to take propranolol more frequently reported fatigue during ordinary activities, sleep disturbance, decrease in sexual activity, and depressed feelings, when compared with the subjects taking placebo, but the numbers of study withdrawals did not differ by drug assignment. No significant difference in total cholesterol and glucose levels was observed by group assignment. Triglycerides increased significantly in the subjects assigned to propranolol (mean difference = +20 mg/dL; 95% CI of difference +1.5, +39). There was no difference in the responses to 21 quality of life items between the subjects assigned to propranolol and those assigned to placebo. CONCLUSIONS: This multicomponent lifestyle modification intervention was unable to promote persistent behavior changes and thus was inferior to propranolol therapy for the treatment for mild diastolic hypertension. Future research should focus on single modifiable factors to lower blood pressure.

Characterization of human thrombospondin-4.

The thrombospondins are a family of extracellular calcium binding proteins that are involved in cell proliferation, adhesion, and migration. We have sequenced full-length human thrombospondin-4 and characterized the recombinant protein. In contrast to Xenopus laevis thrombospondin-4, the human protein contains an RGD cell binding sequence in the third type 3 repeat. Transfection of mouse NIH3T3 fibroblasts or C2C12 myoblasts with a full-length human thrombospondin-4 cDNA results in the expression of a polypeptide with a reduced molecular weight of 140,000. In the absence of reducing agent, the expressed protein has an apparent molecular weight of 550,000. Recombinant thrombospondin-4 has been purified from the culture supernatant by heparin-Sepharose and anti-thrombospondin-4 antibody-Affi-gel affinity chromatography. Electron microscopy indicates that thrombospondin-4 is composed of five subunits with globular domains at each end. The observation of a calcium-dependent change in the electron microscopic appearance of thrombospondin-4 is consistent with limited tryptic digestion data that indicate that thrombospondin-4 is resistant to digestion in the presence of calcium. These data indicate that thrombospondin-4 is a pentameric protein that binds to heparin and calcium.

The evolution of the thrombospondin gene family.

Thrombospondin-1 is an adhesive glycoprotein that is involved in cellular attachment, spreading, migration, and proliferation. To date, four genes have been identified that encode for the members of the thrombospondin gene family. These four genes are homologous to each other in the EGF-like (type 2) repeats, the calcium-binding (type 3) motifs, and the COOH-terminal. The latter has been reported to be a cell-binding domain in thrombospondin-1. Phylogenetic trees have been constructed from the multisequence alignment of thrombospondin sequences from human, mouse, chicken, and frog. Two different algorithms generate comparable results in terms of the topology and the branch lengths. The analysis indicates that an early form of the thrombospondin gene duplicated about 925 million years ago. The gene duplication that produced the thrombospondin-1 and -2 branches of the family is predicted to have occurred 583 million years ago, whereas the gene duplication that produced the thrombospondin-3 and -4 branches of the family is predicted to have occurred 644 million years ago. These results indicate that the members of the thrombospondin gene family have existed throughout the evolution of the animal kingdom and thus probably participate in functions that are common to most of its members.

Identification and characterization of thrombospondin-4, a new member of the thrombospondin gene family.

A new member of the thrombospondin gene family, designated thrombospondin-4, has been identified in the Xenopus laevis genome. The predicted amino acid sequence indicates that the protein is similar to the other members of this gene family in the structure of the type 3 repeats and the COOH-terminal domain. Thrombospondin-4 contains four type 2 repeats and lacks the type 1 repeats that are found in thrombospondin-1 and 2. The amino-terminal domain of thrombospondin-4 has no significant homology with the other members of the thrombospondin gene family or with other proteins in the database. RNAse protection analysis establishes that the initial expression of Xenopus thrombospondin-4 is observed during neurulation. Levels of mRNA expression increase twofold during tailbud stages but decrease by the feeding tadpole stage. The size of the thrombospondin-4 message is 3.3 Kb and 3.4 Kb in the frog and human, respectively. Northern blot analysis of human tissues reveals high levels of thrombospondin-4 expression in heart and skeletal muscle, low levels in brain, lung and pancreas and undetectable levels in the placenta, liver and kidney. These data establish the existence of a new member of the thrombospondin gene family that may participate in the genesis and function of cardiac and skeletal muscle.

The effect of removable partial denture framework design on gingival inflammation: a clinical model.

A clinical trial using the experimental gingivitis model developed for periodontal clinical research was performed to evaluate the effect of a removable partial denture mandibular major connector design on the surrounding gingival tissues. A comparison of the state of health of adjacent gingival tissues was made between the linguoplate (control) and cingulum bar (test) major connectors. Clinical parameters were recorded in a single-blind crossover experimental gingivitis trial. Subjects were brought to a level of optimal gingival health and then randomly assigned to use one framework design while refraining from any oral hygiene. Measurements were made at 7-day intervals for 21 days. The subjects were returned to optimal oral health and repeated the experimental period with the alternate design. Results showed a greater increase in mean gingival inflammation with the control than with the test removable partial denture, suggesting that the cingulum bar has fewer detrimental effects on gingival tissues than the linguoplate major connector. Results of this study suggest that the experimental gingivitis model can be a useful and valid system for studying the potential effects of a removable partial denture design on surrounding oral tissues.

Oral prosthesis and chemosensory taste function. A review of the literature.

Denture use may have a negative impact on the ability to taste food, which in turn can jeopardize one's nutritional well-being. It is important that dentists understand the relationship.

Cryosurvival of Trichomonas vaginalis during cryopreservation of human semen.

Despite a 90% cryosurvival of Trichomonas vaginalis in their growth medium trypticase yeast maltose (TYM) with DMSO, none of these parasites have previously been observed to survive during cryopreservation of infected human semen with glycerol (Andrologia 18, 323 (1986)). This could have been due to the failure of the culture method used to detect low numbers of survivors. The prospects of possible transmission of T. vaginalis by artificial insemination with cryobanked (-196 degrees C) semen prompted an investigation of the cryosurvival of this parasite in the presence of semen with the cryoprotectant glycerol, using a more sensitive culture method for viability evaluation. Semen and seminal fluid from the same 23 ejaculates, as well as culture medium, were inoculated with small clinical numbers of T. vaginalis and evaluated as to their survival before and after cryopreservation. Results indicated: (i) The highest cryosurvival of T. vaginalis (4.5%) was in cryobanked (glycerolated) semen, (ii) semen, as well as glycerol, shows cryoprotective action, and (iii) glycerol reduced survival of parasites in semen, seminal fluid, and TYM medium during exposure prior to freezing. Clinical information on infectivity of small numbers of T. vaginalis and the data presented here suggests that these organisms could be transmitted by artificial insemination with infected cryobanked human semen.

Effects of immunization with B. macacae on induced periodontitis--preliminary findings.

This preliminary study examined the effects of immunization with Bacteroides macacae, the monkey equivalent of the human species of B. gingivalis on ligature-induced periodontitis. During a 12 week immunization period, 8 out of the 12 Macacae fasicularis monkeys were immunized weekly with B. macacae washed cells and 4 were sham-immunized with saline. At the same time, all were scaled and pumiced weekly to establish gingival health. Following this period, the mandibular first molars were ligated in 8 out of the 12 monkeys to induce periodontitis. The immunized, ligated experimental group, the ligated, sham-immunized control group, and the immunized, non-ligated control group were then followed for a 6 months ligation period while plaque was allowed to accumulate. Gingival indices, attachment levels, pocket depths, plaque indices, radiographs, serum and crevicular fluid antibodies and subgingival bacteria were assessed. Immunization led to elevated antibody levels to B. macacae while ligation increased plaque, gingival inflammation, and bone loss. Following the 6 month ligation period, B. macacae comprised 1.7% of the cultivable flora in the immunized, non-ligated monkeys, 2.1% in the immunized, ligated monkeys, and 5.6% in the sham-immunized, ligated monkeys. Similar differences between the immunized, ligated and and the sham-immunized, ligated groups were not seen for B. intermedius, nor B. melaninogenicus. These results suggest a heightened humoral response to B. gingivalis reduces subgingival re-colonization by this organism and modulates the course of ligature-induced periodontitis.

Evaluation of two food frequency methods of measuring dietary calcium intake.

To assess the ability of food frequency methods to measure current dietary calcium intake in elderly women, the authors administered two types of food frequency instruments to 37 randomly selected women who attended two senior citizens centers in San Francisco, and they compared those responses to seven-day food records. A 34-item food frequency instrument (with portion sizes rated as small, medium, or large) correlated well (r = 0.76) with the estimated calcium intake from seven-day records. Limiting the instrument to the top 15, 10, or five foods that contribute to dietary calcium intake had little effect on this correlation (r = 076, 0.75, and 0.67, respectively). Rating all portions as "medium" reduced these correlations somewhat. An 18-item instrument, which asks respondents to rate portion sizes in ounces or cups, did not correlate as well with the seven-day records (r = 0.49). The authors conclude that brief food frequency instruments which rate portion sizes on a simple qualitative scale may be suitable for many clinical uses and adequate for some types of epidemiologic studies of calcium intake in elderly women.

Techniques for assessing alveolar bone mass changes in periodontal disease with emphasis on 125I absorptiometry.

No practical methods are presently available for measurement of alveolar bone activity at one instant of time. However, roentgenological methods making measurements at 2 different times can be used to assess alveolar bone activity. The most sensitive, specific and accurate method for this purpose presently in use is 125I absorptiometry. This method has the further advantage of giving the patient minimal radiation exposure. New methodology is under development which obviates the need for fixed geometry and could provide a 3-dimensional image of alveolar bone.

Continuous ambulatory peritoneal dialysis in children: comparison with hemodialysis.

The clinical and biochemical effects of continuous ambulatory peritoneal dialysis in 20 children and of hemodialysis in 16 children were compared over a 2 1/2-year period. Statistically significant differences between the treatment groups included higher hematocrit, higher serum carbon dioxide and cholesterol levels, large intake of calories and protein, and lower systolic blood pressure and rates of transfusion in the patients receiving continuous ambulatory peritoneal dialysis. These patients had more complications than the patients receiving hemodialysis, but hospitalization rates in the two groups were similar. The cost of continuous ambulatory peritoneal dialysis was +19,600 per patient-year; the cost of hemodialysis was +54,300 per patient-year; the cost of hemodialysis was +54,300 per patient-year. There were four treatment failures with continuous ambulatory peritoneal dialysis and one with hemodialysis. Patients treated with both forms of dialysis preferred continuous ambulatory peritoneal dialysis. We conclude that continuous ambulatory peritoneal dialysis is an important alternative to hemodialysis in children.

Relationship between alveolar bone measured by 125I absorptiometry with analysis of standardized radiographs: 1. Magiscan.

PREVIOUS STUDIES have shown that 125I absorptiometry gives an accurate and sensitive measure of alveolar bone mass. The purpose of this study was to determine the relationship between alveolar bone mass determined by 125I absorptiometry and bone density obtained by analysis of standardized intraoral radiographs by the Magiscan System. A defect of increasing size was made at one site of the alveolar bone in a human skull. The amount of bone remaining at each step was calculated using 125I absorptiometry. Standardized radiographs were also taken at each step and the relative density in the area of the defect was determined by the Magiscan System. The Magiscan's System Computer Memory permits analysis of identical areas on a longitudinal series of films of the same alveolar bone location. The results indicate that in estimating amounts of alveolar bone the Magiscan analysis of standardized intraoral radiography is similar in sensitivity and accuracy to 125I absorptiometry.

Relationship between alveolar bone measured by 125I absorptiometry with analysis of standardized radiographs: 2. Bjorn technique.

THE BJORN TECHNIQUE is widely used in periodontal studies as a standardized measure of alveolar bone. Recent studies have demonstrated the feasibility of using 125I absorptiometry to measure bone mass. The purpose of this study was to compare 125I absorptiometry with the Bjorn technique in detecting small sequential losses of alveolary bone. Four periodontal-like defects of incrementally increasing size were produced in alveolar bone in the posterior segment of the maxilla of a human skull. An attempt was made to sequentially reduce the amount of bone in 10% increments until no bone remained, a through and through defect. The bone remaining at each step was measured using 125I absorptiometry. At each site the 125I absorptiometry measurements were made at the same location by fixing the photon source to a prefabricated precision-made occlusal splint. This site was just beneath the crest and midway between the borders of two adjacent teeth. Bone loss was also determined by the Bjorn technique. Standardized intraoral films were taken using a custom-fitted acrylic clutch, and bone measurements were made from the root apex to coronal height of the lamina dura. A comparison of the data indicates that: (1) in early bone loss, less than 30%, the Bjorn technique underestimates the amount of loss, and (2) in advanced bone loss, more than 60% the Bjorn technique overestimates it.