Effects of Blood Pressure, Smoking, and Their Interaction on Carotid Artery Structure and Function

-In the present study, we examined the relationships among carotid blood pressure, arterial geometry, and wall stress and determined the impact of hypertension, smoking status, and their interaction on these relationships. The study involved 679 subjects aged 49 to 82 years: 372 smokers (190 men and 182 women) and 307 nonsmokers (110 men and 197 women). Blood samples were taken to determine total cholesterol levels. Central pulse pressure was derived from measured brachial artery pressure with a linear regression equation from data obtained in a subgroup of 276 subjects that related brachial and carotid pulse pressures; the latter was measured with applanation tonometry. Carotid intima-media thickness (IMT), lumen diameter (D), and stiffness index (SI) were determined with high-resolution B-mode ultrasound. Mean and pulsatile circumferential stress (final sigma(C)) was calculated according to the Laplace relationship. Indexes of arterial geometry and function were adjusted for age, height, and heart rate. Hypertension (treated and/or screening blood pressure of >140/90 mm Hg) was present in 71 nonsmokers and 186 smokers. Nonsmokers and smokers did not differ in blood pressure and cholesterol levels. Hypertension and smoking individually and interactively significantly increased adjusted IMT, D, and SI. The radius-to-wall thickness ratio (R/IMT) (where R=D/2) and final sigma(C) were increased in hypertensives. SI was correlated with IMT (r=0.56, P:<0.001); radius-to-wall thickness ratio was inversely correlated with central pulse pressure (r=-0.38, P:<0.001). Smoking did not influence these relationships. In conclusion, carotid artery wall remodeling appears to follow Laplace's law but is insufficient to prevent an increase in circumferential stress in hypertensive subjects. Unlike hypertension, smoking does not influence the lumen-to-wall ratio but has a significant effect on wall stiffness.     

Indication, surgical technique and outcome of orthotopic renal transplantation

PURPOSE: We review the indication, surgical technique and outcome of orthotopic renal transplantation. MATERIALS AND METHODS: The medical records of 1,000 patients who underwent renal transplantation at our institution between August 24, 1993 and August 1, 2000, as well as orthotopic renal transplantation were reviewed. RESULTS: Orthotopic renal transplantation was performed in 4 males and 1 female with severe iliac atherosclerosis or retained bilateral iliac fossa kidney transplant. Mean patient age was 56 years. There were 2 patients who received kidneys from living related donors, and 3 underwent cadaveric renal transplantation. Left orthotopic renal transplantation was successful in 4 cases, and 1 was converted to iliac fossa renal transplant because of a pulseless splenic artery and renal artery thrombosis after native renal endarterectomy. Orthotopic renal revascularization was done with splenic artery in 2, native renal artery in 2 and left renal vein in all 4 patients. Urinary tract reconstruction was performed with stented (2) or nonstented (2) ureteroureterostomy. Antibody induction, purine antagonists, calcineurin inhibitors and glucocorticoids were used for immunosuppression. Mean preoperative and 1-month postoperative serum creatinine was 7.9 and 1.3 mg./dl., respectively. Patient and graft survival was 100% during followup, which ranged from 6 months to 5 years. CONCLUSIONS: Despite the technical challenges, orthotopic renal transplantation in patients with unsuitable pelvic vessels can result in excellent patient and graft survival.     

Embryonic platelet activating factor production in the rabbit increases during the preimplantation phase

Objective This study measured platelet activating factor (PAF) production by rabbit embryos in vitro and ascertained if there is increased PAF production associated with advancing embryonic development.Study Design Two-cell rabbit embryos were recovered from superovulated New Zealand White does and cultured in vitro for 96 hr. Every 24 hr embryos were scored for developmental stage and PAF activity from the corresponding culture medium was measured by platelet aggregation and organic phosphate analyses.Results PAF was detected in culture medium at all stages from two cells to blastocysts and rose significantly (P <0.001) at each 24-hr interval, reaching maximal levels at the expanded blastocyst stage. Conclusion Maximal PAF production by expanded blastocysts may be an embryonic paracrine signal that facilitates implantation.Presented at the 48th Annual Meeting of The American Fertility Society, New Orleans, Louisiana, October 31–November 5, 1992.     

Use of fluorescently tagged DNA and an automated DNA sequencer for the comparison of the sequence selectivity of SN1 and SN2 alkylating agents

This paper describes the application of the novel non-radioactivetechnique for studying the sequence selectivity of selectedalkylating agents. N-Nitroso-N-methylurea (MNU) and N-methyl-N'-nitro-nitrosoguanidine(MNNG) were chosen from the S^N1 group of alkylating agents.Dimethyl sulphate (DMS) was used to represent alkylation profileproduced by the S_N2 compounds. Results of S_N1 compounds indicatedthat in a run (G)₃ the latter two Gs are more susceptible toalkylation than the most 5' G. Moreover, in a GG sequence the3' G seems to be more alkylated. This effect is more evidentwhen the GG site was preceded by a 5' pyrimidine. These findingssuggest that a regio-selective mechanism, rather than the formationof diazonium ions, accounts for DNA alkylation by S_Nl compounds.On the other hand, DMS showed preferential alkylation of the5' end in a (G)₃ run. However, at GG sequences no clear preferredsite of alkylation could be distinguished. Lack of specificityof S_N2 compound would seem to suggest that other factors aswell as the primary DNA structure may play a role in determiningthe extent of alkylation at a certain site.     

Age-specific patterns of prostate-specific antigen testing among primary care physician visits

BACKGROUND: Early detection of prostate cancer is thought to be effective, and indirect evidence suggests that men aged 50 to 69 years will benefit most while those aged 70 and older will benefit least from it. The goal of our study was to describe usual care patterns for prostate-specific antigen (PSA) testing by primary care physicians in the United States. METHODS: We analyzed office visits made by adult men to family physicians, general internists, general practitioners, and geriatricians recorded by the 1995 and 1996 National Ambulatory Medical Care Surveys. Our outcome measure was the probability of a primary care physician ordering a PSA test during a visit. RESULTS: Seventeen percent of the tests reported were among men aged younger than 50 years, 50% were for men aged 50 to 69 years, and 33% were for men aged 70 years and older. The frequency of PSA testing was highest during visits by men aged 60 to 64 years (7.1%), 65 to 69 years (7.0%), 70 to 74 years (7.0%), and 75 to 79 years (6.3%) but lower for men aged older than 80 years (3.1%). CONCLUSIONS: Our findings suggest that during the mid-1990s prostate cancer screening decisions by primary care physicians were not sensitive to patients' ages.     

Inflammation in the Uvula Mucosa of Patients With Obstructive Sleep Apnea

This study was conducted to determine whether inflammation is present in the uvula mucosa of patients with obstructive sleep apnea (OSA). Uvulas were obtained by uvulopalatopharyngoplasty in 21 patients with moderate OSA (mean apnea/hypopnea index and standard error of the mean: 32±4) and by autopsy in 5 individuals not known to have OSA. Using point counting in five randomly selected high-power microscopic fields (×100), the authors found that the number of leukocytes in the lamina propria of the uvula mucosa was significantly higher in patients with OSA than in the controls (179±12 cells vs. 71±4 cells, respectively;P<.05). This was due to a significant increase in the number of plasma cells in patients with OSA as compared with controls (89±15 cells vs. 21±5 cells, respectively; P<.05). The thickness of the lamina propria (an index of interstitial edema) was also significantly increased in patients with OSA compared with controls (0.99±0.12 mm vs. 0.27±0.02 mm, respectively; P<0.05). The authors conclude that inflammation, characterized by plasma cell infiltration and interstitial edema, is present in the uvula mucosa of patients with moderate OSA. They also suggest that soft palate inflammation contributes to upper airway occlusion observed during sleep in these patients.     

Dummies and the sudden infant death syndrome.

The association between dummy use and sudden infant death syndrome (SIDS) was investigated in 485 deaths due to SIDS in the postneonatal age group and compared with 1800 control infants. Parental interviews were completed in 87% of subjects. The prevalence of dummy use in New Zealand is low and varies within New Zealand. Dummy use in the two week period before death was less in cases of SIDS than in the last two weeks for controls (odds ratio (OR) 0.76, 95% confidence interval (CI) 0.57 to 1.02). Use of a dummy in the last sleep for cases of SIDS or in the nominated sleep for controls was significantly less in cases than controls (OR 0.44, 95% CI 0.26 to 0.73). The OR changed very little after controlling for a wide range of potential confounders. It is concluded that dummy use may protect against SIDS, but this observation needs to be repeated before dummies can be recommended for this purpose. If dummy sucking is protective then it is one of several factors that may explain the higher mortality from SIDS in New Zealand than in other countries, and may also explain in part the regional variation within New Zealand.     

Facial nerve near the external auditory meatus in man: Computer reconstruction study—Preliminary report

The anatomy of the facial nerve relative to its intratemporal and extratemporal courses varies over time with developmental changes. Otologic and parotid surgery in infants and children demands detailed knowledge of the precise anatomy of the facial nerve with respect to the tympanic ring and external auditory canal, The authors analyzed this area using our three-dimensional (3-D) computer-aided reconstruction and measurement method studying the spatial relations of the facial nerve to the tympanic ring and stylomastoid foramen. Temporal bones from five normal individuals aged 36 gestational weeks, 3 months, 8 months, 4 years, and 17 years were retrieved from the temporal bone collection stored at the Elizabeth McCullough Knowles Otopathology Laboratory in Pittsburgh. Three-dimensional reconstruction of the facial nerve comparing the developmental anatomy across the various age groups provides the surgeon with the technical information necessary to address problems in this area.