NB housing study protocol: investigating the relationship between subsidized housing, mental health, physical health and healthcare use in New Brunswick, Canada.

BACKGROUND: Income and housing are pervasive social determinants of health. Subsidized housing is a prominent affordability mechanism in Canada; however, waitlists are lengthy. Subsidized rents should provide greater access to residual income, which may theoretically improve health outcomes. However, little is known about the health of tenants who wait for and receive subsidized housing. This is especially problematic for New Brunswick, a Canadian province with low population density, whose inhabitants experience income inequality, social exclusion, and challenges with healthcare access.  METHODS: This study will use a longitudinal, prospective matched cohort design. All 4,750 households on New Brunswick's subsidized housing wait list will be approached to participate. The survey measures various demographic, social and health indicators at six-month intervals for up to 18 months as they wait for subsidized housing. Those who receive housing will join an intervention group and receive surveys for an additional 18 months post-move date. With consent, participants will have their data linked to a provincial administrative database of medical records.  DISCUSSION: Knowledge of housing and health is sparse in Canada. This study will provide stakeholders with a wealth of health information on a population that is historically under-researched and underserved.

Acquired CD40-ligand deficiency in chronic lymphocytic leukemia.

Patients with B-cell chronic lymphocytic leukemia (CLL) acquire an immunodeficiency with many characteristics similar to those of persons with inherited defects in the gene encoding the CD40-ligand (CD154). We found that the blood and splenic CD4+ T cells of patients with CLL failed to express surface CD154 after CD3 ligation. However, using an enzyme-linked immunosorbent assay (ELISA)-based quantitative competitive polymerase chain reaction (PCR), we noted that CD3 ligation could induce such T cells to express CD154 messenger RNA at levels similar to that of CD3-activated T cells from normal donors. Moreover, addition of increasing numbers of CLL B cells to activated normal donor T cells rapidly resulted in progressively greater down-modulation of CD154. Such down-modulation of CD154 could be blocked by addition of CD40 monoclonal antibody to cultures in vitro. We propose that leukemia cell-mediated down-modulation of CD154 on activated T cells accounts for some of the acquired immune defects of patients with CLL.

Screening for myocardial infarction and ischemic stroke: a population-based study.

Studies that accurately identify myocardial infarction (MI) and stroke within populations would provide valuable epidemiological information as well as data on vascular disease prevention. We performed a pilot study to assess the feasibility of adding MI surveillance to an ongoing population-based stroke surveillance study, the Brain Attack Surveillance in Corpus Christi (BASIC) Project. We also tested two screening methods for MI ascertainment: discharge International Classification of Diseases, Ninth Revision (ICD-9) codes and cardiac biomarker screening. This pilot study suggests that the addition of MI surveillance to community-based stroke surveillance studies is feasible. Screening for abnormal cardiac biomarkers to identify potential MI cases may be more accurate and efficient than using ICD-9 codes.

Cholera toxin triggers apoptosis in human lung cancer cell lines.

Cholera toxin (ChT) inhibits signals generated by multiple growth factors in human lung cancer cells, resulting in cell growth inhibition. We now report that ChT triggers apoptosis as shown by DNA fragmentation and activation of caspases cleaving poly(ADP-ribose) polymerase and lamin B. Apoptosis induced by ChT in a small cell lung cancer cell line is not affected by manipulations of intracellular cAMP through preincubation with isobutylmethylxanthine but can be modestly increased through inhibition of protein kinase C with chelerythrine. Thus, apoptosis is actively suppressed in lung cancer cells by a ChT-sensitive-growth regulatory pathway, and these observations may have significant implications in the development of novel strategies for lung cancer treatment.

Amrinone-associated thrombocytopenia: pharmacokinetic analysis.

Amrinone-associated thrombocytopenia is thought to result from nonimmune-mediated peripheral platelet destruction. Platelet destruction may be a concentration-dependent toxic effect of amrinone or its principal metabolite N-acetylamrinone. Eighteen children receiving amrinone after heart surgery were prospectively evaluated to correlate the pharmacokinetics of amrinone and N-acetylamrinone with thrombocytopenia. Amrinone and N-acetylamrinone plasma concentrations were determined by HPLC during loading, infusion, and terminal elimination, with concurrent monitoring of platelet counts. Thrombocytopenia developed in eight patients (platelet count, 66 +/- 17 x 10(9) platelets/L [mean +/- SD]). Peak and steady-state amrinone plasma concentration, amrinone total dose, duration of amrinone exposure, and amrinone area under curve (AUC) were similar between patients with and without thrombocytopenia. N-Acetylamrinone peak concentration, steady-state concentration, N-acetylamrinone AUC, and ratio of N-acetylamrinone to amrinone were greater in patients with thrombocytopenia. This association suggests that N-acetylamrinone, and not amrinone, may be the mediator of thrombocytopenia in children receiving amrinone.

Treatment of bladder carcinoma with irradiation combined with misonidazole.

One hundred patients suffering from cancer of the bladder were treated by external beam irradiation, 400 cGy twice a week to a total dose of 4800 cGy. One half of the patients were randomized to receive the electron affinic sensitizer agent, misonidazole, at a dose of 1 gr/m2 and a total dose of 12 gr/m2. There was no statistically significant difference in tumor responses and in recurrence--free survival time between the patients who received irradiation and misonidazole as compared to those who received irradiation and placebos.

Variants of alpha 1-antitrypsin in Puerto Rican children with asthma.

A survey of 393 Puerto Rican and 354 non-Hispanic pediatric patients at Beth Israel Hospital, New York, revealed a significantly larger percentage of asthmatic subjects among Puerto Ricans, confirming findings of a study of Puerto Rican adults in New York. Assays of alpha 1-antitrypsin (AAT) concentration and phenotypes in 61 Puerto Rican asthmatic children revealed a significantly larger number with an S or Z variant in AAT phenotype. The AAT concentration was not a significant variable in this relationship, since four of five subjects with intermediate deficient AAT concentrations and a PiM phenotype were among control nonasthmatic Puerto Rican subjects. A family history of asthma was more common among asthmatic than control subjects and was most common for variant AAT phenotypes in either asthmatic or control subjects. We speculate that the S or Z variant of AAT affects the inflammatory response in such a way as to predispose to asthma.

Differential expression of Met/hepatocyte growth factor receptor in subtypes of non-small cell lung cancers.

Hepatocyte growth factor (HGF)/scatter factor (SF) is a multifunctional factor that stimulates epithelial cell motility, invasion and morphogenesis. Its receptor is a transmembrane tyrosine kinase encoded by the Met proto-oncogene. Several studies have suggested a possible role for HGF/Met in tumor development and progression. To investigate the potential roles of Met in human lung cancer biology, we have studied the mRNA and protein expression of Met in normal lung tissue, primary non-small cell lung carcinoma (NSCLC), and NSCLC cell lines. The results indicated a differential pattern of Met expression among various subtypes of NSCLC. The majority of squamous cell carcinoma (SQCC), either in vivo or in vitro, expressed Met mRNA and its protein product at levels much lower than or similar to normal lung tissue or bronchial epithelium. Moreover, SQCC characteristically over-expressed a variant Met mRNA which corresponds to a 5' partially deleted transcript produced by alternative splicing. In contrast, the expression of Met mRNA and its protein product in adenocarcinoma (ADC) and large cell undifferentiated carcinoma were more heterogeneous. Overexpression was demonstrated in approximately 35% and 20% of these subtypes of NSCLC, respectively. Among ADC, intermediate to high levels of Met immunoreactivity correlated with greater degree of tumor differentiation. Furthermore, an accentuation of Met immunoreactivity was often noted in cancer cells at the advancing edge of tumors. These findings support a role for Met in lung cancer cell invasion and differentiation in vivo, but its expression and functions may be modified by the differentiation phenotype of the tumor cells.

Biexponential T2 relaxation time analysis of the brain: correlation with magnetization transfer ratio.

RATIONALE AND OBJECTIVES: To measure T2 relaxation times of normal white and gray matter using a novel CPMG sequence and investigate if any correlation exists between magnetization transfer ratio (MTR) and T2 relaxation-related parameters. MATERIALS AND METHODS: Seventeen normal volunteers participated on this study. A single-slice 32-echo sequence was used to calculate the T2 relaxation time of frontal and occipital white matter and cortical gray matter. T2 relaxation analysis included monoexponential and biexponential fitting whereas an F test was used to determine if biexponential fitting was statistically more accurate than monoexponential fitting. Short and long T2 constants were calculated as well as the signal fractions of each pool. MTR calculations were based on a three-dimensional gradient echo (3D FFE) proton density weighted sequence with and without an on-resonance composite prepulse. MTR and T2 relaxation times were calculated and linear regression analysis was applied. RESULTS: Biexponential fitting was more accurate comparing with monoexponential fitting in all WM and GM regions (F > 2.47, P < 0.01). Mean values of short T2 constant for frontal white matter (fWM), occipital white matter (oWM) and gray matter (GM) were 8.10, 9.36, and 22.23 milliseconds, respectively, whereas the mean values of long T2 constant were 85.1, 93.02, and 118.72 milliseconds, respectively. Mean restricted water percentages (RWP)-corresponding to the signal fraction of the protons with short T2-for the fWM, oWM, and GM were 22.01%, 23.36%, and 18.7%. Mean free water percentages (FWP)-corresponding to the signal fraction of the protons with long T2-for the fWM, oWM and GM were 77.99%, 76.64%, and 81.3%. Mean MTR values for fWM, oWM and GM were 68.4%, 68.2%, and 61.3%, respectively. No significant correlation was found in fWM and oWM between MTR and RWP, short and long T2 components while a moderate correlation existed in GM between MTR and RWP (r = 0.57; P = 0.02), MTR and short T2 component (r = -0.69; P = 0.004) and MTR and long T2 component (r = -0.62; P = 0.012). CONCLUSIONS: Two proton pools with different T2 decay characteristics can be separated in normal gray and white matter when using a multiecho sequence with short echo spacing. MTR and T2 relaxation times were significantly correlated in gray matter and the combination of both types of measurements may be helpful in studying myelin related disorders.

Effects of angiographic needle size and subsequent catheter insertion on arterial walls. An in vitro experiment in human cadavers.

RATIONALE AND OBJECTIVES: It is widely believed that down-sizing catheters, and possibly needles, will decrease damage to the entry vessel in the performance of angiography. The purposes of this in vitro experiment are to determine if smaller needles produce less arterial wall damage than larger needles and to assess the influence of subsequent catheter insertion. METHODS: Each iliac artery pair from 35 fresh human cadavers was punctured three times with an 18-g needle and three times with a 21-g needle, for a total of 210 punctures. In two of each set of three, a 5- or 7-F dilator was passed. One hundred ninety-eight puncture tracts were usable and examined microscopically. They were graded on a scale of 1 to 3 in each of four categories: size of tract, margin irregularity, approximation of edges, and shape of tract. RESULTS: Chi-square analysis of the grading scores showed a significant shift of cases into lower damage grades when the smaller gauge needle was used for initial punctures (P < .0005). The subsequent insertion of a dilator, however, imposed further damage, such that the initial differences due to needle gauge were obliterated (P > .2). CONCLUSION: These data indicate that a 21-g needle produces less arterial wall damage than an 18-g needle, but that any safety conferred by the smaller needle is eliminated by the subsequent insertion of a 5- or 7-F catheter.

The risk of peripheral vein phlebitis associated with chlorhexidine-coated catheters: a randomized, double-blind trial.

OBJECTIVE: To evaluate the risk of phlebitis associated with chlorhexidine-coated polyurethane catheters in peripheral veins. DESIGN: A randomized, double-blinded trial comparing chlorhexidine-coated polyurethane catheters with uncoated polyurethane catheters. SETTING: A university hospital. PATIENTS: Adult medicine and surgery patients. INTERVENTIONS: Certified registered nurse anesthetists or an infusion team consisting of nurses and physicians inserted the catheters. Catheter insertion sites were scored twice daily for evidence of phlebitis. At the time catheters were removed, a quantitative blood culture was performed, and catheters were sonicated for quantitative culture. RESULTS: Of 221 evaluable catheters, phlebitis developed in 18 (17%) of 105 coated catheters, compared to 27 (23%) of 116 uncoated catheters (relative risk [RR], 0.74; 95% confidence interval [CI95], 0.43-1.26; P = .32). By survival analysis, chlorhexidine-coated catheters had a lower risk of phlebitis during the first 3 days (P = .06), but not when all catheters were considered in both patient groups (P = .31). In the absence of catheter colonization, the incidence of phlebitis was 21% (16/76) and 24% (20/86) for coated and uncoated catheters, respectively (P = .85), whereas in the presence of catheter colonization, the incidence of phlebitis was 14% (1/7) and 80% (4/5) for coated and uncoated catheters, respectively (RR, 0.18; CI95, 0.03-1.15; P = .07). CONCLUSION: The risk of phlebitis in the presence of catheter colonization was 82% lower for chlorhexidine-coated polyurethane catheters compared to otherwise identical uncoated catheters.

Thecoperitoneal shunt for syringomyelia: report of three cases.

During 8 months, three consecutive cases of syringomyelia were treated by the placement of thecoperitoneal shunts. In the first two patients, the cord cavitation was idiopathic in one and thought to be related to spinal trauma in the other. In the third case, there was associated anomaly of the craniocervical junction of the Chiari I type. Surgery was followed by clinical improvement in all patients. Postoperative magnetic resonance images showed definite diminution of the syringomyelic cavity. The results of treatment seem to support the use of the technique as a primary treatment of syringomyelia associated with progressive myelopathy.

Hepatic clotrimazole concentrations and hepatic drug metabolizing enzyme activities in adult male Sprague-Dawley rats.

A single high dose, 75 mg/kg, of clotrimazole (CloTZ) was administered intragastrically (i.g.) to adult male Sprague-Dawley rats. Hepatic CloTZ concentrations were determined in organic extracts of whole liver homogenate, by high-performance liquid chromatography (HPLC). The peak liver CloTZ concentration was found at 2.5 h post dose, and the liver t1/2 was 11 h. With the present procedure CloTZ was detectable in the liver for up to 40 h and during this period, the hexobarbital sleep-time in these treated rats was prolonged. Between 40 and 120 h following a single dose of CloTZ, hexobarbital sleep-times were less than in untreated rats. The shortened sleep-time coincided with cytochrome P-450 induction which could be demonstrated in microsomal fractions obtained from the livers. Cytochrome P-450 catalyzed p-nitroanisole-demethylase activity in the microsomal fractions in vitro was inhibited in the first 24 h and induced in microsomes prepared after that time.

Exposure to ovarian steroids elicits a female pattern of plasma cortisol levels in castrated male macaques.

Our recent observations (1) that there is a difference in circadian patterns of plasma cortisol levels between male and female macaques and (2) that after gonadectomy these differences in the patterns and in the levels of cortisol were reduced prompted us to investigate how 17 beta-estradiol (E2) and progesterone affect cortisol secretion in orchidectomized male rhesus macaques. Five male macaques, castrated as adults, were implanted subcutaneously with segments of silastic tubing filled with E2 and with progesterone in a manner such that the levels and the sequence of these hormones mimicked those that occur during the menstrual cycle of intact female macaques. Since previous studies had shown that the difference in cortisol patterns was due to higher levels in females during the day, these studies were conducted from 0800 to 2000 hours. Blood samples were collected in an adjacent room at 15-minute intervals. Separate trials were conducted 2 weeks after E2 was implanted and levels were 110 +/- 14 pg/ml and again 2 weeks later after progesterone was implanted and E2 levels were 59 +/- 15 pg/ml; progesterone levels averaged 4.0 +/- 0.65 ng/ml. Mean plasma concentrations of cortisol (microgram/100 ml) for the 12-hour period were three-fold higher in orchidectomized males treated with E2 (17.2) and with E2 + progesterone (18.0) than in intact males (4.9). Levels in males treated with ovarian steroids were double that (8.5 micrograms/100 ml) observed for intact females.(ABSTRACT TRUNCATED AT 250 WORDS)

Small fenestra stapedectomy. A preliminary report.

The small fenestra stapedectomy is based on a rationale of creating a more effective acoustical mechanical transmission system, while reducing potential labyrinthine disturbance. Surgical technique for the small fenestra stapedectomy is described, including the creation of the fenestra and the use of McGee stainless steel piston prosthesis with loose areolar tissue around the piston. Postoperative results are compared in a series of 100 cases, 50 having the small fenestra technique, SFT, and 50 having partial or total footplate removal procedure. Vestibular results demonstrate a noticeable reduction in postoperative complaints of balance disorders in the SFT patients. Hearing results, when compared between the two groups, show a statistically significant advantage for the SFT patients in postoperative high frequency threshold sensitivity and speech discrimination scores. Technical difficulties in creating the fenestra without fracturing the entire footplate are discussed and suggestions made for their avoidance. The advantages of lowered risk, based on reduced trauma to and contamination of the labyrinth, as well as improved high frequency hearing sensitivity and speech discrimination, support the use of this procedure and call for further investigation and development of its clinical potential.

O.P.S.C.: improving delivery of otolaryngological surgical care.

Results of over two years' experience with an outpatient surgical center within a private otolaryngology clinic have demonstrated several advantages. Discussed herein are the history of outpatient surgical centers, and the development of our within clinic O.P.S.C. (Outpatient Surgery Center). Developmental stages described include investigation of liability exposure, securing state health department approval, enactment of state legislation, staffing, equipment, and obtaining third party carrier approval. Advantages to the patient, otolaryngologist, community, and third party carriers are enumerated. Statistics regarding types and numbers of procedures performed and types of anesthesia used are included. Experience with the O.P.S.C. indicates that it is a means of improving the delivery of otolaryngological surgical care.

Homograft septal cartilage for attic support in intact canal wall tympanomastoidectomy and tympanoplasty.

The postoperative formation of attic retraction pockets following tympanoplasty, with or without mastoidectomy, has often been a significant cause of recurrent disease accompanied by decreased hearing levels. Nasal septal cartilage is recommended as a successful homograft material for attic support. The basis and indications for its use are discussed. Preparation and storage of the homograft materials and surgical technique are described. Long-term results are reported, including a special group in which the status of the homograft material was assessed during revision surgery. Minimal complications have been encountered. Conclusions support the overall advantages of this technique utilizing homograft septal cartilage as an effective means of posterosuperior canal wall support, an aid in preventing retraction pocket formation.

Acute subarachnoid haemorrhage: detection with magnetic resonance imaging.

The purpose of this study was the evaluation of fluid attenuated turbo inversion recovery (FLAT TIRE) MR pulse sequence for detecting acute subarachnoid hemorrhage (SAH). Seven patients with SAH were studied within 6 days of ictus. Six of them underwent both CT and MRI and one MRI only. Pulse sequences included T1 spin echo (SE), PD and T2 turbo spin echo (TSE) and FLAT TIRE (TR/TI/TE = 6500/1800/140-180). All studies were performed on a 0.5 T system (Gyroscan T5, Philips Medical Systems). Simulated acute SAH was also studied with MRI. The FLAT TIRE sequence was better than the SE and TSE in all seven cases and better than CT in two cases. In two cases MRI was equivalent to CT, and in another two MRI underestimated the extent of SAH. The simulated acute SAH could be detected easily with the FLAT TIRE sequence, with difficulty on the T1 weighted images and not at all on the PD/T2 weighted images. The specific FLAT TIRE sequence used seems promising for the detection of acute SAH.

Infarction of the corpus callosum: computed tomography and magnetic resonance imaging.

OBJECTIVE: To describe the computed tomography (CT) and magnetic resonance (MR) features of corpus callosum (CC) infarctions. METHODS: We reviewed retrospectively 352 consecutive cranial CT and MR scans showing cerebral infarcts. Involvement of the CC was identified in 28 patients. RESULTS: Infarctions of the CC were diffuse (n = 3) or focal (n = 25). The former were seen in the setting of diffuse cerebral ischemia secondary to cardiopulmonary arrest or status epilepticus. The latter were divided into those affecting predominantly the genu, body or splenium. The most common location of the insult was the splenium (n = 13), followed by the body (n = 6) and genu (n = 3). In the remaining three patients combined genu/body infarctions were seen. CONCLUSION: Infarction of the CC may be more common than previously thought and is most often the result of cerebral embolism. MR is better suited than CT for the detection of vascular lesions of the CC.

Antibiotic susceptibilities of periodontal bacteria. In vitro susceptibilities to eight antimicrobial agents.

In vitro susceptibilities of 369 to 966 bacterial isolates from periodontal lesions to eight antibiotics were determined by agar dilution technique as a means of determining which antimicrobial agents were inhibitory for bacteria frequently associated with destructive periodontal diseases. Although most bacteria were relatively susceptible to the penicillins, greater activity was generally noted with amoxicillin than with either penicillin or ampicillin with the exception of Selenomonas sputigena and Peptostreptococcus. Antibacterial activities obtained with minocycline were significantly higher than with tetracycline for Actinobacillus actinomycetemcomitans and Streptococcus but comparable for most other taxa. Clindamycin and metronidazole both demonstrated excellent activity against the anaerobic Gram-negative rods but were less effective against some of the capnophilic and facultative organisms. Eikenella corrodens was exceptionally resistant to both of these drugs; and A. actinomycetemcomitans was generally resistant to clindamycin but relatively susceptible to metronidazole. Erythromycin was considerably less active than the other antibiotics against the majority of the periodontal bacteria. No single antibiotic, at concentrations equivalent to those achieved in body fluids, was uniformly effective in inhibiting all bacteria currently implicated or suspected as etiologic agents of periodontal diseases.