A pilot investigation into the effects of different office chairs on spinal angles

PURPOSE

To investigate the effects of four office chairs on the postural angles of the lumbopelvic and cervical regions.

RESEARCH QUESTION

Which chair(s) produce an "ideal" spinal posture?

METHODS

An experimental same subject design was used involving healthy subjects (n = 14) who conducted a typing task whilst sitting on four different office chairs; two "dynamic" chairs (Vari-Kneeler and Swopper), and two static chairs (Saddle and Standard Office with back removed). Data collection was via digital photogrammetry, measuring pelvic and lumbar angles, neck angle and head tilt which were then analysed within MatLab. A repeated measures ANOVA with Bonferroni corrections for multiple comparisons was conducted.

RESULTS

Statistically significant differences were identified for posterior pelvic tilt and lumbar lordosis between the Vari-Kneeler and Swopper chairs (p = 0.006, p = 0.001) and the Vari-Kneeler and Standard Office chairs (p = 0.000, 0.000); and also for neck angle and head tilt between the Vari-Kneeler and Swopper chairs (p = 0.000, p = 0.000), the Vari-Kneeler and Saddle chairs (p = 0.002, p = 0.001), the Standard Office and Swopper chairs (p = 0.000, p = 0.000), and the Standard Office and Saddle chairs (p = 0.005, p = 0.001). This study confirms a within region association between posterior pelvic tilt and lumbar lordosis, and between neck angle and head tilt. It was noted that an ideal lumbopelvic position does not always result in a corresponding ideal cervical position resulting in a spinal alignment mismatch.

CONCLUSION

In this study, the most appropriate posture for the lumbopelvic region was produced by the Saddle chair and for the cervical region by both the Saddle and Swopper chairs. No chair consistently produced an ideal posture across all regions, although the Saddle chair created the best posture of those chairs studied. Chair selection should be based on individual need.

Identification of contractile vacuole proteins in Trypanosoma cruzi

Contractile vacuole complexes are critical components of cell volume regulation and have been shown to have other functional roles in several free-living protists. However, very little is known about the functions of the contractile vacuole complex of the parasite Trypanosoma cruzi, the etiologic agent of Chagas disease, other than a role in osmoregulation. Identification of the protein composition of these organelles is important for understanding their physiological roles. We applied a combined proteomic and bioinfomatic approach to identify proteins localized to the contractile vacuole. Proteomic analysis of a T. cruzi fraction enriched for contractile vacuoles and analyzed by one-dimensional gel electrophoresis and LC-MS/MS resulted in the addition of 109 newly detected proteins to the group of expressed proteins of epimastigotes. We also identified different peptides that map to at least 39 members of the dispersed gene family 1 (DGF-1) providing evidence that many members of this family are simultaneously expressed in epimastigotes. Of the proteins present in the fraction we selected several homologues with known localizations in contractile vacuoles of other organisms and others that we expected to be present in these vacuoles on the basis of their potential roles. We determined the localization of each by expression as GFP-fusion proteins or with specific antibodies. Six of these putative proteins (Rab11, Rab32, AP180, ATPase subunit B, VAMP1, and phosphate transporter) predominantly localized to the vacuole bladder. TcSNARE2.1, TcSNARE2.2, and calmodulin localized to the spongiome. Calmodulin was also cytosolic. Our results demonstrate the utility of combining subcellular fractionation, proteomic analysis, and bioinformatic approaches for localization of organellar proteins that are difficult to detect with whole cell methodologies. The CV localization of the proteins investigated revealed potential novel roles of these organelles in phosphate metabolism and provided information on the potential participation of adaptor protein complexes in their biogenesis.

Factors modulating cytosolic calcium. Role in lipid metabolism and cardiovascular morbidity and mortality in peritoneal dialysis patients

Studies in the uremic rat indicate that insulin resistance and glucose intolerance leading to dyslipidemia are associated with a hyperparathyroid-induced increase in cytosolic calcium ([Ca++i]). These alterations are reversed with verapamil, but recur after discontinuation of the drug, suggesting that increased [Ca++i] is responsible for the metabolic derangement. To our knowledge, no similar studies have been conducted in humans. We retrospectively examined, over 12-year period, the effects of factors that lower [Ca++i] on total serum cholesterol and triglycerides in 176 peritoneal dialysis (PD) patients. Because the study was retrospective, detailed lipid profiles were not available. We therefore relied on the morbidity and mortality outcome related to atherosclerotic vascular disease. Diabetic patients were excluded from the study, because their dyslipidemia and vascular disease are mediated via a different mechanism. The patients were classified into four groups. Group I [high parathyroid hormone (PTH) in the absence of calcium channel blockers (CCBs), n = 56] represented the highest [Ca++i]. Group II (high PTH in the presence of CCBs, n = 43) and group III (lower PTH in the absence of CCBs, n = 37) represented intermediate [Ca++i]. Group IV (lower PTH in the presence of CCBs, n = 40) represented the lowest [Ca++i]. High PTH was defined as > or = 3.0 times normal; lower PTH, as < 3.0 times normal. Lower [Ca++i] was achieved through the use of CCBs, or through lower PTH, or both. Lower PTH was achieved by parathyroidectomy or calcitriol administration. The four groups showed no differences in age, sex, race, weight, dialysis duration, or primary disease. Group I showed a mean serum cholesterol of 358 +/- 27 mg/dL and serum triglycerides of 469 +/- 41 mg/dL. Group II showed mean serum cholesterol of 198 +/- 21 mg/dL and serum triglycerides of 147 +/- 17 mg/dL. Group III showed a mean serum cholesterol of 205 +/- 20 mg/dL and serum triglycerides of 174 +/- 16 mg/dL. Group IV showed mean serum cholesterol of 184 +/- 10 mg/dL (p = 0.008) and serum triglycerides of 103 +/- 8 mg/dL (p = 0.005). The cardiovascular morbidity and mortality incidences were: group I, 64%; group II, 27%; group III, 31%; and group IV, 20% (p = 0.002). We conclude that, in non diabetic PD patients, dyslipidemia is related to a hyperparathyroid-induced increase in cytosolic calcium [Ca++i]. Lowering [Ca++i] by decreasing the parathormone level (via parathyroidectomy or calcitriol administration), or by blocking calcium entry into cells (via CCBs), or both, is associated with less dyslipidemia and improved long-term morbidity and mortality related to atherosclerotic vascular disease.

Use of bolus intraperitoneal aminoglycosides for treating peritonitis in end-stage renal disease patients receiving continuous ambulatory peritoneal dialysis and continuous cycling peritoneal dialysis

Peritonitis is the most common complication of peritoneal dialysis (PD) and accounts for the most drop-out from PD among patients with end-stage renal disease (ESRD). Antibiotic protocols to treat peritonitis recommend initial treatment for both gram-positive and gram-negative infections, pending culture results. Current literature also suggests comparable therapeutic success using bolus (single-dose) parenteral aminoglycosides to treat systemic gram-negative infections compared to conventional divided-dose aminoglycosides. The single bolus dose antibiotic regimen has the potential for reduced nephrotoxicity and ototoxicity. We therefore hypothesized that intermittent bolus dose intraperitoneal (i.p.) aminoglycosides may be superior to conventional continuous dose i.p. aminoglycosides in treating dialysis-associated peritonitis, and have fewer side effects. Six patients with clinical peritonitis were treated with single, bolus-dose, i.p. gentamicin or tobramycin (5 mg/kg ideal body weight), range 250-440 mg (mean: 355 +/- 68.25 mg) at the start of therapy. No patient grew gram-negative organisms; aminoglycosides were therefore not repeated. Three patients used four continuous ambulatory peritoneal dialysis (CAPD) exchanges per day; three patients used six nightly continuous cycling peritoneal dialysis (CCPD) exchanges with a daytime dwell. Mean PD aminoglycoside clearance was 6.75 +/- 2.27 mm3/min; mean urinary aminoglycoside clearance was 5.75 +/- 1.14 mm3/min. Mean blood aminoglycoside elimination t1/2 was 29.27 +/- 3.55 hours, with a mean blood level of 3.18 +/- 1.45 micrograms/mL 72 hours after initial therapy, and 1.52 +/- 0.81 micrograms/mL 96 hours after initial therapy. Peritoneal equilibration test (PET) scores before and after aminoglycoside administration (performed a mean of 4.6 months apart) were 0.672 +/- 0.097 and 0.705 +/- 0.092 respectively (p = 0.321). Comparative audiograms using pure-air tone conduction with frequencies from 250-12,000 Hz were done within 24 hours of aminoglycosides and again when therapy was complete (mean: 17 days). No significant changes were seen. While efficacy of bolus versus conventional-use aminoglycosides could not be definitely established, the kinetics of bolus aminoglycosides suggests that therapeutic blood levels persist for 72-96 hours and that the risk for oto/vestibular toxicity is negligible. We conclude that use of bolus i.p. aminoglycosides is safe, achieves therapeutic blood levels for extended intervals, demonstrates no clinical oto/vestibular toxicity, is cost-effective, and is a convenient strategy for patients and nursing staff.

Pulse oral versus pulse intraperitoneal calcitriol: a comparison of efficacy in the treatment of hyperparathyroidism and renal osteodystrophy in peritoneal dialysis patients

Controversy exists among various studies in regard to the efficacy of oral (p.o.) versus parenteral calcitriol. Some studies suggest that intravenous (i.v.) calcitriol is superior to p.o. calcitriol for treating renal osteodystrophy in hemodialysis patients; others suggest that these routes of administration are equivalent. To our knowledge, no large, prospective, randomized study compares intraperitoneal (i.p.) to p.o. calcitriol in adult peritoneal dialysis patients. We conducted a prospective randomized study in 76 patients (38 on i.p. calcitriol and 38 on p.o. calcitriol), whom we followed for 48 months. Of the 76 patients, 34 (18 in the i.p. group and 16 in the p.o. group) completed the 48-month study period. Calcitriol dosing was similar in both groups (3-6 micrograms per week in three divided doses). Dose adjustments were made depending on levels of parathyroid hormone (PTH), serum calcium, phosphorus, and calcitriol. No significant difference was seen between the groups in regard to age, sex, race, body mass index, dialysis duration, or cause of ESRD. Neither was any difference in the incidence of peritonitis seen between the groups. In the first 3-6 months, PTH decreased equivalently in both groups. The PTH level remained suppressed in the i.p. group throughout the remainder of the study, but, in the p.o. group, PTH returned to its pretreatment level after 3-6 months. Mean serum calcium was not different in the two groups. In the p.o. group, a considerably higher mean follow-up phosphorus level (6.8 +/- 2.3 mg/dL versus 4.7 +/- 1.4 mg/dL, p = 0.008), PTH level (384 +/- 146 pg/mL versus 162 +/- 64 pg/mL; p = 0.005), and alkaline phosphatase level (178 +/- 37 IU/L versus 72 +/- 21 IU/L, p = 0.02) were seen as compared to the i.p. group. In the i.p. group, resolution of osteodystrophy occurred in all patients at the end of the study; in the p.o. group, 5 patients maintained or developed osteodystrophy by the end of the study (p = 0.016). We conclude that i.p. calcitriol is more effective than pulse p.o. calcitriol in lowering PTH and alkaline phosphatase levels and in resolving renal osteodystrophy, and that i.p. calcitriol is associated with a lower incidence of hyperphosphatemia and elevated Ca x PO4 byproduct.

Role of intraperitoneal urokinase in acute peritonitis and prevention of catheter loss in peritoneal dialysis patients

Some studies have demonstrated the efficacy and safety of intraperitoneal (i.p.) urokinase in the resolution of recurrent or relapsing peritonitis, while others have not. Most studies were small, and they varied in methodology. Furthermore, the role of i.p. urokinase in shortening the duration of peritonitis or in preventing recurrence after initial peritonitis has not been examined. In addition, no previous studies have examined the role of i.p. urokinase in preventing, after first infection, catheter loss due to unresolving (resistant) peritonitis. Over a period of 3 years, we prospectively randomized into two groups all peritoneal dialysis (PD) patients who developed a first episode of peritonitis. Group I (n = 40) received i.p. urokinase on the first day of diagnosis (5000 IU intraluminally in the peritoneal catheter and left for 4 hours before next exchange). Group II (n = 40) received no urokinase. The duration of peritonitis was assessed by daily PD fluid white blood cell (WBC) count. Indications for catheter removal were: persistent peritonitis after four days from initiation of antibiotic therapy, or peritonitis with multiple organisms, suggesting bowel perforation. No statistically significant difference was seen between the two groups in regard to primary cause of end-stage renal disease (ESRD), age, sex, race, weight, type of dialysis [continuous ambulatory peritoneal dialysis (CAPD), automated peritoneal dialysis (APD), continuous cycling peritoneal dialysis (CCPD)], or duration of dialysis prior to first peritonitis. No statistically significant difference was seen between the two groups in the duration of peritonitis or in the severity of symptoms and signs of peritonitis. Neither was any difference seen in the peritonitis recurrence or relapse rate (10% in the urokinase group vs 7.5% in the control group). Nine patients lost their catheters (3 in the urokinase group: 1 Pseudomonas aeruginosa and 2 Candida tropicalis; 6 in the control group: 1 Klebsiella pneumonia, 1 enterococcus, 2 Pseudomonas aeruginosa, and 2 Candida tropicalis). The difference in the rate of catheter loss between the two groups was not statistically significant; it appeared to relate to the type of organism rather than to the response to urokinase. In conclusion, i.p. urokinase plays no significant role in shortening the course of peritonitis or in preventing recurrence or loss of the PD catheter. Loss of PD catheters in patients having their first peritonitis appears to be related primarily to the type of organism causing the infection.

Use of bolus intraperitoneal iron dextran in continuous ambulatory peritoneal dialysis or continuous cyclic peritoneal dialysis patients receiving recombinant human erythropoietin

Impaired erythropoiesis in continuous ambulatory peritoneal dialysis (CAPD) or continuous cyclic peritoneal dialysis (CCPD) patients receiving recombinant human erythropoietin (rHuEPO) is most often secondary to iron deficiency, either as a result of poor intestinal absorption or failure to take oral supplements as prescribed. The inconvenience of giving intravenous (i.v.) iron dextran (ID) to CAPD/CCPD patients precluded its use in this population. We therefore examined the efficacy of bolus intraperitoneal (i.p.) iron dextran (1000 mg) on erythropoiesis in a pilot study of 14 CAPD/CCPD patients. The patients ranged in age from 23-81 years, and all had iron deficiency (transferrin saturation 6%-23%; mean: 15.2% +/- 1.34%). Of the 14 patients studied, 13 were receiving rHuEPO. Pre-treatment hematocrit (Hct) ranged from 21%-38% (mean: 30.2% +/- 1.37%). After infusion of 2 L Dianeal (Baxter Healthcare Corp., Deerfield, Illinois, U.S.A.), 500 mg of undiluted ID was administered directly into the Tenckhoff catheter and subsequently flushed with 30 mm3 normal saline. The peritoneal dialysis (PD) exchange containing ID then dwelled for a period not < 6 hours before standard PD resumed. A second 500 mg dose ID was given to each patient by the same protocol 3-86 days later (mean: 14 days). No complications were seen. No patient complained of abdominal pain or other subjective symptoms during infusion or during the dwell. Repeat iron studies done 1-7 months post ID (mean: 2.8 months) showed a 1.1-fold to 4.9-fold increase (mean: 1.4-fold) in mean iron levels (40.4 +/- 3.9 mg/dL versus 57.5 +/- 5.5 mg/dL, p = 0.036); a 1.1-fold to 5.2-fold increase (mean: 1.6-fold) in mean transferrin saturation (15.2% +/- 1.3% versus 24.5% +/- 2.6%, p = 0.008); a 1.01-fold to 1.60-fold increase (mean: 1.12-fold) in mean Hct (30.2% +/- 1.37% versus 33.8% +/- 1.5%; p = 0.042). The mean dose of rHuEPO was statistically unchanged (170.0 +/- 47.4 U/kg body weight versus 178.8 +/- 49.6 U/kg body weight per week; p = 0.841). Peritoneal equilibration test (PET) score 1-4 months post ID (mean: 2 months) was 0.778 +/- 0.02 compared with a PET score at baseline of 0.767 +/- 0.03 (p = 0.734). No significant delta was observed in blood urea nitrogen (BUN) or creatinine values. We conclude that use of bolus i.p. ID is safe, effective, and convenient, and demonstrates no short-term negative effect on peritoneal membrane integrity. Long-term effects have yet to be determined.

Role of Fogarty catheter manipulation in management of migrated, nonfunctional peritoneal dialysis catheters

Peritoneal dialysis (PD) catheter migration to the upper abdomen is not an uncommon cause of catheter failure. We prospectively examined the role of the Fogarty catheter manipulation technique to reposition the PD catheter in the pelvis and regain patency. All patients with PD catheter malfunction caused by migration, confirmed by abdominal radiograph, underwent the same protocol. The patient was placed flat on the back, and the Fogarty was advanced into the PD catheter to a premarked point at which the end of the Fogarty was near the end of the PD catheter. The Fogarty balloon was inflated with 0.5 mL of sterile saline, and manipulation was performed by tugging movements until proper placement of the PD catheter into the pelvis was suspected. Infusion and drainage of dialysate was performed to determine patency. The return of the PD catheter into the pelvis was then confirmed by repeated radiograph. Success rates of Fogarty catheter manipulation, early and late recurrence (remigration < or =90 days or >90 days), and complications were prospectively examined in 232 patients over a 6-year period. Catheter migration occurred in 34 of 232 patients (15% incidence). All patients had curled-end, double-cuffed, non-swan-neck PD catheters. Successful repositioning occurred in 24 of 34 patients (71%). None of the 24 repositioned catheters had early recurrence, and 1 of 24 catheters (4%) had late recurrence. None of the patients had procedure-related peritonitis, bowel perforation, or exit-site trauma. These results show that PD catheter migration is relatively common (15%). The Fogarty manipulation technique is a simple, cost-effective way to prolong PD catheter life and preserve its long-term patency. This eliminates the need for surgical intervention in approximately 70% of patients with PD catheter migration.

Zinc supplementation is associated with improved neurologic recovery rate and visceral protein levels of patients with severe closed head injury

Sixty-eight patients were entered into a randomized, prospective, double-blinded controlled trial of supplemental zinc versus standard zinc therapy to study the effects of zinc supplementation on neurologic recovery and nutritional/metabolic status after severe closed head injury. One month after injury, the mortality rates in the standard zinc group and the zinc-supplemented group were 26 and 12%, respectively. Glasgow Coma Scale (GCS) scores of the zinc-supplemented group exceeded the adjusted mean GCS score of the standard group at day 28 (p = 0.03). Mean motor GCS score levels of the zinc-supplemented group were significantly higher on days 15 and 21 than those of the control group (p = 0.005, p = 0.02). This trend continued on day 28 of the study (p = 0.09). The groups did not differ in serum zinc concentration, weight, energy expenditure, or total urinary nitrogen excretion after hospital admission. Mean 24-h urine zinc levels were significantly higher in the zinc-supplemented group at days 2 (p = 0.0001) and 10 (p = 0.01) after injury. Mean serum prealbumin concentrations were significantly higher in the zinc-supplemented group (p = 0.003) at 3 weeks after injury. A similar pattern was found for mean serum retinol binding protein level (p = 0.01). A significantly larger number of patients in the standard zinc group had craniotomies for evacuation of hematoma; thus a bias may have been present. The results of this study indicate that zinc supplementation during the immediate postinjury period is associated with improved rate of neurologic recovery and visceral protein concentrations for patients with severe closed head injury.

Individual and group therapies as constructive continuous experiences

We began this paper with the conceptualization that individual and group psychotherapies were potentially continuous just as internal and external experiences are co-extensive. We recognized Winnicott's "holding," "regression to dependence," and "The primary maternal preoccupation." In our specific context of individual and group therapies, a state of being, a new construct of one's self can be invented in ways that can overturn the received. Clinician and patient can invent a new state of being and new meaning. For our patient, individual therapy was experienced as impacted space where she could neither be nor invent new meaning with another. "Intimacy" as a problem could not be dealt with in individual work without the risk of decompensation. In group psychotherapy she found no such risks or congestion. Rather, she found space. She was dislodged and group psychotherapy received her by giving her an opportunity to renegotiate who hosts whom. She recognized that group was in the service of the human being and was able to absorb her intolerable conflicts and transfer them without danger to anyone. It was a trusting attitude to the surrounding and was motivated by connectedness toward others. As a result there can be a state of being and the real possibility of thinking as one's own self and for one's self in the midst of others without losing one's newly established self. In a word she could become. Accordingly, our patient was able to work towards amelioration of psychopathological formations and was ready to make appropriate selection for the necessary therapy.

Marked improvement in parameters of renal osteodystrophy with the use of intraperitoneal calcitriol

Parenteral administration of Calcitriol is felt to be superior to oral Calcitriol in the treatment of renal osteodystrophy in chronic renal failure patients. We analyzed the results of serum calcium, phosphorus, alkaline phosphatase, and N-terminal parathormone level which are the clinical parameters of renal osteodystrophy in twenty-three chronic peritoneal dialysis patients who received varying dosages of intraperitoneal Calcitriol. The results which were analyzed at the end of one to twenty-three months revealed significant increase in serum calcium and a significant decrease in the values of alkaline phosphatase and N-terminal parathormone level.

Comparison of transdermal nitrate and isosorbide dinitrate in chronic stable angina

The effects of transdermal nitrate (TN) (Transiderm-Nitro TTS, Geigy Pharmaceuticals, one 10 cm2 patch daily) and oral isosorbide dinitrate (ISDN) (Sorbitrate, Stuart Pharmaceuticals, 10 mg three times daily) were compared in a group of 20 patients with chronic stable angina pectoris. Treadmill exercise duration was prolonged from a median time of 365 s to 428 s after ISDN (P less than 0.05), but was unchanged after TN. The difference between the active treatments was not significant. Weekly consumption of glyceryl trinitrate (GTN) increased during treatment with TN from a median value of 5.5 to 6.3 (P less than 0.05). A decrease was observed after ISDN (7.8 to 3.9, P = NS), and the difference between the drugs was significant (P less than 0.01). Systolic arterial pressure was significantly lower during the ISDN than during the TN treatment period in both the supine (135 +/- 5 vs 128 +/- 5 mm Hg; P less than 0.05) and standing positions (134 +/- 5 vs 122 +/- 5 mm Hg; P less than 0.05). No change in weekly attack rate, the degree of ST depression at angina on treadmill testing, or the number of episodes of ST depression recorded during a 24 h period by Holter monitoring was observed after either drug. In this study, an antianginal effect was demonstrated for ISDN but not for TN. It is suggested that the dose of TN may have been inadequate to demonstrate such an effect, and further studies using a higher dose schedule will be required.