Common questions and misconceptions about caffeine supplementation: what does the scientific evidence really show?

Caffeine is a popular ergogenic aid that has a plethora of evidence highlighting its positive effects. A Google Scholar search using the keywords "caffeine" and "exercise" yields over 200,000 results, emphasizing the extensive research on this topic. However, despite the vast amount of available data, it is intriguing that uncertainties persist regarding the effectiveness and safety of caffeine. These include but are not limited to: 1. Does caffeine dehydrate you at rest? 2. Does caffeine dehydrate you during exercise? 3. Does caffeine promote the loss of body fat? 4. Does habitual caffeine consumption influence the performance response to acute caffeine supplementation? 5. Does caffeine affect upper vs. lower body performance/strength differently? 6. Is there a relationship between caffeine and depression? 7. Can too much caffeine kill you? 8. Are there sex differences regarding caffeine's effects? 9. Does caffeine work for everyone? 10. Does caffeine cause heart problems? 11. Does caffeine promote the loss of bone mineral? 12. Should pregnant women avoid caffeine? 13. Is caffeine addictive? 14. Does waiting 1.5-2.0 hours after waking to consume caffeine help you avoid the afternoon "crash?" To answer these questions, we performed an evidence-based scientific evaluation of the literature regarding caffeine supplementation.

p53 immunodetection of liquid-based processed urinary samples helps to identify bladder tumours with a higher risk of progression

p53 could help identify bladder tumour cases with a risk of progression from superficial to invasive disease. Semiautomatic, liquid-based cytology (LBC) techniques offer an opportunity to standardise molecular techniques. The aim of our study was to investigate whether LBC could improve p53 immunolabelling, and to assess whether urinary p53 could have a prognostic value. Immunoreactivity for p53 was studied in 198 urine samples after treatment with the Cytyc Thinprep® processor. After antigen retrieval, cells were labelled with a monoclonal antibody that recognises both wild-type and mutant form of the p53 protein (Clone DO-7, Dako), 1/1000. Positivity for p53 was assessed in 17.2% of the cases. High-grade (G3) tumours were positive in 74.1% of the cases. Comparatively, low-grade (G1–2) urothelial carcinomas were positive in 23.5% of the cases. During a median follow-up period of 26 months, recurrence was observed in 52.9% of the cases with p53 overexpression, and in only 10.9% of negative cases (P<0.001). The progression rate was 35.3% of p53-positive cases vs 5.5% of p53-negative cases (P<0.001). Progression-free survival was significantly shorter in patients with p53 accumulation (P=0.007). In a multivariate analysis stratified on grade and stage, p53 was an independent predictor of overall survival (P=0.042). The results show that using Thinprep® LBC, p53 immunolabelling of voided urothelial cells allows most high-grade tumours to be detected and may help identify cases with a higher risk of recurrence and progression.

Preservation of prostate during radical cystectomy: Evaluation of prevalence of prostate cancer associated with bladder cancer

OBJECTIVES

To estimate the frequency and characteristics of prostatic lesions discovered incidentally in radical cystoprostatectomy specimens and to determine whether any factors would allow for the detection of prostate cancer preoperatively.

METHODS

A total of 100 radical cystoprostatectomy specimens with orthotopic bladder reconstruction were performed for malignant bladder disease between 1990 and 2000. The mean patient age at surgery was 62 +/- 8 years (range 32 to 75). Digital rectal examination and prostate-specific antigen (PSA) assay were done routinely before surgery. During the 10-year study period, the same pathologist examined the prostatic tissues from radical cystoprostatectomy specimens using McNeal's technique on fine slices every 2.5 mm.

RESULTS

The overall incidence of prostate cancer discovered incidentally in radical cystoprostatectomy specimens was 51%, of which 29% were microcancers (volume less than 0.5 cm3) and 22% were significantly larger (volume 0.5 cm3 or more). The mean Gleason score was 6. Of the tumors, 24% could be considered "clinically nonsignificant" (less than 0.5 cm3 and Gleason score less than 7). The mean preoperative PSA level was 4.13 +/- 1.36 ng/mL. Of 66 patients with a PSA level of less than 4 ng/mL (mean PSA 1.5 +/- 0.8) and a normal digital rectal examination before surgery, 50% had prostate cancer, of which 69% were microcancers.

CONCLUSIONS

The prevalence of prostate cancer (51%) in our series is among the highest in published reports. Furthermore, our results stress that currently no factors are available to enable the detection of "clinically significant" prostate cancer preoperatively.

Long-term recurrence of primary amyloidosis of the bladder

An 84-year-old man presented to our department with a recurrence of a primary amyloidosis of the bladder 14 years after the first diagnosis. Follow-up had been stopped 5 years after the first procedure because no cystoscopic anomalies were noted. General evaluation confirmed the diagnosis of primary amyloidosis. The lesions were endoscopically resected. At the 3-year follow-up, the patient was free of symptoms and had remained cystoscopically free of disease. However, stable amyloidosis deposits have always been noted on the computed tomography scans. This case emphasizes the necessity of a longer follow-up, including computed tomography of the pelvis, during the 10 to 15 years after the first occurrence of the disease.

[Deferred adjustment of the tension of tension-free vaginal tape (TVT) after surgical repair of stress urinary incontinence in women]

INTRODUCTION

Urinary retention is a frequent complication of repair of female urinary incontinence treated by tension-free vaginal tape (TVT). The authors report a modification of the original technique designed to decrease the risk of postoperative dysuria and retention.

MATERIAL AND METHODS

One hundred and twenty four patients with pure stress urinary incontinence were treated by TVT. In 74 patients (group 1), the TVT was placed according to the original Swedish technique. In 50 patients (group 2), no tension was applied to the suprapubic extremities of the TVT during the operation, but they were preserved and buried in an antiseptic dressing. On the day after the operation, traction was applied to the suprapubic TVT in the case of persistent incontinence. The immediate postoperative results and the results at 3 months, in terms of continence and urethral obstruction, were compared.

RESULTS

Perfect continence was obtained in 84 +/- 6.5% and 94 +/- 4.2% of patients in groups 1 and 2, respectively (p = 0.08). Acute urinary retention (15% vs 2%, p < 0.03) and post-voiding residual urine > 50 cc (38% vs 10% on D1 and 14% vs 2% at 3 months) were more frequent in group 1. At 3 months, the reduction in maximum and mean flow rate was lower in group 2 (p < 0.03). In group 2, deferred traction of the TVT was necessary in 20% of cases, without causing any major infectious complications or pain.

CONCLUSION

Deferred traction of TVT appears to decrease the rate of dysuria and urinary retention following repair of female urinary incontinence by tension-free vaginal tape (TVT). This technical modification does not affect the results on continence, which appears to be at least as satisfactory. This technical variant appears to be associated with a low morbidity.

[Intravesical BCG-therapy: comparison of side effects of Connaught (Toronto) and Pasteur (Paris) strains]

INTRODUCTION

Urologists have felt that the adverse effects of intravesical BCG-therapy have been more serious and more frequent since the use of the Connaught strain. The objective of this retrospective study was to compare the toxicity of this new strain with that previously used in France (Pasteur strain).

MATERIAL AND METHODS

After endoscopic resection, 89 patients with stage Ta grade 1-2 recurrent or T1 grade 3 and/or CIS bladder tumour were treated with 6 instillations of 150 mg of BCG Pasteur from 1992 to 1996 (50 patients: group 1) or 81 mg of BCG Connaught from January 1997 to December 1998 (39 patients: group 2). Adverse effects were classified as minor, lasting less than 48 hours (bladder irritation syndrome and/or macroscopic haematuria and/or fever less than 38 degrees C), moderate (requiring symptomatic treatment, reduction of the dose or an increased interval between instillations), and major (contraindication to continuation of treatment).

RESULTS

74% of patients in group 1 presented at least one adverse effect versus 77% in group 2. The reasons for permanent discontinuation of BCG-therapy in groups 1 and 2, respectively, were as follows: malaise during instillation (1 vs 0), bladder irritation syndrome not controlled by symptomatic treatment (4 vs 5) and epididymitis (0 vs 1). Pulmonary tuberculosis was diagnosed in one patient from group 2, one year after the last instillation. The frequency and severity of adverse effects were not statistically different between the two groups. The number of patients discontinuing BCG-therapy because of severe complications was also not statistically different between the two groups.

CONCLUSION

This study did not reveal any difference of toxicity between Connaught and Pasteur strain in intravesical BCG-therapy of superficial bladder tumours.

Acromioplasty: comparison of outcome in patients with and without workers' compensation

Acromioplasty was performed on 24 shoulders in 23 patients who had a diagnosis of impingement syndrome/rotator cuff tendinopathy. Ten patients were female and 13 were male; mean age was 52.3 years. Patients were divided into two groups, depending on whether they were receiving workers' compensation benefits. Clinical outcomes were evaluated preoperatively and at follow-up postoperatively using the University of California Los Angeles (UCLA) Shoulder Rating Scale. All patients had bursectomy, anterior inferior acromioplasty, and coracoacromial ligament release. The two groups showed significantly different postoperative results in terms of pain, function, strength of forward flexion, and total score, with the workers' compensation group consistently having a lower functional score. Pain did improve significantly for workers' compensation patients over the course of treatment, but relief was not nearly as complete as in the noncompensated group. A positive response to a shoulder bursa steroid injection, even if temporary, was a good predictor of final outcome after an acromioplasty.

Observation/delayed treatment for rising PSA after radical prostatectomy: pros and cons

The protracted natural history of prostate cancer and the absence of a documented effective seconde line curative therapy, once primary treatment has failed, has led in the presence of biochemical failure after radical prostatectomy to a dual attitude: early treatment versus observation with delayed therapy. The objective of this review is to define the subsets of patients who might benefit from either of these attitudes. Depending on the risk of progression, three subgroups of patients may be individualized: a high-risk group (PN1, pT3 B, Gleason score equal or superior to 8), a moderate-risk group (pT3 A, NO with positive margins, and a Gleason score equal or less than 7), and a low-risk group (pT2 NO or pT3 A NO without positive margins and Gleason score equal or lower than 7). As of today, observation seems to be the appropriate option in men with a low or moderate risk of progression, whereas in the high-risk group, early therapy is a reasonable option. New treatment options with intermittent hormonal therapy or with combined adjuvant hormonoradiotherapy show a promising efficacy that may lead to reconsider this attitude.

Treatment of dual urinary and fecal incontinence by implantation of two AMS 800 artificial sphincters. Case report

We report the case of a 61-year-old woman with urinary and anal incontinence due to neurologic disease. An AMS 800 artificial sphincter was implanted first round the bladder neck with recovery of satisfactory urinary continence. Four months later, another AMS 800 artificial sphincter was implanted round the anal sphincter. Two revisional procedures had to be performed: replacement of the pump for mechanical failure, and replacement of the low-pressure balloon by a high-pressure one. Finally the patient has been almost completely continent with only occasional leakage of feces or liquid stools (follow-up 24 months after activation). Defecography shows total rectal evacuation and anorectal manometry records an anal closing pressure of 70 cm H2O. Dual implantation of artificial sphincters is possible for incontinence of neurological origin, provided bladder and rectal compliance are normal.

Ureteropelvic invagination procedure for endopyelotomy (Gelet technique): review of 51 consecutive cases

Between 1990 and 1995, we performed 51 endopyelotomies on 38 cases of primary and 13 of secondary obstruction of the ureteropelvic junction (UPJ) using the ureteropelvic invagination technique. Of the 51 patients in the series, 49 have been followed for a minimum of 3 months postoperatively (mean follow-up 16 months). Overall, success was achieved in 38 (77.5%). Endoscopic endopyelotomy was successful in 11 of 13 cases (84.5%) with secondary strictures. When the technique was used for the treatment of primary UPJ stricture, the success rate was only 75% (27 of 36). The presence of a crossing vessel was identified as the cause of failure in five cases of primary strictures; hence, we advocate the use of angiography to identify crossing vessels preoperatively. We recommend the use of the ureteropelvic invagination technique as the first-line therapy for primary hydronephrosis in adults in the absence of a crossing vessel.

EGF cell surface receptor quantitation on ocular cells by an immunocytochemical flow cytometry technique

A method is presented for the rapid flow cytometric determination of epidermal growth factor (EGF) receptor densities on the surface of cultured ocular cells. The technique uses a biotinylated monoclonal antibody directed against the EGF receptor in conjunction with a streptavidin-bound fluorochrome and requires the specific fluorescence per cell to be measured as a function of ligand and receptor concentration. Because the measurement is noninvasive and restricted to cell surface-bound material, the cells can be kept in a physiologic environment, even at the moment of assay. Calculated receptor densities ranged from 5142/cell (infant human corneal endothelium) to 35,678/cell (infant human keratocytes) to greater than 5 x 10(5)/cell for an A431 control cell line. Species and donor age differences were noted, as was transient receptor downregulation after EGF administration. Flow cytometry represents a valuable time saving procedure for large scale applications while providing the same level of sensitivity as standard radioimmunoassays. This technique is applicable to quantitation of other growth factor cell surface receptors and could greatly expand the use of flow cytometry in the research laboratory.

Pulsus paradoxus in acute asthma in children

One hundred children suffering from acute asthma were studied. Both pulsus paradoxus (PP) and CO2 pressure (PCO2) of the arterialized blood sample were measured in each child. The correlation between the PP and the PCO2 was not statistically significant when the latter was less than 35 mmHg (p less than 0.05). When the PCO2 was equal or higher than 35 mmHg, a directly proportional as well as statistically significant relationship with PP was found (p less than 0.00001). PP is proposed as an indirect indicator of the PCO2 on patients suffering from acute asthma, when the necessary equipment to measure the PCO2 is not available.

Extended incubation times improve corneal endothelial cell transplantation success

To investigate the ability of extended incubation times to improve the success of endothelial cell transplantation, eight human donor corneas were denuded of their native endothelium, seeded twice during a 1-hr interval with a suspension of cultured infant human corneal endothelial cells, and then incubated for 144 hr under standard conditions. Subsequently the corneas were transplanted into African green monkeys using routine penetrating keratoplasty techniques. Rotational autografts and corneas devoid of endothelial cells served as controls. The seeded corneas appeared hazy at the time of surgery (mean pachymetry 48 hr postoperatively, 0.794 mm). Six corneas (75%) subsequently cleared, yielding a mean corneal thickness of 0.541 +/- 0.040 and 0.554 +/- 0.040 at 6 and 12 postoperative months, respectively. All control eyes showed advanced edema (thickness, greater than 1.0 mm) and developed extensive neovascularization. Clinically, the extended postseeding incubation corneas were observed to clear more rapidly and stabilize their thickness earlier than corneas incubated for only 24-48 hr. Scanning electron microscopy of extended postseeding incubation corneas revealed an intact monolayer of contact-inhibited cells with the hexagonal mosaic typical of corneal endothelium in vivo and improved intercellular contact compared with corneas incubated for only 24-48 hr.

Heterologous transplantation versus enhancement of human corneal endothelium

The ability to successfully transplant human corneal endothelium would offer a significant advance in the treatment of many corneal diseases. To investigate the feasibility of this, we established cultures of endothelial cells derived from neonatal human corneas. Eye bank donor corneas were either enhanced with a suspension of cultured endothelial cells or underwent endothelial cell removal and subsequent replacement with cultured endothelium. Following a 48-h incubation, the corneas were transplanted into the eyes of nonhuman primates. Over a 12-month period, 67% of the corneas with complete endothelial cell replacement thinned and remained clear, with a mean corneal thickness of 0.57 mm. Enhanced corneal buttons demonstrated a significantly lower success rate (35%), with opacified and thickened corneas. Control eyes in which the native endothelium was removed demonstrated advanced corneal edema and vascularization, with a mean corneal thickness in excess of 1 mm. By utilizing established tissue-culture techniques, we have demonstrated that human corneal endothelium, when cultured and subsequently transplanted, retains its in vivo pump function. Although further studies are warranted, these results indicate that transplanted human corneal endothelial cells can function normally and suggest the possibility of endothelial cell replacement for therapeutic purposes.

Microcarrier cell culture of neonatal human corneal endothelium

Fresh isolates of neonatal human corneal endothelial cells were maintained in tissue culture using a technique employing collagen-coated, dextran-based microcarrier beads. This method provides large yields of endothelial cells suitable for biochemical and/or transplant studies without exposing the cells to enzymatic passage. Our results suggest that microcarrier culture of human corneal endothelial cells can provide a useful in vitro system for the growth and maintenance of actively mitotic cells.

Transplantation of cultured human neonatal corneal endothelium

Human neonatal corneal endothelial cells were successfully maintained in tissue culture, morphologically resembling adult corneal endothelium. Eyebank donor corneas were obtained, denuded of their native endothelium and seeded with a suspension of the cultivated neonatal endothelial cells. After 48 hours, the eye-bank tissue was then transplanted into the eyes of Rhesus monkeys. Over a five month period, five of eight transplants cleared, with a mean central corneal thickness of 0.480 mm and endothelial cell densities ranging from 560 to 1650 cells/mm2. All control eyes without donor endothelium remained cloudy. In the experimental group three eyes initially thinned but subsequently became edematous. Further studies are needed to improve the seeding procedure and to assess the long-term viability of transplanted endothelium.

True morphology of the Azotobacteraceae-filterable bacteria

The history of bacteriology up to the 1950s contains many references to filterable forms of bacteria but misconceptions regarding the nature of filterability eventually made the entire phenomenon an unresolvable paradox. Although the existence of filterable azotobacter has often been reported, so much doubt in these results has been expressed that now Bergey does not even mention filterability. In 1965 we reported the resistance of soil azotobacter to gamma rays and concluded that the possibilty of a very small Azotobacter form could not be dismissed and as a result of studies on survival in soil, we suggested the possible existence in soil of a still undiscovered phase of the Azotobacter cyst. We report here the discovery of these small, soil azotobacter and provide evidence to support this claim.