Biomedical subjects
H Sanders
Publications and source records attributed to H Sanders.
Pretreatment with indomethacin protects from acute renal failure following ischemia-reperfusion injury.
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Computerized strain-gauge plethysmography - An alternative method for the detection of lower limb deep venous thrombosis?
AIM: To test the ability of computerized strain-gauge plethysmography to act as a screening test for lower limb deep venous thrombosis (DVT). MATERIALS AND METHODS: Over an 8-month period, all patients referred to our Medical Assessment Unit with suspected lower limb DVT were considered for inclusion in the study. Each patient underwent both plethysmography and ascending venography within 24 h, and the presence or absence of thrombus in the popliteal, superficial femoral or iliac veins was noted. The results of the two tests were then used to determine the accuracy of computerized strain-gauge plethysmography in detecting above knee DVT. RESULTS: The screening tests and venograms of 239 patients referred with clinically suspected lower limb DVT were compared. The false negative rate of plethysmography was 15.4%, which is significantly different from the 4.8% claimed by the manufacturers of this device (P = 0.00003). CONCLUSIONS: In a population of acute admissions with suspected lower limb DVT, computerized strain-gauge plethysmography is not suitable for use as a screening test due to an unacceptably high proportion of false negative screens.
Randomized controlled trial of nettle sting for treatment of base-of-thumb pain.
There are numerous published references to use of nettle sting for arthritis pain but no randomized controlled trials have been reported. We conducted a randomized controlled double-blind crossover study in 27 patients with osteoarthritic pain at the base of the thumb or index finger. Patients applied stinging nettle leaf (Urtica dioica) daily for one week to the painful area. The effect of this treatment was compared with that of placebo, white deadnettle leaf (Lamium album), for one week after a five-week washout period. Observations of pain and disability were recorded for the twelve weeks of the study. After one week's treatment with nettle sting, score reductions on both visual analogue scale (pain) and health assessment questionnaire (disability) were significantly greater than with placebo (P = 0.026 and P = 0.0027).
Gastrostomy feeding in the elderly after acute dysphasgic stroke.
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A study of cytokine protein secretion, frequencies of cytokine expressing cells and IFN-G gene polymorphisms in normal individuals.
BACKGROUND: Cytokines are major regulators of immune responses, and there is evidence that they play a role in allograft rejection. Before embarking on a detailed study of pretransplant cytokine profiles in renal allograft recipients, we wished to investigate variations in cytokine protein secretion, numbers of cytokine expressing T cells, and cytokine gene polymorphisms in normal volunteers. METHODS: Twenty normal healthy volunteers were studied. Cytokine protein secretion [interleukin- (IL) 2, IL-4, IL-10, and interferon- (IFN) y] and numbers of cytokine expressing CD3+ T cells (IL-2, IL-4, IL-10, and IFN-gamma) were quantified by means of enzyme-linked immunosorbent assay and two-color flow cytometry respectively. IFN-gamma gene polymorphisms were determined by polymerase chain reaction and autoradio graphy. RESULTS: Large interindividual variations in both the quantity of IL-2, IL-4, IL-10, and IFN-gamma cytokine protein secreted and numbers of IL-2 and IFN-gamma expressing T cells were demonstrated. However, numbers of IL-4 and IL-10 expressing cells were found to be below detectable limits by flow cytometry. In the case of IFN-gamma, a bi-modal distribution was seen for the quantity of protein secreted. In addition, correlations were observed between IL-2 protein and frequency of IL-2 expressing T cells. However, no relationship was found between IFN-gamma protein levels, numbers of IFN-gamma expressing cells and IFN-gamma gene polymorphisms. CONCLUSIONS: We have demonstrated large differences in both numbers of T helper 1 cytokine expressing cells and the quantity of T helper 1 and T helper 2 cytokine protein secreted between normal individuals. Although the amount of IL-2 protein secreted appeared to be determined by the frequency of IL-2 expressing cells, this was not the case for IFN-gamma.
Oxygen administration and explicit memory: no improvement found in healthy volunteers.
It has been suggested that oxygen administration to healthy volunteers could improve their memory. We tested this hypothesis with a twin, double crossover, placebo-controlled study in 20 healthy non-smokers, allocated randomly to one of two groups. Blinded to the nature of the gas, group A breathed air first then oxygen on day 1, and then oxygen first, followed by air on day 2. Group B had all exposures in reverse order. After each gas exposure a written memory test with a list of 20 words was carried out and evaluated by a blinded observer. Recall after oxygen exposure (mean 8.3 words) was not significantly different from that after air exposure (mean 9 words).
Increased incidence of serendipitously discovered renal cell carcinoma.
OBJECTIVES: To determine the proportion of renal cell carcinomas that are discovered serendipitously, and to compare the tumor stages of symptomatic versus incidental tumors. METHODS: We reviewed the charts of 131 consecutive patients who had a nephrectomy for renal cell carcinoma between 1989 and 1993. We excluded from the numerator any patients with abdominal pain or mass related to the tumor, even if the diagnosis of renal cell carcinoma had not been entertained before imaging studies. RESULTS: Eighty (61%) of 131 patients were diagnosed with renal cell tumors in the absence of flank pain, flank mass, or hematuria. Of these 131 patients, 31 (24%) presented with gross hematuria, 13 (10%) with flank pain, and 10 (8%) with flank or abdominal mass. Only 1 patient presented with the classic triad of flank pain, flank mass, and gross hematuria. Eighty-five percent of asymptomatic tumors were Stage I or II, and 77% of symptomatic tumors were Stage I or II. CONCLUSIONS: The great majority of renal cell tumors are found incidentally. The tumor stage is the same in the incidentally discovered cases as it is in the symptomatic cases.
Factors predicting cancer detection in biopsy of the prostatic fossa after radical prostatectomy.
OBJECTIVES: To determine whether the results of anastomotic biopsy for prostate-specific antigen (PSA) recurrence after radical prostatectomy could be predicted by either PSA, PSA velocity, digital rectal examination (DRE), transrectal ultrasound (TRUS), or the interval from prostatectomy to biopsy. METHODS: TRUS with biopsy of the anastomosis was performed for 91 postprostatectomy patients who had either an abnormal DRE or detectable PSA (greater than 0.2 ng/mL). The biopsy results were correlated with the findings of DRE, TRUS, PSA, PSA velocity, interval to PSA recurrence, and with the pathologic stage. RESULTS: Of 131 examinations, there were 50 positive biopsy specimens for a detection rate of 38%. Of 34 patients with PSA 1.0 ng/mL or less, 8 (24%) had positive biopsy (P = 0.02). A negative DRE lowered (but did not eliminate) the probability of a positive biopsy. Of 100 patients with normal DRE, 28 (28%) had positive biopsy. None of the 11 patients with a negative DRE and a PSA of 0.5 ng/mL or less had a positive biopsy (P = 0.02). The mean interval between prostatectomy and biopsy was significantly greater in patients who had a positive biopsy (45 +/- 39) than in patients with a negative biopsy (27 +/- 21) (P = 0.001). The pathologic stage, Gleason score, and PSA velocity were not helpful in predicting the results of biopsy. CONCLUSIONS: Although patients with a negative DRE can have a positive biopsy and patients with a PSA of 1.0 ng/mL or less can have a positive biopsy, no patient with a negative DRE and a PSA of 0.5 ng/mL or less has a positive biopsy.
Ultrasound findings are not useful for defining stage T1c prostate cancer.
The management of stage T1c prostate cancer is identical to that of stage T2 prostate cancer. The treatment of a cancer detected by an elevated PSA level depends primarily on the age and health of the patient, on his preferences for treatment, and on the manner in which the physician presents the options. The distinction between PSA-detected tumors that are visible on ultrasound and PSA-detected tumors that are invisible on ultrasound is not clinically useful.
Comparison of four automated prostate-specific antigen assays for detection of recurrence after radical prostatectomy.
OBJECTIVES: To compare four assays-the Abbott IMx, the Tosoh, the Chiron ACS PSA, and the Chiron ACS PSA2-in their ability to detect prostate-specific antigen (PSA) after radical prostatectomy. METHODS: Serum samples were drawn on all men who had had a previous radical prostatectomy and who were seen in the urology clinic in March 1995. The results of each assay were compared using linear regression. RESULTS: Twenty-two patients had an undetectable PSA by the IMx assay. The PSA was over the residual cancer detection limit (RCDL) of the Tosoh assay in 5 of these patients. The PSA was over the RCDL of the ACS PSA assay in 15 of these patients and over the RCDL of the PSA2 assay in 2 patients. There were no patients whose PSA was less than the RCDL of the ACS PSA assay who had a measurable PSA level by any of the other assays. CONCLUSIONS: There is a difference among PSA assays in their ability to detect low levels of PSA after radical prostatectomy. The ACS PSA assay is the most sensitive, and the IMx assay is the least sensitive.
[Psychiatric admissions in Amsterdam according to ethnic background and diagnosis].
OBJECTIVE: To determine whether patients from ethnic groups in Amsterdam are admitted to psychiatric institutes more often than Dutch natives. DESIGN: Descriptive. SETTING: Amsterdam, The Netherlands METHOD: Admission incidences were calculated from the Amsterdam registry of admissions to psychiatric institutions, 1992-1993, and the country of birth was determined. Only first-generation migrants were studied. RESULTS: Patients from most ethnic groups were not admitted more frequently than Dutch natives. Only people from non-industrialized countries were more often admitted. Schizophrenia was diagnosed significantly more often in Surinam men (a factor 2) than in Dutch natives, among Turkish men the diagnosis was less frequent. CONCLUSION: Earlier findings of two-to-five-fold increased incidence of schizophrenia in first-generation migrants from Surinam, The Netherlands Antilles and Morocco, were in Amsterdam only partly confirmed.
The effects of corticotropin and growth hormone releasing hormones on their respective secretory axes in chronic hemodialysis patients before and after correction of anemia with recombinant human erythropoietin.
Endocrine abnormalities in chronic hemodialysis patients are in part corrected by control of anemia with recombinant human erythropoietin (rHu-EPO). We further examined the role of rHu-EPO in select hormonal abnormalities thought to be anemia related as well as the GH-insulin-like growth factor 1 (GH-IGF-1) axis that is abnormal in hemodialysis patients. We studied responses to the administration of two hypothalamic hormones, GHRH and ovine corticotropin-releasing hormone (CRH), in five anemic male patients on chronic hemodialysis before and after correction of the anemia with rHu-EPO. For comparison, five age-matched normal male volunteers were tested once. Anemic patients on chronic hemodialysis had high basal GH concentrations, an exaggerated GH response to exogenous GHRH, increased levels of IGF-1, and elevated levels of IGF-1 binding protein-3 in comparison to controls. ACTH response to CRH was comparable in dialysis patients and normal controls, but the cortisol response to endogenous ACTH release was prolonged. The cortisol binding globulin was similar to the controls. After correction of anemia, the basal elevation of GH was no longer present, but the exaggerated response of GH to exogenous GHRH persisted. IGF-1 and IGF-1 binding protein-3 levels remained elevated. The ACTH response to CRH, which was normal before correction of the anemia, became exaggerated in terms of elevated levels. Nevertheless, the prolonged cortisol response persisted. It appears that correction of the anemia in hemodialysis patients with rHu-EPO can partly correct perturbations in the GH secretory axis but may lead to new abnormalities in the CRH-ACTH axis.
The development of a simple fecal immunoreactive progestin assay to monitor reproductive function in swine.
The objectives of the study were to (a) develop a simple fecal progestin extraction and radioimmunoassay method to measure immunoreactive progestin in porcine feces and (b) to characterize fecal progestin profiles during the estrous cycle and postpartum. A simple extraction method was developed in trial 1 and the mean (+/- SD) progestin recovery of the method was 84.3 +/- 3.5%. Progesterone levels measured at five different spiked concentrations (50, 100, 200, 400, and 500 ng/0.5 g feces) showed no systematic error. The sensitivity of the assay was 0.16 nmol/L of the extract. Trial 2 involved collecting fecal samples from six cycling sows every second or third day, beginning on the day of estrus (day 0) and continuing until day 22. The mean (+/- SD) fecal progestin concentrations of these sows determined by the above assay during days 0-5, days 6-10, days 11-15, and days 16-21 were 87.1 +/- 17.5, 262.6 +/- 102.1, 1188.2 +/- 454.1, and 897.3 +/- 274.1 x 10(-3) nmol/g feces, respectively. In trial 3, fecal samples from six postpartum sows were collected at weekly intervals beginning from day 7 after farrowing until day 50. The mean (+/- SD) fecal progestin concentrations were 111.0 +/- 61.1, 74.1 +/- 21.3, 66.5 +/- 26.1, 122.7 +/- 58.8 and 533.5 +/- 244.2 x 10(-3) nmol/g feces, during days 7-10, days 11-20, days 21-30, days 31-40, and days 41-50 postpartum, respectively. The results indicate that simple fecal progestin extraction and assay are feasible alternatives to the standard blood progesterone assays for monitoring reproductive function in swine.
A simple technique for the measurement of fractal dimensions in histopathological specimens.
A computer program has been devised which enables a simple method for the fractal dimension analysis of histological or cytological material to be performed rapidly with relatively inexpensive hardware. The fractal dimension of a structure refers to its self-similarity over a range of scales and appears to be well suited to histopathological preparations. Thus, the fine 'roughness' of object profiles can be assessed more appropriately by this technique than by means of conventional Euclidean geometry. Images of the object(s) to be investigated are firstly digitized after presentation to a high-performance computer via a video camera or a graphics tablet system and then analysed using the computer program, which has its basis in a standard perimeter estimate method. It is proposed that such techniques may find extensive use in investigative and diagnostic histopathology.
Hypothalamo-hypophyseal thyroid and gonadal function before and after erythropoietin therapy in dialysis patients.
We examined the effects of administration of two hypothalamic neurohormones, TRH and GnRH, for 3 days in five anemic male dialysis patients and five age-matched normal male volunteers. Patients on chronic hemodialysis have abnormal hypothalamo-hypophyseal thyroid and gonadal functions, including blunted TSH response to TRH, hyperprolactinemia, elevated basal levels of LH with exaggerated response to GnRH, and depressed FSH secretory response to GnRH. After correction of anemia with exogenous erythropoietin, these dialysis patients were given a single injection of the same hypothalamic hormones. The repeat studies after the correction of anemia showed normalization of 1) the TSH response to TRH, 2) basal GH and PRL levels, and 3) the FSH response to GnRH. Although these patients appear to have biochemical evidence of testicular failure, the gonadotropin response (FSH) to GnRH was not exaggerated. In addition, there was no increase in total T4 and free T4 after TRH administration. Although a free T3 response to TRH was present, it was remarkably blunted compared to that of controls. At the present time, it is not known whether these hormonal responses after the correction of anemia are due to better oxygenation or a trophic action of the erythropoietin.
ABO(H) antigens and beta-2 microglobulin in transitional cell carcinoma. Predictors of response to intravesical bacillus Calmette-Guerin.
The response of patients with superficial transitional cell carcinoma of the bladder (STCB) to intravesical chemotherapy is variable; some patients enjoy a long period without recurrence, whereas others have recurrence of tumor within 2 years of removal of the primary lesion. Previously, others have demonstrated that the loss of normal cell surface antigens, such as ABO(H) blood group antigens or beta-2 microglobulin (B2M) has been correlated with more aggressive behavior by tumor. In this study, using immunohistochemical techniques, the authors evaluated the initial pretreatment biopsy specimen of bladder tumors for the presence of ABO(H) antigens and B2M. Data from this sample patient population, all with biopsy-proven STCB, indicate that expression of these two markers is predictive of a therapeutic response to prophylactic intravesical bacillus Calmette-Guerin (BCG) (Tice strain) after resection, and that expression of the two markers is of greater predictive value than expression of either antigen alone.
Antiemetic prophylaxis for chemotherapy using flunitrazepam and antiemetics.
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