Biomedical subjects

A Rademaker

Publications and source records attributed to A Rademaker.

At least 55 records · Page 3Linked to original sources

PubMed1995

Cladribine in the treatment of relapsed or refractory chronic lymphocytic leukemia.

PURPOSE: Cladribine (2-CdA), a purine analog resistant to adenosine deaminase, has significant activity in a variety of lymphoproliferative diseases. This study was designed to determine the efficacy of 2-CdA in patients with relapsed or refractory chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS: Twenty-six patients aged 40 to 88 years (median, 64) who either had relapsed after an initial response or were refractory to conventional chemotherapy with at least an alkylating agent were treated with 2-CdA 0.1 mg/kg/d by continuous intravenous infusion for either 5 or 7 days every 28 days for a maximum of six cycles. RESULTS: No complete remissions (CRs) occurred. Eight of 26 patients (31%) achieved a partial remission (PR). The actuarial median time to progression (TTF) in responding patients is 16 months (range, 6 to 22). The actuarial median survival duration of the responding patients is 12 months (range, 8 to 28). Eight of 26 patients (31%) sustained early toxicity. Seven of these eight patients died before the first reevaluation of infection (n = 3), pericardial tamponade (n = 1), Stevens-Johnson syndrome (n = 1), and stroke (n = 2). No nausea, emesis, alopecia, or renal, hepatic, or cardiac toxicity was observed. CONCLUSION: 2-CdA has activity in patients with relapsed or refractory CLL. However, patients who have received multiple prior regimens that included fludarabine are less likely to respond, and there can be significant morbidity. Treatment of patients with less prior therapy earlier in the natural history of the disease may lead to improved and more durable responses.

Actuarial Analysis↗

PubMed1995

Phase II study of all-trans-retinoic acid and alpha-interferon in patients with advanced non-small cell lung cancer.

Between April 1993 and June 1994, 29 patients (pts) with unresectable, locally advanced, or metastatic non-small cell lung cancer were treated with a combination of p.o. trans-retinoic acid (TRA), 150 mg/m2/day, in three divided doses and s.c. IFN-alpha, 3 x 10(6) units/day. The age range was 41-80 years (median, 63 years). The Eastern Cooperative Oncology Group performance status was 0-1 (24 pts) and 2 (5 pts). Pts had advanced disease, refractory to conventional therapy (5 stage IIIB and 24 stage IV). Twenty-one pts had adenocarcinoma, six had squamous cell carcinoma, and two had large cell carcinoma. Only 3 pts completed 8 weeks of treatment, requiring neither interruption nor dose modification. Fatigue occurred in 88% of pts. A syndrome complex consisting of dry oral and nasal mucosa, recurrent sinus infections, and epistaxis occurred in 64% of pts. Grade II/III dermatitis was seen in 52%. Severe scrotal dermatitis was seen in 7 pts (47% of 15 males). Hypertriglyceridemia was moderate/severe in 11 pts, and 3 pts required gemfibrozil for levels up to 1660 mg/dl. Hematological toxicity was not encountered, and none of the pts had leukocytosis. One pt died with complications of myocardial infarction while on TRA/IFN-alpha. Twenty-five pts had more than 2 weeks of treatment and are evaluable for response; two pts died early with complications of cancer, and two pts declined to continue after only 3 and 5 days of treatment. Final assessment of response was by accepted clinical and radiological criteria at 8 weeks. There have been four objective responses: complete response, 2 (18+ and 17 months) and partial response, 2 (7 and 14 months). Responses were observed in all histologies. Combined differentiation treatment with TRA/IFN-alpha has modest but objective activity in non-small cell lung cancer. Toxicity is considerable. Additional studies to elucidate the biological basis of TRA/IFN-alpha and to define prognostic parameters predicting response are needed.

Adenocarcinoma↗

PubMed1994

Persistence of carcinogen-altered cell population in rat urothelium which can be promoted to tumors by chronic inflammatory stimulus.

Chronic inflammation of the urinary tract is a significant risk factor for the development of urinary bladder cancer in man. Previously we have shown that acute and chronic inflammation induced by repeated intravesical instillation of killed Escherichia coli (KEC) strikingly enhanced N-methyl-N-nitrosourea (MNU)-initiated bladder carcinogenesis in our heterotopically transplanted rat urinary bladder model. We conducted the present study to determine whether delayed onset of KEC treatment can still enhance carcinogenesis of the MNU-initiated urothelium and whether continuous KEC treatment is necessary for the development of tumors. After the initiation of carcinogenesis in heterotopically transplanted bladders by the instillation of a single dose (0.25 mg) of MNU, animals were divided into several groups, for which weekly KEC treatment (5 x 10(8) cells suspended in 0.5 ml of phosphate-buffered 2.1% NaCl solution) was begun 1, 5, and 18 weeks later and continued until termination of the experiment at 31 weeks. In addition, animals received 4-week KEC treatment, which was started 1 or 5 weeks after MNU administration. Treatment with KEC alone or MNU alone induced few tumors. Maximal tumor development was demonstrated in the group receiving KEC treatment continuously throughout the experimental period. Delaying the onset of continuous KEC treatment by 4 weeks resulted in a significant decrease in the number of tumors (P = 0.006). However, a substantial number of tumors were induced even when KEC treatment was delayed as many as 18 weeks, as compared to tumor development in the group receiving MNU only (P = 0.007). The tumor volume (size) was not different between continuous and short-term KEC treatment groups. We conclude that (a) although a large number of cells undergo promutagenic DNA damage by a single dose of MNU, the amounts are reduced quickly during the subsequent 4 weeks; but that (b) a substantial number of genetically altered cells remain for a long time and can be promoted to tumors when stimulated by a chronic inflammatory stimulus; and that (c) the duration of KEC treatment determines the number, but not the volume, of tumors.

Animals↗

PubMed1994

Touch preparation cytological evaluation of radical prostatectomy specimens.

The failure of current histological techniques to predict local failure and disease progression after radical prostatectomy is supported by substantial evidence. Moreover, the characterization of histological findings is hampered by the lack of uniform interpretation. We report a prospective study of 92 patients undergoing radical prostatectomy for clinical stages A and B prostate cancer in which the technique of touch preparation cytological analysis of surgical margins is compared to the standard histological approach. We evaluated 47 pathological stage B, 43 stage C and 2 stage D specimens. Specimens initially assigned to pathological stage B were upstaged to stage C on review by 1 blinded pathologist in 19 of 65 cases (29%). Overall, 15 of 47 histological stage B specimens (32%), 20 of 43 histological stage C specimens (47%) and 2 of 2 histological stage D specimens (100%) had malignant cells identified on the margins by touch preparation cytology. Postoperative mean followup of 7 months (range 0.4 to 26) revealed that 7 of 14 nonstage D cancer patients (50%) with elevated serum prostate specific antigen levels had positive cytology results, including 1 with histologically confirmed organ-confined disease. Among the stage C specimens cytology was more likely to be positive if there was concomitant seminal vesicle invasion. Correlation of this information with eventual patient course during the long term will be necessary to assess its role in patient management.

Aged↗

PubMed1994

Growth of the rat prostate gland is facilitated by the autonomic nervous system.

Many factors are implicated in the development of prostatic growth: androgens, growth factors, and stromo-epithelial interaction. This study examines the role of the sympathetic and parasympathetic branches of the autonomic nervous system control of different aspects of rat prostate growth and atrophy. Unilateral sympathectomy leads to decreases in ventral prostate weight, DNA, and protein content in the lesioned side. Unilateral parasympathectomy leads to increases in ventral prostate weight, DNA, and protein content in the intact side. The separate effects of sympathectomy and parasympathectomy are maintained across a diverse combination of neural manipulations. Significant re-innervation does not occur by 60 days after manipulation as assessed by tissue norepinephrine levels. There appears to be a differential effect of the autonomic nervous system on growth and maintenance of the ventral prostate. The mechanism of contralateral hyperplasia and ipsilateral atrophy has potential significance in understanding human abnormal prostate growth.

Animals↗

PubMed1994

Treatment tolerance of elderly cancer patients entered onto phase II clinical trials: an Illinois Cancer Center study.

PURPOSE: Past research that has compared cancer treatment tolerance between elderly and nonelderly cancer patients has been contradictory. Some investigators concluded that there is no difference between the groups, while others demonstrated elderly patients experienced less tolerance to treatment. As a result, some physicians discriminate against elderly cancer patients by not entering them onto clinical trials out of a belief that they will not tolerate the therapy. METHODS: An analysis was performed using the Illinois Cancer Center (ICC) data base, which contains treatment information for all patients registered onto phase II trials. A maximum of 672 cases was available for evaluation of 11 treatment-related variables. RESULTS: The results demonstrated no significant differences between elderly and nonelderly patients for the following seven treatment-related variables: performance status (PS), number of dose reductions, number of treatment interruptions, total days of delay, best response, reason off-study, and number of grade 3 or greater toxicities. Minor differences were detected for number of courses and number of dose escalations. CONCLUSION: Based on these results, elderly patients should not be denied access to cancer clinical trials relative to age alone.

Aged↗

PubMed1994

Chromosomal breakage in human spermatozoa, a heterozygous effect of the Bloom syndrome mutation.

The chromosome complements of 662 spermatozoa produced by the three fathers of individuals with Bloom syndrome (BS) were analyzed to determine whether the BS mutation could affect chromosome segregation and the frequency of aneuploidy in sperm. The frequency of numerical abnormalities was not significantly different from that in normal controls studied in our laboratory, but the frequencies of structural abnormalities were significantly increased in two of the men, 14.3% and 15.9%, versus 8.6% in controls. More striking was the increase in these two men of cells with multiple structural abnormalities: 8.1% and 6.7% with multiple abnormalities, versus 2.3% in controls.

Abnormalities, Multiple↗

PubMed1993

Enhancement of rat urinary bladder tumorigenesis by lipopolysaccharide-induced inflammation.

Chronic inflammation of the urinary tract is a significant risk factor for the development of urinary bladder cancer in humans. We previously demonstrated that weekly treatment with killed Escherichia coli enhanced rat urinary bladder tumorigenesis initiated by the carcinogen N-methyl-N-nitrosourea. We conducted the present study to determine whether lipopolysaccharide (LPS), a major cell wall component of E. coli, had a tumor-enhancing effect. LPS was instilled twice a week at three doses (100, 1.0, and 0.01 microgram/ml) into heterotopically transplanted rat urinary bladders which were treated with a single low dose (0.25 mg) of N-methyl-N-nitrosourea or vehicle. Rats treated with 100 micrograms/ml of LPS showed a significant increase in the incidence and number of tumors in the bladders pretreated with N-methyl-N-nitrosourea. Treatment with LPS alone did not induce tumors. The enhancing effects were associated with a marked increase in the numbers of polymorphonuclear leukocytes and an increase in the H2O2 concentration in the bladder lumen. Oxidative stress by reactive oxygen intermediates and a proliferative response of the carcinogen-exposed urothelium to the inflammatory stimulation appeared to play a significant role in tumor enhancement by LPS.

Animals↗

PubMed1992

Marked enhancement of rat urinary bladder carcinogenesis by heat-killed Escherichia coli.

Chronic urinary tract infection is an important risk factor for the development of carcinoma in the human urinary bladder. To test the effect of chronic persistent inflammation on bladder carcinogenesis, we instilled heat-killed Escherichia coli (1 x 10(8) cells suspended in 0.5 ml of phosphate-buffered 2.1% NaCl solution) twice a week into the heterotopically transplanted rat urinary bladders in which carcinogenesis was initiated by a single dose (0.25 mg) of N-methyl-N-nitrosourea. When compared with the control animals, the rats treated with killed E. coli showed significantly enhanced bladder tumorigenesis, as reflected by an increase in the incidence of tumor (P = 0.05) and a 6- to 40-fold increase in the number of tumors per bladder (P less than 0.0001). The tumors were characterized by intraepithelial clusterings of neutrophils and by chronic inflammation and marked capillary proliferation in the tumor stroma. All of these features were rare in tumors in the control groups. The accelerated cell proliferation induced by killed E. coli treatment appears to play a significant role in the enhancement of tumorigenesis.

Administration, Intravesical↗

PubMed1992

Impact of the diagnostic procedure on outcome measures of swallowing rehabilitation in head and neck cancer patients.

This study was designed to determine whether swallow rehabilitation outcomes were affected by the type of evaluation procedure utilized by the clinician. The two evaluation techniques compared were the bedside examination and videofluoroscopy (the modified barium swallow). Ten institutions participated in this study, enrolling a total of 103 partial laryngectomized patients, 21 in the bedside arm and 82 in the videofluoroscopy arm. Data on recovery of oral intake were collected weekly. All patients received an X-ray study of swallow at 3 months after the operation. Mean time to oral intake of food was significantly lower in patients assessed with bedside examination. Overall swallow measures of transit times and swallow efficiencies after 3 months revealed significantly better function in the videofluoroscopy group. Results are discussed in terms of the visibility of swallow physiology with the two assessment techniques, the accuracy of therapy planning with the bedside examination versus videofluoroscopy and the ability of head and neck cancer patients to tolerate some aspiration without developing aspiration pneumonia.

Deglutition↗

PubMed1991

Tumor-promoting effect of urinary epidermal growth factor in rat urinary bladder carcinogenesis.

We previously demonstrated that the specific component of rat urine designated as Fraction I (Fr.I), which has been known to enhance carcinogenesis in the rat urinary bladder, contains epidermal growth factor (EGF) and transferrin (TF). The present study was designed to determine whether EGF or TF is responsible for the tumor-enhancing effect of Fr.I. The heterotopically transplanted rat urinary bladder (HTB), which has been developed in our laboratory, was used for the study. Fr.I was prepared from normal rat urine by a method published previously. Fr.I deficient in EGF or TF was prepared by passing this fraction through an Affi-Gel Hz column coupled with anti-rat EGF or TF antibodies, respectively. EGF and TF eluted from the column (designated as eluted EGF and eluted TF) were also tested for tumor-enhancing activity. Fr.I passed through the column coupled with nonimmune rabbit IgG served as control (Fr.I column control). After initiation of carcinogenesis in HTBs by instillation of a single dose of 0.25 mg of N-methyl-N-nitrosourea, test materials were administered into these HTBs once a week for 30 weeks. The results showed that removal of EGF significantly reduced the tumor-enhancing effect of Fr.I (P less than 0.001 as compared to that of the Fr.I column control) and that eluted EGF by itself significantly enhanced the carcinogenesis as compared to that of the vehicle control (P less than 0.006). Removal of TF from Fr.I also reduced the tumor-enhancing effect of Fr.I (P less than 0.01). However, removal of both EGF and TF from Fr.I did not enhance the inhibitory effect demonstrated by the Fr.I which was deficient in EGF. Likewise, combined use of TF and EGF did not exceed the tumor-promoting effect of EGF. The results indicate that EGF in Fr.I may play a significant role in the promotion of bladder carcinogenesis by urine.

Animals↗

PubMed1991

Distribution of aneuploidy in human gametes: comparison between human sperm and oocytes.

The frequency and distribution of aneuploidy was compared in 11,615 karyotyped human sperm and 772 karyotyped human oocytes to determine if all chromosomes are equally likely to be involved in aneuploid events or if some chromosomes are particularly susceptible to nondisjunction. The frequency of hypohaploidy and hyperhaploidy was compared among different chromosome groups and individual chromosomes for human sperm and oocytes. In general, hypohaploid chromosome complements were more frequent than hyperhaploid complements, in sperm and oocytes. The distribution of chromosome loss in the hypohaploid complements indicated that significantly fewer of the large chromosomes and significantly more of the small chromosomes were lost, suggesting that technical loss predominantly affects small chromosomes. A conservative estimate of aneuploidy (2 X hyperhaploidy) was approximately 3-4% in the human sperm and 18-19% in human oocytes. All chromosome groups were represented among hyperhaploid human sperm and oocytes. For human sperm, the observed frequency of hyperhaploidy equaled the expected frequency based on the assumption that the frequency of nondisjunction is equal for all chromosome groups, with two exceptions: group G and the sex chromosomes. Among individual chromosomes in human sperm, chromosomes 1 and 21 and the sex chromosomes had a significant excess of hyperhaploidy. For human oocytes, there were fewer hyperhaploid oocytes than expected for chromosome groups C and F and more than expected for chromosome groups D and G. Among individual chromosomes there was a significant excess for chromosome 21. These results indicate that all chromosomes are susceptible to nondisjunction but that chromosome 21 is particularly prone to aneuploidy in both human sperm and oocytes. They also demonstrate that sex chromosome aneuploidy is common in human sperm but not in human oocytes.

Aneuploidy↗

PubMed1991

Coronary artery bypass grafting within thirty days of acute myocardial infarction. Early and late results in 406 patients.

Between 1981 and 1987, 1726 coronary artery bypass operations were performed by a single group of surgeons at a community hospital. Overall hospital mortality in this group was 2.4% (41/1726). Of these patients 406 were operated on within 30 days of an acute myocardial infarction. The hospital mortality rate in this group was 6.7% (27/406) versus 1.1% (14/1320) in patients operated on without evidence of recent acute myocardial infarction (p less than 0.0001). In these 406 patients, sex, location of acute myocardial infarction, type of infarction, coronary anatomy, presence of postinfarction angina, technique of myocardial preservation, and the time from infarction to operation were not associated with hospital mortality. Univariate and multivariate analyses showed that three factors were significantly associated with increased hospital death: poor ejection fraction, less than 30% (p less than 0.0001), preoperative shock (p = 0.0005), and age greater than 70 years (p = 0.004). Follow-up was 90% complete (365/406 patients) at a mean time of 35 +/- 21 months. Of these patients 80% (292/365) were in New York Heart Association functional class I, and 10% (36/365) were in functional class II. Of all patients 88% were alive at 3 years, and 84% were alive at 5 years after operation. Multivariate comparison of survival curves showed that ejection fraction less than 30% was associated with decreased survival (p = 0.0002), followed by age (p = 0.0009). Patients younger than 70 years with an ejection fraction greater than 30% and not in cardiogenic shock can be operated on at any time after acute myocardial infarction without increased risk. Long-term survival and freedom from symptoms can be expected in these patients.

Adult↗

PubMed1990

Effect of culture conditions and media on the frequency of chromosomal abnormalities in human sperm chromosome complements.

Human sperm chromosomes can be visualized after fusion with hamster eggs. Most laboratories use one of two methods of sperm treatment for capacitation: incubation in a modified Krebs-Ringer medium (BWW) for 5-7 h at 37 degrees C or storage in a TES-Tris yolk buffer (TYB) for 24-72 h at 4 degrees C. To determine whether data from the two methods were comparable, we performed a series of controlled experiments on one normal donor in which ejaculates were split and one aliquot of sperm was capacitated in BWW for 5-7 h at 37 degrees C (fresh) and the second aliquot was capacitated in TYB for 48 h at 4 degrees C (TYB). After capacitation, the technique used to obtain human sperm chromosome complements was identical for both aliquots. Both fresh and TYB sperm were further subdivided into two groups, which were subjected to either a short (1 h) or a long (3 h) gamete coincubation in BWW. This experiment was performed to determine if the longer incubation in BWW might induce chromosomal fragile sites and breaks because of nutritional depletion of the medium. A total of 458 human sperm chromosome complements was analysed. There was no significant difference in the frequency of sperm chromosomal abnormalities or in the sex ratio in the sperm coincubated with eggs for a short (1 h) or long (3 h) time in BWW. When sperm pretreatments were compared, there was a significant increase in the frequency of total sperm chromosomal abnormalities after TYB storage compared to fresh treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Stimulation of urinary bladder tumorigenesis by carcinogen-exposed stroma.

There is evidence to suggest that control mechanisms, either growth-stimulatory, inhibitory or inductive, may play a role in carcinogenesis. To test the hypothesis that treatment of rat urinary bladder with carcinogen induces alterations in the stroma which result in modified epithelial-stromal interactions, experiments were conducted using a rat model specifically designed for the study. Following exposure of Fischer F344 rats in drinking water to the urinary bladder carcinogen, N-butyl-N-(4-hydroxybutyl)nitrosamine (BHBN) for four weeks, bladders were removed and subjected to a brief detergent treatment to completely remove epithelium. The bladders without epithelium ("stroma" bladder) were heterotopically transplanted to syngeneic recipients. Four days later, the denuded mucosa surface was resurfaced with intraluminal instillation of urothelial cells, either untreated or treated with BHBN for six weeks (6w-BHBN) or 10 weeks (10w-BHBN). Examination at 12 weeks posttransplant of the "stroma" bladders that had received 6w-BHBN urothelial cells showed a higher tumor incidence of carcinoma in the BHBN-exposed "stroma" bladders as compared with the incidence in the carcinogen-unexposed "stroma" bladders (p less than 0.05). Examination at 18 weeks posttransplant showed 100% incidence of tumors in all "stroma" bladders irrespective of the lengths of BHBN exposure of urothelial cells. However, among the bladders that had received 6w-BHBN urothelial cells, carcinogen-exposed "stroma" bladders proved to be better "soil" for neoplastic cells to proliferate; the mean tumor volume as well as the mean total tumor volume per bladder were significantly higher than in the control "stroma" bladders (p less than 0.01 for each comparison). Similarly, among the bladders that had been resurfaced with 10w-BHBN urothelial cells, the mean total tumor volume per bladder was greater in the carcinogen-treated "stroma" bladders than in the controls (p less than 0.05). No proliferative or neoplastic changes were observed in the BHBN exposed "stroma" bladders which had been resurfaced with normal urothelial cells. Our data indicate that neoplastic growth of carcinogen treated urothelium is enhanced when such cells interact with the stroma which has also been exposed to carcinogen.

Animals↗

PubMed1990

The frequency of aneuploidy among individual chromosomes in 6,821 human sperm chromosome complements.

The human sperm/hamster egg fusion technique has been used to analyse 6,821 human sperm chromosome complements from 98 men to determine if all chromosomes are equally likely to be involved in aneuploid events or if some chromosomes are particularly susceptible to nondisjunction. The frequency of hypohaploidy and hyperhaploidy was compared among different chromosome groups and individual chromosomes. In general, hypohaploid sperm complements were more frequent than hyperhaploid complements. The distribution of chromosome loss in the hypohaploid complements indicated that significantly fewer of the large chromosomes and significantly more of the small chromosomes were lost, suggesting that technical loss predominantly affects small chromosomes. Among the autosomes, the observed frequency of hyperhaploid sperm equalled the expected frequency (assuming an equal frequency of nondisjunction for all chromosomes) for all chromosome groups. Among individual autosomes, only chromosome 9 showed an increased frequency of hyperhaploidy. The sex chromosomes also showed a significant increase in the frequency of hyperhaploidy. These results are consistent with studies of spontaneous abortions and liveborns demonstrating that aneuploidy for the sex chromosomes is caused by paternal meiotic error more commonly than aneuploidy for the autosomes.

Aneuploidy↗

PubMed1989

Inhibitory action of alpha-difluoromethylornithine on N-butyl-N-(4-hydroxybutyl)nitrosamine-induced rat urinary bladder carcinogenesis.

We previously have shown that urine components capable of stimulating ornithine decarboxylase activity of urothelium can enhance rat urinary bladder carcinogenesis, and that alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, suppresses carcinogen-initiated rat urinary bladder carcinogenesis. The present investigation was conducted to determine whether DFMO's suppressive effect is stage specific during carcinogenesis and whether the suppressive effect lasts with its continued use. Following initiation with 0.05% N-butyl-N-(4-hydroxybutyl)-nitrosamine in drinking water for 6 wk, male Fischer 344 rats initially weighing 125 to 150 g were randomly divided into two groups, the first receiving 0.2% DFMO in drinking water ad libitum and the second receiving tap water only. Groups of animals were killed at regular intervals until the completion of the experiment at 75 wk. The effect of DFMO was evaluated by monitoring the incidence of tumors, the mean number of tumors per rat, the mean volume of individual tumors, and the mean total tumor volume per rat. The results showed that continuous treatment with DFMO significantly reduced tumor formation until 60 wk (P less than 0.017). The effect was only of borderline significance (0.017 less than P less than 0.035) at 75 wk. Discontinuation of DFMO treatment at 40 wk resulted in the loss of protective effect in all comparisons except for the borderline effect on the tumor number and total tumor volume per rat. DFMO had no significant effect on the incidence or development of preneoplastic early lesions. Mucosal polyamine (spermidine and spermine) levels were reduced and correlated well with the reduction in tumor growth, suggesting that the reduction in tumor growth rate by DFMO may be due to its ability to reduce polyamine levels in urothelium. There were no side effects attributable to DFMO treatment. DFMO may be a useful chemopreventive agent to retard the recurrence of human superficial bladder cancer.

Animals↗

PubMed1989

A comparison of chromosomal aberrations induced by in vivo radiotherapy in human sperm and lymphocytes.

Chromosomal aberrations in human sperm and lymphocytes were compared before and after in vivo radiation treatment of 13 cancer patients. The times of analyses after radiotherapy (RT) were 1, 3, 12, 24, 36, 48 and 60 months. The median total radiation dose was 30 Gy and the testicular dose varied from 0.4 to 5.0 Gy. Human sperm chromosome complements were analysed after fusion with golden hamster eggs. There were no abnormalities in sperm or lymphocytes before RT. Following RT there was an increase in the frequency of numerical and structural chromosomal abnormalities in both lymphocytes and sperm. For structural abnormalities there were more rejoined lesions (dicentrics, rings) in lymphocytes and more unrejoined lesions (chromosome breaks, fragments) in sperm. After RT there was a dramatic increase in the frequency of chromosomal abnormalities in lymphocytes: at 1 mo. the frequency was 42%, at 3 mo. 25%, at 12 mo. 14%, at 24 mo. 11%, at 36 mo. 9%, at 48 mo. 7% and at 6 mo. 4%. Since the majority of men were azoospermic after RT, there is little data on sperm chromosome complements before the analyses performed at 24 mo. post-RT. At 24 mo. the frequency of abnormalities was 13%, followed by 21% at 36 mo., 12% at 48 mo. and 22% at 60 mo. Thus it appears that the frequency of lymphocyte chromosomal abnormalities had an initial marked increase after RT followed by a gradual decrease with time whereas the frequency of sperm chromosomal abnormalities was elevated when sperm production recovered and remained elevated from 24 to 60 mo. post-RT. This difference in the effect of time makes it very difficult to compare abnormality rates in lymphocytes and sperm and to use analysis of induced damage in somatic cells as surrogates for germ cells since the ratio between sperm and lymphocytes varied from 1:1 (at 24 mo. post-RT) to 5:1 (at 60 mo. post-RT).

Adult↗