SUNScholar - Browsing by Author "Van Zyl, J. A."

Browsing by Author "Van Zyl, J. A."

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'n Analise van sitogenetiese studies op 2 334 pasiente
(HMPG, 1979-06) Retief, A. E.; Kotze, G. M.; Fox, M. F.; Venter, P. A.; Van Zyl, J. A.; Van Niekerk, W. A.
The chromosome results of a series of 2 334 patients referred for cytogenetic analysis during 1966-1977 were tabulated by computer. The patients were grouped according to indications for referral, the main indications being amenorrhoea, congenital abnormalities, infertility and sex abnormalities. Among the patients with amenorrhoea, the largest percentage of chromosome abnormalities (28%) occurred in the group of 86 cases of primary amenorrhoea, whereas the percentage of chromosome abnormalities in the group of 113 secondary amenorrhoea patients was only 3.5. Of 615 patients with congenital abnormalities, 345 were referred for Down syndrome, of whom 64.6% had an abnormal chromosome constitution with extra chromosome 21 material. In the remainder of patients with chromosome abnormalities, trisomy 13 and trisomy 18 featured, although not all were referred as clearcut cases of Patau's or Edward's syndrome, the respective corresponding phenotypes. The incidence of chromosome abnormalities among patients with congenital abnormalities not typical of the above mentioned three syndromes was low (8.4%), with diverse chromosome constitutions. Among the infertile patients, 70 had azoospermia and 185 had oligozoospermia. The incidence of chromosome abnormalities within the two groups was 11.4% and 8.1% respectively. Of the 233 patients referred with sex abormalities, the highest proportion of chromosome abnormalities was found among those with Turner's and Klinefelter's syndromes. In these two classes 10 patients had a 45,XO or abnormal X chromosome constitution and 6 had 47,XXY karyotypes respectively. Another group of cases was classed among miscellaneous indications for referral. Of 61 amniotic fluid samples for prenatal diagnosis, there were 2 cases of trisomy 21. Of 154 male and female patients with a history of repeated miscarriages, 2.6% had chromosome abnormalities. Of a group of 62 patients with myelo- and lymphoproliferative disorders whose blood and/or bone marrow samples were included, 7 had chromosome abnormalities. Among 61 mentally retarded patients referred, 3 had mosaic chromosome constitutions. In every case a normal cell line was present. No chromosome abnormalities were found in 23 patients with retarded growth. 88 spontaneous and 19 ectopic abortusses showed 10.5% and 10.2% chromosome abnormalities respectively. Relatives of the original index patients were found to have chromosome abnormalities in 7.3% of cases, in most instances a rearrangement corresponding to that of the index patient. The significance of the observed abnormalities in this group of 2 334 individuals, when pooled, is discussed. The distribution of the chromosome abnormalities was 81% autosomal (largely as a result of chromosome 21) and 19% sex chromosomal. Additionally, 80% of all abnormalities were numerical and 20% were structural chromosome abnormalities in both autosomes and sex chromosomes.
Breast-conserving treatment for stage I and II cancer: tumours excision, axillary dissection, peri-operative interstitial irradiation, with or without peri-operative chemotherapy, followed by breast irradiation - the Tygerberg Hospital experience
(Health & Medical Publishing Group, 1989) Van Zyl, J. A.; Muller, A. G. S.
Since 1984 breast-conserving treatment has been the treatment of choice for patients at Tygerberg Hospital with early breast cancer. Peri-operative interstitial brachytherapy in breast cancer is described in detail. In the 221 patients treated (225 breasts), 197 breasts received iridium implants and 26 patients received peri-operative chemotherapy (POPFAC). There were 6 recurrences in treated breasts, 3 within the booster area and 3 outside. There were 5 salvage mastectomies, and 1 patient was treated by excision and radiotherapy. Metastases developed in 27 patients. Two patients underwent mastectomy for severe radiation changes and 7 developed postoperative wound infection after POPFAC. Five patients, who had re-excisions and prolonged seroma formation, developed delayed wound infection after POPFAC. Five patients, who had re-excisions and prolonged seroma formation, developed delayed wound infection. The importance of mammography, patient selection, tumour-free margins and radiation dosage are discussed.
Extracranial internal carotid artery aneurysm : a case report
(Health & Medical Publishing Group, 1984) Du Toit, D. F.; Van Zyl, J. A.; Laker, L.; Groenewald, J. H.
A patient with an asymptomatic, right-sided internal carotid artery aneurysm is reported. The entity was accurately located and diagnosed pre-operatively by utilizing a duplex ultrasonographic scanner. Treatment comprised aneurysmectomy and restoration of arterial continuity by autogenous venous grafting. The patient recovered without the occurrence of any sequelae.
n Fisiologiese studie van vier Suid-Afrikaanse gisrasse met betrekking tot vlugtige suur- en alkoholvorming
(Stellenbosch : Stellenbosch University, 1954) Van Zyl, J. A.; Stellenbosch University. Faculty of AgriSciences. Dept. of Viticulture and Oenology and Institute for Wine Biotechnology.
No Abstract Available
Hemangiosarkoom van die bors : 'n gevallestudie en oorsig van die literatuur
(Health and Medical Publishing Group (HMPG), 1975) Van Zyl, J. A.; Van der Walt, J. J.; Van Zyl, J. J. W.
In this case of angiosarcoma of the breast in a 55 yr old woman, the time from treatment to death was 41 mth, compared with 25 mth in collected cases from the literature. The possible value of adjuvant chemotherapy is recalled. In this case Endoxan (cyclophosphamide) was tried in a dosage of 10 mg/kg body weight i.v.
The infertile couple. Part I. Schedule of management
(Health & Medical Publishing Group, 1980) Van Zyl, J. A.
The regimen for the management of couples who complain of infertility is presented as it is practised at Tygerberg Hospital. The doctor-patient relationship, the importance of the patient's comprehension of the specific treatment regimen and why it should be adhered to are stressed. Special investigations are discussed and certain pitfalls in the management of infertile couples are pointed out. Controversy still exists with regard to many aspects of the management. Decisions about when to start with infertility investigations, whom the couple should consult, whether they should be examined as a couple or separately, and how long they should receive treatment are dealt with.
The infertile couple. Part II. Examination and evaluation of semen
(Health & Medical Publishing Group, 1980) Van Zyl, J. A.
Most laboratories in South Africa have their own methods for examining and evaluating semen. This situation contributes towards conditions unfair to patients and undesirable for physicians dealing with infertility. The technique of obtaining semen specimens for examination is described. All tests that should be done as a routine and according to international standards, as carried out at Tygerberg Hospital, are described, with special reference to pitfalls in the examination and evaluation of semen. An urgent plea to maintain international methods, standards and terminology and for adequate specific training of technologists in the field of andrology is made.
Results of phase I of the in vitro fertilization and embryo transfer programme at Tygerberg Hospital
(Health and Medical Publishing Group (HMPG), 1985-05) Kruger, T. F.; Van Schouwenburg, J. A. M. H.; Stander, F. S. H.; Van den Heever, A. D.; Van Zyl, J. A.; Menkveld, R.; Kopper, K.; De Villiers, A.; Conradie, E.; Odendaal, H. J.; De Villiers, J. N.
Phase I (3 June - 31 October 1983) of the in vitro fertilization (IVF) programme at Tygerberg Hospital is outlined in this article. This programme led to the birth of the first IVF baby in South Africa after fertilization and embryo transfer (ET) took place at this institution. The baby was born on 29 April 1984; a second baby was born on 20 June 1984. During phase I 24 laparoscopies were performed; 32 oocytes were obtained from 56 follicles, of which 62.5% were fertilized. Eleven ETs were performed, which led to 3 pregnancies. An ongoing pregnancy rate of 18% per ET and a pregnancy rate of 12,5% per laparoscopy were achieved.
Results of the in vitro fertilization programme at Tygerberg Hospital, phases II and III
(Health & Medical Publishing Group, 1986-03) Kruger, T. F.; Van der Merwe, J. P.; Stander, F. S. H.; Menkveld, R.; Van den Heever, A. D.; Kopper, K.; Odendaal, H. J.; Van Zyl, J. A.; De Villiers, J. N.
Phases II and III of the human in vitro fertilization programme at Tygerberg Hospital are presented. In phase II, 42 laparoscopies were performed and oocytes were obtained from 76% of the follicles aspirated, but with a fertilization rate of only 37%. The viable pregnancy rate per embryo transfer was 4%. Important changes took place in the programme, which led to a fertilization rate of 77% in phase III. Of the 78 patients subjected to laparoscopy, 65 (83%) reached the embryo transfer stage, resulting in a clinical pregnancy rate per embryo transfer of 23%, and with a 19% pregnancy rate per laparoscopy. The changes, methods and results of phases II and III are discussed.
'n Vergelykende studie van die witselpipet- en Makler-telkamermetodes vir die tel van spermatosoa
(Health and Medical Publishing Group (HMPG), 1980-10) Menkveld, R.; Van Zyl, J. A.; Stander, F. S. H.; Conradie, E.; Kopper, K.
A new method for counting spermatozoa was introduced by Makler. This method was compared with the white blood cell pipette method and the results revealed high precision and accuracy (difference of means = 5,9%). Makler's method, which is very simple to perform, has the advantage that rapid and reliable sperm counts can be done. Therefore, the Makler counting chamber can be used with confidence, in the performance of semen analysis by any doctor or in any laboratory.

Browsing by Author "Van Zyl, J. A."

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