- Email: [email protected]
In-vitro culture of testicular sperm
La Dou J. Occupational medicine. Englewood Cliffs, New Jersey: Prentice Hall, 1990: 297. 3 Centers for Disease Control and Prevention. Preventing lead poisoning in young children: a statement by the Centers for Disease Control and Prevention, 1991. US Department of Health and Human Services. 4 Norman EH, Bordley WC. Lead toxicity intervention in children. J R Soc Med 1995; 88: 121-24. 2
modified to allow for the detection of genetic diseases such as FH.
problem. *Ian Craft, Marinos London Gynaecology and London W1N 1AF, UK
Tsirigotis,
J J Zhu
Fertility Centre Limited, 112A Harley Street,
Screening for familial hypercholesterolaemia in relatives SIR-In Norway, three founder mutations in the low-densitylipoprotein (LDL) receptor gene have been shown to cause up to one-half of clinic cases of familial hypercholesterolaemia (FH).’ Screening for FH in the general population is inefficient, owing to the relatively low prevalence of the disease (about 1 in 300 in Norway). However, the probability of FH, given an elevated cholesterol, increases substantially once a family member with FH is identified. Currently, index cases with FH in Norway are asked to inform other family members about the diagnosis and need for screening. Privacy laws do not permit physicians to contact relatives who are not their patients directly. We included questions to determine the attitude of the public towards screening for FH in a survey conducted in Oslo, Norway. The 1033 respondents were representative of the population over age 15 with regard to age, sex, and income. They were asked: "Your relative has been told by his physician that he has hereditary high cholesterol that, if premature cardiovascular disease or death. Treatment consists of following a diet and taking medication daily. Would you be intersted in knowing whether you have inherited high cholesterol?" If the answer was "Yes" the respondent was asked: "How would you prefer to be told that you may have hereditary high cholesterol: through your relative’s physician directly or should the physician ask your relative to inform you?" 77% answered "yes" to the first question and of these 74% wished to be informed by the physician directly. Other diseases, which are not as treatable as FH, would probably elicit a different response. Privacy laws should probably be not
1438
treated,
may
cause
treatable
*Serena Tonstad, Lars-Erik Vollebaek, Leiv Ose Lipid Clinic, Rikshospitalet, N-0027 Oslo, Norway 1
In-vitro culture of testicular sperm SIR—We have researched the best way to recover and prepare sperm from samples of testicular tissue (TESA) obtained by needle aspiration, rather than open biopsy. We usually place a tissue extract directly into a droplet of invitro fertilisation culture medium under oil with retrieval of motile/twitching sperm observed under a microscope with microinjection apparatus for subsequent intracytoplasmic sperm injection (ICSI). Motile sperm may be recovered from the periphery of the droplet at the interface between the instillate and surrounding culture medium. However, some samples may not exhibit any motility at all making a decision to perform ICSI with totally immotile sperm of doubtful viability a dilemma. We recently left culture dishes containing the instillates to incubate at 37°C for 24-72 h and have been surprised to find a pronounced increase in the number of progressively motile sperm with time in many instances. The activity has generally been greatest between 48 and 72 h and sometimes so marked that it is difficult to believe that the sperm have "come to life" to such an extent. We feel this unexpected finding could potentially improve the fertility prospects for those with a profound male factor
eminently
2
Leren TP, Solberg K, Rødningen OK, Tonstad S, Ose L. Two founder mutations in the LDL receptor gene in Norwegian familial hypercholesterolemia subjects. Atherosclerosis 1994; 111: 175-82. Williams RR, Schumacher C, Barlow GK, et al. Documented need for more effective diagnosis and treatment of familial hypercholesterolemia according to data from 502 heterozygotes in Utah. Am J Cardiol 1993; 72: 18D-24D.
Of worms and red
herrings
SiR-Finding a worm mixed with one’s bowel movement usually implies a parasitic infection, but not always. 1 week after returning from a trip to Aruba a previously healthy 37year-old physician noticed a live worm in the toilet after he had passed a semiformed stool. He denied weight loss, abdominal pain, or preceding diarrhoea, but did report walking barefoot in mud and eating undercooked meat while in the Caribbean. The worm, which was about 6 cm long, was light brown, round, and composed of multiple ring-like segments. Actively motile on removal from the toilet, it died several hours later, after transfer into a plastic dish containing a home-made saline solution. The worm was examined by two laboratories and identified as an oligochaete, most probably Lumbricus terrestes, but definitely a non-pathogenic earthworm. It is not clear how the earthworm got into the toilet. Earthworms are occasionally ingested by accident’ but they cannot survive transit through the human digestive tract.2 It is unlikely that the worm fell off the patient’s trousers since he had not recently been outdoors in them. The most plausible explanation is that the worm gained access to the toilet through a cracked pipe outside the patient’s house.2,3 In fact, on several occasions over the past decade, tree roots had grown into and obstructed its sewer line. This case illustrates some interesting issues in clinical problem solving. A representative heuristic (rule of thumb) guided the initial impression of a parasitic infection.4 The facts (worm in loose stool, tropical travel) closely fitted helminthic infection and, in view of the high pre-test probability, I did not immediately abandon this hypothesis when the first laboratory failed to support it. I questioned whether the specimen could have been misidentified, and repeated the test. Once a second laboratory confirmed its identity, I reluctantly concluded that the simultaneous appearance of the worm and loose stool in the same toilet was nothing more than a bizarre coincidence. The earthworm never really infected the patient, but it did manage to bait his physician. Daniel Mines Department of Emergency Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-4283, USA 1 2 3
Healey T. Radiology of a swallowed earthworm. BMJ 1972; iv: 795. Crew W, Chubb JC. An oligochaete as a spurious parasite of man. Trans R Soc Trop Med Hyg 1979; 73: 324. Borchardt KA, Maida N. Fictitious parasitic infection. Br J Gen Pract 1993; 43: 1174.
4
Kassirer JP, Kopelman RI. Williams & Wilkins, 1991.
Learning clinical reasoning. Baltimore:
DEPARTMENT OF ERROR Tuberculosis control policy in Nepal-Dr D S Bam’s address in this letter (Oct 14, p 1043) should have been National Tuberculosis Programme, Ministry of Health, Nepal.
modified to allow for the detection of genetic diseases such as FH.
problem. *Ian Craft, Marinos London Gynaecology and London W1N 1AF, UK
Tsirigotis,
J J Zhu
Fertility Centre Limited, 112A Harley Street,
Screening for familial hypercholesterolaemia in relatives SIR-In Norway, three founder mutations in the low-densitylipoprotein (LDL) receptor gene have been shown to cause up to one-half of clinic cases of familial hypercholesterolaemia (FH).’ Screening for FH in the general population is inefficient, owing to the relatively low prevalence of the disease (about 1 in 300 in Norway). However, the probability of FH, given an elevated cholesterol, increases substantially once a family member with FH is identified. Currently, index cases with FH in Norway are asked to inform other family members about the diagnosis and need for screening. Privacy laws do not permit physicians to contact relatives who are not their patients directly. We included questions to determine the attitude of the public towards screening for FH in a survey conducted in Oslo, Norway. The 1033 respondents were representative of the population over age 15 with regard to age, sex, and income. They were asked: "Your relative has been told by his physician that he has hereditary high cholesterol that, if premature cardiovascular disease or death. Treatment consists of following a diet and taking medication daily. Would you be intersted in knowing whether you have inherited high cholesterol?" If the answer was "Yes" the respondent was asked: "How would you prefer to be told that you may have hereditary high cholesterol: through your relative’s physician directly or should the physician ask your relative to inform you?" 77% answered "yes" to the first question and of these 74% wished to be informed by the physician directly. Other diseases, which are not as treatable as FH, would probably elicit a different response. Privacy laws should probably be not
1438
treated,
may
cause
treatable
*Serena Tonstad, Lars-Erik Vollebaek, Leiv Ose Lipid Clinic, Rikshospitalet, N-0027 Oslo, Norway 1
In-vitro culture of testicular sperm SIR—We have researched the best way to recover and prepare sperm from samples of testicular tissue (TESA) obtained by needle aspiration, rather than open biopsy. We usually place a tissue extract directly into a droplet of invitro fertilisation culture medium under oil with retrieval of motile/twitching sperm observed under a microscope with microinjection apparatus for subsequent intracytoplasmic sperm injection (ICSI). Motile sperm may be recovered from the periphery of the droplet at the interface between the instillate and surrounding culture medium. However, some samples may not exhibit any motility at all making a decision to perform ICSI with totally immotile sperm of doubtful viability a dilemma. We recently left culture dishes containing the instillates to incubate at 37°C for 24-72 h and have been surprised to find a pronounced increase in the number of progressively motile sperm with time in many instances. The activity has generally been greatest between 48 and 72 h and sometimes so marked that it is difficult to believe that the sperm have "come to life" to such an extent. We feel this unexpected finding could potentially improve the fertility prospects for those with a profound male factor
eminently
2
Leren TP, Solberg K, Rødningen OK, Tonstad S, Ose L. Two founder mutations in the LDL receptor gene in Norwegian familial hypercholesterolemia subjects. Atherosclerosis 1994; 111: 175-82. Williams RR, Schumacher C, Barlow GK, et al. Documented need for more effective diagnosis and treatment of familial hypercholesterolemia according to data from 502 heterozygotes in Utah. Am J Cardiol 1993; 72: 18D-24D.
Of worms and red
herrings
SiR-Finding a worm mixed with one’s bowel movement usually implies a parasitic infection, but not always. 1 week after returning from a trip to Aruba a previously healthy 37year-old physician noticed a live worm in the toilet after he had passed a semiformed stool. He denied weight loss, abdominal pain, or preceding diarrhoea, but did report walking barefoot in mud and eating undercooked meat while in the Caribbean. The worm, which was about 6 cm long, was light brown, round, and composed of multiple ring-like segments. Actively motile on removal from the toilet, it died several hours later, after transfer into a plastic dish containing a home-made saline solution. The worm was examined by two laboratories and identified as an oligochaete, most probably Lumbricus terrestes, but definitely a non-pathogenic earthworm. It is not clear how the earthworm got into the toilet. Earthworms are occasionally ingested by accident’ but they cannot survive transit through the human digestive tract.2 It is unlikely that the worm fell off the patient’s trousers since he had not recently been outdoors in them. The most plausible explanation is that the worm gained access to the toilet through a cracked pipe outside the patient’s house.2,3 In fact, on several occasions over the past decade, tree roots had grown into and obstructed its sewer line. This case illustrates some interesting issues in clinical problem solving. A representative heuristic (rule of thumb) guided the initial impression of a parasitic infection.4 The facts (worm in loose stool, tropical travel) closely fitted helminthic infection and, in view of the high pre-test probability, I did not immediately abandon this hypothesis when the first laboratory failed to support it. I questioned whether the specimen could have been misidentified, and repeated the test. Once a second laboratory confirmed its identity, I reluctantly concluded that the simultaneous appearance of the worm and loose stool in the same toilet was nothing more than a bizarre coincidence. The earthworm never really infected the patient, but it did manage to bait his physician. Daniel Mines Department of Emergency Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-4283, USA 1 2 3
Healey T. Radiology of a swallowed earthworm. BMJ 1972; iv: 795. Crew W, Chubb JC. An oligochaete as a spurious parasite of man. Trans R Soc Trop Med Hyg 1979; 73: 324. Borchardt KA, Maida N. Fictitious parasitic infection. Br J Gen Pract 1993; 43: 1174.
4
Kassirer JP, Kopelman RI. Williams & Wilkins, 1991.
Learning clinical reasoning. Baltimore:
DEPARTMENT OF ERROR Tuberculosis control policy in Nepal-Dr D S Bam’s address in this letter (Oct 14, p 1043) should have been National Tuberculosis Programme, Ministry of Health, Nepal.