The diagnostic efficacy of fine-needle aspiration using cytology and culture in tuberculous lymphadenitis

OBJECTIVE

To retrospectively assess the diagnostic efficacy of fine-needle aspiration (FNA) using cytological and microbiological examinations in tuberculous lymphadenitis.

METHODS

Patients with tuberculous lymphadenitis treated at St Mary's Hospital, London, between January 2001 and June 2007 were identified. The cytological and microbiological reports of 97 patients were found. The criteria for a definite diagnosis of tuberculous lymphadenitis were based on a compatible clinical history, tuberculin positivity and either an indicative cytological result or positive culture.

RESULTS

In 77 of the 97 (79%) cases, FNA cytology showed evidence of a tuberculous process. In 65 cases, Mycobacterium tuberculosis was cultured from the aspirates, and 54 of these 65 cases showed corresponding cytological evidence of a tuberculous process; 23 cases were diagnosed by cytology but not microbiology, while 11 cases were diagnosed by microbiology but not cytology.

CONCLUSION

Cytological and microbiological results appeared to correlate well, but each also gives an exclusive diagnosis. When combining both modalities, the diagnostic efficacy of FNA rises to 91%. A definitive microbiological diagnosis was achieved in 67% of cases and provided information on drug susceptibility. We conclude that samples should be provided for both cytological and microbiological examination when using FNA to diagnose possible tuberculous lymphadenitis.

Retention of marked sensitivity to (S)-4-isopropoxycarbonyl-6-methoxy-3-(methylthiomethyl)-3,4-di hydroquin oxaline-2(1H)-thione (HBY 097) by an azidothymidine (AZT)-resistant human immunodeficiency virus type 1 (HIV-1) strain subcultured in the combined presence of quinoxaline HBY 097 and 2',3'-dideoxy-3'-thiacytidine (lamivudine)

An azidothymidine (AZT)-resistant virus strain (HIV-1/AZT) (containing the 67 Asp --> Asn, 70 Lys --> Arg, 215 Thr --> Phe and 219 Lys --> Gln mutations into its reverse transcriptase) was grown in the combined presence of 2',3'-dideoxy-3'-thiacytidine (3TC, lamivudine) and the nonnucleoside reverse transcriptase inhibitor (S)-4-isopropoxycarbonyl-6-methoxy-3-(methylthiomethyl)-3,4-dih ydroquinoxaine-2(1H)-thione (quinoxaline HBY 097). Replication of HIV-1/AZT was inhibited to a significantly greater extent by the combination of 3TC and quinoxaline HBY 097 than by either drug alone. Virus breakthrough was markedly delayed in the combined presence of 3TC and HBY 097 at drug concentrations as low as 0.05 microg/mL and 0.0025 microg/mL, respectively. The virus that was recovered after exposure to the compounds (3TC and HBY 097) individually had acquired, in the genetic AZT-resistance background of HIV-1/AZT, 103 Lys --> Glu and 106 Val --> Ala mutations. The 103 Lys --> Glu mutation had not been observed before. However, both virus mutants retained marked sensitivity to HBY 097. In all cases, the genotypic AZT-resistance mutations were maintained in the mutant virus RT genomes, and the viruses also remained phenotypically resistant to AZT. Given the exquisite potency of a concomitant combination of 3TC and HBY 097 in suppressing virus replication, this drug combination should be further pursued in clinical trials in HIV-1-infected individuals.

Zidovudine-resistant human immunodeficiency virus type 1 strains subcultured in the presence of both lamivudine and quinoxaline HBY 097 retain marked sensitivity to HBY 097 but not to lamivudine

Replication of zidovudine-resistant human immunodeficiency virus type 1 (HIV-1) strains (containing the 41 Met-->Leu and 215 Thr-->Tyr mutations in reverse transcriptase [RT]) was inhibited to a significantly greater extent by the combination of lamivudine and quinoxaline HBY 097 than by either drug alone or even fully suppressed by concomitant HBY 097 and lamivudine administration at relatively low concentrations. The virus recovered after exposure to the drug combinations individually had acquired the 103 Lys-->Arg, 138 Glu-->Lys, 184 Met-->Ile, and 189 Val-->Ile mutations in the genetic zidovudine-resistance background of zidovudine-resistant HIV-1. These mutants retained marked sensitivity to HBY 097. The genotypic zidovudine-resistance mutations were maintained in the mutant virus RT genomes, and the viruses also remained phenotypically resistant to zidovudine. Given the exquisite potency of the combination of lamivudine and HBY 097 in suppressing viral replication, this combination should be further pursued in clinical trials examining treatment of HIV-1-infected persons.

Decreased tetanic contracture of rat skeletal muscle induced by pyridostigmine

The purpose of this study was to compare the effects of various regimens of pyridostigmine administration on the contractile strength of skeletal muscle. Rats were exposed to pyridostigmine according to 3 dosing schedules: 2 mg/kg ip daily, 5 mg/kg X d by sc infusion, and 25 mg/kg X d by sc infusion. After 1, 4, 10, and 20 d of exposure, measurements were made of muscle tension during tetanic stimulation, and of muscle mass, erythrocyte acetylcholinesterase activity, and body weight. Pyridostigmine produced a dose-dependent decrement in the contracture generated during tetanic stimulation. Peak effect was observed after 4 d of exposure but remained depressed after 20 d. The magnitude of the decrement correlated with the frequency of the tetanic stimulation (from 20 to 100 Hz). Muscle tension at the end of the tetanic stimulus was affected to a greater extent than the initial tension. The 25-mg/kg infusion of pyridostigmine significantly depressed erythrocyte acetylcholinesterase activity throughout the study and also decreased body weight on d 1-4. No change in muscle mass was observed in any treatment group. These results show that pyridostigmine exposure results in decrements in skeletal muscle contracture that are dose-dependent, frequency-dependent, and time-dependent. The effect is probably not the result of muscle wasting and does not correlate well with erythrocyte acetylcholinesterase inhibition. The results are consistent with effects of pyridostigmine, both presynaptically and postsynaptically, at the neuromuscular junction that affect neurotransmitter release and receptor responsiveness.

[Clinical use of NPH insulin (author's transl)]

NPH Insulin-Retard Leo has an even action spread over about 20 hours. Despite this long duration of action, single daily injections proved to be adequate in only 9-12% of diabetic patients. Twice daily injection provided a highly favourable fasting blood sugar level in all instances. Because of the small initial effect, the addition of regular insulin proved necessary in some of the patients. 50:50 mixture of regular and NPH Insulin-Retard Leo is available as Insulin Initard Leo, a 30:70 mixture as Insulin Semitard Leo. There remains a group of diabetics who should mix them to their own individual requirements. There were no local reactions when using highly purified components, as long as it was the first time that the patients used such insulin or were changed over from other reaction-free preparations. Diabetics with cutaneous allergies due to other forms of insulin had the same response to NPH preparations as to highly purified insulins of other forms.