Acute leukaemia after busulphan

During a double-blind study of two years' cytotoxic chemotherapy with busulphan or cyclophosphamide in patients who had had resection of carcinoma of the bronchus the long-term effects of these two drugs were also studied. Four of the 243 patients treated with busulphan developed leukaemia compared with none of the 234 treated with cyclophosphamide and none of the 249 on placebo. None of these four patients received radiotherapy or other cytotoxic chemotherapy before leukaemia was diagnosed, and all four were among the 19 patients who developed pancytopenia while taking busulphan, five to eight years before leukaemia became clinically apparent. These findings suggest that busulphan is leukaemogenic, though its mode of action is uncertain.

An assessment of the carcinogenicity of isoniazid in patients with pulmonary tuberculosis

In an assessment of the carcinogenicity of isoniazid, 3,842 adult tuberculous patients admitted to 2 sanatoria in the period 1950 to 1957 (that is, in the years immediately before and after the introduction of isoniazid) have been followed up for a mean period of over 19 years. Their mortality has been compared with that expected during the same calendar period in a general population group in England and Wales with the same age and sex distribution. The relative risk of death (the observed divided by the expected number of deaths) from all malignant neoplasms in patients first starting chemotherapy in 1950 to 1952, before the general introduction of isoniazid, was 0.8 for those who received isoniazid at some time, compared with 0.5 for those who never received it; for those first starting chemotherapy in 1953 to 1957, after the general introduction of the drug, the respective risks were 1.4 and 1.8. The relative risk of death from malignant neoplasms was 2.1 in the first 4 years after starting the treatment with isoniazid; this high relative risk is unlikely to be attributable to isoniazid and largely disappears subsequently, for in successive 4-year periods it was 1.3, 0.9, 1.2 and 1.4. The relative risks of death from all malignant neoplasms for patients receiving a total dosage of less than 50, 50-99, 100-199 and 200 g or more were 1.5, 1.5, 1.0 and 1.3, respectively. For patients receiving a maximum daily dose of less than 250 g the relative risk was 1.3, and for those receiving 250 g or more it was 1.2. There was a curious and unexplained difference in the mortality from malignant neoplasms in patients first starting chemotherapy in 1950 to 1952 (relative risk 0.6) and those first starting in 1953 to 1957 (relative risk 1.5). This is being studied further. This study has provided no evidence of a carcinogenic effect of isoniazid in a period of follow-up averaging nearly 20 years. The follow-up is being continued.

Fifteen-year follow-up of all patients in a study of post-operative chemotherapy for bronchial carcinoma

The 15-year findings are presented of a double-blind, randomised study planned in 1964 in which cytotoxic chemotherapy with either busulphan or cyclophosphamide prescribed to be given daily for 2 years as an adjuvant to surgery was compared with placebo in the treatment of 726 patients with carcinoma of the bronchus. The two cytotoxic agents administered in this way did not influence survival. At 15y, 8% of the 243 patients allocated busulphan, 9% of the 234 cyclophosphamide, and 10% of the 249 placebo were alive, these being 10% of the patients who had had epidermoid cancers, 12% large-cell, 5% small-cell, 5% adenocarcinomas, and 8% other histological types. The study provides data on long-term results in a large group of patients who were, in effect, treated by surgery alone. Survival was significantly shorter in patients with histological involvement of the resected intrathoracic nodes (log-rank test P much less than 0.001). A finding of particular interest is that the histological type of the tumour did not influence survival in the 390 patients whose nodes were not involved, although, as expected, it did in the 336 whose nodes were involved, the 226 with epidermoid cancers surviving longer than the 57 with small cell carcinoma, the 31 with adenocarcinoma and all 110 with non-epidermoid carcinomas (P much less than 0.001 in each comparison).

5-year follow-up of cytotoxic chemotherapy as an adjuvant to surgery in carcinoma of the bronchus

This report gives the 5-year findings of a double-blind study of long-term cytotoxic chemotherapy as an adjuvant to surgery in patients receiving busulphan or cyclophosphamide for carcinoma of the bronchus compared with a group receiving a placebo. Of 243 patients initially allocated busulphan, 234 cyclophosphamide and 249 placebo, 28%, 27% and 34% respectively were alive at 5 years. There were significant associations between mortality from bronchial carcinoma and histological involvement of the resected intrathoracic nodes and the histology of the tumour. Haematological toxicity, especially thrombocytopenia, was frequent and severe in the busulphan series, and low platelet counts continued long after chemotherapy was stopped.

Studies of case-finding for pulmonary tuberculosis in outpatients at 4 district hospitals in Kenya

This investigation is the sixth in a series of case-finding studies in Kenya. It explores the potential for case-finding by the identification of tuberculosis suspects (individuals with a cough for 1 month or more) through careful screening of general outpatients attending 4 district hospitals for the first time. Of 2299 suspects identified among 87 845 new outpatients attending the hospitals, 4.7% had culture-positive pulmonary tuberculosis, 3.6% having sputum positive on smear as well. In the 3 hospitals with radiographic facilities, 1.3% of suspects (whose sputum was negative on culture) were considered on review of their clinical history and chest radiograph by an independent assessor to have radiographically active tuberculous lesions and a further 2.5% to have inactive lesions. The proportion of bacteriologically positive cases per 1000 of the general population aged 6 years or more decreased as the distance of their homes from the hospital increased (P less than 0.001 for the trend). However, the proportion of cases per 1000 of the suspects identified increased as the distance of their homes from the hospital increased (P less than 0.001 for the trend). History of cough for between 1 and 12 months was the most useful factor for the identification of cases of tuberculosis among the suspects, and would have identified 92% of the smear-positive cases from the examination of 70% of the suspects; a history of weight loss identified 84% of the smear-positive cases from the examination of 64% of the suspects. A history of weight loss and/or a history of cough for between 1 and 12 months would have detected all the smear-positive cases from the examination of 89% of the suspects. The proportion of bacteriologically positive cases in the younger suspects aged 9-32 years (who had been eligible for a mass BCG campaign) was greater among the non-vaccinated than among the vaccinated suspects, 4.9% and 2.3% respectively (P=0.04), implying protection from vaccination of the order of 50%.

An investigation of the chest radiographs in a controlled trial of busulphan, cyclophosphamide, and a placebo after resection for carcinoma of the lung

A standard series of radiographs of 588 patients allocated at random to treatment with busulphan (B patients), cyclophosphamide (C patients), or a placebo (P patients) for two years after surgery for bronchial carcinoma were viewed in three stages (following procedures which avoided bias) by an independent assessor, unaware of the allocated treatment of any patient, with a view to identifying pulmonary changes due to busulphan. Radiographic appearances consistent with busulphan lung were not reported in any of the 195 B patients (receiving a mean dosage of 464 mg of busulphan over 301 days) or of the 192 C patients but were present in one of the 201 patients receiving placebo.

A third study of case-finding methods for pulmonary tuberculosis in Kenya, including the use of community leaders

Five methods of identifying tuberculosis suspects were investigated in the Machakos District of Kenya by: (1) 3-monthly interrogation of the Community Elders, (2) interrogation of household heads, (3) identifying suspects amongst outpatients attending local health units, (4) examination of patients registered during the previous 10 years in the District Tuberculosis Register and also (5) their close contacts. Sputum was bacteriologically examined by smear and culture from suspects found by all the methods. The initial interrogation of the Elders yielded 216 suspects, of whom 9 were culture-positive, including 6 smear-positive. Reinterrogating the Elders 4 times at 3-monthly intervals produced a further 114 suspects including 4 culture-positive cases (3 being smear-positive). The examination of a second sputum specimen from suspects after a 3-month interval yielded 4 further culture-positive cases (all smear-negative) but the examination of a third specimen after a further 3 months yielded no further cases. A single interrogation of 1093 household head suspects yielded 22 culture-positive cases, including 11 smear-positive. The response in 5 health units covering a population of about 24 500 was poor. During a 2-year period only 109 suspects were recorded; 7 were culture-positive, including 3 smear-positive. Of 61 cases of tuberculosis registered during the previous 10 years, 8 were currently culture-positive, 5 being smear-positive. Of 318 household contacts of these cases, 6 were culture-positive cases, 2 being smear-positive. The problems presented by different active case-finding methods are discussed, identifying those that appear promising and those unpromising.

Study of case-finding for pulmonary tuberculosis in outpatients complaining of a chronic cough at a district hospital in Kenya

This investigation is the fifth in a series of case-finding studies in Kenya. It explores the potential for case-finding by the identification of persons with suspected tuberculosis (persons with a cough for 1 month or more) through careful screening of general outpatients attending a district hospital. Of 601 suspects identified among 20,756 new outpatients attending hospital during a period of 11 wk, 5.6% were considered by an independent assessor to have active pulmonary tuberculosis (2.2% with sputum positive on both smear and culture, 1.2% on culture only, and 2.2% negative sputum but radiographically active lesions). A further 2.0% were considered to have inactive tuberculosis. This method of case-finding appears to be uniformly effective within a radius of approximately 9 miles of the hospital, becoming less effective outside this range. There were certain important diagnostic pointers. There was an excess of tuberculosis cases in males, in those with weight loss, in those with a history of cough of less than a year, in those with a history of hemoptysis, and in those 35 yr of age or older. This investigation provides additional support to our previous studies, which demonstrated serious problems of case-finding in the peripheral health units and suggests that unless the infrastructure of primary health care at the periphery can be improved, the policy should be to diagnose tuberculosis in the district hospital and to operate a simple referral system for persons with suspected tuberculosis from the periphery.

A second study of the use of community leaders in case-finding for pulmonary tuberculosis in Kenya

This is the second study of case-finding activities for tuberculosis suspects undertaken in 2 locations of Machakos District. Three methods were investigated, namely (1) the requestioning of the Community Elders 1 year or more after a first questioning in the original study, (2) the examination of patients registered in the District Tuberculosis Register from 1969--1974 and (3) the examination of their close contacts. Requestioning the Elders produced a total of 421 suspects, 129 (31%) of whom had not been identified a year previously. The yield of freshly identified smear-positive, culture-positive cases was 0.7 per 100 suspects examined and of all culture-positive cases was 1.7. However, all the smear-positive and 1.0 per 100 of the culture-positive cases were old patients who had previously been registered in the District Tuberculosis Register. Of the 181 patients with tuberculosis in the Register bacteriological results were available for 97; of these 6 were smear-positive, 9 culture-positive--yields of 6.2 smear-positive, culture-positive cases per 100 registered persons examined. The corresponding yields for the 63 persons who had been registered as having pulmonary disease were 9.5 and 14.3. Of the 9 culture-positive, 7 had strains resistant to isoniazid, but all were sensitive to streptomycin. The examination of the 628 close contacts of the registered patients produced only 3 culture-positive cases, none of whom was smear-positive--a yield of 0.5 culture-positive cases per 100 contacts examined. All 3 strains were sensitive to isoniazid and streptomycin.

Neurotoxic or Neuroprotective? Current Controversies in SCI-Induced Autoimmunity

Controversy exists regarding the autoimmune response that has been observed following traumatic spinal cord injury (SCI). It is not clear if this represents a protective response by the immune system to prevent further tissue damage, a pathological reaction of the immune system to central nervous system antigens released by the injury, or a combination of both. Experimental evidence indicates that B cells produce auto-antibodies following SCI and that the presence of self-reactive antibodies is associated with tissue damage. Conversely, other studies suggest T cell activity at the site of the injury promotes tissue regeneration. Vaccination with dendritic cells exposed to central nervous system (CNS) antigens dramatically improves recovery of motor function in spinal cord injured rats. Further research is required to determine the nature of post-SCI B cell and T cell responses and to establish efficacy of dendritic cell vaccination therapy in clinical studies. This information is critical for the development of therapies to either suppress or promote immune responses following neurotrauma to improve neurological outcomes.

A study of the use of maternity and child welfare clinics in case-finding for pulmonary tuberculosis in Kenya

This investigation is the seventh in a series of case-finding studies in Kenya. It explores the potential value of questioning mothers attending maternity and child welfare (M & CW) clinics to identify tuberculosis suspects (individuals aged 6 years or more with a cough for 1 month or more or hemoptysis) living in their households. The study was carried out in all the eight M & CW clinics in two divisions (populations 86,000 and 112,000) of two different districts. The mothers were asked to give a standard letter, which explained the possible importance of a chronic cough, to each suspect they identified and invited the suspect to attend the district hospital chest clinic. Each suspect attending the clinic was entered in a special register and two sputum specimens were collected. For those who failed to attend, the specimens were collected at a home visit. Of the total of 342 suspects living in the two study areas who were registered at the M & CW clinics during 1 year, 261 were identified by the mothers but 19 denied having received the standard letter. The remaining 81 had not been identified by mothers but had attended the M & CW clinics on their own initiative. Of the 242 suspects who received the letter, 89 (39%) attended the hospital chest clinic, 74% within a week of the letter being issued from the M & CW clinic. The main reasons given for not attending the hospital chest clinic by the remaining suspects were financial or because their cough had improved or disappeared. Sputum was collected from 238 suspects and examined bacteriologically: in six (2.5%) it was positive for tubercle bacilli on smear and culture and in a further two (0.8%) the sputum was positive on culture only. Of those attending the hospital chest clinic 2.9% were smear- and culture-positive and 4.7% were culture positive. This method of case-finding has yielded disappointing results, for only 4% of the estimated annual incidence of smear-positive cases was detected.

Comparative value of sputum smear examination and culture examination in assessing the progress of tuberculous patients receiving chemotherapy

Bacteriological response is generally considered the best criterion for assessing the efficacy of chemotherapy in patients with pulmonary tuberculosis. The bacteriological methods most commonly used are examination of sputum smears for tubercle bacilli, culture of bacilli from sputum specimens, and drug-sensitivity tests on positive cultures. Culture examination, though more sensitive than smear examination in detecting tubercle bacilli, is time-consuming and economically impracticable as a routine method in most developing countries. A study was therefore undertaken at the Tuberculosis Chemotherapy Centre, Madras, to determine the relative value of smear examination and culture examination in predicting the outcome of treatment and assessing the efficacy of chemotherapeutic regimens in 515 patients (all with bacteriologically confirmed disease and isoniazid-sensitive organisms on admission) receiving isoniazid, alone or with sodium PAS. The results showed that the value of smear examination of overnight sputum specimens at monthly intervals closely approached that of culture examination in assessing the progress of the patients, the percentages of correct predictions by smear and by culture being of the same order. Smear examination was slightly less effective than culture examination in detecting differences in the efficacies of regimens, but it has been estimated that this disadvantage can usually be compensated for by increasing the study population by about 20%.