Acquired immune responses to the seasonal trivalent influenza vaccination in COPD

Epidemiological data suggest that influenza vaccination protects against all‐cause mortality in chronic obstructive pulmonary disease (COPD) patients. However, recent work has suggested there is a defect in the ability of some COPD patients to mount an adequate humoral response to influenza vaccination. The aim of our study was to investigate humoral and cell‐mediated vaccine responses to the seasonal trivalent influenza vaccination (TIV) in COPD subjects and healthy controls. Forty‐seven subjects were enrolled into the study; 23 COPD patients, 13 age‐matched healthy controls (HC ≥ 50) and 11 young healthy control subjects (YC ≤ 40). Serum and peripheral blood mononuclear cells (PBMC) were isolated pre‐TIV vaccination and at days 7 and 28 and 6 months post‐vaccine for haemagglutinin inhibition (HAI) titre, antigen‐specific T cell and antibody‐secreting cell analysis. The kinetics of the vaccine response were similar between YC, HC and COPD patients and there was no significant difference in antibody titres between these groups at 28 days post‐vaccine. As we observed no disease‐dependent differences in either humoral or cellular responses, we investigated if there was any association of these measures with age. H1N1 (r = −0·4253, P = 0·0036) and influenza B (r = −0·344, P = 0·0192) antibody titre at 28 days negatively correlated with age, as did H1N1‐specific CD4⁺ T helper cells (r = −0·4276, P = 0·0034). These results suggest that age is the primary determinant of response to trivalent vaccine and that COPD is not a driver of deficient responses per se. These data support the continued use of the yearly trivalent vaccine as an adjunct to COPD disease management.

Renal impairment as a complication of uterine fibroids: a retrospective hospital-based study

Leiomyomas can cause obstructive renal impairment and renal failure. This was a retrospective study of women with renal impairment seen at the University of the West Indies Hospital, Jamaica, between 2000 and 2004, looking at aetiology and severity (group 1). We also evaluated patients, in the same hospital, with fibroids who had ultrasonography during a later period (2006-2011), comparing those who had hydronephrosis and those without (group 2). In group 1, 274 women were coded as renal impairment. Case notes for 160 patients (59%) were analysed. Uterine fibroids accounted for 13/160 (8.1%) of cases. Comparing cases with and without fibroids, none of those with fibroids were over 50 years old compared with 59.3% of the others, OR 0.02 (CI 0.00-0.35) p = 0.0001. Hospital data for renal failure showed that most mean values were significantly better for those with fibroids. Urea, 8.59 mmol/l (SD 9.89) vs 17.00 mmol/l (SD 13.41) p = 0.003; Creatinine 300.15 μmol/l (SD490.92) vs 424.05 μmol/l (SD553.29) p = 0.022 and Creatinine clearance 73.21 ml/min (SD 38.92) vs 44.25 ml/min (SD 49.71) p = 0.017. However, mean potassium values were similar, 4.52 mmol/l (SD 0.61) vs 4.85 mmol/l (SD1.03) p = 0.2. In group 2, there were 216 patients and we found 31 (14.35%) patients at ultrasonography with hydronephrosis from fibroids. These patients had significantly larger uteri than those without hydronephrosis but renal function was similar, with only urea values significantly worse. Leiomyomas can cause renal impairment, however the prognosis appears good.

Adequacy of lymph node harvesting in colorectal cancer management: improving standards, ensuring quality

OBJECTIVE

The aim of this study was to determine the adequacy of nodal sampling in resection specimens for colorectal carcinoma in a Jamaican population.

METHODS

The pathology records of all patients who underwent operation for colorectal carcinoma at the University Hospital of the West Indies (UHWI) during the five-year period, 2003-2007, were reviewed. Pertinent clinical and pathologic data were obtained and analysed.

RESULTS

One hundred and ninety-one patients were identified with M:F ratio of 1.1:1 and a mean age of 66 years. There were 119 (63%) left-sided lesions and 70 (37%) right-sided lesions. Stage T3N0 lesions were the most common and accounted for 41.1% of cases. The predominant histologic type was adenocarcinoma (99.5%) with the majority being moderately differentiated. The mean number of nodes sampled in node-negative cases was 13.8 +/- 9.75 nodes for right-sided lesions and 10.64 +/- 7.25 nodes for left-sided lesions (p = 0.05, CI 95%). The adequacy of nodal sampling was acceptable in cases of N0 right-sided carcinomas but was unsatisfactory in cases of N0 left-sided carcinomas. More importantly, however in two cases from the right and 10 cases from the left, two or fewer nodes were harvested.

CONCLUSION

This review suggests the need for re-examination of the adequacy of surgical resection and/or nodal sampling technique for colorectal cancer resection specimens, given the importance of nodal status in determining the need for adjuvant therapy. Less than adequate node sampling should not be accepted by the reporting pathologist or attending surgeon as this has important prognostic implications.

Cardiovascular disease risk factors in menopausal Jamaican black women after hysterectomy and bilateral oophorectomy: an observational study

OBJECTIVE

To determine differences in prevalence of cardiovascular risks and diseases in black Jamaican postmenopausal women who had hysterectomy (hysgroup) compared with those without (control).

METHOD

Eight hundred and nine (809) women (hysterectomized (HYSGRP) = 403; non-hysterectomized (controls) = 406) were enrolled. Sociodemographic information and lifestyle history, measured blood pressure, waist hip ratio, body mass index, fasting blood glucose, total and HDL cholesterol were obtained.

RESULTS

Of the 809 women, complete cardiovascular risk data were available in 341 controls and 328 in the HYSGRP group. There was no difference in mean age, blood pressure and body mass indices between the subjects excluded and the subjects in the data analytical sample. A significantly lower proportion of women in the control group exercised, attained post-secondary education and were of higher parity. Systolic (mean diference with 95% CI; 6 (3, 9) mmHg and diastolic (3 (1, 5) mmHg) blood pressure were lower in the HYSGRP compared with controls but total cholesterol (0.2 (0.07 to 0.4) mmol/L was greater HDL cholesterol was not different between both groups 1.3 mmol/L (SD 0.3) vs 1.3 mmol/L [SD 0.4] (p = 0.8435). There was no difference in the prevalence of diabetes, hypertension and high waist-hip ratio in hysterectomized women compared with controls adjusting for hormone replacement therapy usage, cigarette smoking, exercise and educational status. Within the HYSGRP there was also no diference in cardiovascular disease or risk in women who had bilateral oophorectomy compared with women who had at least an ovary preserved at time of operation.

CONCLUSION

Hysterectomy was not associated with an increased risk of cardiovascular disease. This must be taken cautiously since data did not allow for analysis on duration of menopause.

Venous thromboembolism as a complication of uterine fibroids: a retrospective descriptive study

This study describes cases of fibroids with venous thromboembolism (VTE) managed at UHWI between the years 1999-2004. We examined records to find patients with fibroids and VTE diagnosed before or after surgery. We found 438 women with VTE and 72 of these (16.4%) with fibroids. A total of 1,979 patients had fibroids during the period; cases were therefore 3.63% of fibroids. Cases were younger, median age 44 years than the total cohort: the median age was 57 and the mean age was 55.43 (SD 19.87) p = 0.000 about 9.5 years older than cases. Age over 50 years was less common in cases 27% vs 52% p = 0.0001 as were other risk factors for VTE such as cancer 4.9 vs 14% p = 0.03; diabetes 8.6 vs 25.2% p = 0.004 and cardiac disease 8.6% vs 26.6% p = 0.002 . However, thrombocytosis was more frequent, 23% vs 9% p = 0.008. Other risk factors were not significantly different. A total of 21 cases (29.1%) had surgery for fibroids; 15 (71.4%) hysterectomy, and six (28.5%) myomectomy. Most cases 67/72 (93%) had VTE without surgery. Of the five cases with VTE after surgery for fibroids, none had prophylactic heparin. Of the cases, 15 died--23% of women with VTE at PM and 0.8% of those with fibroids.

Rhabdomyomatous mesenchymal hamartoma: clinical overview and report of a case with spontaneous regression

A case of cutaneous rhabdomyomatous mesenchymal hamartoma in a 6-year-old Afro-Caribbean girl is reported with review of the literature. The lesions were fine, located on the central face and became inapparent after six months. Spontaneous regression of these lesions has not been previously reported. Although rare, continued reporting will facilitate the elucidation of the clinical features and natural history of these lesions and the relationship to disordered embryogenesis.

Venous thromboembolism in Jamaican women: experience in a university hospital in Kingston

OBJECTIVE

To review cases of venous thromboembolism (VTE) at UHWI from 1999-2004, to identify methods of diagnosis, risk factors and to evaluate differences between survivors and fatalities.

METHODS

Patients coded with the diagnosis of thromboembolism at the University Hospital of the West Indies (UHWI) from 1999-2004 were identified. The medical records were reviewed to determine the prevalence of thromboembolism and possible variables associated with this diagnosis. In addition, variables associated with fatality were examined by evaluating cases diagnosed at autopsy

RESULTS

There were 959 patients coded for thromboembolism between 1999-2004 at UHWI. Of these, 657 (68.5%) were females and 302 were males (31.5%). During that period, 65,657 women and 40,826 men were admitted to hospital with prevalence rates for thromboembolism of 1% in women and 0.7% in men. Of the 657 females, 520 case notes were located (case identification 80%). Of this, 435 were analysed as confirmed thromboembolism. The median age was 51 years with a range of 2-95 years. Common associations were obesity, 53.5%; age over 50 years, 52.5%; hypertension, 44.7%; immobilisation, 36.3%; cardiac disease, 26%; diabetes, 19.4%; fibroids, 16.3%; surgery, 15.8% and cancer 14%. Recurrent venous thromboembolism occurred in 12.8% and 15.8 % of women (66) died, diagnosed with PE at post-mortem. Using logistic regression analysis, leading risk factors in fatalities compared to survivors were hypertension and increased age. Obesity and surgery were significantly more likely in survivors.

CONCLUSION

Venous thromboembolism was common in this cohort of women and avoidance of risk factors and institution of prophylaxis in high risk women is important to decrease morbidity and mortality.

A Caribbean perspective on Barrett's oesophagus

The aim of this study is to evaluate the prevalence of Barrett's oesophagus at the University Hospital of the West Indies which serves a population predominantly of African descent. In order to maximize accession of all cases in this preliminary study, the broad definition of columnar metaplasia of the lower oesophagus was utilized. Nevertheless, of 18 cases identified in the 21-year period, 14/17 cases (82%) available for review had specialized columnar epithelium diagnostic of Barrett's oesophagus. There was male predominance 5:1, the mean age was 53.8 years and there were two associated adenocarcinomas. These data confirm the occurrence but low prevalence of Barrett's oesophagus in this population but with a disease pattern that is consistent with that reported in other populations, warranting systematic evaluation of the gastro-oesophageal junction even in a Caribbean population.

An unusual presentation of group B streptococcal sepsis

This paper describes the devastating outcome of a neonate who presented with severe late onset group B beta-haemolytic streptococcal (GBS) disease. There were extensive infarcts of the brain and gangrene of the toes. The purpose of this report is to alert healthcare workers of the unusual presentation and that fatal late onset group B beta-haemolytic streptococcal disease may occur despite early and effective management.

Hepatic abscesses at the University Hospital of the West Indies. A 24-year autopsy review

A retrospective review of all hepatic abscesses identified at autopsy over the 24-year period 1977-2000 at the University Hospital of the West Indies (UHWI), Kingston, Jamaica, was conducted. Post mortem and microbiology records were reviewed. Data collected included age, gender, predisposing factors, organisms isolated, number of abscesses and associated conditions, such as diabetes mellitus. Data for the adults was analyzed separately. Thirty-nine cases of pyogenic abscesses were identified from 7480 post-mortems. Thirty-three occurred in adults of mean age 59.5 years. Sixty per cent of the abscesses were solitary. Biliary tract disease was the predisposing factor in 33% of cases. Six per cent were cryptogenic: 11/33 patients were diabetic and these were significantly older than non-diabetics (p < 0.014) Klebsiella pneumoniae was the most common organism isolated from diabetics (6.9). Only 2/33 abscesses were diagnosed ante-mortem. The abscesses in children were more frequently multiple and associated with extra-abdominal infection. Gram positive cocci were the commonly isolated organisms in children. There were no cases of amoebic abscess. The prevalence of hepatic abscess was low. Diabetes mellitus was a significant contributing factor. A high index of clinical suspicion is therefore warranted particularly in elderly diabetics.

Smooth muscle tumours of the vulva in Jamaica

Smooth muscle tumours of the vulva are uncommon and their behaviour is unpredictable. A 30-year retrospective analysis of the pathology files and patient records revealed 10 cases diagnosed at the University Hospital of the West Indies, Kingston, Jamaica, with one malignant and one recurrent tumour. Size, infiltrating margins and mitotic count are important parameters to determine prognosis. Although these tumours are of low malignancy, mitotic count may be mandatory in determining their potential for recurrence.

Colonic lipomas at the University Hospital of the West Indies

Lipomas of the colon are uncommon but cause diagnostic difficulty when they are symptomatic. The clinical and pathological features of 17 cases of colonic lipomas diagnosed at the University Hospital of the West Indies between 1970 and 1999 are reported. Ten cases were symptomatic, two of these being diagnosed with adult intussusception. Six patients had incidental lipomas in bowel resected for other pathology while one lipoma was diagnosed on sigmoidoscopy. Increased awareness of these lesions will enhance pre-operative diagnostic accuracy.

Salivary gland lesions: a Jamaican perspective

A retrospective analysis of the spectrum and relative frequency of salivary gland lesions diagnosed in the Department of Pathology, University of the West Indies, Kingston, Jamaica, between 1965 and 1994, is reported. Four hundred and sixty-four salivary gland biopsies were received. Of these 99 (21.3%) were non-neoplastic and the remaining 365 (78.7%) were neoplasms: 261 (71.5%) were benign and 104 (28.5%) malignant. Benign mixed tumour (BMT)/pleomorphic adenoma (PA) was the most common neoplasm (63.3%) while mucoepidermoid carcinoma (MEC) was the most common malignant neoplasm (9.6%), followed by adenoid cystic carcinoma (ACC) (7.4%). The increased frequency of MEC over ACC is at variance with other reported series but the preponderance of pleomorphic adenoma is consistent. In the major salivary glands, benign neoplasms predominate at a ratio of 3:1, while a higher proportion of minor salivary gland neoplasms was malignant, ratio 1.2:1 (p = 0.003). These data represent the first attempt to document the spectrum of disease related to oral and maxillofacial pathology in Jamaica.

Mast cell derangement in salivary glands in patients with Sjögren's syndrome

Mast cells (MCs) have been implicated in many immune-inflammatory disorders. Deranged mast cell distribution and function may contribute to the local pathomechanisms in the labial salivary glands (LSG) in Sjogren's syndrome (SS). Evidence for MC presence, localization, frequency, subtype, and degree of activation was sought by using reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry (IHC)/image analysis, transmission electron microscopy, Western blotting, spectrophotometric activity assay, and radioimmunoassay. The overall expression (densitometric units) of MC tryptase mRNA (1483 +/- 228 vs 1044 +/- 308) did not differ between SS and control LSGs. However, IHC disclosed an uneven distribution of MCs in SS with an absence in lymphocyte foci and increased numbers (cells/mm2 77 +/- 7 vs 38 +/- 4, P < 0.01) elsewhere. Absence of MCs in the lymphocyte foci was not a fixation artefact and was not explained by the presence of "phantom" MCs in these areas. In both SS and controls, 80% of all MCs were chymase containing, but the typical lattices/gratings characteristic for connective tissue MCs (CTMCs) were not found. Instead, MC granules had mostly a homogeneous, finely granular substructure characteristic of "new" granules subjected to a continuous, low-grade release. 32 kDa MC tryptase was found in saliva and its activity/concentration was comparable to that found in controls. However, tryptase output was low in SS (1.30 +/- 0.30 microg/min vs 3.49 +/- 0.66 microg/min, P < 0.001). Normal LSGs contain mostly CTMCs, in close contact with various resident and immigrant cells, characterized by a low-grade release of MC mediators. In SS this normal pattern is disturbed so that MCs are absent in lymphocyte foci (but increased elsewhere in the glands). The net salivary output of MC mediators is low in SS. This derangement of MCs may contribute to the pathogenesis of SS via multiple mechanisms.

Systemic phaeohyphomycosis in pregnancy and the puerperium

Systemic fungal infections are rare. In pregnancy, treatment is problematic because of the risk of possible teratogenic effects of the antifungal drugs. We present the case of a 32 year-old woman who presented during pregnancy with a two-month history of painless subcutaneous nodules. Excision biopsy of one lesion showed dematiaceous fungal elements. Anti-fungal treatment was deferred and the pregnancy proceeded uneventfully. The remaining nodules were excised at the time of caesarean section delivery. Three weeks into the puerperium, she developed generalised seizures and investigations indicated systemic fungal infection with positive cultures for Aureobasidium spp which responded to appropriate antifungal therapy of flucytosine and itraconazole.

Malignant lymphoma of gastric mucosa-associated lymphoid tissue in Jamaica

The recently appreciated concept of Mucosa-Associated Lymphoid Tissue (MALT) and the characteristics of the lymphomas arising therein are discussed with reference to the clinical, histological and immunohistochemical features of the first four cases of gastric MALT lymphomas diagnosed at the University Hospital of the West Indies. These tumours are low-grade B-cell lymphomas, which may undergo high-grade transformation. They are aetiologically associated with Helicobacter pylori (H pylori) infection in the stomach and may be cured in the early stages with antibiotics. Our cases were diagnosed from gastrectomy specimens removed for suspected carcinoma. All were high-grade, and associated with H pylori; 3 cases presented as advanced disease. Documentation of the features of these lymphomas will increase awareness and earlier recognition.

Clinical, pathologic, and immunologic features of human T-lymphotrophic virus type I-associated infective dermatitis in children

OBJECTIVES

To define the clinical and laboratory features associated with infective dermatitis (ID) and confirm its association with human T-lymphotrophic virus type I (HTLV-I).

DESIGN

A case series of patients with ID were compared with patients with atopic dermatitis (AD), which is an important disease in the differential diagnosis of ID.

SETTING

Patients were recruited from dermatology and pediatric clinics at the University Hospital of the West Indies and the Bustamante Children's Hospital, Kingston, Jamaica.

MAIN OUTCOME MEASURES

Clinical and laboratory features of patients with AD were compared with those of patients with ID.

PATIENTS

Consecutive patients older than 1 1/2 years diagnosed as having ID (n=50) and AD (n=35) were enrolled based on clinical findings.

RESULTS

The mean ages of patients with ID and AD were 6.9 and 7.8 years, respectively. Histologically, both diseases were predominantly chronic dermatitis with propensity for skin colonization with Staphylococcus aureus and beta-hemolytic streptococci; however, the distribution of sites of skin involvement differed. Infection with HTLV-I was the most distinguishing feature among patients with ID, with seropositive results in 100%; only 5 (14%) of the 35 patients with AD had results seropositive for HTLV-I. Infective dermatitis was further characterized by dermatopathic lymphadenitis in 16 (67%) of 24 patients with palpable nodes. Anemia, lymphocytosis, and low albumin and elevated serum globulin levels were more prevalent among patients with ID. Significant elevations of IgA, IgD, and IgG levels were observed among patients with ID compared with those with AD. However, both patients with AD and those with ID had levels of IgD and IgE elevated above the normal range. T-cell subsets among patients with ID revealed T-cell activation with a high percentage of HLA-DR antigen positivity, elevated CD4 (2.4 x 10(9)/L) and CD8 (1.4 x 10(9)/L) cell counts, with an increased CD4/CD8 ratio of 1:73.

CONCLUSION

Infective dermatitis is a distinct clinical entity associated with HTLV-I, which plays a role in the pathogenesis and immune perturbations observed.

Vestibular evaluation in patients with early multiple sclerosis

Multiple sclerosis (MS) is a chronic, debilitating disease characterized by multiple areas of focal demyelination that develop throughout the white matter of the central nervous system at varying times. Most patients report disequilibrium at some point in the course of their disease. When balance disturbance occurs early in the course of the disease prior to diagnosis, the patient may present to the otolaryngologist for evaluation. Are there any patterns of balance dysfunction that might suggest the diagnosis to the evaluating physician? An evaluation of ten patients with known early MS suggests that platform posturography and ENG is the test most likely to provide useful diagnostic information in patients with early MS.

Mammary hamartoma--an under-recognised breast lesion

The clinical, histological and immunohistochemical features of the first three cases of mammary hamartoma diagnosed at the University Hospital of the West Indies are reported. These tumours are innocuous and under-recognized although the mammographic features are characteristic. With increased utilization of this test in breast cancer detection in our region, it is likely that more of these lesions will be identified.

Multicentric angiofollicular lymph node hyperplasia in ulcerative colitis. A case report

Multicentric angiofollicular lymph node hyperplasia (MAFH) is a rare disorder which has been associated with various disease entities. This is the first report of its association with ulcerative colitis. Details of lymph node histology and views on pathogenesis are given.

Adult T-cell leukemia/lymphoma in a renal transplant recipient: an opportunistic occurrence

A 42-year-old man with chronic renal failure and homograft transplantation developed adult T cell lymphoma in one native kidney. The role of transfusion in the acquisition of human T-lymphotropic virus type I and its role in the early development of adult T cell lymphoma, particularly on the background of chronic immunosuppression, are discussed. To our knowledge, this is the first such case.

Solitary rectal ulcer syndrome

Solitary Rectal Ulcer Syndrome (Rectal Prolapse Syndrome) is an uncommon and imperfectly understood entity which, however, should be included in the differential diagnosis of ano-rectal symptoms. This article reports on the nine cases so far diagnosed at the University Hospital of the West Indies (UHWI), and offers a brief review of the condition.

The translational activator GCN3 functions downstream from GCN1 and GCN2 in the regulatory pathway that couples GCN4 expression to amino acid availability in Saccharomyces cerevisiae

The GCN4 protein of S. cerevisiae is a transcriptional activator of amino acid biosynthetic genes which are subject to general amino acid control. GCN3, a positive regulator required for increased GCN4 expression in amino acid-starved cells, is thought to function by antagonism of one or more negative regulators encoded by GCD genes. We isolated gcn3c alleles that lead to constitutively derepressed expression of GCN4 and amino acid biosynthetic genes under its control. These mutations map in the protein-coding sequences and, with only one exception, do not increase the steady-state level of GCN3 protein. All of the gcn3c alleles lead to derepression of genes under the general control in the absence of GCN1 and GCN2, two other positive regulators of GCN4 expression. This finding suggests that GCN3 functions downstream from GCN1 and GCN2 in the general control pathway. In accord with this idea, constitutively derepressing alleles of GCN2 are greatly dependent on GCN3 for their derepressed phenotype. The gcn3c alleles that are least dependent on GCN1 and GCN2 for derepression cause slow-growth under nonstarvation conditions. In addition, all of the gcn3c alleles are less effective than wild-type GCN3 in overcoming the temperature-sensitive lethality associated with certain mutations in the negative regulator GCD2. These results suggest that activation of GCN3 positive regulatory function by the gcn3c mutations involves constitutive antagonism of GCD2 function, leading to reduced growth rates and derepression of GCN4 expression in the absence of amino acid starvation.

Mutations in the structural genes for eukaryotic initiation factors 2 alpha and 2 beta of Saccharomyces cerevisiae disrupt translational control of GCN4 mRNA

The SUI2 and SUI3 genes of Saccharomyces cerevisiae encode the alpha and beta subunits, respectively, of translation initiation factor eIF-2 (eukaryotic initiation factor 2). Previously isolated mutations in these genes restore expression from his4 mutant alleles lacking an ATG initiation codon. The SUI mutations also lead to increased levels of HIS4 mRNA. We show that the latter phenotype exists because the SUI mutations elevate expression of GCN4, an activator of HIS4 transcription. Increased GCN4 expression in the SUI mutants occurs independently of the GCN2 and GCN3 gene products that are normally required to stimulate translation of GCN4 mRNA under conditions of amino acid starvation. Derepression of GCN4 expression in the SUI mutants requires the multiple AUG codons in the leader of the GCN4 transcript that normally mediate its translational control by amino acid availability. In these respects, the SUI mutations resemble mutations in GCD genes whose products function as translational repressors of GCN4. Thus, in addition to its general role in AUG start codon selection, eIF-2 appears to be an important factor in GCN4 translational control. We also show that deletion of GCN3 in sui2-1 strains is lethal, suggesting that GCN3 contributes to eIF-2 alpha function in addition to its role as a translational activator of GCN4.

Amoebiasis in Jamaica. A forgotten cause of hepato-intestinal disease

Amoebiasis still occurs in Jamaica. This paper describes the unexpected occurrence of the disease in three adult males, two with colitis and the other with an hepatic abscess. This, to our knowledge, is the first report of amoebiasis in Jamaica for over two decades and serves to underscore the continued need for the inclusion of amoebiasis in the differential diagnosis of unexplained hepato-intestinal disease.

Drug-induced acute liver disease

Fifty-three patients with drug-induced acute liver disease are reported. There were 35 females and 18 males with a mean age of 41 years. All but one patient had jaundice or hyperbilirubinaemia and 51 had abnormal liver enzymes. Histologically 38 patients (72%) had cholestatic injury while 15 had cytotoxic parenchymal damage. Methyldopa, chlorpropamide, chlorpromazine, halothane and the contraceptive pill accounted for 60% of cases. Fifty-one patients recovered after drug withdrawal while 2 died of hepatic failure. Drug-induced liver injury must be considered in patients presenting with evidence of hepatic disease as the majority will recover on withdrawal.

The positive regulatory function of the 5'-proximal open reading frames in GCN4 mRNA can be mimicked by heterologous, short coding sequences

Translational control of GCN4 expression in the yeast Saccharomyces cerevisiae is mediated by multiple AUG codons present in the leader of GCN4 mRNA, each of which initiates a short open reading frame of only two or three codons. Upstream AUG codons 3 and 4 are required to repress GCN4 expression in normal growth conditions; AUG codons 1 and 2 are needed to overcome this repression in amino acid starvation conditions. We show that the regulatory function of AUG codons 1 and 2 can be qualitatively mimicked by the AUG codons of two heterologous upstream open reading frames (URFs) containing the initiation regions of the yeast genes PGK and TRP1. These AUG codons inhibit GCN4 expression when present singly in the mRNA leader; however, they stimulate GCN4 expression in derepressing conditions when inserted upstream from AUG codons 3 and 4. This finding supports the idea that AUG codons 1 and 2 function in the control mechanism as translation initiation sites and further suggests that suppression of the inhibitory effects of AUG codons 3 and 4 is a general consequence of the translation of URF 1 and 2 sequences upstream. Several observations suggest that AUG codons 3 and 4 are efficient initiation sites; however, these sequences do not act as positive regulatory elements when placed upstream from URF 1. This result suggests that efficient translation is only one of the important properties of the 5' proximal URFs in GCN4 mRNA. We propose that a second property is the ability to permit reinitiation following termination of translation and that URF 1 is optimized for this regulatory function.

Ribosomal RNA genes of Neurospora crassa: multiple copies and specificities

Ribosomal RNA genes were isolated from the germinated conidial and mycelial cells of N. crassa by repeated cycles of 3H-DNA:rRNA reactions followed by hydroxyapatite chromatography. Specificity of multiple copies of those rDNAs with respect to N. crassa cell types was studied. The fraction of N. crassa germinated conidial in vitro labelled 3H-DNA recovered in the presence of rRNA isolated from the same cell type was about 2.2%, when compared with approximately 1.2% rDNAs obtained in mycelial cells. These isolated rDNAs reacted specifically to 26S and 17S rRNAs of eukaryotic (N. crassa) organisms and did not react with 4S tRNAs. rRNA:rDNA reassociation kinetics studies indicate that 90% of the rRNA genes were homogeneous and not identical with the other 10% rRNA genes isolated from N. crassa mycelia. These studies suggest that the possible heterogeneity of rDNA sequences of N. crassa cannot be attributed to inclusion of any tDNA sequences as has been shown in the heterogeneity of rDNA sequences of the bacterium Escherichia coli. The heterogeneity of multiple copies of N. crassa rDNAs could be due to differences in internal or external spacer regions of N. crassa rRNA genes.

Germination-defective mutant of Neurospora crassa that responds to siderophores

A conditionally germination-defective mutant of Neurospora crassa has been found to be partially curable by ferricrocin and other siderophores. The mutant conidia rapidly lose their membrane-bound siderophores when suspended in buffer or growth media. Germination is consequently delayed unless large numbers of conidia are present (positive population effect). This indicates that the mutant has a membrane defect involving the siderophore attachment site.

Isolation and identification of the conidial germination factor of Neurospora crassa

The germination-essential substance (germination factor [GF]) that is lost from conidia of Neurospora crassa on exposure to solutions of low water activity has been isolated and identified as a group of iron-transport compounds, or siderochromes. The principal siderochrome of conidia is ferricrocin, a cyclic hexapeptide. A closely related substance, ferrichrome C, is tentatively identified as a minor constituent. The same substances are also present in extracts of mycelium along with small amounts of a third siderochrome, which has not been identified. The GF activity of culture filtrates is due to coprogen, the only siderochrome previously identified with N. crassa.