A Rare Case of Signet Ring Cell Colon Cancer Presenting as Adult Colorectal Intussusception.

Signet ring cell carcinoma of the rectum is rare and typically presents with advanced disease. We report a case of a 68-year-old man who presented with left lower quadrant pain and was found to have signet ring cell carcinoma with intussusception. This case is unusual because of its polypoid growth pattern and apparent early pathological stage. We discuss the differential diagnoses and prognosis.

Spindle Cell Melanoma Presenting as an Ulcer in a Black Diabetic.

Background. Melanoma in blacks is uncommon and exceedingly rare in association with a diabetic ulcer. We present a case of a spindle cell melanoma masquerading as a diabetic ulcer. Case Report. A 57-year-old overweight woman presented to The Maria Holder Diabetes Centre for the Caribbean with a nonhealing ulcer of the right heel after being treated by various primary care physicians over the preceding year. Her general and systematic examinations were unremarkable. There was a 1 × 1.5 cm ulcer with a necrotic base which bled easily on contact with no evidence of peripheral neuropathy nor arterial insufficiency. Microscopic examination of a biopsy of the lesion showed fascicles of spindle cells with plump nuclei and intracytoplasmic yellow-brown pigment. Immunohistochemistry confirmed a diagnosis of melanoma. Discussion. There should be a high index of suspicion of malignancy with nonhealing diabetic ulcer especially when coupled with short disease duration. This case highlights the importance of a biopsy and histological evaluation in ulcers presenting in recently diagnosed diabetics with no evidence of peripheral neuropathy or vascular disease. Melanoma should be considered in spindle cell lesions especially with pigment and residual nevus cells.

Guidelines for preoperative investigations for elective surgery at Queen Elizabeth Hospital: effects on practices, outcomes and costs

OBJECTIVES: Patients who present for elective surgery are often subjected to routine preoperative investigations, which often lead to unnecessary costs, delays or cancellation of surgery. We assessed the current practices, and the impact of guidelines for preoperative investigations on outcomes, practices and costs. DESIGN AND METHODS: The patterns of preoperative testing were assessed by conducting an audit. Preoperative investigation guidelines developed were presented to all surgical departments. The audit was repeated post-intervention compared to the pre-guideline audit. RESULTS: A total of 304 patients (150 before and 154 after) was included. The mean number of tests per patient did not significantly change between the pre-guideline and post guideline groups. For younger patients (under 60 years), the mean number of tests decreased from 3.42 ñ 1.8 in the pre-guideline group to 2.89 ñ 1.98 in the post guideline group (p=0.042). The total number of Chest X-rays decreased by 14.8% (p=0.012) and of Full blood counts (FBC) by 7.6% (p=0.036). For the remainder of investigations, there was no difference. The implementation of changes lead to overall savings of $15,178 per 1000 patients ($81,491 BDS per annum). The most notable savings are due to decreased number of Chest X-Rays. CONCLUSIONS: This study demonstrated that preoperative investigations were performed as a routine even in the absence of any clinical indication. The introduction of guidelines for preoperative investigations significantly decreased costs to the institution without compromising the safety of patient care and without placing patients at risk.

Outcomes and Health-related Quality of Life following Intensive Care Unit Stay in Barbados.

OBJECTIVES: To evaluate the hospital outcome and health-related quality of life (HRQOL) in adult patients admitted to intensive care units (ICUs) in Barbados. METHODS: A prospective observational study was done in the medical and surgical intensive care units of the Queen Elizabeth Hospital, Barbados, to evaluate the outcomes and HRQOL in adult patients. The acute physiology and chronic health evaluation (APACHE) IV score was applied on admission to one hundred and fifty patients admitted to the ICUs. The HRQOL was evaluated by using Short Form 36 (SF-36) in 63 survivors, three months after ICU discharge. RESULTS: There was no significant difference between medical and surgical ICUs with respect to age, gender, APACHE IV scores, 90-day mortality, and length of stay. The mean (± SD) APACHE IV score was 42.6 (± 23.7). The observed mortality was 32.7% and the standardized mortality ratio (SMR) was 1.85. The APACHE IV scores were significantly higher in non-survivors compared to survivors (p < 0.001). Patients with APACHE IV of > 45, and who were ventilated in the first 24 hours had the highest mortality (66%). The mean ICU length of stay was 7.2 days. CONCLUSION: In this study, the SF-36 scores in all eight dimensions indicated that the HRQOL in the majority of the survivors was average or above average. There was a significant negative correlation between APACHE IV score and the SF-36 score.

Pulmonary hypertension in children and adolescents with sickle cell disease.

The prevalence of pulmonary hypertension (PHTN) in the pediatric sickle cell disease (SCD) population is not known despite its high prevalence in adult patients. Our hypothesis was that increased pulmonary artery pressures (PAPs) would be found in SCD children and adolescents, especially those with a history of pulmonary complications: acute chest syndrome, obstructive sleep apnea, asthma, and reactive airway disease. Fifty-two SCD children, 23 of whom had underlying pulmonary disease, were screened for PHTN, which was defined as a tricuspid regurgitant jet velocity (TRV) of at least 2.5 m/s. Twenty-four (46.15%) SCD patients had increased PAP (i.e., TRV > or =2.5 m/s), and 6 (11.5%) had significant PHTN (i.e., TRV > or =3.0 m/s). Pulmonary disease was marginally associated with PHTN (odds ratio 2.80 and confidence interval 0.88 to 8.86; p = 0.0795). As in adult SCD patients with PHTN, this complication was correlated with the degree of hemolysis as manifested by significantly higher lactate dehydrogenase and bilirubin, lower hemoglobin and hematocrit levels, and a strong association with Hb-SS phenotype. However, after statistical adjustment for age and sex, increased serum LDH was not associated with the development of PHTN. Further studies are needed to clarify the prevalence and mechanisms of PHTN in pediatric and adolescent patients with SCD.

Carney complex presenting with Raynaud's phenomenon and erythematous macules of the extremities.

A 12-year-old male presented with a 6-week history of apparent digital vasculitis with color changes of the distal fingers and erythematous macules of the palms and soles. Physical examination revealed skin findings of Carney complex and an abnormal cardiac examination. Echocardiography demonstrated a large left atrial mass, which caused partial obstruction during diastole and moderate mitral valve insufficiency. Surgical excision and pathological examination of the mass confirmed the presence of a large, peduculated myxoma. This case illustrates the presentation of Carney complex with left atrial myxoma as apparent vasculitis and Raynaud's phenomenon.

A comparison of the insertion characteristics of the laryngeal tube and the laryngeal mask airway: a study of the ED50 propofol requirements.

The purpose of this prospective randomised double-blind study was to determine the effective dose of propofol required for the successful first attempt insertion of the laryngeal tube compared with the laryngeal mask airway in patients co-induced using alfentanil 5 microg.kg(-1), undergoing short elective gynaecological procedures. The first patient in each group received propofol 2.5 mg.kg(-1) for induction. In accordance with Dixon's up-and-down method, the dose of propofol for consecutive patients in each group was varied with increments or decrements of 0.5 mg.kg(-1) based on the previous patient 'all-or-none' purposeful movement response to first attempt of insertion of the randomised device. The ED50 (SD) of propofol was 2.66 (0.86) mg.kg(-1) and 2.33 (0.37) mg.kg(-1) for the laryngeal tube and laryngeal mask patients, respectively, which did not reach statistical significance (p = 0.40). We conclude therefore that the insertion of the two airway devices requires similar bolus doses of propofol when alfentanil is used as the co-induction drug.

Functional characterization of two cytochrome P450 monooxygenase genes, P450-1 and P450-4, of the gibberellic acid gene cluster in Fusarium proliferatum (Gibberella fujikuroi MP-D).

Gibberella fujikuroi is a species complex with at least nine different biological species, termed mating populations (MPs) A to I (MP-A to MP-I), known to produce many different secondary metabolites. So far, gibberellin (GA) production is restricted to Fusarium fujikuroi (G. fujikuroi MP-C), although at least five other MPs contain all biosynthetic genes. Here, we analyze the GA gene cluster and GA pathway in the closest related species, Fusarium proliferatum (MP-D), and demonstrate that the GA genes share a high degree of sequence homology with the corresponding genes of MP-C. The GA production capacity was restored after integration of the entire GA gene cluster from MP-C, indicating the existence of an active regulation system in F. proliferatum. The results further indicate that one reason for the loss of GA production is the accumulation of several mutations in the coding and 5' noncoding regions of the ent-kaurene oxidase gene, P450-4.

Energetic determinants of glucose tolerance status in Jamaican adults.

As type 2 diabetes mellitus (DM2), obesity and sedentary lifestyles are increasing in developing countries, this observational study investigated the role of physical activity on DM2 in Jamaica. Anthropometry, body composition (by bioelectrical impedance analysis) and glucose tolerance status was assessed in 722 adults in 1993 and 1997. Energy expenditure was estimated in a subset using measured resting energy expenditure in combination with self-reported activity recalls. The rates of impaired glucose tolerance (IGT) were 23.7 and 27.3%, and DM2 were 16.3 and 23.7% among men and women, respectively. After adjusting for body composition, a one-unit increase in physical activity significantly reduced the odds of having diabetes (OR = 0.05; 95% CI: 0.004, 0.66), but not IGT. Hence, decreased physical activity is a significant independent contributor to the high rates of glucose intolerance in Jamaica. Efforts must be directed at minimizing obesity and increasing physical activity in developing countries.

Obesity in a cohort of black Jamaican children as estimated by BMI and other indices of adiposity.

OBJECTIVE: To examine the relationships of body mass index (BMI) to obesity indices derived from anthropometry and to determine tracking of overweight between late childhood and early adolescence, in a cohort of children with mixed nutritional history. We also compared identification of overweight children using The International Obesity Task Force (IOTF) BMI cut-off points with skinfolds. DESIGN: Prospective study. SETTING: Kingston, Jamaica. SUBJECTS: A total of 306 children examined at 7-8 y and at 11-12 y. MEASUREMENTS: Triceps (TSF) and subscapular skinfolds (SSF), height and weight were measured. The sum of the skinfolds (sum SF), BMI, percentage body fat (%fat) and fat mass (FM) were calculated. Pubertal stage was assessed at 11-12 y. RESULTS: Overweight increased from 3.5 to 9.5% over the follow-up period. BMI was better correlated with the other indices of adiposity in girls and in the older age group. BMI tracking over follow up was high. In regression analysis BMI explained 52 and 61% of the variance in FM in boys and girls at 7-8 y. This increased to 69% in both sexes at 11-12 y. Using the IOTF cut-off points BMI had low sensitivity to identify children >85th percentile of the NHANES references for SSF. The sensitivity for those assessed by TSF and sum SF was higher, but between 14 and 30% of the children were misclassified. The specificity of BMI was high. CONCLUSIONS: Adiposity increased over follow-up. Although the cohort remained relatively lean BMI rank among the fattest children was maintained. Girls were fatter than boys, reflecting adult obesity patterns. Children identified as overweight by the IOTF BMI cut-off points are likely to have high body fatness. However the BMI cut-off points may not identify many children with high body fatness.

Fasting levels of serum glucose, cholesterol and triglyceride at age eleven to twelve years in stunted and non-stunted Jamaican children.

AIM: To determine whether fasting serum concentrations of glucose, cholesterol and triglyceride at age 11-12 y (a) differed between children stunted in early childhood and those who were never stunted, (b) were related to birthweight or current anthropometry and (c) were related to stunting after controlling for current size. METHODS: Anthropometry, serum glucose and lipid concentrations were measured in 112 children stunted in early childhood and 181 non-stunted children. RESULTS: Children who were stunted in infancy remained shorter, weighed less and were significantly less fat than non-stunted children but had a more central distribution of fat. They were also less likely to have entered puberty. Non-stunted children had higher fasting serum triglyceride concentrations than stunted children (p < 0.05). There were no significant correlations between birthweight and fasting glucose or any measure of serum lipids. The percentage of variance in biochemical measures explained by anthropometry was low: between 2.1 for HDL cholesterol and 14.6 for triglyceride. Nutritional status in early childhood (stunted or non-stunted) made no additional contribution to the variance. CONCLUSIONS: Linear growth retardation in early childhood was not independently related to fasting serum concentrations of glucose, cholesterol and triglyceride at age 11-12 y. However, despite being thinner, stunted children had a more central distribution of fat.

The P450-4 gene of Gibberella fujikuroi encodes ent-kaurene oxidase in the gibberellin biosynthesis pathway.

At least five genes of the gibberellin (GA) biosynthesis pathway are clustered on chromosome 4 of Gibberella fujikuroi; these genes encode the bifunctional ent-copalyl diphosphate synthase/ent-kaurene synthase, a GA-specific geranylgeranyl diphosphate synthase, and three cytochrome P450 monooxygenases. We now describe a fourth cytochrome P450 monooxygenase gene (P450-4). Gas chromatography-mass spectrometry analysis of extracts of mycelia and culture fluid of a P450-4 knockout mutant identified ent-kaurene as the only intermediate of the GA pathway. Incubations with radiolabeled precursors showed that the metabolism of ent-kaurene, ent-kaurenol, and ent-kaurenal was blocked in the transformants, whereas ent-kaurenoic acid was metabolized efficiently to GA(4). The GA-deficient mutant strain SG139, which lacks the 30-kb GA biosynthesis gene cluster, converted ent-kaurene to ent-kaurenoic acid after transformation with P450-4. The B1-41a mutant, described as blocked between ent-kaurenal and ent-kaurenoic acid, was fully complemented by P450-4. There is a single nucleotide difference between the sequence of the B1-41a and wild-type P450-4 alleles at the 3' consensus sequence of intron 2 in the mutant, resulting in reduced levels of active protein due to a splicing defect in the mutant. These data suggest that P450-4 encodes a multifunctional ent-kaurene oxidase catalyzing all three oxidation steps between ent-kaurene and ent-kaurenoic acid.

The effects of birth weight and postnatal linear growth retardation on blood pressure at age 11-12 years.

STUDY OBJECTIVE: To determine the effects of birth weight and linear growth retardation (stunting) in early childhood on blood pressure at age 11-12 years. DESIGN: Prospective cohort study. SETTING: Kingston, Jamaica. PARTICIPANTS: 112 stunted children (height for age < -2 SD of the NCHS references) and 189 non-stunted children (height for age > -1 SD), identified at age 9-24 months by a survey of poor neighbourhoods in Kingston. MAIN RESULTS: Current weight was the strongest predictor of systolic blood pressure (beta= 4.90 mm Hg/SD weight 95%CI 3.97, 5.83). Birth weight predicted systolic blood pressure (beta = -1.28 mm Hg/SD change in birth weight, 95% CI -2.17, -0.38) after adjustment for current weight. There was a significant negative interaction between stunting in early childhood and current weight indicating a larger effect of increased current weight in children who experienced linear growth retardation in early childhood. There was no interaction between birth weight and current weight. The increase in blood pressure from age 7 to age 11-12 was greater in children with higher weight at age 11-12 and less in children with higher birth weight and weight at age 7. CONCLUSIONS: Birth weight predicted systolic blood pressure in Jamaican children aged 11-12. Postnatal growth retardation may potentiate the relation between current weight and blood pressure. Greater weight gain between ages 7 and 11 was associated with a greater increase in systolic blood pressure. The relation between growth and later blood pressure is complex and has prenatal and postnatal components.

The P450-1 gene of Gibberella fujikuroi encodes a multifunctional enzyme in gibberellin biosynthesis.

Recent studies have shown that the genes of the gibberellin (GA) biosynthesis pathway in the fungus Gibberella fujikuroi are organized in a cluster of at least seven genes. P450-1 is one of four cytochrome P450 monooxygenase genes in this cluster. Disruption of the P450-1 gene in the GA-producing wild-type strain IMI 58289 led to total loss of GA production. Analysis of the P450-1-disrupted mutants indicated that GA biosynthesis was blocked immediately after ent-kaurenoic acid. The function of the P450-1 gene product was investigated further by inserting the gene into mutants of G. fujikuroi that lack the entire GA gene cluster; the gene was highly expressed under GA production conditions in the absence of the other GA-biosynthesis genes. Cultures of transformants containing P450-1 converted ent-[(14)C]kaurenoic acid efficiently into [(14)C]GA(14), indicating that P450-1 catalyzes four sequential steps in the GA-biosynthetic pathway: 7beta-hydroxylation, contraction of ring B by oxidation at C-6, 3beta-hydroxylation, and oxidation at C-7. The GA precursors ent-7alpha-hydroxy[(14)C]kaurenoic acid, [(14)C]GA(12)-aldehyde, and [(14)C]GA(12) were also converted to [(14)C]GA(14). In addition, there is an indication that P450-1 may also be involved in the formation of the kaurenolides and fujenoic acids, which are by-products of GA biosynthesis in G. fujikuroi. Thus, P450-1 displays remarkable multifunctionality and may be responsible for the formation of 12 products.

Intraoperative stents to rehabilitate severely stenotic pulmonary vessels.

BACKGROUND: Patch enlargement of severe branch pulmonary artery stenosis (PAS) or pulmonary vein ostial stenosis (PVS) can be technically challenging. Recurrences are common and exposure may require long periods of cardiopulmonary bypass (CPB). METHODS: Since 1993, we performed 31 procedures on 27 patients with endovascular stents placed intraoperatively under direct surgical vision: 22 patients with tight PAS and 5 patients with PVS. Selection for intraoperative (vs catheterization laboratory) stent placement was prompted by: (1) the need for a concomitant cardiac surgical procedure (16 cases); (2) limited vascular access for catheterization laboratory stent placement (11 cases); or (3) "rescue" of patients with complications after attempted placement of stents (4 cases). RESULTS: In this group of very complex and challenging patients there were 5 hospital deaths (hospital survival, 81%). Follow-up of survivors has ranged from 1 month to 7 years (mean 2.8 +/- 1.7 years). There have been 3 late deaths (late "series" survival, 70%). No complication or death was related to stent placement. Surviving patients have had significant clinical improvement. Mean pulmonary gradient (postoperative vs preoperative echo) has fallen in all survivors and has decreased from a mean of 66 mm Hg preoperatively to 28 mm Hg postoperatively (p = 0.01). All pulmonary arteries are appreciably enlarged and will be easier to deal with at a later date if necessary. One patient (DORV, HLHS ) with pulmonary vein stents has gone on to a successful Glenn procedure. The other two surviving patients with PV stents have occlusion of their proximal PVs on follow-up catheterization; thus only 1 of 5 patients with stents for PVS has had a successful outcome. Four patients have had repeat surgery. Stents have produced no impediment to subsequent surgical procedures, and the pulmonary arteries were easy to work with. CONCLUSIONS: Intraoperative stenting provides an attractive option for "rehabilitation" of pulmonary vessels. Direct vision insertion on CPB is extremely quick and immediately effective, limiting the CPB exposure required to treat this problem. Once stented, vessels remain open and are amenable to future surgical intervention as necessary. Outcome is better for patients with PAS versus those with PVS.

Gibberellin biosynthesis: metabolic evidence for three steps in the early 13-hydroxylation pathway of rice.

[14C4]GA53, [14C4]GA44, and [2H2/14C4]GA19 were injected separately into seedlings of rice (Oryza sativa) using a dwarf mutant (d35) that has low levels of endogenous gibberellins (GAs). After 8 h incubation, the shoots were extracted and the labeled metabolites were identified by full-scan gas chromatography mass spectrometry (GC-MS) and Kovats retention indices (KRIs). Our results document the metabolic sequence, GA53-->GA44-->GA19-->GA20 and the presence of endogenous GA53, GA44, GA19, GA20 and GA1. Previous metabolic studies have shown the presence of the step, GA20-->GA1 in rice. Taken together, the data establish in vegetative shoots of rice the presence of the early 13-hydroxylation pathway, a pathway that originates from GA12 and leads to bioactive GA1.

Early linear growth retardation and later blood pressure.

OBJECTIVE: To examine the effects of stunting in early childhood on blood pressure in later childhood. DESIGN: A cohort study. SETTING: Kingston, Jamaica. SUBJECTS: Seven to eight year old children, 120 stunted (height for age <-2 s.d. of the NCHS references) and 224 non-stunted (height for age >-1 s.d. of the NCHS references) at age 9-24 months. METHODS: Stunted and non-stunted children were identified at age 9-24 months by house to-house survey of poor neighbourhoods in Kingston, Jamaica. Blood pressure and anthropometry were measured at age 7-8 y. Birth weight was obtained from hospital records (73%) or maternal recall. RESULTS: The stunted children remained shorter and thinner than the non-stunted ones. In multiple regression analysis adjusting for size and pulse rate, the stunted children had higher systolic blood pressure (P<0.05). Birth weight was not a significant predictor of systolic blood pressure. CONCLUSION: Stunting in early childhood may increase the risk of elevated systolic blood pressure in later life. SPONSORSHIP: Nutricia Research Foundation, The Netherlands and the Commonwealth Caribbean Medical Research Council.

Clinical auscultation skills in pediatric residents.

OBJECTIVE: The aim of this study is to determine the level of clinical auscultation skills in pediatric residents at Duke University Medical Center. METHODS: Forty-seven residents from pediatrics and joint medicine/pediatrics training programs at Duke University Medical Center were enrolled in this study. They were asked to examine the cardiovascular patient simulator, Harvey, and report their findings. Five common conditions seen in the pediatric population were presented: ventricular septal defect, atrial septal defect, pulmonary valve stenosis, combined aortic valve stenosis and insufficiency, and innocent systolic ejection murmur. The responses were scored by the number of features and diagnoses accurately reported. Five pediatric cardiologists and cardiologists in training were also asked to participate in a manner similar to the trainees. RESULTS: The mean score of features identified for the resident group was 11.4 +/- 2.6 of a possible 19. The diagnostic accuracy was 33%. There was no significant difference between residents by year of training or by type of residency program, although there was a trend toward improved performance with more training. The difference in performance between the pediatric cardiology group and the residents group was striking. The condition that was most frequently misdiagnosed was the innocent systolic ejection murmur. CONCLUSIONS: The clinical auscultation skills of pediatric residents in this study were suboptimal. There was a trend toward improvement as training progressed, although not statistically significant. These skills are likely to improve further with increased exposure to patients with cardiovascular disease especially in the ambulatory care setting.

Tissue distribution of 2-(2-nitro-4-trifluoromethylbenzoyl)-cyclohexane-1,3-dione (NTBC) and its effect on enzymes involved in tyrosine catabolism in the mouse.

Administration of a single oral dose of 2-(2-nitro-4-trifluoromethyl-benzoyl)-cyclohexane-1,3-dione (NTBC) to mice increases the concentration of tyrosine in the plasma and aqueous humour. The tyrosinaemia is both time and dose-dependent with a single dose of 30 micromol NTBC/kg (10 mg/kg) producing maximal concentrations of tyrosine in plasma of about 1200 nmol/ml and in aqueous humour of about 2200 nmol/ml at 16 h after dosing. Analysis of the key hepatic enzymes involved in tyrosine catabolism, following a single dose of 30 micromol NTBC/kg, showed that 4-hydroxyphenylpyruvate dioxygenase (HPPD) was markedly inhibited soon after dosing and that the activity recovered very slowly. In response to the tyrosinaemia, the activity of hepatic tyrosine aminotransferase (TAT) was induced about two-fold, while the activity of hepatic homogentisic acid oxidase (HGO) was reduced at 4 and 5 days after dosing. Daily oral administration of NTBC at doses up to 480 micromol NTBC/kg (160mg/kg/day) to mice produced a maximal tyrosinaemia of about 600-700nmol/ml plasma, showing some adaptation relative to a single dose. Unlike the rat, no treatment-related corneal lesions of the eye were seen at any dose levels up to 6 weeks. Administration of a single oral dose of [14C]-NTBC at 30 micromol/kg led to selective retention of radiolabel in the liver and to a lesser extent the kidneys. Our studies show that NTBC is a potent inhibitor of mouse liver HPPD, which following repeat exposure produces a marked and persistent tyrosinaemia, which does not result in ocular toxicity.

Gibberellin Biosynthesis in Maize. Metabolic Studies with GA(15), GA(24), GA(25), GA(7), and 2,3-Dehydro-GA(9).

[17-(14)C]-Labeled GA(15), GA(24), GA(25), GA(7), and 2,3-dehydro-GA(9) were separately injected into normal, dwarf-1 (d1), and dwarf-5 (d5) seedlings of maize (Zea mays L.). Purified radioactive metabolites from the plant tissues were identified by full-scan gas chromatography-mass spectrometry and Kovats retention index data. The metabolites from GA(15) were GA(44), GA(19), GA(20), GA(113), and GA(15)-15,16-ene (artifact?). GA(24) was metabolized to GA(19), GA(20), and GA(17). The metabolites from GA(25) were GA(17), GA(25) 16alpha,17-H(2)-17-OH, and HO-GA(25) (hydroxyl position not determined). GA(7) was metabolized to GA(30), GA(3), isoGA(3) (artifact?), and trace amounts of GA(7)-diene-diacid (artifact?). 2,3-Dehydro-GA(9) was metabolized to GA(5), GA(7) (trace amounts), 2,3-dehydro-GA(10) (artifact?), GA(31), and GA(62). Our results provide additional in vivo evidence of a metabolic grid in maize (i.e. pathway convergence). The grid connects members of a putative, non-early 3,13-hydroxylation branch pathway to the corresponding members of the previously documented early 13-hydroxylation branch pathway. The inability to detect the sequence GA(12) --> GA(15) --> GA(24) --> GA(9) indicates that the non-early 3,13-hydroxylation pathway probably plays a minor role in the origin of bioactive gibberellins in maize.