The clinician, the lab and the patient: Understanding lab diagnostics to eradicate tuberculosis

BACKGROUND

Diagnostic modalities for diagnosing Tuberculosis caused by Mycobacterium group of organisms include mainly AFB smear by Ziehl Neelsen carbol fuchsin smear microscopy, GeneXpert (CB NAAT) molecular method, Line probe assay (Molecular method) and AFB culture (Liquid automated systems and solid media) methods.

METHODS

This study was initiated to understand and prioritize TB lab diagnosis, with reference to selection of lab diagnostic tests and its order of preference for MTC and NTM/MOTT closely associating it with the TB irradication program initiated by the Government of India.

RESULT AND CONCLUSION

The results and discussion bring to light the importance of each test and the purpose of their requisition. When diagnosis is handled half heartedly eradication of TB becomes a challenge. All the efforts including planning, resources in the form of manpower, infrastructure, finances, education, time etc., would be hampered. This challenge is not only for India but the globe. For countries harboring TB, Correct diagnostic request and timely diagnosis and treatment is the key to eradication of tuberculosis.

Systematic review with meta-analysis: mucosal healing is associated with improved long-term outcomes in Crohn's disease

BACKGROUND

Clinical manifestations of Crohn's disease (CD) do not reliably correlate with endoscopic activity. While treating to achieve clinical remission (CR) has neither proven to improve CD outcomes nor alter the natural disease course, it is unclear whether targeting objective measures like mucosal healing (MH) is associated with improved long-term outcomes.

AIM

To perform a systematic review and meta-analysis comparing long-term outcomes in active CD patients who achieve MH compared to those who do not.

METHODS

We performed a systematic literature search to identify studies with prospective cohorts of active CD patients that included outcomes of patients who achieved MH at first endoscopic assessment (MH1) compared to those who did not. The primary outcome was long-term (≥50 weeks) CR. Secondary outcomes included CD-related surgery-free rate, hospitalisation-free rate and long-term MH rate. Pooled odds ratio (OR) and 95% confidence intervals (CI) were calculated.

RESULTS

Twelve studies with 673 patients met inclusion criteria. Patients achieving MH1 had a pooled OR of 2.80 (95%CI, 1.91-4.10) for achieving long-term CR, 2.22 (95%CI, 0.86-5.69) for CD-related surgery-free rate, and 14.30 (95%CI, 5.57-36.74) for long-term MH. Sensitivity analyses suggested no difference in outcomes if MH1 was achieved on biologics vs. non-biologics. No significant publication bias or heterogeneity was detected.

CONCLUSIONS

Achieving MH1 is associated with increased rates of long-term clinical remission, and maintenance of mucosal healing in active Crohn's disease and may therefore be a reasonable therapeutic target.

Pattern of Sleep in Infants and Toddlers Visiting at a Teaching Hospital in Lalitpur

Introduction: Sleep is an integral part in a child’s health and development. During different stages of development, there are aberrations in normal physiology of sleep which make children more susceptible to various types of sleep problems. This study was conducted to identify sleep pattern and sleep problems in Nepalese children using Nepali translation of Brief Infant Sleep Questionnaire (BISQ) screening tool.Materials and Methods: This was a descriptive cross-sectional study. Data were collected from parents of children aged 6 to 36 months attending paediatric out-patient clinic for general health check-up from July 2013 to December 2013. Nepali translation of the BISQ was used as a screening tool for sleep problems in this study.Results: The study included 553 children (52.4% boys). Mothers completed the questionnaire in 92% of children. Mean total duration of sleep in 24 hours was 11.7 ±1.7 hours. Respondents reported sleep problem in 16.9% of children whereas 20.3% of children had sleep problems according to BISQ criteria. As per this criteria, 2.7% of children had total sleep duration less than 9 hours, 5.9% of children had total night awakening duration of more than one hour, 13.9% of children had night waking >3 times. These BISQ sleep parameters differed significantly in children with and without sleep problems (p<0.001). In addition, children with sleep problem took longer time to sleep than children without sleep problems (p<0.001).Conclusion: Sleep problems are common in Nepalese infants and toddlers according to the BISQ. Screening for sleep problems is highly recommended during health care visits given the prevalence of sleep problems identified by this study to reduce their potential adverse impact.J Nepal Paediatr Soc 2015;35(1):24-30

Depression is not associated with peripheral insulin resistance in patients with chronic hepatitis C infection

Depression is common in individuals infected with hepatitis C virus (HCV), and both depression and HCV infection are independently associated with insulin resistance (IR). To evaluate the relationship between depression and IR, among other factors, in an HCV-infected cohort. In this cross-sectional analysis, seventy-four non-type 2 diabetic, noncirrhotic, HCV-infected patients underwent comprehensive clinical, histologic and metabolic evaluation. IR was assessed directly with an insulin suppression test by measuring steady-state plasma glucose (SSPG) levels during continuous infusions of octreotide, glucose and insulin. Logistic regression modelling was used to evaluate predictors associated with depression. Thirty-nine (53%) patients were depressed, and 21 (54%) depressed patients were on at least one antidepressant. A higher estimated proportion of depressed patients were Caucasian (51% vs 20%, P = 0.005), unemployed (69% vs 49%, P = 0.07), heavier smokers (18 pack-years vs 13 pack-years, P = 0.07), on substance abuse therapy (16% vs 3%, P = 0.06) and had lower HDL levels (1.2 mmol/L vs 1.4 mmol/L, P = 0.01). The mean SSPG levels in depressed and nondepressed patients were 7.3 and 8.3 mmol/L (P = 0.45), respectively. In multipredictor adjusted analysis, only Caucasian race (OR 4.19, 95% CI 1.42-12.35, P = 0.009) and lower HDL (OR 0.95, 95% CI 0.89-0.99, P = 0.046) were associated with depression. In conclusion, although prevalent, depression was not associated with peripheral IR in this HCV-infected cohort. Attention to other modifiable factors associated with depression in the HCV-infected population is warranted.

Clinical Profile of Acute Poisoning in Children at a Teaching Hospital in Lalitpur

Introduction: Acute poisonings are one of the common cause of emergency visits and hospital admissions and is potentially preventable cause of childhood mortality and morbidity. The objectives of this study were to identify the common type of poisoning in children, to determine types of poisoning according to age and to find out the common age group in which the incidence of poisoning was high.Materials and Methods: It was a descriptive observational study done in a teaching hospital in Lalitpur, Nepal in patients aged 1 month to 18 years who visited the emergency department and were admitted to hospital with history of alleged poisoning from 2009 July to 2014 January.Results: Fifty patients were included. Drugs, kerosene and organophosphorus were most common cause of poisoning. Drugs and kerosene below 10 years of age and organophosphorus and drugs above 10 years of age were common types of poisoning. Maximum numbers (50%) of children with poisoning cases were below five year of age. Mean duration of hospital stay was 2.1days and mean age of poisoning was 7.8 years with a male(54%) predominance. Majority of poisoning occurred at home (84%) and 68% of patients were symptomatic at presentation to hospital with 84% of patients presenting to hospital within six hours.Conclusion: This study showed that drugs, kerosene and organophosphorus were most common forms of poisoning. Young children were most vulnerable for acute poisoning.DOI: http://dx.doi.org/10.3126/jnps.v34i2.10139J Nepal Paediatr Soc 2014;34(2):100-103 

Clinical characteristics of children with febrile seizure

BACKGROUND

Febrile seizure is common in children below five years of age. This study was conducted to evaluate the clinical profile of children presenting with febrile seizure in a teaching hospital.

METHODS

This was a descriptive retrospective study among children presenting with febrile seizure in a teaching hospital from July 2009 to June 2013. Children between six months to six years were included in the study while patients with prior episodes of afebrile seizures, abnormal neurodevelopment and not meeting the age criteria were excluded. Patient's demographic and clinical data were collected from the in-patients records and analyzed.

RESULTS

This study included 103 children with febrile seizure. Out of which 67% were male. Simple febrile seizure and complex febrile seizure were observed in 76.7% and 23.3% of patients respectively. Majority of children (71.8%)had generalized tonic clonic seizure followed by tonic seizures. Most of children (72.8%) who developed first episode of seizure were below 24 months of age with the mean age of 20.7 (±12.1) months. Overall 33% of patients developed recurrence of febrile seizure and first episode of febrile seizure at age one year or below was associated with the seizure recurrence. Upper respiratory tract infections were the commonest cause of fever in these children.

CONCLUSIONS

Febrile seizure was observed predominantly in children below age of two years and simple febrile seizure was the ommonest variety. Recurrence of febrile seizure was common and significantly associated with the first episode of febrile seizure at the age of one year or below.

A report of near fatal ceftriaxone induced anaphylaxis in a child with review of literature

Ceftriaxone is a widely used antibiotic in pediatric clinical practice. Usually ceftriaxone is well tolerated and serious adverse effect like anaphylaxis is rare. We report a near fatal anaphylaxis reaction in a child after the first dose of intravenous ceftriaxone who revived successfully.

Spectrum of pediatric dermatoses in tertiary care center in Nepal

Children with dermatological problems constitute a major group presenting to the Outpatient Department. This study was done to see the pattern of skin disorder among the pediatric age group in a tertiary care center in Nepal. To determine the pattern of skin disorders among children visiting the Department of Dermatology and Pediatrics in a tertiary care center in Nepal. All the patients visiting the Dermatological Out patient Department in the age group 0-14 years were enrolled in the study during the time period of 3 years (2009-2011). The cases were diagnosed based on the detailed clinical history and clinical examination, and the patients were investigated as needed. A total of 1086 (22.64%) patients out of 4795 patients were having skin disorder and among them 584 (53.77%) were males and 502 (46.23%) were females. The age range was 0-14 with the mean age of 7 years. Dermatitis and eczema were the most frequently encountered disease 298 (26.46%), followed by bacterial infections 156 (16.13%), urticarial 190 (15.71%), viral infection (14.12%), fungal infection 76 (7.3%), scabies 54 (5.03%), miliaria 25 (2.75%), vitiligo 27 (2%) and others 87 (6.53%). Nutritional disorders, vascular, pigmentary, nevi, drug eruptions had a comparatively low incidence.

Preliminary experience with use of a selective 5HT3 receptor antagonist (ondansetron) to prevent high dose chemotherapy induced emesis

Ondansetron was used as an antiemetic along with dexamethasone during 16 cycles of highly or moderately ematogenic chemotherapy. There was major control in two cycles and complete control in the remaining 14. Side effects were minor and did not require discontinuation of the drug. This combination, therefore, appears to be safe and effective in preventing chemotherapy induced emesis.

Bilateral phrenic nerve injury after neck dissection: an uncommon cause of respiratory failure

The case of a patient with carcinoma larynx who developed diaphragmatic paralysis and post-operative respiratory failure due to bilateral phrenic nerve injury is reported. The use of portable ultrasonography for an early diagnosis of diaphragmatic paralysis is discussed.

Tricuspid balloon valvuloplasty: a more simplified approach using inoue balloon

We report a more simplified technique of the balloon tricuspid valvuloplasty using inoue balloon set in a patient suffering from severe rheumatic tricuspid stenosis. We believe that this technique may be useful in a difficult case of tricuspid valvuloplasty.

Percutaneous transvenous mitral commissurotomy using Inoue balloon catheter: a left femoral vein approach

Percutaneous transvenous mitral commissurotomy by the Inoue technique is usually recommended from right femoral vein approach only. We report an unusual patient in whom the left femoral vein approach was used successfully. We believe that the left femoral vein approach can be reserved as a last resort in certain cases.

Lack of immune responsiveness to bovine serum albumin in insulin-dependent diabetes

BACKGROUND

Epidemiologic studies have implicated the ingestion of cow's milk in the pathogenesis of insulin-dependent diabetes mellitus (IDDM). Moreover, in a recent study, 100 percent of patients with new-onset IDDM had antibodies against bovine serum albumin (BSA), with a majority directed against a 17-amino-acid BSA peptide (ABBOS). Cellular immune mechanisms are thought to be the principal mediators of pancreatic beta-cell destruction in IDDM.

METHODS

We measured the responses of peripheral-blood mononuclear cells to BSA and ABBOS or serum IgG anti-BSA antibodies (by particle-concentration fluorescence immunoassay) in 71 patients with IDDM, 55 subjects at various degrees of risk for IDDM, 36 patients with other autoimmune disorders (chronic autoimmune thyroiditis, rheumatoid arthritis, and systemic lupus erythematosus), and 48 normal subjects.

RESULTS

The responses of peripheral-blood mononuclear cells to BSA or ABBOS were positive in 2 of 24 patients with new-onset IDDM, 1 of 25 first-degree relatives of patients with IDDM who were negative for islet-cell antibodies, 2 of 30 first-degree relatives of patients with IDDM who were positive for islet-cell antibodies, 1 of 28 patients with established IDDM, and 1 of 29 normal subjects. Similarly, anti-BSA antibodies were not detected significantly more often in patients with new-onset IDDM (3 of 31, 10 percent) than in normal subjects (1 of 37, 3 percent; P = 0.32). However, many patients with autoimmune disease and subjects at increased risk for IDDM had anti-BSA antibodies (frequency, 10 to 31 percent).

CONCLUSIONS

Anti-BSA antibodies may reflect a general defect in the process of immunologic tolerance associated with a predisposition to autoimmunity rather than immunity specific to beta cells. The absence of cellular immunity to BSA and ABBOS in IDDM does not support a role for this antigen in the pathogenesis of the disorder.

Tracheal tear during laryngopharyngectomy with gastric transposition

Tracheal rupture occurred in 7 of 174 (4%) patients undergoing laryngopharyngectomy with gastric transposition. Tracheal tears were classified as proximal if they involved the upper two-thirds of the trachea (five patients), or distal if they extended into the lower one-third of the trachea (two patients) and their clinical features and management analyzed. Predisposing factors, including prior radiotherapy (three patients) and preoperative tracheostomy (1 patient) did not influence the site or severity of tracheal injury. Proximal tears were detected incidentally in four patients, but in one patient, manifested postoperatively with subcutaneous emphysema and pneumothorax. Distal tears manifested dramatically with a ventilatory leak. Adequate access for repair of distal tears may necessitate a right thoracotomy while proximal tears may be sutured through the cervical incision. Gastric transposition alone did not prevent air leak in two patients. Postoperative complications included prolapse of the stomach and bilateral pneumothoraces in one patient. Close interaction between the surgeon and the anesthesiologist ensured a successful outcome in six patients. There was one mortality.

Respiratory depression following combination of epidural buprenorphine and intramuscular ketorolac

A 48-year-old man who had undergone thoracotomy for carcinoma of the middle third of his oesophagus developed severe postoperative respiratory depression following intramuscular ketorolac 30 mg 2 h after 150 micrograms epidural buprenorphine. Summation of analgesia by drugs used in combination can have deleterious respiratory effects.

Response of peripheral-blood mononuclear cells to glutamate decarboxylase in insulin-dependent diabetes

Insulin-dependent diabetes is characterised by autoantibodies to several pancreatic-islet-cell antigens, including glutamate decarboxylase. We measured the proliferative responses to this antigen of peripheral-blood mononuclear cells from patients with newly diagnosed insulin-dependent diabetes, relatives of diabetic patients, and healthy controls. The likelihood of a positive response was substantially greater among the diabetic patients and relatives positive for islet-cell autoantibodies (ICA) than among subjects at low risk of diabetes (controls and ICA-negative relatives). Glutamate decarboxylase may have a pathogenetic role in insulin-dependent diabetes.

Insulin resistance and hyperinsulinemia induce hyperandrogenism in a young type B insulin-resistant female

An adolescent female with type B insulin resistance and hyperandrogenemia is described. Evidence presented suggests that hyperinsulinemia leads to an increase in serum total and free testosterone. Support for this hypothesis is noted during an in vivo experiment in which large doses of regular insulin (305 U/kg-day) were infused iv, and multiple serum total testosterone measurements obtained. After 35 days of iv insulin therapy, the serum total testosterone values rose from 4.9 nmol/L (142 ng/dL) to 22.8 nmol/L (660 ng/dL), and the ovarian volume increased 2-fold. Basal (9.8 nmol/L; 282 ng/dL) and stimulated (16.8 nmol/L; 481 ng/dL) androstenedione measurements were elevated, and the dehydroepiandrosterone/androstenedione ratio was low, suggesting increased 3 beta-hydroxysteroid dehydrogenase activity. After resolution of the insulin-resistant state and the concomitant hyperinsulinemia, the serum total testosterone values returned to normal. This case illustrates that long term hyperinsulinemia leads to elevation of serum total testosterone.

Evaluation of endoscopic variceal sclerotherapy in various grades of liver disease

Forty four patients with portal hypertension of varying etiology, including 25 patients with an acute episode of variceal bleeding and 19 with past history of hematemesis, were followed up for eighteen months following endoscopic variceal sclerotherapy (EVS). Of 11 patients in Child's A group, two died of acute bleed, three were subjected to shunt surgery and the remaining six survived the follow-up period. Ten of 11 cases in Child's C did not survive more than six months in spite of sclerotherapy. We conclude that rebleed and death due to rebleed following EVS occur more commonly in patients with poor hepatic reserve (Child's C) as compared to patients in Child's A and B.

A randomized trial of intensive insulin therapy in newly diagnosed insulin-dependent diabetes mellitus

A period of early, intensive insulin treatment is thought to improve subsequent beta-cell function in insulin-dependent diabetes mellitus (IDDM). To study this hypothesis, we randomly assigned adolescents with newly diagnosed IDDM to receive either conventional treatment (n = 14) (NPH insulin, 1 U per kilogram of body weight per day, in two divided doses) or an experimental treatment (n = 12) (a two-week hospitalization with maintenance of blood glucose levels between 3.3 and 4.4 mmol per liter by continuous insulin infusion delivered by an external artificial pancreas [Biostator]). During the two-week intervention, the experimental-therapy group received four times more insulin than the conventionally treated group, and their endogenous insulin secretion was more completely suppressed, as evidenced by a urinary C-peptide excretion rate one seventh that of the conventionally treated group. After the first two weeks, both groups were treated similarly and received similar amounts of insulin. At one year, the mean (+/- SEM) plasma level of C peptide was significantly higher after mixed-meal stimulation in the experimental-therapy group than in the conventionally treated group (0.51 +/- 0.07 vs. 0.27 +/- 0.06; P less than 0.01). The experimental-therapy group also had better metabolic control, as evidenced by lower glycohemoglobin values (7.2 +/- 0.7 vs. 10.8 +/- 1.2 percent; P less than 0.01). We conclude that suppression of endogenous insulin by intensive, continuous insulin treatment during the first two weeks after the diagnosis of IDDM may improve beta-cell function during the subsequent year.

Hematuria and hypercalciuria in children with diabetes mellitus

Hematuria of unknown origin occurs in 30% of patients with diabetic nephropathy. In nondiabetic persons, hematuria may be caused by hypercalciuria with or without nephrolithiasis. Eight children with type I diabetes mellitus, hematuria, and hypercalciuria were observed in our clinic during a 1-year period. Two of these also had evidence of renal papillary necrosis. To assess the importance of hypercalciuria in the pathogenesis of hematuria in children with diabetes mellitus, we measured urinary calcium excretion in a large population of such patients. The calcium to creatinine ratio in the urine of diabetic children (0.21 +/- 0.01) was greater than that of nondiabetic children (0.12 +/- 0.01). A calcium to creatinine ratio of 0.28 was established as the upper limit of normal in our nondiabetic population, and 27% of the diabetic children were hypercalciuric on this basis. The diabetic children with hypercalciuria also had hyperphosphaturia and a urinary CaHPO4 X 2H2O molar ion product three times that found in the nondiabetic control population. These data suggest that many children with diabetes are at risk for renal damage due to hypercalciuria. Because hypercalciuria is more common in diabetic than nondiabetic children, it may play a previously unrecognized role in the renal disease associated with diabetes mellitus.

Hemoglobin South Florida: a genetic variant with laboratory recognition of only 20% of its product

Hemoglobin South Florida is a recently identified hemoglobin variant that is not associated with any clinical disorder. The standard electrophoretic procedures routinely utilized to identify hemoglobin variants did not recognize hemoglobin South Florida. The acetylated form of this hemoglobin co-eluted with hemoglobin A1c on a Bio-Rex 70 column. The quantity of this hemoglobin component was consistent with the amount of hemoglobin A1c associated with uncontrolled diabetes mellitus. The affected individuals did not have diabetes. This observation led to the characterization of a hemoglobin variant that otherwise would have gone unrecognized. This is an example of a variant peptide that was unrecognized for two generations in one family. It is likely that this type of unrecognized peptide variation is common in mammals. These silent structural alterations may be responsible for the variable physical responses occurring in humans exposed to the same environmental agents.

Comparison of insulin levels after injection by jet stream and disposable insulin syringe

Intermediate-acting biosynthetic human (NPH) insulin was administered by disposable insulin syringe into the right upper thigh of nine insulin-dependent diabetic youths. Seven days later, the same amount and type of NPH insulin was given in the same anatomic site with a Medi-Jector II, which delivers insulin as a jet stream. Blood was collected before insulin injection and at hourly intervals subsequently for the measurement of glucose and insulin. The total serum insulin measured before the first morning dose with the needle and syringe and the Medi-Jector II was 41.2 +/- 10.7 microU/ml and 46.2 +/- 10.7 microU/ml, respectively. During the next 9 h, the areas under the respective total insulin curves were not different, but the area under the free-insulin curve after jet injection was greater than the free-insulin area after needle injection (P less than .01). The ratio of free/total serum insulin was 0.31 +/- 0.02 after needle injection and 0.40 +/- 0.03 after jet injection (P less than .0025). The peak of total insulin concentration occurred 4.2 h after jet injection of NPH: 1 h earlier than the peak after needle injection. The plasma glucose at time zero was 197 +/- 15 mg/dl before needle injection and 242 +/- 19 mg/dl before jet injection. Although the diet consumed by each subject on the 2nd study day was identical to that of the 1st day, the mean glucose increase was greater after needle-injected insulin than after jet-spray injection. This indicates that the greater amount of free insulin observed after jet-injected insulin had a direct effect in lowering the plasma glucose. Jet injection may reduce insulin requirements by increasing the availability of free insulin.

Hemoglobin South Florida. New variant with normal electrophoretic pattern mistaken for glycosylated hemoglobin

An 8.75-yr-old Caucasian boy was discovered to have a markedly elevated (14.8%) hemoglobin A1c (HbA1c) as estimated by ion-exchange chromatography (Bio Rex 70). Glycohemoglobin (GHb) measured by a colorimetric method with thiobarbituric acid (TBA) was normal (equivalent to a 6.4% HbA1c). Nondiabetic quantities of GHb were found with affinity chromatography, and the glucose tolerance test was normal. Intensive efforts to identify an abnormal variant hemoglobin by several electrophoretic methods were unsuccessful. A family survey identified a similar abnormality in 11 other individuals, revealing an autosomal-dominant pattern. None of the affected individuals had any other hematologic abnormality. Structural analysis in one family member revealed a new hemoglobin variant (approximately 45% of the total hemoglobin) with the substitution of methionine for valine at the beta-NH2-terminal. In addition, the initiator methionine residue was preserved. Approximately 20% of the variant hemoglobin was modified by acetylation of the NH2-terminal methionine. The modified variant coeluted with HbA1c. We suggest that patients who do not have an explanation for their elevated HbA1c should have GHb measured by the TBA method or affinity chromatography because hemoglobin electrophoresis does not identify this confounding artifact.

Glycosylated hemoglobin: colorimetric vs chromatographic measurement

Glycosylated hemoglobin (GHb) was measured by a chromatographic method using HPLC (HbA1c) as well as a colorimetric method using thiobarbituric acid (TBA) on samples collected from 40 diabetic subjects. GHb measured by HPLC correlated well with the colorimetric method (r = 0.7). Freezing the samples caused an immediate increase of the HbA1a+b but not the HbA1c results. 4 weeks storage of the red cells at room temperature, 4 degrees C or -20 degrees C altered the results of GHb measured by HPLC but not the TBA reaction. Half of the total ketoamine linked hexoses detected by the TBA reaction was found in the HbA0 fraction as measured by ion exchange chromatography. The colorimetric method (r = 0.53) had better correlation than the HPLC method (r = 0.27) with mean blood glucose values during the 4 weeks preceding sample collection. GHb measured by the TBA reaction more accurately represents the ketoamine linked sugar in hemoglobin, is less subject to handling artifacts and more accurately reflects the blood glucose values during the preceding 4 weeks.

Hypercalciuria, hyperphosphaturia, and growth retardation in children with diabetes mellitus

The role of hypercalciuria and hyperphosphaturia in the growth retardation of children with diabetes mellitus was investigated in 157 children with diabetes whose mean height was less than that of 37 nondiabetic siblings of similar age (P less than .025). Hyperglycemia, hypercalciuria, and hyperphosphaturia were assessed coincident with the height measurement of each child in a cross-sectional survey. The distribution of height percentiles of the children with diabetes was skewed to the left with 61% at or below the 50th percentile. Eleven percent of the insulin-dependent children with diabetes mellitus were shorter than would be anticipated by a normal distribution of the 157 children. The duration of diabetes (hyperglycemia) had the greatest influence upon the children's height. Children with diabetes were shorter than the nondiabetic subjects by the fourth year of hyperglycemia, and this difference in height became statistically significant after 7 years or more of diabetes. The degree of hypercalciuria and hyperphosphaturia was more closely associated with reduced height in children with diabetes than was the degree of hyperglycemia, although the renal wastage of calcium and phosphorus seemed to be the result of glucosuria. Because hypercalciuria and hyperphosphaturia impair growth in nondiabetic children, they may also play an important role in the poor growth of children with diabetes mellitus.

Amino-terminal processing of proteins: hemoglobin South Florida, a variant with retention of initiator methionine and N alpha-acetylation

The hemoglobin variant South Florida has been shown by protein sequencing and fast-atom-bombardment mass spectroscopy to have a substitution of methionine for the NH2-terminal valine of the beta-globin chain. In addition, there was complete retention of the initiator methionine on the mutant polypeptide. Approximately 20% of the protein was acetylated at the NH2 terminus of the beta chain. A search of a comprehensive data bank of protein and gene sequences revealed 84 unrelated vertebrate proteins that have not undergone cleavage of leader sequences. A highly nonrandom distribution of residues at the NH2 termini of these proteins predicts removal of the initiator methionine as well as NH2-terminal acetylation. Proteins that undergo removal commonly have serine, alanine, glycine, or valine, as the NH2-terminal residues. The first three residues favor N alpha-acetylation. Proteins that retain the initiator methionine commonly have a charged residue or methionine at the second position. Information on Hb South Florida and other hemoglobins coupled with this survey of primary sequence provides insights into the NH2-terminal processing of proteins.