Lactoferrin-metal interactions: first crystal structure of a complex of lactoferrin with a lanthanide ion (Sm3+) at 3.4 A resolution

Lactoferrin is an important member of the transferrin family. A characteristic property of transferrins is their ability to bind very tightly (K(app) approximately/= 10(20)) but reversibly two Fe(3+) ions. The structural consequences of binding a metal other than Fe(3+) have been examined by crystallographic analysis at 3.4 A resolution of mare samarium-lactoferrin (Sm(2)Lf). The structure was refined to an R factor of 0.219 for 8776 reflections in the resolution range 17.0-3.4 A. The samarium geometry (distorted octahedral coordination) is similar in both lobes. However, the anion interactions are quite different in the two lobes. In the N lobe, the anion is able to form only two hydrogen bonds instead of the four observed in the C lobe of Sm(2)Lf and the six observed in Fe(2)Lf. This is because Arg121, Thr117 and Gly124 have moved away from the anion as a consequence of the binding of the Sm(3+) ion. The protein ligands in the binding cleft of Sm(2)Lf show large displacements, but the overall protein structure remains the same. The binding of Sm(3+) by lactoferrin shows that the protein is capable of sequestering ions of different sizes and charges, though with reduced affinity. This conclusion should be true of other transferrins also.

Descriptive epidemiology of acute respiratory infections among under five children in an urban slum area

A study was conducted in Sunderpur, Varanasi to study the magnitude of the problem of acute Respiratory Infections among under five children in an urban slum and the clinical profile of it in order to understand the pattern of disease presentation for identifying methods of early diagnosis and timely intervention. 150 under five children were selected by stratified random sampling method and were observed for 52 weeks at weekly interval to record the illnesses. In total 661 episodes were observed in 5623 child-weeks of observation giving an episode rate of 6.11 per child per year. ARI accounted for 67% of all morbidities. Mean duration of all the episodes taken together was 8.15 + 5.44 days. Majority of the episodes (88.96%) were confined to the Upper Respiratory Tract only. Most commonly occurring clinical features were rhinorrhea, nasal stuffiness and cough. 61.4% of all the episodes terminated within seven days, and only 26.2% continued for two weeks.

Serum transferrin receptor assay in iron deficiency anaemia and anaemia of chronic disease in the elderly

The most common cause of anaemia in the elderly is anaemia of chronic disease (ACD). However, iron deficiency anaemia (IDA) may coexist, and can be difficult to diagnose. The serum transferrin receptor (sTfR) blood test may be a better indicator of iron status as it is not affected by inflammation nor by advancing age. We evaluated it in four groups (10 males, 10 females each): 'young' controls, 'elderly' controls, IDA and ACD. All patients in the IDA group had elevated sTfR levels (mean +/- SD 65.2 +/- 17.7 nmol/l). All 'young' controls had normal sTfR (22.3 +/- 7.3 nmol/l) and ferritin levels (92.7 +/- 61.1 micrograms/l). Although all subjects in the 'elderly' controls and ACD group had normal, and raised or normal serum ferritin, respectively (88 +/- 62.3 micrograms/l; 631.2 +/- 509.5 micrograms/l), three (15%) 'elderly' controls and four (20%) ACD patients had raised sTfR levels, suggesting depleted iron stores. Bone-marrow aspirates were available in 3/4 ACD patients with raised sTfR. Haemosiderin was absent in two. The sTfR blood test is comparable to serum ferritin in diagnosing IDA in the elderly but also seems capable of differentiating ACD from IDA. Its potential as a non-invasive test of iron status, especially in elderly anaemic patients, deserves further evaluation.

Reliability of the Tone Assessment Scale and the modified Ashworth scale as clinical tools for assessing poststroke spasticity

OBJECTIVES

To establish reliability of the Tone Assessment Scale and modified Ashworth scale in acute stroke patients.

SETTING

A North Liverpool university hospital.

PATIENTS

Eighteen men and 14 women admitted with acute stroke and still in hospital at the study start date (median age, 74 yrs; median Barthel score, 8).

MAIN OUTCOME MEASURES

The modified Ashworth scale and the Tone Assessment Scale.

STUDY DESIGN

The 32 patients were examined with both scales on the same occasion by two raters (interrater comparison) and on two occasions by one rater (intrarater comparison).

RESULTS

The reliability of the modified Ashworth scale was very good (kappa = .84 for interrater and .83 for intrarater comparisons). The reliability of the Tone Assessment Scale was not as strong as the modified Ashworth scale, with marked variability in the assessment of posture (kappa = .22 to .50 for interrater and .29 to .55 for intrarater comparisons) and associated reaction (kappa/kappaW = -.05 to .79 for interrater and .19 to .83 for intrarater comparisons). However, those aspects of the Tone Assessment Scale that addressed response to passive movement and that are scored similarly to the modified Ashworth scale showed good to very good interrater reliability (kappaW = .79 to .92) and good to very good intrarater reliability (kappaW = .72 to .86), except for the question related to movement at the ankle where agreement was only moderate (kappaW = .59).

CONCLUSIONS

The modified Ashworth scale is reliable. The section of the Tone Assessment Scale relating to response to passive movement is reliable at various joints, except the ankle. It may assist in studies on the prevalence of spasticity after stroke and the relationship between tone and function. Further development of a measure of spasticity at the ankle is required. The Tone Assessment Scale is not reliable for measuring posture and associated reactions.

Congenital scaphoid megalourethra associated with posterior urethral valves

Megalourethra is a very rare mesenchymal congenital anomaly and its association with posterior urethral valves is still rarer. We hereby present such a rare combination and discuss its etiopatho-genesis

Three-dimensional structure of mare diferric lactoferrin at 2.6 A resolution

Lactoferrin is a monomeric glycoprotein with a molecular mass of approximately 80 kDa. The three-dimensional structure of mare diferric lactoferrin (mlf) has been determined at 2.6 A resolution. The protein crystallizes in the space group P 212121with a=85.2 A, b=99.5 A, c=103.1 A with a solvent content of 55 % (v/v). The structure was solved by the molecular replacement method using human diferric lactoferrin as the model. The structure has been refined using XPLOR to a final R -factor of 0.194 for all data in the 15-2.6 A resolution range. The amino acid sequence of mlf was determined using a cDNA method. The final refined model comprises 5281 protein atoms, 2 Fe3+, 2 CO32-and 112 water molecules. The overall folding of mlf is similar to that of other proteins of the transferrin family. The protein folds into two globular lobes, N and C. The lobes are further divided into two domains, N1 and N2, and C1 and C2. The iron-binding cleft is situated between the domains in each lobe. The N lobe appears to be well ordered and is more stable than the C lobe in mlf unlike in other lactoferrins, where the C lobe is the more stable. The opening of the binding cleft in the N lobe of mlf is narrower than those in other proteins of the transferrin family. This is very unusual and is found only in mare lactoferrin. Apart from certain hydrophobic interactions at the mouth of the cleft, one salt-bridge (Lys301 . . . . . . . . Glu216) crosses between the two walls of the cleft. The two lobes are connected covalently by a three-turn alpha-helix involving residues 334-344. The N lobe displays a highly ordered structure with appreciably low temperature factors. The iron coordination is more symmetrical in the N lobe than in the C lobe. There are only 16 intermolecular hydrogen bonds in the structure of mlf.

The immunohistochemical expression of desmoplakin and its role in vivo in the progression and metastasis of breast cancer

Desmoplakin (DP) is a protein located at the inner plaque of desmosomes where it associates with the desmosomal cadherins to form a cell adhesion complex. Reduced expression of DP has been correlated with the progression of several cancers, but its role in in vivo breast cancer is yet to be established. The aim of this present paper was to determine the immunohistochemical (IHC) expression of DP in breast cancer specimens (n = 75) in comparison with ductal carcinoma in situ (DCIS) (n = 26), tumour associated normal (n = 29) and normal breast tissue (n = 7). DP expression was correlated with that of desmosomal cadherin, Desmoglein 2 (Dsg2) and other clinical and IHC prognostic markers. DP staining occurred at the sub-plasma membrane level. There was no significant correlation between the level of DP (as assessed by the H-score) and that of Dsg. Significantly stronger staining was demonstrated in normal breast tissue and well differentiated tumours compared with more moderately or poorly differentiated tumours (P = 0.04). A significant inverse correlation was seen between DP staining and tumour size (P = 0.01). In a limited series of 8 cases, primary tumours demonstrated significantly stronger staining than the matched metastatic lymph nodes (P = 0.046). Of all the IHC markers examined, only Ki-67 showed a significant inverse relationship with DP staining (P = 0.01). In summary, the data suggest that loss of DP may be of potential importance in progression of breast cancer in vivo from normal, DCIS, well differentiated through to poorly differentiated, large tumours. In addition, this loss may be associated with metastasis.

Structure of mare apolactoferrin: the N and C lobes are in the closed form

The structure of mare apolactoferrin (MALT) has been determined at 3. 8 A resolution by the molecular-replacement method, using the structure of mare diferric lactoferrin (MDLT) as the search model. The MDLT structure contains two iron-binding sites: one in the N-terminal lobe, lying between domains N1 and N2, and one in the C-terminal lobe between domains C1 and C2. Both lobes have a closed structure. MALT was crystallized using the microdialysis method with 10%(v/v) ethanol in 0.01 M Tris-HCl. The structure has been refined to a final R factor of 0.20 for all data to 3.8 A resolution. Comparison of the structure of MALT with that of MDLT showed that the domain arrangements in these structures are identical. However, the structure of MALT is very different to the structures of human apolactoferrin (HALT) and duck apo-ovotransferrin (DAOT), in which the domain associations differ greatly. In HALT, the N lobe adopts an open conformation while the C lobe is in the closed form. On the other hand, in DAOT both the N and the C lobes adopt the open form. These results indicate the domain arrangements in these proteins to be an important structural feature related to their specific biological functions. Based on the structures of MALT, HALT and DAOT, it can be stated that the native apoproteins of the transferrin family adopt three forms: (i) with both the N and the C lobes in closed forms, as observed in MALT, (ii) with the N lobe open and the C lobe closed, as observed in HALT, and (iii) with both the N and the C lobes open, as found in DAOT. All these proteins attain a convergent form when iron is bound to them, suggesting an efficient and unique form of iron binding. The interface between the N and C lobes, which is formed by N1-C1 contact in the core of the molecule, does not change significantly.

Stroke like presentation of Creutzfeldt Jakob disease: an unusual variant

Creutzfeldt-Jakob disease (CJD) is a degenerative process of the brain, induced by novel infectious agent or prion, and is usually characterized by a rapidly progressive dementia in association with myoclonus. However different patterns of disease presentation have been identified. The authors describe three probable cases of CJD. None of them had positive family history or any known modes of iatrogenic transmission. Interestingly, all the cases presented like a stroke. This is the first series of CJD cases from this part of country.

Lipid peroxide levels in chronic renal failure

To determine presence of oxidant stress in chronic renal failure and to evaluate the efficacy of vitamin E in its amelioration, we studied 34 patients (Group I, age 32.4 +/- 11 years, M:F 3:1) and 10 healthy controls (Group II, age 27.4 +/- 5 years, M:F 4:1). The difference in baseline values of lipid peroxide (nmol/ml) was statistically significant (Group I 4.19 +/- 1.69, Group II 1.87 +/- 1.39, p = 0.004). Values of vitamin E (mg/l) were also significantly lower in Group I as compared to Group II (12.18 +/- 4.27 vs. 19.32 +/- 2.03, p = 0.003). Serum lipid peroxide values decreased significantly after supplementation with 400 mg/day of vitamin E for six weeks in Group I (4.19 +/- 1.69 to 3.21 +/- 1.13, p = 0.053) but not in Group II (1.87 +/- 1.39 to 1.03 +/- 0.87). Levels of vitamin E increased in both the groups (Group I: 12.18 +/- 4.27 to 16.01 +/- 5.13, Group II: 19.32 +/- 2.03 to 23.21 +/- 1.94, p < 0.005). No significant difference was observed in values of serum creatinine and urea before and after intervention.

The effects of bovine respiratory syncytial on normal ovine lymphocyte responses to mitogens or antigens in vitro

In the present study peripheral blod mononuclear cells (MNC) obtained from normal uninfected lambs were used to study the possible effects of bovine respiratory syncytial virus (BRSV) on lymphocyte responses to the mitogens, phytohaemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) in vitro. Live BRSV had a depressive effect on the proliferative responses of normal MNC to PHA, Con A and PWM. Inactivated BRSV and a commercial preparation of prostaglandin E2 were also found to depress the proliferative responses of normal ovine MNC to PHA but recombinant tumour necrosis factor-alpha (TNF-alpha) had no such effect. Serum samples obtained from BRSV-infected lambs contained substances inhibitory to PHA-driven lymphocyte blastogenesis. Memory blastogenic responses to border disease virus (BDV) of lymyphocytes obtained from lambs previously primed with BDV were significantly reduced when lymphocytes were exposed to infectious BRSV.

Perineurial abnormalities in the spontaneously diabetic dog

Structural abnormalities of the perineurium from six spontaneously diabetic dogs (diabetes duration 4-8 years and six control animals were quantified using detailed electron microscopic morphometric methods on superficial peroneal nerve biopsy specimens. Total perineurial sheath thickness (microm) was significantly increased in diabetic (8.8+/-0.6) compared to control animals (6.2+/-0.3) (P < 0.02). This was attributed to a significant increase in the mean perineurial lamellar width in diabetic (0.49+/-0.03) compared to control (0.40+/-0.01) (P < 0.04) animals. The number of lamellae also showed a non-significant increase in diabetic animals (7.8+/-0.4) compared to controls (6.9+/-0.13) (P < 0.06). There was no change in the mean interlamellar space in diabetic (0.7+/-0.05) compared to control (0.6+/-0.06) (P = 0.15) animals. The total interlamellar space was increased in diabetic (5.7+/-0.5) compared to control (4.1+/-0.36) (P < 0.04) animals. The perineurial cell basement membrane thickness (nm) was significantly increased in diabetic (126.9+/-9.8) compared to control (62.8+/-6.1) (P < 0.005) animals. The current study has demonstrated significant abnormalities of the perineurium in the spontaneously diabetic dog, which may have relevance to the pathogenesis of diabetic neuropathy.

Cor triatriatum in adults: three new cases and a brief review

We report 3 cases of cor triatriatum that were diagnosed late, in the 4th and 5th decades of life. The presentations of these 2 men and 1 woman varied substantially, both in anatomic and symptomatic aspects. The woman had an associated complex congenital anomaly, which is not uncommon in cases of cor triatriatum. We present our cases, along with a review of this rare congenital cardiac anomaly.

Megalourethra with posterior urethral valves

A case of scaphoid megalourethra associated with the posterior urethral valves was seen in a 4-year-old male. The embryology of the anomaly and its management are discussed with a review of the literature.

LIVER RESECTION FOR METASTASES FROM COLORECTAL CANCER

Five percent of patients with liver secondaries from colorectal carcinoma are potentially resectable and several studies have demonstrated significantly improved survival following resection. Two hundred and ten patients operated for colorectal carcinoma were followed up. Computed tomography confirmed potentially resectable metastasis to the liver in 38. On exploration 18 patients who had 4 or less hepatic metastases and no extrahepatic disease, underwent resection of their secondaries. Fourteen were males and 4 females with a mean age of 43.5 (SD 13.6, range 18-72) years. Ten patients presented with synchronous liver metastasis and 8 had metachronous disease. There was no post-operative mortality. All 18 have been followed up. for a median period of 23.5 (range 12-38) months. Seven patients are alive and well with no evidence of recurrence at a median period of 28 months (survival 39%). Four are alive with local recurrence in the liver. Median time to recurrence was 22 months. Seven patients have died of disseminated disease. The disease free survival at 28 months is 39% and the overall survival 61%. A close follow-up protocol for all patient undergoing curative surgery for colorectal cancer is essential, if such patients are to be selected early.

Perineal-mound defects

Perineal-mound (PMD) and genital-fold defects cause anorectal malformations (ARM) in both sexes. They are common in females and usually present as a low anomaly (except rectovestibular fistula). They are rare in males and present as an intermediate anomaly. A common embryological explanation for these defects with varied presentation in males and females is discussed. These anomalies should be grouped separately in the classification of ARM. We present five male patients with PMD, three of whom had imperforate anus with rectobulbar fistula and perineal hypospadias and two who had imperforate anus with rectoperineal fistula.

Mini-lap cholecystectomy: a viable alternative to laparoscopic cholecystectomy for the Third World?

BACKGROUND

Laparoscopic cholecystectomy (LC) requires expensive equipment and special training. Mini-lap cholecystectomy (MLC) has no start-up costs but no large series from a single centre has been reported as the procedure is considered hazardous because of inadequate exposure of the surgical field.

METHODS

We retrospectively reviewed the outcome of 737 cholecystectomies performed through a 3-5-cm transverse subcostal incision and compared the results to published series of laparoscopic cholecystectomy.

RESULTS

The operating time (61.6 min; range 35-130), conversion rate (4%), rate of postoperative complications (3.6%), bile duct injuries (0.3%), number of analgesic doses required (3.4; range 3-8), duration of postoperative hospital stay (1.4; range 1-15 days), and the time off work (13.3 days; range 8-61) compare well with the reported results of laparoscopic and MLC. Ninety-three per cent of the patients were followed up for a median period of 28.4 months and none developed biliary stricture.

CONCLUSIONS

Mini-lap cholecystectomy is considered a safe, viable alternative to LC in the Third World.

Knowledge, attitude, belief and practice (K.A.B.P) study on AIDS among senior secondary students

A cross-sectional survey was done among students of four senior secondary schools including two boys and two girls schools of rural Delhi to know the knowledge, attitude, belief and practices regarding AIDS. A large majority (83.0%) of students though had heard about AIDS, yet majority of them did not know the possible methods for prevention of AIDS. There were only 27.1% girls who knew about regular condom usage. Half of them had permissible attitude for pre-maritial sex, while sexual activity was observed in one-fourth students. Students were less reluctant to discuss about AIDS than sex, and teachers were preferred as compared to parents in this regard. School is an ideal setting to educate adolescents regarding HIV/AIDS transmission and safer sex behaviour.