Anthropometry of Bodies of C3-C6 Cervical Vertebrae in Northwest Indian Population: A Cross-sectional Study

Introduction: Knowledge of morphometric dimensions of cervical vertebrae is of immense help in choosing and designing implants for the cervical spine. Previous studies on this subject have emphasized that these dimensions have significant variations among different populations. Aim: To determine and analyse morphometric parameters of the body of typical cervical vertebrae (C3-C6) in the Northwest Indian population. Materials and Methods: This cross-sectional study was carried out on 164 typical cervical vertebrae (C3 to C6) retrieved from the skeleton collection in the Department of Anatomy at Pandit Bhagwat Dayal Sharma Postgraduate Institute of Medical Sciences, Rohtak, Haryana, India from February 2020 to April 2022. Morphometric parameters measured in the study were anteroposterior diameters and transverse diameter of both surfaces of the body, and height of anterior surface of the body using a digital vernier calipers. Descriptive statistical analysis was done with the help of Microsoft Excel version 2021. Results: Of the total 164 sample, on the superior surface of the body anteroposterior diameter increased from C3 vertebrae (Mean±Standard Deviation {SD}= 14.67±1.42 mm) to C6 vertebrae (Mean±SD=15.73 mm). The anteroposterior diameter of the inferior surfaces of the body increased from C3 vertebrae (Mean±SD=15.71 mm) to C6 vertebrae (Mean±SD=16.26 mm). Similarly, the transverse diameter of the superior surface also increased from C3 vertebrae (Mean value of 20.24 mm) to C6 vertebrae (Mean value of 23.82 mm). Furthermore, the transverse diameter of the inferior surface increased from C3 vertebrae (Mean±SD=19.35 mm) to C6 vertebrae (Mean±SD=22.99 mm). However, the height of vertebral bodies was found minimum in C5 vertebrae (Mean±SD=10.69 mm) and maximum in C3 vertebrae (Mean±SD=12.04 mm). Conclusion: The dimensions of morphometric parameters observed in the present study were differing from those reported by studies carried out in south Indian population and in the Western world. However, the study did not find any significant side differences in morphometric parameters of bodies of typical cervical vertebrae. Population-specific normal data are reported in this study for the first time.

Detection of IEMs by Mass Spectrometry Techniques in High-Risk Children: A Pilot Study

OBJECTIVES

To determine the incidence and types of inborn errors of metabolism (IEMs) in high-risk children using mass spectrometry techniques.

METHODS

Children considered high-risk for IEM were screened for metabolic diseases during a 3-y period. Dried blood spots and urine samples were analyzed by tandem mass spectrometry (LC-MS/MS) and gas chromatograph-mass spectrometry (GCMS). Samples with abnormal amino acids were confirmed by high-performance liquid chromatography (HPLC).

RESULTS

Eight hundred and twenty-two suspected cases were evaluated; of which, 87 possible cases of IEMs were identified. Homocystinuria (n = 51) was the most common IEM detected followed by biotinidase deficiency (n = 7), glutaric aciduria type 1 (n = 7), and carnitine uptake defect (n = 6). Overall, there were 45 (51.7%) cases of organic acidemia, 31 cases (35.6%) of amino acid defect, 9 (10.3%) cases of fatty-acid oxidation disorders, and 2 (2.3%) cases of probable mitochondrial disorder.

CONCLUSION

IEMs are common in India, with a hospital-based incidence of 1 in approximately 6642 among high-risk children. Screening of high-risk children by mass spectrometry techniques is a valuable strategy for early diagnosis of IEMs where universal newborn screening is not yet available.

Role of environmental lead in the occurrence of anemia in Indian children: a systematic review and meta-analysis

Exposure to lead among children, as well as adults, is a major global health issue. With diverse routes of exposure (e.g., food, air, and water) either environmentally or occupationally, lead among children can cause mild, moderate, to severe health complications in the later stages of life. The average blood lead level reported by CDC in 2021 is 3.5 µg/dL, and the level of blood lead toxicity is ≥ 10 μg/dL. In this study, we planned to systematically analyze the association between blood lead levels (BLLs) (≥ 10 μg/dL and < 10 μg/dL) and the risk of anemia (hemoglobin level < 11 g/dL) among Indian children aged between ≥ 1 and ≤ 18 years. An online literature search of 5 databases, PubMed, Ovid, EMBASE, Web of Science, and Google Scholar was accomplished with a search updated until 8^th March 2021. Study designs included cohort, cross-sectional, and case-control studies that have evaluated the association of lead toxicity or exposure with anemia (Hb < 11 g/dL) reported in urban and/or rural Indian children. Meta-analysis was performed among a total of 864 children from 4 cross-sectional studies. The association between lead toxicity (BLLs ≥ 10 μg/dL) and the risk of being anemic was not statistically significant (RR = 1.15 (95% CI: 0.86-1.55, I² = 77%). The risks of bias in all included studies were low according to the Newcastle Ottawa Scale. Increased blood lead levels did not appear to be the major contributor to anemia in Indian Children. We need to focus primarily on improving the nutritional quality, fortified food supplements, and a balanced diet for children to reduce the anemia burden in India. Lead toxicity should be sought as an etiological factor only in areas of high environmental risk factors which were leaded paints, leaded batteries, a house near major road/traffic areas, and pesticide exposure.

Correlation of Morphometric Parameters of Spleen and Height of the Deceased: A Cross-sectional Study in North Indian Population

Introduction: Estimation of stature is a major forensic anthropological concern used in the identification of unknown and mutilated human remains. Studies considering spleen morphometric parameters to decipher the height of the deceased are very rare especially in Haryana though research studies involving correlation between height and other body organs have been done. Aim: To determine the correlation between the morphometric parameters of the spleen and height of the deceased. Materials and Methods: The cross-sectional study was carried out in the Department of Anatomy in collaboration with the Department of Forensic Medicine in Pandit Bhagwat Dayal Sharma Post Graduate Institute of Medical Sciences, Rohtak, Haryana, India, from September 2010 to September 2012. The spleen specimens (30 male and 30 female) obtained from deceased adults in the age group of 16-70 years (both age inclusive) belonging to North India from the Department of Forensic Medicine during autopsy. The measurement of splenic parameters (weight, length, breadth, thickness and surface area) was done using direct measurement (standard methodology) accepted by anthropologists. The data was analysed using Statistical Package for the Social Sciences (SPSS) software version 20.0. Pearson’s correlation test was used to evaluate the association between the splenic parameters and height. Correlation formula was derived to calculate the height from the splenic measurements. Results: Correlation of height was positive with splenic measurements (weight, length, breadth, thickness and total surface area) in both males and females and was significant with splenic weight (r-value=0.54 and p-value=0.02) and splenic length (r-value=0.548; p-value=0.002) in females. It was significant for splenic thickness in males (r-value=0.042; p-value=0.018) and significant for total surface area of spleen for both males and females (r-value=0.80 and p-value <0.00001 in males and r-value=0.58 and p-value=0.000781 in females). Conclusion: Correlation of height was significant for splenic weight and length in females; significant for splenic thickness in males and significant for total surface area of spleen for males and females. This study would help Anthropologists and Forensic Medicine Experts to calculate the height of the deceased using various regression equations if spleen is intact and is measured.

Environmental exposure to urinary Bisphenol-A in North Indian children aged between 6 and 16 years and its association with body mass index

This study investigates the effect of environmental risk factors among North Indian children aged between 6 and 16 years associated with body mass index by comparing fasting and non-fasting urine Bisphenol-A, urine creatinine, and serum thyroid levels with other potential confounding factors. A total of 301 children were enrolled, and term fasting and non-fasting were used based on the sample collection, either first morning or random. Children were grouped into obese, non-obese, and underweight categories based on age- and gender-specific Centre for Disease Control (CDC) 2000 growth chart and grouped according to their body mass index. The overall mean ± SD (standard deviation) of age (years) was 10.45±2.39 (boys age 10.38±2.38 and girls age 10.45±2.40). Urinary Bisphenol-A concentration (ng/mL ± SD) was higher among obese (2.40±4.70) than non-obese (1.30±1.67) and underweight (1.84±3.46) category children. Higher levels of fasting urinary Bisphenol-A (≥2 ng/mL) and thyroid-stimulating hormone (TSH) (≥12.7 μg/dL) were associated with obesity than those of non-fasting children. Being non-fasting among girls at quartile 4 (obese, >2.1800 ng/mL; underweight, >2.1325 ng/mL) had higher odds (obese adjusted odds ratio (aOR) 7.72 (95% CI 0.08-1368.52), underweight adjusted odds ratio (aOR) 12.45 (95% CI 1.55-171.24)] than fasting children. We recommend awareness programs and policy guidelines by engaging teachers and parents for the physical assessment of the presence of Bisphenol-A in food packaging materials to reduce the potential exposure to other chemical migrations sources. Graphical abstract.

Higher body mass index is an important risk factor in COVID-19 patients: a systematic review and meta-analysis

Globally, both obesity and underweight are severe health risks for various diseases. The current study systematically examined the emerging evidence to identify an association between body mass index (BMI) and COVID-19 disease outcome. Online literature databases (e.g., Google Scholar, PubMed, MEDLINE, EMBASE, Scopus, Medrixv and BioRixv) were screened following standard search strategy having the appropriate keyword such as "Obesity", "Underweight", "BMI", "Body Mass Index", "2019-nCov", "COVID-19, "novel coronavirus", "coronavirus disease". Studies published till 20^th April 2020 were included without language restriction. These studies include case reports, case series, cohort, and any other which reported BMI, overweight/obesity or underweight, and its complication with COVID-19 disease. This study observed COVID-19 infection among BMI < 25 kg/m² with prevalence of 0.60 (95%CI: 0.34-0.86, I² = - 76.77) as compared to the 0.34 (95%CI: 0.23-0.44, I² = 53.45% heterogeneity) having BMI > 25 kg/m². The results of the current study show that BMI plays a significant role in COVID-19 severity in all age groups, especially the older individuals. A panel of doctors and nursing staff should review COVID-19 patients with higher BMI with other co-morbidities (diabetes and hypertension), and they should be given increased vigilance, priority in testing, and treatment to control the associated co-morbidities. Further, the COVID-19 patients whose illness entered 7-10 days, age > 50 years, and elevated CRP levels should be given additional medical considerations. Our finding showed that the population and patients with high BMI have moderate to high risk of medical complications with COVID-19, and hence, their health status should be monitored more frequently including monitoring of blood pressure and blood glucose.

Comparison of follicular dynamics, superovulatory response, and embryo recovery between estradiol based and conventional superstimulation protocol in buffaloes (Bubalus bubalis)

Aim:

To evaluate the follicular dynamics, superovulatory response, and embryo recovery following superstimulatory treatment initiated at estradiol-17β induced follicular wave emergence and its comparison with conventional superstimulatory protocol in buffaloes.

Materials and Methods:

Six normal cycling pluriparous buffaloes, lactating, 90-180 days post-partum, and weighing between 500 and 660 kg were superstimulated twice with a withdrawal period of 35 days in between two treatments. In superstimulation protocol-1 (estradiol group) buffaloes were administered estradiol-17β (2 mg, i.m.) and eazibreed controlled internal drug release (CIDR) was inserted intravaginally (day=0) at the random stage of the estrous cycle. On the day 4, buffaloes were superstimulated using follicle stimulating hormone (FSH) 400 mg, divided into 10 tapering doses given at 12 hourly intervals. Prostaglandin F2α analogs (PGF2α) was administered at day 7.5 and day 8, and CIDR was removed with the second PGF2α injection. In superstimulation protocol - 2 (conventional group) buffaloes were superstimulated on the 10^th day of the estrous cycle with same FSH dose regimen and similar timings for PGF2α injections. In both groups, half of the buffaloes were treated with luteinizing hormone (LH) 25 mg and other half with 100 ug buserelin; gonadotrophin releasing hormone (GnRH) analog at 12 h after the end of FSH treatment. All buffaloes in both protocols were inseminated twice at 12 and 24 h of LH/GnRH treatment. Daily ultrasonography was performed to record the size and number of follicles and superovulatory response.

Results:

Significantly higher number of small follicles (<8 mm) was present at the time of initiation of superstimulatory treatment in the estradiol group compared to the conventional group (12.5±0.80 vs. 7.3±1.21, respectively, p=0.019), however, the number of ovulatory size follicles (≥8 mm) did not differ significantly between the respective groups (15.5±1.24 vs. 12.2±1.30; p=0.054). Total embryos and transferable embryos recovered were non-significantly higher in the estradiol group compared to the conventional group (5.83±0.86 vs. 4.67±1.16, p=0.328, and 3.67±0.93 vs. 2.67±0.68, p=0.437, respectively). The significant higher proportion of transferable embryos were recovered in buffaloes treated with LH compared to GnRH (73.3% vs. 48.5%; p=0.044).

Conclusion:

The average number of ovulatory size follicles (>8 mm), corpora lutea, and transferable embryos was higher in buffaloes superstimulated at estradiol-induced follicular wave compared to the conventional protocol: Further the percentage of transferable embryos was significantly higher in buffaloes administered with LH compared to GnRH.

Changes in water and beverage intake and long-term weight changes: results from three prospective cohort studies

OBJECTIVE

To examine the long-term relationship between changes in water and beverage intake and weight change.

SUBJECTS

Prospective cohort studies of 50013 women aged 40-64 years in the Nurses' Health Study (NHS, 1986-2006), 52987 women aged 27-44 years in the NHS II (1991-2007) and 21988 men aged 40-64 years in the Health Professionals Follow-up Study (1986-2006) without obesity and chronic diseases at baseline.

MEASURES

We assessed the association of weight change within each 4-year interval, with changes in beverage intakes and other lifestyle behaviors during the same period. Multivariate linear regression with robust variance and accounting for within-person repeated measures were used to evaluate the association. Results across the three cohorts were pooled by an inverse-variance-weighted meta-analysis.

RESULTS

Participants gained an average of 1.45 kg (5th to 95th percentile: -1.87 to 5.46) within each 4-year period. After controlling for age, baseline body mass index and changes in other lifestyle behaviors (diet, smoking habits, exercise, alcohol, sleep duration, TV watching), each 1 cup per day increment of water intake was inversely associated with weight gain within each 4-year period (-0.13 kg; 95% confidence interval (CI): -0.17 to -0.08). The associations for other beverages were: sugar-sweetened beverages (SSBs) (0.36 kg; 95% CI: 0.24-0.48), fruit juice (0.22 kg; 95% CI: 0.15-0.28), coffee (-0.14 kg; 95% CI: -0.19 to -0.09), tea (-0.03 kg; 95% CI: -0.05 to -0.01), diet beverages (-0.10 kg; 95% CI: -0.14 to -0.06), low-fat milk (0.02 kg; 95% CI: -0.04 to 0.09) and whole milk (0.02 kg; 95% CI: -0.06 to 0.10). We estimated that replacement of 1 serving per day of SSBs by 1 cup per day of water was associated with 0.49 kg (95% CI: 0.32-0.65) less weight gain over each 4-year period, and the replacement estimate of fruit juices by water was 0.35 kg (95% CI: 0.23-0.46). Substitution of SSBs or fruit juices by other beverages (coffee, tea, diet beverages, low-fat and whole milk) were all significantly and inversely associated with weight gain.

CONCLUSION

Our results suggest that increasing water intake in place of SSBs or fruit juices is associated with lower long-term weight gain.

Molecular signaling in pathogenicity and host recognition in smut fungi taking Karnal bunt as a model system

Karnal bunt of wheat, incited by a phytopathogen Tilletia indica (Syn. Neovossia indica) is a floret infecting disease. In the floral tissues fungus proliferates and produces massive amount of black spores. In smut fungi, belonging to order Ustilaginales, communication between cells is necessary to regulate growth, differentiation and monokaryotic to dikaryotic transition during pathogenic and sexual development. Neighbouring cells are able to communicate with each other by direct cell to cell contact through plasma membrane bound signaling molecules or through formation of gap junctions and alternatively through secretion of chemical signals if cells are some distance away. Current research efforts toward understanding of pathogenic and sexual development in phytopathogenic fungi, offer a number of opportunities. These include the analysis of molecular signal(s) for direct contribution of sexual interactions to ability of smut and bunt pathogens to cause disease. These efforts will provide not only to explore the mechanisms of pathogenesis, but also to enhance knowledge of basic cellular biology of an economically important group of fungi.

Level of expression of the tomato rbcS-3A gene is modulated by a far upstream promoter element in a developmentally regulated manner

By Agrobacterium-mediated transformation we have demonstrated that a 1.10-kilobase promoter sequence from the tomato rbcS-3A gene confers light-inducible and organ-specific expression upon fusion to the bacterial chloramphenicol acetyltransferase gene. A biphasic expression profile was obtained by 5' deletion analysis of this promoter, indicating the presence of both positive and negative regulatory elements. A severe reduction in the level of expression was observed when the 5'-terminal 90 base pairs were deleted from the 1.10-kilobase promoter. DNA sequence elements responsible for light inducibility and organ specificity of the gene reside within the -374 base pairs of the proximal part of the promoter and the sequences spanning from -374 to -205 are essential for promoter function. The DNA sequences upstream from -374 modulate the level of expression in leaf tissue; this modulation is under developmental control.

Protein purification

This monograph summarizes recent developments in the purification and analysis of natural and recombinant proteins. The basic strategies employed in protein purification are reviewed with regards to the characteristics of the protein of interest that may aid its isolation, choice of the starting material, and use of denaturants. Preparation of cell-free extracts followed by bulk precipitation and/or phase partition constitute the initial steps of many purification schemes. Chromatographic methods (size exclusion, ion exchange, hydroxylapatite, reversed phase, hydrophobic interaction and affinity based) utilizing either traditional, low pressure or high-performance liquid chromatography instrumentation are discussed. Electrophoretic techniques used to analyze the homogeneity of the protein product include SDS-PAGE, isotachophoresis, IEF and two dimensional gel electrophoresis.

An evolutionarily conserved protein binding sequence upstream of a plant light-regulated gene

A protein factor, identified in nuclear extracts obtained from tomato (Lycopersicon esculentum, Solanaceae) and Arabidopsis thaliana (Brassicaceae) seedlings, specifically binds upstream sequences from the plant light-regulated gene family encoding the small subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase (RBCS). RBCS upstream sequences from tomato, pea (Pisum sativum, Leguminosae), and Arabidopsis are recognized by the factor. The factor recognition occurs via a short conserved sequence (G box) whose consensus sequence is 5'-TCTTACACGTGGCAYY-3' (where Y is pyrimidine). This sequence is distinct from the GT motif described previously in RBCS promoters. Two other conserved sequences, showing a lesser degree of evolutionary conservation, are found upstream of the G box but do not bind to the G box binding factor (GBF). Twelve nucleotides within the G box are sufficient for the formation of a stable DNA-GBF complex. GBF is found in both light-grown and dark-adapted tomato leaf extracts, but it is present in greatly reduced amounts in root extracts.

Isolation and sequence of a tomato cDNA clone encoding subunit II of the photosystem I reaction center

We report here the isolation and nucleotide sequence of a cDNA clone encoding a phtosystem I polypeptide that is recognized by a polyclonal antibody prepared against subunit II of the photosystem I reaction center. The transit peptide processing site was determined to occur after Met50 by N terminal sequencing. The decuced sequence of this protein predicts that the polypeptide has a net positive charge (pI=9.6) and no membrane spanning regions are evident from the hydropathy plot. Based on these considerations and the fact that subunit II is solubilized by alkali treatment of thylakoids, we concluded that subunit II is an extrinsic membrane protein. The absence of hydrophobic regions characteristic of thylakoid transfer domains furthermore implies that subunit II is localized on the stromal side of the membrane.

CR1 - a dispersed repeated element associated with the Cab-1 locus in tomato

Cab-1 is a complex genetic locus in tomato consisting of four clustered genes encoding chlorophyll a/b-binding polypeptide. Southern blot analysis of total tomato DNA with genomic clones corresponding to the Cab-1 locus has revealed the presence of a repetitive element in the 3 kb spacer regions between two of these genes. This repetitive element, named CR1, has been characterized via sequencing, genetic mapping and hybridization to related solanaceous species. Results indicate that there are as many as 30 copies of this element in the tomato genome and that most, if not all, are found at independent loci. Sites corresponding to 12 of the repeats have been located on different regions of chromosomes 2, 4, 5, 7, 10 and 11. A 1.6 kb PstI-EcoRI fragment from the Cab-1 locus containing the element was sequenced and found to be 75% AT-rich. No open reading frames larger than 150 bp were detected. Several imperfect inverted repeats flanked by direct repeats could be found at the ends of the element. This arrangement is reminiscent of known transposons. Southern hybridization analysis indicates that multiple copies of CR1 exist in all species of the genus Lycopersicon as well as in Solanum lycopersicoides and S. tuberosum (potato), but not in eggplant, pepper, petunia, Datura or tobacco. Melt-off experiments indicate that members of the CR1 family in the tomato genome are more closely related to one another than to homologous members in the genomes of S. lycopersicoides or S. tuberosum, suggesting some type of concerted evolution.

Both positive and negative regulatory elements mediate expression of a photoregulated CAB gene from Nicotiana plumbaginifolia

We have analyzed promoter regulatory elements from a photoregulated CAB gene (Cab-E) isolated from Nicotiana plumbaginifolia. These studies have been performed by introducing chimeric gene constructs into tobacco cells via Agrobacterium tumefaciens-mediated transformation. Expression studies on the regenerated transgenic plants have allowed us to characterize three positive and one negative cis-acting elements that influence photoregulated expression of the Cab-E gene. Within the upstream sequences we have identified two positive regulatory elements (PRE1 and PRE2) which confer maximum levels of photoregulated expression. These sequences contain multiple repeated elements related to the sequence-ACCGGCCCACTT-. We have also identified within the upstream region a negative regulatory element (NRE) extremely rich in AT sequences, which reduces the level of gene expression in the light. We have defined a light regulatory element (LRE) within the promoter region extending from -396 to -186 bp which confers photoregulated expression when fused to a constitutive nopaline synthase ('nos') promoter. Within this region there is a 132-bp element, extending from -368 to -234 bp, which on deletion from the Cab-E promoter reduces gene expression from high levels to undetectable levels. Finally, we have demonstrated for a full length Cab-E promoter conferring high levels of photoregulated expression, that sequences proximal to the Cab-E TATA box are not replaceable by corresponding sequences from a 'nos' promoter. This contrasts with the apparent equivalence of these Cab-E and 'nos' TATA box-proximal sequences in truncated promoters conferring low levels of photoregulated expression.

A cDNA clone encoding a photosystem I protein with homology to photosystem II chlorophyll a/b-binding polypeptides

We report here the isolation and nucleotide sequence of a complete cDNA clone encoding a photosystem I (PS I) polypeptide that is recognized by a monoclonal antibody made against photosystem II (PS II) chlorophyll a/b-binding (CAB) proteins. The deduced sequence of this PS I protein shows 30% overall identity to PS II CAB sequences, and two long segments within this protein show 50% and 65% identity to the corresponding segments in the PS II CAB polypeptides. Even though the sequence of this PS I CAB protein is substantially divergent from PS II CAB sequences, their hydropathy plots are very similar and suggest they all traverse the thylakoid membrane three times. A segment of the PS I CAB polypeptide shows similarity to the functionally analogous beta subunits of the antenna proteins of purple bacteria. In contrast, no homology was observed between these bacterial proteins and PS II CAB polypeptides.

Molecular characterization of two clusters of genes encoding the Type I CAB polypeptides of PSII in Nicotiana plumbaginifolia

A Nicotiana plumbaginifolia genomic library in the phage Charon 34 was used to isolate and characterize 7 full-length genes and part of an 8th gene encoding chlorophyll a/b-binding (CAB) polypeptides. These genes are arranged in two clusters. All the genes within the clusters are arranged in opposite orientation to their neighbours. The nucleotide sequences of two genes, one from each cluster, show that both genes, designated Cab-E and Cab-C, encode very similar proteins (95.9% of homology) corresponding to type I photosystem II polypeptides. Southern blot analysis suggests that at least 19 CAB genes encoding type I PSII CAB polypeptides are present in the N. plumbaginifolia genome. We also describe the presence within the N. plumbaginifolia genome of CAB genes encoding PSII type II CAB polypeptides and PSI type I CAB polypeptides. The sequences of the 5' flanking region of three different CAB genes (Cab-E, Cab-C, and CAB-F) were determined. Two of them (Cab-C and Cab-F) share extensive homology, whereas the Cab-E promoter shows homology to Cab-C and Cab-F only in a unique region extending from the CAAT box to the TATA box. This conserved sequence is also found in the same position in promoters of CAB genes encoding type I PSII polypeptides from other plant species.

The tomato Cab-4 and Cab-5 genes encode a second type of CAB polypeptides localized in Photosystem II

The photosynthetic apparatus of plant chloroplasts contains two photosystems, termed Photosystem I (PSI) and Photosystem II (PSII). Both PSI and PSII contain several types of chlorophyll a/b-binding (CAB) polypeptides, at least some of which are structurally related. It has been previously shown that multiple genes encoding one type of PSII CAB polypeptides exist in the genome of many higher plants. In tomato, there are at least eight such genes, distributed in three independent loci. Genes encoding a second type of CAB polypeptides have been isolated from several plant species, but the precise location of the gene products has not been determined. Here we show that tomato has two unlinked genes encoding this second type and that this type of CAB polypeptide is also localized in PSII.

Aluminium phosphide poisoning: a prospective study of 16 cases in one year

Sixteen patients suffering from aluminium phosphide poisoning were treated during the year from January 1985 to December 1985. These accounted for approximately half the total number of cases of acute poisoning. Profuse vomiting, pain in the upper abdomen and shock were the most common presenting features. Six patients succumbed to their illness. Analysis of various prognostic factors revealed that ingestion of 'unexposed' tablets of aluminium phosphide taken from a freshly opened bottle was associated with a greater risk of fatal outcome. Aluminium phosphide poisoning has become an important matter of public health in parts of India.

Effect of chloramphenicol on its biosynthesis by Streptomyces species 3022a

Measurements of (3H) chloramphenicol production in cultures of Streptomyces species 3022a grown on a medium containing (6-3H) D-glucose and (3-14C) chloramphenicol showed that chloramphenicol inhibits its own biosynthesis. Similar results were obtained in cultures supplemented with the antibacterial p-methylthio- analogue of chloramphenicol. Here synthesis of the antibiotic was completely suppressed until the concentration of analogue had been reduced by inactivating enzymes. In contrast, the L-threo- and p-methylsulfonyl- analogues did not delay growth of the organism and had little effect on chloramphenicol biosynthesis. However, like chloramphenicol and its p-methylthio- analogue, the L-threo and p-methylsulfonyl compounds were degraded. Degradation of chloramphenicol and the p-methylsulfonyl-analogue ceased when endogenously produced antibiotic reached a concentration of 10–30 mg/liter, suggesting that changes in cell permeability are associated with the onset of chloramphenicol synthesis.

Metabolism of chloramphenicol by the producing organism. Some properties of chloramphenicol hydrolase

A cell-free enzyme preparation which catalyzed the hydrolysis of chloramphenicol was obtained from Streptomyces species 3022a, a chloramphenicol-producing actinomycete. The enzyme was difficult to release from the mycelium and had low substrate affinity (Ks 0.2 mM) and activity (Vmax 2.86 nmoles/h) towards chloramphenicol. Activity was present in chloramphenicol-sensitive non-producing cultures not previously exposed to the antibiotic and did not increase during development of resistance. The results suggest that inactivation of chloramphenicol may be a subsidiary function of the enzyme.

Metabolism of chloramphenicol by the producing organism

When 14C-labeled chloramphenicol was added to chloramphenicol-producing cultures of Streptomyces strain 13s, radioactive p-nitrophenylserinol, N-acetyl-p-nitrophenylserinol, p-nitrobenzyl alcohol, and p-nitrobenzoic acid were formed. The rate of catabolism varied with culture conditions. It was fastest during rapid growth on a medium supporting low chloramphenicol production. Periodic analysis of cultures indicated that p-nitrophenylserinol accumulated only transitorily and was rapidly N-acetylated. In support of this conclusion 14C-labeled p-nitrophenylserinol was rapidly and completely metabolized, giving mainly the N-acetyl derivative. p-Nitrobenzyl alcohol and p-nitrobenzoic acid were formed in only small amounts during catabolism of chloramphenicol or p-nitrophenylserinol. Chloramphenicol inhibited growth of Streptomyces strain 13s by increasing the lag phase. It also appeared to inhibit antibiotic synthesis. However, cultures supplemented with D-glucose-U-I4C produced radioactive chloramphenicol even when exposed to high concentrations of the antibiotic, and the titer at any time thus represents the product of both catabolic and biosynthetic reactions.